A high selectivity process for the flotation of titanium minerals

Abstract

The application relates to a high-selectivity ilmenite flotation process, and belongs to the technical field of flotation, and aims to solve at least one of the problems of poor ilmenite selectivity and poor collecting performance of the existing flotation method. In the ilmenite flotation process, a specific structure of a collector is selected, two hydroxyl imino groups are introduced into the same molecular structure, the solid-philic group formed by the two hydroxyl imino groups can improve the combination capacity between the collector and metal ions; the adsorption stability of the whole collector molecule on the mineral surface is enhanced, the collecting performance and selectivity of the collector molecule are improved; meanwhile, the raw ore is subjected to a plasma pretreatment method, the mineral surface structure can be changed, the impurities on the mineral surface can be reduced, the reaction activity of the mineral surface can be enhanced, the surface property difference between ilmenite and magnesium olivine can be improved, the collector molecule can chemically react with the ilmenite surface under weak acid conditions, the ilmenite flotation separation efficiency is improved, and the amount of sulfuric acid is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flotation, in particular to a flotation process of ilmenite with high selectivity. BACKGROUND

[0002] China is rich in titanium resources, accounting for about 28% of the world's total reserves. Ilmenite is the main source of titanium resources in China, mainly distributed in Panzhihua and Xichang areas of Sichuan. The ilmenite resources in China are characterized by "more lean ore, less rich ore, and fine particle size", which makes it difficult to achieve efficient separation and restricts the further utilization of titanium resources. Flotation is an important method to realize efficient separation of fine-grained mineral resources. Due to the similar surface properties of the target mineral and the gangue mineral, traditional fatty acid collectors have good collecting properties, but it is difficult to achieve efficient separation of the two. Arsenic acid and phosphoric acid collectors have certain collecting properties and selectivity, but there are problems such as environmental pollution, so it is necessary to develop environmentally friendly high-selectivity flotation collectors.

[0003] In recent years, hydroxamic acid collectors have received widespread attention due to their excellent flotation performance, but the selectivity of the functional groups of the collector is poor and the collecting performance is poor. SUMMARY

[0004] In view of the above analysis, the present application aims to provide a flotation process of ilmenite with high selectivity to solve at least one of the problems of poor selectivity, poor collecting performance, and low recovery rate of the existing rough and clean flotation method.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0006] A flotation process of ilmenite with high selectivity, comprising the following steps:

[0007] (1) The raw ore is subjected to plasma pretreatment, and sodium oleate is added for the first flotation desliming to obtain desliming tailings;

[0008] (2) The desliming tailings are added with a collector with the structural formula shown as formula (I) under weak acid conditions for the second flotation to obtain ilmenite rough concentrate;

[0009] (3) The ilmenite rough concentrate is subjected to the third flotation to obtain ilmenite concentrate;

[0010] Wherein, the collector shown as formula (I) is as follows:

[0011] R is an alkyl group.

[0012] Further, in step (1), the power in the plasma pretreatment is 60-100 W, the treatment time is 3-8 min, and the treatment gas flow rate is 200-500 mL / min.

[0013] Further, the plasma pretreatment adopts a plasma treatment gas, and the plasma treatment gas is argon and oxygen mixed in a volume ratio of 1:1-3.

[0014] Further, a foaming agent is added in the first time of the floatation desliming, and sulfuric acid is added in the second time of the floatation and the third time of the floatation.

[0015] Further, the R is an alkyl group with 8-10 carbon atoms.

[0016] Further, in the step (2), the adding amount of the collector is 300-600 g / t.

[0017] Further, the collector is prepared by the following method:

[0018] (a) dissolving glutamic acid in a methanol solution containing NaOH, then adding a halogenated alkane to perform a substitution reaction, and then acidifying by hydrochloric acid to generate 2-(alkyl) glutaric acid with imino and branched chain;

[0019] (b) dissolving the acyl chloride in methanol to obtain a mixed solution, adding 2-(alkyl) glutaric acid with imino and branched chain into the mixed solution to perform a reaction to obtain 2-(alkyl) glutaric acid methyl ester;

[0020] (c) dissolving the hydroxylamine salt and the base in methanol, ultrasonic dispersion and dissolution, then adding 2-(alkyl) glutaric acid methyl ester, performing a hydroxamic acid reaction after heating, adjusting the pH value to 5-6, filtering, and drying to obtain the collector.

[0021] Further, in the step (a), the halogenated alkane is chloroalkane, bromoalkane or iodoalkane.

[0022] Further, in the step (b), the reaction temperature is 20-35℃, and the reaction time is 16-20h.

[0023] Further, in the step (c), the heating temperature is 40-60℃, and the reaction time is 4-6h.

