A metal ion-nitrogen-containing aromatic heterocycle complexing collector, a preparation method thereof and application thereof in tungsten ore flotation

Abstract

The application discloses a metal ion-nitrogen-containing aromatic heterocyclic complex collector and a preparation method and application thereof in tungsten ore flotation, and belongs to the technical field of ore dressing. The metal ion-nitrogen-containing aromatic heterocyclic complex collector is assembled by a nitrogen-containing aromatic heterocyclic ligand compound with a hydroxamic acid group and a divalent metal ion, and has the following molecular structure: wherein R1, R2, R3, R4 or R5 is a hydroxamic acid group. Compared with an existing Pb-BHA complex collector, the metal ion-nitrogen-containing aromatic heterocyclic complex collector has stronger targeted adsorption and selective collection capacity for tungsten-containing minerals and higher flotation rate, can effectively strengthen the flotation of the tungsten-containing minerals, and in particular, can efficiently realize mixed flotation of various tungsten ores at a lower dosage, and greatly improve the comprehensive recovery rate of tungsten resources.

Description

TECHNICAL FIELD

[0001] The present application relates to a metal ion-nitrogen-containing aromatic heterocyclic complex collector and its preparation method and application in tungsten ore flotation, belonging to the technical field of mineral processing. BACKGROUND

[0002] Tungsten, as an important strategic metal, is known as "industrial teeth", because of its series of excellent physical and chemical properties, it is widely used in military, civilian, industrial and other fields. At present, with the depletion of high-quality single and easy to be separated by gravity separation scheelite resources, the characteristics of tungsten resources "poor, fine, complex and difficult" are gradually exposed, and single scheelite deposit and scheelite and wolframite mixed deposit gradually become the main object of existing tungsten ore resources development and utilization. The characteristics of this type of ore are high content of calcium gangue minerals, complex symbiotic relationship, and finer dissemination size. The traditional process has been more and more difficult to adapt to the change of ore properties, resulting in the deterioration of production index year by year.

[0003] In recent years, the Pb-BHA complex collector developed by Central South University has realized the room temperature mixed flotation of wolframite and scheelite to some extent, and has realized successful industrial application in large tungsten ore dressing plants such as Shizhuyuan, Huangshaping in Hunan, Xingluokeng in Fujian, etc. However, long-term production practice shows that there are differences in the flotation behavior of wolframite and scheelite in the mixed flotation process, and most of the tungsten minerals lost in the tailings are wolframite, and the comprehensive recovery rate needs to be improved. For example, Hunan Shizhuyuan tungsten polymetallic concentrator, with an ore WO3 grade of about 0.32%, is a typical complex low-grade tungsten-molybdenum polymetallic scheelite and wolframite associated resource, in which the main tungsten-bearing minerals are wolframite, scheelite and a small amount of tungsten trioxide, and 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 wolframite loss is serious in the cleaning stage, and the wolframite tailing is more, 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 leads to its falling into the tailings under the action of the depressant in multiple cleaning. The key to strengthening the flotation recovery of this part of wolframite resources lies in the design and development of new flotation reagents. Compared with the changes in process flow such as reducing the number of cleaning stages, separate opening of middlings, and gravity-flotation combination, the development of high-efficiency flotation reagents is simpler and more effective, which can achieve more efficient flotation recovery without reducing the concentrate grade. For example, a hydroxamic acid-alkyl sulfate multi-ligand metal complex collector is disclosed in Chinese patent (publication number: CN111068926A), which introduces a new alkyl sulfate ligand into the original metal ion-hydroxamic acid complex system to strengthen the selective collecting ability of polar metal-based for tungsten minerals, so as to improve the flotation recovery rate. For another example, O-allyl salicyl hydroxamic acid is disclosed in Chinese patent (publication number: CN115228618A), which has good collector molecular structure and intramolecular synergistic effect of substituent groups. The essence is to change the hydrophobic structure of the ligand of the collector to improve the hydrophobicity of froth flotation.

