Method for promoting solid waste to separate out fertilizer efficiency K-containing crystalline salt by utilizing microwave irradiation

Abstract

The invention discloses a method for promoting solid waste to separate out fertilizer efficiency K-containing crystal salt by utilizing microwave irradiation, relates to the technical field of agriculture, and aims to improve the separation rate of the solid waste K-containing crystal salt by utilizing microwave irradiation to promote solid waste to separate out the fertilizer efficiency K-containing crystal salt so as to improve the utilization rate of the solid waste K-containing crystal salt and better enhance the fertilizer efficiency of a fertilizer. And the environmental pollution can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a method for promoting the precipitation of fertilizer-effective K-containing crystal salt from solid waste by using microwave irradiation. Background Art

[0002] Background technology of the present invention is that, with the development of society, the treatment of solid waste has become an environmental problem to be solved urgently. Crystalline salts containing K, which are rich in solid waste, are important fertilizer components of fertilizers, and have far-reaching significance for improving the utilization rate of effective components in solid wastes and reducing environmental pollution, which has opened up new ways for the resource utilization of solid wastes. However, due to the limitations of current processes and materials, there are many limitations in the existing methods for extracting fertilizer components in solid wastes. These methods are often inefficient and cannot fully extract the crystallized salts containing K in solid wastes, resulting in low utilization of effective components of solid wastes, which limits its wide application effect in fertilizers.

[0003] Specifically, existing extraction methods may face problems such as high energy consumption, long processing time, and low precipitation purity when treating solid waste, which not only increases the treatment cost, but also may cause secondary pollution to the environment. In addition, some methods are only applicable to specific types of solid waste, with poor versatility and difficulty in meeting widespread treatment needs.

[0004] Compared with the existing invention patents CN101857330A and CN118204351A, the present invention has a broader application prospect. CN101857330A mainly focuses on the treatment of highly acidic organic waste liquid, and its application scope is relatively limited; while CN118204351A targets the resource treatment of complex polluted chemical waste salts, which is also targeted. In contrast, the present invention targets most solid wastes, whether it is potassium salt-containing solid waste generated by the chemical, metallurgical, pharmaceutical and other industries, or other types of solid waste, which can be treated by the microwave irradiation technology of the present invention, and it is more versatile and has a larger scope of application.

[0005] Microwave irradiation technology, as an efficient and environmentally friendly treatment method, has shown great potential in the field of solid waste treatment. Through microwave irradiation, polar substances (such as water molecules) in solid waste can be prompted to absorb microwave energy, generate a large amount of heat, and then destroy cell walls or membranes, and promote the precipitation of K-containing crystalline salts. This process not only improves the precipitation efficiency, but also retains the high purity of K-containing crystalline salts, providing a strong guarantee for subsequent use as fertilizer. Therefore, the present invention uses microwave irradiation to promote the precipitation of fertilizer-effective K-containing crystalline salts from solid waste, aiming to overcome the limitations of the prior art, improve the utilization rate of effective components in solid waste, reduce environmental pollution, and promote the development of resource utilization of solid waste. Summary of the invention

[0006] Technical problem to be solved: The present invention provides a method for promoting the precipitation of K-containing crystalline salt with fertilizer effect from solid waste by using microwave irradiation, so as to increase the precipitation rate of K-containing crystalline salt from solid waste, thereby improving its utilization rate to better enhance the fertilizer effect of fertilizer and reduce environmental pollution.

