A 11 ID 7 25flbb2

PUBLICATIONS XT *7

NBS SPECIAL PUBLICATION 260-84

\

1 T ' >

U.S. DEPARTMENT OF COMMERCE /National Bureau of Standards

Standard Reference Materials:

Sampling, Materials Handling,

Processing, and Packaging

of NBS Sulfur in Coal

Standard Reference Materials
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts

research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and

the Institute for Computer Sciences and Technology. THE NATIONAL MEASUREMENT LABORATORY provides the national system of

physical and chemical and materials measurement; coordinates the system with measurement

systems of other nations and furnishes essential services leading to accurate and uniform

physical and chemical measurement throughout the Nation's scientific community, industry, and commerce; conducts materials research leading to improved methods of measurement,

standards, and data on the properties of materials needed by industry, commerce, educational

institutions, and Government; provides advisory and research services to other Government

agencies; develops, produces, and distributes Standard Reference Materials; and provides

calibration services. The Laboratory consists of the following centers: Absolute Physical Quantities2 — Radiation Research — Chemical Physics —

Analytical Chemistry — Materials Science THE NATIONAL ENGINEERING LABORATORY provides technology and technical ser- vices to the public and private sectors to address national needs and to solve national problems; conducts research in engineering and applied science in support of these efforts; builds and maintains competence in the necessary disciplines required to carry out this research and technical service; develops engineering data and measurement capabilities; provides engineering measurement traceability services; develops test methods and proposes

engineering standards and code changes; develops and proposes new engineering practices; and develops and improves mechanisms to transfer results of its research to the ultimate user. The Laboratory consists of the following centers:

Applied Mathematics — Electronics and Electrical Engineering2 — Manufacturing

Engineering — Building Technology — Fire Research — Chemical Engineering2 THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts

research and provides scientific and technical services to aid Federal agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards

guidelines, and managing Federal participation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal agencies; and

provides the technical foundation for computer-related policies of the Federal Government. The Institute consists of the following centers: Programming Science and Technology — Computer Systems Engineering.

'Headquarters and Laboratories at Gaithersburg, MD, unless otherwise noted; mailing address Washington, DC 20234. 'Some divisions within the center are located at Boulder, CO 80303.
Standard Reference Materials:

Sampling, Materials Handling, Processing,

and Packaging of NBS Sulfur in Coal

Standard Reference Materials

OS BTA1TDABPC re. /CO

ins

T.E. Gills and R.W. Seward

National Measurement Laboratory

National Bureau of Standards

Washington, DC 20234

with

R.J. Collins

Valley Forge Laboratories, Inc. Six Berkley Road

Devon, PA 19333

and

W.C. Webster

Webster and Associates, Ltd. 3008 Potshop Road

Norristown, PA 19403

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director Issued August 1983
Library of Congress Catalog Card Number: 83-600553

National Bureau of Standards Special Publication 260-84

Natl. Bur. Stand. (U.S.), Spec. Publ. 260-84, 62 pages (Aug. 1983) CODEN: XNBSAV

U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 1983

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402

Price $4.50

(Add 25 percent for other than U.S. mailing)
PREFACE

Standard Reference Materials (SRM's) as defined by the National Bureau of Standards are "well-characterized materials, produced in quantity, that calibrate

a measurement system to assure compatibility of measurement in the Nation."

SRM's are widely used as primary standards in many diverse fields in science,

industry, and technology, both within the United States and throughout the world. In many industries, traceability of their quality control process to the national measurement system is carried out through the mechanism and use of SRM's. For many of the Nation's scientists and technologists it is, therefore,

of more than passing interest to know the details of the measurements made at NBS in arriving at the certified values and of procedures used at NBS in producing SRM's. An NBS series of papers, of which this publication is a member,

called the NBS Special Publication - 260 Series is reserved for this purpose.

This 260 Series is dedicated to the dissemination of information on all phases

of the preparation of NBS Sulfur in Coal SRM's. In general, much more detail

will be found in this 260 than is generally allowed, or desirable, in scientific

journal articles. This enables the user to assess the validity of processes

employed, and to learn details of methods utilized for work entailing the greatest care. It is also hoped that this 260 will provide sufficient additional information not found on the certificate so that new applications of these SRM's may be sought and found. Inquiries concerning the technical content of this paper should be directed to the author(s). Other questions concerned with the availability, delivery,

price, and so forth, will receive prompt attention from: Office of Standard Reference Materials

National Bureau of Standards

Washington, DC 20234

George A. Uriano, Chief Office of Standard Reference Materials

iii
OTHER NBS PUBLICATIONS IN THIS SERIES

Catalog of NBS Standard Reference Materials (1981-83 edition), R. W. Seward, ed., NBS

Spec. Publ. 260 (November 1981). Michaelis, R. E., and Wyman, L. L. Standard

Reference Materials: Preparation of White Cast

Iron Spectrochemical Standards. NBS Misc. Publ. 260-1 (June 1964). COM 74- 1 1 06 1 **

Michaelis, R. E., Wyman, L. L., and Flitsch, R., Standard Reference Materials: Preparation of NBS Copper-Base Spectrochemical Standards. NBS Misc. Publ. 260-2 (October 1964). COM74-

11063**

Michaelis, R. E., Yakowitz, H., and Moore, G. A., Standard Reference Materials: Metallographic

Characterization of an NBS Spectrometric LowAlloy Steel Standard. NBS Misc. Publ. 260-3 (October 1964). COM74-1 1060** Hague, J. L. Mears, T. W., and Michaelis, R. E., Standard Reference Materials: Sources of

Information, NBS Misc. Publ. 260-4 (February

1965). COM74- 11059

Alvarez, R., and Flitsch R., Standard Reference

Materials: Accuracy of Solution X-Ray Spectrometric Analysis of Copper-Base Alloys. NBS

Misc. Publ. 260-5 (March 1965). PB 168068**

Shultz, J. L, Standard Reference Materials: Methods for the Chemical Analysis of White

Cast Iron Standards, NBS Misc. Publ. 260-6

(July 1975). COM74-11068**

Bell, R. K., Standard Reference Materials: Methods for the Chemical Analysis of NBS

Copper-Base Spectrochemical Standards. NBS

Misc. Publ. 260-7 (October 1965). COM74-

11067** Richmond, M.S., Standard Reference Materials: Analysis of Uranium Concentrates at the

National Bureau of Standards. NBS Misc. Publ. 260-8 (December 1965). COM74-1 1066** Anspach, S. C, Cavallo, L. M. Garfinkel, S. B. Hutchinson, J. M. R., and Smith, C. N., Standard Reference Materials: Half Lives of Materials Used in the Preparation of Standard Reference Materials of Nineteen Radioactive Nuclides

Issued by the National Bureau of Standards NBS Misc. Publ. 260-9 (November 1965). COM74-11065**

Yakowitz, H., Vieth, D. L., Heinrich, K. F. J., and

Michaelis, R. E., Standard Reference Materials: Homogeneity Characterization on NBS Spectrometric Standards II: Cartridge Brass and LowAlloy Steel, NBS Misc. Publ. 260-10 (December

1965). COM74-11064**

Napolitano, A., and Hawkins, E. G., Standard Reference Materials: Viscosity of Standard

Lead-Silica Glass, NBS Misc. Publ. 260-11 (November 1966). NBS Misc. Publ. 260-11** Yakowitz, H., Vieth, D. L., and Michaelis, R. E., Standard Reference Materials: Homogeneity

Characterization of NBS Spectrometric Standards 111: White Cast Iron and Stainless Steel Powder Compact, NBS Misc. Publ. 260-12

(September 1966). NBS Misc. Publ. 260-12** Spijkerman, J. L., Snediker, D. K.., Ruegg, F. C,

and DeVoe, J. R., Standard Reference Materials: Mossbauer Spectroscopy Standard for the Chemical Shift of Iron Compounds, NBS Misc. Publ. 260-13 (July 1967). NBS Misc. Publ.

260-13** Menis, O., and Sterling, J. T., Standard Reference

Materials: Determination of Oxygen in Ferrous

Materials - SRM 1090, 1091, and 1092, NBS

Misc. Publ. 260-14 (September 1966). NBS Misc.

Publ. 260-14**

Passaglia, E., and Shouse, P. J. Standard Refer- ence Materials: Recommended Method of Use

of Standard Light-Sensitive Paper for Calibrating Carbon Arcs Used in Testing Textiles for Colorfastness to Light, NBS Misc. Publ. 260-15 (June 1967). (Replaced by NBS Spec. Publ.

260-41.) Yakowitz, H., Michaelis, R. E., and Vieth, D. L., Standard Reference Materials: Homogeneity

Characterization of NBS Spectrometric Standards IV: Preparation and Microprobe Characterization of W-20% MO Alloy Fabricated by Powder Metallurgical Methods, NBS Spec.

" Publ. 260-16 (January 1969). COM74-1 1062** Catanzaro, E. J., Champion, C. E., Garner, E. L., Marinenko, G., Sappenfield, K. M., and Shields, W. R. Standard Reference Materials: Boric

Acid; Isotopic and Assay Standard Reference

Materials, NBS Spec. Publ. 260-17 (February

1970). Out of Print

IV
Geller, S. B., Mantek, P. A., and Cleveland, N.

G., Standard Reference Materials: Calibration of NBS Secondary Standard Magnetic Tape (Computer Amplitude Reference) Using the Reference Tape Amplitude Measurement

"Process A, "NBS Spec. Publ. 260-18 (November

1969). (See NBS Spec. Publ. 260-29.) Paule, R. C, and Mandel, J., Standard Reference

Materials: Analysis of Interlaboratory Measurements on the Vapor Pressure of Gold (Certifica- tion of Standard Reference Material 745). NBS

Spec. Publ. 260-19 (January 1970). PB 190071**

Paule, R. C, and Mandel, J., Standard Reference

Materials: Analysis of Interlaboratory Measurements on the Vapor Pressures of Cadmium and

Silver, NBS Spec. Publ. 260-21 (January 1971). COM74-11359**

Yakowitz, H., Fiori, C. E., and Michaelis, R. E., Standard Reference Materials: Homogeneity

Characterization of Fe-3 Si Alloy, NBS Spec.

Publ. 260-22 (February 1971). COM74-1 1357**

Napolitano, A., and Hawkins, E. G., Standard

Reference Materials: Viscosity of a Standard

Borosilicate Glass, NBS Spec. Publ. 260-23 (December 1970). COM7 1-00 157**

Sappenfield, K. M., Marineko, G., and Hague, J. L., Standard Reference Materials: Comparison

of Redox Standards, NBS Spec. Publ. 260-24 (January 1972). COM72-50058**

Hicho, G. E., Yakowitz, H., Rasberry, S. D., and

Michaelis, R. E., Standard Reference Materials: A Standard Reference Material Containing

Nominally Four Percent Austenite, NBS Spec.

Publ. 260-25 (February 1971). COM74-1 1356** Martin, J. F., Standard Reference Materials:

National Bureau of Standards-US Steel Corportion Joint Program for Determining Oxygen and Nitrogen in Steel, NBS Spec. Publ. 260-26

(February 1971). 85 cents* PB 81176620

Garner, E. L., Machlan, L. A., and Shields, W. R„

Standard Reference Materials: Uranium

Isotopic Standard Reference Materials, NBS

Spec, Publ. 260-27 (April 1971). COM74-

11358**

Heinrich, K. F. J., Myklebust, R. L., Rasberry, S. D., and Michaelis, R. E., Standard Reference Materials: Preparation and Evaluation of SRM's 481 and 482 Gold-Silver and GoldCopper Alloys for Microanalysis, NBS Spec.

Publ. 260-28 (August 1971). COM7 1-50365**

Geller, S. B., Standard Reference Materials: Cali- bration of NBS Secondary Standard Magnetic Tape (Computer Amplitude Reference) Using

the Reference Tape Amplitude Measurement

"Process A-Model 2," NBS Spec. Publ. 260-29 (June 1971). COM71-50282

Gorozhanina, R. S., Freedman, A. Y., and

Shaievitch, A. B. (translated by M. C. Selby), Standard Reference Materials: Standard

Samples Issued in the USSR (A Translation from the Russian). NBS Spec. Publ. 260-30 (June

1971). COM71-50283**

Hust, J. G., and Sparks, L. L., Standard Reference

Materials: Thermal Conductivity of Electrolytic Iron SRM 734 from 4 to 300 K, NBS Spec. Publ.

260-31 (November 1971). COM71-50563**

Mavrodineanu, R., and Lazar, J. W., Standard

Reference Materials: Standard Quartz Cuvettes,

for High Accuracy Spectrophotometry, NBS

Spec. Publ. 260-32 (December 1973). 55 cents* SN003-003-01213-1 Wagner, H. L., Standard Reference Materials: Comparison of Original and Supplemental

SRM 705, Narrow Molecular Weight Distri- bution Polystyrene, NBS Spec. Publ. 260-33 (May 1972). COM72-50526**

Sparks, L. L., and Hust, J. G., Standard Reference

Materials: Thermoelectric Voltage, NBS Spec.

Publ. 260-34, (April 1972). COM72-50371**

Sparks, L. L., and Hust, J. G., Standard Refer- ence Materials: Thermal Conductivity of

Austenitic Stainless Steel, SRM 735 from 5

to 280 K, NBS Spec. Publ. 260-35 (April 1972.) 35 cents* COM72-50368**

Cali, J. P., Mandel, J., Moore, L. J., and Young, D.

S., Standard Reference Materials: A Referee Method for the Determination of Calcium in Serum, NBS SRM 915, NBS Spec. Publ. 260-36 (May 1972). COM72-50527**

Shultz, J. I. Bell., R. K. Rains, T. C, and Menis,

O., Standard Reference Materials: Methods of Analysis of NBS Clay Standards, NBS Spec.

Publ. 260-37 (June 1972). COM72-50692**

Richmond, J. C, and Hsia, J. J., Standard Refer- ence Materials: Preparation and Calibration of Standards of Spectral Specular Reflectance, NBS Spec. Publ. 260-38 (May 1972). COM72-

50528**

Clark, A. F., Denson, V.A., Hust,. J. G., and

Powell, R. L., Standard Reference Materials The Eddy Current Decay Method for Resistivity Characterization of High-Purity Metals, NBS

Spec. Publ. 260-39 (May 1972). COM72-50529**

V
McAdie, H. G., Gam, P.D.,and Menis, O., Standard Reference Materials: Selection of Thermal

Analysis Temperature Standards Through a Cooperative Study (SRM 758, 759, 760), NBS

Spec. Publ. 260-40 (August 1972.) COM72-

50776** Wood, L. A., and Shouse, P. J., Standard

Reference Materials: Use of Standard LightSensitive Paper for Calibrating Carbon Arcs Used in Testing Textiles for Colorfastness to Light, NBS Spec. Publ. 260-41 (August 1972) COM72-50775**

Wagner, H. L. and Verdier, P. H., eds., Standard

Reference Materials: The Characterization of Linear Polyethylene, SRM 1475, NBS Spec. Publ. 260-42 (September 1972). COM72-

50944**

Yakowitz, H., Ruff, A. W., and Michaelis, R. E., Standard Reference Materials: Preparation and Homogeneity Characterization of an Austenitic Iron-Chromium-Nickel Alloy, NBS Spec. Publ. 260-43 (November 1972). COM73-50760**

Schooley, J. F., Soulen, R. J., Jr., and Evans, G. A.,

Jr., Standard Reference Materials: Preparation and Use of Superconductive Fixed Point

Devices, SRM 767, NBS Spec. Publ. 260-44 (December 1972). COM73-50037**

Greifer, B., Maienthal, E. J. Rains, T. C, and

Rasberry, S. D., Standard Reference Materials: Powdered Lead-Based Paint, SRM 1579, NBS

Spec. Publ. 260-45 (March 1973). COM73-

50226**

Hust, J. G., and Giarratano, P. J., Standard Refer- ence Materials: Thermal Conductivity and

Electrical Resistivity Standard Reference Materials: Austenitic Stainless Steel, SRM's 735 and

798, from 4 to 1200 k, NBS Spec. Publ. 260-46 (March 1975). SN003-003-0 1278-5 Hust, J. G., Standard Reference Materials: Electrical Resistivity of Electrolytic Iron, SRM 797, and Austenitic Stainless Steel, SRM 798, from 5 to 280 K, NBS Spec. Publ. 260-47 (February

1974). COM74-50176** Mangum, B. W., and Wise, J. A., Standard Refer- ence Materials: Description and Use of Precision Thermometers for the Clinical Laboratory,

SRM 933 and SRM 934, NBS Spec. Publ. 260-48 (May 1974). 60 cents* SN003-003-0 1278-5 Carpenter, B. S., and Reimer, G. M., Standard Reference Materials Calibrated Glass Standards for Fission Track Use, NBS Spec. Publ. 260-49 (November 1974). COM74-51185

Hust, J. G., and Giarratano, P. J., Standard Refer- ence Materials: Thermal Conductivity and Electrical Resistivity Standard Reference Materials:

Electrolytic Iron, SRM's 734 and 797 from 4 to 1000 K, NBS Spec. Publ. 260-50 (June 1975). $1.00* SN003-003-0 1425-7 Mavrodineanu, R., and Baldwin, J. R., Standard

Reference Materials: Glass Filters As a Standard Reference Material for Spectrophotometry;

Selection; Preparation; Certification; Use-SRM

930, NBS Spec. Publ. 260-51 (November 1975). $1.90* SN003-003-01481-8

Hust, J. G., and Giarratano, P. J., Standard Refer- ence Materials: Thermal Conductivity and Electrical Resistivity Standard Reference Materials 730 and 799, from 4 to 3000 K, NBS Spec. Publ. 260-52 (September 1975). $1.05* SN003-003-

01464-8 Durst, R. A., Standard Reference Materials: Standardization of pH Measurements, NBS

Spec. Publ. 260-53 (December 1975, Revised). $1.05 SN003-003-01551-2

Burke, R. W., and Mavrodineanu, R. Standard

Reference Materials: Certification and Use of Acidic Potassium Dichromate Solutions as an

Ultraviolet Absorbance Standard, NBS Spec. Publ. 260-54 (August 1977). $3.00* SN003-003-

01828-7

Ditmars, D. A., Cezairliyan, A., Ishihara, S., and

Douglas, T. B., Standard Reference Materials: Enthalpy and Heat Capacity; Molybdenum

SRM 781, from 273 to 2800 K, NBS Spec. Publ. 260-55 (September 1977). $2.20* SN003-003-

01836-8

Powell, R. L., Sparks, L. L., and Hust, J. G., Standard Reference Materials: Standard

Thermocouple Materials, Pt.67: SRM 1967, NBS

Spec. Publ. 260-56 (February 1978). $2.20* SN003-003-0 18864

Cali, J. P. and Plebanski, T., Guide to United

States Reference Materials, NBS Spec. Publ. 260-57 (February 1978). $2.20* PB 2771.73 Barnes, J. D., and Martin, G. M., Standard Refer- ence Materials: Polyester Film for Oxygen Gas

Transmission Measurements SRM 1470, NBS

Spec. Publ. 260-58 (June 1979) $2.00* SN003-

003-02077 Chang, T., and Kahn, A. H. Standard Reference

Materials: Electron Paramagnetic Resonance

Intensity Standard; SRM 2601, NBS Spec.

Publ. 260-59 (August 1978) $2.30* SN003-

003-01975-5
Velapoldi, R. A., Paule, R. C, Schaffer, R., Mandel, J., and Moody, J. R., Standard Refer- ence Materials: A Reference Method for the Determination of Sodium in Serum, NBS Spec.

Publ. 260-60 (August 1978). $3.00* SN003-003

01978-0

Verdier, P. H., and Wagner. H. L., Standard Refer- ence Materials: The Characterization of Linear Polyethylene (SRM 1482, 1483, 1484), NBS

Spec. Publ. 260-61 (December 1978). $1.70* SN003-003-02006-1

Soulen, R. J., and Dove, R. B., Standard Reference

Materials: Temperature Reference Standard

for Use Below 0.5 K (SRM 768). NBS Spec.

Publ. 260-62 (April 1979). $2.30* SN003-003-

02047-8 Velapoldi, R. A., Paule, R. C, Schaffer, R. Mandel, J., Machlan, L. A., and Gramlich, J. W., Standard Reference Materials: A Reference Method for the Determination of Potassium in Serum. NBS Spec. Publ. 260-63 (May 1979). $3.75* SN003-003-02068

Velapoldi, R. A., and Mielenz, K. D., Standard

Reference Materials: A Fluorescence Standard

Reference Material Quinine Sulfate Dihydrate (SRM 936), NBS Spec. Publ. 260-64 (January

1980). $4.25* SN003-003-02 148-2 Marinenko, R. B., Heinrich, K. F. J., and Ruegg,

F. C, Standard Reference Materials: Micro- Homogeneity Studies of NBS Standard Reference

Materials, NBS Research Materials, and Other Related Samples. NBS Spec. Publ. 260-65

(September 1979). $3.50* SN003-003-021 14-1 Venable, W. H., Jr., and Eckerle, K. L., Standard

Reference Materials: Didymium Glass Filters for Calibrating the Wavelength Scale of Spectro- photometers (SRM 2009, 2010, 2013). NBS Spec.

Publ. 260-66 (October 1979). $3.50* SN003-003-

02127-0

Velapoldi, R. A., Paule, R. C, Schaffer, R., Mandel,

J., Murphy, T. J., and Gramlich, J. W., Standard

Reference Materials: A Reference Method for the Determination of Chloride in Serum, NBS Spec.

Publ. 260-67 (November 1979). $3.75* SN003-

003-02136-9 Mavrodineanu, R. and Baldwin, J. R., Standard

Reference Materials: Metal-On-Quartz Filters as a Standard Reference Material for Spectrophoto- metry-SRM 2031, NBS Spec. Publ. 260-68

(April 1980). $4.25* SN003-003-02 167-9

Velapoldi, R. A., Paule, R. C, Schaffer, R., Mandel, J., Machlan, L. A., Garner, E. L., and

Rains, T. C, Standard Reference Materials: A

Reference Method for the Determination of Lithium in Serum, NBS Spec. Publ. 260-69 (July)

1980). $4.25* SN003-003-02214-4 Marinenko, R. B., Biancaniello, F., Boyer, P. A., Ruff, A. W., DeRobertis, L., Standard Reference

Materials: Preparation and Characterization of an Iron-Chromium-Nickel Alloy for Microanalysis, NBS Spec. Publ. 260-70 (May 1981). $2.50* SN003-003-02328-1 Seward, R. W., and Mavrodineanu, R., Standard

Reference Materials: Summary of the Clinical Laboratory Standards Issued by the National Bureau of Standards, NBS Spec. Publ. 260-71 (November 1981). $6.50* SN003-003-02381-7

Reeder, D.J., Coxon, B., Enagonio, D., Christensen, R. G., Schaffer, R., Howell, B. F., Paule, R. C,

Mandel, J., Standard Reference Materials: SRM

900, Antiepilepsy Drug Level Assay Standard, NBS Spec. Publ. 260-72 (June. 1981). $4.25* SN003-003-02329-9

Interrante, C. G., and Hicho, G. E., Standard Refer- ence Materials: A Standard Reference Material Containing Nominally Fifteen Percent Austenite (SRM 486), NBS Spec. Publ. 260-73 (January

1982). $2.75* SN003-003-02386-8 Marinenko, R. B., Standard Reference Materials: Preparation and Characterization of K-411 and

K-414 Mineral Glasses for Microanalysis: SRM

470. NBS Spec. Publ. 260-74 (April 1982). $3.50 SN003-003-023-95-7

Weidner, V. R., Hsia, J. J., Standard Reference

Materials: Preparation and Calibration of First Surface Aluminum Mirror Specular Reflectance Standards (SRM 2003a), NBS Spec. Publ. 260-75 (May 1982). $3.75 SN003-003-023-99-0

Hicho, G. E. and Eaton, E. E., Standard Reference Materials: A Standard Reference Material

Containing Nominally Five Percent Austenite (SRM 485a), NBS Spec. Publ. 260-76 (August

1982). $3.50 SN003-003-024-33-3 Furukawa, G. T., Riddle, J. L., Bigge, W. G., and

Pfieffer, E. R., Standard Reference Materials: Application of Some Metal SRM's as Thermometry Fixed Points, NBS Spec. Publ. 260-77 (August 1982). $6.00 SN003-003-024-34-1

v1i
Hicho, G. E. and Eaton, E. E., Standard Reference

Materials: Standard Reference Material Containing Nominally Thirty Percent Austenite (SRM

487), NBS Spec. Publ. 260-78 (September 1982). $3.75 SN003-003-024-35-0 Richmond, J. C, Hsia, J. J., Weidner, V. R., and

Wilmering, D. B., Standard Reference Materials: Second Surface Mirror Standards of Specular

Spectral Reflectance (SRM's 2023, 2024, 2025), NBS Spec. Publ. 260-79 (October 1982). $4.50 SN003-003-024-47-3

Schaffer, R., Mandel, J., Sun, T., Cohen, A., and

Hertz, H. S., Standard Reference Materials: Evaluation by an ID/ MS Method of the AACC

Reference Method for Serum Glucose, NBS

Spec. Publ. 260-80 (October 1982). $4.75 SN003-

003-024-43-1 Burke, R. W., Mavrodineanu, R. (NBS retired), Standard Reference Materials: Accuracy in Analytical Spectrophotometry, NBS Spec. Publ. 260-81 (April 1983). $6.00 SN003-003-024-84-8

Weidner, V. R., Standard Reference Materials: White Opal Glass Diffuse Spectral Reflectance Standards for the Visible Spectrum (SRM's 2015

and 2016), NBS Spec. Publ. 260-82 (April 1983). $3.75 SN-003-003-024-89-9

Bowers,; G. N., Jr., Alvarez, R., Cali, J. P. (NBS

retired), Eberhardt, K. R., Reeder, D. J., Schaffer, R., Uriano, G. A., Standard Reference

Materials: The Measurement of the Catalytic

(Activity) Concentration of Seven Enzymes in NBS Human Serum SRM 909, NBS Spec.

Publ. 260-83 (In Press).

Gills, T. E., Seward, R. W., Collins, R. J., and

Webster, W. C, Standard Reference Materials: Sampling, Materials Handling, Processing, and Packaging of NBS Sulfur in Coal Standard

Reference Materials, 2682, 2683, 2684, and 2685, NBS Spec. Publ. 260-84 (In Press).

* Send order with remittance to Superintendent

of Documents, US Government Printing Office Washington, DC 20402. Remittance from

foreign countries should include an additional one-fourth of the purchase price for postage. ** May be ordered from: National Technical Information Services (NTIS). Springfield

Virginia 22151.

viii
CONTENTS

Page Preface Hi

1. Introduction 2

2. Selection of Coal Sampling Locations 3

3. Collection and Handling of Coals 4

4. Processing of Coal Samples 8 4.1 Air Drying 10 4.2 Hammermilling 10 4.3 Screening 10 4.4 Blending 13 4.5 Packaging of Blended Coals 15

5. Sample Preparation/Homogeneity Testing 15

6. Conclusion 22 Appendix A 24 Appendix B 31 Appendix C 38 Appendix D 46

LIST OF TABLES

Page

1. Summary of coal sampling operations 6

2. Results of sulfur content tests on coal subsamples taken from

individual drums during coal sampling operations 7 3. Summary of coal sample weights before, during, and after processing 13

4. Summary of coal packaging operations 17

5. Individual pail weights and sulfur content after blending

of 0.5 percent sulfur coal 18

6. Individual pail weights and sulfur content after blending

of 2.0 percent sulfur coal 19

7. Individual pail weights and sulfur content after blending

of 3.0 percent sulfur coal 19

8. Individual pail weights and sulfur content after blending

of 4.5 percent sulfur coal 20

9. Drying of coals 21 10. Data for coal homogeneity samples 23

10a. Sulfur percent of controls 23

ix
LIST OF FIGURES

Page

T. Material flow for preparation of Standard Reference Coal Samples . 9

2. Tray loading and oven drying of coal sample 11 3. Hammermill unit used for size reduction of coal samples 11 4. Cyclone screener used for screening of coal samples 12

5. View of 60 mesh screen mounted on cyclone screener shaft 12

6. Cone blender used for blending of coal samples 14

7. Discharging of blended coal into lined 5-gallon pails 14

8. Closing flow from blender during filling of 5-gallon pails .... 16 A-l Layout of Belle Ayr Mine, Gillette, Wyoming 25 A-2 Schematic of coal sampling system 26 A-3 Sampling of coal in 55-gallon drum at Belle Ayr Mine 28 A-4 Riffle splitting of 6000 gram coal sample at Belle Ayr Mine laboratory 28

A- 5 Mined area at Belle Ayr Mine showing two working benches in 72 foot seam 30 A-6 Mined area at Belle Ayr Mine showing depth of excavation and

coal truck 30

B-l Layout of Humphrey Mine and Plant Consolidation Coal Company,

Osage, West Virginia 32 B-2 Humphrey preparation plant and conveyor system 33 B-3 Barge loading system at Humphrey plant 33 B-4 Schematic diagram of coal sampling at Humphrey plant barge

loading facility 35 B-5 Loading of coal barge at Humphrey plant 36

C-l Layout of Delta Mine, Marion, Illinois 39 C-2 View of 1450 open pit and dragline at Delta Mine 40

C-3 Overall view of coal preparation plant at Delta Mine 40

C-4 Collection of coal sample and companion 5000 gram sulfur analysis

sample at Delta Mine 42 C-5 Schematic of coal sampling system Delta Mine 43 C-6 Riffle splitter and laboratory pulverizer equipment

at Delta Mine 45

C-7 Air cleaning of laboratory pulverizer 45

D-l Layout of Mitchell-Captina power plant and Consolidation Coal Company's McElroy Mine, Moundsville, West Virginia 47 D-2 McElroy Mine preparation plant with coal storage

silo in foreground 48

D-3 Mitchell-Captina power plant with cooling towers and conveyor

from sampling building 48

D-4 Schematic diagram of sampling station No. 1 at Mitchell power station 50

x
SAMPLING, MATERIALS HANDLING,

PROCESSING, AND PACKAGING OF NBS SULFUR IN COAL STANDARD REFERENCE MATERIALS

T. E. Gills and R. W. Seward

National Bureau of Standards Washington, DC 20234

R. J. Collins Valley Forge Laboratories, Inc. Devon, Pennsylvania 19333

W. C. Webster Webster and Associates, Ltd. Norristown, Pennsylvania 19401

This publication describes in detail the performance of a grant

given to Valley Forge Laboratories, Inc., by the National Bureau of Standards, to obtain and prepare four standard reference coals, with

nominal sulfur contents of 0.5, 2.0, 3.0, and 4.5 percent to be issu

as SRM's 2682, 2683, 2684, and 2685, respectively. All activities

pertaining to the sampling, preparation, packaging, and homogeneity

testing of the coal SRM's are documented in this report, including a separate description of each of the four coal sampling activities.

Protocols used in the development of these Standard Reference Materials are similar to those used in other NBS SRM preparation pro- cedures to ensure that materials used for SRM's have the highest

possible homogeneity and stability.

Keywords: bituminous coal; blending; drying; hammermil 1 ing;

homogeneity; processing; sampling; screening; Standard Ref- erence Materials; sub-bituminous; sulfur.

DISCLAIMER

In order to describe materials and experimental procedures

adequately, it was occasionally necessary to identify commercial products by the manufacturer's name or label. In no instances

does such identification imply endorsement by the National Bureau

of Standards nor does it imply that the particular products or equipment are necessarily the best available for that purpose.

1
1. Introduction

Valley Forge Laboratories (VFL) and Webster and Associates furnished technical

and logistical services as part of a grant from the National Bureau of Standards

(NBS) to provide for the collection and preparation of coal materials for sub- sequent use by NBS as Standard Reference Materials (SRM's). The purpose of this grant was to obtain, from wel 1 -documented sources, at least 1,000 pounds each of four separate coals having nominal sulfur levels of 0.5, 2.0, 3.0, and 4.5 percent. The collected material was crushed and ground to pass a 60 mesh sieve. These four coal materials were intended for certification and distribution by NBS as Coal SRM's for use in standardization of laboratory facilities and testing equipment for the analysis of sulfur content, ash content, and calorific

value. The four coals described herein have been certified and issued as SRM's

2682, 2683, 2684, and 2685. Moisture content is reported for each coal, but is not certified.

Of the properties to be certified by NBS, the most important is the sulfur

content, particularly because of its impact in the enforcement of environmental

regulations. The ash content, moisture, and calorific value are the three

additional properties commonly used in assessing coal quality and assigning sale value in the marketplace.

In order to adequately describe materials and experimental procedures discussed

in this work, it was occasionally necessary to identify companies or commercial

products by manufacturer's name or label. In no instance does such identification imply endorsement by NBS of that particular product or equipment as being

the best available for that purpose.

This program for providing and preparing Coal SRM's involved the following

activities for each of the coals sampled:

a. Selection of coal sampling locations;

b. Collection and handling of coals;

c. Processing of coals;

d. Packaging of coals; and

e. Sample preparation/homogeneity testing.

A schematic diagram depicting the activities described above is shown in figure

T. All of these activities were completed for each coal before the collection

began for the next coal, starting with the coal with lowest sulfur content and progressing in order of increasing sulfur content.

2
2. Selection of Coal Sampling Locations

From the beginning of the program, the selection of the location and type of

coals was recognized as one of the critical factors influencing the attainment

of the desired sulfur level and required homogeneity for each of the candidate

coal materials. The original plan was to obtain samples from coal burning utility

power plants that use coal from a single documented source. The intent was to utilize available published information from government energy agencies pertaining to target sulfur levels of coals purchased for use in electric utility

plants. It would then be possible to take advantage of the averaging effect of

coal processing equipment at selected utility plants to obtain coal samples with

known uniform properties, particularly sulfur level. After reviewing pertinent publications on sulfur levels of utility coals and identifying candidate locations for each of the four desired sulfur levels, it was decided that sampling at utility locations did not represent the best approach because it was desired to carefully document the coal sources. Coal from a single mine can be obtained from several different locations (possibly

involving more than one coal seam) within the mine itself and coal from a preparation plant may be obtained from several mines. Furthermore, the sulfur

content of the raw coal from a single mine can vary significantly from one area

to another within the same mine and this coal can then be blended at the pre- paration plant to achieve a desired sulfur level. This is particularly so when considering that some of the larger mines extend over an area of several square

miles.

It is usually possible to accurately identify the location and seam of a par- ticular coal coming into a preparation plant and to separate this coal source

from others being handled by the same plant. But, once the coal has been pre- pared and shipped to a utility plant from a coal preparation facility, it already is a blend of coals, each having differences in sulfur content and other

properties. In addition, pressures from regulatory agencies to reduce or maintain current sulfur oxide emission levels result in frequent blending of coals

at utility power plants, even when published reports indicate that coal from a single source is being used. Therefore, it was decided that all coals would be obtained from a single mine and/or preparation plant, in which the coal came from one documented source

having a known sulfur content within the desired range.

To select prospective mine locations for coal sampling, the coal sources feeding

the target utility plants chosen in the initial screening were investigated.

The investigation sought to determine such information as the type of mine

(surface or deep); the number of locations and seams being mined at that time;

the average sulfur content of the coal (before and after washing); the variation

in sulfur content of coal from different locations within the same mine; the moisture content of the coal; the volume of coal prepared and shipped; the number of customers and their sulfur content requirements; and existing sampling

systems for the coal

.

3
The sampling locations selected were:

Coal Company Mine Location Coal Type

Nominal

Sul fur Content

(Percent) Amax Coal Company Belle Ayr Gillette, WY Consolidation Coal Co. Humphrey Osage, WV Amax Coal Company Delta Marion, IL Consolidation Coal Co. McElroy Captina, WV

Sub-bituminous

Bituminous

Bituminous

Bituminous

0.5

2.0 3.0

4.5

One final consideration was the type of sample and the sampling technique to be employed. Mine face sampling was considered, since it would be taken from a specific seam location in the mine where, presumably, the sulfur content would

be known and would be quite consistent. However, obtaining a mine face or channel sample is a long, involved, and very time-consuming procedure that can only be performed by a certified specialist. Because most commercial coals, particularly bituminous coals, are cleaned before

use, it was felt that mine face or channel samples would be representative of most coals being tested in the marketplace and would contain some impurities

that would be removed in the preparation plant. It was also apparent that a considerable amount of sulfur analysis data was available from washed coal samples coming out of the preparation plant, but less sulfur analysis data was available from raw coal samples taken from specific mine face locations at the sampling sites. Therefore, it was decided that all coal samples, except for the

0.5 percent coal (which required no washing), would be taken from coal preparation plants at the selected sampling locations. Sampling locations selected were based on facilities where preparation plants accepted coal from only one mine and would be able to correlate a specific location within the mine with a coal sample taken from the preparation plant during a particular time period.

3. Collection and Handling of Coals Discussions with mine or preparation plant supervisors at each sampling location focused on resolution of logistical considerations, such as:

a. Number of locations and identifiable seams where coal is presently being mined;

b. Average sulfur content of the raw and prepared coal;

c. Consistency of the coal being supplied recently;

d. Variation in sulfur content of coal from different locations or seams within the mine;

e. Ability to obtain a 1-ton coal sample using the mine's conveying

and sampling system;

4
f. Ability to perform sulfur analyses using available laboratory

facilities at the mine;

g. Availability of personnel, equipment, and materials (such as 55- gallon drums and plastic liners) to assist in the coal sampling; and

h. Time period during which the sampling could be scheduled.

