A Coal Combustion Sulphur-fixing Agent Synergized with Red Mud and Mineral Material in Quenched and Tempered Bayer Process

Abstract

The invention discloses a modified Bayer red mud-mineral material collaborative fuel coal sulphur-fixing agent and a preparation method thereof. The sulphur -fixing agent is composed of modified Bayer red mud, dolomite powder and vermiculite dust, wherein the modified Bayer red mud is obtained by soaking Bayer red mud in a sodium ferrocyanide mother solution or its diluent, and then carrying out drying and crushing. The sulphur fixation rate of the modified Bayer red mud-mineral material collaborative fuel coal sulphur-fixing agent can reach 71%-98%, thus being able to effectively reducing SO2 discharged by fuel coal. At the same time, the invention opens up a new way for utilization of the industrial waste Bayer red mud and vermiculite dust, and provides a cheap and efficient sulphur-fixing agent for fuel coal, thereby realizing efficient use of high pollution waste slag.

Description

technical field [0001] The invention belongs to the technical field of coal-burning desulfurization, and relates to a Bayer process red mud sulfur-fixing agent, in particular to a coal-fired sulfur-fixing agent for tempered Bayer process red mud-mineral material synergy. Background technique [0002] Since the 1980s, with the rapid development of my country's economy, the consumption of coal has increased substantially every year. my country is one of the largest coal producers and consumers in the world. However, coal contains a large amount of sulfur, so During the combustion process of coal, not only the soot produced by incomplete combustion, but also the air pollutant SO 2 , while SO 2 It is the main source of air pollution in my country. Therefore, the control of SO in coal-fired industrial boilers 2 emissions are particularly important. [0003] Coal-fired desulfurization technology is the main method to reduce sulfur dioxide pollution. At present, there are three ...

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Problems solved by technology

[0004] At present, the sulfur-fixing agents mainly include calcium-based sulfur-fixing agents, magnesium-based sulfur-fixing agents, sodium-based sulfur-fixing agents, potassium-based sulfur-fixing agents, etc., such as: limestone, dolomite, calcite, calcium oxide, magnesium oxide, sodium carbonate, Sodium hydroxide, etc. Among them, calcium-based sulfur-fixing agents are cheap and easy to obtain, and are widely used, but traditional calcium-based sulfur-fixing agents generally have the disadvantages of low calcium utilization rate and low sulfur-fixing rate at high temperatures

[0005] In the prior art, there is a method of preparing a sulfur-fixing agent with red mud from an alumina plant as an additive, but there are disadvantages such as that the red mud slurry is easy to harden, and the gas permeability deteriorates with the increase of use time, thereby reducing the sulfur-fixing effect. Therefore, the current There are technologies that have developed a sulfur-fixing agent with red mud as a component, such as Chinese patent CN102212406A, which discloses a method for preparing a sulfur-fixing agent with red mud from an alumina plant as an additive. In this method, limestone is used as the main component of the sulfur-fixing agent. active ingredients, and limestone will generate carbon dioxide after calcination, carbon dioxide is a greenhouse gas, causing global climate change, at the same time, this method only uses red mud as an auxiliary additive for sulfur fixation agent, and the consumption of waste red mud is limited. In addition, this method A large number of operations of grinding, crushing and drying red mud are required, and the energy consumption and cost are relatively large

[0006] Another example is the Chinese patent CN101480568A which discloses a method for preparing red mud sulfur fixative. This method needs to continue roasting the dried sintering red mud at 350-700°C. Therefore, it needs to consume a lot of energy. Causes air pollution, with large economic and environmental costs

[0007] Another example is Chinese patent CN1034683443A, which discloses a sulfur-fixing agent for carbon pellets and a preparation method thereof. The industrial manganese slag used in the method can be used to recycle and extract manganese metal. Using it as a sulfur-fixing agent will cause waste of manganese, and at the same time , the amount of red mud consumed by this method is small, and the effect of reducing environmental pollution is not obvious

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