Method for flotation separation of copper-molybdenum sulfide ore

Abstract

The invention relates to a method for flotation separation of copper-molybdenum sulfide ore, belongs to the technical field of flotation, and solves the technical problems of low flotation efficiency, high production cost and serious environmental pollution in a copper-molybdenum sulfide ore flotation method in the prior art. A method for flotation separation of copper-molybdenum sulfide ore comprises the following steps that (1) copper-molybdenum bulk concentrate is subjected to fine grinding treatment, and ore powder is obtained; (2) mixing the mineral powder with water, and adjusting the pH value of the ore pulp; (3) adding a collecting agent, an inhibitor and a foaming agent into the ore pulp; and (4) air inflation flotation is carried out, a foam product is molybdenum concentrate, and a tank bottom product is copper concentrate. The sulfydryl group and the sulfonic acid group of the adopted sulfydryl sulfonic acid compound inhibitor can greatly enhance the hydrophilicity of the chalcopyrite surface, and the collecting agent is added before the sulfydryl sulfonic acid compound inhibitor is added; and the effect of selectively separating the copper-molybdenum sulfide ore by using the sulfydryl sulfonic acid compound inhibitor can be further improved.

Description

Technical Field

[0001] The present invention relates to the field of flotation technology, in particular to a method for flotation separation of copper-molybdenum sulfide ores. Background Art

[0002] The primary source of copper-molybdenum ore is porphyry copper-molybdenum deposits, where sulfide minerals are the predominant metallic mineral type, with chalcopyrite (CuFeS2) and molybdenite (MoS2) often closely coexisting. During the beneficiation process, chalcopyrite and molybdenite have similar floatability, both being highly hydrophobic sulfide minerals. This results in low separation efficiency, posing a challenge to flotation separation. In the flotation separation of copper-molybdenum sulfide ores, the use of inhibitors can improve the separation efficiency between copper and molybdenum.

[0003] However, the existing flotation method of copper-molybdenum sulfide ore has low flotation efficiency, high production cost and serious environmental pollution. Summary of the Invention

[0004] In view of the above analysis, the embodiments of the present invention aim to provide a method for flotation separation of copper-molybdenum sulfide ore, which can improve the flotation efficiency, reduce production costs and minimize environmental pollution in the flotation separation of copper-molybdenum sulfide ore.

[0005] An embodiment of the present invention provides a method for flotation separation of copper-molybdenum sulfide ore, comprising the following steps:

[0006] (1) grinding the copper-molybdenum mixed concentrate to obtain ore powder;

[0007] (2) Mixing the mineral powder with water to adjust the pH value of the slurry;

[0008] (3) adding a collector, an inhibitor, and a foaming agent to the slurry in sequence;

[0009] (4) Aeration flotation: the foam product is molybdenum concentrate and the bottom product is copper concentrate.

[0010] The inhibitor is a mercaptosulfonic acid compound, and its general chemical structure is:

[0011]

[0012] Wherein, R is phenyl or -(CH2)n-, n is an integer of 1-6, R1, R2, and R3 are at least one of H and HS, and at least one of R1, R2, and R3 is -HS, and X is an alkali metal ion or hydrogen.

[0013] Furthermore, the collector is a non-polar collector.

[0014] Furthermore, the non-polar collector is one or more of kerosene and diesel.

[0015] Furthermore, the inhibitor is sodium 2-mercaptoethane sulfonate Sodium 3-mercaptopropane sulfonate Sodium 2,3-dimercaptopropanesulfonate 4-Mercapto-1-butanesulfonic acid 4-Mercaptobenzenesulfonic acid One or more of the .

[0016] Furthermore, the copper-molybdenum mixed concentrate is finely ground to obtain ore powder in which particles with a diameter of more than 200 mesh account for more than 50% or particles with a diameter of 200 mesh to 400 mesh account for more than 50%.

[0017] Furthermore, the pH value of the slurry is 7-11.

[0018] Furthermore, the dosage of the inhibitor is 5 mg / L to 15 mg / L.

[0019] Furthermore, the foaming agent is methyl isobutyl carbinol or pine oil 2.

