Metal ion-nitrogen-containing heteroaromatic complex collecting agent, preparation method thereof and application of metal ion-nitrogen-containing heteroaromatic complex collecting agent in tungsten ore flotation

Abstract

The invention discloses a metal ion-nitrogen-containing heteroaromatic complex collecting agent, a preparation method thereof and application of the metal ion-nitrogen-containing heteroaromatic complex collecting agent in tungsten ore flotation, and belongs to the technical field of ore dressing. The metal ion-nitrogen-containing heteroaromatic complex collecting agent is formed by coordinating and assembling a nitrogen-containing heteroaromatic ligand compound containing a hydroxamic acid group and metal ions with the valence of more than two, the nitrogen-containing heteroaromatic ligand compound containing the hydroxamic acid group and the molecular structure of the nitrogen-containing heteroaromatic ligand compound are as follows: # imgabs0 #, and R1, R2, R3, R4 or R5 are the hydroxamic acid group; compared with an existing Pb-BHA complex collecting agent, the tungsten-containing mineral collecting agent has higher targeted adsorption and selective collecting capacity and higher flotation rate on tungsten-containing minerals, flotation of the tungsten-containing minerals can be effectively enhanced, particularly, bulk flotation of various tungsten ores can be efficiently achieved under the condition of low dosage, and the comprehensive recovery rate of tungsten resources is greatly increased.

Description

Technical Field

[0001] The invention relates to a metal ion-nitrogen-containing aromatic heterocyclic complex collector and a preparation method thereof and application in tungsten ore flotation, belonging to the technical field of ore dressing. Background Art

[0002] As an important strategic metal, tungsten is known as the "teeth of industry". It is widely used in military, civilian, industrial and other fields because of its excellent physical and chemical properties. At present, with the increasing depletion of high-quality single and easy-to-gravure separation black tungsten resources, the characteristics of tungsten ore resources "poor, fine, mixed and difficult" are gradually exposed. Single scheelite deposits and mixed scheelite deposits have gradually become the main objects of the development and utilization of existing tungsten ore resources. The characteristics of this type of ore are high content of calcium gangue minerals, complex symbiotic relationships, and finer embedded particle sizes. Traditional processes have become increasingly difficult to adapt to changes in ore properties, resulting in a year-on-year deterioration of production indicators.

[0003] In recent years, the Pb-BHA complex collector developed by Central South University has achieved the room temperature mixed flotation of wolframite and scheelite to a certain extent, and has been successfully industrialized in large tungsten beneficiation plants such as Shizhuyuan, Huangshaping, Hunan, and Xingluokeng, Fujian. However, long-term production practice shows that in the mixed flotation process of wolframite and scheelite, there are differences in the flotation behavior of the two, and the vast majority of tungsten minerals lost in the tailings are wolframite, and the comprehensive recovery rate needs to be improved. For example, the Hunan Shizhuyuan Tungsten Polymetallic Dressing Plant has an original WO3 grade of about 0.32%, which is a typical complex low-grade tungsten-molybdenum polymetallic black and white tungsten associated resource. The main tungsten-containing minerals are wolframite and scheelite and trace amounts of tungsten fluorite. The ratio of wolframite to scheelite is about 3:7. Under the Pb-BHA flotation system, the ratio of scheelite to wolframite in the rough concentrate is 3:1, the ratio of scheelite to wolframite in the first concentrate is 5:1, and the ratio of scheelite to wolframite in the second concentrate is 6:1. The loss of wolframite in the concentrated stage is serious, there are many wolframite tails, and the flotation efficiency is not high.

