Global consumption of magnesium will rise by a CAGR of over 5% over the next decade, but with considerable regional differences in the pace of growth. China will experience much higher rates of increase than the ROW. Patterns of demand will also vary quite widely across end-use markets, with alloys and titanium displaying stronger growth than traditional uses, such as steel desulphurisation.
Environmental factors will play a major role in influencing future demand and supply for magnesium. The ongoing, and strengthening, impetus to reduce pollution levels will continue to focus very much on the automobile sector, which is a major market for magnesium alloys and aluminium alloys containing magnesium. The drive to reduce vehicle weight, and thus emissions, will see demand for these alloys grow. In China, for example, there are plans to increase the magnesium content of cars from 8.6kg/car in 2017 to 45kg by 2030.
At the same time, a significant change in how magnesium is produced looks highly likely. Until the early 1990s, electrolytic processes dominated global supply. Rapid growth in production in China resulted in thermal processes, notably the Pidgeon process, gaining substantial market share. At present, probably more than 80% of global supply is via the Pidgeon process, which accounts for most Chinese production; electrolytic processes remain the norm in other countries. While the Pidgeon process is relatively low-cost, it has disadvantages, including being considerably more polluting than alternative routes.
Increasingly stringent environmental regulations in China have already caused the closure of several plants using the Pidgeon process and more will probably be shuttered. Given the considerable surplus production capacity available, the market is highly unlikely to move into deficit in the immediate future. In the meantime, alternative processes are gaining ground.
There are only a handful of projects in the pipeline outside China, with Latrobe Magnesium (LMG) in Australia and Alliance Magnesium (AMI) in Canada being the most advanced.
ASX-listed LMG has announced that it is to proceed with construction of a magnesium metal plant in Victoria, Australia, following satisfactory results of a feasibility study completed in 2019. Construction is due to commence in February 2020 with initial production of 3ktpy starting during 2021. Expansion to 40ktpy will follow. The company is seeking financing for the first stage (capex A$34M – US$22.8M) and expansion (A$330M – US$221M). The LMG project is in in the Latrobe Valley, which is a major centre of power generation based on brown coal. LMG will use a patented hydromet/thermal process to produce magnesium and by-products from fly ash. About 25Mt of fly ash is already in inventory. The process is relatively environmentally friendly and would generate a total of 12t CO2 per tonne of Mg. Production in China generates at least 25t CO2 per tonne Mg.
AMI has reported that it will begin construction of a plant in Québec, Canada, during 2020, with full production starting in 2021. The C$600M (US$451M) project calls for initial output of 11.7ktpy, rising to 50ktpy. The plant will process tailings from abandoned asbestos mining operations in Québec. It will use a patented electrolytic process and hydroelectric power, making it relatively clean. The project has the backing of the Canadian government, which has invested C$12M (US$9M) in it through Sustainable Technology Development Canada, and from Japan’s Marubeni, which invested a further C$16.7M (US$12.6M) in December 2019.
Combined, these two projects could contribute nearly 10% to the global market, which is not huge but might signal the start of a move away from traditional processes to “greener” magnesium.