Method for the treatment of aluminium slags treatment and associated plant

Method for the secondary fusion aluminum slags treatment for obtaining finished goods intended for agricultural, domestic, and industrial use comprising the treatment of the aluminous material with concentrated sulfuric acid for obtaining aluminum sulfate, wherein the aluminous material comes from saline slags CER100308 fed in lots of finite-dimension in a plant of aluminum slags treatment and comprises aluminum oxides present for at least 30% in weight, the method comprising:

• a) a first step of separation by means of dry grinding of the metals present in the saline slags CER100308 having at least 30% in weight aluminum oxide, with known methodologies, for obtaining powders of metals Fe, Cu, Zn, and/or Ni and for obtaining an aluminous component in form of aluminum grains;
• b) a following step of de-salting of the aluminous component with additions of water, said de-salting step being followed by a filtration of the aluminous component;
• c) a following step of treatment of brine obtained according to said de-salting, wherein the additions of water in the desalting step caused the formation of saline solutions at various concentrations destined to agricultural use, and the electrolytic treatment of said saline solutions for forming solutions of sodium hypochlorite;
• d) a following step of treatment of the aluminous component with sulfuric acid for obtaining aluminum sulfate in solution and/or in form of crystals,
• wherein the aluminous component is wetted before being treated with the sulfuric acid,
• wherein the reaction takes place at a temperature comprised between 100° C. and 400° C. for an interval of time comprised between 2 and 3 hours,
• wherein the aluminum sulfate is obtained in form of crystals by means of radiation with lamps IR and/or lamps UV, said radiation causing the vaporization of the solvent and the precipitation of the crystals of Al2(SO4)3;
• e) a following step of obtaining a solid residual portion, obtained from the preceding step of treatment of said aluminous component, wherein the solid residual portion is suitable for use as refractory material in applications with thermal character;
• wherein the method is carried out in a non-continuous manner on lots of saline slags CER100308.