At each location, the procedures used to obtain the coal samples were essentially

similar. An existing automatic coal sampling system, which obtained a full- stream conveyor belt cut, was utilized. The belt sample was passed through a crusher and one or more sample cutters and the reject material from the sample cutter (that is, the material that was not included in the coal company's com- posite sample) was collected at pre-determined time intervals over a several hour time period. All coal was collected in plastic-lined 55-gallon steel drums, which were sealed once the drums were filled. A 5000-to-6000 gram com- posite sample was also collected at random intervals during the filling of each drum for subsequent analysis of sulfur content. The time period of sampling was selected to correspond with a particular quantity

of coal, representing a desired total lot size for sampling. The lot size varied depending on the location, type, and capacity of the sampling and coal loading facilities. For example, in the case of the 0.5 percent coal, a time period for sampling was chosen to approximate the amount of coal to fill a silo for later loading of a unit train, while the sampling period for the 2.0 percent

coal corresponded with the time allotted for loading of four coal barges.

A discussion of the mining and preparation plant operations at each sampling

location, together with details of the sampling and handling procedures employed

at each of these locations, is provided in separate Appendixes to this report.

Appendix A discusses the sampling of the 0.5 percent coal; Appendix B, the 2.0 percent; Appendix C, the 3.0 percent; and Appendix D, the 4.5 percent coal. Table 1 provides a summary of the coal sampling time periods, sampling intervals,

lot sizes, and total amount of coal sampled at each sampling location.

As noted previously, samples were taken during the filling of each drum. These

samples were riffle split, providing one sample for the coal company and one for

NBS. Each sample was labeled with the number of the drum from which it was obtained. AH of these subsamples were analyzed as soon as possible to determine their sulfur content. The 0.5 percent subsamples were analyzed at the Amax Coal Company's Western Division laboratory located near Gillette, Wyoming. The 2.0 and 4.5 percent subsamples were analyzed by Tradet, Inc., a commercial coal laboratory located near Wheeling, West Virgina. The 3.0 percent subsamples were

analyzed by the Central Illinois Public Services (CIPS) Laboratory in Newton,

Illinois. Table 2 presents the results of these sulfur content tests, which are also discussed in the Appendixes in relation to the coal sampling at each location.

5
CO CO to to t -O -Q -Q

-M fO ' 1 1 3 o . ^ ^

OJ 4— — O CM CNJ O CO 2 E

r- S_ CO <JO CO

fO QO 4— | Q

+J i s- C U c c to o

•r- E •<- S- co 4- , qj E •-- E

4- 13 e" o" CO 00 Q LO

fo cu CNI r— -O E

CO S— O

4— CXI CO o "O CD O E

(/) C

fO Sw 1

S_ -r- S_ -r- S- TJ_ OJ Q_ f— £ <— £ <— g

Q_ o OJ UT) CNJ (—) Q CM CD

h~ O

ri - grf?

rrj _ .

co -fj (/)" to" CO

rt3 <z £ZO

CO o +j +-> Q

cu* ~S o

OJ Q o

C_> -o

CU O CO O CO O to O to

(X3 4-> r- r-^ c

-t-> O Q- o o o o LO O OJ o O —1 E <- +-> 1— fO oo CO CNJ CO

OJ 1 -!-> c -o C o n3 _Q +J fO SI

CO t— o CU 4_) S_ o CU CT> ry C7> CU

•r- fO CL» C

^r | C •!- o

CD S "O CD O Q_ c iE Q-

>> CD >> o JZ •i- +J E

<C c CU —1

(O SI fO >, fC D- s- CD s- o co "aj E CU -SZ -C CU C 03 «3 -EI r— co Cl CD o -(-> Q- U

CO t— 3 E S- r— CU LU fO CTi +-> CD S- 3 fO CL) S- <_> o

CO O rc oo Q Q_ te: c_> -o

CU 00 00 CO 00

cu i— \ \ +-> Q. CTi OJ o <T3 CNJ OJ OJ CO Q (O \ CO IT)

S- +-> +-> o o O ID

CO
O 0 00 0 0

CD S_ +J +-> 0 O 0 0 CD 3 E E

ra 4— CU cu -l-l +1

S_ 1— (_> cu

CU 3 E S- «d- 0 LO -M > OO O CU 00 0 CD s_ <C O D_ 0 0 , ro CL

cu

1— * cu

ro co •—

-)_) * e

"O 3 E E * * 0 •1— M— CU CU sj- in cm 1— to m m rs r-^ 1— 00 «3- 1-^ c\j N CM O «t O Lf) (J > 1— +-> CJ 00 CT> 00 1— CD CTi ncoooioo co r-^ LO cd r-- co

•r- 3 E S- S- e "O OO O CU OOOOOOOOO 1 1— 1 CNJ 1— 1

CNJ CNJ CO CNJ C0 CO >^t" ^3- ^3- cu E O CO- 4-

CO CO

+-> e co 0

CO •!— cu

cu +-> CD i— CO CO ra Cl S- S- E "D s_ E CU CU 3 CU cu CO CL -Q S- 1— >

co 0 E 0 a. cn CD co CD rO 3 E 3 cn 4- rO cu CO e O CO {—

4-> ,_ , CO cl O E 0 ra

(/) >- s_ e > 0 0 I— e 1 e

CO 0 > co 0 cu

4-> a +j +J ro CD

co rO ** e J~

CU CD CJ cu CU 0 4-> E 0 CD •r— +J CO CO _l , fO S- CL •1— co

+-> si CO rO ro CO CU

CJ3 O 3E 0 ra (j

CU "O 0 0 +-> s_ E CO >, CL O E £ O 3 "O 1

S- S- ra

s- -a ro O 3 CU >, 0 c<- 1— cu i- 0 1— co £Z cu -C CO S- 0 e

CL +-> co ""O , E LxJ cu 3 cu CJ CU "O

4— > CO 0 s: E CU O "1— •1— "O "O £ 3

CO E £_ ,

+-> T- cu 0

4-> E

's E • CU -i— CO 0 0 0

CU &- 0 0 +J C£ 4- cu 0 >

s_ c

>, >, CO >> ro cu e O e 0 2 co

CNJ ro ro ra 0 ra CL CL CL co 2

cu E E e E e cu 0 0 0 0 3 CO _Q 0 0 cS

ro 4-> +J ro CU (— , , ra fO > S- CO "O CO -a s_ 0 O 0 -(-> ra 0 0 E -Q "o 0 cu x CO X +-> cu

ro E ra E CO

£= c3 M 0 O CD eE 0 -E

+J

i_3 E

4- O ,— S_ 3 <+-

+-> +-> co 1— S- E E

fO 3 CU CU LO 0 0 LO 1— ra E 4- +-> O 1— 0

•r- r— E S- O CNJ CO <C O E 3 O CU X * O CO O Q_

z: —

7
On the basis of these sulfur tests, the following decisions were made concerning

the handling and processing of the respective coal samples:

a. The 0.5 percent coal appeared to be very satisfactory with respect to the uniformity of its sulfur content. Due to its relatively high moisture before

drying, it was decided to oven dry and process the contents of all nine of the 55-gallon drums.

b. Two of six drums of the 2.0 percent coal appeared to have a greater deviation

in sulfur content from the mean than would normally be considered acceptable. These were drums 4 and 5. Since the sulfur content from drum 4 was the only one of the six that exceeded 2.0 percent, it was decided to process all but the coal from drum 4. It was not possible to obtain over 1,000 pounds of -60 mesh coal after drying with anything less than five drums; otherwise, drum 5 would have

also been withheld from processing.

c. One of the six drums of the 3.0 percent coal also appeared to have a greater

deviation in sulfur content from the mean than would normally be considered

acceptable. This was drum number 1. This was the lowest sulfur content of the

six samples of 3.0 percent coal that were tested. Therefore, it was decided to process all but the coal from drum 1. d. The uniformity of the sulfur content for the 4.5 percent sulfur coal samples

appeared to be acceptable, except that the sulfur content of the coal in drum 3 was slightly lower and deviated a little more from the mean than the other five

samples. However, this did not appear to be significant and it was decided to oven-dry and process the contents of all six of the 55-gallon drums.

4. Processing of Coal Samples

All four of the coals obtained for this program were collected in plastic-lined

and sealed 55-gallon steel drums and shipped to a processing facility in Camden,

New Jersey. The facility, owned and operated by Alnort Processing, Inc., is used for the custom processing of various raw materials such as minerals, pigments,

and chemicals. All of the processing for each coal in this program was conducted completely and exclusively in this facility.

As shown previously in figure 1, the processing of each coal involved the following steps:

a. First stage air-drying in a temperature-controlled oven;

b. Hammermill to crush coal;

c. Screening hammermilled coal through a 60 mesh sieve;

d. Blending -60 mesh coal in a cone blender; and

e. Packaging the blended coal in individually numbered 5-gallon pails. Each processing step is discussed in detail in the following sections.

8
o Q-DQ E c z h (D O r

J13

CD co Q.

Clo

I

-o

-O

-O

-O

-O

-o

.Q CO I!.

-o = = { -

I

9
4.1 Air Drying

Air drying was accomplished by removing the coal from the drums, placing it in metal trays (approximately 3 feet square and 1 inch deep), and dryigg it in an oven for a period of 18 hours at an average oven temperature of 35 C (95 F)

,

in accordance with procedures outlined in ASTM D2013, "Standard Method of Preparing Coal Samples for Agalysis^" All coals were dried at a constant oven temper- ature no more than 10 C (18 F) above ambient temperature. Figure 2 is a photograph of the oven and the tray loading of one of the coals.

4.2 Hammermilling

Following air drying, each coal was size reduced using a micro-pulverizer

screw- fed hammermill having a feed rate of approximately 400 pounds per hour. Figure 3 is a photograph of the unit used in this phase of the coal processing.

The hammermill was thoroughly cleaned by sandblasting before use as a means of preventing contamination from other materials. The four coals were processed in order of ascending sulfur content. Between the size reduction of each of these

three coals, the hammermill was thoroughly air cleaned, but not sandblasted. A small amount (approximately 100 pounds) of each coal was run through the hammermill after each cleaning to purge the equipment prior to actual hammermilling of that particular coal. The jaw setting of the hammermill was adjusted to assure that the majority of the coal feed was reduced in size from 4 mesh top size to a nominal 60 mesh material. The nature of the hammermilling operation caused some definite dust

loss despite the slow feeding of the hammermill.

4.3 Screening

Upon completion of the hammermilling, each crushed coal was repackaged and stored in the same drums originally used for transport. The screening of the four hammermi 1 1 ed coals was accomplished by means of a cyclone screener, Model

240, manufactured by AZ0, Inc., of Memphis, Tennessee. Figure 4 is a photograph

of the AZ0 screener with a 55-gallon drum positioned to collect the oversize

material

.

The screener operates by receiving material into a small hopper and feeding it into a rotating hollow shaft surrounded by a screen of the desired size, in this case a 60 mesh screen. Material of the desired size passes through the screen

and falls into a collection chute centrally located beneath the screen. Oversize

material passes out a discharge port at the opposite end of the screener from

the receiving hopper. According to the product literature, the maximum feed

rate for the screener when operating with a 60 mesh screen would be approximately

300 pounds per hour. Figure 5 is a closer view of the 60 mesh screen mounted on the shaft.

Each coal was screened separately and the AZ0 screener device was blown clean before each screening. The -60 mesh coal was collected and repackaged into the same drums. A separate 55-gallon drum (or drums) was used to collect, seal, and store any oversize coal resulting from the hammermilling and screening operations

for each coal

.

10

Figure 4. Cyclone Screener Used for Screening

of Coal Samples
A small test sample (approximately 200 grams) was taken from each of the four screened coals prior to blending. Each of these samples was passed through a 60 mesh test screen at Valley Forge Laboratories to evaluate the percentage of material (if any) retained on the 60 mesh screen in the cyclone screener. The results of these rather cursory screen analyses are as follows: Sulfur

Content Percent

of Passing

Sampl60 mesh

(Percent) Screen

0.5 100 2.0 98 3.0 99 4.5 100 The coal sample weights before, during, and after processing are summarized in table 3. 4.4 Blending

Each of the screened coals was blended using a Patterson-Kelly stainless steel cone blender (approximate capacity 30 cubic feet). This blender was not equipped

with an intensifier bar. The blender was of sufficient size to handle more than

1000 pounds of coal or other bulk material while still having enough room to properly blend the material. Figure 6 is a photograph of the cone blender with

the discharge chute at the bottom.

