A composite collector for positive flotation of bauxite with low aluminum-silicon ratio and preparation method thereof

Abstract

The present invention discloses a composite collector for positive flotation of low-aluminum-silicon ratio bauxite and a preparation method thereof. The method comprises the following steps: gradually adding an emulsifier to water and stirring until uniformly mixed to obtain an emulsifier solution; adding a fatty acid soap compound, a hydroxamic acid compound, and an emulsifier to the emulsifier solution, then heating and stirring to obtain a reagent mixture; placing the reagent mixture in an ultrasonic cleaning machine or a stirring emulsifier, adding a synergist to carry out a synergistic reaction, and stirring the solution to obtain a composite collector. The method is simple and easy to implement, can improve the emulsification effect, reduce production costs, reduce the amount of collector used in the separation process, and achieve conservation and efficient utilization of mineral resources. The prepared collector has the advantages of excellent selectivity, strong collecting capacity, good reagent stability, low temperature resistance, etc., is suitable for the beneficiation of low-aluminum-silicon ratio bauxite, can effectively improve the concentrate grade and recovery rate, and significantly improve the concentrate aluminum-silicon ratio.

Description

Technical Field

[0001] The invention belongs to the technical field of metal ore beneficiation, and particularly relates to a method for preparing a composite collector for positive flotation of bauxite with a low aluminum-silicon ratio. Background Art

[0002] my country's bauxite resources primarily consist of low- to medium-grade diaspore-type bauxite. These bauxites cannot be directly used in the Bayer process and require flotation desiliconization to increase the aluminum-silicon ratio before entering the next Bayer process. The industrialized application of bauxite flotation in the Bayer process for alumina production has effectively increased the utilization rate of my country's bauxite resources and enhanced the market competitiveness of the country's alumina industry.

[0003] Collectors for bauxite flotation desiliconization are a key technology in bauxite flotation separation. Developing and synthesizing the most effective collectors is a crucial approach to improving flotation processes and economic performance. Commonly used bauxite direct flotation collectors primarily include fatty acid soaps and hydroxamic acid compounds. These include fatty acids with varying carbon chains and double bond structures, oxidized paraffin soaps, tall oil, cyclohexane acid, sodium dodecyl sulfonate, and sodium dodecyl sulfate. These agents present challenges in bauxite flotation desiliconization processes, including high dosage, poor selectivity, low concentrate recovery, difficulty settling flotation tailings, and difficulties in reclaimed water utilization. Hydroxamic acid compounds, primarily including alkyl hydroxamic acid, benzohydroxamic acid, and salicylic hydroxamic acid, suffer from relatively limited collection capacity and high cost.

[0004] Currently, the method of mixing bauxite collectors is widely used in industry. The conventional preparation method is to mix a certain amount of emulsifier (such as common alkylphenol polyoxyethylene ethers, polyalkylene glycol polyoxyethylene ethers, polyethylene glycols, Tweens, etc.) with fatty acid soap compounds and hydroxamic acid compounds in a room temperature or heated aqueous solution, and then mechanically stir them to obtain a flotation agent solution. Compared with the use of fatty acid soap compounds or hydroxamic acid compounds alone, the use of emulsifiers helps to reduce the amount of reagents used and improve the separation index to a certain extent. However, the mixed collectors obtained by conventional emulsification still have problems such as poor emulsification effect, uneven dissolution of the reagent, poor reagent stability, and high overall reagent cost. Summary of the Invention

[0005] The object of the present invention is to provide a composite collector for the direct flotation of bauxite with a low aluminum-silicon ratio and a preparation method thereof. The method is simple and easy to implement, can improve the emulsification effect, reduce production costs, reduce the amount of collector used in the separation process, and achieve conservation and efficient utilization of mineral resources. The prepared collector has the advantages of excellent selectivity, strong collecting ability, good reagent stability, low temperature resistance, etc., is suitable for the beneficiation of bauxite with a low aluminum-silicon ratio, can effectively improve the concentrate grade and recovery rate, and significantly improve the aluminum-silicon ratio of the concentrate.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: the composite collector is obtained by mixing, emulsifying and synergizing water, an emulsifier, a fatty acid soap compound, a hydroxamic acid compound, an emulsifier and a synergist, wherein the mass ratio of the fatty acid soap compound, the hydroxamic acid compound, the emulsifier, the emulsifier and the synergist before the reaction is 1:(0.2-0.8):(0.05-0.5):(0.05-0.2):(0.1-0.8); the emulsifier is a mixture of polyvinyl pyrrolidone and polyethylene glycol, and the mass ratio of polyvinyl pyrrolidone to polyethylene glycol is 1:1-1:4.

[0007] A method for preparing a composite collector for positive flotation of bauxite with a low aluminum-silicon ratio comprises the following steps:

[0008] A. Gradually add emulsifier to water and stir until mixed to obtain emulsifier solution;

[0009] B. adding a fatty acid soap compound, a hydroxamic acid compound, and an emulsifier to the emulsifier solution prepared in step A, followed by heating and stirring to obtain a pharmaceutical mixture;

[0010] C. Place the mixed solution of reagents prepared in step B in an ultrasonic cleaning machine or a stirring emulsifier, add a synergist to carry out a synergistic reaction, and stir the solution evenly to obtain a composite collector.

[0011] Preferably, in step A, the emulsifier is a mixture of PVP-K30 and PEG-600, the mass ratio of the two is 1:1 to 1:4, and the emulsifier content in the composite collector is 1% to 6%.

[0012] Preferably, in step B, the emulsifier is a mixture of C5-C9 fatty alcohol and sodium carbonate, and the mass ratio of the two is 1:1 to 1:5.

[0013] Preferably, in step B, the mass ratio of the fatty acid soap compound, the hydroxamic acid compound, the emulsifier and the emulsifier is 1:(0.2-0.8):(0.05-0.5):(0.05-0.2).

[0014] Preferably, in step B, the heating temperature is 20-80° C., and the stirring time is 0.5-5 h.

[0015] Preferably, in step B, the fatty acid soap compound is one or more of oleic acid, oxidized paraffin soap, and tall oil.

[0016] Preferably, in step B, the hydroxamic acid compound is a mixture of benzohydroxamic acid and octylhydroxamic acid in a mass ratio of 1:1.

[0017] Preferably, in step C, the synergist is trimethyl silicone oil, octamethyl trisiloxane, lauryl mercaptan, C 12 ~C 14 One or more of fatty alcohol, kerosene, and coal tar.

[0018] Preferably, in step C, the mass ratio between the fatty acid soap compound and the synergist in the pharmaceutical mixture is 1:(0.1-0.8).

[0019] Preferably, in step C, the processing time of the ultrasonic cleaning machine or the stirring emulsifier is 1 to 3 hours.

[0020] In the present invention, the emulsifier is a mixture of polyvinyl pyrrolidone (PVP-K30) and polyethylene glycol (PEG-600). Although polyethylene glycol has been widely used in the preparation of mining emulsifiers, the mixed use of polyethylene glycol and polyvinyl pyrrolidone is still rare. Polyvinyl pyrrolidone has excellent solubility, solubilization, complexation, surface activity and chemical stability. Its use together with polyethylene glycol can effectively improve the mutual solubility between insoluble substances in the composite agent, enhance the solubilization and emulsification between different components and the stability of the entire composite agent.

[0021] In the present invention, fatty acid soap compounds have strong collecting performance, wide sources and low prices. They are an important component of the composite reagent and can reduce the overall reagent cost while ensuring excellent separation indicators. Hydroxamic acid compounds have a selective chelating effect on metal elements (such as Fe, Cu, Zn, etc.) in ores, which helps to improve the selective collecting ability of the composite collector.

[0022] The emulsifier in the present invention is a mixture of C5-C9 fatty alcohol and sodium carbonate. The C5-C9 fatty alcohol and sodium carbonate are inexpensive. They can not only enhance the mutual solubility between the components and improve the low-temperature foaming and flotation performance of the composite reagent, but the sodium carbonate can also adjust the pH of the solution system and enhance the dispersion of ore slime during the separation process, thereby improving the comprehensive separation index.

