m . 4 ,tCH R.I.C.

laracterization: Viscosity of

Coal Slag in Steam

W. S. Brower

J. L. Waring

D. H. Blackburn

Center for Materials Science

National Measurement Laboratory

National Bureau of Standards

U.S. Department of Commerce

Washington, DC 20234

June 1980

lec “' oH r‘"*''ber 1980

| 1

I 100 I

, 056

I I

I 1930

The United States Department of Energy Under Contract EA-77-A-01-6010

NBSIR 80-2124

• « * SLAG CHARACTERIZATION: VISCOSITY OF

SYNTHETIC COAL SLAG IN STEAM

W. S. Brower

J. L. Waring

D. H. Blackburn

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Ubf»ry. E-01 Mm<n. Bid* FEB 1 6 1981

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Center for Materials Science

National Measurement Laboratory

National Bureau of Standards

U S. Department of Commerce

Washington, DC 20234

June 1 980

Issued October 1980

Prepared for The United States Department of Energy

Under Contract EA-77-A-01 -6010

"This report was prepared as an account of work sponsored by the United

States Government. Neither the United States nor the United States

Department of Energy, nor any of their employees, nor any of their

contractors, subcontractors, or their employees, makes any warranty,

express or implied, or assumes any legal liability or responsibility

for the accuracy, completeness, or usefulness of any information,

apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights."

U S. DEPARTMENT OF COMMERCE, Philip M. Klutznick, Secretary

Luther H. Hodges, Jr., Deputy Secretary

Jordan J. Baruch, Assistant Secretary for Productivity. Technology, and Innovation

NATIONAL BUREAU OF STANDARDS. Ernest Ambler, Director
Tf-. S
TABLE OF CONTENTS

1.0 INTRODUCTION 2

2.0 APPARATUS AND PROCEDURE 2

2.1 GENERAL FEATURES 2

2.2 PLATINUM HEATER 3

2.3 VISCOSITY TORSION SUSPENSION 4

2.4 VISCOSITY MEASUREMENT 4

3.0 RESULTS AND DISCUSSION 5

4.0 SUMMARY 11

5.0 REFERENCES 11

FIGURES 12
.
FOREWORD

Since 1974, the National Bureau of Standards has been engaged

in research designed to address materials problems and needs

pertinent to coal conversion and utilization technologies. This

work, sponsored in part, at first by the Office of Coal Research,

then ERDA and currently the DOE, focuses on test method development,

particularly accelerated procedures for materials behavior and

durability; on the determination of the mechanisms of materials

degradation; and on the development and operation of materials data

centers to provide evaluated information on properties and performance including failures occurring in operating plants.

During the FY 77-79 period the NBS program, entitled "Materials

Research for the Clean Utilization of Coal" consisted of a number of

interrelated tasks including:

1. Metal Corrosion

a. Constant Strain Rate Test

b. Pre-cracked Fracture Test

2. Ceramic Deformation, Fracture and Erosion

3. Chemical Degradation of Ceramics

a. Reactions and Transformations

b. Slag Characterization (viscosity)

c. Vaporization and Chemical Transport

4. Failure Prevention

a. Failure Information Center

b. Materials Properties Data Center

The results of the research have been disseminated through quarterly

reports of progress (available from NTIS; report designation EA-6010;

Dist. Category UC-90C) as well as numerous scientific publications

in technical journals. Further, as individual tasks are completed,

an overall report is prepared detailing the results and accomplishments

of the project. This present publication is the final report for

Task 3b. Slag Characterization: Viscosity.

SAMUEL J. SCHNEIDER

Program Manager

Center for Materials Science

National Bureau of Standards
< I I
ABSTRACT

A rotating cylinder apparatus has been designed and constructed

for measuring the viscosity of molten slags under steam pressure in

the range 15 to ^300 psi and up to about 1400 °C. Two synthetic

coal slags, one high in alkali and the other lower in alkali but

higher in calcia were studied with this apparatus. In the high

alkali slag equilibrium was probably not achieved and the viscosity

appeared to increase with time. In the low alkali slag although

the viscosity appeared to be increased with increasing steam pressure

the ambient and higher pressure curves appear to tend to coalesce

with increasing temperature.