[0007] Technical solution: A method for promoting the precipitation of potassium-containing crystalline salt from solid waste by microwave irradiation, comprising the following steps: (1) screening and crushing at least one solid waste containing K element to make the particle size of the solid waste reach a predetermined range; (2) adding the pretreated solid waste containing K element to deionized water (solid-liquid mass ratio is 1:20), stirring the solid-liquid mixture, and then standing and soaking; (3) collecting the supernatant and solid waste residue, respectively, recorded as supernatant No. 1 and residue No. 1, placing residue No. 1 in a microwave generator for microwave irradiation treatment; (4) placing residue No. 1 after microwave irradiation in deionized water (solid-liquid mass ratio is 1:10), stirring the solid-liquid mixture, and standing and soaking; then collecting the supernatant and solid waste residue, respectively, recorded as supernatant No. 2 and residue No. 2; taking supernatant No. 2 for K element content detection, and recording the K element ratio at this time as X K2 ; (5) placing residue No. 2 in a microwave generator for microwave irradiation treatment; (6) placing residue No. 2 after microwave irradiation in deionized water (solid-liquid mass ratio of 1:10), stirring the solid-liquid mixture, and letting it stand to soak; then collecting the supernatant and solid waste residue, respectively, and recording them as supernatant No. 3 and residue No. 3; taking supernatant No. 3 for K element content detection, and recording the K element ratio at this time as X K3 (7) Repeat the above steps (3)-(6), and record the K element ratio of the last supernatant i as X Ki ; (8) Compare the proportion of K element |X Ki-1 -X Ki |≤1%, and X Ki ≤1.5%, stop repeating; (9) Mix the supernatants No. 1 to No. i, test and record the K element ratio at this time as X K终 ; (10) adjusting the pH of the mixed supernatant to neutral; finally obtaining a K content of X K终 of solution.

[0008] The solid waste containing K element is selected from biomass ash, unburned carbon, steel slag or ash slag.

[0009] The above-mentioned pulverization method includes using a grinder and manual grinding; grinding the solid waste to a particle size of 200μm, and then further grinding to a desired particle size according to different materials: wherein the particle size of biomass ash is <200μm; the particle size of unburned carbon is 200μm-300μm; the particle size of ash is 200μm-300μm, 50μm-100μm and <50μm; the particle size of steel slag is 50μm-100μm and <50μm.

[0010] The microwave generator is a multi-mode microwave generator or a single-mode microwave generator.

[0011] The above K element proportion analysis adopts methods including but not limited to atomic absorption spectrophotometry and ion chromatography.

[0012] The water content in the microwave irradiated residue is 15% to 25% by weight.

[0013] When residues No. 1 and No. i are treated with microwave irradiation, the microwave irradiation frequency and power used are the same, but the irradiation time decreases as the number of processed samples increases. The first microwave time is 8 min-10 min, and the subsequent microwave time is reduced by 1 min-3 min each time.

[0014] The above microwave frequency and power depend on the specific type of solid waste and the mixing ratio of multiple solid wastes. For only one type of solid waste, the microwave frequency used is 1450MHz-1850MHz, and the power is 300w-450w; for multiple solid wastes, the microwave frequency used is 1850MHz-2450MHz, and the power is 400w-500w.

[0015] The K-containing solution prepared by the above method.

[0016] The K-containing solution is dried to obtain solid K-containing crystalline salt; or mixed with a porous carrier and dried to prepare solid fertilizer; or directly used in the preparation of liquid fertilizer.

[0017] Beneficial effect: The beneficial effect of the present invention is that, by utilizing microwave irradiation technology, the precipitation rate of K-containing crystalline salts in solid waste can be significantly improved, thereby effectively improving its utilization rate as a fertilizer, greatly enhancing the fertilizer efficiency of the fertilizer. This innovative method not only effectively solves the problem of waste of potassium resources in solid waste, but also promotes the recycling of resources, providing strong support for the sustainable development of agriculture. At the same time, the implementation of the present invention also helps to reduce environmental pollution, because by efficiently precipitating K-containing crystalline salts, the potential harm of potassium salts in solid waste to soil and water bodies is reduced, and the ecological environment is protected. In addition, the method is easy to operate, has low energy consumption, has high economic and social benefits, and is of great significance for promoting the development of the environmental protection industry and the practice of green agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0019] Example 1

[0020] 25 g of biomass ash with a particle size of less than 200 μm was sieved and added to 500 mL of deionized water. The solid-liquid mixture was placed in a magnetic stirrer for 4 h and then allowed to soak for 8 h.