[0023] The synergist (trimethyl silicone oil, octamethyl trisiloxane, lauryl mercaptan) in the present invention has excellent surface activity, can significantly adjust the foam characteristics of the composite collector, control the selective interaction between different components and mineral particles, thereby improving the flotation foam condition and increasing the flotation selectivity; C 12 ~C14 The prices of fatty alcohols, kerosene and coal tar are lower than those of commonly used fatty acid soap agents. When added as synergists, they can not only adjust flotation foam, but also significantly improve the recovery of coarse and fine particles, thereby reducing the overall reagent cost and increasing the flotation recovery rate.

[0024] like Figure 1 As shown, common anionic collectors (such as anionic fatty acid soaps and hydroxamic acid compounds) mainly change the surface hydrophilicity and hydrophobicity of bauxite by adsorbing on the surface of bauxite through the molecular-ion association effect. The single molecule and ion action ability in this modification is limited. In order to achieve sufficient hydrophobicity on the mineral surface, a large amount of reagents are often consumed. The strong emulsification and strong dispersion promoting agents in the composite collector solution prepared by the present invention act with the mineral in the form of free molecules, microemulsions, and nanoparticles, which can significantly improve the comprehensive utilization efficiency of the reagents and improve the floatability of the mineral. At the same time, due to the porous nature of bauxite, the nanoemulsions and nanoparticles present in the composite collector can effectively fill the pores of the bauxite particles, significantly reducing the amount of reagents used while strengthening the hydrophobicity of the bauxite particles, thereby improving the comprehensive separation efficiency and benefits.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) Based on the occurrence form of bauxite, the process mineralogy characteristics (bauxite generally has the characteristics of easy mudification, developed pores on the surface of the block ore, and large specific surface area due to mineralization), and the characteristics of the beneficiation and enrichment process and method, the present invention has developed a simple and easy preparation method. The method can improve the emulsification effect, reduce production costs, reduce the amount of collector used in the separation process, and achieve the conservation and efficient utilization of mineral resources. The prepared collector has the advantages of excellent selectivity, strong collection ability, good reagent stability, and low temperature resistance. It is suitable for the beneficiation of low aluminum-silicon ratio bauxite, can effectively improve the concentrate grade and recovery rate, and significantly improve the aluminum-silicon ratio of the concentrate; in addition, the composite collector prepared by the present invention can directly and effectively float bauxite without removing fine mud, and is suitable for the positive flotation desiliconization process of different types of low aluminum-silicon ratio bauxite (including diaspore type, boehmite type and gibbsite type).

[0027] (2) Based on the comprehensive consideration of reagent cost and mineral processing efficiency, the present invention is based on the principle of synergistic enhancement of different reagent combinations. Through the effective compound combination of emulsifiers, fatty acid soap compounds, hydroxamic acid compounds, emulsifiers and synergists, the components of the collector are adsorbed and acted synergistically on the bauxite surface. The types and ratios of different reagents in the compound reagents are the key to ensuring the final good bauxite separation indicators. This method can selectively increase the hydrophobicity of the target mineral surface of the bauxite, enhance the adsorption selectivity and collection capacity of the reagents, and thus improve the mineral processing technical indicators of low aluminum-silicon ratio bauxite.

[0028] (3) The collector prepared by the present invention has good stability and can exist stably in the form of an emulsion at room temperature. After being diluted with water, the emulsion still maintains good stability and can play a stable role during the slurry flotation time; it has strong dispersibility in the slurry, fully reacts with the minerals, and significantly improves the flotation index; it has good foaming properties, fine and uniform foam, and does not require the addition of additional foaming agents; the raw materials are widely available, and the overall agent cost is low; the overall agent usage is small, and the agent cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagrams showing the interaction between surface porous bauxite and conventional collectors and the composite collector prepared by the present invention;

[0030] Figure 2 This is a flow chart of the bauxite separation process of the present invention;

[0031] Figure 3 Surface morphology and structure diagrams of bauxite at different magnifications, (a), scale 1mm, (b), scale 500μm, (c), scale 200μm, (d), scale 10nm. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] The present invention uses a bauxite mine from Zunyi, Guizhou Province. The Al2O3 grade in the raw bauxite is 58.18%, the SiO2 grade is 17.59%, and the aluminum-silicon ratio (A / S) is 3.31. Al2O3 is primarily produced in the form of diaspore, primarily monohydrate. The ore appears gray to the naked eye, with a mottled gray color, a loose structure, and is easily broken by knocking, showing obvious signs of weathering. Figure 3 The surface morphology of the electrical bauxite lump at different magnification ratios shows that the bauxite has well-developed pores on the surface and has typical bauxite process mineralogy characteristics.

