Zinc removal from viscose plant effluent - by extraction with alkyl phosphoric acid into an organic solvent and re-extraction decompsn. therefrom

摘要

Zn is removed from aq. soln. by contacting the soln. in an extraction stage with an org. soln. contg. an alkyl phosphoric acid (I) so that a chemical cpd. is formed which is more sol. in the organic phase. This phase is then contacted with an aq. soln. in a stripping stage, this treatment cleaving the cpd. and causing the Zn to pass into aq soln. Finally, the Zn-free organic soln. is recycled to the extraction stage opt. after removing any other impurities. The process is esp. applicable in the treatment of effluent from viscous prodn. plant.