Method for preparing aluminum and coproducing cement from flyash

A technology of alumina and fly ash, which is applied in the production of alumina/aluminum hydroxide and cement, can solve the problems of high cost, high energy consumption, and high sintering temperature, and achieve the effect of facilitating industrialization and low energy consumption

Inactive Publication Date: 2010-02-24
SHENYANG ALUMINIUM MAGNESIUM INSTITUTE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the extraction of alumina from fly ash by limestone sintering has p...

Method used

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  • Method for preparing aluminum and coproducing cement from flyash

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Effect test

Embodiment 1

[0023] The composition of raw fly ash is: Al 2 o 3 : 40%, SiO 2 : 48%, Fe 2 o 3 : 3%, CaO: 3%, TiO 2 :1%. The composition of the raw coal fly ash can also adopt other components and specific dosages, any conventional fly ash can be used, which cannot be used to limit the protection scope of the present invention.

[0024] Limestone is calcined at 1200°C to obtain active lime; fly ash, lime, Na 2 CO 3 Mixed ingredients with a small amount of coal powder, in which CaO and SiO 2 The molar ratio is 2:1, Na 2 O and Al 2 o 3 The molar ratio is 1:1 to prepare raw slurry; sinter the raw slurry at 1200°C to obtain clinker containing sodium aluminate, sodium ferrite and dicalcium silicate; Grind and dissolve to obtain crude liquid and residue, and the resulting calcium-silicon slag is used to prepare cement after washing; the crude sodium aluminate solution is desiliconized under pressure at 165°C, and then added lime milk for deep desiliconization to obtain sodium aluminate ...

Embodiment 2

[0026] The fly ash composition is the same as in Example 1.

[0027] Limestone is calcined at 1200°C to obtain active lime. fly ash, lime, Na 2 CO 3 Mixed ingredients with a small amount of coal powder, in which CaO and SiO 2 The molar ratio is 1.8:1, Na 2 O and Al 2 o 3 The molar ratio was 0.8:1 to prepare raw slurry. The raw material slurry is sintered at 1100°C to obtain clinker containing sodium aluminate, sodium ferrite and dicalcium silicate; the clinker is broken at 70°C and eluted by a second-stage mill to obtain crude liquid and residue, and the resulting calcium-silicon The slag is used to prepare cement after washing; the CO produced when calcined limestone is passed into the crude liquid 2 , using pressurized carbon in the carbon tank for carbonation and decomposition to obtain high-silicon aluminum hydroxide; 2 O180g / L alkali solution is dissolved under pressure, the residence time is 40min, and pure sodium aluminate solution is obtained after solid-liquid...

Embodiment 3

[0029] The fly ash composition is the same as in Example 1.

[0030] Limestone is calcined at 1200°C to obtain active lime. fly ash, lime, Na 2 CO 3 Mixed ingredients with a small amount of coal powder, in which CaO and SiO 2 The molar ratio is 2.4:1, Na 2 O and Al 2 o 3 The molar ratio is 1.6:1 to prepare raw slurry; sinter the raw slurry at 1400°C to obtain clinker containing sodium aluminate, sodium ferrite and dicalcium silicate; Dissolution to obtain liquid crude liquid and residue, the resulting calcium silicate slag is used to prepare cement after washing; the CO produced when calcined limestone is passed into the crude liquid 2 , using pressurized carbon in the carbon tank for carbonation and decomposition to obtain high-silicon aluminum hydroxide; 2 The alkaline solution of O200g / L is pressurized and dissolved, and the residence time is 60min. After solid-liquid separation, pure sodium aluminate solution is obtained; in the seed sub-trough, aluminum hydroxide c...

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Abstract

The invention discloses a method for preparing aluminum and coproducing cement, and in particular relates to a method for preparing the aluminum and coproducing the cement from flyash, which comprisesprocess steps of: preparing raw slurry, sintering clinker aggregate, precipitating the clinker aggregate, preparing aluminium hydroxide, preparing alumina and preparing the cement from residue generated in the process of precipitating the clinker aggregate. By strictly controlling alkali ratio and calcium ratio, the method can enable the alumina in the flyash to fully react at high temperature and then precipitate effectively under normal pressure, and has the extraction ratio of the alumina above 90 percent. The sintering temperature is 200 DEG C lower than that of a limestone sintering method, the energy consumption is lower than that of the limestone sintering method, and the residue can prepare the cement and is fully utilized to accord with the national policy of environmental protection, energy conservation and recycling economy. The equipment used by the method is common equipment in the alumina industry and cement industry, and is favorable for industrialization.

Description

technical field [0001] The invention relates to a method for preparing alumina co-production cement, in particular to a method for preparing alumina co-production cement by using fly ash. Background technique [0002] Fly ash is a solid waste from coal-fired power plants. At present, my country's annual discharge of fly ash is hundreds of millions of tons, and the total stockpiles of fly ash in my country are more than one billion tons. The discharge of a large amount of fly ash not only occupies a large amount of land, but also seriously pollutes the environment, which constitutes a double damage to the ecology and the environment. Therefore, the comprehensive utilization of fly ash has great practical and long-term strategic significance. Similarly, my country is a country that is not rich in aluminum resources. It is reported that 45 major minerals in my country can guarantee the demand in 2010. There are 10 minerals that cannot be guaranteed, including bauxite. Accord...

Claims

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Application Information

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IPC IPC(8): C01F7/02C04B7/26
CPCY02P40/10
Inventor 李来时廖新勤周凤禄刘瑛瑛
Owner SHENYANG ALUMINIUM MAGNESIUM INSTITUTE
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