Study of Microscopic Structure of Ceramic Materials Prepared from Nonmetallic Mineral Group Associated with Skarn-Type Gold Deposits

摘要

The microscopic structure of ceramic bodies has an essential influence on their performance. In this study, a ceramic material was prepared by modifying a nonmetallic mineral group (J) associated with a skarn-type gold mine in Hubei. The nano and microsized structures of thefired ceramic bodies under different contents of nonmetallic mineral group (J) and varying temperature conditions were systematically observed and tested by scanning electron microscopy (SEM), Malvern laser particle size analysis, differential scanning calorimetry (DSC) and X-ray diffraction(XRD). The J content affects the sintering and melt degree of the ceramic body, the contact mode of the particles inside the ceramic body and the pore structure. When the content of J is less than 70%, the performance parameters of the sintered body can meet the requirementsof Group AII in the International Standard of Ceramic Tiles. It is concluded that the microscopic structure of the ceramic body is affected by the complex phase transition process including the dehydration, oxidation, melting and recrystallization of nonmetallic minerals during the firingprocess and is closely related to the properties of the ceramic body. It is feasible to improving the properties of ceramic bodies by adJusting the gradation parameters of J and increasing the proportion of fine grains under the same dosage. Considering the features of the ceramicbody and J′ utilization ratio, the optimum content of nonmetallic minerals associated with the skarn-type gold deposit in Hubei Province is 68–43%, and the optimum sintering temperature is approximately 1150 °C.