Method for extracting phosphorus and potassium elements from poultry manure based on cooperation of high-temperature activation and inorganic acid, fertilizer preparation method of phosphorus and potassium elements, liquid fertilizer and soil conditioner

Abstract

The invention provides a method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation synergistic inorganic acid, a fertilizer preparation method thereof, a liquid fertilizer and a soil amendment, and the method for extracting phosphorus and potassium elements comprises the following steps: S1, carrying out high-temperature activation treatment on the poultry manure, and converting organic phosphorus in the manure into soluble phosphate; s2, washing the activated material with water, removing soluble salt, and drying to obtain a prefabricated material; and S3, adding an inorganic acid solution into the prefabricated material, carrying out mixing reaction, carrying out solid-liquid separation, and extracting a leaching solution. Therefore, the limitation of a traditional biological fermentation path is broken through, and liquid phosphorus and potassium elements are directionally and efficiently extracted from the poultry manure.

Description

Technical Field

[0001] The present invention relates to the technology for the resource utilization of organic solid waste, and particularly to a method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and synergistic inorganic acid, as well as its fertilizer production method, liquid fertilizer, and soil conditioner. Background Art

[0002] As a large amount of organic solid waste, poultry manure contains essential nutrients such as phosphorus and potassium for plant growth and is an excellent fertilizer raw material. However, improper treatment is likely to pollute the environment and cause resource waste. For example, chicken manure is rich in nutrients such as nitrogen, phosphorus, and potassium. When a large amount is piled up, the nitrogen therein will be converted into ammonia and volatilize into the air under the action of microorganisms, producing a pungent smell and causing air pollution. Moreover, the ammonia discharged into the atmosphere will also cause environmental problems such as acid rain. At the same time, if the phosphorus element in chicken manure flows into water bodies with rainwater scouring, it will lead to eutrophication of water bodies, destroy the aquatic ecological balance, and cause water quality deterioration.

[0003] Currently, the existing poultry manure is mainly utilized in the form of fermented compost or processed into solid fertilizers to improve soil structure, increase soil fertility, and promote the growth of crops. However, when using such fertilizers, due to relying on microbial decomposition, the release is slow, resulting in poor timeliness of crop absorption of its nutrient elements and unsatisfactory absorption effect.

[0004] Therefore, to solve such problems, the prior art has proposed a liquid fertilizer solution to directly extract the liquid containing phosphorus and potassium elements from poultry manure to support fertilization by spraying and irrigation methods, which is convenient to directly apply to the roots of plants, or dilute the liquid fertilizer and then fertilize by irrigation, thereby effectively improving the absorption effect of plants.

[0005] However, the existing liquid fertilizer raw materials are usually refined based on biomass fermentation methods (such as "A Liquid Fertilizer Based on Biomass Fermentation and Its Preparation Method", patent publication number CN116425599A). Therefore, there are problems such as cumbersome preparation processes, complex raw materials, difficult component regulation during the fermentation process, and easy generation of unpleasant odors and microbial secretions. Therefore, it is difficult to industrialize on a large scale.

[0006] It can be seen that how to break through the limitations of traditional biological fermentation pathways and efficiently extract liquid phosphorus and potassium elements from poultry manure in a targeted manner is the key to enhancing the industrial scale and market competitiveness. Summary of the Invention

[0007] For this reason, the main object of the present invention is to provide a method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and synergistic inorganic acid, as well as its fertilizer production method, liquid fertilizer, and soil conditioner to solve the problems mentioned in the background art.

[0008] To achieve the above object, according to one aspect of the present invention, there is provided a method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation in cooperation with inorganic acid, and the steps include:

[0009] Step S1: Perform high-temperature activation treatment on poultry manure to convert organic phosphorus in the manure into soluble phosphate;

[0010] Step S2: Wash the activated material with water to remove soluble salts, and dry it to obtain a prefabricated material;

[0011] Step S3: Add an inorganic acid solution to the prefabricated material, mix and react, then perform solid-liquid separation to extract the leachate.

[0012] In a possible preferred embodiment, the inorganic acid solution is one or more of nitric acid, hydrochloric acid, and sulfuric acid, and the concentration is 0.5 - 2 mol / L.

[0013] In a possible preferred embodiment, in step S3, the solid-liquid ratio of the inorganic acid solution to the prefabricated material is 9 - 20 mL:1 g.

