Organic fertilizer prepared based on purification treatment of coal gangue and preparation method of organic fertilizer

Abstract

The invention discloses an organic fertilizer prepared based on purification treatment of coal gangue and a preparation method of the organic fertilizer, and belongs to the technical field of bio-organic fertilizers. The method comprises the steps of coal gangue washing selection, coal gangue material activation, coal gangue fermentation, mixed fermentation and bacteria treatment. The preparation method comprises the following steps: firstly, performing water crushing, sorting, ball milling and the like on coal gangue, then soaking and activating in acid liquor, then sequentially performing aerobic fermentation and mixed fermentation, and then performing aging and bacteria treatment to prepare the organic fertilizer. According to the method, the problem that the organic fertilizer produced by using the coal gangue is weak in efficacy is solved based on the full pretreatment of the coal gangue for producing the organic fertilizer in the early stage in combination with an optimized fermentation process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bio-organic fertilizer, and particularly relates to an organic fertilizer prepared based on purification treatment of coal gangue and a preparation method thereof. BACKGROUND

[0002] Coal gangue is a waste in the process of coal mining and washing, and is one of the largest industrial solid wastes at present. Long-term accumulation of coal gangue occupies farmland and pollutes water quality, and harmful gases are generated after spontaneous combustion, which increases the greenhouse effect. The main components of coal gangue are SiO2 and Al2O3, and contain many nutrients required for plant growth, such as N, P, K, Ca, Mg, C, O and H, and also contain trace metal elements such as Ti, V, Co, Cd and Cr. The existing technology has used coal gangue for the production of bio-fertilizer, and the principle is to activate the dormant functional groups in coal gangue by biological degradation method to obtain humic acid required by plants, so as to prepare organic fertilizer. However, the existing technology has a complex production preparation method and high production cost for preparing organic fertilizer from coal gangue. Moreover, the coal gangue is not fully pretreated in the early stage, so that too many impurities are brought into the subsequent biological fermentation environment, which finally affects the fertilizer efficiency of the bio-organic fertilizer. SUMMARY

[0003] The application overcomes the shortcomings of the prior art, and provides an organic fertilizer prepared based on purification treatment of coal gangue and a preparation method thereof. The coal gangue used for producing the organic fertilizer is fully pretreated in the early stage, and an optimized fermentation process is combined to solve the problem of weak efficiency of the organic fertilizer produced from coal gangue. The application is realized by the following technical scheme: A method for preparing an organic fertilizer based on purification treatment of coal gangue, comprising the following steps: Step one, coal gangue washing and selection: The coal gangue is crushed into wet coal particles by adding water, and the particle size of the wet coal particles is 3mm-5mm. Water is further added to the wet coal particles to form coal slurry, and then the coal slurry is sent into a sorting machine for sorting. A part of the particles on the screen sorted from the sorting machine is collected for ball milling, and then the ball-milled part is mixed with the part not ball-milled to obtain treated coal gangue material; Step two, activation of coal gangue material The treated coal gangue material is soaked in a potassium nitrate solution with a mass fraction of 5-10% for 10-12h; Step three, fermentation of coal gangue The activated coal gangue material is mixed with 2-5% of fermentation bacteria liquid by mass to perform aerobic fermentation; Step four, mixed fermentation The fermented coal gangue is mixed with rural waste to form a mixture, and EM bacterial liquid is fully stirred with the mixture and fermented; after the fermentation is completed, the fermented product is transferred to an environment with a temperature of 55-65 DEG C for aging, and is placed for 10-20 days; Step five, bacterial treatment Beneficial bacteria are added to the aged mixture, the temperature is controlled at 30-35 DEG C, and the mixture is placed in a light-proof production workshop for 70-75 hours to complete the bacterial treatment, and the effective viable bacterial count reaches 2*10 8 cfu / g or more; Step six, granulation and packaging.

[0004] Preferably, in step one, the mass percentage of coal gangue in the coal slurry is 30-40%.

[0005] Preferably, in step one, after the separation is completed, the particles on the screen are sent to a magnetic separator to separate the metal components in the particles on the screen, and then ball milling is performed.

[0006] Preferably, in step two, calcium sulfate with a mass of 2-6% of the coal gangue material is added to the soaked coal gangue material, and the mixture is uniformly mixed. More preferably, after the calcium sulfate is added, the mixture is placed in an ultrasonic homogenizer for 1-2 hours for homogenization treatment to obtain the activated coal gangue material.

[0007] Preferably, in step three, the temperature of the aerobic fermentation is 35-38 DEG C, and the aerobic fermentation time is 2-3 days.

[0008] More preferably, in step three, the fermentation bacterial liquid contains bacillus mucilaginosus and bacillus megaterium.

[0009] Preferably, in step four, 0.5-1 kg of EM bacterial liquid is added per ton of the mixture.

[0010] Preferably, the rural waste includes animal manure and straw; the mass ratio of the fermented coal gangue, the animal manure and the straw is 7:2:1; and the length of the straw is ≤2 cm.

[0011] An organic fertilizer is prepared by the method.

[0012] The beneficial effects of the present application relative to the prior art are: The present application forms wet coal particles by water crushing the coal gangue, and the coal gangue with increased humidity and reduced particle size is beneficial to subsequent activation; through further separation, magnetic separation and ball milling, the coal gangue is further purified and refined, which can fully dissociate the minerals and is beneficial to subsequent fermentation treatment.

[0013] The activation of the coal gangue can further remove the metal impurities, and more importantly, through the acid pickling soaking, the alkaline components in the coal gangue can be degraded, and the bonding force of the organic matters in the coal gangue can be loosened, so that the fermentation can be more sufficient.

[0014] The coal gangue is fermented first, then mixed with the agricultural waste, and then subjected to secondary fermentation, so that the fermentation can be more sufficient, and through the aging, the fermentation product can be naturally degraded in a certain time, so that the prepared organic fertilizer has higher efficiency and quality. DETAILED DESCRIPTION

[0015] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. The technical solutions of the present application will be described in detail below in conjunction with the embodiments, but the protection scope is not limited thereto. Embodiment 1

[0016] The embodiment provides a method for preparing an organic fertilizer based on coal gangue purification treatment, which comprises the following steps: Step 1, coal gangue washing and selection: Water and coal gangue are added to a hammer crusher, and the hammer crusher is used for water crushing the coal gangue to form wet coal particles; the particle size of the wet coal particles is 4 mm; water is added to the wet coal particles to form a coal slurry, and the concentration of the coal gangue in the coal slurry is 35%; then the coal slurry is sent to a sorting machine for sorting, and the particles on the screen are collected from the sorting machine; then the particles on the screen are sent to a magnetic separator, the metal components in the particles on the screen are separated, and half of the particles on the screen after the magnetic separation are subjected to ball milling, and then mixed with the particles not subjected to the ball milling to obtain a treated coal gangue material.

[0017] Step 2, activation of the coal gangue material The treated coal gangue material is added into a potassium nitrate solution with a mass fraction of 8%, and soaked for 11 h; then calcium sulfate with a mass of 4% of the coal gangue material is added and uniformly mixed; the mixture is subjected to homogenization treatment in an ultrasonic homogenizer for 1.5 h to obtain an activated coal gangue material.

[0018] Step 3, fermentation of the coal gangue In the activated coal gangue material, 3.5% of the fermentation bacteria liquid by mass is added, and the fermentation bacteria liquid is the existing conventional starter used for fermentation of organic fertilizer; in this embodiment, the fermentation bacteria liquid contains Bacillus mucilaginosus and Bacillus megaterium; the fermentation temperature is controlled at 37°C, and aerobic fermentation is carried out for 2 days; in the process of aerobic fermentation, the fermentation starter releases the carbon, phosphorus, potassium, silicon, calcium and magnesium nutrients in the coal gangue; due to the sufficient washing and selection and activation of the coal gangue in the early stage, the microorganisms can quickly and fully decompose the coal gangue, and the formed minerals are more easily absorbed by plants, and the content of the minerals is higher.

[0019] Step four, mixed fermentation The fermented coal gangue is mixed with rural waste to form a mixture, wherein the rural waste is animal manure and straw; the mass ratio of the fermented coal gangue, animal manure (cow dung) and straw is 7:2:1; the length of the straw is ≤2 cm. 0.8 kg of EM bacteria liquid is added per ton of the mixture, the EM bacteria liquid is fully stirred with the mixture; and then conventional organic fertilizer fermentation is carried out. Step five, aging treatment After the fermentation is completed, the fermented material is transported to an aging tank in an aging workshop; the bottom of the aging tank is heated by a pipeline, and the top absorbs sunlight to reach a temperature of 65°C; and the fermented material is left to stand for 15 days. The mortality rate of insect eggs is ensured to be ≥99%, and a standard soil conditioner is produced.