All four coals were blended in the same manner. The screened coal was loaded

into the top of the blender, the blender sealed, and blending accomplished by

rotating the blender at 12 rpm for at least 20 minutes. The blender was blown

clean and thoroughly wiped before blending of each coal.

Table 3. Summary of coal sample weights

before, during, and after processing

Sulfur

Level (Percent)

Weight

of Coal Sample

Received*

(Pounds)

Weight

of -60 Mesh

Coal after Screening

(Pounds)

Weight

of -60 Mesh

Coal after Blending

(Pounds) 0.5 3150 1151 1139 2.0 2100 1050 988 3.0 2100 1089 976 4.5 2100 1200 1122 *Based on an estimated net weight of 350 pounds of moist

coal in filled 55-gallon drum. Actual net weight will vary depending on the extent the drum was filled, the density of the crushed coal, and the moisture content

of the coal at sampling.

13
Figure 6. Cone Blender Used for Blending of Coal Samples
4.5 Packaging of Blended Coals After blending, the discharge chute at the bottom of the cone blender was opened sufficiently to allow the coal to flow into a pail, as shown in figure

7. Each 5-gallon pail had a plastic liner for sealing. Care was taken to not

fill each pail to capacity, so that at a later date, each pail could be rolled

to mix the contents. Figure 8 shows the closing of a control lever to stop the flow of material from the blender when a pail is filled. During the filling of each pail, two small samples for homogeneity testing were

taken from the coal stream, approximately halfway through the filling of each

pail. These samples were collected in 4 ounce glass bottles labeled with the sulfur content of the coal, the pail number, and the number of the sample taken from that pail. For example, the label "0.5, 10-2" indicates the second bottle

taken from the 0.5 percent sulfur coal during filling of the tenth pail. All pails were labeled with the sulfur content of the coal and were numbered con- secutively according to the order in which they were filled. At least once or twice during the unloading of each coal, the blender was rotated several times

to minimize segregation of particles.

The total number of pails filled with each coal ranged from 32 to 50, depending

on the total weight of the coal blended and the amount of coal placed into each

pail. Table 4 summarizes the number of pails collected for each coal, the

total weight of the coal, and the average amount of coal contained in each pail for that coal. Tables 5 through 8 are tabulations of individual pail weights

for the 0.5, 2.0, 3.0, and 4.5 percent sulfur coals, respectively, and the sulfur concentrations of selected pails. These sulfur analyses were performed

by an independent laboratory for purposes of testing the gross homogeneity and sulfur content of the processed samples. These preliminary analyses provided

the basis for the decision to bottle the coals for subsequent certification. After collecting and weighing each coal, the lined pails were shipped to Valley Forge Laboratories for eventual packaging into bottles. Individual 4 ounce bottles (two from each pail) were packaged and delivered to the National Bureau of Standards for acceptance and homogeneity testing.

5. Sample Preparation/Homogeneity Testing

Homogeneity testing is crucial in the preparation of an SRM. It is useless to perform highly accurate analyses on materials that exhibit high variability.

Although homogeneity tests differ radically with various types of materials and with the various properties to be certified, all have the same common goal: to ensure that the material is sufficiently uniform to completely satisfy the end

use. This helps to ensure that tests made in different laboratories will produce the same values within reasonable limits, and that test results obtained

in one laboratory on one date will match those obtained at some later date. Thus, these tests are designed to ensure that candidate SRM materials meet two important criteria: homogeneity and stability.

15
Figure 8. Closing Flow from Blender During

Filling of 5-Gallon Pails

16
* E to * -o O CM CM CO E

in CO O CO

S- 03 c O CM CM

<D Du Q_

Q4-> ro .E 3

CnXJ

^ cu > E

13 O CM O CO

-a E E

c 3 r>» CM in X O CM CO CO CO

(0 D_

s:

.e

cn

fO

cu D_ co "D CO 00 LO CM

(/I -c: E

e CU o 3 CM* 00 o o Cn fO O CM CM CO CO

(O LU Q_

s_ fO cu s- s- > o

CU

+-> -e -a

a> cu

•i- -o *

cu e cu 3 (Uri— Q.

'— CD E

03 03 +> <4— CO O O

O

O to

i— 4-> +-> 03 S- e C 3 CD CD .,-(+_ +J Ei— E O 3 O CU ^ co o a.

03 c <a E

o

e cn

+J CD s- e en CO o S- >

o cu E o —

1

e o cu > E +-> c CU CO

cr> •r- +J E CU e 2: co CU ^ •r- 3 cu E »—

i

s: >> cu >>3

a. CU IE - >> 03 E 4-> S- *« E O E

03 cu cu _e cu 03 O S- •-

CO q. en 4-> -r- i— -M E «3 i— S_ LU Q_

'a* 3 CO CU CO O 03 CO CD nz o q s: 2: o

o

4- Q- O

i— to

•-- 03

CU enr— E E 03

•r- -r- O

i— S_ O

3

-a -a <4- e o

03 s-cu r—

r— -a -r-

•i— E 03

03 CU Q. D_r—

-Q -a

4_ CU O E r—

-e crmcn e

"cu *E r—

3 r03 03

CU E E

S_ CU S- 03 S- O

i— CU +-> O 3 -E E cn

•i— CO -i—

+-> CU

4-> E 3 O CU E CO +>

CU CO

CO S- CU

<u as o cu o Q D£ I

17
Table 5. Individual pail weights and sulfur content after blending of 0.5 percent sulfur coal

Pail Net Sample Sulfur Content

No. Weight (lbs) Weight Percent

Pail Net Sample

No. Weight (lbs) Sulfur Content Weight Percent

1

1 6. 1 D AA 0 dR 9fi 97C 1 c

1 7

1 / C 1 99CC

•3o 11 JR CO9R 1 Q

A

1 o 9QC -7 9RCO

5 t. c C O u

1 7 0 \ 97CO

7 99c c f) dfi fl dR 9 A

Qo 99£. C 77 99cc

g ?1£. 1 ^d 97Co

l1 nu c c n dR n dR ?r 9 A

1

1

c99c 00 97CO

1 ? 99 o37/ CO

11 J7 99C-C JO7R c o

1 d 97c o 3Q 9 A

1 0 C 1 dn 97CO

1 D C99C dl 9 A 17 22 42 25 18 22 43 25 19 22 44 23 20 23 45 24

21 22 46 26

22 24 47 27 23 24 48 24 24 24 49 24 25 23 50 23 Sulfur Content, Weight Percent = 0.45

0.45, 0.45

0.45, 0.45

18
Table 6. Individual pail weights and sulfur content

after blending of 2.0 percent sulfur coal

Pail Net Sample Sulfur Content Pail Net Sample Sulfur Content

No. Weight (lbs) Weight Percent No. Weight (lbs) Weight Percent

1 31 1 .76, 1 .84 18 29

2 32 1.84, 1..78 19 27

3 30 1 .82 20 31 4 28 1 .75 21 30

5 27 1 .83 22 31 6 26 23 32

7 26 24 31 8 26 25 29

9 28 26 31 10 27 27 32

11 32 28 28

12 25 29 31 13 29 1.85 30 27

14 27 31 31 15 27 1.87 32 29 16 29 33 30

17 32 1.74 34 23

1.85, 1.80

Sulfur Content, Weight Percent = 1.81 ± 0.05

Table 7. Individual pail weights and sulfur content

after blending of 3.0 percent sulfur coal

Pail Net Sample Sulfur Content Pail Net Sample Sulfur Content

No. Weight (lbs) Weight Percent No. Weight (lbs) Weight Percent

3.06

1 32 3.06 17 30

2 35 3.06 18 27

3 36 3.06 19 29

4 30 3.04 20 28

5 30 3.05 21 30

6 31 2.97 22 32

7 29 2.93 23 29

8 28 24 33

9 32 25 34

10 29 26 34

11 33 27 37

12 28 28 30

13 31 2.96, 3.01 29 31 14 31 30 34

15 28 31 32

16 32 32 10

3.03

2.99 Sulfur Content, Weight Percent = 3.02 ± 0.05

19
Table 8. Individual pail weights and sulfur content after blending of 4.5 percent sulfur coal

Pail Net Sample Sulfur Content Pail Net Sample Sulfur Content

No. Weight (lbs) Weight Percent No. Weight (lbs) Weight Percent

1 33 4.64, 4.51 19 29

2 27 4.38 20 31 3 30 4.57 21 33

4 27 4.68 22 32

5 29 4.51 23 33

6 31 4.69 24 30

7 27 25 30

8 29 26 29

9 33 27 32

10 32 4. 71 28 32

11 32 29 32

12 30 30 31 13 36 31 31 14 33 32 30

15 34 4.68 33 31 16 33 34 33

17 31 35 32 18 32 36 33 Sulfur Content, Weight Percent = 4.59 ± 0.10

20
The homogeneity of each of the four coals was determined using an x-ray fluores- cence wavelength spectrometer to measure the sulfur content. However, before

analysis, a series of drying studies were performed to evaluate the moisture

content of the blended coals. A one-gram sample of each coal was dried under vacuum at room temperature until constant weight was reached and then exposed

to air at 15% relative humidity and then at 52% humidity (over saturated Ca(NCL)

solution) to measure the sorption of moisture. The samples were then redried

to measure the reversibility of this hydration. The drying and rehydration

data are summarized below in table 9. All four coals reached constant weight

(± 0.03%) after about 16 hours under vacuum at room temperature.

All regained much of their moisture after prolonged exposure to humid air. For

the most part, this water adsorption is reversible, although the 0.5% sulfur

coal shows noticeable hysteresis. The rate of moisture exchange is fairly

rapid, but none of the materials is hydroscopic enough to cause significant

analytical error if closed weighing bottles are used.

Table 9. Drying of coals Conditions for Evaluating

Weight Change 0.5% 2.0% 3.0%' 4.!5% Loss on drying, percent

(Vacuum drying for 16 hours at 24 18.5

'C) 1.7 3.6 1 .6

Uptake 2 1/2 hr at 15% RH, percent 0.7 0.3 0.4 0 .3 + 2 d at 15% RH, percent 2.3 0.2 0.5 0 .3 + 2 hr at 50% RH, percent 1.7 0.7 1.0 0 .8 + 5 d at 50% RH, percent 7.4 0.3 1.0 0 .4 Total sorption, percent 12.1 1.5 2.9 1 .8 Loss on redrying, percent 11.6 1.5 2.8 1 .7

The basis for calculating weight loss on initial drying is the weight

as received; the basis weight for sorption and redrying is the dry

weight.

21
A statistical evaluation of the gross homogeneity of the coal materials indicated

that they were sufficiently homogeneous (_< 2 percent variation), to proceed with

bottling. The bottling of each coal began with pail number 1 and proceeded in consecutive order using as many pails of coal as necessary to bottle 1500 50-g

units. During the bottling process, the bottled units were sequentially numbered

(1 to 1500) so that any variability that may have been caused by bottling could

be detected and to assess any sample variability in the 1500 units.

In order to test the variability of sulfur in the four SRM's, two samples were

removed from bottles numbered 241, 398, 410, 809, 1227, and 1500 for each of the proposed SRM's and vacuum dried for ^16 hours at 24 C. After drying, the samples were pressed into pellets of 3-cm diameter. The relative sulfur content

of each of the 12 samples of four SRM's was determined and the sulfur content in SRM's 1632a and 1635, Trace Elements in Coal, were used as controls. The results

are shown in tables 10 and 10a. No correlation was found between measured

values and the bottling sequence. Also, the relative sulfur content in the coals from different bottles was not significantly different from replicate

samples from single bottles. Accordingly, all bottles of these proposed SRM's

are homogeneous with respect to their sulfur content.

6. Conclusion

Four coals of different sulfur levels were collected, processed, bottled, and tested to determine their suitability as Standard Reference Materials. These four coals were of acceptable quality and the process of certifying them as SRM's was undertaken. These new SRM's were numbered sequentially from the lowest sulfur content to the highest as SRM's 2682, 2683, 2684, and 2685, respectively. The details of the analytical procedures leading to the certification of these

coals as SRM's are to be published in another NBS Special Publication in this "260 Series."

The success of this project was a direct result of the efforts of many people.

Special acknowledgment is made by the authors to Mrs. G. P. Bowyer for her assistance in preparing this publication.

