Lining brick of lean iron ore magnetizing and roasting rotary kiln and preparation method of lining brick

Abstract

The invention relates to a lining brick of a lean iron ore magnetizing and roasting rotary kiln and a preparation method of the lining brick. The lining brick is characterized by taking 60 weight percent to 65 weight percent of high-purity magnesia particle as aggregate, and taking 10 weight percent to 15 weight percent of rho-Al2O3 micro-powder, 20 weight percent to 25 weight percent of light-burnt magnesia fine powder and 1 weight percent to 4 weight percent of nickel sesquioxide micro-powder as a matrix material; the preparation method comprises the following steps: preparing the materials according to the content of the aggregate and the components and content of the matrix material; uniformly mixing the matrix material; adding the uniformly mixed matrix material into the aggregate and uniformly mixing; additionally adding zirconium sol which accounts for 5 weight percent to 8 weight percent of the sum of the matrix material and the aggregate, and uniformly mixing; vibrating and molding; curing and drying; finally, putting a mixture into a muffle furnace and rising the temperature to be 1500 DEG C to 1600 DEG C at the temperature rate of 3 DEG C / min to 5 DEG C / min; keeping the heat for 1h to 2h; cooling along a furnace to prepare the lining brick of the lean iron ore magnetizing and roasting rotary kiln. The lining brick of the lean iron ore magnetizing and roasting rotary kiln and the preparation method of the lining brick have the characteristics of low cost and simple process flow; the prepared lining brick of the lean iron ore magnetizing and roasting rotary kiln has high slag corrosion resistance, small coefficient of heat conductivity and great cold-state compressive strength.

Description

technical field [0001] The invention belongs to the technical field of magnetized roasting rotary kiln lining bricks. Specifically, it relates to a magnetized roasting rotary kiln lining brick of lean iron ore and a preparation method thereof. Background technique [0002] Lean iron ore refers to iron ore with low iron oxide content, generally Fe 2 O 3 The content is 30~40wt%, or even lower. The lean iron ore contains a lot of gangue, which is easy to produce a large amount of slag during the smelting process, which increases the fuel consumption and reduces the productivity of the equipment. In addition, gangue in lean iron ore contains a large amount of impurity elements, which affects the quality of steel. Therefore, magnetization roasting pretreatment should be carried out before the lean iron ore is put into the furnace (to facilitate the magnetic separation of iron ore) to increase the iron content, reduce the gangue content and reduce harmful elements. [0003] M...

AI Technical Summary

Problems solved by technology

[0005] Mullite bricks are used as the lining bricks of the lean iron ore magnetized roasting rotary kiln, which not only has high refractoriness, but also has good mechanical properties (wear resistance) and chemical corrosion resistance. CaO, SiO in slag 2 Other components react and are consumed by slag, which reduces the service life of mullite bricks

[0006] Mullite-silicon carbide castable / prefabricated parts are used as lean iron ore magnetized roasting rotary kiln lining bricks. Although its high-temperature mechanical and thermal properties are excellent, especially the introduction of SiC enhances the slag erosion resistance and erosion resistance of the lining bricks. However, the thermal conductivity of mullite-silicon carbide castables / preforms is large, which increases the heat loss of the rotary kiln body during the magnetization roasting of lean iron ore, resulting in high temperature and deformation of the rotary kiln body, and the oxidation of SiC also affects Improve the service life of the lining brick of the rotary kiln in magnetized roasting of lean iron ore

[0007] In addition, the cost of refractory raw materials such as mullite and silicon carbide is relatively high, and the preparation process of mullite-silicon carbide refractory materials is complicated (especially the anti-oxidation process of SiC), which further increases the cost of magnetizing and roasting rotary kiln lining for lean iron ore. Brick development cost