A coking desulfurization waste liquid treatment process and equipment

Abstract

The invention discloses a coking desulfurization waste solution treatment process and device, relating to the technical field of desulfurization waste solution treatment. The coking desulfurization waste solution treatment process comprises the steps that a desulfurization waste solution is subjected to catalytic oxidation by a catalyst in an oxidation pot, and then is transferred to a centrifugal machine for removing elemental sulfur generated in an oxidation process, a flocculant is added into a filtrate under the condition of stirring, meanwhile the PH value of oxidation liquid is adjusted, then settlement is performed for 24 hours, so that Fe (OH)2 colloid produced by the reaction of the elemental sulfur and Fe<2+> in the oxidation liquid and OH<-> in a solution is fully flocculated, supernatant passes through a membrane filtering device so as to remove the flocculated elemental sulfur and Fe(OH)2 colloidal impurities, then filtered liquid is subjected to activated charcoal decoloration in a decolouring kettle, and is put into a filtering machine for treatment, the liquid enters into an evaporation kettle and a crystallization kettle and is subjected to evaporative crystallization, and ammonium sulfate and ammonium thiocyanate products with high purity are produced. The coking desulfurization waste solution treatment process is low in production cost, easy to operate, energy conservation and stable operation are realized, and meanwhile the purity of the products are remarkably improved.

Description

technical field [0001] The invention relates to the technical field of desulfurization waste liquid treatment, in particular to a coking desulfurization waste liquid treatment process and equipment for producing high-purity ammonium sulfate and ammonium thiocyanate from coking desulfurization waste liquid. Background technique [0002] At present, in the process of domestic treatment of coking desulfurization waste liquid, the traditional salt extraction process is: the material enters a separate oxidation tank, and the temperature is raised to catalyze oxidation, so that ammonium thiosulfate is oxidized to ammonium sulfate, and the by-product is elemental sulfur; The oxidizing solution is first centrifuged by a centrifuge to filter elemental sulfur; the obtained filtrate enters the decolorization kettle through a centrifugal pump and adds activated carbon for decolorization, and the decolorized solution passes through a plate and frame filter to separate the decolorized clea...

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Problems solved by technology

[0003] That is to say, the traditional salt extraction process is to directly enter the decolorization section after the desulfurization solution is oxidized. This process has the following disadvantages: (1) Although the solution is filtered by a centrifuge after the oxidizing solution is filtered, it still contains fine particles generated by oxidation that cannot be filtered out by the centrifuge. Elemental sulfur particles, ferric iron, chloride and other impurities will affect the purity of subsequent products, making it difficult to meet the national standard; (2) After the oxidizing solution is filtered, the solution still contains fine particles generated by oxidation, even though it has been filtered by a centrifuge. The elemental sulfur particles that cannot be filtered out by the centrifuge, due to the fineness of these elemental sulfur particles after oxidation and filtration, will form sulfur foams floating on the upper end of the decolorization kettle and adsorbed on the surface of the activated carbon during the decolorization process, which greatly improves the decolorization ability of the activated carbon. Decrease, the amount of activated carbon consumed per unit processing capacity increases; (3) The solution after oxidation and filtration still contains Fe 2+ The ions are stable in the solution, and the existence of this substance will affect the product purity of ammonium sulfate, ammonium thiocyanate and sodium thiocyanate, so that the product purity cannot meet the national standard

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