Ilmenite collecting agent and preparation method and application thereof

Abstract

The invention provides an ilmenite collecting agent and a preparation method and application thereof, and relates to the technical field of mineral flotation separation. According to the preparation method, the ilmenite collecting agent can be efficiently and stably prepared by performing a hydroximation reaction on the cycloalkane carboxylic acid methyl ester compound and the free hydroxylamine solution and combining a preparation process of methanol separation treatment, acidification treatment and freeze-drying treatment; the preparation method is simple and easy to operate, large-scale production is easy, and great innovation is brought to large-scale obtaining of high-grade and high-recovery-rate concentrates through a flotation process of oxidized minerals. The molecular formula of the ilmenite collecting agent is Cn + 1H2n + 1O2N; or is Cn + 2H2n + 2O2N (n is an integer from 3 to 10). And the method can show remarkable advantages in ilmenite flotation. The high-temperature-resistant environment-friendly paint can keep excellent performance under the conditions of different pH values and temperatures, is high in adaptability and low in toxicity, and meets the environment-friendly requirements of green mines.

Description

Technical Field

[0001] This invention relates to the field of mineral flotation and separation technology, and in particular to an ilmenite collector, its preparation method, and its application. Background Technology

[0002] In the flotation process of oxidized minerals, the development of novel and efficient collectors is crucial for improving separation performance. Currently, commonly used industrial collectors for oxidized minerals mainly fall into four categories: carboxylic acids, hydroxamic acids, arsenolic acids, and phosphonic acids. While carboxylic acid collectors possess strong collecting ability, their selectivity is poor. Arsenolic acid and phosphonic acid collectors, although exhibiting some flotation effect, are strictly limited in industrial applications due to their high toxicity and potential harm to the environment and human health. In contrast, hydroxamic acid collectors, due to the presence of lone pairs of oxygen and nitrogen atoms in their molecular structure, and the close proximity of these atoms, can form stable chelates with metal ions, thus exhibiting excellent selectivity and collecting ability. Domestic and international practice has shown that hydroxamic acid collectors possess significant advantages such as strong collecting ability, good selectivity, and low toxicity, achieving remarkable results in the field of oxidized mineral flotation and representing a collector with great development potential.

[0003] However, existing hydroxamic acid collectors are still used in the flotation process of oxidized minerals, and the grade and recovery rate of the obtained concentrate are still relatively low. Summary of the Invention

[0004] The main objective of this invention is to provide an ilmenite collector, its preparation method, and its application, aiming to solve the problems of high toxicity and low grade and recovery rate of existing ilmenite collectors in the flotation process of oxidized minerals.

[0005] To achieve the above objectives, the present invention provides a method for preparing an ilmenite collector, comprising the following steps: Provided are cycloalkane carboxylic acid methyl ester compounds; said cycloalkane carboxylic acid methyl ester compounds include at least one of cycloalkane carboxylic acid methyl ester and 1,1-cycloalkane dicarboxylic acid dimethyl ester.

[0006] Provide a solution of free hydroxylamine.

[0007] The cycloalkane carboxylic acid methyl ester compound and the free hydroxylamine solution are mixed and subjected to a hydroxyoxime reaction to obtain the reaction solution.

[0008] The reaction liquid was subjected to methanol separation, acidification, and freeze-drying in sequence to obtain an ilmenite collector.

[0009] Furthermore, the temperature of the hydroxyoximation reaction is 50~60℃; the duration of the hydroxyoximation reaction is 3~5h.

[0010] Furthermore, the method for obtaining the cycloalkane carboxylic acid methyl ester compound includes the following steps: An intermediate is obtained by esterification of cycloalkane carboxylic acid compounds and methanol under the catalysis of concentrated sulfuric acid.

[0011] The pH value of the intermediate is adjusted to be neutral or weakly alkaline.

[0012] The cycloalkane carboxylic acid compounds include at least one of cycloalkane carboxylic acids and 1,1-cycloalkane dicarboxylic acids.

