In 1997, Mr. Liu Mandui, who engaged in the production and research of resin coated sands ot the inspiration from the fused ceramic sand used as the oilfield fracturing proppant. He questioned about if it is a perfect foundry sand. Meanwhile, he made the test on the particle size distribution, refractoriness, pH value, acid demand value and chemical composition of the fused ceramic sand. Furthermore, its strength, gas evolution and permeability using various of binders are also studied. The unique characteristics benefit to foundry use verified Mr. Liu Mandui’s original research ideas.