Lignite drying process and system

Abstract

The invention discloses a lignite drying process and system. At present, when dealing with germanium-containing lignite and recovering germanium-containing fumes, due to the characteristics of high water content and high volatile content of lignite, the raw material steam drying system used cannot fully meet the production requirements. The technology of the new lignite drying system adopted by the present invention is to use the high-temperature flue gas produced by the cyclone combustion furnace to quickly mix, crush, and dry the lignite powder with a moisture content of about 40% in the crushing airflow dryer to reach 10-12% After being taken out by the air flow, it is collected by multiple sets of cyclone dust collectors and bag filter, and then used in the cyclone combustion furnace. The controllability of the system of the present invention is relatively strong, because the fuel of the cyclone combustion furnace is provided by the dried powdered lignite in the system, and the generated germanium-containing smoke is enriched in the dried lignite for the extraction of germanium in the next step. Increased production.

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, Ø402×5000 five-pass steam spiral dryer, the design output of this dryer is 0.5-0.7t / h, the required material particle size is 0-5mm, the moisture content of the dried material 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 be dehydrated by about 20—25%. 15-20%, resulting in high moisture content in the charge, large pa...

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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, Ø402×5000 five-pass steam spiral dryer, the design output of this dryer is 0.5-0.7t / h, the required material particle size is 0-5mm, the moisture content of the dried material is <15%, and the steam 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 cyclone combustion furnace is lowered, the volatilization rate of metals is reduced, and the recovery rate is reduced. The production of the cyclone combustion furnace cannot be fully utilized. ability, resulting in the loss of benefits

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