Heat-insulating products based on exfoliated perlite for steel casting in ingots

Abstract

Heat-insulating inserts of various grades are widely used to warm up the riser section of ingots making killed steel in metallurgical factories of the USSR.The most common of these are the aluminous and magnesium-silicate grades KRTV-I, KRTV-II, and MSTU-II, as specified by TU 14-8-357-80, and also mullite-silica tiles and inserts grades MKRP-340, and MKRV-340 as specified by GOST ~3619-79.Inserts designated KRTV-I are made on the basis of quartz sand, fireclay, unbleached cellulose, with the bond in the form of ligno-sulfonate; the KRTV-II and MSTV-II inserts are produced from quartz sand or calcined dunite, waste paper, asbestos and the bond is carbamide-formaidehyde resin KFMT; the heat-insulating tiles grade MKRP-340 and MKRV-340 are based on mullite-silica fiber (kaolin wool), and the bond is poiyvinyl acetate emulsion PVAD, silica-sol, and lignosuifonate.