A method for asynchronous flotation of tungsten and tin

Abstract

The invention discloses a tungsten-tin asynchronous flotation method, which comprises the following steps: crushing, grinding, de-ironizing and desulfurizing tungsten-tin raw ore in sequence to obtain tungsten-tin mixed ore pulp, firstly using a metal ion complex as a collector to flotate the tungsten-tin mixed ore pulp under weak alkaline conditions to obtain tungsten concentrate, and then using a metal ion complex as a collector to flotate the tungsten-tin mixed ore under strong alkaline conditions to obtain tungsten-tin mixed concentrate; the method is to separate WO in the tungsten-tin raw ore into tungsten-tin mixed ore pulp. 3 The recovery rate of tungsten is as high as over 80%, and the recovery rate of Sn is over 50%. It has short process, simple reagents, convenient operation, low labor intensity, low energy consumption, environmental protection and high efficiency, avoiding the limitation of strong pulling and pressing on the recovery rate, which not only greatly reduces the cost but also significantly improves the utilization rate of tungsten resources.

Description

Technical Field

[0001] The invention relates to a tungsten-tin ore dressing method, in particular to a tungsten-tin asynchronous flotation method, belonging to the technical field of tungsten ore flotation. Background Art

[0002] Tungsten is a precious rare metal with the highest melting point, lowest thermal expansion coefficient, and lowest vapor pressure among metal elements. It is also one of the metal elements with the highest density. Tungsten has a series of unique properties such as excellent high-temperature mechanical properties, very high compression modulus and elastic modulus, excellent high-temperature creep resistance, high electrical conductivity and thermal conductivity, and very high electron emission coefficient. Therefore, it is widely used in various fields such as civil, industrial, and military.

[0003] For a long time, the mineral resources developed by my country's tungsten industry are mainly wolframite. The domestically announced reserves of wolframite (WO3) were 1.4405 million tons by the end of 2000, accounting for 27.4% of the total reserves of tungsten minerals in China, of which A+B+C grade (industrial) reserves were 536,000 tons. It is particularly important to increase the development of mixed multi-metal resources of black and white tungsten, improve the beneficiation technology of black and white tungsten ore, and improve the overall recycling rate of tungsten resources to ensure the sustainable development of my country's tungsten industry. At present, the symbiosis of black and white tungsten has become a common phenomenon in many large tungsten deposits being developed in my country. For example, the ratio of black and white tungsten in the tungsten minerals supplied by the Shizhuyuan Polymetallic Ore Dressing Plant is close to 1:1, and the ratio of black and white tungsten in Xingluokeng is about 4:6. In addition, even in a single scheelite deposit, there are often about 3-8% black and white tungsten conversion bodies (tungsten minerals that exist in accessory minerals as black tungsten independent minerals or in isomorphous forms), such as Huangshaping, Xintianling and other mines.

[0004] For the black tungsten minerals (and tungsten minerals in isomorphous form) in such black and white tungsten mixed deposits, the traditional flotation reagent system has extremely poor capture capacity, resulting in a large loss of useful tungsten resources. On the other hand, the occurrence characteristics of such ores are more complex, the content of calcium gangue minerals is getting higher and higher, and the mineral embedding particle size is finer and the symbiotic relationship between minerals is more complex. The addition of fatty acids in the traditional flotation system makes the grade of coarse concentrate lower (containing a large amount of calcite and fluorite), and the high-grade concentrate can only be obtained by heating flotation of scheelite. The whole process is long and the cost is high. The large-scale use of water glass seriously restricts the improvement of tungsten recovery rate. Taking Shizhuyuan as an example, the difficulty of ore selection continues to increase over time, and traditional flotation technology is increasingly difficult to adapt to changes in ore properties. The comprehensive recovery rate of tungsten has gradually dropped to 63% to 65%, and production indicators continue to deteriorate, which puts higher requirements on tungsten beneficiation technology.

