US3663207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct process for smelting of lead sulphide concentrates to lead
Assignee: Noranda Inc
•
Filing: 1970-04-21
•
Granted: 1972-05-16
•
Expires: 1990-04-21
Abstract
Abstract A process for continuously smelting and converting lead sulphide concentrates to molten lead or bullion in a furnace comprises introducing pelletized lead sulphide concentrate onto the surface of a molten bath in the furnace and smelting the same therein, introducing oxidizing gas into the furnace to convert the lead sulphide concentrates to molten lead, tapping off molten metallic lead, treating the slag in a slag fuming zone to reduce zinc oxide in the slag to zinc vapor, introducing an oxidizing gas above the slag in the slag fuming zone to oxidize the zinc vapor to zinc oxide fume, passing the fume to a fume collecting area and thereafter withdrawing substantially zinc free slag.
Inventors
- 👤 Nickolas J Themelis
- 👤 John R Rawling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:29
CPC Classifications
C; C22; C22B; C22B13/00; C22B13/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
32 words
A process as claimed in claim 1 including the step of supplying to the charging end of the furnace auxiliary heat sufficient to make up the heat balance of the smelting process.
Claim 2
Dependent Claim
25 words
A process as claimed in claim 2 including the step of introducing silica flux into the furnace with the lead sulfide concentrates to be smelted.
Claim 3
Dependent Claim
40 words
A process as claimed in claim 3 in which the flux is ground to an average particle size below 10 mesh (ASTM Standard Sieve) and is then incorporated in the pelletized concentrate prior to the introduction thereof into the furnace.
Claim 4
Dependent Claim
24 words
A process as claimed in claim 3 wherein the pelletized concentrate is separately mixed with the silica flux prior to feeding into the furnace.
Claim 5
Dependent Claim
18 words
A process as claimed in claim 1 wherein the pelletized concentrate is fed into the furnace while wet.
Claim 6
Dependent Claim
60 words
A process as claimed in claim 1 wherein the concentrates are fed into the furnace in such a manner that substantially the entire area of the molten bath in the smelting zone is covered with the uniformly thin layer of pellets, the feeding of the pellets being so controlled as to prevent the pellets from forming masses of unsmelted material.
Claim 7
Dependent Claim
34 words
A process as claimed in claim 1 including the step of supplyIng to the slag tapping end of the furnace auxiliary heat sufficient to make up the heat balance of the slag fuming process.
Claim 8
Dependent Claim
14 words
A process as claimed in claim 1 wherein said reductant is a reducing gas.
Claim 9
Dependent Claim
13 words
A process as claimed in claim 1 wherein said reductant is pulverized coal.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |