Composite oxide based on phosphate tailings and phosphogypsum residues as well as preparation method and application of composite oxide
By mixing the phosphorus tailings and the phosphogypsum residues after desilicate and decarbonization in a specific proportion and calcining them to prepare composite oxides, the problem of difficult use of phosphorus tailings and phosphogypsum in phosphorus chemical enterprises is solved, and the comprehensive utilization of soil resources and sustainable environmental development is achieved.
Patent Information
- Application Number
- CN202411513527.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-02-25
AI Technical Summary
Phosphorus tailings and phosphogypsum produced in phosphate chemical enterprises are difficult to comprehensively utilize, resulting in waste of resources and environmental pollution.
Compound oxide is prepared by mixing the phosphorus tailings and the phosphogypsum residues after desiliceration and decarbonization in a specific proportion, and calcining at 800~1200°C for use as soil conditioning agent.
The resource utilization of phosphorus tailings and phosphogypsum has been achieved, the soil structure and quality has been improved, beneficial elements such as calcium, magnesium, and silicon have been provided, and plant growth and soil microbial activities have been promoted.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of phosphorus chemical solid waste disposal and utilization, and in particular relates to a composite oxide based on phosphorus tailings and phosphogypsum residues, and a preparation method and application thereof. Background Art
[0002] High-magnesium phosphate ore is an important raw material for the current phosphorus chemical industry. However, phosphate ore often contains a lot of impurities, especially magnesium-containing impurity minerals, such as dolomite. These impurities not only reduce the grade of phosphate ore, but also increase the difficulty of subsequent treatment. Therefore, effectively removing magnesium-containing minerals from phosphate ore through mineral processing methods and improving the quality of phosphate concentrate have always been a research hotspot in the field of phosphate ore beneficiation. However, the solid waste of phosphate tailings generated in this process is difficult to be comprehensively utilized due to its low phosphorus content, resulting in a large amount of phosphate tailings accumulation and occupying a large amount of land. Therefore, the comprehensive utilization of phosphate tailings resources is of great significance for the sustainable development of the phosphorus chemical industry. On the other hand, phosphogypsum, as another by-product of the phosphorus chemical industry, mainly comes from the production process of phosphate fertilizers, phosphoric acid and other phosphorus chemical products. It is usually grayish white or grayish black. Its main component is calcium sulfate dihydrate, and there are also impurities such as quartz and organic matter. Studies have shown that the production of 1 ton of phosphoric acid using a wet process will produce about 4 to 5 tons of phosphogypsum, and the resource utilization of phosphogypsum has always been a thorny problem. Therefore, the problems of phosphate tailings and phosphogypsum have become issues that need to be focused on and solved in the field of phosphorus chemical industry. In order to achieve the sustainable development of phosphate resources, the comprehensive utilization of phosphate tailings and phosphogypsum is imminent.
[0003] At the same time, with the rapid economic development and the continuous acceleration of urbanization, the excessive use of pesticides and fertilizers by humans has not only caused serious environmental pollution and the decline of agricultural product quality, but also led to the deterioration of soil properties and changes in soil structure. Soil conditioners can effectively improve the physical and chemical properties of soil, increase soil fertility and crop yields, and even benefit the survival of soil microorganisms. Therefore, the research and development of soil conditioners is crucial to the sustainable development of land.
[0004] Calcium magnesium silicon soil conditioning material is a fertilizer specially used to improve soil acid-base disorders or organic matter deficiency. It improves soil quality and production capacity by improving the physical and chemical properties of the soil. Calcium magnesium silicon soil conditioning material not only has stable effects and small dosage, but also is simple to operate, safe and environmentally friendly. This material plays an important role in promoting plant growth and development, enhancing disease resistance and adaptability to adversity, and can also improve crop yield and quality. The alkaline components in calcium magnesium silicon soil conditioning materials can improve acidic soil, promote soil microbial activity and soil enzyme decomposition, effectively improve the nutritional function, environmental function and structural function of the soil, and increase soil fertility. Therefore, if phosphate tailings and phosphogypsum residues can be fully utilized and used as soil conditioners, it will have significant social benefits, ecological benefits and economic value. Summary of the invention
[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a composite oxide based on phosphate tailings and phosphogypsum residues, and its preparation method and application. The present invention effectively solves the problem of difficult treatment of phosphate tailings and phosphogypsum accumulation in phosphorus chemical enterprises, and realizes the coordinated treatment and utilization of multi-source solid waste in phosphorus chemical industry. The purpose of the present invention is achieved through the following technical solutions: A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue comprises the following steps: The phosphorus tailings and phosphogypsum residue are mixed in a ratio of 30-100:50-100, and then calcined at 800-1200°C to obtain a composite oxide; wherein the phosphogypsum residue is a silicon-containing and organic substance recovered from the phosphogypsum after desiliconization and decarbonization. The phosphogypsum residue contains 20.0-40.0w% SiO2 and 5.0-10.0w% organic carbon.
[0006] Preferably, the phosphate tailings and phosphogypsum residue are mixed in a mass ratio of 1.5 to 2:1.
[0007] Preferably, the phosphate tailings are tailings produced after flotation of high-magnesium phosphate ore. The tailings produced after flotation of high-magnesium phosphate ore contain 3.0-7.0wt% total phosphorus (P2O5) and more than 25.0wt% calcium and magnesium (CaO+MgO), and the mass fraction of water (H2O) does not exceed 20%.
[0008] Preferably, the specific operation of recovering silicon-containing and organic substances from phosphogypsum through desiliconization and decarbonization treatment is carried out in one of the following ways: Method 1: Adjust the phosphogypsum into a slurry with a concentration of 15-25%, add a collector for reverse flotation, filter, dry and grind the foam after flotation to obtain silicon- and organic-containing substances; Method 2: Fully dissolve the phosphogypsum in a solvent, then separate the insoluble matter, and grind the insoluble matter to obtain a substance containing silicon and carbon.
[0009] Preferably, in method 1, the amount of collector added is 0.2~0.6 kg / t.
[0010] Preferably, the collector is at least one of dodecylamine, kerosene, etheramine and alkylammonium bromide. The collector used in the present invention has foaming properties and does not require additional foaming agent.
[0011] Preferably, in the second method, the solvent is one of ammonium chloride solution, ammonium acetate solution, hydrochloric acid and disodium ethylenediaminetetraacetic acid solution.
[0012] Preferably, in method 2, the mass ratio of phosphogypsum to solvent is 1:10-30, and the time for full dissolution is 15-30 minutes.
[0013] Preferably, the calcination time is 0.5 to 2 hours.
[0014] The composite oxide based on phosphate tailings and phosphogypsum residue is prepared by the method for preparing the composite oxide based on phosphate tailings and phosphogypsum residue.
[0015] The above-mentioned composite oxide based on phosphate tailings and phosphogypsum residue is used as a soil conditioner.
[0016] The inventive concept of the present invention is: In the process of comprehensive utilization of phosphogypsum, different types of slags are produced by extracting useful components from phosphogypsum. Through X-ray diffraction analysis of these slags, it is found that the main component is SiO2, and it contains a certain amount of elements such as Ca, P, K, Mg and a small amount of organic carbon. Considering the component content, the present invention mixes the high-magnesium phosphate tailings with the above-mentioned slag in different proportions and then calcines them. Under high temperature conditions, complex compounds decompose into corresponding oxides. Subsequently, the obtained product is crushed. The composite oxide can provide a variety of nutrients required for plant growth (such as Ca, P, K, Mg), while improving soil structure; it can effectively neutralize acidic soil and improve soil quality and production capacity.
[0017] Compared with the prior art, the beneficial effects of the present invention include: The soil conditioning material prepared by the method not only realizes the resource utilization of phosphorus tailings and phosphogypsum, but also effectively improves acidic soil, provides beneficial elements such as calcium, magnesium, silicon, etc. to the soil, and promotes food production. In addition, the process flow of the invention is simple, the cost is low, and a variety of solid wastes in the phosphorus chemical process are reasonably utilized. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1This is the XRD diffraction pattern of the residue after treatment with disodium ethylenediaminetetraacetate as described in Example 4.
[0019] Figure 2 This is the XRD diffraction pattern of the tailings after flotation treatment as described in Example 2 of the present invention.
[0020] Figure 3 This is the XRD diffraction pattern of the composite oxide described in Example 2 of the present invention. DETAILED DESCRIPTION
[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0022] The phosphate tailings described in the examples are tailings produced after flotation separation of high-magnesium phosphate ore. The phosphate tailings and phosphogypsum described in Examples 1 to 3 and 5 are both taken from a phosphorus chemical enterprise in Hubei, and the phosphate tailings and phosphogypsum described in Example 4 are both taken from a phosphorus chemical enterprise in Guizhou.
[0023] Example 1 A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue, the steps are as follows: (1) Weigh 5.0 kg of phosphogypsum, add 20% ammonium acetate solution at a solid-liquid ratio of 1:20, stir at room temperature for 30 min, and then filter to obtain a residue; (2) Drying and crushing the filter residue to obtain 0.75 kg of silicon- and organic-containing material, mixing the material evenly with 0.3 kg of phosphate tailings powder, and placing the material in a high-temperature box-type muffle furnace for high-temperature calcination. The furnace temperature is set to 1200° C. and the calcination time is 30 min. After cooling to room temperature, the material is ground into powder to obtain the composite oxide.
[0024] The composite oxide prepared in Example 1 was tested for component content, and the test results are shown in Table 1. Among them, effective calcium refers to effective calcium oxide without calcium carbonate, and its detection method is based on the ICP method in the standard NY / T 296-1995 "Determination of Total Calcium, Magnesium and Sodium in Soil". Effective magnesium refers to soluble and dissociated Mg 2+ Active magnesium is detected by the ICP method in NY / T 296-1995 "Determination of total calcium, magnesium and sodium in soil". Available silicon refers to soluble silicon, which is detected by spectrophotometry, referring to NY / T 1121.15-2006 "Soil Testing Part 15: Determination of Available Silicon in Soil".
[0025] Table 1 Detection of composite oxide components in Example 1
[0026] Example 2 A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue, the steps are as follows: (1) Weigh 250g of phosphogypsum and prepare it into a 20% slurry; first add dodecylamine (concentration of 2%) according to the standard of 0.15 kg / t, and add 1mL kerosene (purity of 100%) at the same time for rough flotation; then add dodecylamine (concentration of 2%) according to the standard of 50 g / t for fine flotation. During the rough flotation and fine flotation process, the total amount of dodecylamine added is 0.2 kg / t. The foam product is filtered, dried and ground to obtain 62g of silicon- and organic-containing substances; (2) 50 g of silicon- and organic-containing substances were mixed evenly with 50 g of phosphate tailings powder, and the mixture was placed in a high-temperature box-type muffle furnace for high-temperature calcination. The furnace temperature was set to 1200° C. and the calcination time was 30 min. After cooling to room temperature, the mixture was ground into powder to obtain the composite oxide.
[0027] The component contents of the composite oxide prepared in Example 2 were tested, and the test results are shown in Table 2.
[0028] Table 2 Detection of composite oxide components in Example 2
[0029] Example 3 A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue, the steps are as follows: (1) Weigh 5.0 kg of phosphogypsum, add 20% hydrochloric acid solution at a solid-liquid ratio of 1:15, stir at room temperature for 30 minutes, and then filter to obtain a residue; (2) Dry and crush the filter residue to obtain 0.8 kg of silicon- and organic-containing material, mix it evenly with 1.0 kg of phosphate tailings powder, put it into a high-temperature box-type muffle furnace for high-temperature calcination, set the furnace temperature to 1000° C., and the calcination time to 45 min. After cooling to room temperature, grind it into powder to obtain the composite oxide.
[0030] The component contents of the composite oxide prepared in Example 3 were tested, and the test results are shown in Table 3.
[0031] Table 3 Detection of composite oxide components in Example 3
[0032] Example 4 A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue, the steps are as follows: (1) Weigh 5.0 kg of phosphogypsum, add 20% disodium ethylenediaminetetraacetic acid solution at a solid-liquid ratio of 1:15, stir at room temperature for 30 minutes, and then filter to obtain a residue; (2) Dry and crush the filter residue to obtain 0.5 kg of silicon- and organic-containing material, mix it evenly with 1.0 kg of phosphate tailings powder, put it into a high-temperature box-type muffle furnace for high-temperature calcination, set the furnace temperature to 900°C, and the calcination time to 1 hour. After cooling to room temperature, grind it into powder to obtain the composite oxide.
[0033] The component contents of the composite oxide prepared in Example 4 were tested, and the test results are shown in Table 4.
