Abstract: A composition for use in extracting metals from aqueous solutions of metals salts comprises at least one o-hydroxyaryloxime containing at least 5 aliphatic or alicyclic carbon atoms and at least one ester containing from 10 to 30 carbon atoms, the weight ratio of o-hydroxyaryloximes to the esters being in the range of 10:1 to 1:3. A process for extracting metal from aqueous solutions using the composition is also disclosed.

Abstract: A composition for use in extracting copper values from aqueous solutions of metal salts comprises one or more o-hydroxyaryloximes containing at least 5 aliphatic or alicyclic carbon atoms which are strong metal extractants which, in 0.2 molar solution in an aliphatic hydrocarbon solution when loaded with 50% of the theoretical uptake of copper, will be in equilibrium with a 0.1 molar solution of copper as copper perchlorate at a pH less than 1 and one or more branched chain aliphatic or aliphatic-aromatic esters containing 10 to 30 carbon atoms, wherein the ratio of the number of methyl carbon atoms to the number of non-methyl carbon atoms is higher 1:5 and the weight ratio of A to B being in the range of 10:1 to 1:3.

Abstract: A process for extracting metal values, especially zinc values, from aqueous solutions of metal salts, which comprises contacting the aqueous solution with an organic phase comprising a compound of the formula, ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently, represents an optionally substituted hydrocarbyl or hydrocarbyloxy group or R.sup.1 and R.sup.2 together with the attached phosphorus atom and/or R.sup.3 and R.sup.4 together with the attached phosphorus atom from a 5- to 8-membered heterocyclic ring.

Abstract: 5-(2-Hydroxyphenyl)tetrazoles having substituents containing at least 5 aliphatic or alicyclic carbon atoms are prepared from the corresponding o-hydroxybenzyl cyanides with alkali metal azides. These tetrazoles are useful as extracting agents in liquid-liquid extraction processes for metals, especially copper. When used in such processes in combination with o-hydroxyaryl oximes they improve the extraction kinetics of the oximes.