1. A process for the selective removal of a least a portion of at least one precious metal in the form of a precious metal-cyanide complex from an ion-exchange resin to which the precious metal and at least one base metalcyanide complex are bound, wherein the at least one precious metal is eluted from the resin by contacting the resin with an eluent comprising at least one counter-ion contained in a solvent selected from an organic solvent or a combination of an organic solvent and an aqueous solvent.
2. A process according to claim 1, wherein the one precious metal is selected from the group consisting of gold, silver, platinum, palladium and a combination of two of more thereof.
3. A process according to claim 1, wherein the at least one base metal is selected from the group consisting of copper, zinc, iron, lead, tin and a combination of two of more of thereof.
4. A process according to claim 1, wherein the counter-ion is selective for stripping gold over copper.
5. A process according to claim 4, wherein the counter-ion is selected from the group consisting of CN, OH, HSO3, HSO4, SCN and Cl.
6. A process according to claim 1, wherein the counter-ion is in the form of an alkali metal salt.
7. A process according to any claim 1, wherein the organic solvent is a single organic solvent or a mixture of two or more organic solvents.
8. A process according to claim 1, wherein the organic solvent is a single solvent of sufficient polarity for the at least counter-ion to form therein.
9. A process according to claim 1, wherein the organic solvent is a mixture of two or more organic solvents.
10. A process according to claim 1, wherein the solvent is a combination of an organic solvent and an aqueous solvent.
11. A process according to claim 1, wherein the organic solvent is a polar organic solvent that is soluble in water.
12. A process according to claim 1, wherein the organic solvent is a compound including the group:
2
wherein:
X is selected from C, S or P;
Y is selected from C, N or 0;
the dotted line ( – – – ) from X represents at least one chemical bond; and
the dotted line ( – – – ) from Y represents at least one chemical bond; or
the dotted lines from X and Y form part of an optionally substituted carbocyclic ring optionally interrupted by one or more heterocyclic atoms.
13. A process according to claim 1, wherein the organic solvent is selected from one or more of the group consisting of a ketone, an organic amine, an organic nitrile, an organic phosphate, a heterocyclic solvent, an alkoxy alkane, sulfur-containing organic solvent, an organic carbonate, and an alcohol.
14. A process according to claim 13, wherein the solvent is selected from one or more of the group consisting of acetone, methyl ethyl ketone, ethylamine, ethylenediamine, triethylamine, formamide, diethylformamide, dimethylformamide, dimethylacetamide, diethylacetamide), dimethylsulfoxide, acetonitrile, triethylphosphate, trimethylphosphate, tributylphosphate, N-methyl-2-pyrrolidone, tetrahydrofuran dioxane, pyridine, dioxolane), dimethoxyethane, propylene carbonate, methanol and ethanol.
15. A process according to claim 1, wherein the solvent is selected from a ketone or an amide.
16. A method according to claim 1, wherein the solvent is a combination of an organic solvent and an aqueous solvent.
17. A process according to claim 1, wherein the aqueous solvent comprises water.
18. A process according to claim 16, wherein the solvent comprises the organic solvent in an amount of at least about 50 vol %.
19. A process according to claim 16, wherein the solvent comprises the organic solvent in amount of at least 60 vol %.
20. A process according to claim 16, wherein the organic solvent content is present in an amount of about 60 to 95 vol % of the eluent composition.
21. A process according to claim 1, wherein the counter-ion is present in the solvent at a concentration of up to about 1 M.
22. A process according to claim 1, wherein the counter-ion is present in a concentration of 0.2M or less.
23. A process according to claim 1, wherein the resin is an ion-exchange resin.
24. A process according to claim 1, wherein the resin is an anion-exchange resin.
25. A process according to claim 24, wherein the ion-exchange resin is of the strong base anion type.
26. A process according to claim 25, wherein the ion-exchange resin has quaternary amine functionality.
27. A process according to claim 1, wherein the resin has a macroporous resin bead structure.
28. A process according to claim 27, wherein the resin is based on polystyrene and polyurethane.
29. A process according to claim 1, wherein the precious metal is gold and optionally one or more other precious metal(s).
30. A process according to claim 1, further including the step of removing the at least one base metal-cyanide complex from the resin.
