煤的超细粉碎与超净煤的分选

分析了6种不同变质程度煤样的无机矿物组成、嵌布粒度，研究了煤样粒度和煤中无机矿物的解离度与磨煤时间之间的关系,并通过分选试验探明了粉碎粒度、无机矿物解离程度及其种类对分选效果的影响.试验研究表明,只有当煤的粒度粉碎到<10 μm时，无机矿物才能得到较充分的解离；煤中的无机矿物主要是黏土，黏土含量小的煤可以分选出超净煤，反之，黏土和黏土与有机物连生体含量高的煤，很难分选出灰分低于2%的超净煤；黏土含量高的煤，经过球磨后，在煤浆中出现大量和稳定的微小气泡，影响了超净煤的分选精度；低阶煤经球磨后，表面亲水性增加，即使粉碎粒度很细，用絮团-浮选也无法分选出超净煤.

Ultra-fine coal grinding and ultra-clean coal preparation

Six coals of different rank were analyzed and investigated regarding to their constituent and size of embedded minerals, the liberation of minerals against grinding time, and the influence of particle size of ground coal and degree of mineral liberation on separation. The research results showed that the most embedded minerals are clay, which can be sufficiently liberated by coal grinding only down to less than 10 μm; ultra-clean coal can be obtained for coal containing less clay minerals and in the contrary, clean coal with less than 2% ash can hardly be obtained for coal containing more clay minerals finely dissimulated in coal matrix; more stable micro babbles occur in grinding of coal with high content of clay, which hinder the precise separation; for low rank coal, hydrophilicity increased after its grinding, ultra-clean coal can not be obtained even ground to more fineness followed by the flocculation-flotation process.