Microwave drying and upgrading method of lignite or coal slime

Abstract

The invention discloses a microwave drying and upgrading method of lignite or coal slime. The method is characterized in that coal is preheated and performs thermal dehydration treatment before drying and the waste heat generated by coal in the drying process is utilized to perform the hot press moulding of coal. By adopting the method of the invention to perform the drying and upgrading of lignite or coal slime, the effects of reducing the energy consumption and increasing the quality and the cost of microwave drying can be further reduced; and the method is a brand-new drying and upgrading method of lignite or coal slime.

Description

Technical field [0001] The invention relates to a coal drying method, in particular to a microwave drying and upgrading method for lignite or coal slime. Background technique [0002] At present, the commonly used drying and upgrading equipment for lignite and coal slime at home and abroad mainly include drying furnace or drum dryer. Many years of production practice have found that this technology has the following problems: ① The moisture content of the powder and lumps in the dried product is not uniform, The powder is over-dried, but the lumps are not dried enough; ②The lump coal is smashed during the drying process, and the product is excessively crushed; ③The drying amount is small, and it is difficult to control the temperature; The temperature of the surface is higher than that of the inner surface, and the heating is uneven; ⑥ It is not easy to dry the inner water. These problems make the application of this technology greatly restricted. In recent years, microwav...

AI Technical Summary

Problems solved by technology

[0002] At present, the commonly used drying and upgrading equipment for lignite and coal slime at home and abroad mainly include drying furnace or drum dryer. Many years of production practice have found that this technology has the following problems: ① The moisture content of the powder and lumps in the dried product is not uniform, The powder is over-dried, but the lumps are not dry enough; ②The lump coal is smashed during the drying process, and the product is over-crushed; ③The drying amount is small, and it is difficult to control the temperature; The temperature of the surface is higher than that of the inner surface, and the heating is uneven; ⑥It is not easy to dry the inner water

These problems limit the application of this technology

In recent years, microwaves have been used for drying coal. Under the action of microwaves, microwave energy preferentially heats water instead of coal. It is more suitable for drying lignite and coal slime, but existing methods are not suitable for lignite and coal slime. Drying, high drying cost, and no comprehensive consideration of product quality