Low-temperature-resistant rare earth ore collecting agent, preparation method and application thereof

Abstract

This invention provides a low-temperature resistant rare earth ore collector, its preparation method, and its application. By weight, the rare earth ore collector comprises the following raw materials: 50-70 parts modified fatty acid, 10-20 parts hydroxamic acid, 5-10 parts frother, and 3-8 parts surfactant; the rare earth ore collector also includes 5-10 parts auxiliary collector, wherein the modified fatty acid is obtained by reacting ricinoleic acid with sodium 2-[(2-aminoethyl)amino]ethanesulfonate. The rare earth ore collector of this invention exhibits good low-temperature resistance and excellent collecting properties, effectively solving the problem of low low-temperature activity of conventional flotation collectors, and is suitable for industrial flotation.

Description

Technical Field

[0001] This invention belongs to the field of rare earth mineral processing technology, specifically relating to a low-temperature resistant rare earth ore collector, its preparation method, and its application. Background Technology

[0002] Rare earth elements are key metals supporting strategic emerging industries such as new materials, new energy, and aerospace. Their efficient development and utilization are of great strategic significance for ensuring national resource security. Although my country has abundant rare earth reserves, after long-term mining, high-quality and easily beneficiated rare earth ores are nearing depletion. Currently, industrially utilized deposits generally exhibit characteristics such as low grade, fine mineral grain size, and complex associated relationships, leading to severe challenges in the raw material pretreatment stage of metal production and refining.

[0003] Metal production and refining is a comprehensive technological system encompassing the complete transformation from ore to metal, and rare earth beneficiation technology is the crucial initial step in this system. As a front-end processing step, it enriches raw ore containing only 0.03%–0.3% rare earth oxides (REO) into concentrates with a grade of 30%–60% through physicochemical methods such as flotation and magnetic separation. Its technical indicators directly determine the raw material quality and processing costs for subsequent hydrometallurgical extraction, separation and purification, and metal electrolysis. Given the current continuous decline in resource grades, every 1 percentage point increase in beneficiation recovery rate can reduce smelting acid and alkali consumption by 2%–3% and lower overall production costs by 1.5%–2.5%. Therefore, innovation in beneficiation technology is not only a prerequisite for the economic utilization of low-grade, difficult-to-process mineral resources but also a core support for optimizing the entire metal extraction chain and ensuring the security of the strategic rare earth metal supply chain.

[0004] Flotation is currently the most important technology for rare earth ore separation, and its core lies in the development and application of highly efficient collecting reagents. Hydroxime acid reagents have become the mainstream flotation reagents due to their excellent selectivity for rare earth minerals. However, traditional hydroxime acid products have significant low-temperature adaptability defects. When the pulp temperature is below 10℃ (the pulp temperature in concentrators in northern and cold regions of my country is generally 5-15℃ in winter), the solubility of the reagent decreases sharply, the dispersion performance deteriorates, and the activity with the mineral surface decreases, resulting in a 30%-40% drop in flotation recovery rate. To maintain production targets, concentrators generally use steam to heat the pulp, which increases energy costs by 15%-25%, increases process complexity, and contradicts the current green mineral processing development direction under the "dual carbon" target.

[0005] To address the aforementioned issues, existing technologies primarily improve the low-temperature performance of reagents by compounding surfactants or adding cosolvents. However, these methods suffer from problems such as unstable reagent systems, sticky foams, decreased selectivity, and high reagent consumption. While some modified hydroxamic acid products exhibit certain low-temperature adaptability, they suffer from drawbacks such as complex preparation processes, high costs, and insufficient adaptability to complex and difficult-to-process rare earth ores.

