Relation of Composition of Coking, and ByGEOKGE C. SPKUNK AND KEINIMKDT THIESSEN
U. S. Bureau of Mines Experiment Station, Pittsburgh, Pa.
THE
valiie iinil suitability o? a coal for a certain purpose depends on its rank, type, aiid piirity. 'The rank of u coal is do pendent oir tlie degree of met;iiiiorpIiisni, while tlx t,ype do perids on the different, petrographic constituents. Yieldner et al. (6) define the different tyiies as ( I ) bright, ('2) semisplint, (3) splint, (4) cannel, and ( 5 ) I ~ ~ g l i e coal. ad 'The scparatiorr of coal into t,ypes is not only of a scient,ific interest but is OS ~ a l u ein i t s teclinical practice. Icor eaumple, in Euglt111:1, nccording to Seyler (10) \v/icn tlic 1:tyers of dull and brigliL c o d are tliirk eiioiigh, they are oiteir wparated into soEts (bright coal) and liar& (splint coal) r r i i i l are sold im different purposes. flecently i n Geriiiarr awl l ? i l ~ ~ l l i R I(l i )with , a vicn tu ut,iliziiig the re. tuniitiiius co:il more econoinically, hare iri\w~tmlthe 1,ehiiiann-Iloffman process ?or the seyarat,ion of jii,triigrapliic ingredients. 13y passing the mal tlirwgli an iiiip:x':t iiiill it is pnssihlr to make a separation into liriglit coal, dull coal, : ~ n diusain. It v a s round that a bet,ter mke rould be 011r:tined iroiii the briglit, coal after ren~oviligthe fussin and dull wd Emm a iiiixturc. In Anrerica coal beds having a uiiifonii xriim>scupicul composition are rare. AIaiiy of the beds are composed o? three ur more d e f i d e types of coal which may O D C U ~iii alternating layers. Often these types are repeated a number of times in a single coluinn. This paper covers obser\,ations of the clieinical lielravior of the individual constituents of coals, and also the clreniical and by-product-making properties of types OS coal as t,liey occur iii layers of the same bed.
0
Microscopic Composition of Coal Cual (1) is composed essentially of three visibly different classes of constituents: (1) antliraxylon, (2) attritus, (3) fusain. .~iithr:ixyIw comiirises tlioac constituents in coal derived from tlie wiody tissiies of plants, such as stems, limbs, twigs, and r