1
I. INTRODUCTION

In recent years NBS has been involved in research on materials and

methodology employed in coal gasification reactors which are used to

convert coal into synthetic gaseous fuel. In some of these gasification

processes, the coal is reacted in the presence of high pressure gases

including steam at 1000 psi* and temperatures up to 1500°C. The

residual molten liquid (slag) is allowed to gravitate to the bottom

of the reactor for extraction from the system. The integrity of the

process is dependent upon the continuous flow of this liquid. The

objective of this study is to obtain high pressure-temperature viscosity

data on molten liquids which may be representative of those encountered

in the gasification process. With this basic information the slag can

be modified if necessary to enhance uniform flow and to prevent

catas tropic reactor failure.

Various methods have been described in the literature for measurement

of viscosity of glass melts at ambient pressure [1]. However, the

literature is apparently void of techniques to measure viscosity under

steam pressures in the >15 to 1000 psi range. The rotating cylinder

method [2] has become over the years a standard method of measuring

viscosity up to 107 poises. The viscosity limit 107 poises is well

within the range of interest for molten coal slag. For this investigation

an apparatus has been constructed for measurements in this range employing

an internally heated pressure vessel.

2.0 APPARATUS AND PROCEDURE

2.1 GENERAL FEATURES

The apparatus (Fig. 1,2) was fabricated from 304L stainless steel

and is approximately 24" long and 10" in diameter. The main body of the

vessel was fabricated from schedule 40 pipe. The top and bottom (Fig. 3) are class 300 flanges which are 17.5" in diameter and fastened with

sixteen one inch bolts. The two side ports are 4" pipe also ASI class

300. The flanges are held in place with eight 3/4" bolts. These

flanges (Fig. 4) serve to introduce two massive copper leads

necessary to conduct sufficient current at low voltages to heat the

platinum heater in the presence of high pressure steam while maintaining

the pressure integrity of the vessel. The leads are isolated from the

The use of psi, bar and kbar follows the current common practice of

workers in the field. Note that 1 bar = 10 5 N/m2 (or pascal) = 10 G dyn/cm2 = 0.9869 atm = 14.504 psi. The accepted international

standard (SI) unit of pressure is the pascal or newton per meter

squared.

2
vessel body by mica sleeves with the pressure seal being made with

the flange using an "0" ring in conjunction with a split lock collar

(Fig. 5) and a retaining ring (Fig. 6).

The steam used in the apparatus is generated internally by vaporizing

water using nine bayonet type heaters which together dissipate approximately

3600 watts. These heaters are isolated from the internal pressure by

three finned copper heat exchangers. There are three heaters in each

copper radiator. The internal and external surfaces of the radiators

are pressure isolated by an 0-ring seal. All 0-ring seals employed in

this apparatus were fabricated from ethylene propylene, this material

being appropriate for use with high pressure steam. Figure 7 shows the

relationship between the heaters and the heat exchangers. The bayonet

heaters are supplied power from a 10 KVA S.C.R. power supply used in

conjunction with a current adjusting type controller. These bayonet

heaters must be controlled since they in effect control the steam

pressure in the vessel. A baffle assembly is used above the copper

heat exchangers to reduce bumping caused by the evolution of steam.

A copper-copper constantan thermocouple is used with this device to

monitor steam temperature, hence total pressure.

2.2 PLATINUM HEATER

The platinum heater (Figs. 8,9) consists of a hollow right cylinder

2" I.D. and 6" long. The cylinder was fabricated from sheet 0.040" thick.

Two large platinum tabs approximately .120" thick, 3.152" long and 6"

high were welded to the cylinder at 180 °. These tabs are clamped

into the copper electrodes. A cylinder of high alumina material 0.5"

thick was cast around the platinum cylinder. A second layer of material

0.5" thick was cast around the first to further insulate the heater from

the steam enviroment. Both layers of castable were reinforced with

platinum wire. The cooling of the platinum heater by the steam is

the greatest single problem encountered in the operation of the viscometer.

The platinum crucible used to contain the molten slag is 1.5" O.D.

and 2.5" long. A tab was welded on the bottom of the crucible which

was embedded into a notch at the top of the alumina spindle. The

alumina spindle is in turn clamped at the opposite end into a stainless

steel rotating shaft. This interlocking device helped to prevent

accidentally contacting the crucible with the heater.

