Abstract: The present invention refers to an improved process for recovering zinc from primary and secondary raw materials, said process comprising a first leaching step wherein the ratio between the zinc weight contained in the raw material and the volume of the leaching solution is at least 20 kg zinc per m3 of acid aqueous solution; a neutralization step; and a solvent extraction stage in the presence of organic extractant, wherein the temperature is maintained from 47 to 52° C.

Abstract: The present invention refers to a process for the purification of levulinic acid, an aqueous solution comprising levulinic acid and a process for the production of levulinic acid.

Abstract: The device of the invention includes the following 5 new elements in each mixer-settler: a) agitators with blunt edged turbines, b) decreasing degree of agitation throughout the series of mixing compartments, c) baffle with a central window in the settler interface, located after the flow buffers, and d) baffle without a window, centered in the settler interface, located after the baffle with a window. These elements allow for an operative method which inhibits secondary dispersion, reducing the formation of micro-droplets, without affecting the mass transfer between the phases. Consequently, this obtains a phase separation process with entrainments so small that it is possible to drastically increase the quality of the product, by obtaining an ultra-pure aqueous extract, simultaneously reducing the settling surface required.

Abstract: The device of the invention includes the following new elements in each mixer-settler: a) Agitators with blunt edged turbines, b) Decreasing degree of agitation throughout the series of mixing compartments, c) Baffle with a central window in the settler interface, located after the flow buffers, d) Baffle without a window, centred in the settler interface, located after the baffle with a window. These elements allow for an operative method which inhibits secondary dispersion, reducing the formation of micro-droplets, without affecting the mass transfer between the phases. Consequently, this obtains a phase separation process with entrainments so small that it is possible to drastically increase the quality of the product, by obtaining an ultra-pure aqueous extract, simultaneously reducing the settling surface required.

Abstract: The invention relates to a process involving the following steps: a) performing leaching of the raw material with an acid aqueous solution to dissolve the zinc if said raw material is a solid; b) optionally performing solid-liquid separation; c) neutralizing the aqueous solution once the zinc-containing raw material is in liquid form; d) performing solid-liquid separation of the solution rich in zinc from the solids precipitated during the neutralization step; e) extracting the zinc using an acid organic solvent; f) purifying the organic solvent from the extraction step; g) re-extracting zinc from the organic solvent using an acid aqueous solution; h) recovering the zinc by electrolysis and/or crystallization and/or precipitation.

Abstract: The process comprises the following stages: a) leaching; b) solid-liquid separation; c) neutralization of the aqueous solution; d) solid-liquid separation of the zinc-rich solution; e) zinc extraction; f) purification of the organic solvent from the extraction stage; g) stripping the ionic zinc loaded in the organic solvent; h) recovering the zinc contained in the aqueous acid solution from the stripping. The following barriers to impurities have been established: gentle leaching; alkaline pulp treatment; treatment of a small stream of aqueous solution, collected before and/or after the zinc extraction at step e); high selectivity of the dissolved zinc extraction; treatment of the zinc loaded in the organic solvent; cleaning treatment of the zinc-laden organic solvent, with an ultra-pure acid solution; partial bleeding and treatment of the stripped organic solvent; bleed of small stream of the final product producing loop, which will be recycled to the organic loop.