Abstract: This invention relates to a process for the recovery of indium from aqueous acid solutions. More particularly, it concerns the use of a combination of a dialkyl phosphoric acid and a mixture of trialkyl phosphine oxides to extract indium from acidic sulphate leach liquors.

Abstract: Metals selected from the group consisting of zinc (II), cadmium (II), nickel (II), cobalt (II), manganese (II), iron (III) and copper (II) from aqueous solutions containing the same are extracted therefrom by contacting said solution with an extractant having the formula ##STR1## wherein R and R.sup.1 are, individually, selected from the group consisting of substituted or unsubstituted alkyl, cyloalkyl, alkoxyalkyl, alkylcycloalkyl, aryl, alkaryl, aralkyl and cycloalkylaryl radicals having 2-24 carbon atoms and X is hydrogen, ammonium or an alkali or alkaline earth metal salt-forming radical.

Abstract: Disclosed are processes for the selective extraction of tin from aqueous acidic solutions bearing tin and other metal cations. Branched tertiary phosphine oxides comprising at least two branches per alkyl group show higher extraction coefficients, E, for tin than other metals, e.g. zinc (III), iron (II), iron (III), copper (II) and lead (II). Novel compositions for selectively extracting tin comprising combinations of symmetrical branched phosphine oxides and unsymmetrical phosphine oxides are also disclosed.

Abstract: A process for the removal of difficult-to-remove acidic organic compounds from aqueous solutions using novel phosphine oxide mixtures in which mixtures (1) at least two phosphine oxides are present, the total number of carbon atoms in a first oxide being at least 15 and the difference in the total number of carbon atoms in the first and second oxides being present in an amount of at least 5% by weight and not more than 60% by weight or (2) at least four phosphine oxides are present, the total number of carbon atoms in an oxide having at least no. of C atoms being at least 15, said phosphine oxides being present in an amount of at least 1% by weight and not more than 60% by weight. Unexpectedly high extractability is achieved using the mixtures.

Abstract: This invention relates to a process for the recovery of uranium from wet process phosphoric acid. More particularly, it concerns the use of a combination of a dialkyl phosphoric acid and a mixture of trialkyl phosphine oxides to extract uranium from wet process phosphoric acid.

Abstract: A process for the extraction of metals selected from the group consisting of zinc (II), silver (I), cadmium (II), mercury (II), nickel (II), cobalt (II), and copper (II) from an aqueous solution containing, in addition to said metals, metals selected from the group consisting of calcium (II) and magnesium (II) is disclosed. The process comprises contacting the aqueous solution having an equilibrium pH within the range of about 0.2 to about 3 with an extractant. The extractant comprises an organic-soluble dithiophosphinic acid or ammonium, alkali or alkaline earth metal salt thereof represented by the formula: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and are selected from the group consisting of substituted or unsubstituted alkyl, cycloalkyl, alkoxyalkyl, alkylcycloalkyl, aryl, alkylaryl, aralkyl and cycloalkylaryl radicals having from about 2 to about 24 carbon atoms and X is either hydrogen or an ammonium, alkali or alkaline earth metal salt forming radical.

Abstract: Silver or palladium metals are selectively extracted from aqueous sulfuric acid solution by contacting the solution with a water-immiscible organic solvent extraction solution comprising a tertiary phosphine sulfide compound; separating the resulting silver- or palladium- phosphine sulfide complex from the aqueous solution; and recovering the silver or palladium metal from the complex by suitable stripping means.

Abstract: A process for the extraction of Co (III) from ammoniacal solutions comprising Co (III) and Ni (II). The process comprises:(a) contacting said ammoniacal solution with(b) bis (2,4,4-trimethylpentyl)phosphinic acid or an ammonium or alkali metal salt thereof,said ammoniacal solution forming the aqueous phase and said phosphinic acid, or salt thereof, forming the organic phase, and(c) a phase modifierwhereby the Co (III) values are extracted from said aqueous phase to said organic phase.

Abstract: Cobalt(II)-bearing aqueous solutions may be treated with an extractant comprising an organic-soluble phophinic acid, or a salt thereof, to separate the cobalt(II) from the aqueous solution. Typical extraction techniques compatible with the instant process include liquid-liquid extraction employing either mixer settlers or columns, packed beds of supported extractants as in ion exchange, liquid membrane extraction and selective supported membrane extraction.

Abstract: Cobalt(II)-, nickel(II)-bearing aqueous solutions may be treated with an extractant comprising an organic-soluble phosphinic acid, or a salt thereof, to separate the cobalt(II) from the aqueous solution. Typical extraction techniques compatible with the instant process include liquid- liquid extraction employing either mixer settlers or columns, packed beds of supported extractants as in ion exchange, liquid membrane extraction and selective supported membrane extraction.

Abstract: Cobalt(II)-bearing aqueous solutions may be treated with an extractant comprising an organic-soluble phosphinic acid, or a salt thereof, to separate the cobalt(II) from the aqueous solution. Typical extraction techniques compatible with the instant process include liquid-liquid extraction employing either mixer settlers or columns, packed beds of supported extractants as in ion exchange, liquid membrane extraction and selective supported membrane extraction.