矿泥重选理论初探

来源期刊：中南大学学报(自然科学版)1979年第2期

论文作者：黄枢

文章页码：20 - 30

关键词：离心选矿机； 矿泥； 矿粒； 摩擦系数； 流膜； 横流皮带溜槽； 重选设备； 分散压； 细颗粒； 矿浆流态

摘    要：现有矿泥重选设备,除离心选矿机外,矿浆流态都属层流。运用层流理论公式可求出单个矿粒的移动速度,同时得知流膜厚度、底面的坡度和摩擦系数是影响矿粒分选好坏的重要因素。当粒群在层流流膜中运动时,促使矿粒悬浮的不是水流的紊动作用而是颗粒与颗粒间的切应力。过去提出的一些矿浆分层概念都不够全面。本文根据泥沙运动的一般规律及结合矿泥流膜的特点,将矿浆分成扰动层、悬移层、推移层和沉积层,并阐明各层的作用。指出下部推移层的松散不足和沉积层压紧是固定式矿泥溜槽效率低的原因。利用摇动可以强化矿泥分选过程。

Abstract: The flow pattern of pulp in currently used gravity slime concentrators except centrifugal separator belongs to laminar type. The travelling velocity of single particle sliding along an inclined surface in laminar flow may be calculated by the theoretical formula, and consequently it is known that the major factors affecting the separating efficiency of particles are the thickness of flow film, the slope of inclined surface and the coefficient of friction between particles and inclined surface. In practice, however, a mass movement of particles really takes place there and the acting force which causes particles maintaining in suspension is the shear stress between particles involved and not the eddy movement at all. Previous concepts proposed for the stratification of pulp in slime concentrator are considered to be not complete. According to the general role of pulp movement and the characteristics of slime flow film, in this paper the author proposes that the pulp in slime concentrator may be divided into four layers, i.e. turbulent layer, suspension layer, transportation layer and sedimentation layer, and explains the mechanism of each layer. A low efficiency of slime sluice of fixed type is due to inadequacy of loosing at trasportation layer and the packing of sedimentation layer. The process of slime concentration may be improved by the application of a shaking force to the bed of a concentrator.