Abstract: A method for producing an emulsion by dispersing a liquid to form a dispersed phase into a liquid to form a continuous phase through a microporous membrane, in which:(a) a W/O type emulsion is produced by dispersing an aqueous phase at low pressure into a fatty phase through a hydrophilic microporous membrane previously treated with the fatty phase;(b) an 01/W/02 type emulsion is produced by dispersing an O/W type emulsion at low pressure into the fatty phase (02) through the same microporous membrane as (a) above;(c) an O/W type emulsion is produced by dispersing a fatty phase containing a hydrophobic emulsifying agent into an aqueous phase through a hydrophilic microporous membrane.

Abstract: There is disclosed an improved method of treating a spent electrolyte of copper from a cell for electrolytic refining of copper for the purpose of purification and reuse of the spent electrolyte. The process comprises the steps of: pretreating the spent electrolyte for removing copper therefrom until the copper content is greatly reduced but still remains at a level which is substantially higher than the total content of various metal ion impurities, preferably to a concentration of 10-13 g/l of Cu; blowing a hydrogen sulfide gas into the pretreated solution at a temperature of 40.degree. C. or higher until the redox potential of solution becomes a certain predetermined value to precipitate metal ions; filtering the treated solution to separate the residue available as a raw material for copper smelting from a filtrate which consists essentially of sulfuric acid; and returning the filtrate to the cell for electrolytic refining of copper.