Synthesis of Calcium Hexaluminate from Waste Slag of Aluminum and Oyster Shell

摘要

Waste aluminum slag and oyster shell were used as raw materials to synthesize calcium hexaluminate(CA_6). The effects of different source materials of CaO and sintering temperature on the structures and properties of CA_6 were investigated,respectively. The results show that compared to calcium oxide,oyster shell can lower the formation temperature of CA_6,hence CA_6 can be detected at 1300 ℃ by using oyster shell as the starting raw materials. Increasing the sintering temperature can promote the crystal growth. CA_6 crystals show typical platelet shape,and its optimum sintering temperature falls in the 1450~1550 ℃ region. The bulk density is 1.54~1.83 g/cm^3,the apparent porosity is 44.1~55.2% and the flexural strength is 10.8~25.3 MPa.