炼焦中煤在螺旋搅拌磨中的磨碎解离效果研究

A study on the effect of grinding-liberation of coking coal middlings in vertical spiral agitating grinding mill

炼焦中煤的磨碎解离是实现炼焦煤资源节约化利用的基本前提。利用螺旋搅拌磨分别对>300、300~74、<74μm粒级中煤进行磨煤试验,结合扫描电镜、能谱仪和激光粒径分析仪,掌握了不同粒级中煤在螺旋搅拌磨中的磨碎解离效果。研究结果表明:各粒级中煤所嵌布的矿物质以细粒分散的高岭石为主,少量以聚集状形式嵌布,且主要集中在300~74μm粒级中。在所有粒级中,以300~74μm粒级中煤的磨碎解离效果最好:磨后产品累计灰分为10%时,精煤产率增加20个百分点,磨碎比最高;磨后产品中<45μm粒级产率增量为35.57个百分点,显著高于其他两个粒级;此外300~74μm粒级磨煤前后高密度物、低密度物的平均粒径比均高于其他两个粒级。

Grinding-liberation of coking coal middlings is a basic precondition for realizing efficient utilization of coking coal resources.Test is made on the grinding of the>300,300~74 and<74μm coking coal middling products using the spiral agitating grinding mill,and the effects of liberation of the middlings in different sizes are assessed with the use of scanning electron microscope(SEM),energy spectrometer and laser particle size analyzer.Test result shows that of all the 3 sizes of middlings,the disseminated minerals are predominately scattered fine-grained kaolinite with some kaolinite distributed in aggregated form mainly in the 300~74μm size fraction;the best liberation effect can be obtained through grinding of the 300~74μm size fraction;through grinding of this size fraction,the yield of clean coal with a cumulative ash of 10%is increased by 20 percentage points became of the much higher ratio of size reduction,and there can be seen a rise of the yield of the<45μm size coal in the ground product by 35.57 percentage points,an increase noticeably greater than those in the case of grinding the other two size fractions;and the mean particle grain-size ratio of either high-density or low-density material before and after grinding of the 300~74μm middling is likewise higher as compared with the grinding of the other two size fractions.