Method for extracting aluminum from aluminum-containing minerals

Abstract

The invention provides a method for extracting aluminum from aluminum-containing minerals. The method comprises the following steps: mixing the aluminum-containing minerals with ammonium salt, and roasting in an atmosphere containing water vapor to obtain roasted clinker and tail gas; leaching the roasted clinker and then carrying out solid-liquid separation to obtain leachate and leaching residues; mixing the leachate with a pH regulator, reacting and then carrying out solid-liquid separation to obtain mixed precipitate and a precipitate mother solution; and mixing the mixed precipitate with an alkali solution, reacting, and then carrying out solid-liquid separation to obtain an aluminate solution and residual precipitate. According to the method, water vapor is introduced in the mixed roasting process of the aluminum-containing minerals and the ammonium salt, conversion of the aluminum-containing minerals is facilitated, then the leaching rate of aluminum and the utilization rate of the ammonium salt in the subsequent leaching process are increased, the problem that the utilization rate of the ammonium salt is low is effectively solved, and separation of aluminum from impurity elements can be effectively achieved through the method; and the method is simple to implement, environmentally friendly, low in equipment requirement, low in energy consumption and raw material cost and good in economic benefit, and has good industrial application prospects.

Description

technical field [0001] The invention belongs to the technical field of mineral utilization and relates to a method for extracting aluminum from aluminum-containing minerals. Background technique [0002] Bauxite is the main raw material for industrial production of alumina, and its industrial methods are mainly alkaline methods, including Bayer method, sintering method and combined method. Among them, the Bayer method directly treats bauxite with caustic soda solution. Although it has the advantages of simple process flow, good product quality and high economic benefits, this process is only suitable for processing low-silicon bauxite, especially when the aluminum-silicon ratio is >7 The gibbsite-type bauxite; the sintering method is to mix the bauxite with sodium carbonate and lime, and roast at high temperature to obtain clinker containing sodium aluminate solids, and the clinker is dissolved with dilute alkali to obtain sodium metaaluminate solution. After purificatio...

AI Technical Summary

Problems solved by technology

CN 1160019A discloses an ammonium sulfate method for extracting alumina from low-grade aluminum-containing ores. The method is carried out by crushing the ore, sieving, activating roasting, and then mixing with ammonium sulfate for solid-phase reaction. The reaction product is extracted by water, After solid-liquid separation, dissociate with ammonia water, then obtain aluminum hydroxide through iron removal and subsequent separation and refining processes, and then calcined to obtain alumina; in this method, ammonium sulfate is easily decomposed when directly roasted, resulting in a decrease in its utilization rate and affecting The leaching rate of aluminum, and this method needs to be roasted twice, which is easy to cause excessive sintering and affect the subsequent leaching

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