Phosphorite reverse flotation low-temperature collecting agent and preparation method thereof

Abstract

The invention relates to the technical field of mineral flotation, in particular to a phosphorite reverse flotation low-temperature collecting agent and a preparation method thereof.The phosphorite reverse flotation low-temperature collecting agent is composed of fatty acid sodium, fatty alcohol polyoxyethylene ether sodium sulfate, palmitoleic acid, an auxiliary anionic surfactant, petroleum sulfonic acid and palm fatty acid light components according to a specific proportion. The preparation method comprises the following steps: heating, melting and mixing the oil-phase components to obtain an oil-phase mixture, dissolving the water-phase surfactant in hot water to obtain a water-phase solution, slowly adding the oil phase into the water phase at a specific stirring rate, and then carrying out high-speed shearing emulsification and cooling to obtain a final product. By microcosmically constructing a stable composite micelle structure, the problems that a conventional collecting agent is poor in dispersity and prone to crystallization at the low temperature are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of mineral flotation technology, and in particular to a low-temperature collector for reverse flotation of phosphate rock and its preparation method. Background Technology

[0002] Phosphate rock, as an important non-metallic mineral resource, is a key raw material for the preparation of phosphate fertilizers, phosphoric acid, and fine phosphate chemical products. With the increasing depletion of high-quality phosphate rock resources, efficient separation of low-grade phosphate rock has become an urgent need to ensure the sustainable development of agriculture and industry. Reverse flotation is one of the main processes for phosphate rock separation. Its principle is to selectively adsorb the collector onto the surface of gangue minerals (such as carbonates), causing them to float hydrophobically, thereby obtaining high-grade phosphate concentrate. However, in actual production, especially in northern my country or under low-temperature conditions in winter, the pulp temperature often drops to 10-15℃. Conventional collectors will encounter a series of problems under this low-temperature environment, which seriously restricts the separation efficiency.

[0003] Under low-temperature conditions, the solubility and dispersibility of conventional fatty acid collectors decrease significantly, leading to agglomeration or crystallization in the slurry and making it difficult to uniformly adsorb onto the surface of the target mineral. At the same time, the collecting performance and selectivity of the reagents deteriorate sharply, resulting in insufficient inhibition of impurities such as carbonates, difficulty in improving the grade of phosphate concentrate, and a significant reduction in the recovery rate of useful minerals. To solve the problem of low-temperature flotation, existing technologies usually adopt the methods of heating the slurry or increasing the amount of reagents. This not only significantly increases energy consumption and production costs, but may also cause environmental pollution due to excessive reagents. In addition, some researchers have tried to improve the low-temperature fluidity of collectors by compounding emulsifiers or solvents, but these methods are often only treating the symptoms and not the root cause, or introducing toxic and harmful solvents, bringing new environmental and safety problems.

[0004] Therefore, developing a new type of phosphate rock reverse flotation collector that is specifically designed for low-temperature environments and possesses good dispersibility, high selectivity, and strong collecting ability is of great significance for reducing production energy consumption, improving resource utilization, and promoting the green and sustainable development of phosphate rock beneficiation technology. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a low-temperature collector for reverse flotation of phosphate rock and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A low-temperature collector for reverse flotation of phosphate rock, comprising the following raw materials in parts by weight: Sodium fatty acid 60-100 parts, sodium fatty alcohol polyoxyethylene ether sulfate 10-30 parts, palmitoleic acid 10-30 parts, auxiliary anionic surfactant 5-10 parts, petroleum sulfonic acid 1-5 parts, and light components of palm fatty acid 5-15 parts.

[0007] Furthermore, the sodium fatty acid has a pH value of 9-11.

[0008] Furthermore, the auxiliary anionic surfactant is selected from at least two of the group consisting of alkyl sulfonates, sodium dodecylbenzene sulfonate, and sodium cocoyl hydroxyethyl sulfonate.

[0009] Furthermore, the auxiliary anionic surfactant is composed of alkyl sulfonate, sodium dodecylbenzene sulfonate, and sodium cocoyl hydroxyethyl sulfonate in a mass ratio of 1:(2-5):(3-8), and the preferred mass ratio of alkyl sulfonate, sodium dodecylbenzene sulfonate, and sodium cocoyl hydroxyethyl sulfonate is 1:3.5:5.5.

[0010] Furthermore, the preparation method includes the following steps: S1. Weigh out sodium fatty acid, palmitoleic acid, light components of palm fatty acid and petroleum sulfonic acid according to the proportion, place them in a mixer, heat to 70-90℃, stir to melt the materials and mix them evenly to obtain an oil phase mixture. S2. Weigh out sodium fatty alcohol polyoxyethylene ether sulfate and auxiliary anionic surfactant in proportion, dissolve them in hot water with a total weight of 1-3 times, control the water temperature at 60-80℃, stir until completely dissolved, and obtain an aqueous solution. S3. At a stirring rate of 200-500 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 3000-8000 rpm for 10-30 minutes, controlling the emulsification temperature at 70-85℃ to obtain a uniform and stable emulsion. S4. Cool the emulsion obtained in S3 to room temperature to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0011] Furthermore, in S1, the heating temperature is 75-85°C.

[0012] Furthermore, in S2, the amount of hot water added is 1.5-2 times the total weight of sodium fatty alcohol polyoxyethylene ether sulfate and auxiliary anionic surfactant.

[0013] Furthermore, in S3, the shear rate of the high-speed shear emulsifier is 5000-7000 rpm, and the emulsification time is 15-25 min.

[0014] Furthermore, in S3, the emulsification temperature is 75-80°C.

[0015] Furthermore, when this collector is used in reverse flotation of phosphate rock at a low temperature of 10-15℃, it can increase the grade of phosphate concentrate to more than 35% and achieve a recovery rate of more than 88%.

[0016] The beneficial effects of this invention are: 1. In this invention, through precise formulation design and a two-step emulsification process, a uniform and stable nanocomposite micelle system was successfully constructed at the microscopic level. The physicochemical mechanism is manifested in the formation of a dense and robust interfacial film at the oil-water interface by sodium fatty alcohol polyoxyethylene ether sulfate and compounded auxiliary anionic surfactant, which effectively encapsulates the active components of the oil phase. This unique structure ensures that the collector can maintain good kinetic stability in low-temperature slurry at 10-15℃, effectively preventing crystallization, precipitation or agglomeration caused by the decrease in solubility of conventional collectors at low temperatures, and laying a solid physicochemical foundation for exerting efficacy at low temperatures.

[0017] 2. In this invention, the various surfactants used are not simply mixed, but rather their functions are complemented and synergistically enhanced through molecular structure design (such as differences in hydrophobic chain length and hydrophilic group properties). When acting on the mineral surface, each component can be adsorbed in a directional and orderly manner, forming a more uniform adsorption layer with moderate binding strength. The unsaturated long chain of palmitoleic acid remains flexible at low temperatures, which is conducive to full contact with the mineral surface, while petroleum sulfonic acid enhances the stability of the adsorption layer. This synergistic mechanism enables the collector to still have high selectivity and strong collecting power for carbonate impurities at low temperatures, effectively overcoming the problem of low-temperature selectivity deterioration mentioned in the background art.

[0018] 3. In this invention, the low-temperature adaptability of the collector is optimized at the molecular level. Its special microstructure allows it to work efficiently at low temperatures without the need for additional energy to heat the slurry. At the same time, the excellent synergistic effect enables the ideal separation effect to be achieved at a low dosage, avoiding the overuse of reagents. This not only reduces production costs but also reduces potential negative environmental impacts, meeting the development requirements of green mineral processing.

[0019] 4. In this invention, by ensuring high selectivity (improving the grade of phosphate concentrate) while maintaining high recovery rate, and possessing good dispersion stability and adaptability, this feature of combining low-temperature effectiveness, high selectivity, environmental friendliness and economy makes it of great application value and broad prospects for promotion in the processing of low-grade phosphate ore, especially in northern regions or in low-temperature winter conditions. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise specified, the raw materials used in this invention are all from commercially available conventional products.

