Waste foundry sand is made to be reclaimed sand after calcining at high temperature and grinding. The grain shape of the reclaimed sand is improved and its thermal expansion is reduced significantly. The castings made With reclaimed sand have the following salient advantages:
1.Less thermal expansion reduce the occurrence of cracks, finning, distortion and other casting defects.
2.Because lower binder and catalyst addition are required to achieve equivalent strengths, little gas is produced during the process. Thus it can reduce the formation of casting defects caused by the gas and improve the working environment.
3.Reduced additive can reduce the cost of molding.