The stainless steel rotating shaft which supports the alumina

spindle passes through the bottom flange. This shaft is Sealed with

two ethylene proplene 0 rings. Outside the vessel the shaft is cooled

to prevent degradation of the 0 ring. This cooling is accomplished by

passing water through a jacket (Fig. 10) surrounding the shaft. The

shaft is attached to the motor drive transmission by a universal coupling.

3
2.3 VISCOSITY TORSION SUSPENSION

The viscosity torsion suspension is shown in Figures 11, 12. The

platinum bob consists of a small cylinder 9/16" O.D. and 1 1/8" long

with a flat disc welded to the top. A platinum tube with the end sealed

containing the thermocouple was welded through the top of the bob to a depth of about 1/8 of an inch. This small sealed projection provided

the necessary isolation between the thermocouple bead and the molten

slag. The thermocouple wire employed was 0.015" diameter Pt-PtlO%Rh

inserted into 2 mm - 2 hole thermocouple tubing. Two short lengths of

smaller Pt-Ptl 0%Rh thermocouple wire were passed out of the suspension

through ceramic isolation yokes and welded to finer .005" diameter

Pt-PtT 0%Rh thermocouple wire, to allow unhindered deflection of the

torsion wire to which they run parallel. Above the suspension the

thermocouple wire is passed through a teflon pressure seal to the outside of the vessel. This design provided a means to measure the

temperature of the melt simultaneously with viscosity.

A short length of spring wire .013" diameter served as a torsion

member which was attached to the thermocouple assembly at the lower

end. The upper end of the torsion member is attached to a stainless

steel tube which served to raise or lower the entire assembly.

A permanent magnet attached to the suspension served as a rotation

indicator when used in conjunction with a small compass located on the

outside of the pressure vessel.

2.4 VISCOSITY MEASUREMENT

A typical viscosity measurement was conducted in the following

manner. The temperature of the slag was raised to about 800°C (below

melting) and the steam pressure was generated. The system was vented

of air. The temperature and pressure were allowed to rise concurrently

until the slag was melted, and the steam pressure was adjusted to the

desired value. The molten material was allowed to come to temperaturepressure equilibrium with the surroundings for several hours. The bob,

prewarmed at the surface of the melt, was slowly introduced into the

melt. The bob was manually rotated until the compass pointer was at zero degrees. This position on the scale was now defined as zero for

reference. The compass is situated on an arm which was rotatable about

the long axis of the pressure vessel. The arm holding the compass was rotated an appropriate amount, usually about 10 to 20 degrees. The

amount depending on the viscosity of the melt and the diameter of the

torsion members. These values were empirically established to produce

the desired angular deflection. The melt was rotated at a speed

sufficient to return the compass needle to the zero. The motor speed

was determined by visually counting the revolutions over a fixed period

4
of time. Previously the torsion wire was calibrated with a silicone

fluid with a known viscosity in the range of interest. The motor speed

was recorded for various angular deflections. The viscosity was determined by the following relationship:

(cal i brant viscosity) (calibrantRPM) (measured deflection)

n unknown = (measured RPM) (calibrant deflection)

at constant T and P, n = poises

where:

n = viscosity of the calibration liquid in poises; calibrant RPM = motor speed necessary to produce calibrant deflection; calibrant

deflection = preselected deflection of calibrant; measured deflection - deflection of compass; measured RPM = the RPM necessary to return the

compass needle to the zero position.

3.0 RESULTS AND DISCUSSION

Two slags were investigated in this study: The first, a slag high

in alkali similar to a western coal ash contained Si02 , 42%, A1 2 03 , 3%; Fe2 03 , 25%; CaO, 5%; MgO, 5%; Na 2 0, 15% and K2 0, 5% (expressed

in wt percent).

The viscosity of this melt was measured at 55 psi steam pressure

and ambient pressure in air at 1197°C, 1143°C and 1081°C. The viscosities

in steam were log10 n = 1.90, 2.05 and 2.33, respectively. Each of

these measurements was made after the temperature was held for 1/2

hour. The results are plotted on Figure 13, curve 3. When these data

are compared to those values measured at ambient pressure it appears

that the viscosity for a given temperature increases with pressure.

