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:
Apr. 06, 1976
Filed:
Aug. 20, 1973
Japan Metals and Chemicals Co., Ltd., Tokyo, JA;
Abstract
An ion exchanger consisting of crushed lignite or brown coal retaining alkali ions, which is obtained by immersing the particles in a dilute caustic alkali solution. The concentration of the caustic alkali ranges from 2 to 20 weight percent, preferably from 3 to 10 weight percent. Following the treatment with the alkali, the system is washed with an acid with a pH of 3 to 7 to remove the alkali liquid. The resultant lignite has less than 4 meq/g, for instance 2.60 to 3.50 meq/g, of sodium ions and exhibits abilities of ion exchange. By treating the alkali treated lignite with hydrochloric acid or sulfuric acid it is possible to retain hydrogen ions, and by using a solution of a calcium salt such as calcium chloride calcium ions can be retained. Thus, calcium ions or potassium ions may be exchanged with cations of a salt of metal of Group second in the periodic table such as calcium, magnesium, barium and zinc.