Course of development of fine coal flotation process in China
CHENG Hongzhi;ZHANG Bo
浮选工艺和设备是构成煤泥浮选系统的核心要素,共同决定产品质量和生产效率。浮选设备处理能力和性能、煤泥可浮性和产品灰分要求,是制定工艺流程的重要影响因素。随着浮选设备大型化和高效化发展、煤质和煤炭市场需求变化,以及生态环境保护政策的刚性约束,我国煤泥浮选工艺大致经历了浓缩浮选、直接浮选、脱泥/分级浮选、两段/多段浮选等发展过程。浮选机大型化发展为煤泥水直接浮选工艺奠定了设备基础,解决了浓缩浮选细泥积聚难题。一次浮选工艺一般能够满足易浮煤泥生产要求,一粗一精工艺通常适合细泥含量较高的难浮煤泥浮选,一粗一扫二精或三精工艺对中间密度物含量大的极难浮煤泥亦可选出精、中、尾三种合格产品。在煤泥充分解离条件下,多段闭路流程浮选效率高于开路流程。
Flotation process and process equipment are two core elements that form up a flotation system and determine both product quality and flotation efficiency. On the other hand, the capacity and performance of equipment, flotability of feed coal and required ash value of concentrate are important influencing factors in determination of flotation process. Along with the equipment becoming increasingly larger in size and higher in efficiency changes of coal property and market demands as well as rigid constraint of environmental protection policies, the flotation technology has seen many changes in the course of its development, such shifting from the use of thickened slurry flotation process to direct flotation process, dislimed / sized coal flotation process and to two-stage / multistage flotation process. The development of large-size flotation machines provides a basis for the use of direct flotation process to treat coal slurry water and tacking the difficulties in flotation of thickened pulp caused by accumulation of fine slime. It is noted that the use of primary flotation process can generally meet the requirements in flotation of easy-to-float coal; the one roughing + one cleaning process is generally suited to treating difficult-to-float coal with a high proportion of fine slime; with the use of one roughing + one scavenging + two / three cleaning process for treating extremely hard-to-float coal containing a high proportion of intermediate-density materials, the up-to-standard concentrate, middling and tailing products can also be obtained; and for treating the coal which has gone through sufficient liberation, the multistage closed-circuit process in higher in efficiency compared with the open-circuit one.
fine coal flotation;flotation equipment;high-ash fine slime;intermediate-density material;flotation process
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会