Numerical Simulation of the Spatial Distribution of the Magnetic Field in Devices for the Magnetic Sedimentation of Nanoparticles from Aqueous Media

Abstract

Abstract—A method of magnetic sedimentation using a permanent magnets is a promising “green” technology to separate nanoparticles from water. In this work, numerical simulation of the magnetic field distribution in the devices based on combination of alternating flat permanent magnets (NdFeB) and soft magnetic steel inserts is carried out. Two types of devices with different magnetization directions of permanent magnets are considered: vertical (V) and horizontal (G). A criterion for evaluating the performance of the magnetic device R is proposed, depending on the effective volume of the water area, where the value of the product \({\text{|}}{{B}_{z}}d{{B}_{z}}{\text{/}}dz{\text{|}}\)  4 T2/m is realized, where Bz is the vertical component of magnetic induction. The dimensions of the permanent magnets and soft magnetic inserts along the horizontal x axis, the ratio of the thicknesses of magnetic and steel plates, and the number of plates are varied. It is shown that the maximum value R = 31% is performed using the V-type magnetic device with the thickness of the magnetic (Lx) and the steel (Ls) elements 30 mm and 2.5 mm, respectively. For G-type magnetic device maximum value R = 19% is realized at Lx = 12.5 mm and Ls = 10 mm. Magnetic devices are effective for the height of a water layer 20 mm at the given dimensions of the magnetic system.