Abstract: A method of and an apparatus for the treatment of mineral coal containing pyrite wherein the mined mineral product is milled, classified into a fine component and a coarse component, the coarse component is recycled and the coarse component in whole and in part is subjected to density suspension so that a light product consisting predominantly of coal is separated from a heavy product comprising the pyrite and mineral detritus. This latter product forms a combustible mixture which is subjected to fluidized bed combustion in the presence of lime to produce an exhaust gas which is used to fluidize the vibrating trough serving as the density separator and as the drying gas and entrainment gas for the mill. The solid residue consists of gypsum (calcium sulfate) and ash and can be used, e.g. in the mixture of cement or plastic, but in any event does not pose an environmental hazard.

Abstract: 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.