リサイクリング 塩化物経由のアルミニウムスクラップリサイクルとケミカルコジェネレーション

Abstract

The recycling of aluminum scrap reduces the energy consumption and environmental burden, comparing to the primary metal production. However, the amount of the recovered metal from scrap is limited because of the difficulties to remove the impurities in the scrap. Sometimes the removal of the impurities requires significant energy consumption.The performance of the metal chlorination and co-generation procecss, in which aluminum scrap reacts with chlorine to form aluminum chloride and its reaction energy is recovered by electrochemical means, was investigated.The power generation of about 6 W was accomplished with 20 mass % Cu added Al or 50 mass % Fe added Al. This power generationis almost equivalent to that with pure aluminum. The selective reaction of Al was also confirmed by the fact that there was no Cu or Fe in the dust and the salt electrolyte. This proved the high capability to purify aluminum from its scrap. The energy consumption in the total recycling system, whichconsists of the metal chlorination and co-generation, metal chlorides purification, and electro-winning, was evaluated to be less than half of that in the conventional Hole-Heroult process.