22
Table 10. Data for coal homogeneity samples

Relative Sulfur Percent*

Bottle No. 0.5 2.0 3.0 4.5 241A 0.999 0.989 1.001 1 .001

241

B

0.992 1.016 1.000 1.012 398A 0.990 0.988 1 .007 0.978

398B 0.993 0.994 1.003 0.999

41 OA 0.997 0.985 0.994 1 .000 410B 0.996 0.997 1 .012 0.995 809A 1.017 0.997 1.000 1.010 809B 1.001 1.004 0.987 1.005 1227A 1.002 1.001 0.997 1.004

1227B 1.010 1.015 1.004 1.010 1500A 0.995 1.009 0.998 0.990

1500B 1.010 1.005 0.995 0.996

Average: 1.000 1.000 1.000 1.000 a(n-l): ±0.008 ±0.010 ±0.006 ±0.010

*The relative sulfur percent was determined by ratioing the average intensity

of the sulfur x-ray line in all the measured bottles to that of each individual

bottle.

Table 10a. Sulfur percent of controls*

Control 1632a Analyses: 1 1.60

2 1.57

3 1.57

4 1.57 Average 1.58 ± 0.02

Control 1635 Analyses: 1 0.33

2 .33

3 .32

4 .33 Average 0.33 ± 0.01 *The controls, SRM's 1632a and 1635 are certified for sulfur values of 1.58 ± 0.04

and 0.33 ± 0.03 percent, respectively.

23
Appendix A Sampling of 0.5 Percent Sulfur Coal From Belle Ayr Mine - Gillette, Wyoming

A low sulfur coal was obtained from the Amax Coal Company's Belle Ayr mine near

Gillette, in Campbell County, Wyoming. This mine, opened for production in 1973, is an open-pit mine that produces subbi tuminous coal from the Wyodak- Anderson coal seam, which is part of the Powder River Coal Basin. The average

seam thickness at the mine is 72 feet. The overburden depth varies, but averages

113 feet. During 1980, the Belle Ayr mine produced over 16 million tons of

coal, making it the largest coal mine in the United States. This mine has a life expectancy of at least 20 years. Coordination of sampling activities at the mine's coal preparation facility was handled through Thomas J. Lien, Manager of Preparations for the Western Division

Amax, whose office is located in Gillette. The actual collection of the coal was done by Terry R. Bosecker, Chemist at Amax Western Division Laboratory, and Brian Pleuss, who also works at the Western Division Laboratory. The coal was collected in nine 55-gallon plastic-lined steel drums over a 2-1/4 hour period. The Belle Ayr mine has two crushing plants. The smaller plant is rated at 2500

tons of coal per hour. The larger plant can handle 4000 tons of coal per hour. Each crushing plant feeds two concrete silos. All four silos are the same size

and have a capacity of approximately 11,000 tons of coal. The coal from these

silos is fed into unit trains comprised of 100 to 110 coal hopper cars and then shipped to coal -burning electrical utility plants in eleven states.

The coal sampled for this program was obtained from the larger plant (Plant No.

2) between 11:00 a.m. and 12:00 noon and between 1:00 p.m. and 2:15 p.m. on Tuesday, May 25. Actually, the coal sampled was a blend of coal from the upper

and lower benches of the mine. During the time of sampling, the coal was being

fed from the crushing plant into Silo No. 4 for eventual train loading. Since

approximately 3000 tons of coal had already been fed into Silo No. 4, the coal obtained during the 2-1/4 hour sampling period was sampled from a total of approximately 8000 tons, representing most of a unit train load of coal. Figure A-l is a layout of the mine, with its crushing plants, silos, rail facilities, laboratory, and office. This general layout provides readers with a perspective of the mine operation and where the coal was obtained with respect

to locations of various mine facilities.

The coal sampling operation was conducted using the existing coal sampling

facilities within the crushing plant. Incoming coal crushed to nominal 2" size

is periodically removed from the conveyor belt by a primary sample cutter. A

total sample of approximately 500 pounds of coal is separated from the main feed

at regular intervals of approximately 2 to 3 minutes. The sampled coal is directed down a chute to a crusher, which reduces it in size to 8 mesh. The crushed coal is then passed through a series of two rotary sample cutters, each

of which operates at 20 RPM. These cutters are equipped with four blades that separate a portion of the incoming coal for subsequent laboratory analysis. The balance from these sample splitters is returned to the main conveyor belt feeding

the silos by means of an enclosed auger feed chute. A sampling pipe located at the downstream end of the auger chute was used to obtain the coal sample.

Figure A-2 is a schematic diagram that shows the layout and function of the sampling system in the crushing plant.

24
25
Raw

Coal

Hopper

Crusher

|

-#8x0

VFL

Sample

Figure A-2. Schematic of coal sampling system

26
The sampling interval selected was based on filling nine 55-gallon drums with

coal in a time period corresponding to that required to fill one unit train (approximately 10,000 tons). Therefore, one drum was to be filled every 15 minutes.

The first drum was approximately two- thirds full after it had been filled for three minutes. It was then decided to use a 15-minute period to fill each drum

by opening the sampling gate for one minute, closing it for two minutes, then alternately opening and closing the sampling gate using the same timing until the nine drums were completely filled. All drums were filled over an elapsed

time of 2 hours, 15 minutes with an average of five 1 -minute samples taken to

fill each drum. Drums were numbered consecutively from 1 to 9 according to filling order. Concurrently, separate small grab samples were taken directly from the coal stream at the discharge chute during each one-minute sampling period. These

small grab samples were placed into individual plastic bags, one for each 55- gallon drum. Each of the plastic bags was given a number corresponding to the drum number. An estimated 6 kg of coal was placed into each of the plastic

bags. Figure A-3 shows the filling of a 55-gallon drum.

All plastic liners inside the 55-gallon drums were tied closed after sample

collection. Each drum contained approximately 350 pounds of coal. Therefore,

the total weight of the coal sampled was approximately 3,150 pounds. The moisture content of this coal is known to range from 28 to 30 percent. Even after ASTM first-stage drying, Amax personnel advised that the average moisture

content of this coal would still be somewhere around 15 percent. The plastic

bags containing grab samples were tied, placed inside the proper drums, and the drums were then transported from the crushing plant to a receiving area located adjacent to the laboratory building.

Each 6 kg bag sample was taken into the laboratory, passed through an enclosed

riffle splitter once or twice (depending on the sample size), and split into one

1.5 kg sample and two 750 g samples. All samples were placed into plastic bags,

labeled, and sealed. The 1.5 kg sample bags were placed into their respective

drums. One of each of the 750 g samples was sent to Valley Forge Laboratories.

All or part of these bag samples will be made available to NBS for laboratory

analysis. The remaining 750 g samples were retained by Amax for laboratory

analysis of sulfur content. Figure A-4 shows a coal sample being divided with a riffle splitter.

27
Figure A-4. Riffle Splitting of 6000 Gram Coal Sample

at Belle Ayr Mine

28
The results of sulfur and moisture determination tests performed at the Amax Western Division laboratory on each of the nine 750 g bag samples of this

coal are as follows: Second

Grab Stage Percent Percent

Sample Moisture Sulfur Sulfur

No. (percent) (wet basis) (dry basis)

1 13.72 0.38 0.44

2 15.28 0.38 0.45

3 17.13 0.39 0.47

4 17.22 0.35 0.42

5 16.32 0.35 0.41

6 16.17 0.39 0.46

7 14.76 0.37 0.43

8 16.34 0.35 0.42

9 13.99 0.41 0.47

The average sulfur content (dry basis) for the nine samples tested is 0.44

percent. The standard deviation is 0.02 percent. Therefore, the sample was considered acceptable for further processing.

The nine sealed drums were shipped to Alnort, Inc., in Camden, New Jersey, for subsequent processing.

Figures A-5 and A-6 provide some idea of the vast extent of the mined area at Belle Ayr. Figure A-5 shows the main portion of the mined area with the upper

and lower benches. Figure A-6 provides some perspective of the depth of the mined area when considering that the capacity of the coal truck shown in the photograph is 100 tons.

29
Figure A-5. Mined Area at Belle Ayr Mine Showing

Two Working Benches in 72 Foot Seam
Appendix B Sampling of 2.0 Percent Sulfur Coal From Humphrey Mine - Osage, West Virginia

A one-ton sample of coal was obtained from the Humphrey No. 7 Mine and coal preparation plant of the Consolidation Coal Company, Christopher Coal Company

Division, located in Osage, West Virginia, near Morgantown in Monongalia County. This mine produces bituminous coal with a sulfur content of 1.8 to 1.9 percent

(dry basis) after washing. This coal is obtained from an underground mine that recovers coal from the Pittsburgh seam, which is considered the single most valuable and extensive coal seam in the United States. This seam reportedly

averages 7 feet in thickness. The Pittsburgh seam lies in the Northern West

Virginia coal field and is geologically part of the Monongahela Group. During

1980, 2.1 million tons of coal were mined at the Humphrey No. 7 mine.

The Humphrey No. 7 mine is approximately 15 miles away from the Humphrey preparation plant, which is situated along the Monongahela River. The preparation

plant and an associated blending bin were constructed some twenty years ago to supply 1.6 percent sulfur metallurgical coal for the U.S. Steel Company plants

in the Pittsburgh area. Over the years, the demand for the metallurgical coal

by the steel industry has diminished to the point where now all low sulfur coal from the Humphrey plant is being shipped by barge to the West Penn Power Company's

Mitchell plant in Monongahela, Pennsylvania.

Raw coal from the Humphrey No. 7 mine has a sulfur content (dry basis) of approximately 2.2 percent. After washing, the sulfur content (dry basis) has been reduced to approximately 1.8 to 1.9 percent. The raw coal is normally

stored in a 10,000-ton coal silo next to the plant. The washed coal is conveyed

from the plant to a blending facility, where twelve different feeders each fill four pockets, so that a total of 48 separate pockets of coal are available for blending during barge loading. One of the blending bins usually contains 2.2 percent sulfur coal in the event other coal users require a higher sulfur product.

The blended coal is transported approximately a half mile to the barge loading

facility along the Monongahela River by an overhead conveyor system. An automatic

float-sink processing unit precedes the barge loading facility to further remove

any trace impurities that may be present in the coal. The coal loaded into barges is nominal 1-1/4 inch size. Figure B-l is a sketch showing the location of the preparation plant, blending

bins, silo, and barge unloading facilities at the Humphrey complex. Figure B-2 shows the Humphrey preparation plant, silo, and overhead conveyor system. The

coal sample obtained for the Standard Reference Materials program was taken

using the sampling system at the barge loading facility during the loading of four barges on the evening of July 29, 1981. Figure B-3 shows the barge loading

facility at the Humphrey plant.

Arrangements for the coal sampling at Humphrey Mine were handled by James

Cryster, quality control engineer for the Northern West Virginia region of the Consolidation Coal Company and by Don Jones, shift manager at the barge loading

facility. During the sampling period, which lasted from 7:00 to 10:20 p.m., minor modifications were made to the coal sampling system located on the second floor of the loading building.

The existing coal sampling system consists of a primary sample cutter, which

takes a full belt 240 pound cut every four minutes; a primary crusher, which

reduces the size of the sample to nominal 3/8 inch; a secondary cuttef, which

31
Pursglove Prep Plant Washed

Coal (When Needed)

/

Humphrey

Washed

Coal

To Humphrey

Mine

Enclosed Conveyor

Met Coal Blending

Building

(48 Bins)

Usually

Washed

Met

Coal (Sometimes Raw Coal) Approx.

2 Miles

to Arkwright Lab

Existing To Morgantown

Inclined. Ramp

Drums

Left Here

Humphrey

Cleaning

Plant

Raw Coal (when

Needed)

Enclosed Conveyor

Road

Automatic

Float-Sink Device Sample

Taken

Here

900 Ton Coal Barges Barge

Loading

Facility r^cz=i 900 Ton Coal Barges Flow

Monongahela River Figure B-1. Layout of Humphrey Mine and Plant Consolidation Coal Company, Osage, West Virginia

32
Figure B-2. Humphrey Preparation Plant and Conveyor System.
separates a sample for Consolidation Coal Company; and a chute to convey the rejects from the sampling stream back to the barge loading chute. A sheer

metal plate was inserted into an existing opening in the reject chute to divert

the reject stream into lined 55-gallon steel drums to obtain the required

sample of coal. Normally, the reject stream comprises about 25 percent of a full stream cut. Figure B-4 shows a schematic of the coal sampling system and the collection of the coal sample at the barge loading facility.

