Molybdenite organic small-molecule flotation depressant, preparation method and application thereof

Abstract

This invention discloses an organic small-molecule flotation inhibitor for molybdenite, its preparation method, and its application. This organic small-molecule inhibitor is a solid organic reagent of nitrosylphenyl ester compounds obtained through a chemical reaction using hydroxylamine hydrochloride, sodium hydroxide, and gallic acid as raw materials. The inhibitor of this invention effectively inhibits molybdenite, enabling the flotation separation of molybdenite-containing ores such as copper-molybdenum sulfide ores, talc-type molybdenum ores, talc-bearing porphyry copper ores, and molybdenum-bismuth ores. This invention not only overcomes the poor selectivity of commonly used molybdenite inhibitors but also has advantages such as simple preparation method, mild process conditions, low raw material cost, convenient use, and low environmental pollution. This invention provides an effective method for the separation of molybdenite-containing ores such as copper-molybdenum sulfide ores, talc-type molybdenum ores, talc-bearing porphyry copper ores, and molybdenum-bismuth ores, with low reagent dosage, convenient use, and low environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of sulfide ore beneficiation technology, and in particular to an organic small molecule flotation inhibitor for molybdenite, its preparation method, and its application. Background Technology

[0002] Flotation separates minerals based on differences in their surface physicochemical properties. The reagents used in the flotation process are called flotation reagents. Their main function is to alter the hydrophilicity / hydrophobicity of different mineral surfaces and their adhesion to air bubbles. The greater the difference in hydrophobicity between mineral particles, the higher the separation efficiency and the better the flotation performance. Therefore, flotation reagents play a crucial role in adjusting the surface properties of minerals and improving flotation selectivity.

[0003] As an indispensable type of flotation reagent, depressants play a crucial role in the flotation of sulfide ores. Depressants can disrupt or weaken the adsorption of collectors by minerals, enhancing the hydrophilicity of mineral surfaces; simultaneously, they adsorb onto the surface of the target mineral, increasing its wettability. Currently, commonly used depressants in sulfide ore flotation include Na₂S, mercaptoacetic acid, and other organic compounds. Na₂S is widely used industrially due to its low price, wide availability, effective inhibition of sulfide minerals other than molybdenite, and ability to reduce and desorb the hydrophobic film adsorbed on the sulfide ore surface, thus achieving a de-removal effect. However, Na₂S is a strong reducing agent and easily oxidizes and becomes ineffective during flotation, resulting in higher costs due to its larger dosage. Mercaptoacetic acid, on the other hand, shows a vigorous development trend in industrial applications due to its low toxicity, short reaction time, high selectivity, good water solubility, wide pH range, and ability to improve the recovery rate of associated rare and precious metals such as gold and silver in ores. However, pure or high-concentration mercaptoacetic acid is prone to oxidation and self-esterification, leading to the loss of its effective components. Furthermore, its high price makes it difficult to reduce the cost of mineral processing reagents, thus limiting its use in production. While some macromolecular organic compounds have good inhibitory effects on most sulfide ores, they exhibit poor selectivity.

[0004] Currently, commonly used depressants for sulfide ore flotation have drawbacks such as high dosage, poor selectivity, and high cost. Therefore, developing economical, environmentally friendly, efficient, green, and low-toxicity flotation depressants is still of profound significance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing sulfide ore flotation inhibitors and to synthesize a novel small-molecule inhibitor for molybdenite, which can be used for the flotation separation of molybdenite-containing ores such as copper-molybdenum sulfide ores, talc-type molybdenum ores, talc-bearing porphyry copper ores, and molybdenum-bismuth ores. This invention also provides a method for preparing and using a flotation inhibitor that can effectively reduce the amount of inhibitor used, reduce environmental pollution, and improve production conditions.

[0006] A molybdenite organic small molecule flotation inhibitor, wherein the inhibitor is a solid powder reagent of a nitrosylphenyl ester compound obtained by chemical reaction of hydroxylamine hydrochloride, sodium hydroxide and gallic acid as raw materials.

