Periclase-pleonaste and hercynite/forsterite composite brick

Abstract

The invention discloses a periclase-pleonaste and hercynite / forsterite composite brick prepared by compounding a working layer and a heat insulation layer, wherein the working layer is prepared from magnesium-iron sand, hercynite sand and fused magnesite which serve as main raw materials; the heat insulation layer is prepared from medium-heavy synthetic olivine sand, medium-light synthetic boltonite sand, magnesite particles, fine magnesia powder and rice hull ash which serve as main raw materials; and the periclase-pleonaste and hercynite / forsterite composite brick is prepared through the steps of proportioning; mixing; molding; drying; sintering and the like. The working layer of the composite brick disclosed by the invention is strong in erosion resistance, good in thermal shock resistance and low in heat conductivity coefficient and is easily adhered to a kiln coating; the heat insulation layer is favorable in high-temperature volume stability, relatively high in mechanical strength and relatively low in heat conductivity coefficient. Therefore, the composite brick can be used for a high-temperature zone of a rotary cement kiln and is long in service life and capable of remarkably reducing the heat loss of a kiln body and has favorable energy-saving and emission reduction effects.

Description

Technical field [0001] The invention relates to the field of refractory materials, in particular to a periclase-mafic aluminum spinel / forsterite composite brick. Background technique [0002] The cement production industry is a famous energy consumer and a major carbon dioxide emitter. At present, my country is planning to develop the second generation of new dry-process cement production technology to reduce the heat consumption of the clinker production process from 700-750kcal / kg to 650kcal / kg, that is, to reduce the heat consumption by 50-100kcal / kg. In the cement production process, the heat consumption caused by surface heat dissipation accounts for about 10% of the total production process heat consumption, which is 70kcal / kg; and in the surface heat dissipation heat consumption, the heat consumption caused by kiln body heat dissipation accounts for about 50%. Heater and decomposition furnace account for about 35%, and tertiary air duct and cooler account for about 15%. ...

AI Technical Summary

Problems solved by technology

[0003] At present, the refractory bricks used in the firing zone of cement kilns are mainly periclase-magnesia-iron / aluminum-spinel bricks (magnesia-iron bricks for short), and their thermal conductivity is about 3.0W / mk; there are still a small amount of use in the transition zone. The thermal conductivity of magnesia-magnesia-alumina spinel bricks (referred to as magnesia-alumina bricks) is about 3.5W / mk; from the perspective of thermal conductivity, whether it is magnesia-iron bricks or magnesia-alumina bricks, the thermal conductivity is relatively high, and the actual use The energy saving effect in the process is not significant

The application number is 201210183879.9, and the patent named "magnesia-iron spinel thermal insulation composite brick" discloses a magnesia-iron spinel thermal insulation composite brick. The composite brick mainly uses high-purity magnesia / fused magnesia and synthetic magnesia-iron Aluminum spinel is used as the main material of the refractory layer, and olivine is used as the main material of the heat-insulating layer; however, magnesia is a material with high thermal conductivity, and the working layer (refractory layer) uses high-purity magnesia / fused magnesia as raw material. Greatly increase the thermal conductivity of the material to offset the energy-saving effect brought by the heat insulation layer. At the same time, the main raw material of the heat insulation layer - olivine is heavy olivine, and its thermal conductivity is relatively high. Only by adding some olivine to the matrix Pore ​​agent (sawdust / poly light ball) can not effectively reduce the thermal conductivity of the material. Therefore, the composite brick has poor heat insulation effect, and the energy saving effect is not significant when used in the firing zone of cement rotary kiln with kiln skin, and the service life is short. Failed to be promoted

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