[0005] my country is rich in tin resources, but tin ores have many associated components, and are poor, fine, and mixed, which makes the enrichment and recovery of cassiterite difficult. Only 12% of China's tin ores appear as a single mineral, and most of them are polymetallic associated resources, among which tungsten-associated tin resources are an important component. At present, most of my country's tungsten-tin polymetallic mines select wolframite, scheelite, and cassiterite into the same concentrate product to obtain a mixed concentrate of black and white tungsten and cassiterite. However, the practice of selecting these three minerals into the same product will cause valuable minerals to fall in the flotation process, resulting in a loss of recovery rate. Taking Shizhuyuan as an example, the annual cassiterite recovery rate is less than 10%, and the cassiterite grade in the concentrate is unstable, which cannot be priced as a stable product, resulting in a serious loss of tin resources. Summary of the invention

[0006] In view of the problems in the prior art of the beneficiation process of tungsten-tin polymetallic ores, such as poor simultaneous enrichment of scheelite and wolframite and low recovery rate of associated cassiterite, the purpose of the present invention is to provide a method with low energy consumption, low cost and capable of achieving efficient flotation enrichment of tungsten-containing minerals (scheelite, wolframite) and cassiterite.

[0007] In order to achieve the above technical purpose, the present invention provides a tungsten-tin asynchronous flotation method, which is to crush, grind, remove iron and desulfurize the tungsten-tin ore in sequence to obtain a tungsten-tin mixed ore pulp, the tungsten-tin mixed ore pulp first uses a metal ion complex I as a collector, and performs flotation I under a pH of 7.5 to 8.5 to obtain a tungsten concentrate I, and then uses a metal ion complex II as a collector, and performs flotation II under a pH of 9.0 to 9.5 to obtain a tungsten-tin mixed concentrate;

[0008] The metal ion complex I is composed of a divalent or trivalent metal ion and a ligand of formula 1;

[0009]

[0010] The metal ion complex II is composed of a divalent or trivalent metal ion and a ligand of formula 2;

[0011]

[0012] in,

[0013] Ar is an aryl group;

[0014] R is a C6-C8 alkyl group;

[0015] The divalent or trivalent metal ion is Fe 3+ , Fe 2+ , Pb 2+ , Cu 2+ 、Zn 2+ 、Al 3+ , Mn2+ 、Ni 2+ or Ca 2+ At least one of them.

[0016] The technical solution of the present invention is based on the mineral composition and distribution characteristics of tungsten-tin polymetallic ore. The key lies in the coordinated control of flotation pH conditions and the selection of flotation collector types. The characteristics of different flotation pH ranges of scheelite and cassiterite and different selectivity of different metal ion complexes for scheelite and cassiterite are utilized. The two coordinately control to amplify the floatability difference between scheelite, wolframite and cassiterite, and implement asynchronous flotation separation of scheelite, wolframite and cassiterite. Based on the fact that the weak alkaline pulp environment is conducive to the floating of scheelite, while the strong alkaline pulp environment is conducive to the floating of wolframite and cassiterite, and the metal ion complex with high selective collection effect on scheelite, wolframite and cassiterite is used as a collector in the weak alkaline pulp environment and the strong alkaline pulp environment, the efficient flotation enrichment of tungsten-containing minerals (scheelite, wolframite, tungsten ore, etc.) and cassiterite is achieved through a double process, and the enrichment ratio of the roughing operation is as high as 50 times or more, and the total recovery rate is greater than 80%, creating favorable conditions for subsequent concentration operations. The development of the dual process of the present invention avoids the cassiterite falling in the process due to the inability to adapt to the flotation conditions under the single process, greatly improving the Sn recovery rate. Compared with the existing single product technology, asynchronous flotation not only solves the problems of low tungsten ore recovery efficiency caused by the "strong pulling and strong pressing" method in the existing technology, but also achieves a significant improvement in the recovery rate of tin resources.

[0017] As a preferred solution, Ar is phenyl or substituted phenyl; the substituted phenyl is a phenyl containing at least one of C1-C5 alkyl, halogen substituent, carboxyl, and hydroxyl. When Ar is phenyl or substituted phenyl, the metal ion complex I exhibits high selectivity for scheelite, thereby facilitating the preferential flotation separation of scheelite. The alkyl group may be methyl, ethyl, propyl, pentyl, etc., and may also include a branched alkyl group such as isopropyl, etc. when the number of carbon atoms exceeds 3. Halogen substituents such as fluorine, chlorine, etc.

[0018] When R in the metal ion complex II of the present invention is a C6-C8 alkyl group, the corresponding metal ion complex II has a strong collection ability for both wolframite and cassiterite. After the scheelite is preferably separated, the use of the metal ion complex II is beneficial to improve the recovery efficiency of wolframite and cassiterite. In a further preferred embodiment, R can be a straight-chain alkyl group, a branched-chain alkyl group or a cycloalkyl group, more specifically, a hexyl group, an octyl group, a cyclohexyl group, and the like.

