Forecasting the temporal stock generation and recycling potential of metals towards a sustainable future: The case of gallium in China

Disna Eheliyagoda; Xianlai Zeng; Zhishi Wang; Eva Albalghiti; Jinhui Li

doi:10.1016/j.scitotenv.2019.06.413

Forecasting the temporal stock generation and recycling potential of metals towards a sustainable future: The case of gallium in China

Sci Total Environ. 2019 Nov 1:689:332-340. doi: 10.1016/j.scitotenv.2019.06.413. Epub 2019 Jun 26.

Authors

Disna Eheliyagoda¹, Xianlai Zeng², Zhishi Wang³, Eva Albalghiti⁴, Jinhui Li⁵

Affiliations

¹ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
² State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: xlzeng@tsinghua.edu.cn.
³ Macau Environmental Research Institute, Macau University of Science and Technology, Macau, China.
⁴ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA.
⁵ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: jinhui@tsinghua.edu.cn.

PMID: 31277001
DOI: 10.1016/j.scitotenv.2019.06.413

Abstract

Gallium is one such co-product mineral, being used for consumer electronics and contemporary renewable energy applications. China is the top producer of gallium and supplies over 70% of global demand. However, supply uncertainty of primary gallium is increasing due to a shortage of reserves. Thus, development of recycling technologies to complement primary production should be prioritized, with more country-specific attention due to its low investment cost and short-term feasibility. In this study, possible end-of-life (EoL) gallium waste generation in China until 2050 was forecasted using linear regression and constructed a scenario analysis based on population and annual demand growth parameters. Similarly, cumulative domestic demand was estimated using 1%, 5%, 10%, 15%, 20%, and 30% recycling rates to investigate the effect of recycling on sustainability of gallium resources. Based on the used method, study results were different; however, continuous demand growth and resource use are expected in most cases. The annual total gallium stock generation in 2050 will reach to 368 t under linear regression forecasting while it will likely fall between 59 t and 148 t according to scenario analysis. Linear projections show that cumulative demand will surpass even reserve base in 2047 whilst scenario analyses demonstrate that cumulative demand will exceed reserve between 2037 and 2047, if there would be unable to implement necessary recycling routes in the short term. The linear regression cumulative demand prediction urges the need of substitution, while the scenario analysis demonstrates the importance of increasing EoL recycling rates. The latter should also be supported with improved EoL collection rates, technological transfer from high-tech countries to China and appropriate policy advancement. The output of the study also convinces the importance of moving towards a circular economic model in the anthropogenic flow of gallium utilization.

Keywords: Anthropogenic flow; Consumer electronics; Gallium; Recycling; Sustainability.