Preparation Of Lithium Silicate Powders By Wet Chemical Method

Energy shortages become the focus in each country, with the human society continuous development. To some extent, studies of nuclear energy solve the energy problems that mankind faces. In order to achieve controlled nuclear fusion energy and commercialization, the United States and the Soviet Union proposed construction of the International Thermonuclear Experimental Reactor (ITER) program at the Geneva summit, in1985. There is a test blanket module (TBM) in ITER program. The module is designed to validate the commercial fusion tritium production reactor and how to get energy. Li4SiO4ceramic microsphere is tritium breeder agent in test blanket module. Therefore, the study of preparation and properties of lithium orthosilicate pellets is very important for experimental verification in test blanket module.In this paper, lithium orthosilicate powder is prepared by sol-gel with the lithium acetate and TEOS as a raw material, deionized water and ethanol as solvents, ammonia as a catalyst. When the reaction temperature is80℃, pH value is7, the amount of water/ethanol/TEOS molar ratio=15:4:1, the dry gel is prepared. And then it is sintered for2hours at700℃. At this point average grain diameter of the lithium orthosilicate powder is minimum size, about50nm.In this paper, polyvinyl alcohol is used as a gelling agent. Different types of PVA lead to different solubility, dissolution time and dissolution temperature. In this paper the model PVA-124is used. When the PVA concentration is less than9%, the dissolution temperature is80℃, the dissolution time is2h, polyvinyl alcohol can be completely dissolved.In this paper, when H2O/Li4SiO4/PVA mass ratio=15:10:1, the mixture is dropped into hydrogen peroxide solution that a small amount of silicone oil attach to the solution surface can gain good pellets. And then these pellets are sintered at1000℃for2h with a constant heating rate of2℃/min that get the largest crushing strength.