[0005] Overall, the new tungsten flotation reagents at the present stage mainly focus on the modification of the hydrophobic group in the hydroxamic acid molecular structure and the development of multi-ligand collectors. These collectors have some obvious shortcomings in the tungsten flotation process, such as the typical Pb-BHA complex used in the room temperature mixed flotation process of black and white tungsten, which has the problems of serious tailing running caused by poor floatability and low flotation rate of wolframite, and low flotation efficiency. SUMMARY

[0006] In view of the technical problems of the Pb-BHA complex in the existing art in the room temperature mixed flotation process of black and white tungsten, such as serious tailing running caused by poor floatability and low flotation rate of wolframite, and low flotation efficiency, the first object of the present application is to provide a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which has a benzene ring and a pyrrole fused large conjugated system in the nitrogen-containing aromatic heterocyclic ligand containing a hydroxamic acid group, can improve the chelation ability between the chelating groups on the ligand and the metal ions, has a larger adsorption capacity, higher adsorption strength and stability, has a stronger selective collecting ability for tungsten-containing minerals than the existing Pb-BHA complex, can strengthen the floatability and flotation rate of wolframite, and realize efficient mixed flotation of black and white tungsten.

[0007] The second object of the present application is to provide a preparation method of the metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is simple in operation, mild in conditions, low in cost, and conducive to large-scale production.

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

[0009] In order to achieve the above technical purposes, the present application provides a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is assembled by a nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group and a divalent or higher metal ion:

[0010] The nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group has the structure of formula 1:

[0011] Formula 1

[0012] Among them, R1, R2, R3, R4 or R5 is a hydroxamic acid group.

[0013] The metal ion-nitrogen-containing aromatic heterocyclic complex collector of the present application is obtained by optimizing the molecular structure of the benzyl hydroxamic acid ligand on the basis of the traditional Pb-BHA complex collector. The key to the improvement of the benzyl hydroxamic acid ligand in the present application is to use benzopyrrole to replace the benzene ring. Benzopyrrole has a larger conjugated system than benzene ring, and nitrogen heterocycle is introduced. The pyrrole structure has a strong electron-donating conjugation effect due to the existence of double bond and electronegative nitrogen heteroatom, and the electron reactivity in the delocalized pi bond formed by benzene ring is higher, so that the bonding ability of the hydroxyl oxygen and the oxime oxygen which play a chelating role on the conjugated system is strengthened, which further shows better selectivity, stronger collecting ability and faster flotation rate. The metal ion-nitrogen-containing aromatic heterocyclic complex formed by the nitrogen-containing aromatic heterocyclic complex containing a hydroxamic acid group and the metal ion 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 helps intermolecular interaction, so that the adsorption strength and adsorption density of the collector on the surface of the target mineral are larger, which can significantly improve the surface roughness, strengthen the hydrophilic and hydrophobic difference between the target mineral and the gangue mineral, and thus more conducive to the efficient co-enrichment of the target mineral.

[0014] As a preferred scheme, the divalent or higher metal ion includes Pb 2+ , Ca 2+ , Mg 2+ , Cu 2+ , Mn 2+ , Fe 2+ , Al 3+ or Fe 3+at least one. Different metal ions and the nitrogen-containing aromatic heterocyclic ligand compounds containing hydroxamic acid group assembled to form metal ion-nitrogen-containing aromatic heterocyclic complex collectors have different flotation abilities, and the further preferred divalent or more metal ions in the application are Pb 2+ . Since the radius of divalent lead ion is 1.2 Å, it has a large polarizability, and its outer electron configuration is [Xe]4f 14 5d 10 6s 2 , unlike other transition metal ions in the d region, the electrons in the d and f orbits of lead ions cannot effectively shield the s electrons in the valence shell, which also endows it with unique properties, and its role in the coordination regulation assembly at the mineral flotation interface is particularly significant.

[0015] As a preferred scheme, the coordination molar ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to the divalent or more metal ion is (1-16):(1-4). The divalent or more metal ion and the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group are pre-generated into a relatively stable metal ion-nitrogen-containing aromatic heterocyclic complex through coordination reaction, and it is generally a mixture of multiple metal ion-nitrogen-containing aromatic heterocyclic complexes, and the components are relatively complex, and the effect on the mineral surface is a synergistic effect of multiple physical and chemical adsorptions. The ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to the divalent or more metal ion will affect the spatial structure of the complex, and controlling the metal ion in a suitable range is helpful to exert the "template effect" of the metal ion, but if the content of the metal ion is too high, it will activate silicate gangue minerals such as quartz and garnet, and also cause the increase of foam viscosity, poor flowability, and serious deterioration of the foam enrichment state. The coordination molar ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to the divalent or more metal ion is further preferably (6-12):(1-2).