[0024] Compared with the prior art, the present application can at least achieve one of the following beneficial effects:

[0025] (1) The specific structure of the collector in the ilmenite flotation process of the application introduces two hydroxylamine groups and imino groups into the same molecular structure, the solidophilic group composed of two hydroxylamine groups can improve the binding capacity between the collector and metal ions; while one hydroxylamine group forms a stable chelate ring with the surface active site, the other hydroxylamine group can rotate flexibly, which not only reduces the induction effect and steric hindrance effect between the two polar groups, but also improves the matching performance of the molecule and the double active sites on the ilmenite surface; in addition, the imino group in the carbon chain of the collector molecule can promote the association between the collector molecules through hydrogen bonding; the adsorption stability of the collector molecule on the mineral surface is improved, and the collecting property and selectivity of the collector molecule are improved;

[0026] (2) The method of the application simultaneously uses plasma pretreatment method on the raw ore, which can change the mineral surface structure, reduce the impurities on the mineral surface, enhance the reactivity of the mineral surface, improve the difference in surface properties between ilmenite and peridot, so that the collector molecules can react with the ilmenite surface under weakly acidic conditions, improve the ilmenite flotation separation efficiency, and reduce the amount of sulfuric acid.

[0027] (3) The method of the application uses the flotation pre-desliming method under natural pH conditions to effectively reduce the influence of gangue argillization on ilmenite flotation, reduce the adsorption probability of the collector on the surface of the gangue mineral, thereby improving the mineral flotation efficiency, improving the concentrate grade and recovery rate, and reducing the consumption of reagents.

[0028] In the application, the above technical solutions can be combined with each other to realize more preferred combination solutions. Other features and advantages of the application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the application. The purposes and other advantages of the application can be realized and obtained from the contents specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the application and are incorporated herein and constitute a part of the application. The drawings illustrate embodiments of the application and, together with the description, serve to explain the principles of the application. In the drawings:

[0030] Figure 1 The infrared spectrum of the collector prepared for the embodiment 1 of the application;

[0031] Figure 2 The mass spectrum of the collector prepared for the embodiment 1 of the application;

[0032] Figure 3 The nuclear magnetic resonance spectrum of the collector prepared for the embodiment 1 of the application. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present application will be described in detail below with reference to the drawings, wherein the drawings constitute a part of the present application and serve to explain the principles of the present application together with the embodiments of the present application, but are not intended to limit the scope of the present application.

[0034] In one specific embodiment of the present application, a high-selectivity flotation process of ilmenite is disclosed, comprising the following steps:

[0035] (1) subjecting the raw ore to plasma pretreatment, adding sodium oleate to perform first flotation desliming, and obtaining desliming tailings;

[0036] (2) adding a collector with a structural formula as shown in formula (I) to the desliming tailings under weakly acidic conditions to perform second flotation, and obtaining ilmenite rough concentrate;

[0037] (3) performing third flotation on the ilmenite rough concentrate, and obtaining ilmenite concentrate;

[0038] wherein the collector with a structural formula as shown in formula (I) is as follows:

[0039] R is an alkyl group.

[0040] Compared with the prior art, in the ilmenite flotation process of the present application, a specific structure of the collector is selected, two hydroxyl imino groups and an imino group are introduced into the same molecular structure, the solidophilic group composed of the two hydroxyl imino groups can improve the binding capacity between the collector and metal ions; while one of the hydroxyl imino groups forms a stable chelate ring with the surface active site, the other hydroxyl imino group can rotate flexibly, not only reducing the induction effect and steric hindrance effect between the two polar groups, but also improving the matching performance of the molecule and the double active sites on the ilmenite surface, in addition, the imino group in the carbon chain of the collector molecule can promote the association between the collector molecules through hydrogen bonding; the adsorption stability of the overall collector molecule on the mineral surface is enhanced, the collecting property and selectivity of the collector molecule are improved; at the same time, the raw ore is subjected to plasma pretreatment, which can change the mineral surface structure, reduce the impurities on the mineral surface, enhance the reactivity of the mineral surface, improve the difference in surface properties between ilmenite and forsterite, so that the collector molecule can chemically react with the ilmenite surface under weakly acidic conditions, improve the ilmenite flotation separation efficiency, and reduce the amount of sulfuric acid used. In addition, the flotation pre-desliming method under natural pH conditions can effectively reduce the influence of gangue sliming on ilmenite flotation, reduce the adsorption probability of the collector on the surface of the gangue mineral, thereby improving the mineral flotation efficiency, improving the concentrate grade and recovery rate, and reducing the consumption of reagents.

