Oil removal process for quality improving sewage of coal

Abstract

The invention discloses an oil removal process for quality improving sewage of coal. The process comprises the following steps: a, filtering quality improving sewage of coal to remove large particle pollutants; filtering and feeding into a sewage pool; b, pumping sewage in the sewage pool by using a material feeding pump into a #1 ceramic membrane filter to be filtered; and c, feeding sewage discharged from a drain outlet of the #1 ceramic membrane filter into a #2 ceramic membrane filter to be filtered, returning sewage discharged from the drain outlet of the #2 ceramic membrane filter directly back to the inlet of the material feeding pump, and feeding wastewater discharged from the water outlets of the #1 ceramic membrane filter and the #2 ceramic membrane filter into the next step. By using the process disclosed by the invention for removing oil from quality improving sewage of coal, the oil ratio of effluent is less than 20mg / L, so that the requirement of a subsequent extraction and biochemical system on the oil ratio is satisfied. The oil removal process for quality improving sewage of coal disclosed by the invention is simple, rapid, efficient and energy-saving, the cleaning period reaches 6-8 days, and the process is worth popularizing and applying.

Description

technical field [0001] The invention relates to the technical field of coal chemical industry, in particular to a coal upgrading sewage degreasing process. Background technique [0002] Coal upgrading (the process of indirect heating of raw coal at 600-800°C) technology is still immature, and the wastewater treatment process it produces is blank. At present, the wastewater treatment technology of individual coal upgrading projects is mostly coal coking wastewater or coal gasification Using the sewage treatment technology for reference, the actual operation effect is not ideal, and the investment and operation costs are relatively high. The technologies for treating coal upgrading sewage mainly include: incineration process (including sewage incineration, vapor state incineration before "sewage" is formed), adsorption process (flocculation, adsorption), traditional process (oil removal, dephenolization, ammonia distillation, biochemical treatment and advanced oxidation). ...

AI Technical Summary

Problems solved by technology

[0008] 1) The coal tar content in coal upgrading sewage is high, and the sewage is easy to emulsify during the operation of the extraction unit, which affects the extraction and sewage treatment effect. After a period of operation, the ammonia distillation unit will agglomerate, block pipes, and block heat exchangers, etc. problems that affect the stability of the process

[0009] 2) The oil content in the sewage is too high, which affects the normal metabolism of the bacteria in the subsequent biochemical system, resulting in unsatisfactory biochemical operation results

Generally, media filtration, gravity separation + air flotation and other processes are used, and media filtration is mostly in the form of dead-end filtration. Pollutants in sewage are easier to adhere to and block the filter media, resulting in interruption of operation, frequent flushing, and increased backwash consumption. The amount of water affects the stable operation of the system

For the gravity separation + air flotation process, if air flotation is used, part of the coal tar and ammonia nitrogen in the sewage will be oxidized, which will affect the quality of recovered phenol; when nitrogen is used as the air flotation medium, it is necessary to increase the nitrogen generator to increase the energy consumption of the system.

During the operation of air flotation, the quality of effluent water will be greatly affected by the compatibility of chemicals, water temperature, and the degree of emulsification of oil. The oil content of effluent water is often greater than 50mg / L, which cannot meet the requirements of subsequent processes and biochemical systems with an oil content of less than 20mg / L.

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