Method for removing sodium in high-sodium coal

Abstract

The invention provides a method for removing sodium in high-sodium coal. The method is characterized by comprising the following steps: step 1, crushing high-sodium coal into crushed raw coal of a certain size, putting the crushed raw coal into a container tank, and adding a washing solution into the container tank; step 2, putting the container tank into microwave equipment, performing microwave treatment on the crushed raw coal and the washing solution, heating the crushed raw coal and the washing solution to the temperature of 160-260 DEG C to obtain a high-temperature mixed solution, and preserving the temperature of the high-temperature mixed solution for 5-30 minutes to wash the crushed raw coal by using the washing solution, wherein the microwave equipment comprises a pressure control system, and the air pressure in the container tank is maintained to be 1-2 times that of saturated vapor pressure which corresponds to the temperature of the washing solution; and step 3, taking the container tank out of the microwave equipment, filtering the high-temperature mixed solution, and washing the filtered product with water, thereby obtaining low-sodium coal. According to the method for removing sodium in high-sodium coal disclosed by the invention, the content of sodium in the high-sodium coal can be effectively reduced, and the quality of the raw coal is improved.

Description

technical field [0001] The invention relates to a method for removing sodium from high-sodium coal, which belongs to the field of coal chemical industry. Background technique [0002] Generally, the sodium content (calculated by ash content, the same below) in raw steam coal is below 1%, but in some coal production areas, the sodium content in coal is above 2%, or even as high as above 10%, such as the coal in Zhundong, Xinjiang, These coals are often referred to as high-sodium coals. The sodium component in the coal ash of high-sodium coal will condense on the heat exchange surface tube wall of boilers and other equipment, and form a dense bonding layer with sodium sulfate and other substances generated by the reaction of sulfur dioxide and sulfur trioxide in the flue gas. On the one hand, the bonding layer reacts with the metal pipe wall to cause high-temperature corrosion, and on the other hand, it can capture coal ash particles in the flue gas to cause high-temperature ...

AI Technical Summary

Problems solved by technology

However, the electric furnace heating used in this method is a slow temperature rise, which has little influence on the structure of the coal block, and the sodium removal effect is poor, making the sodium removal efficiency low

Moreover, there will still be some sodium on the surface of the upgraded wet coal, which has not been washed, which further limits the efficiency of sodium removal.

In addition, the coal liquid is directly stirred during the desodiumization process, which may easily cause coal loss