Reduction of residual chloride in iron oxides
AssigneeShell Oil Company
InventorDavid M. Hamilton, Jr.
Life of this patent
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Abstract
A process for reducing the residual chloride present in iron oxides, particularly in regenerated iron oxides produced from hydrochloric acid waste liquid generated from steel pickling, by post-synthesis treatment of the iron oxides with sulfuric acid optionally followed by drying and calcining. The purified regenerated iron oxides are particular suitable for making iron oxide based catalysts such as ethylbenzene dehydrogenation catalysts and high-grade ferrites.
Claims19
A process for removing chloride from a chloride-containing iron oxide, which process comprises the steps of:
- (a) mixing the chloride-containing iron oxide with an aqueous solution comprising a molar amount of H.sub.2 SO.sub.4 from about 0.5 to about 5 times the molar amount of chloride in the chloride-containing iron oxide to form a mixture;
- and
- (b) separating the iron oxide from said mixture formed in step (a).
A process for removing chloride from a chloride-containing iron oxide, which process comprises the steps of:
- (a) mixing the chloride-containing iron oxide with an aqueous solution comprising a molar amount of H.sub.2 SO.sub.4 of from about 0.5 to about 5 times the molar amount of chloride present in the chloride-containing iron oxide for a period of time from about 1 minute to about 48 hours to form a mixture;
- (b) separating the iron oxide from said mixture formed in step (a);
- and
- (c) heating the separated iron oxide from step (b) at a temperature from about 1.degree. C. above ambient temperature to about 14000.degree. C. at a pressure from about 0.1 atm to about 10 atm for a period of time from about 1 minute to about 100 hours.
A process for removing chloride from a regenerated iron oxide comprising from about 800 to about 5000 ppm by weight of chloride, wherein said regenerated iron oxide is produced from a hydrochloric acid waste liquid generated from steel pickling, which process comprises the steps of:
- (a) mixing the regenerated iron oxide with an aqueous solution comprising a molar amount of H.sub.2 SO.sub.4 of from about 0.5 to about 5 times the molar amount of chloride in the regenerated iron oxide for a period of time ranging from about 1 minute to about 48 hours at a pressure from about 0.5 atm to about 100 atm to form a mixture;
- (b) separating the iron oxide from said mixture formed in step (a);
- and
- (c) heating the separated iron oxide from (b) at a temperature ranging from about 100.degree. C. to about 1400.degree. C. at a pressure from about 0.1 atm to about 10 atm for a period of time from about 1 minute to about 72 hours.
Dependencies are inferred from the claim text.