面向膏体充填尾砂浓密的絮团结构研究进展综述

Summary of Research Progress on Floc Structure of Tailings Thickening for Paste Backfill

膏体充填的技术难题之一是如何在尾砂浓密环节制备出浓度稳定、适宜的底流,从而满足后续工艺环节的需要,以期为矿山安全高效生产提供技术保障。但实际工程中尾砂浓密的底流浓度常常不稳定,基于国内外尾砂浓密领域的最新研究进展发现,底流浓度除了受浓密工艺的宏观因素影响外,根本原因取决于浓密脱水过程中的絮团微细观结构。为此通过综述国内外浓密中尾砂絮凝、尾砂絮团结构改变、絮团水含量变化、床层孔隙通道发展演化以及压密区脱水等方面的研究进展,系统分析了浓密中外界条件对絮团结构变化的作用机理,絮团结构形态影响絮团水含量变化的致因,压密区絮团水与床层孔隙通道对底流浓度的影响,得出絮凝条件决定絮团结构的初始形态,沉降区流体剪切力、压密区尾砂床层压力以及耙架剪切作用改变絮团结构状态,絮团水含量伴随絮团结构状态改变而变化、并经床层孔隙通道排出,提高了浓密机底流浓度。进而基于国内外研究进展深入探讨了絮团结构改变对尾砂浓密脱水的微细观作用,提出了尾砂浓密脱水目前存在的问题以及未来发展的趋势。

One of the technical problems of paste backfill is how to prepare a stable and suitable underflow in the process of tailings thickening,so as to meet the needs of subsequent process links and provide technical support for safe and efficient production in mines.However,in actual engineering,the underflow concentration of the tailings thickening is often unstable.Based on the latest research progress in the field of tailings thickening,it is found that the underflow concentration is affected by the macroscopic factors of the thickening process,and the root cause depends on the microscopic view of the floc structure during the thick dehydration process.Therefore,by reviewing domestic and foreign research progress of tailings thickening in tailings flocculation,tailings floc structure change,floc water content change,bed pore channel development and evolution,and compaction zone dewatering,systematic analysis of the mechanism of the external conditions on the change of the floc structure in the dense,the cause of the change of the floc water content by the structure of the floc,the influence of the floc water and the pore channels in the compaction zone on the underflow concentration,it is concluded that the flocculation conditions determine the initial form of the floc structure,the fluid shear force in the settlement zone,the pressure of the tailings bed in the compaction zone and the shearing effect of the rake change the structure of floc,the water content of the floc will change with the change of floc structure,it changes and is discharged through the pore channels of the bed to increase the underflow concentration of the thickener.Furthermore,based on the research progress at home and abroad,the microscopic effect of the change of floc structure on the thick dewatering of tailings is deeply discussed,and the current problems and future development trends of tailings thickening of dewatering are put forward.