[0019] As a preferred embodiment, the coordination molar ratio of the divalent or trivalent metal ion to the ligand of formula 1 or formula 2 in the metal ion complex I or the metal ion complex II is 1:2 to 16. The coordination molar ratio of the divalent or trivalent metal ion to the ligand of formula 1 or formula 2 is more preferably 1:2, 1:4, 1:8 or 1:16.

[0020] As a preferred solution, the tungsten-tin ore contains scheelite, wolframite and cassiterite, as well as gangue minerals. The mass percentage of WO3 in the tungsten-tin ore is greater than 0.18%, and the gangue minerals are mainly garnet, calcite, fluorite, barite and silicate minerals.

[0021] As a preferred solution, the particle size of the grinding satisfies that the mass percentage of the -200 mesh particle size is more than 60%. After crushing and grinding to an appropriate particle size, the dissociation degree of tungsten-containing mineral monomers can be greater than 90%, and the dissociation degree of tin-containing mineral monomers can be greater than 60%.

[0022] As a preferred solution, the concentration of the tungsten-tin mixed ore slurry is 30-55wt%.

[0023] As a preferred solution, the flotation I comprises one roughing separation and at least one fine separation.

[0024] As a more preferred solution, the amount of metal ion complex I added to the tungsten-tin ore during the roughing process is 300-500 g / t.

[0025] As a more preferred solution, salted water glass is used as an inhibitor in the concentration process, and the salted water glass contains Al2(SO4)3 and / or Pb(NO3)2 and water glass, and the mass ratio of Al2(SO4)3 and / or Pb(NO3)2 to water glass is 1:2-8; the amount of inhibitor added relative to the tungsten-tin ore in the concentration process is 100-300g / t. The mass ratio of Al2(SO4)3 and / or Pb(NO3)2 to water glass is more preferably 1:2, 1:3, 1:4, 1:8. The use of the preferred inhibitor can selectively inhibit the flotation of gangue minerals and improve the enrichment efficiency of scheelite.

[0026] As a preferred solution, the flotation II comprises one roughing separation and at least one cleaning separation.

[0027] As a preferred solution, the amount of metal ion complex II added relative to the tungsten-tin ore during the roughing process is 100-300 g / t.

[0028] As a preferred solution, at least one of guar gum, sodium hexametaphosphate, sodium fluorosilicate and carboxymethyl cellulose is used as an inhibitor in the concentration process.

[0029] As a preferred solution, the amount of inhibitor added to the tungsten-tin ore during the concentration process is 100-200 g / t. The preferred inhibitor can selectively inhibit the flotation of gangue minerals and improve the enrichment efficiency of wolframite and cassiterite.

[0030] The deironing process of the present invention adopts the conventional magnetic separation deironing process in the art, and the magnetic separation deironing process reduces the mass percentage content of magnetite in the tungsten ore to less than 10%.

[0031] The desulfurization process of the present invention adopts conventional flotation desulfurization in the art, with butylamine black medicine and the like as a collector.

[0032] The present invention uses sodium carbonate and / or sodium hydroxide as a pH adjuster to adjust pH. The pH adjuster mainly makes the particle surface carry the same charge to promote particle dispersion.

[0033] In the roughing process of flotation I and flotation II of the present invention, water glass and any other inhibitors are not added.

[0034] The slurry mixing process of the present invention adopts aeration strong shear stirring.

[0035] The sodium carbonate, sodium hydroxide, hydroxamic acid and the like involved in the present invention are all commercially available conventional pharmaceutical agents.

[0036] The asynchronous flotation method of tungsten and tin of the present invention specifically comprises the following steps:

[0037] Step 1: Crushing, grinding, deironing, desulfurization:

[0038] After crushing and wet grinding, the tungsten-tin ore has a particle size of -200 mesh with a mass percentage of more than 60%, a dissociation degree of tungsten-containing mineral monomers of more than 90%, and a magnetite content of less than 10% after magnetic separation and iron removal by a strong magnetic machine; the magnetic separation tailings are freed from sulfide ores by flotation.

