Evaluation of Light Gauge Aluminum Scrap Remelting After Consolidation via the Extrusion Process

摘要

In the current aluminum processing industry, a more cost-effective method for remelting light gauge aluminum scrap is needed. Light gauge aluminum scrap may include machine chips and swarfs, light gauge wire, or other particles. Additionally, remelting this type of material is often not feasible because of extensive oxidation due to the high surface to volume ratio. Cold extrusion experiments have been performed using aluminum powder as a modeling material and shredded aluminum wire to understand the effect of particle size and shape on the pressure necessary to produce consolidated aluminum material. These extrusion experiments were performed using an aluminum front-pad technique to introduce different levels of counter pressure to control the degree of material densification. The performed remelting experiments showed an over 20 percent increase in melt recovery using consolidated material. For many years now, the aluminum recycling industry has matured both in terms of its technology and efficiency. Despite the progress in increasing yield from aluminum scrap, the light gauge scrap (on the order of less than 1.5 mm or 0.06 inches in diameter) is processed for remelting in an inefficient manner due to recovery losses. For example, in the production of light gauge aluminum wire, the scrap generated (Figure 1) is extremely difficult to remelt. The main cause for the inefficiency of light gauge aluminum scrap recycling is due to its very high surface area to volume ratio, which causes extensive oxidation when heated to the melting temperature. Extensive oxidation leads to high dross formation and loss of recoverable metal.