A kind of air separation lignite fine powder and rumen content composite water-saving type organic fertilizer and its preparation method

Abstract

The present application relates to the field of agricultural waste resource utilization and organic fertilizer preparation technology, and provides a kind of air separation lignite fine powder and rumen content composite water-saving organic fertilizer and a preparation method thereof.The fertilizer is prepared by using air separation lignite fine powder, fresh cattle and sheep rumen content, anaerobic fermentation liquid as main raw materials, and by compounding zeolite powder and composite fermentation agent.The present application solves the industry problem of high-value utilization of regional lignite air separation fine powder, and realizes the collaborative resource utilization of three types of waste;the biogas slurry completely replaces water for fermentation, is suitable for water-saving production in arid areas, accurately controls the carbon-nitrogen ratio to 22-24:1, and effectively reduces nitrogen loss.The finished product has organic matter≥50%, humic acid≥18%, and moisture≤30%, can significantly improve degraded soil, saline-alkali soil and grassland, improve soil water and fertilizer retention capacity, and has simple process, low cost, and significant ecological and economic benefits.

Description

Technical Field

[0001] This invention relates to the fields of agricultural waste resource utilization and organic fertilizer preparation technology, specifically to a water-saving organic fertilizer composed of air-separated lignite powder and rumen contents, and its preparation method. Background Technology

[0002] During the dry air classification and upgrading process of lignite, a large amount of by-product, fine lignite powder (particle size ≤0.15mm), is generated annually. This powder has a low humic acid content of only 12%–22%, and a relatively high ash content (approximately 25%–35%), containing a certain amount of clay minerals such as montmorillonite. If used specifically for humic acid extraction, it suffers from low extraction efficiency, high purification costs, and poor economic returns. Therefore, humic acid processing enterprises generally do not choose this type of air-classified lignite powder as a production raw material. Consequently, the fine lignite powder generated in Xilinhot and surrounding lignite-producing areas has long been disposed of in low-value ways, such as open-air stockpiling, landfilling, or low-cost incineration. This not only wastes resources but also easily generates dust and leaching water pollution, failing to achieve high-value utilization and becoming a prominent problem in the disposal of lignite processing by-products in the region.

[0003] Local large-scale slaughterhouses slaughter a large number of cattle and sheep annually, generating a large amount of fresh rumen contents. Traditional disposal methods mainly involve landfilling and incineration, which not only wastes the rich nutrients such as crude protein and organic matter, but also easily produces foul odors, breeds pathogens, and causes secondary environmental pollution. At the same time, if the biogas slurry produced by anaerobic fermentation in large-scale farms is directly discharged, it can easily cause eutrophication of water bodies; and the traditional organic fertilizer production process relies on a large amount of clean water for moisture regulation, which is difficult to promote sustainably in the arid and water-scarce conditions of Xilingol League.

[0004] Existing technologies have the following significant shortcomings: First, while existing reports involve the co-fermentation of lignite with livestock and poultry manure or the utilization of biogas slurry, none have proposed feasible resource utilization solutions for the low-humic-acid, high-ash air-classified fine powder from Xilinhot and surrounding production areas. Second, there is a lack of synergistic utilization processes for the three types of waste: lignite air-classification byproducts, slaughterhouse waste, and agricultural biogas slurry, resulting in low resource utilization efficiency. Third, the fermentation process consumes a large amount of water and lacks targeted improvement capabilities for degraded soils. Therefore, developing an organic fertilizer technology that addresses low-quality lignite fine powder from specific production areas, achieves synergistic utilization of the three wastes, and saves water throughout the entire process, possesses significant novelty and creativity. Summary of the Invention

[0005] To overcome the shortcomings of the above-mentioned technologies, this invention provides a water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents, and its preparation method. This invention solves the technical problems in the prior art, such as the difficulty in high-value utilization of air-separated lignite fine powder from the Datang Shengli Coalfield and surrounding lignite producing areas in Xilinhot City due to its low humic acid content, high ash content, and high refining cost, as well as the poor synergy of resource utilization of various wastes, high water consumption during fermentation, insufficient soil improvement effect, and high nitrogen loss.

