Organic acid curing tunnel tapping auxiliary composting method and fertilizer

Abstract

The invention discloses an organic acid curing tunnel tapping auxiliary composting method and a fertilizer, and belongs to the technical field of composting, and the method comprises the following steps: taking rock powder as a raw material, adding a binary organic acid solution as a curing agent, fully stirring, reacting, adding into a pile body formed by mixing cow dung, sheep manure and straw, and composting according to the composting raw material ratio: 0.5-2 parts of cured rock powder, 5-10 parts of cow dung, 5-10 parts of sheep manure and 5-10 parts of straw. 1-3 parts of sheep manure and 2-4 parts of straw. According to the invention, the rock powder acidified by the organic acid and the pile body are jointly used for composting, so that the pH value and conductivity of the pile body can be improved, the composting progress can be accelerated, the composting humification effect can be improved, and a large number of nutrient elements required by plant growth can be supplemented for the pile body. In this way, reasonable treatment of the waste rock powder can be achieved, the composting effect can be improved, the dual effect of resource utilization is achieved, and the method has important significance on economic sustainable development and environmental protection.

Description

Technical Field

[0001] The invention relates to the field of composting, and in particular to a method and fertilizer for slag-assisted composting in an organic acid maturation tunnel. Background Art

[0002] Many industries in my country generate a large amount of waste rock powder every year, such as machine-made sand preparation, mining, stone processing and metallurgy. The accumulation of rock powder not only takes up space, wastes resources and affects engineering safety, but also pollutes the air, threatens human health and affects ecological safety. Therefore, the rational use of rock powder has become an issue that urgently needs to be studied. At present, the research on rock powder mainly focuses on the construction field, where it is used to improve the performance of cement slurry and concrete, prepare geopolymers, and be used as roadbed fillers. In addition, the stone industry also studies the use of rock powder to prepare sintered bricks, unfired bricks, artificial stones, tiles, ceramics and imitation stone materials. In summary, the application research of rock powder involves multiple fields such as construction, stone and environment, but the application research of composting in the agricultural field has not been reported.

[0003] Rock dust is generally composed of a variety of minerals, containing most of the nutrients necessary for plants except nitrogen. Most of these nutrients exist in a stable chemical form and are not easily directly absorbed by organisms, but organisms can secrete organic acids to obtain these nutrients. With the intensive and large-scale development of agriculture and animal husbandry in my country, about 2.7×108t corn straw and 3.8×109t livestock and poultry manure are produced each year. It is estimated that the comprehensive utilization rate of these solid wastes is less than 50%. A large amount of straw is burned or abandoned, and a large amount of livestock and poultry manure is randomly piled up, which not only causes waste of resources, but also brings serious pollution to the surrounding environment. Therefore, the resource utilization of crop straw and livestock and poultry manure is of great significance for economic sustainable development and environmental protection. Composting is a recognized process of converting organic solid waste into stable and safe products. Composting can make full use of the rich nitrogen, phosphorus, potassium and organic matter contained in straw and livestock and poultry manure.

[0004] Microorganisms are a key component in the composting process. They convert organic matter into fertilizer through metabolic activities, but at the same time they also cause a large loss of nitrogen (such as pythium converting nitrogen into volatile nitrogen), which reduces the quality of the compost product and causes environmental pollution. At the same time, composting currently still has problems such as insufficient degradation, low product maturity (humification degree), and low content of nutrients such as potassium, phosphorus, calcium, and magnesium, which limits the application of composting.

[0005] Therefore, in view of the above technical background, this scheme is specially proposed to improve the quality of compost products by enhancing the humification degree of compost, supplementing the content of nutrients such as potassium, phosphorus, calcium, and magnesium, and reducing nitrogen loss. Summary of the invention

[0006] In order to solve the ecological problems caused by the accumulation of waste rock powder and the problem of poor quality of current compost products, the present invention proposes a method and fertilizer for organic acid matured tunnel slag assisted composting, which accelerates the composting process by assisting with organic acid matured rock powder, can not only achieve the rational treatment of waste rock powder, but also improve the composting effect, achieving the dual effect of resource utilization, which is of great significance to economic sustainable development and environmental protection.

[0007] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows: A method for organic acid slagging tunnel assisted composting comprises: using rock powder as raw material, adding a binary organic acid solution as a slagging agent, fully stirring and reacting, and then adding the mixture into a pile of cow dung, sheep dung and straw for composting, wherein the composting raw material ratio is: 0.5-2 parts of slagging rock powder, 5-10 parts of cow dung, 1-3 parts of sheep dung and 2-4 parts of straw.

[0008] According to an exemplary embodiment of the present invention, the dibasic organic acid includes acetic acid, tartaric acid, succinic acid and malonic acid.

[0009] According to an exemplary embodiment of the present invention, the dibasic organic acid is malonic acid, the concentration of the malonic acid solution is 0.01-0.5 mol / L, the pH is 1-2.5, and the solid-liquid ratio of the rock powder to the malonic acid solution is 1:2-1:100.

[0010] According to an exemplary embodiment of the present invention, the rock powder aging time is 8 to 72 hours, and the aging temperature is above 25°C.

[0011] According to an exemplary embodiment of the present invention, during the composting process, the moisture content of the compost is controlled at 50% to 60%.

[0012] According to an exemplary embodiment of the present invention, the composting process is controlled according to the process of heating period-high temperature period-cooling period-stabilization period. The heating period lasts for 1 to 3 days, and the ambient temperature is controlled at 35 to 40°C; the high temperature period lasts for 3 to 7 days, and the ambient temperature is controlled at 40 to 45°C; the cooling period lasts for 15 to 30 days, and the ambient temperature is controlled at 30 to 40°C; the ambient temperature during the stabilization period is controlled at room temperature.

[0013] According to an exemplary embodiment of the present invention, during the composting process, the aeration rate is maintained at 0.5-0.8 L / kg·min, forced ventilation is performed for 5 minutes, and paused for 45 minutes.

[0014] According to an exemplary embodiment of the present invention, the compost is not turned in the first two days of composting. When the temperature rises to above 55°C, the compost is turned every day. After the temperature drops below 50°C, the compost is turned every 3 days and moisture is replenished at the same time.

[0015] According to an exemplary embodiment of the present invention, the composting time is 25 to 45 days.

[0016] The present invention also provides a fertilizer, which is prepared by using the above-mentioned organic acid maturation tunnel slag-assisted composting method.

[0017] In summary, the present invention has the following advantages: 1. The present invention utilizes rock powder acidified with organic acid to compost together with the pile, which can improve the pH and conductivity of the pile, accelerate the composting progress, enhance the composting humification effect, and supplement the pile with a large amount of nutrients required for plant growth. This can not only achieve the rational treatment of waste rock powder, but also enhance the composting effect, achieving the dual effect of resource utilization, which is of great significance to economic sustainable development and environmental protection; 2. In the present invention, under the action of organic acid, the surface structure of the matured rock powder is improved, and the specific surface area of ​​the rock powder is increased. At this time, the matured rock powder is used as a compost mineral additive, which can provide abundant effective nutrients and growth sites for the rapid reproduction of microorganisms, accelerate the compost humification process, and facilitate the compost maturation; 3. In the present invention, the addition of organic acid matured rock powder can improve the pH value during the composting process: the pH value of the compost body rises rapidly due to the generation of ammonia during the composting process, and the organic acid matured rock powder is weakly acidic, which can neutralize part of the alkalinity generated by ammonia, thereby improving the pH value of the compost body; 4. In the present invention, adding organic acid matured rock powder can improve the conductivity during the composting process: since matured rock powder can promote the rapid growth of microorganisms, it consumes more active ions in the pile faster, thereby reducing the conductivity of the pile; 5. In the present invention, due to the addition of mature rock powder, part of the nitrogen and carbon lost in the compost can be adsorbed and retained, making up for the nitrogen and carbon losses during the composting process, making the nutrient content of ammonium nitrogen, nitrate nitrogen and soluble organic carbon higher, thereby improving the quality of the compost product; 6. The present invention is suitable for areas with large accumulation of rock dust or lack of topsoil for ecological restoration. It uses low molecular weight organic acid to mature rock dust. Based on the dissolution of minerals by organic acids, it can promote the rapid release of rock dust nutrients, and the released nutrients are in the form of effective nutrients and mineral element-organic chelates that are easily absorbed and utilized by plants.