[0041] In one specific embodiment, in step (1), the power in the plasma pretreatment is 60-100 W, for example, 60 W, 65 W, 70 W, 75 W, 80 W, 85 W, 90 W, 95 W, 100 W, the processing time is 3-8 min, for example, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, and the processing gas flow rate is 200-500 mL / min, for example, 200 mL / min, 250 mL / min, 300 mL / min, 350 mL / min, 400 mL / min, 450 mL / min, 500 mL / min.

[0042] In one specific embodiment, the plasma pretreatment uses a plasma processing gas, and the plasma processing gas is a mixture of argon and oxygen in a volume ratio of 1:1-3.

[0043] It should be noted that if there is only argon and no oxygen, the plasma cleaning machine only has the effect of cleaning surface impurities, and with oxygen, the surface of the ilmenite can be oxidized to be more hydrophilic, and the divalent iron ions can be oxidized to trivalent iron ions, which is more conducive to the adsorption of the collector. The surface of the forsterite (gangue) is oxidized, which is more hydrophilic, and the difference in the surface properties of the two minerals after the pretreatment is greater, which is conducive to flotation. The volume ratio of the present application is selected to ensure that the ilmenite is not oxidized too much, so that the surface oxidation degree is too large and the hydrophilicity is enhanced. If the oxidation is too much, both the surfaces of the two minerals will have strong hydrophilicity, and the difference will decrease. Therefore, the proportion of oxygen is controlled.

[0044] In one specific embodiment, a frother is also added in the first flotation desliming, and sulfuric acid is also added in the second flotation and the third flotation.

[0045] Preferably, the frother is methyl isobutyl carbinol.

[0046] Specifically, in step (1), the pretreated raw ore is dispersed in water, sodium oleate and a frother are added for the first flotation desliming.

[0047] Specifically, the amount of sodium oleate added is 600-800 g / t, for example, 600 g / t, 650 g / t, 700 g / t, 750 g / t, 800 g / t.

[0048] In step (2), the collector is added to the desliming tailings and dispersed uniformly, sulfuric acid is added to adjust the pH value to 6-6.5, the second flotation is carried out, and the ilmenite rough concentrate is obtained.

[0049] Specifically, the collector is added in an amount of 300-600 g / t. For example, 300 g / t, 350 g / t, 400 g / t, 450 g / t, 500 g / t, 550 g / t, 600 g / t.

[0050] In step (3), the ilmenite rough concentrate is added into sulfuric acid to adjust the pH value to 6-6.5, and then the third flotation is performed to obtain the ilmenite concentrate.

[0051] In a specific embodiment, R is an alkyl group with 8-10 carbon atoms, and preferably, R is octyl or decyl. When R is an alkyl group with 8-10 carbon atoms, the collecting property and selectivity of the collector are better, and the number of carbon atoms being too low or too high will affect the collecting property and selectivity.

[0052] It should be noted that the crude ore in the present application is calcium-magnesium-iron-titanium ore, and the gangue mineral is forsterite or calcite, and the TiO2 grade in the crude ore is ≤13%.

[0053] In a specific embodiment, the collector is prepared by the following method:

[0054] (a) dissolving glutamic acid in a methanol solution containing NaOH, then adding a haloalkane to perform a substitution reaction, and then acidifying with hydrochloric acid to generate 2-(alkyl) glutaric acid with an imino group and a branched chain;

[0055] (b) dissolving acyl chloride in methanol to obtain a mixed solution, adding 2-(alkyl) glutaric acid with an imino group and a branched chain into the mixed solution to perform a reaction to obtain 2-(alkyl) glutaric acid methyl ester;

[0056] (c) dissolving hydroxylamine salt and alkali in methanol, ultrasonic dispersion and dissolution, then adding 2-(alkyl) glutaric acid methyl ester, performing hydroxamic acid reaction after heating, adjusting the pH value to 5-6, filtering, and drying to obtain the collector.

[0057] In a specific embodiment, in step (a), the haloalkane is chloroalkane, bromoalkane or iodoalkane.

[0058] Specifically, in step (a), the molar ratio of haloalkane to glutamic acid is 1:0.7-0.8, for example, 1:0.7, 1:0.71, 1:0.72, 1:0.73, 1:0.74, 1:0.75, 1:0.76, 1:0.77, 1:0.78, 1:0.79, 1:0.8, and hydrochloric acid is added to adjust the pH value to 5.

[0059] In a specific embodiment, in step (b), the reaction temperature is 20-35℃, for example, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃, 35℃, and the reaction time is 16-20h, for example, 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h.

[0060] Specifically, in step (b), the molar ratio of 2-(alkyl)glutaric acid with imino and branched chain to acyl chloride is 1:2-2.5, for example, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5.

