Gasified water-coal-slurry and preparation method thereof

Abstract

The invention discloses a preparation method of gasified water-coal-slurry. The method comprises the following steps: (1) crushing low-rank coal to pulverized coal, wherein the grain diameter of the pulverized coal is less than 13mm; (2) inputting pulverized coal a to a roughing machine, and adding an additive and water to carry out high concentration pulping; (3) inputting pulverized coal b to an atomizer mill, adding an additive and water and grinding to prepare water-coal-slurry, wherein the mass concentration of the water-coal-slurry is 40-45% and the granularity of the water-coal-slurry is less than 40 mu m; and (4) inputting the water-coal-slurry prepared in the step (3) to the roughing machine in the step (2), and grinding to obtain the gasified water-coal-slurry. According to the preparation method disclosed by the invention, the original graded grinding process, i.e., after all coal passing through the crusher enters into the roughing machine to carry out ore grinding, part of crushed coal is directly fine-grinded and then enters into the roughing machine carry out mixed ore grinding is changed, so that not only is coal slurry granularity distribution of the atomizer mill more suitable for granularity distribution of gasified coal slurry, but also the grinding load increased by 10-30% caused by repeated grinding of the roughing machine is reduced. Therefore, the grinding energy consumption is further reduced.

Description

technical field [0001] The invention relates to a gasified coal-water slurry and a preparation method thereof, in particular to a pulping method using low-rank coal as a raw material, and the gasified coal-water slurry with a higher concentration can be obtained by using the pulping method. Background technique [0002] At present, the coal used for coal-water slurry gasification is mainly low-rank coal (long-flame coal, non-caking coal and weakly caking coal), and these coals have large reserves (proven reserves of 432.075 billion tons, accounting for the national proven resources Amount of 42.46%), good reactivity, generally low ash melting point, is a very good coal water slurry gasification raw material. However, low-rank coal has the characteristics of many oxygen-containing functional groups on the surface, high porosity, poor surface hydrophobicity, and poor grindability. The conventional gasification coal-water slurry preparation technology mainly has the following p...

AI Technical Summary

Problems solved by technology

[0003] (1) Low pulping concentration

Generally around 55%, the concentration of lignite slurry is lower, and the existence of too much water increases the coal consumption and oxygen consumption of coal-water slurry gasification, which seriously affects the gasification efficiency and reduces the economical efficiency of coal-water slurry gasification;

[0004] (2) Unreasonable particle size distribution

The conventional pulping process adopts a mill (rod mill or ball mill) pulping process, the particle size distribution is too concentrated, and a good particle size gradation cannot be formed, and the rheological properties and atomization properties of the slurry are poor, resulting in low coal conversion efficiency;

[0005] (3) Particle size is coarse

This method can achieve better dehydration of low-rank coal, thereby increasing the concentration of coal-water slurry, but requires high-temperature and high-pressure equipment, which not only increases the investment and heat energy consumption of the modification device, but also makes the process more complicated.

Causes high operating costs and is extremely uneconomical for large-scale production

At present, there is also a method of preparing coal-water slurry by coarse and fine grinding of low-rank coal, but the feed to the fine mill is the coal-water slurry from coarse grinding, and the particle size distribution of the prepared coal-water slurry is suitable for fuel coal slurry. There is no comparison for the preparation of low-rank coal. Pulping Technology of High Concentration Gasified Coal Water Slurry

Images