柔性隔离层下多漏斗矿岩流动特性及影响因素正交模拟试验

Orthogonal simulation test for flowing characteristics of ore-rock and influence factor in ore drawing from multiple funnels under flexible isolation layer

研究散粒体的流动性能及其影响因素对于降低损失和贫化具有重要的意义.借鉴前人研究成果,选择了隔离层厚度、隔离层界面摩擦系数、颗粒摩擦系数、颗粒半径、墙体摩擦系数5项主要影响因素,采用正交实验法。建立了五因素三水平正交放矿数值模型;通过对多漏斗放矿条件下矿岩流动规律的模拟,探讨了柔性隔离层作用下多漏斗放矿流动特性;结合多漏斗放矿试验特点,选取放出量与放出体交线高度比与隔离层起伏角为评价指标.利用矩阵分析法,获取指标体系的权矩阵,阐明了影响因素作用规律.研究结果表明:多漏斗放矿条件下,因各放矿口间的相互影响而产生交错、缺失等不同程度的变异,放出体并不呈规则椭球体形状;隔离层界面在放矿初期呈近似水平下移,后期弯曲起伏较大,呈圆弧形下移,直至放矿终了以波浪形悬浮于底部结构;隔离层运动形态对放矿效果的影响起着至关重要的作用;5项主要因素影响的主次顺序是墙体摩擦系数、颗粒摩擦系数、颗粒半径、界面摩擦系数、隔离层厚度;当墙体摩擦系数为0.2、颗粒摩擦系数为0.8、颗粒半径为0.008m、界面摩擦系数为0.8、厚度为0.005 m时,放矿效果最佳.

The study on granular flow characteristics of ore-rock and its influencing factors is significant for controlling ore dilution-loss. With the reference of predecessor＇s research achievements, isolation layer thickness, friction coefficient of isolation layer interface, particle friction coefficient, particle radius and wall friction coefficient are considered as main influence factors. The orthogonal ore drawing numerical model, which contains four factors and three levels, is established with orthogonal test. The flow characteristics in ore drawing from multiple funnels under flexible isolation layer is explored through the simulation on ore-rock flow law in ore drawing from multiple funnel. Combined with the test characteristics of ore drawing from multiple funnels, the ratio of drawing quantity to intersecting line height of drawing ore body and undulating angle of isolation layer are chosen as evaluating indicators. Weight matrix of index system is obtained and action law of influencing factors is elucidated with the use of matrix analysis. The study results show that the drawing ore body is not a regular ellipsoid in ore drawing from multiple funnels due to the varying degrees variation, e.g.,interleaving and deletion caused by interplay between each drawing holes. The isolation layer interface drops at a approximate level at early stage of ore drawing and later at a circular-arc. At the end of the ore drawing, isolation layer suspends in the bottom structure,showing a wave shape. The movement pattern of the isolated layer plays an important role in the effect of ore drawing. The effect weights ranking of each factor is wall friction coefficient, particle friction coefficient, particle radius, interface friction coefficient and isolation layer thickness. The best flowing effects of ore happens when wall friction coefficient is 0.2, particle friction coefficient is0.8, particle radius is 0.008 m,interface friction coefficient is 0.8 and isolation layer thickness is 0.005 m.