Investigation of leaching behaviour of selected coal
Date
2020-06-08
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Publisher
German Mongolian Institute for Resouce and Technology
Abstract
This bachelor thesis aimed to study chemical demineralization and desulphurization of selected coal by using various inorganic and organic acids, alkalis, oxidizing agents and their combination to reduce the ash and sulfur content of coal. Throughout the study, chemical enrichment of low-grade coal was an effective method of reducing minerals of low value coal to upgrade into high quality coal.
Currently global development is moving towards a clean energy but coal still plays an important role in producing energy supply worldwide. High quality coal reserves are gradually depleting while cost of the higher quality coal mining is becoming more and more expensive which leads to economic disadvantage. Fortunately, low grade coal reserves are still abundant and could be used as an alternative energy source to minimize the cost. Yet low grade coals are not only having high content of minerals and moisture which gives serious impact on their consumption but also along its usage the formation of unwanted, toxic metals and harmful gases emissions leads into critical environmental issues. Therefore, the purification of low grade coal using bacteriological, physical or chemical processes becomes extremely important. Physical enrichment methods have very limited effect on the low grade coals to produce low ash coals. In such low grade coals chemical enrichment method could reach much higher degree of demineralization due to its effect on the structure of coal. Chemical reagents diffuse inside the carbon matrix through the pores and subsequently dissolve the unwanted minerals.
Similarly, in Mongolia there are abundant coal reserves in several regions but high grade coals are depleting while low grade coals have high ash, moisture and sulfur content.
Especially, the coals that have acceptable coking property but have high content of sulfur and ash are very suitable to be processed by chemical beneficiation method than bacteriological and physical methods.