[0020] Furthermore, the dosage of the foaming agent is 0.1-2 mg / L.

[0021] Furthermore, the slurry mass concentration is 2%-5%.

[0022] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0023] 1. Compared to existing technologies, the flotation method of the present invention utilizes a mercaptosulfonic acid compound as a depressant, in conjunction with a non-polar collector. The dosing sequence is first the collector and then the depressant. Furthermore, by controlling the slurry pH, depressant dosage, and ore particle size, the method effectively separates chalcopyrite and molybdenite. Experimental results using the flotation method of the present invention show that the Mo grade in molybdenum concentrate is 48.5% to 54.2%, and the Cu grade in molybdenum concentrate is 0.9% to 5.6%.

[0024] 2. Conventional methods of obtaining a mixed copper-molybdenum sulfide concentrate through mixed flotation often require drug removal to eliminate the effects of collectors on separation efficiency. The present invention utilizes mercaptosulfonic acid compound inhibitors for flotation separation of chalcopyrite and molybdenite, eliminating drug removal and thus reducing production costs. Furthermore, due to the poor selectivity of conventional chalcopyrite inhibitors, improving separation performance often requires a complex process. The present flotation process is simple and highly efficient.

[0025] 3. The mercaptosulfonic acid compound inhibitor used in the flotation method of the present invention is less toxic and therefore environmentally friendly. In addition, since the flotation method of the present invention has high sorting efficiency (see Examples), the amount of inhibitor used is relatively small, which can further reduce the impact of the flotation process of chalcopyrite and molybdenite on the environment.

[0026] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the subsequent description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the contents particularly pointed out in the description. DETAILED DESCRIPTION

[0027] Preferred embodiments of the present invention are described in detail below.

[0028] During mineral processing, chalcopyrite and molybdenite have similar floatability. Both are highly hydrophobic sulfide minerals, resulting in low separation efficiency, which poses a challenge for flotation separation. In the flotation separation of copper-molybdenum sulfide ores, the use of inhibitors can improve the separation efficiency between copper and molybdenum. However, existing flotation methods for copper-molybdenum sulfide ores suffer from low flotation efficiency, high production costs, and significant environmental pollution.

[0029] A specific embodiment of the present invention discloses a method for flotation separation of copper-molybdenum sulfide ore, comprising the following steps:

[0030] (1) grinding the copper-molybdenum mixed concentrate to obtain ore powder;

[0031] (2) Mixing the mineral powder with water to adjust the pH value of the slurry;

[0032] (3) adding a collector, an inhibitor, and a foaming agent to the slurry in sequence;

[0033] (4) Aeration flotation, the foam product is molybdenum concentrate, and the bottom product is copper concentrate;

[0034] The inhibitor is a mercaptosulfonic acid compound, and its general chemical structure is:

[0035]

[0036] Wherein, R is phenyl or -(CH2)n-, n is an integer of 1-6, R1, R2, and R3 are at least one of H and HS, and at least one of R1, R2, and R3 is -HS, and X is an alkali metal ion or hydrogen.

[0037] It should be noted that the type of inhibitor will affect the sorting index. The inventors have found that compared with other commonly used inhibitors (such as sodium thioglycolate and sodium sulfide), mercaptosulfonic acid compounds have a stronger inhibitory effect on copper in copper-molybdenum mixed concentrates. It should be noted that in the prior art, for the flotation of copper-molybdenum mixed concentrates, the conventional order of adding inhibitors and collectors is to add the collector first and then the inhibitor. The inventors have found that when mercaptosulfonic acid compounds are used as inhibitors, changing the conventional order of adding inhibitors and collectors, that is, adding the collector first and then the inhibitor, can achieve unexpectedly good sorting effects. The inventors have also found that when mercaptosulfonic acid compounds are used as inhibitors, and the order of adding the collector first and then the inhibitor is adopted, only non-polar collectors can achieve the above-mentioned unexpected good effects, while the use of polar collectors commonly used in sulfide ores (such as isobutyl xanthate) cannot achieve the above-mentioned unexpected good effects.

