US3709681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the recovery noble metals
Assignee: ATE ENTERPRISES Inc
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Filing: 1970-01-08
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Granted: 1973-01-09
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Expires: 1990-01-08
Abstract
Abstract Processes for and compositions utilized in the recovery of noble metals from noble metal containing substances by subjecting such substances- preferably in comminuted form- to the action of a solvent preferably comprising diacetone alcohol as a major component, water, minor amounts of glacial acetic acid potassium iodide and elemental iodine. Solvation of the noble metal occurs during agitation and heating of the slurry. The noble metal contents are removed from the noble metal pregnant solution by displacement onto a non-noble metal surface. The solid noble metal containing residue is treated with sufficient aqueous hydroxide solution to convert excess non-noble metal into its water-soluble salt. The remaining insoluble material containing the noble metal recovered is rinsed to remove any remaining unreacted alkali and the soluble salts and is then digested with concentrated sulfuric acid to dissolve any remaining acid soluble impurities, the remaining acid insoluble residue is rinsed, dried and comprises substantially pure noble metal.
Inventors
- 👤 H Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:30
CPC Classifications
C; C22; C22B; C22B3/00; C22B3/04; C22B3/16; C01; C01G; C01G5/00; C01G5/003; C01G55/00; C01G55/001; C01G7/00; C01G7/003; C22B11/00; C22B11/06; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
26 words
The process of claim 1 wherein the solvent additionally contains at least about 50 percent by weight acetic acid, based on the weight of said salt.
Claim 2
Dependent Claim
22 words
The process of claim 2 wherein the solvent contains about 0.3 percent acetic acid, based on the weight of the solvent composition.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the ketonic solvent is selected from the group consisting of diacetone alcohol, mesityl oxide and admixtures thereof.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein said solubilizing step includes agitating said halogen-containing ketonic solvent.
Claim 5
Dependent Claim
34 words
The process of claim 1 wherein said solvent contains iodine in an amount at least sufficient to react all the reactable metals in the system, and further wherein said salt is an iodide salt.
Claim 6
Dependent Claim
14 words
The process of claim 6 wherein said salt is an alkali metal iodide salt.
Claim 7
Dependent Claim
22 words
The process of claim 6 wherein said salt is selected from the group consisting of potassium iodide, ferrous iodide and aluminum iodide.
Claim 8
Dependent Claim
88 words
The process according to claim 1 wherein the noble metal content of said noble metal-pregnant solution is recovered by: a. placing a quantity of non-noble metal selected from the group consisting of silver, copper, iron, zinc and aluminum into said noble-metal pregnant solution, b. heating said solution for a time and at a temperature sufficient so that the noble metal becomes substantially displaced from the solution, and c. removing the solvent freed of its noble metal contents from the noble metal, leaving a solid noble metal containing residue.
Claim 9
Dependent Claim
22 words
A process for recovering the noble metal contents from a noble metal-pregnant solution comprising a solvent selected from the group consisting of:
Claim 10
Dependent Claim
21 words
The process of claim 10 wherein the non-noble metal employed for displacement of the noble metal is aluminum in sheet form.
Claim 11
Dependent Claim
39 words
The process of claim 10 wherein the solvent which has been freed of its contents of noble metal is thereafter fortified with elemental iodine and is adapted to be re-used for solvation of noble metals from substances containing same.
Claim 12
Dependent Claim
174 words
The process of claim 10 wherein the said solid noble metal containing residue after being separated from the solvent is thereafter sequentially subjected to the following steps: a. washing free of any remaining noble metal pregnant solution with a portion of iodine-free ketone solvent, b. heating to about 80* to 100* C. to volatilize residual ketone and cause sublimation of any occluded elemental iodine, c. treating with an aqueous sodium hydroxide solution containing 5-20% NaOH and heating to boiling to convert the non-noble metal residue into its soluble salt thereby leaving an insoluble noble metal residue, and rinsing to remove the dissolved non-noble metal salts and unreacted alkali from the remaining solid noble metal containing residue, d. digesting the noble metal containing residue with concentrated sulfuric acid to effect removal of any residual alkaline matter and to dissolve any remaining base metals displaced together with the noble metals, and e. rinsing the insoluble solid residue with water to remove sulfate salts drying the said solid residue, leaving a residue of essentially pure noble metal.
Claim 13
Dependent Claim
19 words
The process of claim 10 wherein the heating in step b is carried out at about 120* to 140*F.
Claim 14
Dependent Claim
49 words
A process for sEparating and recovering noble metals from a solid substance containing said noble metals comprising: a. finely dividing the solid noble metal-containing substance, b. admixing with the finely divided noble metal containing-substance a composition consisting essentially of (1) a ketonic solvent selected from the group consisting of:
Claim 15
Dependent Claim
150 words
A process for separating a noble metal from a substance containing said noble metal comprising: a. finely dividing the noble metal-containing substance, b. solubilizing said noble metal by intimately admixing said finely divided substance with a ketonic solvent containing (1) dissolved elemental halogen selected from the group consisting of iodine, bromine, chlorine or admixtures thereof, the amount of dissolved elemental halogen being at least about 0.003 percent by weight but not more than 120 percent of the amount stoichiometrically necessary to react all the reactable metals in the system, (2) at least about 0.01 percent by weight dissolved salt, the cation of said salt being a non-noble metal and the anion of said salt being selected from the group consisting of iodine, chlorine and bromine, and (3) more than trace amounts, but not more than 15 percent by weight, water, said ketonic solvent being selected from the group consisting of:
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |