Low-thermal-conductivity low-thermal-expansion magnesium-based raw material and preparation method thereof

Abstract

The invention relates to a magnesium-based raw material with low thermal conductivity and low thermal expansion and a preparation method thereof. According to the technical scheme, the preparation method comprises the following steps: firstly, stirring and uniformly mixing 40-60wt% of fused magnesia particles, 30-40wt% of monoclinic zirconium oxide fine powder, 5-20wt% of zirconium oxychloride fine powder, 0.5-1.5 wt% of nano calcium hydroxide powder, 0.5-1.5 wt% of nano calcium hydroxide powder and 0.1-0.3 wt% of maleic acid for 15 minutes by adopting a high-speed mixing mill under the condition of constant temperature of 25 DEG C to obtain mixed powder; and then mixing the mixed powder by a ball mill at a constant temperature of 25 DEG C for 3 minutes, roasting the mixed powder in a high-temperature furnace at a temperature of 250-400 DEG C for 0.5-3 hours, and finally cooling the mixed powder to room temperature. The preparation method disclosed by the invention is simple in processand easy for industrial production, and the prepared magnesium-based refractory material has the advantages of relatively low heat conductivity coefficient, low thermal expansion coefficient, good dispersity and strong slag permeation and erosion resistance.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a magnesium-based raw material with low thermal conductivity and low thermal expansion and a preparation method thereof. Background technique [0002] Refractory materials are directly used in high-temperature industrial production processes in various fields of the national economy such as steel, nonferrous metals, cement, glass, ceramics, chemicals, machinery, and electric power. They are essential basic materials to ensure the operation and technological development of the above industries. Magnesia has the advantages of high melting point, high temperature resistance, good alkali high temperature slag corrosion resistance, etc. It is one of the most important raw materials in refractory materials and is widely used in various high temperature industrial refractory materials. Its service performance and service life It is directly related to the normal...

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Problems solved by technology

However, due to the large thermal expansion coefficient of magnesia, when the large crystal magnesia is subjected to drastic temperature changes, due to the small number of grain boundaries, the thermal stress is difficult to be released, and the thermal shock resistance is usually poor.

In addition, considering that the pore size in the existing magnesia is usually large and the degree of direct bonding is low, the development of microporous magnesia effectively reduces the pore size and increases the proportion of closed pores in the pores, which can alleviate the high temperature to a certain extent. Penetration and erosion of the melt, but the balance of heat insulation and slag resistance after light weight and porosity is still not good enough and needs to be improved

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