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A kind of method that utilizes industrial by-product gypsum to prepare calcium oxide

A by-product, calcium oxide technology, applied in the direction of carbon monoxide, chemical instruments and methods, calcium/strontium/barium oxide/hydroxide, etc., can solve the problems of difficult separation of reaction residues, high reaction temperature, uneven mixing, etc. Achieve high convection heat transfer efficiency, large contact area, and improve process economy

Active Publication Date: 2022-06-14
INST OF PROCESS ENG CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the above-mentioned patents, in the process of using industrial by-product gypsum to prepare calcium oxide, the solid raw material is used as the reducing agent to decompose the gypsum, and the solid reducing agent has uneven mixing during the reaction process, and problems such as reaction dead ends are prone to occur; moreover, the solid-state reduction The reagent is also easy to substitute impurities, resulting in more by-products and difficult separation of reaction residues. In addition, the required reaction temperature is high and energy consumption is large.

Method used

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  • A kind of method that utilizes industrial by-product gypsum to prepare calcium oxide
  • A kind of method that utilizes industrial by-product gypsum to prepare calcium oxide
  • A kind of method that utilizes industrial by-product gypsum to prepare calcium oxide

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Embodiment 1

[0053] The present embodiment provides a method for preparing calcium oxide by utilizing industrial by-product gypsum, and the process flow of the method is as follows figure 2 As shown, the method includes the following steps:

[0054] (1) Reduction treatment: the phosphogypsum is air-dried, crushed, ground and sieved to obtain solid powder raw materials and react with the introduced CO at 900 ° C for 90 min to obtain calcium sulfide and CO 2 ;

[0055] (2) Oxidation treatment: the obtained calcium sulfide is oxidized in CO 2 It is oxidized under gas, and the temperature is raised to 1050 ° C for 40 minutes to obtain solid product calcium oxide and gaseous products CO and SO 2 ;

[0056] (3) Gas separation and recovery treatment: the obtained gas products are separated to obtain independent CO and SO 2 , the CO is used for reduction treatment, the SO 2 For the preparation of sulfur-containing products.

Embodiment 2

[0058] The present embodiment provides a method for preparing calcium oxide by utilizing industrial by-product gypsum, and the process flow of the method is as follows figure 2 As shown, the method includes the following steps: except that the temperature in step (1) is changed to 1100°C, and the reaction time is changed to 30min; the temperature described in step (2) is changed to 1100°C, and the reaction time is changed to 30min; Other conditions are the same as in Example 1.

Embodiment 3

[0060] The present embodiment provides a method for preparing calcium oxide by utilizing industrial by-product gypsum, and the process flow of the method is as follows figure 2 As shown, the method includes the following steps:

[0061] (1) Reduction treatment: the phosphogypsum is air-dried, crushed, ground and sieved to obtain solid powder raw materials and react with the introduced CO at 900 ° C for 150 min to obtain calcium sulfide and CO. 2 ;

[0062] (2) Oxidation treatment: the obtained calcium sulfide is oxidized in CO 2 and O 2 It is oxidized under the mixed gas, and the temperature is raised to 950 ° C for 150 min to obtain solid product calcium oxide and gaseous products CO and SO 2 ;

[0063] (3) Gas separation and recovery treatment: the obtained gas products are separated to obtain independent CO and SO 2 , the CO is used for reduction treatment, the SO 2 For the preparation of sulfur-containing products.

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Abstract

The invention provides a method for preparing calcium oxide by using the industrial by-product gypsum, the method comprising: reducing the industrial by-product gypsum, and the obtained calcium sulfide is 2 Oxidation treatment is carried out under atmosphere. The method adopts two treatment processes of reduction-oxidation, which can effectively reduce the initial reaction temperature, improve the decomposition rate and conversion rate of raw materials, and the heat released in the oxidation treatment can not only provide heat for self-reaction, but also provide heat for reduction reaction. Reduce system energy consumption and operating costs, improve process economy. The present invention does not discharge secondary pollutants in the process of preparing calcium oxide, the gas generated in the process can be reused, the decomposition rate of gypsum reaches 99%, and the conversion rate of calcium oxide reaches 97%, realizing the efficient recycling of industrial by-product gypsum waste residue use.

Description

technical field [0001] The invention belongs to the technical field of solid waste resource utilization, and in particular relates to a method for preparing calcium oxide by utilizing industrial by-product gypsum. Background technique [0002] According to statistics, the current natural gypsum ore reserves are about 57 billion tons, and only 8% of the reserves are high-quality gypsum (calcium sulfate content greater than 90%) resources, and the content of low-grade ore and anhydrite is relatively large. In addition, the distribution of gypsum resources is extremely uneven, but the market demand for gypsum resources has continued to expand in recent years. Industrial by-product gypsum refers to the industrial by-product with calcium sulfate as the main component generated by chemical reaction in industrial production, mainly including phosphogypsum, desulfurization gypsum, titanium gypsum, mirabilite gypsum, fluorine gypsum, salt gypsum and lemon gypsum, etc. Among them, pho...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F11/02C01F11/08C01F11/10C01B32/40C01B17/50
CPCC01F11/02C01F11/08C01F11/10C01B32/40C01B17/508
Inventor 李松庚郝丽芳何海蔚范垂钢
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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