[0034] Table 4 Detection of composite oxide components in Example 4
[0035] Example 5 A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue, the steps are as follows: (1) Weigh 5.0 kg of phosphogypsum, add 20% ammonium acetate solution at a solid-liquid ratio of 1:15, stir at room temperature for 30 minutes, and then filter to obtain a residue; (2) Dry and crush the filter residue to obtain 1 kg of silicon- and organic-containing material, mix it evenly with 0.75 kg of phosphate tailings powder, put it into a high-temperature box-type muffle furnace for high-temperature calcination, set the furnace temperature to 800°C, and the calcination time to 2 h. After cooling to room temperature, grind it into powder to obtain the composite oxide.
[0036] The component contents of the composite oxide prepared in Example 5 were tested. The test results are shown in Table 5.
[0037] Table 5 Detection of composite oxide components in Example 5
[0038] According to Tables 1 to 5, it can be seen from the measurement results that the effective silicon, effective calcium and effective magnesium contents in Example 4 are the highest. This may be because the proportion of phosphorus tailings increased, resulting in an increase in the content of fluorapatite (component Ca5F(PO4)3), quartz (component SiO2) and dolomite (mainly composed of CaMg(CO3)2) in the mixed sample, thereby increasing the content of effective calcium, effective magnesium and effective silicon in the final product. In contrast, the effective silicon content in Example 5 is the lowest, which may be due to the failure of quartz to completely melt at a calcination temperature of 800°C, resulting in a decrease in the content of effective silicon in the product.
[0039] Figure 1is the XRD diffraction pattern of the residue after treatment with disodium ethylenediaminetetraacetate as described in Example 4; Figure 1 It can be seen that the main component of the residue obtained by leaching is SiO2.
[0040] Figure 2 is the XRD diffraction pattern of the tailings (i.e., silicon- and organic-containing substances) after flotation treatment as described in Example 2 of the present invention; Figure 2 It can be seen that the main components of tailings residue are dolomite and quartz, and also contain a small amount of apatite and feldspar; Figure 3 is the XRD diffraction pattern of the composite oxide described in Example 2 of the present invention; Figure 3 It can be seen that after calcination, the product contains a large amount of SiO2, CaO and MgO. These substances can provide rich nutrients for the soil and improve soil quality and production capacity.
[0041] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.
Claims
1. A method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue, characterized in that: The steps include: The phosphate tailings and phosphogypsum residue are mixed at a ratio of 30-100:50-100, and then calcined at 800-1200° C. to obtain the composite oxide; wherein the phosphogypsum residue is a silicon- and organic-containing substance recovered from phosphogypsum after desiliconization and decarbonization.
2. The method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue according to claim 1, characterized in that: The phosphate tailings and phosphogypsum residue are mixed in a mass ratio of 1.5 to 2:1; The phosphate tailings are tailings produced after flotation separation of high-magnesium phosphate ore.
3. The method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue according to claim 1, characterized in that: The specific operation of recovering silicon-containing and organic substances from the phosphogypsum through desiliconization and decarbonization treatment is one of the following methods: Method 1: Adjust the phosphogypsum into a slurry with a concentration of 15-35%, add a collector for reverse flotation, filter, dry and grind the foam after flotation to obtain silicon- and organic-containing substances; Method 2: Fully dissolve the phosphogypsum in a solvent, and then separate the insoluble matter. The insoluble matter is filtered, dried, and then ground to obtain a substance containing silicon and organic matter.
4. The method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue according to claim 3, characterized in that: In the first method, the amount of the collector added is 0.2-0.6 kg / t.
5. The method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue according to claim 4, characterized in that: The collector is at least one of dodecylamine, kerosene, ether amine salt and alkyl ammonium bromide.
6. The method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue according to claim 3, characterized in that: In the second method, the solvent is one of ammonium chloride solution, ammonium acetate solution, hydrochloric acid and disodium ethylenediaminetetraacetate solution.
7. The method for preparing a composite oxide based on phosphate tailings and phosphogypsum residue according to claim 3, characterized in that: In the second method, the mass ratio of phosphogypsum to solvent is 1:10-30, and the time for sufficient dissolution is 15-30 min.
8. The method for preparing composite oxides based on phosphate tailings and phosphogypsum residue according to claim 1, characterized in that: The calcination time is 0.5 to 2 hours.
9. The composite oxide based on phosphate tailings and phosphogypsum residue prepared by the method for preparing the composite oxide based on phosphate tailings and phosphogypsum residue according to any one of claims 1 to 8.
10. Use of the composite oxide based on phosphate tailings and phosphogypsum residue according to claim 9 as a soil conditioner.