[0007] Furthermore, the inhibitor contains the following chemical structural formula:

[0008]

[0009] and / or

[0010] and / or

[0011] and / or

[0012] and / or

[0013] A method for preparing an organic small molecule flotation inhibitor for molybdenite, wherein the organic small molecule flotation inhibitor for molybdenite is prepared through the following steps:

[0014] Step 1: Prepare 3 parts sodium hydroxide and 15 parts water by molar ratio; Step 2: Mix the raw materials prepared in Step 1 evenly; Step 3: Prepare 3 parts hydroxylamine hydrochloride and 30 parts water by molar ratio; Step 4: Mix the raw materials prepared in Step 3 evenly; Step 5: Mix the raw materials obtained in Step 2 and Step 4 at room temperature to prepare a solution; Step 6: Prepare 2 parts gallic acid and 5 parts anhydrous ethanol; Step 7: Mix the raw materials prepared in Step 6 evenly to prepare a solution; Step 8: Slowly add the solution obtained in Step 5 to the solution obtained in Step 7, and react at 0-10℃ for 0.5-3 hours; Step 9: Filter the product obtained in Step 8 to obtain a solid substance; Step 10: Dissolve the solid substance obtained in Step 9 in hot water and cool to crystallize; thus obtaining the molybdenite organic small molecule flotation inhibitor.

[0015] Furthermore, the molar ratio of hydroxylamine hydrochloride, sodium hydroxide, and gallic acid is 1-10:1-15:1-12.

[0016] Furthermore, the preferred molar ratio of hydroxylamine hydrochloride, sodium hydroxide, and gallic acid is 2:2:1, yielding 1-nitrosoyl-3,4,5-trinitrosophenyl ester, with the molecular structure shown below.

[0017]

[0018] Furthermore, in step eight, a solid substance precipitates from the solution system during the reaction process.

[0019] Furthermore, in step ten, the solid material obtained in step nine is dissolved in hot water at 70-90°C to prepare a saturated solution, and then cooled and crystallized at 0-10°C to obtain a molybdenite organic small molecule flotation inhibitor with high purity.

[0020] An application of a molybdenite organic small molecule flotation inhibitor or its preparation method, wherein the molybdenite organic small molecule flotation inhibitor is added during flotation slurry preparation, and after stirring for 3-5 minutes, butyl xanthate or emulsified kerosene and methyl isobutyl methanol are added in sequence.

[0021] Furthermore, a molybdenite organic small molecule flotation inhibitor is added at a ratio of 10-100 mg / L.

[0022] The inhibitor of this invention is a solid organic reagent prepared by chemical reaction of hydroxylamine hydrochloride, sodium hydroxide, and gallic acid. It effectively inhibits molybdenite and enables the flotation separation of molybdenite-containing ores, such as copper-molybdenum sulfide ores, talc-type molybdenum ores, talc-bearing porphyry copper ores, and molybdenum-bismuth ores. This invention not only overcomes the poor selectivity of commonly used molybdenite inhibitors but also has advantages such as simple preparation method, mild process conditions, low raw material cost, convenient use, and low environmental pollution. This invention provides an effective method for the separation of molybdenite-containing ores, such as copper-molybdenum sulfide ores, talc-type molybdenum ores, talc-bearing porphyry copper ores, and molybdenum-bismuth ores, with low reagent dosage, convenient use, and low environmental pollution. Detailed Implementation

[0023] The technical solutions 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] A molybdenite organic small molecule flotation inhibitor, wherein the inhibitor is a solid powder reagent of a nitrosylphenyl ester compound obtained by chemical reaction of hydroxylamine hydrochloride, sodium hydroxide and gallic acid as raw materials.

