CA1237283A - Method for recovering precious metals from precious metal-bearing materials such as ore and tailings - Google Patents
Method for recovering precious metals from precious metal-bearing materials such as ore and tailingsInfo
- Publication number
- CA1237283A CA1237283A CA000475772A CA475772A CA1237283A CA 1237283 A CA1237283 A CA 1237283A CA 000475772 A CA000475772 A CA 000475772A CA 475772 A CA475772 A CA 475772A CA 1237283 A CA1237283 A CA 1237283A
- Authority
- CA
- Canada
- Prior art keywords
- solution
- particulate
- gold
- recovering
- solids
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/04—Obtaining noble metals by wet processes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/08—Obtaining noble metals by cyaniding
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/10—Obtaining noble metals by amalgamating
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/006—Wet processes
- C22B7/008—Wet processes by an alkaline or ammoniacal leaching
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
METHOD FOR RECOVERING PRECIOUS METALS
FROM PRECIOUS METAL-BEARING MATERIALS
SUCH AS ORE AND TAILINGS
by JAMES J. RUSS
and JOHN W. SMITH
ABSTRACT OF THE DISCLOSURE
A method for recovering precious metals such as gold and silver from precious metal-bearing materials that include other solids comprises treating the precious metal-bearing materials with an aqueous, basic solution having a pH in the range of about 12 to about 14 for a time sufficient to suspend the precious metals in substantially free form in the solution, followed by recovery of precious metals from solids and from the solution by known methods.
FROM PRECIOUS METAL-BEARING MATERIALS
SUCH AS ORE AND TAILINGS
by JAMES J. RUSS
and JOHN W. SMITH
ABSTRACT OF THE DISCLOSURE
A method for recovering precious metals such as gold and silver from precious metal-bearing materials that include other solids comprises treating the precious metal-bearing materials with an aqueous, basic solution having a pH in the range of about 12 to about 14 for a time sufficient to suspend the precious metals in substantially free form in the solution, followed by recovery of precious metals from solids and from the solution by known methods.
Description
~ Z~37~33 SPECIFICATION
This invention relates to a method $or recovering such precious metals as gold, silver, palladium, platinum and rhodium from precious metal-bearing mixtures such as silver-containing and gold-containing ores and tailings.
Heretofore, methods for recovering precious metals from precious metal-bearing mixtures such as silver-containing and gold-containing ores commo~ly included the steps of crushing the ore, washin~ or frothing the cru~hed ore to eliminate clays and ~ther contaminants, and then solubilizing the ore in an agueous lo cyanide solution, an aqueous thiourea solution, an aqueous ammonium thiosulfate solution or aqua regia. Thereafter, these ~olu-bilized, precious metal-bearing solutions are treated for recovery of the precious metals by such techniques as carbon absorption, carbon-in-pulp absorption/desorption, amalgamation, ion exchange, electrowinning or precipitation. All of these methods depend upon availability of the precious metals in substantially free form in solution, for only the substantially free metals will be solubilized by such methods.
Despite the development of highly sophisticated crushing and milling techniques, much of the precious metals such as gold and silver in gold-bearing and silver-bearing ores fail to become sufficiently freed to be susceptible to solubilization.
As a result, from 20~ to 40% of the gold and silver in such ores escapes solubilization and goes unrecovered. Still other quantities of very fine precious metals, such as gold and silver, called flour gold and flour silver, are so fine that they escape solubilization and are discarded with the so-called waste which is also termed tailings.
~3~7~83 This invention provides a process for recovering a higher percentage by weight of precious metals such as gold, silver, platinum, palladium and rhodium from precious metal bearing materials, such as raw ores, crushed ores and tailings that have previously undergone trea~ment for precious metal removal with a thiourea or cyanide solution among others.
The new process can also enhance recovery of each precious metal if two or more are present.
In the first step of the new process, the precious o metal-bearing materials are treated with an aqueous basic solution having a pH in the range of about 12 to about 14 for a time sufficient to suspend the precious metal from the materials in substantially free form in the solution. The basic solution preferably contains an alkali metal or alkaline earth metal hydroxide, most preferably sodium hydroxide, and preferably has a concentration in the range of about 1~% to about 15% by volume. The treatment preferably continues for a time in the range of about 20 minutes to about 40 minutes, depending upon the particle size, and the nature of the precious metal-bearing materials. These materials may be silicates, carbonates, sulfides, or some combination of two or more of these types. The temperature of the so1ution during the treatment is preferably in the range of about 60C to about 90 C, depending upon the particle size, and the nature of the precious metal-bearing materials.
After treatment with an aqueous basic solution, the suspended precious metals are separated from the aqueous solution by a conventional method such as carbon absorption, carbon-in-pulp absorption/desorption, amalgamation, ion exchange, electrowinning or precipitation. The remaining solids are ~;~3~ 83 treated, separately, for recovery of additional precious metals with an aqueous cyanide solution, ~n aqueous thiourea solution, an aqueous ammonium thiosulfate solution, or aqua regia.
The process of this invention not only increases the percentage by weight of precious metals such as gold and silver recovered from precious metal-bearing materials of many different kinds, but also reduces greatly the time required to achieve this result. For ex~nple, our two-step o process requires as little as 40 to 80 minutes to effect gold or silver recovery. By contrast, conventional proces~es require several hours, or even days to complete~
The following examples demonstrate that the process of this invention effectively, even drama~ically, increases substantially the quantity of gold recovered from a given quantity of gold-bearing materials such as gold bearing oxes and gold-bearing tailings.
EX~MPLES
We obtained gold-bearing tailings that had been discarded as so-called waste from the treatment of crushed, gold-bearing ores by the conventional cyanide or amalgamation methods. We analyzed the gold-bearing tailings before treatment according to this invention, and found ~hat the tailings contained about 0.16 ounce to about 0.31 ounce of gold per ton.
We drew two separate samples of tailings from different parts of the same accumulation of so-called waste, and divided the first of these samples, called tailings No. 1, into three parts. We treated the first sample of tailings No. 1 with a 10% aqueous sodium hydroxide solution at a ~'~3~ 3 temperature of 90DC for a time of 20 minutes and recovered .0006~ by weight of gold, as determined by atomic absorption spectrophotometer.
We treated the second part of tailings No. l by the conventional cyanide leaching process, and obtained .D002% by weight of gold from this sample. Againl we used the atomic absorption spectrophotometer to make the measurement. The time required ior this conventional process exceeded 40 hours.
We treated the third part of tailings No. 1 by the o process o~ this invention. That is, we pretreated the third sample with a 10% a~ueous sodium hydroxide bath for a period of 20 minutes, then treated the solids with an agueous cyanide leaching solution, and obtained a total of 0.0008~ by weight of gold. Total time elapsed for the two steps was about 80 minutes.
We treated the sample designated tailings No. 2 in the same way and obtained 0.0009% by weight of gold. As can be seen, the process of this invention increased the percentage of gold recovered from a given sample weight of gold-bearing tailings by a factor of up to 3, and reduced the time to completion by a factor of 20 or more.
We also obtained gold bearing and silver-bearing concentrates from a domestic mine. The concentrates included about 0.5 ounce of gold per ton and about 20 ounces of silver per ton.
In similar fashion, we treated the li~uid samples designated concentrate No. l and concentrate No. 2 by the same pretreatment and leaching s~eps, and obtained the results set forth in Table l below. Again/ as with th~ tailings, the method ~L~3~7~33 of this invention more than doubled the quantity of gold recovered over the prior art technique t and reduced the time reyuired for completion from 30-40 hours to 1-2 hours.
In these examples, we measured the quantity of gold recovered using atomic absorption methods employing a Perkin-Elmer digital corlputer against a Bureau of Mines standard employing a gold lamp. To confirm the validity of the data, we conducted mass spectrographic analyses of the concentxates, and found that the gold content of the concentrates was .48 to .52 o troy ounce per ton for a good correlation to O . 5 ou~ce of gold per ton.
Significantly, the data from these examples prove that a substantial quantity of gold was freed in the basic pretreatment step, permitting 60~ to 80% of the available gold to be recovered in the pretreatment step itself.
TABLE I
Wei~ht Percent Sample Pretreat Leach Pretreat and Leach Concentrate No. 1 .0017 .0008 .0025 Concentrate No. 2 .0016 .0006 .0022
This invention relates to a method $or recovering such precious metals as gold, silver, palladium, platinum and rhodium from precious metal-bearing mixtures such as silver-containing and gold-containing ores and tailings.