[0034] Comparative Example 1

[0035] A method for preparing a composite collector for positive flotation of bauxite with a low aluminum-silicon ratio comprises the following steps:

[0036] A. Gradually add 25 parts of sodium carbonate to 120 parts by mass of water and stir until mixed to obtain a sodium carbonate solution;

[0037] B. Add 30 parts of oleic acid, 8 parts of benzohydroxamic acid, and 8 parts of octylhydroxamic acid to the sodium carbonate solution prepared in step A in sequence, and then mechanically mix and stir at 65° C. for 3 hours to obtain a composite collector solution.

[0038] Example 1

[0039] A method for preparing a composite collector for positive flotation of bauxite with a low aluminum-silicon ratio comprises the following steps:

[0040] A. Gradually add 6 parts of PEG-600 to 120 parts by mass of water and stir until mixed to obtain an emulsifier solution;

[0041] B. Add 30 parts of oleic acid, 8 parts of benzohydroxamic acid, 8 parts of octylhydroxamic acid, and 25 parts of sodium carbonate to the emulsifier solution prepared in step A, and then mechanically mix and stir at 65° C. for 3 hours to obtain a pharmaceutical mixture;

[0042] C. Place the pharmaceutical mixture prepared in step B in a stirring emulsifier, add 3 parts of trimethyl silicone oil, 6 parts of C 12 ~C 14 The fatty alcohol and 8 parts of kerosene are subjected to synergistic reaction and the solution is stirred evenly to obtain a composite collector.

[0043] Example 2

[0044] In this embodiment, "the emulsifiers selected in step A are PVP-K30 and PEG-600 in a mass ratio of 1:2, and the total mass fraction of the emulsifiers remains unchanged at 6 parts, i.e., 2 parts of PVP-K30 and 4 parts of PEG-600", and the other steps remain the same as in Example 1.

[0045] The composite collectors prepared in Comparative Example 1, Example 1 and Example 2 were used in bauxite flotation. The flotation process was as follows: Figure 2 As shown, the ore is ground to a particle size of less than 0.074mm, accounting for about 78% of the mass percentage of the entire bauxite. After grinding, under the flotation temperature of 18-22°C, sodium carbonate, sodium hexametaphosphate, and a composite collector are added in the roughing operation in sequence and stirred to adjust the slurry. After slurry adjustment, the ore enters the flotation tank for flotation. The slurry undergoes one roughing, two sweeping, and four fine operations, and the middling ore returns to the previous operation in sequence. A small amount of sodium hexametaphosphate is added to the refinery I and refinery II operations, and the refinery III and refinery IV are blank selection operations. A small amount of composite collector is added to sweeping I and sweeping II. The flotation results are shown in Table 1:

[0046] Table 1 Effect of emulsifier type on positive flotation index of low aluminum-silicon ratio bauxite

[0047]

[0048]

[0049] As shown in Table 1, compared with the traditional combined collector of fatty acid soap compounds and hydroxamic acid compounds, the composite collector prepared by adding emulsification and performing synergistic reaction in the present invention has higher collection performance and selectivity for the flotation of low aluminum-silicon ratio bauxite. The composite collector can obtain a higher concentrate Al2O3 recovery rate and aluminum-silicon ratio than conventional oleic acid; the overall effect of mixed use of PEG-600 and PVP-K30 is better than that of using PEG-600 alone. Specifically, when using PEG-600 and PVP-K30, the Al2O3 grade in the bauxite concentrate was reduced by 0.23%, the Al2O3 recovery rate was increased by 1.47%, and the A / S ratio was only reduced by 0.02 compared with the use of PEG-600 alone. This is related to the good solubilization effect of PVP-K30 on various organic matter and the selective flocculation effect on aluminosilicate gangue (such as kaolinite, mica, pyrophyllite, etc.) in the ore mud.

