Silicon and ferrosilicon are manufactured using broadly the same process and are physically similar, but are very different in terms of their applications. Silicon metal is used in the manufacture of aluminium alloys, silicones, semiconductors and, increasingly, in photovoltaic solar applications. In contrast, over 90% of ferrosilicon is consumed in the production of iron and steel.
World production of both silicon metal and ferrosilicon is dominated by China; in 2017, China accounted for 68% of world silicon metal production, and for 66% of global ferrosilicon output. However, Chinese production of these products is following a different trajectory. China’s output of ferrosilicon peaked in 2011, and was 21% lower in 2017 than its 2011 level. By contrast, silicon metal output in China continues to grow strongly; in 2017 it exceeded 2Mt for the first time. Chinese ferrosilicon production has been subject to increasingly stringent government controls on overcapacity and emissions, whilst the country’s silicon metal capacity and output has been permitted to increase further. The extent to which this will remain the case over the coming decade is important for the wider sector.
Over the past decade, consumption growth for silicon metal has diverged significantly from that for ferrosilicon. The reason for this lies in the different end-use sectors which drive demand for these alloys. Global silicon metal consumption grew 6.3%py between 2010 and 2017, supported by strong growth in all of its main end-use sectors, especially solar. Consumption in solar applications almost quadrupled between 2010 and 2017, driven by the enormous growth of photovoltaic solar installations worldwide.
In contrast, global ferrosilicon consumption was 10% higher in 2010 than it was in 2017, despite the fact that world crude steel output grew by 20% over the same period. The main reasons for this decline in ferrosilicon consumption have been a trend towards using less ferrosilicon per tonne of crude steel in China, and very slow growth in world output of iron castings, partly as a result of greater use of aluminium in place of cast iron in automobiles.
Prices for both silicon metal and ferrosilicon are primarily cost driven in the long term, though supply-demand factors can have a major impact on prices in the short term. Through 2017 and the first half of 2018, prices for both silicon metal and ferrosilicon have been much higher than in the preceding two years, partly due to rising production costs, and partly because of market tightness.