METHOD FOR RECOVERING PRESS POWDER PRODUCED BY WET METHOD FROM THE SLUDGE OF GRINDERS MACHINING HIGH-SPEED STEEL SUITABLE AS STARTING MATERIAL FOR PRODUCING CUTTING TOOLS MADE ON SINTERING OR POWDER METALLURGICAL WAY

摘要

Tool steel grinding sludges are dispersed to form a suspension following the addn. of a liq. medium in three settling cylinders (H1,H2,H3) equipped with pistons. The respective cylinders are surrounded by a rotational and a unidirectional magnetic field. The latter being a prod. of several pairs of poles. The cylinders, the liq. medium, and the magnetic fields together form a sepn. system for sepg. solids of the sludge, i.e. metals, into magnetisable perlitic, bainitic, martensitic and non magnetisable austenitic and metal carbide portions and into grinding stone particles which also contain ceramic grains and bonding agents. Liquids, as emulsified cooling lubricating oils and persisting aq. emulsions of polymers are also sepd.. Resultant moist powders are dried by vacuum and heat at 180-200 deg.C. Dried powders are sieved into fractions to suit subsequent mouldings. Moulding powders of predetermined chemical compsn. and of required particle size are obtained by mechanically mixing and homogenising given proportions of individual or mixed powders for the prodn. of high speed cutting tools by means of sintering or power metallurgy.