Highly active aluminum hydroxide crystals, low-zinc aluminum hydroxide and its preparation method, alumina

Abstract

The invention discloses a high-activity aluminum hydroxide crystal, a low-zinc aluminum hydroxide and a preparation method thereof, and alumina. The preparation method of the high-activity aluminum hydroxide crystal is: adding aluminum hydroxide seeds to sodium aluminate Clustering reaction is carried out in the solution to obtain highly active aluminum hydroxide crystals, the quality of adding the aluminum hydroxide seed crystals is 1g / L~100g / L sodium aluminate solution, the aluminum hydroxide of the aluminum hydroxide crystal seeds Granularity D 50 1 μm ~ 60 μm; the sodium aluminate solution meets the following conditions: Na 2 o k Mass concentration is 100g / L~200g / L, caustic ratio α k 1.2 to 2.0; the temperature of the clustering reaction is 65°C to 90°C. Use high-activity aluminum hydroxide crystals to adsorb zinc in sodium aluminate solution, and then decompose to obtain low-zinc aluminum hydroxide. Using high-activity aluminum hydroxide crystals as a dezincification agent does not introduce new impurities, is environmentally friendly, low in cost, and high in efficiency, and the dezincification slag can be used with high value.

Description

High-activity aluminum hydroxide crystal, low-zinc aluminum hydroxide and preparation method thereof, alumina technical field The present invention relates to aluminium oxide production technical field, particularly a kind of low zinc aluminium hydroxide and preparation method thereof, oxygen Aluminum. Background technique [0002] Impurities are one of the important factors that affect the quality of alumina products. Zinc is an impurity in bauxite, High-pressure dissolution enters into the alumina production process, and in the decomposition process, the product is precipitated into aluminum hydroxide, thereby polluting the oxidation aluminum products. The standard electrode potential of zinc is -0.762V, and the standard electrode potential of aluminum is -1.66V. Since the potential of zinc is higher than that of aluminum, In the process of aluminum electrolysis, it is reduced to metal element, which pollutes the aluminum ingot and affects the purity of the aluminu...

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Problems solved by technology

Although the physical dezincification process can avoid the impact of excessive sulfur and organic matter on the production system, it is difficult to perform due to the need for regular cleaning and replacement of the filter layer, and the equipment is susceptible to acid and alkali corrosion during the cleaning process. Large-scale industrial application

[0007] The above existing dezincification technologies have a certain dezincification effect, but will introduce new impurities, and cause a series of negative effects on the production system, such as high iron content in the product, serious equipment corrosion, slow red mud sedimentation speed, and high organic matter in the system. Dezincification The efficiency is low, the cost is high, the environmental pollution is large, and the process is complicated

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