Tracing magnesium flows in China: A dynamic material flow analysis

Magnesium is a unique and widely-applied alkaline earth metal. China is the major magnesium producer and exporter, but the key features of its magnesium flows, such as the total production, the structure of demand, the efficiency of utilization, the volume of recycling, remain unclear. This study aims to investigate magnesium metabolism in China from 2002 to 2021 by employing a retrospective, dynamic material flow analysis method. Results show that (1) China's magnesium supply has doubled to meet its tripled demand during the last 20 years; (2) more than 69% of the magnesium produced in China was used for making refractory materials, while the pure magnesium application accounted for less than 5%; (3) the total net magnesium export reached 1.8 megatons (Mt) in 2021; (4) 1.4 Mt of magnesium was recycled during the study period, only accounting for 9.8% of the total primary magnesium production. Finally, policy recommendations are proposed by considering the Chinese realities, including improving resource efficiency, incubating efficient production technologies, increasing added values of magnesium-containing products, and optimizing trading for magnesium-containing products.