The same experimental procedure was employed and the viscosities

were measured at 75 psi and 1192 °C, 1133 °C, 1106 °C and 1070 °C. The

values were log 10 n = 2.20, 2.37, 2.77 and 2.76, respectively. These

results are plotted in Figure 13, curve 4.

At this point it was thought that either equilibrium was not

achieved or that crystallization had taken place in the melt. Several

attempts were made to achieve equilibrium by heating the melt for longer

periods of time. The first experiment was conducted at 1150°C, 77 psi

for 185 minutes. During the duration of the run, the values varied

from log 10 n =2.23 to 2.69.

5
A similar experiment was conducted at higher temperatures (1170 °C)

and 80 psi. While the temperature remained constant ±5 °C, the viscosity

of the melt increased from log 10 n = 2.09 to 2.34 in 135 minutes. Some

of this material heated in 80 psi steam pressure was remelted in air and

the viscosity was compared to that of the starting material. The results

shown in Fig. 13, curves 1 and 2, show that the viscosities compare

favorably. From these data, it would appear that volatility of a component was not a factor in increasing the viscosity during the

pressure experiments. In the last of this series of experiments, the

viscosity of the same material was rechecked at 77 psi and 1100 °C ± 5 °C.

In 165 minutes the viscosity changed from logio n

= 2.48 to 2.68

(Fig. 14).

Since the viscosity of this high alkali slag appeared to be time

related, it was decided to "soak" the molten slag in steam at a constant

temperature with continuous monitoring of the viscosity until the value

appeared constant. The melt was maintained at 60 psi and 1155 °C ± 5 °C

for 420 minutes (8.67 hours). The results are given in Fig. 15. From

this figure it can be seen that some small short range inflections exist

which might appear to enter steady state. However, with progression of

time it can be seen that equilibrium is not achieved and that the

viscosity of this particular melt increases with time.

A second slag lower in alkali content was investigated. This slag

has the following composition: Si0 2 , 48.30%; A1 20 3 , 12.10%; Fe 2 0 3 , 12.00%; CaO, 14.90%; MgO, 8.00% and Na 20, 4.7% (expressed in wt percent). At the initiation of this investigation, the viscosity of the

above mentioned slag was compared independently in another rotating

crucible apparatus. The viscosity of the material was found to be

about log 10 n poises = 1.86 at 1277 °C at ambient pressure. The

viscosity of this melt was measured in the high pressure steam apparatus

operating at ambient pressure. The viscosity of the material was found

to be log 10 n = 1.90 poises at 1277 °C. These values are in excellent

agreement. This same material was next subjected to an environment of

N 2 to reduce the partial pressure of oxygen in the steam atmosphere.

The apparatus was purged four times with nitrogen; the total N 2 pressure

over the slag was set at 25 psi. The temperature was maintained at

approximately 1279°C, the viscosity was reduced from log 10 n poises = 1.91 (value in air) to log 10 n poises = 1.71 at which time the

experiment was terminated. This lowering of viscosity was probably

due to the reduction of Fe 3 to Fe 2 in the melt.

An attempt was made to reoxidize the melt previously heated in

nitrogen while monitoring the viscosity. The viscosity was then

remeasured at 1277°C in air. This temperature was maintained for

2 hours 15 min and the viscosity increased steadily from log 10 n = 1.82

to log 10 n poises = 2.22 which greatly exceeded the original value in

air. A large mass of well formed crystals were found radiating from

6
the bob. This material was examined by x-ray powder diffraction and

found to contain a phase which is apparently isostructural with a naturally occurring mineral in the pyroxene family, fassaite (an Al-augite).

The effect of varying the partial pressure of oxygen in steam on viscosity of the melt was investigated with a different gaseous media.

The viscosity was measured in 50% C02 and 50% steam at a total pressure

of 97 psi. At 1321 °C, 1240 °C, 1232 °C and 1161 °C, the viscosity was found to be log 10 n =1.46, 1.72, 1.73, 1.98, respectively. From

Figure 16 it can be seen that the effect of reduced partial pressure

of oxygen significantly lowered the viscosity in the melt when com- pared to the values obtained at ambient pressure. With this effect

noted, it was decided not to continue the viscosity measurements in

mixed gaseous environments but to attempt to increase the temperature

of measurement in effort to determine if the viscosity curves in Fig.

