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:
Jun. 25, 1991
Filed:
Oct. 18, 1989
Applicant:
Inventors:
Jan L Jonsson, Skellefte.ang., SE;
Sten A Nilsson, Ursviken, SE;
Assignee:
Boliden Contech AB, Stockholm, SE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ; C01B / ;
U.S. Cl.
CPC ...
423525 ; 423523 ; 423531 ; 423513 ;
Abstract
The present invention relates to a method for decoloring sulphuric acid produced in accordance with the contact method, comprising one or more absorption circuits. The produced sulphuric acid is decolored by adding hydrogen peroxide to the system. The method is characterized by adding the hydrogen peroxide to the sulphuric acid in the final absorption circuit, and by maintaining the temperature in this circuit above about 70.degree. C.