Heretofore, methods for recovering precious metals from precious metal-bearing mixtures such as silver-containing and gold-containing ores commo~ly included the steps of crushing the ore, washin~ or frothing the cru~hed ore to eliminate clays and ~ther contaminants, and then solubilizing the ore in an agueous lo cyanide solution, an aqueous thiourea solution, an aqueous ammonium thiosulfate solution or aqua regia. Thereafter, these ~olu-bilized, precious metal-bearing solutions are treated for recovery of the precious metals by such techniques as carbon absorption, carbon-in-pulp absorption/desorption, amalgamation, ion exchange, electrowinning or precipitation. All of these methods depend upon availability of the precious metals in substantially free form in solution, for only the substantially free metals will be solubilized by such methods.
Despite the development of highly sophisticated crushing and milling techniques, much of the precious metals such as gold and silver in gold-bearing and silver-bearing ores fail to become sufficiently freed to be susceptible to solubilization.
As a result, from 20~ to 40% of the gold and silver in such ores escapes solubilization and goes unrecovered. Still other quantities of very fine precious metals, such as gold and silver, called flour gold and flour silver, are so fine that they escape solubilization and are discarded with the so-called waste which is also termed tailings.
~3~7~83 This invention provides a process for recovering a higher percentage by weight of precious metals such as gold, silver, platinum, palladium and rhodium from precious metal bearing materials, such as raw ores, crushed ores and tailings that have previously undergone trea~ment for precious metal removal with a thiourea or cyanide solution among others.
The new process can also enhance recovery of each precious metal if two or more are present.
In the first step of the new process, the precious o metal-bearing materials are treated with an aqueous basic solution having a pH in the range of about 12 to about 14 for a time sufficient to suspend the precious metal from the materials in substantially free form in the solution. The basic solution preferably contains an alkali metal or alkaline earth metal hydroxide, most preferably sodium hydroxide, and preferably has a concentration in the range of about 1~% to about 15% by volume. The treatment preferably continues for a time in the range of about 20 minutes to about 40 minutes, depending upon the particle size, and the nature of the precious metal-bearing materials. These materials may be silicates, carbonates, sulfides, or some combination of two or more of these types. The temperature of the so1ution during the treatment is preferably in the range of about 60C to about 90 C, depending upon the particle size, and the nature of the precious metal-bearing materials.
After treatment with an aqueous basic solution, the suspended precious metals are separated from the aqueous solution by a conventional method such as carbon absorption, carbon-in-pulp absorption/desorption, amalgamation, ion exchange, electrowinning or precipitation. The remaining solids are ~;~3~ 83 treated, separately, for recovery of additional precious metals with an aqueous cyanide solution, ~n aqueous thiourea solution, an aqueous ammonium thiosulfate solution, or aqua regia.
The process of this invention not only increases the percentage by weight of precious metals such as gold and silver recovered from precious metal-bearing materials of many different kinds, but also reduces greatly the time required to achieve this result. For ex~nple, our two-step o process requires as little as 40 to 80 minutes to effect gold or silver recovery. By contrast, conventional proces~es require several hours, or even days to complete~
The following examples demonstrate that the process of this invention effectively, even drama~ically, increases substantially the quantity of gold recovered from a given quantity of gold-bearing materials such as gold bearing oxes and gold-bearing tailings.
EX~MPLES
We obtained gold-bearing tailings that had been discarded as so-called waste from the treatment of crushed, gold-bearing ores by the conventional cyanide or amalgamation methods. We analyzed the gold-bearing tailings before treatment according to this invention, and found ~hat the tailings contained about 0.16 ounce to about 0.31 ounce of gold per ton.
We drew two separate samples of tailings from different parts of the same accumulation of so-called waste, and divided the first of these samples, called tailings No. 1, into three parts. We treated the first sample of tailings No. 1 with a 10% aqueous sodium hydroxide solution at a ~'~3~ 3 temperature of 90DC for a time of 20 minutes and recovered .0006~ by weight of gold, as determined by atomic absorption spectrophotometer.
We treated the second part of tailings No. l by the conventional cyanide leaching process, and obtained .D002% by weight of gold from this sample. Againl we used the atomic absorption spectrophotometer to make the measurement. The time required ior this conventional process exceeded 40 hours.
We treated the third part of tailings No. 1 by the o process o~ this invention. That is, we pretreated the third sample with a 10% a~ueous sodium hydroxide bath for a period of 20 minutes, then treated the solids with an agueous cyanide leaching solution, and obtained a total of 0.0008~ by weight of gold. Total time elapsed for the two steps was about 80 minutes.
We treated the sample designated tailings No. 2 in the same way and obtained 0.0009% by weight of gold. As can be seen, the process of this invention increased the percentage of gold recovered from a given sample weight of gold-bearing tailings by a factor of up to 3, and reduced the time to completion by a factor of 20 or more.
We also obtained gold bearing and silver-bearing concentrates from a domestic mine. The concentrates included about 0.5 ounce of gold per ton and about 20 ounces of silver per ton.
In similar fashion, we treated the li~uid samples designated concentrate No. l and concentrate No. 2 by the same pretreatment and leaching s~eps, and obtained the results set forth in Table l below. Again/ as with th~ tailings, the method ~L~3~7~33 of this invention more than doubled the quantity of gold recovered over the prior art technique t and reduced the time reyuired for completion from 30-40 hours to 1-2 hours.
In these examples, we measured the quantity of gold recovered using atomic absorption methods employing a Perkin-Elmer digital corlputer against a Bureau of Mines standard employing a gold lamp. To confirm the validity of the data, we conducted mass spectrographic analyses of the concentxates, and found that the gold content of the concentrates was .48 to .52 o troy ounce per ton for a good correlation to O . 5 ou~ce of gold per ton.
Significantly, the data from these examples prove that a substantial quantity of gold was freed in the basic pretreatment step, permitting 60~ to 80% of the available gold to be recovered in the pretreatment step itself.
TABLE I
Wei~ht Percent Sample Pretreat Leach Pretreat and Leach Concentrate No. 1 .0017 .0008 .0025 Concentrate No. 2 .0016 .0006 .0022
Claims (15)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for recovering at least one precious metal from a mixture including said at least one precious metal comprising treating a mixture including at least one precious metal and other solids with a substantially cyanide ion-free aqueous basic solution having a pH in the range of about 12 to about 14 for a time sufficient to suspend said at least one precious metal in substantially free form in said solution, said time being at least about 20 minutes; separating the unsuspended, undissolved solids from said solution; and recovering said at least one suspended precious metal from the aqueous basic solution.
2. The method of claim 1 wherein said mixture includes flour gold and other inorganic solids.
3. The method of claim 1 wherein said mixture includes flour gold and other inorganic solids, and said flour gold constitutes about 20% to about 40% by weight of said mixture.
4. The method of claim 1 wherein said mixture includes particulate gold or silver and other particulate inorganic solids and wherein said mixture has been pretreated for removal of gold or silver with an aqueous thiourea solution, an aqueous cyanide solution, an ammonium thiosulfate solution, aqua regia, or by amalgamation.
5. The method of claim 4 wherein an aqueous cyanide solution is used for the pretreatment.
6. The method of claim 4 wherein an aqueous thiourea solution is used for said pretreatment.
7. The method of claim 1 wherein said aqueous basic solution includes sodium hydroxide in a concentration range of about 1.0% to about 15% by volume.
8. The method of claim 1 wherein said time is in the range of about 20 minutes to about 40 minutes.
9. The method of claim 1 wherein said aqueous basic solution is an aqueous sodium hydroxide solution.
10. The method of claim 1 further comprising recovering said precious metals from the separated solids.
11. The method of claim 10 further comprising recovering said precious metal from said separated solids by treatment with a thiourea solution, a cyanide solution, an ammonium thiosulfate solution, or aqua regia.
12. A method for recovering a precious metal from a mixture including said precious metal comprising treating a mixture including at least one of particulate gold, particulate silver, particulate platinum and particulate palladium and other particulate inorganic solids with a substantially cyanide ion-free aqueous basic solution having a pH in the range of about 12 to about 14 for a time of at least about 20 minutes to suspend said at least one of particulate gold, particulate silver, particulate platinum and particulate palladium in said solution; separating the unsuspended, undissolved solids from said solution; and recovering the suspended, said at least one of particulate gold, particulate silver, particulate platinum and particulate palladium from the aqueous basic solution.
