The method and application of recovering tungsten from waste scr catalyst regenerated spent caustic soda

A technology of SCR catalyst and waste lye, which is applied in the field of tungsten recovery, can solve the problems of waste of resources, impact on metal recovery, and impact on recovery efficiency of tungsten elements, and achieve the effect of improving separation efficiency and saving consumption

Active Publication Date: 2021-09-28
INST OF PROCESS ENG CHINESE ACAD OF SCI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During the leaching process, some valuable metals in the spent SCR denitrification catalyst will be dissolved in the leach solution, and if this part of the leach solution is directly discharged, it will cause a waste of resources
At the same time, some impurities will also be mixed into the leach solution, which will affect the recovery of valuable metals in the leach solution. For example, when recovering tungsten, the arsenic element mixed into the leach solution will increase the recovery of tungsten. Difficulty of element process and influence on recovery efficiency of tungsten element

Method used

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  • The method and application of recovering tungsten from waste scr catalyst regenerated spent caustic soda

Examples

Experimental program
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Effect test

Embodiment 1

[0039] This embodiment provides a method for recovering tungsten from spent SCR catalyst regenerated spent lye, said method comprising the following steps:

[0040] The waste lye was sampled and tested to obtain the concentrations of sodium hydroxide, tungsten, arsenic, silicon and phosphorus in the waste lye.

[0041] Take a preset volume of spent lye, evaporate and concentrate the spent lye until the mass concentration of sodium hydroxide is 20wt.%, to obtain a concentrated solution, cool down the concentrated solution, crystallize and filter, and obtain pretreated crystallization and recovery solution. Wherein, the temperature range for the crystallization and filtration of the concentrated solution is 45°C to 50°C.

[0042] Deionized water is used to fully dissolve the pretreatment crystals to obtain a pretreatment solution. Wherein, the quality of the added deionized water is 1.5 times of the quality of the pretreated crystals.

[0043] A sulfuric acid solution is added...

Embodiment 2

[0050] This embodiment provides a method for recovering tungsten from spent SCR catalyst regenerated spent lye, said method comprising the following steps:

[0051] The waste lye was sampled and tested to obtain the concentrations of sodium hydroxide, tungsten, arsenic, silicon and phosphorus in the waste lye.

[0052] Take a preset volume of spent lye, evaporate and concentrate the spent lye until the mass concentration of sodium hydroxide is 20wt.%, to obtain a concentrated solution, cool down the concentrated solution, crystallize and filter, and obtain pretreated crystallization and recovery solution. Wherein, the temperature range for cooling the concentrated solution for crystallization and filtration is 45°C to 50°C.

[0053] Deionized water is used to fully dissolve the pretreatment crystals to obtain a pretreatment solution. Wherein, the quality of the added deionized water is 3.0 times of the pretreatment crystal quality.

[0054] Sulfuric acid solution is added to...

Embodiment 3

[0061] This embodiment provides a method for recovering tungsten from spent SCR catalyst regenerated spent lye, said method comprising the following steps:

[0062] The waste lye was sampled and tested to obtain the concentrations of sodium hydroxide, tungsten, arsenic, silicon and phosphorus in the waste lye.

[0063] Take a preset volume of spent lye, evaporate and concentrate the spent lye until the mass concentration of sodium hydroxide is 20wt.%, to obtain a concentrated solution, cool down the concentrated solution, crystallize and filter, and obtain pretreated crystallization and recovery solution. Wherein, the temperature range for cooling the concentrated solution for crystallization and filtration is 45°C to 50°C.

[0064] Deionized water is used to fully dissolve the pretreatment crystals to obtain a pretreatment solution. Wherein, the quality of the added deionized water is 3.0 times of the pretreatment crystal quality.

[0065] Sulfuric acid solution is added to...

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Abstract

This application discloses the method and application of recovering tungsten from the regenerated waste lye of waste SCR catalyst. The method of evaporative concentration and crystallization is used to separate tungsten and other substances from the alkaline solution, and the concentration of sodium hydroxide in the process of evaporative concentration is controlled. , Effectively improve the separation efficiency of tungsten and other substances. Then acid treatment is used to remove carbonate ions, magnesium sulfate is added to remove impurities, and calcium oxide is added to separate tungsten elements to obtain scheelite concentrate. The way of adding acid to remove carbonate ions first can avoid the consumption of magnesium sulfate in the subsequent process of carbonate ions; the contents of arsenic, silicon and phosphorus elements are all counted and then added to the secondary treatment solution. Magnesium sulfate, to avoid the existence of silicon and phosphorus elements, resulting in insufficient precipitation of arsenic elements. The method for recovering tungsten in this application can realize the precipitation rate of tungsten element in the waste lye solution greater than 91%, the recovered product scheelite concentrate has no arsenic element detected, and the content of tungsten trioxide is greater than 65%.

Description

technical field [0001] This application relates to the technical field of secondary resource utilization, in particular to a method and application for recovering tungsten from spent SCR catalyst regenerated waste lye. Background technique [0002] In coal-fired power plants, the denitrification activity of SCR catalysts for denitrification gradually decreases due to the poisoning of active components, aging and other reasons with the increase of operating time. When the activity is lower than the design deactivation threshold, it must be replaced layer by layer. At present, commercial SCR denitration catalysts are vanadium-titanium catalysts, and their main components include 80~85wt% TiO 2 , 0.5%~1wt%V 2 o 5 , 4~10wt%WO 3 , and SiO 2 、Al 2 o 3 and other structural auxiliary components. The V, W contained in the waste SCR denitration catalyst and the heavy metals such as Fe, As, Pb adsorbed during use will cause serious harm to the environment. At the same time, val...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B34/36C22B7/00
CPCC22B7/008C22B34/365Y02P10/20
Inventor 王兴瑞王晨晔李会泉
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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