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. 11, 2011
Filed:
Mar. 14, 2008
Reinhard Uwe Scholz, Kerken, DE;
Ray Sirey Ruemekorf, Rosmalen, NL;
Reinhard Uwe Scholz, Kerken, DE;
Ray Sirey Ruemekorf, Rosmalen, NL;
Niro Process Technology B.V., EE's-Hertogenbosch, NL;
Abstract
The invention relates to a method for the purification or recovery of orthophosphoric acid rich streams by suspension-based melt crystallization. The orthophosphoric acid is crystallized as the hemi-hydrate form and subsequent separation of such crystals in a wash-column produce a high purity acid/water solution that has been depleted of most of the metals and impurities other than water, thereby separating an orthophosphoric acid rich feed liquor into an ultra-pure orthophosphoric acid hemi-hydrate and a mother liquor containing almost all impurities originally present in the feed. The orthophosphoric acid rich feed liquor typically contains no more than 15 wt % water and 1 wt % other impurities. Individual metal ion composition in the purified orthophosphoric acid product is in the range of 100 to 1000 ppb (parts per billion= 1/1000 ppm) of each metal ion. The metal ion composition of the resulting purified product is thus typically below the detection limit of typical analysis equipment.