16 would converge. To accomplish this the pure platinum heater was replaced with a 60% platinum 40% rhodium heater.

The new heater was installed and several attempts were made to remeasure the viscosity of the low alkali slag at higher temperatures.

Since heat loss due to steam cooling is significant, a flat disc or

lid with a small hole to allow passage of the bob was placed over

the heater. This lid essentially obscured the view of the melt. In

subsequent experiments when this heat shield was removed, the molten

liquid was found to foam and the bob serve to "guide" or extract

the liquid from the crucible. For example in one experiment all

of the liquid was extracted from the platinum crucible and redeposited

on the insulation of the heater. The foaming problem in this material

is+probably due to evolution of oxygen gas as Fe 3 is converted to

Fe & on heating. From additional experimentation it was found that

the foaming problem could be eliminated by annealing the starting

melt at 1500 °C for 4 hours before placing it in the viscometer.

Several experiments were conducted with this composition. The first

two were performed prior to high temperature annealing in air at 1500 °C

for 4 hours. The last experiment received this annealing.

In the first experiment of the series at 50 psi of steam the

following values (Table 1) of viscosity were obtained:

Table 1. Viscosity of a Silicate Slag in 50 psi Steam.

Viscosity at

Steam Pressure Melt. Temp. Time Viscosity ambient pressure

psi °C min 1 og

i

0

n in poises log-|Q n (in poises)

50 1364 25 1.48 1.49

53 1359 45 1.50 1.51

43 1355 55 1.50 1.53

54 1357 150 1.52 1.52

7
From the above it can be seen that the addition of 50 psi of steam did

not significantly effect the viscosity.

The results of the second experiment with foaming are given below

(Table 2) at about 80 psi compared to those values obtained at ambient

pressure.

Table 2. Viscosity of a Silicate Slag in 80 psi Steam (foaming

detected)

.

Viscosity Viscosity

at Melt Temp. Viscosity (most reliable value) in air

min °C l°9l0 n log

10 n in poises log-j 0

n poises

0 1276 1.73

13 1275 1.74

23 1275 1.62 1.71 1.88

27 1275 1.67

33 1273 1.76

46 1275 1.69

63 1272 1.75

0 1292 1.56

2 1294 1.59 1.65 1.76

5 1295 1.69

10 1296 1.69

25 1298 1.72

0 1351 1.32

10 1351 1.44 1.50 1.56

14 1348 1.50

0

3

1378

1381

1.44

1.44 1.44 1.44

In Figure 16 the 80 psi data are compared to the ambient pressure

data. From these data it appears that the viscosity values for this

material are lowered with increasing steam pressure. The values of

log 10 n “1.44 at 1378°C at both ambient pressure and 80 psi would

indicate that the viscosity curves, determined under steam pressure,

tend to coalesce with increasing temperature.

8
In the third experiment, the melt was annealed at 1500°C for four

hours in air. This material was placed in the viscometer and melted.

The temperature was maintained at about 1380°C while the bob was introduced into the melt. The surface of the melt could be observed

with the lid off. There was no foaming and the bob was centered in the

melt. At this point steam was generated to 75 psi and the melt was allowed to saturate. The entire run took about 15 hours to complete.

The results of the last experiment are given in Table 3 and Figure 17.

Table 3. Values of Viscosity at 75 psi Steam for the High Temperature

Annealed Low Alkali Slag. No foam detected.

At Melt Temp. Viscosity Viscosity (most

reliable value)

Viscosity in air

min °C l°9l0 n l°g

10 n l°g

10 n

0 1298 2.00

17 1295 2.08 2.10 1.78

32 1295 2.23

0 1343 1 .91—^

3 1342 1.98

7 1341 1.96

0 1395 1.72

20

33

1410

1399

1.67

1.69

1.70 1.36

53 1400 1.70

0

8

1328

1322

1.84

1.92 1.88 1.70

0

15

1222

1221

2.52

2.52 2.52 2.20

0 1244 2.58

2.28 2.00 5 1272 2.28

— Pressure increased from 75 to 85 psi.

In the second experiment, foaming was probably a significant

factor in producing apparently erroneous data resulting in a reduction

of viscosity with pressure.

