A pb-bha-sdbs collector and a tungsten-tin separation method for tungsten-tin polymetallic ore

Abstract

The application discloses a Pb-BHA-SDBS collector and a tungsten-tin separation method for a tungsten-tin polymetallic ore. The Pb-BHA-SDBS collector is formed by the coordination of benzohydroxamic acid, sodium dodecyl benzene sulfonate and lead ions, has high selectivity and high strong collecting capacity for tungsten-tin minerals in a complex tungsten-tin polymetallic ore system, and can realize the co-enrichment of wolframite, scheelite and cassiterite. Based on this, the tungsten minerals and cassiterite in the tungsten-tin polymetallic ore are preliminarily co-enriched by using the Pb-BHA-SDBS flotation reagent system, the mixed concentrate is treated by removing the reagent, the tetradecyl imino dimethyl phosphonic acid flotation reagent system is used, the separation of the cassiterite and the tungsten minerals is easily realized, the cassiterite enters the concentrate to become tin concentrate, and the tungsten minerals enter the tailings to become tungsten concentrate, so that the efficient separation and recovery of the tungsten minerals and the cassiterite in the tungsten-tin polymetallic ore are realized, and the tungsten and tin resources are synergistically extracted.

Description

TECHNICAL FIELD

[0001] The present application relates to a metal complex collector, in particular to a Pb-BHA-SDBS collector formed by co-coordination of benzohydroxamic acid and sodium dodecyl benzene sulfonate with lead ions, and relates to a tungsten-tin separation method for tungsten-tin polymetallic ore, belonging to the technical field of ore dressing. BACKGROUND

[0002] Tungsten is a valuable rare metal, widely used in civil, industrial, military and other fields. Tungsten mainly exists in nature in the form of wolframite ((Fe, Mn)WO4) and scheelite (CaWO4). For a long time, the mineral resources developed by China's tungsten industry are mainly wolframite. The published wolframite reserves in China, as of the end of 2000, were 1,440,500 tons of tungsten trioxide (WO3), accounting for 27.4% of the total tungsten reserves in China. At present, the reserves of single wolframite in China have been basically exhausted or are very small. In the face of the disappearance of China's wolframite resource advantage, it is particularly important to increase the development of single scheelite resources or mixed tungsten-tin polymetallic resources. On the other hand, China is rich in tin resources, but tin ore is characterized by poor, fine and complex composition, which makes it difficult to enrich and recover. Only 12% of China's tin ore exists as a single mineral, and most of it is polymetallic associated resources, among which tungsten associated with cassiterite (SnO2) resources is an important part.

[0003] PCT / CN2018 / 102839 (Hydroximic acid-metal hydroxide coordination complex, and preparation and application thereof) discloses a Pb-BHA complex method for mixed flotation of black and white tungsten at room temperature, which uses a single collector to realize the mixed flotation of black and white tungsten, and has been applied in large tungsten mines such as Shizhuyuan, Huangshaping and Xingluokeng. However, in tungsten-tin polymetallic mines, Pb-BHA is used as the only collector to separate wolframite, scheelite and cassiterite into the same final concentrate product. Due to the difference in floatability of different tungsten-tin minerals in the Pb-BHA system, the difficult-to-float tungsten-tin minerals will fall off in the flotation process (especially cassiterite), resulting in a loss of recovery rate. For example, in Shizhuyuan and Huangshaping, the annual recovery rate of tin is less than 10%, and the grade of tin in the concentrate is unstable, which cannot be priced as a stable product, resulting in a serious waste of tin resources.

[0004] In summary, with the increasing complexity of the mineral composition of the current treated ore, the complex association of wolframite, scheelite and cassiterite, the traditional flotation reagent system and flotation process cannot meet the comprehensive recovery of multiple products, and new reagents and new processes are urgently needed to greatly improve the recovery rate of tungsten-tin polymetallic mines. SUMMARY

[0005] In view of the defects in the prior art, a first object of the present application is to provide a Pb-BHA-SDBS collector, which has high selectivity and strong collecting ability for tungsten-tin minerals in a complex tungsten-tin polymetallic ore system, and can realize co-enrichment of wolframite, scheelite and cassiterite.

