Ultrafine coal dewatering: Relationship between hydrophilic lipophilic balance (HLB) of surfactants and coal rank

摘要

Dewatering process is one of the most costly steps in mineral processing and coal washing plants. This fact becomes an important industrial challenge in lignite cleaning. The presence of micropores and relatively low hydrophobic nature of lignitic coal lead to trapping of large quantities of water in the coal matrix especially in fine sizes. Since lignites are used as a common fuel in power stations, they need to be dried to a certain moisture level before feeding to the combustion chamber. Dump feeding in power plants cause inevitable loss of efficiency and may be deleterious for combustion sections. It is thus generally wise to dewater coal as much as possible by physical means before it is dried. However, further dewatering cost in some cases may be prohibitive particularly for fine and hydrophilic particles.