Methods for the petrographic analysis of bituminous coal and anthracite -- Part 4: Method of determining microlithotype, carbominerite and minerite composition
This standard has been revised by ISO 7404-4:2017.
This part of ISO 7404 applies only to determinations made on polished particular blocks using reflected white ligth. The examination is carried out by using reflected ligth microscope and point count procedure. The microlithotypes are identified from their maceral composition under an immersion medium. The proportions of the macerals are determined using a graticule having a grid with 20 points of intersection.