High-quality steam coals

NoritPAC 20B High quality steam activatioa Selected grades of coal Less than 100 mesh (150l%i) -95%. Less than 200 mesh (75Pm)-87% Less than 325 mesh (45l m) -80% Color bodies compounds causmg taste and odor... 

Coal Used. The coal charged in all the tests discussed here was a single batch of high-volatile bituminous coal (Bruceton, Pa.) that had been pretreated at 450°C with a steam-air mixture to destroy its caking quality. The pretreated coal was crushed and sieved to a particle size of 20 to 60 mesh. Proximate and ultimate analyses of the pretreated coal are shown in Table I, in weight percent. 

Indirect coal liquefaction first gasifies the coal with steam to form synthesis gas (syngas—a mixture of hydrogen and carbon monoxide). The sulfur is removed from this gas and the mixture is adjusted according to the desired product. The synthesis gas is then condensed over a catalyst—the Fischer-Tropsch process— to produce high-quality, ultraclean products. 

A tendency toward a decrease in coal quality is reported from various parts of the world, especially in the coking coal sector. In terms of steam coals, countries such as South Africa [1], India [2], Japan [3], or even China [4] report about utilization of coal with elevated ash content. According to MacDonald et al. [5] and the ISO 11760 classification [6], coals are referred to as high ash or moderately high ash if they have an ash yield greater than 20 wt% (wf). In terms of gasification, several disadvantages can be expected as the ash content increases ... 

The charcoal required for firing and reduction processes took enormous quantities of wood and rapidly depleted forest stands near smelters in Europe and North America [4, 5]. This led to many attempts to fire blast furnaces with coal with uniformly poor results. The sulfur content of the coal produced a high-sulfur iron which made it brittle when hot, an undesirable property. Gradually it was learned that prior coking of the coal could be used to obtain an equivalent quality of iron as could be obtained using wood charcoal. Only subsequently it was learned that sulfur in the coal produced the brittle iron. As the size of blast furnaces became larger, the steam engine became available to provide power for the air blast. 

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