A composite collector for rare earth minerals and its application in flotation

Abstract

The present invention provides a composite collector for rare earth ores and its application in flotation, relating to the technical field of rare earth flotation. The composite collector is composed of a hydroxamic acid organic compound, an ether organic compound, and a phosphate organic compound in a mass ratio of (15-20):(3-8):(1-3). When the composite collector is used in flotation, the rare earth ore is crushed and ground, and then the rare earth composite collector, an inhibitor, and a frother are sequentially added to the slurry at a set slurry concentration, temperature, and pH for flotation. When the composite collector of the present invention is used to separate rare earth minerals from gangue minerals, the main agent, the hydroxamic acid organic compound, selectively binds to metal ions on the surface of the rare earth mineral to achieve selective separation of the rare earth mineral from the gangue. The auxiliary agent, the ether, enhances the solubility of the hydroxamic acid and reduces the amount of hydroxamic acid used. The auxiliary agent, the phosphate, enhances the recovery of the rare earth ore by the hydroxamic acid, improves the foaming, and improves the grade and recovery rate of the rare earth concentrate.

Description

Technical Field

[0001] The present invention relates to the technical field of rare earth flotation, in particular to a composite collector for rare earth ores and application thereof in flotation. Background Art

[0002] Due to their unique spatial structure and physical and chemical properties, rare earth elements (REEs) are widely used in key fields such as high-end manufacturing, artificial intelligence, and aerospace. They are key raw materials for pillar and leading industries and are known as "industrial vitamins." Bastnaesite, monazite, and other minerals are the primary hosts of REEs, often coexisting with calcium-containing minerals such as fluorite and dolomite. Flotation is the most common method for separating rare earth minerals from calcium-containing minerals, but their similar flotation properties make separation difficult. Furthermore, the activation and mechanical entrainment of metal ions during flotation causes silicate minerals such as quartz, amphibole, and feldspar to float, reducing the grade of the rare earth concentrate.

[0003] Currently, hydroxamic acid or fatty acids are commonly used in industry as collectors, and water glass is used as a gangue inhibitor. However, hydroxamic acid has low solubility and high reagent consumption, while fatty acids, due to their chemical properties, result in high flotation foam viscosity, poor amalgamation, and severe flotation foam entrainment. Furthermore, water glass is not ideal for inhibiting calcium-containing minerals. Therefore, the development of collectors with high solubility and low foam viscosity that are selective for rare earth minerals, and inhibitors that are selective for calcium-containing minerals, is of great significance. Summary of the Invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention provides a composite collector for rare earth ores and its application in flotation. The technical solution is as follows:

[0005] A composite collector for rare earth ores, which is prepared by mixing hydroxamic acid organic matter, ether organic matter and phosphate organic matter in a mass ratio of 15-20:3-8:1-3;

[0006] The hydroxamic acid organic compound is two or more of 1-hydroxy-2-naphthohydroxamic acid, 2-hydroxy-3-naphthohydroxamic acid, benzohydroxamic acid, 4-tert-butylbenzohydroxamic acid, cycloalkanehydroxamic acid, and octylhydroxamic acid;

[0007] The ether organic compound is one or more of alkylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and tristyrylphenol polyoxyethylene ether;

[0008] The phosphate organic compound is one or more of tributyl phosphate and triisobutyl phosphate.

[0009] When the composite collector is used in flotation, specifically, after the rare earth ore is crushed and ground to a certain fineness, the rare earth composite collector, inhibitor and frother are added to the slurry in sequence under suitable slurry concentration, temperature and pH to carry out flotation.

[0010] The rare earth ore is one or more of bastnaesite, monazite, xenotime, bastnaesite and natronaite.

[0011] The grinding to -0.074 mm accounts for 70% to 98%, the mass concentration of the ore pulp is 40% to 70%, the pH value of the ore pulp is 7 to 11, and the ore pulp temperature is 45 to 70° C. The pH of the ore pulp is adjusted by adding sodium carbonate and / or sodium hydroxide.

[0012] The addition amount of the composite collector is 0.6-2.0 Kg / t.