[0006] Therefore, developing a new rare earth ore collector that combines excellent low-temperature resistance, high selectivity, simple preparation process, and controllable cost to achieve efficient collection of rare earth minerals under low-temperature conditions has become a technical problem that the rare earth beneficiation industry urgently needs to solve. Summary of the Invention

[0007] To address the existing technical problems, the present invention aims to provide a low-temperature resistant rare earth ore collector and its preparation method. The rare earth ore collector of the present invention exhibits excellent resistance to low temperatures and high humidity, and shows promising application prospects.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention provides a low-temperature resistant rare earth ore collector, which, by weight, comprises the following raw materials: 50-70 parts modified fatty acid, 10-20 parts hydroxamic acid, 5-10 parts foaming agent, and 3-8 parts surfactant; wherein... The modified fatty acid is obtained by reacting ricinoleic acid with sodium 2-[(2-aminoethyl)amino]ethanesulfonate.

[0009] In some embodiments of the present invention, the method for preparing the modified fatty acid includes the following steps: Castor oil acid and p-toluenesulfonic acid are mixed, nitrogen gas is introduced, and the mixture is heated to 60℃~80℃. Then, sodium 2-[(2-aminoethyl)amino]ethanesulfonate is added in portions, and the temperature is raised to 110℃~140℃. The mixture is stirred and reacted for 30min~60min to obtain modified fatty acids.

[0010] In some embodiments of the present invention, the molar ratio of ricinoleic acid to sodium 2-[(2-aminoethyl)amino]ethanesulfonate is 1:(1.05-1.25).

[0011] In some embodiments of the present invention, the hydroxamic acid is any one or more of benzohydroxyxamic acid, salicylic acid, and 1-naphthohydroxyxamic acid.

[0012] In some embodiments of the present invention, the foaming agent is any one or more of BK201, BK204, MIBC and pine oil.

[0013] In some embodiments of the present invention, the surfactant is any one or more of Tween 60, Tween 80, Span 60, Span 80, cocoyl diethanolamide, and fatty alcohol polyoxyethylene ether.

[0014] Preferably, the surfactant is a combination of cocoyl diethanolamide and fatty alcohol polyoxyethylene ether.

[0015] In some embodiments of the present invention, the rare earth mineral collector further includes 5 to 10 parts by weight of an auxiliary collector.

[0016] In some embodiments of the present invention, the auxiliary collector is 6-phosphonohexanoic acid.

[0017] The second invention provides a method for preparing a low-temperature resistant rare earth ore collector, comprising the following steps: S1. Add hydroxamic acid and foaming agent to the modified fatty acid, and stir and mix at 30℃~50℃ to obtain a mixture; S2. Add an auxiliary collector to the mixture obtained in step S1 and stir to mix. Then add a surfactant and stir to mix at 50℃~65℃ to obtain the rare earth mineral collector.

[0018] The third invention provides an application of a low-temperature resistant rare earth ore collector, comprising the following steps: After grinding the rare earth ore, water is added to prepare a slurry with a mass concentration of 50% to 65%. The slurry is heated to 40°C to 60°C, alkali solution is added, and the mixture is stirred. Then, an inhibitor and a rare earth ore collector are added before flotation can be carried out.

[0019] Furthermore, the alkaline solution is a 1%–2% sodium hydroxide aqueous solution; the inhibitor is a 5%–15% water glass solution.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The rare earth ore collector of the present invention is a multi-component synergistic combination system with good low-temperature resistance, which can reduce mineral processing energy consumption and improve resource recovery rate.

[0021] 2. This invention modifies ricinoleic acid by modifying it with sodium 2-[(2-aminoethyl)amino]ethanesulfonate to obtain modified fatty acids. On the one hand, it significantly reduces intermolecular van der Waals forces, disrupting the ordered crystalline arrangement at low temperatures. Simultaneously, the modified molecular structure introduces nitrogen-containing branches, further forming steric hindrance and hindering the orderly arrangement of intermolecular hydrogen bonds at low temperatures, thus maintaining the agent in a fluid and dispersed state in low-temperature slurry. On the other hand, the modified fatty acid structure contains polar groups such as carbonyl, thiooxy, amino, and hydroxyl groups, significantly enhancing its water solubility and reactivity. Its active sites can generate multiple synergistic effects: through the coupling of electrostatic attraction, hydrogen bonding, and chemical bonding, a stable multi-point adsorption configuration is formed, thereby significantly enhancing the collection efficiency of rare earth minerals.

