Claims
- 1. A process for producing substantially pure aluminum from a raw kyanite ore, comprising, in sequence, the steps of:
- a. comminuting the raw kyanite ore into particles about minus 35 mesh in size, then beneficiating the ore particles via flotation to remove micas, pyrites and quartz sand, and then magnetically separating the iron containing minerals from the product to form a particulated kyanite concentrate;
- b. agglomerating the particulated kyanite concentrate into ore compactions of a predetermined size and shape;
- c. carbothermically reducing the ore compactions in an electric arc furnace to produce an aluminumsilicon alloy, slag and effluent fume, and recycling said slag and effluent fume to the agglomerating step;
- d. comminuting the aluminum-silicon alloy to a particle size of about minus 100 mesh;
- e. subjecting the particulated aluminum-silicon alloy to hydroalumination with propylene, hydrogen and a sodium catalyst to form tripropylaluminum and diporpylaluminum hydride and silicon residue; separating said aluminum alkyls and said silicon residue; heating said silicon residue in a furnace with calcium oxide, silicon dioxide and iron as needed to produce a ferrosilicon alloy of a desired ratio of silicon and iron and a quantity of slag; and separating the ferro-silicon alloy from the slag and casting it into a desired shape; and,
- f. pyrolyzing the mixture of tripropylaluminum and dipropylaluminum hydride in an inert diluent to produce substantially pure aluminum powder, propylene and hydrogen; recovering the propylene and hydrogen and transferring them to the hydroaluminating step.
- 2. The process of claim 1, including the additional step of:
- h. compacting the aluminum powder into a desired form, melting the aluminum powder compacts in the presence of a fluxing agent and casting the molten aluminum metal into a desired shape, thereby forming a substantially pure casting of aluminum metal.
- 3. The process of claim 1, wherein the silicon residue produced in step (e), the hydroalumination step, is heated to about 1600.degree.C.
- 4. The process of claim 1, wherein the slag produced from the ferro-silicon furnace is comminuted to a desired particle size and recycled to the agglomerating step (b) of claim 1.
- 5. The process of claim 1, wherein process waters from the flotation operation are recycled.
- 6. The process of claim 1, wherein the agglomerates are pillow shaped briquettes of a size of about two inches by two inches by 1 inch.
- 7. The process of claim 1, wherein the kyanite compactions are fed into the electric arc furnace with an amount of carbon of from about 90% to about 110% of the theoretical carbon necessary for effective reduction of the ore compactions.
- 8. The process of claim 1, wherein the carbon feed comprises coal, coke and wood.
- 9. The process of claim 1, wherein the fixed carbon content of the carbon feed is about 12% wood, 60% coal and 28% coke.
- 10. The process of claim 1, wherein the carbon feed is a mixture of coke and coal.
- 11. The process of claim 1, wherein the inert diluent is a hydrocarbon.
- 12. The process of claim 1, wherein the molten aluminumsilicon alloy produced in the electric arc furnace is periodically tapped therefrom and refined by holding it at a temperature of about 1100.degree.C-1200.degree.C under a flux comprising NaCl, KCl and cryolite.
- 13. The process of claim 1, wherein after step (c) and before step (d), the crude aluminum-silicon alloy is cleaned by holding it at a temperature of about 1100.degree.C to about 1200.degree.C under a flux.
- 14. The process of claim 1, wherein carbon is agglomerated with the particulated kyanite concentrate to form mixed compactions of kyanite and carbon.
- 15. The process of claim 1, wherein the agglomerates contain only kyanite concentrate and carbon is separately added to the electric arc furnace.
- 16. The process of claim 1, wherein the furnace feed is comprised of mixed compactions of carbon and kyanite, and additional quantities of carbon.
- 17. The process of claim 1, wherein the silicon dioxide is in the form of quartz and the calcium oxide is in the form of limestone.
- 18. The process of claim 1, wherein the iron is in the form of steel turnings.
- 19. The process of claim 1, including the additional step of:
- g. filtering, washing and drying the substantially pure aluminum powder thereby separating the inert diluent used in the pyrolyzing step from the aluminum powder and recycling said inert diluent to said pyrolyzing step.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 277,383, filed Aug. 2, 1972, now U.S. Pat. No. 3,860,415.
US Referenced Citations (8)
Continuation in Parts (1)
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Number |
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277383 |
Aug 1972 |
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