Cassiterite flotation collecting agent and application thereof

Abstract

The invention discloses a cassiterite flotation collecting agent and application thereof, and belongs to the technical field of mineral flotation. According to the cassiterite flotation collecting agent, (2-ethylhexyl) phosphate mono-2-ethylhexyl ester is used as the cassiterite flotation collecting agent, the (2-ethylhexyl) phosphate mono-2-ethylhexyl ester contains multi-branched chain alkyl, the surface hydrophobicity of cassiterite is improved by enhancing the adsorption capacity to the cassiterite mineral surface, and the cassiterite flotation collecting agent is obtained. And high-efficiency separation of cassiterite and gangue minerals can be realized under the condition that the pH is neutral or alkalescent. The cassiterite flotation collecting agent used in the method is non-toxic, harmless, green and environmentally friendly, has excellent water solubility, is beneficial to dissolution of the agent in ore pulp, and is high in collecting capacity and selectivity, and the cassiterite concentrate recovery rate is high.

Description

Technical Field

[0001] This invention relates to the field of mineral flotation technology, and in particular to a cassiterite flotation collector and its application. Background Technology

[0002] Tin, as a key basic material supporting modern electronics and metallurgical industries, has seen its global consumption continue to rise, making efficient tin ore sorting technology a core link in resource security. Cassiterite, the most important industrial tin mineral, is commonly found in complex polymetallic deposits, exhibiting two main characteristics in its occurrence: first, it forms a micron-scale interlocking symbiotic structure with zirconite, tantalum-niobium minerals, and silicate gangues (such as quartz and feldspar), requiring physical decomposition by grinding the ore to below -20μm; second, it often densely cements with calcium-bearing minerals such as calcite and fluorite, leading to mutual interference of surface chemical properties. Although cassiterite has a high content of 6.8–7.1 g / cm³... 3 The density of cassiterite makes it naturally suitable for gravity separation. However, the over-grinding phenomenon caused by the development of crystal cleavage planes during fine grinding (with -10μm particles accounting for over 30%) drastically deteriorates the separation efficiency of gravity separation equipment. Specifically, the recovery rate of fine cassiterite is generally below 50% due to the combined effects of weakened mass effect and increased fluid resistance. Global high-quality tin ore resources are becoming increasingly depleted, with easily beneficiated placer tin ore accounting for less than 20%. Difficult-to-process primary ore and tailings reprocessing resources have become the main body of tin ore resources, and the median cassiterite particle size has dropped to 15–25μm. Flotation technology, with its highly efficient capture capability of fine particles (down to 5μm), has become an inevitable choice to overcome resource bottlenecks. However, gangues such as quartz and calcite, due to their similar surface active sites to cassiterite, tend to float simultaneously in conventional flotation systems, making it difficult to break through the 40% technical ceiling for concentrate tin grade.

