一用机械方法开采的苏联烟煤含-0.5毫米的细煤大约20%。这种细煤实际上只能用浮选方法选别。因此,特别是最近时期,煤浮选有很大的发展。大家知道,煤浮选过程并不复杂。然而,更确切些说,这仅仅是掌握它的第一阶段;只有在一定的理论基础上才可能进一步使浮选过程更加完善,特别是 A mechanically mined Soviet bituminous coal contains about 20% fine coal - 0.5 mm. This kind of fine coal can be used only by flotation method. Therefore, especially in recent times, coal flotation has made great progress. We all know that coal flotation process is not complicated. More precisely, however, it is only the first phase of its mastery; it is only possible on a theoretical basis to further refine the flotation process, in particular