[0022] 3. This invention uses modified fatty acids and hydroxamic acid substances to float rare earth minerals, achieving strong adsorption at multiple anchor points on the surface of rare earth minerals; furthermore, the applicant introduced an auxiliary collector and unexpectedly discovered that it has a synergistic effect with hydroxamic acid substances that is far greater than that of conventional phosphorus-containing auxiliary collectors, which greatly improves the collection efficiency and low-temperature resistance. Detailed Implementation

[0023] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0024] According to the following examples and comparative examples, the proportions and preparation methods of each raw material are specified to prepare various rare earth ore collecting agents.

[0025] To facilitate implementation of this invention by those skilled in the art, the manufacturers of some raw materials for the embodiments and comparative examples are described below: Nonylphenol polyoxyethylene ether: purchased from Jinan Yuanfang Chemical Co., Ltd.; Unless otherwise specified, all other raw materials can be purchased from the market.

[0026] Preparation Example 1 The method for preparing modified fatty acids includes the following steps: Mix 0.3 mol of ricinoleic acid and 1.5 g of p-toluenesulfonic acid, purge with nitrogen, heat to 70 °C, add 0.345 mol of sodium 2-[(2-aminoethyl)amino]ethanesulfonate in three equal portions, raise the temperature to 130 °C, and react with stirring until the acid value is < 5 mgKOH / g, then stop the reaction. Cool to room temperature, wash twice with hot water at 70 °C, and dry under vacuum to obtain the modified fatty acid. Example 1

[0027] A low-temperature resistant rare earth ore collector, comprising the following raw materials by weight: 60 parts modified fatty acid, 15 parts salicylic acid hydroxamic acid, 7.5 parts MIBC, 2 parts cocoyl diethanolamide, 4 parts nonylphenol polyoxyethylene ether, and 7.5 parts 6-phosphonohexanoic acid.

[0028] The preparation method of the rare earth ore collecting agent in this embodiment includes the following steps: S1. Add salicylic acid and MIBC to the modified fatty acid and stir at 40°C to obtain a mixture; S2. Add 6-phosphonohexanoic acid to the mixture obtained in step S1 and stir to mix. Then add cocoa butteracrylic acid diethanolamide and nonylphenol polyoxyethylene ether and stir to mix at 55°C to obtain the rare earth mineral collector. Example 2

[0029] A low-temperature resistant rare earth ore collector, comprising the following raw materials by weight: 60 parts modified fatty acid, 15 parts salicylic acid hydroxamic acid, 7.5 parts MIBC, 2 parts cocoyl diethanolamide, and 4 parts nonylphenol polyoxyethylene ether.

[0030] The preparation method of the rare earth ore collecting agent in this embodiment includes the following steps: S1. Add salicylic acid and MIBC to the modified fatty acid and stir at 40°C to obtain a mixture; S2. Add cocoagulant diethanolamide and nonylphenol polyoxyethylene ether to the mixture obtained in step S1, and stir and mix at 55°C to obtain the rare earth mineral collector. Example 3

[0031] A low-temperature resistant rare earth ore collector, comprising, by weight, the following raw materials: 50 parts modified fatty acid, 10 parts salicylic acid hydroxamic acid, 5 parts MIBC, 1 part coconut oil diethanolamide, 2 parts nonylphenol polyoxyethylene ether, and 5 parts 6-phosphonohexanoic acid.

[0032] The preparation method of the rare earth ore collecting agent in this embodiment includes the following steps: S1. Add salicylic acid and MIBC to the modified fatty acid and stir at 30°C to obtain a mixture; S2. Add 6-phosphonohexanoic acid to the mixture obtained in step S1 and stir to mix. Then add cocoa butteracrylic acid diethanolamide and nonylphenol polyoxyethylene ether and stir to mix at 50°C to obtain the rare earth mineral collector. Example 4

[0033] A low-temperature resistant rare earth ore collector, comprising, by weight, the following raw materials: 70 parts modified fatty acid, 20 parts salicylic acid hydroxamic acid, 10 parts MIBC, 4 parts coconut oil diethanolamide, 4 parts nonylphenol polyoxyethylene ether, and 10 parts 6-phosphonohexanoic acid.