[0006] A second object of the present application is to provide a tungsten-tin separation method for a tungsten-tin polymetallic ore, which is based on the research of the inventors that tungsten minerals and cassiterite exhibit similar flotation behaviors under the Pb-BHA-SDBS flotation reagent system, and thus the idea of preliminary co-enrichment of tungsten minerals and cassiterite is proposed. After the mixed concentrate is treated by removing the reagent, the separation of cassiterite and tungsten minerals is easily realized by using a tetradecyl imino dimethyl phosphonic acid flotation reagent system, and the cassiterite enters the concentrate as a tin concentrate, while the tungsten minerals enter the tailings as a tungsten concentrate, thereby realizing efficient separation and recovery of tungsten minerals and cassiterite in a tungsten-tin polymetallic ore, and truly realizing the synergistic extraction of tungsten and tin resources.

[0007] In order to achieve the above technical purposes, the present application provides a Pb-BHA-SDBS collector, which is formed by the coordination of benzohydroxamic acid and sodium dodecyl benzene sulfonate with lead ions.

[0008] The Pb-BHA-SDBS collector of the present application contains two ligands, BHA and SDBS, which are simultaneously combined with lead ions through coordination, thereby forming a metal ion multi-ligand collector. It is accidentally found through research that under weak alkaline conditions, the Pb-BHA-SDBS collector can selectively collect tungsten-tin minerals with strong collecting ability and high selectivity, and can realize co-enrichment of wolframite, scheelite and cassiterite.

[0009] The BHA ligand in the Pb-BHA-SDBS collector contains hydroxamic acid chelating groups, which can selectively act on the surfaces of tungsten minerals and cassiterite, and the alkyl group in the SDBS ligand has a long carbon chain and strong hydrophobicity, which can strengthen the floating of the refractory tungsten-tin minerals (scheelite, wolframite and cassiterite), and the structure of the SDBS ligand has a benzene ring, which is of the same nature and is more likely to form larger colloids, and after the BHA and SDBS ligands are combined by lead ions, a tungsten-tin mineral collector with high selectivity and strong collecting capacity is formed. The metal ion in the complex structure of the Pb-BHA-SDBS multi-ligand collector is also a polar group, which has better selectivity than the traditional anionic collector; compared with the traditional Pb-BHA single ligand collector, the Pb-BHA-SDBS has a longer carbon chain, which can provide stronger hydrophobicity to the mineral surface after selective adsorption on the mineral surface, and the Pb-BHA-SDBS multi-ligand collector has a larger particle size, which can significantly improve the roughness of the mineral surface and form a surface "micro-nano structure" on the surface of the valuable mineral, further improving the hydrophobicity of the mineral surface, so as to realize the mixed flotation of the easy-to-float and the refractory tungsten-tin minerals.

[0010] As a preferred scheme, the molar ratio of benzohydroxamic acid and sodium dodecyl benzene sulfonate is 5:1-3:1; the total amount of benzohydroxamic acid and sodium dodecyl benzene sulfonate and the molar ratio of lead ions are 1:1-1:2. The lead ion has a good "template effect", which can regulate the molecular structure of BHA and SDBS coordinated with it, but excessive lead ions can easily cause non-selective activation of other gangue minerals; as for the organic ligand, BHA has better selectivity and SDBS has stronger collecting capacity, and when the proportion of SDBS is too high, lead dodecyl benzene sulfonate will be directly generated, which will affect the reaction activity of the reagent, and the cooperation of SDBS and BHA can selectively strengthen the collection of tungsten-tin minerals.

[0011] The application also provides a tungsten-tin separation method for tungsten-tin polymetallic ore, which comprises the following steps: crushing, grinding, iron removal and desulfurization of the tungsten-tin polymetallic ore in sequence to obtain a desulfurized tailing slurry; adjusting the pH of the desulfurized tailing slurry to alkaline, and then using the Pb-BHA-SDBS as a collector, a metal organic macromolecular complex and a salted water glass as inhibitors to perform tungsten-tin mixed flotation and obtain a tungsten-tin mixed concentrate; after the desulfurized tailing slurry is treated, the pH is adjusted to be acidic, and then using tetradecyl imino dimethyl phosphonic acid as a collector and an organic acid as an inhibitor to perform cassiterite flotation and obtain a tin concentrate and a tungsten-rich tailing.

[0012] The technical scheme of the present application is based on the characteristics of the tungsten-tin polymetallic ore, such as the mineral composition and the occurrence state (the main metal minerals are scheelite, wolframite and cassiterite, the gangue minerals are mainly silicate minerals (mainly including garnet, chlorite, quartz and mica), and then are fluorite and calcite), the key of the present application is to use Pb-BHA-SDBS as the co-collector of tungsten minerals and cassiterite, and to use the metal organic macromolecular complex and the salted water glass to inhibit the floating of argillaceous gangue (fine particle grade) and other gangue minerals, so that the tungsten minerals and cassiterite can be simultaneously and efficiently enriched under the weak alkaline condition, and then the mixed concentrate is recovered, and after the mixed concentrate is treated by removing the reagent, tetradecyl imino dimethyl phosphonic acid is used as the collector, the organic acid inhibits the floating of scheelite and wolframite, and the selectivity of the tin ore is good under the weak acid condition, and the tungsten ore has almost no collecting effect, so that the tungsten ore enters the tailings, and the tin ore is recovered in the form of tin concentrate, and finally the comprehensive recovery of tungsten and tin is realized.

