Method for producing cement accelerator through comprehensive treatment of secondary aluminum ash

Abstract

The invention discloses a method for producing a cement accelerator through comprehensive treatment of secondary aluminum ash, and belongs to the cross technical field of aluminum industry solid waste resource treatment and comprehensive utilization and cement accelerator production. The method comprises the following steps: mixing secondary aluminum ash, a calcium source and an alkaline additive to obtain a mixed raw material, calcining the raw material in gas fuel, and cooling to obtain the cement accelerator, and flue gas generated by calcination is discharged through dust removal and denitration, and dust is recycled. According to the method, the aluminum ash is effectively converted into the accelerator, resource utilization is achieved while treatment is conducted, and remarkable economic benefits are achieved; by regulating and controlling the types of the alkaline additives, a synergistic effect is generated, and the dynamic performance of the cement setting process is improved; especially, green conversion and migration of nitrogen and fluorine elements in the secondary aluminum ash are effectively achieved in the treatment process, and remarkable environmental and social benefits are achieved.

Description

technical field [0001] The invention relates to the technical field of comprehensive utilization of solid waste resources in the aluminum industry, in particular to a method for producing cement quick-setting agent through comprehensive disposal of secondary aluminum ash. Background technique [0002] Secondary aluminum ash is the solid waste after recycling metal aluminum from primary aluminum ash. The main components are aluminum and its oxides, aluminum nitride, aluminum carbide and a certain amount of fluoride, which has high recovery and utilization value. However, when the secondary aluminum ash meets water, the aluminum nitride can be hydrolyzed to release ammonia gas, and the fluoride will also be leached to form pollution. Therefore, the secondary aluminum ash is judged as hazardous waste. Coupled with the lack of low-cost, large-scale and relatively mature treatment technologies, the main measures to deal with aluminum ash are landfill or stockpiling, which will ...

AI Technical Summary

Problems solved by technology

Secondary aluminum ash is rich in aluminum and can partially replace bauxite in the production of cement accelerators, but how to control the conversion and migration of nitrogen and fluorine elements is a difficult problem

[0005] Some studies have found that roasting can convert nitrogen in aluminum ash into nitrogen, or reduce subsequent NOx emissions, and then achieve aluminum recovery, but the fluorine element is easy to migrate into the gas phase, causing pollution; at the same time, if the appropriate process conditions cannot be adjusted, the fluorine will still remain in the solid in a soluble state, and will still be leached later

Wet recovery of fluorine is another process, but the process is long, and other methods must be used to remove nitrogen at the same time, so the technical economy is poor

[0006] On the whole, currently secondary aluminum ash is mainly used to prepare materials such as polyaluminium chloride and alumina, and there is no one that can both efficiently dispose of secondary aluminum ash and An efficient method for resource utilization of cement quick-setting agent