Development of CWM Producing Method by Dry Type Pulverizer and Application for Low Rank Coal

Abstract

Coal water mixture (CWM) is a useful technology as a coal fluidification method. Usually, the wet type ball mill is applied as the CWM producing method. However, there is a problem in that the electric power consumption of wet type ball mill is high and the consumption of expensive surface-active agent is also high. To lower the energy consumption and production cost of CWM, Central Research Institute of Electric Power Industry (CRIEPI) is trying to develop the CWM production method using the dry type pulverizer. In this report, to improve the fluidity of CWM, the production method of fine coal particles, which cause Brownian movement is investigated, and the protective colloid injection method is developed to reduce the CWM production cost. The protective colloid injection method can reduce the injection ratio of the surface-active agent by about 30% ∼ 50%. These technologies are developed for bituminous coal, and are also possible to apply for low rank coal like sub-bituminous coal and lignite.