We investigated whether the vertical roller mill can be efficiently used in the beneficiation of low-grade magnesite and whether it can improve upon the separation indices achieved by the ball mill. We conducted experiments involving the reverse flotation and positive flotation of low-grade magnesite to determine the optimum process parameters, and then performed closed-circuit beneficiation experiments using the vertical roller mill and ball mill. The results show that the optimum process parameters for the vertical roller mill are as follows: a grinding fineness of 81.6wt% of particles less than 0.074 mm, a dodecyl amine (DDA) dosage in magnesite reverse flotation of 100 gt^-1, and dosages of Na₂CO₃, (NaPO₃)₆, and NaOL in the positive flotation section of 1000, 100, and 1000 gt⁻¹, respectively. Compared with the ball mill, the use of the vertical roller mill in the beneficiation of low-grade magnesite resulted in a 1.28% increase in the concentrate grade of MgO and a 5.88% increase in the recovery of MgO. The results of our causation mechanism analysis show that a higher specific surface area and greater surface roughness are the main reasons for the better flotation performance of particles ground by the vertical roller mill in the beneficiation of low-grade magnesite.

我们研究了立式辊磨机是否可以有效地用于低品位菱镁矿的选矿，以及是否可以改善球磨机获得的分离指数。我们进行了包括低品位菱镁矿的反向浮选和正浮选的实验，以确定最佳工艺参数，然后使用立式辊磨机和球磨机进行了闭路选矿实验。结果表明，立式辊磨机的最佳工艺参数如下：小于0.074 mm的颗粒的细度为81.6wt％，菱镁矿逆浮选中的十二烷基胺（DDA）剂量为100 gt ^-1，剂量为的Na ₂ CO ₃，（NaPO ₃）₆和正浮选区中的NaOL分别为1000 gt ^-1和100 gt ^-1。与球磨机相比，在低品位菱镁矿的选矿中使用立式辊磨机可使MgO的精矿品位提高1.28％，MgO的回收率提高5.88％。我们的因果关系分析结果表明，较高的比表面积和较大的表面粗糙度是在低品位菱镁矿选矿中用立式辊磨机磨碎的颗粒具有较好浮选性能的主要原因。