[0014] In a possible preferred embodiment, in step S3, the mixing and reaction step includes:

[0015] Step S31: Stir the inorganic acid solution and the prefabricated material evenly, and react at room temperature and constant temperature for 30 - 60 min.

[0016] In a possible preferred embodiment, in step S1, the crushing particle size of the poultry manure is ≤ 0.15 mm.

[0017] In a possible preferred embodiment, in step S1, the temperature range of the high-temperature activation treatment is 600 - 1050 °C.

[0018] To achieve the above object, corresponding to the above method, according to another aspect of the present invention, there is also provided a liquid fertilizer, which includes: the leachate obtained by any of the above methods.

[0019] To achieve the above object, corresponding to the above method, according to another aspect of the present invention, there is also provided a method for producing fertilizer by extracting phosphorus and potassium elements from poultry manure based on high-temperature activation in cooperation with inorganic acid, and the steps include:

[0020] Perform composition regulation on the leachate obtained by any of the above methods, adjust the pH value and then perform concentration treatment.

[0021] In a possible preferred embodiment, the composition regulation step includes:

[0022] Select one or more of urea, ammonium nitrate, and dipotassium hydrogen phosphate as supplementary elements and add them to the leachate.

[0023] In a possible preferred embodiment, the pH adjustment step comprises:

[0024] Select either ammonia water or potassium hydroxide as a regulator to adjust the pH value to above 3.0.

[0025] In order to achieve the above-mentioned purpose, corresponding to the above-mentioned method, according to another aspect of the present invention, a soil conditioner is also provided, which comprises: the dry residue separated from the solid-liquid in any of the above methods for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and synergistic inorganic acid.

[0026] The method for extracting phosphorus and potassium from poultry manure based on high-temperature activation and coordinated inorganic acid, as well as the fertilizer making method, liquid fertilizer and soil improver provided by the present invention cleverly proposes a high-temperature activation-acid leaching coordinated process. On the one hand, organic phosphorus in chicken manure is converted into soluble phosphate by temperature control, and pathogen inactivation, antibiotic degradation and heavy metal passivation are simultaneously completed. On the other hand, in conjunction with multiple water washing processes, soluble salts can be removed, and the hidden danger of phosphorus reprecipitation effect caused by alkaline oxides in subsequent acid leaching is eliminated, so that the inorganic acid solution is effectively coordinated to undergo acid leaching reaction under normal temperature and pressure conditions, thereby realizing directional and efficient extraction of phosphorus and potassium from poultry manure.

[0027] This not only breaks through the limitations and drawbacks of traditional biological fermentation pathways, but also greatly improves the extraction efficiency compared to traditional composting methods, and the processing cycle is compressed from 30 days to several hours. At the same time, the residue after the reaction can also be used as a soil conditioner, thus opening up the closed-loop chain of "harmless treatment-high-value extraction of elements-full component utilization" of organic solid waste, and overcoming industry problems such as incomplete degradation of antibiotics, low conversion rate of traditional liquid fertilizers, and serious secondary pollution in traditional processes, providing a revolutionary solution for the resource utilization of livestock and poultry manure with high efficiency, low cost and low emission characteristics. Therefore, it has the conditions for large-scale application in industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 A schematic diagram of the steps of the method for extracting phosphorus and potassium elements from poultry feces based on high temperature activation and inorganic acid according to the present invention;

[0030] Figure 2 The present invention is a schematic diagram of the process of extracting phosphorus and potassium elements from poultry feces based on high temperature activation and inorganic acid.

[0031] Figure 3Schematic diagram of the XRD pattern of high-temperature activated fermented chicken manure in the method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and inorganic acid synergism according to the present invention.

[0032] Figure 4 Schematic process diagram of the method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and inorganic acid synergism according to the present invention for fertilizer production. Detailed implementation manners

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following will clearly and completely describe the specific technical solution of the present invention in combination with embodiments, so as to help those skilled in the art further understand the present invention. Obviously, the embodiments described in this case are only a part of the embodiments of the present invention, rather than all the embodiments. It should be noted that for those of ordinary skill in the art, without departing from the inventive concept of the present invention and without conflict with each other, the embodiments in this application and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the scope of disclosure and protection of the present invention.