[0016] The application also provides a preparation method of a metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is to stir and react a solution of a nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group with a solution of a divalent or more metal salt under alkaline conditions.

[0017] As a preferred scheme, the stirring reaction conditions are as follows: the stirring rate is 200-2000 r / min, the pH is 8.0-10.0, the temperature is 10-50 DEG C, and the time is 1-20 min. In the pH control of the coordination reaction under the alkaline condition of 8.0-10.0, most of the metal ions with valence of two or more exist in the form of hydroxyl complex, the introduction of hydroxyl group helps to control the molecular structure of the assembled complex and overcome the hydration barrier of the hydroxamic acid action in advance, but too high pH will lead to the generation of hydroxide precipitate and hinder the adsorption on the mineral surface. The metal salt solution with valence of two or more is mainly provided by soluble metal salt, such as nitrate and chloride.

[0018] The nitrogen-containing aromatic heterocyclic organic compound is prepared by the following method:

[0019] 1) Preparation of free hydroxylamine: hydroxylamine hydrochloride is added with appropriate amount of sodium hydroxide to obtain free hydroxylamine, and sodium chloride solid generated in the reaction is removed by filtration to obtain hydroxylamine alkali solution;

[0020] 2) Hydroxamic acid reaction: the organic carboxylic acid ester compound is mixed with the hydroxylamine alkali solution in a certain proportion, the reaction condition is controlled to be alkaline, and the hydroxamic acid reaction is carried out at a suitable temperature to obtain the corresponding hydroxamic acid salt;

[0021] The organic carboxylic acid ester compound has the structure of formula 2:

[0022] Formula 2

[0023] Wherein, R 1 , R 2 , R 3 , R 4 or R 5 is a carboxylic acid ester group;

[0024] 3) Acidification reaction: concentrated sulfuric acid or concentrated hydrochloric acid is added to the oximation system to carry out acidification reaction, and the nitrogen-containing aromatic heterocyclic ligand compound containing hydroxamic acid group is obtained.

[0025] The application also provides an application of the metal ion-nitrogen-containing aromatic heterocyclic complex collector, which is used as a collector for the flotation separation of tungsten-containing minerals.

[0026] As a preferred scheme, the tungsten-containing minerals include at least one of wolframite, scheelite and tungstic acid. The tungsten-containing minerals can be mixed tungsten-containing minerals of various minerals, such as black and white mixed tungsten ore.

[0027] As a preferred scheme, the tungsten-containing mineral is subjected to grinding, iron removal and desulfurization pretreatment to obtain a desulfurized tailing slurry, the desulfurized tailing slurry is subjected to pulp conditioning, and then tungsten ore flotation is carried out by using flotation reagents including a metal ion-nitrogen-containing aromatic heterocyclic complex collector and a salted water glass inhibitor to obtain a tungsten concentrate.

[0028] As a preferred scheme, the concentration of the desulfurized tailing slurry is adjusted to 40-50 wt.%, and the pH is adjusted to 9.0-10.0. The pH adjustment is carried out by using sodium carbonate.

[0029] As a preferred scheme, the tungsten ore flotation includes one roughing, two or more cleanings and two or more scavengings; the reagent system of the roughing is that the dosage of the metal ion-nitrogen-containing aromatic heterocyclic complex collector is 300-600 g / t, and the dosage of the 2# oil frother is 30-50 g / t; the reagent system of the cleaning is that the dosage of the salted water glass inhibitor is 50-500 g / t, and the halving principle is followed; the salted water glass is composed of aluminum sulfate and water glass according to the mass ratio of aluminum sulfate to water glass being 1:(2-4); the reagent system of the scavenging is that the dosage 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 the nitrogen-containing aromatic heterocyclic complex contained in the metal ion-nitrogen-containing aromatic heterocyclic complex collector. Under the preferred reagent system, the flotation efficiency of the tungsten-containing mineral, especially wolframite, can be effectively enhanced, tungsten tailing loss can be reduced, and the grade and recovery rate of the final tungsten concentrate can be improved.

[0030] The nitrogen-containing aromatic heterocyclic compound involved in the present application can be regarded as a hydroxamic modification product of indole, and indole and its homologues and derivatives exist widely in nature, mainly in natural flower oils such as jasmine, bitter orange flower, narcissus and lavender. In addition, they also exist in coal tar and decomposed proteins. Industrially, indole can be prepared by various methods, for example, extraction from high-temperature coal tar, and refined indole can be obtained by alkaline washing, acid washing, rectification, hydrolysis and other steps of coal tar and wash oil fraction. At present, there are few reports on such compounds in the field of flotation reagent synthesis, and they have good application prospect.