[0061] In a specific embodiment, in step (c), the heating temperature is 40-60℃, for example, 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, and the reaction time is 4-6h, for example, 4h, 4.2h, 4.4h, 4.6h, 4.8h, 5.0h, 5.2h, 5.4h, 5.6h, 5.8h, 6h.

[0062] Specifically, in step (c), the molar ratio of 2-(alkyl)glutaric acid methyl ester, hydroxylamine salt and base is 1:2-2.5:4-5, for example, 1:2:4, 1:2.1:4.2, 1:2.2:4.4, 1:2.3:4.6, 1:2.4:4.8, 1:2.5:5.

[0063] The collector in the present application not only has two hydroxylamine groups, but also has excellent collecting property and selectivity, and the three carbon atoms between the two hydroxylamine groups make the collector molecule have a certain flexibility, and the two polar functional groups can be adjusted by the spatial distribution of the active site to better match the active site on the mineral surface. In addition, the imino group in the molecule can be bridged by hydrogen bond interaction, so that the collector molecules are stably arranged in a network structure on the mineral surface. The hydrophobicity of the mineral surface is improved.

[0064] The flotation method of the present application can be used not only for ilmenite, but also for phosphate rock, rutile, fluorite, tungsten ore and the like.

[0065] The technical solutions of the present application are further explained in combination with specific examples.

[0066] Example 1

[0067] The flotation process of ilmenite with high selectivity in this example comprises the following steps:

[0068] (1) the raw ore is subjected to plasma pretreatment, wherein the raw ore is ilmenite, the power of the plasma treatment is 60 W, the treatment time is 8 min, the treatment gas flow rate is 200 mL / min, and the plasma treatment uses a treatment gas, wherein the treatment gas is argon and oxygen mixed at a volume ratio of 1:1;

[0069] The pretreated raw ore is dissolved in water, 800 g / t of sodium oleate and 1 drop of a frother are added for first-time flotation desliming, and a desliming tailing is obtained;

[0070] (2) 500 g / t of the collector is added to the desliming tailing and uniformly dispersed, sulfuric acid is added to adjust the pH value to 6-6.5, and second-time flotation is performed, and an ilmenite rough concentrate is obtained;

[0071] (3) the ilmenite rough concentrate is added to sulfuric acid to adjust the pH value to 6-6.5, and third-time flotation is performed, and an ilmenite concentrate is obtained;

[0072] The structural formula of the collector of the embodiment is as follows:

[0073]

[0074] The preparation method of the collector of the embodiment is as follows:

[0075] (a) 1-bromon-octane (10 g) and glutamic acid are weighed in a molar ratio of 1:0.7, the glutamic acid is dissolved in a methanol solution containing NaOH (pH=10.3-10.8), then 1-bromon-octane is added, heated to 45℃ (control the reaction pH>10), and reacted for 5 h, after the reaction is completed, 1.0 mol / L HCl is added to adjust the pH of the obtained mixture to 5, the white precipitate is filtered and washed with a mixture of acetone and water, and then crystallized twice in an equal mixture of ethanol and water, to obtain 2-(octylamine) glutaric acid.

[0076] (b) 2-(octylamine) glutaric acid (10 g) and acetylamide are weighed in a molar ratio of 1:2, the acetylamide is first dissolved in methanol, stirred for 5 min, then the 2-(octylamine) glutaric acid is added to the mixed solution, and then reacted at 20-35℃ for 16-20 h, to obtain 2-(octylamine) glutaric acid methyl ester;

[0077] (c) 2-(octylamine)pentanedioic acid methyl ester (5 g), hydroxylamine hydrochloride and NaOH were weighed in a molar ratio of 1:2-2.5:4-5, and the hydroxylamine hydrochloride and NaOH were separately dissolved in 40 mL of methanol and ultrasonically dispersed and dissolved, and then the mixture was stirred in an ice water bath for 0.5 h to allow the hydroxylamine to fully dissociate, and then 2-(octylamine)pentanedioic acid methyl ester was added and the reaction was carried out at 40°C for 6 h to obtain 2-(octylamine)-N,N'-dihydroxypentanediamine sodium; the solution was acidified using 1.0 mol / L hydrochloric acid to adjust the pH to 5-6, and then filtered to obtain 2-(octylamine)-N,N'-dihydroxypentanediamine crude product, which was dispersed in 15% acetic acid solution, filtered using a sand core funnel to remove the 15% acetic acid solution, and dried to obtain 2-(octylamine)-N,N'-dihydroxypentanediamine (collector) pure product.