[0025] The inhibitor contains the following chemical formula:

[0026]

[0027] and / or

[0028] and / or

[0029] and / or

[0030] and / or

[0031]

[0032] A method for preparing an organic small molecule flotation inhibitor for molybdenite, wherein the organic small molecule flotation inhibitor for molybdenite is prepared through the following steps:

[0033] Step 1: Prepare 3 parts sodium hydroxide and 15 parts water by molar ratio; Step 2: Mix the raw materials prepared in Step 1 evenly; Step 3: Prepare 3 parts hydroxylamine hydrochloride and 30 parts water by molar ratio; Step 4: Mix the raw materials prepared in Step 3 evenly; Step 5: Mix the raw materials obtained in Step 2 and Step 4 at room temperature to prepare a solution; Step 6: Prepare 2 parts gallic acid and 5 parts anhydrous ethanol; Step 7: Mix the raw materials prepared in Step 6 evenly to prepare a solution; Step 8: Slowly add the solution obtained in Step 5 to the solution obtained in Step 7, and react at 0-10℃ for 0.5-3 hours; Step 9: Filter the product obtained in Step 8 to obtain a solid substance; Step 10: Dissolve the solid substance obtained in Step 9 in hot water and cool to crystallize; thus obtaining the molybdenite organic small molecule flotation inhibitor.

[0034] The molar ratio of hydroxylamine hydrochloride, sodium hydroxide, and gallic acid is 1-10:1-15:1-12.

[0035] The preferred molar ratio of hydroxylamine hydrochloride, sodium hydroxide, and gallic acid is 2:2:1, yielding 1-nitrosoyl-3,4,5-trinitrosophenyl ester, with the molecular structure shown below.

[0036]

[0037] In step eight, a solid substance precipitates from the solution system during the reaction process.

[0038] In step ten, the solid material obtained in step nine is dissolved in hot water at 70-90°C to prepare a saturated solution, and then cooled and crystallized at 0-10°C to obtain a molybdenite organic small molecule flotation inhibitor with high purity.

[0039] An application of a molybdenite organic small molecule flotation inhibitor or its preparation method, wherein the molybdenite organic small molecule flotation inhibitor is added during flotation slurry preparation, and after stirring for 3-5 minutes, butyl xanthate or emulsified kerosene and methyl isobutyl methanol are added in sequence.

[0040] Add molybdenite organic small molecule flotation inhibitor at a ratio of 10-100 mg / L.

[0041] The preparation and application of this organic small molecule flotation inhibitor for molybdenite will be further explained below with reference to specific implementation methods.

[0042] Example 1

[0043] The preparation of a molybdenite organic small molecule flotation inhibitor includes the following steps:

[0044] (1) Weigh 14g of hydroxylamine hydrochloride (0.2mol) into a 100mL beaker, add 40mL of deionized water to dissolve it, and obtain a hydroxylamine hydrochloride solution.

[0045] (2) Weigh 8g of sodium hydroxide (0.2mol) into a 100mL beaker, add 20mL of deionized water to dissolve it, and obtain a sodium hydroxide solution.

[0046] (3) Mix the obtained hydroxylamine hydrochloride solution and sodium hydroxide solution at room temperature and stir for 30 min to obtain hydroxylamine solution.

[0047] (4) Weigh 34g (0.2mol) of gallic acid into a 500mL beaker, add 170mL of ethanol to dissolve it, and obtain a homogeneous gallic acid solution. Place the solution in an ice bath.

[0048] (5) Slowly add the obtained hydroxylamine solution to the gallic acid solution, ensuring that the system temperature does not exceed 10°C. Continue stirring for 2 hours after the addition is complete.

[0049] (6) Hydroxylamine reacts with gallic acid to precipitate solid substances from the solution system, which are then filtered and washed repeatedly with anhydrous ethanol.

[0050] (7) The washed solid material was dissolved in deionized water at 85°C to obtain a saturated solution, and then cooled and crystallized at 4°C. After filtration, it was washed with anhydrous ethanol and dried at 60°C for 24 hours to obtain a solid product. It was then ground into powder to obtain molybdenite organic small molecule flotation inhibitor.

[0051] Example 2

[0052] (1) Weigh 28g of hydroxylamine hydrochloride (0.4mol) into a 250mL beaker, add 80mL of deionized water to dissolve it, and obtain a hydroxylamine hydrochloride solution.

