Method for realizing separation of aluminium, iron and calcium by activating coal gasification ash

Abstract

The invention relates to the technical field of a chemical process and discloses a method for realizing separation of aluminium, iron and calcium by activating coal gasification ash. The method comprises the following steps of: the first step, drying the coal gasification ash; the second step: calcining the dried coal gasification ash at a temperature in the range from 700 to 1100 DEG C for 15-75 minutes and then quenching the coal gasification ash to obtain an activated material; and the third step: carrying out a reaction on the activated material and a hydrochloric acid solution or a sulfuric acid solution at a temperature in the range from 60 to 100 DEG C for 30-120 minutes. The method is characterized in that no any auxiliary needs to be added, the mineral composition in the coal gasification ash can be changed at a low temperature, the reaction activity is effectively improved and the leaching reaction time is shortened, so that effectively separation of aluminium, iron and calcium is realized; besides, the heat value of carbon residue in the coal gasification ash can be utilized.

Description

technical field [0001] The invention relates to the technical field of chemical technology, in particular to a method for activating coal gasification ash to realize the separation of aluminum, iron and calcium. Background technique [0002] With the development of my country's economy, the contradiction between the large demand for alumina and the extremely low basic reserves of bauxite in my country has become increasingly prominent. How to develop bauxite alternative resources and avoid the embarrassing situation of iron ore has become a problem that must be faced in the sustainable development of my country's economy. In this context, my country has set off an upsurge in finding alternative resources for bauxite, and the extraction of alumina from fly ash has received special attention. There are many related literature reports and patents, which can be divided into direct method, auxiliary dissolution method, auxiliary sintering method, etc. according to different proc...

AI Technical Summary

Problems solved by technology

Looking at these methods, because the resource utilization of coal gasification ash is only focused on the extraction of alumina, without considering that there are about 80% of silicon, iron, calcium and other resources in the ash, the reduction of ash The gasification effect is very small, and it increases the difficulty of utilizing the secondary residue; on the other hand, due to the large carbon content and low activity of the coal gasification ash residue, the method of direct acid leaching has the disadvantages of large consumption, long acid leaching time, and subsequent Difficult to achieve industrial applications such as filtration difficulties