Patent US4543122A successfully refreshed from Google Patents.
US4543122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnesium production
Assignee: JCI Ltd
•
Filing: 1984-10-03
•
Granted: 1985-09-24
•
Expires: 2004-10-03
Abstract
Abstract Magnesium is recovered from a slag produced in a pyrometallurgical process and which contains magnesium oxide and other oxides. The slag is delivered, preferably in a hot state, to a reduction stage where the magnesium oxide is reduced and the magnesium vaporized. The reductant includes an alkaline earth metal in non-oxidic form, preferably calcium carbide. The vaporized magnesium is delivered to a condenser where it is condensed directly from the vapor state to a powder form.
Inventors
- 👤 Johannes J. Bodenstein
- 👤 Leslie J. Farrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:54
CPC Classifications
C; C22; C22B; C22B26/00; C22B26/20; C22B26/22; C22B7/00; C22B7/04; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
A method of recovering magnesium values from a material containing oxides of magnesium, chromium, aluminum, silicon, iron, and calcium, including the steps of delivering said material and reductant to a reduction stage, said reductant including an alkaline earth metal carbide, heating said material and reductant in said reduction stage in an inert atmosphere to reduce the magnesium oxide and produce vaporized magnesium, feeding vaporized magnesium to a condenser and converting the vaporized magnesium directly to a powder form in said condenser.
Claim 2
Independent Claim
81 words
A method of recovering magnesium values from a material containing oxides of magnesium, chromium, aluminum, silicon, iron, and calcium, including the steps of delivering said material and reductant to a reduction stage, said reductant including an alkaline earth metal carbide, heating said material and reductant in said reduction stage in an inert atmosphere to reduce the magnesium oxide and produce vaporized magnesium, feeding vaporized magnesium to a condenser and converting the vaporized magnesium directly to a powder form in said condenser.
Claim 3
Dependent Claim
12 words
A method of claim 1 wherein the alkaline earth metal is calcium.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein said magnesium powder produced has a particle size of between 50 and 200 microns.
Claim 5
Dependent Claim
12 words
A method according to claim 1 wherein the inert gas is argon.
Claim 6
Dependent Claim
33 words
A method according to claim 1, wherein said reductant includes an agent selected from the group consisting of silicon, ferrosilicon, aluminum and an aluminum/silicon alloy in addition to said alkaline earth metal carbide.
Claim 7
Dependent Claim
13 words
A method of claim 1 wherein the reductant is calcium carbide and silicon.
Claim 8
Dependent Claim
39 words
A method according to claim 1 wherein the material is a slag material having the following composition: ______________________________________
Quantity
Oxide (% by weight)
______________________________________
Cr.sub.2 O 3-8
FeO <2
CaO 12-17
Al.sub.2 O.sub.3
29-33
MgO 22-25
SiO.sub.2 19-25
______________________________________
Claim 9
Dependent Claim
38 words
A method of claim 1 wherein the material is a slag material having the following composition: ______________________________________
Quantity
Oxide (% by weight)
______________________________________
Cr.sub.2 O 0,3-0,4
FeO 20-25
CaO 8-15
Al.sub.2 O.sub.3
4-6
MgO 16-20
SiO.sub.2 35-45
______________________________________
Claim 10
Dependent Claim
18 words
A method of claim 1 wherein the material is delivered to the reduction step in a hot state.
Claim 11
Dependent Claim
21 words
A method of claim 9 wherein the material delivered to the reduction step has a temperature in excess of 1300° C.
Claim 12
Dependent Claim
16 words
A method of claim 1 wherein the material is enriched by the addition of magnesite thereto.
Claim 13
Dependent Claim
12 words
A method of claim 11 wherein the magnesite is a calcined magnesite.
References Cited (Backward Citations)
US4190434A
Cited
EP0065225A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |