(1. 中南大學 資源加工與生物工程學院，長沙 410083；
2. 鞍鋼集團北京研究院有限公司，北京 102209)
摘 要: 為了解決傳統(tǒng)干式磁選機的脈石夾雜問題，引入空氣作為分選介質，利用氣流曳力破壞磁團聚。采用3 mm以下大范圍粒度的磁鐵礦進行預選實驗，通過改變磁場強度、風速大小和滾筒轉速，得到不同條件下的精礦品位、回收率、分選效率等指標。結果表明：風力與磁場的適當耦合能夠強化物料分選過程中的分散作用，減少因物料沉積和磁團聚作用所帶來的脈石夾雜，特別在磁場強度足夠大的情況下，能夠在提高精礦品位的同時保證較高的回收率。對礦物顆粒的受力情況進行了分析計算，并利用Comsol仿真軟件對不同風速下的顆粒運動軌跡進行了模擬，同時對實驗前后礦樣的化學成分進行了對比，得出了分選過程中風力的作用機理。風力作用下的干式磁選機選礦成本低，具有較大的推廣應用價值。
關鍵字: 風力；干式預選；作用機理；磁鐵礦；磁團聚；脈石夾雜；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