[0031] The iron removal and desulfurization of the present application are the conventional tungsten ore pretreatment processes in the prior art.

[0032] The salted water glass of the present application is the conventional inhibitor for tungsten ore flotation in the prior art.

[0033] Compared with the prior art, the present application has the following beneficial technical effects:

[0034] (1) The metal ion-nitrogen-containing aromatic heterocycle complex collector provided by the application has excellent flotation performance, stronger collecting capacity, better selectivity and higher flotation rate than the existing Pb-BHA complex collector, the nitrogen-containing aromatic heterocycle organic ligand is a conjugated system containing 10 pi electrons, including a six-membered benzene ring and a five-membered nitrogen-containing pyrrole ring, the nitrogen atom provides a pair of lone pair electrons to form a stable conjugated system, and the whole presents a strong electron pushing effect, and the hydroxyl oxygen and oxime oxygen in the hydroxamic acid molecular structure have stronger chelating capacity.

[0035] (2) The metal ion-nitrogen-containing aromatic heterocycle complex collector provided by the application can be used in a lower amount to intensify the flotation recovery of tungsten-containing minerals under weak alkaline conditions, has better selectivity, helps to reduce the tailing of black tungsten, realizes efficient bulk flotation of black and white tungsten, and improves the grade and recovery rate of the final tungsten concentrate.

[0036] (3) The beneficiation method for recovering tungsten polymetallic ore by using the metal ion-nitrogen-containing aromatic heterocycle complex collector provided by the application is simple to operate, low in reagent cost, suitable for various single white tungsten, mixed tungsten ore and other tungsten polymetallic ores, and conducive to further popularization and use.

[0037] (4) The preparation method of the metal ion-nitrogen-containing aromatic heterocycle complex provided by the application has high yield, few impurities, easily available raw materials and low cost, and is conducive to large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is the nuclear magnetic resonance hydrogen spectrum of 1H-indole-7-hydroxamic acid of the application.

[0039] Figure 2 It is the infrared spectrum of the lead-based complex collector of Example 1.

[0040] Figure 3 It is the nuclear magnetic resonance hydrogen spectrum of 1H-indole-3-hydroxamic acid of the application.

[0041] Figure 4 It is the pure mineral flotation test result of Example 3 and Comparative Example 1.

[0042] Figure 5 It is the flotation process flowchart of Example 4. DETAILED DESCRIPTION

[0043] The following examples are further detailed descriptions of the content of the application, but not limit the scope of the claims of the application.

[0044] Example 1

[0045] Preparation of the lead-based complex collector:

[0046] In a flask, 50 ml of methanol was added as a solvent, 10.42 g of hydroxylamine hydrochloride with a purity of 98.5% (0.15 mol) was added to the flask under stirring, after the hydroxylamine hydrochloride was dissolved, 12 g of sodium hydroxide solid with a purity of 99% (0.3 mol) was added in batches (3 g, 3 g, 3 g, 3 g), after stirring for 1 h, the sodium chloride solid generated in the reaction was removed by filtration to obtain the free hydroxylamine base solution. The hydroxylamine base solution was transferred to a three-necked flask, 17.52 g of 1H-indole-7-carboxylic acid methyl ester with a purity of 97% (0.1 mol) was added, the pH of the reaction system was controlled at about 12.0, the circulation condensation reflux system was started, and stirring was carried out at 55°C for 4 h to obtain the hydroxamic acid modified product. After the hydroxamic acid reaction was completed, concentrated hydrochloric acid was added to the reaction system at room temperature while stirring, the pH of the reaction system was adjusted to less than 5.0, a weak acid was prepared using a strong acid, after the addition was completed, the filter residue generated was removed by filtration, and the filtrate was distilled under reduced pressure to obtain a purple red solid, which was the crude 1H-indole-7-hydroxamic acid product, and its nuclear magnetic resonance 1H NMR is shown in Figure 1 .

[0047] 0.125 mol of lead nitrate was added to a 1L 1H-indole-7-hydroxamic acid solution with a concentration of 1.0 mol / L, the stirring speed was controlled at 1000 r / min, the pH was adjusted to 9.0 with sodium hydroxide, and the reaction was carried out at room temperature for 3 min to obtain the lead-based complex collector, and its infrared spectrum is shown in Figure 2 .

