Phosphorus tailing modification method and application thereof in bio-organic fertilizer

Abstract

The invention discloses a phosphate tailing modification method and application thereof in a biological organic fertilizer. According to the method disclosed by the invention, the phosphate tailings are used as the raw material, so that the reutilization of the mineral waste residues is realized, and the environmental pollution and resource waste are reduced. Phosphorus tailings are modified through mechanical and chemical pretreatment, so that the specific surface area and the pore structure of the phosphate tailings can be increased, the solubility of phosphorus and the availability of plants are improved, and the fertilizer efficiency of the fertilizer is enhanced. The added composite biological bacterium compound ingredient and plant-based pest-prevention compound ingredient can enhance the soil microbial community, promote the decomposition of organic matters, improve the soil fertility and facilitate the prevention and treatment of plant diseases and insect pests. The plant-based pest-preventing compound ingredient can make the prepared selenium-enriched nutrient solution emit aromatic smell in the subsequent spraying process, and the smell can dispel mosquitoes and prevent plants from being invaded by the mosquitoes during growth, so that the plant leaf surfaces are protected, the plant yield is increased, and more economic benefits are brought to fruit farmers.

Description

Technical Field

[0001] The invention belongs to the technical field of tailings treatment and bio-organic fertilizer, and particularly relates to a phosphorus tailings modification method and application thereof in bio-organic fertilizer. Background Art

[0002] Phosphate tailings refer to solid waste generated during the mining and processing of phosphate ore. It is the slag left after the phosphorus element in the phosphate ore is extracted after physical and chemical treatment of phosphate ore, such as grinding and flotation. Since phosphate tailings contain a certain amount of phosphorus and other nutrients, such as calcium and magnesium, it has certain agricultural utilization value. The discharge of phosphate tailings has a serious impact on the environment. The stacking of a large amount of phosphate tailings not only occupies land resources, but also may cause soil and water pollution. In addition, the discharge of phosphate tailings may also cause damage to the ecosystem and affect the surrounding vegetation and water resources. However, phosphate tailings also have certain utilization potential. Through modification, it can be converted into useful products such as building materials, soil conditioners, adsorbents, etc. Modified phosphate tailings can be used in agricultural production as fertilizers or soil conditioners to provide the nutrients required for plant growth, improve soil structure, and promote crop growth. In addition, phosphate tailings can also be used for environmental remediation, such as the remediation of heavy metal contaminated soil and the control of eutrophication of water bodies.

[0003] For example, the application with publication number CN117342892A discloses a method for preparing a bio-organic fertilizer based on modified phosphate tailings, comprising the following steps: S1. mixing phosphate tailings, modified phosphate tailings, restaurant kitchen waste, and / or plant straw, and / or poultry excrement to obtain a mixture, and then inoculating phosphate-solubilizing microorganisms; S2. fermenting to obtain a base material; S3. inoculating black soldier fly eggs on the fermented base material, and then raising them to obtain black soldier fly larvae; S4. separating the black soldier fly larvae and worm sand to obtain bio-organic fertilizer and black soldier fly larvae; wherein the modification method of the modified phosphate tailings is: A1. mixing the phosphate tailings and calcium oxide evenly, putting them into water, and then adding hydrogen peroxide to generate bubbles and heat and stir to form balls to obtain an intermediate product; A2. drying and sintering the intermediate product to obtain a modified phosphate tailings. The present invention adopts biological method to synergistically treat waste organic matter, treats phosphorus tailings and waste organic matter with high efficiency, safety and pollution-free, shortens the breeding cycle of black soldier flies, reduces modification and optimization costs, and obtains more economically efficient bio-organic fertilizer.

[0004] However, in the process of preparing fertilizer from phosphate tailings in this application, plants cannot be dewormed and controlled. At the same time, since a lot of poultry excrement is added during the production process, it has a certain odor, which affects the overall efficacy of the organic fertilizer. Summary of the invention

[0005] In order to solve the above problems, the present invention aims to provide a method for modifying phosphate tailings and its application in bio-organic fertilizer.

