Purity Systems, Inc.

Dr. Ed Rosenberg (Chemistry)

Dan Nielsen (Ph.D. Student – Chemistry)

Joel Clancey (Research Assistant)

Jeff McKenzie (Research Assistant)

Functionalized Silica Polyamine Composites for Metal Recovery from Hazardous Mining Wastewater and Acid Leach Solutions

Toxic and polluting metals contaminate waters worldwide. The reported materials exhibit exceptional metalselectivity and capacity at high flowrates. Functionalized silica polyamine composites were utilized to recovercopper(II), zinc(II) and manganese(II) from Berkeley Pit Lake water (Butte, MT). Additional composite materialswere used to separate five rare earth elements from an authentic acid leach matrix. Iron(III) was removed froma synthetic copper(II) electrowinning solution. All reported process strategies allow for continuous high flowtreatment. Bench-scale studies show the potential for these materials to be used at an industrial-scale.

Acknowledgments

• Dr. Bob Fischer

• Dr. Johnnie Moore

• Carolyn Hart

• John Deming

• Montana Board of Research &

Commercialization Technology

• Department of Energy

The target metals Cu(II),Zn(II), and Mn(II) have beenselectively removed producingrecovery solutions concentrated10 - 50 fold, with high purity(83 - 99.98%). Molecularstructures illustraterudimentary metal coordinationfor clarity. Bench scaletreatment used 5.0 mLcolumns, and data is reportedas a function of columnvolume. CuWRAM was able toseparate Cu(II) directly fromBerkeley Pit Lake water in thepresence of Fe(III) and Al(III).Treated effluent from CuWRAMwas then adjusted to pH 5.2and the produced Fe(III) andAl(III) hydroxide precipitatewas removed by filtration. HighZn(II) capacity using WP-2 wasthen achieved with very highpurity. Mn(II) was nextrecovered with the use of BP-2.

In 2003 the U.S. Geological Survey had identifiedover 230,000 abandoned hardrock mines in thewestern U.S., 6,000 of these are located inMontana state. 350 of Montana’s sites have beendetermined to affect water quality designatingthem as high priority sites. The Berkeley Pit (Butte,MT) contains Cu(II), Zn(II), and Mn(II)concentrations ideal for metal recovery using silicacomposite technology. These three metals areubiquitous among mining waste sites as acid minedrainage (AMD), and their recovery offsets the costof waste treatment. Multistage treatment begins bythe extraction of copper from the Berkeley Pit Lakeutilizing the picoline silica poly(allylamine)composite “CuWRAM.” Fe(III) and Al(III) are thenprecipitated and removed as the metal hydroxidesat pH 5.2. The acetate silica poly(ethyleneimine)composite “WP-2” is next used to concentrate andpurify zinc. Manganese is subsequently recoveredvia “BP-2” (acetate silica poly(allylamine)composite) in the sodium ion (base form). Montana State’s High Priority Cleanup SitesAbandoned Hardrock Mines in the Western U.S.

The Berkeley Pit 1981 (top), 1999 (bottom) Diagram of Treatment Process

Pump

Berkeley Pit

Feed Reservoir

Treated Solution

pH

Meter

Settling

Tank

Mixer

Sludge to Dump

pH Adjustment & Floculation Chamber

- Raise pH to 5.2 (using base)

- Add ~0.1% (by volume) floculant

Recycle Filtrate Filter Press

Pump

Sludge to Dump

C

u

Z

nM

n

Pump

Pump

Holding

Tank

Major Species Conc. (mg/L) of Berkeley Pit Lake Water (at Various Depths)

Depth (ft) Fe Zn Mg Ca Al Mn Cu Cd As

0 270 378 430 512 195 179 86.8 1.84 <0.22

50 892 578 538 494 281 212 145 2.39 0.34

500 986 580 536 494 281 209 177 2.43 0.78

Schematic Structure of BP-2 (base form)

P

P

NO

N

H O

N

H

N

OSi N

O

O

Si

H

O

O

O

O-

O-

O-

H

HMn2+

Na+

Na+

Berkeley Pit Lake Metal Ion Recovery Data

Cu(II) Zn(II) Mn(II)

Berkeley Pit (% purity) 5.0 18 6.0

Recovery (% purity) 97 99.98 83

Berkeley Pit (g/L) 0.17 0.58 0.21

Recovery (g/L) 10 6.5 9.0

Schematic Structure of CuWRAM

Cu2+

P

P

N

H

N

H

N

OSi N

O

O

Si

H

O

O

H N

N

H

N

H

L L

L = H2O, HSO4-, or SO4

2-

CuWRAM Cu(II) Extraction/Recovery

0.50 CV/min., Feed pH = 2.2, 32 mg/g Cu(II) Capacity

0

100

200

300

400

500

600

700

0 50 100 150 200 250

Column Volume (CV = 5.0 mL)

Meta

l C

on

c.

(mg

/L)

Cu(II) Feed = 193 mg/L

Fe(III) Feed = 300 mg/L

Al(III) Feed = 253 mg/L

Zn(II) Feed = 602 mg/L

Mn(II) Feed = 172 mg/L

0.50 CV/min., 9.0 N H2SO4, 97% Cu(II) Purity, 3% Fe(III)

0

2000

4000

6000

8000

10000

12000

1-2 3-4 5-6 7-8

Column Volume (CV = 5.0 mL)

Meta

l C

on

c.

(mg

/L)

Cu(II) 32 mg/g

Fe(III) 1 mg/g

Al(III) 0.0 mg/g

Zn(II) 0.0 mg/g

Mn(II) 0.0 mg/g

Berkeley Pit Precipitation/Filtration Study

P

P

O

O-

NN

OSi N

O

O

Si

O

O

H

NNN

O

HO

H

H

O

HO

P

Zn2+

Schematic Structure of WP-2

0

100

200

300

400

500

600

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5

pH

Meta

l C

on

c.

(mg

/L)

Zn

Fe

Al

Mn

BP-2 Mn(II) Extraction/Recovery

BP-2-CF Breakthrough Curve

0.50 CV/min., Feed pH = 4.9, 23 mg/g Mn(II) Capacity

0

100

200

300

400

500

600

700

800

0 10 20 30 40 50 60 70 80 90 100

Column Volume (CV = 5.0 mL)

Meta

l C

on

c.

(mg

/L)

Mn(II) Feed = 255 mg/L

Ca(II) Feed = 407 mg/L

Mg(II) Feed = 501 mg/L

0.50 CV/min., 9 N H2SO4, 83% Mn(II) Purity

0

2000

4000

6000

8000

10000

12000

1 2 3 4 5

Column Volume (CV = 5.0 mL)

Meta

l C

on

c.

(mg

/L)

Mn(II) 30 mg/g

Ca(II) 4 mg/g

Mg(II) 2 mg/g

WP-2 Zn(II) Extraction/Recovery

WP-2-CF Breakthrough Curve (4 CV 0.010 M NaOH to pH 1.9)

0.50 CV/min., Feed pH = 5.3, 26 mg/g Zn(II) Capacity

0

100

200

300

400

500

600

700

0 20 40 60 80 100 120

Column Volume (CV = 5.0 mL)

Meta

l C

on

c.

(mg

/L)

Zn(II) Feed = 620 mg/L

Mn(II) Feed = 248 mg/L

WP-2-CF Strip Fractions

0.50 CV/min., 9 N H2SO4, 99.98% Zn(II) Purity

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

1 2 3 4 5 6

Column Volume (CV = 5.0 mL)

Meta

l C

on

c.

(mg

/L)

Zn(II) 22 mg/g

Mn(II) 0 mg/g

The phosphonic acid silicapoly(allylamine) composite (BPAP)exhibits superior metal exchangekinetics compared to a leadingcrosslinked polystyrene resin(Diphonix®). Additionally, BPAP wascapable of removing Fe(III) from a 2 MH2SO4 synthetic electrowinning solutioncontaining 10 g/L Cu(II). Areproducable second load/strip cycleconfirms complete stripping of Fe(III).Rare earth elements (REEs) wereseparated from an authentic sulfuricacid leach solution to 99% REE purity.This was accomplished by removingFe(III) using the oxine poly(allylamine)composite (WP-4), followed by REEseparation using BPAP. Secondload/strip cycles were identical to thefirst for both WP-4 and BPAP (resultsnot shown for clarity). Eu(III) andFe(III) can both be stripped from BPAPusing either EDTA (pH 10.6) or H3PO3,although slow flow rates must beemployed for Fe(III).

BPAP-CF 041504-DN0.050 CV/min., 1.5 M EDTA pH 10.6, 99% Stripped

0

1000

2000

3000

4000

5000

6000

7000

S-1-2 S-3-4 S-5-6 S-7-8 S-9-10 S-11-12 S-13-14

Fe(I

II)

mg

/L

Fe(III) #1 (30 mg/g)

Fe(III) #2 (30 mg/g)

BPAP-CF 041504-DN0.50 CV/min., Feed Solution = 4 N H2SO4, 30 mg/g Fe(III) Capacity

0

100

200

300

400

500

600

0 10 20 30 40 50 60 70 80 90

Column Volume (CV = 5.0 mL)

Fe(I

II)

mg

/L

0

2000

4000

6000

8000

10000

12000

Cu

(II)

mg

/L

Fe(III) #1 Feed = 407 mg/L

Fe(III) #2 Feed = 407 mg/L

Cu(II) #1 Feed = 10.3 g/L

Cu(II) #2 Feed = 10.3 g/L

BPAP Fe(III) Extraction/Recovery

87% to 99% Ln(III) Purity [ <1% Al(III), <<1% Ca(II), Fe(III), Ti(IV)]

0

1000

2000

3000

4000

5000

6000

Ce(III) La(III) Nd(III) Sm(III) Pr(III) Fe(III) Mn(II) Ca(II) Mg(II) Al(III) Zn(II) Ti(IV)

Meta

l C

on

c.

(mg

/L)

REE Feed (50%)

WP-4 Flowthrough

BPAP Recovery Sol.

P

P

NH

N

H

N

H

N

OSi N

O

O

Si

H

O

O

H

H

N

OH

NHO

Schematic Structure of WP-4

REE Acid Leach Metal Ion Recovery Data WP-4-CF 101205-DN Strip Profile

0.50 CV/min., 9 N H2SO4, 25 mg/g Fe(III) Capacity

0

2000

4000

6000

8000

10000

12000

14000

S-1 S-2 S-3 S-4

Column Volume (CV = 12 mL)

Meta

l C

on

c.

(mg

/L)

Fe(III)

Ti(IV)

Ce(III)

Nd(III)

La(III)

WP-4-CF 101205-DN Breakthough Curve

0.50 CV/min., Feed pH = 1.30, 25 mg/g Fe(III) Capacity

0

1000

2000

3000

4000

5000

6000

0 5 10 15 20 25

Column Volume (CV = 12 mL)

Fe(I

II)

Co

nc.

(mg

/L)

Ce(III)

La(III)

Nd(III)

Sm(III)

Pr(III)

Fe(III)

WP-4 Fe(III) Extraction/Recovery

BPAP-CF 041504-DN Breakthrough Curve #2

0.50 CV/min., Feed pH = 1.31

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0 1 2 3 4 5 6 7 8

Column Volume (CV = 9.0 mL)

Me

tal

Co

nc

. (m

g/L

)

Ce(III)

La(III)

Nd(III)

Sm(III)

Pr(III)

Ca(II)

Mn(II)

Al(III)

0.50 CV/min., 2 M H3PO3, 59 mg/g Ln(III) Capacity

99% Ln(III) Purity [< 1% Al(III), << 1% Ca(II), Fe(III), Ti(IV)]

0

500

1000

1500

2000

2500

3000

3500

4000

4500

S-1-2 S-3-4 S-5-6 S-7-8 S-9-10

Column Volume (CV = 9.0 mL)M

eta

l C

on

c.

