Zero discharge treatment process of desulfurization wastewater in coking industry

Abstract

The invention relates to a zero discharge treatment process of desulfurization wastewater in the coking industry. The treatment process comprises the following steps: (1) wastewater pretreatment: pumping the desulfurization wastewater in a settling basin and removing most suspended matters through settling separation; (2) oxidation and decoloration: adding an oxidizing agent to the desulfurization wastewater, oxidizing sulfite in the wastewater into corresponding sulfate and oxidizing thiosulfate in the wastewater into solid sulfur and corresponding sulfate; then adding an activated carbon adsorbent to the oxidized desulfurization wastewater to obtain clear materials; and (3) salt extraction through crystallization: separating sulfate and thiocyanate in the desulfurization wastewater respectively by crystallization, wherein heat sources in the steps (2) and (3) come from recovered waste heat of coke oven tail gases in the coking industry. The treatment process is combined with flue gas waste heat recovery, thus achieving triple recovery of coke oven tail gas waste heat, solid salt and high-quality condensed water.

Description

Technical field [0001] The invention belongs to the technical field of desulfurization wastewater treatment in the coking industry, and specifically relates to a treatment process that uses coke oven tail gas waste heat as a heat source to crystallize desulfurization wastewater to achieve zero discharge. Background technique [0002] With the strengthening of national resource conservation and environmental protection, energy conservation and emission reduction are the inevitable choice for building a resource-saving and environment-friendly society. The "Outline" of the "Eleventh Five-Year Plan" puts forward the goal of reducing energy consumption per 10,000 yuan of GDP by 20% and reducing the discharge of major pollutants by 10%. At the same time, it is clearly proposed to develop a circular economy. [0003] At present, it is difficult to treat the thiocyanate-containing desulfurization wastewater produced by the domestic coking industry. The removal of the biochemical treatmen...

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Problems solved by technology

[0003] At present, it is very difficult to treat the desulfurization wastewater containing thiocyanate produced by the domestic coking industry. Going to the biochemical treatment station will poison the microorganisms and kill the bacteria; some manufacturers choose to spray them on the coal yard for coal blending and coking. A large amount of waste water is produced, not only is it difficult to completely absorb the waste water, but it will also affect the original quality of coke, and the excess waste water will pollute the groundwater source due to infiltration

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