Embodiments of the invention relate to a process for removing fluoride from a solution or suspension containing zinc, in particular a solution of zinc sulfate, a defluoridated solution of zinc sulfate obtainable by such a process, its use as well as processes for producing zinc and hydrogen fluoride or hydrofluoric acid. The process for removing fluoride comprises (i) providing a solution or suspension A containing zinc, wherein the solution or suspension A containing zinc further contains fluoride ions; (ii) adding a solution B containing a dissolved salt of a rare earth element to the solution or suspension A containing zinc, wherein a solid comprising a rare earth element fluoride and a solution C containing zinc are formed; and (iii) separating the solid from the solution C containing zinc, wherein the solution C containing zinc has a lower concentration of fluoride ions than the solution or suspension A containing zinc.

A solvent extraction method for separation and recovery of nickel, cobalt, manganese, and zinc is proposed. More particularly, the present method relates to a solvent extraction method for separation and recovery of nickel, cobalt, manganese, and zinc, the method being capable of separately recovering four kinds of valuable metals as respective monotype metals from a starting material containing nickel, cobalt, manganese, and zinc by involving: a first solvent extraction step in which the starting material is separated into a first aqueous phase solution containing nickel and cobalt and a second aqueous phase solution containing nickel, cobalt, manganese, and zinc; a second solvent extraction step in which nickel (Ni) and cobalt (Co) are separated and recovered; a third solvent extraction in which zinc (Zn) is recovered; and a fourth solvent extraction step in which manganese (Mn) and cobalt (Co) are separated and recovered.

A method of recovering iron from a zinc sulfate solution according to an embodiment of the present disclosure is associated with recovering iron from a zinc sulfate solution produced by a leaching process in which zinc ore is dissolved in sulfuric acid. The method comprises a conditioning process including a step of reducing a conditioning process input solution, which is the zinc sulfate solution, and an iron precipitation process for recovering iron as hematite, including a step of pressurizing and oxidizing an iron precipitation process input solution discharged from the conditioning process. The iron precipitation process is performed at a temperature ranging from 135 C. to 150 C. and a pressure ranging from 5 barg to 10 barg.

The present invention provides a method of recovering copper and zinc from an aqueous sulfate and chloride containing solution. In the first process step zinc and copper are simultaneous extracting with an extraction solution comprising a liquid chelating cation exchanger and a liquid anion exchanger. The extraction is followed by consecutive stripping stages. First the anionic species are washed from the organic phase with one or more aqueous solutions and finally the copper is stripped with an aqueous acidic solution.

A system and method for decoating a scrap coated metal in a leach solution uses direct measuring of the corrosion potential of the scrap metal in the system to determine the progress of the decoating process and end the process when the scrap is decoated. Corrosion potential measurements are made using a working electrode comprising more than one piece of scrap coated-metal within the system. The decoating system and method may include a system for recycling leach solution.

The present invention relates to separation and recovery of metals from ground alkaline batteries using anode mud (zinc electrolysis waste) and other manganese and zinc containing materials. The material commonly referred to as alkaline black (AKB) is solubilized into sulfate media and the manganese to zinc ratio is adjusted. The solution containing metals is processed using crystallization and ion exchange methods to produce manganese sulfate and zinc sulfate solutions for several possible applications.

A zinc production method includes a reaction step such as a leaching step (101) of bringing electric arc furnace dust (1) containing zinc oxide or the like into contact with a chlorine gas (8) to obtain a zinc oxide component in the electric arc furnace dust (1) or the like as crude zinc chloride (3), a purification step (102) of heating the crude zinc chloride (3) obtained at the reaction step to produce zinc chloride vapor, and cooling and condensing the zinc chloride vapor, thereby obtaining purified zinc chloride (6), and an electrolysis step (103) of electrolyzing the purified zinc chloride (6) obtained at the purification step (102) in a molten state to obtain a zinc melt (9) and the chlorine gas (8).

A process has been developed in order to recover and recycle the metals present in spent batteries, including alkaline spent batteries alone or mixed with other types of spent batteries. This method shows a good potential in terms of metals recoveries efficiencies and economic feasibility. Firstly, the spent batteries are crushed (optionally after having been frozen in the case of spent batteries of mixed types). Then, the undesirable parts (plastics, steel cases, papers, etc.) are removed by screening. The collected powder, containing the metals, is mixed with a solution of sulfuric acid in the presence of a reducing agent. The solid/liquid separation is carried out by filtration and the leachate is purified in order to selectively recover the metals. The purification steps consist of: a) recovering Zn by solvent extraction followed by an electrowinning process; b) simultaneously recovering Mn and Cd by solvent extraction process; c) selectively recovering Cd from the mixture solution of Cd and Mn by electrowinning process; d) precipitating Mn from a pure solution of MnSO.sub.4 in a carbonate form; e) removing the impurities present in the effluent by solvent extraction in order to obtain a pure NiSO.sub.4 solution; f) precipitating Ni from a NiSO.sub.4 solution in a carbonate form.

The invention relates to a method for treating a solution containing zinc sulphate, so that at least one of the rare metals such as indium, gallium and germanium can be separated from it. A portion of the metals to be separated can be precipitated from zinc sulphate solution by neutralizing the acidic solution and at least a portion is cemented by means of metal powder. The solid precipitates that are formed can be combined and treated subsequently in some suitable way to leach out the desired metals.

The present invention relates to a method for the elution of aluminum ions and/or zinc ions of polymers containing aminomethylphosphonic acid groups.