Process for preparing refractory molded articles and binders therefor

Abstract

This invention provides a process for preparing a refractory molded article comprising the steps of (a) forming a molded article matrix from an aggregate and the first binder, (b) impregnating the molded article matrix formed in step (a) with the second binder consisting of an alcoholic solution of one kind or two or more kinds of metal alkoxides selected from alkoxides of metals of Group 4A or Group 4B (excepting carbon) and Group 3A or Group 3B of the periodic table and their partial hydrolysates and an alkaline compound of alkali metal or alkaline earth metal (one kind or a mixture of two or more kinds selected from alkoxides, hydroxides and salts of the metal) and (c) drying and firing the molded article matrix at high temperature and also provides a binder for the preparation of such refractory molded article. The invention provides a process for preparing a refractory molded article and a binder with advantages such as casting of a molten metal without generation of gases and prevention of such defects as blow holes, good flow of a molten metal enabling thin-wall casting of steel, reduced requirement of riser in steel casting compared with cold casting, good dimensional precision, wide applicability to materials ranging from light alloy to steel, and an inner part for adjustment of strength and improvement of crumbling characteristics.