Soil conditioner containing phosphorus and potassium tailings and preparation method thereof

Abstract

The invention belongs to the technical field of soil amendments, and particularly discloses a soil amendment containing phosphorus and potassium tailings and a preparation method of the soil amendment. The invention discloses a soil conditioner containing phosphorus and potassium tailings. The soil conditioner comprises 35-50 parts of phosphorus tailing powder, 30-40 parts of potassium feldspar powder, 5-10 parts of a composite activator, 3-10 parts of zeolite and 0-10 parts of a pH regulator. The preparation method comprises the following steps: firstly, mixing phosphate tailing mineral powder, potassium feldspar mineral powder, a composite activator and water, grinding and activating, then mixing with a pH regulator and zeolite, and grinding again to obtain the soil conditioner containing the phosphate and potassium tailings. The soil conditioner disclosed by the invention is rich in phosphorus and potassium elements, can improve a soil nutrient structure, and also has the characteristics of high bioavailability and capability of realizing a slow release effect; in addition, the preparation method disclosed by the invention is simple and relatively low in cost, and resourceful treatment of tailings can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of soil conditioners, and particularly to a soil conditioner containing phosphorus and potassium tailings and a preparation method thereof. Background Art

[0002] Soil conditioners are a class of materials used to improve the physical, chemical, and biological properties of soil, aiming to optimize soil structure, enhance fertility, improve water retention and air permeability, thereby creating a more suitable environment for plant growth. They can act by increasing organic matter, adjusting the pH value, supplementing nutrients, or improving soil microbial activity. Common soil conditioners include organic materials (such as compost, humus), inorganic materials (such as lime, gypsum), mineral materials (such as bentonite), and biological agents (such as microbial inoculants). By reasonably using soil conditioners, problems such as soil compaction, infertility, acidification, or salinization can be effectively solved, and crop yields and soil sustainable utilization capabilities can be improved.

[0003] Phosphorus tailings are low-grade waste generated during the beneficiation process of phosphate ore, and their main components include unutilized phosphorus minerals and impurities such as quartz and clay. Since the phosphorus content in phosphorus tailings is relatively low and cannot be directly used in industrial production, they are usually stacked in tailing ponds. However, phosphorus tailings still contain certain amounts of elements such as phosphorus, calcium, and magnesium, and have potential resource utilization value. Through appropriate technical treatment, phosphorus tailings can be expected to be used for preparing soil conditioners, thereby realizing waste resource utilization, reducing environmental pollution and land occupation, and promoting sustainable development.

[0004] Potassium feldspar is a common silicate mineral, mainly composed of oxides of potassium, aluminum, and silicon. It is commonly found in rocks such as granite and gneiss. Potassium feldspar has important application values in agriculture and industry due to its rich potassium content.

[0005] Currently, there are common problems of phosphorus and potassium deficiency in crops in agricultural production. The main reasons include: imbalance of soil nutrients. Due to long-term overuse of nitrogen fertilizers, while the input of phosphorus and potassium fertilizers is relatively insufficient, the phosphorus and potassium elements in the soil are gradually depleted, and the nutrient ratio is unbalanced; the phosphorus and potassium content in the soil of some areas is relatively low, making it difficult to meet the growth requirements of crops. Unreasonable fertilization structure. The prices of phosphorus and potassium fertilizers are relatively high. In order to reduce costs, it is customary to overemphasize the use of nitrogen fertilizers and neglect the supplementation of phosphorus and potassium fertilizers, resulting in insufficient absorption of phosphorus and potassium by crops. Mismatch between crop demand and soil supply. High-yield crops have a large demand for phosphorus and potassium, while the supply capacity of available phosphorus and potassium in the soil is limited, making it difficult to meet the growth requirements of crops. Obvious regional differences. In acidic soil areas in the south, phosphorus is easily fixed and has low effectiveness; in calcareous soil areas in the north, potassium loss is relatively serious. Long-term unreasonable fertilization methods lead to soil compaction and acidification, which further reduces the effectiveness of phosphorus and potassium.

[0006] Therefore, how to provide a soil conditioner containing phosphorus-potassium tailings and its preparation method to improve the soil nutrient structure, solve the problem of phosphorus and potassium deficiency in existing crops at low cost, and at the same time realize the resource utilization of phosphorus tailings is a difficult problem to be solved urgently in this field. Summary of the Invention

[0007] In view of this, the present invention provides a soil conditioner containing phosphorus-potassium tailings and its preparation method to solve the problem of phosphorus and potassium deficiency in existing crops, realize the resource utilization of phosphorus tailings, and avoid environmental pollution.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A soil conditioner containing phosphorus-potassium tailings, comprising the following components in parts by mass: 35-50 parts of phosphorus tailings powder, 30-40 parts of potassium feldspar powder, 5-10 parts of composite activator, 3-10 parts of zeolite, and 0-10 parts of pH regulator.

