Abstract: A process for producing composite materials with a metal matrix and with a content of powder reinforcer agent lower than is minimum theoretical compaction value, with said process being based on an infiltration technique, is disclosed, which essentially consists in charging the reinforcer material to a casting mould, and then infiltrating into the same mould the metal matrix in the molten state, with said metal matrix being let cool until it solidifies, and characterized in that the reinforcer agent, consisting of non-metal powders, is blended, before being charged to said casting mould, with a diluting agent having a different compaction degree, constituted by metal fibres and/or ceramic fibres and/or ceramic whiskers and/or metal powders of the same composition as of the matrix.

Abstract: A process is described for treating spent batteries of any type, comprising essentially the following stages:a) disintegrating the spent batteries in water to a piece size of less than 7 mm followed by stirring in water, then screening to obtain a pulverlent aqueous turbid fraction (underscreen fraction) and a coarse fraction (overscreen fraction);b) stirring the pulverulent aqueous turbid fraction at a pH of between 7 and 8, followed by filtering by which the solids are separated from the aqueous solution, which is fed to water treatment;c) removing mercury both from the coarse fraction of point a) and from the separated solids of point b) in an indirectly heated continuously rotating mercury removal furnace operating in total absence of air and to which calcium hydroxide has been added, to obtain residues essentially free of mercury.

Abstract: There is disclosed a method for the separation of antimony from acidic solutions which contain antimony, alone, or together with other metallic ions, by extracting antimony with an organic, water-immiscible, polyol-containing diluent. The method comprises the steps of contacting the antimony-containing acidic solution with a water-immiscible organic diluent containing at least one polyol dissolved therein, preferably a diol, said polyol serving to extract the antimony. The polyol serves to selectively extract the antimony from the acidic solution to the exclusion of other metallic ions such as copper and nickel.

Abstract: A composite material is disclosed, which contains a matrix of Zn-Al alloy reinforced with silicon carbide powder, which powder has a granulometric distribution comprised within the range of from 1 to 200 .mu.m.

Abstract: A process for separating arsenic from acid aqueous solutions containing arsenic and other metal ions. The process involves bringing the acid aqueous solution into contact with a water-immiscible organic diluent consisting of hydrocarbons, alcohols or their mixtures, in which there is dissolved as solvent at least one polyol. The solvent thereby extracts the arsenic, which is then re-extracted with a counter-solvent.

Abstract: The present invention relates to a composite material comprising a porous lead alloy containing from 0.7 to 1.0% silver or 0.1 to 1.0% calcium or 0.7 to 1.0% silver and 0.1 to 1.0% calcium and having its pores filled by a resin such as epoxy resin. The product has utility as a battery electrode and as a sound absorbing material.