[0003] The technological development of cassiterite flotation collectors is limited by three core contradictions: First, the defects in the selectivity mechanism, such as the interaction between the carboxyl functional groups of fatty acid reagents (e.g., sodium oleate) and the silanol groups (Si-OH) of quartz and the calcium sites (Ca) of calcite. 2+ Non-specific adsorption occurs, resulting in a total silicon and calcium impurity content of 15-25% in the concentrate, significantly reducing smelting economics. Although alkyl sulfonated succinates can improve flotation kinetic efficiency by 50%, they still cannot overcome the selectivity bottleneck for calcium-containing gangue. Secondly, there is an imbalance between environmental and process compatibility. Arsorbic acid reagents (such as styrene-arsorbic acid) can achieve a cassiterite-gangue selectivity index >8.0, but the arsenic residue >200ppm violates the ISO 14046 environmental standard. Alkyl sulfate collectors require strongly acidic conditions (pH <3) to be effectively activated. This strongly acidic environment not only exacerbates the corrosion of mineral processing equipment but also leads to Fe... 2+ And Al 3+The metal ions dissolve, thereby inhibiting the floatability of the target mineral. Thirdly, when short-chain phosphates are used as cassiterite collectors, the selectivity is poor, and a large amount of heavy metal activators need to be added in conjunction, such as short-chain alkyl phosphates (e.g., diisobutyl phosphate) and Sn. 4+ Its complexing ability is weak (only 46% of that of arsenopyrate drugs), and it must rely on high doses of Pb. 2+ / Fe 3+ The activator (500-1000g / t) not only increases the cost of the reagents by more than 30%, but also causes the Cu / Pb content in the tailings water to exceed the standard by 10-20 times. More importantly, when Fe in the slurry... 3+ When the concentration exceeds 50 mg / L, 40% of the effective reagent component will be consumed preferentially. In addition, although extending the carbon chain to C12 can enhance hydrophobicity, the steric hindrance effect will significantly reduce the diffusion rate (by up to 60%) and cause low-temperature crystallization problems, further restricting the flotation effect. Furthermore, when using long-chain phosphoric acid as a cassiterite collector, the electron-donating ability of the polar functional groups phosphorus and oxygen atoms is enhanced, resulting in a decrease in the selectivity of the collector, while the solubility of the reagent in solution becomes worse.

[0004] The core problem in cassiterite flotation recovery lies in the lack of collectors that can accurately identify the surface characteristics of cassiterite and achieve efficient separation without activation. Therefore, it is necessary to develop collectors based on the synergistic effect of a three-in-one mechanism of "multi-toothed strong complexation, rigid hydrophobicity, and anti-interference". Summary of the Invention

[0005] To address the lack of collectors in cassiterite flotation that can accurately identify the surface characteristics of cassiterite and achieve efficient separation without activation, this invention provides a cassiterite flotation collector and its application. This collector enhances the adsorption capacity on the surface of cassiterite minerals and improves the hydrophobicity of the cassiterite surface, thereby enabling efficient separation of cassiterite from gangue minerals.

[0006] The collector described in this invention is (2-ethylhexyl)phosphate mono-2-ethylhexyl ester, and the molecular formula of the collector is [CH3(CH2)3CH(C2H5)CH2O][CH3(CH2)3CH(C2H5)CH2]HPO2;

[0007] The structural formula of the collector is:

[0008]

[0009] The cassiterite flotation collector described in this invention can be applied to the flotation of cassiterite and gangue.

[0010] The flotation process described in this invention includes one roughing stage, two to three scavenging stages, and two to three cleaning stages, with the collector added during the roughing and scavenging stages.

[0011] As a preferred embodiment of the present invention, the amount of collector added during the first roughing process is 600-1000 g / t.

[0012] As a preferred embodiment of the present invention, in the 2-3 scavenging processes described herein, the amount of collector added in scavenging operation I is 300-500 g / t, the amount of collector added in scavenging operation II is 150-250 g / t, and the amount of collector added in scavenging operation III is 75-125 g / t.

[0013] The application of the collector described in this invention in the flotation separation of cassiterite and gangue specifically includes the following steps:

[0014] (1) Prepare cassiterite slurry and adjust the pH of the slurry to 7-9.

[0015] (2) Activator, inhibitor, collector and frother are added to the slurry in sequence for roughing to obtain rough concentrate and rough tailings.

[0016] (3) Add collector and frother to the obtained coarse tailings and perform 2 to 3 scavenging operations to obtain scavenged concentrate. No frother is added in the last scavenging operation.

[0017] (4) Add inhibitors to the obtained crude concentrate and perform 2 to 3 fine selections to obtain tin concentrate.

[0018] The roughing, scavenging, and cleaning processes described in this invention are conventional operations. As a preferred embodiment of this invention, during the roughing process, the activator is lead nitrate, added at a rate of 50–100 g / t; the inhibitor is a mixture of carboxymethyl cellulose and sodium fluorosilicate, added at a rate of 200–400 g / t, wherein the mass ratio of carboxymethyl cellulose to sodium fluorosilicate is 1:0.5–1.5; and the frother is methyl isobutyl methanol, added at a rate of 40–80 g / t.