13. The method of claim 12 further comprising recovering said at least one of particulate gold, particulate silver, particulate platinum and particulate palladium from the separated solids.
14. A method for recovering flour gold from a mixture including said flour gold comprising treating a mixture including flour gold in combination with other inorganic solids with a substantially cyanide ion-free aqueous basic solution having a pH
in the range of about 12 to about 14 for a time of at least about 20 minutes to suspend said flour gold in said solution, separating the undissolved unsuspended solids from said solution and recovering said suspended flour gold from said solution, substantially free of particulate, inorganic solids.
in the range of about 12 to about 14 for a time of at least about 20 minutes to suspend said flour gold in said solution, separating the undissolved unsuspended solids from said solution and recovering said suspended flour gold from said solution, substantially free of particulate, inorganic solids.
15. The method of claim 14 further comprising recovering said flour gold from the separated solids.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/588,093 US4592779A (en) | 1984-03-09 | 1984-03-09 | Method for recovering precious metals from precious metal-bearing materials such as ore and tailings |
| US588,093 | 1984-03-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1237283A true CA1237283A (en) | 1988-05-31 |
Family
ID=24352467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000475772A Expired CA1237283A (en) | 1984-03-09 | 1985-03-05 | Method for recovering precious metals from precious metal-bearing materials such as ore and tailings |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4592779A (en) |
| CA (1) | CA1237283A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5342449A (en) * | 1990-12-11 | 1994-08-30 | Holbein Bruce E | Process for the decontamination of toxic, heavy-metal containing soils |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4979987A (en) | 1988-07-19 | 1990-12-25 | First Miss Gold, Inc. | Precious metals recovery from refractory carbonate ores |
| US5256187A (en) * | 1992-11-12 | 1993-10-26 | Sherex Chemical Company, Inc. | Separation of precious metals by an ion exchange process |
| US5942098A (en) * | 1996-04-12 | 1999-08-24 | Technologies Unlimited, Inc. | Method of treatment of water and method and composition for recovery of precious metal |
| US6406675B1 (en) | 2000-09-13 | 2002-06-18 | Hercules Incorporated | Method for reducing cyanide consumption during processing of gold and silver ores to remove base metals |
| AU2002213147A1 (en) * | 2000-10-16 | 2002-04-29 | Xenolix Technologies, Inc. | Basic treatment of ores for the recovery of metals therefrom |
| TW200624151A (en) * | 2004-11-12 | 2006-07-16 | Monsanto Technology Llc | Recovery of noble metals from aqueous process streams |
| US7604783B2 (en) | 2004-12-22 | 2009-10-20 | Placer Dome Technical Services Limited | Reduction of lime consumption when treating refractor gold ores or concentrates |
| US8061888B2 (en) | 2006-03-17 | 2011-11-22 | Barrick Gold Corporation | Autoclave with underflow dividers |
| US8252254B2 (en) | 2006-06-15 | 2012-08-28 | Barrick Gold Corporation | Process for reduced alkali consumption in the recovery of silver |
| RU2579858C1 (en) * | 2014-11-20 | 2016-04-10 | Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский технологический университет "МИСиС" | Method of extracting gold from ores |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3443933A (en) * | 1964-06-11 | 1969-05-13 | Leesona Corp | Method of preparing metal blacks |
| US3238038A (en) * | 1964-08-07 | 1966-03-01 | Zareba Corp Ltd | Precious metal recovery |
| US3969244A (en) * | 1970-06-09 | 1976-07-13 | Hokuetsu Carbon Industry Co., Ltd | Method of adsorbing heavy metals |
| US3920789A (en) * | 1972-08-10 | 1975-11-18 | Swarsab Mining | Separation of pgm's from each other and from gold |