[0021] The supernatant and solid waste residue were collected separately and recorded as supernatant No. 1 and residue No. 1;

[0022] The wet residue No. 1 was placed in a microwave generator, and the microwave frequency was adjusted to 1850 MHz, the power to 400 W, and the irradiation time to 8 min for microwave irradiation treatment;

[0023] The microwave-irradiated residue No. 1 (the mass at this time was 23.89 g) was added to 240 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0024] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 2 and residue No. 2;

[0025] The K content of supernatant No. 2 was analyzed by ion chromatography. K2 , X K2 3.32%;

[0026] The wet residue No. 2 was placed in a microwave generator, and the microwave frequency was adjusted to 1850 MHz, the power to 400 W, and the irradiation time to 5 min for microwave irradiation treatment;

[0027] The microwave-irradiated residue No. 2 (the mass at this time was 20.17 g) was added to 210 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0028] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 3 and residue No. 3;

[0029] The K content of supernatant No. 3 was analyzed by ion chromatography. K3 , X K3 0.92%;

[0030] The wet residue No. 3 was placed in a microwave generator, and the microwave frequency was adjusted to 1850 MHz, the power to 400 W, and the irradiation time to 3 min for microwave irradiation treatment;

[0031] The microwave-irradiated residue No. 3 (mass at this time is 19.68 g) was added to 200 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to stand and soak for 1 h;

[0032] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 4 and residue No. 4;

[0033] The K content of supernatant No. 4 was analyzed by ion chromatography. K4 , X K4 0.19%;

[0034] At this time, the proportion of K element |X K3 -X K4 |=0.73%≤1%, and X K4 ≤1.5%, then stop repeating;

[0035] Mix the supernatants No. 1 to No. 4 and analyze their K content by ion chromatography. K终 , X K终 The solution was 1.37%. Since the water mass in the solution accounted for a large proportion at this time, the present invention used a drying box with a set temperature of 70°C and a drying time of 50 hours for drying.

[0036] After drying, the solution remains about 200mL, and the K element ratio is measured at this time. K终 The content of iodine was 7.89%, and the sample was saved as liquid fertilizer.

[0037] Example 2

[0038] 25 g of biomass ash with a particle size of less than 200 μm, 3 g of ash slag with a particle size of 200-300 μm, and 2 g of steel slag with a particle size of less than 100 μm were sieved and added to 600 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 4 h, and then allowed to stand and soak for 8 h;

[0039] The supernatant and solid waste residue were collected separately and recorded as supernatant No. 1 and residue No. 1;

[0040] The wet residue No. 1 was placed in a microwave generator, and the microwave frequency was adjusted to 2450 MHz, the power to 400 W, and the irradiation time to 8 min for microwave irradiation treatment;

[0041] The microwave-irradiated residue No. 1 (the mass at this time was 27.17 g) was added to 280 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0042] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 2 and residue No. 2;

[0043] The K content of supernatant No. 2 was analyzed by ion chromatography.K2 , X K2 4.91%;

[0044] The wet residue No. 2 was placed in a microwave generator, and the microwave frequency was adjusted to 2450 MHz, the power to 400 W, and the irradiation time to 5 min for microwave irradiation treatment;

[0045] The microwave-irradiated residue No. 2 (the mass at this time was 22.97 g) was added to 230 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0046] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 3 and residue No. 3;

[0047] The K content of supernatant No. 3 was analyzed by ion chromatography. K3 , X K3 1.78%;

[0048] The wet residue No. 3 was placed in a microwave generator, and the microwave frequency was adjusted to 2450 MHz, the power to 400 W, and the irradiation time to 3 min for microwave irradiation treatment;

[0049] The microwave-irradiated residue No. 3 (the mass at this time was 20.89 g) was added to 210 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0050] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 4 and residue No. 4;

[0051] The K content of supernatant No. 4 was analyzed by ion chromatography. K4 , X K4 0.88%;

[0052] At this time, the proportion of K element |X K3 -X K4 |=0.90%≤1%, and X K4 ≤1.5%, then stop repeating;

[0053] Mix the supernatants No. 1 to No. 4 and analyze their K content by ion chromatography. K终 , X K终 The solution was 2.67%. Since the water mass in the solution accounted for a large proportion at this time, the present invention used a drying box with a set temperature of 70°C and a drying time of 60 hours for drying.

