Patent US4054442A successfully refreshed from Google Patents.
US4054442A
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US
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Method for recovering scheelite from tungsten ores by flotation
Assignee: US TUNGSTEN Corp A CORP OF
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Filing: 1976-02-23
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Granted: 1977-10-18
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Expires: 1996-02-23
Abstract
Abstract A flotation process for recovering scheelite from low-grade tungsten ores containing calcium-bearing minerals other than scheelite. Calcium oxide (lime) is added to an ore pulp together with a carbonate alkalizing agent, dispersant and anionic collector. The pulp is subsequently subjected to flotation and the scheelite recovered.
Inventors
- 👤 Ronald Vedova
- 👤 Norman LeRoy Grauerholz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:10
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/02; B03D1/06; B03D1/001; B03D1/002; B03D1/004; B03D1/008; B03D2201/00; B03D2201/005; B03D2201/02; B03D2203/00; B03D2203/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
155 words
In a flotation process for recovering scheelite by the flotation thereof from an aqueous pulp of low-grade tungsten ore containing calcium bearing minerals in addition to scheelite said process involving the addition to the aqueous ore pulp of a carbonate alkalizing agent and a dispersant followed by an anionic collector, the improvement which comprises adding to the ore pulp, prior to the addition of the anionic collector and the dispersant, if added as a silicate dispersant, an amount of calcium oxide sufficient to raise the pH of the aqueous media of the pulp by 0.1 pH unit and form a precipitate of calcium upon conditioning the pulp by agitation sufficient to suspend substantially all of the solids in the pulp in the aqueous pulp media, said conditioning being for at least about five minutes and the pH of the ore pulp, prior to the addition of anionic collector being in the range of about 9-12.
Claim 2
Dependent Claim
155 words
In a flotation process for recovering scheelite by the flotation thereof from an aqueous pulp of low-grade tungsten ore containing calcium bearing minerals in addition to scheelite said process involving the addition to the aqueous ore pulp of a carbonate alkalizing agent and a dispersant followed by an anionic collector, the improvement which comprises adding to the ore pulp, prior to the addition of the anionic collector and the dispersant, if added as a silicate dispersant, an amount of calcium oxide sufficient to raise the pH of the aqueous media of the pulp by 0.1 pH unit and form a precipitate of calcium upon conditioning the pulp by agitation sufficient to suspend substantially all of the solids in the pulp in the aqueous pulp media, said conditioning being for at least about five minutes and the pH of the ore pulp, prior to the addition of anionic collector being in the range of about 9-12.
Claim 3
Dependent Claim
21 words
A method in accordance with claim 1 wherein the calcium oxide addition is from about 0.1 to 4 pounds per ton.
Claim 4
Dependent Claim
28 words
A method in accordance with claim 1 wherein the pH of the ore pulp prior to the addition of the anionic collector is from about 9.5 to 10.5.
Claim 5
Dependent Claim
24 words
A method in accordance with claim 1 wherein the anionic collector is naphthenic acid and oleic acid in a weight ratio about about 1:1.
Claim 6
Dependent Claim
29 words
A method in accordance with claim 1 wherein the calcium oxide addition is in a form selected from the group consisting of solutions, aqueous slurries and finely divided solids.
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) | 1980-10-17 | 1981-04-18 | 1981-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-17 | 1985-04-18 | 1985-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-17 | 1989-04-18 | 1989-10-18 | $7700.00 | Window Closed / Lapsed |