(1. 中南大学 资源加工与生物工程学院，长沙 410083；
2. 鞍钢集团北京研究院有限公司，北京 102209)
摘 要: 为了解决传统干式磁选机的脉石夹杂问题，引入空气作为分选介质，利用气流曳力破坏磁团聚。采用3 mm以下大范围粒度的磁铁矿进行预选实验，通过改变磁场强度、风速大小和滚筒转速，得到不同条件下的精矿品位、回收率、分选效率等指标。结果表明：风力与磁场的适当耦合能够强化物料分选过程中的分散作用，减少因物料沉积和磁团聚作用所带来的脉石夹杂，特别在磁场强度足够大的情况下，能够在提高精矿品位的同时保证较高的回收率。对矿物颗粒的受力情况进行了分析计算，并利用Comsol仿真软件对不同风速下的颗粒运动轨迹进行了模拟，同时对实验前后矿样的化学成分进行了对比，得出了分选过程中风力的作用机理。风力作用下的干式磁选机选矿成本低，具有较大的推广应用价值。
关键字: 风力；干式预选；作用机理；磁铁矿；磁团聚；脉石夹杂；Comsol仿真
（1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. Beijing Research Institute Co., Ltd., Ansteel Group Corporation Limited, Beijing 102209, China）
Abstract:In order to solve the problem of gangue inclusion in the traditional dry magnetic separator, the air was introduced as a sorting medium, and the magnetic reunion was destroyed by the drag force of the air flow. Magnetite with a large range of particle sizes below 3 mm was used for pre-selection experiments. By changing the magnetic field strength, wind speed and drum speed, indicators such as concentrate grade, recovery rate, and separation efficiency under different conditions were obtained. The results show that the proper coupling of wind force and magnetic field can strengthen the dispersion in the material sorting process and reduce the inclusion of gangues caused by material deposition and magnetic agglomeration. Especially when the magnetic field strength is large enough, it can improve the precision. The mineral grade guarantees a higher recovery rate. The force of mineral particles was analyzed and calculated. Comsol simulation software was used to simulate the particle trajectory under different wind speeds. At the same time, the chemical compositions of the ore samples before and after the experiment were compared, and the action mechanism of wind force during the separation process was obtained. The dry-type magnetic separator under the action of wind force has a low beneficiation cost and is of great value for popularization and application.
Key words: wind; dry preselection; action mechanism; magnetite; magnetic agglomeration; inclusion of gangue; Comsol simulation