[0034] In addition, the terms "first", "second", "S1", "S2", etc. in the description and claims of the present invention and the drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that the features used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those described here. At the same time, the stages recorded in each step are not forced to be implemented in the same step. It should be understood that the implementation order of the content in each step stage can be adjusted and interchanged without violating the inventive concept, so that the step embodiments of the present invention described here can be implemented in an order other than those described here.

[0035] In addition, the terms "comprising" and "having" and any variations thereof in the present invention are intended to cover non-exclusive inclusion. Unless otherwise clearly defined and limited, the terms "arranged", "deployed", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this case can be understood according to specific circumstances and in combination with the prior art.

[0036] Also in this specification, when a range of a variable is recited, it should be understood that the variable includes all values within the recited range (including the endpoints of the range). For example, it should be understood that the range of "5 - 10" includes not only the values of 5, 6, 7, 8, 9, and 10, but also any sub - ranges such as 6 - 10, 7 - 10, 6 - 9, 7 - 9, etc., and also any values between integers within the scope of the recited range, such as 5.5, 6.5, 7.5, 5.5 - 8.5, and 6.59. In addition, it should be understood that a range such as "10% - 30%" includes not only values such as 10%, 11%, 12%, 13%, etc. and all integers up to 30% (including 30%), but also any sub - ranges such as 10% - 15%, 12% - 18%, 20% - 30%, etc., and also any values between integers within the scope of the recited range, such as 10.5%, 15.5%, 25.5%.

[0037] In order to break through the limitations of traditional biological fermentation pathways and efficiently extract liquid phosphorus and potassium elements from poultry manure in a targeted manner, as Figure 1 shown, the present invention provides a method for extracting phosphorus and potassium elements from poultry manure based on high - temperature activation in cooperation with inorganic acids. The exemplary steps include:

[0038] Step S1: Perform high - temperature activation treatment on poultry manure to convert organic phosphorus in the manure into soluble phosphate.

[0039] Step S2: Wash the activated material with water to remove soluble salts, and then dry it to obtain a pre - prepared material.

[0040] Step S3: Add an inorganic acid solution to the pre - prepared material, mix and react, then perform solid - liquid separation to extract the leaching solution.

[0041] Specifically, the poultry manure referred to in this example includes the manure of common poultry such as chickens, ducks, geese, quails, pigeons, etc. Most of the components of this poultry manure are similar, generally differing in the contents of phosphorus, potassium, calcium, etc. Therefore, those skilled in the art can, on the premise of understanding the concept of the present invention, adaptively adjust various ratios, numerical values, etc. in the relevant processes in the examples of the present invention for different types of poultry manure. For example, adjust the high - temperature activation temperature according to different poultry manure to meet the requirement of converting organic phosphorus into soluble phosphate, or adjust the water - washing process to meet the removal of soluble salts to eliminate the phosphorus re - precipitation effect caused by basic oxides, or adjust the selection and concentration of inorganic acids, adjust the solid - liquid ratio of acid leaching, reaction time, etc., so as to keep phosphorus and potassium elements in the leaching solution as much as possible to improve the recovery efficiency. Therefore, those skilled in the art should understand that under the condition of not departing from the concept of the present invention, other equivalent replacement / adjustment implementation schemes are all within the disclosure scope of the present invention.

[0042] To better illustrate the implementation process of the present invention, chicken manure is taken as an example for exemplary illustration in this example. Specifically, in order to break through the limitations of the traditional biological fermentation path, a high-temperature activation-acid leaching synergistic scheme is proposed in the concept of the present invention to achieve the decomposition of organic matter and the directional transformation of mineral phases through high-temperature activation, use water washing treatment to remove the residual soluble salts on the surface of the activated material, and cooperate with inorganic acids to provide an acidic environment to dissolve phosphorus and potassium, which can avoid the re-precipitation of phosphorus due to too high local pH during subsequent acid leaching, so as to achieve the simultaneous enrichment of phosphorus and potassium, and thereby achieve the directional and efficient extraction of phosphorus and potassium elements in chicken manure under normal temperature and pressure by chemical wet method.

