对含有Al_2O_3的铝熔体电磁分离实验研究

Experimental research on electromagnetic separation of Al_2O_3 from aluminum melts

通过向Al熔体中加入SiO2颗粒,成功制备了Al-10%Al2O3复合材料;并采用远大于集肤层厚度的直径30mm陶瓷分离管和中空管进行了分离实验.结果表明大尺寸分离管同样能实现电磁净化,只是分离时间比中空管略长,可能是因电磁搅拌效应引起的流动造成的.对含有30～200μm Al2O3颗粒的铝熔体的电磁连续净化实验结果显示:仅使用泡沫陶瓷过滤该合金时,平均净化效率为96.15%;当施加0.06T的高频磁场时,复合过滤净化效率的平均值为97.30%,比泡沫陶瓷单独净化的效率高了1.15%.对Al-10%Mg合金的连续净化实验结果表明,仅用泡沫陶瓷过滤该合金时,经过两次过滤后可将合金中的氧含量从0.000 9%降低为0.000 4%,净化效率为55.6%;而当泡沫陶瓷外加0.04T磁场复合净化时,氧含量从0.001 4%降低为0.000 3%,净化效率达到78.6%.

Al-10%Al2O3 composite material is successfully fabricated by adding SiO2 into the pure aluminum melt,and used to engage in the electromagnetic separation experiment through the ceramic separation pipes of 30 mm diameter far bigger than the skin depth and hollow pipes.It is found that the Al2O3 particles accumulate in periphery of specimen by separation pipes with big diameter,which may be helped by the flow caused by electromagnetic stirring,although it takes more time to reach the periphery than that of hollow pipe.The continuous elimination results with the molten aluminum which contains 30-200 μm Al2O3 particles show that the average elimination efficiency is 96.15% and it increases to 97.30% when the magnetic induction intensity is 0.06 T,and the latter is higher about 1.15% than that without magnetic field.The continuous elimination results with the Al-10%Mg alloy show that without magnetic force,the percentage of oxygen in the alloy decreases from 0.000 9% to 0.000 4% after twice elimination and the elimination efficiency is 55.6%.When the magnetic induction intensity around the foam ceramic filter is 0.04 T,the percentage of oxygen decreases from 0.001 4% to 0.000 3% and the elimination efficiency is 78.6%.