A process to significantly improve the copper chemical leaching process for primary and secondary minerals, using calcium chloride including the agglomeration, curing, and leaching with a high content of chloride, iron and copper stages. The mineral is then washed with a low concentration of copper and a high concentration of acid, where the impregnated copper is extracted from the pit and wherein a recirculated solution is used in the agglomeration stage.

Disclosed is a process for extracting or separating metal ions using a composition including: an ionic liquid of formula C.sup.+,−X, in which: C.sup.+ is an onium cation including at least one hydrocarbon chain R.sup.1 including from 6 to 20 carbon atoms; X.sup.P− is an anion of charge p, the ionic liquid having a solubility in water at 20° C. of at least 10 g/l; an acid; and water. The composition includes two liquid phases: a phase enriched in ionic liquid ϕ.sub.IL; and a phase enriched in water ϕ.sub.w, the pH of which is less than or equal to 4.7. The composition is useful for extracting a metal ion from an acidic aqueous medium including a metal ion, for separating metal ions from an aqueous medium including at least two metal ions or for purifying an acidic aqueous solution including a metal ion.

The invention relates to a hydrometallurgical process which makes it possible to selectively recover at least one “heavy” rare earth metal, i.e. a rare earth metal with an atomic number at least equal to 62, that is in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets. It also relates to a hydrometallurgical process which makes it possible to selectively recover, on the one hand, at least one heavy rare earth metal present in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets and, on the other hand, at least one “light” rare earth metal, i.e. a rare earth metal with an atomic number at most equal to 61, that is also in this acidic aqueous phase. The invention has in particular an application in the recycling of rare earth metals present in spent or scrapped permanent magnets of the type Neodymium-Iron-Boron (or NdFeB) and, in particular, dysprosium, praseodymium and neodymium, and also in the recycling of samarium present in spent or scrapped permanent magnets of the type samarium-cobalt (or SmCo).

The inventive extraction/separation method involves the step of contacting an organic phase containing a dialkyldiglycol amic acid extractant: R.sup.1R.sup.2NCOCH.sub.2OCH.sub.2COOH with an aqueous solution containing scandium and zirconium and/or hafnium for thereby extracting zirconium and/or hafnium into the organic phase. The purity of scandium can be efficiently increased by the simple step of solvent extraction.

The inventive extraction/separation method involves the step of contacting an organic phase containing a dialkyldiglycol amic acid extractant: R.sup.1R.sup.2NCOCH.sub.2OCH.sub.2COOH with an aqueous solution containing scandium and zirconium and/or hafnium for thereby extracting zirconium and/or hafnium into the organic phase. The purity of scandium can be efficiently increased by the simple step of solvent extraction.

An apparatus for separating a mixture of two liquids of different densities which liquids are substantially insoluble in one another includes a hollow permeable body having a recess for receiving a first fluid which can flow from the recess through the permeable body to an exterior of the permeable body. A housing surrounds and is spaced from the exterior of the permeable body. The housing has an inlet for a second fluid and an outlet for a mixture of the first and second fluid. A baffle or baffles are provided in the space between the exterior of the permeable body and the housing, and to define a mixing channel in space between the exterior of the permeable body and the housing so that the second fluid can enter the housing inlet and flow through the mixing channel to the outlet, while picking up fluid on the exterior of the permeable body.

A method of selectively removing impurities from a scandium-containing feed solution includes contacting an aqueous scandium-containing solution with an organic solvent stream containing an extractant, thereby forming a loaded organic solvent stream containing the impurity or impurities while leaving the scandium in the raffinate. The aqueous stream containing the scandium is washed, diluted and has inorganic salts added before being contacted with a second organic solvent stream to extract the scandium selectively, and followed by stripping the scandium from the scandium-containing loaded organic extractant stream by adding oxalic acid to the loaded organic extractant stream to form scandium oxalate.

A method for producing metal zinc by liquid/liquid extraction, comprising leaching of a zinc-bearing solid raw material containing antimony with a slightly acid aqueous solution, at a pH value maintained above 3 and less than or equal to 5, with formation of a suspension, drawing-off from the suspension of an aqueous phase containing zinc in solution to be subject to the extraction, additional leaching of the remaining suspension with an acid aqueous solution, at a pH value maintained below 3.5 and greater than or equal to 1, with formation of a pulp, introduction of a neutralizing agent in this pulp with coprecipitation of antimony and other impurities and separation from this neutralized pulp of a zinc-bearing aqueous solution which is recycled to the step for leaching the zinc-bearing solid raw material.

A method for producing metal zinc by liquid/liquid extraction, comprising leaching of a zinc-bearing solid raw material containing antimony with a slightly acid aqueous solution, at a pH value maintained above 3 and less than or equal to 5, with formation of a suspension, drawing-off from the suspension of an aqueous phase containing zinc in solution to be subject to the extraction, additional leaching of the remaining suspension with an acid aqueous solution, at a pH value maintained below 3.5 and greater than or equal to 1, with formation of a pulp, introduction of a neutralizing agent in this pulp with coprecipitation of antimony and other impurities and separation from this neutralized pulp of a zinc-bearing aqueous solution which is recycled to the step for leaching the zinc-bearing solid raw material.

In the present invention, nickel is selectively extracted from an acidic solution that contains a high concentration of manganese. This valuable metal extraction agent is represented by the general formula. In the formula, R.sup.1 and R.sup.2 are alkyl groups that may be the same or different, R.sup.3 is a hydrogen atom or an alkyl group, and R.sup.4 is a hydrogen atom or any group, other than an amino group, bonded to an α carbon atom of an amino acid. The general formula preferably has a glycine unit, a histidine unit, a lysine unit, an aspartic acid unit or a n-methylglycine unit. When extracting nickel by using this extraction agent, it is preferable to adjust the pH of the acidic solution to 2.3 to 5.5 inclusive.