[0006] The technical solution of this invention is as follows: In a first aspect, this invention provides a water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents, comprising the following raw materials in parts by weight: 20-25 parts of dry air-separated lignite fine powder, 60-65 parts of fresh bovine and ovine rumen contents, 10-12 parts of anaerobic fermentation biogas slurry, 5 parts of zeolite powder, and 0.25 parts of compound fermentation agent; wherein, the dry air-separated lignite fine powder is a by-product of dry air separation and upgrading of lignite from the Datang Shengli Coalfield and surrounding lignite producing areas in Xilinhot City, and the compound fermentation agent is a mixed inoculant of *Phanerochaete chrysosporium*, *Bacillus subtilis*, and effective microbial flora in a weight ratio of 1:1:2, with an effective viable count ≥2.5 × 10⁻⁶. 8 cfu / g.

[0007] The effective microbial flora is a commercially available EM effective microbial flora.

[0008] Further optimization includes the following raw materials in parts by weight: 20 parts dry air-separated lignite powder, 65 parts fresh rumen contents of cattle and sheep, 10 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent.

[0009] Further optimization includes the following raw materials in parts by weight: 25 parts dry air-separated lignite powder, 60 parts fresh rumen contents of cattle and sheep, 10 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent.

[0010] Further optimization includes the following raw materials in parts by weight: 20 parts dry air-separated lignite powder, 63 parts fresh rumen contents of cattle and sheep, 12 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent.

[0011] Further optimization resulted in the following organic composition parameters for this organic fertilizer: organic matter ≥50%, humic acid ≥18%, total nutrients ≥6.0%, carbon-nitrogen ratio of 22~24:1, germination index ≥85%, and moisture ≤30%.

[0012] Secondly, the present invention provides a method for preparing a water-saving organic fertilizer composed of air-separated lignite powder and rumen contents, comprising the following steps: Step 1: Mix the pretreated rumen contents with the compound fermentation agent and build windrows. Ferment at 55-65℃ for 5 days to complete the initial fermentation. Step 2: Add air-separated lignite powder and zeolite powder to the material that has undergone preliminary fermentation and mix well. Spray anaerobic fermentation biogas slurry to adjust the moisture content to 58%. Continue fermentation at 50-55℃ for 9 days to complete the secondary fermentation. Step 3: The material from the secondary fermentation is aged at 15~35℃ for 8 days, dried until the moisture content is ≤28%, crushed and sieved to obtain the finished organic fertilizer.

[0013] Further optimization involves the following pretreatment method for the rumen contents: Unfermented material collected after slaughter is selected and subjected to high-temperature (170-180℃) treatment for 1-3 hours to achieve a moisture content of 62%-64%, a crude protein content ≥13%, and an organic matter content ≥88%. Further optimization resulted in the following: the fine powder of the air-separated lignite had a particle size of ≤0.15mm, a moisture content of ≤15%, and a humic acid content of 12%~22%.

[0014] Further optimization resulted in the following component percentages for the anaerobic fermentation slurry: nitrogen 0.4%~0.6%, phosphorus 0.15%~0.25%, potassium 0.25%~0.35%; and a pH value of 6.8~7.2.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In response to the pain points of low humic acid content, high ash content, and high refining cost of air-separated lignite fine powder, this invention eliminates the need for humic acid extraction and directly prepares high-value-added organic fertilizer through co-fermentation with rumen contents and biogas slurry, providing a stable and sustainable utilization path for low-quality lignite by-products in the region. 2. Co-utilization of waste gas, wastewater, and solid waste yields significant environmental benefits. For every 10,000 tons of finished organic fertilizer (moisture content ≤30%) produced, approximately 3,000 tons of dry-process air-separated lignite powder, approximately 9,800 tons of fresh bovine and ovine rumen contents, and approximately 1,500 tons of anaerobic fermentation biogas slurry can be disposed of, demonstrating significant effects in waste reduction, resource recovery, and harmlessness. 3. The entire process of biogas slurry replaces clean water, resulting in significant water conservation. Biogas slurry completely replaces water used in production, saving approximately 1,500 tons of water per 10,000 tons of organic fertilizer products, making it highly suitable for production in arid and water-scarce regions. 4. Precise control of carbon-nitrogen ratio, stable fertilizer effect and low nitrogen loss. The carbon-nitrogen ratio of the system is stable at 22~24:1, and the nitrogen loss rate is reduced to about 12% (compared to about 20% in traditional processes). The finished product has high organic matter and humic acid content, and has outstanding effects on improving degraded grasslands and saline-alkali land. It can significantly improve forage yield and soil water and fertilizer retention capacity. 5. Raw material costs are significantly reduced, resulting in substantial economic benefits. Both rumen contents and air-separated lignite powder are low-cost byproducts, and the overall raw material cost is 40% to 60% lower than that of the traditional sheep manure and cow manure system, making it suitable for large-scale promotion. 6. Simple process, short cycle, and easy to implement. The step-by-step windrow fermentation method requires no complicated equipment, has a short fermentation cycle, and can be used locally in Xilingol League, making it highly valuable for promotion. Attached Figure Description

[0016] Figure 1 The temperature change curves of the pile body during the pre-composting stage (0-5d) for Example 1 and Comparative Example 1 are shown. Figure 2 The temperature change curves of the pile body during the re-curing stage (6-14 days) for Example 1 and Comparative Example 1 are shown. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0018] The present invention provides a water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents, comprising the following raw materials in parts by weight: 20-25 parts of dry air-separated lignite fine powder, 60-65 parts of fresh cattle and sheep rumen contents, 10-12 parts of anaerobic fermentation biogas slurry, 5 parts of zeolite powder, and 0.25 parts of compound fermentation agent.

[0019] Among them, the dry air-classified lignite fine powder is a by-product of the dry air-classification and upgrading of lignite in the Datang Shengli Coalfield and surrounding lignite producing areas in Xilinhot City. It has a particle size of ≤0.15mm, moisture content of ≤15%, humic acid content of 12%~18%, and contains clay minerals such as montmorillonite.

[0020] Fresh rumen contents of cattle and sheep are unfermented materials collected within 2 hours after slaughter, with impurities (hair, feed residue, etc.) content ≤5%. They are treated at 170~180℃ for 1~3 hours to achieve a harmless effect, and dehydrated to a moisture content of 62%~64%, with a crude protein content ≥13% and an organic matter content ≥88%.

[0021] The anaerobic fermentation biogas slurry originates from the biogas project of Inner Mongolia Yuanhao Cashmere Products Co., Ltd. Its preparation process involves using fresh cow and sheep manure (C / N 20-25:1) as raw material. After crushing, it is fed with approximately 5% TS (total saturation). A fully mixed anaerobic fermentation process is employed at a mesophilic temperature of 38℃ for stable fermentation. The residence time is 30 days, and continuous stable gas production lasts for six months or more, indicating a stable fermentation process. After stable operation, the fermentation liquid that enters the sedimentation tank daily is the anaerobic fermentation biogas slurry. The anaerobic fermentation biogas slurry contains 0.4%–0.6% nitrogen, 0.15%–0.25% phosphorus (P2O5), and 0.25%–0.35% potassium (K2O), with a pH of 6.8–7.2. The nitrogen and phosphorus contents in the anaerobic fermentation biogas slurry are determined using methods in GB 11894-89 and GB 11893-89, respectively, while the potassium content is determined using inductively coupled plasma atomic emission spectrometry (ICP-AES). In this invention, biogas slurry completely replaces clean water to regulate the moisture content of the fermentation system. The active microorganisms and nutrients it contains can quickly start fermentation, buffer the pH of the system, and improve the uniformity of fermentation.

[0022] The zeolite powder is 90 mesh with an adsorption capacity ≥18mg / g. Its porous structure can adsorb ammonia nitrogen, reduce nitrogen loss, improve material permeability, stabilize the fermentation environment, and enhance fertilizer safety.

[0023] The compound fermentation agent is a mixture of commercially available *Phanerochaete chrysosporium*, *Bacillus subtilis*, and EM (Effective Microorganisms) microbial flora, formulated in a weight ratio of 1:1:2, with an effective viable count ≥2.5 × 10⁻⁶. 8 cfu / g. All three microbial agents were purchased from Hubei Qiming Biotechnology Co., Ltd.; among them, the commercially available EM effective microbial flora is the liquid form of EM stock solution: the liquid EM stock solution contains Lactobacillus lactis, Streptococcus lactis, and Rhodopseudomonas palustris.

[0024] A method for preparing a water-saving organic fertilizer composed of air-separated lignite powder and rumen contents includes the following steps: Step 1: Mix the pretreated rumen contents with the compound fermentation agent evenly, pile them into windrows 2.2m wide and 1.3m high, control the temperature of the pile at 55~65℃, ferment for 5 days, turn the pile every 2 days to complete the initial decomposition and kill pathogens and insect eggs; Step 2: Add air-separated lignite powder and zeolite powder to the pre-composted material, stir evenly, spray biogas slurry to adjust the material moisture to 58%, and do not add water throughout the process; control the pile temperature at 50~55℃, continue fermentation for 9 days, turn the pile every 3 days, and the carbon-nitrogen ratio of this system is 22~24:1. Step 3: The fermented material is naturally aged at a temperature of 15~35℃ for 8 days, then dried at a temperature of 55℃ until the moisture content is ≤28%. After crushing and sieving, the finished organic fertilizer is obtained.

[0025] Depending on actual production needs, the finished organic fertilizer can be granulated, dried, cooled, and packaged after adding a binder. Example 1

[0026] A water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents, comprising the following raw materials in parts by weight: 20 parts air-separated lignite fine powder, 65 parts fresh bovine / sheep rumen contents, 10 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent. The air-separated lignite fine powder is a byproduct of dry air separation and upgrading of lignite from the Datang Shengli coalfield and surrounding lignite-producing areas in Xilinhot City. Its preparation method is as follows: Step 1: Mix the pretreated rumen contents with the compound fermentation agent evenly, pile them into windrows 2.2m wide and 1.3m high, control the temperature of the pile at 55~65℃, ferment for 5 days, turn the pile every 2 days to complete the initial decomposition and kill pathogens and insect eggs; Step 2: Add air-separated lignite powder and zeolite powder to the pre-composted material, stir evenly, spray biogas slurry to adjust the material moisture to 58%, and do not add water throughout the process; control the pile temperature at 50~55℃, continue fermentation for 9 days, turn the pile every 3 days, and the carbon-nitrogen ratio of this system is 22~24:1. Step 3: The fermented material is naturally aged at a temperature of 15~35℃ for 8 days, then dried at a temperature of 55℃ until the moisture content is ≤28%. After crushing and sieving, the finished organic fertilizer is obtained.

[0027] The organic fertilizer product was tested for organic matter, total nutrients, seed germination index, and moisture according to the testing methods specified in NY / T 525-2021; the humic acid content was tested according to GB / T 11957-2001, and its organic composition is shown in Table 1. Table 1 Organic Composition Table of Product in Example 1

[0028] The organic fertilizer prepared in this embodiment was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot. It was evenly spread using a wheeled fertilizer spreader at a rate of 1.5 tons per mu. The effects of application were as follows: forage yield increased by 18%, soil organic matter increased by 1.2 percentage points, soil bulk density decreased by 0.15 g / cm³, porosity increased by 8%, and soil water retention capacity (field water holding capacity) increased by 22%.

[0029] Comparative Example 1 It is basically the same as Example 1, except that: clean water is used instead of anaerobic fermentation biogas slurry.

[0030] The organic fertilizer prepared in this comparative ratio was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot at a rate of 1.5 tons / mu. The effects were as follows: the fermentation cycle was extended by 2 days, the nitrogen loss rate increased to 22%, the organic matter was 48%, the humic acid was 17%, the forage yield increased by only 12%, and there was no water-saving effect.

[0031] Comparative experiment A two-stage comparative experiment was conducted on Example 1 and Comparative Example 1 over 14 days: a pre-curing stage (0-5 days) and a re-curing stage (6-14 days). The temperature change of the compost pile was continuously monitored, and the results are as follows: Figure 1-2 .

