Treatment processes of coke oven gas desulfurization and decyanation waste water

Abstract

The invention discloses a subsequent disposing method of waste water through HPF method, which comprises the following steps: adding activated charcoal in the waste water to decolor; filtering to obtain supernatant and waste activated charcoal; returning waste activated charcoal to coal field into coke oven; evaporating supernatant under decompressing condition; condensing; cooling condensate to indoor temperature to obtain the solid of multi-amino composite salt; returning steam in the evaporating course into desulfurizing decyanating device to recycle after condensing.

Description

technical field [0001] The invention relates to waste water formed after desulfurization and decyanation treatment of coke oven gas, in particular to a subsequent treatment method for waste water formed after desulfurization and decyanation treatment of coke oven gas by using an ammonia liquid phase catalysis method, and belongs to the technical field of separation and recovery of industrial waste water. Background technique [0002] In the coking industry, the desulfurization and decyanation treatment of coke oven gas is a very important process. There are many desulfurization and decyanation processes, among which the AS method has the lowest investment, but the desulfurization and decyanation efficiency is poor; the ADA method and the HPF method (ammonia liquid phase catalytic method) with higher efficiency are available. In comparison, the ADA method consumes a lot of raw materials and has high production costs; while the ammonia water liquid-phase catalytic method uses ...

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Problems solved by technology

Shanghai Baosteel Group uses this wastewater treatment process, but this method requires high equipment and high production costs, and generally small and medium-sized enterprises cannot use it.

The second method is the ammonium thiocyanate recovery technology proposed by the Shanghai Research Institute of Chemical Industry. This method is used in Suzhou Iron and Steel Plant and Tianjin No. 2 Gas Plant. The disadvantage of this method is that only part of the thiocyanate can be recovered from waste water. Ammonium, the remaining solids (mainly containing ammonium sulfate, ammonium thiosulfate, ammonium thiocyanate and impurities) cannot be processed, they are piled up and lost in large quantities, causing secondary pollution; moreover, the catalyst used in the desulfurization and decyanation process species has a greater impact on this method, which further limits the generalization of the method

The third method is to return the waste water to the coke oven, which will not only cause equipment corrosion, but also the problem of sulfur accumulation will become more and more serious

[0004] It is precisely because of the above technical problems that some enterprises, especially small and medium-sized enterprises, cannot handle coke oven gas desulfurization and decyanation wastewater. These wastewater are discharged without effective treatment, causing environmental pollution in some areas serious

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