[0022] Example 1

[0023] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of auxiliary anionic surfactant (mixed from 1g of alkyl sulfonate, 3.5g of sodium dodecylbenzene sulfonate and 5.5g of coconut oil-based hydroxyethyl sulfonate in a mass ratio of 1:3.5:5.5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0024] Example 2

[0025] S1: Take 60g of sodium fatty acid (pH value 10), 10g of palmitoleic acid, 5g of light components of palm fatty acid and 1g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 10g of sodium fatty alcohol polyoxyethylene ether sulfate and 5g of auxiliary anionic surfactant (mixed from 0.5g of alkyl sulfonate, 2g of sodium dodecylbenzene sulfonate and 2.5g of coconut oil hydroxyethyl sulfonate in a mass ratio of 1:4:5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0026] Example 3

[0027] S1: Take 100g of sodium fatty acid (pH value 10), 30g of palmitoleic acid, 15g of light components of palm fatty acid and 5g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 30g of sodium fatty alcohol polyoxyethylene ether sulfate and 10g of auxiliary anionic surfactant (made by mixing 1g of alkyl sulfonate, 4g of sodium dodecylbenzene sulfonate and 5g of coconut oil hydroxyethyl sulfonate in a mass ratio of 1:4:5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0028] Example 4

[0029] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 70℃, stir at a stirring rate of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of auxiliary anionic surfactant (mixed from 1g of alkyl sulfonate, 3.5g of sodium dodecylbenzene sulfonate and 5.5g of coconut oil-based hydroxyethyl sulfonate in a mass ratio of 1:3.5:5.5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0030] Example 5

[0031] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of auxiliary anionic surfactant (mixed from 1g of alkyl sulfonate, 3.5g of sodium dodecylbenzene sulfonate and 5.5g of coconut oil-based hydroxyethyl sulfonate in a mass ratio of 1:3.5:5.5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 3000 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0032] Comparative Example 1

[0033] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate, dissolve it in 55g of hot water, control the water temperature at 70℃, stir at 150rpm for 20min until completely dissolved, and obtain an aqueous solution. S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0034] Comparative Example 2

[0035] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of sodium dodecylbenzene sulfonate as auxiliary anionic surfactants, dissolve them in 55g of hot water, control the water temperature at 70℃, stir at a stirring rate of 150rpm for 20min until completely dissolved, and obtain an aqueous solution. S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0036] Comparative Example 3

[0037] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 100℃, stir at a stirring rate of 200rpm for 30min to make the materials completely melt and mix evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of auxiliary anionic surfactant (mixed from 1g of alkyl sulfonate, 3.5g of sodium dodecylbenzene sulfonate and 5.5g of coconut oil-based hydroxyethyl sulfonate in a mass ratio of 1:3.5:5.5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0038] Comparative Example 4

[0039] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of auxiliary anionic surfactant (mixed from 1g of alkyl sulfonate, 3.5g of sodium dodecylbenzene sulfonate and 5.5g of coconut oil-based hydroxyethyl sulfonate in a mass ratio of 1:3.5:5.5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 5 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0040] Comparative Example 5

[0041] S1: Take 80g of sodium fatty acid (pH value 10), 20g of palmitoleic acid, 10g of light components of palm fatty acid and 3g of petroleum sulfonic acid, put them in a mixer, heat to 80℃, stir at a stirring speed of 200rpm for 30min, so that the materials are completely melted and mixed evenly to obtain an oil phase mixture. S2: Take 20g of sodium fatty alcohol polyoxyethylene ether sulfate and 7.5g of auxiliary anionic surfactant (mixed from 1g of alkyl sulfonate, 3.5g of sodium dodecylbenzene sulfonate and 5.5g of coconut oil-based hydroxyethyl sulfonate in a mass ratio of 1:3.5:5.5), dissolve them in 55g of hot water, control the water temperature at 70℃, and stir at a stirring speed of 150rpm for 20min until completely dissolved to obtain an aqueous solution; S3: At a stirring rate of 350 rpm, slowly add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2, with the addition time controlled at 10 min. After the addition is complete, transfer the mixture to a high-speed shear emulsifier and emulsify at a shear rate of 6500 rpm for 20 min, controlling the emulsification temperature at 78℃, to obtain a homogeneous and stable emulsion; S4: Cool the emulsion obtained in S3 naturally to room temperature of 25°C to obtain the low-temperature collector for reverse flotation of phosphate rock.

