A systematic evaluation method for vanadium leaching characteristics in catalysts
By testing and calculating the leaching characteristics of vanadium in the catalyst, using a variety of solutions and weight coefficient methods, the accuracy of leaching characteristics of vanadium element in the catalyst is solved, and an effective judgment of the hazards of waste catalysts is achieved.
Patent Information
- Application Number
- CN202310047062.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-01-31
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2043-01-31
AI Technical Summary
The prior art lacks systematic methods to evaluate the leaching characteristics of vanadium elements in catalysts, resulting in the inability to accurately judge the hazards of waste catalysts and affect environmental safety.
By testing the original vanadium content and the vanadium content after impregnation of the dry catalyst, the vanadium leaching coefficient and comprehensive leaching characteristics were calculated, and a variety of immersion solutions were used for evaluation, including sulfuric acid and sodium hydroxide solutions, and the leaching risk of vanadium was calculated based on the weight coefficient.
It provides an accurate method for evaluating vanadium element leaching characteristics, a simple operating process, suitable for industrial promotion, and can effectively judge the risk level of waste catalysts.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of analysis, testing and evaluation, and particularly relates to a systematic evaluation method for vanadium element leaching characteristics in a catalyst. Background Art
[0002] Selective catalytic reduction (SCR) technology is widely used in the denitrification sector, with vanadium being the primary active element in the catalyst. Vanadium is highly reactive and easily leached from the catalyst, potentially escaping into the environment and causing environmental damage. Consequently, spent catalysts are classified as hazardous waste. In practice, the storage environments and leaching conditions of spent catalysts vary widely. However, there is currently no reliable method for evaluating the leaching characteristics of vanadium in catalysts, making it impossible to clearly identify the hazards of spent catalysts generated by different projects.
[0003] In view of this, it is very necessary and important to develop a comprehensive and systematic evaluation method for the leaching characteristics of vanadium in catalysts. Summary of the Invention
[0004] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a systematic evaluation method for the leaching characteristics of vanadium in catalysts.
[0005] In order to achieve the above-mentioned purpose and the above-mentioned technical effect, the technical solution adopted by the present invention is:
[0006] A method for systematically evaluating the leaching characteristics of vanadium in a catalyst comprises the following steps:
[0007] Test the original vanadium content in the dried catalyst and keep records;
[0008] The vanadium content after immersion was tested in two groups:
[0009] One group is to divide the catalyst into two parts, one part is used to calculate the water absorption rate X, and the other part is immersed in at least two different impregnation solutions. After drying, the vanadium content after impregnation is tested and recorded;
[0010] The remaining group impregnated the dried catalyst into at least two different impregnation solutions, dried it, and tested the vanadium content after impregnation, and kept records;
[0011] Calculate the vanadium leaching coefficients corresponding to the two different impregnation solutions;
[0012] The coefficient P corresponding to the vanadium leaching coefficient i The comprehensive leaching characteristic D is calculated with the weight coefficient and used to evaluate the vanadium leaching characteristics.
[0013] In a systematic evaluation method for vanadium leaching characteristics in a catalyst provided by the present invention, the catalyst is dried at 80-420° C. for 1-5 hours before testing the original vanadium content in the catalyst.
[0014] In a systematic evaluation method for vanadium leaching characteristics in a catalyst provided by the present invention, a group of steps includes dividing the catalyst into two parts, one part is used to calculate the water absorption rate X, and the other part is immersed in at least two different impregnation solutions. After drying, the vanadium content after impregnation is tested and recorded. The steps include:
[0015] 1) Take two identical catalyst samples and dry them at 80-420°C for 1-5 hours;
[0016] 2) Weigh the first catalyst and record it as w1';
[0017] 3) Immersing the catalyst in deionized water;
[0018] 4) After taking it out of the water, gently shake off the residual water on the wall and weigh it immediately, recording it as w2';
[0019] 5) Water absorption rate X = (w2'-w1') / w1';
[0020] 6) Weigh the second catalyst and record it as w1;
[0021] 7) Testing the original vanadium content V1 of the catalyst;
[0022] 8) Measure a volume of w1×X of standard impregnation solution and allow the second catalyst to absorb it completely;
[0023] 9) After absorption is completed, let it stand for 1 hour, and then dry it at 80-420℃ for 1-5 hours;
[0024] 10) Cooling the dried catalyst to room temperature, and then immersing it in deionized water;
[0025] 11) drying the impregnated catalyst sample at 80-420° C. for 1-5 hours, and then measuring the vanadium content V2 after impregnation;
[0026] 12) Calculate V2 / V1 to obtain a leaching coefficient greater than 0 and less than 1;
[0027] The impregnation solutions in step 8) are two standard impregnation solutions A and B, and the above steps 1) to 12) are performed respectively to obtain two sets of leaching coefficient data.
