SBIR-STTR Award

This Small Business Technology Transfer (STTR) Phase I project aims to apply knowledge developed from a laboratory astrophysics experiment to the challenge of purification of aluminum. Aluminum more readily oxidizes than any metallic impurities such as iron, which makes purifying aluminum cost prohibitive. This project began as an investigation in liquid metal of angular momentum transport mechanisms responsible for evolution of astrophysical accretion disks. By tailoring the flow properties of the liquid metal, separation of solid impurities entrained in the metal was observed. This project will extend those initial observations to determine the efficiency of impurity separation over a variety of flow parameters. These observations will be used to design an apparatus to demonstrate impurity separation with molten aluminum. The broader impact/commercial potential of this project is to improve the efficiency of aluminum recycling and reduce the energy intensity of aluminum refining. Recycling aluminum requires only 5-8% of the energy required to refine, but accumulates tramp elements which cannot cost effectively be removed. Currently, recycled aluminum is "down cycled" into lower valued products, or diluted with primary aluminum. By developing a cost-effective means of removing impurities, the present project will enable recyclers to produce higher value aluminum alloys with less use of primary aluminum. Primary production of aluminum from alumina uses roughly 1% of global electrical energy, and produces 2.5% of anthropogenic greenhouse gas emissions. Alternative refining processes which would dramatically reduce both electricity needs and emissions are not yet commercially viable, in part due to a need for cost effectively purifying the finished aluminum. As an enabling technology, this project may contribute to the commercialization of alternative refining processes leading to billions of dollars in savings over present production means.

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is in reducing the environmental impact of Aluminum production. Global production of aluminum from bauxite ore currently accounts for 1% of global electricity consumption, and 2.5% of CO2 emission. Over the last 15 years global production has doubled, and is expected to continue to increase over the next decades with expanded use in automotive applications. To meet increasing demand while reducing the environmental impact of production requires cost effective means of removing contaminating metals such as iron from aluminum. Commercial application of the technologies investigated here would positively affect the global aluminum industry and reduce its environmental impact. Applied to conventional primary production, the technology can be used to increase the yield from bauxite, or allow kaolinite clays to be used for primary production. The former will reduce the environmental and economic costs of production, while the latter would allow domestic producers to reduce their reliance on imported bauxite. If the technology is applied to primary production using carbothermic reduction, the impacts on the global aluminum industry would be even greater. Greenhouse gas emissions could be reduced by up to 50%, and electricity consumption reduced by up to 20%.The objective of this Phase II SBIR research is to demonstrate a cost effective barrier centrifuge technology to remove contaminating elements from aluminum alloys. In the Phase I research we demonstrated the basic technology using a liquid gallium alloy instead of aluminum. In Phase II, we will fabricate an apparatus for handling liquid aluminum and characterize its purification efficiency and costs to own and operate. Using the barrier centrifuge to purify aluminum in secondary production would reduce the need for dilution by primary aluminum, thereby reducing the demand for the primary aluminum with a consequent reduction in electricity consumption, greenhouse gas production and waste disposal needs from the bauxite refining process.