[0013] The addition amount of the inhibitor is 0.5-1.5 kg / t, and the inhibitor is a composite inhibitor prepared by mixing water glass, organic acids and hydroxyethyl cellulose in a mass ratio of 5-9:0.5-3:0.5-2.

[0014] The organic acid is one or more of oxalic acid, citric acid, ethylenediaminetetraacetic acid, gallic acid, and tartaric acid.

[0015] The amount of the foaming agent added is 50-200 g / t. Conventional foaming agents can be used. Preferably, 2# oil is used as the foaming agent.

[0016] During the process of adding the composite collector and the inhibitor to the ore pulp, when adding the composite collector, the hydroxamic acid organic matter and the ether organic matter are first mixed evenly and then added to the ore pulp, and then the phosphate organic matter is added to the ore pulp; when adding the inhibitor, the water glass, organic acids and hydroxyethyl cellulose are mixed evenly and then added to the ore pulp.

[0017] The gangue minerals in the above rare earth ores are mainly calcium-containing minerals and silicate gangue minerals, among which the calcium-containing minerals are one or more of fluorite, dolomite, apatite and calcite; and the silicate gangue minerals are one or more of quartz, feldspar, amphibole and nepheline.

[0018] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0019] (1) When the composite collector of the present invention is used to separate rare earth minerals from gangue minerals, the main agent, hydroxamic acid organic matter, can selectively combine with metal ions on the surface of rare earth minerals, thereby achieving selective separation of rare earth minerals from gangue. The auxiliary agent, ether, can enhance the solubility of hydroxamic acid and reduce the amount of hydroxamic acid used. The auxiliary agent, phosphate, can enhance the recovery of rare earth minerals by hydroxamic acid and improve foam annealing. The synergistic effect of the three agents greatly improves the grade and recovery rate of rare earth concentrates, and the effect is better than that of a single hydroxamic acid collector.

[0020] (2) In the flotation process of rare earth ores, the inhibitor composed of water glass, organic acids and hydroxyethyl cellulose has a strong inhibitory ability on both calcium-containing minerals and silicate minerals, and has better selectivity for calcium-containing gangue minerals than selecting a single water glass.

[0021] (3) The composite collector and composite depressant selected in the flotation process of rare earth ores of the present invention have strong adaptability to various ores, small dosage, low cost, and have the potential for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 The present invention provides a process flow chart for the application of a composite collector for rare earth ores in flotation. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0025] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.

[0026] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0027] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0028] The embodiment of the present invention provides a composite collector for rare earth ores and its application in flotation.

[0029] The collector is prepared by mixing hydroxamic acid organic matter, ether organic matter and phosphate organic matter in a mass ratio of 15-20:3-8:1-3;

[0030] The hydroxamic acid organic compound is two or more of 1-hydroxy-2-naphthohydroxamic acid, 2-hydroxy-3-naphthohydroxamic acid, benzohydroxamic acid, 4-tert-butylbenzohydroxamic acid, cycloalkanehydroxamic acid, and octylhydroxamic acid;

[0031] The ether organic compound is one or more of alkylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and tristyrylphenol polyoxyethylene ether;

[0032] The phosphate organic compound is one or more of tributyl phosphate and triisobutyl phosphate.

[0033] like Figure 1 The flow chart shown is for the application of a composite collector for rare earth ores in flotation. Specifically, after the rare earth ore is crushed and ground to a certain fineness, the rare earth composite collector, inhibitor and bubbling agent are sequentially added to the slurry at a suitable slurry concentration, temperature and pH for flotation.

[0034] The following describes this with reference to specific embodiments.

[0035] Example 1

[0036] The composite collector of the present invention comprises a hydroxamic acid organic compound, dodecylphenol polyoxyethylene ether and tributyl phosphate in a mass ratio of 16:5:1.5, wherein the hydroxamic acid organic compound comprises 9 parts of 1-hydroxy-2-naphthohydroxamic acid, 5 parts of p-tert-butylbenzohydroxamic acid and 2 parts of cycloalkanehydroxamic acid (calculated by mass).