[0019] As a preferred embodiment of the present invention, during the scavenging process, the frother is methyl isobutyl methanol; the amount of frother added in scavenging operation I is 20-40 g / t; and the amount of frother added in scavenging operation II is 10-20 g / t.

[0020] As a preferred embodiment of the present invention, in the refining process, the inhibitor is a mixture of carboxymethyl cellulose and sodium fluorosilicate, with a mass ratio of carboxymethyl cellulose to sodium fluorosilicate of 1:0.5 to 1.5; the amount of inhibitor added in refining operation I is 100 to 200 g / t; the amount of inhibitor added in refining operation II is 50 to 100 g / t; and the amount of inhibitor added in refining operation III is 25 to 50 g / t.

[0021] As a preferred embodiment of the present invention, the (2-ethylhexyl)phosphate mono-2-ethylhexyl ester is added in an aqueous solution with a mass percentage concentration of 0.1-1%; the methyl isobutyl methanol is added using the stock solution; the lead nitrate is added in an aqueous solution with a mass percentage concentration of 1-5%; the carboxymethyl cellulose is added in an aqueous solution with a mass percentage concentration of 1-5%; and the sodium fluorosilicate is added in an aqueous solution with a mass percentage concentration of 1-5%.

[0022] Mechanism of the invention:

[0023] This invention achieves a breakthrough improvement in the cassiterite flotation process through a synergistic mechanism of "multi-toothed strong complexation, rigid hydrophobicity, and anti-interference." In terms of molecular structure design, the phosphate ester groups of 2-ethylhexyl phosphate mono-2-ethylhexyl ester interact with the Sn on the cassiterite surface. 4+ A stable five-membered ring chelate is formed, constituting a multidentate coordination core, while the two 2-ethylhexyl branches exert an anti-interference function through steric hindrance. The synergistic effect of these two components ensures selective adsorption of the reagent. Simultaneously, the rigid conformation of the branches and the appropriate carbon chain length enhance intermolecular van der Waals forces to form a dense hydrophobic layer, and the steric hindrance inhibits water molecule penetration, generating a stereohydrophobic effect. This synergistic effect of "stereohydrophobicity-stable adhesion and anti-interference" significantly improves bubble mineralization efficiency. The synergistic effect of multidentate coordination and steric sieving solves the problem of poor selectivity in traditional long-chain phosphates, while the synergy of rigid hydrophobicity and anti-interference groups overcomes the contradiction between reagent solubility and collection capacity, thus achieving selective capture of cassiterite at the molecular level and providing a breakthrough solution for the efficient recovery of fine-particle cassiterite.

[0024] The technical solution provided by this invention may include the following beneficial effects:

[0025] This invention uses 2-ethylhexyl phosphate mono-2-ethylhexyl ester, an organophosphate compound with multiple branches, as a flotation collector for cassiterite. This ensures the selectivity of the collector for the target mineral cassiterite while enhancing its hydrophobicity, allowing for the introduction of more branches to enhance the collector's ability. This improves both the collector's ability and selectivity for cassiterite, enabling efficient separation of cassiterite from quartz and calcite in mixed mineral flotation.

[0026] This invention uses a multi-branched phosphate collector that is non-toxic, harmless, and environmentally friendly. It has excellent water solubility, which is beneficial for the dissolution of the agent in the slurry. It can be used in a low-alkaline environment and is suitable for industrial applications. Attached Figure Description

[0027] Figure 1 This is a flowchart of the cassiterite flotation process in Embodiment 1 of the present invention.

[0028] Figure 2This is a flowchart of the cassiterite flotation process for Comparative Example 1 of the present invention.

[0029] Figure 3 This is a flowchart of the cassiterite flotation process in Embodiment 2 of the present invention.

[0030] Figure 4 This is a flowchart of the cassiterite flotation process for Comparative Example 2 of the present invention.

[0031] Figure 5 This is a flowchart of the cassiterite flotation process in Embodiment 3 of the present invention.

[0032] Figure 6 This is a flowchart of the cassiterite flotation process for Comparative Example 3 of the present invention.

[0033] Figure 7 This is a flowchart of the cassiterite flotation process in Embodiment 4 of the present invention. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0035] Example 1

[0036] The application of the cassiterite flotation collector described in this embodiment in the flotation of pure cassiterite minerals specifically includes the following steps, as shown in the flowchart. Figure 1 :

[0037] (1) Preparation of cassiterite slurry: 2g of mixed ore with a particle size of -74 to +38μm (cassiterite and quartz / calcite in a mass ratio of 1:1) and 35mL of distilled water were added to a 40mL hanging flotation tank. The slurry was stirred and adjusted at a speed of 1602r / min to obtain cassiterite slurry. The pH value of the slurry was adjusted to about 7 to 9.

[0038] (2) First, add the collector (2-ethylhexyl) phosphate mono-2-ethylhexyl ester, and control the collector concentration to be 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L and 60 mg / L respectively; then add methyl isobutyl methanol frother (concentration of 15 mg / L); after all the flotation reagents are added, aeration flotation is performed, and after the flotation is completed, the froth product and the tailings in the flotation cell are obtained.

[0039] (3) Dry the foam product and tailings separately, weigh them, and calculate the yield, i.e., the recovery rate. The results of pure mineral flotation are shown in Table 1 below. The results show that this phosphate collector is effective in separating cassiterite from both quartz and calcite, with similar indicators. When the collector concentration in the pulp is in the range of 45–60 mg / L, the cassiterite recovery rate is approximately 90%, and the cassiterite grade is above 73%. Too low a concentration will result in a low cassiterite flotation recovery rate; too high a concentration will lead to meaningless reagent consumption and an increase in the recovery rate of quartz or calcite.

[0040] Table 1

[0041]

[0042] Comparative Example 1

[0043] This comparative example uses JG-12 (dodecyl phosphite) and JG-8 (octyl phosphite) as collectors in the flotation of pure cassiterite. The specific steps include the following, and the flowchart is shown below. Figure 2 :

[0044] (1) Preparation of cassiterite slurry: 2g of mixed ore with a particle size of -74 to +38μm (cassiterite and quartz / calcite in a mass ratio of 1:1) and 35mL of distilled water were added to a 40mL hanging flotation tank. The slurry was stirred and adjusted at a speed of 1602r / min to obtain cassiterite slurry. The pH value of the slurry was adjusted to about 7 to 9.

[0045] (2) First, add collectors JG-12 (dodecyl phosphite) and JG-8 (octyl phosphite), and control the collector concentrations to 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L and 60 mg / L respectively; then add methyl isobutyl methanol frother (concentration of 15 mg / L); after all the flotation reagents are added, ventilate for flotation, and after the flotation is completed, obtain the froth product and the tailings in the flotation cell.

[0046] (3) Dry the foam product and tailings separately, weigh them, and calculate the yield, i.e., the recovery rate. The flotation results of the pure minerals are shown in Table 2 below. The results show that the phosphate collector is effective in separating cassiterite from quartz and calcite, and the indicators are similar. When the concentration of the collector in the pulp is in the range of 55 mg / L, the flotation indicators reach stability, the grade is about 59%, and the recovery rate is about 75%, which is far lower than the flotation indicators of (2-ethylhexyl)phosphate mono-2-ethylhexyl ester.