[0010] Preferably, the particle sizes of the phosphorus tailings powder and the potassium feldspar powder are independently 60-100 mesh.

[0011] Preferably, the composite activator is composed of organic acid and / or inorganic activator;

[0012] The organic acid includes humic acid and / or citric acid, and the inorganic activator includes potassium carbonate and / or potassium hydroxide.

[0013] Preferably, the mass ratio of the organic acid to the inorganic activator in the composite activator is 6.5-7:3-3.5.

[0014] Preferably, the particle size of the zeolite is 0.5-2 mm.

[0015] Preferably, the pH regulator includes one or more of calcium carbonate, sulfur, and humic acid.

[0016] Another object of the present invention is to provide a preparation method of a soil conditioner containing phosphorus-potassium tailings, comprising the following steps:

[0017] Mix the phosphorus tailings powder, potassium feldspar powder, composite activator and water, carry out grinding activation, and then mix the product obtained by grinding activation with the pH regulator and zeolite and grind again to obtain a soil conditioner containing phosphorus-potassium tailings.

[0018] Preferably, the time of grinding activation is 0.5-3 h.

[0019] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The soil conditioner disclosed by the present invention contains phosphorite tailing powder and potassium feldspar powder. As a soil conditioner, it can increase the content of phosphorus and potassium elements in the soil, improve the soil nutrient structure, avoid the problem of phosphorus and potassium deficiency commonly existing in current agricultural production, and provide the necessary phosphorus and potassium elements for crop growth.

[0021] 2. The solution of the present invention also includes an activator. The present invention activates the phosphorite tailing powder and potassium feldspar powder through the activator. Most of the phosphorus in the phosphorite tailings exists in an insoluble form and cannot be absorbed by crops when directly applied. The present invention activates the phosphorus therein through the activator, which can promote plant absorption and utilization; the potassium in potassium feldspar also needs to be converted into a form available to plants, which needs to be achieved through an activation reaction.

[0022] 3. Zeolite has a regular microporous structure, which can increase the soil porosity, improve the soil aeration and water retention capacity, is beneficial to promoting microbial activity, can also adsorb nutrients and phosphorus sources, reduce leaching; and has a certain buffering capacity, which can adjust the soil pH value. Zeolite also has a relatively high cation exchange capacity, which can adsorb nutrient ions such as potassium, calcium, and magnesium in the soil and slowly release them for plant absorption, and has a significant slow-release effect on potassium. In addition, zeolite can prevent heavy metal ions in the tailings from transferring to the soil and reduce its harm to plants and the environment.

[0023] 4. The raw materials disclosed by the present invention are widely available and low in cost, can effectively control the preparation cost of the soil conditioner, and realize the resource treatment of tailings. Specific Embodiments

[0024] The present invention provides a soil conditioner containing phosphorus and potassium tailings, including the following components in parts by mass: 35 - 50 parts of phosphorite tailing powder, 30 - 40 parts of potassium feldspar powder, 5 - 10 parts of composite activator, 3 - 10 parts of zeolite, 0 - 10 parts of pH regulator; at the above parts by mass, the addition parts of the phosphorite tailing powder can specifically be 36 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 parts; the addition parts of the potassium feldspar powder can specifically be 32 parts, 34 parts, 35 parts, 36 parts, 38 parts; the addition parts of the composite activator can specifically be 6 parts, 7 parts, 8 parts, 9 parts; the addition parts of the zeolite can specifically be 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts; the addition parts of the pH regulator can specifically be 1 part, 2 parts, 4 parts, 5 parts, 6 parts, 8 parts.

[0025] In the present invention, the particle sizes of the phosphorite tailing powder and potassium feldspar powder are independently 60 - 100 mesh, specifically can be 70 mesh, 80 mesh, 90 mesh; the particle sizes of the phosphorite tailing powder and potassium feldspar powder disclosed by the present invention are relatively small, which is beneficial to the release of phosphorus and potassium elements and the progress of the activation reaction.

[0026] In the present invention, the composite activator is composed of organic acids and / or inorganic activators.

[0027] In the present invention, the organic acids include humic acid and / or citric acid. The organic acids can react with phosphorus to form long-acting phosphorus with a slow-release effect. When combined with zeolite, it can effectively improve the biological utilization rate of phosphorus. The inorganic activators include potassium carbonate and / or potassium hydroxide.