[0078] The infrared spectrum of the collector prepared in this example is shown in Figure 1 The mass spectrum is shown in Figure 2 The nuclear magnetic resonance spectrum is shown in Figure 3

[0079] Example 2

[0080] The flotation process of this example for ilmenite with high selectivity is the same as that of Example 1, except that the power of the plasma treatment is 80 W, the treatment time is 5.5 min, and the treatment gas flow rate is 350 mL / min, and the treatment gas is a mixture of argon and oxygen in a volume ratio of 1:2.

[0081] In this example, the collector is prepared as follows:

[0082] (a) 1-bromon-octane (10 g) and glutamic acid were weighed in a molar ratio of 1:0.75, and the glutamic acid was dissolved in a methanol solution containing NaOH (pH = 10.3-10.8), and then 1-bromon-octane was added and the reaction was carried out at 55°C (the pH of the reaction was controlled to be >10) for 4.5 h, and then 1.0 mol / L HCl was added to adjust the pH of the obtained mixture to 5, and then the white precipitate was filtered and washed with a mixture of acetone and water, and then crystallized twice in an equal mixture of ethanol and water to obtain 2-(octylamine)pentanedioic acid.

[0083] (b) 2-(octylamine)pentanedioic acid (10 g) and acetylamide were weighed in a molar ratio of 1:2.25, acetylamide was first dissolved in methanol, and then 2-(octylamine)pentanedioic acid was added to the mixture, and then the reaction was carried out at 27°C for 18 h to obtain 2-(octylamine)pentanedioic acid methyl ester;

[0084] ​(c) 2-(octylamine)pentanedioic acid methyl ester (5 g), hydroxylamine hydrochloride and NaOH were weighed in a molar ratio of 1:2.25:4.5, and the hydroxylamine hydrochloride and NaOH were dissolved in 40 mL of methanol respectively, and were ultrasonically dispersed and dissolved, and then the mixture was stirred in an ice-water bath for 1.0 h to allow the hydroxylamine to be fully dissociated, and then 2-(octylamine)pentanedioic acid methyl ester was added, and the temperature was raised to 50°C for reaction for 5 h to prepare sodium 2-(octylamine)-N,N'-dihydroxypentanediamine; the solution was acidified to pH 5-6 using 1.0 mol / L hydrochloric acid, and filtration was performed to obtain 2-(octylamine)-N,N'-dihydroxypentanediamine crude product, which was dispersed in 15% acetic acid solution, and the 15% acetic acid solution was removed by filtration using a sand core funnel, and drying was performed to obtain 2-(octylamine)-N,N'-dihydroxypentanediamine (collector) pure product.

[0085] The collector prepared in this example was also subjected to the test of Example 1, and the results were basically consistent. Due to the limited space, they are not listed one by one. Example 3

[0086] The flotation process of this example for high selectivity of ilmenite was the same as that of Example 1, except that the power of the plasma treatment was 100 W, the treatment time was 8 min, and the treatment gas flow rate was 500 mL / min, and the treatment gas was a mixture of argon and oxygen in a volume ratio of 1:3.

[0087] In this example, the collector was prepared as follows:

[0088] (a) 1-bromon-octane (10 g) and glutamic acid were weighed in a molar ratio of 1:0.8, and the glutamic acid was dissolved in a methanol solution containing NaOH (pH=10.3-10.8), and then 1-bromon-octane was added, and the temperature was raised to 65°C (the reaction pH was controlled to be >10) for reaction for 4 h, and then 1.0 mol / L HCl was added to adjust the pH of the obtained mixture to 5, and filtration was performed, and the white precipitate was washed with a mixture of acetone and water, and then was crystallized twice in an equal mixture of ethanol and water to prepare 2-(octylamine)pentanedioic acid.

[0089] (b) 2-(octylamine)pentanedioic acid (10 g) and acetylamide were weighed in a molar ratio of 1:2.5, acetylamide was first dissolved in methanol, and then 2-(octylamine)pentanedioic acid was added to the mixed solution after stirring for 5 min, and then the temperature was raised to 35°C for reaction for 16 h to prepare 2-(octylamine)pentanedioic acid methyl ester;

[0090] (c) 2-(octylamine) glutaric acid methyl ester (5 g), hydroxylamine hydrochloride and NaOH were weighed in a molar ratio of 1:2.5:5, and the hydroxylamine hydrochloride and NaOH were dissolved in 40 mL of methanol respectively, and were ultrasonically dispersed and dissolved, and then were mixed and stirred in an ice water bath for 1.5 h to allow the hydroxylamine to be fully dissociated, and then 2-(octylamine) glutaric acid methyl ester was added, and the temperature was raised to 60°C for reaction for 4 h to prepare sodium 2-(octylamine)-N,N'-dihydroxy pentane diamine; the solution was acidified to pH 5-6 using 1.0 mol / L hydrochloric acid, and was filtered to obtain 2-(octylamine)-N,N'-dihydroxy pentane diamine crude product, which was dispersed in 15% acetic acid solution, and was filtered using a sand core funnel to remove the 15% acetic acid solution, and was dried to obtain 2-(octylamine)-N,N'-dihydroxy pentane diamine (collector) pure product.

