US4250027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for recovering the lead and zinc values in secondary scrubber muds from blast furnace gases
Assignee: Bpifrance Financement SA
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Filing: 1979-01-29
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Granted: 1981-02-10
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Expires: 1999-01-29
Abstract
Abstract The method consists of subjecting said muds to a particle size grading to concentrate the lead and zinc contained notably in the fines, and recovering said fraction containing the lead and the zinc, the other fraction being recyclable to the blast furnaces. The invention is useful in the preparation of feed materials for Waelz-Berzelius furnaces.
Inventors
- 👤 Jean M. Cases
- 👤 Georges Valence
- 👤 Olivier Lietard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:29
CPC Classifications
B; B03; B03B; B03B9/00; B03B9/04; C; C21; C21B; C21B3/00; C21B3/04; C21B5/00; C21B5/008; C22; C22B; C22B1/00; C22B1/005; C22B7/00; C22B7/02; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y02W; Y02W30/00; Y02W30/50; Y10; Y10S; Y10S75/00; Y10S75/961
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A process for recovering lead and zinc values from blast furnace scrubber mud which comprises: (a) separating from said mud a fraction having a particle size greater than about 10 to 50 μm; (b) scouring by attrition said fraction having a particle size greater than about 10 to 50 μm to separate lead and zinc values from said fraction; (c) separating the particles from steps (a) and (b) having a size less than about 10 to 50 μm for recovery of the lead and zinc values contained therein; and (d) recycling to the feed of the blast furnace the fractions from steps (a) and (b) having a particle size greater than about 10 to 50 μm.
Claim 2
Dependent Claim
116 words
A process for recovering lead and zinc values from blast furnace scrubber mud which comprises: (a) separating from said mud a fraction having a particle size greater than about 10 to 50 μm; (b) scouring by attrition said fraction having a particle size greater than about 10 to 50 μm to separate lead and zinc values from said fraction; (c) separating the particles from steps (a) and (b) having a size less than about 10 to 50 μm for recovery of the lead and zinc values contained therein; and (d) recycling to the feed of the blast furnace the fractions from steps (a) and (b) having a particle size greater than about 10 to 50 μm.
Claim 3
Dependent Claim
20 words
The process of claim 1, wherein the fraction separated in step (a) has a particle size greater than 50 μm.
Claim 4
Dependent Claim
20 words
The process of claim 1, wherein the scouring by attrition is carried out in the presence of a mineral charge.
Claim 5
Dependent Claim
11 words
The process of claim 3, wherein said mineral charge is sand.
Claim 6
Dependent Claim
31 words
The method of claim 3, wherein the sand has a particle size between about 210 and 350 μm, and the concentration of solids in the pulp is between 50 and 80%.
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) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |