Fire halts polysilicon production at East Hope for one month

A fire that broke out at Chinese polysilicon manufacturer East Hope on June 17 is expected to halt production for about one month. According to Chinese media reports, the fire was caused by the leakage of a superheater in the hydrogenation unit of East Hope’s Phase 1 plant, which is located in the Wucaiwan Industrial Park in the Zhundong Economic and Technological Development Zone of Xinjiang in northwestern China.

Through hydrogenation (better known as hydrochlorination in the western world), trichlorosilane (SiHCl₃) is produced from silicon metal powder, recycled silicon tetrachloride (SiCl₄) and hydrogen (H₂) in a fluidized bed reactor at high pressure and temperatures between 500 and 550 °C. A five-second video clip of the accident at East Hope on the Chinese news website in-en.com shows a large plume of smoke fuming from the factory.

East Hope says it was planning for regular maintenance anyway; thus, the shortfall of production after the fire would be limited. Provided the approval of the safety supervision agency, the company expects the shutdown to take about one month and to affect the output of 2,500 metric tons (MT) of polysilicon. That apparently refers to the Phase 1 facility’s nominal annual production capacity of 30,000 MT; as the effective capacity is 40,000 MT, however, the shortfall could be higher.

According to Chinese experts, the hot summer months are a high-risk period for polysilicon production. Almost exactly two years ago, two other polysilicon manufacturers experienced accidents as well, and both are also located in Xinjiang: On July 1, 2020 a small fire occurred at the plant of Daqo New Energy; on July 19, 2020 a series of explosions ripped through the factory of Xinjiang GCL.

On top of the hot weather, polysilicon manufacturers are currently running at full speed in view of the supply shortage and high prices. That may loosen the attention to safety concerns.

Ironically, June is the national “safe production month” in China. On June 13 – just four days before the accident at East Hope – an expert group from the Chinese Ministry of Emergency Management visited the factory to provide guidance and hold a symposium. Obviously, it was not enough to prevent the accident.