Abstract: A process for processing metallurgic residue that is obtained from electric steelworks dust, ESD, essentially containing iron and zinc in the form of zinc oxide and zinc ferrites, as well as a processing of the blast-furnace slags, BFS, and a combination with a synergy effect.

Abstract: A process for processing metallurgic residue that is obtained from electric steelworks dust, ESD, essentially containing iron and zinc in the form of zinc oxide and zinc ferrites, as well as a processing of the blast-furnace slags, BFS, and a combination with a synergy effect.

Abstract: A method for treating residues derived from garbage and/or industrial waste incineration fumes including the steps of desalting the residues by washing with sodium carbonate in sufficient amount or slightly in excess to solubilize all the salts including the sulphates and precipitate the soluble calcium, the pH being higher than 11, then carrying out a solid/liquid separation to obtain a desalinated cake; leaching the desalinated cake with sodium carbonate in sufficient amount or slightly in excess to obtain, by reaction with the lime present in the cake or added thereto if necessary, the alkalinity required for solubilising amphoteric metals, the pH being higher than 12, and obtaining by solid/liquid separation a cake and a supernatant which is neutralised with carbon dioxide, and filtering the recovered solution to obtain metal hydroxide sludge and an aqueous sodium carbonate solution; and neutralising the resulting residues at a pH between 6.5 and 8.5.

Abstract: The invention relates to a hydrometallurgical process for decontaminating soils 1 which are polluted with metallic elements, comprising a stage of basic leaching I so as to bring about the dissolution of the metallic elements to be removed, a cementation stage II bringing about the precipitation 6 of said elements in metal form, performed by electrochemical exchange with a zinc powder 5 produced by a stage of electrolysis III of the solution 7 originating from the cementation stage. In accordance with the invention a complementary addition of zinc is performed, preferably at the exit of the leaching stage in the form of a leachate 17 of waste from iron and steel manufacture, especially of dust 13 from electrical steel manufacture 15.