A method for preparing sapphire-grade high-purity alumina by using aluminum material anodic oxidation waste liquid

Abstract

The invention relates to the field of recycling of aluminum profile anode oxidation waste liquids, in particular to a method for preparing sapphire-level high-purity alumina from aluminum profile anodic oxidation waste liquids. The aluminum profile anodic oxidation waste liquids are taken as a raw material, firstly, impurity ions in the aluminum profile anodic oxidation waste liquids are removed through waste liquid pretreatment, the pH is adjusted to 1.5-3.0 with ammonia water, a crude product of aluminum ammonium sulfate is prepared, aluminum ammonium sulfate is further purified through repeated recrystallization, and finally, the sapphire-level high-purity alumina can be prepared through sintering. The preparation method has the advantages that raw materials are cheap, a process is simple, waste is turned into valuables, and state strongly advocated concepts of green and environmental protection and sustainable development are met, and the method is suitable for large-scale use andhas better social benefits.

Description

technical field [0001] The invention relates to the field of recycling and utilization of aluminum material anodic oxidation waste liquid, in particular to a method for preparing sapphire-grade high-purity alumina by using aluminum material anodic oxidation waste liquid. Background technique [0002] With the rapid development of industry, aluminum profiles are more and more widely used in industrial production, construction and civil materials. There is a process in the production of aluminum profiles called anodizing. Pickling is required before anodizing, which is to use the corrosion of acid to remove rust. Depending on the degree of rust, sulfuric acid solution is used to dip and clean the surface until the surface is smooth and clean. After a certain period of time, the dipping solution becomes waste liquid and replaced. Mixed discharge to form aluminum-containing pickling wastewater. About 65% of the aluminum profiles used are subject to surface treatment, while alm...

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Problems solved by technology

The existing high-purity alumina powder preparation technologies mainly include alkoxide hydrolysis, Al(OH) 3 Sintering method, AlCl 3 Gas-phase synthesis method, sol-gel method, improved Bayer method, aluminum ammonium sulfate pyrolysis method, etc., wherein the product purity of the alkoxide hydrolysis method is high, but the operation is complicated, the time required is relatively long, and it is difficult to form a batch production scale; Al( Oh) 3 Although the sintering method is simple in process, it is difficult to remove impurities; AlCl 3 The gas phase synthesis method has uniform product size, fine particles, and no pollution in the reaction process, but the reaction conditions are harsh, professional equipment is required, and the production cost is high; the sol-gel method has a wide range of raw materials, low production cost, and no waste gas pollution. In the process of gelation, the process parameters are difficult to control; the improved Bayer method can produce high-purity alumina powder, but the production process is complicated and the conditions required in the industry are harsh; the aluminum ammonium sulfate pyrolysis method is the best way to produce high-purity alumina powder One of the main methods, its technology is mature, the operation is simple, the product purity is high, but the production cost is high, and the production cycle is long

At present, there is no relevant report on the method of preparing sapphire-grade high-purity powder from aluminum anodic oxidation waste liquid

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