Brown coal drying technology and system

Abstract

The invention discloses a brown coal drying technology and system. When brown coal containing germanium is processed at present and smoke containing germanium is recycled, due to the fact that brown coal has the characteristics of being high in water content and volatile component, the requirement for production cannot be completely met through a raw material steam drying system. According to the novel brown coal drying system technology, high-temperature smoke generated in a cyclone combustion furnace and brown coal with the water content of about 40% are rapidly mixed, crushed and dried in a crushing airflow drying machine, powdery brown coal with the water content of 10-12% after water removing is brought out through airflow, and the powdery brown coal is used for a cyclone furnace after being collected by a plurality of sets of cyclone dust collectors and a plurality of sets of bag-type dust collectors. The controllability of the system is high. Due to the fact that fuel of the cyclone combustion furnace is supplied through the dried powdery brown coal in the system, the smoke containing germanium is enriched in the dried brown coal for next germanium extraction, and the yield is increased.

Description

technical field [0001] The invention relates to the technical field of lignite drying, in particular to a lignite drying process and system. Background technique [0002] At present, when dealing with germanium-containing lignite and recovering germanium-containing fumes, due to the characteristics of lignite with high water content and high volatile matter, the raw material steam drying system used cannot fully meet the production requirements. The main problem lies in the currently used lignite drying equipment (such as Model ZLG-3, specification? 402×5000 five-pass steam spiral dryer, the design output of a single dryer is 0.5-0.7t / h, the required particle size of the material is 0-5mm, the moisture content of the material after drying is <15%, and the steam Pressure 0.4—0.6MPa, temperature 140°C—158°C.) In actual production, the drying capacity of the steam screw dryer is low, and the material can only dehydrate about 20—25%, and the lignite with a water content of ab...

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Problems solved by technology

[0002] At present, when dealing with germanium-containing lignite and recovering germanium-containing fume, due to the characteristics of lignite with high water content and high volatile matter, the raw material steam drying system used cannot fully meet the production requirements. The main problem lies in the currently used lignite drying equipment (such as Model ZLG-3, specification ? 402×5000 five-pass steam spiral dryer, the design output of a single dryer is 0.5-0.7t / h, the particle size of the material is required to be 0-5mm, and the moisture content of the material after drying is <15%. Pressure 0.4—0.6MPa, temperature 140°C—158°C

) In the actual production, the drying capacity of the steam screw dryer is low, and the material can only be dehydrated by about 20-25%. The lignite with a water content of about 40% reaches 15-20% after being dried by the dryer, resulting in a high water content in the furnace charge. It is relatively large, and the output of drying charge is low. Moreover, the high-temperature steam used for drying charge and the steam used for blowing are large in consumption, and the steam is difficult to recover.

The waste of steam resources is serious, and a large amount of coal dust generated pollutes the workplace and the external environment. The moisture content of the material is so high that the combustion temperature of the vortex furnace is lowered, the volatilization rate of metals is reduced, and the recovery rate is reduced. The production capacity of the vortex furnace cannot be fully utilized. loss of benefits

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