High-purity silicon tetrachloride: a scarce material in the optical fiber industry chain in the AI era

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The 25th National \"Safety Production Month\" in 2026: Everyone talks about safety, and everyone knows how to handle emergencies; identifying and addressing risks and hazards. -------------------------------------------------- With the large-scale deployment of AI data center clusters, the widespread adoption of 5G networks worldwide, and the ongoing advancement of fiber-to-the-home projects across the country, global data transmission volumes are increasing exponentially, prompting a new upward cycle for the fiber optic cable industry. The supply and demand for optical fiber preforms, which are the key materials at the upstream stage of the industry chain, remain tight. In 2026, there will be increased investment in expanding the production capacity for such preforms, resulting in a high level of operational activity in this industry. As the primary raw material for optical fiber preforms, the supply-demand gap for high-purity silicon tetrachloride continues to widen. Due to the high barriers in this industry and the slow development of new production capacity, the market size is expected to keep growing, along with positive trends in product prices. Fiber preforms are the raw materials for optical fibers; one preform can be used to produce tens of thousands of kilometers of communication fibers. This stage represents the highest technical barriers and the largest cost proportion in the optical communication industry chain. Industry data shows that silicon tetrachloride accounts for as much as 30% of the production costs of fiber optic preforms; it is in high demand as a raw material, and the production ratio remains fixed: 5–7 tons of high-purity silicon tetrachloride are required to produce 1 ton of fiber optic preforms. Moreover, the purity of the raw materials directly determines the transmission performance of optical fibers. The industry categorizes these materials into two main grades: 6N and 9N. The higher the numerical value, the greater the purity and fewer the impurities; such materials are suitable for the production of high-end low-loss optical fibers, special optical fibers for overseas use, and high-end core rods. The technology required to produce 9N-grade ultra-high-purity materials is extremely complex. The growth in global fiber optic demand is currently highly certain. According to CRU’s projections, the annual compound growth rate of global optical cable demand will remain at 4% from 2025 to 2029 ； AI computing power has driven a surge in the demand for optical fibers in data centers; by 2025, global usage of optical fibers in data centers is expected to increase by 75.9% on a year-on-year basis, reaching 69.6 million fiber-kilometers, with usage likely to exceed 100 million fiber-kilometers by 2026. Currently, 70% of the global production capacity for optical fibers and optical rods is concentrated in China. Not only has China achieved self-sufficiency in optical rod manufacturing processes, but it is also at the forefront in advanced technologies such as hollow optical fibers. The pace of domestic production expansion directly determines the global demand for high-purity silicon tetrachloride. On the demand side, optical fiber rod manufacturers are expanding production on a large scale, leading to a surge in demand for raw materials ； However, the supply side has inherent weaknesses. Firstly, high-purity silicon tetrachloride is a by-product of the silicon chemical industry; it is primarily produced as a by-product of processes involving trichlorosilane and polysilicon. In 2025, domestic polysilicon production declined, and restrictions on the expansion of trichlorosilane production further contributed to a rigid supply of raw materials ； Secondly, the high-purity purification process is complex, and the certification process for downstream fiber optic manufacturers is extremely lengthy; it takes at least 1–2 years from the time new production capacity comes online until products can be supplied. As a result, it is not possible to quickly fill any shortages in the short term. The industry’s supply elasticity is very low, which means there is ample room for price increases in high-purity silicon tetrachloride, thus opening up opportunities for growth in this industry. The domestic market is currently divided into two categories: one consists of large fiber optic manufacturers such as Yangtze Optical Fiber and Fibre Optic and Zhongtian Technology, which have their own production facilities for internal use only and do not sell their products externally ； Secondly, specialized chemical companies supply products to the market; the supply available on the market is highly concentrated, with leading companies operating at near full capacity. Sanfu Co., Ltd. is the undisputed leader in China; it has an annual production capacity of 30,000 tons of high-purity silicon tetrachloride, covering both 6N general-grade and 9N ultra-high-purity grades. Its products can be supplied to the high-end specialty fiber markets in Europe, enabling the substitution of imported materials used in high-end PCVD mandrels. At present, its production capacity is fully utilized, and deliveries are made at fixed prices agreed upon in long-term contracts. By 2025, the company is expected to see an increase in both the production and sales of high-purity silicon tetrachloride, with production volume rising by 21% on a year-on-year basis. Meanwhile, it is focusing on the development of electronic-grade chlorosilane materials; its electronic-grade dichlorodihydrosilane product has already been subject to anti-dumping actions in Japan, enabling domestic substitution for high-purity silicon sources used in semiconductors. Driven by its two business segments in the silicon and potassium areas, the company achieved sustained strong growth in performance in 2025 and the first quarter of 2026, with profitability that ranks at the top in the industry. The remaining enterprises are in the construction or pending-commissioning phase, and the pace of adding production capacity is slow; therefore, it will be difficult to alleviate the supply-demand tension in the short term. A subsidiary in which Xinan Shares holds a stake has a production capacity of 40,000 tons of silicon tetrachloride. The 6N-9N high-purity products began production in June, along with the D4 product, which is a key raw material for fiber coatings; these products are supplied on a long-term basis to leading fiber manufacturers both at home and abroad ； The construction of Jianghan New Materials’ 10,000-ton capacity project for fiber-grade 6N high-purity silicon tetrachloride is progressing at an accelerated pace; completion is expected six months earlier than planned, with deliveries to customers set to begin in 2027 ； Hongbai New Materials plans to build a production capacity of 20,000 tons for 9N-grade high-purity materials; construction will begin in the second half of the year with production starting in 2027, thereby entering the market for high-end fiber optic and semiconductor raw materials. In addition, the applications of high-purity silicon tetrachloride are expanding. Outside the field of optical communication, 6N/9N high-purity grades can be further processed into electronic-grade chlorosilanes, which are used in the etching processes of memory chips and logic chips, thus being linked to the semiconductor materials industry. Overall, AI computing power, 5G, and the development of computing power networks contribute to sustained demand for optical fibers. There is a short-term shortage of high-purity silicon tetrachloride, while the addition of new production capacity takes time in the medium to long term; as a result, the supply-demand balance in this industry is improving. As a critical silicon-based new material for optical communications and semiconductors, the industry associated with high-purity silicon tetrachloride continues to enjoy growing benefits. Leading companies that possess the capability for high-purity mass production as well as the necessary high-end certification will continue to reap significant advantages from rising prices and increased production capacity in this sector.