[0013] Furthermore, the molar ratio of the cycloalkane carboxylic acid compound to the methanol is 1:3~20.

[0014] Furthermore, the mass ratio of the cycloalkane carboxylic acid compound to the concentrated sulfuric acid is 1:0.01~0.05.

[0015] Furthermore, the temperature of the esterification reaction is 60~80℃; the duration of the esterification reaction is 2~4h.

[0016] Furthermore, the method for obtaining the free hydroxylamine solution includes: subjecting a methanol solution of hydroxylamine hydrochloride and sodium hydroxide to an ice-water bath treatment; the duration of the ice-water bath treatment is 1-2 hours.

[0017] This invention also provides an ilmenite collector prepared by any of the above methods, wherein the molecular formula of the ilmenite collector is C n+1 H 2n+1 O2N; or C n+2 H 2n+2 O2N; where n is an integer from 3 to 10.

[0018] The present invention also provides an application of the ilmenite collector described above in the roughing flotation of ilmenite rough ore.

[0019] Furthermore, an ilmenite collector is added to the ilmenite rough for roughing flotation treatment; the amount of the ilmenite collector added is 1250~2500g / t; the pH value of the roughing flotation is 4~5.

[0020] The beneficial effects achieved by this invention are as follows: The method for preparing the ilmenite collector provided by this invention involves "hydroxoximation reaction of cycloalkane carboxylic acid methyl ester compounds and free hydroxylamine solution", combined with "methanol separation treatment, acidification treatment and freeze-drying treatment" to efficiently and stably prepare the ilmenite collector. This preparation method is simple to operate and easy to scale up, bringing a major innovation to the flotation process of oxidized minerals to obtain high-grade and high-recovery concentrates on a large scale.

[0021] The molecular formula of the ilmenite collector provided by this invention is C n+1 H 2n+1 O2N; or C n+2 H 2n+2 O2N (where n is an integer from 3 to 10) exhibits significant advantages in ilmenite flotation: its high selectivity allows it to preferentially adsorb onto the surface of ilmenite, achieving efficient separation from gangue minerals; simultaneously, it enhances the hydrophobicity of the minerals by forming stable complexes, significantly improving flotation efficiency. This ilmenite collector maintains excellent performance under different pH and temperature conditions, demonstrating strong adaptability and low toxicity, meeting the environmental requirements of green mining. Furthermore, its high efficiency and low dosage characteristics reduce overall reagent costs, resulting in outstanding economic benefits.

[0022] This ilmenite collector has broad application prospects in the roughing and flotation of ilmenite rough ore, providing strong technical support for the efficient and environmentally friendly development of ilmenite resources. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementations and not for limiting the scope of protection of this invention.

[0025] Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, can be applied to implement this invention using any prior art methods, equipment, and materials similar to or equivalent to those described, used, or made in the embodiments of this invention. When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range, as well as any value between the two endpoints, may be used. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers. Materials or reagents required in the following embodiments are commercially available unless otherwise specified.

[0026] To address the problems of high toxicity and low grade and recovery rate in existing ilmenite collectors used in the flotation of oxidized minerals, this invention provides a method for preparing an ilmenite collector, comprising the following steps: The invention provides cycloalkane carboxylic acid methyl ester compounds; these compounds include at least one selected from cycloalkane carboxylic acid methyl esters and 1,1-cycloalkane dicarboxylic acid dimethyl esters. Optionally, the cycloalkane carboxylic acid methyl ester compound is a cycloalkane carboxylic acid methyl ester. Alternatively, the cycloalkane carboxylic acid methyl ester compound is a 1,1-cycloalkane dicarboxylic acid dimethyl ester. Specifically, the cycloalkane carboxylic acid methyl ester includes cyclobutene carboxylic acid methyl ester, cyclopentene carboxylic acid methyl ester, and cyclohexene carboxylic acid methyl ester. The 1,1-cycloalkane dicarboxylic acid dimethyl ester includes 1,1-cyclobutane dicarboxylic acid dimethyl ester, 1,1-cyclopentane dicarboxylic acid dimethyl ester, and 1,1-cyclohexane dicarboxylic acid dimethyl ester.

