Purification technology of molten aluminum^①

来源期刊：中南大学学报(英文版)2004年第2期

论文作者：孙宝德 丁文江 疏达 周尧和

文章页码：134 - 141

Key words：aluminum; purification; hydrogen; inclusion; electromagnetic separation; filtration

Abstract: Various purification methods were explored to eliminate the dissolved hydrogen and nonmetallic inclusions from molten aluminum alloys. A novel rotating impeller head with self-oscillation nozzles or an electromagnetic valve in the gas circuit was used to produce pulse gas currents for the rotary impeller degassing method. Water simulation results show that the size of gas bubbles can be decreased by 10% 20% as compared with the constant gas current mode. By coating ceramic filters or particles with active flux or enamels, composite filters were used to filter the scrap A356 alloy and pure aluminum. Experimental results demonstrate that better filtration efficiency and operation performance can be obtained. Based on numerical calculations, the separation efficiency of inclusions by high frequency magnetic field can be significantly improved by using a hollow cylinder-like separator or utilizing the effects of secondary flow of the melt in a square separa-tor. A multi-stage and multi-media purification platform based on these methods was designed and applied in on-line pro-cessing of molten aluminum alloys. Mechanical properties of the processed scrap A356 alloy are greatly improved by thecomposite purification.