[0048] Example 2

[0049] Preparation of iron-based complex collector:

[0050] In a flask, 30 ml of methanol was added as a solvent, 1.042 g of hydroxylamine hydrochloride with a purity of 98.5% (0.015 mol) was added to the flask under stirring, after the hydroxylamine hydrochloride was dissolved, 1.2 g of sodium hydroxide solid with a purity of 99% (0.03 mol) was added in batches (0.3 g, 0.3 g, 0.3 g, 0.3 g), after stirring for 1 h, the sodium chloride solid generated in the reaction was removed by filtration to obtain the free hydroxylamine base solution. The hydroxylamine base solution was transferred to a three-necked flask, 1.7518 g of 1H-indole-3-carboxylic acid methyl ester with a purity of 98% (0.01 mol) was added, the reaction conditions were controlled to be alkaline, the circulation condensation reflux system was opened, and stirring was performed at 50°C for 3 h to obtain the hydroxamic acid modified compound. After the reaction was completed, at room temperature, concentrated sulfuric acid was added dropwise to the reaction system while stirring, the pH of the reaction system was adjusted to 4.0-5.0, a weak acid was prepared using a strong acid, after the dropwise addition was completed, the filtrate was distilled under reduced pressure to obtain a gray-white solid, which was 1H-indole-3-hydroxamic acid crude product, which could be further purified by recrystallization with ethanol and water, and the specific nuclear magnetic resonance 1H NMR was as shown in Figure 3

[0051] Other compounds of the same type can be synthesized and prepared by this method.

[0052] Under stirring, 0.15 mol of iron 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 be 1200 r / min, sodium hydroxide was used to adjust the pH to 9.0, and the reaction was performed at room temperature for 3 min to obtain the iron-based complex collector.

[0053] The metal ion-nitrogen-containing aromatic heterocyclic complex collectors used in the following specific examples were prepared by this method.

[0054] Example 3

[0055] Black and white tungsten flotation rate of the new lead-based complex collector:

[0056] The dosage of the new lead-based complex collector described in Example 1 was 5.0×10 -5 mol / L, sodium hydroxide was used to adjust the pH of the flotation slurry to 9, the dosage of the frother methyl isobutyl carbinol (MIBC) was 12.5 μL / L, the N2 flow rate was 300 mL / min, the flotation operation was performed on the white tungsten ore with a particle size of -0.074~+0.038 mm and the black tungsten ore with a particle size of -0.038 mm, the scraper was used to manually scrape the foam in batches at a frequency of every 5 s, and the foam was collected every 15 s.

[0057] Comparative Example 1

[0058] Black and white tungsten flotation rate of the Pb-BHA complex:​

[0059] The dosage of the conventional Pb-BHA complex collector is 5.0 x 10 -5 The pH of the flotation slurry is adjusted to 9 by sodium hydroxide, the dosage of the foaming agent methyl isobutyl carbinol (MIBC) is 12.5 μL / L, the N2 flow rate is 300 mL / min, the flotation operation is performed on the scheelite with a particle size of-0.074+0.038 mm and the wolframite with a particle size of-0.038 mm, the froth is manually scraped in batches at a frequency of every 5 s, and the froth is collected every 15 s.

[0060] From Figure 3 It can be seen that, under the Pb-BHA system, the floatability of the scheelite is better, the flotation rate is faster, the cumulative recovery rate of the scheelite in the first 90 s is increased more, and then tends to be stable, and the final recovery rate reaches about 45%. Under the same conditions, the flotation efficiency of the 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 in the scheelite and wolframite mixed flotation process. The new Pb-NHIC complex collector has stronger collecting capacity and faster flotation rate for the wolframite and the scheelite, the cumulative recovery rates of the two tend to be balanced at about 60 s, and the final recovery rates of the two both reach more than 90%, which also shows that the new metal ion-nitrogen-containing aromatic heterocyclic complex collector has better flotation performance.

