Method for coproduction of bleaching powder, active carbon, sodium chloride and sulphuric acid from waste gypsum plaster

A technology of bleaching powder and waste gypsum, which is applied in the direction of sulfur trioxide/sulfuric acid, hypochlorous acid, hypochlorite, etc., and can solve problems such as land occupation

Inactive Publication Date: 2009-07-22
LIWANG CHEM NANTONG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

While effectively overcoming a large amount of costs incurred in the treatment of waste gypsum mud, it basically eliminates secondary pollution and achieves zero emissions, and also solves the problem of land occupation due to accumulation

Method used

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  • Method for coproduction of bleaching powder, active carbon, sodium chloride and sulphuric acid from waste gypsum plaster
  • Method for coproduction of bleaching powder, active carbon, sodium chloride and sulphuric acid from waste gypsum plaster

Examples

Experimental program
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Effect test

Embodiment 1

[0019] Example 1: Take 400kg of waste gypsum mud from a titanium dioxide factory and inject industrial water into the preprocessor (1) at a weight ratio of 1:6, stir to form an emulsion and naturally settle to remove impurities at the bottom to obtain a relatively pure gypsum emulsion. Then inject the clarifier (2) with hydrochloric acid in a mass ratio of 1:0.4 and carry out the stirring reaction to obtain a mixed solution of calcium chloride and sulfuric acid, and centrifuge (3) to obtain a filter cake that can refine 24kg of activated carbon, and obtain the filtrate respectively. Calcium chloride 192.62 kg and sulfuric acid 171.82kg; Filtrate and sodium sulfate are mixed in side reactor (6) by mass ratio 1:1.2 and react to generate pure calcium sulfate 223.68kg and sodium chloride 192.42kg, get filtrate through distillation ( 8) sodium chloride crystals (9) and concentrated sulfuric acid; the remaining filter cake continues to react with sodium hydroxide in the main reactor ...

Embodiment 2

[0020] Example 2: Take 400kg of waste gypsum mud and water into the preprocessor at a ratio of 1:4 and stir to form a uniform emulsion. After standing still, the relatively pure emulsion and hydrochloric acid are injected into a purifier at a ratio of 1:0.2 to generate chloride A mixture of calcium 97.32kg and sulfuric acid 85.92kg. The filtered filter cake can be used as 24kg of activated carbon; the filtrate is reacted with sodium sulfate at a ratio of 1:1 to obtain precipitated calcium sulfate 119.24kg and sodium chloride 102.58kg, and the filtered filtrate is distilled to obtain chlorine Sodium chloride and sulfuric acid; filter cake and sodium hydroxide are reacted by 1:0.2 to obtain calcium hydroxide 22.06kg and sodium sulfate 42.32kg, through filtering sodium sulfate; filter cake and chlorine are sent into chlorination tower and chlorinated by 1:0.4 respectively to obtain 12.7kg of bleaching powder and 6.9kg of calcium chloride were separated to obtain a calcium chloride...

Embodiment 3

[0021] Example 3: Take 400kg of waste gypsum mud and water and inject it into the preprocessor at a ratio of 1:8 and stir it into a uniform emulsion. The mixed solution of calcium 261.18kg and sulfuric acid 230.58kg, the filtered filter cake can be used as activated carbon 24kg; the filtrate is reacted with sodium sulfate at a ratio of 1:1.4 to obtain precipitated calcium sulfate 320kg and sodium chloride 275.3kg, and the filtered filtrate is distilled to obtain chloride Sodium and sulfuric acid; filter cake and sodium hydroxide are reacted by 1:0.7 to obtain calcium hydroxide 175.2kg and sodium sulfate 334.4kg, after filtering sodium sulfate; filter cake and chlorine are sent into chlorination tower respectively by 1:1.1 to obtain bleaching 180.28 kg of fine powder and 97.94 kg of calcium chloride were separated to obtain a calcium chloride solution. The bleaching powder was dried, pulverized, and packaged to become a standard product.

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Abstract

The invention discloses a method for producing bleaching powder concentrate and activated carbon co-production sodium chloride and sulphuric acid by using waste gypsum mud. The method comprises the following specific steps: after being pretreated, the waste gypsum mud reacts with hydrochloric acid, a mixed solution of calcium chloride and sulphuric acid and a filter cake are obtained by filtration; the filtrate reacts with sodium sulfate to generate pure white plaster deposit and sodium chloride; a sodium chloride solution and a pure plaster filter cake are obtained by filtration; sodium chloride crystal and a sulphuric acid solution are obtained by the slight distillation of the filtrate, and the sulphuric acid solution can be made into concentrated sulfuric acid products by slight concentration; the plaster filter cake continues to react with sodium hydroxide to generate pure calcium hydroxide and a sodium sulfate solution, the sodium sulfate solution can be reused and the bleaching powder concentrate is obtained by the chlorination, separation, drying and crushing of the pure calcium hydroxide. The method effectively and reasonably utilizes chemical reaction principle to treat waste gas, waste water and waste residues and changes waste into valuables, thus not only saving the cost of treating waste acid, but also creating remarkable economic value. The method can be considered to be canonical in the comprehensive utilization of waste gas, waste water and waste residues, deeply embodies the advantage of circular economy, and simultaneously, greatly improves the deep processing capability of enterprises.

Description

Technical field: [0001] The invention relates to the technical field of comprehensive utilization of three industrial wastes, in particular to a method for manufacturing bleaching powder concentrate from waste gypsum mud and co-producing sodium chloride and sulfuric acid with activated carbon. technical background: [0002] At present, there are various waste sulfuric acid treatment methods in sulfuric acid titanium dioxide plant, but most of them use calcium carbide slag and limestone powder for neutralization and treatment. As a result, a large amount of waste gypsum mud quickly piled up like a mountain. The current amount of accumulation has become unbearable for the enterprise, so they can only be buried in ravines or pits outside. After all, it is not an option to go on like this. Apart from pollution, it also occupies a large amount of land area, which is not good for the country or the people. [0003] The enterprise sent the gypsum mud to the cement factory in orde...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B11/06C01B31/08C01B17/69C01D3/04C01F11/02
Inventor 王嘉兴
Owner LIWANG CHEM NANTONG
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