Study on moisture and ash characteristics of clean coal products of Linhuan Coal Preparation Plant

The study is made with the clean coal product of Linhuan Coal Preparation Plant as the object with an aim to make a thorough investigation into the compositions of moisture and ash of the total clean coal and their sources, so as to seek the new approach for reducing the moisture and ash of the coal and tackle the problem caused by high moisture and ash of outloaded clean coal. The compositions of moisture and minerals as well as the surface properties of the coarse coal and coarse slime, two kinds of clean products obtained in separate washing of two different kinds of raw coal, and the flotation concentrate are explored by means of thermogravimetric analysis, X-ray diffraction analysis (XRD) specific surface area analysis (BET) and scanning electron microscopy analysis (SEM). Results of study show that the Linhuan clean coking coal obtained through separate washing has a moisture of over 12%; for reducing the moisture of total clean coal product, the Linhuan coking coal and the fat coal from Xutuan Mine should be washed preferably in a mixed manner; compared with the flotation concentrate of Xutuan fat coal, the Linhuan coking coal flotation concentrate is noticeably larger in specific surface area and pore volume, causing therefore the latter to have a higher moisture; and the gangue minerals in coarse clean slime are predominantly associated minerals while in the flotation concentrate the gangue minerals are chiefly distributed on surface of coal particles in form of fine mud cover. The research-derived achieved achievements can serve as a theoretical guidance and provide data support for effective dewatering, reduction of ash and upgrading of the clean coal products of Linhuan Plant.