[0028] In the method for systematically evaluating the vanadium leaching characteristics of a catalyst provided by the present invention, the remaining group comprises the steps of immersing the dried catalyst in at least two different impregnation solutions, drying the catalyst, testing the vanadium content after impregnation, and recording the results. The steps include:
[0029] Weigh the catalyst and record it as w3;
[0030] Measure 5-20 times the volume of w3 of the standard impregnation solution and impregnate the catalyst sample for 0.5-2 hours;
[0031] The impregnated catalyst was dried at 80-420°C for 1-5 hours, and then the vanadium content after impregnation was tested and recorded.
[0032] In a systematic evaluation method for the leaching characteristics of vanadium elements in a catalyst provided by the present invention, the impregnation solutions include two types, namely standard impregnation solution A and standard impregnation solution B. The standard impregnation solution A is a 0.5-2 mol / L sulfuric acid solution, and the standard impregnation solution B is a 0.5-2 mol / L sodium hydroxide solution.
[0033] In the method for systematically evaluating the vanadium leaching characteristics in a catalyst provided by the present invention, the vanadium leaching coefficient is the ratio of the vanadium content after immersion to the original vanadium content.
[0034] In the method for systematically evaluating the leaching characteristics of vanadium in a catalyst provided by the present invention, the coefficient P i The calculation formula is:
[0035] P i =-ln(1-p i )
[0036] Where p i is the vanadium leaching coefficient.
[0037] In the system evaluation method for vanadium leaching characteristics in a catalyst provided by the present invention, the calculation formula of the comprehensive leaching characteristic D is:
[0038] D=∑P i ×N i
[0039] Where N i is the weight coefficient; D ranges from 0 to 5, and the smaller the value, the higher the risk of vanadium leaching.
[0040] Compared with the prior art, the present invention has the following beneficial effects:
[0041] The present invention discloses a systematic evaluation method for the leaching characteristics of vanadium in catalysts. The method provides relatively accurate evaluation results of the leaching characteristics of vanadium in catalysts, provides technical guidance for determining the hazard level of discarded catalysts, has a simple overall operation process, comprehensively covers actual situations, and is suitable for industrial promotion and use. DETAILED DESCRIPTION
[0042] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.
[0043] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.
[0044] Example 1
[0045] A systematic evaluation method for the leaching characteristics of vanadium in a catalyst is disclosed, wherein the leaching characteristics of vanadium in a catalyst are comprehensively evaluated by method one and method two.
[0046] Method 1 includes the following steps:
[0047] 1) Take two identical catalyst samples and dry them at 110°C for 3 hours.
[0048] 2) Weigh the first piece of catalyst and record it as w1'.
[0049] 3) Soak the catalyst in deionized water for 15 minutes.
[0050] 4) After taking it out of the water, gently shake off the residual water on the wall and weigh it immediately, recording it as w2'.
[0051] 5) Water absorption rate X = (w2'-w1') / w1'
[0052] 6) Weigh the second catalyst and record it as w1.
[0053] 7) Test the original vanadium content V1 of the catalyst.
[0054] 8) Measure a volume of w1×X of standard impregnation solution and allow the second catalyst to absorb it completely.
[0055] 9) After absorption is completed, let it stand for 1 hour, and then dry it at 110℃ for 3 hours.
[0056] 10) After the dried catalyst is cooled to room temperature, it is immersed in deionized water with a mass 10 times that of w1 for 15 minutes.
[0057] 11) The impregnated catalyst sample was dried at 110° C. for 3 h, and then the vanadium content V2 after impregnation was measured.
[0058] 12) Calculate V2 / V1 and obtain a leaching coefficient greater than 0 and less than 1.