[0004] In fact, the main reason for the loss of this part of wolframite is its poor floatability and low flotation rate, which causes it to fall into the tailings under the action of inhibitors in multiple concentrations. The key to strengthening the flotation recovery of this part of wolframite resources lies in the design and development of new flotation agents. Compared with the changes in process flow such as reducing the number of concentration stages, opening a separate circuit for middlings, and combining gravity and flotation, the development of efficient flotation agents is simpler and more effective, and can achieve more efficient flotation recovery without reducing the grade of the concentrate. For example, a Chinese patent (publication number: CN111068926A) discloses a hydroxamic acid-alkyl sulfate multi-ligand metal complex collector, which introduces a new alkyl sulfate ligand into the original metal ion-hydroxamic acid complex system to enhance the selective capture ability of polar metal bases for tungsten minerals, so as to improve its flotation recovery rate. For another example, a Chinese patent (publication number: CN115228618A) discloses an O-allyl salicylic acid having a good collector molecular structure and intramolecular synergy of substituents, the essence of which is to change the hydrophobic structure of the collector ligand to improve the hydrophobicity of froth flotation.

[0005] In general, the current new tungsten flotation reagents mainly focus on the modification of hydrophobic groups in the molecular structure of hydroxamic acid and the development of multi-ligand collectors. These collectors have some obvious disadvantages in the flotation process of tungsten ore. For example, the typical Pb-BHA complex is used in the mixed flotation process of black tungsten and black tungsten at room temperature, but there are problems such as poor floatability of black tungsten ore, serious tailing caused by low flotation rate, and low flotation efficiency. Summary of the invention

[0006] Aiming at the technical problems that the Pb-BHA complex in the prior art has poor floatability of wolframite, serious tailing caused by low flotation rate, and low flotation efficiency during the mixed flotation of black and white tungsten at room temperature, the first object of the present invention is to provide a metal ion-nitrogen-containing aromatic heterocyclic complex collector, wherein the nitrogen-containing aromatic heterocyclic ligand containing a hydroxamic acid group has a large conjugated system fused with a benzene ring and a pyrrole, which can improve the chelating ability between the chelating group on the ligand and the metal ion, has a larger adsorption amount, higher adsorption strength and stability, has a stronger selective collection ability for tungsten-containing minerals than the existing Pb-BHA complex, can enhance the floatability and flotation rate of wolframite, and realize the efficient mixed flotation of black and white tungsten.

[0007] The second object of the present invention is to provide a method for preparing a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which has simple operation, mild conditions, low cost and is conducive to expanding production.

[0008] The third object of the present invention is to provide an application of a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is used for the flotation of tungsten-containing minerals. It has strong collecting ability and good selectivity, can greatly improve the flotation concentrate grade and recovery rate of tungsten-containing minerals, is particularly suitable for the flotation of mixed tungsten ores, and has a low cost of use, which is conducive to further promotion and application.

[0009] In order to achieve the above technical objectives, the present invention provides a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is assembled by coordination of a nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group and a divalent or higher metal ion: The nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group has a structure of Formula 1: Formula 1 Wherein, R1, R2, R3, R4 or R5 is a hydroxamic acid group.

[0010] The metal ion-nitrogen-containing aromatic heterocyclic complex collector of the present invention is obtained by optimizing the molecular structure of the benzohydroxamic acid ligand on the basis of the traditional Pb-BHA complex collector. The key to the improvement of the benzohydroxamic acid ligand of the present invention is to use benzopyrrole to replace the benzene ring. Compared with the benzene ring, benzopyrrole has a larger conjugated system and introduces a nitrogen heterocycle. The pyrrole structure exhibits a strong electron-donating conjugated effect due to the presence of double bonds and highly electronegative nitrogen heteroatoms, and the electron reaction activity in the delocalized π bond formed with the benzene ring is higher, so that the bonding ability of the hydroxyl oxygen and the oxime oxygen that play a chelating role on the conjugated system can be strengthened, which further manifests as better selectivity, stronger capture ability and faster flotation rate. The metal ion-nitrogen-containing aromatic heterocyclic complex further assembled by the nitrogen-containing aromatic heterocyclic complex containing hydroxamic acid groups and metal ions has a larger colloidal particle size than the existing Pb-BHA complex, and the nitrogen heteroatom in the pyrrole structure is a good hydrogen bond donor and contributes to intermolecular interaction, which makes the adsorption strength and adsorption density of the collector on the surface of the target mineral greater, can significantly improve its surface roughness, and strengthen the difference in hydrophilicity and hydrophobicity between the target mineral and the gangue mineral surface, which is more conducive to achieving efficient co-enrichment of the target mineral.