[0034] The preparation method of the rare earth ore collecting agent in this embodiment includes the following steps: S1. Add salicylic acid and MIBC to the modified fatty acid and stir at 50°C to obtain a mixture; S2. Add 6-phosphonohexanoic acid to the mixture obtained in step S1 and stir to mix. Then add cocoa butteracrylic acid diethanolamide and nonylphenol polyoxyethylene ether and stir to mix at 65°C to obtain the rare earth mineral collector.

[0035] Comparative Example 1 A low-temperature resistant rare earth ore harvesting agent and its preparation method are described. The specific implementation method is the same as in Example 1, except that an equal amount of ricinoleic acid is used to replace the modified fatty acid.

[0036] Comparative Example 2 A low-temperature resistant rare earth ore harvesting agent and its preparation method are described. The specific implementation method is the same as in Example 1, except that an equal amount of phenylphosphonic acid is used instead of 6-phosphonohexanoic acid.

[0037] Effect evaluation: The rare earth ore collectors prepared in Examples 1-4 and Comparative Examples 1-2 were tested and analyzed. The specific results are shown in Tables 1-2.

[0038] Performance testing: The application of a low-temperature resistant rare earth ore collector includes the following steps: 1. Grind the rare earth ore to a fineness of less than 200 mesh, add water to prepare a slurry with a mass concentration of 50% to 65%, heat it to 50°C, add a 1% sodium hydroxide aqueous solution, adjust the pH to 9.5, and stir for 3 minutes. II. Roughing: Maintain the pulp temperature at approximately 40℃ throughout the process. Add 1000g / t of a 10% water glass aqueous solution to the pulp and stir for 3 minutes. Add 1500g / t of rare earth mineral collector and stir for 3 minutes. Then turn on the aeration device of the flotation machine and perform flotation for 6 minutes. The resulting froth product is the rare earth flotation roughing concentrate, and the sediment is the rare earth flotation tailings. III. Primary Cleaning: Adjust the roughing concentrate to a slurry concentration of 45%, maintain the slurry temperature at approximately 40℃ throughout the process, stir for 2 minutes, add a 1% sodium hydroxide aqueous solution to adjust the pH to 9.5, stir for 3 minutes, then add 1000 g / t of a 10% water glass aqueous solution, stir for 3 minutes; then add 1200 g / t of rare earth mineral collector, stir for 3 minutes; subsequently, turn on the aeration device of the flotation machine and perform flotation for 4 minutes. The resulting froth product is the primary cleaned concentrate of rare earth flotation, and the sediment is the primary cleaned tailings. IV. Secondary Refinement: Adjust the concentrate from the primary rare earth flotation to a slurry with a mass concentration of 40%, maintain the slurry temperature at approximately 40℃ throughout the process, add a 1% sodium hydroxide solution to adjust the pH to 9.5, stir for 3 minutes, then add 500g / t of a 10% water glass solution, stir for 3 minutes, then add 900g / t of rare earth ore collector, stir for 3 minutes, and then turn on the flotation machine's aeration device to perform aeration and stirring flotation for 3 minutes. The resulting froth product is the secondary rare earth flotation concentrate, and the sediment is the secondary refinement tailings. V. Repeated Cleaning: The tailings from the primary and secondary cleaning processes are combined and returned to the roughing process. Steps 2 to 4 are repeated until the yield and rare earth grade of the combined product of the primary and secondary cleaning flotation tailings do not change by more than 5%. The resulting secondary cleaning concentrate is the final concentrate, and the flotation tailings are the final tailings.

[0039] Tailings from a certain region were used as rare earth ore samples, with a rare earth oxide (REO) grade of 6.67%.

