A METHOD TO PROCESS WASTE SOLUTIONS BEARING COMPOUNDS OF HEXAVALENT CHROMIUM Russian patent published in 2003 - IPC

FIELD: treatment of industrial waste waters; purification of waste electrolytes, etc. SUBSTANCE: invention presents the method for treatment of industrial waste waters, in particular, purification of waste electrolytes, baths of passivation and a chromate treatment from hexavalent chromium, that allows to prevent a natural water pollution and soils and to salvage(recover) conversion products of solutions. For realization of the method of processing of the waste solutions bearing compounds of hexavalent chromium, its recovery up to trivalent chromium using a waste of the industrial production. As the chemical reducing agent is used petrowaste KEK (concentrated sludge) received in process of production of dopant DPh and having the following composition (mass %): the organic part 28-31, zinc oxide 2.5-3.8, magnesium oxide 1.2- 1.22, aluminum oxide 63.98-68.30; at that its organic part includes alkylbenzenes, indenes, phenanthenes and mononaphthenes at following components ratio, mass %: alkylbenzenes 81-85, indenes 1-4, phenanthrenes 3-6, mononaphthenes 5-15, at a mass ratio of petroslime and hexavalent chromium in a solution the equal to 2-3 : 1. EFFECT: method ensures decrease of duration of the waste solutions treatment process, simplifies it at the expense of exclusion of operations of neutralization, separation and drying the sedimentation at simultaneous production of the dry sedimentation. 1 tbl