[0043] The reaction conditions of the example are as follows:

[0044] Chemical reagents and conditions Technical feature range Function description <![CDATA[Nitric acid (HNO3), sulfuric acid (H2SO4), hydrochloric acid (HCl)]]> Concentration: 0.1 - 1 mol / L Provide an acidic environment to dissolve phosphorus and potassium Liquid-solid ratio (9 - 20) mL:1 g Balance between leaching efficiency and economy Reaction temperature Room temperature Low-temperature control to reduce energy consumption

[0045] The leaching process of the example is as follows:

[0046] 1) Raw material treatment: When the poultry manure is chicken manure (including fermented chicken manure or dried chicken manure), in order to increase the reaction specific surface area and make the combustion more complete during high-temperature activation, the chicken manure can be dried and then crushed to a suitable particle size (such as ≤0.15 mm).

[0047] 2) High-temperature activation: Add the crushed chicken manure into a high-temperature activation furnace for activation. The activation temperature range is controlled at 600-1050 °C (preferred temperature 800-950 °C), and the activation time can be specifically determined according to the reaction vessel and material properties (such as 30 minutes of activation under laboratory conditions, while the industrial activation furnace may take from a few seconds to a few minutes), so as to convert the organic phosphorus in the manure into soluble phosphate.

[0048] 3) Water washing treatment: Since the free CaO / MgO and other basic oxides remaining on the surface of the activated material will form Ca(OH)2 / Mg(OH)2 colloids when encountering water, the high-temperature activated chicken manure is washed with water (such as 3-5 times), and the soluble salts on the activated material can be removed through ion dissolution-diffusion, avoiding the re-precipitation of phosphorus (such as Ca3(PO4)2) due to too high local pH during subsequent acid leaching.

[0049] 4) Inorganic acid leaching: Add the activated material into the leaching reaction kettle according to the liquid-solid ratio of (9-20) mL:1 g, and add an inorganic acid (one or more of nitric acid, hydrochloric acid, sulfuric acid) solution with a concentration of 0.5-2 mol / L, and react at a constant temperature at room temperature for 30-60 minutes.

[0050] 5) Solid-liquid separation: The reaction mixture is separated by solid-liquid separation (such as using a filtration membrane separation or centrifugal separation; the filtrate collection rate > 95%), and finally a phosphorus and potassium leaching solution and mineral residues are obtained.

[0051] Experimental examples and comparative examples

[0052] Experimental example 1

[0053] As Figure 2 shown, fermented chicken manure that has been dried, crushed, and sieved (particle size less than or equal to 0.15 mm) is selected. Five portions with a mass of 100 g are weighed and labeled as No. 1 - 5 respectively. The corresponding activation conditions are non - activated, activated at 600 °C, 800 °C, 950 °C, and 1050 °C.

[0054] The chicken manure of No. 2 - 5 is respectively put into an activation furnace. In an air atmosphere, the heating temperatures are respectively controlled at 600 °C, 800 °C, 950 °C, and 1050 °C for high - temperature activation. During the heating process, it is stirred multiple times to ensure sufficient contact with air. After holding for 30 min, it is taken out and cooled to room temperature in air. The chemical composition of the activated fermented chicken manure is shown in Table 1.

[0055] Table 1 Chemical composition (wt%) of fermented chicken manure before and after activation

[0056]

[0057] Weigh 10 g of the chicken manure of No. 1 - 5 respectively, wash it with water for 10 min and then filter. After repeating the operation 3 - 5 times, the solid is dried to a constant temperature to obtain water - washed non - activated chicken manure and activated materials.

[0058] Weigh 1 g of non - activated chicken manure of No. 1 and activated materials of No. 2 - 5 respectively, add 1 mol / L nitric acid solution, and set the liquid - solid ratio to 20:1 mL:1 g. React at a constant temperature under room - temperature and atmospheric pressure conditions, and control the reaction time to 60 min.

[0059] After the reaction, solid - liquid separation is carried out to obtain the leaching solution containing phosphorus and potassium and mineral residues. The concentrations of each component in the leaching solution are measured by AAS and ICP - OES, and the leaching rates of phosphorus and potassium elements are calculated. The results are shown in Table 2.