[0047] Table 2

[0048]

[0049] Example 2

[0050] This embodiment uses raw tin ore from a tin mine in Guangxi Zhuang Autonomous Region, with a tin content of 0.28%. (2-ethylhexyl)phosphate mono-2-ethylhexyl ester is used as the collector for flotation. The specific steps include the following, and the flowchart is shown below. Figure 3 :

[0051] (1) In the preparation of mineral samples, the ore is first added to the grinding mill and ground until the mineral monomers are dissociated to obtain a slurry with 90% of the particles being -200 mesh. Then the pH value of the slurry is adjusted to the range of 7 to 9.

[0052] (2) Add 50 g / t of lead nitrate, 100 g / t of carboxymethyl cellulose, 100 g / t of sodium fluorosilicate and 600 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the slurry in sequence, then add 40 g / t of methyl isobutyl methanol, and then purge for roughing to obtain rough concentrate and rough tailings.

[0053] (3) Add 300 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the obtained crude tailings, then add 20 g / t of methyl isobutyl methanol, and then perform the first scavenging; add 150 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the obtained first scavenged tailings, and then perform the second scavenging to obtain flotation tailings (the scavenged tailings are returned to the previous stage of flotation to form a closed loop).

[0054] (4) Add 50 g / t of carboxymethyl cellulose and 50 g / t of sodium fluorosilicate to the obtained crude concentrate, and then carry out the first cleaning; add 25 g / t of carboxymethyl cellulose and 25 g / t of sodium fluorosilicate to the obtained first cleaned concentrate, and then carry out the second cleaning to obtain flotation concentrate (the middlings of the cleaned concentrate are returned to the previous flotation operation to form a closed loop).

[0055] (5) Dry the obtained foam product concentrate and tailings separately, weigh them and calculate the recovery rate.

[0056] With a tin grade of 0.28% in the feed ore, after one roughing, two cleaning, and two scavenging processes, a tin concentrate with a tin content of 33.13% and a recovery rate of 83.86% can be obtained.

[0057] Comparative Example 2

[0058] This comparative example uses raw tin ore from a tin mine in Guangxi Zhuang Autonomous Region, with a tin content of 0.28%. JG-12 was used as the collector for flotation. The specific steps are as follows, and the flowchart is shown below. Figure 4 :

[0059] (1) In the preparation of tin ore samples, the ore is first added to a grinding mill and ground until the mineral monomers are dissociated to obtain a slurry with 90% of the particles being -200 mesh. Then the pH value of the slurry is adjusted to the range of 7 to 9.

[0060] (2) Add 50 g / t of lead nitrate, 100 g / t of carboxymethyl cellulose, 100 g / t of sodium fluorosilicate and 600 g / t of JG-12 to the cassiterite slurry in sequence, then add 40 g / t of methyl isobutyl methanol, and then purge for roughing to obtain rough concentrate and rough tailings.

[0061] (3) Add 300 g / t of JG-12 to the obtained crude tailings, then add 20 g / t of methyl isobutyl methanol, and then perform the first scavenging; add 150 g / t of JG-12 to the obtained first scavenged tailings, and then perform the second scavenging to obtain flotation tailings (the scavenged tailings are returned to the previous flotation operation to form a closed loop).

[0062] (4) Add 50 g / t of carboxymethyl cellulose and 50 g / t of sodium fluorosilicate to the obtained crude concentrate, and then carry out the first cleaning; add 25 g / t of carboxymethyl cellulose and 25 g / t of sodium fluorosilicate to the obtained first cleaned concentrate, and then carry out the second cleaning to obtain flotation concentrate (the middlings of the cleaned concentrate are returned to the previous flotation operation to form a closed loop).

[0063] (5) Dry the obtained foam product concentrate and tailings separately, weigh them and calculate the recovery rate.

[0064] With a tin grade of 0.28% in the feed ore, after one roughing, two cleaning, and two scavenging processes, a tin concentrate containing 12.48% tin and a recovery rate of 57.40% can be obtained, which is far lower than the flotation index of (2-ethylhexyl)phosphate mono-2-ethylhexyl ester collector.

