低阶煤煤泥和浮选精煤制备水煤浆的影响机制研究

以低阶煤煤泥(LS)和浮选精煤煤泥(LF)为原料,通过成浆性实验并结合两种煤泥煤样的粒度分布、表面特性、灰分特征、润湿特性及对分散剂吸附性的测试结果,对LS和LF制备水煤浆的影响机制进行研究。结果表明:分别使用LS和LF作为原料制备水煤浆,当分散剂添加量(干基分散剂与干基原料的质量比)从0%增加至0.7%时,LS的最高成浆浓度(干基煤粉与煤浆的质量比)从58%提高至59%;LF的最高成浆浓度从51%提高至57%;LF与LS相比,灰分质量分数从37.05%降低至13.62%,有机组成无变化,无机矿物中石英含量降低显著,粒度分布范围较窄,对分散剂的饱和吸附量降低;LS和LF煤样中颗粒的径距分别为2.22和1.51,LF中颗粒的堆积效率较低,粒度分布是造成LS和LF成浆性差异显著的主要因素,LF的颗粒较细且尺寸较为接近,煤样颗粒表面的静电力使LF颗粒容易团聚在一起,分散剂作用于粒度较细且粒径相近的LF时,主要用于抵抗分子间的作用力,从而造成LF分散剂消耗量大,采用LF制备水煤浆,需充分考虑粒度分布的影响,选用分散性能较优的水煤浆分散剂。

Influence Mechanism of Low Rank Coal Slime and Flotation of Clean Coal on Preparation of Coal Water Slurry

To explore the influence mechanism of low rank coal slime(LS)and floating clean coal(LF)on the preparation of coal water slurry(CWS),LS and LF from Shiyaodian coal preparation plant were selected as the research objectives and their characteristics were analyzed by the slurry forming test combined with the tests of particle size distribution,surface characteristics,ash characteristics,wetting characteristics,and adsorption of dispersant of two raw materials.The results show that when the dispersant content(mass ratio of dry based dispersant to dry based raw materials)increases from 0%to 0.7%,the maximum slurry concentration of LS increases from 58%to 59%,and the maximum slurry concentration(Mass ratio of dry basis pulverized coal to coal slurry)of LF increases from 51%to 57%.Compared with LS,the ash content for LF decreases significantly from 37.05%to 13.62%,meanwhile,the organic composition is unchanged,quartz content is reduced,the particle size distribution range is narrow,and the saturated adsorption capacity of LF to dispersant is lower too.The span of particles in LS and LF samples are 2.22and 1.51,respectively.Particle size distribution is the main factor causing the significant difference in the palpability between LS and LF.The LF particles are fine and similar in size,and the electrostatic force on the particle surface makes the floating fine particles easy to cluster.The additional dispersant is mainly used to resist the intermolecular force.As the result,the concentration of coal slurry produced by LF is low and the consumption of dispersant is large.The above discovery is helpful to the utilization of low rank coal slime.When preparing coal water slurry with LF,the influence of particle size distribution should be fully considered and the dispersant with better dispersion performance should be selected.