[0027] Provide a solution of free hydroxylamine.

[0028] A mixture of cycloalkane carboxylic acid methyl esters and a free hydroxylamine solution was subjected to a hydroxyoximation reaction to obtain the reaction solution.

[0029] Specifically, the cycloalkane carboxylic acid methyl ester compound and the free hydroxylamine solution are mixed by slowly adding the cycloalkane carboxylic acid methyl ester compound dropwise to the free hydroxylamine solution until the reaction is complete. The molar ratio of the cycloalkane carboxylic acid methyl ester compound to the free hydroxylamine is 0.8~1:1~3.

[0030] The reaction liquid was subjected to methanol separation, acidification, and freeze-drying in sequence to obtain an ilmenite collector.

[0031] Optionally, the methanol separation process can be carried out by vacuum distillation of the reaction liquid; the vacuum distillation temperature is 40~50℃.

[0032] Alternatively, the acidification process can be carried out by slowly adding dilute sulfuric acid dropwise to the mixture while stirring under ice-water bath conditions until the pH is less than 5.

[0033] Optionally, the freeze-drying process involves freezing the acidified mixture with liquid nitrogen and then placing it in a freeze dryer for 24 hours.

[0034] The method for preparing the ilmenite collector provided by this invention involves "hydroxoximation reaction of cycloalkane carboxylic acid methyl ester compounds and free hydroxylamine solution", combined with "methanol separation treatment, acidification treatment and freeze-drying treatment" to efficiently and stably prepare the ilmenite collector. This preparation method is simple to operate and easy to scale up, bringing a major innovation to the flotation process of oxidized minerals to obtain high-grade and high-recovery concentrates on a large scale.

[0035] Furthermore, the temperature of the hydroxyoximation reaction is 50~60℃; the duration of the hydroxyoximation reaction is 3~5h.

[0036] Furthermore, the method for obtaining cycloalkane carboxylic acid methyl ester compounds includes the following steps: An intermediate is obtained by esterification of cycloalkane carboxylic acid compounds and methanol under the catalysis of concentrated sulfuric acid.

[0037] The pH value of the intermediate is adjusted to be neutral or weakly alkaline. Specifically, after the esterification reaction, the esterified product has already been obtained, and the pH is adjusted to facilitate subsequent reactions. The concentrated sulfuric acid used in this invention is 98% sulfuric acid by mass.

[0038] The cycloalkane carboxylic acid compound includes at least one selected from cycloalkane carboxylic acids and 1,1-cycloalkane dicarboxylic acids. Optionally, the cycloalkane carboxylic acid compound is a cycloalkane carboxylic acid. Optionally, the cycloalkane carboxylic acid compound is a 1,1-cycloalkane dicarboxylic acid.

[0039] Preferably, the cycloalkane carboxylic acid is cyclobutane carboxylic acid, or cyclopentane carboxylic acid, or cyclohexane carboxylic acid.

[0040] Preferably, the 1,1-cycloalkane dicarboxylic acid is 1,1-cyclobutane dicarboxylic acid, or 1,1-cyclopentane dicarboxylic acid, or 1,1-cyclohexane dicarboxylic acid.

[0041] Furthermore, the molar ratio of cycloalkane carboxylic acid compounds to methanol is 1:3~20.

[0042] Preferably, when the cycloalkane carboxylic acid compound is a cycloalkane carboxylic acid, the molar ratio of the cycloalkane carboxylic acid to methanol is 1:3~10.

[0043] Preferably, when the cycloalkane carboxylic acid compound is a 1,1-cycloalkane dicarboxylic acid, the molar ratio of the 1,1-cycloalkane dicarboxylic acid to methanol is 1:6~20.

