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Method for preparing building gypsum by recycling nitration waste sulfuric acid

A technology of nitrifying waste acid and building gypsum, which is applied in the field of reusing nitrifying waste sulfuric acid to prepare building gypsum, which can solve the problems of waste acid pollution, waste acid can not be reused, and high cost of waste acid, so as to reduce environmental pollution and offset disposal Cost, the effect of solving the difficult problem of waste acid treatment

Inactive Publication Date: 2022-03-11
JIANGSU BAOZONG & BAODA PHARMACHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a method for reusing nitrated waste sulfuric acid to prepare building gypsum, which can solve the pollution caused by waste acid to the environment, the treatment of waste acid requires high cost, and the waste acid cannot be fully recovered through simple steps. the problem of reuse

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] S1. Pretreatment of waste nitrification acid: Add 200g of carphenol nitrification waste acid to a 500ml four-neck flask, add 200g of water to dilute, stir at room temperature for 1h to precipitate organic matter, dry the precipitated organic matter, weigh 3.5g, add 1g of activated carbon, and then Stir at room temperature for 1 hour, let stand for 1 hour, and then filter to remove the spent activated carbon to obtain pretreated waste acid with a lighter color.

[0025] S2. Decolorization of nitrated waste acid: Add 2 g of activated carbon to the obtained pretreated waste acid, raise the temperature to 60 ° C, stir for 0.5 h, and then filter, then add 2 g of activated carbon to the filtrate, heat up to 60 ° C, stir for 0.5 h, and then filter to obtain light yellow The clarified liquid, the filtrate is used for the next reaction, and the spent activated carbon is applied to step S1 for waste acid pretreatment.

[0026] S3. Preparation of calcium sulfate by-products: add 2...

Embodiment 2

[0028] S1. Pretreatment of waste nitrification acid: add 300 g of waste carphenol nitrification acid to a 500 ml four-neck flask, add 300 g of water to dilute, stir at room temperature for 0.5 h to precipitate organic matter, dry the precipitated organic matter, weigh 5.1 g, add Example 1 3 g of activated carbon for decolorization after filtering in step S2, then stirred at room temperature for 0.5 h, stood still for 0.5 h, and then filtered to obtain pretreated spent acid.

[0029] S2. Decolorization of nitrated waste acid: add 6 g of activated carbon to the obtained pretreated waste acid, heat up to 50 ° C, stir for 1 hour and filter, then add 6 g of activated carbon to the filtrate, heat up to 50 ° C, stir for 1 hour and filter to obtain light yellow The liquid is clarified, the filtrate is used for the next reaction, and the spent activated carbon is applied to step S1 for waste acid pretreatment.

[0030] S3. Preparation of calcium sulfate by-product: add 300g of calcium ...

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Abstract

The invention discloses a method for preparing building gypsum by recycling nitration waste sulfuric acid, and relates to the technical field of comprehensive utilization of industrial waste acid. The method specifically comprises the following steps: diluting waste acid with water, stirring, adding mechanically-applied activated carbon, stirring, standing, and filtering to obtain pretreated waste acid; adding activated carbon into the pretreated waste acid, heating, stirring and filtering, adding activated carbon, heating, stirring and filtering to obtain faint yellow clear liquid, applying filtrate to next reaction, and applying waste activated carbon; adding waste calcium carbonate into a reaction bottle, adding water, uniformly stirring, dropwise adding the decolorized waste acid, stirring and filtering to obtain a calcium sulfate wet product, and calcining to obtain calcium sulfate hemihydrate. The method has the advantages that the waste acid can be effectively recycled to generate building gypsum, so that the treatment cost of the waste acid solution is counteracted, the environmental pollution is reduced, and economic benefits can be obtained; the residual organic matters in the waste acid can be effectively removed, the activated carbon is recycled, the operation steps are simple, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of comprehensive utilization of industrial waste acid, in particular to a method for preparing building gypsum by reusing nitrated waste sulfuric acid. Background technique [0002] Nitrification reaction is an important synthesis step of carphenol pesticide. At present, the most commonly used nitrating agent in industrial nitration reaction is the mixed acid of nitric acid and sulfuric acid. As human beings attach importance to global environmental protection, the treatment of waste nitrification acid is a big problem. Many factories have no ability to deal with it themselves, so they have to invest in qualified institutions to deal with it, which greatly increases the cost of the company. [0003] In the prior art, the patent with the publication number CN104649910A discloses a method for preparing 2,5-dichloronitrobenzene by continuous nitration of acid, which extracts the organic matter with p-dichlorobe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B11/26C04B11/02
CPCC04B11/26C04B11/02
Inventor 赵海华李宾张智红张鹏
Owner JIANGSU BAOZONG & BAODA PHARMACHEM