锡石多金属硫化矿三元体系矿石新概念及其磨矿优化操作的关键基础问题研究

Tin is one of the dominant strategic metals in our country. The cassiterite-polymetallic sulfide ore is the most important mineral resource to provide raw materials for tin extractive metallurgy, which is rich in our country especially in Guangxi and Yunnan provinces. It is well known that a prominent contradiction exists in grinding of cassiterite-polymetallic sulfide ores that either fine grinding causes cassiterite overground, or coarse grinding leads to not enough liberation of sulfide minerals, which easily results in losing great quantities cassiterite in tailing in the form of tin-slimes and decreasing the recovery of cassiterite together with reducing the quality of sulfide ore concentrate. Based on the similarity in physical properties, mechanical properties and processing methods of different minerals contained in cassiterite-polymetallic sulfide ores, the ore minerals could be divided into three components such as cassiterite, sulfide ores and gangue. Proceed from the objective facts that there are significant differences in density, brittleness, hardness among above three components, and taking selective grinding as the breakthrough point to increasing grinding efficiency, four key fundamental problems will be studied profoundly in this project, including the behavior, the mechanism together with the regulatory mechanism of selective grinding for cassiterite-polymetallic sulfide ores, the mathematical model and characteristic of grinding kinetics and population balance model for cassiterite-polymetallic sulfide ores and its components, the calculation methods and models of appropriate grinding media size, the coupling relationship and mechanism among the grinding behavior of cassiterite-polymetallic sulfide ores and those of its components. The objective of this study is to provide the theory basis for optimizing the operating conditions of grinding and formulating a reasonable grinding and mineral processing flowsheet.

锡是我国四大优势战略性金属之一，锡石多金属硫化矿是锡石矿石的主要类型，也是广西和云南两省的优势矿产资源。本项目针对锡石多金属硫化矿选矿生产中由于存在锡石过磨和硫化矿欠磨的突出矛盾造成锡石回收率低和硫化矿精矿质量低的实际问题，根据矿物的晶体化学分类法和矿物的物理、机械性质和选矿方法的相似性，将矿石矿物划分为锡石、硫化矿物和脉石三个矿物组元，提出锡石多金属硫化矿三元体系矿石新概念，并从该类矿石组元数多，矿物组元之间的密度、脆性、硬度存在显著差异的事实出发，以选择性磨矿为切入点，系统研究锡石多金属硫化矿选择性磨矿行为、机理及调控机制，磨矿动力学及其应用，磨矿适宜介质尺寸和配比计算方法，矿石磨矿行为与各矿物组元磨矿行为的耦合关系和机制等四个方面的基础问题，为优化锡石多金属硫化矿的磨矿操作条件提供理论依据。

锡是我国四大优势战略性金属之一，也是广西和云南两省的优势矿产资源。本项目围绕从磨矿优化提高锡石回收率的实际需要，将锡石多金属硫化矿的矿石矿物划分为锡石、硫化矿物和脉石三个矿物组元，并基于不同矿物组元之间的密度、脆性、硬度存在显著差异的事实，以选择性磨矿为切入点，系统研究锡石多金属硫化矿选择性磨矿行为、机理及调控机制，磨矿动力学及其应用，矿石磨矿行为与各矿物组元磨矿行为的耦合关系和机制等涉及磨矿优化的基础问题。通过研究，提出用“矿石组成金属的筛上累积品位的变化值”和“筛上累积金属量的相对变化值”两个新的指标来评价矿石矿物的选择性磨矿特征的表征新方法，该新方法物理意义明晰，表征过程简单，结果一致性好，准确度高，克服了传统显微镜下观察表征耗时长、消耗大、表征准确度和精度差的不足，创新性强，具有广泛适应性和很好的推广价值。按照该选择性磨矿表征新方法，系统研究了锡石多金属硫化矿磨矿过程中磨机类型、磨矿时间、磨矿浓度、磨机转速等因素对选择性磨矿行为的影响，以及矿石中不同组成矿物优先破碎顺序，从定量描述角度发现了锡石多金属硫化矿磨矿中硫化矿优先于锡石破碎，形成了系统的新的认识。按照组成矿物和矿物组元分离磨矿优化的新思路，探索了基于批次磨矿实验预测锡石多金属硫化矿中锡石和硫化矿两类组成矿物的各自磨矿目标粒度产率极大值的新方法，发现了两类矿物磨矿目标粒度产率极大值时间分离现象；探索提出了基于磨矿技术效率与金属分布率混合相乘运算的磨矿合格粒级指数新概念并用它作为磨矿优化表征的新方法，有望推广应用于多金属矿石的磨矿优化表征。利用JKMRC落重试验数据，完整构建了磨矿总体平衡动力学破裂分布函数和选择函数求解的技术路线和方法步骤。利用实验室批次磨矿试验数据，求解获得了一定磨矿条件下锡石多金属硫化矿磨矿总体平衡动力学模型选择函数与破裂分布函数，成功预测了实验室磨矿产物粒度组成，发现了锡石多金属硫化矿磨矿选择函数均随着粒度的增大先增大后减少，在粒度为0.6519mm时达到最大值。将实验室磨矿试验结果与磨矿总体平衡动力学模型预测结果比较时，相同粒级产物的产率试验值与预测值的最大绝对误差为1.45%。总之，项目围绕锡石多金属硫化矿磨矿效果的表征、评价、过程模拟、结果预测和优化开展了系统性创新性研究，成果原创性强，具有重要的学术价值，奠定了重要的方法和技术基础。