Method for preparing coal water slurry by modifying low-rank coal

Abstract

The invention provides a method for preparing coal water slurry by modifying low-rank coal. The method comprises a step of mixing and pulping low-rank coal slurry and modified low-rank coal to obtainthe coal water slurry. The method specifically comprises the following steps: (1) crushing the low-rank coal, dividing the crushed low-rank coal into a first raw material and a second raw material, performing wet pulping on the first raw material to obtain the low-rank coal slurry, and sequentially drying and modifying the second raw material to obtain the modified low-rank coal; and (II) performing wet pulping on the low-rank coal slurry and the modified low-rank coal to obtain the coal water slurry. Through physical and chemical modification modes, the content of oxygen-containing functionalgroups on the surface of the low-rank coal is reduced, reabsorption of the low-rank coal is inhibited, and the porosity of the low-rank coal is reduced, so the highest slurry concentration of the low-rank coal is improved.

Description

technical field [0001] The invention belongs to the technical field of pulping, and relates to a method for preparing coal-water slurry, in particular to a method for preparing coal-water slurry by modifying low-rank coal. Background technique [0002] my country has abundant low-rank coal reserves, but due to the characteristics of high moisture, low calorific value, easy weathering and spontaneous combustion, the transportation cost is high, which is not conducive to long-distance transportation and storage. Direct combustion of low-rank coal has low thermal efficiency and large greenhouse gas emissions, making it difficult to develop and utilize on a large scale. With the improvement of energy conservation and environmental protection awareness, clean and efficient utilization of coal has become an inevitable requirement for the development of China's coal chemical industry. Therefore, using low-rank coal to prepare high-concentration coal-water slurry has become one of t...

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Problems solved by technology

[0003] Due to the high internal water content of low-rank coal, rich oxygen-containing functional groups on the surface, and strong hydrophilicity, it is not conducive to slurry formation. It is difficult to produce high-concentration coal-water slurry, and the low concentration of coal-water slurry will cause oxygen consumption during the gasification process. high coal consumption and low gasification efficiency

The research on preparing high-concentration coal-water slurry by modifying low-rank coal as raw material has been paid attention to. At present, the existing methods include hydrothermal modification and pyrolysis modification. The process is complicated and the investment is large, which is not conducive to Large-scale industrial application of low-rank coal to prepare high-concentration coal-water slurry

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