A kind of low thermal conductivity magnesia-iron-aluminum spinel brick for cement rotary kiln and production method thereof

Abstract

The invention discloses a magnesium-iron-aluminum spinel brick with low thermal conductivity for a cement rotary kiln and a production method thereof, which can reduce the external temperature of the kiln body and achieve the effect of energy saving and emission reduction. The composition of the magnesium-iron-aluminum spinel brick is: 3-1mm high-purity magnesia or fused magnesia; 1-0mm high-purity magnesia or fused magnesia; less than 0.088mm high-purity magnesia or fused magnesia; Molten iron-aluminum spinel or sintered iron-aluminum spinel; chemical fiber; 4-5% of paper pulp waste liquid; the steps of the method include: batching; mixing and milling; pressing into green body; drying; high-temperature sintering. The invention leaves uniform fibrous micropores at corresponding positions in the internal structure of the magnesia-iron-aluminum brick, increases the gas-solid interface in the brick structure, increases the phonon scattering of solid-phase heat conduction, and effectively reduces the thermal conductivity of the brick , reducing the heat loss in the kiln.

Description

technical field [0001] The invention relates to a refractory material and a production method thereof, in particular to a magnesium-iron-aluminum spinel brick with low thermal conductivity for a cement rotary kiln and a production method thereof. Background technique [0002] The hexavalent chromium produced by the magnesia-chrome bricks used in the firing zone of the cement rotary kiln during the use and storage of discarded bricks has caused serious harm to the environment. The development of chromium-free refractory materials for the firing zone of the cement rotary kiln has become a research topic in the field of refractory materials. focus. The chromium-free products currently developed mainly include: magnesia spinel brick, dolomite brick, magnesia-zirconium brick and magnesia-iron-aluminum spinel brick. Through the long-term research and use of the above-mentioned products, it is found that the magnesia-iron-aluminum spinel brick has excellent high-temperature perfor...

AI Technical Summary

Problems solved by technology

[0003] In the process of use, it was found that the magnesium iron aluminum spinel brick has the disadvantage of high thermal conductivity

On the one hand, the high thermal conductivity of cement rotary kiln kiln lining refractory material causes the external temperature of the kiln body to rise, causing the steel structure of the kiln body to easily deform during operation, and serious cases will cause kiln shutdown accidents; High thermal conductivity will cause a large amount of heat loss in the kiln, resulting in waste of energy

In view of the high thermal conductivity of magnesia-iron-aluminum spinel bricks, researchers focused on reducing the thermal conductivity of materials on the optimization of materials, such as preparing iron-aluminum with lower overall thermal conductivity through the production process of composite bricks. For spinel bricks, this method has high production costs, low yield, and short service life due to easy breakage at the joints. At the same time, the effect of reducing the temperature of the kiln skin is not obvious

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