[0020] Step six, bacteria treatment Beneficial bacteria such as Bifidobacterium (the beneficial bacteria are commercially available bacteria) are uniformly added to the soil conditioner; the temperature is controlled at 30°C; the production workshop is kept in the dark; and the bacteria treatment is completed after 72 hours of standing; and the effective viable bacterial count needs to be ≥2×10 8 cfu / g.

[0021] Step seven, nutrient allocation of organic fertilizer According to the standard NY / T 525-2021 “Organic Fertilizer”, the total content of nitrogen, phosphorus and potassium in the bacteria-treated material is detected; urea (nitrogen source), monoammonium phosphate (phosphorus source) and potassium sulfate (potassium source) are added for nutrient allocation; the total nutrient content (N+P2O5+K2O) is ensured to be ≥5.0%; and the organic matter content is ensured to be ≥30%.

[0022] Step eight, granulation processing, quality inspection and packaging in the finished product workshop The allocated organic fertilizer is crushed to a certain fineness, and is granulated by using a granulator; the effective viable bacterial count, total nutrient content, organic matter content, heavy metal content and hygiene index of the finished product are detected to ensure that the finished product meets the standard NY / T 525-2021; the finished product is packaged by using a film-coated woven bag to ensure good sealing, and the content is accurately and completely marked. Embodiment 2

[0023] The embodiment provides a method for preparing organic fertilizer based on coal gangue purification treatment, and specifically comprises the following steps. Step one, coal gangue washing and selection: Water and coal gangue are added into a hammer crusher, and the hammer crusher is used for water crushing of the coal gangue to form wet coal particles; the particle size of the wet coal particles is 3 mm; water is added into the wet coal particles to form coal slurry, and the concentration of the coal gangue in the coal slurry is 40%; then the coal slurry is sent into a separator for separation, and the particles on the screen are collected from the separator; then the particles on the screen are sent into a magnetic separator, the metal components in the particles on the screen are separated, and then ball milling is performed to obtain treated coal gangue materials.

[0024] Step two, activation of the coal gangue materials The treated coal gangue materials are added into a potassium nitrate solution with a mass fraction of 5%, soaked for 10 h, and then calcium sulfate with a mass of 2% of the coal gangue materials is added and uniformly mixed; the mixture is subjected to homogenization treatment in an ultrasonic homogenizer for 1 h to obtain activated coal gangue materials.

[0025] Step three, fermentation of the coal gangue The activated coal gangue materials are added with 2% of fermentation bacteria liquid by mass, and the fermentation bacteria liquid is a conventional existing fermentation agent used for organic fertilizer fermentation; in the embodiment, the fermentation bacteria liquid contains bacillus mucilaginosus and bacillus megaterium; the fermentation temperature is controlled at 35 DEG C, and aerobic fermentation is performed for 2 days; in the process of aerobic fermentation, the carbon, phosphorus, potassium, silicon, calcium and magnesium nutrients in the coal gangue are released by the fermentation agent; due to the sufficient washing and activation of the coal gangue in the early stage, the microorganisms can rapidly and fully decompose the coal gangue, the formed minerals are more easily absorbed by plants, and the content of the minerals is higher.

[0026] Step four, mixed fermentation The fermented coal gangue is mixed with rural waste to form a mixture, wherein the rural waste is animal manure and straw; the mass ratio of the fermented coal gangue, the animal manure (cow dung) and the straw is 6:2:2; the length of the straw is less than or equal to 2 cm; 0.5 kg of EM bacteria liquid is added per ton of the mixture, the EM bacteria liquid is fully stirred with the mixture; and then conventional organic fertilizer fermentation is performed.

[0027] Step five, aging treatment After the fermentation is completed, the fermented material is transported into an aging tank in an aging workshop; the bottom of the aging tank is heated through a pipeline, and the top absorbs sunlight, so that the temperature reaches 65 DEG C; and the fermented material is statically placed for 15 days, so that the mortality of insect eggs is greater than or equal to 99%, and a standard soil conditioner is produced.