[0013] As a preferred scheme, the concentration of the desulfurization tailing slurry is controlled to be 40-50wt%, and the pH is adjusted to be 9.5-10.0. Adjusting the pH to 9.5-10.0 is beneficial to the participation of part of the hydroxyl ions in coordination, and is beneficial to improving the collecting ability and selectivity of the Pb-BHA-SDBS collector. Sodium carbonate can be used as the pH adjusting agent for adjusting the pH.

[0014] As a preferred scheme, the tungsten-tin mixed flotation includes one roughing, two or more than two cleaning and two or more than two scavenging. As a more preferred scheme, the reagent system of the roughing is that the dosage of Pb-BHA-SDBS is 300-800g / t, and the dosage of the metal organic macromolecular complex is 50-150g / t; the metal organic macromolecular complex is a complex formed by the divalent or higher metal ion and the organic macromolecule; the organic macromolecule includes at least one of starch, dextrin, polyacrylamide and guar gum; the divalent or higher metal ion includes Mn 2+ , Mg 2+ , Ca 2+ , Fe 3+ , Al 3+ , Pb 2+The mass ratio of the divalent or more metal ion and the macromolecule is 1:5-4:1. Meanwhile, the 2# oil is used as a foaming agent, and the amount of the 2# oil is 30-50 g / t. The amount of the Pb-BHA-SDBS is measured according to the mass of the BHA. As a more preferred scheme, the selected reagent system is that the salted water glass is 50-100 g / t, the salted water glass is formed by mixing aluminum sulfate and water glass, and the mass ratio of the aluminum sulfate and the water glass is 1:1-1:4. According to the surface state density analysis of the scheelite (CaWO4), the wolframite ((Fe, Mn)WO4) and the cassiterite (SnO2), the Pb-BHA-SDBS collector has a metal base as a polar base, can interact with the active oxygen atoms (O 2p orbital) on the surfaces of the scheelite, the wolframite and the cassiterite, and thus realizes the synchronous collection of the scheelite, the wolframite and the cassiterite. As a more preferred scheme, the sweeping selection is blank sweeping selection. In view of the problems that the clay minerals adsorb reagents in the flotation system and deteriorate the flotation, the fine particle level clay minerals are difficult to be inhibited in the subsequent concentration process once they are hydrophobic, and thus it is necessary to control the floating of the fine particle level clay minerals in the rough selection, the metal organic macromolecular complex is used as an inhibitor to control the floating of the argillaceous gangue (fine particle level) in the rough selection, the metal ion in the metal organic macromolecular complex can be combined with the macromolecule rich in hydroxyl groups, so that the -CH2-OH hydroxyl groups on the polymer chain of the macromolecule are converted into -CH2-O-Me, thereby greatly improving the selectivity of the organic macromolecule, the organic macromolecule is selectively adsorbed on the surface of the argillaceous mineral, and at the same time, the argillaceous mineral is made to form a hydrophilic cluster through the flocculation of the macromolecule, so as to reduce the floating of the argillaceous mineral in the rough selection. The starch, dextrin and the like contain ether oxygen bonds, so that the metal organic macromolecular complex has better dispersibility and inhibition capacity, and is not easy to hydrolyze and fail in an alkaline environment.

[0015] As a preferred scheme, the process of the reagent removal treatment is that the pH is adjusted to be greater than 11.0, stirring reaction is performed for more than 15 min, and then reagent removal is performed through concentration. The reagent removal treatment mainly adopts the mode of adding caustic soda, and the OH - competes with the combination of the benzhydroxamic acid and the metal ion, so that the adsorption structure of the metal ion-hydroxamic acid complex on the mineral surface is destroyed, and thus the reagent removal is realized. The metal ion in the supernatant after the concentration of the tungsten-tin mixed concentrate slurry after the reagent removal treatment exists in the form of a metal hydroxyl complex (such as Pb(OH)3 - ), and the benzhydroxamic acid and the sodium dodecyl benzene sulfonate exist in the form of molecules. Further preferably, the supernatant obtained after the concentration is returned to the original tungsten-tin mixed flotation process, and the reagent consumption of the original process can be greatly reduced. The mass percentage concentration of the tungsten-titanium mixed concentrate slurry after the reagent removal treatment is about 40-45%.

