Patent US4011146A successfully refreshed from Google Patents.
US4011146A
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Process for separation and recovery of metal values from sulfide ore concentrates
Assignee: Cyprus Mines Corp
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Filing: 1975-11-13
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Granted: 1977-03-08
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Expires: 1995-11-13
Abstract
Abstract An improvement in conventional processes for recovering metal values from sulfide ores containing lead, zinc and silver sulfides in which process the metal sulfides are converted to chlorides by chlorination followed by solubilization of the chlorides with a sodium chloride leach and subsequent recovery of the metals from their chlorides in accordance with a conventional flow sheet including crystallization, cementation, precipitation, fused salt electrolysis, etc., with chlorine being recovered for reuse by electrolysis of the sodium chloride leach solution substantially depleted of lead, silver and zinc, the improvement being a pollution-free process which comprises: 1. recycling the sodium chloride solution depleted of a major percentage of lead and silver to the sodium chloride or brine leaching step; and 2. controlling the concentration of zinc and other impurities in the sodium chloride or brine leaching solution by bleeding a portion from the recycle stream of (1) above, removing lead, zinc and other metal impurities from the bleed stream, electrolyzing the bleed stream to produce chlorine, sodium hydroxide and a weak sodium chloride solution followed by recycle of the chlorine to the dry chlorination step and weak sodium chloride solution, after concentration, to the leach solution to control the concentration of zinc chloride and other impurities in the leach solution. A further improvement is the use of an alternate dry chlorination procedure for the sulfide ores and, particularly, ores such as the tetrahedrite-tennantite series which are more satisfactorily chloridized by dry chlorination than by wet chlorination. Another improvement is use of a flow sheet by which no impurities are removed from the process in the form of chlorides so that no chlorine is lost from the system.
Inventors
- 👤 Enzo L. Coltrinari
- 👤 James E. Reynolds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:21
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/04; C22B1/00; C22B1/02; C22B1/08; C22B13/00; C22B13/04; C22B19/00; C22B19/20; C22B3/00; C22B3/04; C22B3/06; C22B3/10; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
178 words
A process for recovering metals from a sulfide ore concentrate containing lead, silver and zinc sulfides comprising the steps of: a. chlorinating the concentrate to convert the metal sulfides to metal chlorides and convert the sulfide sulfur in the ore to elemental sulfur; b. leaching the residue of step (a) with aqueous sodium chloride to dissolve lead and silver chlorides and remove these chlorides from the remaining solids; c. cooling the sodium chloride leach solution to precipitate substantially all of the lead chloride followed by separating it from the leach solution; d. recovering the silver from the lead chloride depleted leach solution remaining from step (c); e. removing a bleed stream from the solution remaining from step (d) and recycling the remainder of the solution to the leach solution of step (b); f. removing substantially all of the zinc and other impurities from the bleed stream; g. subjecting the bleed stream to electrolysis to produce chlorine gas; h. recycling the purified bleed stream to leaching step (b); and i. recycling the chlorine gas to the chlorination step (a).
Claim 2
Dependent Claim
178 words
A process for recovering metals from a sulfide ore concentrate containing lead, silver and zinc sulfides comprising the steps of: a. chlorinating the concentrate to convert the metal sulfides to metal chlorides and convert the sulfide sulfur in the ore to elemental sulfur; b. leaching the residue of step (a) with aqueous sodium chloride to dissolve lead and silver chlorides and remove these chlorides from the remaining solids; c. cooling the sodium chloride leach solution to precipitate substantially all of the lead chloride followed by separating it from the leach solution; d. recovering the silver from the lead chloride depleted leach solution remaining from step (c); e. removing a bleed stream from the solution remaining from step (d) and recycling the remainder of the solution to the leach solution of step (b); f. removing substantially all of the zinc and other impurities from the bleed stream; g. subjecting the bleed stream to electrolysis to produce chlorine gas; h. recycling the purified bleed stream to leaching step (b); and i. recycling the chlorine gas to the chlorination step (a).
Claim 3
Dependent Claim
7 words
The process of claim 1 performed continuously.
Claim 4
Dependent Claim
31 words
The process of claim 1 in which any lead and silver remaining in the bleed stream of step (e) is removed by iron cementation before removal of zinc in step (f).
Claim 5
Dependent Claim
32 words
The process of claim 1 in which zinc is removed from the bleed stream of step (f) by neutralizing the bleed stream with sodium carbonate to form sodium chloride and zinc carbonate.