[0054] After drying, the solution remains about 200mL, and the K element ratio is measured at this time. K终 17.65%;

[0055] At this time, since the solid waste residue has dissolved most of the water-soluble substances and formed a large number of porous structures, it can be used as a carrier. The present invention combines residue No. 4 with the above-mentioned solution dried to 200 mL, continues to use a drying oven, sets the temperature to 70°C, and the time to 24 hours, and preserves the dried sample as a solid slow-release fertilizer.

[0056] Example 3

[0057] 15 g of biomass ash with a particle size of less than 200 μm, 5 g of ash with a particle size of 200-300 μm, 5 g of steel slag with a particle size of less than 100 μm, and 5 g of unburned carbon with a particle size of more than 200 μm were sieved and added to 600 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 4 hours, and then allowed to stand and soak for 8 hours;

[0058] The supernatant and solid waste residue were collected separately and recorded as supernatant No. 1 and residue No. 1;

[0059] The wet residue No. 1 was placed in a microwave generator, and the microwave frequency was adjusted to 2450 MHz, the power to 400 W, and the irradiation time to 8 min for microwave irradiation treatment;

[0060] The microwave-irradiated residue No. 1 (the mass at this time was 28.47 g) was added to 290 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0061] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 2 and residue No. 2;

[0062] The K content of supernatant No. 2 was analyzed by ion chromatography. K2 , X K2 2.62%;

[0063] The wet residue No. 2 was placed in a microwave generator, and the microwave frequency was adjusted to 2450 MHz, the power to 400 W, and the irradiation time to 5 min for microwave irradiation treatment;

[0064] The microwave-irradiated residue No. 2 (the mass at this time was 25.24 g) was added to 260 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0065] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 3 and residue No. 3;

[0066] The K content of supernatant No. 3 was analyzed by ion chromatography. K3 , X K3 1.39%;

[0067] The wet residue No. 3 was placed in a microwave generator, and the microwave frequency was adjusted to 2450 MHz, the power to 400 W, and the irradiation time to 3 min for microwave irradiation treatment;

[0068] The microwave-irradiated residue No. 3 (the mass at this time was 23.81 g) was added to 240 mL of deionized water, and the solid-liquid mixture was placed in a magnetic stirrer for 0.5 h, and then allowed to soak for 1 h;

[0069] The supernatant liquid and the solid waste residue are separated and recorded as supernatant No. 4 and residue No. 4;

[0070] The K content of supernatant No. 4 was analyzed by ion chromatography. K4 , X K4 0.62%;

[0071] At this time, the proportion of K element |X K3 -X K4 |=0.77%≤1%, and X K4 ≤1.5%, then stop repeating;

[0072] Mix the supernatants No. 1 to No. 4 and analyze their K content by ion chromatography. K终 , X K终 The solution was 1.47%. Since the water mass in the solution accounted for a large proportion at this time, the present invention used a drying box with a set temperature of 70°C and a drying time of 60 hours for drying.

[0073] After drying, the solution remains about 200mL, and the K element ratio is measured at this time. K终 10.25%;

[0074] The solution is then placed in a drying oven, the temperature is set to 70°C, the time is 24 hours, and the dried sample is stored and can be used as a K-containing crystalline salt according to different needs.

