Purification of barium values

A process for the production of a purified barium salt essentially devoid of strontium impurities, comprising extracting an aqueous solution of impure barium values with an organic solvent medium which comprises at least one of the following substantially water-insoluble organic extractants:

• (i) a carboxylic acid having the following general formula (I):
• ##STR11## in which R.sub.1 and R.sub.2 are straight or branched chain alkyl radicals, or substituted such alkyl radicals, with the proviso that the total number of carbon atoms present in said two radicals is at least equal to 6;
• (ii) a phosphonic acid monoester having the following general formula (II):
• ##STR12## in which R'.sub.1 and R'.sub.2 are straight or branched chain, nonhalogenated alkyl or alkenyl radicals;
• (iii) an 8-hydroxyquinoline having the following general formula (III):
• ##STR13## in which R.sub.3, R.sub.4, R.sub.5, R`hd 6, R.sub.7 and R.sub.8, which may be identical jor different, are each hydrogen, or a substituted or unsubstituted alkyl, alkenyl, alicyclic or aromatic radical, with the proviso that R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 may not all be hydrogen at the same time;
• separating the mixture of extraction into a purified aqueous phase comprising the desired barium salt values and an organic phase comprising those impurity values sought to be removed;
• and thence recovering said purified aqueous phase.