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. 12, 1982
Filed:
May. 07, 1981
Lucretia R Quatrini, Athens, PA (US);
GTE Products Corporation, Stamford, CT (US);
Abstract
Tungsten is recovered from tungsten ore concentrates in the form of sodium tungstate by a basic process in which ground ore is first digested in a sodium hydroxide solution followed by diluting the solution to dissolve sodium tungstate separating the solution from the caustic insoluble sludge and crystallizing soluble sodium tungstate, wherein the present invention permits improved recovery of tungsten from difficult to process ores by the process steps of drying the insoluble sludge portion, comminuting the dried sludge to a particle size less than about 200 mesh, and dissolving said comminuted sludge in 4.5-5.5 molar NaOH to recover substantially all of the tungsten values.