[0006] The technical solution of the present invention is as follows: A method for modifying phosphate tailings, the method comprising the following steps: S1: Mechanical pretreatment, crushing and grinding of phosphate tailings: S2: chemical pretreatment, first acid-base treatment: use acid and alkali to treat the phosphate tailings together, dissolve and remove impurity elements such as aluminum and silicon in the phosphate tailings, and form a mixed solution with phosphoric acid compounds; S3: preparing a modifier, weighing calcium hydroxide, polyacrylamide, carboxymethyl cellulose, hexamethylcyclotrisiloxane, and water; S4: polyacrylamide and carboxymethyl cellulose are added to water in proportion and stirred until they are completely dissolved to form a mixed solution; hexamethylcyclotrisiloxane is then added, the solution is heated and evenly mixed to form solution A; cellulose and polyacrylamide work together to increase the surface tension of the mixture and reduce the amount of deposition, and hexamethylcyclotrisiloxane can enhance the group activity of the mixture; S5: dissolving calcium hydroxide in water to form an alkaline solution, and performing ionization treatment to obtain an ionized and electrolyzed calcium hydroxide solution; S6: the ionized and electrolyzed calcium hydroxide solution obtained in step S5 and the solution A obtained in step S4 are uniformly mixed at 30-50° C. and stirred to obtain a modifier; wherein the highly active calcium hydroxide solution reacts with a phosphate compound to obtain a calcium phosphate precipitate, and the solution A mainly plays a role in agglomerating the calcium phosphate precipitate; S7: adding the prepared modifier to the pretreated phosphate tailings obtained in step S2 at a mass ratio of modifier to phosphate tailings of 1:(8-12), and stirring to obtain modified phosphate tailings.

[0007] Preferably, in step S1, the phosphate tailings are selected to contain more than 20% of phosphorus; in step S1, the phosphate tailings are crushed to a particle size of less than 150 microns.

[0008] Preferably, in step S2, the acid is one of hydrochloric acid or sulfuric acid, the alkali is sodium hydroxide, the mass ratio of the phosphorus tailings to the acid is 1: (1-1.2), and the mass ratio of the phosphorus tailings to the alkali is 1: (1-1.5), and the mixture is stirred at a stirring speed of 250-350 r / min and a stirring time of 10-20 min. The amount of alkali used is slightly higher than the amount of acid used because the phosphorus tailings themselves are acidic and have a pH lower than 6.5.

[0009] Preferably, in step S3, the mass ratio of calcium hydroxide, polyacrylamide, carboxymethyl cellulose and water is (1.5-2.5):0.1:0.3:(8-15), and the amount of hexamethylcyclotrisiloxane added is 0.1-0.5% of the total mass of cellulose, polyacrylamide and water; In step S3, the stirring speed is controlled to be 110-130 r / min, and the stirring time is controlled to be 20-40 min.

[0010] Preferably, in step S4, the stirring speed is 180-220 r / min, and the stirring time is 50-65 min.

[0011] Preferably, in step S5, the specific operation of the ionization treatment is: adding 1-1.5% of glycerol fatty acid ester as an auxiliary agent, mixing it with the calcium hydroxide solution, completely dissolving it, controlling the solution concentration range of 10-20%, the ionization temperature of 30-40°C, the current density of 50~150A / m², and the ionization time of 15-20min, ionizing and electrolyzing the calcium hydroxide solution, mainly to increase the activity of the calcium hydroxide solution and optimize the binding precipitation effect of calcium hydroxide on the phosphate compound.

[0012] The modified phosphate tailings obtained by the phosphate tailings modification method is used for the preparation of bio-organic fertilizer.

[0013] Preferably, the bio-organic fertilizer comprises the following components in parts by weight: 100-150 parts of modified phosphate tailings, 20-30 parts of composite biological bacteria compound, 20-30 parts of plant-based pest control compound, 20-30 parts of lignite, 20-30 parts of cake fertilizer and 30-40 parts of straw biogas residue are mixed and fermented; after the fermentation is completed, the bio-organic fertilizer of the modified phosphate tailings is obtained.

[0014] Preferably, the fermentation period is 10 to 20 days, the fermentation temperature is 25 to 35° C., and the relative humidity is 70 to 90%.

