Method for preparing calcium sulfate whiskers from sintering flue gas semidry method desulfurization ash based on acid oxidation

A semi-dry desulfurization and calcium sulfate whisker technology, which is applied in the field of resource utilization of desulfurization ash, can solve problems such as poor oxidation efficiency, and achieve the effects of improving quality, improving performance, and high surface finish

Active Publication Date: 2017-11-28
ANHUI UNIVERSITY OF TECHNOLOGY
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the problem of poor oxidation efficiency of semi-dry desulfurization in the prior art, and to provide a method for preparing calcium sulfate whiskers from sintered flue gas semi-dry desulfurization ash based on acid oxidation. Treating the desulfurization ash can improve the purity of calcium sulfate dihydrate in the reaction product, thereby improving the whiteness and solid content of the prepared calcium sulfate

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  • Method for preparing calcium sulfate whiskers from sintering flue gas semidry method desulfurization ash based on acid oxidation
  • Method for preparing calcium sulfate whiskers from sintering flue gas semidry method desulfurization ash based on acid oxidation

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Embodiment 1

[0046] A method for preparing calcium sulfate whiskers based on acidic oxidation of sintered flue gas semi-dry desulfurization ash of the present invention, wherein the oxygen promoter used includes an acidic promoter whose acidity is between sulfurous acid and sulfuric acid Between, that is, the pKa of the acidic additive 1 The acidity coefficient is between the pKa of sulfurous acid and sulfuric acid 1 Between the acidity coefficients, the oxygen promoter is used to oxidize the calcium sulfite in the desulfurization ash, the acid promoter is easily soluble in water, and the pKa of the acid promoter in 25°C water 1 The acidity coefficient is: 1.00-1.89, where the pKa 1 Is the first-order acidity coefficient of the acidic auxiliary agent, and the acidic auxiliary agent of the present embodiment is oxalic acid, and its pKa 1 is 1.27; the oxygen promoter in the present embodiment is oxalic acid, and the oxygen promoter solution is obtained after mixing oxalic acid with water. ...

Embodiment 2

[0066] The basic content of this embodiment is the same as that of Example 1, except that the acidic additive is dichloroacetic acid (CHCl 2 COOH), its pKa in water at 25°C 1 is 1.30, the oxygen promoter in this embodiment is dichloroacetic acid, and the oxygen promoter solution is obtained after dichloroacetic acid is mixed with water. The oxygen promoter of the invention greatly improves the oxidation efficiency of the desulfurization ash, and realizes the oxidation of the desulfurization ash under the condition of low temperature in an open container. After the reaction, the reactant precipitate is oxidatively modified desulfurization ash, which is heated and dried at a temperature of 100° C. to obtain a dry powder. The content of calcium sulfate dihydrate in the dry powder reaches 95.3%. The quality of prepared whiskers is basically the same as in Example 1. The theoretical strength of calcium sulfate whiskers prepared by this method reaches 0.02E-0.05E, and the surface ...

Embodiment 3

[0068] The basic content of this embodiment is the same as that of Example 1, except that the acidic auxiliary agent is composed of oxalic acid and dichloroacetic acid, and the mass ratio of oxalic acid and dichloroacetic acid is 2:1. The agent consists of oxalic acid and dichloroacetic acid. The use of the oxygen promoter of the present invention greatly improves the oxidation efficiency of desulfurization ash, and realizes the oxidation of desulfurization ash under the low temperature condition of an open container. It is heated and dried at a temperature of 100° C. to obtain a dry powder, and the content of calcium sulfate dihydrate in the dry powder reaches 94.8%. The quality of prepared whiskers is basically the same as in Example 1.

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Abstract

The invention discloses a method for preparing calcium sulfate whiskers from sintering flue gas semidry method desulfurization ash based on acid oxidation and belongs to the field of desulfurization ash resource utilization. An oxidizing aid and water are mixed to form an oxidizing aid solution, oxygen-containing gas is blown into a mixed solution of desulfurization ash and water, the oxidizing aid solution is uniformly injected to the bottom of the desulfurization ash mixed solution, the oxidizing aid comprises an acid aid with the pKa1 acidity coefficient between pKal acidity coefficients of sulphurous acid and sulfuric acid, oxidized desulfurization ash is mixed and emulsified to form slurry, and the calcium sulfate whiskers are prepared through a hydrothermal reaction of the slurry. The purity of calcium sulfate is increased by changing sufficient oxidation modification of desulfurization ash with the reaction interface in the desulfurization ash oxidation process, the theoretical strength of the prepared calcium sulfate whiskers is 0.02 E-0.05 E, the surface finish is higher, and the performance of the calcium sulfate whiskers is greatly improved.

Description

technical field [0001] The invention relates to the application field of resource utilization of desulfurization ash, and more specifically, relates to a method for preparing calcium sulfate whiskers from sintering flue gas semi-dry desulfurization ash based on acid oxidation. Background technique [0002] In 2016, the total output of crude steel in the world reached 1.6285 billion tons, a year-on-year increase of 0.8%. Among them, my country's crude steel output was 808.4 million tons (accounting for 49.6% of global crude steel production), still an increase of 1.2% year-on-year. As an important link in the modern steel production process, the sintering process is also the main pollutant emission source of the steel industry, of which more than 70% of the SO 2 from the sintering process. In the latest revision of "Iron and Steel Industry Pollution Emission Standards", SO 2 As one of the important contents, the emission control of the iron and steel industry is mandatory t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/62C30B29/46C30B7/14
CPCC30B7/14C30B29/46C30B29/62
Inventor 龙红明魏汝飞王毅璠李家新王平孟庆民春铁军狄瞻霞余正伟钱立新
Owner ANHUI UNIVERSITY OF TECHNOLOGY
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