Title: Treatment for rinsig waste water from low chromium passivating process during zinc plating
Application Number: 87102036 Application Date: 1987.06.13
Publication Number: 1015420 Publication Date: 1987.12.23
Approval Pub. Date: Granted Pub. Date: 1990.05.02
International Classifi-cation: C02F1/66,C02F1/70,C25D21/20
Applicant(s) Name: Zhuzhou Electric Locomotive Plant, Ministry of Rai Address:
Inventor(s) Name:
Attorney & Agent: WANG QIXIA
Abstract:
     This invention is characterized by the comprehensive treatment which combines the rinsing waste water treatment eith zinc plating technology. Ferric salts produced due to the rust-removing procedure are utilized to reduce hezavalent chromium carrieed over by plating surfaces after low chromium passivating into trivalent chromium, while the alkaline liquid carried over by plating surfaces after zinc plating is used to reversely neutralize the acid solution on plating surfaces after rust-removing. This invention offers the advantages of a large saving in processing water; treating waste by waste without additional expense; treating waste water contg. hexavalent chromium simply and conveniently; saving in raw materials (including plating liquid, rinsing acid solution and alkaline materials required for acid neutralizing ) etc.
Time: 6
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