[0059] The impregnation solutions in step 8) are two standard impregnation solutions A and B, and the above steps 1) to 12) are performed respectively to obtain two sets of leaching coefficient data.
[0060] Method 2 includes the following steps:
[0061] 1) Take a catalyst sample and dry it at 110°C for 3 hours.
[0062] 2) The original vanadium content of the catalyst was tested and recorded as V3.
[0063] 3) Weigh the catalyst and record it as w3.
[0064] 4) Measure 10 times the volume of w3 of the standard impregnation solution and immerse the catalyst sample for 1 hour.
[0065] 5) The impregnated catalyst sample was dried at 110° C. for 3 h, and then the vanadium content V4 after impregnation was measured.
[0066] 6) Calculate V4 / V3 to obtain a leaching coefficient greater than 0 and less than 1.
[0067] The impregnation solutions in step 4) are two standard impregnation solutions A and B, and the above steps 1) to 5) are respectively carried out to obtain two sets of leaching coefficient data.
[0068] A standard immersion solution:
[0069] 98% concentrated sulfuric acid and desalted water were used as raw materials to prepare a 1 mol / L sulfuric acid solution.
[0070] B standard immersion solution:
[0071] Sodium hydroxide and desalted water are used as raw materials to prepare a 1 mol / L sodium hydroxide solution.
[0072] The residual proportion of vanadium is denoted as p i The vanadium residual proportions obtained by using the two standard impregnation solutions A and B for method 1 and method 2 are recorded as p1, p2, p3, and p4, respectively.
[0073] Take the logarithm and get the coefficient P i , P i=-ln(1-p i ).
[0074] Let the weight coefficient be N i The weight coefficients obtained by using two standard impregnation solutions A and B for method one and method two are recorded as N1, N2, N3, and N4, respectively, N1=0.45, N2=0.30, N3=0.15, and N4=0.10.
[0075] The calculation formula for comprehensive leaching characteristics D is:
[0076] D=∑P i ×N i , where i = 1, 2, 3, 4
[0077] Generally, D ranges from 0 to 5, and the smaller the value, the higher the risk of vanadium leaching.
[0078] If D is less than 1, the vanadium in the catalyst is in the dangerous range of easy leaching;
[0079] If D is greater than 2, the vanadium in the catalyst is in a range with low leaching risk.
[0080] The catalyst of a certain project was subjected to a vanadium leaching characteristic test according to the method of Example 1. The results are shown in Table 1 below.
[0081] The method 1 using standard impregnation solution A was marked as group IA, the method 1 using standard impregnation solution B was marked as group IB, the method 2 using standard impregnation solution A was marked as group OA, and the method 2 using standard impregnation solution B was marked as group OB.
[0082] Table 1
[0083] Group IA IB Group OA group OB Group <![CDATA[Initial V2O5 content (%)]]> 0.52 0.55 0.54 0.56 <![CDATA[V2O5 content after treatment (%)]]> 0.45 0.43 0.5 0.47 <![CDATA[p i ]]> 86.5％ 78.2％ 92.6％ 83.9％ <![CDATA[P i ]]> 2.002 1.523 2.604 1.826 <![CDATA[N i ]]> 0.45 0.30 0.15 0.10 Weighted value 0.90 0.46 0.39 0.18 D 1.93
[0084] The comprehensive leaching characteristic D is 1.93, and the comprehensive evaluation of vanadium leaching characteristics is: generally small.
[0085] Example 2
[0086] The catalyst of a certain project was subjected to a vanadium leaching characteristic test according to the method of Example 1. The results are shown in Table 2 below.
[0087] Table 2
[0088] Group IA IB Group OA group OB Group <![CDATA[Initial V2O5 content (%)]]> 0.77 0.78 0.78 0.75 <![CDATA[V2O5 content after treatment (%)]]> 0.41 0.34 0.59 0.52 <![CDATA[p i ]]> 53.2％ 43.6％ 75.6％ 69.3％ <![CDATA[P i ]]> 0.759 0.573 1.411 1.181 <![CDATA[N i ]]> 0.45 0.30 0.15 0.10 Weighted value 0.34 0.17 0.21 0.12 D 0.84
[0089] The comprehensive leaching characteristic D is 0.84, and the comprehensive evaluation of vanadium leaching characteristics is: large.
