Preparation method of coal water slurry of blended coal

Abstract

The invention provides a preparation method of coal water slurry of blended coal. The preparation method comprises the following steps: blending feed coal, petroleum coke and fly ash, and carrying outcrushing to obtain first slurry; mixing petroleum coke and fly ash with water and an additive to obtain second slurry; mixing the first slurry and the second slurry under stirring to obtain third slurry; then performing shaping and fine grinding to obtain fourth slurry; carrying out screening, wherein screened slurry is fifth slurry, and residues on a sieve are sixth slurry; returning a part of the sixth slurry for mixing with the second slurry, and returning the rest of the sixth slurry for shaping and fine grinding; and outputting the fifth slurry to obtain the coal water slurry. Accordingto the method, a coal blending technology is adopted, petroleum coke and coal ash are added on the basis of feed coal to form blended coal, the blended coal improves the slurry forming performance ofcoal types and the concentration of coal water slurry; the stacking efficiency of the coal water slurry can be improved through cooperation of the particle sizes of blended coal components; and therefore, the heat value of the coal water slurry is increased, and the coal water slurry can be better used as gasified coal water slurry.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry and relates to a method for preparing coal-water coal slurry. Background technique [0002] As a new type of coal-based fluid fuel, coal-water slurry is a clean fuel that can replace heavy oil and coal. It has the advantages of high concentration, fine particle size, and high combustion efficiency, and is widely used. As coal gasification is an important basic process of coal chemical industry, the gasification of coal water slurry is also the focus of research. The concentration of coal water slurry directly determines the level of energy consumption index of the gasification process. Key parameters such as efficiency, low specific coal consumption, and low specific oxygen consumption are crucial. [0003] The preparation of high-concentration coal-water slurry has always been a difficult problem in the field of coal-water slurry, especially for coal types that are difficult to sl...

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Problems solved by technology

[0003] The preparation of high-concentration coal-water slurry has always been a difficult problem in the field of coal-water slurry, especially for coal types that are difficult to slurry. Low-rank coal is recognized as a coal type with poor pulping performance. High, poor grindability, low calorific value, and low concentration of prepared coal slurry, which cannot meet the application requirements in the field of gasification

CN101173765A discloses a method for preparing coal-water slurry using low-rank coal, which includes mixing the crushed low-rank coal with water in proportion, and then performing wet coarse grinding, and mixing part of the coal slurry after wet rough grinding with water for wet fine grinding. After being ground, it is sent to the filter device, and the other part of the coal slurry is directly sent to the filter device, and then high-speed stirring, standing or low-speed stirring is carried out to obtain the coal-water slurry product; but the low-order raw materials used in this method have high coal water content and require more operations. , the concentration of the resulting coal water slurry product is limited

[0004] CN 105038878A discloses a method for preparing coal-water slurry. By crushing low-rank coal, and then performing steps such as coarse grinding, dehydration, fine grinding, and ultra-fine grinding in parts, and then kneading and strong shearing treatment, the obtained For coal water slurry products, the low-rank coal used in this method has a high water content and needs to be milled multiple times, and it also includes a dehydration step. The operation steps are many and the difficulty is increased.

[0005] In order to increase the concentration and gasification performance of coal-water slurry products, changing or improving raw materials will often result in increased costs. Therefore, other ways to increase the concentration of coal-water slurry, such as coal blending technology, although coal blending technology is currently used, but There is not much involved in the preparation of coal-water slurry, and there is no clear statement on which material to use with coal and the selection of the proportion of ingredients. It needs to be studied. This method will not increase the cost of raw materials. even lower costs

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