[0091] The collector prepared in this example was also subjected to the test of Example 1, and the results were basically consistent. Due to the limited space, they are not listed one by one.

[0092] Example 4

[0093] The flotation process of this example for high selectivity of ilmenite is the same as that of Example 1, except that the structural formula of the collector is as follows:

[0094]

[0095] The preparation method of the collector of this example is as follows:

[0096] (a) 1-bromodecane (10 g) and glutamic acid were weighed in a molar ratio of 1:0.7, and the glutamic acid was dissolved in a methanol solution containing NaOH (pH = 10.3-10.8), and then 1-bromodecane was added, and the temperature was raised to 55°C (the pH of the reaction was controlled to be greater than 10) for reaction for 4.5 h, and then 1.0 mol / L HCl was added to adjust the pH of the obtained mixture to 5, and the white precipitate was filtered and washed with a mixture of acetone and water, and was crystallized twice in an equal mixture of ethanol and water to prepare 2-(octylamine) glutaric acid.

[0097] (b) 2-(decylamine) glutaric acid (10 g) and acetylamide were weighed in a molar ratio of 1:2, acetylamide was first dissolved in methanol, and then 2-(decylamine) glutaric acid was added to the mixed solution after stirring for 5 min, and then the temperature was raised to 20°C for reaction for 20 h to prepare 2-(octylamine) glutaric acid methyl ester;

[0098] (c) 2-(decylamine)pentanedioic acid methyl ester (5 g), hydroxylamine hydrochloride and NaOH were weighed in a molar ratio of 1:2:4, and the hydroxylamine hydrochloride and NaOH were dissolved in 40 mL of methanol respectively, and were ultrasonically dispersed and dissolved, and then the mixture was stirred in an ice water bath for 0.5 h to allow the hydroxylamine to be fully dissociated, and then 2-(decylamine)pentanedioic acid methyl ester was added, and the temperature was raised to 40°C for reaction for 6 h to prepare 2-(decylamine)-N,N'-dihydroxypentane diamine sodium; the solution was acidified with 1.0 mol / L hydrochloric acid to adjust the pH to 5-6, and filtration was performed to obtain 2-(decylamine)-N,N'-dihydroxypentane diamine crude product, which was dispersed in 15% acetic acid solution, and the 15% acetic acid solution was removed by filtration using a sand core funnel, and drying was performed to obtain 2-(decylamine)-N,N'-dihydroxypentane diamine relatively pure product.

[0099] Example 5

[0100] The flotation process of the ilmenite with high selectivity in this example is the same as that in Example 4, except that the power of the plasma treatment is 80 W, the treatment time is 5.5 min, and the treatment gas flow rate is 350 mL / min, and the treatment gas is argon and oxygen mixed in a volume ratio of 1:2.

[0101] The preparation method of the collector in this example is as follows:

[0102] (a) 1-bromodecane (10 g) and glutamic acid were weighed in a molar ratio of 1:0.75, and the glutamic acid was dissolved in a methanol solution containing NaOH (pH = 10.3-10.8), and then 1-bromodecane was added, and heating was performed to 55°C (the reaction pH was controlled to be >10) for reaction for 4.5 h, and then 1.0 mol / L HCl was added to adjust the pH of the obtained mixture to 5, and filtration was performed, and the white precipitate was washed with a mixture of acetone and water, and then crystallization was performed twice in an equal mixture of ethanol and water to prepare 2-(octylamine) pentanedioic acid.

[0103] (b) 2-(decylamine)pentanedioic acid (10 g) and acetylamide were weighed in a molar ratio of 1:2.25, acetylamide was first dissolved in methanol, and then 2-(decylamine)pentanedioic acid was added to the mixed solution after stirring for 5 min, and then reaction was performed at 27°C for 18 h to prepare 2-(octylamine)pentanedioic acid methyl ester;

[0104] (c) 2-(decylamine) glutaric acid methyl ester (5 g), hydroxylamine hydrochloride and NaOH were weighed in a molar ratio of 1:2.25:4.5, and the hydroxylamine hydrochloride and NaOH were dissolved in 40 mL of methanol respectively, and were ultrasonically dispersed and dissolved, and then the mixture was stirred in an ice water bath for 1.0 h to allow the hydroxylamine to be fully dissociated, and then 2-(decylamine) glutaric acid methyl ester was added, and the temperature was raised to 50°C for reaction for 5 h to prepare sodium 2-(decylamine)-N,N'-dihydroxy pentane diamine; the solution was acidified to pH 5-6 using 1.0 mol / L hydrochloric acid, and filtration was performed to obtain 2-(decylamine)-N,N'-dihydroxy pentane diamine crude product, which was dispersed in 15% acetic acid solution, and the 15% acetic acid solution was removed by filtration using a sand core funnel, and drying was performed to obtain 2-(decylamine)-N,N'-dihydroxy pentane diamine relatively pure product.