[0016] As a preferred scheme, the cassiterite flotation includes 1 roughing, 2-3 cleaning and 2-3 scavenging. As a more preferred scheme, the reagent system of the roughing is that the organic acid is 100-300 g / t, and the dosage of tetradecyl imino dimethyl phosphonic acid is 200-300 g / t; the organic acid includes at least one of citric acid, cinnamic acid, tannic acid and oxalic acid. As a more preferred scheme, the pH of the slurry system of the roughing is adjusted to 3.5-6.5. As a more preferred scheme, the cleaning is blank cleaning without adding any reagent. As a preferred scheme, the reagent system of the scavenging is that the dosage of tetradecyl imino dimethyl phosphonic acid is 20-60 g / t. The use of alkyl imino dimethyl phosphonic acid in the tungsten-tin separation process can selectively collect cassiterite under acidic conditions, and the organic acid such as citric acid, cinnamic acid, tannic acid and oxalic acid is used to inhibit scheelite and wolframite, so that the tin concentrate is obtained by reverse flotation, the tailings are tungsten concentrate, and finally the tungsten and tin products are obtained, realizing efficient utilization of tungsten-tin polymetallic resources.

[0017] The iron removal and sulfur removal of the present application is a conventional tungsten ore pretreatment process in the prior art.

[0018] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0019] The technical scheme of the present application realizes preliminary co-enrichment of tungsten minerals and cassiterite in the tungsten-tin polymetallic ore by using the Pb-BHA-SDBS flotation reagent system, and then the tungsten minerals and cassiterite are efficiently separated and recovered as concentrates by using the tetradecyl imino dimethyl phosphonic acid collector flotation reagent system after the removal of the reagent, and the supernatant returned after the removal and concentration of the reagent can greatly reduce the dosage of the reagent in the tungsten-tin mixed flotation section. Compared with the current technology, not only the influence of a large amount of tin entering the tungsten concentrate on the grade of the tungsten concentrate is avoided, but also the tin concentrate product is separated on the basis of the existing technology, realizing comprehensive resource recovery of the tungsten-tin polymetallic ore.

[0020] The technical scheme of the present application has the advantages of simple operation, low reagent cost and adaptability to various tungsten-tin polymetallic ores, and is conducive to large-scale popularization and use.

[0021] The Pb-BHA-SDBS collector provided by the present application can selectively collect tungsten-tin minerals with strong collecting ability under weak alkaline conditions, and can realize co-enrichment of wolframite, scheelite and cassiterite. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The infrared spectra of SDBS, Pb-BHA and Pb-BHA-SDBS.

[0023] Figure 2AFM of scheelite surface after adsorption of Pb-BHA and Pb-BHA-SDBS; (a) is the AFM 2D height map of scheelite surface after adsorption of Pb-BHA; (b) is the AFM 3D height map of scheelite surface after adsorption of Pb-BHA; (c) is the AFM 2D height map of scheelite surface after adsorption of Pb-BHA-SDBS; (d) is the AFM 3D height map of scheelite surface after adsorption of Pb-BHA-SDBS.

[0024] Figure 3 Flow chart of the flotation test of Example 1.

[0025] Figure 4 Flow chart of the flotation test of Comparative Example 1.

[0026] Figure 5 Actual figure of the tungsten-tin mixed concentrate of Comparative Example 2. DETAILED DESCRIPTION

[0027] The following examples are further illustrations of the content of the present application and are not intended to limit the scope of the claims.

[0028] Example 1

[0029] In the following specific examples, the Al-starch colloidal depressant is prepared as follows:

[0030] A 20 mg / L soluble starch solution and a 40 mg / L aluminum ion solution (added in the form of aluminum sulfate) are prepared. 20 mL of the soluble starch solution is placed in a constant-temperature magnetic stirring water bath, and stirred at a constant speed at 90°C. 20 mL of the aluminum ion solution is slowly added to the soluble starch solution, and the pH of the solution is adjusted to 10.5 using a sodium hydroxide solution. The solution is reacted at 90°C for 30 min, and the Al-starch colloidal depressant is obtained after cooling.

[0031] In the following specific examples, the Pb-BHA-SDBS collector is prepared as follows:

[0032] Under stirring, 0.25 mol of sodium dodecyl benzene sulfonate is added to 1 L of a 1.0 mol / L benzohydroxamic acid solution, and 1.5 mol of lead nitrate is added after mixing. The reaction is carried out for 3 min to obtain the metal ion multi-ligand collector Pb-BHA-SDBS.

