Method for making and using chromium III salts
AssigneeBulk Chemicals, Inc.
InventorJose B. Rivera
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Abstract
A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.
Claims4
An aqueous composition comprising dissolved Cr2(GF6)3, in which G is a Group IV-B element, and containing less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and which tests negative for chromium VI using s-diphenylcarbazide, wherein the composition contains one or more contaminating ions, and wherein each of said one or more contaminating ions is present at less than 1000 ppm relative to chromium, wherein said one or more contaminating ions are ions that are not part of the canonical formula of Cr2(FG6)3.
Dependencies are inferred from the claim text.