9
There are many possible factors which may act singly or in

combination to contribute to an apparent increase in viscosity of

high alkali slags under steam pressures. A few are listed below.

(1) Crystal formation in the melt is a possiblity (see Fig. 13, curve

4). However, x-ray powder diffraction shows no crystalline phases.

From the x-ray data, crystals would be present to an extent of less

than 5%, the detection limit of x-ray powder techniques. Examination

with a polarizing microscope indicated that the primary phase present

was isotropic and that a few fragments were birefringent. This

birefringence does not necessarily indicate the presence of crystalline

phases since glass that has been strained exhibits birefringence.

(2) The interaction of H 2 0 with a melt high in alkali (15% Na 2 0 and

5% K2 0, first slag) may contribute to a change in viscosity. It has

been shown that for a given temperature the viscosity of alkali silicate

glass is increased as the concentration of K2 0 is increased [3] with a maximum occurring about 15 wt %. These types of glasses may be viewed

as a three dimensional random network with each silicon tetrahedral ly

surrounded by four oxygens with each oxygen bonded by two silicons.

In an alkali glass each silicon is tetrahedrally surrounded by four

oxygens but some of the oxygens are bonded to only one silicon. The

alkali ions are believed to be held weakly in the silicon-oxygen

network. If some of the alkali were lost and the bonds were compensated

in some manner by HOH then the viscosity may change markedly with

changing HOH concentration. However, chemical analysis has shown

that the total loss of alkali is less than one tenth percent.

(3) A change in chemical species by oxidation/reduction may change

the viscosity. The Fe+3 ions have a tendency to reduce partially to

Fe+2 in air. The ratio of Fe+2 to Fe+3 may be significantly different

at melt condition in steam then it is in air. If the correct ratio

of Fe+2 /Fe+3 can be quenched-in then Mossbauer studies of these

glasses may be instructive.

(4) The increased frictional drag produced by temperature gradients may

be of sufficient magnitude to affect viscosity. In this study it was determined that vertical gradients were enhanced in the melt by

increasing steam pressure. At ambient pressure the difference between

the surface melt temperature and the temperature at the level of the bob

is about 36 °C. The increased drag produced by the cooler melt at the

surface may account for some if not all of the apparent increase in

viscosity with increasing steam pressure.

10
4.0 SUMMARY

A viscosity measuring apparatus was designed and constructed which

has a capability of measuring viscosity of melts up to ^1 400 °C with

steam pressures up to ^90 psi . The results of the viscosity determinations

were not without some ambiguity. Additional experiments would be necessary,

using a series of different slags having systematic compositional variations

to determine if the effects of hLO on the viscosity of the limited

compositions is in fact real and^not due to other causes such as equipment errors. The data obtained here, however, indicate an increase in

viscosity with increasing steam pressures.

5.0 REFERENCES

1. H. R. Lillie, J. Amer. Ceram. Soc., 12^505 (1929).

2. A. Napolitano, P. B. Macedo and E. G. Hawkins, NBS J. Res., 69A

449 (1965).

3. W. Capps, Conf. on High Temperature Science Related to Open

Cycle Coal Fired MHD Systems at Argonne National Laboratory,

Argonne, Illinois, April 4-6, 1977. (

11
Figure 1. Assembled pressure vessel.

12
—0—

Figure 2. Full assembly schematic drawing of high pressure-temperature

viscometer.

A - position detector

B - magnet

C - torsion wire

D - water condensation shields

E - electrodes

F - heating elements

G - temperature control

thermocouple

H - bob

I - crucible

J - molten slag

K - spindle

L - anti -convection baffle

M - heat exchangers

N - bayonet heaters

0 - shaft seal

P - shaft cooling jacket

Q

- shaft bearing

R - shaft drive mechanism

13
Figure 3. Bottom flange layout.

14
Figure 4. Side flange with copper electrode in place.

15
Figure 5. Split lock collar.

16
Figure 6. Retaining ring for copper electrode.

.OO 3 .oaZ.

17
Figure 7. Relationship between bayonet heaters and heat exchangers

18
Figure 8. Platinum resistance element for heating slag container

in steam.

19
Figure 9. Platinum heater covered with refractory castable.

20
'J

I

I

I

j

21

Figure

10.