[0033] A certain associated tungsten-tin polymetallic ore in Hunan Province was treated by the process. The tungsten and tin grades of the ore were 0.37% and 0.12% respectively, the ratio of black tungsten to white tungsten was 3:7, and tin was mostly present in the form of cassiterite, with gangue mainly being garnet, calcium fluoride and calcium carbonate. After crushing and grinding, the mass percentage of the -200 mesh fraction was 72%, then a drum wet magnetic separator (magnetic field strength 0.4T) was used for weak magnetic separation to remove iron, and the tailings after the weak magnetic separation were subjected to desulfurization flotation using 200g / t copper sulfate as an activator, 80g / t butyl xanthate and 40g / t ethyl thiourea as collectors, and 30g / t 2# oil as a frother. The desulfurization tailings were first adjusted to pH 9.5 using sodium carbonate, then 60g / t Al-starch colloid inhibitor was added, followed by 380g / t Pb-BHA-SDBS and 30g / t 2# oil as a frother, and after 5 minutes of stirring with aeration, the pH was adjusted to 8.5, and the tungsten-tin mixed roughing and two blank scavenging operations were carried out. The Al-SBL salted water glass was used as an inhibitor (mass ratio of aluminum sulfate to water glass 1:2) in the total amount of 100g / t in the cleaning operation, and after two cleaning operations, a tungsten-tin mixed concentrate with WO3 content of 24.84% and Sn grade of 4.00% was obtained. After adding 330g / t NaOH to the mixed concentrate to adjust the pH to 11.6 and stirring for 20 minutes, the slurry was concentrated to a concentration of 42% and then subjected to tungsten-tin separation.

[0034] The tungsten-tin separation operation first added 500g / t sulfuric acid to the slurry of the mixed concentrate, stirred and adjusted the pH to 5.5, and then used 180g / t citric acid and 30g / t oxalic acid as mixed inhibitors for black and white tungsten ore, and 250g / t tetradecyl imino dimethyl phosphonic acid as a collector for cassiterite roughing, and the roughing was carried out at pH 4.0 to obtain a roughing froth product. Scavenging one and two were carried out by adding 30g / t and 20g / t of tetradecyl imino dimethyl phosphonic acid respectively, and the froth products obtained by scavenging and the roughing froth product were combined as a tin concentrate, and the tailings after scavenging were a tungsten concentrate.

[0035] As can be seen from Table 1, the tungsten-tin polymetallic ore in Hunan Province was treated by the process, and a tungsten concentrate with WO3 content of 30.64% was obtained, with a recovery rate of 80.09%, and a tin concentrate with Sn grade of 18.40% was obtained, with a recovery rate of 37.69%, and the recovery rates of tungsten and tin were both high (significantly better than the control example 1), and two products that could be priced were obtained through tungsten-tin separation operation, and the comprehensive utilization of tungsten and tin resources was truly realized.

[0036] Table 1 Test results of Example 1

[0037]

[0038] Example 2

[0039] The preparation of the Al-CMC colloid inhibitor in the following specific examples is as follows:

[0040] A solution of 40 mg / L carboxymethyl cellulose sodium (CMC) and 40 mg / L aluminum sulfate was configured. 20 mL of the CMC solution was placed in a constant-temperature magnetic stirring water bath and stirred at a constant temperature of 90°C. 20 mL of the aluminum sulfate solution was slowly added to the soluble starch solution, and the pH of the solution was adjusted to 10.5 using a sodium hydroxide solution. The solution was reacted at 90°C for 30 min, and the Al-CMC inhibitor was obtained after cooling.

[0041] The preparation method of the Pb-BHA-SDBS collector in the following specific examples is as follows:

[0042] Under stirring, 0.25 mol of sodium dodecyl benzene sulfonate was added to 1 L of a 1.0 mol / L benzohydroxamic acid solution, and 1.5 mol of lead nitrate was added after mixing. The solution was reacted for 3 min to obtain the metal ion multi-ligand collector Pb-BHA-SDBS solution.

[0043] A certain associated tungsten-tin polymetallic ore in Jiangxi was treated by the process. The tungsten-tin grade of the ore was 0.38% and 0.17%, respectively, and the ratio of black and white tungsten was 1:6. Tin was mostly present in the form of cassiterite, and the gangue was mainly garnet, chlorite, calcium fluoride, and calcium carbonate.

[0044] After crushing and grinding, the particle size met the requirement of a mass percentage of 74% in the -200 mesh size fraction. Subsequently, a drum-type wet magnetic separator (magnetic field strength 0.6 T) was used for weak magnetic iron removal. The tailings after weak magnetic iron removal were subjected to desulfurization flotation using 200 g / t copper sulfate as an activator, 80 g / t butyl xanthate and 40 g / t ethylthiuram disulfide as collectors, and 30 g / t 2# oil as a frother. The desulfurization tailings were first adjusted to a pH of 9.6 by adding sodium carbonate, and then 50 g / t of the Al-CMC colloid inhibitor was added. Subsequently, 400 g / t of Pb-BHA-SDBS was added, and 20 g / t of 2# oil was used as a frother. After stirring for 5 min at a pH of 8.6, the slurry was aerated and mixed, and tungsten-tin mixed roughing and two times of blank scavenging were performed. The total amount of the salted water glass Al-SBL used as an inhibitor (mass ratio of aluminum sulfate to water glass 1:2) was 120 g / t. After three times of cleaning, a tungsten-tin mixed concentrate with a WO3 grade of 25.23% and a Sn grade of 5.21% was obtained. After adding 360 g / t of NaOH to the mixed concentrate to reach a pH of 11.2 and stirring for 20 min, the concentrated slurry was subjected to tungsten-tin separation.

[0045] The tungsten-tin separation operation first adds sulfuric acid 510 g / t to the mixed concentrate slurry, stirs and conditions the slurry, adjusts the pH to 5.2, adds 180 g / t of phytic acid and 30 g / t of oxalic acid as mixed depressants for black and white tungsten ore, adds 225 g / t of tetradecyl imino dimethyl phosphonic acid as a collector for roughing of tin ore, and carries out flotation at pH = 4.1 to obtain a roughing froth product; 30 g / t and 15 g / t of tetradecyl imino dimethyl phosphonic acid are added respectively in the first and second scavenging, and flotation is carried out, and the froth products obtained by scavenging are combined with the roughing froth product as tin concentrate, and the tailings after scavenging are tungsten concentrate.

[0046] As can be seen from Table 2, the method is used to treat a certain associated tungsten-tin polymetallic ore in Jiangxi, and finally a tungsten concentrate containing WO3 32.45% is obtained, with a recovery rate of 81.73%, and a tin concentrate with a Sn grade of 19.44% and a recovery rate of 34.58%, the recovery rates of tungsten and tin are both high, and two products that can be priced are obtained through tungsten-tin separation operation, and the comprehensive utilization of tungsten and tin resources is truly realized.

[0047] Table 2 Test results of Example 2

[0048]

[0049] Comparative Example 1

[0050] Comparative Example 1 is used for comparison with Example 1, the crushing, grinding, low-intensity magnetic separation, desulfurization and other processes in Comparative Example 1 are consistent with those in Example 1, the difference lies in that the tungsten-tin flotation uses a relatively traditional single ligand collector Pb-BHA, and the tungsten-tin separation process is not set in the flow sheet, and the flow sheet is as shown in Figure 2

[0051] Under stirring conditions, 0.125 mol of lead nitrate is added to a 1L benzohydroxamic acid solution with a concentration of 1.0 mol / L, and the reaction is carried out for 3 min to obtain the Pb-BHA metal ion complex collector;

[0052] The desulfurization tailings are first adjusted to pH 9.4 by sodium carbonate, 480 g / t of the metal ion complex collector Pb-BHA is added, the slurry is stirred and conditioned for 5 min after aeration, the pH is 8.5, 30 g / t of 2# oil is used as a frother, tungsten roughing and two times of blank scavenging are carried out, the total amount of Al-SBL (1:2) in cleaning is 200 g / t, and tungsten concentrate WO3 30.12% and Sn grade 3.66% are obtained after four times of cleaning. The total recovery rate of WO3 is 74.25%, and the total recovery rate of Sn is 18.93%.

[0053] ​The results of the control example 1 show that the traditional tungsten-tin mixed flotation scheme is difficult to obtain satisfactory beneficiation indexes, and the Sn recovery rate is only 18.93%. This is because the different tungsten-tin minerals in the actual ore have obvious differences in crystal structure, natural floatability, and surface reactivity, etc. Therefore, the process system using Pb-BHA as a single collector cannot realize the co-enrichment of different tungsten-tin minerals. Especially, the natural floatability of cassiterite is poor, which is easy to drop in the subsequent cleaning process, resulting in low tin grade and recovery rate.