[0039] Step 2: Roughing I (mainly for scheelite):

[0040] The mass percentage concentration of the ore pulp is 30-55%. A pH adjuster is added to the ore pulp, and then a metal ion complex collector I is added in an amount of 300-500 g / t relative to the tungsten-tin ore. The pH of the ore pulp before flotation is maintained at 7.5-8.5. After aeration and stirring for 3-5 minutes, flotation enrichment is performed. The foam product is a tungsten rough concentrate, with a WO3 grade of more than 7% and a recovery rate of more than 55%.

[0041] The metal ion complex I is composed of a divalent or trivalent metal ion and a ligand of formula 1;

[0042]

[0043] Ar is an aryl group.

[0044] Step 3: Selection I:

[0045] The tungsten rough concentrate slurry obtained in the second step is sent to the flotation equipment for selection. During the selection process, salted water glass is used as an inhibitor. The salted water glass contains Al2(SO4)3 and / or Pb(NO3)2 and water glass, and the mass ratio of Al2(SO4)3 and / or Pb(NO3)2 to water glass is 1:2~8. The amount of inhibitor added relative to the tungsten-tin ore during the selection process is 100~300g / t, so as to obtain a tungsten concentrate with a WO3 grade greater than 40%, and the tailings are returned to the roughing I operation.

[0046] Step 4: Rough Selection II (mainly for cassiterite and wolframite):

[0047] To the tailings obtained in the second step, a pH adjuster and a metal ion complex collector II are added in sequence, and the amount of the added agent relative to the tungsten-tin ore is 100-300 g / t, and the pH of the slurry before flotation is maintained at 9.0-9.5. After aeration and stirring for 3-5 minutes, flotation enrichment is carried out, and the foam product is a tungsten-tin mixed coarse concentrate, and the WO3 and Sn grades are both greater than 1%, and the operating recovery rates of tungsten and tin are greater than 55% and 75% respectively. The flotation tailings are the final tailings;

[0048] The metal ion complex II is composed of a divalent or trivalent metal ion and a ligand of formula 2;

[0049]

[0050] in,

[0051] R is a C6-C8 alkyl group.

[0052] Step 5: Selection II:

[0053] The tungsten-tin mixed rough concentrate slurry obtained in the fourth step is fed into the flotation equipment for selection. During the selection process, at least one of guar gum, sodium hexametaphosphate, sodium fluorosilicate and carboxymethyl cellulose is used as an inhibitor, and the amount of the inhibitor added relative to the tungsten-tin ore is 100-200g / t, so as to obtain a tungsten-tin mixed concentrate with a WO3 grade greater than 10% and a Sn grade greater than 5%. The tailings are returned to the roughing II operation.

[0054] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0055] 1. The technical solution of the present invention applies the idea of ​​"asynchronous flotation" to the mixed flotation of tungsten and tin. Different flotation conditions are used in the two sets of flotation processes, which are respectively suitable for the floating of different valuable minerals. At the same time, a weak alkaline environment and a metal ion complex collector with better selectivity are used in flotation I to obtain high-grade scheelite concentrate; and a strong alkaline environment and a metal ion complex collector with stronger collection ability are used in flotation II to ensure the overall recovery rate of tungsten and tin, and obtain a low-grade tungsten-tin mixed concentrate. It avoids the problems of low tungsten recovery rate and difficulty in recovering tin resources caused by the single process and single flotation conditions of the existing technology, greatly improves the recovery rate of tungsten, and realizes the recovery of associated cassiterite;

[0056] 2. The technical solution of the present invention realizes the asynchronous flotation of tungsten-tin polymetallic mixed ores under the condition of coordinated control of pH and the use of suitable metal ion complex collectors, and efficiently enriches tungsten-containing minerals (scheelite, wolframite, etc.) and cassiterite. The enrichment ratio of roughing I operation is as high as more than 50 times, creating favorable conditions for subsequent concentration operations.

[0057] 3. The technical solution of the present invention can achieve tungsten ore purification at room temperature with low energy consumption and low cost.

[0058] 4. The technical solution of the present invention has a short process, is easy to operate, has low labor intensity, and is environmentally friendly and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a process flow chart of the present invention.

[0060] Figure 2 It is the process flow chart of comparative example 1 (currently the common process flow of tungsten-tin multi-metal beneficiation). DETAILED DESCRIPTION

[0061] The following examples are provided to further illustrate the present invention in detail, but are not intended to limit the scope of protection of the claims of the present invention.

[0062] Comparative Example 1 (Compared with Example 1)

[0063] Under stirring conditions, 0.125 mol of lead nitrate was added to 1 L of 1.0 mol / L benzohydroxamic acid solution and reacted for 3 minutes to obtain the metal ion complex collector I.

[0064] The process method is used to process the high-calcium polymetallic ore of Chaishan, Shizhuyuan. After two stages of closed-circuit grinding, the raw ore with a fineness of 70% is obtained. The raw ore uses a 1500Gs weak magnetic separator to remove magnetite, and the iron tail enters the desulfurization flotation process. In the desulfurization stage, butyryl and ethylthiocyanate are used as collectors, and the sulfide ore is selected through a coarse and sweep process.

[0065] The pH of the desulfurized tailings was adjusted by sodium carbonate, and then 600g / t of metal ion complex collector I was added. After aeration and slurry stirring for 5 minutes, the slurry pH was 8.5. Rough selection I obtained tungsten rough concentrate WO3 5.25%. Salted water glass was added as an inhibitor to the obtained rough concentrate (the ratio of Al2(SO4)3 and water glass was 1:2, and the amount was 200g / t). After two rounds of selection, WO3 30.59% and Sn grade of 2.01% were obtained. The overall recovery rate of WO3 was 71.17%, and the overall recovery rate of Sn was 12.95%.

[0066] It can be seen that under the traditional existing process, the comprehensive recovery effect of cassiterite is very poor, with a recovery rate of only 12.95%. At the same time, it can be seen from the screening results in Table 2 that fine-grained tungsten minerals can enter the final concentrate more efficiently. The distribution rate of WO3 metal of -400 mesh in the final concentrate is as high as 95.18%, and +400 mesh accounts for only 4.82%, while the distribution rate of WO3 metal of +400 mesh in the sulfur tail is close to 16%. This is because the conjoined bodies above +400 mesh are tungsten minerals that are more difficult to select. They cannot enter the final concentrate in the entire flotation process, are easily dropped during the selection process, and circulate in the flotation closed-circuit system, eventually leading to tailing.

[0067] Table 1 Results of the current process test at Shizhuyuan

[0068]

[0069]

[0070] Table 2 Screening results of the current process test of Shizhuyuan

[0071]

[0072] Example 1

[0073] Under stirring conditions, 0.125 mol of lead nitrate was added to 1 L of 1.0 mol / L benzohydroxamic acid solution and reacted for 3 minutes to obtain the metal ion complex collector I.

[0074] Under stirring conditions, 0.025 mol of ferric sulfate was added to 1 L of 0.5 mol / L n-decyl hydroxamic acid solution and reacted for 3 minutes to obtain the metal ion complex collector II.

[0075] The process method is used to process the high-calcium polymetallic ore of Chaishan, Shizhuyuan. After two stages of closed-circuit grinding, the raw ore with a fineness of 70% is obtained. The raw ore uses a 1500Gs weak magnetic separator to remove magnetite, and the iron tail enters the desulfurization flotation process. In the desulfurization stage, butyryl and ethylthiocyanate are used as collectors, and the sulfide ore is selected through a coarse and sweep process.

[0076] The pH of the desulfurized tailings was adjusted by sodium carbonate, and then 400g / t of metal ion complex collector I was added. After aeration and slurry stirring for 5 minutes, the slurry pH was 8.0, and rough selection I obtained tungsten rough concentrate WO3 7.25%. Salted water glass was added as an inhibitor to the obtained rough concentrate (the mass ratio of Al2(SO4)3 and water glass was 1:2, and the amount was 200g / t). After two rounds of selection, high-grade tungsten concentrate WO3 43.56% was obtained. The tailings from flotation I enter flotation II, where the pH is adjusted with sodium carbonate, and then 200 g / t of metal ion complex collector II is added. After aeration and slurry stirring for 5 minutes, the slurry pH is 9.2. Flotation II undergoes a one-rough and three-fine process, with 150 g / t of sodium carboxymethyl cellulose as an inhibitor to obtain a low-grade tungsten-tin mixed concentrate with a WO3 grade of 10.0% and a Sn grade of 5.9%. The overall WO3 recovery rate is 84.34%, and the overall Sn recovery rate is 53.01%.

