Preparation and Properties of Porous Ceramsite from Waste Foundry Sand and Ash

This experiment used waste foundry sand and ash as the main raw materials; with only a small amount of pore-forming agent and stabilizer added, porous ceramsite with excellent comprehensive performance was obtained at a lower sintering temperature. When the content of waste sand/ash is 75 wt.% and the sintering temperature is 800 degrees C, the porosity of the ceramsite is 87.8% and the cylinder compressive strength reaches 3.1 MPa. There is a positive correlation between sintering temperature, waste sand content, and ceramsite physical property (volume density and cylinder compression strength). The SEM images showed that the internal pore distribution of the ceramic particles was uniform. The testing results of the concentration of some heavy metal ions in the leaching solution of ceramsite showed that the leakage of heavy metal ions during use was much lower than the national standard requirements, which indicates the high environmental safety.