[0015] Preferably, the composite biological bacteria compound comprises the following components in parts by weight: 3-6 parts of lactic acid bacteria, 4-6 parts of Pseudomonas, 4-6 parts of Bacillus, and 4-6 parts of yeast; The plant-based pest control compound includes Quisqualis creeper, mugwort sticks, mosquito repellent grass and mugwort, and the weight ratio of Quisqualis creeper, mugwort sticks, mosquito repellent grass and mugwort is (1.5-2.5):(2-4):(2-4):(1.5-2.5).

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, after the phosphorus tailings are modified according to this method, the tailings contain fewer impurities, and through the modification, the beneficial elements such as phosphorus contained in the tailings can be effectively dissolved in the fertilizer. In most land use environments, it can also better adapt to its acid-base environment and have better decomposition conditions and availability.

[0017] (2) In the present invention, the method utilizes phosphate tailings as raw materials, realizes the reuse of mineral waste, and reduces environmental pollution and resource waste. The added composite biological bacteria compound and plant-based pest control compound can enhance the soil microbial community, promote the decomposition of organic matter, improve soil fertility, and help prevent and control plant diseases and insect pests. The addition of straw sludge and cake fertilizer can improve the physical properties of the soil, increase the organic matter content of the soil, and improve the water retention and ventilation capacity of the soil. Through the fermentation process, microorganisms can convert organic matter into a form that can be absorbed by plants, providing the nutrients required for plant growth.

[0018] (3) In the present invention, environmental protection is taken into consideration during the entire preparation process. The modifiers and microorganisms used are environmentally friendly, which reduces the negative impact of chemical fertilizers on the environment. By using modified phosphate tailings to prepare bio-organic fertilizers, the dependence on chemical fertilizers can be reduced, and the sustainable development of agriculture can be promoted. Using waste materials such as phosphate tailings as raw materials can reduce the production cost of fertilizers, while increasing the yield and quality of agricultural products, thereby bringing economic benefits. This method not only increases the resource value of phosphate tailings, but also provides an efficient and environmentally friendly fertilizer product, which has positive significance for the sustainable development of agriculture.

[0019] (4) In the present invention, the plant-based pest control compound can make the prepared selenium-rich nutrient solution emit an aromatic odor during the subsequent spraying process, and the odor can repel mosquitoes and prevent the plants from being attacked by mosquitoes during growth, thereby protecting the plant leaves and increasing the plant yield, bringing more economic benefits to fruit farmers. At the same time, it also minimizes the odor of the fertilizer and improves the overall hygiene during use. DETAILED DESCRIPTION

[0020] The following will be combined with the specific embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0021] Example 1 A method for modifying phosphate tailings, the method comprising the following steps: S1: Mechanical pretreatment, crushing and grinding of phosphate tailings: crushing and fine grinding of phosphate tailings to reduce particle size and increase specific surface area in preparation for subsequent chemical treatment; S2: Chemical pretreatment, first acid-base treatment: Use acid and alkali to treat the phosphate tailings to dissolve or react some mineral impurities and improve its pore structure; S3: preparing a modifier, weighing calcium hydroxide, polyacrylamide, carboxymethyl cellulose, and water, adding 1% by mass of hexamethylcyclotrisiloxane as a coupling agent, and stirring at room temperature until the calcium hydroxide is completely dissolved to form a uniform mixed solution; S4: After weighing polyacrylamide and carboxymethyl cellulose, add them to the remaining water in proportion, slowly stir at room temperature until they are completely dissolved to form solution A. Cellulose and polyacrylamide work together to increase the surface tension of the material and reduce the amount of deposition. Add 1% by mass of hexamethylcyclotrisiloxane, heat the solution to about 40 degrees, and make solution A uniform; S5: The dissolved calcium hydroxide solution is ionized. The main operation content is: add 1.2% glycerol fatty acid ester as an ionization aid, mix it with the calcium hydroxide solution, dissolve it completely, control the solution concentration range to 15%, the temperature to 33°C, the current density is usually within the range of 120A / m², the ionization time is 20min, and the calcium hydroxide solution is ionized and electrolyzed to increase the activity of OH- and form highly active groups; S6: Mix the ionized electrolyzed calcium hydroxide solution obtained in step S5 and solution A obtained in step S4, and stir to obtain a modifier; stir for a period of time to ensure that the two solutions are evenly mixed to form a modifier, and the treated modifier has a good pH application range and a strong adsorption capacity, and can treat impurities and fluorides in phosphate tailings.