Water

cooled

seal

on

the

rotating

viscometer

shaft.
<yi

!

i Figure 11. Viscometer torsion suspension

assembly.

THERMOCOUPLE

LEAD

SHAFT CONTAINING

THERMOCOUPLE

j

l

i

THERMOCOUPLE BEAD

BOB

UPPER SECTION

22

LOWER SECTION
Figure 12. Viscosity torsion assembly.

23
CO/

03

i~

C3lO

(/) <u

s-Q.

+-> C

<u f-

.QE

rd

OO. CM /

<cc

•a

cuc 5s* /

CD

id

toU

+-> 03

>3

to

<ao

>1

toou

to

Sa>

+-> ai o03

S- -DC

Id

a> to

$- o.

zjto oto CO

a>t- o

Q.+J

ida>

+-> too

03

s-too

ClX

03

S- S_ o o>

•r- +J

S- 1+- Q. id CD CD

id id

0- *4- O O

>> >3

+-> 4-> f— *i— to to o o -»-> •r— a 0 2 - > CO (/) •r- *r— CM CO in in in in in > > CM r— • CO

r— • • r— Cvl 03 CO CO S_ 03 03 cvo o o r3 > > O CM CM O o CM 0 CD S_ S-

•r— r— 03 id CD fO CM •r* =3

n

in < LL_ <_> 2: Ll. <_> c_> oLT> OO

in o LD

CM CM

(asiod ul)

u 0 L

6o l

24

Curve

3.

Viscosity

of

slag

at

55

psi

steam

pressure

Curve

4.

Viscosity

of

slag

at

75

psi

steam

pressure
LO

fcS = = = =

+J = S = =

S- CO LO Lf) LO n w

CO

co o

ro O o CO CO O O •r* r— <U «3 CT) CO < Li- C_> s; oCO o rtJ CO

oooo

+J

COCD

<o

co • <u o s_

•I- 3

+-> 10

<D (/) -c ou

+-> i_ c o. W E

fO

rO <D

-t-> 4- co O

>> CO

+-> CL

co r-^ o

o

CO XJ

•I— C > <o

cu

S-3

CT>

1 i

IO

IO

*iO

un

jr-.

oLO

I

LO

CO

ro CO f—

• • • • CM co CO CM

(asLod ul) u

°'- 6o|>

25

TIME

MINUTES
Oxide

wt%

ooLT>

_1 i~ U3 LD

CVJ CM

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26

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wt%

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27

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-> C\J

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TEMPERATURE
OXIDE

wt %

Si02

48.30

A1

20

3

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28

TEMPERATURE
NBS-114A (REV. ©-78) 2.Gov*tAeca$sion NoJ 5. Salient's Accession No.

' U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 80-2124 pi pp /

1

4. TITLE AND SUBTITLE

SLAG CHARACTERIZATION: VISCOSITY OF SYNTHETIC COAL SLAG

IN STEAM

5. Publication Date October 1980

$. Performing Organization Code

7. AUTHOR(S)

W.S. Brower, J.L. Waring and D.H. Blackburn

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

18, Project/Task/Worfc Unit No.

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, state, ZIP)

Department of Energy

Washington, D.C. 20550

13. Type of Report & Period Covered

15. SUPPLEMENTARY NOTES

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

16. ABSTRACT (A 200-word or less factual summary of most significant information, if document includes a significant bibliography or

literature survey, mention it here.)

A rotating cylinder apparatus has been designed and constructed

for measuring the viscosity of molten slags under steam pressure in

the range 15 to ^300 psi and up to about 1400 °C. Two synthetic

coal slags, one high in alkali^and the other lower in alkali but

higher in calcia were studied with this apparatus. In the high

alkali slag equilibrium was probably not achieved and the viscosity

appeared to increase with time. In the low alkali slag although

the viscosity appeared to be increased with increasing steam pressure

the ambient and higher pressure curves appear to tend to coalesce

with increasing temperature.

17. KEY WORDS (six to twelve entries ; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Coal gasification; coal slag; high temperature; steam; viscosity

18. AVAILABILITY £*} Unlimited

I I For Official Distribution. Do Not Release to NTIS

I I Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

Px~l Order From National Technical Information Service (NTIS), Springfield, VA. 22161

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF

PRINTED PAGES

32

22. Price

$ 6.00

USCOMM-DC