Process for the production of lead hydrate or monoxide of high purity from materials and/or residues containing lead in the form of sulphates, monoxides and/or other compounds

摘要

Process for the production of lead hydrate or monoxide of high purity, from materials and/or residues containing lead in the form of sulphates, monoxides and/or other compounds, such as the paste coming from exhaust acid batteries, comprising the following steps: €¢ desulphurisation of the material and/or residue containing lead sulphate in an aqueous suspension with a suitable carbonate or hydrate in order to get conversion of the lead sulphate into a carbonate or hydrate; €¢ calcination of this desulphurised material and/or residue in order to get impure lead monoxide, followed by cooling and grinding; €¢ leaching of the impure lead monoxide by an aqueous solution of acetic acid followed by filtering to separate a solid residue, consisting mainly of non converted lead sulphate, from a lead acetate solution; €¢ precipitation of the lead acetate in solution by means of an alkaline hydroxide or alkaline-earth hydroxide, able to obtain soluble acetates, in order to get a precipitate, depending on the precipitation temperature, in the form of either lead hydrate or lead monoxide, followed by filtering of the obtained precipitate, separating a solution, at least one washing cycle and subsequent separation of the washing liquid; €¢ drying and optional calcination of the filtered and washed precipitate to get high purity lead hydrate or monoxide depending on the drying temperature.