Effects of Technological Parameters on Carbothermal Reduction and Nitridation of Zircon

摘要

Carbothermal reduction and nitridation(CRN)of zircon(ZrSiO4)permits obtaining different composites of oxides and nitrides such as ZrO2-Si2N2O and ZrN-Si3N4.The effects of technological parameters(carbon source,reaction temperature,and carbon content)on the reaction rate and product phase composition of CRN of zircon were investigated by TGA and XRD.The results show that:(1)carbon source is an important factor for a rapid reaction,and activated carbon is chosen as the carbon source considering the expect products and reaction rate;(2)reaction temperature has vital effect on reaction rate and product.In case of carbon content above 20%,the zircon phase and m-ZrO2 phase decrease with increasing temperature,while the Zr7N8O4 phase increases firstly and then decreases,and the ZrN phase increases continually;(3)different carbon contents result in different reaction products.The higher the carbon content,the lower the starting temperature for the CRN of zircon.