[0011] As a preferred solution, the divalent or higher metal ions include Pb 2+ , Ca 2+ Mg 2+ , Cu 2+ , Mn 2+ , Fe 2+ 、Al 3+ or Fe 3+At least one of the above. The metal ion-nitrogen-containing aromatic heterocyclic complex collector formed by assembling different metal ions with the nitrogen-containing aromatic heterocyclic ligand compound containing hydroxamic acid group has different flotation capabilities. The preferred divalent or higher metal ion of the present invention is Pb 2+ Since the radius of the divalent lead ion is 1.2 Å, it has a large polarizability and its extranuclear electron configuration is [Xe]4f 14 5d 10 6s 2 Different from other transition metal ions in the d-block, the electrons in the d and f orbitals of lead ions cannot effectively shield the s electrons in the valence layer, which also gives them unique properties, and their role in coordination-regulated assembly at the mineral flotation interface is particularly significant.

[0012] As a preferred solution, the coordination molar ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing hydroxamic acid groups to the divalent or higher metal ions is (1-16): (1-4). The divalent or higher metal ions and the nitrogen-containing aromatic heterocyclic ligand compound containing hydroxamic acid groups are preliminarily subjected to coordination reaction to generate relatively stable metal ion-nitrogen-containing aromatic heterocyclic complexes, and the metal ion-nitrogen-containing aromatic heterocyclic complexes are generally a mixture of multiple metal ion-nitrogen-containing aromatic heterocyclic complexes, and the components are relatively complex. The effect on the mineral surface is reflected in the synergistic effect of multiple physical adsorption and chemical adsorption. The ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing hydroxamic acid groups to the divalent or higher metal ions will affect the spatial structure of the complex, and controlling the metal ions within an appropriate range will help to exert the "template effect" of the metal ions. However, if the metal ion content is too high, silicate gangue minerals such as quartz and garnet will be activated, and the foam viscosity will increase, the fluidity will be poor, and the foam enrichment state will be seriously deteriorated. The coordination molar ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to the divalent or higher-valent metal ion is more preferably (6-12):(1-2).

[0013] The present invention also provides a method for preparing a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which comprises stirring a nitrogen-containing aromatic heterocyclic ligand compound solution containing a hydroxamic acid group with a divalent or higher metal salt solution under alkaline conditions to obtain the collector.

[0014] As a preferred solution, the stirring reaction conditions are: stirring rate of 200-2000r / min, pH of 8.0-10.0, temperature of 10-50°C, and time of 1-20min. The pH of the coordination reaction is controlled at an alkaline condition of 8.0-10.0, and most of the divalent or higher metal ions will exist in the form of hydroxyl complexes, and the introduction of hydroxides will help to regulate the molecular structure of the assembled complexes and overcome the hydration barrier of the hydroxamic acid during its pre-activation in advance, but too high a pH will cause it to form hydroxide precipitation, hindering its adsorption on the mineral surface. The divalent or higher metal salt solution is mainly provided by soluble metal salts, such as nitrates and chlorides.

[0015] The nitrogen-containing aromatic heterocyclic organic compound of the present invention is prepared by the following method: 1) Preparation of free hydroxylamine: using methanol as solvent, adding an appropriate amount of sodium hydroxide to hydroxylamine hydrochloride to obtain free hydroxylamine, filtering and removing the sodium chloride solid generated by the reaction to obtain a hydroxylamine base solution; 2) Hydroximation reaction: Mix the organic carboxylic acid ester compound and the hydroxylamine alkaline solution in a certain proportion, control the reaction conditions to be alkaline, and carry out the hydroximation reaction at a suitable temperature to obtain the corresponding hydroxamate; The organic carboxylic acid ester compound has a structure of Formula 2: Formula 2 Among them, R 1 , R 2 , R 3 , R 4 or R 5 is a carboxylate group; 3) Acidification reaction: Add concentrated sulfuric acid or concentrated hydrochloric acid to the oximation system for acidification reaction to obtain a nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group.

