Method for processing secondary salt in desulphurization waste liquid

Abstract

The invention relates to a method for processing secondary salt in desulphurization waste liquid, comprising the following steps: a, carrying out pre-treatment on the desulphurization waste liquid, and removing the impurities in the desulphurization waste liquid; b, conveying the desulphurization waste liquid to a de-coloring kettle via a centrifugal pump; c, after atomizing via the nozzle of a spray dryer, drying the desulphurization waste liquid, so that Na2S2O3, Na2SO4 and NaCNS secondary salts can be separated by a manner of solid salts, and recycling the secondary salts which are adopted as inorganic salts to realize the discharge without wastewater. The method for processing the secondary salt in the desulphurization waste liquid disclosed by the invention can rationally process the waste liquid which is produced in the desulphurization step in gas production factories and has a high content of the secondary salt, realizes the discharge without wastewater, effectively recycles the waste heat of systems, realizes the reuse of the heat, reduces the production cost, has simple process and has performance of environmental-friendliness.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for treating secondary salt in desulfurization waste liquid. Background technique [0002] At present, the domestic water gas purification process generally uses Na 2 CO 3 As the alkali source, phthalocyanine cobalt sulfonate ammonium (PDS-600) is used as the catalyst, and the H in water gas is removed by wet oxidation method 2 S craft. The water gas produced by the gas plant enters the bottom of two series-connected desulfurization towers in turn, and contacts the desulfurization liquid sprayed on the top of the tower in reverse, and removes most of the H in the water gas under the action of the PDS-600 catalyst. 2 S. The desulfurization liquid discharged from the bottom of the two desulfurization towers is transported to the rich liquid tank, and then pumped to the regeneration tank by the rich liquid pump, after flotation in the regeneration tank, the ...

AI Technical Summary

Problems solved by technology

Although the method of directly discharging to the coal yard is simple, it will destroy the quality of coking coke, increase the energy consumption in the coking process, the materials cannot be recycled, waste materials, waste water cannot be recycled, and water resources are wasted; although electrodialysis Thiocyanate can be produced, but industrialized production has not been realized due to the complicated treatment process, high device cost, and large power consumption; the thiosulfate conversion method has many operating steps, and the reaction needs to be carried out in a pressure vessel, which requires a large investment; The acid decomposition method has problems such as complicated process, high cost, and low yield, and it is difficult to realize industrial production; the evaporation crystallization method is to extract secondary salts through evaporation, concentration, crystallization, separation and other operating units and their combinations, but there are difficulties in process parameters. Control, unsatisfactory secondary salt separation, low purity when sold as inorganic salt products, etc.

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