A mixed-material lignite drying and upgrading method and the device used therein

Abstract

The invention provides a mixing type brown coal drying and upgrading method and a used device. The method includes the steps that raw brown coal is crushed through a crushing device and then sent to a screening device to be screen, screened lump coal with the particle size being over 5-8 mm is sent to a drying device and dried at the temperature of 150-350 DEG C, so that the moisture in the brown coal is lowered to below 5%-10%, dried hot brown coal with the temperature being 50-150 DEG C is sent to a cooing device to be cooled, and the temperature of the dry brown coal is lowered to 40-80 DEG C; the dry brown coal obtained after preliminary cooling is sent to a mixing device, the dry brown coal is mixed with and in contact with crushed raw brown coal or the screened powdered coal with the particle size being 5-8 mm according to the weight ratio of 1 to 20%-60% in the mixing device and generates heat transfer, and finally the upgraded coal with the temperature being 20-40 DEG C is obtained. According to the mixing type brown coal drying and upgrading method and the used device, the brown coal after upgrading can be directly used for being transported or piled and stored, spontaneous combustion does not occur easily, and the calorific value of the brown value is improved.

Description

technical field [0001] The invention relates to a lignite upgrading process and device in the technical field of lignite and other low-rank coal drying, in particular to a mixing type lignite drying and upgrading method and the device used. Background technique [0002] China is rich in lignite resources, with proven reserves of 130 billion tons, accounting for 13% of the country's total coal reserves. Lignite is a low-rank coal resource, with a moisture content of more than 25%, and is prone to weathering and spontaneous combustion, so it is not conducive to long-distance transportation and storage. The direct combustion of lignite not only has low thermal efficiency, but also causes serious pollution. The deep processing and utilization of lignite, such as coal gasification and liquefaction, also needs to reduce the moisture content of lignite to less than 10%. Therefore, it is necessary to dry lignite for development and utilization. dehydration. [0003] Domestic ligni...

AI Technical Summary

Problems solved by technology

In view of the above two common methods: the first method needs to shape lignite. Domestic lignite itself is an old lignite that is difficult to shape. The molding rate is not high. Some lignite molding processes even need to add binders, and lignite high pressure molding The price is expensive, so this method will not only increase the equipment investment, but also greatly increase the production cost; the second method will transport the high-moisture lignite for a long distance, which will greatly increase the transportation cost, so it is necessary to develop a method that can The dried and upgraded lignite is directly used for transportation or storage

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