磁铁矿/石英/方解石多元矿物体系中选择性磨矿机理研究

Over-comminution in ball mill from industrial production process is the focus of attention. The cause of over-comminution is from two aspects of existing mineral properties and the factors of mechanical and operating. However, the former can be awfully neglected and the latter easily observed by mineral processing plant in industrial application. In this project, grinding behavior based on multi-component mineral system that magnetite, quartz and calcite are on behalf of useful minerals, gangue minerals and clay minerals respectively will be carried out in different volume ratio, feed size and grinding time when the factors of mechanical and operating immobilized and JK size breakage model applied. Meanwhile, selective grinding mechanism will be discussed in theory when these minerals are the intrinsic properties of the difference of hardness and size. Through the magnetic separation and acid solution, a single mineral component can be separated from their blended samples, which will help to solve breakage matrix function and the ground product size distribution according the mixed minerals system and single mineral. The project will reveal the selective grinding law from intrinsic mineral properties of the difference of hardness and size in order to predict the particle size distribution of ground product in any mineral property and control the over-comminution of the industrial ball mill on the basis of theory.

球磨机在工业生产过程中产生的过粉碎现象非常受关注。造成过粉碎现象的原因既有矿物的内在属性，又有机械和操作因素。后者容易被选矿厂所观察到，而内在属性却被严重忽视。本项目固定化机械和操作因素，应用粒度破碎建模方法，以磁铁矿代表有用矿物，石英代表脉石矿物，方解石代表易泥化矿物，研究它们组成的多元矿物体系在不同的体积配比、给矿粒级和输入比能量下的磨矿行为，从理论上探讨矿物的内在属性存在硬度和粒度差基础上的选择性磨矿机理。通过磁选和酸解，可以相互分离出多元矿物体系中各个单矿物组分，从而求解出各混合矿及其组成单矿物的磨矿产品粒度分布和破碎矩阵函数，揭示出矿物内在属性存在硬度、粒度差下的选择性磨碎规律，预测任一内在属性作用下磨矿产品粒度分布，为工业磨机的过粉碎调控提供理论依据。

磨矿是一个粒度减少和消耗能量的过程。工业磨矿生产容易产生过粉碎现象，调控过粉碎具有重要意义。但过粉碎受到矿物内在因素影响较大。本项目以磁铁矿、方解石、石英为研究对象，以磨矿产品粒度分布建模和过粉碎调控为目标，系统研究了磁铁矿、石英、方解石在单矿物、二元、三元矿物体系中的选择性磨矿行为。采用JK粒度破碎模型以及能量特征值S建立了多元矿物体系中磨矿产品和分离的各组分的磨矿细度t10与能量的关系。在三元混合磨矿过程中存在选择性磨碎，比重大的磁铁矿磨碎减弱，比重小的石英和方解石的磨碎加强。磨矿产品的过粉碎随着给矿粒度的变细，过粉碎含量增加，因此在工业生产过程中细磨更应该注重过粉碎的调控，最后通过破碎矩阵求解，建立了多组分矿物的粒度分布预测模型。