Process for recovering useful values from waste pickle liquor and raw coke oven gas

Claim 1

THE METHOD OF TREATING IRON SULFATE CONTAINING PICKLE LIQUOR WITH RAW COKE OVEN GAS FOR PURIFYING SAID GAS AND RECOVERING USEFUL VALUES WHICH COMPRISES: REACTING RAW COKE OVEN GAS WITH IRON SULFATE CONTAINING PICKLE LIQUOR AND COMPLETING THE REACTION AT A PH OF ABOUT 7.5-7.8, THEREBY TO PRECIPITATE SUBSTANTIALLY ALL FERROUS IRON PRESENT AS INSOLUBLE IRON SULFIDE AND AMMONIUM-FERROCYANIDES IN AN AQUEOUS SLURRY CONTAINING AMMONIUM SULFATE IN SOLUTION, OXIDIZING THE ENTIRE RESULTING SLURRY TO CONVERT THE IRON SULFIDE INTO INSOLUBLE IRON OXIDE AND FREE SULFUR, CONTINUING THE OXIDATION UNTIL THE IRON SULFIDE IS REDUCED TO NOT LESS THAN ABOUT 0.2-0.5% BY WEIGHT OF THE TOTAL SLURRY SEPARATING THE AMMONIUM SULFATE SOLUTION FROM SAID SLURRY, SEPARATING THE SULFUR FROM THE RESULTING SLURRY BY FLOTATION, TREATING THE RESIDUE WITH ALKALI TO SOLUBILIZE THE FERROCYANIDES, AND SEPARATING THE SOLUBILIZED FERROCYANIDES FROM THE INSOLUBLE IRON OXIDE.

Claim 2

THE METHOD OF TREATING IRON SULFATE CONTAINING PICKLE LIQUOR WITH RAW COKE OVEN GAS FOR PURIFYING SAID GAS AND RECOVERING USEFUL VALUES WHICH COMPRISES: REACTING RAW COKE OVEN GAS WITH IRON SULFATE CONTAINING PICKLE LIQUOR AND COMPLETING THE REACTION AT A PH OF ABOUT 7.5-7.8, THEREBY TO PRECIPITATE SUBSTANTIALLY ALL FERROUS IRON PRESENT AS INSOLUBLE IRON SULFIDE AND AMMONIUM-FERROCYANIDES IN AN AQUEOUS SLURRY CONTAINING AMMONIUM SULFATE IN SOLUTION, OXIDIZING THE ENTIRE RESULTING SLURRY TO CONVERT THE IRON SULFIDE INTO INSOLUBLE IRON OXIDE AND FREE SULFUR, CONTINUING THE OXIDATION UNTIL THE IRON SULFIDE IS REDUCED TO NOT LESS THAN ABOUT 0.2-0.5% BY WEIGHT OF THE TOTAL SLURRY SEPARATING THE AMMONIUM SULFATE SOLUTION FROM SAID SLURRY, SEPARATING THE SULFUR FROM THE RESULTING SLURRY BY FLOTATION, TREATING THE RESIDUE WITH ALKALI TO SOLUBILIZE THE FERROCYANIDES, AND SEPARATING THE SOLUBILIZED FERROCYANIDES FROM THE INSOLUBLE IRON OXIDE.