Petrographic structure and composition of the Lower Carboniferous coal seams,western Donbas; their influence on chemical and technological properties of coals

The Lower Carboniferous coals which have been discovered and explored in the western Donbas since the war differ from those in the productive series of the old Donbas in age, petrographic composition and chemotechnological properties. From the Orel' river in the west to me Kal'mius river M the east the following have been recognized in the Lower Carboniferous: Visean coals of the sub-coal measures suite C² ₁(b), Viséan coals of the Samarsk suite C³ ₁ (c), and Namurian coals of suites C⁴ ₁ and C⁵ ₁ (d and c). The Lower Carboniferous coals over most of the western Donbas have (for a given rank) a higher yield of volatiles and primary tar, heat of combustion, sintering capacity, and hydrogen content. The rank increases to the northeast and produces a zonal disposition of coals of industrial type. The degree of coalification also increases with burial of the seams in the southwest limb of the Dneprovsk-Donets basin at depth. The basic aspect of metarnorphisrn is regional.' The petrographic structure and composition of the C³ ₁ suite coals in the western Donbas are responsible for their high chemical potential, whereby these coals are of great interest in the production of metallurgical coke. — C. E. Sears.