[0065] Example 3

[0066] This comparative example uses raw tin ore from a cassiterite mine in Yunnan Province, with a tin content of 0.32%. (2-ethylhexyl)phosphate mono-2-ethylhexyl ester was used as the collector for flotation. The specific steps include the following, and the flowchart is shown below. Figure 5 :

[0067] (1) In the preparation of mineral samples, the ore is first added to the grinding mill and ground until the mineral monomers are dissociated to obtain a slurry with 90% of the particles being -200 mesh. Then the pH value of the slurry is adjusted to the range of 7 to 9.

[0068] (2) Add 75 g / t of lead nitrate, 200 g / t of carboxymethyl cellulose, 100 g / t of sodium fluorosilicate and 800 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the slurry in sequence, then add 60 g / t of methyl isobutyl methanol, and then purge for roughing to obtain rough concentrate and rough tailings.

[0069] (3) Add 400 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the obtained crude tailings, stir for 3 min, then add 25 g / t of methyl isobutyl methanol, and then perform the first scavenging; add 200 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the obtained first scavenging tailings, and then perform the second scavenging to obtain flotation tailings (the scavenged tailings are returned to the previous flotation operation to form a closed loop).

[0070] (4) Add 100 g / t of carboxymethyl cellulose and 50 g / t of sodium fluorosilicate to the obtained crude concentrate, and then carry out the first cleaning; add 50 g / t of carboxymethyl cellulose and 25 g / t of sodium fluorosilicate to the obtained first cleaned concentrate, and then carry out the second cleaning to obtain flotation concentrate (the middlings of the cleaned concentrate are returned to the previous flotation operation to form a closed loop).

[0071] (5) Dry the obtained foam product concentrate and tailings separately, weigh them and calculate the recovery rate.

[0072] With a tin grade of 0.32% in the feed ore, after one roughing, two cleaning, and two scavenging processes, a tin concentrate with a tin content of 35.18% and a recovery rate of 82.49% can be obtained.

[0073] Comparative Example 3

[0074] This comparative example uses raw tin ore from a tin mine in Yunnan Province, with a tin content of 0.32%. JG-8 was used as the collector for flotation. The specific steps are as follows, and the flowchart is shown below. Figure 6 :

[0075] (1) In the preparation of mineral samples, the ore is first added to the grinding mill and ground until the mineral monomers are dissociated to obtain a slurry with 90% of the particles being -200 mesh. Then the pH value of the slurry is adjusted to the range of 7 to 9.

[0076] (2) Add 75 g / t of lead nitrate, 200 g / t of carboxymethyl cellulose, 100 g / t of sodium fluorosilicate and 800 g / t of JG-8 to the slurry in sequence, then add 60 g / t of methyl isobutyl methanol, and then ventilate for roughing to obtain rough concentrate and rough tailings.

[0077] (3) Add 400 g / t of JG-8 to the obtained crude tailings, then add 25 g / t of methyl isobutyl methanol, and then perform the first scavenging; add 200 g / t of JG-8 to the obtained first scavenged tailings, and then perform the second scavenging to obtain flotation tailings (the scavenged tailings are returned to the previous flotation operation to form a closed loop).

[0078] (4) Add 100 g / t of carboxymethyl cellulose and 50 g / t of sodium fluorosilicate to the obtained crude concentrate, and then carry out the first cleaning; add 50 g / t of carboxymethyl cellulose and 25 g / t of sodium fluorosilicate to the obtained first cleaned concentrate, and then carry out the second cleaning to obtain flotation concentrate (the middlings of the cleaned concentrate are returned to the previous flotation operation to form a closed loop).

[0079] (5) Dry the obtained foam product concentrate and tailings separately, weigh them and calculate the recovery rate.

[0080] With a tin grade of 0.32% in the feed ore, after one roughing, two cleaning, and two scavenging processes, a tin concentrate containing 10.38% tin and a recovery rate of 53.68% can be obtained, which is far lower than the flotation index of (2-ethylhexyl)phosphate mono-2-ethylhexyl ester collector.

