Treatment of Metal Drosses via Ionic Liquid Electrolytes

One of the most abundant metals on earth aluminum composes 8% of the earth’s crust in oxide or silicate form. Twenty-nine million tons of aluminum are needed to meet annual worldwide demands. Of this twenty-two million tons are new aluminum and seven million tons comes from recycled aluminum scrap. Of the twenty-two million tons of new aluminum used annually only 50% of it is ever recycled. New aluminum is made from bauxite which is energy intensive and utilizes a costly electrolyte and forms dross as a by-product. Conventional processes for producing secondary aluminum from alloy require less than 20% of the energy that is needed to make primary aluminum from bauxite however these processes still require melting aluminum scrap at high temperatures in addition to degreasing and other cleaning steps. The conventional recycling processes also produces a large quantity of aluminum dross that is skimmed off the aluminum melt and discarded. Even state of the art dross recycling can currently only recover 3-10% of the aluminum in a process that is highly energy intensive. This invention deals with a novel process that can obtain aluminum from the dross formed during both the primary smelting process as well as during the aluminum recycling process. In this process aluminum is extracted by dissolution of the dross in ionic liquids at less than 100 ºC followed by electrolysis. Over 3% of the world’s total electricity goes toward making new aluminum and this invention could help significantly lower that percentage through a substantial reduction in energy costs and emissions over conventional aluminum recycling processes. Applications: ·Aluminum Recycling ·Uses less energy ·Produces less pollutants ·Reduces the need to produce new aluminum