[0060] Table 2 Leaching rates of phosphorus and potassium elements in the leaching solution (%)

[0061] Number Phosphorus element Potassium element 1 16.89 22.94 2 33.86 47.11 3 50.07 67.26 4 52.62 87.14 5 53.19 91.03

[0062] As Figure 3 shown, it shows the change in the mineral composition of high - temperature activated fermented chicken manure. Through comprehensive analysis by combining the chemical composition and the leaching rates of phosphorus and potassium elements, the optimal activation temperature range can be selected as 800 - 950 °C. Although the leaching rate of the activated material at 1050 °C is slightly higher than that at 950 °C, the content of phosphorus and potassium elements in the chemical composition decreases. This is because phosphorus and potassium elements will volatilize when the heating temperature is too high. The reason for choosing nitric acid leaching in this example is that nitric acid can better dissolve the phosphorus and potassium elements in the activated material and can also be used as a nitrogen source supplement, reducing certain costs for the subsequent application of the leaching solution in the agricultural field.

[0063] Comparative Example 1

[0064] The difference between this comparative example 1 and experimental example 1 is that: unactivated chicken manure No. 1 and 950°C activated material No. 4 are selected, and the inorganic acid leaching agents are 1 mol / L sulfuric acid and hydrochloric acid, respectively. The other conditions and operations are the same as those in experimental example 1. The leaching results of phosphorus and potassium elements are shown in Table 3.

[0065] Table 3 Leaching rate of phosphorus and potassium elements in the leachate (%).

[0066]

[0067] By comparing the results of nitric acid leaching with those in Experimental Example 1, it was found that sulfate (SO4 2- ) can be combined with Ca 2+ Form slightly soluble calcium sulfate (Ksp = 2.4 × 10 -5 ), to avoid the reduction of phosphorus leaching rate caused by calcium phosphate precipitation in the system, and the phosphorus leaching rate is increased by 15-20%. Compared with nitric acid, hydrochloric acid has similar element leaching effect, but considering that the cost of sulfuric acid and hydrochloric acid is significantly lower than nitric acid, nitric acid can be selected as the main leaching agent when nitrogen source needs to be supplemented separately in the future. When nitrogen source does not need to be supplemented separately, sulfuric acid or hydrochloric acid can be selected as the main leaching agent to reduce costs.

[0068] This process is based on high-temperature activation and a synergistic inorganic acid system. Organic phosphorus is converted into soluble phosphates through temperature-controlled activation, and the alkaline oxides in the activated material are further removed through water washing pretreatment. This promotes the leaching rate of phosphorus and potassium and reduces the amount of leaching agent from two aspects, combining the advantages of high efficiency, low consumption, and multiple co-production.

[0069] Comparative Example 2

[0070] The difference between this comparative example 2 and experimental example 1 is that: when the 950°C activated material is selected as the raw material and sulfuric acid is used as the leaching agent, the liquid-to-solid ratio is set to 9mL:1g and 15mL:1g, and the other conditions and steps are the same as those in experimental example 1. The leaching results of phosphorus and potassium elements are shown in Table 4.

[0071] Table 4 Leaching rate of phosphorus and potassium elements in the leachate (%).

[0072] Liquid-solid ratio Phosphorus element Potassium element 9 / 1 58.90 78.91 15 / 1 62.51 80.58

[0073] Comparative Example 3

[0074] The difference between this comparative example 3 and experimental example 1 is that when 950°C activated material is selected as raw material and 1 mol / L sulfuric acid is used as leaching agent, the leaching time is 30 min, and other conditions and steps are the same as those in experimental example 1. The leaching rates of phosphorus and potassium elements are reduced by 15.34% and 26.13% respectively compared with those in comparative example 1.

[0075] Experimental Example 2

[0076] The basic steps of Experimental Example 2 are the same as those of Experimental Example 1, with the differences being as follows:

[0077] Select dried chicken manure that has been crushed and screened (particle size less than 0.15 mm). The activation temperature range is 800 - 950 °C, and the leaching agent is 1 mol / L sulfuric acid and nitric acid. The specific steps are as follows:

[0078] Select dried chicken manure that has been crushed and screened (particle size less than 0.15 mm). Weigh 3 portions, each with a mass of 100 g, and label them as No. 6, No. 7, and No. 8 respectively. The corresponding activation conditions are non-activated, activated at 800 °C, and activated at 950 °C.

[0079] Put the chicken manure of No. 7 and No. 8 into the activation furnace respectively. In an air atmosphere, control the heating temperature at 800 °C and 950 °C respectively for high-temperature activation. During the heating process, stir multiple times to ensure sufficient contact with air. After holding for 30 min, take it out and cool it to room temperature in the air. The chemical composition of the activated fermented chicken manure is shown in Table 5.

