Process for comprehensive recovery of metal-containing oxides in disabled SCR (selective catalytic reduction) denitration catalyst

A denitration catalyst and oxide technology, applied in the direction of improving process efficiency, can solve the problems of valuable metal resources failing to be recycled, occupying land resources, waste of effective resources, etc. Effect

Inactive Publication Date: 2015-06-24
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Catalysts based on titanium oxide are widely used at present. If these waste catalysts are piled up randomly without disposal, on the one hand, it will occupy a large amount of land resources and increase the cost of the enterprise; Some toxic and harmful substances adsorbed enter the natural environment, especially water bodies, causing serious harm to the environment; the various valuable metal resources contained in the discarded catalysts have not been recycled, which also causes a huge waste of effective resources

Method used

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  • Process for comprehensive recovery of metal-containing oxides in disabled SCR (selective catalytic reduction) denitration catalyst

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] A comprehensive recovery process for metal oxides contained in spent SCR denitrification catalysts, the process flow is shown in figure 1 , the specific process is as follows:

[0029] 1. Raw material pretreatment: Take the invalid denitrification catalyst and wash it with ultrasonic and bubbling water to wash off the loads such as residual ash and soluble inorganic matter on the surface, put it into the electric furnace, and carry out high-temperature roasting at 650°C. Remove carbon deposits, arsenic and organic impurities that may be adsorbed on the surface, and keep the temperature constant for 4 hours.

[0030] 2. Pulverization: Add the denitrification catalyst after high-temperature roasting into a crusher, and pulverize it to a particle size of ≤200 μm to obtain a uniform powder.

[0031] 3. Sodium solution dissolution: Mix the powder obtained in the previous step with NaOH solution at a ratio of 1g:5ml for reaction, and the concentration of NaOH solution is 600...

Embodiment 2

[0037] 1. Raw material pretreatment: Take the invalid denitrification catalyst and wash it with ultrasonic and bubbling water to wash off the loads such as residual ash and soluble inorganic matter on the surface, put it into the electric furnace, and carry out high-temperature roasting at 650°C. Remove carbon deposits, arsenic and organic impurities that may be adsorbed on the surface, and keep the temperature constant for 4 hours.

[0038] 2. Pulverization: Add the denitrification catalyst after high-temperature roasting into a crusher, and pulverize it to a particle size of ≤200 μm to obtain a uniform powder.

[0039] 3. Dissolving in sodium solution: Mix the powder obtained in the previous step with NaOH solution at a ratio of 1g:6ml, and the concentration of NaOH solution is 500g / L. Add co-solvent Na to the mixture 2 CO 3 , the amount of co-solvent added is twice the mass of the powder, heated at a constant temperature at 100°C and stirred for 90 minutes to obtain a sol...

Embodiment 3

[0045] 1. Raw material pretreatment: Take the invalid denitrification catalyst and wash it with ultrasonic and bubbling water to wash off the loads such as residual ash and soluble inorganic matter on the surface, put it into the electric furnace, and carry out high-temperature roasting at 650°C. Remove carbon deposits, arsenic and organic impurities that may be adsorbed on the surface, and keep the temperature constant for 4 hours.

[0046] 2. Pulverization: Add the denitrification catalyst after high-temperature roasting into a crusher, and pulverize it to a particle size of ≤200 μm to obtain a uniform powder.

[0047] 3. Sodium solution dissolution: Mix the powder obtained in the previous step with NaOH solution at a ratio of 1g:4ml for reaction, and the concentration of NaOH solution is 400g / L. Add co-solvent Na to the mixture 2 CO 3 , the amount of co-solvent added is 3 times the mass of the powder, heated at a constant temperature at 80°C and stirred for 60 minutes to ...

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Abstract

The invention relates to a method for disposal and recovery of wastes and particularly relates to a process for comprehensive recovery of metal-containing oxides in a disabled SCR (selective catalytic reduction) denitration catalyst. The process for comprehensive recovery of the metal-containing oxides in the disabled SCR denitration catalyst comprises the following steps: (1) performing pretreatment on raw materials: performing sweeping, ultrasonic treatment, bubbling and water washing on the disabled SCR denitration catalyst and performing high-temperature roasting at the temperature of 500-700 DEG C; (2) crushing: crushing the SCR denitration catalyst after high-temperature roasting, and crushing till the particle size is not more than 200 mu m to obtain uniform powder; (3) dissolving in a sodium solution; (4) separating and extracting titanium; (5) separating and extracting vanadium; and (6) reutilizing tungsten. By using the process provided by the invention, the yield of the metal oxides in the disabled SCR denitration catalyst is higher, wherein the recovery rate of TiO2 can be 95% or more, the recovery rate of V2O5 can be 95% or more, and the yield of a sodium tungstate product can be 98% or more.

Description

technical field [0001] The invention relates to a waste disposal and recovery method, in particular to a comprehensive recovery process for metal oxides contained in an invalid SCR denitration catalyst. Background technique [0002] The principle of Selective Catalytic Reduction (SCR) is that under the action of a catalyst, the reducing agent NH 3 At 290-400°C, NO and NO 2 reduced to N 2 , while NH hardly occurs 3 oxidation reaction, thereby increasing the N 2 selectivity, reducing the NH 3 consumption. The SCR system is composed of ammonia supply system, ammonia / air injection system, catalytic reaction system, and control system. In order to avoid the energy consumption of flue gas reheating, the SCR reactor is generally placed after the economizer and before the air preheater. That is, the layout of the high dust section. Ammonia gas is added in the horizontal pipe before the air preheater and mixed with the flue gas. Due to the mature technology and high denitrifi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B34/12C22B34/36C22B34/22
CPCY02P10/20
Inventor 高翔骆仲泱岑可法倪明江宋浩吴卫红唐丁玲徐甸余鸿敏施正伦周劲松
Owner ZHEJIANG UNIV
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