A flotation activator for molybdenite inhibited by lime and a flotation method for molybdenite

Abstract

The present invention discloses an activator for lime-inhibited molybdenite flotation and a molybdenite flotation method, belonging to the field of mineral processing technology. The activator comprises a compound having a nitrogen-containing five-membered heterocyclic ring, having the following molecular structure: #imgabs0#, wherein R1 is a C1-C5 alkyl group or hydrogen, X is N or C-H, and R2 and R3 are independently selected from a C1-C6 alkyl group, a benzene ring, or a benzene ring containing a C1-C6 alkyl group. The use of this activator can significantly alleviate the inhibitory effect of lime on molybdenite flotation in a sulfide ore flotation system, thereby improving the flotation efficiency of the molybdenite, effectively saving collector costs, and reducing the environmental protection pressure brought about by the use of sulfur-containing reagents.

Description

Technical Field

[0001] The invention relates to an activator, in particular to a lime-inhibited molybdenite flotation activator, belonging to the technical field of mineral processing. Background Art

[0002] Molybdenum metal is widely used in chemical industry, agriculture, medicine, electronics, aerospace and other fields, and is a precious key strategic metal. At present, molybdenite is the main source of molybdenum metal, and it often coexists with pyrite, chalcopyrite and other sulfide ores in the ore. In the flotation of copper-molybdenum sulfide ores, a large amount of lime is often needed to suppress other sulfide ores, which leads to a significant inhibition of the floating of molybdenite. Especially in the copper-molybdenum mixed flotation, a large amount of lime is added to suppress the floating of pyrite and the subsequent copper-molybdenum separation. The relative amount of lime is larger, which often leads to the failure of hydrocarbon oil collectors or the need to increase the amount exponentially to restore the floatability of molybdenite suppressed by lime. Lime is a commonly used pH adjuster in sulfide ore flotation, and it also has a strong inhibitory effect on molybdenite. The inhibition mechanism is that CaO promotes the hydrolysis of HMoO-4 in molybdenite, reducing its floatability, or ... 2+ Hydrolysis to form CaOH + It adsorbs on the basal micro-ridges and end faces of molybdenite, reducing its floatability. Therefore, in order to improve the recovery rate of molybdenite and restore the collector's collection performance on molybdenite, it is necessary to add an activator to alleviate the inhibitory relationship between the selected depressant and molybdenite in the flotation system.

[0003] In previous reports, thiol-containing azoles are usually used as collectors in the flotation recovery of valuable metals from ores containing copper, silver or gold minerals (for example, Chinese patent CN106362869A discloses the application of a 1,2,4-triazole-3-thiol flotation collector). Among the thiol-containing azoles, mercaptobenzothiazole is more widely used and can be used as a collector for copper-cobalt waste rock (for example, Chinese patent CN117599960A discloses a flotation separation agent for copper-cobalt waste rock and its application), iron-containing mica, etc. The refractory pyrochlore ore (for example, Chinese patent CN118616217A discloses a beneficiation method for refractory pyrochlore ore containing iron mica) can be effectively enriched. In addition, studies have shown that the use of mercaptoazoles as molybdenite protective agents in the flotation of talc and molybdenite can effectively prevent the adverse effects of large amounts of talc inhibitors added in the flotation process on the subsequent flotation of molybdenite (for example, Chinese patent CN115025888A discloses a molybdenite inhibitor and a beneficiation method for molybdenum ores containing easily floatable phyllosilicate gangue minerals).

