尾矿库干滩尾矿粒径的淤积特性研究

Study on deposition characteristics of tailings particle size in dry beach of tailings pond

基于江西贵溪某尾矿库的取样数据,采用试验和理论相结合的分析方法,对干滩尾矿粒径和坝体堆积尾矿的淤积特性进行了分析,结果表明：尾矿经旋流器分级后粒径变化明显,与原尾矿相比,干滩近端排放尾矿粒径大,而干滩远端排放尾矿粒径小;随着距子坝距离的增加,尾矿粒径百分比分布图的峰值和峰值对应的粒径逐渐减小,并且越往库内,尾矿的细粒百分比逐渐增大,细粒含量逐渐增加。干滩上的淤积尾矿平均粒径以及各粒径特征值总体上具有取样点距子坝越远,尾矿粒径逐渐变细的趋势。干滩上的淤积尾矿粒径在距子坝3.6 m和10.1 m处发生了突变,淤积尾矿的粒径变化可分为3个阶段：粗化阶段、缓慢细化阶段和快速细化阶段。由于水力分选、重力作用和筑坝方式的改变等原因,坝体堆积的尾矿有上粗下细的淤积规律。推导出不同粒径颗粒在干滩的运移距离公式,公式表明尾矿颗粒在干滩面淤积的位置与尾矿排放的初始流速成正比,与颗粒粒径和放矿浓度成反比。分析结果可为该类尾矿库的尾矿淤积规律和放矿方式的优化等提供借鉴和参考。

The characteristics of particle size and dam accumulated tailings are analyzed based on sampling data of a tailings pond in Guixi,Jiangxi Province,by the combination of experiment and theory analysis. Results show that the particle size variation of tailings sorted by hydrocyclone is more obvious,compared with the original tailings,the size of the tailings near the dry beach are large,while the tailings far away are small.With the distance from the sub-dam increase,the tailings particle size percentage distribution of the peak and peak corresponding to the particle size is gradually reduced. The proportion of fine particle tailings gradually increased along the pond to the dam. The size of deposition tailings on the dry beach changed abruptly at 3. 6 m and 10. 1 m away from the sub-dam,and the size changes of deposition tailings can be divided into three stages,coarsening stage,slow refinement stage and rapid refinement stage. The formula of the migration distance of particles with different grain sizes in dry beach is deduced,the formula shows that the location of tailings particles in the dry beach surface is proportional to the initial velocity of tailings discharge,inversely proportional to the particle size and ore concentration. The analysis results can provide reference for the deposition characteristic of tailings and the optimization of ore drawing method.