Lime-inhibited molybdenite flotation activator and molybdenite flotation method

Abstract

The invention discloses a flotation activator for molybdenite inhibited by lime and a flotation method for the molybdenite, and belongs to the technical field of mineral separation. The activator comprises a compound having a nitrogen-containing five-membered heterocyclic ring having the following molecular structure: # imgabs0 # wherein R1 is C1-C5 alkyl or hydrogen, X is N or C-H, R2 and R3 are independently selected from C1-C6 alkyl, benzene ring or benzene ring containing C1-C6 alkyl. By adopting the activating agent, the inhibiting effect of lime in a sulphide ore flotation system on molybdenite flotation can be obviously relieved, so that the flotation efficiency of molybdenite is improved, the cost of a collecting agent is effectively saved, and meanwhile, the environmental protection pressure caused by adopting sulfur-containing agents is relieved.

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 ore dressing. 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 required 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 for 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+ Hydrolyzes to form CaOH + It is adsorbed on the micro-ridges and end faces of the basal surface of molybdenite, reducing the floatability of molybdenite. In view of this, in order to improve the recovery rate of molybdenite and restore the collection performance of the collector on molybdenite, it is necessary to add an activator to alleviate the inhibitory relationship between the selected inhibitor and molybdenite in the flotation system.

[0003] In previous reports, thiophene azoles are usually used as collectors in the flotation recovery of valuable metals in ores containing copper, silver or gold minerals (for example, Chinese patent CN106362869A discloses the application of 1,2,4-triazole-3-thione flotation collectors). Among the thiophene 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 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 large amount of talc inhibitors added in the flotation process from having an adverse effect on the subsequent flotation of molybdenite (for example, Chinese patent CN115025888A discloses a molybdenite inhibitor and a beneficiation method for molybdenum ore containing easily floatable layered silicate gangue minerals).

[0004] Nitrogen heterocyclic compounds are currently commonly used for corrosion protection of metal materials such as copper and molybdenum. There are few research cases on their application in mineral processing and mineral flotation agents. For example, Chinese patent CN 103934112A discloses a method for mineral processing of lithium ore, in which benzotriazole is used to assist tall oil in flotation of lithium ore to enhance the capture effect of spodumene. However, so far, there is no use of nitrogen heterocyclic compounds to solve the technical problem of low flotation efficiency due to the inhibition of molybdenite in lime inhibition system. Summary of the invention

[0005] In view of 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 activator including nitrogen heterocyclic compounds is used in the flotation system of molybdenite inhibited by lime, which can well activate the molybdenite and reduce the inhibitory effect of lime on the molybdenite, thereby effectively solving the problems of poor further flotation effect and low recovery rate of the existing molybdenite inhibited by lime.

[0006] The 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 leads to the inhibition of the flotation of molybdenite. 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 the flotation of molybdenite inhibited by lime, 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 compound with nitrogen-containing five-membered heterocyclic ring involved in the present invention has nitrogen-containing five-membered heterocyclic ring as the parent, and the number of nitrogen atoms is at least two or more. The compound with the parent structure can act well on molybdenite and has a good activation effect on the flotation of molybdenite. Other groups modified on the nitrogen-containing five-membered heterocyclic ring mainly affect its hydrophobicity and lipophilicity, such as short-chain alkyl or benzene ring, etc. The introduction of nitrogen-containing five-membered heterocyclic ring can enhance its coordinated capture effect with kerosene. In the compound with nitrogen-containing five-membered heterocyclic ring, R1 is more preferably methyl or hydrogen, and most preferably methyl, and R2 and R3 are more preferably benzene rings or benzene rings substituted with short-chain alkyl. When R1 is a short-chain alkyl group, compared with when R1 is hydrogen, the hydrophobicity is better, and it 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 with a nitrogen-containing five-membered heterocyclic ring and reduce its dispersibility in water, thereby causing its effect of activating molybdenite to become worse. 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, compared with R2 and R3 being an alkyl group, the hydrophobicity and solubility are moderate. 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 , and 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 contains a solubilizer, and the mass of the solubilizer is not higher than 0.5 times the mass of the compound with a nitrogen-containing five-membered heterocyclic ring. Since the compound with a nitrogen-containing five-membered heterocyclic ring needs to introduce a hydrophobic group to ensure its activation of molybdenite under kerosene conditions, it is often poorly water-soluble. Therefore, a solubilizer needs to be added to the poorly water-soluble nitrogen heterocyclic nitrogen azole compounds 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 mineral powder to prepare a slurry, and then sequentially adding lime, a collector, an activator and a frother to perform flotation to obtain a molybdenite concentrate. +It can be adsorbed on the molybdenite base surface, thereby greatly improving 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 be preferentially adsorbed on the molybdenite end surface, which cannot fully alleviate the subsequent inhibition relationship between lime and molybdenite. Therefore, the activator is added later, and chemically adsorbed with the hydroxyl calcium layer on the molybdenite surface, and the introduced hydrophobic base interacts with the collector kerosene to 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 solution, the collector is a non-polar hydrocarbon oil, more preferably 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: 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 prior art, the technical solution of the present invention has 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 non-polar hydrocarbon oil collectors on molybdenite flotation due to lime, 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 on the basis of ensuring the flotation index of molybdenite, which is beneficial to reducing production costs.

