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.

Date of Patent:
Mar. 29, 2022

Filed:

Sep. 12, 2017
Applicant:

Kurita Water Industries Ltd., Tokyo, JP;

Inventors:

Shuhei Izawa, Tokyo, JP;

Ippei Tanaka, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C02F 1/52 (2006.01); C02F 1/58 (2006.01); C02F 1/62 (2006.01); C02F 9/00 (2006.01); C02F 11/122 (2019.01); C02F 101/10 (2006.01); C02F 101/14 (2006.01); C02F 101/20 (2006.01); C02F 103/16 (2006.01); C02F 1/00 (2006.01);
U.S. Cl.
CPC ...
C02F 1/5209 (2013.01); C02F 1/58 (2013.01); C02F 1/583 (2013.01); C02F 1/62 (2013.01); C02F 9/00 (2013.01); C02F 11/122 (2013.01); C02F 2001/007 (2013.01); C02F 2101/101 (2013.01); C02F 2101/14 (2013.01); C02F 2101/20 (2013.01); C02F 2103/16 (2013.01); C02F 2209/06 (2013.01);
Abstract

A calcium fluoride precipitation inhibitor is added to waste water containing sulfuric acid, fluorine (fluoride ions and hydrogen fluoride) and heavy metal ions to generate pretreated water. A calcium compound is added to the pretreated water to generate a first insolubilized product at a pH of less than 5, followed by solid-liquid separation. A calcium compound is added to a first separated water after the solid-liquid separation to generate a second insolubilized product at a pH of 3 to 7 (provided that the pH is a pH higher than in the first reaction step), followed by solid-liquid separation. An alkali is added to a second separated water after the solid-liquid separation to give a pH of 8 or more, thereby generating a third insolubilized product, followed by solid-liquid separation.


Find Patent Forward Citations

Izawa, Shuhei. (2022). Treatment method and treatment apparatus for waste water containing sulfuric acid, fluorine and heavy metal ions (U.S. Patent No. 11286181). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/11286181

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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