Study Of Mineralogical Characteristics And Their Comparative Of China's Synthetic Mica

With the changes in China's mica consumption structure,the continuous reduction of natural resources,coupled with the unstable quality of natural mica and impurities,and other factors,can often not meet the industrial needs,so the artificial production of synthetic mica has become the inevitable development of the times.In China,synthetic mica began to be researched in the 1950s.In 1963,the Institute of Non-metallic Mining of the Ministry of Building Materials?the former body of the SinomaArtificialCrystalResearchInstitute?successfullysynthesized fluorophlogopite using the internal heat method for the first time;in the research of large crystals of mica,China passed The large mica crystals synthesized by the internal thermal method and the seed method can reach a maximum area of 506 cm²and are currently the largest artificial mica sheets.At present,the world's annual demand for mica products is nearly 500,000 tons,and the annual demand is growing at a rapid rate.It is actively exploring and researching and striving to develop the mica synthesis industry,which has a very broad research value and application prospect.At present,China has become the world's largest producer of synthetic fluorophlogopite and can provide industrial-grade,pearlescent,cosmetic grades and other products of different grades.Although foreign countries have comprehensively introduced the physical and chemical properties of synthetic mica,they lack Chinese product data,especially the lack of reports on the physical and chemical properties of different grades in China and their differences.Therefore,based on the characteristics of synthetic mica,this work has examined some of the important physicochemical properties of synthetic mica of different grades in China's major producing areas,and compared their advantages and disadvantages with natural muscovite and phlogopite.Understanding the quality of synthetic mica products in China and its research and application are all very helpful.In order to learn about the quality of China's synthetic mica and provide a scientific basis for its researches and application,we carried out the study of physical-chemical properties and their comparative of China's synthetic fluorine phlogopite,including various grades such as industry grade,pearly-lustre grade and cosmetic grade from main production regions.Our experimental results proves that China's synthetic mica of various grades almost has the same main chemical components,and the average values of which are??SiO₂?44.08%,??MgO?24.80%,??Al₂O₃?12.92%,??K₂O?11.12%,??F?6.65%.The contents of harmful elements in China's synthetic mica are very low,the average value of Pb+Cd is 0.42×10^-6,and the average value of Pb in cosmetic grade is 0.05×10^-6,which is significantly lower than that in jewelry grade and industry grade.When heated from room temperature to1000?,synthetic mica of various grades present good thermal stability,which almost don not lose weight except weight loss caused by absorbed water.The average value of whiteness is 98.87%,wherein cosmetic grade>pearly-lustre grade>industry grade.The resistivity of synthetic mica are almost the same,and the average values of the volume resistivity and the surface resistivity are 1.79×10⁹?·cm and 1.86×10⁹?respectively,which ensures excellent electric insulating properties.Except resistivity,other physical-chemical properties of China's synthetic mica are much better than that of natural muscovite and phlogopite.