Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB9997/33A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IG Farbenindustrie AG
Original Assignee
IG Farbenindustrie AG
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Filing date
Publication date
Application filed by IG Farbenindustrie AGfiledCriticalIG Farbenindustrie AG
Publication of GB417331ApublicationCriticalpatent/GB417331A/en
Potassium bichromate is produced by heating chromic oxide or a substance containing it, for example, chromic hydroxide, in admixture with an amount of caustic potash not more than sufficient, and preferably about half that required, for conversion of the total quantity of the chromic oxide into bichromate, in the presence of oxygen or a gas containing uncombined oxygen, e.g. air, at atmospheric pressure and at a temperature above 250 DEG C., but below the decomposition temperature of the bichromate. Oxidation is effected solely by means of free oxygen. An operating temperature of 300--380 DEG C. is suitable. The chromic oxide is suitably mixed with an aqueous solution of the caustic potash. Mixing may be effected in a ball mill, and the reaction take place in a rotating dish.
GB9997/33A1932-04-041933-04-03Process for the manufacture of potassium dichromate
ExpiredGB417331A
(en)