[0037] The composite depressant of this embodiment was applied to the flotation process of a rare earth ore in Inner Mongolia (REO grade is 6.45%, rare earth minerals are mainly bastnaesite and monazite, and gangue are mainly fluorite, dolomite, amphibole and nepheline). The process flow chart is as follows: Figure 1 The specific process is as follows:

[0038] First, the rare earth ore is ground to -0.074mm with a mass ratio of 95%, the pulp concentration is 60%, and the flotation temperature is 60℃. Then, sodium carbonate is used to adjust the pulp pH to 9.5, and a composite inhibitor (a mixture of water glass, ethylenediaminetetraacetic acid and hydroxyethyl cellulose with a mass ratio of 6:3:1) and a composite collector (a mixture of hydroxamic acid organic matter and dodecylphenol polyoxyethylene ether is added first, and then tributyl phosphate is added. The reagents of the composite collector in the subsequent process need to be added according to this step). After one roughing, three refining and one sweeping (the roughing dosage of the composite inhibitor is 1.5Kg / t, the dosage of the composite collector is 0.8Kg / t, and the dosage of the foaming agent 2# oil is 1 10g / t; the dosage of composite depressant for refined 1 is 0.5Kg / t, that for refined 2 is 0.25Kg / t, and that for refined 3 is 0.1Kg / t; the dosage of composite collector for refined 1 is 0.2Kg / t, that for refined 2 is 0.1Kg / t, and that for refined 3 is blank selection; the dosage of frother 2# oil for refined 2 is 20g / t; the dosage of composite collector for sweep 1 is 0.3Kg / t, and that of frother 2# oil is 30g / t), after the closed-circuit flotation process with the middlings returned in sequence, the REO grade of the obtained rare earth concentrate is 60.14%, and the recovery rate is 62.57%; the CaO content is 5.13%, and the recovery rate is 2.21%; the SiO2 content is 0.64%, and the recovery rate is 0.96%.

[0039] Comparative Example 1:

[0040] The flotation steps in this comparative example were identical to those in Example 1, except that the composite depressant and composite collector in Example 1 were replaced with equal amounts of water glass and 1-hydroxy-2-naphthohydroxamic acid. The final REO grade and recovery rate in the rare earth concentrate were 56.36% and 50.54%, respectively; the CaO content was 11.06%, with a recovery rate of 3.81%; and the SiO2 content was 0.95%, with a recovery rate of 1.44%. Comparative test results show that the REO grade and recovery rate, particularly the recovery rate, in this comparative example were significantly lower than those in Example 1. Furthermore, the SiO2 and CaO contents, particularly the CaO content, in the rare earth concentrate were also significantly higher than those in Example 1. This demonstrates that the flotation performance of the rare earth ore composite depressant and composite collector using the single depressant, water glass, and single collector, hydroxamic acid, is significantly superior.

[0041] Comparative Example 2:

[0042] The flotation steps of this comparative example are consistent with those of Example 1, with the only difference being that the composite collector in Example 1 is replaced with an equal amount of 1-hydroxy-2-naphthohydroxamic acid collector. The final REO grade and recovery rate in the rare earth concentrate are 58.24% and 53.18%, respectively; the CaO content is 9.06%, the recovery rate is 3.31%; and the SiO2 content is 0.82%, with a recovery rate of 1.15%. The REO grade in this comparative example is lower than that in Example 1, while the REO recovery rate is significantly lower than that in Example 1. Furthermore, the CaO and SiO2 contents in the rare earth concentrate are both higher than those in Example 1, indicating that the flotation effect of the composite collector used in the flotation process is significantly better than that of the single 1-hydroxy-2-naphthohydroxamic acid.

[0043] Comparative Example 3:

[0044] The flotation process in this comparative example was identical to that in Example 1, except that the composite depressant in Example 1 was replaced with an equal amount of water glass. The resulting rare earth concentrate had an REO grade and recovery of 59.21% and 58.54%, respectively; a CaO content of 8.73% with a recovery of 2.95%; and a SiO2 content of 0.66% with a recovery of 0.94%. Comparative test results show that the REO grade and recovery in this comparative example were lower than those in Example 1, and the SiO2 and CaO contents in the rare earth concentrate were also significantly higher than those in Example 1. This demonstrates that the use of a composite depressant for rare earth ore significantly outperforms water glass alone in flotation.

