Figure 1 4 general Commentaries on coal As ARRUDA (1981) the existing types of coal in the south region of Brazil are antracito (half-antracito, antracito and goal-antracito), bituminous (high volatile, high the volatile B, high volatile C, volatile volatile and low medium), sub-bituminous (sub-bituminous, B and C) and linhito. All these types of coal can occur in Santa Catarina, Paran and Rio Grande Do Sul. In Santa Catarina the types predominate bituminous high the volatile medium in the layers Pretty (bituminous high volatile), White Adobe (bituminous high medium the volatile one) and Irapu (bituminous high volatile). In the Rio Grande Do Sul the types predominate sub-bituminous in the cities of Candiota and Recreio sub-bituminous coals, Teresinha Saint we have sub-bituminous coals for bituminous high to the volatile medium. 4,1 Chemical constitution of the coal the constituent of the coal are carbon, hydrogen and sulphur, the mineral materials gifts in the coal are argilas, piritas and calcareous rocks, the oxides gifts are aluminum and silicon. The coal can be defined basically as being a combustible rock sedimentary, formed from determined vegetal, that had suffered to burial and compacting in originally little deep basins.
The diverse periods of training of carbonificao, of the minor for the greater rank, follow the sequncia: turf? sapropelito? linhito? sub-bituminous coal? bituminous coal? antracito. The minimum period of training for the industrial use of the coal is of the linhito. 7 Combustion of the coal the main purposes of the direct combustion of the coal are industrial vapor generation, termoeletricidade, heat of process in ovens and furnaces in the industry of the cement, glass, ceramics, agricultural drying of minerals and grains, locomotives the coal, in other words, the burning of the coal if make necessary in the industry because of the energy that is set free through its burning. The direct burning constitutes the form cheapest, efficient and traditional in the use of the coal as power plant.