[0040] Table 1 Table 2 As shown in Table 1, the rare earth ore collectors in Examples 1-4 have high recovery rates, all exceeding 70%. A comparison between Examples 1 and 2 reveals that the addition of 6-phosphonohexanoic acid significantly improves collection efficiency, exhibiting a synergistic effect. Comparative Example 1, which uses an equal amount of ricinoleic acid to replace the modified fatty acid, shows unsatisfactory recovery results. Comparative Example 2, which uses an equal amount of phenylphosphonic acid to replace 6-phosphonohexanoic acid, achieves a higher recovery rate than Example 2 (which does not include the collector), but its results are still far lower than those of Example 1. This demonstrates that even with a synergistic effect, the results are significantly less effective than those achieved with 6-phosphonohexanoic acid.

[0041] As shown in Table 2, Example 1 was the most stable at a low temperature of 10℃, with a recovery rate of rare earth concentrate decreasing by only 2.45%, while Comparative Examples 1 and 2 showed relatively larger reductions. This indicates that the rare earth ore collector of the present invention is a multi-component synergistic combination system.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present application in any way. Although the present application discloses the preferred embodiment as described above, it is not intended to limit the present application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. A low-temperature resistant rare earth ore collector, characterized in that, By weight, the rare earth ore collector comprises the following raw materials: 50-70 parts modified fatty acid, 10-20 parts hydroxamic acid, 5-10 parts foaming agent, and 3-8 parts surfactant; wherein... The modified fatty acid is obtained by reacting ricinoleic acid with sodium 2-[(2-aminoethyl)amino]ethanesulfonate.

2. The low-temperature resistant rare earth ore collector according to claim 1, characterized in that, The method for preparing the modified fatty acid includes the following steps: Castor oil acid and p-toluenesulfonic acid are mixed, nitrogen gas is introduced, and the mixture is heated to 60℃~80℃. Then, sodium 2-[(2-aminoethyl)amino]ethanesulfonate is added in portions, and the temperature is raised to 110℃~140℃. The mixture is stirred and reacted for 30min~60min to obtain modified fatty acids.

3. The low-temperature resistant rare earth ore collector according to claim 2, characterized in that, The molar ratio of ricinoleic acid to sodium 2-[(2-aminoethyl)amino]ethanesulfonate is 1:(1.05-1.25).

4. The low-temperature resistant rare earth ore collector according to claim 1, characterized in that, The hydroxamic acid is any one or more of benzohydroxyxamic acid, salicylic acid, and 1-naphthohydroxyxamic acid.

5. The low-temperature resistant rare earth ore collector according to claim 1, characterized in that, The foaming agent is any one or more of BK201, BK204, MIBC, and pine oil.

6. The low-temperature resistant rare earth ore collector according to claim 1, characterized in that, The surfactant is any one or more of Tween 60, Tween 80, Span 60, Span 80, cocoyl diethanolamide, and fatty alcohol polyoxyethylene ether.

7. The low-temperature resistant rare earth ore collector according to claim 1, characterized in that, The rare earth ore collector also includes 5 to 10 parts by weight of auxiliary collector.

8. The low-temperature resistant rare earth ore collector according to claim 7, characterized in that, The auxiliary collector is 6-phosphonohexanoic acid.

9. A method for preparing the low-temperature resistant rare earth ore collector as described in claim 8, characterized in that, Includes the following steps: S1. Add hydroxamic acid and foaming agent to the modified fatty acid, and stir and mix at 30℃~50℃ to obtain a mixture; S2. Add an auxiliary collector to the mixture obtained in step S1 and stir to mix. Then add a surfactant and stir to mix at 50℃~65℃ to obtain the rare earth mineral collector.

10. The application of the low-temperature resistant rare earth ore collector as described in claim 8, characterized in that, Includes the following steps: After grinding the rare earth ore, water is added to prepare a slurry with a mass concentration of 50% to 65%. The slurry is heated to 40°C to 60°C, an alkaline solution is added, and the mixture is stirred. Then, an inhibitor and the rare earth ore collector are added to carry out flotation.

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