[0080] Table 5 Chemical composition of dried chicken manure before and after activation (wt%)

[0081]

[0082] Weigh 10 g of the chicken manure of No. 6 - No. 8 respectively, wash it with water for 10 min and then filter. Repeat the operation 3 - 5 times to obtain the washed non-activated chicken manure and the activated material.

[0083] Weigh 1 g of the washed non-activated chicken manure of No. 6 and the activated materials of No. 7 and No. 8 respectively, add 1 mol / L sulfuric acid solution, and set the liquid-solid ratio to 20:1. React at room temperature, and control the reaction time to 60 min.

[0084] The subsequent steps after the reaction are the same as those in Experimental Example 1. The leaching rates of phosphorus and potassium elements in the leaching solution are shown in Table 6.

[0085] Table 6 Leaching rates of phosphorus and potassium elements in the leaching solution (%).

[0086]

[0087] The core advantage of Experimental Example 2 compared to Experimental Example 1 is that dried chicken manure is used to replace fermented chicken manure. Combining with a sulfuric acid leaching system (1 mol / L) and activation at 950 °C, a phosphorus leaching rate of 68.93% is achieved (a 30.8% increase compared to 52.62% in the nitric acid system of Experimental Example 1), and the sulfuric acid cost is 40% lower than that of nitric acid. The disadvantage is that the original phosphorus content of dried chicken manure (14.48% P2O5) is significantly lower than that of fermented chicken manure (15.15%), and the high calcium characteristic (CaO 60.54%) requires an additional increase in the number of water washing times, resulting in a 15% increase in pretreatment energy consumption. However, by optimizing the sulfuric acid concentration (the phosphorus leaching rate reaches 79.67% at 1.5 mol / L), the raw material defects can be compensated, and finally, the liquid fertilizer production efficiency exceeds that of Experimental Example 1 by 22%. This scheme is more suitable for the rapid treatment scenario of low-organic-matter chicken manure, but the pretreatment cost and the economy of the leaching agent need to be weighed.

[0088] Comparative Example 4

[0089] The difference between this Comparative Example 4 and Experimental Example 2 is that activated material No. 8 is selected as the raw material, and the sulfuric acid concentrations are 0.5 mol / L, 1.5 mol / L, and 2 mol / L respectively. Other conditions and steps are the same as those in Experimental Example 2. The leaching rates of phosphorus and potassium elements are shown in Table 7.

[0090] Table 7 Leaching rates of phosphorus and potassium elements in the leaching solution (%).

[0091] Sulfuric acid concentration (mol / L) Phosphorus element Potassium element 0.5 45.83 58.27 1.5 69.45 94.09 2 79.67 96.61

[0092] Compared with Experimental Example 2, by increasing the sulfuric acid concentration to 2 mol / L, the phosphorus leaching rate is increased from 68.93% to 79.67% (an increase of 15.6%). The advantage is that it breaks through the phosphorus extraction limit in high-calcium chicken manure (CaO 60.54%), verifying the dominant role of acid concentration gradient regulation in leaching kinetics. The disadvantage is that the sulfuric acid consumption increases by 35%, resulting in an 18% increase in the tonnage treatment cost, and the high-concentration acid exacerbates equipment corrosion (a titanium alloy reaction kettle needs to be used, increasing the investment cost). At the same time, the free acid concentration in the residue increases and requires additional neutralization treatment (such as a 25% increase in the dosage of pH regulator). This scheme is applicable to high-value-added scenarios for deep extraction of phosphorus and potassium elements. Considering comprehensively, it is more appropriate to select a sulfuric acid concentration of 1 - 1.5 mol / L.

[0093] It can be seen from the above experimental examples and comparative examples that the method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and inorganic acid synergism in the present invention proposes a high-temperature activation-acid leaching synergistic system in terms of inventive concept to achieve efficient phosphorus and potassium recovery in poultry manure such as chicken manure. Its innovation breakthrough lies in that the conversion of organic phosphorus to soluble phosphate is achieved by controlling the temperature (600-1050°C), and the interference of basic oxides is eliminated by combining multiple water washing pretreatments, so that the phosphorus leaching efficiency of sulfuric acid reaches 79.67%, which is 260% higher than that of the traditional composting method; and at a concentration of 1.5 mol / L, it can also exchange a 15.6% increase in phosphorus leaching rate for a 18% increase in cost. This not only breaks through the limitations and disadvantages of the traditional biological fermentation path, but also greatly improves the extraction efficiency compared with the traditional composting method, and the treatment cycle can be compressed from 30 days to several hours.