[0090] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.
[0091] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A method for systematically evaluating the leaching characteristics of vanadium in catalysts, characterized in that: The following steps are involved: Test the original vanadium content in the dried catalyst and keep records; The vanadium content after immersion was tested in two groups: One group is to divide the catalyst into two parts, one part is used to calculate the water absorption rate X, and the other part is immersed in at least two different impregnation solutions. After drying, the vanadium content after impregnation is tested and recorded; The remaining group impregnated the dried catalyst into at least two different impregnation solutions, dried it, and tested the vanadium content after impregnation, and kept records; Calculate the vanadium leaching coefficients corresponding to the two different impregnation solutions; The coefficient P corresponding to the vanadium leaching coefficient i The comprehensive leaching characteristic D is calculated with the weight coefficient and used to evaluate the vanadium leaching characteristics.
2. The method for systematically evaluating the vanadium leaching characteristics of a catalyst according to claim 1, characterized in that: Before testing the original vanadium content in the catalyst, the catalyst was dried at 80-420°C for 1-5 hours.
3. The method for systematically evaluating the leaching characteristics of vanadium in a catalyst according to claim 1, characterized in that: One group is to divide the catalyst into two parts, one part is used to calculate the water absorption rate X, and the other part is impregnated in at least two different impregnation solutions. After drying, the vanadium content after impregnation is tested and recorded. The steps include: 1) Take two identical catalyst samples and dry them at 80-420°C for 1-5 hours; 2) Weigh the first catalyst and record it as w1 ’ ; 3) Immersing the catalyst in deionized water; 4) After taking it out of the water, gently shake off the remaining water on the wall and weigh it immediately, record it as w2 ’ ; 5) Water absorption rate X = (w2 ’ -w1 ’ ) / w1 ’ ; 6) Weigh the second catalyst and record it as w1; 7) Testing the original vanadium content V1 of the catalyst; 8) Measure a volume of w1×X of standard impregnation solution and allow the second catalyst to absorb it completely; 9) After absorption is completed, let it stand for 1 hour, and then dry it at 80-420℃ for 1-5 hours; 10) Cooling the dried catalyst to room temperature, and then immersing it in deionized water; 11) drying the impregnated catalyst sample at 80-420° C. for 1-5 hours, and then measuring the vanadium content V2 after impregnation; 12) Calculate V2 / V1 to obtain a leaching coefficient greater than 0 and less than 1; The impregnation solutions in step 8) are two standard impregnation solutions A and B, and the above steps 1) to 12) are performed respectively to obtain two sets of leaching coefficient data.
4. The method for systematically evaluating the leaching characteristics of vanadium in a catalyst according to claim 1, characterized in that: The remaining group is to immerse the dried catalyst in at least two different impregnation solutions, test the vanadium content after drying, and record the results. The steps include: Weigh the catalyst and record it as w3; Measure 5-20 times the volume of w3 of the standard impregnation solution and impregnate the catalyst sample for 0.5-2 hours; The impregnated catalyst was dried at 80-420°C for 1-5 hours, and then the vanadium content after impregnation was tested and recorded.
5. The method for systematically evaluating the leaching characteristics of vanadium in a catalyst according to claim 1, characterized in that: The impregnation solutions include two types, namely standard impregnation solution A and standard impregnation solution B. The standard impregnation solution A is a 0.5-2 mol / L sulfuric acid solution, and the standard impregnation solution B is a 0.5-2 mol / L sodium hydroxide solution.
6. The method for systematically evaluating the leaching characteristics of vanadium in a catalyst according to claim 1, characterized in that: The vanadium leaching coefficient is the ratio of the vanadium content after leaching to the original vanadium content.
7. The method for systematically evaluating the leaching characteristics of vanadium in a catalyst according to claim 1, characterized in that: The coefficient P i The calculation formula is: Q i =-ln(1-p i ) Where p i is the vanadium leaching coefficient.
8. The method for systematically evaluating the leaching characteristics of vanadium in a catalyst according to claim 1, characterized in that: The calculation formula of the comprehensive leaching characteristic D is: D=∑P i ×N i Where N i is the weight coefficient; D ranges from 0 to 5, and the smaller the value, the higher the risk of vanadium leaching.
Citation Information
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