College of Chemical and Biological Engineering,Shandong University of Science and Technology

我国褐煤资源丰富,较高的氧含量、水含量导致其利用困难,热提质是实现褐煤清洁高效利用的有效手段之一,在热提质过程中褐煤极易碎裂、粉化,造成焦油粉尘含量高,除尘困难、管路堵塞等问题,成为阻碍褐煤提质技术发展的“瓶颈”。以先锋褐煤(XF)为原料,在回转炉热提质实验装置上考察了XF在不同温度的粒度变化、累积分布曲线、整体粒度分布、相对破碎率、分形维数,研究了XF在不同温度的热碎产物分布规律,利用X射线荧光仪(XRF)和X射线衍射仪(XRD)分析了热碎产物灰分组成差异,结果表明,XF在热提质过程中发生了明显的破碎,1~6mm粒度是破碎颗粒的主要生成范围,粉化粒度随着温度的升高而增加,其中0~0.1mm的粒度增长幅度最大。在450~500℃时XF相对破碎率增幅最大,温度的升高促使破碎发生,分形维数增加,煤颗粒的破碎程度变复杂。灰分随破碎粒度变化不显著,煤中的矿物质更容易存在于粉化粒度中,随着热碎产物粒度的减小,灰分含量逐渐升高。550℃的热碎产物灰分高于450℃和350℃的热碎产物,Ca元素含量随粒度减小而降低,Si、Fe元素含量随粒度减小而升高,Al元素含量变化不明显。XRD结果表明石英、方解石属于被动分配,而黄铁矿受热分解导致其更容易分配到粉化粒度中,属于主动分配,在煤颗粒内部形成的裂隙和空洞是导致褐煤破碎的诱因之一。

China’s lignite resources are abundant,it is difficult to utilize for the high oxygen content and water content.Thermal upgrading is one of the effective means to achieve clean and efficient utilization of lignite. However,the lignitein the process of thermal upgrading faces the problem of easy fragmentation and pulverization, resulting in highdust content in tar,difficulty in dust removal,and pipeline blockage,which has become a bottleneck hindering the de⁃velopment of lignite upgrading technology. This article takes Xianfeng lignite ( XF) as the raw coal, the particlesize change,cumulative distribution curve,overall particle size distribution,relative fragmentation rate and fractal di⁃mension of XF at different temperatures were investigated on the rotary furnace thermal upgrading experimentaldevice,and the distribution of XF thermal fragmentation product at different temperatures was studied,and the differ⁃ences inashcontentandmineralcompositionofthermalupgradingproductswereanalyzedbyX⁃rayfluorescence (XRF) and X⁃ray diffraction (XRD). The results show that XF undergoes significant fragmentation dur⁃ing the thermal upgrading process,with a particle size of 1-6 mm being the main generation range of fragmented parti⁃cles. The pulverization particle size increases with increasing temperature,with the largest increase observed at 0 -0.1 mm. At 450-500 ℃,the relative fragmentation rate of XF increase the most,and the increase of temperature pro⁃motes the fragmentation,leading to an increase in fractal dimension and a more complex degree of coal particle frag⁃mentation. The variation of ash content with fragmentation particle size is not significant,and minerals in coal are morelikely to exist in the pulverization particle size. The ash content gradually increases with the decrease of particle sizeof thermal fragmentation products. The ash content of the thermal fragmentation product at 550 ℃ is higher than that at450 ℃ and 350 ℃,the Ca element content decreases with decreasing particle size,the Si and Fe element content in⁃creases with decreasing particle size,and the change of Al element content is not obvious. The XRD results show thatquartz and calcite belong to passive distribution, while pyrite is more easily distributed to pulverization particlesize due to thermal decomposition,which belongs to active distribution,and pyrite thermal decomposition leads to theformation of cracks and cavities inside the coal particles,which is one of the causes of lignite fragmentation.

国家自然科学基金面上资助项目(22078177);新疆自治区重点研发任务专项资助项目(2022B03029-2)

李松泽,秦锡壮,郝美鲁,等.先锋褐煤在热提质过程中的破碎特性[J].绿色矿山,2024,2(3):323-331.

LI Songze,QIN Xizhuang,HAO Meilu,et al.Fragmentation characteristics of Xianfeng lignite during thermal up⁃grading[J].Journal of Green Mine,2024,2(3):323-331.