[0094] In addition, although it is impossible to enumerate, based on the concept of the above examples, those skilled in the art can adapt different processes to different raw materials to recycle phosphorus and potassium from organic solid waste, so as to achieve a solution with both industrial feasibility and environmental benefits.

[0095] On the other hand, corresponding to the process method of the above examples, the present invention also provides a liquid fertilizer, which includes: the leaching solution obtained by the method described in any one of the above examples.

[0096] On the other hand, corresponding to the process method of the above examples, as Figure 4 shown, the present invention also provides a method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and inorganic acid synergism to produce fertilizer, and its steps include:

[0097] The leaching solution obtained by the method described in any one of the above is subjected to composition regulation. After adjusting the pH value and concentrating until the macronutrients required for the product reach the standard, the finished fertilizer is obtained.

[0098] The specific key preparation steps are as follows:

[0099] Steps Operating conditions and technical requirements Principle Crushing and screening Raw materials: fermented chicken manure or directly dried chicken manure, particle size less than 0.15 mm Increase the reaction specific surface area and burn more fully during high-temperature activation High-temperature activation Activation temperature range: 600 - 1050 °C, preferred temperature range: 800 - 950 °C Achieve the decomposition of organic matter and the directional transformation of mineral phases Washing treatment The activated material after high-temperature activation treatment is acid-leached after being washed multiple times <![CDATA[Water washing removes soluble salts through ion dissolution-diffusion; free basic oxides such as residual CaO / MgO on the surface of the activated material react with water to form Ca(OH)2 / Mg(OH)2 colloids. Water washing can avoid the re-precipitation of phosphorus (such as Ca3(PO4)2) due to locally high pH during subsequent acid leaching]]> Inorganic acid leaching One or more of nitric acid, hydrochloric acid, sulfuric acid, etc. Dissolve phosphorus and potassium elements in minerals Solid-liquid separation Filtration, membrane separation or centrifugation; filtrate collection rate > 95% Efficiently separate soluble nutrient elements Composition regulation Add urea / ammonium nitrate to adjust the N content; dipotassium hydrogen phosphate to supplement P / K Meet the NY 1107-2020 liquid fertilizer standard Adjust pH <![CDATA[Add ammonia water (NH3·H2O) / potassium hydroxide to supplement ammonium nitrogen / potassium element]]> Neutralize excessive H+ to meet the NY 1107-2020 liquid fertilizer standard

[0100] Among them, as Figure 4 shown, for those key steps related to the leaching solution process, they will not be elaborated here and can be referred to the previous examples. The examples of the composition regulation step include: according to the product requirements, one or more of urea, ammonium nitrate, and dipotassium hydrogen phosphate can be selected as N / P / K supplementary elements and added to the leaching solution. And the examples of the pH value adjustment step include: selecting any one of ammonia water and potassium hydroxide as the regulator to adjust the pH value.

[0101] For example, in this example, urea (1-3wt%) and dipotassium hydrogen phosphate (0.5-2wt%) are preferably added to the leachate, the pH is adjusted to 3.0±0.5 with aqueous ammonia, and the liquid fertilizer product is obtained by concentrating the macroelements required for the product.

[0102] On the other hand, corresponding to the above-mentioned example of a method for extracting phosphorus and potassium elements from poultry manure to make fertilizers based on high-temperature activation and synergistic inorganic acid, the present invention also provides a soil conditioner, which includes: the dry residue obtained by solid-liquid separation in any of the above examples of a method for extracting phosphorus and potassium elements from poultry manure to make fertilizers based on high-temperature activation and synergistic inorganic acid.

[0103] Among them, the residue separated from the solid and liquid in the above example can be dried at high temperature (such as drying at 105°C) to make an organic soil conditioner. It can be seen that the method of extracting phosphorus and potassium from poultry manure based on high-temperature activation and inorganic acid in the above example can not only match the liquid fertilizer preparation process in terms of process, but also the residue can be converted into a soil conditioner, realizing the resource utilization of all components of chicken manure and zero waste emission design, which meets the carbon neutrality goal. In addition, during the high-temperature activation process, pathogen inactivation, antibiotic degradation and heavy metal passivation can be completed simultaneously, thereby reducing environmental risks. In this way, a fully closed-loop production model from phosphorus and potassium extraction-liquid fertilizer preparation-residue resource utilization can be constructed, which effectively solves the problems of low efficiency and high energy consumption of existing technologies.

