Environment-friendly low-temperature solid-phase synthesis method of magnesia-alumina spinel powder

Abstract

An environment-friendly low-temperature solid-phase synthesis method of magnesia-alumina spinel powder belongs to the solid-phase low-temperature synthesis method of complex oxide powder. The method comprises the following steps: selecting magnesium nitrate powder or other crystalline hydrate powder with purity more than 95% and alumina powder or various alumina precursor powders as the raw materials; decomposing magnesium nitrate at low temperature by conventional milling, mixing and low-temperature solid-phase co-firing process to obtain high-activity magnesium oxide and oxygen; and synthesizing the magnesia-alumina spinel powder from the high-activity magnesium oxide and oxygen at 350 to 600 DEG C. Compared with the prior solid-phase synthesis method, the calcination temperature is reduced by 500 to 700 DEG C, thereby greatly reducing the energy consumption and obviating emission of greenhouse gas CO2. Compared with liquid-phase synthesis and sol-gel process, the calcination temperature is reduced by hundreds of centigrade, the unavoidable environment pollution of the liquid-phase process is obviated, and the method can achieve low material cost, simple facility and short production flow. The method can be used for synthesizing high-temperature ceramics, high-temperature electric-insulation refractory materials, catalyst carriers and transparent materials.

Description

technical field [0001] The invention relates to an environment-friendly ultra-low temperature solid-phase synthesis method of magnesium-aluminum spinel powder in the fields of high-temperature structural ceramics, electronic industry, optical equipment, and catalyst carrier. Background of the invention [0002] Magnesium aluminum spinel (MgAl 2 o 4 ) is a refractory oxide with a high melting point (2100 ° C), which has superior mechanical properties, excellent chemical resistance, high electrical conductivity and optical isotropy, so it has great potential in the fields of high-temperature structural ceramics, electronic industry and optical equipment. Wide range of applications. Magnesia-aluminum spinel refractory products are mainly used in the firing zone of large cement kiln, the storage zone of large glass kiln, the refining furnace outside the furnace and the lining of large steel drum. Alumina-rich spinel is used in blast furnace tap trough, and magnesium-rich spin...

AI Technical Summary

Problems solved by technology

The disadvantages of using the sol-gel method are that the raw materials in the sol-gel process are expensive, the environmental pollution is serious, and the gel particles are prone to agglomeration.

[0009] To sum up, the existing magnesia-aluminum spinel high-temperature solid-phase synthesis method has high calcination temperature, high energy consumption, and poor powder quality; the chemical process of wet process has serious environmental pollution and high raw material prices

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