Recycling method of iron and steel multiple waste

A waste, multi-component technology, applied in the field of recycling and utilization of steel multi-component waste, can solve the problems of large floor space, ammonium sulfate crystal blockage, waste of sulfuric acid resources, etc. cost effect

Active Publication Date: 2022-01-18
武汉钢铁有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The dilute sulfuric acid produced during the carbon-based desulfurization process of coke oven flue gas has a sulfuric acid concentration of about 6-20%, and contains a small amount of iron (1-5g / L), aluminum (0.5-3g / L) and magnesium (0.2-3g / L) / L) impurity, which cannot be sent to the coking ammonium sulfate section to replace part of the sulfuric acid, mainly because the impurity content is high, and the ammonium sulfate crystallization process is blocked when entering the ammonium sulfate section. At present, dilute sulfuric acid (sulfuric acid wastewater) is a by-product of coke oven flue gas desulfurization. Discharge after acid-base neutralization, high processing cost and waste of sulfuric acid resources
[0006] To sum up, in view of the above-mentioned problems in the utilization process of desulfurization ash and chrome sludge, which are difficult to utilize as resources, occupy a large area, and easily cause secondary pollution, etc., a multi-utilization solid waste comprehensive treatment and resource utilization method was developed. , using sulfite in sintering desulfurization ash, unreacted lime and hexavalent chromium in chromium wastewater to reduce and co-precipitate, and then mixed with returned ore for sintering ingredients, truly realizing the separation of the four metallurgical wastes Harmless and resourceful utilization, to achieve the real purpose of energy saving, emission reduction and cost reduction

Method used

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  • Recycling method of iron and steel multiple waste
  • Recycling method of iron and steel multiple waste
  • Recycling method of iron and steel multiple waste

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0058] This embodiment discloses a recycling method for multiple iron and steel wastes, which includes the following specific processes:

[0059] (1) Take dilute sulfuric acid, a by-product of coking flue gas desulfurization, and add it to the chromium-containing wastewater to adjust the pH of the solution to 2 to 3; if the chromium-containing wastewater contains CrO 4 2- , then it transforms into Cr in acidic environment 2 o 7 2- ; The dilute sulfuric acid by-product of coking flue gas desulfurization contains 9.5% dilute sulfuric acid and 0.7% sulfurous acid in mass percentage.

[0060] (2) Cr in the solution obtained from step (1) 2 o 7 2- The molar concentration of 0.5mmol / L, first add the first reductant NaHSO in the solution obtained in step (1) 3 , add according to the standard of 1.2mmol / L, then add the sintered desulfurization ash according to the standard of 18g / L, the CaSO in the said sintered desulfurization ash 3 content of 270g / kg, f-CaO content of 150g / k...

Embodiment 2

[0066] This embodiment discloses a recycling method for multiple iron and steel wastes, which includes the following specific processes:

[0067] (1) Take dilute sulfuric acid, a by-product of coking flue gas desulfurization, and add it to the chromium-containing wastewater to adjust the pH of the solution to 2 to 3; if the chromium-containing wastewater contains CrO 4 2- , then it transforms into Cr in acidic environment 2 o 7 2- ; The coking flue gas desulfurization by-product dilute sulfuric acid contains 12.5% ​​dilute sulfuric acid and 1.0% sulfurous acid in mass percent.

[0068] (2) Cr in the solution obtained from step (1) 2 o 7 2- The molar concentration of 0.75mmol / L is added to the solution obtained in step (1) according to the standard of 1.8mmol / L, and then the sintered desulfurization ash is added according to the standard of 27g / L, and the CaSO in the sintered desulfurization ash 3 content of 300g / kg, f-CaO content of 150g / kg to the solution Cr 2 o 7 2...

Embodiment 3

[0074] This embodiment discloses a recycling method for multiple iron and steel wastes, which includes the following specific processes:

[0075] (1) Take dilute sulfuric acid, a by-product of coking flue gas desulfurization, and add it to the chromium-containing wastewater to adjust the pH of the solution to 2 to 3; if the chromium-containing wastewater contains CrO 4 2- , then it transforms into Cr in acidic environment 2 o 7 2- ; The coking flue gas desulfurization by-product dilute sulfuric acid contains 15% dilute sulfuric acid and 1.2% sulfurous acid in mass percent.

[0076] (2) Cr in the solution obtained from step (1) 2 o 7 2- The molar concentration of 1.0mmol / L is added to the solution obtained in step (1) according to the standard of 2.4mmol / L, and then the sintered desulfurization ash is added according to the standard of 36g / L, and the CaSO in the sintered desulfurization ash 3 The content is 350g / kg, and the content of f-CaO is 250g / kg to Cr in the soluti...

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Abstract

The invention discloses a method for recycling iron and steel multi-component waste, which belongs to the technical field of ironmaking waste utilization. The method comprises the steps of taking chromium-containing waste water and sintering desulfurization ash to undergo oxidation-reduction reaction under the action of dilute sulfuric acid, a by-product of coking flue gas desulfurization, to obtain chromium sludge, and mixing the chromium sludge with returned ore as sintering ingredients. Compared with the traditional desulfurization ash, chromium-containing sewage, waste sulfuric acid and returning ore utilization and recycling treatment methods, this method has the advantages of thorough treatment effect and no secondary pollution to the society.

Description

technical field [0001] The invention relates to the comprehensive treatment and resource utilization of iron and steel multi-element waste, which belongs to the technical field of ironmaking, and in particular relates to a recycling method for iron and steel multi-element waste. Background technique [0002] With the large-scale promotion and utilization of the semi-dry SDA desulfurization process in various iron and steel plants, the comprehensive utilization of desulfurization ash has gradually been put on the agenda. Desulfurization ash is in the sintering / pellet flue gas desulfurization process, the lime milk slurry reacts rapidly with the flue gas and fluoride in the desulfurization tower, and absorbs SO 2 products after desulfurization. The desulfurization ash is mainly composed of CaSO produced by the desulfurization process. 3 , CaSO 4 , CaCl 2 , CaF 2 and its unreacted Ca(OH) 2 and flue fly ash free f-CaO, etc., where CaSO 3 About 30%-45%; free f-CaO and CaSO...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B09B3/00B09B5/00
CPCB09B3/00B09B5/00
Inventor 张垒赵春晖王丽娜刘尚超林义刘璞付本全卢丽君
Owner 武汉钢铁有限公司
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