Low-silicon magnesium-containing pellets and production method thereof

Abstract

The invention discloses low-silicon magnesium-containing pellets and a production method thereof. The method comprises the following steps of: proportioning 95 to 98.5 mass percent of low-silicon ore concentrate powder, 1 to 4 mass percent of magnesium-containing additive and 0.5 to 1.0 mass percent of binder, uniformly mixing the low-silicon ore concentrate powder, the magnesium-containing additive and the binder by using a blender mixer, adding an appropriate amount of water and controlling the water content of the mixture to be between 7.0 and 8.5 percent, wherein the magnesium-containing additive can be selected from magnesia powder, caustic calcined dolomite, dolomite, olivine and boric sludge and the binder can be selected from bentonite or a composite binder; pelletizing the mixture in a pan pelletizer, forming a mother pellet, adding materials and water gradually to allow the mother pellet to grow bigger and denser, screening green pellets of between 9 and 16 millimeters and performing a continuous roasting process consisting of drying, preheating, roasting and cooling; drying the pellets at the temperature of between 200 and 450 DEG C for 8 to 10 minutes, preheating the pellets at the temperature of between 700 and 1,050 DEG C for 10 to 15 minutes and roasting the preheated pellets at the high temperature of between 1,280 and 1,350 DEG C for 12 to 18 minutes; and cooling the roasted pellets to be less than 100 DEG C after roasting is finished so as to obtain the low-silicon magnesium-containing pellets serving as finished products.

Description

technical field [0001] The invention belongs to the technical field of iron ore pellet production for blast furnace ironmaking, and in particular provides a low-silicon magnesium-containing pellet and a production method thereof. Background technique [0002] With the increasingly severe energy and environmental issues, all industries around the world are advocating low-carbon economy. Iron and steel enterprises, as large energy-consuming and polluting enterprises, should pay more attention to this issue and actively take measures to enhance their competitiveness. [0003] Pellet is one of the main raw materials for blast furnace ironmaking. The pellets have the characteristics of high strength, uniform particle size and high grade, which are beneficial to increase the output of the blast furnace and reduce the coke ratio. The blast furnace with the best smelting index in the world is the global pellet smelting blast furnace. However, most of the pellets are acid pellets, ...

AI Technical Summary

Problems solved by technology

If the silica content of acidic pellets is low, it is easy to cause severe reduction and expansion, and the blast furnace cannot be used

Therefore, the silica content of acidic pellets is generally higher, and the reducibility and droplet performance are not as good as those of alkaline magnesium-containing pellets, which is unfavorable for indicators such as blast furnace slag ratio and coke ratio.

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