Claim 6
Dependent Claim
32 words
The process of claim 4 in which sodium hydroxide formed in the electrolysis of sodium chloride in step (g) is carbonated to form sodium carbonate which is recycled to the neutralization step.
Claim 7
Dependent Claim
21 words
The process of claim 1 in which the bleed stream of step (h) is concentrated before recycling to leaching step (b).
Claim 8
Dependent Claim
21 words
The process of claim 1 in which the concentrate is chlorinated in step (a) by dry chlorination with dry chlorine gas.
Claim 9
Dependent Claim
23 words
The process of claim 7 in which the dry chlorination is carried out at a temperature below the melting point of elemental sulfur.
Claim 10
Dependent Claim
20 words
The process of claim 7 in which the temperature of dry chlorination is from about 50° C to 150° C.
Claim 11
Dependent Claim
26 words
The process of claim 7 in which the sodium chloride leach solution contains from about 250 to 300 grams per liter of solution of sodium chloride.
Claim 12
Dependent Claim
12 words
The process of claim 7 in which the concentrate is galena/tetrahedrite ore.
Claim 13
Dependent Claim
21 words
The process of claim 1 in which the leaching step (b) is carried out at about 80° C to 100° C.
Claim 14
Dependent Claim
25 words
The process of claim 1 in which the sodium chloride leach solution in step (c) is cooled to about 20° C to precipitate lead chloride.
Claim 15
Dependent Claim
19 words
The process of claim 1 in which the silver is recovered in step (d) by cementation with metallic iron.
Claim 16
Dependent Claim
19 words
The process of claim 1 in which the concentrate is chlorinated in step (a) by a wet chlorination step.
Claim 17
Dependent Claim
317 words
A process for treating a galena/tetrahedrite ore concentrate including lead, silver, antimony and zinc sulfides comprising the steps of: a. dry chlorinating the pulverized concentrate with chlorine gas to convert the sulfides to chlorides, volatilize the antimony chloride, and convert the sulfide sulfur to elemental sulfur, said chlorination being carried out at a temperature of from about 50° C to 150° C; b. leaching at a temperature of about 80° C to 100° C, the residue from step (a) with an aqueous sodium chloride solution containing about 250 to 300 grams/liter of sodium chloride to dissolve lead chloride and silver chloride to extract these chlorides from the remaining solids; c. cooling the sodium chloride leach solution from step (b) to about 20° C to precipitate substantially all of the lead chloride and separating the lead chloride therefrom; d. fusing the lead chloride from step (c) and electrolyzing the fused salt to produce chlorine gas and lead; e. recycling the chlorine gas from step (d) to step (a); f. recovering the silver from the lead chloride depleted leach solution remaining from step (c) by cementation with metallic iron; g. removing from about 5% to 15% by weight of the silver and lead depleted leach solution from step (f) as a bleed stream and recycling the remainder of the solution to the leach solution of step (b); h. removing any lead and silver remaining in the bleed stream by iron cementation; i. precipitating zinc and other impurities from the bleed stream with sodium carbonate; j. regenerating chlorine gas from sodium chloride in the bleed solution by electrolysis; k. recycling the chlorine gas from step (j) to the dry chlorination step of step (a); l. carbonating the sodium hydroxide formed in step (j) to form sodium carbonate and recycling the sodium carbonate to precipitation step (i); and m. recycling sodium chloride solution from step (j) to the leaching step (b).
Claim 18
Dependent Claim
317 words
A process for treating a galena/tetrahedrite ore concentrate including lead, silver, antimony and zinc sulfides comprising the steps of: a. dry chlorinating the pulverized concentrate with chlorine gas to convert the sulfides to chlorides, volatilize the antimony chloride, and convert the sulfide sulfur to elemental sulfur, said chlorination being carried out at a temperature of from about 50° C to 150° C; b. leaching at a temperature of about 80° C to 100° C, the residue from step (a) with an aqueous sodium chloride solution containing about 250 to 300 grams/liter of sodium chloride to dissolve lead chloride and silver chloride to extract these chlorides from the remaining solids; c. cooling the sodium chloride leach solution from step (b) to about 20° C to precipitate substantially all of the lead chloride and separating the lead chloride therefrom; d. fusing the lead chloride from step (c) and electrolyzing the fused salt to produce chlorine gas and lead; e. recycling the chlorine gas from step (d) to step (a); f. recovering the silver from the lead chloride depleted leach solution remaining from step (c) by cementation with metallic iron; g. removing from about 5% to 15% by weight of the silver and lead depleted leach solution from step (f) as a bleed stream and recycling the remainder of the solution to the leach solution of step (b); h. removing any lead and silver remaining in the bleed stream by iron cementation; i. precipitating zinc and other impurities from the bleed stream with sodium carbonate; j. regenerating chlorine gas from sodium chloride in the bleed solution by electrolysis; k. recycling the chlorine gas from step (j) to the dry chlorination step of step (a); l. carbonating the sodium hydroxide formed in step (j) to form sodium carbonate and recycling the sodium carbonate to precipitation step (i); and m. recycling sodium chloride solution from step (j) to the leaching step (b).
