- May 10, 2017 -
Industrial silicon and ferrosilicon smelting process in high temperature, with the dust exhaust gas is called silica or silica fume, its main component is SiO2 content in the flue gas accounts for about 90% of the total dust, which contains free SiO2 accounts for about 10%. Particle size is very small, the average particle size of about 0.3 m, it is said that the micro silica fume, it can directly into the human body through the respiratory alveolar, great harm to human health. China currently has thousands of ferrosilicon and industrial silicon furnace, in the production process, the annual production of about 250 thousand T. Environmental protection equipment has been able to capture up to about 50 thousand T, the rest of the basic directly into the atmosphere, not only pollute the environment, but also a waste of resources. At present, there is no precise pricing standards of micro silica powder, the price of 1800 yuan per ton to $3800, if the price per ton by the calculation of 2000 yuan, the annual direct row of micro silica powder as the value of the loss of resources utilization of about $500 million. Therefore, it is imperative to smoke. It is not only an environmental benefit and social benefit, but also a great economic and scientific value.
Micro silica powder is an excellent material with wide application prospect in the field of high and new technology. Widely used in construction, chemical industry, metallurgy and other industries. A large number of micro silica is mainly used in cement or concrete admixture, used to improve the performance of cement or concrete, preparation with high strength and high wear resistance, erosion resistance, corrosion resistance, frost resistance, permeability and early strength of special concrete or composite cement, for large hydropower, water scraper, harbor wharf, railway bridge, highway, airport runway tunnel and city high-rise building engineering. It can be used in paint, paint, resin and other polymer materials. It can improve the elongation, tear resistance and tensile strength of rubber. Can also be used for the production of refractories and ceramic products, effectively improve the strength and durability of the product.
As early as the early 80s, developed countries have successfully used this technology. The annual output of micro silica powder in the United States reached 300 thousand T, accounting for the world's total annual output of micro silica powder of 1 / 4, followed by the former Soviet Union and Norway, the annual output of micro silica powder were t and 120 thousand T, respectively. The United States in 1980 in the Texas commercial building, the use of silica fume concrete, its strength is 1OOMPa. In recent years, the United States has formulated 250MPa ultra-high strength concrete. The practical application of major water conservancy buildings, bridges and culverts, tunnels, cultural relics and historic sites in our country has also proved that adding appropriate amount of micro silica fume in concrete engineering can greatly improve the quality of the project.