[0054] Table 3 results of control experiments of a certain associated tungsten-tin polymetallic ore in Hunan

[0055]

[0056] Control Example 2

[0057] The control example 2 is used for comparison with example 2. The crushing, grinding, weak magnetic separation, desulfurization, tungsten-tin mixed flotation, and tungsten-tin separation processes in the control example 2 are consistent with those in example 2. The only difference is that no metal-organic macromolecular depressant is added in the roughing of tungsten-tin mixed flotation.

[0058] After crushing and grinding, the mass percentage content of the-200 mesh size fraction is 74%, and then a drum type wet magnetic separator (magnetic field strength 0.6T) is used for weak magnetic iron removal. The tailings after weak magnetic iron removal are subjected to desulfurization flotation with 200g / t copper sulfate as an activator, 80g / t butyl xanthate and 40g / t ethylthiuram disulfide as collectors, and 30g / t 2# oil as a frother. The desulfurization tailings are first adjusted to pH 9.6 by sodium carbonate without adding Al-CMC, and then Pb-BHA-SDBS 400g / t and 20g / t 2# oil as a frother are added. After stirring for 5min at pH 8.6, tungsten-tin mixed roughing and two blank scavenging are carried out. The total amount of salted water glass Al-SBL used as a depressant (mass ratio of aluminum sulfate to water glass is 1:2) is 120g / t. After three cleaning, tungsten-tin mixed concentrate with WO3 grade of 22.52% and Sn grade of 3.88% is obtained. Due to the presence of a large amount of garnet and chlorite in the raw ore, the roughing without adding a depressant to control the same results in a low grade of tungsten-tin mixed concentrate containing a large amount of argillaceous minerals, as shown below Figure 5 which affects the subsequent tungsten-tin separation.

[0059] After the pH of the mixed concentrate reaches 11.2 by adding 360 g / t of NaOH, the reaction is stirred for 20 min, and the concentrated slurry is subjected to tungsten-tin separation. In the tungsten-tin separation, 510 g / t of sulfuric acid is added to the slurry of the mixed concentrate, and the slurry is stirred to adjust the pH to 5.2. 180 g / t of phytic acid and 30 g / t of oxalic acid are added as mixed depressants for scheelite and wolframite. 225 g / t of tetradecyl imino dimethyl phosphonic acid is added as a collector for cassiterite roughing, and flotation is performed at a pH of 4.1 to obtain a roughing froth product. In the scavenging, 30 g / t and 15 g / t of tetradecyl imino dimethyl phosphonic acid are added in the first and second scavenging, respectively, and flotation is performed to obtain a froth product. The froth product obtained by scavenging and the roughing froth product are combined as a tin concentrate, and the tailings after scavenging are the tungsten concentrate.

[0060] As can be seen from Table 4, the method is used to treat a certain associated tungsten-tin polymetallic ore in Jiangxi, and finally a tungsten concentrate containing 28.44% of WO3 is obtained, with a recovery rate of 73.34%, and a tin concentrate containing 14.10% of Sn is obtained, with a recovery rate of 28.30%. The recovery rates of tungsten and tin are both significantly reduced compared with Example 2. This shows that the addition of metal-organic macromolecular depressants in the tungsten-tin mixed roughing can cause fine mud to be enriched in the tungsten-tin roughing stage, and to be in a vicious cycle in the subsequent cleaning and tungsten-tin separation processes, competing with valuable tungsten-tin minerals for adsorption of reagents and entering the final concentrate, resulting in a decrease in both the recovery rate and the grade.

[0061] Table 4 Comparison of test results of Example 2

[0062]

[0063] Figure 1 The infrared spectra of SDBS, Pb-BHA and Pb-BHA-SDBS are shown in Figure 1. Figure 1 As can be seen from Figure 1, the characteristic peaks of sulfonate anions (SO3 2- ) appear at 1192.008 cm -1 and 1045.42 cm -1 , corresponding to asymmetric and symmetric stretching vibrations, respectively; the characteristic peaks at 2854.378 cm -1 and 2926.014 cm -1 correspond to the long-chain alkyl group of sodium dodecyl benzene sulfonate; and the above characteristic peaks all appear in the infrared spectrum of Pb-BHA-SDBS, indicating that SDBS participates in the structure of Pb-BHA to form the Pb-BHA-SDBS multi-metal complex collector.

[0064] Figure 2 The AFM of scheelite after adsorbing Pb-BHA and Pb-BHA-SDBS on the surface is shown in Figure 2. Figure 2(a) and (b) are AFM 2D and 3D height maps of 2 pm x 2 pm scheelite crystal surface, which show that the adsorption of Pb-BHA on scheelite surface results in the mountainous protrusions of collector colloids, which are sparsely distributed on the scheelite surface in the height range of -14.7 nm to 52 nm. AFM height map analysis shows that the maximum height roughness R max = 63.8 nm after the adsorption of Pb-BHA on scheelite surface, which indicates that the roughness of scheelite surface increases after the adsorption of Pb-BHA.

