Method for reducing contamination of high-sodium coal

Abstract

The invention relates to a method for reducing contamination of high-sodium coal. The method comprises the following steps: breaking the high-sodium coal and an ash fusion point regulating agent and screening, then mixing the high-sodium coal with the ash fusion point regulating agent so that the ash composition of the mixture meets certain conditions, then putting the mixture into a boiler for burning, and controlling the temperature and excess air coefficient of the burning boiler; and starting a boiler slag removing system for removing slag. The method has the advantages that the high-sodium coal is combined with the ash fusion point regulating agent in different ratios, so that the composition ratio of each ash of a mixed ash sample is changed, the ratio of contents of various elements is regulated, especially the ratio of silicon and aluminum elements is improved, an ash fusion point of the mixed ash sample rises, the sodium element migrates into sodium silicate and sodium silicoaluminate and is discharged outside along with coal residues, and thus the problems of contamination, scorification and corrosion of the high-sodium coal during burning in the boiler are solved; and meanwhile, the technology is simple, the operation is safe, and the investment is low.

Description

technical field [0001] The invention relates to a method for reducing the contamination of the heat exchange surface of a high-sodium coal boiler, in particular to a method for reducing the contamination of the high-sodium coal by mixing the high-sodium coal and an ash melting point regulator. technical background [0002] Zhundong, Xinjiang, my country is an area rich in coal reserves, with predicted reserves of 390 billion tons. At present, the cumulative proven reserves of coal resources are 213.6 billion tons, and the coal-forming area of ​​the coal field is 14,000 square kilometers. It is currently the largest integrated coal field in my country. Most of the coal in Zhundong area is high-sodium coal with sodium content (ash content) higher than 2%, which is much higher than that of power coal in other areas. The coal quality in this area is medium-high moisture, medium calorific value, easy to catch fire, easy to burn out, strong coking, high alkali metal, strong pollut...

AI Technical Summary

Problems solved by technology

[0005] Many experts also consider improving fuel equipment and combustion conditions to control sodium contamination. According to the existing technology, pulverized coal furnaces and circulating fluidized bed boilers burning high-sodium coal have been built in the Zhundong area of ​​China and the Midong area of ​​Xinjiang. There are some problems that are difficult to solve radically: one is the slagging of the water wall; the other is the serious corrosion of the superheater and reheater tube; the third is the contamination and dust accumulation on the heating surface and serious wear

The current transformation of the boiler can only partially alleviate the pollution problem, and cannot guarantee that the boiler will burn 100% high-sodium coal under full load, and the reconstruction project is expensive, complicated and cumbersome, and the operation of the boiler after the transformation is also unknown, and there are certain risks

[0007] At present, there is little domestic research experience on Zhundong high-sodium coal. How to reduce the alkali metal content of high-sodium coal, prevent slagging, anti-contamination and corrosion, and ensure the safe and economical long-term operation of boilers is a major challenge for the coal industry.

Images