Claims
- 1. A method of recovering precious metal from oxidic, refractory, or semi-refractory ore material containing said metal, said method comprising comminuting said ore material in a material bed comminuting zone under pressure sufficient to form particles from said ore material and to form cracks in at least some of said particles, each of said particles having a surface area, each of those particles having cracks therein having its surface area increased by the presence of such cracks; discharging comminuted particles from said comminuting zone; classifying the particles discharged from said comminuting zone into relatively coarse and relatively fine fractions; returning the relatively coarse fraction particles to said comminuting zone for further comminution; oxidizing the relatively fine fraction particles in an oxidizing zone if the ore material is refractory or semi-refractory; diverting the relatively fine fraction particles away from the oxidizing zone if the ore material is oxidic; delivering the relatively fine fraction comminuted particles to a mixing zone containing a leaching fluid capable of dissolving the precious metal, thereby forming in said mixing zone a mixture of said relatively fine fraction particles and said leaching fluid; agitating the mixture at said mixing zone with such intensity as to maintain at least the majority of said relatively fine fraction particles in suspension in said leaching fluid and separated from one another so that said leaching fluid contacts the entire surface area of at least said majority of said relatively fine fraction particles; leaching at least some of the precious metal from said relatively fine traction particles into said leaching fluid in said mixing zone; separating the relatively fine fraction particles from said mixture following leaching of precious metal from said relatively fine fraction particles into said leaching fluid; and extracting the leached metal from said leaching fluid.
- 2. The method according to claim 1 including subjecting said ore material to primary comminution prior to comminuting said ore material in said comminuting zone.
- 3. The method according to claim 1 including fine grinding the relatively fine fraction particles following comminuting said ore material in said comminuting zone and prior to delivering the relatively fine fraction particles to said mixing zone.
- 4. The method according to claim 3 wherein the fine grinding is performed in a mill.
- 5. The method according to claim 3 wherein the fine grinding is performed in a roller bed mill.
- 6. The method according to claim 3 wherein the fine grinding is performed in an agitator mill.
- 7. The method according to claim 3 wherein the fine grinding is performed in a drum mill.
- 8. The method according to claim 3 wherein the fine grinding is performed in a ball mill.
- 9. The method according to claim 1 including concentrating those relatively fine fraction particles containing precious metal downstream of said comminuting zone and upstream of said mixing zone so that the relatively fine fraction particles delivered to said mixing zone are those containing precious metal.
- 10. The method according to any one of the preceding claims wherein the comminuting of said ore material in said comminuting zone is performed in the absence of the addition of binding material.
- 11. The method according to any one of claims 1-9 wherein the pressure applied in said comminuting zone is greater than 50 MPa.
- 12. The method according to claim 1 including disagglomerating particles that may have agglomerated in said comminuting zone and prior to delivering the relatively fine fraction particles to said mixing zone, classifying the disagglomerated particles into relatively coarse and relatively fine proportions, and returning the relatively coarse proportion to said comminuting zone for further comminution.
- 13. The method according to claim 1 including separating agglomerations of comminuted particles from other comminuted particles discharged from said comminuting zone and returning said agglomerations directly to said comminuting zone for further comminution.
- 14. A method of recovering precious metal from oxidic, refractory, or semi-refractory ore material containing said metal, said method comprising comminuting said ore material in a material bed comminuting zone under pressure sufficient to form particles from said ore material and to form cracks in at least some of said particles, each of said particles having a surface area, each of those particles having cracks therein having its surface area increased by the presence of such cracks; discharging comminuted particles from said comminuting zone; classifying in a classifying zone at least a portion of the particles discharged from said comminuting zone into relatively coarse and relatively fine fractions; returning the relatively coarse fraction particles to said comminuting zone for further comminution; oxidizing the relatively fine fraction particles in an oxidizing zone if the ore material is refractory or semi-refractory; diverting the relatively fine fraction particles away from the oxidizing zone if the ore material is oxidic; delivering the relatively fine fraction comminuted particles to a mixing zone containing a leaching fluid capable of dissolving the precious metal, thereby forming in said mixing zone a mixture of said relatively fine fraction particles and said leaching fluid; agitating the mixture at said mixing zone with such intensity as to maintain at least the majority of said relatively fine fraction particles in suspension in said leaching fluid and separated from one another so that said leaching fluid contacts the entire surface area of at least said majority of said relatively fine fraction particles; leaching at least some of the precious metal from said relatively fine fraction particles into said leaching fluid in said mixing zone; separating the relatively fine fraction particles from said mixture following leaching of precious metal from said relatively fine fraction particles into said leaching fluid; and extracting the leached metal from said leaching fluid.
- 15. The method according to claim 14 including returning the relatively coarse fraction particles following classifying of the particles discharged from said comminuting zone directly from said classifying zone to said comminuting zone.
Priority Claims (1)
Number |
Date |
Country |
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44 00 796 |
Jan 1994 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 08/366,496 filed on Dec. 30, 1994, now abandoned.
US Referenced Citations (13)
Continuations (1)
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Number |
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Parent |
366496 |
Dec 1994 |
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