[0065] AFM height maps of scheelite surface after the adsorption of Pb-BHA-SDS Figure 2 (c) and (d) are AFM 2D and 3D height maps of 2 pm x 2 pm scheelite crystal surface, which show that the adsorption of Pb-BHA-SDS on scheelite surface also results in the mountainous protrusions of collector colloids, but to a certain extent, the protrusions are more concentrated than those of Pb-BHA. AFM height map analysis shows that the maximum height roughness R max = 66.9 nm after the adsorption of Pb-BHA-SDS on scheelite surface, which indicates that the adsorption of Pb-BHA-SDS on scheelite surface results in larger colloids and a larger difference between the peaks and valleys of the scheelite surface after the adsorption.

Claims

1. A method for separating tungsten and tin in a tungsten-tin polymetallic ore, characterized by: The tungsten-tin polymetallic ore is sequentially crushed, ground, de-ironed and desulfurized to obtain a desulfurized tailing slurry; after the pH of the desulfurized tailing slurry is adjusted to alkaline, Pb-BHA-SDBS is used as a collector, a metal organic macromolecular complex and a salted water glass are used as inhibitors to perform tungsten-tin mixed flotation to obtain a tungsten-tin mixed concentrate; after the tungsten-tin mixed concentrate is treated by de-drugging, the pH is adjusted to acidic, tetradecyl imino dimethyl phosphonic acid is used as a collector, and an organic acid is used as an inhibitor to perform cassiterite flotation to obtain a tin concentrate and a tungsten enriched tailing; The Pb-BHA-SDBS collector is formed by coordination of benzohydroxamic acid, sodium dodecyl benzene sulfonate and lead ions; the molar ratio of benzohydroxamic acid to sodium dodecyl benzene sulfonate is 5:1-3:1; and the molar ratio of the total amount of benzohydroxamic acid and sodium dodecyl benzene sulfonate to lead ions is 1:1-1:

2.

2. The method according to claim 1, wherein the method is characterized by: The concentration of the desulfurized tailing slurry is controlled to be 40-50wt%, and the pH is adjusted to 9.5-10.

0.

3. The method according to claim 1, wherein the method is characterized by: The tungsten-tin mixed flotation includes one roughing, two or more cleanings and two or more scavengings.

4. The tungsten-tin separation method of the tungsten-tin polymetallic ore according to claim 3, characterized in that: The reagent system of the roughing is that the dosage of Pb-BHA-SDBS is 300-800 g / t, and the dosage of the metal organic macromolecular complex is 50-150 g / t; The metal organic macromolecular complex is a complex formed by a divalent or higher metal ion and an organic macromolecule; the organic macromolecule includes at least one of starch, dextrin, polyacrylamide and guar gum; The divalent or more metal ions include at least one of Mn 2+ , Mg 2+ , Ca 2+ , Fe 3+ , Al 3+ , and Pb 2+ ; meanwhile, 2# oil is used as a foaming agent, and the amount of the 2# oil is 30-50 g / t; wherein, the amount of the Pb-BHA-SDBS is measured by the mass of the BHA. The reagent system of the cleaning is that the dosage of the salted water glass is 50-100 g / t, the salted water glass is formed by mixing aluminum sulfate and water glass, and the mass ratio of aluminum sulfate to water glass is 1:2-1:4; The scavenging is blank scavenging.

5. The method according to claim 1, wherein the method is characterized by: The process of the de-drugging treatment is to adjust the pH to be greater than 11.0, to perform stirring reaction for more than 15 min, and then to perform concentration de-drugging.

6. The method according to claim 1, wherein the method is characterized by: The cassiterite flotation includes one roughing, two or three cleanings and two or three scavengings.

7. The method according to claim 6, wherein the method is characterized by: The reagent system of the roughing is that the dosage of the organic acid is 100-300 g / t, and the dosage of tetradecyl imino dimethyl phosphonic acid is 200-300 g / t; the organic acid includes at least one of citric acid, cinnamic acid, tannic acid and oxalic acid; The pH of the slurry system of the roughing is adjusted to be between 3.5 and 6.5; The cleaning is blank cleaning without adding any reagent; The reagent system of the scavenging is that the dosage of tetradecyl imino dimethyl phosphonic acid is 20-60 g / t.

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