Traveling Wave Magnetic Field Used For The Purification Of Aluminum Melt

During pyrometallurgical processing of molten aluminum, it is easily reacted with other elements to form multiple compounds staying in molten aluminum, which can greatly influence the mechanical properties of aluminum and its alloys. Seperating the impurities from molten aluminum is the key factor to improve the qualities and mechanical properties of aluminum alloys. And metallurgists have paid close attention to the molten aluminum purification. Compared with traditional technology, traveling magnetic field purifying molten aluminum has the advantages on both processing volume and depth of purification, and this new technology was carefully studied in this paper.Firstly the parameters affecting the distribution and magnititude of induced current in molten aluminum purified by traveling magnetic field was studied by simulative experiments. It proves that increasing the layers of the net composed of molten metal streams along the direction of the magnetic field has little effect on the distribution of induced current, but along the direction perpendicular to the magnetic field, the span of the net should be lager than polar distance of the generator of the traveling magnetic field so as to keep the homogeneity of the induced current, the ultimate current induced in the molten aluminum under the industrial condition(the distance between two neighboring metal streams inclines to zero, and magnetic flux density is 0.1T) is deduced by extrapolation. Besides the calculation on trajectory model shows: when the aluminum molten flows with a speed of 2m/s in a ceramic tube with section area of 4mm~2 over 0.42m distance, and the impurities lager than 10 micrometer diameter will be removed thoroughly.Based on technical parameters of simulative experiments and experiences of building former electromagnetic generator, a new one for industrial uses was developed. After adjusting the experimental equipments to running suitably, Several comparative industrial experiments between traveling magnetic field and foamed ceramic filter were carried out. The industrial experiments of electromagnetic generator shows: the impurities larger than 40 micrometers canbe removed completely and impurities size between 10 to 30 micrometers can be removed nearly 50%; the capability of electromagnetic generator can reach 4t/h. The traveling magnetic field has the advantages over foamed ceramic filter both on efficiency and depth of purification.