[0028] Step six, bacteria treatment The soil conditioner is uniformly added with bifidobacterium and other beneficial bacteria (beneficial bacteria are commercially available strains), and is placed in a temperature-controlled 30℃, light-proof production workshop for 72 hours to complete the bacterial treatment, and the effective viable count needs to reach 2×10 8 cfu / g or more.

[0029] Step seven, nutrient allocation of organic fertilizer According to the NY / T 525-2021 "Organic Fertilizer" standard, the total content of nitrogen, phosphorus and potassium in the material after bacterial treatment is detected, and the nutrient allocation is carried out by adding urea (nitrogen source), monoammonium phosphate (phosphorus source) and potassium sulfate (potassium source) to ensure that the total nutrient (N+P2O5+K2O) is ≥5.0%, and the organic matter content is ≥30%.

[0030] Step eight, granulation processing, quality inspection and packaging in the finished product workshop The allocated organic fertilizer is crushed to a certain fineness and granulated by a granulator; the effective viable count, total nutrient, organic matter, heavy metal and hygiene index of the finished product are detected to ensure that they meet the NY / T 525-2021 standard; a film-wrapped woven bag is used for packaging to ensure good sealing and accurate and complete labeling. Example 3

[0031] The embodiment provides a method for preparing an organic fertilizer based on coal gangue purification treatment, and specifically comprises the following steps: Step one, coal gangue washing and selection Water and coal gangue are added to a hammer crusher, and the hammer crusher is used for water crushing of the coal gangue to form wet coal particles; the particle size of the wet coal particles is 5 mm; water is added to the wet coal particles to form a coal slurry, and the concentration of the coal gangue in the coal slurry is 30%; then the coal slurry is sent to a sorting machine for sorting, and the particles on the screen sorted out from the sorting machine are collected; then the particles on the screen are sent to a magnetic separator to separate the metal components in the particles on the screen, and then ball milling is performed to obtain treated coal gangue material.

[0032] Step two, activation of coal gangue material The treated coal gangue material is added into a 10% potassium nitrate solution, soaked for 12 hours, and then 6% calcium sulfate is added to the treated coal gangue material, and the mixture is uniformly mixed; the mixture is placed in an ultrasonic homogenizer for homogenization treatment for 2 hours to obtain activated coal gangue material.

[0033] Step three, coal gangue fermentation In the activated coal gangue material, 5% of the fermentation bacteria liquid by mass is added, the fermentation bacteria liquid is the existing conventional starter used in the fermentation of organic fertilizer; in this embodiment, the fermentation bacteria liquid contains Bacillus mucilaginosus and Bacillus megaterium; the fermentation temperature is controlled at 38°C, and aerobic fermentation is carried out for 3 days; in the process of aerobic fermentation, the fermentation starter releases the carbon, phosphorus, potassium, silicon, calcium and magnesium nutrients in the coal gangue; due to the full washing and selection and activation of the coal gangue in the early stage, the microorganisms can quickly and fully decompose the coal gangue, and the formed minerals are more easily absorbed by plants, and the content of the minerals is higher.

[0034] Step four, mixed fermentation The fermented coal gangue is mixed with rural waste to form a mixture, wherein the rural waste is animal manure and straw; the mass ratio of the fermented coal gangue, animal manure (cow dung) and straw is 7:1:2; the length of the straw is ≤2 cm. According to the addition of 1 kg of EM bacteria liquid per ton of the mixture, the EM bacteria liquid is fully stirred with the mixture; and then conventional organic fertilizer fermentation is carried out.

[0035] Step five, aging treatment After the fermentation is completed, the fermented material is transported to the aging pool of the aging workshop, the bottom of the aging pool is heated through a pipeline, the top absorbs sunlight, the temperature reaches 60°C, and the mixture is statically placed for 20 days. The mortality rate of insect eggs is ensured to be ≥99%, and a standard soil conditioner is produced.

[0036] Step six, bacteria treatment Beneficial bacteria such as Bifidobacterium are uniformly added to the soil conditioner, the temperature is controlled at 30°C, the production workshop is placed in the dark for 72 hours, the bacteria treatment is completed, and the effective viable count needs to reach 2×10 8 cfu / g or more.