[0004] Nitrogen heterocyclic compounds are currently commonly used for corrosion protection of metal materials such as copper and molybdenum. However, their application in mineral processing and as flotation agents is relatively rare. For example, Chinese patent CN 103934112A discloses a method for beneficiating lithium ore, which uses benzotriazole as an auxiliary to tall oil to enhance the capture of spodumene during lithium ore flotation. However, to date, no nitrogen heterocyclic compounds have been used to address the technical problem of low flotation efficiency due to the inhibition of molybdenite in lime-inhibited systems. Summary of the Invention

[0005] In response to the problems existing in the prior art, the first object of the present invention is to provide an activator for the flotation of molybdenite inhibited by lime. The use of an activator including nitrogen heterocyclic compounds in the flotation system of molybdenite inhibited by lime can effectively activate the molybdenite, reduce the inhibitory effect of lime on the molybdenite, and effectively solve the problems of poor further flotation effect and low recovery rate of the existing molybdenite inhibited by lime.

[0006] A second object of the present invention is to provide a flotation method for molybdenite. In the flotation process of molybdenite, lime is inevitably used, which inhibits the flotation of molybdenite. However, the use of an activator containing nitrogen heterocyclic compounds can effectively improve the flotation effect of molybdenite and increase the recovery rate.

[0007] In order to achieve the above technical objectives, the present invention provides an activator for lime-inhibited molybdenite flotation, comprising a compound having a nitrogen-containing five-membered heterocyclic ring; the compound having a nitrogen-containing five-membered heterocyclic ring is at least one of the following molecular structural formulas:

[0008] ;

[0009] Wherein, R1 is a C1-C5 alkyl group or hydrogen, X is N or CH, and R2 and R3 are independently selected from a C1-C6 alkyl group, a benzene ring, or a benzene ring containing a C1-C5 alkyl group.

[0010] The present invention relates to a compound having a nitrogen-containing five-membered heterocyclic ring, which has at least two nitrogen atoms and is preferably a parent ring. Compounds having this parent structure can effectively act on molybdenite, effectively activating its flotation. Other groups modified on the nitrogen-containing five-membered heterocyclic ring, such as short-chain alkyl groups or benzene rings, primarily affect its hydrophobicity and lipophilicity. Introduction of the nitrogen-containing five-membered heterocyclic ring can enhance its coordinated capture effect with kerosene. In compounds having a nitrogen-containing five-membered heterocyclic ring, R1 is more preferably a methyl group or hydrogen, most preferably a methyl group, and R2 and R3 are more preferably a benzene ring or a benzene ring substituted with a short-chain alkyl group. When R1 is a short-chain alkyl group, it has better hydrophobicity than when R1 is hydrogen, and can play a good role in activating molybdenite. However, the introduction of a long-chain alkyl group will increase the oil solubility of the compound having a nitrogen-containing five-membered heterocyclic ring and reduce its dispersibility in water, thereby causing its effect of activating molybdenite to deteriorate. Therefore, R1 is further preferably a methyl group; when R2 and R3 are further preferably a benzene ring or a benzene ring containing a C1~C5 alkyl group, the hydrophobicity and solubility are moderate compared to when R2 and R3 are alkyl groups. While ensuring strong hydrophobicity, it has good solubility under simple solubilization and has an excellent activation effect. Therefore, R2 and R3 are further preferably a benzene ring or a benzene ring containing a C1~C5 alkyl group.

[0011] As a preferred embodiment, when the compound having a nitrogen-containing five-membered heterocyclic ring is , and R1 is a C1~C5 alkyl group, X is N or CH, or, when the compound having a nitrogen-containing five-membered heterocyclic ring is or When R2 or R3 is a C2-C6 alkyl group, a benzene ring, or a benzene ring containing a C1-C6 alkyl group, the activator includes a solubilizer, and the mass of the solubilizer is no more than 0.5 times the mass of the compound containing the nitrogen-containing five-membered heterocyclic ring. Because compounds containing nitrogen-containing five-membered heterocyclic rings require the introduction of hydrophobic groups to ensure their activation of molybdenite under kerosene conditions, they often have poor water solubility. Therefore, for nitrogen heterocyclic azole compounds with poor water solubility, a solubilizer must be added to prepare a stable activator solution.

