This document discusses the use of hydrometallurgy in recovering metals from mine waste. It begins by introducing the types and classification of mine waste like waste rock, tailings, and slags. It then discusses aspects like economics and the environment. Mine waste leaching is examined as a process to extract metals. Various metals that can be recovered from mine waste are discussed, like aluminum from red mud, copper from different ore types, and platinum from native ores. References are provided to support the information presented.

1. USE OF HYDROMETALLURGY IN METAL
RECOVERY FROM MINE WASTES
BY : ALI MEHRI
SUPERVISOR : DR. KARIMI
1

2. CONTENT
 Introduction
 Types of mine waste
 Classification of minerals wastes
 Mine waste leaching
 References
2

3. Aspects :
1. Economical
2. Environmental
3
THE IMPORTANCE OF RECOVERING WASTE[1]

4.  Creates jobs
 Growth of an industry
 Utilize smaller solid waste dumpsters
 Converting waste materials into new products
 Reduce the consumption of fresh raw materials
4
ECONOMICAL ASPECTS

5.  Resource conservation
 Reduce energy usage
 Air pollution, including reductions in greenhouse gas generation
 Reduce water pollution (from land filling)
5
ENVIRONMENTALASPECTS[2]

6. 6
MINERAL EXTRACTION: FROM MINING TO METAL[3]
Mining
Mineral processing
(beneficiation)
Metallurgical
extraction
Mineral
concentrate
Metal
Waste
rock
Tailings
Slags

7. 7
COMPARISON OF WASTE AND PRODUCT[11]

8.  Cut – off grade ores
 Tailings from mineral products
 Residues
8
TYPES OF MINE WASTE[4][5]

9. 9
CLASSIFICATION OF MINERALS WASTES[4]

10. 10
WASTE CUT OFF GRADES[6]

11.  “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.
11
WHAT IS AMD[3]

12. 12
PROCESS[7]

13. 13
IMPACTS OF AMD

14. 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+
14
WHAT IS AMD[8]

15.  Aluminum
1. Gibbsite
2. Bohmite
3. Diaspore
15
MINE WASTE LEACHING[9]

16. RED MUD
16

17. 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
17
RED MUD[10]

18. 18
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 reduction
Disadvantage
• High Na contents in Red Mud:
sodium oxide deposition -.
• High drying cost of red mud
2) Pyro + Hydro
Pig 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

19. 19
RECOVERY OF IRON[10]

20. 20
RECOVERY OF TITANIUM OXIDE[10]

21. Sintering
Al2O3 + Na2CO3 = 2NaAlO2 + CO2(g)
Temperature of operation : 850-1100oC
Time : 2 hours
Leaching
NaAlO2(s) = NaAlO2(aq)
Temperature of operation : 25-100 oC
Time : 5-30 minutes, Red Mud to water :
2-50 gpl
21
SINTERING AND LEACHING OF ALUMINA[10]

22.  Copper
1. Sandy ore (granular)
2. Slimy ore (composed of very fine particles that are difficult to
settle)
3. Molybdenite
4. Rhenium
5. Cobalt
22
MINE WASTE LEACHING[9]

23. 23
SANDY ORE[9]

24. SLIMY ORE[9]
• Using sponge iron • Using hydrogen sulfide
24

25. 25
MOLYBDENITE & RHENIUM[9]

26. 26
COBALT[9]

27.  Platinum
1. Native platinum ores
2. Gold ores
3. Nonferrous metals sulfide ores
27
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

28. 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
28
REFERENCES

29. 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/
29
REFERENCES