[0018] 7. The composting method of the present invention has simple procedures, low cost, strong practicability, convenient application and good practical effect. It can be used to improve the matrix for ecological restoration, improve the nutrient structure of the matrix, reduce the risk of site instability, reduce soil erosion on the site, and solve the problems of high cost of ecological restoration, poor nutrient structure of the matrix and difficulty in obtaining soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The effect of organic acid type on nutrient release from rock dust; Figure 2 The effect of organic acid concentration on the nutrient release of rock dust; Figure 3 The effect of organic acid pH on the nutrient release of rock dust; Figure 4 The effect of aging time on the nutrient release of rock dust; Figure 5 The effect of aging temperature on the nutrient release of rock dust; Figure 6 The effect of solid-liquid ratio on the nutrient release of rock dust; Figure 7 The influence of nutrient release of rock powder of different lithologies; Figure 8 The effect of organic acid-cured rock dust on the temperature during composting; Fig. 9 The effect of organic acid-ripened rock dust on pH during composting; Fig.10 The effect of organic acid-cured rock powder on the electrical conductivity during composting; Fig.11 The effect of organic acid-cured rock dust on ammonium nitrogen during composting; Fig.12 The effect of organic acid-cured rock dust on nitrate nitrogen during composting; Fig.13 The effect of organic acid-cured rock dust on soluble organic carbon during composting; Fig.14 SEM images of rock powder (a) and mature rock powder (b); Fig.15 The effect of organic acid-cured rock dust on available phosphorus during composting; Fig.16 The effect of organic acid-cured rock powder on available potassium in the composting process; Fig.17 The effect of organic acid-cured rock dust on exchangeable calcium during composting; Fig.18 The effect of organic acid-cured rock dust on exchangeable magnesium during composting; Fig.19 The effect of organic acid-cured rock dust on available iron in the composting process; Fig. 20 The effect of organic acid-cured rock dust on available manganese in composting process; Fig.21 The effect of organic acid-cured rock powder on available copper in the composting process; Fig. 22 The effect of organic acid-cured rock dust on available zinc in the composting process; Fig.23 The effect of organic acid-ripened rock dust on humus during composting; Fig.24 The effect of organic acid-ripened rock powder on fulvic acid during composting. DETAILED DESCRIPTION

[0020] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments and drawings. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0021] Example 1 In order to solve the ecological problems caused by the accumulation of waste rock powder, the present invention proposes a method and fertilizer for organic acid matured tunnel slag assisted composting, which accelerates the composting process by assisting with organic acid matured rock powder, and can not only achieve the rational treatment of waste rock powder, but also improve the shortcomings of current composting methods. The method specifically includes the following steps: Step 1: Use waste rock powder as raw material, add dibasic organic acid solution as a curing agent, stir and react thoroughly to obtain mature rock powder. The solid-liquid ratio of the rock powder to the dibasic organic acid is 1:2~1:100; the concentration of the dibasic organic acid is 0.01~0.5 mol / L; the pH value of the dibasic organic acid is 1~2.5; the rock powder curing time is 8~72h, and the curing temperature is above 25°C.

[0022] Rock powder is generally composed of a variety of minerals and contains all the nutrients necessary for plants except nitrogen. Most of these nutrients exist in a stable chemical form and are not easily absorbed by plants directly. The low-molecular organic acid secreted by organisms can be used to mature rock powder, which can quickly release a large amount of effective nutrients and form water-soluble ions or water-soluble metal-organic chelates that are more easily absorbed by plants. At the same time, organic acids can improve the microstructure of rock powder minerals, increase the specific surface area of ​​rock powder, and facilitate the re-maturation of rock powder by plants and microorganisms.