[0016] The present invention also provides an application of a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is used as a collector for flotation separation of tungsten-containing minerals.

[0017] As a preferred solution, the tungsten-containing mineral includes at least one of wolframite, scheelite, and tungsten-containing ore. The tungsten-containing mineral can be a mixed tungsten-containing mineral of multiple minerals, such as black and white mixed tungsten ore.

[0018] As a preferred solution, the tungsten-containing mineral is subjected to grinding, iron removal and desulfurization pretreatment to obtain a desulfurized tailings slurry. After the desulfurized tailings slurry is slurried, the tungsten ore is floated using a flotation agent including a metal ion-nitrogen-containing aromatic heterocyclic complex collector and a salinized water glass inhibitor to obtain a tungsten concentrate.

[0019] As a preferred solution, the concentration of the desulfurized tailings slurry is adjusted to 40-50 wt.%, and the pH is adjusted to 9.0-10.0. Sodium carbonate is used for pH adjustment.

[0020] As a preferred solution, the tungsten ore flotation includes 1 roughing, 2 or more cleaning and 2 or more scavenging; the reagent system of the roughing is: the amount of the metal ion-nitrogen-containing aromatic heterocyclic complex collector is 300-600 g / t, and the amount of the 2# oil frother is 30-50 g / t; the reagent system of the cleaning is: the amount of the salted water glass inhibitor is 50-500 g / t, and follows the principle of halving; the salted water glass is composed of aluminum sulfate and water glass according to the mass ratio of aluminum sulfate to water glass of 1: (2-4); the reagent system of the scavenging is: the amount of the 2# oil frother is 0-20 g / t; wherein, the mass of the metal ion-nitrogen-containing aromatic heterocyclic complex collector is measured according to the mass of its nitrogen-containing aromatic heterocyclic complex. Under the preferred flotation reagent system, the flotation efficiency of tungsten-containing minerals, especially wolframite, can be effectively enhanced, tungsten tailing can be reduced, and the grade and recovery rate of the final tungsten concentrate can be improved.

[0021] The nitrogen-containing aromatic heterocyclic compounds involved in the present invention can be regarded as the hydroximation modification products of indole. Indole and its homologues and derivatives are widely present in nature, mainly in natural flower oils, such as jasmine, bitter orange flower, daffodil, vanilla, etc. In addition, indole also exists in coal tar and corrupted protein. In industry, indole can be prepared by a variety of methods, such as extraction from high-temperature coal tar, coal tar and washing oil fractions can be subjected to alkali washing, acid washing, distillation, hydrolysis and other steps to obtain refined indole. At present, there are few reports on the use of such compounds in the field of flotation agent synthesis, and they have good application prospects.

[0022] The iron removal and desulfurization of the present invention are conventional tungsten ore pretreatment processes in the prior art.

[0023] The salted water glass of the present invention is a conventional inhibitor for tungsten ore flotation in the prior art.

[0024] Compared with the existing technology, the beneficial technical effects brought by the present invention are as follows: (1) The metal ion-nitrogen-containing aromatic heterocyclic complex collector provided by the present invention has excellent flotation performance. Compared with the existing Pb-BHA complex collector, it has stronger collection ability, better selectivity and higher flotation rate. The nitrogen-containing aromatic heterocyclic organic ligand is a conjugated system containing 10 π electrons, including a six-membered benzene ring and a five-membered nitrogen-containing pyrrole ring. The nitrogen atom provides a pair of lone pairs of electrons to form a stable conjugated system, which exhibits a strong electron-donating effect as a whole. The hydroxyl oxygen and oxime oxygen in the hydroxamic acid molecular structure that form a bond with the metal ion have stronger chelating ability.

