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:
Oct. 11, 1988
Filed:
Jan. 30, 1987
Applicant:
Inventor:
Klaus Schrodter, Cologne, DE;
Assignee:
Hoechst Aktiengesellschaft, Hurth Knapsack, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01B / ; C01B / ;
U.S. Cl.
CPC ...
4233 / ; 423531 ;
Abstract
Mineral acids are freed from heavy metals, especially copper, arsenic, antimony and lead by precipitating the metals in sulfide form. To this end, the mineral acid is reacted with hydrogen sulfide or an alkali metal sulfide solution under pressure and with thorough agitation, and formed solid matter is subsequently separated from the mineral acid under the pressure selected. The mineral acid may conveniently by admixed initially with a filter aid and then treated with hydrogen sulfide or the alkali metal sulfide solution.