Hot-dip galvanizing waste acid resource treatment method

A treatment method, hot-dip galvanizing technology, which is applied in metallurgical wastewater treatment, energy wastewater treatment, chemical instruments and methods, etc., can solve the problems of inability to effectively recycle waste acid iron, inability to promote industrial application, and high cost, so as to facilitate recycling , Efficient recycling, and the effect of reducing the workload

Pending Publication Date: 2017-04-26
QINGDAO NORTH ENERGY & ENVIRONMENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a hot-dip galvanizing waste acid resource treatment method and its device, which solves the problem that the iron in the waste acid cannot be effectively recovered in the existing method, or the cost of the recovery process is too high to be popularized and applied in an industrialized manner

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  • Hot-dip galvanizing waste acid resource treatment method

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Effect test

Embodiment 1

[0038] The composition of waste acid in a hot-dip galvanizing plant is as follows:

[0039] List of waste acid components (concentration unit: mg / L)

[0040] components Fe 2+

Fe 3+

Ni sn total copper total zinc Pb acidity concentration 120000 5000 200 1.59 15.4 16.4 40 55370

[0041] Process flow of waste hydrochloric acid:

[0042] (1) Collect the volatile acid mist in the upper part of the acid mist collection pool 1 through the induced draft fan to the acid mist absorption tower absorption 2 to form acid liquid, and the acid liquid enters the first medium through the liquid outlet of the acid mist absorption tower absorption 2 And in the reaction pool 3;

[0043] (2) Add sodium chlorate (mass fraction 28%) and sodium hydroxide (mass fraction 30%) in the first neutralization reaction tank 3 to adjust pH to 4.5, and sodium chlorate oxidizes ferrous ion to ferric iron According to the solubility product constant of metal io...

Embodiment 2

[0048] The composition of waste acid in a hot-dip galvanizing plant is as follows:

[0049] List of waste acid components (concentration unit: mg / L)

[0050] components Fe 2+

Fe 3+

Ni total copper total zinc Pb acidity concentration 200000 1000 285 15.4 2000 40 55370

[0051] Process flow of waste hydrochloric acid:

[0052] (1) Collect the volatile acid mist in the upper part of the acid mist collection pool 1 through the induced draft fan to the acid mist absorption tower absorption 2 to form acid liquid, and the acid liquid enters the first medium through the liquid outlet of the acid mist absorption tower absorption 2 And in the reaction pool 3;

[0053] (2) Add sodium chlorate (mass fraction 28%) and sodium hydroxide (mass fraction 30%) in the first neutralization reaction tank 3 to adjust pH to 4.5, and sodium chlorate oxidizes ferrous ion to ferric iron According to the solubility product constant of metal ions, ferric ...

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Abstract

The invention discloses a hot-dip galvanizing waste acid resource treatment method, which comprises: (1) adding an oxidizing agent to hot-dip galvanizing waste acid to oxidize Fe<2+> ions in the waste acid into Fe<3+> ions, adjusting the pH value of the waste acid to 4.5, generating Fe(OH)3 precipitate from the Fe<3+>, carrying out solid-liquid separation, recovering the Fe(OH)3 precipitate, and performing the next step on the filtrate; (2) adjusting the pH value of the filtrate obtained in the step (1) to 9.5, generating the corresponding insoluble salt precipitate from the heavy metal ions, carrying out solid-liquid separation, and performing the next step on the filtrate; and (3) adjusting the pH value of the filtrate obtained in the step (2) to a neutral pH value, heating and evaporating the filtrate, carrying out crystallizing precipitating and recovering on the soluble salt in the filtrate, and reusing the condensed water produced during the evaporation process. According to the present invention, with the method, the separation between the iron and the heavy metal and the efficient recovery of the iron are achieved, the heavy metal hazardous waste achieves the decrement treatment requirement, the operating cost of the whole system is reduced, the workload of the follow-up treatment unit is reduced, and the zero discharging treatment of the waste acid is achieved.

Description

technical field [0001] The invention belongs to the technical field of waste acid treatment and resource recycling, and in particular relates to a hot-dip galvanizing waste acid resource treatment method and a device used therefor. [0002] technical background [0003] In the hot-dip galvanizing process, the surface of the plated parts is firstly treated, and the metal surface is repeatedly washed with hydrochloric acid to remove oil and oxides. When the metal ion content in the hydrochloric acid reaches a certain concentration, waste acid (acidic waste liquid) is formed. At present, there are two main treatment methods for waste acid: one is the acid-base neutralization method, adding alkali to precipitate metal ions and neutralize the acid in the solution, and the precipitated metal ions are treated as sludge by the sludge treatment plant. This solution not only wastes useful ferric chloride resources, but also significantly increases the salt content in the wastewater dis...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/10C02F11/12B01D53/14C22B7/00C02F103/16
CPCB01D53/1456C22B7/006C02F9/00C02F11/122C02F1/76C02F1/66C02F2001/5218C02F2103/16C02F2301/08C02F1/04C02F1/02Y02W10/37
Inventor 刘瑞聪孟宪礼马准柯爌琼孙德林黄成慧
Owner QINGDAO NORTH ENERGY & ENVIRONMENT
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