[0023] Since the difficulty of breaking chemical bonds of different elements is different, the chemical bonds that break first will release more corresponding elements first. The release amount of a single element does not represent the release degree of all nutrient elements in the rock powder. Therefore, the present invention uses the release amount of the macroelements P and K, the medium elements Ca and Mg, and the trace element Fe required for plant growth during the ripening process as the quantitative evaluation standard.

[0024] The rock powder was matured under the experimental conditions of 0.1 mol / L organic acid concentration, room temperature, aging time of 2h, and solid-liquid ratio of 1:200. The nutrient release of the rock powder was measured after aging. The effect of organic acid type on the nutrient release of rock powder is shown in Figure 2. Figure 1As shown in the figure, the test results of distilled water, citric acid, oxalic acid, acetic acid, tartaric acid, fumaric acid, malic acid, succinic acid and malonic acid on nutrients phosphorus, potassium, magnesium, iron and calcium are shown. It can be seen from the figure that acetic acid, tartaric acid, succinic acid and malonic acid have good release effects on nutrients in rock powder. After comprehensive evaluation, it can be seen that malonic acid has the strongest release effect on phosphorus, magnesium and iron, and has a stronger release effect on potassium and calcium. Specifically, the release amounts of malonic acid for phosphorus, potassium, magnesium, iron and calcium reached 0.63, 0.58, 0.70, 2.76 and 24.11 mg / g, respectively, and the release ratios were 39.37%, 0.52%, 11.54%, 5.80% and 24.45%, respectively. Therefore, this scheme preferably uses malonic acid as the maturation agent. After determining the maturation agent, under the same experimental conditions, the effect of malonic acid on the release of nutrients from rock powder of different lithologies was studied, and the results are as follows. Figure 7 As shown in the figure, we can see that malonic acid has an obvious release effect on nutrients such as phosphorus, potassium, magnesium, iron, and calcium in rock powder of different rock types (sandstone, gneiss, slate, granite).

[0025] This study further explored the effects of organic acid concentration, pH value, aging time, aging temperature and solid-liquid ratio on nutrient release. The results can be found in the attached Figure 2 To Attachment Figure 6 As shown, when the organic acid concentration is 0.01~0.5mol / L, the organic acid pH is 1~2.5, the aging time is 8~72h, and the aging temperature is above 25℃, the nutrients phosphorus, potassium, magnesium, iron and calcium are released in a better amount.

[0026] Step 2: Mix the matured rock powder with cow dung, sheep dung, straw, etc. for composting. The ratio is: 0.5-2 parts of matured rock powder, 5-10 parts of cow dung, 1-3 parts of sheep dung, and 2-4 parts of straw.

[0027] When implementing composting in this step, you should choose a composting site with sufficient area to accommodate enough raw materials and facilitate the entry and exit of machinery trucks. It is preferred to choose a site that is close to the construction site and has convenient transportation. The site should preferably have a hardened road surface, be protected from light and rain, and be easy to ventilate. If the above conditions are not available, you can also use an open space at the construction site for composting, but you need to do a good job of insulation and rain protection.

[0028] Preferably, in the scheme of the present invention, the moisture content of the pile during the composting process is controlled at 50% to 60%. At this moisture content, the microorganisms have higher activity, which is beneficial to the composting process.

[0029] Preferably, the pile is not turned over in the first two days of composting to ensure that the pile can quickly enter the high temperature period. When the temperature rises to above 55°C, the oxygen and water consumption of the microorganisms are large, and the pile needs to be turned over every day. After the temperature drops below 50°C, the oxygen consumption of the microorganisms decreases, and the pile is turned over every 3 days, and water is added at the same time.