[0038] Preferably, the mercaptosulfonic acid compound inhibitor is sodium 2-mercaptoethanesulfonate Sodium 3-mercaptopropane sulfonate Sodium 2,3-dimercaptopropanesulfonate 4-Mercapto-1-butanesulfonic acid 4-Mercaptobenzenesulfonic acid One or more of the .

[0039] Preferably, the non-polar collector is one or more of kerosene or diesel. The dosage of the non-polar collector is 0.5-5 mg / L.

[0040] It should be noted that the particle size of the ore powder after grinding can affect the flotation performance of the copper-molybdenum mixed concentrate. If the particle size is too coarse, the degree of dissociation of the mineral monomers is insufficient, and the flotation process will experience "coarse run-off", affecting the concentrate grade and recovery rate. If the particle size is too fine, the reagent consumption increases and the selectivity of the reagent deteriorates.

[0041] Preferably, in some embodiments, the copper-molybdenum mixed concentrate is finely ground to obtain a mineral powder in which particles with a diameter of +200 mesh account for more than 50% or particles with a diameter of 200 mesh to 400 mesh account for more than 50%.

[0042] It should be noted that the pH value of the slurry can affect the flotation index of the copper-molybdenum mixed concentrate. The inventors found that for the mercaptosulfonic acid compound inhibitor used in the present invention, when the slurry is acidic, the mercaptosulfonic acid compound inhibitor has a poor inhibitory effect on chalcopyrite, or even fails to work, while when the slurry is alkaline, the mercaptosulfonic acid compound inhibitor has a stronger inhibitory effect on chalcopyrite. However, the stronger the alkalinity, the better the separation index.

[0043] Preferably, in some embodiments, the pH value of the slurry is 7 to 11, such as 7.0, 7.5, 8.0, 8.5, 9, 9.5, 10, 10.5, or 11. More preferably, the pH value of the slurry is 9, 9.5, or 10. Particularly preferably, the pH value of the slurry is 9.5.

[0044] Preferably, in some embodiments, the concentration of the slurry is 2%-5%.

[0045] It should be noted that the dosage of the inhibitor affects the separation performance. The inventors have found that if the dosage of the inhibitor is too low, the inhibitory effect on the target mineral is not significant, resulting in poor flotation performance. However, if the dosage of the inhibitor is too high, the inhibitor will also inhibit molybdenite, resulting in a loss of selectivity.

[0046] Preferably, in some embodiments, the dosage of the inhibitor is 5 mg / L to 15 mg / L. More preferably, the dosage of the inhibitor is 12.5 mg / L.

[0047] Preferably, in some embodiments, the foaming agent is one or more of methyl isobutyl carbinol or pine oil 2. The dosage of the foaming agent is 0.1-2 mg / L.

[0048] The technical solution of the present invention is further explained below through examples and comparative examples.

[0049] Example 1

[0050] Weigh 1.5 g of chalcopyrite and 0.5 g of molybdenite with a particle size of 200-400 mesh accounting for more than 50% and mix them into a 2.0 g sample, add it into a small suspended flotation cell, add 40 mL of water and stir to form a uniform slurry, adjust the slurry pH to 9.5, first add 1.2 mg / L emulsified kerosene and stir for 3 minutes, then add 12.5 mg / L sodium 2-mercaptoethane sulfonate and stir for 3 minutes, then add 0.5 mg / L methyl isobutyl carbinol, stir for 3 minutes and then start aeration, and the flotation machine aeration flow rate is maintained at 0.06 m 3 / h, scrape the foam for 2min to obtain the foam product and the tank bottom product.

[0051] Examples 2-5

[0052] Compared with Example 1, the inhibitors used are sodium 3-mercaptopropane sulfonate, sodium 2,3-dimercaptopropane sulfonate, 4-mercaptobenzenesulfonic acid, and 4-mercapto-1-butanesulfonic acid, respectively. Other conditions are the same as those in Example 1.

[0053] Example 6

[0054] Compared with Example 1, the collector used is diesel, and other conditions are the same as those in Example 1.

[0055] Examples 7-8

[0056] Compared with Example 1, the pH of the slurry was adjusted to 7 and 11 respectively, and other conditions were the same as those in Example 1.

