Process for treating ferruginous aluminum-bearing ores

Claim 2

METHOD OF RECOVERING IRON AND ALUMINUM VALUES FROM A FERRUGINOUS ALUMINUM-BEARING ORE CONTAINING LESS THAN ABOUT 3% IRON, COMPRISING THE STEPS OF (A) LEACHING SAID ORE WITH AQUEOUS NITRIC ACID IN WHICH SAID NITRIC ACID CONTENT RANGES BETWEEN 20 AND 50% BY WEIGHT, THE QUANTITY OF NITRIC ACID USED BEING EQUIVALENT TO BETWEEN 80 AND 110% OF THE STOICHIOMETRIC REQUIREMENT BASED UPON THE AL2O3 CONTENT OF SAID ORE; (B) FILTERING THE RESULTING LEACH LIQUOR TO ISOLATE THE FILTRATE WHICH COMPRISES A SOLUTION OF AL(NO3)3.9H2O AND RESIDUAL IRON VALUES; (C) TREATING SAID FILTRATE WITH AN ORGANIC CATION-EXCHANGE COMPLEXING REAGENT SPECIFIC TO THE IRON IONS IN SAID FILTRATE AND BEING A COMPOUND OF THE FORMULA HRR''PO4 WHEREIN R IS ALKYL CONTAINING AT LEAST 8 CARBON ATOMS AND R'' IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYL, THEREBY TO TRANSFER SUBSTANTIALLY ALL OF SAID IRON VALUES FROM THE AQUEOUS PHASE OF SAID FILTRATE TO THE ORGANIC PHASE OF SAID COMPLEXING REAGENT AND TO FORM A SUBSTANTIALLY IRONFREE ALUMINUM NITRATE SOLUTION ; AND (D) DECOMPOSING SAID IRON-FREE ALUMINUM NITRATE SOLUTION AT ELEVATED TEMPERATURES IN AN OXYGEN-CONTAINING ATMOSPHERE TO FORM AL2O3 OF SUFFICIENT PURITY TO PERMIT ITS DIRECT REDUCTION TO ALUMINUM METAL.

Claim 3

METHOD OF RECOVERING IRON AND ALUMINUM VALUES FROM A FERRUGINOUS ALUMINUM-BEARING ORE CONTAINING LESS THAN ABOUT 3% IRON, COMPRISING THE STEPS OF (A) CALCINING SAID ORE AT A TEMPERATURE BETWEEN ABOUT 700 AND 850*C. THEREBY TO BREAK TO ALUMINUMSILICATE BONDING IN SAID ORE; (B) LEACHING THE RESULTING CALCINED ORE WITH AQUEOUS NITRIC ACID IN WHICH SAID NITRIC ACID CONTENT RANGES BETWEEN 20 AND 50% BY WEIGHT, THE QUANTITY OF NITRIC ACID USED BEING EQUIVALENT TO BETWEEN 80 AND 110% OF THE STOICHIOMETRIC REQUIREMENT BASED UPON THE AL2O3 CONTENT OF SAID ORE; (C) FILTERING THE RESULTING LEACH LIQUOR TO ISOLATE THE FILTRATE WHICH COMPRISES A SOLUTION OF AL(NO3)3.9H2O AND RESIDUAL IRON VALUE; (D) TREATING SAID FILTRATE WITH AN ORGANIC CATION-EXCHANGE COMPLEXING REAGENT SPECIFIC TO THE IRON IONS IN SAID FILTRATE AND BEING A COMPOUND OF THE FORMULA HRR''PO4 WHEREIN R IS ALKYL CONTAINING AT LEAST 8 CARBON ATOMS AND R'' IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYL, THEREBY TO TRANSFER SUBSTANTIALLY ALL OF SAID IRON VALUES FROM THE AQUEOUS PHASE OF SAID FILTRATE TO THE ORGANIC PHASE OF SAID COMPLEXING REAGENT AND TO FORM A SUBSTANTIALLY IRONFREE ALUMINUM NITRATE SOLUTION; AND (E) DECOMPOSING SAID IRON-FREE ALUMINUM NITRATE SOLUTION AT ELEVATED TEMPERATURES IN AN OXYGEN-CONTAINING ATMOSPHERE TO FORM AL2O3 OF SUFFICIENT PURITY TO PERMIT ITS DIRECT REDUCTION TO ALUMINUM METAL.

Claim 4

METHOD OF RECOVERING IRON AND ALUMINUM VALUES FROM A FERRUGINOUS ALUMINUM-BEARING ORE CONTAINING LESS THAN ABOUT 3% IRON, COMPRISING THE STEPS OF (A) CALCINING SAID ORE AT A TEMPERATURE BETWEEN ABOUT 700 AND 850*C. THEREBY TO BREAK TO ALUMINUMSILICATE BONDING IN SAID ORE; (B) LEACHING THE RESULTING CALCINED ORE WITH AQUEOUS NITRIC ACID IN WHICH SAID NITRIC ACID CONTENT RANGES BETWEEN 20 AND 50% BY WEIGHT, THE QUANTITY OF NITRIC ACID USED BEING EQUIVALENT TO BETWEEN 80 AND 110% OF THE STOICHIOMETRIC REQUIREMENT BASED UPON THE AL2O3 CONTENT OF SAID ORE; (C) FILTERING THE RESULTING LEACH LIQUOR TO ISOLATE THE FILTRATE WHICH COMPRISES A SOLUTION OF AL(NO3)3.9H2O AND RESIDUAL IRON VALUE; (D) TREATING SAID FILTRATE WITH AN ORGANIC CATION-EXCHANGE COMPLEXING REAGENT SPECIFIC TO THE IRON IONS IN SAID FILTRATE AND BEING A COMPOUND OF THE FORMULA HRR''PO4 WHEREIN R IS ALKYL CONTAINING AT LEAST 8 CARBON ATOMS AND R'' IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYL, THEREBY TO TRANSFER SUBSTANTIALLY ALL OF SAID IRON VALUES FROM THE AQUEOUS PHASE OF SAID FILTRATE TO THE ORGANIC PHASE OF SAID COMPLEXING REAGENT AND TO FORM A SUBSTANTIALLY IRONFREE ALUMINUM NITRATE SOLUTION; AND (E) DECOMPOSING SAID IRON-FREE ALUMINUM NITRATE SOLUTION AT ELEVATED TEMPERATURES IN AN OXYGEN-CONTAINING ATMOSPHERE TO FORM AL2O3 OF SUFFICIENT PURITY TO PERMIT ITS DIRECT REDUCTION TO ALUMINUM METAL.

