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USE OF HYDROMETALLURGY IN METAL RECOVERY FROM MINE WASTES

BY : ALI MEHRISUPERVISOR : DR. KARIMI

CONTENT

Introduction Types of mine waste Classification of minerals wastes Mine waste leaching References

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3

Aspects :1. Economical2. Environmental

THE IMPORTANCE OF RECOVERING WASTE[1]

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Creates jobs Growth of an industry Utilize smaller solid waste dumpsters Converting waste materials into new products Reduce the consumption of fresh raw materials

ECONOMICAL ASPECTS

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Resource conservation Reduce energy usage Air pollution, including reductions in greenhouse gas generation Reduce water pollution (from land filling)

ENVIRONMENTAL ASPECTS[2]

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MINERAL EXTRACTION: FROM MINING TO METAL[3]

MiningMineral processing

(beneficiation)

Metallurgical extraction

Mineralconcentrate

Metal

Waste rock

Tailings

Slags

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COMPARISON OF WASTE AND PRODUCT[11]

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Cut – off grade ores

Tailings from mineral products

Residues

TYPES OF MINE WASTE[4][5]

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CLASSIFICATION OF MINERALS WASTES[4]

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WASTE CUT OFF GRADES[6]

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“Acid mine drainage” refers to a particular process whereby low pH

mine water is formed from the oxidation of sulphide minerals

AMD is particularly prevalent in both metallic mineral and coal

mines.

WHAT IS AMD[3]

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PROCESS[7]

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IMPACTS OF AMD

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General equations for this process are: 2FeS2 + 7O2+ 2H2O → 2Fe2+ + 4SO4

2- + 4H+ 4Fe2+ + O2 + 4H+ 4Fe3+ + 2H2O 4Fe3+ + 12H2O 4Fe(OH)3 + 12H+ FeS2 + 14Fe3+ + 8H2O → 15Fe2++ 2SO4

2- + 16H+

WHAT IS AMD[8]

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Aluminum1. Gibbsite2. Bohmite3. Diaspore

MINE WASTE LEACHING[9]

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RED MUD

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50 % of bauxite is red-mud:- a waste-product from the Bayers Process:

Fe2O3: 70 wt. pct. (35-38% metal value) Al2O3: 10 wt. pct. TiO2: 7.0 wt. pct. CaO: 7.5 wt. pct

RED MUD[10]

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RED MUD RECOVERY

Product Note

1) Pyro only

Pig iron,Ti-rich slag

(REE)/Metallic iron

① smelting : Iron oxide Reduction in blast furnace or similar reacto

② solid state reductionDisadvantage• High Na contents in Red Mud: sodium oxide deposition -.• High drying cost of red mud

2) Pyro + HydroPig iron,

REE(from REE slag)

• Pig iron by reluctant, Concentration of REE in slag• Recovery of Concentrated REE by hydro method• High sodium contents and Waste water problem

3) Hydro only REE

• Selective leaching of REE (Fe2O3 is not leached, Using HNO3, Y• 96%, Sc 80%, light lanthanides 30-50%)Selective precipitation and Solvent Extraction

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RECOVERY OF IRON[10]

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RECOVERY OF TITANIUM OXIDE[10]

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SinteringAl2O3

+

Na2CO3

=

2Na

Al

O2

+

CO2(g)Te

mperature

of

operation

:

850-1100oCTi

me

:

2

hours

LeachingNa

Al

O2(s)

=

Na

Al

O2(aq)Te

mperature

of

operation

:

25-100

oCTi

me

:

5-30

m

inutes,

Red

Mud

to

water

:

2-50

gpl

SINTERING AND LEACHING OF ALUMINA[10]

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Copper1. Sandy ore (granular)2. Slimy ore (composed of very fine particles that are difficult to

settle)3. Molybdenite4. Rhenium5. Cobalt

MINE WASTE LEACHING[9]

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SANDY ORE[9]

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SLIMY ORE[9]

• Using sponge iron • Using hydrogen sulfide

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MOLYBDENITE & RHENIUM[9]

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COBALT[9]

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Platinum1. Native platinum ores2. Gold ores3. Nonferrous metals sulfide ores

MINE WASTE LEACHING[9]PtC14 + 2NH4Cl →(NH4)2[PtCl6]

PdC12 + 4NH3 →[Pd(NH3)4]C12

[Pd(NH3)4]C12 + 2HCI → [Pd(NH3)2]C12 + 2NH4C1

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1. Mattias Bäckström. 2007-2013. Compendium of mining and processing waste management technologies

2. https://en.wikipedia.org/wiki/Recycling

3. Mark Muller. 2009. Mine wastes. Pages 3-7

4. CJ Mitchell, DJ Harrison, Dr. HL Robinson, Dr N Ghazireh.2004. minerals from waste. Pages 1-2

5. Pranjit Sharmah. 2013. dumping of mining waste. Pages 5-7

6. S.Najmedin Almasi, Amir Khademian, Reza Yarahmadi. 2015. Determination of Leaching Cutoff Grade Using. Page 1279

REFERENCES

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7. Mark Muller. 2009. Environmental and Social Concerns. Pages 3-4

8. V.GOUTHAM. 2011. Treatment methods of acid mine drainage and a case study on selective recovery of metals. Page 3

9. Fathi Habashi. 1999. Hydrometallurgy. Pages 242-252 & 229-233

10. Brajendra Mishra. 2015. Bauxite Residue Valorisation and Best Practices. Pages 3-28

11. https://www.ausimmbulletin.com/feature/towards-zero-waste/

REFERENCES