| China is the largest coal producer of the world, dehydration treatment of the coal preparation plant slime is both important part and difficult of the production. In order to solve the problem of filter press cycle for a long period of slime and slime high moisture, the method that without changing the existing filter press equipment and process conditions added filter aid to the slurry can improve pressure filtration result of the fine material with the advantages of rapid and simple, saving investment quick. Paper presents research that the influence on the use of particular hydrophobically modified reagent to slime pressure filtration characteristics, intended to reflect the particular reagent to improve the effectiveness of the slime dehydration by this study and provide theoretical and technical support for the development of new filter aids for coal use.In the paper, design and construction the slime pressure filtration dewatering process test system. On the test system carry out the influence of reagent types, reagent dosage, slime water properties, process operating conditions on the slime pressure filtration characteristics and optimize the filter press conditions. Research shows:1) With the increase of reagent dosage, within a certain range of filter press dewatering cake moisture occurred greatly reduced, when the reagent dosage around500g/t, the cake moisture reach to minimize and then gradually increased. Indicating that if the amount of reagents too high, it can make the filtration rate decreases and increase the moisture content of the cake.2) When comparing the cake moisture absolute increasing and reducing value of maximum with the three hydrophobically modified reagents at500g/t reagent dosage,1#reagent is1.50%,2#reagent is2.09%,3#reagent is2.25%. Results show that3#reagent have the best effect to the cake on the optimal reagent dosage,1#reagent have the weakest improvement. The three reagents have obvious drainage effect on the slime.3) When comparing the the influences of pressure filtration effect with hydrophobically modified reagents, sodium lauryl sulfate, anionic polyacrylamide polymer10million and polyaluminum chloride, indicating that hydrophobically modified reagents have the best drainage effect on filter press dewatering and hydrophobically modified of the slime particle surface have great impact on pressure filtration.4) With the feed pressure increases, within a certain range of the pressure, the pressure higher the moisture cake lower and when reagent dosage at the point with the best reagent, the increases of feed pressure can make the maximum extent reduce of cake moisture.5) With the reduce of coarse particle content of sample, level of granularity develop in the fine particle level, the resulting cake moisture by filter press is a growing trend overall, indicating that the finer granularity composition of feed slurry water, the drainage effect of hydrophobically modified reagent worse.6) To add quartz, kaolin, illite, smectite minerals have different degrees of deterioration in the filter press dewatering process, all the cake moisture values are higher than the blank sample.7) Through observation and comparative analysis microscopic imaging of the internal pore structure of cake drawn:The cake of blank test obtained in the internal structure is densification. The number of fine particles in the cake was significantly reduced by adding hydrophobically modified reagent and the structure of cake become loose. Indicating that with the particular hydrophobically modified reagent effect enhance the ability of filter and dewatering. |
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