Coal meta-anthracite

George Kapo. What percentage of the carbon in meta-anthracite coal do you think is in the platelets (800-1000 A.) you observed ... 

The meta-anthracite sample behaved in a completely different way compared with the rest of the coals. It had a negligible capacity for argon consequently, diffusion measurements could not be made. Helium, even at 250°C., could not enter into its micropores. Helium was shown to be able to pene-... 

The critical dimension of the micropores in anthracite is large compared with that in coking bituminous coal, but when the meta-anthracite region is reached the microporosity disappears. 

High-rank coal Refers to anthracite, meta-anthracite, and bituminous coals, which are relatively low in moisture, high in combustible carbon, and have high heat contents (compare low-rank coal, lignite, and subbituminous coal). 

It is interesting that a bituminous coal (Sample 4) gave organic acids qualitatively similar to those of lignite coal see Figure Id). Major identified compounds were p-hydroxybenzoic acid and two isomers of hydroxybenzenedicarboxylic acid, benzene di- and tricarboxylic acids. No ortho or meta isomer of hydroxybenzoic acid was detected. We have found that solvent-extractable hydrocarbons obtained from this raw coal consist mainly of n-alkanes (Cjj to 3 ). This is quite different from other results which showed that aromatic hydrocarbons were the major solvent-extractable material of several bituminous and anthracite coals (21). Indeed, petrographic analysis shows that this coal has a high content of sporinite (14.3 wt %) and a low content of vitrinite (30.2 wt %) (33). 

Anthracite is the highest rank of coal and has a carbon content of over 87% on a dry ash-free basis. Anthracite coal generally has the highest heating value per ton on a mineral matter-free basis. It is often subdivided into semianthracite, anthracite, and meta-anthracite on the basis of carbon content. Anthracite is often referred to as hard coal but this is a Layman s term and has little to do with the hardness of the coal. 

ASTM class cation, group name Meta an- thra- cite Anthracite Semianthradte Low-volatile bituminous coal Medium-volatile bituminous coal High-volatile A bituminous coal -[ -volatile B bituminous coal High-volatile C bituminous coal and subbituminous A coal Subbituminous B coal ... 

---