GB189815619A - Improvements in and relating to the Preparation of Sand and like Substances to be Used in Making Moulds and Cores for Casting. - Google Patents

Abstract

15,619. Hargreaves, J., and Poulson, A. July 16. Casting and moulding.-Sand or like material for moulds &c. is prepared by mixing with the sand a mixture of hydrates of silica or alumina, silicate of alumina, or silicates or aluminates of the alkaline earths, or like substances which may be made to give a gelatinous mixture, imparting cohesion to the sand and making the mould porous. The salts may be mixed in the form of solutions. Residual salts, other than the gelatinous mixture, may be washed out if desired. Various methods of obtaining the mixtures are given in the Specification, such as the addition of acid to the silicates, aluminates, &c., or the addition of rosin to a hot solution of them. A suitable composition is as follows :-Sand 1 ton, water 12 gallons, hydrated silica 4 lbs., hydrated alumina 8 lbs., and silicate of alumina, or silicate or aluminate of the alkaline earths, or a mixture of hydrate of silica or alumina and rosin, 12 lbs. To produce smooth castings, bituminous or carbonaceous material such as coal, tar, pitch, &c. may be added to the extent of 2 to 6 per cent.