基于磁介质结构和体系特征的梯级磁场调控机制及其对弱磁性铁矿的分选特性

There are a few difficulties in recovering fine weakly magnetic iron minerals. High gradient magnetic separation is one of the most effective ways of recovering such minerals. Magnetic particles aggregate on the surface of the magnetic matrices in mineral processing. The structural and system feature parameters of magnetic matrices will play a key role in magnetic field distribution and the sorting process of diffient minrals. Thus, in order to ascertain the effect of characteristic parameters on magnetic field distribution and the separation characteristic of iron minrals, the systematic study should be carried on. This project intends to start from the study of 3D magnetic field characteristics of magnetic martices. The influence law of the morphology ,structure and system characteristic parameters on magnetic field distribution will be systematically drawn by the means of numerical simulation and physical simulation. The optimization mechanism based on characteristic parameters and structure parameters of the matrices will be established. The action law of characteristic parameters effecting on separation performance will be predicted. Then, throughα-Fe2O3 single-mineral tests and weakly magnetic iron minerals separation tests，theoretical model of optimizing parameters of magnetic matrices will be established to absolutely increasing the recovery of micro-fine weakly magnetic iron minerals. The research has important theoretical guidance for strengthening efficient recovery of micro-fine weakly magnetic iron ore resources.

微细粒弱磁性铁矿物的回收一直是选矿界的难题，高梯度磁选法是回收该类矿物最有效的途径之一。磁介质是高梯度磁选过程中磁性颗粒的聚集载体，其结构与体系特征参数对分选区域磁场分布起到关键作用，进而影响矿物分选过程。为了系统地探索磁介质特征参数对磁场分布及矿物分选特性的影响，本项目拟从介质的三维磁场特性研究入手，通过数值模拟和物理测试系统地掌握介质的形貌、结构及体系特征参数变化对磁场分布的影响规律，建立介质结构参数及体系特征参数的优化机制，预测相应参数变化对分选效果的作用规律，通过考察介质特征参数对α-Fe2O3单矿物的磁吸附规律和对弱磁性铁矿分选特性的基础研究，建立优化磁介质特征参数的理论模型，探讨磁介质进一步优化的研究方向，最大限度地提高微细粒弱磁性铁矿物的磁选回收率。本项目的开展对强化微细粒弱磁性铁矿资源的高效回收具有重要的理论指导意义。

当前难选铁矿资源多以弱磁性铁矿物为主，在该类难选铁矿资源的回收利用过程中高梯度强磁选设备的使用较为广泛。面对难选铁矿资源“贫、细、杂”的开发利用现状，对高梯度强磁选设备的技术改进及性能提升提出更高要求。聚磁介质位于高梯度磁选机的核心分选区域，探明磁介质结构参数变化对该区域的磁场分布规律及影响机制，对强化细粒弱磁性铁矿物的回收意义重大。本项目从介质的三维磁场特性研究入手，建立了适宜的三维介质物理模型，开展了单根和多根介质体系下的介质结构参数变化对磁感应特性影响研究，发现了介质表面凸起有助于增强介质表面的磁场不均匀性，进而利于强化细粒铁矿物的回收。通过物理测试系统地掌握了介质的形貌、结构及体系特征参数变化对周围磁场分布的影响规律，验证了数值模拟对磁场分布预测的准确性。通过考察介质特征参数对α-Fe2O3单矿物的磁吸附规律和吸附形态的基础研究，发现了凸极介质对磁性颗粒的吸附首先发生在凸极牙尖处，且凸极螺距与介质间隙会显著影响颗粒在介质表面的累积形态，证实了凸极螺距与介质间隙是影响凸极介质感应磁场特性的重因素。开展了东鞍山强磁给矿、强磁尾矿和海南石碌铁尾矿三个细粒弱磁性铁矿的实际矿石分选试验，确定了适宜的分选参数和介质结构参数，明确了介质凸极结构的设置对强化细粒铁矿物分选具有重要的作用，为最大限度地提高微细粒弱磁性铁矿物的磁选回收率提供理论借鉴。本项目的开展对强化微细粒弱磁性铁矿资源的高效回收具有重要的理论指导意义。