Fly ash low-temperature wet activating treatment method

Abstract

The invention provides a fly ash low-temperature wet activating treatment method, comprising the following steps of: (1) mixing the fly ash with the strong alkali solution of which the concentration is 300-700g / l, to perform activating treatment, wherein the volume-to-mass ratio of the alkali solution and the fly ash is (3:1)-(20:1) (ml / g), the activating temperature is 130-180 DEG C, the activating time is 0.5-10 hours, and the activating pressure is normal pressure to 0.5Mpa; performing liquid-solid separation after activation to get the crude alkali liquor and the activated fly ash; (2) diluting the crude alkali liquor, then, adding calcium oxide into the diluted crude alkali liquor for purification, performing liquid-solid separation to get calcareous residues and strong alkali solution, wherein the calcareous residues is output to the system as byproducts, and the strong alkali solution is recycled for fly ash activating treatment. In the method, the alkali solution is NaOH water solution, KOH water solution, sodium aluminate solution or potassium aluminate solution, after being activated, the fly ash is dissolved out by diluted acid, and the dissolution rate of aluminum oxide is up to 95-99%. In the method, the activation temperature is low, the activation effect is excellent, the activation process cannot cause secondary pollution, and essential conditions for follow-up fly ash treatment, especially for extraction of aluminum oxide, zeolite preparation, and the like, are created.

Description

technical field [0001] The invention relates to a low-temperature wet activation treatment method for fly ash. Background technique [0002] With the rapid development of my country's national economy, my country's aluminum industry is facing a serious shortage of resources, and the safety of the aluminum industry has been severely challenged. At the same time, because my country is one of the few countries in the world that use coal as the main energy source, coal has always occupied a dominant position in my country's energy consumption pattern. After coal combustion, a large amount of coal-fired solid waste is produced, one of which is fly ash. For every four tons of coal consumed by thermal power plants, one ton of fly ash will be produced. In 2010, the discharge of fly ash in my country was about 480 million tons. . Due to the low utilization rate of fly ash and the high concentration of production areas, a large amount of fly ash has been stockpiled in my country, and...

AI Technical Summary

Problems solved by technology

However, the energy consumption of grinding and sintering is high; the method of adding fluoride may not only pollute the atmosphere, but also produce highly toxic fluosilicic acid during the decomposition process of fly ash, causing secondary pollution; microwave heating technology is difficult to implement in industry, The outlook is not good

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