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:
Sep. 26, 1978
Filed:
Apr. 04, 1977
Applicant:
Inventors:
Wilhelm Wengeler, Bochum-Stiepel, DE;
Egbert Hoffmann, Bochum, DE;
Assignee:
Uhde GmbH, Dortmund, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B02C / ;
U.S. Cl.
CPC ...
241 24 ; 241 81 ;
Abstract
Freshly mined phosphate rock is subjected to screen classification in at least two stages. Only coarse grained phosphate rock with a grain size over 2 mm from the last screen classification step is fed to a plain-roller grinding mill. The rollers of the grinding mill run at different peripheral speeds, so that the grains are ground by radial and tangential forces. This produces a fine grained phosphate rock whose natural moisture content is advantageous when further processed to phosphoric acid by means of sulphuric acid.