[0053] (2) Weigh 16g of sodium hydroxide (0.4mol) into a 100mL beaker, add 40mL of deionized water to dissolve it, and obtain a sodium hydroxide solution.

[0054] (3) Mix the obtained hydroxylamine hydrochloride solution and sodium hydroxide solution at room temperature and stir for 30 min to obtain hydroxylamine solution.

[0055] (4) Weigh 34g (0.2mol) of gallic acid into a 500mL beaker, add 170mL of ethanol to dissolve it, and obtain a homogeneous gallic acid solution. Place the solution in an ice bath.

[0056] (5) Slowly add the obtained hydroxylamine solution to the gallic acid solution, ensuring that the system temperature does not exceed 10°C. Continue stirring for 2 hours after the addition is complete.

[0057] (6) Hydroxylamine reacts with gallic acid to precipitate solid substances in the solution system, which are then filtered and washed repeatedly with anhydrous ethanol.

[0058] (7) The washed solid material was dissolved in deionized water at 85°C to obtain a saturated solution, and then cooled and crystallized at 4°C. After filtration, it was washed with anhydrous ethanol and dried at 60°C for 24 hours to obtain a solid product. It was then ground into powder to obtain molybdenite organic small molecule flotation inhibitor.

[0059] Example 3

[0060] This embodiment is an example of the application of the molybdenite organic small molecule flotation inhibitor in the flotation separation of chalcopyrite and molybdenite.

[0061] Two g of chalcopyrite and molybdenite samples with a particle size of -74 to +38 μm (80-85%) were weighed into a flotation cell. Water was added to prepare a 3% slurry, and the mixture was stirred for 3 minutes to completely wet the minerals. Then, a small-molecule organic flotation inhibitor for molybdenite (20 mg / L) was added and stirred for 3 minutes. Butyl xanthate (1 mg / L) was then added and stirred for 3 minutes. Methyl isobutyl methanol (0.1 mg / L) was then added and stirred for 2 minutes. Aeration was then initiated and frothing was started. After 3 minutes of frothing, the flotation concentrate was obtained. The recovery rate of chalcopyrite reached 94.05%, while the recovery rate of molybdenite was only 2.91%.

[0062] Example 4

[0063] This embodiment is an example of the application of the molybdenite organic small molecule flotation inhibitor in the flotation separation of chalcopyrite and molybdenite.

[0064] Chalcopyrite and molybdenite samples with a particle size of -74 to +38 μm accounting for 80-85% were mixed at a mass ratio of 3:1 to obtain a sample with a chalcopyrite content of 75% and a molybdenite content of 15%. 2g of the ore sample was weighed into a flotation cell, and water was added to prepare a 3% slurry. The mixture was stirred for 3 minutes to completely wet the minerals. Then, a small-molecule organic flotation inhibitor for molybdenite was added at a concentration of 50 mg / L. After stirring for 3 minutes, butyl xanthate was added at a concentration of 1 mg / L. After stirring for 3 minutes, methyl isobutyl methanol was added at a concentration of 0.1 mg / L. After 2 minutes, aeration was initiated and frothing was started. After frothing for 3 minutes, the flotation concentrate was obtained. The recovery rate of chalcopyrite in the concentrate reached 96.50%, while the recovery rate of molybdenite was only 6.71%. The copper content in the concentrate was 33.14%, and the molybdenum content was 1.58%, both calculated as elemental content.

[0065] Example 5

[0066] This embodiment is an example of the application of the molybdenite organic small molecule flotation inhibitor in the flotation separation of talc and molybdenite.

[0067] Two g of talc and molybdenite samples with a particle size of -74 to +38 μm (80-85%) were weighed into a flotation cell. Water was added to prepare a 3% slurry, and the mixture was stirred for 3 minutes to completely wet the minerals. Then, a small-molecule organic flotation inhibitor for molybdenite (20 mg / L) was added and stirred for 3 minutes. Emulsified kerosene (1 mg / L) was then added and stirred for 3 minutes. Methyl isobutyl methanol (0.1 mg / L) was then added and stirred for 2 minutes. Aeration was then initiated to begin skimming the bubbles. After skimming for 3 minutes, the flotation concentrate was obtained. The recovery rate of talc reached 86.76%, while the recovery rate of molybdenite was only 1.78%.

