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Title:
CHROMIUM-CONTAINING WATER TREATMENT METHOD
Document Type and Number:
WIPO Patent Application WO/2016/113946
Kind Code:
A1
Abstract:
The present invention provides a chromium-containing water treatment method that allows treatment of water that contains chromium (chromium-containing water) at low cost. A chromium-containing water treatment method according to the present invention comprises: a reduction step in which chromium-containing water 11 and a liquid 12 containing 5-50 ppm of hydrogen sulfide are mixed, and the mixture is adjusted to pH 3.5 or lower and ORP 200-400 mV by adding an acid 13 thereto, so as to reduce chromium contained in the water; and a precipitation separation step in which a neutralizing agent is added to a solution 11' obtained via the reduction step so as to adjust the solution 11' to pH 8-9, thereby precipitating and separating, as a hydroxide, the reduced chromium contained in the solution.

Inventors:
MITSUI, Hiroyuki (11-3, Shimbashi 5-chome, Minato-k, Tokyo 16, 〒1058716, JP)
NAKAI, Osamu (11-3, Shimbashi 5-chome, Minato-k, Tokyo 16, 〒1058716, JP)
SHIBAYAMA, Keisuke (11-3, Shimbashi 5-chome, Minato-k, Tokyo 16, 〒1058716, JP)
SHIRAI, Sho (11-3, Shimbashi 5-chome, Minato-k, Tokyo 16, 〒1058716, JP)
Application Number:
JP2015/076199
Publication Date:
July 21, 2016
Filing Date:
September 15, 2015
Export Citation:
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Assignee:
SUMITOMO METAL MINING CO., LTD. (11-3, Shimbashi 5-chome Minato-k, Tokyo 16, 〒1058716, JP)
International Classes:
C02F1/70; C02F1/62; C22B3/44
Foreign References:
JP2010022926A2010-02-04
JP2010227737A2010-10-14
JPS631497A1988-01-06
JP2014218719A2014-11-20
JP2005161116A2005-06-23
JP2004209424A2004-07-29
JP2005342694A2005-12-15
JPS4836962A1973-05-31
JPS51113357A1976-10-06
JPS516195A1976-01-19
US4260491A1981-04-07
Other References:
See also references of EP 3246290A4
Attorney, Agent or Firm:
SHOBAYASHI, Masayuki et al. (Sapia Tower, 1-7-12 Marunouchi, Chiyoda-k, Tokyo 05, 〒1000005, JP)
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