US3849121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zinc oxide recovery process
Assignee: Individual
•
Filing: 1971-11-30
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Granted: 1974-11-19
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Expires: 1991-11-30
Abstract
Abstract Method for the selective recovery from a number of industrial waste material of various components, including zinc, copper, lead and iron, comprising the steps of leaching the waste material with an ammonium chloride solution maintained at an elevated temperature, separating the undissolved iron component from solution, treating the solution with zinc metal to displace the copper and lead from the solution, and cooling the solution to precipitate therefrom the zinc component as zinc oxide.
Inventors
- 👤 W Burrows
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:23
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/02; C22B3/00; C22B3/04; C22B3/12; C22B3/14; C22B3/20; C22B3/44; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A METHOD FOR THE SELECTIVE RECOVERY OF VARIOUS COMPONENTS FROM ELECTRIC FURNACE FLUE DUST WHICH CONTAINS THE OXIDES OF ZINC, IRON, LEAD AND COPPER, COMPRISING THE STEPS OF: A. TREATING SAID FLUE DUST WITH AN AMMONIUM CHLORIDE SOLUTION MAINTAINED AT AN ELEVATED TEMPERATURE TO FORM A SOLUTION COMPRISING ZINC CHLORIDE SALT, A COPPERAMMONIUM COMPLEX, AND LEAD CHLORIDE SALT; B. SEPARATING SAID SOLUTION FROM THE UNDISSOLVED IRON OXIDE; C. ADDING ZINC METAL TO SAID SOLUTION WHEREBY THE COPPER AND LEAD IONS ARE DISPLACED BY SAID ZINC AND PRECIPITATE OUT OF SAID SOLUTION AS COPPER AND LEAD METALS; AND, D. LOWERING THE TEMPERATURE OF SAID SOLUTION WHEREBY THE ZINC COMPONENT IS PRECIPITATED THEREFROM AS ZINC OXIDE.
Claim 2
Independent Claim
114 words
A METHOD FOR THE SELECTIVE RECOVERY OF VARIOUS COMPONENTS FROM ELECTRIC FURNACE FLUE DUST WHICH CONTAINS THE OXIDES OF ZINC, IRON, LEAD AND COPPER, COMPRISING THE STEPS OF: A. TREATING SAID FLUE DUST WITH AN AMMONIUM CHLORIDE SOLUTION MAINTAINED AT AN ELEVATED TEMPERATURE TO FORM A SOLUTION COMPRISING ZINC CHLORIDE SALT, A COPPERAMMONIUM COMPLEX, AND LEAD CHLORIDE SALT; B. SEPARATING SAID SOLUTION FROM THE UNDISSOLVED IRON OXIDE; C. ADDING ZINC METAL TO SAID SOLUTION WHEREBY THE COPPER AND LEAD IONS ARE DISPLACED BY SAID ZINC AND PRECIPITATE OUT OF SAID SOLUTION AS COPPER AND LEAD METALS; AND, D. LOWERING THE TEMPERATURE OF SAID SOLUTION WHEREBY THE ZINC COMPONENT IS PRECIPITATED THEREFROM AS ZINC OXIDE.
Claim 3
Dependent Claim
21 words
A method as described in claim 1 wherein said elevated temperature of said ammonium chloride solution ranges from 90*C to 102*C.
Claim 4
Dependent Claim
20 words
A method as described in claim 1 wherein the concentration of said ammonium chloride solution is 30 percent by weight.
Claim 5
Dependent Claim
15 words
A method as described in claim 1 wherein saId zinc metal is in powdered form.
Claim 6
Dependent Claim
25 words
A method as described in claim 1 wherein the temperature of said solution is lowered to at least 20*C to precipitate the zinc component therefrom.
Claim 7
Dependent Claim
28 words
A method as described in claim 1 further including the step of recycling said solution after said zinc oxide is precipated therefrom to be employed in step (a).
Claim 8
Independent Claim
124 words
A method for the selective recovery of various components from electric furnace flue dust which contains the oxides of zinc, iron, lead and copper, comprising the steps of: a. treating said flue dust with an approximately 30 percent solution by weight of ammonium chloride maintained at a temperature ranging from 90*C to 102*C to form a solution comprising zinc chloride salt, a copper-ammonium complex, and lead chloride salt; b. separating said solution from the undissolved iron oxide; c. adding zinc metal to said solution whereby the copper and lead ions are displaced by said zinc and precipitate out of said solution as copper and lead metals; and, d. lowering the temperature of said solution whereby the zinc component is precipitated therefrom as zinc oxide.
Claim 9
Independent Claim
124 words
A method for the selective recovery of various components from electric furnace flue dust which contains the oxides of zinc, iron, lead and copper, comprising the steps of: a. treating said flue dust with an approximately 30 percent solution by weight of ammonium chloride maintained at a temperature ranging from 90*C to 102*C to form a solution comprising zinc chloride salt, a copper-ammonium complex, and lead chloride salt; b. separating said solution from the undissolved iron oxide; c. adding zinc metal to said solution whereby the copper and lead ions are displaced by said zinc and precipitate out of said solution as copper and lead metals; and, d. lowering the temperature of said solution whereby the zinc component is precipitated therefrom as zinc oxide.
Claim 10
Dependent Claim
15 words
A method as described in claim 7 wherein said zinc metal is in powdered form.
Claim 11
Dependent Claim
25 words
A method as described in claim 7 wherein the temperature of said solution is lowered to at least 20*C to precipitate the zinc component therefrom.
Claim 12
Dependent Claim
28 words
A method as described in claim 7 further including the step of recycling said solution after said zinc oxide is precipated therefrom to be employed in step (a).
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) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |