溜井储矿段矿岩散体运移轨迹及速度预测模型

Prediction model for the migration trajectory and velocity of ore-rock dispersions in an orepass storage section

  • 摘要: 为准确预测溜井储矿段内矿岩散体运移状态,以放矿漏斗中心线与溜井中心线重合的溜井结构为研究对象,建立了溜井储矿段矿岩运移轨迹和速度预测模型。首先,根据筒仓卸载过程中颗粒运动特点和理想流体流动单元流动特点的相似性,分析储矿段内矿岩运移规律;其次,引用流动网络概念和Beverloo经验公式,建立了储矿段矿岩运移网络,分析了储矿段矿岩运动截面与矿岩运移速度的关系;最后,在一定的假设条件下,根据流线和等位面分布特征,建立了矿岩位移、运移轨迹和速度方程。研究结果表明:(1)矿岩进入储矿段后依次经过匀速区、变速区,分别进行匀速直线下向运动、变速曲线运动;(2)当放矿口倾角较小时存在平衡区,该区域下矿岩不发生位移,导致“空环效应”;(3)单位时间内放出矿岩质量和穿过同一等位面的矿岩质量相等。所建立的预测模型表明,匀速区内矿岩运移状态与储矿段和放矿口断面直径、矿岩粒径等有关,变速区内矿岩运移状态还与矿岩所处位置、放矿口倾角等有关。

     

    Abstract: For the accurate prediction of the migration state of ore-rock dispersions in the ore pass storage section, a prediction model of an ore pass trajectory and velocity was established by taking the orepass structure, which coincided the centerlines of the ore drawing funnel, and the orepass as the research objects. First, during the silo unloading process, the movement law of ore-rock dispersions in the ore-storage section was analyzed according to the similarity of the particles’ movement characteristics and the flow characteristics of an ideal fluid flow unit. Next, the ore-rock migration network was established based from the flow network concept and the Beverloo empirical formula. Analysis was then conducted on the relationship between the section and the velocity of the ore-rock movement in the ore-storage section of ore pass. Finally, under certain assumed conditions, the displacement equation, the migration trajectory, and the velocity of the ore-rock moving in the ore-storage section were established according to the distribution characteristics of streamline and equipotential surface. Results reveal that after entering the ore-storage section of the ore pass, the ore-rock will pass through two speed zones: (1) a uniform speed zone leading to a uniform linear downward motion and (2) a variable speed zone leading to a variable speed curve motion. When the dip angle of the ore draw-hole is small, an “empty ring effect” is achieved, where no displacement of the lower ore-rock is observed. Finally, the quality of the ore-rock drawing-out in a unit time is found to be equal to that of the ore-rock passing through the same equipotential surface. The predicting model reveals the dependency of the ore-rock migration state in the uniform speed zone with a number of parameters such as the diameter of the section of ore-storage and ore-discharge, ore-rock particle size. Conversely, the ore-rock migration state in the variable speed zone is mainly related to the ore-rock’s location and the inclination angle of ore draw-hole.

     

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