Recovery method of magnesium oxide flue gas desulfurization product

Abstract

The invention discloses a recovery method of a magnesium oxide flue gas desulfurization product, belonging to the technical field of resource utilization of flue gas desulfurization products and comprising the following steps of: inhibiting the oxidation of an absorption liquid during circulation desulfurization, facilitating the crystallization and the precipitation of MgSO3 (magnesium sulfite), pumping out concentrated slurry from the bottom of a circulation pool by using a centrifugal pump when the concentrated slurry is reached, filter-pressing the concentrated slurry into a solid through a plate frame, transporting the solid to a professional desulfurization product recovery plant, and reacting concentrated sulfuric acid with the MgSO3 to generate an MgSO4 (magnesium sulfate) serous liquid and an SO2 (sulfur dioxide) gas; and collecting the SO2 through a tiny negative pressure, drying, cooling, liquefying and canning the SO2, filtering, crystallizing and centrifugally dewatering the serous liquid so that the separation of solid-phase and liquid phase impurities is realized, and stoving to form an industrial product. By virtue of the method, the industrial production of MgSO4.7H2O and liquid-state SO2 is realized, a set of green chemical process is created with the flue gas desulfurization, the desulfurization, the recovery efficiency and the economic benefit are improved, and the technical and economical properties of the magnesium oxide flue gas desulfurization are comprehensively enhanced.

Description

technical field [0001] The invention belongs to the technical field of resource utilization of flue gas desulfurization products, in particular to a method for recovering magnesium oxide flue gas desulfurization products, in particular to MgSO, a primary product of magnesium oxide desulfurization 3 to MgSO 4 conversion and product recovery process. technical background [0002] Wet flue gas desulfurization technology is currently the 2 Emissions and acid rain pollution are the most effective and commonly used methods, especially calcium flue gas desulfurization technology, which accounts for more than 80% of flue gas desulfurization in the world. However, the by-product gypsum of this technology has a large output, low price, and low quality. In addition, my country is rich in gypsum, so companies generally have to pile it up idle, occupying a large amount of land resources and causing secondary pollution. At the same time, companies continue to increase desulfurization co...

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Problems solved by technology

However, this process also has obvious deficiencies: ①For low-sulfur coal, the concentration level of the desulfurization liquid is not high, and a large amount of steam is required for concentration; 3 The amount is large, but the MgSO in the thick slurry 3 The oxidation rate is not ideal, generally need more than 30 hours to make 1 ton of desulfurization liquid MgSO 4 The mass ratio is up to 30%. The long-term circulation enrichment increases the loss of each desulfurization equipment and greatly increases the energy consumption of stirring and blowing.

②Continuous generation of MgSO during the cycle detachment process 3 and Mg(HSO 3 ) 2 , some of them have not been oxidized and transformed in time, once out of circulation, it is difficult to re-oxidize and utilize

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