对应用高压电选机制备低灰洁净煤进行了理论及试验研究。首先从原料煤的煤岩组成及介电性质研究入手，对粉状物料介电常数的测量方法和计算公式进行了深入研究及理论修正，在此基础上选定原料煤，并进行了电选机操作参数及入料性质等多因素的试验研究。研究结果表明：原料煤的煤岩级成及介电常数是判断其电选可选性的有效依据；煤与大部分矿物质有较大的介电常数差导；分级给料、中等转速及中高电极电压会带来良好的分选效果。最后，通过研究制备出了灰分小平3%的低灰洁净煤，高压电选技术为煤的洁净利用开辟了一条新的途径。

The effect of removing pyrite and ash from fine coal with electrostatic separator is determined by the electric property of coal, the distribution of corona ion and electrostatic field, and the disperse and even feed. The dielectric constant of coal and mineral matter is studied in this paper and the amendment has been made to survey theory. The oscillogram is adopted to study the distribution of corona ion and electrostatic field. The paper details the study of remoing pyrite and ash from fine coal, and the test results demonstrate the high efficiency of removing pyrite and ash with electrostatic separator.