[0050] Example 3

[0051] In this embodiment, "the fatty acid soap compound selected in step B is oleic acid, oxidized paraffin soap and tall oil in a mass ratio of 3:2:1, and the total addition amount of the fatty acid soap compound remains unchanged, which is still 30 parts", and the other steps remain the same as in Example 2.

[0052] Example 4

[0053] In this embodiment, "the emulsifier selected in step B is sodium carbonate and C5-C9 fatty alcohol in a mass ratio of 18:8, and the total amount of the emulsifier is 26 parts", and the other steps remain the same as in Example 2.

[0054] Example 5

[0055] In this embodiment, "the temperature of the mixed raw materials in step B is changed to 50° C. and the mixing time is changed to 2 h", and the other steps remain the same as in Example 4.

[0056] The composite collectors prepared in Examples 3-5 were used in bauxite flotation. The flotation process was as follows: Figure 2 The flotation results are shown in Table 2:

[0057] Table 2 Effects of fatty acid soap compounds, emulsifier types, and preparation conditions on positive flotation indices of low aluminum-silicon ratio bauxite

[0058]

[0059] As shown in Table 2, the separation performance achieved using oleic acid as a fatty acid soap compound additive is similar to that achieved using a mixture of oleic acid, oxidized paraffin soap, and tall oil, demonstrating the compound's excellent compatibility with a variety of fatty acid soap compounds. When sodium carbonate and C5-C9 fatty alcohols are used together as emulsifiers, the Al2O3 recovery rate in the concentrate is significantly improved compared to using only sodium carbonate. Specifically, a comparison of the corresponding indicators in Example 4 and Example 2 reveals that the addition of C5-C9 fatty alcohols reduces the Al2O3 grade in the concentrate by 0.63%, increases the Al2O3 recovery by 1.04%, and reduces the A / S ratio by 0.07. This is because the short-chain fatty alcohols effectively solubilize other organic agents, enhancing the selective adsorption of fatty acid soap compounds and hydroxamic acid compounds on the bauxite surface and improving the stability of the flotation froth. At the same time, by comparing the corresponding selection indicators of Example 5 and Example 4, it was found that lower temperature and stirring time when mixing the raw materials are helpful to improve the activity of the composite collector and further improve the final selection index. This is because low temperature conditions are more conducive to the retention of volatile substances such as alcohol, thereby enhancing the solubilization of other organic substances.

[0060] Example 6

[0061] In this embodiment, "trimethyl silicone oil is no longer added as a synergist in step C, and the types and addition amounts of other synergists remain unchanged", and the other steps remain the same as those in Example 5, specifically including the following steps:

[0062] A. Gradually add 2 parts of PVP-K30 and 4 parts of PEG-600 to 120 parts by mass of water and stir until mixed to obtain an emulsifier solution;

[0063] B. Add 30 parts of oleic acid, 8 parts of benzohydroxamic acid, 8 parts of octylhydroxamic acid, 18 parts of sodium carbonate, and 8 parts of C5-C9 fatty alcohol to the emulsifier solution prepared in step A, and then mechanically mix and stir at 50° C. for 2 hours to obtain a pharmaceutical mixture;

[0064] C. Place the pharmaceutical mixture prepared in step B in a stirring emulsifier and add 6 parts of C. 12 ~C 14 The fatty alcohol and 8 parts of kerosene are subjected to synergistic reaction and the solution is stirred evenly to obtain a composite collector.

[0065] Example 7

[0066] In this embodiment, the synergist in step C is changed to 2 parts of lauryl mercaptan, 1 part of octamethyl trisiloxane, 6 parts of C 12 ~C 14 Fatty alcohol; 8 parts of kerosene. Other steps are consistent with Example 6.

[0067] Example 8

[0068] In this embodiment, the synergist in step C is changed to 3 parts trimethyl silicone oil and 6 parts C 12 ~C 14 Fatty alcohol, 8 parts of coal tar", and other steps were consistent with Example 6.

[0069] Example 9

[0070] In this embodiment, the synergist in step C is changed to 3 parts trimethyl silicone oil and 6 parts C 12 ~C 14 Fatty alcohol", and other steps were consistent with Example 6.

[0071] Example 10

[0072] In this embodiment, the synergist in step C is changed to 3 parts trimethyl silicone oil and 6 parts C 12 ~C 14 Fatty alcohol, 10 parts of coal tar, 2 parts of lauryl mercaptan" and other steps are consistent with Example 6.

