Method for preparing high-purity alpha-Al2O3 powder by calcining aluminum ammonium sulfate at low temperature

Abstract

The invention discloses a method for preparing high-purity alpha-Al2O3 powder by calcining aluminum ammonium sulfate at low temperature. The method comprises the following steps: by taking high-purityaluminum ammonium sulfate powder as a raw material, putting the high-purity aluminum ammonium sulfate powder into a certain amount of deionized water, adjusting the pH value to 10-12 with ammonia water, heating at 75-85 DEG C to completely dissolve aluminum ammonium sulfate to form an aluminum ammonium sulfate solution with the concentration of 3060%, cooling to room temperature, naturally crystallizing (the crystallization time is controlled within 10 hours), taking out a crystallization product, after cleaning and drying, and calcining the product in a muffle furnace at 1050 DEG C for 1-2 hours to obtain the high-purity single-phase alphaAl2O3 powder which is about 150 DEG C lower than the temperature required by direct calcination with aluminum ammonium sulfate. According to the method, no doping additive is used, the high purity of the obtained alpha-Al2O3 powder can be ensured, the process is simple, and large-scale production is facilitated.

Description

technical field

[0001] The invention is a low-temperature calcination of aluminum ammonium sulfate to prepare high-purity α-Al 2 o 3 The powder method belongs to material science and technology, and the field of advanced ceramic powder preparation. Background technique

[0002] High purity α-Al 2 o 3 Powder is a common inorganic non-metallic material powder, which has the advantages of high hardness, high temperature resistance, corrosion resistance, good mechanical and insulating properties, and is widely used in many fields such as advanced ceramics, high-end abrasives, and thermally conductive fillers. Currently preparing high-purity α-Al 2 o 3 There are many powder processes, including metal alkoxide method, sol-gel method and so on. Among them, ammonium aluminum sulfate thermal decomposition method is the industrial preparation of high-purity α-Al 2 o 3 A commonly used powder. The basic process is: calcining high-purity aluminum ammonium sulfate crystals at hig...

Examples

Embodiment 1

[0012] Example 1: Take 100g of high-purity ammonium aluminum sulfate powder, add 200ml of deionized water, add ammonia water dropwise to adjust pH = 11, put it in an oven at 80°C, cool to room temperature after the ammonium aluminum sulfate is completely dissolved, and crystallize naturally for 2 hours; The crystallized product was fully washed, filtered with suction, and dried in an oven at 50°C for 24 hours. The obtained product was put into a corundum crucible and calcined at 1050°C for 2 hours, and the final powder was obtained after cooling. The XRD analysis of the above powder shows that the obtained powder is pure α-Al 2 o 3 powder, such as figure 1 shown.

technical field

[0001] The invention is a low-temperature calcination of aluminum ammonium sulfate to prepare high-purity α-Al 2 o 3 The powder method belongs to material science and technology, and the field of advanced ceramic powder preparation. Background technique

[0002] High purity α-Al 2 o 3 Powder is a common inorganic non-metallic material powder, which has the advantages of high hardness, high temperature resistance, corrosion resistance, good mechanical and insulating properties, and is widely used in many fields such as advanced ceramics, high-end abrasives, and thermally conductive fillers. Currently preparing high-purity α-Al 2 o 3 There are many powder processes, including metal alkoxide method, sol-gel method and so on. Among them, ammonium aluminum sulfate thermal decomposition method is the industrial preparation of high-purity α-Al 2 o 3 A commonly used powder. The basic process is: calcining high-purity aluminum ammonium sulfate crystals at hig...

Examples

Embodiment 1

[0012] Example 1: Take 100g of high-purity ammonium aluminum sulfate powder, add 200ml of deionized water, add ammonia water dropwise to adjust pH = 11, put it in an oven at 80°C, cool to room temperature after the ammonium aluminum sulfate is completely dissolved, and crystallize naturally for 2 hours; The crystallized product was fully washed, filtered with suction, and dried in an oven at 50°C for 24 hours. The obtained product was put into a corundum crucible and calcined at 1050°C for 2 hours, and the final powder was obtained after cooling. The XRD analysis of the above powder shows that the obtained powder is pure α-Al 2 o 3 powder, such as figure 1 shown.

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