[0081] Example 4

[0082] This comparative example uses cassiterite ore from a cassiterite mine in Yunnan Province, with a tin content of 0.45%. (2-ethylhexyl)phosphate mono-2-ethylhexyl ester was used as the collector for flotation. The specific steps include the following, and the flowchart is shown below. Figure 7 :

[0083] (1) In the preparation of mineral samples, the ore is first added to the grinding mill and ground until the mineral monomers are dissociated to obtain a slurry with 90% of the particles being -200 mesh. Then the pH value of the slurry is adjusted to the range of 7 to 9.

[0084] (2) Add 100 g / t of lead nitrate, 160 g / t of carboxymethyl cellulose, 240 g / t of sodium fluorosilicate and 1000 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the slurry in sequence, then add 80 g / t of methyl isobutyl methanol, and then purge for roughing to obtain rough concentrate and rough tailings.

[0085] (3) Add 500 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester and 40 g / t of methyl isobutyl methanol to the obtained crude tailings, and then perform the first scavenging; add 250 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester and 20 g / t of methyl isobutyl methanol to the obtained first scavenged tailings, and then perform the second scavenging; add 125 g / t of (2-ethylhexyl) phosphate mono-2-ethylhexyl ester to the obtained second scavenged tailings, and then perform the third scavenging to obtain flotation tailings (the scavenged tailings are returned to the previous flotation operation to form a closed loop).

[0086] (4) Add 80 g / t of carboxymethyl cellulose and 120 g / t of sodium fluorosilicate to the obtained crude concentrate, and then perform the first cleaning; add 40 g / t of carboxymethyl cellulose and 60 g / t of sodium fluorosilicate to the obtained first cleaned concentrate, and then perform the second cleaning; add 20 g / t of carboxymethyl cellulose and 30 g / t of sodium fluorosilicate to the obtained second cleaned concentrate, and then perform the third cleaning to obtain flotation concentrate (the middlings from the cleaned concentrate are returned to the previous flotation operation to form a closed loop).

[0087] (5) Dry the obtained foam product concentrate and tailings separately, weigh them and calculate the recovery rate.

[0088] With a tin grade of 0.45% in the feed ore, after one roughing, three cleaning, and three scavenging processes, a tin concentrate with a tin content of 47.12% and a recovery rate of 79.49% can be obtained.

[0089] This invention uses (2-ethylhexyl) phosphate mono-2-ethylhexyl ester, an organophosphate compound with multiple branches, as a flotation collector for cassiterite, which significantly improves the collection capacity and selectivity of cassiterite and enables efficient separation of cassiterite in mixed ore flotation.

[0090] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A cassiterite flotation collector, characterized in that, The collector is (2-ethylhexyl) phosphate mono-2-ethylhexyl ester, and the molecular formula of the collector is [CH3(CH2)3CH(C2H5)CH2O][CH3(CH2)3CH(C2H5)CH2]HPO2; The structural formula of the collector is: 。 2. The application of the cassiterite flotation collector according to claim 1 in the flotation of cassiterite and gangue.

3. The application of the cassiterite flotation collector according to claim 2 in the flotation of cassiterite and gangue, characterized in that, The flotation process includes one roughing stage, two to three scavenging stages, and two to three cleaning stages, with the collector added during the roughing and scavenging stages.

4. The application of the cassiterite flotation collector according to claim 2 or 3 in the flotation of cassiterite and gangue, characterized in that, The amount of collector added during the first roughing process is 600-1000 g / t.

5. The application of the cassiterite flotation collector according to claim 2 or 3 in the flotation of cassiterite and gangue, characterized in that, During the 2nd to 3rd scavenging processes, the amount of collector added in scavenging operation I is 300 to 500 g / t, the amount of collector added in scavenging operation II is 150 to 250 g / t, and the amount of collector added in scavenging operation III is 75 to 125 g / t.

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