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. 26, 1990
Filed:
Apr. 14, 1989
Applicant:
Inventors:
Donald W Kirk, Bolton, CA;
Murray C Robinson, Don Mills, CA;
Assignee:
Materials-Concepts-Research Limited, Don Mills, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01F / ;
U.S. Cl.
CPC ...
423155 ; 423173 ; 4235 / ; 423519 ;
Abstract
Processes for the selective leaching of magnesium-containing solids, which contain calcium and/or heavy metals, and the selective precipitation and crystallization of the leached magnesium are provided. The leaching is conducted with aqueous sulphur dioxide at elevated temperatures with feed pulp densities which are sufficiently high to produce a leach liquor which is substantially saturated with magnesium. The selective crystallization and precipitation processes which preferably follow the selective leaching process, utilize controlled cooling, heating and pH conditions to yield a high purity magnesium sulphite product.