[0019] The present invention adopts a compound with a nitrogen-containing five-membered heterocyclic ring as a molybdenite flotation activator, which has the characteristics of being sulfur-free and low in toxicity, can simplify the subsequent wastewater and waste residue treatment process of mineral processing, and at the same time 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 an obvious activation effect and can effectively activate the molybdenite which is inhibited 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 accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying 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 The effect of lime concentration on the flotation recovery rate of molybdenite single mineral provided in Example 1 of the present invention is a curve diagram.

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

[0025] Figure 4 This is a curve diagram of 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 clearly and completely described 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 recovery rate of lime-inhibited molybdenite 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 put into a pulverizer 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 and placed in a beaker for stirring for 1 min at a speed of 500 rpm. 120 mg / L of lime was added and the slurry was adjusted for 3 min. The pH value was measured to be 11.5~11.8. 30 mg / L of kerosene, activator, and 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, activator A (4×10 -3 mol / L) increased the molybdenite recovery by 40 percentage points. -3 mol / L) increased the molybdenite recovery by 30 percentage points, and the addition of activator C (2.5×10 -3 mol / L) was added, the recovery rate of molybdenite increased by 45 percentage points. Without using activator, and continuing to add activators A, B, and C, the recovery rate of molybdenite can reach more than 95%; adding activator D (8×10 -3 mol / L) after the recovery rate of molybdenite increased by 25 percentage points. Increasing the amount of kerosene by 10 times, the recovery rate of molybdenite only increased by 10 percentage points, and molybdenite was severely suppressed.

[0040] Embodiment 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] Group 1: 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 slurry for flotation for 3 min, then dry and weigh the foam product and the product in the tank, and 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 min, add lime 50 mg / L, react for 3 min, add collector (kerosene) 10 mg / L, react for 3 min, then add MIBC 1.5×10 -4 mol / L, react for 1 min, transfer slurry for flotation for 3 min, then dry and weigh the foam product and the product in the tank, and calculate the recovery rate.

[0047] Group 3: 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 50 mg / L of lime, react for 3 min, add 10 mg / L of collector (kerosene), react for 3 min, add 2.5×10 -3 mol / L, and then add MIBC1.5×10 -4 mol / L, react for 1 min, transfer slurry for flotation for 3 min, then dry and weigh the foam product and the product in the tank, 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 slurry for flotation for 3 min, then dry and weigh the foam product and the product in the tank, calculate the recovery rate, and the data are shown in Table 1.

[0049] Group 5: 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 80 mg / L of lime, react for 3 min, add 70 mg / L of collector (kerosene), react for 3 min, add 5×10 -4mol / L, and then add MIBC1.5×10 -4 mol / L, react for 1 min, transfer slurry for flotation for 3 min, then dry and weigh the foam product and the product in the tank, 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 a good activation performance for lime-inhibited molybdenite, and the activator A can increase the recovery rate of molybdenite by nearly 60 percentage points, and the recovery rate of the activator B in the second and third groups of experiments is increased by about 35 and 44 percentage points respectively; wherein different dosing orders of the activators have different activation effects on the molybdenite inhibited by lime, and the recovery rates of the third group of experiments of the activators A and activators B are both higher than those of the second group, so adding the activator after the collector can effectively enrich the molybdenite; at the same time, for the fourth and fifth groups of experiments, the activators A and B can both improve the recovery rate of molybdenite, and the activation effect of the activator A with a larger hydrophobic group is stronger than that of the activator B.

[0052] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. An activator for the flotation of molybdenite inhibited by lime, 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 the molybdenite mineral powder is slurried with water, lime, a collector, an activator according to any one of claims 1 to 3 and a frother are sequentially added for flotation to obtain a 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 reagent system of the flotation 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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