[0030] In the scheme of the present invention, the composting process is controlled according to the process of heating period-high temperature period-cooling period-stabilization period. Among them, the heating period lasts for 1 to 3 days, and the ambient temperature is controlled at 35 to 40°C; the high temperature period lasts for 3 to 7 days, and the ambient temperature is controlled at 40 to 45°C; the cooling period lasts for 15 to 30 days, and the ambient temperature is controlled at 30 to 40°C; the ambient temperature is controlled at room temperature during the stabilization period. By controlling the ambient temperature, the composting process can be accelerated as much as possible, and the heat lost due to turning the pile can be reduced. The controlled temperature is lower than the temperature of the pile itself, which is conducive to monitoring the composting process. The influence of organic acid matured rock powder on the temperature during the composting process is as follows Figure 8 As shown in the attached figure, compared with the control group CK without the addition of organic acid matured rock powder, the group M-YF with the addition of organic acid matured rock powder can make the pile enter the high temperature stage faster, and the temperature during composting is generally slightly higher than that of the control group. The composting enters the cooling stage around 20 days, indicating that matured rock powder can accelerate the composting process and enhance the decomposition effect of microorganisms on the pile.

[0031] Composting is an aerobic fermentation process of microorganisms, in which microorganisms consume a lot of oxygen. Too low aeration is not conducive to the aerobic respiration of microorganisms, and too high aeration is not conducive to the maintenance of the temperature of the compost. Therefore, in the composting process of the present invention, the preferred aeration rate is maintained at 0.5-0.8L / kg·min, forced ventilation is adopted for 5 minutes, and paused for 45 minutes.

[0032] Preferably, the composting time in the present invention is 25 to 45 days.

[0033] like Fig.14 The SEM images of rock powder (a) and mature rock powder (b) are shown. As can be seen from the figure, compared with the surface microstructure of rock powder, the morphology of some areas on the surface of mature rock powder is almost unchanged, while the morphology of some areas changes greatly, which mainly depends on the mineral type in the area where the rock powder is located. For example, clinochlore is a typical clay mineral, and calcite is a carbonate mineral. The crystal structure stability of these minerals is poor and they are easily destroyed. Therefore, these minerals mainly show overall dissolution (the red line area in Figure a and b). In addition, after malonic acid dissolution, a series of pits and holes appeared on the surface of mature rock powder (the orange line area in Figure a and b), and some dissolution cracks were also produced (the green line area in Figure a and b). The above morphological changes indicate that the nutrients of mature rock powder have been significantly released and the surface structure has been significantly improved.

[0034] The test results of the structural characteristics of rock powder and matured rock powder are shown in Table 1 below. It can be seen that under the action of organic acid, the surface structure of the matured rock powder is improved and the specific surface area of ​​the rock powder is increased. At this time, using matured rock powder as a compost mineral additive can provide rich effective nutrients and growth sites for the rapid reproduction of microorganisms, accelerate the compost humification process, and facilitate compost maturation.

[0035] Table 1 Test results of structural characteristics of rock powder and matured rock powder At the same time, the pH value of the pile increases rapidly due to the generation of ammonia during the composting process. The organic acid matured rock powder is weakly acidic and can neutralize part of the alkalinity generated by ammonia, thereby improving the pH value of the pile. The effect of organic acid matured rock powder on the pH value during the composting process can be found in the attached Fig. 9 As shown, it can be seen that compared with the control group CK, the pH value during the composting process was significantly improved after adding mature rock powder.

[0036] In addition, since mature rock powder can promote the rapid growth of microorganisms, it consumes more active ions in the pile faster, thereby reducing the conductivity of the pile. The effect of organic acid mature rock powder on the conductivity during composting can be found in the attached Fig.10 It can be seen that compared with the control group CK, the conductivity was gradually improved during the composting process after adding mature rock powder.

[0037] And due to the addition of mature rock powder, the rock powder can absorb and retain some nitrogen and carbon, thus compensating for the nitrogen and carbon losses during the composting process. The effects of organic acid mature rock powder on ammonium nitrogen / nitrate nitrogen during composting can be referred to the attached Fig.11 and 12 It can be seen that compared with the control group CK, the addition of mature rock powder increased the content of ammonium nitrogen and nitrate nitrogen during composting; the effect of organic acid mature rock powder on soluble organic carbon during composting can be referred to the attached Fig.13 It can be seen that the addition of mature rock powder significantly increased the soluble organic carbon content during the composting process.

