Extraction of Al from Coarse Al-Si Alloy by The Selective Liquation Method.

A selective liquation process to extract Al from a coarse Al-Si alloy, produced by carbothermal reduction, was investigated on the laboratory scale. The products obtained by selective liquation-vacuum distillation were analyzed by X-ray diffraction, inductively coupled plasma optical emission spectrometry and scanning electron microscopy. During the selective liquation process with the use of zinc as the solvent, the pure aluminum in the coarse Al-Si alloy dissolved in the zinc melt to form an α-solid solution with zinc, and most of the silicon and iron-rich phases and Al-Si-Fe intermetallics precipitated and grew into massive grains that entered into the slag and separated with the Zn-Al alloy melt. However, some fine silicon particles remained in the Zn-Al alloy. Thus, Al-Si alloys conforming to industrial application standards were obtained when the Zn-Al alloys were separated by a distillation process.