Method for fully recovering silicon dioxide in waste SCR (Selective Catalyst Reduction) catalyst

A SCR catalyst and silica technology, applied in the field of flue gas denitrification, can solve the problem of inapplicable metal oxide recovery, etc., and achieve the effect of realizing recycling and utilization, saving investment, product quality and high recovery efficiency

Inactive Publication Date: 2015-01-07
沈阳远大固废处理有限公司
View PDF5 Cites 29 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is a method for recovering metals from waste petroleum refining catalysts under the basic condition of not dissolving a significant amount of catalyst, and its catalyst composition is quite different from that of waste SCR catalysts, so it cannot be applied to the recovery of metal oxides in waste SCR catalysts

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] In the waste SCR catalyst of the present embodiment, mainly include: V 2 o 5 Accounting for 1.34wt%, WO 3 Accounting for 3.02wt%, TiO 2 85wt%, SiO 2 Accounting for 7.5wt%, Fe 2 o 3 Accounting for 0.36wt%, Al 2 o 3 It accounts for 0.58wt%, and the rest are unavoidable impurity elements. The specific steps for fully recovering silica in the waste SCR catalyst are as follows:

[0044] 1) Pulverization: Pulverize the spent catalyst to 150 mesh and set aside.

[0045] 2) Soak powder in water to remove impurities: Soak the crushed waste SCR catalyst with 3.5 times the volume of water to remove the adsorbed arsenic, mercury, alkali metal salts and organic substances, and the filtered wastewater is adsorbed by activated carbon to absorb arsenic, mercury and organic substances. Substances can be recycled.

[0046] 3) Leaching: add 5 times the volume of NaOH aqueous solution with a concentration of 70wt% to the wet powder after removal of impurities, heat to 145 ° C, soa...

Embodiment 2

[0066] In the waste SCR catalyst of the present embodiment, mainly include: V 2 o 5 Accounting for 1.34wt%, WO 3 Accounting for 3.02wt%, TiO 2 85wt%, SiO 2 Accounting for 7.5wt%, Fe 2 o 3 Accounting for 0.36wt%, Al 2 o 3 It accounts for 0.58wt%, and the rest are unavoidable impurity elements. The specific steps for fully recovering silica in the waste SCR catalyst are as follows:

[0067] 1) Pulverization: pulverize the spent catalyst to 200 mesh, and set aside.

[0068] 2) Soak powder in water to remove impurities: Soak the crushed waste SCR catalyst with 3 times the volume of water to remove the adsorbed arsenic, mercury, alkali metal salts and organic substances, and the filtered waste water is adsorbed by activated carbon to absorb arsenic, mercury and organic substances. Substances can be recycled.

[0069] 3) Leaching: add 4 times the volume of NaOH aqueous solution with a concentration of 75wt% to the wet powder after removal of impurities, heat to 142 ° C, and...

Embodiment 3

[0089] In the waste SCR catalyst of the present embodiment, mainly include: V 2 o 5 Accounting for 1.34wt%, WO 3 Accounting for 3.02wt%, TiO 2 85wt%, SiO 2 Accounting for 7.5wt%, Fe 2 o 3 Accounting for 0.36wt%, Al 2 o 3 It accounts for 0.58wt%, and the rest are unavoidable impurity elements. The specific steps for fully recovering silica in the waste SCR catalyst are as follows:

[0090] 1) Pulverization: Pulverize the spent catalyst to 300 mesh and set aside.

[0091] 2) Soak powder in water to remove impurities: Soak the crushed waste SCR catalyst in 4 times the volume of water to remove the adsorbed arsenic, mercury, alkali metal salts and organic substances, and the filtered waste water is adsorbed by activated carbon Substances can be recycled.

[0092] 3) Leaching: Add 6 times the volume of NaOH aqueous solution with a concentration of 65wt% to the wet powder after removal of impurities, heat to 148°C, and soak for 3.5 hours to make the TiO 2 , V 2 o 5 、WO ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to the field of smoke denitration, in particular to a method for fully recovering silicon dioxide in a waste SCR (Selective Catalyst Reduction) catalyst. The method comprises the following steps: soaking the pulverized waste SCR catalyst with three to four times of water to remove impurities, leaching powder from which the impurities are removed with excessive thick alkaline solution with the concentration of 60-80wt%, filtering to obtain a Na2TiO3 solid, adding sulfuric acid into filtrate, regulating pH to 11.5-12.5 at a temperature of 70-90 DEG C, leaving the mixture to stand for 0.5-1h, filtering, and discarding filter cakes; adding sulfuric acid into the filtrate until the pH is regulated to 9-10 to obtain the silicate filter cakes, heating and stirring the silicate filter cakes in mixed acid of dilute sulfuric acid and oxalic acid at a temperature of 40-60 DEG C for 1-2h, filtering, washing the filter cakes with deionized water, washing off acid radical ions in the solid, and obtaining high-purity silicon dioxide through heating and decomposition. Therefore, the recovery of the silicon dioxide in the waste SCR catalyst can be realized without a roasting process.

Description

technical field [0001] The invention relates to the field of flue gas denitrification, in particular to a method for completely recovering silicon dioxide in waste SCR catalysts. Background technique [0002] Nitrogen oxides are the main substances that form acid rain and photochemical smog, and their emissions mainly come from power plants. The control of nitrogen oxides is mainly divided into pre-combustion and post-combustion. The pre-combustion control technologies mainly include low-nitrogen combustion and re-combustion technologies; the post-combustion control technologies mainly include wet and dry methods, and the selective catalytic reduction method ( SCR) flue gas denitrification technology is popular because of its high denitrification rate, low cost, and good selection. It is currently the most widely used denitrification technology in industry. [0003] At present, the most widely used SCR flue gas denitrification catalyst is TiO 2 is an effective carrier for ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/12C01G23/00
CPCY02P20/584
Inventor 李锋黄动昊吕腾飞杨俊杰
Owner 沈阳远大固废处理有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap