Performance optimization of the magnetic roller of eddy current separator is an issue of great significance in the recycling industry. In this study, the Halbach array is proposed for the first time to be used in the eddy current separator. And the new concepts of area field intensity and magnet efficiency density are proposed to quantitatively evaluate the magnetic field intensity around the magnetic roller surface and the utilization efficiency of the magnet respectively. Then the effects of various structural parameters of the Halbach magnetic roller on the area field intensity and magnet efficiency density were systematically investigated by employing finite element analysis and response surface methodology. The results showed that the regression models of the area field intensity ($R^2=0.9846$, $Pred.R^2=0.9420$) and magnet efficiency density ($R^2=0.9946$, $Pred.R^2=0.9782$) are extremely significant and have good prediction capability. The magnetic roller can form a stronger magnetic field by selecting a larger magnetic block, and the utilization efficiency of the magnet is higher when the magnetic block’s shape tends to be flat or has larger curvature. Furthermore, a multi-objective optimization model with the area field intensity, magnet efficiency density, and magnetic pole number is established, and a multi-objective genetic algorithm is applied to get the optimal combinations of various structural parameters. It was found that the points of the Pareto-optimal solution are concentrated on a spatial surface, which reflects the trade-off relationship among the three objectives. It also shows that the performance parameters of many Pareto-optimal solutions are superior to that of previous studies and the eddy current separators found in the vicinity. The proposed method framework and the results are useful for the design and optimization of the magnetic roller, which will improve the separation efficiency of eddy current separation.

涡流分离器磁辊的性能优化在回收行业中具有重要意义。在这项研究中，首次提出将Halbach阵列用于涡流分离器。提出了面积磁场强度和磁体效率密度的新概念，分别定量评估了磁辊表面周围的磁场强度和磁体的利用效率。然后，通过有限元分析和响应面方法，系统地研究了Halbach磁辊的各种结构参数对面积场强度和磁体效率密度的影响。结果表明，区域场强的回归模型（${\mathrm{[R}}^2=0.9846$， $P\mathrm{[R}Ëd。{\mathrm{[R}}^2=0.9420$）和磁铁效率密度（${\mathrm{[R}}^2=0.9946$， $P\mathrm{[R}Ëd。{\mathrm{[R}}^2=0.9782$）非常重要，并且具有良好的预测能力。通过选择更大的磁性块，磁性辊可以形成更强的磁场，并且当磁性块的形状趋于平坦或具有较大的曲率时，磁体的利用效率更高。此外，建立了一个具有区域磁场强度，磁体效率密度和磁极数的多目标优化模型，并应用多目标遗传算法来获得各种结构参数的最优组合。发现帕累托最优解的点集中在空间表面上，这反映了三个目标之间的权衡关系。这也表明，许多帕累托最优解的性能参数都优于先前的研究和附近的涡流分离器。提出的方法框架和结果对磁辊的设计和优化是有用的，它将提高涡流分离的分离效率。