Method for preparing beta-SiAlON from aluminum ash residues

Abstract

The invention relates to a method for preparing beta-SiAlON from aluminum ash residues. The method comprises the following steps: grinding the aluminum ash residues, adding a Si powder and a diluent Si3N4 powder in proportion, performing uniform mixing by a ball mill, adding the obtained mixture into a zirconia crucible, placing the crucible in a tubular atmosphere furnace, introducing nitrogen, carrying out ohmic heating to reach a reaction temperature, cooling the furnace to room temperature after a nitridation reaction is completed, and taking out the obtained product. The industrial solidwastes which are aluminum ash residues are used as the raw material to prepare high-purity beta-SiAlON powder, so the method has the advantages of simple process, realization of recycling of the aluminum ash residues, reduction of the environmental burden, and reduction of resource waste.

Description

technical field [0001] The invention relates to resource utilization of industrial solid waste and preparation of nitrogen oxide ceramic powder, in particular to a method for preparing β-SiAlON material by using aluminum ash. Background technique [0002] Aluminum ash is a kind of industrial waste, which is generally produced in the aluminum processing and production processes such as aluminum electrolysis and aluminum smelting. The composition of aluminum ash slag is complex, mainly containing metals (Al, Fe, Ca, Mg, etc.), alumina, silica, nitrides, carbides, etc., among which aluminum and alumina are the most abundant, up to 10-50%. In order to make full use of aluminum resources and avoid waste of resources, it is necessary to carry out the research and development of high value-added recycling technologies for aluminum ash slag and further improve the comprehensive utilization efficiency of aluminum ash slag. [0003] In the comprehensive utilization of aluminum ash sl...

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Problems solved by technology

Aluminum ash + blast furnace slag + metal silicon system, synthesized Ca-α-SiAlON-AlN polytype composite ceramics, due to the high content of CaO, it is easy to form a glass phase, which is not conducive to the synthesis of SiAlON phase; aluminum ash + pulverized coal Ash + carbon black system, the main phase prepared by the optimized carbothermal aluminothermic composite reduction nitriding process (1450 °C, Si / Al ratio of 1, 1.5) is β-SiAlON and AlN polytype, but must pass two The preparation of the material can only be realized by the single-step method; the aluminum ash + metal silicon system was synthesized by holding β-SiAlON at 1450°C for 6h, 1550°C for 3h and 1600°C for 3h under a flowing nitrogen atmosphere, but the product still contained a large amount of AlN. Form body and Ca-α-SiAlON, the purity is not high

[0008] At present, SiAlON materials are prepared by using aluminum-containing industrial waste as the main raw material. Due to the complex composition of raw materials and difficult process control, the purity of SiAlON obtained is not high, which affects the recycling of aluminum-containing solid waste.

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