A Novel Approach for Mercury Capture

Christopher L. Poling, BEng, MSc

Melissa Harrison, PE

Paul Longo, PE
1. PCA Report, R&D Serial No. 2888, ”Mercury and Lead Content in Raw Materials”, Hills and Stevenson, 2006

2. Sikkems, Joel K., “ Fate and transport of mercury in portland cement manufacturing facilities” ( 2011). Graduate Thesis and Dissertations. Paper 11907.

http://lib.dr.iastate.edu/etd/11907

3. * Data gathered during various SCB Trial s ( 2010 – 2012 ) C.Poling , T.Lesniak CKD Generated during Raw Mill Off scenario

Cement Kiln Raw Materials

(mercury concentrations, ppb)

Limestone 17 – 1,753

Sand 29 – 585

Clay 52 – 425

Mill Scale 12 – 50

Shale 57 – 445

Bottom Ash 48 – 390

Slag 12 – 180

Iron Ore 78 – 745

Fly Ash 50 – 755

CKD 253 - 41,000*

on site quarry

delivered to the plant

continually returned

to the process
Break the internal mercury cycle

Remove the mercury from the kiln system

Reduce the mercury emissions at the stack

Return the CKD as a raw material

Prevent the mercury from ever getting back into

the environment...
cooler

mill stack

cement kiln dust

CKD

silo

VRM

kiln

baghouse

raw materials

coal
cooler

mill stack

CKD

silo

VRM

kiln

baghouse

cement kiln dust

raw materials

coal
cooler

mill stack

CKD

silo

VRM

kiln

baghouse

coal

raw materials

cement kiln dust
cooler

mill stack

VRM

kiln

baghouse

cement kiln dust

Mercury

Capture

Systems

Mercury

Sulfide

raw materials

coal
MCS residue created from the

introduction of a particulate free

gas stream. The collected

residue settles out leaving very

clear water above it.

MCS General Process
MCS

Technologies

Downcomer

Injection

Cement

Manufacturing

Thermal

Desorber and

Gas Reactor

Cement

Manufacturing

(CKD)

Power Industry

(Fly Ash)

Activated Carbon

Regeneration

Gas Reactor Other Industries

(Gold Mining)
MCS

Technologies

Downcomer

Injection

Cement

Manufacturing

Thermal

Desorber and

Gas Reactor

Cement

Manufacturing

(CKD)

Power Industry

(Fly Ash)

Activated Carbon

Regeneration

Gas Reactor Other Industries

(Gold Mining)
Cement Kiln Dust Treatment System and Method

 Prototype confirmed

mercury reduction of

CKD

 Confirmed the ability

of the reagents to

remove mercury

from the gas stream

 Confirmed

generation of

concentrated residue

CKD Feed

Heavy Metal Vapor Capture

Tube Screw Furnace

Gas Reactor

Thermal Desorber Gas Reactor Prototype
Prototype Results: June – October 2012

analyzed from samples

collected after test completion

The mercury is removed

from the CKD and

captured in the residue...
Prototype Results: June – October 2012

Average CKD Mercury Concentration Before and After Processing
Average Gas Stream Mercury Reduction Inlet vs. Outlet

Prototype Results: June – October 2012

70%

75%

80%

85%

90%

95%

100%

82.5%

98.4%

Including Particulate Gas Stream Only

Hand- Held

Analyzers

Sorbent

Trap

Section II
Mercury Capture Effectiveness :

What does this mean to a cement plant?

Conservatively we can

remove 87% of the mercury

present on the CKD. Actual

test results have shown this

to be as high as 99%

Analysis of SCB data

indicates that mercury

concentrations on the CKD

increase when the vertical

raw mill is down.

34,426 ppb Hg CKD in

4,387 ppb Hg CKD out

87% ppb Hg reduction

8,760

92%

8,059

10%

805.9

hours per year

utilization

operational hours per year

raw mill down time

raw mill down hours per year
 Analysis of mercury concentrations within various cement kiln dusts have

illustrated a range of 25 ppb Hg – 41,000 ppb Hg

 1,000 ppb Hg removed from 1 ton of CKD represents 0.0020 lb Hg

 Cement kilns produce up to +/- 20 tph of CKD.

Mercury Capture Effectiveness :

What does this mean to a cement plant?

1,000 = 1 = , , = =

.