[0077] In addition, it can be seen from the screening results in Table 4 that, in addition to the fine-grained tungsten minerals entering the high-grade concentrate (the WO3 metal distribution rate of -400 mesh is as high as 96.93%, and +400 mesh accounts for only 3.07%), the recovery of coarse-grained tungsten minerals is effectively achieved in the flotation II process, and the WO3 metal distribution rate of +400 mesh in the low-grade concentrate is 15.42%, effectively recovering the coarse-grained tungsten minerals that cannot enter the high-grade concentrate in the original process.

[0078] Table 3 Test results of asynchronous flotation process of tungsten and tin in Shizhuyuan

[0079]

[0080] Table 4 Screening results of asynchronous flotation process of tungsten and tin in Shizhuyuan

[0081]

[0082]

[0083] Comparative Example 2 (Compared with Example 2)

[0084] Under stirring conditions, 0.25 mol of lead nitrate is added to 1 L of a 1.0 mol / L salicylic hydroxamic acid solution, and the mixture is reacted for 3 minutes to obtain the metal ion complex collector I;

[0085] The process method is used to treat the Ninghua Xingluokeng polymetallic ore. The pH of the desulfurized tailings is adjusted by sodium carbonate, and then 580g / t of metal ion complex collector I is added. After aeration and slurry stirring for 5 minutes, the slurry pH is 8.6. Rough selection I obtains tungsten rough concentrate WO3 5.94%. Salted water glass is added as an inhibitor to the obtained rough concentrate (the ratio of Al2(SO4)3 to water glass is 1:4, and the amount is 200g / t). After two rounds of selection, high-grade tungsten concentrate WO3 42.99% is obtained.

[0086] The tailings from flotation I enter flotation II. Flotation II undergoes a one-rough and three-fine process, and the reagent system is a full-process blank flotation to obtain a low-grade tungsten-tin mixed concentrate with a WO3 grade of 7.99% and a Sn grade of 2.98%. The overall WO3 recovery rate is 75.13%, and the overall Sn recovery rate is 24.24%.

[0087] As can be seen from Table 6, with the progress of flotation I, from coarse concentrate to first concentrate, and then to second concentrate, the proportion of black and white tungsten has changed significantly, indicating that there are obvious differences in the enrichment trends of black and white tungsten; the proportion of wolframite gradually decreases, indicating that the loss of wolframite is serious during flotation I. Since flotation II was not re-slurried and added in the comparative test, the wolframite lost in flotation I did not float significantly in the flotation II process, and scheelite still accounted for a large proportion of the low-grade mixed concentrate.

[0088] Table 5 Results of the comparative process tests at Xingluokeng

[0089]

[0090]

[0091] Table 6 Changes in the ratio of black and white tungsten in the comparative process test samples of Xingluokeng

[0092]

[0093] Example 2

[0094] Under stirring conditions, 0.25 mol of lead nitrate is added to 1 L of a 1.0 mol / L salicylic hydroxamic acid solution, and the mixture is reacted for 3 minutes to obtain the metal ion complex collector I;

[0095] Under stirring conditions, 0.025 mol of aluminum sulfate was added to 1 L of 1.0 mol / L n-octyl hydroxamic acid solution and reacted for 3 minutes to obtain the metal ion complex collector II.

[0096] The process method is used to treat the Ninghua Xingluokeng polymetallic ore. The pH of the desulfurized tailings is adjusted by sodium carbonate, and a metal ion complex collector I 380g / t is added. After aeration and slurry stirring for 5 minutes, the slurry pH is 7.8, and rough selection I obtains tungsten rough concentrate WO39.98%. Salted water glass is added as an inhibitor to the obtained rough concentrate (the ratio of aluminum sulfate to water glass is 1:2, and the amount is 150g / t). The obtained rough concentrate is subjected to two rounds of selection to obtain a high-grade tungsten concentrate WO3 45.98%.

[0097] The tailings from flotation I enter flotation II, where the pH is adjusted with sodium carbonate, and then 180 g / t of metal ion complex collector II is added. After aeration and slurry stirring for 5 minutes, the slurry pH is 9.1. Flotation II undergoes a one-rough and three-fine process, with 120 g / t of sodium fluorosilicate used as an inhibitor to obtain a low-grade tungsten-tin mixed concentrate with a WO3 grade of 10.9% and a Sn grade of 6.01%. The overall WO3 recovery rate is 85.08%, and the overall Sn recovery rate is 52.24%.