[0028] In the present invention, the mass ratio of the organic acid to the inorganic activator in the composite activator is 6.5 - 7:3 - 3.5, preferably 6.6 - 6.9:3.1 - 3.4, and more preferably 6.7 - 6.8:3.2 - 3.3. The organic acids and inorganic activators disclosed in the present invention can not only ensure the rapid activation of tailings but also ensure the utilization rate after activation.

[0029] In the present invention, the particle size of the zeolite is 0.5 - 2 mm, specifically it can be 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm.

[0030] In the present invention, the pH regulator includes one or more of calcium carbonate, sulfur, and humic acid. By adding the pH regulator, the requirements of acidic / alkaline soils can be met.

[0031] The present invention also provides a preparation method of a soil conditioner containing phosphorus and potassium tailings, comprising the following steps:

[0032] Mix the phosphorus tailings powder, potassium feldspar powder, composite activator, pH regulator, and water, and grind and activate them. The product obtained by grinding and activation is mixed with zeolite and then ground again to obtain a soil conditioner containing phosphorus and potassium tailings.

[0033] In the present invention, in the grinding and activation process, the mass ratio of the total mass of the phosphorus tailings powder, potassium feldspar powder, composite activator, and pH regulator to the mass of water is 1:0.1 - 0.5, preferably 1:0.2 - 0.4, and more preferably 1:0.3.

[0034] In the present invention, the time for grinding and activation is 0.5 - 3 h, specifically it can be 0.8 h, 1 h, 1.5 h, 2 h, 2.5 h.

[0035] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] The main chemical compositions of the phosphorus tailings used in all embodiments of the present invention are shown in Table 1, and the main chemical compositions of the potassium feldspar used are shown in Table 2.

[0037] Table 1 Main Chemical Compositions of Phosphorus Tailings

[0038] Composition <![CDATA[P2O5]]> <![CDATA[SiO2]]> CaO MgO <![CDATA[Fe2O3]]> <![CDATA[Al2O3]]> wt% 10.35 11.26 32.68 8.61 0.55 0.67

[0039] Table 2 Main Chemical Compositions of Potassium Feldspar

[0040] Composition <![CDATA[K2O]]> <![CDATA[Al2O3]]> <![CDATA[SiO2]]> CaO <![CDATA[Fe2O3]]> wt% 12.43 18.92 62.18 0.96 0.65

[0041] The specific compositions of the phosphorus tailings and potassium feldspar disclosed in the present invention are not regarded as limitations to the technical solutions of the present invention.

[0042] Example 1

[0043] The phosphorus tailings and potassium feldspar were respectively ground to 70 - 80 mesh for standby.

[0044] Take 40 parts of phosphorus tailings powder, 35 parts of potassium feldspar powder, 8 parts of composite activator (citric acid: potassium carbonate = 7:3) and 20 parts of water, mix them and grind for 2 h at room temperature for activation reaction. After grinding, dry to obtain the activated product. Mix the activated product with 5 parts of pH regulator (humic acid) and 8 parts of natural zeolite and grind again to obtain a soil conditioner containing phosphorus and potassium tailings.

[0045] Example 2

[0046] The phosphorus tailings powder and potassium feldspar powder were respectively ground to 70 - 80 mesh for standby.

[0047] Take 35 parts of phosphorus tailings powder, 35 parts of potassium feldspar powder, 5 parts of composite activator (citric acid: potassium carbonate = 7:3) and 20 parts of water, mix them and grind for 2 h at room temperature for activation reaction. After grinding, dry to obtain the activated product. Mix the activated product with 5 parts of pH regulator (humic acid) and 4 parts of natural zeolite and grind again to obtain a soil conditioner containing phosphorus and potassium tailings.

[0048] Example 3

[0049] The phosphorus tailings powder and potassium feldspar powder were respectively ground to 60 - 80 mesh for standby.

[0050] Take 45 parts of phosphorus tailings powder, 30 parts of potassium feldspar powder, 10 parts of composite activator (citric acid: potassium carbonate = 7:3) and 20 parts of water, mix them and grind for 1 h at room temperature for activation reaction. After grinding, dry to obtain the activated product. Mix the activated product with 5 parts of pH regulator (humic acid) and 10 parts of natural zeolite and grind again to obtain a soil conditioner containing phosphorus and potassium tailings.

[0051] Example 4

[0052] The phosphate tailings powder and potassium feldspar powder are respectively ground to 60 - 80 mesh for standby.

[0053] Take 50 parts of phosphate tailings powder, 40 parts of potassium feldspar powder, 10 parts of composite activator (citric acid: potassium carbonate = 7:3) and 20 parts of water, mix them and grind for 3 h at room temperature for activation reaction. After grinding, dry them to obtain the activated product. Mix the activated product with 5 parts of pH regulator (humic acid: sulfur = 1:1) and 10 parts of natural zeolite and grind again to obtain the soil conditioner containing phosphate and potassium tailings.

[0054] Example 5

[0055] The phosphate tailings powder and potassium feldspar powder are respectively ground to 80 - 100 mesh for standby.

[0056] Take 50 parts of phosphate tailings powder, 30 parts of potassium feldspar powder, 8 parts of composite activator (citric acid: potassium carbonate = 7:3) and 20 parts of water, mix them and grind for 2 h at room temperature for activation reaction. After grinding, dry them to obtain the activated product. Mix the activated product with 2 parts of pH regulator (calcium carbonate) and 10 parts of natural zeolite and grind again to obtain the soil conditioner containing phosphate and potassium tailings.

[0057] Comparative Example 1

[0058] The difference between this comparative example and Example 1 is only that natural zeolite is not added.

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 1 is only that the total addition amount of the composite activator is adjusted to 1 / 4 of that in Example 1.

[0061] Experimental Example 1

[0062] Using slightly alkaline soil as the potting substrate, carry out simulated salinization planting, set up a potting application test, and set up blank group 1, experimental group 1 and control groups 1 - 2 respectively. Blank group 1 is not treated, experimental group 1 adds the soil conditioner prepared in Example 1, and control groups 1 - 2 add the soil conditioners prepared in Comparative Examples 1 - 2 correspondingly (the addition ratio of the potting substrate to the soil conditioner in experimental group 1 and control groups 1 - 2 is 200:1). Control the room temperature at 25 °C, sow wheat seeds, and keep the five most well - growing seedlings in each pot after seed germination. Respectively test the influence of the soil conditioner on the soil properties (improvement rate compared with blank group 1) at the time of seed germination and maturity. The test results are shown in Table 3:

[0063] Table 3 Influence of the soil conditioner on the soil properties at the time of seed germination and maturity

[0064]

[0065] As can be seen from Table 3, the available phosphorus and available potassium at different stages have been greatly improved after applying the soil conditioner of the present invention. In Control Group 1, natural zeolite was not added, resulting in a much higher increase rate of available potassium and available phosphorus in the early stage than in the later stage. The slow-release effect of available phosphorus in Control Group 1 was better than that of available potassium, indicating that there was a reaction between humic acid and phosphorus, which could play a certain slow-release role. The available potassium and available phosphorus in Control Group 2 were generally low, because of insufficient activation.

[0066] In addition, the soil pH value was also detected. The soil pH values of Experimental Group 1 and Control Groups 1-2 were greatly improved compared with that of Blank Group 1. At the mature stage, the pH value of Experimental Group 1 was 7.3 (the pH value of the blank group was 8).

[0067] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0068] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A soil conditioner comprising phosphate and potassium tailings, characterized in that: The invention comprises the following components in parts by weight: 35 to 50 parts of phosphorus tailings powder, 30 to 40 parts of potassium feldspar powder, 5 to 10 parts of composite activator, 3 to 10 parts of zeolite and 0 to 10 parts of pH regulator.

2. A soil conditioner comprising phosphate and potassium tailings according to claim 1, characterized in that: The particle sizes of the phosphate tailings powder and the potassium feldspar powder are independently 60-100 meshes.

3. A soil conditioner comprising phosphate and potassium tailings according to claim 2, characterized in that: The composite activator is composed of an organic acid and / or an inorganic activator; The organic acid includes humic acid and / or citric acid, and the inorganic activator includes potassium carbonate and / or potassium hydroxide.

4. A soil conditioner comprising phosphate and potassium tailings according to any one of claims 1 to 3, characterized in that: The mass ratio of the organic acid to the inorganic activator in the composite activator is 6.5-7:3-3.

5.

5. A soil conditioner comprising phosphate and potassium tailings according to claim 4, characterized in that: The particle size of the zeolite is 0.5-2 mm.

6. A soil conditioner comprising phosphate and potassium tailings according to claim 5, characterized in that: The pH regulator includes one or more of calcium carbonate, sulfur and humic acid.

7. The method for preparing a soil conditioner comprising phosphate and potassium tailings according to any one of claims 1 to 6, characterized in that: The steps include: Phosphate tailings powder, potassium feldspar powder, a composite activator and water are mixed, and the mixture is ground and activated. The product obtained by the grinding and activation is mixed with a pH regulator and zeolite and ground again to obtain a soil conditioner containing phosphate potassium tailings.

8. The method for preparing a soil conditioner comprising phosphate and potassium tailings according to claim 7, characterized in that: The grinding activation time is 0.5 to 3 hours.

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