Microscopy: Xylite classification

Important for the construction and dimensioning of mills, which for example are installed in generating stations and refinement plants to crush coal, is the content of varieties of fossil wood in the lignite seam.

For evaluating the xylite content in lignite two methods can be used. The identification of the microlithotypes eu-xylo-textite, medio-xylo-textite and gelo-xylo-textite takes place by QMAT. The sum of these three microlithotypes (XT) results in the xylite content.

The microlithotypes eu-xylo-textite includes not only fibrous xylite but also cellulose-containing parts of brittle xylite. Hence, for specification of fibrous xylite, which interfere with the technological and milling process, the selection method after Jacob & Wagner-Beeger1) is applied additionally to the fraction > 1 mm. Using the stereomicroscope fibrous xylite as well as brittle xylite (plus subsidiary texture and gel xylite) are picked out separately.

1) JACOB, H.; WAGNER-BEEGER, S., 1955. Zur Methodik und praktischen Bedeutung der Bestimmung des Xylitgehaltes in Weichbraunkohlen. Freib. Forsch.-H. A 44, 80-95.