[0012] As a more preferred solution, the solubilizing agent is selectively added with at least one of sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0013] The present invention also provides a flotation method for molybdenite, which comprises the following steps: adding water to molybdenite powder to prepare a slurry, and then sequentially adding lime, a collector, an activator and a frother to carry out flotation to obtain molybdenite concentrate. +It can adsorb on the basal surface of molybdenite, thereby significantly increasing the hydrophilicity of the molybdenite surface and forming a water film on the molybdenite surface, which kerosene cannot capture through hydrophobic attraction. If the activator is added in advance, it will preferentially adsorb on the end face of the molybdenite, which cannot fully alleviate the subsequent inhibition relationship between lime and molybdenite. Therefore, the activator is added later, chemically adsorbed with the hydroxyl calcium layer on the molybdenite surface, and through the introduced hydrophobic group and the collector kerosene, synergistically capture the inhibited molybdenite.

[0014] As a preferred solution, the foaming agent includes at least one of an alcohol foaming agent, an ether foaming agent and a phenol foaming agent.

[0015] As a preferred embodiment, the collector is a non-polar hydrocarbon oil. More preferably, it is at least one of kerosene, diesel, and transformer oil. These collectors are conventional molybdenite flotation reagents.

[0016] As a preferred solution, the flotation reagent system is as follows: lime dosage 30~200 mg / L, kerosene dosage 10~100 mg / L, activator dosage 1×10 -4 ~5×10 -2 mol / L, foaming agent dosage 1×10 -4 ~2×10 -4 As a more preferred solution, the amount of lime added to the slurry is measured to adjust the pH of the slurry to 11-12.

[0017] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0018] The present invention adopts a compound having a nitrogen-containing five-membered heterocyclic ring as an activator, which can significantly improve the inhibitory effect of lime on the flotation of molybdenite on the non-polar hydrocarbon oil collector, solves the technical problem that the recovery rate cannot be improved even if the amount of non-polar hydrocarbon oil collector is increased, and can significantly reduce the amount of collector while ensuring the flotation index of molybdenite, which is conducive to reducing production costs.

[0019] The present invention adopts a compound with a nitrogen-containing five-membered heterocyclic ring as a molybdenite flotation activator. The compound is sulfur-free and has low toxicity. It can simplify the subsequent wastewater and waste residue treatment process of mineral processing and reduce the environmental pressure in the mineral flotation process.

[0020] The present invention adopts a compound with a nitrogen-containing five-membered heterocyclic ring as a molybdenite flotation activator, which has a small dosage and obvious activation effect and can effectively activate the molybdenite that is suppressed by lime and has lost its floatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of 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 paying any creative work.

[0022] Figure 1 This is a schematic diagram of a process for promoting the flotation recovery of molybdenite inhibited by lime using a compound having a nitrogen-containing five-membered heterocyclic ring provided in Example 1 of the present invention.

[0023] Figure 2 This is a graph showing the effect of lime concentration on the flotation recovery rate of molybdenite provided in Example 1 of the present invention.

[0024] Figure 3 This is a graph showing the relationship between the amount of the compound activator having a nitrogen-containing five-membered heterocyclic ring and the flotation recovery rate of molybdenite single mineral provided in Example 1 of the present invention.

[0025] Figure 4 This is a graph showing the effect of increasing kerosene dosage on the flotation recovery rate of molybdenite single mineral provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below through specific embodiments.

[0027] In the following examples, unless otherwise specified, all the drugs used were commercially available products.

[0028] Ore raw material: pure molybdenite mineral.

[0029] Example 1

[0030] Pure mineral experiment:

[0031] This embodiment provides a lime-inhibited molybdenite flotation activator and a method for recovering the lime-inhibited molybdenite recovery rate by using the activator in a kerosene capture system.

[0032] As attached Figure 1 The specific steps are as follows:

[0033] Prepare four activators A, B, C, and D:

[0034] The mass ratio of 5-methylbenzotriazole to sodium hydroxide in activator A is 1:0.1.