[0061] Example 4

[0062] Mixed flotation of the new lead-based complex collector for the wolframite and the scheelite:

[0063] A certain tungsten polymetallic ore in Hunan is treated by the process method of the present application, and the specific process flow is shown in Figure 4The ore has a WO3 grade of 0.36%, with the ratio of black to white tungsten being 3:7, and the gangue mainly being garnet, calcite and fluorite. After crushing and grinding, the quality content of the -200 mesh fraction is more than 75%, and then a drum wet magnetic separator is used to remove iron at a magnetic field strength of 0.4 T. The iron removal tailings are subjected to desulfurization flotation using 160 g / t copper sulfate as an activator, 60 g / t butyl xanthate and 40 g / t ethyl thiourea as collectors, and 30 g / t 2# oil as a frother. The desulfurization tailings are first adjusted to a pH of 9.0 using sodium carbonate, and then the lead-based complex collector described in Example 1 is added at a dosage of 450 g / t, and 2# oil is used as a frother at a dosage of 40 g / t. After stirring for 5 min, the pH is stabilized at about 8.3, and mixed tungsten flotation roughing is performed. Scavenging is performed by adding 2# oil at dosages of 20 g / t and 10 g / t, respectively, and salted water glass Al-SBL is used as an inhibitor (mass ratio of aluminum sulfate to water glass being 1:2) at a total dosage of 150 g / t in cleaning. After four times of cleaning, a tungsten concentrate containing WO3 31.51% is obtained, with a recovery rate of 78.22%.

[0064]

[0065] Comparative Example 2

[0066] Mixed tungsten flotation using the Pb-BHA complex collector:

[0067] Under stirring conditions, 0.125 mol of lead nitrate is added to a 1.0 mol / L solution of benzohydroxamic acid in 1 L, and the reaction is carried out at room temperature for 3 min to obtain the Pb-BHA complex collector.

[0068] The flotation of scheelite with the new type of metal ion-nitrogen-containing aromatic heterocyclic complex collector is as follows: the desulfurization tailings are first adjusted to a pH of 9.5 by adding sodium carbonate, 600 g / t of the Pb-BHA complex collector, and 40 g / t of the foaming agent 2# oil, and then stirred for 5 min to stabilize the pH at about 8.5, and then the rough flotation of mixed black and white tungsten is performed. In the scavenging operation, 2# oil is added in an amount of 20 g / t and 10 g / t, respectively, and in the cleaning operation, the saltified water glass Al-SBL is added as the depressor (the mass ratio of aluminum sulfate to water glass is 1:2), and the total amount of the saltified water glass Al-SBL used in the cleaning operation is 150 g / t. After four times of cleaning, a tungsten concentrate containing 30.05% of WO3 is obtained, and the recovery rate is 72.28%. It can be seen from the flotation test results that the new type of metal ion-nitrogen-containing aromatic heterocyclic complex collector can achieve higher flotation efficiency at a lower dosage, the grade of the tungsten concentrate is increased from 30.05% to 31.51%, the recovery rate is increased from 72.28 to 78.22%, and the new type of metal ion-nitrogen-containing aromatic heterocyclic complex collector has a good application prospect.

[0069]

[0070] Example 5

[0071] Flotation of scheelite with the new type of iron-based complex collector

[0072] The process method of the application is used to treat a tungsten polymetallic ore in Hunan. The ore is single scheelite, and the content of wolframite is very low. The tungsten grade of the raw ore is about 0.18%, and the content of fluorite is high. The main gangue minerals are mainly calcite, garnet and quartz. The particle size of the scheelite is uniform, and the main particle size range is 0.04-0.32 mm, which belongs to the fine-micro fine uniform embedded type. After the raw ore is crushed and ground, the mass content of the-200 mesh particle size is 75%. Then, the weak magnetic iron removal is performed on the non-magnetic product thickened by a thickener under the condition of a magnetic field intensity of 0.3 T, and then the desulfurization flotation is performed by adding 200 g / t of copper sulfate as an activator, 150 g / t of xanthate and 10 g / t of kerosene as a collector, and 40 g / t of 2# oil as a foaming agent. The desulfurization tailings are adjusted to a pH of 9.5 by adding sodium carbonate, and 600 g / t of the iron-based complex collector described in Example 2 and 40 g / t of the foaming agent 2# oil are added, and then stirred for 5 min to stabilize the pH at about 7.8, and then the tungsten roughing operation is performed. In the scavenging operation, 2# oil is added in an amount of 20 g / t, and in the cleaning operation, the total amount of the saltified water glass Al-SBL (1:2) added is 400 g / t. After four times of cleaning, a tungsten concentrate containing 45.33% of WO3 is obtained, and the recovery rate is 70.51%.