[0038] Therefore, the present invention uses the rock powder acidified with organic acid to compost together with the pile, which can improve the pH and conductivity of the pile, accelerate the composting progress, enhance the composting humification effect, and supplement the pile with a large amount of nutrients required for plant growth. In this way, the waste rock powder can be rationally treated and the composting effect can be enhanced, achieving the dual effect of resource utilization, which is of great significance to economic sustainable development and environmental protection.

[0039] like Figures 15 to 22As shown in the figure, with no rock powder added and mature rock powder added as controls, the effects of mature rock powder on the changes in the content of available phosphorus, available potassium, exchangeable calcium, exchangeable magnesium, available iron, available manganese, available copper, and available zinc during the composting process were respectively demonstrated. The results show that mature rock powder makes the mature compost richer in available nutrients, indicating that mature rock powder can enrich the content of various available nutrients in compost.

[0040] Effect of mature rock powder on the changes of humus and fulvic acid content during composting Figure 23-24 The results showed that the humus and fulvic acid contents of mature rock powder compost were higher, indicating that mature rock powder can make the compost reach a higher degree of humification.

[0041] This method can be applied to improve the matrix of ecological restoration and perfect the nutrient structure of the matrix, thereby reducing the risk of site instability and soil erosion. It can also solve the problems of high ecological restoration costs, poor matrix nutrient structure and difficulty in obtaining soil.

[0042] Exemplary Embodiment 2 This exemplary embodiment provides a method for slag-discharging and assisted composting in an organic acid maturation tunnel, comprising the following steps: Step 1: Use waste rock powder as raw material, add malonic acid solution as a curing agent, and obtain mature rock powder; wherein the solid-liquid ratio of machine-made sandstone powder to malonic acid solution is 1:10; the concentration of malonic acid solution is 0.2 mol / L, the pH is 1.5, the curing time is 20 hours, and the curing temperature is 25°C.

[0043] Step 2: Mix the matured rock powder with cow dung, sheep dung, straw, etc. for composting. The ratio is: 0.5 parts of matured rock powder, 5 parts of cow dung, 1 part of sheep dung, and 2 parts of straw.

[0044] The composting process is controlled according to the process of heating period-high temperature period-cooling period-stable period. The heating period lasts for 1 day, and the ambient temperature is controlled at 35℃; the high temperature period lasts for 3 days, and the ambient temperature is controlled at 40℃; the cooling period lasts for 15 days, and the ambient temperature is controlled at 30℃. No turning of the pile is performed in the first two days of composting. When the temperature rises above 55℃, the pile is turned every day. After the temperature drops below 50℃, the pile is turned every 3 days, and water is added at the same time to control the moisture content of the pile at 55%. During the composting process, the aeration volume is maintained at 0.5L / kg·min, and forced ventilation is adopted for 5 minutes, and then paused for 45 minutes. Composting is completed after 20 days.

[0045] Exemplary Embodiment 3 This exemplary embodiment provides a method for slag-discharging and assisted composting in an organic acid maturation tunnel, comprising the following steps: Step 1: Use waste rock powder as raw material, add malonic acid solution as a curing agent, and obtain mature rock powder; wherein the solid-liquid ratio of rock powder to malonic acid solution is 1:50; the concentration of malonic acid solution is 0.2 mol / L, the pH is 1.5, the curing time is 40h, and the curing temperature is 25°C.

[0046] Step 2: Mix the matured rock powder with cow dung, sheep dung, straw, etc. for composting. The ratio is: 1 part of matured rock powder, 7 parts of cow dung, 2 parts of sheep dung, and 3 parts of straw.

[0047] The composting process is controlled according to the process of heating period-high temperature period-cooling period-stable period. The heating period lasts for 2 days, and the ambient temperature is controlled at 35℃; the high temperature period lasts for 5 days, and the ambient temperature is controlled at 40℃; the cooling period lasts for 20 days, and the ambient temperature is controlled at 30℃. No turning of the pile is performed in the first two days of composting. When the temperature rises above 55℃, the pile is turned every day. After the temperature drops below 50℃, the pile is turned every 3 days, and water is added at the same time to control the moisture content of the pile at 55%. During the composting process, the aeration volume is maintained at 0.5L / kg·min, and forced ventilation is adopted for 5 minutes and paused for 45 minutes. Composting is completed after 30 days.

