Additive for improving slagging feature of high-iron Zhundong coal and application method thereof

Abstract

The invention discloses an additive for improving the slagging feature of high-iron Zhundong coal and an application method of the additive. The additive is composed of, by mass, 15%-65% of aluminum ash, 25%-50% of magnesium oxide and the balance dolomite. According to the application method of the additive, mixed coal is prepared according to the mass ratio of (3-8):100 between the additive and the high-iron Zhundong coal, wherein the aluminum ash accounts for 1%-6% of the mass of the high-iron Zhundong coal, the magnesium oxide accounts for 1%-5% of the mass of the high-iron Zhundong coal, and the dolomite accounts for 1%-5% of the mass of the high-iron Zhundong coal. The application method comprises the implementation steps that firstly, according to the mass of the high-iron Zhundong coal, the mass of each ingredient of the additive is determined; the additive and the high-iron Zhundong coal are crushed and mixed in a coal mill or undergo flowing mixing in a primary air pipeline, and finally the mixture is fed into a hearth to be combusted. The additive is composed of natural minerals and industrial waste, the ingredients are simple, the cost of the additive is low, and the additive has the effects of fixing sodium, improving an ash fusion point and fixing sulphur, can significantly improve the features of ash deposition, coking and slagging of the high-iron Zhundong coal and improve the blending combustion ratio of the high-iron Zhundong coal.

Description

technical field [0001] The invention belongs to the technical field of improving the slagging characteristics of Zhundong coal, in particular to an additive for improving the slagging characteristics of high-speed railway Zhundong coal and an application method thereof. Background technique [0002] With the gradual improvement of my country's economic situation, the national electricity demand has continued to pick up since 2016, reaching 6,791.24 billion kWh / year in 2018 (a year-on-year increase of 6.8%). China's energy and power structure is dominated by thermal power generation. In 2018, thermal power generation accounted for 73.32% of the country's total power generation (a year-on-year increase of 6%), of which coal-fired power generation accounted for more than 90% of the total thermal power generation. China's power generation sector remains dominant. In 2005, the Zhundong coalfield, the largest integrated coalfield so far, was discovered in the Xinjiang region of m...

AI Technical Summary

Problems solved by technology

Therefore, there are the following problems when burning Zhundong coal: (1) The alkali metal salt sodium sulfate (melting point 884°C) is volatile, and condensation occurs when the flue gas flows to the heat exchange surface with a lower temperature, forming on the heated surface It has a viscous ash layer and continuously absorbs light components in the flue gas, which intensifies the pollution and ash accumulation; (2) The alkali metal / alkaline earth metal remaining in the Zhundong coal is easy to form a low melting point with the product of the coal combustion process Substances or low-temperature eutectics lead to a low melting point of Zhundong coal ash, and the ash particles tend to be in a molten state, which aggravates the problem of boiler slagging and reduces boiler output

In the existing technology, the silicon oxide particles and aluminum oxide particles are directly sent into the boiler furnace through the conveying device to react with flue gas to form a mixture with stable physical and chemical properties, and at the same time, the secondary air of silicon oxide and aluminum oxide particles is transported for flushing Heating surface, clean ash layer, but this method has difficulty in estimating the chemical reaction between additives and flue gas, excessive waste of silicon oxide and aluminum oxide, and difficulty in washing away the viscous ash layer on the heating surface by secondary air, etc. Potential problems; the existing technology provides an additive to improve the combustion and coking characteristics of Zhundong coal. The main components are 8 kinds of pure oxides and 1 waterproof binder. The problem with this formula is: compared with natural minerals, Pure substances are more difficult to obtain, the particle size requirements are smaller, and the price is more expensive. In actual use, it will increase the cost of burning Zhundong coal and reduce the economy of coal power

Images