. . =
In 2012 we designed a full scale

industrial unit

 20 tph CKD throughput rate

 CKD input temperature +/- 70

degrees F minimum input

 CKD Hg concentration up to

60,000 parts per billion

 CKD output to have 90% of the

mercury removed or better

Cement Kiln Dust Treatment System and Method: Patented Process

CKD TREATMENT
FEED SILO

THERMAL DESORBER DISCHARGE

PUGMILL

BAGHOUSE

CONDENSER

GAS REACTOR

Over the past 24 months we built our first

Thermal Desorber Gas Reactor
REAGENT MIXING

TANK

CONCENTRATED NON-LEACHABLE

RESIDUE COLLECTION

CLEAN GAS STREAM

OUTLET

REAGENT CHEMICAL

CONCENTRATED

HEAVY METAL INLET

GAS STREAM FROM

DESORBER

MCS General Process
Gas Reactor relocated near

a smaller Thermal Desorber.

MCS General Process
Small Thermal Desorber

allows testing of batch

materials in drums rather

than 25 ton loads for full scale

Thermal Desorber.

MCS General Process
Inside of the reagent

mixing tank, we mix the

chemicals to a desired

concentration. This

particular case was a 10:1

ratio achieved by 60

gallons of water mixed

with 6 gallons of reagent.

MCS General Process
After mixing the liquid is

transferred to the residue

collection /recirculation tank.

RETURN PIPE FROM SCRUBBER

FILL PIPE FROM MIXING TANK

DILUTE REAGENT PUMP IS

BEHIND THE WEIR AND

CIRCULATES FLUID FROM THIS

TANK INTO THE SCRUBBER

MCS General Process
TDGR Unit Results 2014

Average CKD Mercury Concentration Before and After Processing

0.0

0.5

1.0

1.5

2.0

2.5

2.16 ppm

ND

Unprocessed CKD Processed CKD

mercury concentration, ppm
80%

85%

90%

95%

100%

88.1%

99.2%

Including Particulate Gas Stream Only

Average Gas Stream Mercury Reduction Inlet vs. Outlet

Hand- Held

Analyzers

Sorbent

Trap

Section II

TDGR Unit Results 2014
Average Gas Stream Mercury Reduction Inlet vs. Outlet

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

88.08%

99.18%

82.5%

98.40%

Mercury Reduction

Including Particulate Gas Stream Only

Hand Held

Analyzer Hand Held

Analyzer

Sorbent

Trap Sorbent

Trap
Costs of Dust Shuttling

• 20,000 tons per year dust shuttled

• Dust @$24/ton

• Limestone @$7.50/ton

$480,000 – 150,000 = $330,000 additional cost

• Raw mix replacement @$8.82/ton

$180,000 additional raw mix for same clinker

Total: $510,000 per year
Costs in Sold Out Market

• Raw mill limited

• 20,000 tons per year dust sent to finish mills

• Lost additional clinker production ≈ 16,000 tpy

• 18,000 tpy cement @$98.50/ton

$1,700,000 sales revenue lost
MCS

Technologies

Downcomer

Injection

Cement

Manufacturing

Thermal

Desorber and

Gas Reactor

Cement

Manufacturing

(CKD)

Power Industry

(Fly Ash)

Activated Carbon

Regeneration

Gas Reactor Other Industries

(Gold Mining)
MCS for Raw

Materials

Coal Fly Ash
0

200

400

600

800

1,000

1,200

1,400

1,600

Raw Fly Ash Processed Fly Ash

1,500 ppb

<20 ppb

mercury concentration, ppb

Coal Fly Ash Mercury Concentration Before and After Processing

FLY ASH TREATMENT
MCS

Technologies

Downcomer

Injection

Cement

Manufacturing

Thermal

Desorber and

Gas Reactor

Cement

Manufacturing

(CKD)

Power Industry

(Fly Ash)

Activated Carbon

Regeneration

Gas Reactor Other Industries

(Gold Mining)
During a recent demonstration on a landfilled activated carbon the

mercury reduction was over 99% with material concentration

levels started as high as 240 ppm. The concentrated gas stream

which was treated by our MCS Gas Reactor measured up to 8,388

ppm Hg at various times during the demonstration. Carbon

content was reduced to 1.4% LOI . For the first pass the carbon was left and only the mercury was

removed. For the second pass the carbon was combusted in order

to recover other precious metals...

A cement kiln using MCS technology could process spent activated

carbon into a viable fuel source and potentially get paid to take the

material...

