Magnesium composite additive

Abstract

A magnesia composite additive relates to an additive material when making pellets. The magnesia composite additive is composed of bentonite, high magnesium stone powder, soda ash and organic binder, and the weight percentages of their content are 20-75%, 20-75%, 0-5%, 0-1% respectively; when making, Mix bentonite, high magnesium stone powder, soda ash and organic binder evenly, and crush to 200 mesh with 90% passing. In the production of pellets, the metallurgical properties of pellets have been improved, the reflow temperature can be increased by 100-150°C, the thickness of the blast furnace reflow zone has been reduced, the air permeability of the middle and lower parts of the blast furnace has been improved, and the air permeability index has increased by more than 5%. The coke ratio is reduced by 10kg / ton of iron, and the output is increased by 5-7%.

Description

technical field [0001] A magnesia composite additive relates to an additive material when making pellets. Background technique [0002] Before ironmaking, the selected ore should be made into pellets. In order to make iron ore into pellets, it is necessary to add a certain amount of bentonite to iron ore. For high alkalinity sinter, the addition of bentonite will give good results. However, ordinary acid pellets have problems such as high reduction expansion rate, softening, low melting temperature, and poor high-temperature metallurgical properties. In particular, the problem of pellet softening under load is more significant. Due to the low initial softening temperature of ordinary acidic pellets (SiO in pellets 2 It is more prominent when it is high), which causes the thickening of the reflow zone in the blast furnace and reduces the gas permeability index of the blast furnace, thereby affecting the output and furnace condition of the blast furnace. Contents of the ...

AI Technical Summary

Problems solved by technology

Due to the low initial softening temperature of ordinary acidic pellets (SiO in pellets 2 It is more prominent when it is high), which causes the thickening of the reflow zone in the blast furnace and reduces the air permeability index of the blast furnace, thus affecting the output and furnace condition of the blast furnace.