[0057] Examples 9-10

[0058] Compared with Example 1, the dosage of the inhibitor sodium 2-mercaptoethane sulfonate was 10 mg / L and 15 mg / L, respectively, and other conditions were the same as those in Example 1.

[0059] Example 11

[0060] Compared with Example 1, the particle size of the particles is greater than 200 mesh and accounts for more than 50%, and other conditions are the same as those in Example 1.

[0061] Comparative Examples 1-4

[0062] Compared with Example 1, the inhibitors, namely sodium 2-mercaptoethane sulfonate, sodium thioglycolate, sodium sulfide, and sodium 2,3-dimercaptopropane sulfonate, were added first, and then the emulsified kerosene was added. Other conditions were the same as those in Example 1.

[0063] Comparative Examples 5-6

[0064] Compared with Example 1, the collectors used were O-isopropyl-N-ethylthiocarbamate and isobutyl propylene xanthate, and other conditions were the same as those in Example 1.

[0065] Comparative Example 7

[0066] Compared with Example 1, the pH of the slurry was adjusted to 4, and other conditions were the same as those in Example 1.

[0067] Comparative Examples 8-9

[0068] Compared with Example 1, the dosage of the inhibitor sodium 2-mercaptoethane sulfonate was 30 mg / L and 5 mg / L respectively, and other conditions were the same as those in Example 1.

[0069] Comparative Example 10

[0070] Compared with Example 1, the particle size of 400 mesh to 625 mesh accounts for more than 50%, and other conditions are the same as those in Example 1.

[0071] The analysis and calculation methods of the molybdenum concentrate in the foam products of the embodiments and comparative examples are as follows:

[0072] The dried foam product and the bottom product are weighed and the yield of each product is calculated. The ratio of the product mass to the original ore mass is the yield of the product, expressed as γ.

[0073] Take 60-80 mg of the foam and bottom products, digest them with acid, and then dilute to a constant volume for ICP-OES analysis. Calculate the Cu and Mo grades of the two products based on the elemental analysis results. Grade refers to the ratio of the mass of the metal or useful component in a product to the mass of the product itself. Ore grade is typically expressed as α, concentrate grade as β, and tailings grade as θ.

[0074] The recovery rates of Cu and Mo in the product are then calculated using the following formula. The ratio of the mass of the useful component in the concentrate to the mass of the useful component in the original ore is the recovery rate, represented by ε. ε = γβ / 100α × 100%, where ε is the recovery rate, %; α is the original ore grade, %; β is the concentrate grade, %; and γ is the concentrate yield, %.

[0075] The results of the analysis and calculation of the grades and recovery rates of Mo and Cu in the molybdenum concentrates in the foam products of the Examples and Comparative Examples are shown in Table 1:

[0076] Table 1 Grade and recovery of Mo and Cu in molybdenum concentrate in foam products

[0077]

[0078] The analysis results are as follows:

[0079] 1. The experimental results of Examples 1-6 show that, using the flotation method defined in the present invention, the Mo grade in the molybdenum concentrate is 48.5%-54.2%, and the Cu grade in the molybdenum concentrate is 0.9%-5.6%, achieving good separation results. Furthermore, Examples 1, 2, and 3 show that when the carbon chain in the inhibitor is relatively short (n≤3), the Cu recovery rate is 0.7%-2.0%. In contrast, Examples 4 and 5 show that when the carbon chain in the mercaptosulfonate inhibitor is relatively long (n>4), the Cu recovery rates are 26.06% and 31.25%, respectively. These comparisons indicate that, using the inhibitor type defined in the present invention, the inhibitory effect of mercaptosulfonic acid inhibitors on chalcopyrite decreases as the carbon chain in the inhibitor increases.

[0080] 2. The experimental results of Comparative Examples 1-6 show that the type of inhibitor, the relative order of adding collector and inhibitor, and the type of collector work together to achieve the technical effect of the flotation method of the present invention. Specifically:

[0081] (1) The experimental results of Comparative Examples 2 and 3 show that when sodium thioglycolate is used for flotation, the Mo grade in the molybdenum concentrate is only 19.60%, and the Mo and Cu recoveries are 99.34% and 94.35%, respectively. When sodium sulfide is used for flotation, the Mo grade in the molybdenum concentrate is only 12.40%, and the Mo and Cu recoveries are 92.49% and 94.39%, respectively. In other words, the conventional inhibitors sodium thioglycolate and sodium sulfide are not able to effectively inhibit chalcopyrite. However, the experimental results of Examples 1-3 show that the mercaptosulfonic acid compound inhibitors used in the present invention can effectively separate chalcopyrite and molybdenite and achieve good separation indicators. This may be because the thiol group in the thiolsulfonic acid compound inhibitor will first react with the copper ion site on the chalcopyrite surface. The S atom on the thiol group donates electrons to the Cu atom, and chemical adsorption is formed between the two. At this time, the sulfonic acid group at the other end of the inhibitor molecule can form a hydrogen bond with the water molecule, increasing the hydrophilicity of the chalcopyrite surface and forming an inhibitory effect. At the same time, the O atom on the sulfonic acid group in the thiolsulfonic acid compound inhibitor is negatively charged, and it will also react with the Cu atom on the chalcopyrite surface to form a stable compound, further enhancing the hydrophilicity of the chalcopyrite surface.

[0082] (2) The experimental results of Comparative Examples 1 and 4 show that although sodium 2-mercaptoethane sulfonate and sodium 2,3-dimercaptopropane sulfonate were used as inhibitors, the conventional dosing order of adding the inhibitor first and then the collector was adopted, and the Mo recovery rates in the molybdenum concentrate were only 48.56% and 30.06%. However, when the dosing order of adding the inhibitor first and then the collector was adopted according to the present invention, the Mo recovery rates in the molybdenum concentrate could reach 76.74% (see Example 1) and 72.24% (see Example 3). It can be seen that the dosing order of adding the inhibitor first and then the collector adopted by the present invention can significantly increase the Mo recovery rate in the molybdenum concentrate. This may be because emulsified kerosene is added before adding the mercaptosulfonic acid compound inhibitor. The emulsified kerosene relies on the non-polar force between it and the molybdenite to be adsorbed and covered on the surface of the molybdenite, avoiding the interaction between the mercapto and sulfonic acid groups on the inhibitor and the active sites of Mo atoms on the surface of the molybdenite, which can further expand the effect of the mercaptosulfonic acid compound inhibitor in selectively separating copper sulfide molybdenum ore.

[0083] (3) The experimental results of Comparative Examples 5 and 6 show that although sodium 2-mercaptoethane sulfonate is used as an inhibitor and the dosing order of adding the collector first and then the inhibitor is adopted, the polar collectors (O-isopropyl-N-ethylthiocarbamate and isobutyl xanthate) are used. The recoveries of Mo and Cu in the molybdenum concentrates of the two examples are 98.74%, 95.43%, 99.31%, and 96.86%, respectively, and the grades of Mo and Cu are only 17.35%, 23.64%, 22.46%, and 20.57%, respectively. Compared with the experimental results of Examples 1 and 6 using non-polar collectors (kerosene and diesel), the grade and recovery of Cu in the molybdenum concentrate are very high. This may be because the polar collector mainly relies on strong chemical adsorption on the surface of chalcopyrite, reducing the Cu active sites on the surface of chalcopyrite, hindering the adsorption of subsequent inhibitors, and failing to inhibit the flotation of chalcopyrite.

[0084] 3. The experimental results of Comparative Examples 7-10 show that the pH value of the slurry, the amount of inhibitor used, and the particle size of the ore powder also have an important impact on the realization of the technical effect of the present invention. Specifically:

[0085] (1) From the experimental results of Comparative Example 7, it can be seen that when the pulp pH is 4, sodium 2-mercaptoethane sulfonate is used as an inhibitor, the Mo grade in the molybdenum concentrate is only 18.61%, and the Mo and Cu recoveries are 95.80% and 75.90%, respectively. It can be seen that sodium 2-mercaptoethane sulfonate cannot effectively inhibit chalcopyrite under acidic conditions. When the pulp pH is 7 (Example 7), the Mo grade in the molybdenum concentrate is 38.90%, and the Mo and Cu recoveries are 93.70% and 5.27%, respectively. When the pulp pH is 9.5 (Example 1), the Mo grade in the molybdenum concentrate is 49.33%, and the Mo and Cu recoveries are 76.74% and 1.87%, respectively, that is, good flotation indicators are achieved. When the pulp pH is 11 (Example 8), the Mo grade in the molybdenum concentrate is 37.84%, and the Mo and Cu recoveries are 84.16% and 3.47%, respectively. It can be seen that the mercaptosulfonic acid compound inhibitor used in the present invention can achieve a good separation effect of chalcopyrite and molybdenite when the pulp pH value is 7-11, especially the best effect at pH = 9.5. When the pulp pH value is 4, the mercaptosulfonic acid compound inhibitor is ineffective.

[0086] (2) From the experimental results of Comparative Examples 8 and 9, it can be seen that when the amount of the inhibitor sodium 2-mercaptoethane sulfonate is too much or too little, the separation index cannot be well obtained. In addition, combined with the analysis of the amount of Example 9 (10 mg / L), Example 1 (12.5 mg / L), and Example 10 (15 mg / L), as the amount of sodium 2-mercaptoethane sulfonate increases from 5 mg / L to 30 mg / L, the effect of separating chalcopyrite and molybdenite shows a trend of first increasing and then decreasing. This may be attributed to the fact that when the concentration of sodium 2-mercaptoethane sulfonate is low, it cannot completely inhibit the flotation of chalcopyrite, resulting in a lower Mo grade and a higher Cu grade in the concentrate; when the concentration of sodium 2-mercaptoethane sulfonate is too high, it will also inhibit molybdenite, and the flotation loses selectivity.

[0087] (3) The experimental results of Comparative Example 10 show that the particle size of the finely ground ore can affect the flotation index of the copper-molybdenum mixed concentrate. When the mineral particle size of 400-625 mesh accounts for more than 50%, the Mo grade in the molybdenum concentrate is 30.86%, and the Mo and Cu recoveries are 67.27% and 19.70%, respectively, indicating poor separation indexes. This may be because the selectivity of the reagent deteriorates at this particle size.

[0088] The above description is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the protection of the present invention.

Claims

1. A method for flotation separation of copper-molybdenum sulfide ore, characterized in that: The steps include: (1) grinding the copper-molybdenum mixed concentrate to obtain ore powder; (2) Mixing the mineral powder with water to adjust the pH value of the slurry; (3) adding a collector, an inhibitor, and a foaming agent to the slurry in sequence; (4) Aeration flotation, the foam product is molybdenum concentrate, and the bottom product is copper concentrate; The inhibitor is a mercaptosulfonic acid compound, and its general chemical structure is: Wherein, R is phenyl or -(CH2)n-, n is an integer of 1-6, R1, R2, and R3 are at least one of H and HS respectively, and at least one of R1, R2, and R3 is -HS, and X is an alkali metal ion or hydrogen.

2. The method according to claim 1, characterized in that The collector is a non-polar collector.

3. The method according to claim 2, characterized in that The non-polar collector is one or more of kerosene and diesel.

4. The method according to claim 1, wherein The inhibitor is sodium 2-mercaptoethane sulfonate Sodium 3-mercaptopropane sulfonate Sodium 2,3-dimercaptopropanesulfonate 4-Mercapto-1-butanesulfonic acid 4-Mercaptobenzenesulfonic acid One or more of the .

5. The method according to claim 4, characterized in that The copper-molybdenum mixed concentrate is finely ground to obtain ore powder in which particle sizes of more than 50% are larger than 200 meshes or particles of 200 meshes to 400 meshes account for more than 50%.

6. The method according to claim 5, characterized in that The pH value of the slurry is 7-11.

7. The method according to claim 6, characterized in that The dosage of the inhibitor is 5-15 mg / L.

8. The method according to claim 7, characterized in that The foaming agent is methyl isobutyl carbinol or pine oil.

9. The method according to claim 8, characterized in that The dosage of the foaming agent is 0.1-2 mg / L.

10. The method according to claim 9, characterized in that The mass concentration of the ore pulp is 2%-5%.

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