[0032] 1. Temperature changes during the pre-fermentation stage (0~5 days) During the pre-composting stage, the initial temperature of both piles was 25°C. From 0 to 3 days, the temperature of both piles continued to rise, with rapid proliferation of microorganisms and degradation of organic matter releasing a large amount of heat. Both piles reached their temperature peaks on the 3rd day: the highest temperature in Example 1 was 65°C, and the highest temperature in Comparative Example 1 was 55°C. Throughout the entire heating cycle, the temperature of the pile in Example 1 was always higher than that in Comparative Example 1.

[0033] The temperature drops during the 3-5 day cooling phase. The easily degradable organic matter is gradually consumed, the heat generation rate decreases, and the temperature of the pile slowly drops. By the 5th day, the temperature of Example 1 drops to 55°C, and that of Comparative Example 1 drops to 45°C.

[0034] The results showed that adding biogas slurry could enhance the activity of microorganisms in the compost pile, promote rapid heating of the system, increase the maximum temperature of the compost pile, extend the high-temperature composting range, and facilitate the initial degradation of raw materials.

[0035] 2. Temperature changes during the re-fermentation stage (6-14 days) During the re-maturation stage (6-14 days), the temperature of both sets of piles showed a trend of first rising and then continuously decreasing. The pile temperature rose a second time from 6 to 7 days, reaching the peak temperature of the re-maturation stage on the 7th day: 54℃ in Example 1 and 45℃ in Comparative Example 1.

[0036] From day 7 to 14, as the available substrate was continuously consumed, the heat generation capacity gradually weakened, and the temperature of both sets of reactors steadily and continuously decreased; on day 14, the temperature of Example 1 was 45°C, and the temperature of Comparative Example 1 was 35°C.

[0037] Throughout the entire re-fermentation cycle, the temperature of the compost pile in Example 1 remained higher than that in Comparative Example 1, indicating that the microbial advantage brought by the biogas slurry inoculation continued to play a role in the re-fermentation stage, maintaining a stable fermentation temperature and ensuring the further transformation of recalcitrant organic matter.

[0038] In summary, throughout the entire composting cycle, the pile temperature in Example 1 was significantly higher than that in Comparative Example 1 in both stages. Whether in the pre-composting or re-composting stages, biogas slurry inoculation effectively activated the microorganisms in the composting system, enhanced the pile's heat production capacity, achieved a higher peak temperature, and maintained a higher pile temperature throughout the entire process. The higher pile temperature promoted organic matter degradation and also helped kill harmful microorganisms in the material, improving the quality of the composted products. This demonstrates that biogas slurry, as an inoculant, has a significant promoting effect on the composting process. Example 2

[0039] The preparation steps are basically the same as in Example 1, except for the proportions of raw materials: 25 parts of air-separated lignite fine powder, 60 parts of fresh bovine and ovine rumen contents, 10 parts of anaerobic fermentation biogas slurry, 5 parts of zeolite powder, and 0.25 parts of compound fermentation agent.

[0040] The organic fertilizer product was tested, and its organic composition is shown in Table 2: Table 2 Organic Composition Table of Product in Example 2

[0041] The organic fertilizer prepared in this embodiment was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot at a rate of 1.5 tons per mu. The effects of application were as follows: forage yield increased by 17%, soil organic matter increased by 1.3 percentage points, and soil water retention capacity increased by 24%. The increased proportion of fine lignite powder made the soil aggregate structure improvement effect more prominent. Example 3

[0042] The preparation steps are basically the same as in Example 1, except for the proportions of raw materials: 20 parts of air-separated lignite fine powder, 63 parts of fresh bovine and ovine rumen contents, 12 parts of anaerobic fermentation biogas slurry, 5 parts of zeolite powder, and 0.25 parts of compound fermentation agent.

[0043] The organic fertilizer product was tested, and its organic composition is shown in Table 3: Table 3 Organic ingredient list of the product in Example 3

[0044] The organic fertilizer prepared in this embodiment was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot at a rate of 1.5 tons per mu. The effects of the application were: the forage yield increased by 19%, the fermentation start-up speed was 1 day earlier than in Example 1, and the decomposition was more uniform and thorough.

[0045] Comparative Example 2 It is basically the same as Example 1, except that no air-separated lignite fine powder is added.