MCS for Raw Materials

Activated Carbon
Average Activated Carbon

Mercury Concentration Before and After Processing

FLY ASH TREATMENT

148.31 ppm Hg

2.25 ppm Hg

195.16 ppm Hg

0.7 ppm Hg

Unprocessed Activated Carbon Processed Activated Carbon

mercury concentation , ppm
Moisture Hg

Concentration

LOI @ 1000 C

ACTIVATED CARBON: BLEND 1 23.27% 148.31 ppm 78.14

ACTIVATED CARBON: BLEND 2 26.92% 195.16 ppm 78.40
Processed Hg

Concentration

Processed

LOI @1000 C

Hg

Reduction

LOI

Reduction

ACTIVATED CARBON: BLEND 1 2.25 ppm 1.4 98.48% 98.21%

ACTIVATED CARBON: BLEND 2 0.7 ppm 1.5 99.64% 98.09%

Potential Recovery of Rare Earth Elements
13,502

215

5,384

383

5,840

223

Gas Reactor Inlet Gas Reactor Outlet

mercury concentration,

u

g/m

3

Gas Stream Mercury Inlet vs. Outlet
TOTAL HG GAS REACTOR INLET GAS REACTOR OUTLET

Gas

Reactor

Inlet

Gas

Reactor

Outlet

Removal Particulate

Bound

Ionic

Hg

Elemental

Hg

Particulate

Bound

Ionic

Hg

Elemental

Hg

ug/m3 ug/m3 % ug/m3 ug/m3 ug/m3 ug/m3 ug/m3 ug/m3

13,502 215 98.4 10 13,492 215

5,384 383 92.9 32 2 5,850 1 3 380

3,564 244 93.1 9 3,655 244

4,882 324 93.4 25 14 4,843 1 2 321

5,840 223 96.2 14 5,826 223

MCS residue created from the

introduction of a particulate free

gas stream. The collected

residue settles out leaving very

clear water above it.

MCS General Process
Heavy Metals MCS RESIDUE

LIQUID SOLID UNIT

Total Mercury ND 2360 mg/kg

Metals SM3120 B

Arsenic 0.043 147 mg/kg

Barium 0.054 141 mg/kg

Cadmium ND 49 mg/kg

Chromium ND 166 mg/kg

Lead ND 16 mg/kg

Selenium ND ND mg/kg

Silver ND 514 mg/kg

Activated Carbon - MCS Residue

MCS for Raw Materials
HEAVY METAL

2015 MCS COLLECTED

RESIDUE 2015 TCLP TEST RESULT HAZARDOUS

WASTE CODE

liquid solid unit result test limit EPA limit unit

Total Mercury ND 2360 ppm 0.0538 0.0002 0.2 ppm D009

Metals SM3120 B

Arsenic 0.043 147 ppm ND 0.100 5 ppm D004

Barium 0.054 141 ppm 0.627 0.100 100 ppm D005

Cadmium ND 49 ppm ND 0.100 1 ppm D006

Chromium ND 166 ppm ND 0.100 5 ppm D007

Lead ND 16 ppm ND 0.100 5 ppm D008

Selenium ND ND ppm ND 0.100 1 ppm D010

Silver ND 514 ppm ND 0.100 5 ppm D011
Total

Mercury

Arsenic Barium Cadmium Chromium Lead Silver

TCLP Result EPA Limit MCS Residue

mercury concentration, ppm
MCS

Technologies

Downcomer

Injection

Cement

Manufacturing

Thermal

Desorber and

Gas Reactor

Cement

Manufacturing

(CKD)

Power Industry

(Fly Ash)

Activated Carbon

Regeneration

Gas Reactor Other Industries

(Gold Mining)
Downcomer Injection
MCS

Technologies

Downcomer

Injection

Cement

Manufacturing

Thermal

Desorber and

Gas Reactor

Cement

Manufacturing

(CKD)

Power Industry

(Fly Ash)

Activated Carbon

Regeneration

Gas Reactor Other Industries

(Gold Mining)
Alternative Process

VAPOR PRESSURE SYSTEM: ELIMINATES THE

HEATING PROCESS & SEPARATES THE MERCURY
Reagent catalysts have been in use for a long time in the

cleanup of soils and waterways. MCS utilizes these to effectively bind mercury from CKD as HgS. This technology has been successfully adapted:

- removal of mercury from powdered activated carbon

- fly ash and other coal combustion products

- various industrial dust streams

Additional testing is planned for work related to:

- hexavalent chrome

- selenium

- cadmium

- other heavy metals resulting from the use of natural ores
For more information please contact:

SCB INTERNATIONAL MATERIALS

MERCURY CAPTURE SYSTEMS

153 South Main Street

Newtown Connecticut

06470

(203) 270 - 2766

Peter D’Amico (pdamico@scbinternational.com)

Tom Lesniak (tlesniak@scbinternational.com)

Chris Poling (cpoling@scbinternational.com)

Melissa Harrison (mharrison@scbinternational.com)

Paul Longo (plongo@scbinternational.com)