[0073]

[0074] Comparative Example 3

[0075] Flotation of scheelite with Fe-BHA complex collector:

[0076] Under stirring condition, 0.15 mol of ferric chloride was added into 1 L of benzohydroxamic acid solution with concentration of 1.0 mol / L, and the reaction was carried out for 3 min to obtain Fe-BHA complex collector. Comparative Example 3 was used for comparison with Example 5. In Comparative Example 3, the crushing, grinding, iron removal, desulfurization and other processes were consistent with those in Example 5. The desulfurization tailings were adjusted to a pH of 9.0 by sodium carbonate, and then 800 g / t of Fe-BHA complex collector and 40 g / t of frother 2# oil were added. After the pH was stabilized at about 7.5 by stirring for 5 min, the tungsten roughing operation was carried out. The scavenging was supplemented with 200 g / t of Fe-BHA collector and 10 g / t of 2# oil. The total amount of salted water glass Al-SBL (1:2) added in the cleaning was 400 g / t. After four times of cleaning, tungsten concentrate with a grade of 42.89% and a recovery rate of 67.69% was obtained. As can be seen from the flotation test results, the new metal-based complex collector can also realize the flotation recovery of single scheelite, and has lower dosage, higher concentrate grade and recovery rate. Under the condition of reducing the dosage by one fourth, the concentrate grade is increased by about 2.5%, and the recovery rate is increased by about 3%.

[0077]

Claims

1. A metal ion-nitrogen-containing aromatic heterocycle complexing collector characterized by: The metal ion is coordinated with a nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to form a complex: The nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group has a structure of formula 1: ； R1, R2, R3, R4, or R5 is a hydroxamic acid group. The divalent or more metal ion includes at least one of Pb 2+ , Ca 2+ , Mg 2+ , Cu 2+ , Mn 2+ , Fe 2+ , Al 3+ , or Fe 3+ ​ The coordination molar ratio of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group to the metal ion is (1-16):(1-4).

2. A process for the preparation of a metal ion-nitrogen containing aromatic heterocycle complex collector as claimed in claim 1, characterized in that: The solution of the nitrogen-containing aromatic heterocyclic ligand compound containing a hydroxamic acid group is stirred with the solution of the metal salt under alkaline conditions to obtain the complex.

3. The method for preparing a metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 2, characterized in that: The stirring rate is 200-2000 r / min, the pH is 8.0-10.0, the temperature is 10-50°C, and the time is 1-20 min.

4. Use of a metal ion-nitrogen-containing aromatic heterocycle complex collector according to claim 1, characterized in that: The complex is used as a collector for flotation separation of tungsten-containing minerals.

5. Use of a metal ion-nitrogen-containing aromatic heterocycle complex collector according to claim 4, characterized in that: The tungsten-containing minerals include at least one of wolframite, scheelite, and tungstic acid.

6. Use of a metal ion-nitrogen-containing aromatic heterocycle complex collector according to claim 4 or 5, characterized in that: The tungsten-containing minerals are pretreated by grinding, iron removal, and desulfurization to obtain a desulfurized tailing slurry, which is adjusted by pulp conditioning and then subjected to tungsten ore flotation using flotation reagents including a metal ion-nitrogen-containing aromatic heterocyclic complex collector and a salted water glass depressant to obtain a tungsten concentrate.

7. Use of a metal ion-nitrogen-containing aromatic heterocycle complex collector according to claim 6, characterized in that: The concentration of the desulfurized tailing slurry is adjusted to 40-50 wt.%, and the pH is adjusted to 9.0-10.

0.

8. The application of the metal ion-nitrogen-containing aromatic heterocyclic complex collector according to claim 6, characterized in that: The tungsten ore flotation includes one roughing, two or more cleanings, and two or more scavengings; The reagent system for the roughing includes 300-600 g / t of the metal ion-nitrogen-containing aromatic heterocyclic complex collector and 30-50 g / t of 2# oil frother; The reagent system for the cleaning includes 50-500 g / t of the salted water glass depressant, and the amount of the salted water glass depressant is halved in each cleaning; The salted water glass is composed of aluminum sulfate and water glass in a mass ratio of 1:(2-4); The reagent system for the scavenging includes 0-20 g / t of 2# oil frother; The mass of the metal ion-nitrogen-containing aromatic heterocyclic complex collector is measured based on the mass of the nitrogen-containing aromatic heterocyclic complex contained therein.

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