[0045] Comparative Example 4:

[0046] The flotation steps of this comparative example are the same as those of Example 1, with the only difference being that all reagents in the composite collector of Example 1 are mixed uniformly before being added to the slurry. The final REO grade and recovery rate in the rare earth concentrate are 49.33% and 37.19%, respectively; the CaO content is 13.68%, the recovery rate is 4.37%; the SiO2 content is 1.88%, and the recovery rate is 1.42%. By comparing the test results, it is found that the REO grade and recovery rate of the rare earth concentrate in Comparative Example 4 are lower than those in Example 1, and the SiO2 and CaO contents in the rare earth concentrate are also much higher than those in Example 1, indicating that adding a partially mixed composite collector is better than adding a fully mixed composite collector. This may be because a chemical reaction occurs after the composite collector is fully mixed, producing components that are not conducive to the capture of rare earth minerals.

[0047] Example 2

[0048] A composite collector of the present invention comprises a hydroxamic acid organic compound, tristyrylphenol polyoxyethylene ether and triisobutyl phosphate in a mass ratio of 18:3:2, wherein the hydroxamic acid organic compound comprises 10 parts of 2-hydroxy-3-naphthohydroxamic acid, 7 parts of benzohydroxamic acid and 1 part of octylhydroxamic acid (calculated by mass).

[0049] The composite depressant of this embodiment was applied to the flotation process of a rare earth ore in India (REO grade of 3.85%, rare earth minerals mainly bastnaesite and bastnaesite, gangue mainly calcite, apatite and feldspar). The specific process is as follows: first, the rare earth ore was ground to -0.074 mm with a mass ratio of 80%, the slurry concentration was 65%, and the flotation temperature was 55°C. Then, the slurry pH was adjusted to 10 with sodium carbonate, and a composite depressant (a mixture of water glass, organic acid and hydroxyethyl cellulose in a mass ratio of 5:3:2, wherein the organic acid includes 2 parts of citric acid and 1 part of oxalic acid) and a composite collector (a mixture of hydroxamic acid organic matter and tristyrylphenol polyoxyethylene ether was added first, and then tributyl phosphate was added. In the subsequent process, the reagents of the composite collector need to be added according to this step). After one coarse, four fine and one sweep (coarse, composite, and final separation), the slurry was separated and the mixture was separated. The dosage of the combined depressant is 1.0Kg / t, the dosage of the composite collector is 1.2Kg / t, and the dosage of the frother 2# oil is 80g / t; the dosage of the composite depressant in the first refinery is 0.6Kg / t, the dosage of the second refinery is 0.3Kg / t, the dosage of the third refinery is 0.15Kg / t, and the fourth refinery is blank selection; the dosage of the composite collector in the first refinery is 0.3Kg / t, the second refinery is blank selection, the dosage of the third refinery is 0.1Kg / t, and the fourth refinery is blank selection; the dosage of the frother 2# oil in the third refinery is 10g / t; the dosage of the composite collector in the first sweep is 0.4Kg / t, and the dosage of the frother 2# oil is 20g / t). After the closed-circuit flotation process with the middlings returned in sequence, the REO grade of the obtained rare earth concentrate is 61.55%, the recovery rate is 70.52%; the CaO content is 4.93%, the recovery rate is 1.85%; the SiO2 content is 0.37%, and the recovery rate is 1.14%.

[0050] Example 3

[0051] The composite collector of the present invention comprises hydroxamic acid organic matter, octylphenol polyoxyethylene ether and triisobutyl phosphate in a mass ratio of 15:6:1, wherein the hydroxamic acid organic matter comprises 10 parts of benzohydroxamic acid and 5 parts of cycloalkanehydroxamic acid.

