Aluminum Recovery from White Aluminum Dross by a Mechanically Activated Phase Separation and Remelting Process

Abstract

The aluminum recovery from white aluminum dross by a mechanical treatment and sizing followed by remelting process was investigated. The dross was subjected to a ball mill, and the obtained particles were sized in different ranges. They were studied by advanced materials characterization techniques. It was found that the larger particles contain high metallic portions, and most non-metallic components of the dross are in the fine fraction < 1 mm. The Al-rich particles (> 1 mm) were remelted at 900°C to recover aluminum. It was found that the metal structure after remelting is homogeneous and consisted of a dominant metallic aluminum matrix, containing an average of > 96% Al with around 99% total metallic components. The results show that the applied method is a good economic alternative for the aluminum recovery from white dross, which is important for the valorization/recycling of industrial waste and circular economy.

Valorization of Aluminum Dross with Copper via High Temperature Melting to Produce Al-Cu Alloys

“…Aluminum alloys are light, conductive, and corrosion resistant, properties that have made them a widely used material with applications in the aerospace, architectural construction, and marine industries, as well as in many domestic contexts [1,2]. Pure aluminum is the Earth's third most abundant element, accounting for about 8% of the mass of the Earth's crust, and it never occurs as a free element in nature [3,4]. At present, aluminum is mainly produced via two different methods: (I) a primary aluminum production from bauxite ore via the Bayer process for alumina extraction, followed by Hall-Heroult electrolysis for Al extraction from alumina, and (II) by recycling aluminum from process scrap and used aluminum products [3][4][5][6][7].…”

“…Pure aluminum is the Earth's third most abundant element, accounting for about 8% of the mass of the Earth's crust, and it never occurs as a free element in nature [3,4]. At present, aluminum is mainly produced via two different methods: (I) a primary aluminum production from bauxite ore via the Bayer process for alumina extraction, followed by Hall-Heroult electrolysis for Al extraction from alumina, and (II) by recycling aluminum from process scrap and used aluminum products [3][4][5][6][7]. The world's production of aluminum is increasing every year and was approx.…”

“…The world's production of aluminum is increasing every year and was approx. 64 million metric tons in 2019 with a daily average of 174.5 thousand tons [3,7], while in 2020 it was over 65 million metric tons in 2020 [8]. As a result of the exposure of liquid aluminum to the oxidizing atmosphere that is present during the process of melting and alloying, a surface oxidation takes place, leading to the formation of a semisolid skin over the molten Al metal, which also hinders further oxidation [7].…”

“…The recycling of Al dross, which is a by-product, is important from both environmental protection and economic points of view [4,6]. Generally, there are two types of Al dross: (I) White Dross (the primary dross) and (II) Black Dross (the secondary dross) [3,7].…”

“…Materials 2021, 14, 4117 2 of 18 Aluminum White Dross (AWD) forms during the primary production of aluminum and contains a high percentage of Al and Al 2 O 3 i.e., around 75% Al, and below 5% of salts [3,11]. Aluminum Black Dross (ABD) consists of a low amount of metal substance and is formed at secondary aluminum production routes.…”