[0037] Step seven, nutrient allocation of organic fertilizer According to the standard NY / T 525-2021 "Organic Fertilizer", the total content of nitrogen, phosphorus and potassium of the material after bacteria treatment is detected, and the nutrient allocation is carried out by adding urea (nitrogen source), monoammonium phosphate (phosphorus source) and potassium sulfate (potassium source), so as to ensure that the total nutrient (N+P2O5+K2O) is ≥5.0% and the organic matter content is ≥30%.

[0038] Step eight, granulation processing, quality inspection and packaging in the finished product workshop The allocated organic fertilizer is crushed to a certain fineness, and a granulator is used for granulation; the effective viable count, total nutrient, organic matter, heavy metal and health index of the finished product are detected to ensure that the NY / T 525-2021 standard is met; a film-coated woven bag is used for packaging to ensure good sealing, and the marked content is accurate and complete.

[0039] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be considered that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the present invention, which should be regarded as belonging to the scope of patent protection determined by the submitted claims of the present invention.

Claims

1. A method for preparing organic fertilizer based on purification of coal gangue, characterized in that: The following steps are involved: Step 1: Washing of coal gangue: The gangue is crushed into wet coal particles with a particle size of 3mm~5mm by adding water; water is added to the wet coal particles to form coal slurry, which is then sent to a separator for separation. A portion of the particles above the sieve separated by the separator is collected and ball milled, and the spherical graphite is mixed with the non-spherical graphite to obtain the processed gangue material; Step 2: Activation of coal gangue materials: Add the treated gangue material into a potassium nitrate solution with a mass fraction of 5-10% and soak for 10-12 hours; Step 3: Fermentation of coal gangue: Adding 2-5% of the mass of fermentation bacteria liquid to the activated gangue material for aerobic fermentation; Step 4: Mixed fermentation: The fermented gangue is mixed with rural waste to form a mixture, and the EM bacterial solution and the mixture are fully stirred and fermented; after the fermentation is completed, the fermented product is transferred to an environment with a temperature of 55-65°C for aging and left to stand for 10-20 days; Step 5: Bacterial treatment: Beneficial bacteria were added to the aged mixture, and the temperature was controlled at 30-35°C in a dark production workshop for 70-75 hours to complete the bacterial treatment. The effective viable bacteria count reached 2×10 8 cfu / g or more; Step 6: Granulation and packaging.

2. The method for preparing organic fertilizer based on coal gangue purification according to claim 1, wherein: In step 1, the mass percentage of coal gangue in the coal slurry is 30-40%.

3. The method for preparing organic fertilizer based on coal gangue purification treatment according to claim 1, characterized in that: In step 1, after the separation is completed, the above-sieve particles are sent to a magnetic separator to separate the metal components in the above-sieve particles, and then ball milling is performed.

4. The method for preparing organic fertilizer based on coal gangue purification treatment according to claim 1, characterized in that: In step 2, calcium sulfate in an amount of 2-6% by mass of the gangue material is added to the soaked gangue material and mixed evenly.

5. The method for preparing organic fertilizer based on coal gangue purification treatment according to claim 4, characterized in that: After adding calcium sulfate, the coal gangue material is placed in an ultrasonic homogenizer and homogenized for 1 to 2 hours to obtain activated coal gangue material.

6. The method for preparing organic fertilizer based on coal gangue purification treatment according to claim 1, characterized in that: In step 3, the temperature of the aerobic fermentation is 35-38° C., and the time of the aerobic fermentation is 2-3 days.

7. The method for preparing organic fertilizer based on coal gangue purification according to claim 6, characterized in that: In step 3, the fermentation broth contains Bacillus subtilis and Bacillus megaterium.

8. The method for preparing organic fertilizer based on coal gangue purification according to claim 1, characterized in that: In step 4, add 0.5-1 kg of EM bacterial solution per ton of mixture.

9. The method for preparing organic fertilizer based on coal gangue purification according to claim 1, characterized in that: Rural waste includes animal excrement and straw; the mass ratio of fermented coal gangue, animal excrement and straw is 7:2:1; the length of the straw is ≤2cm.

10. Organic fertilizer prepared by the method for preparing organic fertilizer based on purification of coal gangue as described in claims 1 to 9.