[0073] Example 11

[0074] In this embodiment, "in step C, ultrasonic treatment is used instead of emulsifier stirring for 3 hours to perform the synergistic reaction", and the other steps remain the same as in Example 10.

[0075] The composite collectors prepared in Examples 6-11 were used in bauxite flotation. The flotation process was as follows: Figure 2 The flotation results are shown in Table 3:

[0076] Table 3 Effects of synergist type, dosage and synergistic reaction conditions on positive flotation indexes of low aluminum-silicon ratio bauxite

[0077]

[0078] As shown in Table 3, comparative example 5, embodiment 6 and embodiment 7 corresponding sorting results show that if trimethicone is not added, final concentrate Al o grade will significantly decline, concentrate Al simultaneously o rate of recovery does not significantly promote, and after using lauryl mercaptan and octamethyl trisiloxane to substitute trimethicone, flotation index remains unchanged (concentrate Al substantially o rate of recovery has reduced by 0.52%, and concentrate A / S has improved by 0.15).This explanation is in this composite reagent, and the interpolation of trimethicone, lauryl mercaptan and octamethyl trisiloxane is indispensable, and can consider that index needs and medicament price use lauryl mercaptan and octamethyl trisiloxane to substitute trimethicone during actual use simultaneously.Trimethicone, lauryl mercaptan, octamethyl trisiloxane all belong to the stronger surfactant of activity, have good sudsing effect, and their interpolation helps to reduce the flotation process gangue and carries away, and can promote the selective adsorption of fatty acid soap compound and hydroxamic acid compound at purpose mineral surface.

[0079] As shown in Table 3, by comparing the results of Example 5, Example 8, and Example 9, it can be seen that the addition of non-polar oil (kerosene, coal tar) in the synergist is necessary. Non-polar oil is cheap, and its addition can significantly reduce the overall reagent cost, and the presence of non-polar oil can ensure a higher concentrate Al2O3 recovery rate. At the same time, when coal tar is used instead of kerosene as a synergist, the final concentrate Al2O3 recovery rate is further improved. This is because bauxite has the characteristic of being naturally porous (the surface morphology of bauxite is shown in FIG. Figure 3 As shown in the figure, there are a large number of super-hydrophobic nano-solid particles in coal tar. When the composite agent interacts with the mineral particles, these super-hydrophobic nano-particles can effectively fill the hydrophilic pores, effectively improving the hydrophobicity of the bauxite surface while significantly reducing the amount of agent used.

[0080] As shown in Table 3, by comparing the corresponding separation results of Example 8 and Example 10, it can be seen that while ensuring that other reagent components remain unchanged, a slightly increased amount of coal tar is used and a small amount of lauryl mercaptan is added, a higher quality bauxite concentrate can be obtained (the concentrate Al2O3 grade is increased from 66.46% to 67.59%, and the concentrate A / S is increased by 0.2), while the concentrate Al2O3 recovery rate only decreases by 0.31%, indicating that lauryl mercaptan can effectively improve the flotation selectivity of bauxite, and the addition of coal tar ensures a higher concentrate Al2O3 recovery rate.

[0081] As can be seen from Table 3, by comparing the corresponding separation results of Example 10 and Example 11, it can be seen that the use of an ultrasonic cleaner to move to a stirring emulsifier for synergistic reaction and prolonging the processing time can significantly improve the flotation performance of the final composite reagent. When the Al2O3 grade of the concentrate decreases by 0.12%, the Al2O3 recovery rate of the concentrate increases by 1.38%, and the A / S of the concentrate decreases by only 0.05. This shows that the use of ultrasonic waves with better emulsification and dispersion effects for synergistic reaction is more conducive to improving the comprehensive separation performance of the composite reagent.

