extraction of metal ions and polyvalent acidic phosphorus compound with sulfate and chloride and / or neutral

摘要

Extracting polyvalent metal ions from aq. solns. or suspensions of their salts using an essentially water-insoluble phosphorus acid of general formula (I) (where R1 and R2 are each opt. substd. aliphatic araliphatic or aromatic radicals and R1 and R2 can also be linked to the P atom via an oxygen atom). the solution also contg. at least one neutral salt of sulphuric or hydrochloric acid. Specifically using di (3-ethyl-1-hexyl)phosphate or phenyl (2-ethyl-1-hexyl) phosphate with sodium or magnesium chloride, or sodium or ammonium sulphate as the neutral salt. Particularly for extracting Fe+++ using sodium chloride and/or ammonium chloride and/or calcium chloride as the neutral sa also extracting Zn using sodium and/or ammonium sulphate. The extraction may also be carried out in the presence of an organic solvent pref. benzene, toluene, xylene, hexane, cyclohexane or heptane. The extraction is pref. carried out at 0-75 degrees C and pH 0-5. Improved extraction is achieved as a result of the neutral salt present.