A MOULD AND A METHOD FOR THE CASTING OF METALS AND REFRACTORY COMPOSITIONS FOR USE THEREIN

摘要

A mould for metal casting contains a bonded refractory composition comprisin g hollow stamina-containing microspheres in which the stamina content is at least 40 % by weight. The mould may be an ingot mould and the bonded refractory composition may be in the form of a sleeve or boards located in the top of the mould or in the head bo x thereto. The mould may be a sand mould and the bonded refractory composition may be in the form of a sleeve or boards located in a feeder cavity or in the form of a board or pad located so as to constitute a metal casting surface where it is desired to promote directiona l solidification in cast metal. The bonded refractory composition may also be in the form of a breaker core. In a preferred composition the microspheres contain stamina and silica and the composition may also contain one or more other particulate refractory materials, a readily oxidisable metal, an oxidising agent for the metal and a fluoride salt.