[0098] As can be seen from Table 8, as flotation I proceeds, the proportion of wolframite gradually decreases, indicating that wolframite is seriously lost during flotation I. However, based on the re-slurrying and dosing before flotation II, the optimal pH range and the selective collection effect of the metal ion complex collector II are fully utilized to effectively recover the wolframite that did not float in flotation I. In the flotation II investigation sample, the ratio of black wolframite to black wolframite in the fine third concentrate is as high as 20:1, indicating that wolframite floats in large quantities in the flotation II process, effectively realizing the asynchronous flotation of black wolframite and cassiterite.

[0099] Table 7 Test results of asynchronous flotation process of tungsten and tin in Xingluokeng

[0100]

[0101] Table 8 Changes in the ratio of black and white tungsten in the comparative process test samples of Xingluokeng

[0102]

Claims

1. A tungsten-tin asynchronous flotation method, characterized in that: The tungsten-tin ore is crushed, ground, deironed and desulfurized in sequence to obtain a tungsten-tin mixed ore pulp, wherein the tungsten-tin mixed ore pulp is first subjected to flotation I at a pH of 7.5 to 8.5 using a metal ion complex I as a collector to obtain a tungsten concentrate I, and then subjected to flotation II at a pH of 9.0 to 9.5 using a metal ion complex II as a collector to obtain a tungsten-tin mixed concentrate; the metal ion complex I is composed of a divalent or trivalent metal ion and a ligand of formula 1; The metal ion complex II is composed of a divalent or trivalent metal ion and a ligand of formula 2; in, Ar is an aryl group; R is a C6-C8 alkyl group; The divalent or trivalent metal ion is Fe 3+ , Fe 2+ , Pb 2+ , Cu 2+ 、Zn 2+ 、Al 3+ , Mn 2+ 、Ni 2+ or Ca 2+ At least one of them.

2. A tungsten-tin asynchronous flotation method according to claim 1, characterized in that: Ar is a phenyl group or a substituted phenyl group; the substituted phenyl group is a phenyl group containing at least one substituent selected from the group consisting of a C1-C5 alkyl group, a halogen substituent, a carboxyl group, and a hydroxyl group.

3. The asynchronous flotation method of tungsten and tin according to claim 1, characterized in that: The coordination molar ratio of the divalent or trivalent metal ion to the ligand of formula 1 or the ligand of formula 2 in the metal ion complex I or the metal ion complex II is 1:2-16.

4. A tungsten-tin asynchronous flotation method according to any one of claims 1 to 3, characterized in that: The tungsten-tin ore contains scheelite, wolframite and cassiterite, as well as gangue minerals.

5. The asynchronous flotation method for tungsten and tin according to any one of claims 1 to 3, characterized in that: The particle size of the ore grinding satisfies that the mass percentage of the -200 mesh particle size is more than 60%.

6. A tungsten-tin asynchronous flotation method according to any one of claims 1 to 3, characterized in that: The concentration of the tungsten-tin mixed ore slurry is 30-55wt%.

7. A tungsten-tin asynchronous flotation method according to any one of claims 1 to 3, characterized in that: The flotation I comprises a roughing step and at least one cleaning step.

8. The asynchronous flotation method of tungsten and tin according to claim 7, characterized in that: In the roughing process, the amount of metal ion complex I added to the tungsten-tin ore is 300-500 g / t; In the concentrating process, salted water glass is used as an inhibitor, and the salted water glass contains Al2(SO4)3 or Pb(NO3)2 and water glass, and the mass ratio of Al2(SO4)3 and / or Pb(NO3)2 to water glass is 1:2-8; In the above-mentioned concentration process, the amount of inhibitor added relative to the tungsten-tin ore is 100-300 g / t.

9. A tungsten-tin asynchronous flotation method according to any one of claims 1 to 3, characterized in that: The flotation II comprises a roughing process and at least one cleaning process.

10. The asynchronous flotation method of tungsten and tin according to claim 9, characterized in that: In the roughing process, the amount of metal ion complex II added relative to the tungsten-tin ore is 100-300 g / t; In the selection process, at least one of guar gum, sodium hexametaphosphate, sodium fluorosilicate and carboxymethyl cellulose is used as an inhibitor; In the above-mentioned concentration process, the amount of inhibitor added relative to the tungsten-tin ore is 100-200 g / t.

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