Coal barges loaded from the Humphrey plant have a capacity of approximately 900

tons each. Generally, these barges are loaded in sets of four during a half shift or four hour period. The coal sample was taken during a half shift and,

therefore, was sampled from a total lot of 3,600 tons of barge loaded coal. Figure B-5 shows a loaded coal barge with another barge in the process of being

1 oaded. Because approximately 60 pounds of coal were anticipated from the reject stream

for each 4 minute cut, it was initially decided to obtain a sample from each

cut. During drum filling, intermittent samples of the reject stream were also sampled and placed into sealed plastic bags, one for each drum sample. During

the first half hour of the sampling, one full drum and approximately 75 percent

of a second drum had already been filled. At the same time, Consolidation Coal Company's foreman in the control room noted that they had been unable to obtain

their usual coal sample. At the end of the first half hour, during the dinner

break, it was discovered that the secondary cutter had not been operating and most of the entire cut during the sampling period had been diverted to the reject stream. An electrician was able to make the necessary repairs before resuming barge loading and the remainder of the sampling process proceeded

without any problems.

However, the rate of sampling was reduced to be able to sample from a sufficiently large lot of barge loaded coal. Upon resumption of barge loading, at approximately 8:10 p.m., every other cut was sampled from the reject stream, instead of every cut, as had been done previously. The last of the six lined 55-gallon drums was loaded at 10:20 p.m. By that time, approximately 2,000

tons of coal had been loaded into the four barges. The six loaded drums were

later transported by Valley Forge Laboratories directly to the Alnort coal processing facility in Camden, New Jersey. Sulfur analyses of the Consolidation Coal Company's Humphrey samples were

performed at the company's nearby Arkwright laboratory. Typically, only four samples are analyzed during a half shift loading period. These samples cor- respond to quarter, half, three-quarter, and fully loaded conditions. The results of the sulfur tests from the Arkwright lab are:

Loading Condition

Quarter

Half Three-quarter

Full

As Determined*

Percent Sulfur

1.91 1.93

1.81 1.85

1 .88 Average

*"As Determined" refers to the sulfur level at time of test, with an approximate moisture of 0.5 percent for each sample.

34
35
Figure B-5. Loading of Coal Barge at Humphrey Plant

36
The six sealed plastic bag samples were later riffle split, with one portion of each sample given to Valley Forge Laboratories in a sealed plastic bag and part

of the other portion being placed in individual 4 ounce plastic bottles for analysis by Tradet, Inc., an independent coal testing laboratory from Wheeling,

West Virginia. The samples analyzed by Tradet were pulverized to -60 mesh size

and tested for sulfur content using a Leco furnace model number SC37. The results of the Tradet sulfur analysis tests are:

Percent Moisture Percent Sample Sulfur Content Sulfur

No. (as received) (percent) (dry basis)

1 1.80 3.94 1.87

2 1.85 3.27 1.91

3 1.74 3.92 1.82

4 2.07 3.49 2.14

5 1.62 3.10 1.67

6 1.85 3.65 1.92

The average sulfur content of the six samples is 1.89 percent. However, it was

noted that samples 4 and 5 have a greater deviation from the mean than the other

samples. Tradet was asked to recheck the sulfur level of these two samples and after retest, reported dry basis sulfur levels of 2.18 and 1.65 percent, respectively. Because these values essentially confirm the initial analyses, it was suggested that all the coal, except for drum number 4, (the only sample with a sulfur level in excess of 2 percent) be processed if at least 1000 pounds of -60 mesh coal could be obtained from the remaining five drums. All barrels of the Humphrey coal, except for number 4, were processed.

37
Appendix C Sampling of 3.0 Percent Sulfur Coal From Delta Mine - Marion, Illinois

A one- ton sample of coal was obtained from the Delta mine of the Amax Coal Company. The mine, which was expanded and reopened in 1978, is a surface mine

located near the small town of Crab Orchard, roughly six miles east of Marion,

Illinois. This mine originally began operation in 1934 and produces bituminous

coal with a sulfur content after washing of 2.8 to 2.9 percent (dry basis). It

is situated in Williamson County in southern Illinois. The coal mined at the Delta mine is obtained from the Illinois No. 6 Herri n seam, which is the most extensively mined coal in Illinois. In the district comprising Franklin, Jefferson, and Williamson Counties, the Illinois No. 6 Herri n seam has a reported average thickness of 8 feet in these counties, according to the Keystone Coal Industry Manual. At the Delta mine, this coal seam is 5-1/2 feet thick and lies below 81 feet of overburden.

During 1980, the Delta mine produced more than 2 million tons of steam grade

coal. Nearly all of this coal is shipped to coal -fired power plants, with

several unit train loads each week going to a Central Illinois Public Service

(CIPS) plant in Newton, Illinois. At least one unit train each week goes to Consumers Power in Wisconsin for loading onto lake boats. A certain amount of

coal is also trucked away from the mine and taken to barges on the Ohio River

for shipment to Florida Light and Power Company. Some coal is also taken by

barge to New Orleans for export to Japan.

Coal produced at the Delta mine is currently being obtained from two operating

open pits. These pits are located several miles away from and on opposite sides

of the mine buildings and preparation plant. Figure C-l is a sketch showing the layout of the mine and the two open pits. These two pits are referred to as the 1450 pit and the 3270 pit. The pits are so named because of the size of the respective draglines that are being used to excavate each pit. The 1450-W is a smaller dragline than the 3270-W, which is the second largest dragline ever put

into operation. The coal from the 1450 pit is considered to be of better quality

than coal from the 3270 pit because a rock fault exists through part of the coal seam in the 3270 pit. During the time that the coal sample was being taken, all of the coal fed into the preparation plant was taken from the 1450 pit. Figure

C-2 is a view of this open pit with the 1450-W dragline in the background.

The raw coal from the pit is first crushed to a maximum 5 inch particle size by

a rotary breaker, then fed into the preparation plant. Figure C-3 shows an overall view of the preparation plant. The coal is first separated from rock

and other impurities by heavy media separation in the flotation cells or wash

boxes. The coal product is then split into several sieve fractions and further

processed by washing, froth flotation, or further size reduction, depending on the sieve fraction being prepared. After final preparation, all sieve fractions

are dewatered and combined into a single feed stream. The top size of the washed coal coming out of the preparation plant is 2 inches. Coordination of sampling activities at the Delta mine was handled by Dick Lawrence, preparation plant manager at the mine. The actual collection of the

coal sample was done by three Amax employees who were members of the

38
39
Figure C-2. View of 1450 Open Pit and Dragline

at Delta Mine
United Mine Workers Union. Sample collection activities were conducted in the sampling building, where washed coal is fed from the preparation plant to a 15,000 ton coal silo. Samples are ordinarily collected for analysis by Amax

Coal Company at this location.

The existing coal sampling facilities were modified slightly and utilized for

the collection of the coal sample for the Standard Reference Materials program.

The sampling system consists of a primary sample cutter, which takes a full-belt

cut of approximately 358 pounds every four minutes. The coal is conveyed by elevator and screw auger to a crusher, which reduces the top size of coal to 4 mesh. This crushed coal is fed into a secondary rotary sample splitter, where a bag sampler on the second floor collects a coal sample for later use by Amax

personnel. Normally, the reject stream from the secondary cutter is discharged

into a rectangular chute and then onto the main conveyor belt feeding the coal silo. To obtain a coal sample for this program, an adjustable metal deflector

plate was installed into the rectangular discharge chute for the reject stream

and the reject coal was diverted at selected intervals onto an open loading area

on the second floor. From the second floor, the reject coal was shoveled into a circular chute passing into the ground floor area of the sampling building, where the flow was captured in lined 55-gallon steel drums. Figure C-4 shows

the collection of the coal sample. Figure C-5 is a schematic diagram that shows

the layout of the coal sampling system utilized at the Delta mine.

The flow rate of the washed coal on the main conveyor belt feeding the silo was initially estimated at 775 tons per hour. A four-hour sampling period was employed, between 8:20 a.m. and 12:20 p.m., representing a sampling from approximately 3100 tons of coal. Actually, belt recording equipment later indicated

that a total of 3500 tons of coal passed over the main feed belt during the

four- hour sampling period.

A total of six 55-gallon plastic-lined drums of coal were collected in four

hours. The reject coal from the one sample cut was enough to fill at least half

of a drum. Therefore, every fifth cut was taken and half a drum was filled every 20 minutes, and one drum was filled every 40 minutes. During the drum

filling, small full -stream cuts were also taken at different times and placed

into plastic sample bags. Each plastic bag of coal represented a sample from

one of the six drums. Approximately 5 kg of coal were collected in each plastic

bag. Both the 55-gallon drums and the plastic sample bags were numbered con- secutively from one to six according to filling order. Once the coal samples were collected in 55-gallon drums, the drum liners were

tied and the drums were stored outside the sampling building. Each drum had an estimated weight of approximately 350 pounds of coal, so that the total sample

comprised a little over one ton of coal. This coal is reported to have a moisture content between 8 and 10 percent with an ash content between 10 and 12 percent. On July 28, the six drums were shipped to Alnort, Inc., in Camden, New Jersey, for further processing.

Each 5 kg bag was taken to a processing area inside the preparation plant, where

the coal was twice passed through an enclosed riffle splitter. One portion from

each bag was placed back into its respective plastic bag, sealed, and given to Valley Forge Laboratories for later use by NBS. Six small plastic bottles, one from each bag, were also filled with the as-received coal and were also given to Valley Forge Laboratories for later use by NBS.

41
Figure C-4. Collection of Coal Sample and Companion

5000 Gram Sulfur Analysis Sample

at Delta Mine

42
Figure C-5. Schematic of coal sampling system, Delta Mine

43
The other portion from each bag was reduced to -60 mesh size in a laboratory

model pulverizer. Figure C-6 shows the riffle splitter and laboratory pulverizer equipment. Figure C-7 shows the air cleaning of this equipment between

samples from each drum. The -60 mesh coal from the bag was placed into two plastic bottles, one of which was given to Valley Forge Laboratories and one retained for sulfur analysis in the laboratory at the Delta mine. The six -60 mesh samples given to Valley Forge Laboratories were taken to the Central Illinois Public Service (CIPS) laboratory in Springfield, Illinois, for sulfur analysis.

The results of the sulfur and moisture determination tests performed at the CIPS laboratory on each of the -60 mesh samples of this coal are as follows: Percent Moisture Percent

Sample Sulfur Content Sulfur

No. (as received) (percent) (dry basis)

1 2.57 7.84 2.77

2 2.67 6.70 2.85

3 2.87 6.93 3.07

4 2.75 6.98 2.94

5 2.87 6.67 3.06

6 2.88 6.74 3.07

The average sulfur content (dry basis) for the six samples tested at CIPS is 2.96 percent, although the sulfur content of sample 1 is somewhat lower than the average. Without sample 1, the average sulfur content (dry basis) of the remaining five samples is 3.00 percent. The as-received sulfur content values for the

six samples tested at the Delta mine laboratory are: Percent

Sample Sulfur

No. (as received)

1 2.43

2 2.49

3 2.61

4 2.51

5 2.67

6 2.72

Although no direct comparison is made between the percent sulfur values from the

two laboratories, it is significant to note that each laboratory reported the sulfur level of sample 1 as the lowest of all six samples. Therefore, a decision was made to process five of the six drums of 3.0 percent coal and, with NBS concurrence, to withhold drum 1 if a sufficient quantity of -60 coal could be obtained from the remaining drums.

44
Figure C-6. Riffle Splitter and Laboratory Pulverizer Equipment

at Delta Mine.

Figure C-7. Air Cleaning of Laboratory Pulverizer.

45
Appendix D Sampling of 4.5 Percent Sulfur Coal From McElroy Mine - Captina, West Virginia

A one ton sample of coal was obtained from the McElroy mine and coal preparation

plant of the Consolidation Coal Company, Ohio Valley Division, located in Captina, West Virginia, some 20 miles south of Wheeling along the Ohio River in Marshall County. This mine produces bituminous coal with a sulfur content of approximately 4.5 percent (dry basis) after washing. This coal is obtained from

an underground mine that is a part of the Pittsburgh No. 8 coal seam, which is in the northern West Virginia coal field. The seam thickness at the McElroy

mine is 5-1/2 feet. The mine is 275 feet underground at the portal and, during

1980, produced 1.4 million tons of coal. The McElroy mine is located 3 to 4 miles east of the preparation plant, which is on the east side of West Virginia Route 2 along the Ohio River. The mine and preparation plant were constructed sometime in the late 1 960 ' s to provide coal for the Mitchell power station of the Ohio Power Company in Captina, West Virginia. All of the coal for Unit No. 1 of the Mitchell plant is obtained from

the McElroy mine. Coal from the preparation plant goes across Route 2 on an enclosed overhead conveyor to a coal sampling building owned by Consolidation

Coal Company on the power plant property, where samples are obtained for analysis by both the coal and the power company. The layout of the mine, preparation

plant, and the Mitchell power plant are shown in Figure D-l . Figure D-2 shows the McElroy preparation plant. Figure D-3 shows the Mitchell Power Plant. During the past year, a series of ten channel samples were taken from within the McElroy mine. These samples were all taken at different locations, in some instances as much as one or two miles apart from each other. The channel samples were often taken from portions of the coal seam where few impurities were present,

resulting many times in raw coal samples that are roughly the equivalent of washed coal. The average sulfur content (dry basis) of the ten channel samples

was 4.52 percent with sulfur levels varying from 4.12 to 4.98 percent. Washed

coal from the McElroy preparation plant has been averaging from 4.2 to 4.5 percent sulfur. The most recently available data, from February, 1980, indicates

that the average sulfur level was running at 4.38 percent (dry basis) during

that time. The average moisture content of this coal is 4.7 percent.

