METHOD FOR RECOVERING PALLADIUM FROM ACIDIC WASTE LIQUID OF HYDROCHLORIC ACID CONTAINING IRON

摘要

PURPOSE: To separate and extract only Pa ions in a short period of time by adjusting the concn. of free hydrochloric acid in a waste liquid to a prescribed value or below, then extracting the Pa ions by using an oil phase contg. dialkyl sulfide, water phase contg. thiourea and specific emulsifier. ;CONSTITUTION: Only Pa ions are substantially separated by an emulsification type liquid film extraction method from an HCl-acidic waste liquid in which iron ions coexist in a large amt. The concn. of the free hydrochloric acid in the above-mentioned waste liquid is previously adjusted to ≤2000, more preferably ≤1500mol/m³ by thickening or reaction with iron, etc., and then the extraction is executed. Further, the compd. of the general formula R-S-R' (R, R' are an alkyl group) is added to a satd. hydrocarbon of a low arom. content such as ≥6C kerosene, etc., to form the oil phase. On the other hand, the water added with thiourea as a reverse extracting agent is prepd. or the hydrochloric acid is formed as the internal water phase. The dioleyl glutamic ribitol expressed, by formula, which is a neutral surfactant and/ or amphoteric surfactant of a higher fatty acid ester system of sorbitan, is used as the emulsifier.;COPYRIGHT: (C)1993,JPO&Japio