Although the recycling of aluminium has many environmental and economic benefits, the accumulation of impurities is a problem in the case of repeated recycling. In this study, the purification of A7075 wrought aluminium alloy and ADC12 based hypereutectic aluminium alloy was conducted by the backward extrusion process under a semisolid condition. The effect of process parameters such as the semisolid temperature and backward extrusion ratio was investigated. From the results of optical microscopic imaging, scanning electron microscopy (SEM) and energy-dispersive X-Ray spectroscopy (EDS) analysis, it was confirmed that the percentage of purified aluminium, the distribution of aluminium and the yield of the purified part for A7075 alloy were significantly affected by the semisolid temperature and extrusion ratio. For ADC12 based hypereutectic aluminium alloy, it was found that the silicon flakes still remained even in the unextruded part after the purification process.