[0105] Example 6

[0106] The flotation process of the ilmenite with high selectivity in this example is the same as that in Example 4, except that the power of the plasma treatment is 100 W, the treatment time is 8 min, and the treatment gas flow rate is 500 mL / min, and the treatment gas is argon and oxygen mixed in a volume ratio of 1:3.

[0107] The preparation method of the collector in this example is as follows:

[0108] (a) 1-bromodecane (10 g) and glutamic acid were weighed in a molar ratio of 1:0.8, and the glutamic acid was dissolved in a methanol solution containing NaOH (pH = 10.3-10.8), and then 1-bromodecane was added, and the temperature was raised to 65°C (the reaction pH was controlled to be >10) for reaction for 4 h, and then 1.0 mol / L HCl was added to adjust the pH of the obtained mixture to 5, and filtration was performed, and the white precipitate was washed with a mixture of acetone and water, and then was crystallized twice in an equal mixture of ethanol and water to prepare 2-(octylamine) glutaric acid.

[0109] (b) 2-(decylamine) glutaric acid (10 g) and acetylamide were weighed in a molar ratio of 1:2.5, acetylamide was first dissolved in methanol, and then 2-(decylamine) glutaric acid was added to the mixed solution after stirring for 5 min, and then reaction was performed at 35°C for 16 h to prepare 2-(octylamine) glutaric acid methyl ester;

[0110] (c) 2-(decylamine) pentanedioic acid methyl ester (5 g), hydroxylamine hydrochloride and NaOH were weighed in a molar ratio of 1:2.5:5, and the hydroxylamine hydrochloride and NaOH were dissolved in 40 mL of methanol respectively, and were ultrasonically dispersed and dissolved, and then were mixed and stirred in an ice water bath for 1.5 h to allow the hydroxylamine to be fully dissociated, and then 2-(decylamine) pentanedioic acid methyl ester was added, and the temperature was raised to 60°C for reaction for 4 h to prepare sodium 2-(decylamine)-N,N'-dihydroxypentane diamine; the solution was acidified with 1.0 mol / L hydrochloric acid to adjust the pH to 5-6, and filtration was performed to obtain 2-(decylamine)-N,N'-dihydroxypentane diamine crude product, which was dispersed in 15% acetic acid solution, and filtration was performed with a sand core funnel to remove the 15% acetic acid solution, and drying was performed to obtain 2-(decylamine)-N,N'-dihydroxypentane diamine relatively pure product.

[0111] Comparative Example 1

[0112] The flotation process of the ilmenite of the present comparative example is the same as that of Example 1, except that in step (1), the step of plasma pretreatment of the raw ore is removed.

[0113] Comparative Example 2

[0114] The flotation process of the ilmenite of the present comparative example is the same as that of Example 1, except that in step (1), the step of first-stage flotation desliming is removed.

[0115] Comparative Example 3

[0116] The flotation process of the ilmenite of the present comparative example is the same as that of Example 1, except that in step (1), the plasma pretreatment power is 100 W, the treatment time is 10 min, the gas flow rate is 600 mL / min, and the argon:oxygen ratio is 1:5.

[0117] Comparative Example 4

[0118] The flotation process of the ilmenite of the present comparative example is the same as that of Example 1, except that the structure of the collector is as follows:

[0119]

[0120] Test Example 1

[0121] The flotation processes of Examples 1-6 and Comparative Examples 1-4 were used respectively, and specifically, ilmenite actual ore with a grade of 12.54% was subjected to flotation. Among them, 200 g of ilmenite actual ore was weighed in each group and dissolved in 0.5 L of water, the time of first-stage flotation desliming, second-stage flotation and third-stage flotation was the same, and the flotation time was 5 min each time, 5 min of stirring after adding the frother, and 5 min of froth scraping time, and the flotation results are shown in Table 1.

[0122] Table 1

[0123]

[0124] From the above table, under the same conditions, only the carbon chain length of the collector is changed, the longer the carbon chain length of the collector, the stronger the collecting property, and the selectivity is weakened. Under the same flotation conditions, the longer carbon chain length of the collector leads to a slight decrease in the grade of ilmenite and an increase in the recovery rate. Compared with Example 1, the plasma pretreatment can effectively improve the difference in surface properties between the target mineral and the gangue mineral, promote the selective flotation of the target mineral under weakly acidic conditions, and improve the grade of the concentrate.

