Precipitated Silica: It’s Going to Be ‘Green’ and Environment-Friendly

By Zhu Chunyu, Guo Yiqiong, CNOOC Tianjin Chemical Research & Design Institute

Driven by the recovery of the consumer goods market and export volumes, Chinese industry consumed 1.245 million tons of precipitated silica in 2014. Some details of this activity show that “green”, environment-friendly applications of precipitated silica have especially favorable development prospects. To follow this trend, domestic tire makers are increasing their use of precipitated silica in tires. Replacing 50% of the carbon black usually used in Chinese tires with high dispersion silica would generate demand for 1 million tons of high dispersion silica. Under the new environmental protection law, China’s new water based environment-friendly coatings – which must incorporate precipitated silica as a delustering agent and thickener – have developed fast and have found more applications and buyers. Demand for special precipitated silica in the manufacture of coatings is projected to grow fast.

Production

China had 52 precipitated silica producers in 2014, 10 fewer than in 2013. Their total capacity is 1.99 million t/a and last year’s output was 1.515 million tons. Fourteen of these companies have production capacity exceeding 50 kt/a, see table 1. Fujian Haineng New Materials Company Limited, with 80 kt/a capacity, suspended production in 2014 and is facing bankruptcy; it is not included in the list of 14 companies.
In 2014, private companies held 82.81% of the total capacity and produced 79.04% of the total output; state-owned companies contributed 1.76% and 1.85% respectively; and foreign funded companies 15.43% and 19.12%. In recent years, state-owned companies have owned less and less of the precipitated silica capacity, because state-owned CNOOC Shandong Haihua Group Co., Ltd. and Chongqing Jianfeng Chemicals Co., Ltd. withdrew from the field. By region, 82.76% of China’s precipitated silica is produced in eastern China, particularly in the three provinces of Fujian, Shandong and Jiangsu, because eastern China is the nation’s major region of tire and shoe manufacture.  

Table 1   China’s precipitated silica makers with capacity exceeding 50 kt/a in 2014

Company    Capacity
(kt/a)    Remarks
Wuxi Quechen Silicon Chemical Co., Ltd.    240    Private company
Zhuzhou Xinglong Chemical Industry Company    120    Private company
Fujian Zhengsheng Inorganic Materials Co., Ltd. (including two subsidiaries: Zhengchang Chemical Co., Ltd. and Anhui Fengyang Saijiyuan Inorganic Materials Co., Ltd.)    120    Private company
Rhodia Silica (Qingdao) Company Limited    110    Foreign funded
Sanming Fengrun Chemical Co., Ltd.    110    Private company
Fujian Sanming Zhengyuan Chemical Co., Ltd.(including Sanming Jufeng Chemical Co.)    95    Private company
Evonik Jialian Silica (Nanping) Co., Ltd.    100    Foreign funded
Shandong Link Industry Co., Ltd. (including Qingzhou Link Caldic Silica Co., Ltd.)     80    Foreign funded
Sha County Jinsha Silica Co., Ltd.    65    Private company
Shuanglong Tonghua Chemical Co., Ltd. (including Wanzai Shuanglong Chemicals Co., Ltd.)    65    Private company
Shandong Jinneng Coal Gasification Co., Ltd.    60    Private company
Wuxi Hengcheng Silicon Co., Ltd.     50    Private company
Fujian Sanming Tongsheng Chemical Co., Ltd.     50    Private company
Jiaxiang (Fujian) Silicon Industry Co., Ltd.    50    Private company
Total    1 315    


Export

Starting in 2014, the foreign trade data of silica (silicon dioxide) in China’s custom statistics has been divided under two commodity codes: 28112210, “silicon gum” and 28112290, “other silicon dioxide.” Data under the code 28112290, “other silicon dioxide,” mainly refers to precipitated silica and fumed silica. In 2014 China exported 355 kt of “other silica” under 28112290, with export value of US$364 million and export unit price of US$1 025.52/t; China imported 68.6 kt of other silica at a price of US$2 585.86/t, with a total value of US$177 million. Although the export volume was several times higher than the imported amount, the export unit price was very much lower. China-made precipitated silica for special purposes lags far behind the products made by foreign companies.     

