Particle Separation in Method for Recovering Magnetite from Bauxite Residue
AssigneeGmr, LLC
InventorMohsen Amiran
Life of this patent
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Abstract
A method of recovering magnetite from bauxite residue, comprising reducing the pH of the bauxite residue to form a treated bauxite residue, drying the treated bauxite residue, adding to and mixing into the treated bauxite residue a solid source of carbon, to create a mixture, heating the mixture to a reduction temperature of at least 800° C. in a reducing reactor to produce a reduced bauxite residue in which a major portion of Fe2O3 present in the treated bauxite residue has been converted to Fe3O4, exposing the reduced bauxite residue to a particle separation step, and then separating the reduced bauxite residue into an iron-enriched portion and an iron-depleted portion.
Claims15
A method of recovering magnetite from bauxite residue that has a pH, comprising:
- reducing the pH of the bauxite residue to form a treated bauxite residue;
- drying the treated bauxite residue;
- adding to and mixing into the treated bauxite residue a solid source of carbon, to create a mixture;
- heating the mixture to a reduction temperature of at least 800° C. in a reducing reactor to produce a reduced bauxite residue in which a major portion of Fe2O3 present in the treated bauxite residue has been converted to Fe3O4;
- exposing the reduced bauxite residue to a particle separation step;
- and then
- separating the reduced bauxite residue into an iron-enriched portion and an iron-depleted portion.
A method of recovering magnetite from bauxite residue that has a pH, comprising:
- reducing the pH of the bauxite residue to a pH in the range of 4-9, to form a treated bauxite residue;
- drying the treated bauxite residue to from 3% to 6% moisture by weight;
- adding to and mixing into the dried treated bauxite residue coke, to create a mixture, wherein the coke comprises from 30% to 60% by weight of the mixture;
- heating the mixture to a reduction temperature of from 800° C. to 1100° C. in a reducing reactor to produce a reduced bauxite residue in which a major portion of Fe2O3 present in the treated bauxite residue has been converted to Fe3O4;
- exposing the reduced bauxite residue to a particle separation step;
- and then
- magnetically separating the Fe3O4 from the reduced bauxite residue, to create an iron-enriched portion and an iron-depleted portion.
Dependencies are inferred from the claim text.