How is microsilica produced?
Keywords
Microsilica, silica fume, production process, collection
In fact, microsilica is a by-product and not a customized product. During the production process of ferroalloy plants, industrial silicon and ferrosilicon will emit a large amount of high-temperature exhaust gas containing dust during the high-temperature smelting process. Direct discharge of this waste gas into the atmosphere will cause serious environmental pollution, and the main content of dust in the waste gas is SiO2 dust, which is a small spherical particle formed by the condensation of high-temperature gasified SiO2, accounting for almost 90% of the weight. This kind of microsilica powder is an important raw material. It can be widely used in construction engineering, water conservancy projects, refractory materials and other fields, and the market prospect is extremely broad. Therefore, waste gas treatment and collection of microsilica powder are a good thing that is both environmentally friendly and has high economic value.
Microsilica powder collected through ferroalloy plants generally needs to be purified and encrypted to finally become commercial microsilica powder. Commercial microsilica powder is also called silica fume, microsilica powder, and picosilica powder in engineering. Its main component is SiO2, followed by a small amount of Al2O3, CaO, K2O, Fe2O3, MgO and other substances.
Step 1: Exhaust gas purification
The flue gas at the outlet of the electric furnace passes through the hood and main flue gas pipe, is cooled by the cooler, and then enters the cyclone dust collector, and then passes through the bag dust collector. The flue gas enters the bag dust collector through the fan, and the dust is captured by the inner surface of the filter bag. The purified flue gas that meets environmental standards is discharged from the outside of the filter bag, rises to the top of the dust collector, and is discharged into the atmosphere from the discharge port.
Step 2: Microsilica collection
When the equipment operating resistance or time reaches the set value, the ash unloading process begins. Using the negative pressure in the front section of the main fan, the dust cleaning process of each chamber of the bag dust collector is realized by switching the reverse suction duct and the inlet and outlet valves. The recovered dust is sent by the fan to the microsilica powder for homogenization through the ash conveying pipe device.
