The rising cost of raw materials pushed up Chinese 553 silicon metal prices to $1,490-1,520/mt FOB China last week, up $10-20/mt week on week, the China Nonferrous Metals Industry Association, or CNIA, said in its silicon sector report Monday. 

Due to China's environment checks, the domestic electrode sector's operating rate was lower than last year, pushing up prices, CNIA said. 

This, plus surging costs of pet coke, silica, coal as well as other raw materials pushed up industrial silicon production costs by Yuan 1,000-1,500/mt ($150-225) this year, compared with last year, cutting [producers' margins, it added. 

Since the end of May, environment protection inspectors have been carrying out checks in the Xinjiang Uyghur Autonomous Region, a key silicon producing area. 

The checks are mainly aimed at silicon producers with their own power plants. 

Xinjiang is the second-largest silicon producing region in China with an output capacity of 1.05 million mt/year, according to CNIA. 

Silicon stocks in Chinese warehouses were low, which was also pushing up prices, CNIA said. 

China's silicon metal exports over January-May rose 7% year on year to 325,000 mt, data from the General Administration of Customs showed.

The information above comes from Guidechem.