The Recycling Technology Research Of Purification Ash From Calcium Carbide Furnace

Sealed calcium carbide furnace to produce exhaust dust containing 50-150 g/Nm~3, generally by purifying device for processing before recycling. Tail gas purification treatment into the first settler to 40%-50%of the large particles of dust settling down, the air cooler cooling dust, and then into the fine filter bag dust collector, the settler, air cooler and solid dust bag dust collector to collect generally called purification dust ash,hereinafter referred to as purification. The main way for the landfill, and ash content contains high calcium oxide, magnesium oxide, alkali and cyanide and so on, will cause serious environmental pollution and resource waste. Therefore, to improve purifying the ash recycling technology has great environmental, economic and social benefits.This paper first analyzes the purification mechanism, the physical and chemical properties, make use of to choose to purify a gray alternative to burning charcoal powder of the recycling program, through the purification ash collecting system, pipeline system, terminal storage system, burning system, ash recycling system and so on five big system through analyzing the existing defects of the original design process and the optimization design, one good results were obtained in production practice. The main work is as follows:1. Purifying ash physical and chemical properties analysis showed that purification ash calcium and magnesium content is higher, low water content, almost negligible, compared with blue at the end of the carbon is about 6 times of carbon at the end of the volatile, carbon content is about at the end of the carbon of the half, calorific value is less than a third of the LAN at the end of the carbon.2. Original purification ash storage warehouse using artificial control dust discharging valve, after the improvement, storage warehouse and nitrogen tank connection, ensure sufficient nitrogen concentration, to prevent purification grey spontaneous combustion, and the system automatically start ash storage warehouse transportation program, transportation again after the completion of discharge, such intermittent transmission.3. The original delivery process using ash dump truck, high cost and pollution of the environment and security risks. After the improvement, the pneumatic conveying technology, realize the enclosed delivery, ensure the safe transportation, reduce the ash discharging, transportation pollution to the environment.4. Purification of pipeline and ash concentration is stored in conical ash storage tank. Original storage systems did not pass into the nitrogen protection, prone to spontaneous combustion, not add fluidization board, under the grey not free easy pipeline, bring great difficulty in maintenance and repair work. After the improvement, solve the purification under the grey wall sticking, ash and pipeline, ash content is difficult to control and dust explosion risk, and many other problems.5. Using pure blue carbon powder fluidized bed duct when the pressure is higher, when using purify gray, duct fluidized bed pressure drop. Using purify gray instead of blue carbon, therefore, appropriate to reduce fluidized bed duct pressure, and the effect is better.6. Optimizing the ash recovery system design, namely the top mounted cyclone in ash storehouse, large particles of ash after a whirlwind settlement directly into the ash bin, a small amount of fine in the ash slag and ash content in the suction to sack dust catcher by the negative pressure pipe. The technology has good effect, not existing burning problems, extending the bag replacement cycle, at the same time reduces the maintenance workload.