[0044] Furthermore, the mass ratio of cycloalkane carboxylic acid compounds to concentrated sulfuric acid is 1:0.01~0.05.

[0045] Furthermore, the esterification reaction temperature is 60~80℃; and the esterification reaction duration is 2~4h.

[0046] Furthermore, the free hydroxylamine solution is obtained by subjecting a methanol solution of hydroxylamine hydrochloride and sodium hydroxide to an ice-water bath treatment for 1-2 hours. Specifically, methanol is used as a solvent and does not participate in the reaction. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution is 1:4 to 1:1.

[0047] Optionally, in the methanol solution, the molar ratio of hydroxylamine hydrochloride to sodium hydroxide is 1~1.3:2~2.6.

[0048] Preferably, the temperature for the ice-water bath treatment is 0~5℃.

[0049] This invention also provides an ilmenite collector prepared by any of the above methods, wherein the molecular formula of the ilmenite collector is C n+1 H2n+1 O2N; or C n+2 H 2n+2 O2N; where n is an integer from 3 to 10.

[0050] The molecular formula of the ilmenite collector provided by this invention is C n+1 H 2n+1 O2N; or C n+2 H 2n+2 O2N (where n is an integer from 3 to 10) exhibits significant advantages in ilmenite flotation: its high selectivity allows it to preferentially adsorb onto the surface of ilmenite, achieving efficient separation from gangue minerals; simultaneously, it enhances the hydrophobicity of the minerals by forming stable complexes, significantly improving flotation efficiency. This ilmenite collector maintains excellent performance under different pH and temperature conditions, demonstrating strong adaptability and low toxicity, meeting the environmental requirements of green mining. Furthermore, its high efficiency and low dosage characteristics reduce overall reagent costs, resulting in outstanding economic benefits.

[0051] The present invention also provides an application of the above-mentioned ilmenite collector in the roughing flotation of ilmenite rough, wherein the ilmenite collector is added to the ilmenite rough for roughing flotation treatment; the amount of ilmenite collector added is 1250~2500g / t.

[0052] This ilmenite collector has broad application prospects in the roughing and flotation of ilmenite rough ore, providing strong technical support for the efficient and environmentally friendly development of ilmenite resources.

[0053] Furthermore, the pH value for roughing flotation is 4-5.

[0054] To further illustrate the present invention, the following examples are provided: Example 1 (1) Preparation of methyl cyclobutene carboxylate: Methanol, concentrated sulfuric acid, and cyclobutane carboxylic acid were added sequentially to a three-necked flask and refluxed at 80°C for 2.5 h to obtain methyl cyclobutane carboxylate; wherein the molar ratio of cyclobutane carboxylic acid to methanol was 1:5, and the mass ratio of cyclobutane carboxylic acid to concentrated sulfuric acid was 1:0.03. The pH was adjusted to neutral.

[0055] The following reaction occurs specifically: (2) A methanol solution of hydroxylamine hydrochloride and sodium hydroxide was heated in an ice-water bath (0°C) for 1 hour to obtain a free hydroxylamine solution; wherein the molar ratio of hydroxylamine hydrochloride to sodium hydroxide was 1:2. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution was 1:3.

[0056] (3) Add the methyl cyclobutene carboxylate obtained in step (1) dropwise to the free hydroxylamine solution obtained in step (2); react at 50°C for 3.5 h. Remove excess methanol by vacuum distillation at 40°C, perform acid washing with dilute sulfuric acid, and freeze-dry sequentially to obtain the ilmenite collector. The molar ratio of methyl cyclobutene carboxylate to free hydroxylamine is 1:1.3.

[0057] The following reaction occurs specifically: (4) The raw ore was roughed and floated using the ilmenite collector obtained in step (3): the pH was adjusted to about 4.5 and 2500 g / t of ilmenite collector was added; concentrate and tailings were obtained; the specific experimental results are shown in Table 1.

