Abstract: This process in which the used bath is recycled after concentration at (1) by elimination of water at (2), followed by a treatment for recovering iron oxides at (10), is characterized in that it comprises carrying out a tangential microfiltration at (5) of the concentrated bath so as to separate therefrom the silicon compounds in the non-ionic form and thereby concentrate them, and recirculating the major part of the fraction of this bath (11-17) containing these concentrated silicon compounds so as to promote the precipitation of the non-ionic compounds of the silicon.

Abstract: A process for conditioning carbon rich material in the form of finely divided solid particles includes the steps of mixing at least 70% of the finely divided solid particles with an aqueous solution, mixing in approximately 0.1 to 5% of a surface active additive with foaming properties, homogenizing and aerating the resultant to produce a carbon foam.

Abstract: Process and apparatus for hydrometallurgical treatment of metallurgical dust by acid leaching followed by a solid-liquid separation. The invention is characterized in that the leaching phase is effected by moderate acid attack (pH at the end of the reaction about 4 or 5) and in which a supplementary solid-solid separation stage is provided, before the solid-liquid separation or after. The invention is applicable to all dusts resulting from treatment of metals, notably ironworking dusts, and particularly those formed in blast furnaces so as to permit the separation and recovery of useful elements contained therein, such as iron, zinc and lead.