| With the update of electronic products,more and more electronic waste(e-waste)has emerged.The metal contained in e-waste is extremely high and has great recycling value.Therefore,the research and development of the recycling and reuse of e-waste is crucial to sustainable development of metal industry.Metal separation is the key step for e-waste recycling process.Due to the integration of electronic and electrical products and the increasingly miniaturization of electronic products,the realization of small size(particle size of 1-5 mm)metal separation is of great realistic significance for the e-waste recycling.In this paper,a new type of vertical eddy-current separation device is designed on the basis of traditional eddy-current separation device.The influences of magnetic roller parameters on magnetic field are analyzed in detail by Maxwell software.The force in the separation process was analyzed and the trajectory of different particles was investigated by using Maxwell and Matlab software together.In this paper,the prototype of vertical eddy-current separation device was produced and the preliminary experiment was carried out.In addition,the design of a new type of non-uniform magnetic roller is proposed in this paper,it is of great significance to future research.The main contents and results are as follows:(1)The simulation results of magnetic field of magnetic roller:with the increase of the thickness of magnetic roller d the maximum field intensity of the magnetic roller surface increases first and then decreases,and the effective distance of magnetic fields changed hardly.With the increase of the magnetic roll radius(R),the maximum field intensity of the magnetic roller surface as well as the effective distance of magnetic fields growth is slowing down.With the increase of the pair of magnetic pole,k,the maximum field intensity of the magnetic roller surface increases first and then decreases,but the effective distance of magnetic field of the magnetic roller decreases gradually.According to the actual production process,the optimum parameters are adopted as d=40 mm,R=138mm,k=9.(2)The calculation results of the force and trajectory of particles:according to the results of particles with spheres,cylinders and tetrahedron morphologies.it can be found that when the particle size is the same,the eddy force of the cylinder is maximum,then tetrahedron,sphere is the last.The trajectory of particles were calculated by Matlab and Maxwell software,it is found that at the same rotational speed,the falling distance follows the following rules:sphere<tetrahedron<cylinder.When the rotation speed of magnetic roller is greater than 2500 rpm,the separation of small size material can be realized effectively.(3)The production and separation experiment of the vertical eddy-current separation.The magnetic roller and other auxiliary devices are designed according to the results of(1)and(2).Funnel ring feed and circular brush collection are adopted for the way of feeding and collection,respectively.The collecting baffle needs to be designed according to the kind of materials.The overall height is 2 m,which can separation of various of materials effectively.The separation experiment was carried out using particles made from circuit board with 1-5 mm,the results show that the primary separation of different materials can be achieved. |
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