Abstract: A substituted 8-hydroxyquinoline is added to the alphahydroxyoxime extractant, which allows extracting germanium at lower acidity and with a better yield.

Abstract: Germanium is separated from an aqueous solution by means of a substituted 8-hydroxyquinoline extractant.Re-extraction of germanium from the extractant is carried out above 40.degree. C. and with an organic phase: aqueous phase volume ratio less than 1, whereby obtaining a high re-extraction yield.

Abstract: A multistage liquid-liquid extraction apparatus of the mixer-settler type, which is especially suited for performing liquid-liquid extractions accompanied by the formation of a solid phase, comprises a vessel the side-wall of which defines a cylinder or a regular polygonal body, the vessel being divided by means of radial partitions into sectors, each sector comprising a mixer and a settler, and the mixers and the settlers being located near the side-wall of the vessel.The agitators of the mixers are constituted by pumping turbines; the outlets of the mixers are constituted by weirs located near the side-wall of the vessel; means are provided for making the mixed liquids, discharged at the outlet of the mixers, flow by gravity towards a zone near the axis of the vessel; and the bottom of the vessel is inclined towards the axis of the vessel so as to define a reversed cone or pyramid.

Abstract: Battery-grade MnO.sub.2 is produced by(a) treating a MnCl.sub.2 solution with Cl.sub.2 and Mg(OH).sub.2 whereby obtaining a MgCl.sub.2 solution that contains a MnO.sub.2 precipitate; and said MgCl.sub.2 solution contains at least 85 g/l of magnesium(b) allowing to digest the precipitate in the MgCl.sub.2 solution in presence of Cl.sub.2 under pressure;(c) separating the digested precipitate from the solution; and(d) washing and drying the precipitate.Owing to step (b), operating conditions in step (a) may be such that a concentrated MgCl.sub.2 solution is obtained, which is important for the further processing of that solution by pyrohydrolysis.

Abstract: A multistage liquid-liquid extraction apparatus of the mixer-settler type, which is especially suited for performing liquid-liquid extractions accompanied by the formation of a solid phase, comprises a vessel the side-wall of which defines a cylinder or a regular polygonal body, the vessel being divided by means of radial partitions into sectors, each sector comprising a mixer and a settler, and the mixers and the settlers being located near the side-wall of the vessel.The agitators of the mixers are constituted by pumping turbines; the outlets of the mixers are constituted by weirs located near the side-wall of the vessel; means are provided for making the mixed liquids, discharged at the outlet of the mixers, flow by gravity towards a zone near the axis of the vessel; and the bottom of the vessel is inclined towards the axis of the vessel so as to define a reversed cone or pyramid.

Abstract: In a process for treating a metal bearing material containing arsenic and antimony by leaching in an acid solution with an oxygen-containing gas under pressure at a temperature of between 20.degree. and 200.degree. C, the improvement which consists in adding at least one element chosen from the group consisting of arsenic and phosphorus in such an amount to the leach mixture that the molar ratio (As + 4P) : Sb therein shall be at least equal to 8, thus dissolving at least the major part of the arsenic and antimony contained in the starting material.

Abstract: A process for separating cobalt from nickel in an aqueous acid solution containing the above metals, which comprises contacting said solution with an organic phase comprising (a) 65-98% by volume of a concentrated alpha-hydroxyoxime extractant, a 1% by volume solution of which in xylene has per liter a maximum loading capacity of about 0.864 g. of copper, and (b) 2-35% by volume of an organophosphoric acid of the general formula: ##STR1## wherein R.sub.1 represents an alkyl, aryl or aralkyl radical, while maintaining the pH of said solution between 1 and 6, whereby cobalt is extracted from the aqueous phase to the organic phase and separating the resultant cobalt pregnant organic phase from the aqueous phase.

Abstract: A process for treating an aqueous acid solution containing at least one element selected from the group of elements consisting of As, Sb and Bi, said process comprising contacting the aqueous solution with an organic phase comprising an organophosphoric compound having the general formula (RO).sub.3 P = O wherein R represents an unsubstituted or substituted alkyl, aryl or aralkyl group, while maintaining a temperature of between 10.degree. and 60.degree. C and an organic phase/aqueous phase ratio of between 0.1 and 5, whereby the elements of said group and acid are extracted from the aqueous phase to the organic phase, and separating the resultant pregnant organic phase from the aqueous phase.

Abstract: Process for extraction of germanium from aqueous acid solution by contacting with an organic liquid containing a hydroxy-oxime and recovering the extracted germanium from the organic phase.