The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 1983
Filed:
Nov. 30, 1981
Klaus Jodden, Hurth, DE;
Gero Heymer, Erftstadt, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
The invention relates to a process for making aqueous alkali metal phosphate solutions by subjecting aqueous alkali metal phosphite solutions to catalytic oxidation with oxygen or air. More particularly, oxygen or air in stoichiometric excess proportions is introduced into the aqueous alkali metal phosphite solution at about 30.degree. to 110.degree. C., at a pH-value of 0 to about 8, and in the presence of SiO.sub.2 or aluminum silicate containing at most 10 weight % Al.sub.2 O.sub.3, for as long as necessary to achieve conversion of the alkali metal phosphite to alkai metal phosphate. After completion of the oxidation, the aqueous solution is separated from the catalyst.