[0068] Example 6

[0069] This embodiment is an example of the application of the molybdenite organic small molecule flotation inhibitor in the flotation separation of chalcopyrite and molybdenite.

[0070] Talc and molybdenite samples with a particle size of -74 to +38 μm accounting for 80-85% were mixed at a mass ratio of 3:1 to obtain a mineral sample with a talc content of 75% and a molybdenite content of 15%. 2g of the ore sample was weighed into a flotation cell, and water was added to prepare a 3% slurry. The mixture was stirred for 3 minutes to completely wet the minerals. Then, a molybdenite organic small molecule flotation inhibitor was added at a concentration of 30 mg / L. After stirring for 3 minutes, emulsified kerosene was added at a concentration of 1 mg / L. After stirring for 3 minutes, methyl isobutyl methanol was added at a concentration of 0.1 mg / L. After 2 minutes, aeration was initiated and frothing was started. After frothing for 3 minutes, the flotation concentrate was obtained. The recovery rate of talc in the concentrate reached 94.25%, while the recovery rate of molybdenite was only 0.54%. The magnesium content in the concentrate was 22.18%, and the molybdenum content was 0.14%, both calculated as elemental content.

[0071] Comparative Example 1

[0072] This comparative example demonstrates the flotation of chalcopyrite and molybdenite without the addition of molybdenite organic small molecule flotation inhibitors.

[0073] Two g of chalcopyrite and molybdenite samples with a particle size of 38-74 μm and a proportion of 80-85% were weighed into a flotation cell. Water was added to prepare a slurry with a concentration of 3%. The slurry was stirred for 3 min to completely wet the minerals. Then, butyl xanthate was added at a concentration of 1 mg / L. After stirring for 3 min, methyl isobutyl methanol at a concentration of 0.1 mg / L was added. After 2 min, aeration was started and frothing was initiated. After frothing for 3 min, the flotation concentrate was obtained. The recovery rate of chalcopyrite reached 95.70%, and the recovery rate of molybdenite was 91.96%.

[0074] Comparative Example 2

[0075] This comparative example demonstrates the flotation of chalcopyrite and molybdenite without the addition of molybdenite organic small molecule flotation inhibitors.

[0076] Chalcopyrite and molybdenite samples with a particle size of 38-74 μm (80-85%) were mixed at a mass ratio of 3:1 to obtain a sample containing 75% chalcopyrite and 15% molybdenite. 2 g of this sample was weighed into a flotation cell, and water was added to prepare a 3% slurry. The mixture was stirred for 3 minutes to completely wet the minerals. Then, butyl xanthate (1 mg / L) was added and stirred for 3 minutes. Next, methyl isobutyl methanol (0.1 mg / L) was added. After 2 minutes, aeration was initiated and frothing was started. After 3 minutes of frothing, a flotation concentrate was obtained. The recovery rate of chalcopyrite in the concentrate reached 97.69%, and the recovery rate of molybdenite was 96.42%. The copper content in the concentrate was 25.57%, and the molybdenum content was 16.94%, both based on elemental composition.

[0077] Comparative Example 3

[0078] This comparative example demonstrates the flotation of talc and molybdenite without the addition of organic small-molecule flotation inhibitors for molybdenite.

[0079] Two g of chalcopyrite and molybdenite samples with a particle size of 38-74 μm and a proportion of 80-85% were weighed into a flotation cell. Water was added to prepare a slurry with a concentration of 3%. The slurry was stirred for 3 min to completely wet the minerals. Then, emulsified kerosene was added at a concentration of 1 mg / L. After stirring for 3 min, methyl isobutyl methanol at a concentration of 0.1 mg / L was added. After 2 min, aeration was started and frothing was initiated. After frothing for 3 min, the flotation concentrate was obtained. The recovery rate of talc reached 89.34%, and the recovery rate of molybdenite was 91.96%.

