Laboratory Studies of the Combined Method of Dehydration by Internal Heat Sources in the Conditions of Electric Heating

Abstract

The constant deterioration of the quality of iron ore necessitates the processing of hard-to-enrich minerals that require deep enrichment, and complicates dehydration. Coal processing plants widely use processes carried out in aquatic environments, during which, along with the separation of mineral impurities in the coal remains a significant amount of ballast - water. Therefore, the final operations in the enrichment process are mechanical and thermal dehydration of coal enrichment products, primarily coal concentrates and sludges. The main difficulties are the drying of flotation concentrate (0…0,5 mm) and fine concentrate (0,5…6 mm), which retained after mechanical dehydration residual humidity of 23…27 % and about 13 %, respectively, which necessitates additional heat drying, the quality of coal concentrate, fuel consumption, energy and metal consumption of the process depend on the method and hardware design. The use of thermal drying for humidity adjustment is associated with a sharp increase in investment and consumption of scarce energy, which in today’s raw materials market and the situation in the economy are impractical. Dehydration by filtration on vacuum filters, which has become widespread in concentrators, does not allow obtaining enrichment products with conditioned humidity. At the raised humidity of concentrate expenses for its transportation to the consumer increase, and in the winter time it’s freezing in railway cars is possible. The development of effective methods for drying and heat treatment of dispersed materials is becoming important in practice due to the high requirements for the quality of finished products and the need to move to energy- and resource-saving technologies. Dehydration of sludge sediments is a big problem, because the existing filtration methods are not very suitable for this. Thus, the establishment of patterns of dehydration of finely dispersed materials is an urgent scientific task.