[0048] Example 4 This exemplary embodiment provides a method for slag-discharging and assisted composting in an organic acid maturation tunnel, comprising the following steps: Step 1: Use waste rock powder as raw material, add malonic acid solution as a curing agent, and obtain mature rock powder; wherein the solid-liquid ratio of rock powder to malonic acid solution is 1:80; the concentration of malonic acid solution is 0.2 mol / L, the pH is 1.5, the curing time is 60h, and the curing temperature is 25°C.

[0049] Step 2: Mix the matured rock powder with cow dung, sheep dung, straw, etc. for composting. The ratio is: 2 parts of matured rock powder, 10 parts of cow dung, 3 parts of sheep dung, and 4 parts of straw.

[0050] The composting process is controlled according to the process of heating period-high temperature period-cooling period-stable period. The heating period lasts for 3 days, and the ambient temperature is controlled at 35℃; the high temperature period lasts for 7 days, and the ambient temperature is controlled at 45℃; the cooling period lasts for 30 days, and the ambient temperature is controlled at 30℃. No turning of the pile is performed in the first two days of composting. When the temperature rises above 55℃, the pile is turned every day. After the temperature drops below 50℃, the pile is turned every 3 days, and water is added at the same time to control the moisture content of the pile at 55%. During the composting process, the aeration volume is maintained at 0.8L / kg·min, and forced ventilation is adopted for 5 minutes, and then paused for 45 minutes. Composting is completed after 40 days.

[0051] Exemplary Embodiment 5 This exemplary embodiment provides a fertilizer, which includes the fertilizer prepared by the method of organic acid maturation tunnel slag assisted composting described in exemplary embodiments 1 to 4.

[0052] In this embodiment, the soluble organic carbon content in the fertilizer is 12-18 g / kg, the nitrate nitrogen content is 1.2-1.8 g / kg, and the ammonium nitrogen content is 0.3-0.7 g / kg.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for slag-assisted composting in an organic acid maturation tunnel, characterized in that: include: Take rock powder as raw material, add binary organic acid solution as maturation agent, stir and react fully, then add it into the mixed pile of cow dung, sheep dung and straw for composting. The ratio of composting raw materials is: 0.5~2 parts of maturation rock powder, 5~10 parts of cow dung, 1~3 parts of sheep dung and 2~4 parts of straw.

2. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: The dibasic organic acids include acetic acid, tartaric acid, succinic acid and malonic acid.

3. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 2, characterized in that: The dibasic organic acid is malonic acid, the concentration of the malonic acid solution is 0.01-0.5 mol / L, the pH is 1-2.5, and the solid-liquid ratio of the rock powder to the malonic acid solution is 1:2-1:

100.

4. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: The rock powder aging time is 8~72h, and the aging temperature is above 25℃.

5. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: During the composting process, the moisture content of the pile is controlled at 50%~60%.

6. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: The composting process is controlled according to the process of heating period-high temperature period-cooling period-stabilization period. The heating period lasts 1 to 3 days, and the ambient temperature is controlled at 35 to 40°C; the high temperature period lasts 3 to 7 days, and the ambient temperature is controlled at 40 to 45°C; the cooling period lasts 15 to 30 days, and the ambient temperature is controlled at 30 to 40°C; the ambient temperature during the stabilization period is controlled at room temperature.

7. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: During the composting process, the aeration volume was maintained at 0.5~0.8L / kg·min, and forced ventilation was adopted for 5 minutes and paused for 45 minutes.

8. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: Do not turn the pile in the first two days of composting. When the temperature rises above 55℃, turn the pile every day. After the temperature drops below 50℃, turn the pile every 3 days and replenish moisture in the pile.

9. The method for slag-assisted composting in an organic acid maturation tunnel as claimed in claim 1, characterized in that: The composting time is 25 to 45 days.

10. A fertilizer, characterized in that: The fertilizer is prepared by using the organic acid maturation tunnel slag-assisted composting method as described in any one of claims 1 to 9.

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