[0080] Comparative Example 4

[0081] This comparative example demonstrates the flotation of talc and molybdenite without the addition of organic small-molecule flotation inhibitors for molybdenite.

[0082] Talc and molybdenite samples with a particle size of 38-74 μm (80-85%) were mixed at a mass ratio of 3:1 to obtain a ore sample with a talc content of 75% and a molybdenite content of 15%. 2 g of this ore sample was weighed into a flotation cell, and water was added to prepare a 3% slurry. The mixture was stirred for 3 minutes to completely wet the minerals. Then, emulsified kerosene (1 mg / L) was added and stirred for 3 minutes. Next, methyl isobutyl methanol (0.1 mg / L) was added. After 2 minutes, aeration was initiated and frothing was started. After 3 minutes of frothing, a flotation concentrate was obtained. The recovery rate of talc in the concentrate reached 90.81%, and the recovery rate of molybdenite was 88.1%. The magnesium content in the concentrate was 15.84%, and the molybdenum content was 17.44%, both based on elemental composition.

[0083] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A molybdenite organic small molecule flotation inhibitor, characterized in that: The inhibitor is a solid powder preparation of a nitrosylphenyl ester compound obtained by chemical reaction using hydroxylamine hydrochloride, sodium hydroxide, and gallic acid as raw materials. The inhibitor is prepared through the following steps: Step 1, prepare 3 parts sodium hydroxide and 15 parts water by molar ratio; Step 2, mix the raw materials prepared in Step 1 thoroughly; Step 3, prepare 3 parts hydroxylamine hydrochloride and 30 parts water by molar ratio; Step 4, mix the raw materials prepared in Step 3 thoroughly; Step 5, mix the raw materials obtained in Step 2 and Step 4 at room temperature to obtain a solution; Step 6, prepare 2 parts gallic acid and 5 parts anhydrous ethanol; Step 7, mix the raw materials prepared in Step 6 thoroughly to obtain a solution; Step 8, slowly add the solution obtained in Step 5 to the solution obtained in Step 7, and react at 0-10℃ for 0.5-3 hours; Step 9, filter the product obtained in Step 8 to obtain a solid substance; Step 10, dissolve the solid substance obtained in Step 9 in hot water and cool to crystallize. The molybdenite organic small molecule flotation inhibitor was obtained.

2. The molybdenite organic small molecule flotation inhibitor according to claim 1, characterized in that: The inhibitor contains the following chemical structural formula: ； and / or ； and / or ； and / or ； and / or 。 3. The molybdenite organic small molecule flotation inhibitor according to claim 1, characterized in that: Hydroxylamine hydrochloride, sodium hydroxide, and gallic acid were in a molar ratio of 1-10:1-15:1-12.

4. The molybdenite organic small molecule flotation inhibitor according to claim 3, characterized in that: The molar ratio of hydroxylamine hydrochloride, sodium hydroxide, and gallic acid is 2:2:1, yielding 1-nitroso-3,4,5-trinitrosophenyl ester, with the molecular structure shown below: 。 5. The molybdenite organic small molecule flotation inhibitor according to claim 1, characterized in that: In step eight, a solid substance precipitates from the solution system during the reaction process.

6. The molybdenite organic small molecule flotation inhibitor according to claim 1, characterized in that: In step ten, the solid material obtained in step nine is dissolved in hot water at 70-90℃ to obtain a saturated solution, and then cooled and crystallized at 0-10℃ to obtain a molybdenite organic small molecule flotation inhibitor with high yield and purity.

7. The application of a molybdenite organic small molecule flotation inhibitor as described in any one of claims 1-6, characterized in that: When preparing the flotation slurry, add the molybdenite organic small molecule flotation inhibitor, stir for 3-5 minutes, and then add butyl xanthate or emulsified kerosene and methyl isobutyl methanol.

8. The application according to claim 7, characterized in that: Add molybdenite organic small molecule flotation inhibitor at a ratio of 10-100 mg / L.

Images