Method for preparing aluminum hydroxide by adopting alumina rock as raw material for cell grinding and water milling of seed crystals

Abstract

The invention relates to the technical field of preparation of aluminum hydroxide micro-powder, in particular to a method for preparing aluminum hydroxide by adopting alumina rock as a raw material for cell grinding and water milling of seed crystals. The aluminum rock is activated by crushing, ball milling and microwave radiation. Leaching of aluminum oxide in the aluminum rock by a mixed acid isimproved; after sulfuric acid and nitric acid are mixed into the mixed acid, leaching treatment is performed, so that sulfuric acid leaches aluminum components, sulfate radicals and calcium components form calcium sulfate at the same time, and a process flow of adopting the aluminum rock as the raw material for treatment is shortened. The difficulty of removing calcium ions, magnesium ions, ironions and the like in the later period is lowered, so that the relative content of the aluminum components entering a leachate is relatively high. After sodium hydroxide is adopted for adjusting the pHvalue, cell grinding is conducted to obtain an aluminum hydroxide seed crystal pulp, and then the aluminum hydroxide seed crystal pulp is added into a solution containing sodium aluminate, then crystallized, decomposed and washed to obtain aluminum hydroxide micro-powder with the sodium content lower than 0.1% and the particle size of 0.5-8 microns.

Description

technical field [0001] The invention relates to the technical field of aluminum hydroxide micropowder preparation, in particular to a method for preparing aluminum hydroxide by using aluminum rock as a raw material for cell milling and water milling seeds. Background technique [0002] Aluminous rocks are hydroxides containing aluminum. In my country, aluminous rocks mainly contain diaspore and clay minerals, and also contain siliceous and anatase. With the increasing scarcity of resources and the strengthening of people's awareness of environmental protection, the comprehensive utilization of alumina rock has attracted more and more attention. Aluminous rocks contain high amounts of Al 2 o 3 , Aluminum hydroxide powder can be obtained after leaching with alumina rock and mixed acid to remove impurities, and the obtained aluminum hydroxide powder can be widely used in various flame retardants and inorganic fillers. [0003] For this reason, some researchers in the prior a...

AI Technical Summary

Problems solved by technology

However, in the prior art, during the treatment process, carbon dioxide is used to carbonize sodium aluminate solution to realize the precipitation of aluminum hydroxide, resulting in an unbalanced precipitation rate of aluminum hydroxide, and sodium will be continuously adsorbed on the surface of aluminum hydroxide crystals. Composition, so that there is a large amount of sodium in the aluminum hydroxide crystal, and the sodium content in aluminum hydroxide is one of the key factors that determine the quality of aluminum hydroxide powder. The lower the sodium content, the better the quality of aluminum hydroxide ; At the same time, in the process of using alumina rock as raw material in the production process, the rationalization of the alumina rock and the rationalization ratio of the leaching mixed acid will greatly affect the relative content of the aluminum component in the leach solution, which in turn will affect the addition of sodium hydroxide. Amount, resulting in the content of sodium components into the leachate, resulting in poor quality of carbonization and precipitation of aluminum hydroxide in the leachate