[0025] (2) The metal ion-nitrogen-containing aromatic heterocyclic complex collector provided by the present invention can enhance the flotation recovery of tungsten-containing minerals at a lower dosage under weakly alkaline conditions, and at the same time has better selectivity, which helps to reduce the tailing of black tungsten, realize the efficient mixed flotation of black and white tungsten, and improve the grade and recovery rate of the final tungsten concentrate.

[0026] (3) The ore dressing method provided by the present invention for flotation recovery of tungsten polymetallic ores using a metal ion-nitrogen-containing aromatic heterocyclic complex collector is simple to operate and has a low reagent cost. It is applicable to various tungsten polymetallic ores such as single scheelite, mixed scheelite and white scheelite ores, and is conducive to further promotion and use.

[0027] (4) The method for preparing the metal ion-nitrogen-containing aromatic heterocyclic complex of the present invention has high yield, few impurities, readily available raw materials, low cost, and is conducive to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of 1H-indole-7-hydroxamic acid of the present invention.

[0029] Figure 2 This is the infrared spectrum of the lead-based complex collector of Example 1.

[0030] Figure 3 It is the hydrogen nuclear magnetic resonance spectrum of 1H-indole-3-hydroxamic acid of the present invention.

[0031] Figure 4 The results of pure mineral flotation tests of Example 3 and Comparative Example 1 are shown.

[0032] Figure 5 This is a flotation process flow chart of Example 4. DETAILED DESCRIPTION

[0033] The following examples are provided to further illustrate the contents of the present invention in detail, but are not intended to limit the scope of protection of the claims of the present invention.

[0034] Example 1 Preparation of lead-based complex collector: 50ml of methanol was added to the flask as a solvent, and 10.42g of 98.5% pure hydroxylamine hydrochloride (0.15mol) was added to the flask under stirring. After the hydroxylamine hydrochloride was dissolved, a total of 12g of 99% pure sodium hydroxide solid (0.3mol) (3g, 3g, 3g, 3g) was added in batches. After stirring for 1h, the sodium chloride solid generated by the reaction was filtered to obtain the free hydroxylamine alkaline solution. The hydroxylamine alkaline solution was transferred to a three-necked flask, 17.52g of 97% pure 1H-indole-7-methyl formate (0.1mol) was added, the pH of the reaction system was controlled to be about 12.0, the circulating condensation reflux system was opened, and the hydroxylamine was stirred at 55°C for 4h to obtain the hydroxamate modified product. After the hydroxamic acid reaction is completed, concentrated hydrochloric acid is added dropwise to the reaction system under stirring at room temperature to adjust the pH of the reaction system to below 5.0, and a weak acid is prepared by using a strong acid. After the addition is completed, the generated filter residue is removed by filtration, and the filtrate is distilled under reduced pressure to obtain a purple-red solid, i.e., a crude product of 1H-indole-7-hydroxamic acid, whose nuclear magnetic resonance 1H NMR is as follows: Figure 1 shown.

[0035] Add 0.125 mol of lead nitrate to 1L of 1.0 mol / L 1H-indole-7-hydroxamic acid solution, control the stirring speed to 1000 r / min, adjust the pH to 9.0 with sodium hydroxide, and react at room temperature for 3 minutes to obtain the lead-based complex collector, whose infrared spectrum is as follows: Figure 2 shown.

[0036] Example 2 Preparation of iron-based complex collector: 30 ml of methanol was added to the flask as a solvent, and 1.042 g of 98.5% pure hydroxylamine hydrochloride (0.015 mol) was added to the flask under stirring. After the hydroxylamine hydrochloride was dissolved, a total of 1.2 g of 99% pure sodium hydroxide solid (0.03 mol) (0.3 g, 0.3 g, 0.3 g, 0.3 g) was added in batches. After stirring for 1 hour, the sodium chloride solid generated by the reaction was filtered to obtain the free hydroxylamine alkaline solution. The hydroxylamine alkaline solution was transferred to a three-necked flask, 1.7518 g of 98% pure 1H-indole-3-carboxylic acid methyl ester (0.01 mol) was added, the reaction conditions were controlled to be alkaline, the circulating condensation reflux system was opened, and the hydroxylamine was stirred at 50 ° C for 3 hours to obtain the hydroxamate modified compound. After the reaction is completed, concentrated sulfuric acid is added dropwise to the reaction system under stirring at room temperature to adjust the pH of the reaction system to 4.0-5.0, and a weak acid is prepared by using a strong acid. After the addition is completed, the filtrate is distilled under reduced pressure to obtain an off-white solid, i.e., a crude product of 1H-indole-3-hydroxamic acid, which can be further purified by recrystallization from ethanol and water. The specific nuclear magnetic resonance 1H NMR is as follows Figure 3shown.

