无底柱分段崩落法放矿规律的数值试验研究

Research on Numerical Simulation of Ore Drawing Rules under Non-pillar Sublevel Caving

为了解决无底柱分段崩落法损失贫化较大的问题,数值模拟了崩落体的形态以及放矿过程中崩落体和放出体的形态演变过程。结果表明,崩落体形态接近于椭球缺,呈上宽下窄状,崩落体的宽度约为崩矿步距的1.2~1.5倍,但崩矿步距对崩落体的高度基本没有影响;放出体的形态也是近似椭球缺形,其演变规律表现为由初态的上宽下窄逐渐演变为上尖下宽,说明随放矿进行崩落体内矿石垂直流动性逐渐加强。研究中对放矿技术指标进行了统计分析,结果表明,放矿过程中,出矿口矿石品位是震荡式降低的,造成品位震荡降低的原因是少量正面废石的混入,而造成放矿截止的主要原因是顶部废石的大量混入。

To solve high loss and dilution of ore in the nonpillar sublevel caving,the shape of the caving body and shape evolution from caving body to draw body in ore drawing were researched by numerical simulation.The results showed as follows,firstly the shape of caving body was approximate to a wide top and narrow bottom ellipsoid,and the width of caving body was about 1.2~1.5times of caving space,but the caving space had little effect on the height of caving body.Secondly,the shape of draw body was also approximate to an ellipsoid,and the evolution process presented from wide top and narrow bottom in the beginning to a spike-like top and wide bottom gradually,which proved that vertical mobility of ore particles gradually strengthened along with ore drawing.Thirdly,statistical analysis of drawing technology index showed that the ore grade of the drawing hole was oscillatory decreased during ore drawing and the reason for this phenomenon was the mixture of a small amount of front waste rocks.And the mixture of large amounts of top waste rocks caused the cutoff grade of ore drawing.