Research on Processing Technology of Calcined Kaolin Powder Using A Fluidized Bed Jet Mill at Different Temperatures

Abstract

The calcined kaolin powder was obtained using a fluidized bed jet mill at the temperatures 17℃ and 280℃.The theoretical arithmetic, numerical simulation and experiment were used to compare and discuss the results at the two temperatures. The particle size D 50 =2.401μm 与 D 50 =2.003μm of kaolin powder was obtained. The theoretical arithmetic shows that the outlet velocity of the nozzle at the temperature 280℃ is higher (38%) than that at the temperature 17℃. The grinding kinetic energy of the jet mill at the temperature 280℃is twice as that at the temperature 17℃. The numerical simulation of grinding cavity at the temperatures 17℃and 280℃shows that nozzle axial velocity is 513m/s at the temperature 17℃and nozzle axial velocity is 712m/s at the temperature 280℃. Therefore, the grinding particle size at the temperature 280℃is smaller than that at the temperature 17℃. The yields of calcined kaolin powder and energy consumption of jet mill are obtained through the experiment. The yield of calcined kaolin powder at the temperature 280℃is higher (14%) than that at the temperature 17℃. The energy consumption of air jet mill at the temperature 280℃is higher (30%) than that at the temperature 17℃. The results show that the calcined kaolin powder at the temperature 280℃is beneficial to grinding materials with the smaller particle size and higher yield than that at the temperature 17℃. Otherwise, the energy consumption of jet mill increase from the temperature 17℃to 280℃.