Method for preparing aluminum sulfate from aluminum-containing acid treatment solution

Abstract

The invention provides a method for preparing aluminum sulfate from an aluminum-containing acid treatment solution. The method comprises the following steps: (1) gelatinizing the aluminum-containing acid treatment solution, and filtering and separating to obtain gel and a gel filtrate; (2) adding concentrated sulfuric acid into the gel filtrate, and carrying out primary salting-out crystallization to obtain crude aluminum sulfate; (3) adding water to dissolve the crude aluminum sulfate, and filtering to obtain calcium sulfate and calcium-removed filtrate; (4) adding concentrated sulfuric acid into the calcium-removed filtrate, and carrying out secondary salting-out crystallization to obtain high-purity aluminum sulfate; and (5) evaporating and concentrating the secondary salting-out crystallization filtrate to obtain high-purity sodium sulfate precipitate. The invention develops the comprehensive treatment and resource utilization method aiming at the acid treatment waste liquid of minerals, especially the acid treatment waste liquid of a coal acid-base ash removal method. By adopting the method, aluminum oxide can be effectively extracted, aluminum sulfate can be prepared, and market requirements are met. And the method has very good industrial application value.

Description

technical field [0001] The invention relates to a method for preparing aluminum sulfate from an aluminum-containing acid treatment solution. Background technique [0002] The energy structure with relatively abundant coal and relatively poor oil and natural gas determines that China's energy consumption is dominated by coal. Electric coal and coking coal are the main uses of coal, and other uses include coal for chemical industry and building materials. Although the proportion of coal in primary energy consumption has shown a downward trend in recent years, the total consumption in 2015 was still 3.965 billion tons, accounting for more than 62.3%. In the next few decades, the current status of coal as the main energy consumption of the country will not change fundamentally. [0003] The types of coal in China are complex, the quality of the coal is generally poor, and the ash content is relatively high. After years of mining, the quality of the coal has continued to declin...

AI Technical Summary

Problems solved by technology

However, the product of extracting aluminum from fly ash is single, the process energy consumption is high, and the economy is poor