等堆积效率条件下水层厚度对浆体特性变化影响  

Effect of water layer thickness on slurry properties under the same packing density conditions

作　　者：徐志强[1,2] 郑剑平 李凡飞[1,2] 王磊 涂亚楠 XU Zhi-qiang;ZHENG Jian-ping;LI Fan-fei;WANG Lei;TU Ya-nan(School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;MOE Engineering Research Center of Coal-based Slurry Fuel,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]教育部煤基浆体燃料工程研究中心,北京100083

出　　处：《煤炭工程》2020年第5期18-21,共4页Coal Engineering

基　　金：国家自然科学基金面上资助项目(51974325);国家自然科学基金面上资助项目(51574251)。

摘　　要：在已有的堆积效率评估模型基础上,引入颗粒膨胀率这一参数,提出了颗粒外围水层厚度,并进行理论计算。利用该方法,通过控制一种长焰煤的粒度分布,得到等堆积效率但水层厚度不等的四种样品,进行了水煤浆制备试验,并考察了其制浆浓度和稳定性。结果表明:在堆积效率评估指标为84. 61±0. 05%条件下,可制浆浓度随水层厚度的增大而呈现线性增加的趋势,但其值均分布在59. 95±0. 3%内,表明利用堆积评估指标指导制浆过程仍然有效;背散射光谱稳定性测试结果表明,由于水层厚度的增大,水煤浆体系中形成的煤、水、分散剂的三维空间结构中所包含的自由水就越多,导致析水率增大,而体系内颗粒的迁移范围增加使得体系整体的聚沉现象加重,稳定性下降。Based on the existing evaluation model of packing density,a calculation method for the thickness of water layer around the particle is proposed through introducing the particle expansion rate. CWS preparation test is carried out on a long flame coal to reveal the influence of the abovementioned thickness on the CWS rheological properties and stabilities. The CWS samples have the same packing density but different thickness of water layer. The results show that the concentration of CWS is positively related to water layer thickness while the packing density is 84. 61± 0. 05%. However,its value distributes within59. 95±0. 3%,illustrating that the packing density is still effective for instructing the preparation of CWS. The backscattering spectrum test results show that,free water content in the three-dimensional structure of coal,water and dispersant in CWS,rises due to the increase of water layer thickness. As a result,the water cleavage rate increases with the thickness. In addition,the particles ’ migration range in the system also expends with the thickness, and the coagulation of particles aggravates,worsening the CWS stability.

关 键 词：堆积效率 水煤浆 浓度 稳定性 

分 类 号：TD94[矿业工程—选矿] TQ536[化学工程—煤化学工程]