[0022] S7: adding the prepared modifier to the pretreated phosphate tailings obtained in step S2 at a mass ratio of modifier to phosphate tailings of 1:10, and stirring to obtain modified phosphate tailings.

[0023] Preferably, in step S1, the phosphate tailings are selected to contain more than 20% of phosphorus; in step S1, the phosphate tailings are crushed to a particle size of less than 150 microns.

[0024] Preferably, in step S2, the acid is hydrochloric acid, the mass ratio of the phosphate tailings to the acid is 1:1, and the mixture is stirred after being mixed, with a stirring speed of 300 r / min and a stirring time of 15 min.

[0025] Preferably, in step S3, the mass ratio of calcium hydroxide, polyacrylamide, carboxymethyl cellulose and water is 2:0.1:0.3:10; hexamethylcyclotrisiloxane with a mass fraction of 0.1% of the total mass of cellulose, polyacrylamide and water is added, and in step S3, the stirring speed is controlled to be 120 r / min and the stirring time is 30 min.

[0026] Preferably, in step S4, the stirring speed is controlled to be 200 r / min and the stirring time is 55 min. The modified phosphate tailings obtained by the phosphate tailings modification method is used for the preparation of bio-organic fertilizer.

[0027] Preferably, the bio-organic fertilizer comprises the following components in parts by weight: 120 parts of modified phosphate tailings, 25 parts of composite biological bacteria compound, 25 parts of plant-based pest control compound, 25 parts of lignite, 20 parts of cake fertilizer and 35 parts of straw sludge.

[0028] Further preferably, the composite biological bacteria compound comprises the following components in parts by weight: 5 parts of lactic acid bacteria, 5 parts of Pseudomonas, 5 parts of Bacillus, and 5 parts of yeast; The plant-based pest control compound includes Quisqualis creeper, mugwort sticks, mosquito repellent grass and mugwort, and the weight ratio of Quisqualis creeper, mugwort sticks, mosquito repellent grass and mugwort is 2:3:3:2.

[0029] The above components are mixed and fermented; after the fermentation is completed, the bio-organic fertilizer of the modified phosphate tailings is obtained.

[0030] The fermentation time was 18 days, the fermentation temperature was 25°C, and the relative humidity was 80%.

[0031] Example 2 Based on Example 1, in step S3, the mass ratio of calcium hydroxide, polyacrylamide, carboxymethyl cellulose and water is 2.5:0.1:0.3:15; hexamethylcyclotrisiloxane having a mass fraction of 1% of the total mass of cellulose, polyacrylamide and water is added.

[0032] Example 3 Based on Example 1, in step S3, the mass ratio of calcium hydroxide, polyacrylamide, carboxymethyl cellulose and water is 1.8:0.1:0.3:13; hexamethylcyclotrisiloxane with a mass fraction of 1% of the total mass of cellulose, polyacrylamide and water is added.

[0033] Comparative Example 1 Based on Example 1, the phosphate tailings are not processed in step S2, and the rest are the same as Example 1.

[0034] Comparative Example 2 Based on Example 1, the S3 modifier is not treated with S5, and the rest is the same as Example 1.

[0035] Comparative Example 3 Based on Example 1, the S3 modifier does not include calcium hydroxide and is not treated with S5, and the rest is the same as Example 1.

[0036] Comparative Example 4 Based on Example 1, the S3 modifier does not include polyacrylamide and carboxymethyl cellulose, and the rest is the same as Example 1.

[0037] Comparative Example 5 Based on Example 1, the S3 modifier does not include hexamethylcyclotrisiloxane, and the rest is the same as Example 1.

[0038]

[0039] By comparing the indicators of the above embodiments and comparative examples before and after modification, it can be seen that the phosphorus tailings before modification have low specific surface area and porosity. Under conventional use methods, the solubility of phosphorus in the tailings is low, and the phosphorus tailings cannot be effectively used as fertilizers. The modification of phosphorus tailings in the embodiments effectively improves the solubility of phosphorus tailings by increasing its specific surface area and porosity, and increases the utilization rate of phosphorus, which can improve soil properties.