[0082] In summary, under the same material conditions, the use of composite collectors instead of conventional fatty acid soap and hydroxamic acid combined collectors in the direct flotation of low aluminum-silicon ratio bauxite can achieve higher concentrate Al2O3 grade, concentrate Al2O3 recovery rate and concentrate A / S, which fully demonstrates that the composite collector has better comprehensive separation performance than the conventional combined collector (a mixture of fatty acid soap compounds and hydroxamic acid compounds). Furthermore, the use of a mixed emulsifier of PEG-600 and PVP-K30 achieved superior separation performance compared to PEG-600 alone. Oleic acid, oxidized paraffin soap, and tall oil were all suitable raw materials for fatty acid soap compounds. A mixed emulsifier of sodium carbonate and C5-C9 fatty alcohols achieved superior separation performance compared to sodium carbonate alone. Among the synergists, trimethyl silicone oil, lauryl mercaptan, and octamethyltrisiloxane effectively modulated flotation froth and promoted the selectivity of fatty acid soap compounds and hydroxamic acid compounds for bauxite, thereby improving flotation selectivity. Non-polar kerosene and coal tar helped increase the final concentrate Al₂O₃ recovery rate, with coal tar having a more pronounced effect due to the superhydrophobic nanoparticles in the compound producing a "pore-filling" effect on the hydrophilic mineral surface. The performance of the composite agent was also influenced by the ratio of the various components and the preparation conditions. Most of the components in the composite agent were cheaper than the fatty acid soap compounds and hydroxamic acid compounds, ensuring a low cost and excellent cost-effectiveness.

[0083] There are many specific implementation ways of the present invention. The above is only the preferred implementation method of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be considered as the scope of protection of the present invention.

Claims

1. A method for preparing a composite collector for positive flotation of bauxite with a low aluminum-silicon ratio, characterized in that: The composite collector is obtained by mixing, emulsifying, and reacting water, an emulsifier, a fatty acid soap compound, a hydroxamic acid compound, an emulsifier, and a synergist. Before the reaction, the mass ratio of the fatty acid soap compound, the hydroxamic acid compound, the emulsifier, the emulsifier, and the synergist is 1:(0.2-0.8):(0.05-0.5):(0.05-0.2):(0.1-0.8); the emulsifier is a mixture of polyvinyl pyrrolidone and polyethylene glycol, and the mass ratio of polyvinyl pyrrolidone to polyethylene glycol is 1:1-1:4; The preparation method comprises the following steps: A. Gradually add emulsifier to water and stir until mixed to obtain emulsifier solution; B. adding a fatty acid soap compound, a hydroxamic acid compound, and an emulsifier to the emulsifier solution prepared in step A, followed by heating and stirring to obtain a pharmaceutical mixture; C. Place the mixed solution of reagents prepared in step B in an ultrasonic cleaning machine or a stirring emulsifier, add a synergist to carry out a synergistic reaction, and stir the solution evenly to obtain a composite collector.

2. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1, characterized in that: In step A, the emulsifier is a mixture of PVP-K30 and PEG-600, the mass ratio of the two is 1:1~1:4, and the emulsifier content in the composite collector is 1%~6%.

3. The method for preparing a composite collector for positive flotation of bauxite with a low aluminum-silicon ratio according to claim 1 or 2, characterized in that: In step B, the emulsifier is a mixture of C5-C9 fatty alcohol and sodium carbonate, and the mass ratio of the two is 1:1-1:

5.

4. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1, characterized in that: In step B, the mass ratio of the fatty acid soap compound, the hydroxamic acid compound, the emulsifier, and the emulsifier is 1: (0.2-0.8): (0.05-0.5): (0.05-0.2).

5. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1 or 2, characterized in that: In step B, the heating temperature is 20-80° C., and the stirring time is 0.5-5 h.

6. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1 or 2, characterized in that: In step B, the fatty acid soap compound is one or more of oleic acid, oxidized paraffin soap, and tall oil.

7. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1 or 2, characterized in that: In step B, the hydroxamic acid compound is a mixture of benzohydroxamic acid and octylhydroxamic acid in a mass ratio of 1:

1.

8. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1 or 2, characterized in that: In step C, the synergist is trimethyl silicone oil, octamethyl trisiloxane, lauryl mercaptan, C 12 ~C 14 One or more of fatty alcohol, kerosene, and coal tar.

9. The method for preparing a composite collector for direct flotation of bauxite with a low aluminum-silicon ratio according to claim 1 or 2, characterized in that: In step C, the mass ratio between the fatty acid soap compound and the synergist in the pharmaceutical mixture is 1: (0.1~0.8).

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