(mg

/L)

Ce(III)

La(III)

Nd(III)

Sm(III)

Pr(III)

Al(III)

BPAP REE Extraction/Recovery

BPAP-CF 041504-DN0.050 CV/min., 1.5 M EDTA (pH 10.6), 5.0 M H3PO3, 5.0 M H3PO4

0

1000

2000

3000

4000

5000

6000

7000

S-1-2 S-3-4 S-5-6 S-7-8 S-9-10

Column Volume (CV = 5.0 mL)

Fe

(III)

mg

/L

1.5 M EDTA (99% stripped)

5.0 M H3PO3 (94% stripped)

5.0 M H3PO4 (78% stripped)

0.50 CV/min., Various Strip Solutions (percent strip)

0

2000

4000

6000

8000

10000

12000

14000

16000

S-1-2 S-3-4 S-5-6 S-7-8 S-9-10

Column Volume (CV = 5.0 mL)

Eu

(III

) m

g/L

1.0 M EDTA pH 10.6 (100%)

5.0 M H3PO3 (100%)

5.0 M H3PO4 (99%)

4.0 M HNO3 (92%)

9.0 M H2SO4 (80%)

10 M HCl (39%)

BPAP Eu(III) & Fe(III) Stripping Studies

P

P

N

H

P

O

OH

OH

N

H

P

OHHO

N

OSi N

O

O

Si

H

O

OH

O

N

POH

OH

P

O

OH

OH

O

Schematic Structure of BPAP

Berkeley Pit Water Treatment using BPAP-CF (120902-DN)

0

0.2

0.4

0.6

0.8

1

1.2

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0

Colume Volume (CV = 33.1 mL)

C/C

o

Iron (516 mg/L)

Copper (113 mg/L)

Zinc (671 mg/L)

Aluminum (310 mg/L)

Flow Rate = 1.0 CV/min.

pH Feed = 2.3

BPAP-CF 120902-DN Breakthrough Curve1.0 CV/min., Feed pH = 1.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5 10 15 20 25

Column Volume (CV = 33 mL)

Meta

l C

on

c. (C

/Co)

Feed pH = 1.5

1.0 CV/min. Flowrate

Fe(III) Feed = 1,250 mg/L

Cu(II) Feed = 9,570 mg/L

Berkeley Pit Water Treatment using BPAP-CF (120902-DN)

0

0.2

0.4

0.6

0.8

1

1.2

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0

Colume Volume (CV = 33.1 mL)

C/C

o

Iron (516 mg/L)

Copper (113 mg/L)

Zinc (671 mg/L)

Aluminum (310 mg/L)

Flow Rate = 1.0 CV/min.

pH Feed = 2.3

BPAP-CF 120902-DN Breakthrough Curve1.0 CV/min., Feed pH = 1.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5 10 15 20 25

Column Volume (CV = 33 mL)

Meta

l C

on

c. (C

/Co)

Feed pH = 1.5

1.0 CV/min. Flowrate

Fe(III) Feed = 1,250 mg/L

Cu(II) Feed = 9,570 mg/L

Diphonix® Resin (top), BPAP (bottom)

Berkeley Pit Water Treatment using BPAP-CF (120902-DN)

0

0.2

0.4

0.6

0.8

1

1.2

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0

Colume Volume (CV = 33.1 mL)

C/C

o

Iron (516 mg/L)

Copper (113 mg/L)

Zinc (671 mg/L)

Aluminum (310 mg/L)

Flow Rate = 1.0 CV/min.

pH Feed = 2.3

BPAP-CF 120902-DN Breakthrough Curve1.0 CV/min., Feed pH = 1.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5 10 15 20 25

Column Volume (CV = 33 mL)

Meta

l C

on

c. (C

/Co)

Feed pH = 1.5

1.0 CV/min. Flowrate

Fe(III) Feed = 1,250 mg/L

Cu(II) Feed = 9,570 mg/L

Berkeley Pit Water Treatment using BPAP-CF (120902-DN)

0

0.2

0.4

0.6

0.8

1

1.2

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0

Colume Volume (CV = 33.1 mL)

C/C

o

Iron (516 mg/L)

Copper (113 mg/L)

Zinc (671 mg/L)

Aluminum (310 mg/L)

Flow Rate = 1.0 CV/min.

pH Feed = 2.3

BPAP-CF 120902-DN Breakthrough Curve1.0 CV/min., Feed pH = 1.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5 10 15 20 25

Column Volume (CV = 33 mL)

Meta

l C

on

c. (C

/Co)

Feed pH = 1.5

1.0 CV/min. Flowrate

Fe(III) Feed = 1,250 mg/L

Cu(II) Feed = 9,570 mg/L