US3709680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removal of arsenic from sulfo-ore
Assignee: Sunshine Mining Co
•
Filing: 1971-07-09
•
Granted: 1973-01-09
•
Expires: 1991-07-09
Abstract
Abstract A process and apparatus for the removal of arsenic values from an ore concentrate includes the steps of leaching the concentrate with a solution which dissolves the arsenic, separating undissolved residue therefrom, acidifying the arsenic pregnant solution to precipitate arsenic and other mineral values as insoluble salts and treating the arsenic barren solution to regenerate sulfur and sodium values for recycle to the process.
Inventors
- 👤 W Holmes
- 👤 E Coltrinari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:27
CPC Classifications
C; C22; C22B; C22B3/00; C22B3/04; C22B3/06; C22B3/08; C22B30/00; C22B30/04; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
15 words
A process according to claim 1 wherein said leaching solution is a hot caustic solution.
Claim 2
Dependent Claim
30 words
A process according to claim 1 wherein said leaching solution is a hot solution of sodium sulfide containing from about 100 to about 600 grams per liter of sodium sulfide.
Claim 3
Dependent Claim
35 words
A process according to claim 3 wherein said leaching solution is at a temperature of from about 75* to about 105*C and said leaching is carried out for from about 4 to about 12 hours.
Claim 4
Dependent Claim
13 words
A process according to claim 1 wherein said acidifying gas is sulfur dioxide.
Claim 5
Dependent Claim
36 words
A process according to claim 5 wherein said pH is reduced to about 9 to about 11, any precipitated residue filtered off and recovered and thereafter the pH further reduced to about 2 to about 6.
Claim 6
Dependent Claim
22 words
A process according to claim 1 wherein said precipitated salts are roasted to a temperature of from about 150* to about 600*C.
Claim 7
Dependent Claim
38 words
A process according to claim 1 wherein said solid residue is roasted to a temperature of from about 850* to about 1,200* C for from about 3 to about 6 hours in the presence of a reducing agent.
Claim 8
Dependent Claim
13 words
A process according to claim 8 wherein said reducing agent is pulverized coal.
Claim 9
Dependent Claim
216 words
A process for the removal of arsenic from ore concentrates containing the same which comprises the steps of leaching said ore concentrate with a solution containing from about 100 to about 600 grams per liter of sodium sulfide at a temperature of from about 100* to about 105* C to form an arsenic pregnant solution and an insoluble residue; separating said arsenic pregnant solution from said residue; treating said arsenic pregnant solution with sulfur dioxide gas to reduce thE pH to about 9 to about 11 to precipitate gold compounds therefrom; separating the precipitated gold compounds; further reducing the pH of the solution with sulfur dioxide gas to about 3-4 to precipitate arsenic compounds and to form an arsenic barren solution; separating and discarding said arsenic compounds; evaporating said arsenic barren solution to crystallize salts therefrom; roasting said crystallized salts in the presence of oxygen at a temperature of from about 400* to about 500* C to form a recycle dioxide and a solid residue; recycling said sulfur dioxide to the process; furnacing said solid residue at a temperature of from about 850* to 1,200* C in the presence of carbon to recover solid sodium sulfide therefrom; dissolving solid sodium sulfide in water to form a solution thereof; and recycling sodium sulfide solution to the process.
References Cited (Backward Citations)
GB189922619A
Cited
US683325A
Cited
US726294A
Cited
US2835569A
Cited
US3218161A
Cited
US3476553A
Cited
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 |