Claim 19
Dependent Claim
22 words
The process of claim 16 in which the concentrate includes arsenic sulfide and the arsenic is volatilized in dry chlorination step (a).
Claim 20
Dependent Claim
124 words
In the process of recovering metals from sulfide ores containing at least the sulfides of lead, silver and zinc in which the sulfides are converted to elemental sulfur and chlorides by chlorination, the chlorides solubilized in sodium chloride, lead chloride removed from the leach solution by crystallization for recovery of lead, silver recovered from the leach solution by cementation, the leach solution after removal of lead and silver therefrom recycled to the sodium chloride leaching step, the improvement comprising preventing the build-up of zinc in the leach solution in the leaching step by removing a bleed stream from the lead and silver depleted leach solution, removing zinc from the bleed stream and recycling the bleed stream to the leaching solution in the leaching step.
Claim 21
Dependent Claim
124 words
In the process of recovering metals from sulfide ores containing at least the sulfides of lead, silver and zinc in which the sulfides are converted to elemental sulfur and chlorides by chlorination, the chlorides solubilized in sodium chloride, lead chloride removed from the leach solution by crystallization for recovery of lead, silver recovered from the leach solution by cementation, the leach solution after removal of lead and silver therefrom recycled to the sodium chloride leaching step, the improvement comprising preventing the build-up of zinc in the leach solution in the leaching step by removing a bleed stream from the lead and silver depleted leach solution, removing zinc from the bleed stream and recycling the bleed stream to the leaching solution in the leaching step.
Claim 22
Dependent Claim
31 words
The process of claim 18 including subjecting the bleed stream to electrolysis after removal of zinc therefrom to produce chlorine gas and recycling the chlorine gas to the dry chlorination step.
Claim 23
Dependent Claim
45 words
The process of claim 19 in which the zinc is removed by precipitating it as zinc carbonate by the addition of sodium carbonate, the sodium hydroxide produced in the electrolyis is carbonated to sodium carbonate and the sodium carbonate recycled to the zinc precipitation step.
Claim 24
Dependent Claim
77 words
The process of recovering metal values from minerals of the polymorphic series of complex metal sulfides tetrahedrite-tennantite comprising: a. subjecting the minerals to dry chlorination with chlorine gas in the absence of oxygen at a temperature between about 50° C and the melting point of sulfur to convert substantially all of the sulfide sulfur to elemental sulfur in solid form and to effect conversion of the metal compounds to metal chlorides, and recovering metal from the chlorides.
Claim 25
Dependent Claim
77 words
The process of recovering metal values from minerals of the polymorphic series of complex metal sulfides tetrahedrite-tennantite comprising: a. subjecting the minerals to dry chlorination with chlorine gas in the absence of oxygen at a temperature between about 50° C and the melting point of sulfur to convert substantially all of the sulfide sulfur to elemental sulfur in solid form and to effect conversion of the metal compounds to metal chlorides, and recovering metal from the chlorides.
Claim 26
Dependent Claim
23 words
The process of claim 21 in which chlorination is performed at a temperature between about 80° C and the melting point of sulfur.
Claim 27
Dependent Claim
11 words
The process of claim 21 in which the minerals contain silver.
Claim 28
Dependent Claim
13 words
The process of claim 23 in which the silver containing mineral is tetrahedrite.
Claim 29
Dependent Claim
26 words
The process of claim 21 in which sulfur chlorides formed during dry chlorination are reacted with the metal sulfides to form metal chlorides and elemental sulfur.
Claim 30
Dependent Claim
54 words
The process of claim 25 in which the process is performed by introducing the metal sulfides and dry chlorine gas countercurrently into the reaction zone and an inert sweep gas is introduced into the reaction zone to bring sulfur chlorides formed during the dry chlorination into contact with metal sulfides entering the reaction zone.
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) | 1980-03-07 | 1980-09-06 | 1981-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-07 | 1984-09-06 | 1985-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-07 | 1988-09-06 | 1989-03-08 | $7700.00 | Window Closed / Lapsed |