[0058] Table 1. Results of roughing flotation experiments using the ilmenite collector in Example 1 Comparative Example 1 The roughing flotation experiment was conducted using octyl hydroxamic acid, a commonly used collector in the market, under the same conditions as in step (4) of Example 1; the specific results are shown in Table 2.

[0059] Table 2. Results of roughing flotation experiments using octyl hydroxamic acid, a commonly used collector in the market. As can be seen from Tables 1 and 2, the grade and recovery rate of the concentrate obtained after roughing and flotation of the ilmenite collector prepared in Example 1 are significantly improved.

[0060] Example 2 (1) Preparation of cyclopentene carboxylic acid methyl ester: Methanol, concentrated sulfuric acid, and cyclopentenic acid were added sequentially to a three-necked flask, and the mixture was refluxed at 80°C for 2.5 h to obtain methyl 1-cyclopenten-1-carboxylate; wherein the molar ratio of cyclopentenic acid to methanol was 1:5, and the mass ratio of cyclopentenic acid to concentrated sulfuric acid was 1:0.03. The pH was adjusted to neutral.

[0061] The following reaction occurs specifically: (2) A methanol solution of hydroxylamine hydrochloride and sodium hydroxide was heated in an ice-water bath (0°C) for 1 hour to obtain a free hydroxylamine solution; wherein the molar ratio of hydroxylamine hydrochloride to sodium hydroxide was 1:2. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution was 1:3.

[0062] (3) Add the cyclopentane carboxylate methyl ester obtained in step (1) dropwise to the free hydroxylamine solution obtained in step (2); react at 50°C for 3.5 h. Perform vacuum distillation at 40°C to remove excess methanol, acid washing with dilute sulfuric acid, and freeze drying sequentially to obtain the ilmenite collector. The molar ratio of cyclopentane carboxylate methyl ester to free hydroxylamine is 1:1.3.

[0063] The following reaction occurs specifically: (4) The raw ore was roughed and floated using the ilmenite collector obtained in step (3): the pH was adjusted to about 4.5 and 2500 g / t of ilmenite collector was added; concentrate and tailings were obtained; the specific experimental results are shown in Table 3.

[0064] Table 3. Results of roughing flotation experiments using the ilmenite collector in Example 2 As can be seen from Tables 2 and 3, the grade and recovery rate of the concentrate obtained after roughing and flotation of the ilmenite collector prepared in this embodiment are significantly improved.

[0065] Example 3 (1) Preparation of methyl cyclohexene carboxylate: Methanol, concentrated sulfuric acid, and cyclohexene carboxylic acid were added sequentially to a three-necked flask and refluxed at 80°C for 2.5 h to obtain methyl cyclohexene carboxylate; wherein the molar ratio of cyclohexene carboxylic acid to methanol was 1:5, and the mass ratio of cyclohexene carboxylic acid to concentrated sulfuric acid was 1:0.03. The pH was adjusted to neutral.

[0066] The following reaction occurs specifically: (2) A methanol solution of hydroxylamine hydrochloride and sodium hydroxide was heated in an ice-water bath (0°C) for 1 hour to obtain a free hydroxylamine solution; wherein the molar ratio of hydroxylamine hydrochloride to sodium hydroxide was 1:2. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution was 1:3.

[0067] (3) Add the methyl 1-cyclohexene-1-carboxylate obtained in step (1) dropwise to the free hydroxylamine solution obtained in step (2); react at 50°C for 3.5 h. Remove excess methanol by vacuum distillation at 40°C, perform acid washing with dilute sulfuric acid, and freeze-dry sequentially to obtain the ilmenite collector. The molar ratio of methyl cyclohexene-1-carboxylate to free hydroxylamine is 1:1.3.

[0068] The following reaction occurs specifically: (4) The raw ore was roughed and floated using the ilmenite collector obtained in step (3): the pH was adjusted to about 4.5 and 2500 g / t of ilmenite collector was added; concentrate and tailings were obtained; the specific experimental results are shown in Table 4.

[0069] Table 4. Results of roughing flotation experiments using the ilmenite collector in Example 3. As can be seen from Tables 2 and 4, the grade and recovery rate of the concentrate obtained after roughing and flotation of the ilmenite collector prepared in this embodiment are significantly improved.

[0070] Example 4 The ilmenite collector prepared in Example 1 and the commonly used collector octyl hydroxamic acid used in Comparative Example 1 were placed in an oven at 50°C for 3 days. Then, they were applied to flotation. The flotation steps were the same as step (4) in Example 1, and their effects were observed.

[0071] The flotation results of the ilmenite collector prepared in Example 1 after being treated in an oven at 50°C for 3 days are shown in Table 5; the flotation results of the commonly used collector octyl hydroxamic acid used in Comparative Example 1 after being treated in an oven at 50°C for 3 days are shown in Table 6.

[0072] Table 5. Flotation test results of the ilmenite collector in Example 1 after treatment in a 50℃ oven for 3 days. Based on Tables 1 and 5, the flotation effect of the ilmenite collector prepared in Example 1 after being treated in a 50°C oven for 3 days was not significantly different from that before treatment.

[0073] Table 6. Flotation results of octylhydroxamic acid in Comparative Example 1 after treatment in an oven at 50°C for 3 days. Combining Tables 2 and 6, the flotation effect of octyl hydroxamic acid, a commonly used collector in Comparative Example 1, was significantly lower after being treated in a 50°C oven for 3 days compared to before treatment.

[0074] Example 5 The ilmenite collector prepared in Example 1 and the commonly used collector octyl hydroxamic acid used in Comparative Example 1 were placed in an oven at 50°C for 7 days. Then, they were applied to flotation. The flotation steps were the same as step (4) in Example 1, and their effects were observed.

[0075] The flotation results of the ilmenite collector prepared in Example 1 after being treated in an oven at 50°C for 7 days are shown in Table 7; the flotation results of the commonly used collector octyl hydroxamic acid used in Comparative Example 1 after being treated in an oven at 50°C for 7 days are shown in Table 8.

[0076] Table 7. Flotation test results of the ilmenite collector in Example 1 after treatment in a 50℃ oven for 7 days. Based on Tables 1 and 7, the flotation performance of the ilmenite collector prepared in Example 1 was slightly lower after being treated in a 50°C oven for 7 days compared to before treatment.

[0077] Table 8. Flotation results of octylhydroxamic acid in Comparative Example 1 after treatment in an oven at 50°C for 7 days. Combining Tables 2 and 8, the flotation effect of octyl hydroxamic acid, a commonly used collector in Comparative Example 1, became very poor after being treated in a 50°C oven for 7 days compared to before treatment.

[0078] Example 6 (1) Preparation of dimethyl 1,1-cyclobutanedicarboxylate: Methanol, concentrated sulfuric acid, and 1,1-cyclobutanedicarboxylic acid were added sequentially to a three-necked flask and refluxed at 80°C for 2.5 h to obtain dimethyl 1,1-cyclobutanedicarboxylic acid; wherein the molar ratio of 1,1-cyclobutanedicarboxylic acid to methanol was 1:10; and the mass ratio of 1,1-cyclobutanedicarboxylic acid to concentrated sulfuric acid was 1:0.05. The pH was adjusted to neutral.

[0079] The following reaction occurs specifically: (2) A methanol solution of hydroxylamine hydrochloride and sodium hydroxide was heated in an ice-water bath (0°C) for 1 hour to obtain a free hydroxylamine solution; wherein the molar ratio of hydroxylamine hydrochloride to sodium hydroxide was 1:2. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution was 1:3.

[0080] (3) The 1,1-cyclobutanedicarboxylic acid dimethyl ester obtained in step (1) was added dropwise to the free hydroxylamine solution obtained in step (2); the reaction was carried out at 50°C for 3.5 h. Excess methanol was removed by vacuum distillation at 40°C, followed by acid washing with dilute sulfuric acid and freeze drying; ilmenite collector was obtained. The molar ratio of 1,1-cyclobutanedicarboxylic acid dimethyl ester to free hydroxylamine was 1:2.6.

[0081] The following reaction occurs specifically: (4) The raw ore was roughed and floated using the ilmenite collector obtained in step (3): the pH was adjusted to about 4.5 and 1250 g / t of ilmenite collector was added; concentrate and tailings were obtained; the specific experimental results are shown in Table 9.

[0082] Table 9. Results of roughing flotation experiments using the ilmenite collector in Example 6 As can be seen from Tables 2 and 9, the amount of ilmenite collector prepared in this embodiment used for rough flotation is half that used for rough flotation of octyl hydroxamic acid, a commonly used collector in Comparative Example 1; however, the flotation performance of this embodiment is still better than that of octyl hydroxamic acid in Comparative Example 1.

[0083] Example 7 (1) Preparation of dimethyl 1,1-cyclopentanedicarboxylate: Methanol, concentrated sulfuric acid, and 1,1-cyclopentanedicarboxylic acid were added sequentially to a three-necked flask and refluxed at 80°C for 2.5 h to obtain dimethyl 1,1-cyclopentanedicarboxylic acid; wherein the molar ratio of 1,1-cyclopentanedicarboxylic acid to methanol was 1:10; and the mass ratio of 1,1-cyclopentanedicarboxylic acid to concentrated sulfuric acid was 1:0.05. The pH was adjusted to neutral.

[0084] The following reaction occurs specifically: (2) A methanol solution of hydroxylamine hydrochloride and sodium hydroxide was heated in an ice-water bath (0°C) for 1 hour to obtain a free hydroxylamine solution; wherein the molar ratio of hydroxylamine hydrochloride to sodium hydroxide was 1:2. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution was 1:3.

[0085] (3) The 1,1-cyclopentanedicarboxylic acid dimethyl ester obtained in step (1) was added dropwise to the free hydroxylamine solution obtained in step (2); the reaction was carried out at 50°C for 3.5 h. Excess methanol was removed by vacuum distillation at 40°C, followed by acid washing with dilute sulfuric acid and freeze drying; ilmenite collector was obtained. The molar ratio of 1,1-cyclopentanedicarboxylic acid dimethyl ester to free hydroxylamine was 1:1.3.

[0086] The following reaction occurs specifically: (4) The raw ore was roughed and floated using the ilmenite collector obtained in step (3): the pH was adjusted to about 4.5 and 1250 g / t of ilmenite collector was added; concentrate and tailings were obtained; the specific experimental results are shown in Table 10.

[0087] Table 10 Results of roughing flotation experiments using the ilmenite collector in Example 7 As can be seen from Tables 2 and 10, the amount of ilmenite collector prepared in this embodiment used for rough flotation is half that used for rough flotation of octyl hydroxamic acid, a commonly used collector in Comparative Example 1; however, the flotation performance of this embodiment is still better than that of octyl hydroxamic acid in Comparative Example 1.

[0088] Example 8 (1) Preparation of dimethyl 1,1-cyclohexanedicarboxylate: Methanol, concentrated sulfuric acid, and 1,1-cyclohexanedicarboxylic acid were added sequentially to a three-necked flask and refluxed at 80°C for 2.5 h to obtain dimethyl 1,1-cyclohexanedicarboxylic acid; wherein the molar ratio of 1,1-cyclohexanedicarboxylic acid to methanol was 1:10; and the mass ratio of 1,1-cyclohexanedicarboxylic acid to concentrated sulfuric acid was 1:0.05. The pH was adjusted to neutral.

[0089] The following reaction occurs specifically: (2) A methanol solution of hydroxylamine hydrochloride and sodium hydroxide was heated in an ice-water bath (0°C) for 1 hour to obtain a free hydroxylamine solution; wherein the molar ratio of hydroxylamine hydrochloride to sodium hydroxide was 1:2. The solid-liquid ratio of hydroxylamine hydrochloride in the methanol solution was 1:3.

[0090] (3) The 1,1-cyclohexanedicarboxylic acid dimethyl ester obtained in step (1) was added dropwise to the free hydroxylamine solution obtained in step (2); the reaction was carried out at 50°C for 3.5 h. Excess methanol was removed by vacuum distillation at 40°C, followed by acid washing with dilute sulfuric acid and freeze drying; ilmenite collector was obtained. The molar ratio of 1,1-cyclohexanedicarboxylic acid dimethyl ester to free hydroxylamine was 1:1.3.

[0091] The following reaction occurs specifically: (4) The raw ore was roughed and floated using the ilmenite collector obtained in step (3): the pH was adjusted to about 4.5 and 1250 g / t of ilmenite collector was added; concentrate and tailings were obtained; the specific experimental results are shown in Table 11.

[0092] Table 11 Results of roughing flotation experiments using the ilmenite collector in Example 8 As can be seen from Tables 2 and 11, the amount of ilmenite collector prepared in this embodiment used for rough flotation is half that used for rough flotation of octyl hydroxamic acid, a commonly used collector in Comparative Example 1; however, the flotation performance of this embodiment is still better than that of octyl hydroxamic acid in Comparative Example 1.

[0093] In summary, the above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A process for the preparation of an ilmenite collector agent characterised in that, The method comprises the steps of: providing a cycloalkane carboxylic acid methyl ester compound; the cycloalkane carboxylic acid methyl ester compound comprises at least one of a cycloalkane carboxylic acid methyl ester and a 1,1-cycloalkane dicarboxylic acid dimethyl ester; providing a free hydroxylamine solution; mixing the cycloalkane carboxylic acid methyl ester compound and the free hydroxylamine solution to perform a hydroxamidation reaction to obtain a post-reaction liquid; performing, in sequence, methanol separation treatment, acidification treatment and freeze-drying treatment on the post-reaction liquid to obtain an ilmenite collector.

2. The production method according to claim 1, characterized by, The hydroxamidation reaction is performed at a temperature of 50-60 DEG C for 3-5 hours.

3. The preparation method according to claim 1, characterized in that, The cycloalkane carboxylic acid methyl ester compound is obtained by the steps of: performing esterification reaction on a cycloalkane carboxylic acid compound and methanol under catalysis of concentrated sulfuric acid to obtain an intermediate; adjusting the pH value of the intermediate to be neutral or weakly alkaline; wherein the cycloalkane carboxylic acid compound comprises at least one of a cycloalkane carboxylic acid and a 1,1-cycloalkane dicarboxylic acid.

4. The production method according to claim 3, characterized by, The molar ratio of the cycloalkane carboxylic acid compound to the methanol is 1:3-20.

5. The preparation method according to claim 3, characterized in that, The mass ratio of the cycloalkane carboxylic acid compound to the concentrated sulfuric acid is 1:0.01-0.

05.

6. The preparation method according to claim 3, characterized in that, The esterification reaction is performed at a temperature of 60-80 DEG C for 2-4 hours.

7. The preparation method according to claim 1, characterized in that, The free hydroxylamine solution is obtained by performing ice-water bath treatment on a methanol solution of hydroxylamine hydrochloride and sodium hydroxide for 1-2 hours.

8. An ilmenite collector prepared by the process of any one of claims 1 to 7, characterised in that, The molecular formula of the ilmenite collector is C n+1 H 2n+1 O2N; or C n+2 H 2n+2 O2N; wherein n is an integer of 3-10.

9. Use of the ilmenite collector according to claim 8 in roughing flotation of ilmenite rough ore.

10. Use according to claim 9, characterized in that, The ilmenite collector is added to the ilmenite rough ore to perform roughing flotation treatment; the addition amount of the ilmenite collector is 1250-2500 g / t; and the pH value of the roughing flotation is 4-5.

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