[0046] The organic fertilizer prepared in this comparative example was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot at a rate of 1.5 tons per mu. The results showed that the humic acid content of the finished product was only 10%, the soil improvement effect was significantly reduced, and the forage yield increased by only 10%, which failed to achieve the high-value utilization of lignite processing by-products.

[0047] Comparative Example 3 It is basically the same as Example 1, except that 40 parts of sheep manure and 25 parts of cow manure are used instead of fresh rumen contents.

[0048] The organic fertilizer prepared in this comparative example was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot at a rate of 1.5 tons per mu. The effects were as follows: the raw material cost was more than 2.1 times that of Example 1, the fermentation cycle was extended to 16 days, the forage yield increased by 14%, the nitrogen loss rate was 20%, and the economic benefits were significantly reduced.

[0049] Comparative Example 4 The process is basically the same as in Example 1, except that: an unfermented fresh cow and sheep manure slurry (manure + water) with an equivalent nitrogen content (0.5% nitrogen) is used instead of anaerobic fermentation biogas slurry. The fermentation and post-treatment conditions are exactly the same as in Example 1.

[0050] Regarding fermentation: the fermentation temperature rises slowly, the high-temperature period lasts for a short time, the highest temperature is about 52℃, and the maturation period is extended to 22 days.

[0051] In terms of finished product composition: organic matter 47%, humic acid 15%, total nutrients 5.2%; nitrogen loss rate increased to 24%, germination index (GI) was 72%.

[0052] The organic fertilizer prepared in this comparative ratio was applied to the degraded grassland of Baiyinxile Ranch in Xilinhot at a rate of 1.5 tons / mu. The effects were as follows: the forage yield increased by only 11%, and the soil water retention capacity increased by 9%; the material had a strong odor, was not fully decomposed, posed a risk of pathogen residue, and did not have a water-saving effect because it was mixed with water.

[0053] Comparative Example 5 This is basically the same as Example 1, except that fine lignite powder from a certain production area in Yunnan is used instead of air-separated lignite powder.

[0054] Regarding the composition of the finished product: the humic acid content of the organic fertilizer in this comparative example is only 16.8%, which is far lower than the 20% in the organic fertilizer of Example 1, and the former has a 35% higher increase in soil cation exchange capacity (CEC) than the latter. This indicates that the high montmorillonite content in the lignite fine powder of this production area synergistically promotes humification and fertilizer retention capacity during fermentation, and the geographical limitation has substantial technical significance.

[0055] Comparative Example 6 This comparative example uses commercially available organic fertilizers as test samples, of which 2 # To blend lignite granular organic fertilizer, 3 # To produce organic fertilizer made from blended lignite powder and wool, 4 # The coarse-grained organic fertilizer is a common commercial organic fertilizer without any added lignite fines, and the pure air-classified lignite fines selected in Examples 1-3 are labeled as 1. # As a control, the core indicators of moisture, total humic acid, and free humic acid in the samples were uniformly tested.

[0056] The test results show that, as shown in Table 4, 1 # The raw material used in Examples 1-3 is pure air-classified lignite fine powder with a moisture content of 18.52%, humic acid content of 14.86%, and free humic acid content of 15.65%. Although it possesses highly active free humic acid, the raw material is singular and lacks a mature organic system for support, making it unsuitable for direct use as a finished organic fertilizer. It also lacks water-saving and fertilizer-retaining functions. The total humic acid content in the compound water-saving organic fertilizer prepared using the methods in Examples 1-3 reaches over 20%. # The granular organic fertilizer contains 13.03% moisture, 15.80% humic acid, and 11.65% free humic acid. Conventional granulation processes significantly reduce the activity of free humic acid. Furthermore, to ensure granulation and storage stability, the production process requires deep drying and external water replenishment for humidity control, resulting in high water consumption and no water-saving advantages. # The powdered wool organic fertilizer contains 28.30% moisture, 13.64% humic acid, and 14.84% free humic acid. Although the powdered form retains the activity of humic acid well, the high moisture content makes it prone to caking and mold growth, resulting in poor storage and transportation stability. # The coarse-grained organic fertilizer is a conventional lignite-free organic fertilizer with a moisture content of 17.13%. It is stable during storage and transportation, but contains only 15.78% humic acid and 14.57% free humic acid. Compared to lignite-blended systems, it lacks mineral-derived humic acid synergistic components, significantly weakening its core performance in soil improvement, nutrient activation, and water retention. Overall, existing commercially available lignite-blended organic fertilizers suffer from simple processing, activity loss, poor stability, and lack of water-saving characteristics. Ordinary lignite-free organic fertilizers have low humic acid content and weak soil-improving and efficiency-enhancing capabilities. Neither type of product utilizes a rumen-containing complex microbial system or gradient fermentation process, thus failing to simultaneously achieve the multiple advantages of high-activity humic acid, excellent storage and transportation performance, and water-saving production.