| US3856507A (en) * | 1973-03-12 | 1974-12-24 | Owens Illinois Inc | Recovery of gold from solution in aqua regia |
| DE2329352C2 (en) * | 1973-06-08 | 1982-05-19 | Demetron Gesellschaft für Elektronik-Werkstoffe mbH, 6540 Hanau | Process for the production of gold powder |
| NL7414149A (en) * | 1974-10-29 | 1976-05-04 | Leuven Res & Dev Vzw | PROCEDURE FOR RECOVERING SILVER FROM SOLUTIONS. |
| US4039327A (en) * | 1976-08-02 | 1977-08-02 | American Chemical & Refining Company Inc. | Stepwise process for recovering precious metals from solution |
| BE847441A (en) * | 1976-10-19 | 1977-02-14 | PROCESS FOR RECOVERING PRECIOUS METALS FROM CONTAINER MATERIALS. | |
| GB1594361A (en) * | 1977-03-04 | 1981-07-30 | Foster Wheeler Ltd | Extraction of gold and silver |
| US4131455A (en) * | 1977-12-09 | 1978-12-26 | Gaf Corporation | Silver recovery |
| US4319923A (en) * | 1979-12-26 | 1982-03-16 | Western Electric Co., Inc. | Recovery of gold and/or palladium from an iodide-iodine etching solution |
| JPS5693836A (en) * | 1979-12-27 | 1981-07-29 | Asaka Riken Kogyo Kk | Gold recovering method |
| US4369061A (en) * | 1979-12-28 | 1983-01-18 | Kerley Jr Bernard J | Recovery of precious metals from difficult ores |
| US4421724A (en) * | 1981-09-08 | 1983-12-20 | Anglo Mineral Resources, Inc. | Extraction method for refractory precious metal ore |
| US4540435A (en) * | 1983-08-26 | 1985-09-10 | University Of Utah | Solvent extraction of gold and silver anions under alkaline conditions |
-
1984
- 1984-03-09 US US06/588,093 patent/US4592779A/en not_active Expired - Fee Related
-
1985
- 1985-03-05 CA CA000475772A patent/CA1237283A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5342449A (en) * | 1990-12-11 | 1994-08-30 | Holbein Bruce E | Process for the decontamination of toxic, heavy-metal containing soils |
Also Published As
| Publication number | Publication date |
|---|---|
| US4592779A (en) | 1986-06-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5215575A (en) | Recovery of gold, silver and platinum group metals with various leachants at low pulp densities | |
| US7985277B2 (en) | Process for extracting gold from gold-bearing ore | |
| US4070182A (en) | Recovery of precious metals from metal sulphides | |
| US4738718A (en) | Method for the recovery of gold using autoclaving | |
| US5536480A (en) | Method for treating mineral material having organic carbon to facilitate recovery of gold and silver | |
| CA1237283A (en) | Method for recovering precious metals from precious metal-bearing materials such as ore and tailings | |
| RU96102036A (en) | HYDROMETALLURGICAL PROCESS FOR RESTORING THE CONTENT OF PRECIOUS METALS FROM PRECIOUS METALS BY THIOSULPHATE LEACHING | |
| CA1107077A (en) | Extraction of gold and silver | |
| US5401296A (en) | Precious metal extraction process | |
| US4439235A (en) | Chlorination process for removing precious metals from ore | |
| CA1090584A (en) | Aluminum containing precipitating agent for precious metals and method for its use | |
| US4421724A (en) | Extraction method for refractory precious metal ore | |
| US5034055A (en) | Process for the enhanced production of silver from gold and silver bearing ore | |
| CA1213150A (en) | Recovery of precious metals | |
| US20030154822A1 (en) | Recovery of precious metals | |
| Kongolo et al. | The extractive metallurgy of gold | |
| WO2001042519A1 (en) | Recovery of precious metals | |
| CA1236308A (en) | Process for hydrometallurgical extraction of precious metals | |
| US5320720A (en) | Extraction of precious metals from ores thereof | |
| Yen et al. | Hypochlorite leaching of gold ore | |
| Faye et al. | New Fire Assay Method for Rhodium in Ores and Concentrates. | |
| Espiell et al. | Gold and silver recovery by cyanidation of arsenopyrite ore | |
| RU2754726C1 (en) | Method for recovering gold from refractory ores | |
| CA1321077C (en) | Process for the recovery of silver from zinc plant calcines and neutral or low acid leach residues with thiourea | |
| US1539120A (en) | Treatment of ores |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |