Production method of desiliconized coal ash

Abstract

The invention provides a production method of desiliconized coal ash. The method comprises the following steps: (1) roasting and activating coal ash; (2) after cooling the activated coal ash to the room temperature, mixing the activated coal ash with 140-160g / L sodium hydroxide for carrying out pre-desiliconization, so as to generate coal ash slurry; (3) after cooling the coal ash slurry to 70-80 DEG C, enabling the coal ash slurry to react with 100-150g / L sodium hydroxide at 70-100 DEG C, and filtering, washing and drying reaction products, so as to generate the desiliconized coal ash. By utilizing the production method, the aluminum-silicon ratio of the produced desiliconized coal ash can reach 2.3-2.5, and the production method has the advantages of simple process, low cost and high aluminum-silicon ratio.

Description

technical field [0001] The invention relates to a production method of desiliconized fly ash, which belongs to the technical field of comprehensive utilization of fly ash. Background technique [0002] Fly ash is a solid waste produced after coal combustion in the power generation industry. The discharge and dumping of a large amount of fly ash has caused great harm to the environment, so the comprehensive utilization of fly ash is extremely important. At present, the comprehensive utilization of fly ash is mainly focused on the production of alumina by using fly ash. After continuous and painstaking research by technicians in this field, three commonly used processes for extracting alumina from fly ash have been found. They are acid method, ammonium sulfate method and pre-desilication-soda lime sintering method. In the process of using fly ash to produce alumina, the fly ash is pre-desiliconized to obtain desiliconized fly ash with a high aluminum-silicon ratio as a raw ma...

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Problems solved by technology

However, the aluminum-silicon ratio of the desiliconized fly ash produced by this method is only 2.14 at the highest; the patent CN101913615A "a method for increasing the aluminum-silicon ratio of low-grade bauxite" discloses the use of crushing and grinding, adding solid sodium carbonate Roasting activation, leaching desiliconization, carbon content, additives and water recovery and other steps, finally obtain desiliconized fly ash with a high aluminum-silicon ratio, but the process of this method is relatively complicated and has the disadvantage of high energy consumption

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