[0040] It can be known from Example 1 and Comparative Example 1 that after impurities are removed from the phosphate tailings after acid treatment, the porosity can be effectively increased, and the reaction sufficiency of the tailings particles in the modification process is improved, and the modification efficiency is increased. It can be known from Example 1 and Comparative Example 2 that by ionization treatment of calcium hydroxide solution, the hydroxide content in the solution is increased, and the specific surface area of ​​the phosphate tailings is effectively improved, and the modification effect of the phosphate tailings is increased. It can be known from Example 1 and Comparative Examples 3, 4, and 5 that polyacrylamide, carboxymethyl cellulose, and hexamethylcyclotrisiloxane act together, and the specific surface area can be effectively improved, and the modification effect of the phosphate tailings is increased. Therefore, by the application of the modification method of the present invention and the modifier to the phosphate tailings, the dissolution rate of phosphorus in the tailings can be effectively improved, the fertilizer utilization rate and the soil optimization effect are increased, and the modification method reduces the processing cycle, which is of great benefit to agricultural production.

[0041] Example 1 Effect Data: Improvement of soil chemical properties: The available phosphorus content in the soil increased from the original 10 mg / kg to 30 mg / kg.

[0042] The organic carbon content in the soil increased from the original 1.2% to 1.8%.

[0043] The ratio of nitrogen, phosphorus and potassium nutrient content in the soil reaches 1:0.5:1.2, which is more in line with the growth needs of crops.

[0044] Crop growth indicators: The average corn plant height increased by 10% and the stem diameter increased by 8%.

[0045] The number of soybean pods increased by 15% and the number of grains per pod increased by 6%.

[0046] Pest and disease control effect: The incidence of corn borers decreased by 40%, and the incidence of soybean aphids decreased by 28%.

[0047] Environmental Impact Assessment: The heavy metal content (such as lead and cadmium) in the soil was not found to exceed the standard and met the national soil environmental quality standards.

[0048] The microbial diversity index in the soil increased by 20%, and the ecological balance was maintained.

[0049] Example 2 Effect Data: Improvement of soil physical properties: The soil bulk density decreased from 1.5 g / cm³ to 1.2 g / cm³, and the soil permeability increased by 25%.

[0050] The content of water-stable aggregates in the soil increased from 30% to 50%, and the stability of the soil structure was enhanced.

[0051] Crop growth indicators: The number of effective tillers of rice increased by 18% and the thousand-grain weight increased by 5%.

[0052] Wheat ear length increased by 12% and the number of grains per ear increased by 9%.

[0053] Pest and disease control effect: The incidence of rice sheath blight decreased by 32%, and the incidence of wheat powdery mildew decreased by 26%.

[0054] Economic benefit analysis: After using this biological organic fertilizer, the income from crops per mu increases by RMB 200-300.

[0055] The use of fertilizers and pesticides has been reduced, saving RMB 150 per mu.

[0056] Example 3 Effect Data: Improvement of soil biological activity: The activity of soil enzymes (such as urease and phosphatase) increased by 30%, accelerating the transformation and absorption of soil nutrients.

[0057] Soil microbial biomass carbon increased from the original 200 mg / kg to 300 mg / kg.

[0058] Crop growth indicators: The yield of vegetables (such as tomatoes and cucumbers) per plant increased by 20%, and the sugar content of the fruit increased by 1.5 degrees.

[0059] The yield of fruit trees (such as apples and pears) per plant increased by 15%, and the fruit firmness increased by 10%.

[0060] Pest and disease control effect: The incidence of vegetable downy mildew decreased by 22%, and the incidence of fruit tree rot decreased by 18%.

[0061] Ecological and environmental benefits: The number of earthworms in the soil increased by 50%, improving soil aeration and water retention.

[0062] The increased carbon sequestration capacity of soils can help mitigate climate change.

[0063] The technical solution of the present invention is explained through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above specific embodiments to be implemented. Any improvements made by technicians in the relevant field based on the present invention, or equivalent replacement of the materials selected by the present invention, etc., fall within the scope of protection of the patent.

