Dry desulfurization method for cement production

Abstract

The invention belongs to the field of cement production, and particularly relates to a desulfurization method implemented by using a rare earth-containing dry desulfurization agent. The desulfurization method comprises the following specific steps: in the cement producing process, crushing cement raw material into a blocky material with the particle size being smaller than 25mm, mixing the blocky material with a dry desulfurization agent which contains rare earths, vanadium pentoxide and quick lime, calcining in a kiln, and synchronously desulfurizing by the dry desulfurization agent in the calcining process. Compared with the conventional dry desulfurization and semidry desulfurization, the dry desulfurization method provided by the invention has the advantages of higher desulfurization efficiency and easiness in operation; compared with the wet desulfurization with complicated working procedures, the dry desulfurization method provided by the invention has the advantages of saving of more equipment transformation and labor cost, and easier popularization and implementation; in the dry desulfurization method, a cement producing way, a cement producing method and cement producing equipment are not required to be changed, and only the dry desulfurization agent is proportionally added in a raw material calcining link, so that the dry desulfurization method is simple and convenient and easy to operate.

Description

technical field [0001] The invention belongs to the field of cement production, in particular to a desulfurization method implemented by using a rare earth-containing dry desulfurizer. Background technique [0002] Energy and the environment are two major issues in the development of today's society. China's resource characteristics and economic development level determine the long-term existence of a coal-based energy structure in society, and with the rapid development of economic construction, the demand for important building materials such as cement The demand is also rising continuously. In view of the current situation of burning cement with coal as the main fuel, a large amount of pollutants mainly sulfur dioxide and nitrogen oxides are produced in the process of cement burning. These sulfur and nitrogen oxides are in the form of gas Floating into the air is the main cause of acid rain. Therefore, reducing the emission of sulfur oxides produced in the cement firing ...

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Problems solved by technology

[0003] After continuous exploration, there are many desulfurization methods in existing cement plants, and the more representative ones are: "A Preliminary Study on Low-temperature Desulfurization Technology for Flue Gas in Cement Plants" recorded in the second issue of Volume 21 of "Environmental Engineering" in April 2003. The spray drying technology is used to desulfurize the exhaust gas. This method has specific requirements for the equipment in the process, and the cost and complexity of operation are high.

Wet desulfurization is also common in cement desulfurization. The general principle is that after the flue gas is washed with alkaline solution, the SO in the flue gas 2 Absorbed by the solution, the sulfite solution is nearly saturated and then oxidized to produce sulfate, which produces desulfurization by-products after crystallization. Although the desulfurization efficiency of this method is high, the process is complicated. If the desulfurization by-products are not properly treated, it will also cause secondary Pollution

For the traditional dry and semi-dry desulfurization methods, the milky desulfurizer (calcium hydroxide) prepared by quicklime and water is used to spray the flue gas countercurrently or downstream, and the resulting gypsum is desulfurized after dust removal and solid recovery. Generally speaking, in addition to the need for spraying, dry and semi-dry methods also have relatively low desulfurization efficiency. Generally, the desulfurization rate can only reach about 65%.

[0004] Looking at many existing desulfurization methods, the wet desulfurization process with high desulfurization efficiency is often complicated and the operation cost is high, while the traditional dry and semi-dry desulfurization methods with relatively convenient operation have relatively low desulfurization efficiency. A new desulfurization method with simple process and high desulfurization efficiency has become the work that many cement plants are exploring

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