[0052] The composite depressant of this embodiment was applied to the flotation process of a rare earth ore in Australia (REO grade of 5.73%, rare earth minerals are mainly xenotime, and gangue are mainly quartz and amphibole). The specific process is as follows: first, the rare earth ore is ground to -0.074 mm by mass, accounting for 95%, the slurry concentration is 55%, and the flotation temperature is 50°C. Then, the slurry pH is adjusted to 8.5 with sodium carbonate, and a composite depressant (a mixture of water glass, gallic acid and hydroxyethyl cellulose in a mass ratio of 8:0.5:1.5) and a composite collector (a mixture of hydroxamic acid organic matter and octylphenol polyoxyethylene ether is added first, and then tributyl phosphate is added. In the subsequent process, the reagents of the composite collector need to be added according to this step). After the first coarse and three fine ( The dosage of composite depressant for roughing is 0.6Kg / t, the dosage of composite collector is 1.8Kg / t, and the dosage of frother 2# oil is 150g / t; the dosage of composite depressant for refined one is 0.2Kg / t, that for refined two is 0.1Kg / t, and that for refined three is 0.1Kg / t; the dosage of composite collector for refined one is 0.6Kg / t, that for refined two is 0.2Kg / t, and that for refined three is 0.1Kg / t; the dosage of frother 2# oil for refined one is 40g / t, and that for refined two is 10g / t). After the closed-circuit flotation process with the middlings returned sequentially, the REO grade of the obtained rare earth concentrate is 54.15%, and the recovery rate is 79.82%; the CaO content is 1.03%, and the recovery rate is 0.49%; the SiO2 content is 9.48%, and the recovery rate is 3.66%.

[0053] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A composite collector for rare earth ores, characterized in that: The hydroxamic acid organic matter, the ether organic matter and the phosphate organic matter are mixed in a mass ratio of 15-20:3-8:1-3; The hydroxamic acid organic compound is two or more of 1-hydroxy-2-naphthohydroxamic acid, 2-hydroxy-3-naphthohydroxamic acid, benzohydroxamic acid, 4-tert-butylbenzohydroxamic acid, cycloalkanehydroxamic acid, and octylhydroxamic acid; The ether organic compound is one or more of alkylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and tristyrylphenol polyoxyethylene ether; The phosphate organic compound is one or more of tributyl phosphate and triisobutyl phosphate; When the composite collector is added to the ore pulp, the hydroxamic acid organic matter and the ether organic matter are first mixed evenly and then added to the ore pulp, and then the phosphate organic matter is added to the ore pulp.

2. The use of the composite collector for rare earth ores in flotation according to claim 1, characterized in that: After the rare earth ore is crushed and ground to a desired fineness, the composite collector, inhibitor and frother are sequentially added to the slurry at a suitable slurry concentration, temperature and pH value for flotation.

3. The use of the composite collector for rare earth ores in flotation according to claim 2, characterized in that: The rare earth ore is one or more of bastnaesite, monazite, xenotime, bastnaesite and natronaite.

4. The use of the composite collector for rare earth ores in flotation according to claim 2, characterized in that: The grinding to -0.074 mm accounts for 70% to 98%, the mass concentration of the ore pulp is 40% to 70%, the pH value of the ore pulp is 7 to 11, and the ore pulp temperature is 45 to 70°C.

5. The use of the composite collector for rare earth ores in flotation according to claim 2, characterized in that: The addition amount of the composite collector is 0.6-2.0 Kg / t.

6. The use of the composite collector for rare earth ores in flotation according to claim 2, characterized in that: The addition amount of the inhibitor is 0.5-1.5 kg / t, and the inhibitor is a composite inhibitor prepared by mixing water glass, organic acids and hydroxyethyl cellulose in a mass ratio of 5-9:0.5-3:0.5-2.

7. The use of the composite collector for rare earth ores in flotation according to claim 6, characterized in that: The organic acid is one or more of oxalic acid, citric acid, ethylenediaminetetraacetic acid, gallic acid, and tartaric acid.

8. The use of the composite collector for rare earth ores in flotation according to claim 2, characterized in that: The added amount of the foaming agent is 50 to 200 g / t.

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