Germany's Evonik and its Chinese partner, Jiangsu Zhongneng Polysilicon Technology Development Co., a wholly owned subsidiary of GCL-Poly

Energy Holdings, have signed a letter of intent to form a 60:40 joint venture to produce fumed silica and ultra-pure silicon tetrachloride compounds in China.

Production capacity for more than 20,000 t/y of the compounds will be built in Xuzhou in China's Jiangsu Province and is planned to go on stream 2016 following all approvals.

Jiangsu Zhongneng is a global leading manufacturer of polycrystalline silicon (PCS), of which silicon tetrachloride is a byproduct. The jv will purchase this to produce Evonik's Aerosil brand fumed silica and Siridion STC HP ultra-pure silicon tetrachloride.

The planned investment is aimed at strengthening Evonik's market position for fumed silica and ultra-pure silicon tetrachloride and to promote growth, particularly in the attractive Chinese market, said CEO Klaus Engel. GCL-Poly is the largest global supplier of photovoltaic materials.

Main drivers of the positive market development for fumed silica in China are the silicone industry for adhesives and sealants in buildings and vehicles as well as gel batteries, used in e-bikes. Ultra-pure silicon tetrachloride is used in the fiber optics industry.

Growth rates for ultra-pure silicon tetrachloride in China are well above growth rates for the global market, Evonik said, noting that half of the demand for fiber optics worldwide now comes from China.

Overall, the German company has a global capacity for more than 500,000 t/y of precipitated and fumed silica as well as matting agents. In addition to ultra-pure silicon tetrachloride, it markets a portfolio of ultra-pure chlorosilanes for the electronics industry.