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:
Jul. 14, 1981
Filed:
Jul. 24, 1979
Hugh R Falcon-Steward, St. Austell, GB;
English Clays Lovering Pochin & Co., Ltd., St. Austell, GB;
Abstract
A method of comminuting a solid material comprising calcium carbonate to obtain a product containing at least 60% by weight of particles smaller than 2 microns equivalent spherical diameter is disclosed. The method comprises forming an aqueous suspension of the solid material which has a solids content of up to 50% by weight and contains a dispersing agent, comminuting the solid material in the suspension by agitating the suspension in admixture with a particulate grinding medium, separating from the suspension thereby obtained an aqueous suspension containing comminuted solid material, classifying the latter suspension to obtain an aqueous suspension of a fine product which contains at least 60% by weight of particles smaller than 2 microns equivalent spherical diameter, flocculating the fine product by means of an electrolyte having a multivalent cation, and dewatering the aqueous suspension containing the comminuted and flocculated fine product.