Alumina high pressure dissolution dilution ore slurry exhaust steam recovery method

Abstract

The present invention relates to an alumina high pressure dissolution dilution ore slurry exhaust steam recovery method, which is characterized in that alumina high pressure dissolution dilution ore slurry exhaust steam and water are subjected to direct heat exchange during a recovery process. According to the alumina high pressure dissolution dilution ore slurry exhaust steam recovery method, the adopted column plate type large channel heat exchanger process position is that an inlet exhaust steam interface is a hot water tank gas exhaust cylinder, wherein the high pressure dissolution dilution ore slurry exhaust steam passes through the hot water tank, such that an alkali liquid and a material can enter the hot water by gravity settling so as to substantially reduce the alkali carried by the exhaust steam and the material carried by the exhaust steam, and slow down a scab speed of equipment and pipelines. In addition, various levels of column plate flow channels of the column plate type large channel heat exchanger are large and are provided with large cleaning manholes so as to easily clean and repair.

Description

Technical field [0001] The invention relates to a method for recovering the exhaust steam of alumina high-pressure eluted and diluted ore slurry. Background technique [0002] In the alumina production process, the high-pressure stripping and stripping slurry is discharged from the final flash evaporator, enters the dilution tank and is diluted and flashed for further cooling, and then sent to the diluted tank. The exhausted steam after flashing is passed through the wash water heater and spray The water is emptied after heat exchange, and the hot water is sent to the filtered hot water tank. Due to the following defects in the existing wash water heater and process, the exhaust steam and waste heat recovery is not complete and the production operation is abnormal. The main defects are: the spent steam after high-pressure stripping and flashing carries alkali and material, and the heater and pipeline are easily blocked, and the operation period is only about one month; the existi...

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Problems solved by technology

[0002] In the process of alumina production, the high-pressure stripping and stripping slurry is discharged from the final flash evaporator, enters the dilution tank for dilution, and flashes to further cool down, and then is sent to the post-diluted tank, and the exhausted steam after flashing goes through the washing water heater and spraying The water is emptied after heat exchange, and the hot water is sent to the filtered hot water tank. Due to the following defects in the existing washing water heater and process, the waste heat recovery of exhaust steam is not complete, and the production operation is not normal.

The main defects are: after high-pressure stripping and flash evaporation, the exhausted gas with alkali and material, the heater and pipeline are very easy to block, and the operation cycle is only about one month; the existing washing water heater is blocked due to its unreasonable structure and process. Difficult to clean and maintain, resulting in poor operating effect; the heat cannot be fully absorbed and utilized, and there is still a large amount of exhausted steam, resulting in a waste of heat energy

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