BURNING PREVENTION SAND AND SUPPLY SAND USED IN FURAN SELF-HARDENING CLOSED METHOD

摘要

PROBLEM TO BE SOLVED: To provide mixed sand between silica sand and Ni slag sand used in a furan self-hardening closed method which does not obstruct the hardening of a mold.;SOLUTION: The invention is a refractory mixture used in a furan self-hardening method, and a coarse, spherical refractory produced by the weathering of molten slag essentially consisting of 2MgO-SiO₂ and generated upon Ni refining, which has a grain size in the range of 0.08 to 3.50 mm and AFS fineness number in the range of 8 to 35, and whose surface is treated with organic acid is beforehand mixed into silica sand in the weight ratio of 10 to 70%, and it is blended so as to be applied to the molding of a mold as it is. By beforehand subjecting the Ni slag sand to acid treatment, even if the mixing ratio of the Ni slag sand is increased, the obstruction of the hardening in a furan resin can be improved.;COPYRIGHT: (C)2007,JPO&INPIT