Mixed desulfurizing agent prepared from red mud and seawater and flue gas desulfurization method with mixed desulfurizing agent

Abstract

The invention relates to a mixed desulfurizing agent prepared from red mud and seawater and a flue gas desulfurization method with the mixed desulfurizing agent. The invention is characterized in thatthe mixed desulfurizing agent is seawater red mud slurry formed by mixing red mud generated in an alumina production process with seawater; and the mass percentage of a red mud dry base in the seawater red mud slurry is 1-20%. In a flue gas desulfurization process, the seawater red mud slurry is contacted with the flue gas entering the tower in a countercurrent manner for circulating desulfurization, the desulfurized flue gas can meet a requirement of ultra-low emission, and the discharged invalid slurry is oxidized in an oxidation tank; liquid-solid separation is carried on the oxidized slurry, the separated desulfurized seawater and fresh seawater are mixed in a buffer tank, and a standard requirement of discharged seawater is met after mixing; and the dehydrated desulfurized red mud issent to a red mud storage yard or used for preparing building materials. The method provided by the invention has the advantages of simple process, low cost, no secondary pollution, and high desulfurization efficiency, not only solves the problem of SO2 pollution of coal-fired enterprises in coastal areas, but also can save the desulfurization cost for the coal-fired enterprises, and simultaneously reduces environmental hazards caused by red mud.

Description

technical field [0001] The invention relates to a mixed desulfurizing agent prepared by using red mud and seawater and a method for desulfurizing flue gas thereof. Background technique [0002] SO 2 It is the main pollutant in the atmosphere. With the strict control of air pollution in the country, SO 2 The emission concentration requirements are becoming more and more stringent. Currently governing SO in the world 2 The main technical means of pollution is flue gas desulfurization. There are more than 200 kinds of flue gas desulfurization technologies researched, developed and used in various countries, of which about 20 kinds have been industrialized, and wet desulfurization is the main method. Absorbent absorbs sulfur dioxide in flue gas, such as lime / limestone / gypsum method, ammonia method, etc. [0003] Red mud is the industrial solid waste produced by refining alumina from bauxite. For every ton of alumina produced, 1.0-1.8 tons of red mud will be produced. Red mu...

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Problems solved by technology

[0005] The purpose of the present invention is to address the shortcomings of the above-mentioned prior art, to provide a method that can effectively save desulfurization costs, reduce the environmental hazards caused by red mud, and solve the problem of SO in coal-fired enterprises in coastal areas. 2 Pollution problem, simple process, low cost, no secondary pollution, high desulfurization efficiency using mixed desulfurizer prepared from red mud and seawater and its flue gas desulfurization method

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