[0125] Compared with Comparative Example 2, the use of the flotation desliming process can remove part of the gangue impurities in the mineral in advance, reduce the sliming of the ore slurry, and reduce the influence on the subsequent flotation, and promote the adsorption process of the flotation collector on the surface of the target mineral.

[0126] Compared with Comparative Example 3, the flotation effect is not good under the plasma treatment conditions of the present application.

[0127] Compared with Comparative Example 4, the flexibility of the two polar groups in the dual functional collector of the present application is higher, which makes it easy to match with the active sites on the mineral surface, and the selectivity is stronger. The method of the present application combines plasma pretreatment and flotation desliming process to maximize the removal efficiency of gangue minerals and impurities in the ore slurry, and promotes the targeting process of the selective collector, thereby improving the flotation grade and recovery rate.

[0128] Test Example 2

[0129] The flotation process of Example 2 is used, and the method of Test Example 1 is used, only the collector in step (2) is replaced with octylhydroxamic acid or MOH, and the flotation effect is shown in Table 2.

[0130] Table 2 Flotation effect of different collectors and addition amount on ilmenite actual ore

[0131]

[0132] According to Table 2, the collector of the present application has good collecting effect at a lower dosage compared with high dosage of octylhydroxamic acid or MOH, which shows that the use of the collector of the present application significantly reduces the dosage of the reagent.

[0133] The above description is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application.

Claims

1. A process for the flotation of ilmenite with high selectivity, characterized in that, It comprises the following steps: (1) the raw ore is subjected to plasma pretreatment, sodium oleate is added for first-time flotation desliming, and a desliming tailing is obtained; (2) the desliming tailing is added with a collector with a structural formula as shown in formula (I) under weak acid condition for second-time flotation, and a rough ilmenite concentrate is obtained; (3) the rough ilmenite concentrate is subjected to third-time flotation, and a fine ilmenite concentrate is obtained; The collector with a structural formula as shown in formula (I) is as follows: R is alkyl.

2. A process for the flotation of ilmenite with high selectivity according to claim 1, characterized in that, In step (1), the power in the plasma pretreatment is 60-100 W, the treatment time is 3-8 min, and the treatment gas flow rate is 200-500 mL / min.

3. A high selectivity process for the flotation of ilmenite according to claim 2, characterized in that, The plasma pretreatment adopts plasma treatment gas, and the plasma treatment gas is a mixture of argon and oxygen in a volume ratio of 1:1-3.

4. A process for the flotation of ilmenite with high selectivity as claimed in claim 1 wherein, A foaming agent is further added in the first-time flotation desliming, and sulfuric acid is further added in the second-time flotation and the third-time flotation.

5. A high selectivity process for the flotation of ilmenite according to any one of claims 1 to 4, characterised in that, The R is an alkyl group with 8-10 carbon atoms.

6. A high selectivity process for the flotation of ilmenite according to any one of claims 1 to 4, characterised in that, In step (2), the addition amount of the collector is 300-600 g / t.

7. A high selectivity process for the flotation of ilmenite according to any one of claims 1 to 4, characterised in that, The collector is prepared by the following method: (a) glutamic acid is dissolved in a methanol solution containing NaOH, a haloalkane is added for substitution reaction, and then hydrochloric acid is added for acidification to generate 2-(alkyl) glutaric acid with an imino group and a branched chain; (b) acyl chloride is dissolved in methanol to obtain a mixed solution, and 2-(alkyl) glutaric acid with an imino group and a branched chain is added into the mixed solution for reaction to obtain 2-(alkyl) glutaric acid methyl ester; (c) hydroxylamine salt and alkali are dissolved in methanol, ultrasonic dispersion dissolution is performed, then 2-(alkyl) glutaric acid methyl ester is added, hydroximic acidization reaction is performed after heating, the pH value is adjusted to 5-6, filtration and drying are performed, and the collector is obtained.

8. A high selectivity process for the flotation of ilmenite according to claim 7, characterized in that, In step (a), the haloalkane is chloroalkane, bromoalkane or iodoalkane.

9. A process for the flotation of ilmenite with high selectivity as claimed in claim 7 wherein, In step (b), the reaction temperature is 20-35 ℃, and the reaction time is 16-20 h.

10. A process for the flotation of ilmenite with high selectivity as claimed in claim 7 wherein, In step (c), the heating temperature is 40-60 ℃, and the reaction time is 4-6 h.

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