Claims

1. A method for modifying phosphate tailings, characterized in that: The method comprises the following steps: S1: Mechanical pretreatment, crushing and grinding of phosphate tailings: S2: chemical pretreatment, first acid-base treatment: using acid or alkali to treat the phosphate tailings to form a mixed solution containing phosphoric acid compounds; S3: preparing a modifier, weighing calcium hydroxide, polyacrylamide, carboxymethyl cellulose, hexamethylcyclotrisiloxane, and water; S4: polyacrylamide and carboxymethyl cellulose are added to water in proportion and stirred until they are completely dissolved to form a mixed solution; hexamethylcyclotrisiloxane is then added, and the solution is heated and uniformly mixed to form solution A; S5: dissolving calcium hydroxide in water to form an alkaline solution, and performing ionization treatment to obtain an ionized and electrolyzed calcium hydroxide solution; S6: the ionized electrolyzed calcium hydroxide solution obtained in step S5 and the solution A obtained in step S4 are uniformly mixed together at 30-50° C., and stirred to obtain a modifier; S7: adding the prepared modifier to the pretreated phosphate tailings obtained in step S2 at a mass ratio of modifier to phosphate tailings of 1:(8-12), and stirring to obtain modified phosphate tailings.

2. The method for modifying phosphate tailings according to claim 1, wherein: In the step S1, the phosphorus tailings are selected to contain more than 20% phosphorus; in the step S1, the phosphorus tailings are crushed to a particle size of less than 150 microns.

3. The method for modifying phosphate tailings according to claim 1, characterized in that: In step S2, the acid is one of hydrochloric acid or sulfuric acid, the alkali is sodium hydroxide, the mass ratio of the phosphate tailings to the acid is 1: (1-1.2), and the mass ratio of the phosphate tailings to the alkali is 1: (1-1.5). After mixing, stirring is performed at a stirring speed of 250-350 r / min and a stirring time of 10-20 min.

4. The method for modifying phosphate tailings according to claim 1, characterized in that: In step S3, the mass ratio of calcium hydroxide, polyacrylamide, carboxymethyl cellulose and water is (1.5-2.5):0.1:0.3:(8-15), and the amount of hexamethylcyclotrisiloxane added is 0.1-0.5% of the total mass of cellulose, polyacrylamide and water; In step S3, the stirring speed is controlled to be 110-130 r / min, and the stirring time is controlled to be 20-40 min.

5. The method for modifying phosphate tailings according to claim 1, characterized in that: In step S4, the stirring speed is 180-220 r / min, and the stirring time is 50-65 min.

6. The method for modifying phosphate tailings according to claim 1, characterized in that: In step S5, the specific operation of the ionization treatment is: adding 1-1.5% glycerol fatty acid ester as an auxiliary agent, mixing it with the calcium hydroxide solution, completely dissolving it, controlling the solution concentration range to 10-20%, the ionization temperature to 30-40°C, the current density to 50~150A / m², and the ionization time to 15-20min.

7. The modified phosphate tailings obtained by the phosphate tailings modification method according to any one of claims 1 to 6 are used for the preparation of bio-organic fertilizer.

8. The use according to claim 7, characterized in that: The bio-organic fertilizer comprises the following components in parts by weight: 100-150 parts of modified phosphate tailings, 20-30 parts of composite biological bacteria compound, 20-30 parts of plant-based pest control compound, 20-30 parts of lignite, 20-30 parts of cake fertilizer and 30-40 parts of straw biogas residue are mixed and fermented; after the fermentation is completed, the bio-organic fertilizer of the modified phosphate tailings is obtained.

9. The use according to claim 8, characterized in that: The fermentation period is 10 to 20 days, the fermentation temperature is 25 to 35°C, and the relative humidity is 70 to 90%.

10. The use according to claim 8, characterized in that: The composite biological bacteria compound comprises the following components in parts by weight: 3-6 parts of lactic acid bacteria, 4-6 parts of Pseudomonas, 4-6 parts of Bacillus, and 4-6 parts of yeast; The plant-based pest control compound includes Quisqualis creeper, mugwort sticks, mosquito repellent grass and mugwort, and the weight ratio of Quisqualis creeper, mugwort sticks, mosquito repellent grass and mugwort is (1.5-2.5):(2-4):(2-4):(1.5-2.5).

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