Claim 5

METHOD OF RECOVERING IRON AND ALUMINUM VALUES FROM A FERRUGINOUS ALUMINUM-BEARING ORE, COMPRISING THE STEPS OF (A) CALCINING SAID ORE AT A TEMPERATURE BETWEEN ABOUT 700 AND 850*C. IN THE PRESENCE OF A REDUCING ATMOSPHERE THEREBY TO BREAK THE ALUMINUM-SILICATE BONDING IN SAID ORE AND TO REDUCE THE IRON PRESENT TO A MAGNETIC FORM, (B) MAGNETICALLY SEPARATING SAID IRON FROM SAID ORE THEREBY TO FORM A CALCINED ORE CONTAINING A SMALL AMOUNT OF RESIDUAL IRON; (C) LEACHING SAID CALCINED ORE WITH AQUEOUS NITRIC ACID TO FORM A LEACH LIQUOR COMPRISING A SOLUTION OF AL(NO3)3.9H2O AND SAID RESIDUAL IRON; (D) FILTERING SAID LEACHING LIQUOR TO ISOLATE THE FILTRATE; (E) TREATING SID FILTRATE WITH AN ORGANIC CATION-EXCHANGE COMPLEXING REAGENT SPECIFIC TO THE IRON IONS IN SAID FILTRATE AND BEING A COMPOUNDOF THE FORMULA HRR''PO4 WHEREIN R IS ALKYL CONTAINING AT LEAST 8 CARBON ATOMS AND R2 IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYL, THEREBY TO TRANSFER SUBSTANTIALLY ALL OF SAID RESIDUAL IRON VALUES FROM THE AQUEOUS PHASE OF SAID FILTRATE TO THE ORGANIC PHASE OF SAID COMPLEXING REAGENT AND TO FORM A SUBSTANTIALLY IRON-FREE ALUMINUM NITRATE SOLUTION; AND (F) DECOMPOSING SAID IRON-FREE ALUMINUM NITRATE SOLUTION AT ELEVATED TEMPERATURES IN AN OXYGEN-CONTAINING ATMOSPHERE TO FORM AL2O3 OF SUFFICIENT PURITY TO PERMIT ITS DIRECT REDUCTION TO ALUMINUM METAL.

Claim 6

METHOD OF RECOVERING IRON AND ALUMINUM VALUES FROM A FERRUGINOUS ALUMINUM-BEARING ORE, COMPRISING THE STEPS OF (A) CALCINING SAID ORE AT A TEMPERATURE BETWEEN ABOUT 700 AND 850*C. IN THE PRESENCE OF A REDUCING ATMOSPHERE THEREBY TO BREAK THE ALUMINUM-SILICATE BONDING IN SAID ORE AND TO REDUCE THE IRON PRESENT TO A MAGNETIC FORM, (B) MAGNETICALLY SEPARATING SAID IRON FROM SAID ORE THEREBY TO FORM A CALCINED ORE CONTAINING A SMALL AMOUNT OF RESIDUAL IRON; (C) LEACHING SAID CALCINED ORE WITH AQUEOUS NITRIC ACID TO FORM A LEACH LIQUOR COMPRISING A SOLUTION OF AL(NO3)3.9H2O AND SAID RESIDUAL IRON; (D) FILTERING SAID LEACHING LIQUOR TO ISOLATE THE FILTRATE; (E) TREATING SID FILTRATE WITH AN ORGANIC CATION-EXCHANGE COMPLEXING REAGENT SPECIFIC TO THE IRON IONS IN SAID FILTRATE AND BEING A COMPOUNDOF THE FORMULA HRR''PO4 WHEREIN R IS ALKYL CONTAINING AT LEAST 8 CARBON ATOMS AND R2 IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYL, THEREBY TO TRANSFER SUBSTANTIALLY ALL OF SAID RESIDUAL IRON VALUES FROM THE AQUEOUS PHASE OF SAID FILTRATE TO THE ORGANIC PHASE OF SAID COMPLEXING REAGENT AND TO FORM A SUBSTANTIALLY IRON-FREE ALUMINUM NITRATE SOLUTION; AND (F) DECOMPOSING SAID IRON-FREE ALUMINUM NITRATE SOLUTION AT ELEVATED TEMPERATURES IN AN OXYGEN-CONTAINING ATMOSPHERE TO FORM AL2O3 OF SUFFICIENT PURITY TO PERMIT ITS DIRECT REDUCTION TO ALUMINUM METAL.