Method for extracting aluminum oxide, monox and ferric oxide from gangue combustion ashes

Abstract

The invention relates to a method for extracting aluminum oxide, monox and ferric oxide from gangue combustion ashes. Coal blending is carried out according to heating value conditions after the gangue is pretreated, gangue activation is achieved while calcination generation is carried out, and the produced electricity and steam are supplied for a system to use; the aluminum oxide is extracted from the ashes by an acid method, the monox is extracted by an alkaline method, and the ferric oxide is extracted by comprehensive utilization of by-products; and acid, alkaline, lime, an extractant andCO2 which are required by each craft link are recycled inside the system. The invention has the beneficial effects that gangue reclamation is implemented by using the method; the energy and the chemical components in the gangue are fully utilized; the discharge amounts of greenhouse gases and waste ashes are greatly reduced, and the economic benefit of the system is improved; and the method is a novel technology of gangue greening and high added-value utilization, and has obvious competitive advantage.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for extracting alumina, silicon oxide and iron oxide from coal gangue combustion ash. Background technique [0002] my country is a big producer of alumina, with an output of 25.37 million tons in 2008. Although the total amount of alumina resources in my country is abundant, the ore types are mainly characterized by high silicon, high iron, low aluminum-silicon ratio and diaspore. It is difficult to produce alumina by economical Bayer process, which has mining and utilization value China's bauxite resources are facing depletion in the next 6-7 years. Therefore, finding new alumina resources and developing an alumina production process that saves energy and reduces consumption will be the key to the sustainable development of China's aluminum industry. The practice of alumina production shows that my country's alumina resources are only suitable for the sintering proces...

AI Technical Summary

Problems solved by technology

Although scholars have conducted in-depth research on the extraction and utilization of aluminum and silicon in coal gangue and obtained different experimental results, the key technical issues involved in this technology, such as energy utilization, material circulation, impurity removal and final The production of alumina, silicon oxide and iron oxide has not been reported in the literature

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