[0035] Activator B contained only benzotriazole.

[0036] Activator C contains only 5-methylbenzimidazole.

[0037] The activator D contains 5-phenyltetrazolyl and sodium hydroxide in a mass ratio of 1:0.25.

[0038] The raw ore was placed in a crusher for grinding, and the particle size of the grinding product was controlled at -200~+400 mesh. 2 g of the obtained sample was mixed with 220 mL of deionized water in a beaker and stirred for 1 min at 500 rpm. 120 mg / L of lime was added and the slurry was mixed for 3 min. The pH value was measured to be 11.5~11.8. 30 mg / L of kerosene, an activator, and a foaming agent (MIBC dosage was 1.5×10 -4 mol / L), the slurry preparation time was 3 min, 3 min, and 1 min respectively; the obtained slurry was transferred to a single bubble tube, the speed was 400 rpm, nitrogen was introduced, and foam flotation was performed for 3 min. Finally, the concentrate tailings obtained by flotation were filtered, dried, weighed, and the recovery rate was calculated.

[0039] Depend on Figure 2 It can be seen that the addition of lime inhibits the flotation of molybdenite. When only lime and frother are added, when the amount of lime increases and the pH increases to above 11, the recovery rate of molybdenite decreases to 30%. The flotation results of using activator are as follows: Figure 3 、 Figure 4 (MIBC dosage is 1.5×10 -4 mol / L), when a large dose of lime is used, the addition of activator A (4×10 -3 mol / L) and the recovery rate of molybdenite increased by 40 percentage points. -3 mol / L) was added, and the recovery rate of molybdenite increased by 30 percentage points. -3 mol / L) was added, the molybdenite recovery rate increased by 45 percentage points. Without using activator, and subsequently adding activators A, B, and C, the molybdenite recovery rate could reach more than 95%. When adding activator D (8×10 -3 mol / L) after the molybdenite recovery rate increased by 25 percentage points. Increasing the kerosene dosage by 10 times only increased the molybdenite recovery rate by 10 percentage points, and molybdenite was severely suppressed.

[0040] Example 2:

[0041] Pure mineral experiment:

[0042] Prepare two activators A and B.

[0043] The mass ratio of 5-methylbenzotriazole to sodium hydroxide in activator A is 1:0.1.

[0044] Activator B contained only benzotriazole.

[0045] One group: First, weigh 2.00g of molybdenite sample and put it into a 250mL beaker, add 220mL of deionized water, stir for 3min, add 50mg / L of lime, react for 3min, add 10mg / L of collector (kerosene), react for 3min, and then add 1.5×10 -4 mol / L, react for 1 min, transfer the pulp for flotation for 3 min, then dry and weigh the foam product and the product in the tank separately to calculate the recovery rate.

[0046] Group 2: First, weigh 2.00 g of molybdenite sample and put it into a 250 mL beaker, add 220 mL of deionized water, stir for 3 min, add 2.5 × 10 -3 mol / L, react for 3 minutes, add lime 50mg / L, react for 3 minutes, add collector (kerosene) 10mg / L, react for 3 minutes, then add MIBC1.5×10 -4 mol / L, react for 1 min, transfer the pulp for flotation for 3 min, then dry and weigh the foam product and the product in the tank separately to calculate the recovery rate.

[0047] Group 3: First, 2.00 g of molybdenite sample was weighed and placed in a 250 mL beaker. 220 mL of deionized water was added and stirred for 3 min. 50 mg / L of lime was added and reacted for 3 min. 10 mg / L of collector (kerosene) was added and reacted for 3 min. 2.5 × 10 -3 mol / L, and then add MIBC1.5×10 -4 mol / L, react for 1 min, transfer pulp for flotation for 3 min, then dry and weigh the foam product and the product in the tank respectively, calculate the recovery rate, and the data are shown in Table 1.