The coal sample collected for the Standard Reference Materials program was obtained at the coal sampling building (referred to at the plant as sampling

station number 1). The sample was obtained between 9:45 a.m. and 12:05 p.m. on July 30, 1981. Originally, the coal sample was to have been collected earlier

in the week, but repair of a broken screen in the preparation plant and mechanical

difficulties with the longwall miner in the mine forced postponement of the coal sampling.

Arrangements for the sampling of McElroy coal at sampling station number 1 were

coordinated by Bob Knaul , Chief Chemist at the Mitchell power station. Bert Shalek of Consolidation Coal Company, who works in the nearby laboratory

shared by the McElroy and Ireland mines, was responsible for making the necessary

arrangements with the preparation plant.

46
47
Figure D-3 . Mitchell-Captina Power Plant with

Cooling Towers and Conveyor

from Sampling Building

48
The existing coal sampling system consists of a primary sample cutter, which

normally takes a full-belt cut every 7-1/2 minutes; a crusher, which reduces the

coal from -2" to -4 mesh; a rectangular feed chute with a removable plate for sampling; and a secondary sample cutter for the collection of coal samples for

the Mitchell plant and for Consolidation Coal Company. To obtain a sample of the McElroy coal, the removable plate was opened along the bottom of the feed chute during alternate sample cuts and the coal stream was diverted directly by gravity

into lined 55-gallon steel drums. The drum samples were collected on the second floor of the sampling station building. Figure D-4 shows a schematic of the existing coal sampling system and how the coal sample was collected at the sampling station.

The normal flow rate of washed coal from the McElroy preparation plant through

sampling station number 1 to the stockpile location for Unit No. 1 on the Mitchell plant property is 20 tons per minute. On the day the sample was collected, the longwall miner was still being repaired, but enough coal had been mined during the previous day by two continuous miners to allow the preparation

plant to be run at full capacity. Although the continuous miners were also working during the time of sampling, Bert Shalek noted that only a four-hour

supply of coal was available. The initial reading of the coal scale at the conveyor before entry into the sampling station was recorded at 61,372 tons when

sampling began. At the outset of sampling, a full stream cut was being taken every 7-1/2 minutes and a sample was being collected every 15 minutes. During

each sampling interval, approximately half of a 55-gallon drum was filled. Therefore, two samplings were needed to fill a 55-gallon drum and the first two drums required an elapsed time of an hour for sample collection. During drum

filling, intermittent samples of the coal stream were also taken and placed into sealed plastic bags, one for each drum. After the first two drums were filled, concern existed that the coal stream

could be unexpectedly cut off before completing coal sampling because of the limited amount of coal available for that day's production. Therefore, an electrician from the mine was summoned and the timing interval on the sample cutter was changed from 7-1/2 minutes to 4 minutes. The coal sampling was still conducted on every other cut so that the mine and the plant could also obtain

their samples, but at this point it required only 16 minutes to obtain a full drum sample, compared to 30 minutes each for the first two drums. The last 55- gallon drum was filled at 12:05 p.m. and approximately 15 minutes later the coal supply ran out. The reading on the coal scale immediately after filling the last drum was 63,645 tons. Therefore, a total of 2,273 tons of coals were fed into the sampling station during the time that the six drums were filled. Sulfur analyses were not performed on mine samples of that day's coal by the Consolidation Coal Company's mine laboratory because the Leco furnace at that

lab was not operating at the time.

49
Enclosed Conveyor

Coal

| Scale From

Preparation

Plant

Primary

Cutter -2"xfJ

4th Floor mmnmnzL

3rd Floor

Washed Coal

2"xQ

Coal Crusher Secondary

Cutter

mm

f///////////////jmw////////////////s///^^^^

#4x0

Removable

Sample

Plate [®1

VFL

Sample

2nd Floor

f////////////////////)///\//?/////

Plastic Lined 55 Gallon Drums

l_l

J

Reject

i

1st Floor

Consol Mitchell Sample Sample

L

mm

7m

Enclosed Conveyor

to Unit No. 1 Stockpile

Figure D-4. Schematic Diagram of Sampling Station No. 1 at Mitchell Power Station

50
The six sealed plastic bag samples were riffle split in the power plant laboratory. One portion of each sample was given to Valley Forge Laboratories in a sealed plastic bag, and part of the other portion was placed in individual 4 ounce plastic bottles for analysis by Tradet, Inc., an independent coal testing

laboratory from Wheeling, West Virginia. The samples analyzed by Tradet were pulverized to a -60 mesh size and tested for sulfur content using a Leco furnace

model number SC37. The results of the Tradet sulfur analysis tests are:

Percent Sample Sulfur

No. (as received)

1 4.50

2 4.53

3 4.35

4 4.48

5 4.53

6 4.50

Moisture Percent

Content Sulfur

(percent) (dry basis) 3.59 4.67

4.02 4.72

3.46 4.50

3.47 4.64

3.52 4.70

3.20 4.65

The average sulfur content of the six samples is 4.65 percent. As very little

deviation exists between the sulfur levels of samples taken from any of the six drums, all of these drums were processed in preparation of the -60 mesh Standard

Reference Materials. Following sample collection, the six drums were removed from the second floor of

the sampling station and transported (by a Valley Forge Laboratories employee)

directly to the coal processing facilities of Alnort, Inc., Camden, New Jersey.

51

NBS-114A 1REV. 2-8C) U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Perform ing Organ. Report No. 3. Publication Date BIBLIOGRAPHIC DATA

SHEET (See instructions) REPORT NO. NBS SP 260-84 August 1983

4. TITLE AND SUBTITLE Standard Reference Materials:

Sampling, Materials Handling, Processing, and Packaging of NBS Sulfur in Coal Standard Reference Materials

5. AUTHOR(S)

T. E. Gills, R. W. Seward, R. J. Collins, and W. C. Webster

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions) U. S. Department of Commerce, National Bureau of Standards,

Washington, DC 20234 / Valley Forge Laboratories, Inc., Six Berkley Road, Devon, PA 19333 / Webster and Associates, Ltd. 3008 Potshop Road, Norristown, PA 19403.

7. Contract/Grant No.

8. Type of Report & Period Covered Final

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP) U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

10. SUPPLEMENTARY NOTES Library of Congress Catalog Card Number: 83-600553

I | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a si gnificant bibliography or literature survey, mention it here) This publication describes in detail the performance of a grant given to Valley

Forge Laboratories, Inc., by the National Bureau of Standards, to obtain and pre- pare four standard reference coals, with nominal sulfur contents of 0.5, 2.0, 3.0, and 4.5 percent to be issued as SRM's 2682, 2683, 2684, and 2685, respectively.

All activities pertaining to the sampling, preparation, packaging, and homogeneity

testing of the coal SRM's are documented in this report, including a separate des- cription of each of the four coal sampling activities. Protocols used in the development of these Standard Reference Materials are similar to those used in other NBS SRM preparation procedures to ensure that materials used for SRM's have

the highest possible homogeneity and stability.

.2. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons) bituminous coal; blending; drying; hammermi 11 ing; homogeneity; processing; sampling;

screening; Standard Reference Materials; sub-bituminous; sulfur.

13. AVAILABILITY

[7J Unlimited

| | For Official Distribution. Do Not Release to NTIS

[A] Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C

20402. Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

62

15. Price$4.50

•£ U.S. GOVERNMENT PRINTING OFFICE : 1983 O—380-997 (5159XjscOMM-pc 6043-P80

NBS TECHNICAL PUBLICATIONS

PERIODICALS

JOURNAL OF RESEARCH—The Journal of Research of the National Bureau of Standards reports NBS research and develop- ment in those disciplines of the physical and engineering sciences in which the Bureau is active. These include physics, chemistry,

engineering, mathematics, and computer sciences. Papers cover a broad range of subjects, with major emphasis on measurement

methodology and the basic technology underlying standardization. Also included from time to lime are survey articles on topics

closely related to the Bureau's technical and scientific programs. As a special service to subscribers each issue contains complete

citations to all recent Bureau publications in both NBS and non- NBS media. Issued six times a year. Annual subscription: domestic

$18; foreign $22.50. Single copy, $5.50 domestic; $6.90 foreign. NONPERIODICALS

Monographs—Major contributions to the technical literature on

various subjects related to the Bureau's scientific and technical activities. Handbooks— Recommended codes of engineering and industrial practice (including safety codes) developed in cooperation with in- terested industries, professional organizations, and regulatory

bodies. Special Publications— Include proceedings of conferences sponsored by NBS, NBS annual reports, and other special publications appropriate to this grouping such as wall charts, pocket cards, and

bibliographies. Applied Mathematics Series— Mathematical tables, manuals, and

studies of special interest to physicists, engineers, chemists,

biologists, mathematicians, computer programmers, and others engaged in scientific and technical work.

National Standard Reference Data Series— Provides quantitative data on the physical and chemical properties of materials, compiled from the world's literature and critically evaluated. Developed under a worldwide program coordinated by NBS under

the authority of the National Standard Data Act (Public Law

90-396). NOTE: The principal publication outlet for the foregoing data is the Journal of Physical and Chemical Reference Data (JPCRD)

published quarterly for NBS by the American Chemical Society (ACS) and the American Institute of Physics (AIP). Subscriptions,

reprints, and supplements available from ACS, 1 155 Sixteenth St., NW, Washington, DC 20056.

Building Science Series—Disseminates technical information developed at the Bureau on building materials, components,

systems, and whole structures. The series presents research results,

test methods, and performance criteria related to the structural and

environmental functions and the durability and safety characteristics of building elements and systems. Technical Notes—Studies or reports which are complete in themselves but restrictive in their treatment of a subject. Analogous to monographs but not so comprehensive in scope or definitive in treatment of the subject area. Often serve as a vehicle for final reports of work performed at NBS under the sponsorship of other government agencies. Voluntary Product Standards—Developed under procedures

published by the Department of Commerce in Part 10, Title 15, of

the Code of Federal Regulations. The standards establish nationally recognized requirements for products, and provide all concerned interests with a basis for common understanding of the

characteristics of the products. NBS administers this program as a supplement to the activities of the private sector standardizing

organizations. Consumer Information Series— Practical information, based on NBS research and experience, covering areas of interest to the con- sumer. Easily understandable language and illustrations provide

useful background knowledge for shopping in today's tech- nological marketplace. Order the above NBS publications from: Superintendent of Documents. Government Printing Office. Washington. DC 20402. Order the following NBS publications—FlPS and NBSIR s—from

the National Technical Information Service , Springfield. VA 22161.

Federal Information Processing Standards Publications (FIPS PUB)—Publications in this series collectively constitute the Federal Information Processing Standards Register. The Register

serves as the official source of information in the Federal Govern- ment regarding standards issued by NBS pursuant to the Federal Property and Administrative Services Act of 1949 as amended.

Public Law 89-306 (79 Stat. 1127), and as implemented by Executive Order 11717(38 FR 12315, dated May II, 1973) and Part 6 of Title 15 CFR (Code of Federal Regulations). NBS Interagency Reports (NBSIR)—A special series of interim or

final reports on work performed by NBS for outside sponsors

(both government and non-government). In general, initial dis- tribution is handled by the sponsor: public distribution is by the National Technical Information Service , Springfield, VA 22161,

in paper copy or microfiche form.
U.S. Department of Commerce

National Bureau of Standards Washington, D C. 20234

Official Business

Penalty for Private Use $300

U.S. MAIL V J

POSTAGE AND FEES PAID U S DEPARTMENT OF COMMERCE

COM-215

SPECIAL FOURTH-CLASS RATE BOOK