MOLDING SAND FOR MAKING DISPENSABLE CASTING MOLDS AMD PROCESS FOR PREPARING IT Russian patent published in 2004 - IPC

FIELD: foundry, namely manufacture of dispensable casting molds at making castings of cast iron, steel, aluminum. SUBSTANCE: molding sand contains, mass%: bentonite, 7 - 8%; industrial-grade carbon, 0.01 -0.5; water, 7.0; surface active matter such as monoalkyl ether of polyethylene glycol on base of primary aliphatic alcohols, 0.0005 - 0.025; refractory filler, the balance. Industrial-grade carbon is preliminarily treated with surface active matter. Water, refractory filler and bentonite are added to prepared suspension and agitated in edge- runner mill for 10 - 15 min. Industrial-grade carbon has optimal fraction size and linear structure of aggregated particles. Due to treatment by means of surface active matter such carbon has hydrophilic properties providing uniform distribution of it in molding sand. EFFECT: enhanced strength, gas permeability, burning-prevention properties of molding sand with reduced gas generating capability. 2 cl, 2 tbl, 3 ex