[0048] Group 4: First, weigh 2.00g of molybdenite sample and put it into a 250mL beaker, add 220mL of deionized water, stir for 3min, add 80mg / L of lime, react for 3min, add 70mg / L of collector (kerosene), react for 3min, add 1.5×10 -4 mol / L, react for 1 min, transfer pulp for flotation for 3 min, then dry and weigh the foam product and the product in the tank respectively, calculate the recovery rate, and the data are shown in Table 1.

[0049] Group 5: First, weigh 2.00g of molybdenite sample and put it into a 250mL beaker, add 220mL of deionized water, stir for 3min, add 80mg / L of lime, react for 3min, add 70mg / L of collector (kerosene), react for 3min, add 5×10 -4mol / L, and then add MIBC1.5×10 -4 mol / L, react for 1 min, transfer pulp for flotation for 3 min, then dry and weigh the foam product and the product in the tank respectively, calculate the recovery rate, and the data are shown in Table 1.

[0050]

[0051] By comparing the first three groups of experiments, the activator disclosed in the present invention has excellent activation performance for lime-inhibited molybdenite. Activator A can increase the recovery rate of molybdenite by nearly 60 percentage points, and the recovery rate of activator B in the second and third groups of experiments is increased by about 35 and 44 percentage points, respectively. Among them, different dosing orders of the activators have different activation effects on the lime-inhibited molybdenite. The recovery rates of activators A and B in the third group of experiments are both higher than those in the second group. Therefore, adding the activator after the collector can effectively enrich the molybdenite. At the same time, for the fourth and fifth groups of experiments, both activators A and B can improve the recovery rate of molybdenite, and the activation effect of activator A with a larger hydrophobic group is stronger than that of activator B.

[0052] Although the present invention has been described in detail above using general explanations, specific embodiments, and experiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. An activator for lime-inhibited molybdenite flotation, characterized in that: Compounds comprising a nitrogen-containing five-membered heterocyclic ring; The compound having a nitrogen-containing five-membered heterocyclic ring is at least one of the following molecular structural formulas: ； Wherein, R1 is a C1-C5 alkyl group or hydrogen, X is N or CH, and R2 and R3 are independently selected from a C1-C6 alkyl group, a benzene ring, or a benzene ring containing a C1-C5 alkyl group.

2. The flotation activator for lime-inhibited molybdenite according to claim 1, characterized in that: When the compound having a nitrogen-containing five-membered heterocyclic ring is , and R1 is a C1~C5 alkyl group, X is N or CH, or, when the compound having a nitrogen-containing five-membered heterocyclic ring is or , and when R2 or R3 is a C2~C6 alkyl group, a benzene ring, or a benzene ring containing a C1~C5 alkyl group, the activator contains a solubilizer, and the mass of the solubilizer is not higher than 0.5 times the mass of the compound having a nitrogen-containing five-membered heterocyclic ring.

3. The flotation activator for lime-inhibited molybdenite according to claim 2, characterized in that: The solubilizing agent is at least one of sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

4. A flotation method for molybdenite, characterized in that: After molybdenite mineral powder is slurried with water, lime, a collector, the activator according to any one of claims 1 to 3, and a frother are sequentially added to carry out flotation to obtain molybdenite concentrate.

5. A flotation method for molybdenite according to claim 4, characterized in that: The foaming agent includes at least one of an alcohol foaming agent, an ether foaming agent and a phenol foaming agent.

6. A flotation method for molybdenite according to claim 4, characterized in that: The collector is a non-polar hydrocarbon oil.

7. A flotation method for molybdenite according to any one of claims 4 to 6, characterized in that: The flotation reagent system is as follows: lime dosage 30~200 mg / L, kerosene dosage 10~100 mg / L, activator dosage 1×10 -4 ~5×10 -2 mol / L, foaming agent dosage 1×10 -4 ~2×10 -4 mol / L.

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