[0037] Other compounds of the same type can be synthesized using this method.

[0038] Under stirring conditions, 0.15 mol of ferric chloride was added to 1 L of 1H-indole-3-hydroxamic acid solution with a concentration of 1.0 mol / L, the rotation speed was controlled to 1200 r / min, the pH was adjusted to 9.0 with sodium hydroxide, and the reaction was carried out at room temperature for 3 minutes to obtain the iron-based complex collector.

[0039] The metal ion-nitrogen-containing aromatic heterocycle complex collectors used in the following specific examples are all prepared by this method.

[0040] Example 3 Flotation rate of black and white tungsten with new lead-based complex collector: The dosage of the novel lead-based complex collector described in Example 1 was 5.0×10 -5 mol / L, the pH value of the flotation pulp was adjusted to 9 with sodium hydroxide, the dosage of frother methyl isobutyl carbinol (MIBC) was 12.5μL / L, the N2 flow rate was 300mL / min, and the flotation operation was carried out on scheelite with a particle size of -0.074~+0.038mm and wolframite with a particle size of -0.038mm. The foam was manually scraped in batches at a frequency of once every 5s using a scraper and collected every 15s.

[0041] Comparative Example 1 Flotation rate of black and white tungsten of Pb-BHA complex: The dosage of conventional Pb-BHA complex collector is 5.0×10 -5 mol / L, the pH value of the flotation pulp was adjusted to 9 with sodium hydroxide, the dosage of frother methyl isobutyl carbinol (MIBC) was 12.5 μL / L, the N2 flow rate was 300 mL / min, and the flotation operation was carried out on scheelite with a particle size of -0.074+0.038 mm and wolframite with a particle size of -0.038 mm. The foam was manually scraped in batches at a frequency of once every 5 seconds using a scraper and collected every 15 seconds.

[0042] from Figure 3It can be seen that under the Pb-BHA system, the floatability of scheelite is better and the flotation rate is faster. Its cumulative recovery rate increases more in the first 90s, and then tends to be stable, and the final recovery rate reaches about 45%. Under the same conditions, the flotation efficiency of wolframite is not high, the flotation rate is low, and the final recovery rate is only about 20%, which also leads to more wolframite loss in the tailings during the mixed flotation of black and white tungsten. The new Pb-NHIC complex collector has a stronger collection ability and faster flotation rate for wolframite and scheelite. The cumulative recovery rates of the two have tended to balance in about 60s, and the final recovery rates have reached more than 90%, which also shows that the new metal ion-nitrogen-containing aromatic heterocyclic complex collector has better flotation performance.

[0043] Example 4 Mixed flotation of black and white tungsten with new lead-based complex collector: The process method of the present invention is used to treat a tungsten polymetallic ore in Hunan. The specific process flow is shown in Figure 4 . The ore has a WO3 grade of 0.36%, of which the ratio of black and white tungsten is 3:7, and the gangue is mainly garnet, calcite and fluorite. After crushing and grinding, the raw ore meets the mass content of -200 mesh size of more than 75%, and then a drum wet magnetic separator is used to remove iron weakly under the condition of magnetic field strength of 0.4T. The iron removal tailings are desulfurized and flotated with 160g / t copper sulfate as an activator, 60g / t butyl xanthate and 40g / t ethyl thiocyanate as collectors, and 30g / t 2# oil as a frother. The desulfurized tailings are first adjusted to a pulp pH of 9.0 by sodium carbonate, and the lead-based complex collector described in Example 1 is added in an amount of 450g / t, and the frother 2# oil is 40g / t. After aeration and slurry mixing for 5 minutes, the pH is stabilized at about 8.3, and the black and white tungsten mixed flotation roughing operation is carried out. 2# oil 20g / t and 10g / t were added in the scavenging operation, and saline water glass Al-SBL was added as a depressant (the mass ratio of aluminum sulfate to water glass was 1:2), and the total amount of saline water glass Al-SBL used in the selection was 150g / t. After four rounds of selection, a tungsten concentrate containing WO331.51% was obtained, with a recovery rate of 78.22%.