31. A process according to claim 30, wherein base metal-cyanide complex(es) present on the resin isare eluted by contacting the resin with a separate aqueous solvent containing a counter-ion that results in the elution of base metal-cyanide complex(es).
32. A process according to claim 31, wherein the base metal(s) isare removed by elution with an aqueous solvent containing a counter-ion.
33. A process according to claim 32, wherein the counter-ion is selected from the group consisting of CN, OH, HSO3, HSO4, SCN and Cl.
34. A process according to claim 1, wherein the precious metal is recovered from the eluant.
35. A process according to claim 34, wherein the precious metal is recovered by a precipitation of the precious metal.
36. A process according to claim 35, wherein the precious metal is precipitated by evaporation andor cooling the eluant until saturation temperature of the eluant is reached.
37. A process according to claim 36, wherein the precious metal is precipitated by compressed gas precipitation (CGP).
38. A process for the selective recovery of at least one precious metal in the form of a precious-cyanide complex from a mixture or composition containing at least one base metal, comprising;
(a) cyaniding the mixture or composition to produce a treated stream comprising a cyanide complex(es) of the at least one precious metal and the at least one base metal;
(b) contacting at least part of the treated stream with an ion-exchange resin to adsorb at least part of the cyanide complex(es);
(c) selectively eluting at least part of the at least one precious metal-cyanide complex from the resin of step (b) using an eluant comprising a counter-ion in a solvent selected from an organic solvent or an organic solvent and an aqueous solvent;
(d) optionally removing at least part of the at least one basic metal-cyanide complex from the resin of step (c); and
(e) optionally recovering the at least one precious metal from the eluted precious metal-cyanide complex.
39. A process according to claim 38, wherein the mixture or composition comprises one or more other precious metals.
40. A process according to claim 38, wherein the mixture or composition is in liquid form.
41. A process according to claim 40, wherein the composition is a rinse solution.
42. A process according to claim 45, wherein the rinse solution is recovered from waste material.
43. A process according to claim 42, wherein the rinse solution results from the production of electrical or electronic component(s) or plating or depositing of precious metals onto substrate(s).
44. A process according to claim 38, wherein the mixture or composition is a precious metal-containing catalysts.
45. A process according to claim 1, when used for the selective stripping of adsorbed gold cyanide over a base metal complex(es).
46. A process according to claim 45, wherein the base metal complex is a copper or zinc cyanide complex.
47. A process according to claim 1, when used for the recovery of gold from a gold bearing ore body or tailing.
48. A process according to claim 1, when used in resin-in-pulp (RIP) or resin-in-column (RIC) operations for the separation of gold and other basemetals from a leach solution.
49. A process according to claim 38, when used to recover a precious metal from a copper containing gold bearing ore.
50. A process according to claim 49, wherein the copper is present in the ore in the form of one or more of azurite (CU3(CO3)2(OH)2), malachite (Cu2CO3(OH)2), cuprite (CuO2), tenorite (CO2), chalcocite (Cu2S), covellite (CuS), bornite (CuFe5S4), chrysocalla (Cu2H2Si2O5(OH)4) and chalcopyrite (CuFeS2).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A heater comprising:
a first heating unit comprising a substrate and a resistive heating element embedded in the substrate, the substrate having a heating surface for supporting a workpiece, a back surface, and a center area, the first heating unit generating a first temperature profile prior to operation of the heater; and
a second heating unit external to the substrate and disposed proximate the back surface and the center area of the substrate,
wherein prior to operation of the heater, the second heating unit is designed based on the first temperature profile of the first heating unit such that the second heating unit is designed to compensate for heat loss before operating the heater.
2. The heater according to claim 1, further comprising a shaft disposed proximate the back surface of the substrate, the shaft defining an inner space for receiving the second heating unit inside the shaft.
3. The heater according to claim 2, further comprising lead wires for electrically connecting at least one of the first and second heating units to a power supply and wherein the lead wires are received in the inner space of the shaft.
4. The heater according to claim 2, wherein the shaft defines a material comprising a ceramic material selected from the group consisting of aluminum nitride (AlN), silicon nitride (Si3N4), alumina (Al2O3).
5. The heater according to claim 2, wherein the shaft is joined to the substrate by active alloy brazing.
6. The heater according to claim 2, wherein the shaft is joined to the substrate by direct bonding between the substrate and the shaft at high temperature through a diffusion process.
