Economic feasibility of recycling rare earth oxides from end-of-life lighting technologies

摘要

Transition to efficient lighting technologies, such as fluorescent and LED lamps, is an important strategy to mitigate climate change. However, it also increases the demand for critical materials such as rare earth oxides (REOs). While recycling can alleviate the dependence on primary REOs, recycling these materials from lighting technologies is currently economically infeasible, limiting its adoption. As more REOs will become available for recycling, the economy of scale is expected to reduce the cost, therefore improving their circularity. Here we analyze the effects that the scale of recycling operation and REO prices have on the economic feasibility of REO recycling using dynamic material flow analysis and technology learning curve approaches. Our results show that end-of-life REOs from lighting technologies are expected to peak between 2020 and 2027. Increasing recycling plant capacity can reduce cost from about $7200/t REO phosphors at 100 t/yr capacity to about $2500/t REO phosphors at 1500 t/yr capacity. Nevertheless, we found that REO recycling would not be economically feasible under 2018 REO prices, irrespective of scale. For a plant at 800 t/yr capacity, recycling becomes profitable only after a threefold increase from 2018 REO prices. The break-even point can be further reduced at a larger scale. Our results suggest that scaling-up recycling plants in the course of growing volume of end-of-life lighting technologies alone will not automatically increase REO recycling under current market conditions. Significant improvement of REO recycling rate in lighting technologies would therefore require substantially higher REO prices or commensurate policy interventions.