[0042] Performance testing methods and results

[0043] Flotation test conditions: Phosphate ore: Typical phosphate ore is used, with a grade of 20.0% P2O5 and a baseline recovery rate of 80.0% (without the use of collectors). The ore contains impurities such as carbonates. Reverse flotation process: 500g of raw ore is used for each experiment and reverse flotation is carried out in a 1L flotation machine; Fixed conditions: pulp pH 9.5 (adjusted with NaOH), starch inhibitor dosage 0.5 kg / t, MIBC frother dosage 0.1 kg / t, flotation temperature controlled at 12±2℃, flotation time 5 min, collector dosage 0.5 kg / t (based on dry ore). Evaluation indicators: phosphate concentrate grade (% P2O5) and recovery rate (%). Each experiment was repeated 3 times, and the average value was taken. Physical property tests of the collector: Viscosity test: Using a rotational viscometer, at 25°C and a shear rate of 100 s. -1 The viscosity of the collector emulsion was measured. Stability test: Place the collector in a 10℃ environment and let it stand for 24 hours. Observe whether it separates into layers or precipitates. Record the stability as "stable" or "unstable". pH test: Use a pH meter to measure the pH value of the collector; The flotation performance results are shown in Table 1, and the physical properties of the collector are shown in Table 2. Table 1. Comparison of Flotation Performance between Examples and Comparative Examples

[0044] Table 2. Comparison of physical properties of the collectors in the examples and comparative examples

[0045] As shown in Table 1, through the verification of Examples 1-5, the present invention can achieve excellent flotation results under low temperature conditions of 10-15℃. The phosphate concentrate grade in all examples reached above 34.5%, and the recovery rate was maintained above 88%. This result fully proves that the standard formula and its parameter range adjustments have reliable applicability. Its mechanism of action is the synergistic effect of multiple components in the formula: sodium fatty acid, as the main collector, has its low-temperature crystallization defect improved by the emulsifying and stabilizing effect of sodium fatty alcohol polyoxyethylene ether sulfate. Palmitoleic acid provides the necessary low-temperature fluidity due to its unsaturated structure. In particular, the auxiliary anionic surfactant system composed of multiple surfactants produces a significant synergistic effect, which greatly enhances the dispersibility of the collector in the low-temperature slurry and the selective adsorption capacity for carbonate impurities. The heating melting and high-speed shear emulsification in the preparation process ensure the formation of a uniform and stable emulsion with a viscosity maintained in the ideal range of 800-900 mPa·s, laying the foundation for effective action at low temperatures.

[0046] However, the comparative experimental results, from the opposite perspective, confirmed the importance of the aforementioned key design elements. The flotation performance (grades of 28.5% and 30.2%, respectively) of Comparative Example 1 (without auxiliary surfactant) and Comparative Example 2 (with a single auxiliary surfactant) was significantly worse than the examples, and the emulsions showed precipitation or stratification, indicating poor stability. This directly proves that the formulation of auxiliary surfactants is crucial for generating synergistic effects, obtaining a stable dispersion system at low temperatures, and achieving selectivity. Single or missing components cannot form an effective composite micelle structure. Although the emulsion in Comparative Example 3 (prepared at high temperature) was stable, the flotation performance was poor. The decrease in performance (grade 32.0%) indicates that excessively high heating temperatures may lead to degradation of active components. Comparative Example 4 (short-time emulsification) suffers from poor dispersibility due to insufficient emulsification, resulting in poor flotation performance (grade 31.5%) and stratification. This highlights the necessity of sufficient emulsification time for forming stable microemulsions. Comparative Example 5 (stearic acid replacing palmitoleic acid) is particularly typical, as it has the worst flotation performance (grade 29.8%) and the emulsion solidifies at low temperatures. This clearly demonstrates that the unsaturated structure of palmitoleic acid plays an irreplaceable role in maintaining the fluidity of the collector system at low temperatures.

[0047] The above positive and negative comparisons demonstrate that the excellent low-temperature performance of the collector described in this invention is not due to a single factor, but rather the result of a close combination of specific formulation design and precise preparation process. The absence or substitution of any key component, or deviation from key process parameters, will disrupt the balance of the system, leading to a significant decrease in performance. Therefore, in practical applications, strictly adhering to the component ratios and preparation conditions provided by this invention is crucial to ensuring that the low-temperature collector for phosphate rock reverse flotation achieves its best effect. In summary, through the comparison of examples and comparative examples, this invention verifies the advanced nature and reliability of the provided low-temperature collector formulation and preparation method for phosphate rock reverse flotation. Its success stems from the organic combination of multi-component synergy and process control, providing an effective solution for low-temperature phosphate rock flotation.

[0048] In the description of this specification, the terms "preparation example," "example," "various examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that example or preparation example, which are included in at least one example or preparation example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same example or preparation example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more examples or preparation examples.

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A low-temperature collector for reverse flotation of phosphate rock, characterized in that, It consists of the following raw materials in parts by weight: Sodium fatty acid 60-100 parts, sodium fatty alcohol polyoxyethylene ether sulfate 10-30 parts, palmitoleic acid 10-30 parts, auxiliary anionic surfactant 5-10 parts, petroleum sulfonic acid 1-5 parts, and light components of palm fatty acid 5-15 parts.

2. The low-temperature collector for reverse flotation of phosphate rock according to claim 1, characterized in that, The sodium fatty acid has a pH value of 9-11.

3. The low-temperature collector for reverse flotation of phosphate rock according to claim 1, characterized in that, The auxiliary anionic surfactant is selected from at least two of the group consisting of alkyl sulfonates, sodium dodecylbenzene sulfonate, and sodium cocoyl hydroxyethyl sulfonate.

4. The low-temperature collector for reverse flotation of phosphate rock according to claim 3, characterized in that, The auxiliary anionic surfactant is composed of alkyl sulfonate phenyl ester, sodium dodecylbenzene sulfonate, and sodium cocoyl hydroxyethyl sulfonate in a mass ratio of 1:(2-5):(3-8).

5. A method for preparing a low-temperature collector for reverse flotation of phosphate rock as described in any one of claims 1-4, characterized in that, The preparation method includes the following steps: S1. Weigh out sodium fatty acid, palmitoleic acid, light components of palm fatty acid and petroleum sulfonic acid according to the proportion, place them in a mixer, heat to 70-90℃, stir to melt the materials and mix them evenly to obtain an oil phase mixture. S2. Weigh out sodium fatty alcohol polyoxyethylene ether sulfate and auxiliary anionic surfactant in proportion, dissolve them in hot water with a total weight of 1-3 times, control the water temperature at 60-80℃, stir until completely dissolved, and obtain an aqueous solution. S3. At a stirring rate of 200-500 rpm, add the oil phase mixture obtained in S1 to the aqueous phase solution obtained in S2 over a feeding time of 10-30 min. After the feeding is completed, transfer the mixture to a high-speed shear emulsifier and emulsify it at a shear rate of 3000-8000 rpm for 10-30 min, controlling the emulsification temperature at 70-85℃ to obtain a uniform and stable emulsion. S4. Cool the emulsion obtained in S3 to room temperature to obtain the low-temperature collector for reverse flotation of phosphate rock.

6. The preparation method according to claim 5, characterized in that, In S1, the heating temperature is 75-85°C.

7. The preparation method according to claim 5, characterized in that, In S2, the amount of hot water added is 1.5-2 times the total weight of sodium fatty alcohol polyoxyethylene ether sulfate and auxiliary anionic surfactant.

8. The preparation method according to claim 5, characterized in that, In S3, the shear rate of the high-speed shear emulsifier is 5000-7000 rpm, and the emulsification time is 15-25 min.

9. The preparation method according to claim 5, characterized in that, In S3, the emulsification temperature is 75-80°C.

10. The low-temperature collector for reverse flotation of phosphate rock according to any one of claims 1-4, characterized in that, When used in reverse flotation of phosphate rock at a low temperature of 10-15℃, this collector can increase the grade of phosphate concentrate to over 35% and achieve a recovery rate of over 88%.

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