7. The heater according to claim 1, wherein the second heating unit contacts the back surface of the substrate.
8. The heater according to claim 7, wherein the second heating unit is bonded to the back surface of the substrate by brazing, glass bonding or mechanical attachment.
9. The heater according to claim 1, wherein the second heating unit defines a ring shape.
10. The heater according to claim 1, further comprising a first power supply electrically connected to the first heating unit and a second power supply electrically connected to the second heating unit.
11. The heater according to claim 1, wherein the first heating unit is manufactured by hot pressing.
12. The heater according to claim 1, wherein the second heating unit comprises a resistive heating element embedded in a substrate.
13. The heater according to claim 12, wherein the resistive heating element of the second heating unit defines a composition comprising molybdenum (Mo) and aluminum nitride (AlN).
14. The heater according to claim 1, wherein the substrate defines a material comprising aluminum nitride (AlN).
15. The heater according to claim 1, wherein the resistive heating element defines a composition comprising molybdenum (Mo) and aluminum nitride (AlN).
16. A heater for wafer processing comprising:
a first heating unit comprising a substrate and a resistive heating element embedded in the substrate, the substrate having a top surface, a back surface, and a center area, the first heating unit generating a first temperature profile prior to operation of the heater;
a shaft disposed proximate the back surface and the center area of the substrate, the shaft defining an inner space; and
a second heating unit external to the substrate and disposed proximate the back surface of the substrate and within the inner space of the shaft,
wherein prior to operation of the heater, the second heating unit is designed based on the first temperature profile of the first heating unit such that the second heating unit is designed to compensate for heat loss before operating the heater.
17. The heater according to claim 16, wherein the substrate and the shaft define a material comprising aluminum nitride (AlN).
18. The heater according to claim 16, wherein the second heating unit comprises a resistive heating element embedded in a substrate.
19. The heater according to claim 18, wherein the resistive heating elements define a composition comprising molybdenum (Mo) and aluminum nitride (AlN).
20. A method of operating a heater for wafer processing, the method comprising the steps of:
providing a first heating unit comprising a substrate and a first resistive heating element embedded in the substrate, the substrate having a top surface, a back surface, and a center area, the first resistive heating element generating a first temperature profile on the top surface prior to operation of the heater;
providing a second heating unit external to the substrate and proximate the back surface and the center area of the substrate, the second heating element generating a second temperature profile on the top surface of the substrate prior to operation of the heater;
measuring a combined temperature profile on the top surface of the substrate prior to operation of the heater, the combined temperature profile defined by a combination of the first temperature profile and the second temperature profile; and
adjusting the second temperature profile to achieve a predetermined combined temperature profile on the top surface prior to operation of the heater.
21. The method according to claim 20, wherein the predetermined combined temperature profile is a uniform temperature profile.
22. The method according to claim 20, wherein the predetermined combined temperature profile is a non-uniform temperature profile.
23. The method according to claim 20, further comprising the step of determining an actual temperature profile on the top surface of the first heating unit and the step of designing the second heating unit based on the actual temperature profile of the first heating unit.
24. The method according to claim 20, wherein the second heating unit is disposed within a shaft proximate the back surface of the substrate.
25. The method according to claim 24, wherein the second heating unit provides additional heat to compensate for heat loss associated with the shaft.
26. A method of manufacturing a heater for wafer processing, the method comprising the steps of:
forming a first heating unit by hot pressing, the first heating unit defining a resistive heating element embedded in a substrate;
forming a second heating unit by hot pressing, the second heating unit defining a resistive heating element embedded in a substrate;
forming a shaft by sintering; and
bonding the shaft and the second heating unit to a back surface of the first heating unit, the second heating unit being disposed within the shaft.
27. The method according to claim 26, wherein the shaft is bonded to the first heating unit by a process selected from the group consisting of a brazing process and a diffusion process.
28. The method according to claim 26, wherein the second heating unit is bonded to the first heating unit by a brazing process.
29. The method according to claim 26, wherein the resistive heating elements define a composition comprising molybdenum (Mo) and aluminum nitride (AlN).
30. The method according to claim 26, wherein the substrates of the first and second heating element and the shaft define a material comprising aluminum nitride (AlN).