[0044]

[0045] Comparative Example 2 Mixed flotation of black and white tungsten with Pb-BHA complex collector: Under stirring conditions, 0.125 mol of lead nitrate was added to 1 L of 1.0 mol / L benzohydroxamic acid solution and reacted at room temperature for 3 minutes to obtain a Pb-BHA complex collector.

[0046] Comparative Example 2 is used for comparison with Example 4. The crushing, grinding, iron removal, desulfurization and other processes in Comparative Example 2 are consistent with those in Example 4. The only difference is that the traditional Pb-BHA complex collector is used in the roughing. The desulfurized tailings are first adjusted to a pulp pH of 9.5 by sodium carbonate, the amount of Pb-BHA complex collector is 600g / t, the foaming agent 2# oil is 40g / t, and the pH is stabilized at about 8.5 after aeration and slurry stirring for 5 minutes, and the black and white tungsten mixed flotation roughing operation is carried out. 2# oil 20g / t and 10g / t are added to the scavenging operation, respectively, and salinized water glass Al-SBL is added as an inhibitor (the mass ratio of aluminum sulfate to water glass is 1:2) for the selection, and the total amount of salinized water glass Al-SBL used for the selection is 150g / t. After four selections, a tungsten concentrate containing WO330.05% is obtained, with a recovery rate of 72.28%. From the flotation test results, it can be seen that the new metal ion-nitrogen-containing aromatic heterocyclic complex collector can achieve higher flotation efficiency at a lower dosage. The grade of tungsten concentrate is increased from 30.05% to 31.51%, and the recovery rate is increased from 72.28 to 78.22%, which has good application prospects.

[0047]

[0048] Example 5 Flotation of scheelite with a new iron-based complex collector: The process method of the present invention is used to treat a tungsten polymetallic ore in Hunan. The ore is a single scheelite with extremely low wolframite content. The tungsten grade of the original ore is about 0.18%, of which the fluorite content is relatively high. The main gangue minerals are calcite, garnet and quartz. The particle size of the scheelite is relatively uniform, and the main particle size range is 0.04~0.32mm, which belongs to the fine-micro-fine particle uniform embedding type. After the original ore is crushed and ground, the mass content of the -200 mesh particle size is 75%, and then a drum wet magnetic separator is used to remove iron weakly under the condition of a magnetic field intensity of 0.3T. After the non-magnetic product is concentrated by a thickener, 200g / t copper sulfate is added as an activator, 150g / t yellow medicine and 10g / t kerosene are added as collectors, and 40g / t 2# oil is used as a frother for desulfurization flotation. The pH of the desulfurized tailings slurry was adjusted to 9.5 by carbonate ore, 600 g / t of the iron-based complex collector described in Example 2 and 40 g / t of frother 2# oil were added, and the pH was stabilized at about 7.8 after aeration and slurry stirring for 5 minutes. Tungsten roughing operation was carried out, 20 g / t of 2# oil was added for scavenging, and 400 g / t of salinized water glass Al-SBL (1:2) was added for concentrating. After four times of concentrating, tungsten concentrate WO345.33% was obtained, and the recovery rate was 70.51%.