Green tire market drives demand for silica

In 2014 China’s apparent consumption of precipitated silica was 1.245 million tons. Seventy percent of the reinforcing material used in making shoes, tires and light-colored rubber articles is precipitated silica.  
Consumption of silica in the production of shoes and similar articles increased in 2014, but its ratio in the total consumption of silica continued to decline. In contrast, the consumption ratio of silica in the tire making sector went up. China produced 1.114 billion rubber tires in 2014, according to the National Bureau of Statistics of China, a year over year growth of 15.4%. Among those were 630 million radial tires, an increase of 8%. To meet the requirements of “green” environment-friendliness, China’s domestic tire makers have gradually increased the amount of silica used in tires, which has been driving the consumption of silica in the tire sector to grow fast.  
Precipitated silica is widely used in rubber articles such as silicone rubber materials, grain rollers, tape and cables, contributing to a consumption ratio of 12%.
China’s precipitated silica capacity projects mainly target the needs of tire makers. Wuxi Quechen Silicon Chemical Co., Ltd. expanded the capacity of its factory in Anhui province by 70 kt/a, completed in 2014. Sichuan Zigong Zhonghao Chemical Co., Ltd. started up a new 20 kt/a plant in 2014. Three expansion projects are scheduled for startup in 2015: Sanming Shengda Chemicals Co., Ltd’s 30 kt/a, Guizhou Wengfu Lantian Fluorchem Co., Ltd’s 30 kt/a and Jiangxi Blackcat Carbon Black Inc., Ltd’s 30 kt/a.  

Requirements of energy conservation and environmental protection pushing improvement of technology

To meet the growing environmental requirements in the rubber processing industry, especially those arising from the marketplace, the production of micropearl bead silica and agglomerated silica has developed rapidly in China. Wuxi Quechen Silicon Chemical Co., Ltd., Jiangxi Blackcat Carbon Black Inc. Ltd., Hebei Longxing Chemical Stock Company Limited, Wuxi Hengcheng Silicon Co., Ltd. and other silica makers have purchased spray granulation equipment and extrusion agglomerating equipment from Germany, Korea and Denmark.  
Some traditional carbon black manufacturers have entered the silica production sector. In recent years, some of China’s most prominent carbon black makers, such as Jiangxi Blackcat Carbon Black Inc. Ltd., Hebei Longxing Chemical Stock Company Limited, Shandong Jinneng Coal Gasification Co., Ltd. have announced plans to make high dispersion silica. Also, some of China’s existing precipitated silica companies have tried to produce carbon black. For instance, Shandong Link Industry Co., Ltd. started up a 80 kt/a carbon black factory, which can effectively reduce production cost of both carbon black and precipitated silica by comprehensive utilization of resources.

Demand will grow

In the future the growth of China’s demand for precipitated silica is driven mainly by growing demand for tires, silicone elastomers, tooth paste, coatings and thermal insulation materials, as detailed below.
1. High dispersion precipitated silica used in “green” tires
A “green” tire may incorporate silica instead of carbon black. It is expected that the share of “green” tires in China’s tire market may exceed 20% in 2015, up from 2% in 2010, and the “green” share is predicted to surpass 60% by 2020.
At present, the application of high dispersion silica in tire manufacture is still just beginning in China. The country now consumes more than 2 million tons of carbon black per year. Replacing 50% of that carbon black by high dispersion silica will create an annual demand for 1 million tons of high dispersion silica. The market prospect is indeed great.
2. Precipitated silica used in silicone elastomers
It is predicted that making silicone elastomers (silicone rubber) will consume 10%-15% of China’s rubber supply in 2015, i.e. 1.0-1.5 million tons. In 2020, silicone elastomers’ market share is expected to reach 20%-33%, meaning an annual consumption of 3.0-5.0 million tons of rubber. The demand for precipitated silica as a reinforcing agent for silicone rubber is predicted to reach 100-150 kt in 2020.
3. Special precipitated silica used in coatings
China’s production of coatings has maintained a steady growth on the whole in recent years, reaching 16.4819 million tons in 2014 with a year on year growth of 26.5%, the fastest growth in the past five years. From 9.6663 million tons in 2010, output has increased nearly 7 million tons. In the formulation of water-borne environment-friendly coatings, precipitated silica is typically used as a delustering agent and thickener. Coating makers’ demand for special precipitated silica will maintain fast growth for the foreseeable future.
4. Silicon dioxide aerogels
Silicon dioxide aerogels are good thermal insulation materials. Many institutes in China are researching and developing silicon dioxide aerogels. The 306 Branch of the Third Institute of China Aerospace Science and Industry Corp. has researched silicon dioxide aerogel-based thermal insulation materials with controllable structure, and the results have been approved by the authorities. Tongji University has much experience in the preparation, structure control and performance tuning of silicon dioxide aerogels, as well as their applications. Beijing University of Science and Technology has fabricated compound thermal insulation materials from calcium silicate secondary particles and aerogels. The Central South University has completed its research of new transparent aerogel materials and a related application project, all of which have been approved by the expert team organized by Hunan Provincial Science & Technology Department. Shanxi Tianyi Nano Materials Co., Ltd. has obtained national patents for silicon dioxide aerogel thermal insulation materials. The company has gradually introduced the products to the market, and they have good prospects.