Silica fume, also known as Micro-silica fume, micro-silica, is the dust recovered from flue gas in the smelting of metal silicon or ferrosilicon and other alloys. At present, the micro-silica fume sold in the market is part of the silica fume that is directly sold after the smelting flue gas is collected by the dust collector, and some is the silica fume that is processed and sold after the smelting flue gas is collected by the dust collector. The average particle size of silica fume is 0.15-0.20μm, and the specific surface area is 15000-20000m2/kg. Its main component is silicon dioxide, the content is generally 80-92%, and the impurity components include sodium oxide, calcium oxide, magnesium oxide, iron oxide, aluminum oxide and activated carbon. The ore composition, smelting process, and the operation of the dust collection system will all cause composition fluctuations. Because silicon dioxide in microsilica powder is an amorphous substance with high activity, small particles, large specific surface area, and excellent physical and chemical properties, it was considered as an industrial waste in the past, but now it is increasingly considered as a A precious resource, a cheap ultrafine powder that does not need to be pulverized. It can be widely used in important fields such as concrete, refractory materials, and cement used in special projects.
The application research and recycling of silica fume started late of China, and most ferrosilicon production enterprises did not pay enough attention to the recycling of microsilica fume. Although some large-scale enterprises recycled microsilica fume, they did not find the value in it. Moreover, the silica content of these recovered microsilica powders is mostly not up to the standard, and is still an extensive industrial by-product. In recent years, due to the country’s emphasis on environmental protection, the management of polluting enterprises has been gradually strengthened, especially the domestic demand for high-strength concrete has increased. Many ferroalloy production enterprises have been equipped with dust collection equipment, and have developed and introduced encryption technology. China’s silica fume products are developing rapidly, and the gap with foreign countries in this field is narrowing. Scientific research achievements such as high-strength concrete, micro-silica fume sprayed concrete, composite reinforced density agent, silica fume mortar, and low-cement castables have passed the technical appraisal at the ministerial level or provincial and municipal levels, and have been applied in many projects. The effect is remarkable. Some applied technologies have approached or reached the level of foreign countries in the early 1980s.
At present, most industrial silicon factories can recover one ton of high-quality microsilica for every three tons of industrial silicon produced. One ton of microsilica can be recovered for every five tons of ferrosilicon produced. According to incomplete statistics, in 2004 China’s micro-silicon fume output reached more than 120,000 tons, most of which contained SiO2 below 90%.
Anyang Lishi Industrial Co., Ltd is a leading Silica Fume Manufacturer in China. Through 20 years efforts, Our markets covers Japan, Korea, Mid-east, Southeast Asia, south America, European more than 20 countries and regions. No matter where you are located in the world, we have a reliable supply network to meet your needs. We shall welcome friends both old and new to join us for sincere cooperation!