[0075] The above examples are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for promoting the precipitation of potassium-containing crystalline salts with fertilizer effect from solid waste by microwave irradiation, characterized in that: The following steps are involved: (1) screening and crushing at least one solid waste containing K element so that the particle size of the solid waste reaches a predetermined range; (2) adding the pretreated solid waste containing K element into deionized water, stirring the solid-liquid mixture, and then allowing it to soak; (3) collecting the supernatant and the solid waste residue respectively, recording them as supernatant No. 1 and residue No. 1, and placing residue No. 1 into a microwave generator for microwave irradiation treatment; (4) Place the residue No. 1 after microwave irradiation in deionized water, stir the solid-liquid mixture, and let it stand and soak; then collect the supernatant and solid waste residue respectively, which are recorded as supernatant No. 2 and residue No. 2; take supernatant No. 2 for K element content detection, and record the K element ratio at this time as X K2 ; (5) placing residue No. 2 into a microwave generator for microwave irradiation treatment; (6) Place the residue No. 2 after microwave irradiation in deionized water, stir the solid-liquid mixture, and let it stand to soak; then collect the supernatant and solid waste residue respectively, which are recorded as supernatant No. 3 and residue No. 3; take supernatant No. 3 to test the K element content, and record the K element ratio at this time as X K3 ; (7) Repeat the above steps (3)-(6) and record the K element ratio of the last supernatant i as X Ki ; (8) Comparison of K element proportion | X Ki-1 - X Ki |≤1%, and X Ki ≤1.5%, stop repeating; (9) Mix the supernatants No. 1 to No. i, test and record the proportion of K element at this time: X K终 ; (10) Adjust the pH of the mixed supernatant to neutral; the final K content is X K终 of solution.

2. The method of promoting the precipitation of potassium-containing crystalline salts from solid waste by microwave irradiation according to claim 1, characterized in that: The solid waste containing K element is selected from biomass ash, unburned carbon, steel slag or ash slag.

3. The method for promoting the precipitation of potassium-containing crystalline salts with fertilizer effect from solid waste by microwave irradiation according to claim 2, characterized in that: The crushing method includes using a grinder and manual grinding; crushing the solid waste to a particle size of 200 μm, and then further grinding to a desired particle size according to different materials: wherein the particle size of biomass ash is less than 200 μm; the particle size of unburned carbon is 200 μm-300 μm; the particle size of ash slag is 200 μm-300 μm, 50 μm-100 μm and less than 50 μm; the particle size of steel slag is 50 μm-100 μm and less than 50 μm.

4. The method of promoting the precipitation of fertilizer-containing potassium crystalline salt from solid waste by microwave irradiation according to claim 1, characterized in that: The microwave generator is a multi-mode microwave generator or a single-mode microwave generator.

5. The method of promoting the precipitation of fertilizer-containing potassium crystalline salt from solid waste by microwave irradiation according to claim 1, characterized in that: The K element proportion analysis adopts methods including but not limited to atomic absorption spectrophotometry and ion chromatography.

6. The method of promoting the precipitation of potassium-containing crystalline salts with fertilizer effect from solid waste by microwave irradiation according to claim 1, characterized in that: The water content in the residue after microwave irradiation accounts for 15% to 25% by weight.

7. The method of promoting the precipitation of potassium-containing crystalline salts with fertilizer effect from solid waste by microwave irradiation according to claim 1, characterized in that: When using microwave irradiation to treat residues No. 1 and No. i, the microwave irradiation frequency and power used are the same, but the irradiation time decreases as the number of processed samples increases. The first microwave time is 8min-10min, and the subsequent microwave time is reduced by 1min-3min each time.

8. The method of promoting the precipitation of potassium-containing crystalline salts with fertilizer effect from solid waste by microwave irradiation according to claim 1, characterized in that: The microwave frequency and power depend on the specific type of solid waste and the mixing ratio of multiple solid wastes. For only one type of solid waste, the microwave frequency used is 1450MHz-1850MHz, and the power is 300w-450w; for multiple types of solid wastes, the microwave frequency used is 1850MHz-2450MHz, and the power is 400w-500w.

9. A K-containing solution obtained by the method according to any one of claims 1 to 8.

10. The K-containing solution according to claim 9 is dried to obtain solid K-containing crystalline salt; or mixed with a porous carrier and dried to prepare solid fertilizer; or directly used in the preparation of liquid fertilizer.

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