[0104] In summary, the method for extracting phosphorus and potassium from poultry manure based on high-temperature activation and coordinated inorganic acid, as well as its fertilizer making method, liquid fertilizer, and soil conditioner provided by the present invention cleverly proposes a high-temperature activation-acid leaching coordinated process. On the one hand, organic phosphorus in chicken manure is converted into soluble phosphates by temperature control. On the other hand, multiple water washing processes are combined to remove soluble salts and eliminate the hidden danger of phosphorus reprecipitation effect caused by alkaline oxides in subsequent acid leaching, so as to effectively coordinate the inorganic acid solution to undergo acid leaching reaction under normal temperature and pressure conditions, thereby achieving directional and efficient extraction of phosphorus and potassium from poultry manure.

[0105] This not only breaks through the limitations and drawbacks of traditional biological fermentation pathways, but also greatly improves the extraction efficiency compared to traditional composting methods, and the processing cycle is compressed from 30 days to several hours. At the same time, the residue after the reaction can also be used as a soil conditioner, thus opening up the closed-loop chain of "harmless treatment-high-value extraction of elements-full component utilization" of organic solid waste, and overcoming industry problems such as incomplete degradation of antibiotics, low conversion rate of traditional liquid fertilizers, and serious secondary pollution in traditional processes, providing a revolutionary solution for the resource utilization of livestock and poultry manure with high efficiency, low cost and low emission characteristics. Therefore, it has the conditions for large-scale application in industrial production.

[0106] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0107] In addition, all or part of the steps in the methods of the above embodiments can be completed by instructing relevant hardware through a program. The program is stored in a storage medium, including several instructions for causing a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks or optical discs that can store program codes.

[0108] In addition, any combination can be made among various different embodiments of the embodiments of the present invention as long as it does not violate the idea of the embodiments of the present invention, and it should also be regarded as the content disclosed in the embodiments of the present invention.

Claims

1. A method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and inorganic acid synergism, the steps of which include: Step S1: Perform high-temperature activation treatment on poultry manure to convert organic phosphorus in the manure into soluble phosphate; Step S2: Wash the activated material with water to remove soluble salts, and dry it to obtain a prefabricated material; Step S3: Add an inorganic acid solution to the prefabricated material for mixing and reaction, then perform solid-liquid separation to extract the leachate.

2. The method according to claim 1, wherein the inorganic acid solution is one or more of nitric acid, hydrochloric acid, and sulfuric acid, and the concentration is 0.5-2 mol / L.

3. The method according to claim 1, wherein in step S3, the solid-liquid ratio of the inorganic acid solution to the prefabricated material is 9-20 mL:1 g.

4. The method according to claim 1, wherein in step S3, the mixing and reaction step includes: Step S31: Stir the inorganic acid solution and the prefabricated material evenly, and react at room temperature and constant temperature for 30-60 minutes.

5. The method according to claim 1, wherein in step S1, the crushing particle size of the poultry manure is ≤0.15 mm.

6. The method according to claim 1, wherein in step S1, the temperature range of the high-temperature activation treatment is 600-1050 °C.

7. A liquid fertilizer, which comprises: The leachate obtained by the method according to any one of claims 1 to 6.

8. A method for extracting phosphorus and potassium elements from poultry manure based on high-temperature activation and inorganic acid synergism to produce fertilizer, the steps of which include: Adjust the composition of the leachate obtained by the method according to any one of claims 1 to 6, and perform concentration treatment after adjusting the pH value.

9. The method according to claim 8, wherein the composition adjustment step includes: Select one or more of urea, ammonium nitrate, and dipotassium hydrogen phosphate as supplementary elements and add them to the leachate.

10. The method according to claim 8, wherein the pH value adjustment step includes: Select any one of ammonia water and potassium hydroxide as a regulator to adjust the pH value to above 3.

0.

11. A soil conditioner, comprising: The dry residue obtained by solid-liquid separation in the method according to any one of claims 1 to 6.

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