Method of and apparatus for the dry separation of pyrite from coal

摘要

A dry method of removing pyrite from mineral coal in which the coal is mill-dried in a milling gas stream and the milled product is subjected to classification to recover a predominantly coal combustible fine fraction and a gravel or coarse fraction containing mining detritus, pyrite and coal. The gravel or coarse fraction, according to the invention, is subjected to density separation in whole or in part before being recycled to the milling stage and the density separation separates a light coal fraction from a heavy fraction containing the pyrite and detritus. This coal fraction can be returned to the miling stage while the heavy fraction can be subjected to further separation to recover the pyrite for other use or treatment.