High-purity silicon powder (Microsilica or Silica Fume) is also called micro silicon, and its scientific name is “Silicon Society”. During the process of smelting industrial silicon and silicon in industrial furnaces at high temperatures, the smoke and dust that escape together with the exhaust gas are collected by a special collection device Collection and processing. The scientific name “silica fume”, Microsilica or Silica Fume is a special capture device that collects and processes the smoke emitted with the exhaust gas during the process of smelting industrial silicon and silicon in industrial furnaces at high temperatures. In the escaping smoke, the SiO2 content accounts for about 90% of the total smoke. The particles are very small, and the average particle size is almost nanometer, so it is called silicon.
What is the research on high-purity silicon powder?
In 1985, the Scientific Research Institute of the Ministry of Water Power and the 10th Engineering Bureau of the Ministry of Water Power tested the use of silica fume concrete for the first time in the Sichuan Caviar Secondary Power Plant. 3% to 7% silica fume was added to the factory concrete to increase the initial strength and speed up the production process. The formwork was rotated to achieve the desired effect. 715% silica fume was mixed into the diversion tunnel shotcrete to reduce the amount of concrete. The Southern Academy of Sciences has been involved in the Hongfang Reservoir Project, Longyang Gorge Runoff Construction, Gezhouba Dam Repair and other projects. The Academy of Water Resources has conducted some research on the durability of silica concrete and silica cement tank fillers. In addition, silica fume concrete and silica fume are used in the foundation consolidation grouting of peat hydropower stations, Panjiaba overflow repair project, Ankang and Sichuan Qiutian power plant diversion tunnel repair projects. All these indicate that silica concrete is increasingly important as a high-performance concrete in engineering applications, and therefore research on performance, especially strength and durability, has also received attention.
What is the mixing ratio of high-purity silicon powder?
The mix proportion design of silica fume concrete is mainly determined based on the design requirements and general concrete design methods such as the silica fume mixing method, the optimal content of silica fume, the optimal content of water reducing agent, and gravel adjustment.
1) High-purity silica fume mixing method: Silica fume is generally mixed with concrete in two ways: one is internal mixing, and the other is external mixing, used together with water-reducing agent. The internal mixing method uses silica powder instead of cement, uses an equal amount of silicon instead of an equal amount of cement, and partially uses 1 kg of silicon to replace 1 to 3 kg of cement. As a research, it is generally 5% to 30%, and the water dues are generally unchanged. . The external mixing method means that silica powder is mixed into the concrete like an admixture.
2) The optimal content of high-purity silica fume: The content of silica fume in concrete is too small and will not significantly improve the performance of the concrete. However, if the content is too high, the concrete will be too different, difficult to construct, suffer from large shrinkage and deformation, and have poor cold resistance. When incorporating silica fume, the optimal level must be found in order to obtain the best results. Generally speaking, the effect is more satisfactory if the content is within 10%. The titration of silicon is usually determined by selecting 3, 5, 7, 10% silicon, etc., based on the type of silica powder, cement used, and the properties of the aggregate, to form a concrete specimen, and draw an R-SF (strength-silicon content) curve. Sure. It is worth noting that the price of silicon powder is very high. Technical and economic indicators should be considered when determining the optimal content of silicon fume.