[0057] Table 4.1 # -4 # Sample core indicator component table

[0058] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A water-saving organic fertilizer composed of air-separated lignite powder and rumen contents, characterized in that, The raw materials include the following parts by weight: 20-25 parts of dry-classified lignite fine powder, 60-65 parts of fresh bovine and ovine rumen contents, 10-12 parts of anaerobic fermentation slurry, 5 parts of zeolite powder, and 0.25 parts of compound fermentation agent; wherein, the dry-classified lignite fine powder is a by-product of dry-classification and upgrading of lignite from the Datang Shengli Coalfield and surrounding lignite producing areas in Xilinhot City, and the compound fermentation agent is a mixed inoculum of *Phanerochaete chrysosporium*, *Bacillus subtilis*, and effective microbial flora in a weight ratio of 1:1:2, with an effective viable count ≥2.5 × 10⁻⁶. 8 cfu / g.

2. The water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents as described in claim 1, characterized in that, The raw materials include the following parts by weight: 20 parts dry air-separated lignite powder, 65 parts fresh rumen contents of cattle and sheep, 10 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent.

3. The water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents as described in claim 1, characterized in that, The raw materials include the following parts by weight: 25 parts dry air-separated lignite powder, 60 parts fresh rumen contents of cattle and sheep, 10 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent.

4. The water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents as described in claim 1, characterized in that, The raw materials include the following parts by weight: 20 parts dry air-separated lignite powder, 63 parts fresh rumen contents of cattle and sheep, 12 parts anaerobic fermentation biogas slurry, 5 parts zeolite powder, and 0.25 parts compound fermentation agent.

5. The water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents as described in claim 1, characterized in that, The organic composition parameters of this organic fertilizer are: organic matter ≥50%, humic acid ≥18%, total nutrients ≥6.0%, carbon-nitrogen ratio of 22~24:1, germination index ≥85%, and moisture ≤30%.

6. The method for preparing a water-saving organic fertilizer composed of air-separated lignite fine powder and rumen contents according to claim 1, characterized in that, Includes the following steps: Step 1: Mix the pretreated rumen contents with the compound fermentation agent and build windrows. Ferment at 55-65℃ for 5 days to complete the initial fermentation. Step 2: Add air-separated lignite powder and zeolite powder to the material that has undergone preliminary fermentation and mix well. Spray anaerobic fermentation biogas slurry to adjust the moisture content to 58%. Continue fermentation at 50-55℃ for 9 days to complete the secondary fermentation. Step 3: The material from the secondary fermentation is aged at 15~35℃ for 8 days, dried until the moisture content is ≤28%, crushed and sieved to obtain the finished organic fertilizer.

7. The preparation method according to claim 6, characterized in that, The pretreatment method for the rumen contents is as follows: select unfermented materials collected after slaughter, treat them at a high temperature of 170~180℃ for 1~3 hours to remove moisture to 62%~64%, crude protein content ≥13%, and organic matter content ≥88%.

8. The preparation method according to claim 6, characterized in that, The air-separated lignite fine powder has a particle size ≤0.15mm, moisture content ≤15%, and humic acid content 12%~22%.

9. The preparation method according to claim 6, characterized in that, The anaerobic fermentation slurry contains the following percentage components: nitrogen 0.4%~0.6%, phosphorus 0.15%~0.25%, and potassium 0.25%~0.35%; its pH value is 6.8~7.2.

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