[0049]

[0050] Comparative Example 3 Flotation of Scheelite with Fe-BHA Complex Collector: Under stirring conditions, 0.15 mol of ferric chloride was added to 1L of 1.0 mol / L benzohydroxamic acid solution, and the reaction was carried out for 3 minutes to obtain a Fe-BHA complex collector. Comparative Example 3 was used for comparison with Example 5. The crushing, grinding, iron removal, desulfurization and other processes in Comparative Example 3 were consistent with those in Example 5. The pH of the desulfurized tailings was adjusted to 9.0 by sodium carbonate, and 800 g / t of Fe-BHA complex collector and 40 g / t of frother 2# oil were added. After aeration and slurry stirring for 5 minutes, the pH was stabilized at about 7.5, and tungsten roughing was carried out. 200 g / t of Fe-BHA collector and 10 g / t of 2# oil were added for scavenging. The total amount of salted water glass Al-SBL (1:2) added for selection was 400 g / t. After four selections, tungsten concentrate WO342.89% was obtained, and the recovery rate was 67.69%. It can be seen from the flotation test results that the new metal-based complex collector can also achieve the flotation recovery of single scheelite, with lower dosage, higher concentrate grade and recovery rate. Under the condition of reducing the dosage by one quarter, the concentrate grade is increased by about 2.5% and the recovery rate is increased by about 3%.

[0051]

Claims

1. A metal ion-nitrogen-containing aromatic heterocyclic complex collector, characterized in that: It is assembled by coordination of nitrogen-containing aromatic heterocyclic ligand compounds containing hydroxamic acid groups and divalent or higher metal ions: The nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group has a structure of Formula 1: Formula 1; Wherein, R1, R2, R3, R4 or R5 is a hydroxamic acid group.

2. The metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 1, characterized in that: The divalent or higher metal ions include Pb 2+ , Ca 2+ Mg 2+ , Cu 2+ , Mn 2+ , Fe 2+ 、Al 3+ or Fe 3+ At least one of them.

3. A metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 1 or 2, characterized in that: The coordination molar ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to the divalent or higher metal ion is (1-16): (1-4).

4. A method for preparing a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to any one of claims 1 to 3, characterized in that: The solution of nitrogen-containing aromatic heterocyclic ligand compound containing hydroxamic acid group and the solution of divalent or higher metal salt are stirred and reacted under alkaline conditions to obtain the product.

5. The method for preparing a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 4, characterized in that: The stirring reaction conditions are: stirring rate of 200-2000 r / min, pH of 8.0-10.0, temperature of 10-50° C., and time of 1-20 min.

6. The use of a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to any one of claims 1 to 3, characterized in that: Used as collector for flotation separation of tungsten-containing minerals.

7. The use of a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 6, characterized in that: The tungsten-containing minerals include at least one of wolframite, scheelite and tungsten ore.

8. The use of a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 6 or 7, characterized in that: The tungsten-containing mineral is subjected to grinding, iron removal and desulfurization pretreatment to obtain desulfurized tailings slurry. After the desulfurized tailings slurry is slurried, the tungsten ore is floated using a flotation agent including a metal ion-nitrogen-containing aromatic heterocyclic complex collector and a salinized water glass inhibitor to obtain a tungsten concentrate.

9. The use of a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 8, characterized in that: The concentration of the desulfurized tailings slurry is adjusted to 40-50wt.%, and the pH is adjusted to 9.0-10.

0.

10. The use of a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 8, characterized in that: The tungsten ore flotation includes one roughing selection, two or more cleaning selections and two or more scavenging selections; The reagent system for the rough selection is as follows: the amount of the metal ion-nitrogen-containing aromatic heterocyclic complex collector is 300-600 g / t, and the amount of the 2# oil foaming agent is 30-50 g / t; The selected reagent system is as follows: the dosage of the salt water glass inhibitor is 50-500 g / t, and follows the principle of halving; The salted water glass is composed of aluminum sulfate and water glass in a mass ratio of aluminum sulfate to water glass of 1:(2-4); The reagent system for the sweeping is: the dosage of 2# oil foaming agent is 0~20g / t; The mass of the metal ion-nitrogen-containing aromatic heterocyclic complex collector is measured according to the mass of its nitrogen-containing aromatic heterocyclic complex.

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