US4404022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dore slag treatment
Assignee: Noranda Inc
•
Filing: 1981-12-28
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Granted: 1983-09-13
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Expires: 2001-12-28
Abstract
Abstract A method is disclosed for treating dore slag resulting from smelting of a dore furnace charge, by grinding such slag and then subjecting the obtained pulp to froth flotation in the presence of a suitable frother and collector to produce a precious metals concentrate which is then filtered and returned to the dore furnace with the next charge. The tails from the froth flotation may then be finely ground and subjected to several additional flotation stages to improve recovery of the precious metals, and the entire operation is preferably carried out as a closed loop process so that only the tailings from the rougher flotation are removed and shipped to the smelter.
Inventors
- 👤 Peter W. Godbehere
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:34
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/04; B; B03; B03B; B03B9/00; B03B9/04; B03D; B03D1/00; B03D1/001; B03D1/004; B03D1/008; B03D1/014; B03D1/02; C22B11/00; C22B11/02; C22B11/021; C22B11/023; B03D1/08; B03D1/085; B03D2201/00; B03D2201/02; B03D2201/04; B03D2203/00; B03D2203/02; B03D2203/025; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
71 words
A method of treating dore slag which comprises the steps of grinding the slag, mixing the obtained pulp with water to form a slurry, adding a suitable collector to the slurry for selective flotation of precious metals, adding a suitable frother, aerating the slurry to produce a precious metals concentrate in the form of a froth on top of the slurry, and separating said concentrate from the remainder of the slurry.
Claim 2
Independent Claim
71 words
A method of treating dore slag which comprises the steps of grinding the slag, mixing the obtained pulp with water to form a slurry, adding a suitable collector to the slurry for selective flotation of precious metals, adding a suitable frother, aerating the slurry to produce a precious metals concentrate in the form of a froth on top of the slurry, and separating said concentrate from the remainder of the slurry.
Claim 3
Dependent Claim
36 words
Method according to claim 1, further comprising regrinding the tails from said selective flotation and subjecting them to a rougher flotation stage and at least one cleaner flotation stage to improve recovery of the precious metals.
Claim 4
Dependent Claim
14 words
Method according to claim 1, in which the grinding is effected by semi-autogenous grinding.
Claim 5
Dependent Claim
21 words
Method according to claim 1, in which the grinding proceeds until about 80% of the pulp passes a 100 mesh screen.
Claim 6
Dependent Claim
13 words
Method according to claim 1, in which the collector is sodium di-isobutyl dithiophosphate.
Claim 7
Dependent Claim
13 words
Method according to claim 1, in which the frother is methyl iso-butyl carbinol.
Claim 8
Dependent Claim
20 words
Method according to claim 1, in which the resulting concentrate is returned to the dore furnace with a new charge.
Claim 9
Dependent Claim
25 words
Method according to claim 2, in which the regrinding of the tails proceeds until about 95% of the resulting pulp passes a 325 mesh screen.
Claim 10
Dependent Claim
12 words
Method according to claim 2, in which two cleaner flotations are performed.
Claim 11
Dependent Claim
26 words
Method according to claim 2, which is carried out as a closed loop operation so that only the tailings from the rougher flotation are removed therefrom.
Claim 12
Dependent Claim
31 words
Method according to claim 1 wherein said dore slag is obtained from the dore furnace by skimming off the slag formed therein into pots and allowing said pots to air cool.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |