"We have had concerns voiced to us by customers about global supply chains and their surety of supply," said Chris Bowes, commercial director for North America for Ferroglobe.
Ferroglobe maintains quartz mines in South Africa, Spain and the U.S., and the entirety of its refined silicon metal produced in North America is used by North American customers, Bowes told Rubber News.
Silicon dioxide is one of the most ubiquitous materials in the Earth's crust, coming from quartz rock or sand, so it is not nearly as finite in its mining capacity as lithium, cobalt or manganese — other elements that are increasing in demand as the EV revolution sets in.
Silicon metal comes from SiO2, or silicon dioxide, which, when combined with a small percentage of carbon under an extreme amount of electricity-driven heat, loses most of its oxygen to the carbon, leaving 99.99-percent pure silicon metal.
Monomer facilities for the silicone rubber industry — like those from Momentive and Dow — purchase the refined chemical-grade silicon, then add polydimethylchloride, a catalyst and several processing steps (hydrolysis, in particular) that result in base silicone products — polydimethylsiloxane, or PDMS monomer, the "simplest" and most versatile member of the silicone family.
Converting silicon dioxide requires massive amounts of energy, and since China achieved the required high temperatures from coal, the atmosphere suffered, until the Chinese facilities were forced to shut down for a period.
The shutdowns were realized immediately by those in the silicone rubber processing, microchip and aluminum manufacturing industries, as prices rose and allocations, especially on the silicone rubber side, began in earnest.
Over the past two years, lead times for specification-grade silicone sheet, sponge and foam have been extended from a traditional lead time of six weeks to 24 and 30 weeks, Stockwell said.
"As the U.S.-based technology sector recovers from the effects of the pandemic and begins its next round of new product development, the silicone supply chain will not be able to supply gaskets and cushioning solutions for ruggedized equipment that are designed to operate in extreme environments," he said. "Gaskets are often the last component specified in the design of technical equipment. We foresee delays in new product launches.