Ilmenite flotation process

Abstract

The ilmenite flotation process comprises the steps of roughing, specifically, minerals are placed in a flotation tank, water is added for size mixing, even stirring is conducted, the pH value is adjusted to 7-9, a composite collecting agent is added, roughing flotation is conducted, and roughing titanium concentrate and roughing tailings are obtained; the roughed titanium concentrate is placed in a flotation tank, water is added for size mixing, uniform stirring is carried out, the pH value is adjusted to 7-9, a composite collecting agent is added, concentration flotation is carried out, and titanium concentrate is obtained; wherein the composite collecting agent comprises citric acid hydroximic acid and sodium oleate. Citric acid hydroximic acid prepared from citrate and hydroxylamine hydrochloride is compounded with sodium oleate to obtain the composite collecting agent, the composite collecting agent serves as the collecting agent in the ilmenite flotation process, efficient separation of ilmenite and titanaugite can be achieved, the method is environmentally friendly, and therefore flotation can be conducted on ilmenite in an environment-friendly and efficient mode.

Description

Technical Field

[0001] The invention belongs to the technical field of ilmenite beneficiation, and in particular relates to an ilmenite flotation process. Background Art

[0002] Ilmenite is mainly used to extract the rare metal titanium. Titanium has good temperature adaptability, acid-base adaptability, high strength and low density. It can be used as structural materials, corrosion-resistant containers, pipelines, superconducting materials, etc. It is widely used. my country's ilmenite resources are mainly vanadium-titanium magnetite resources in the Panzhihua area. The main gangue minerals are pyroxene and feldspar minerals. The secondary gangue minerals are mainly composed of olivine, amphibole and their altered minerals. Among them, titanium pyroxene and olivine are similar to ilmenite in surface chemical properties and active particles, which makes it difficult to separate ilmenite from titanium pyroxene and olivine.

[0003] At present, the flotation collectors used in ilmenite flotation have problems such as large dosage, harsh operating conditions, and low environmental friendliness. The development of efficient and green collectors is an effective way to solve the problem of ilmenite flotation separation. Summary of the invention

[0004] In view of the above situation, in order to overcome at least part of the defects of the above-mentioned prior art, the present invention provides an ilmenite flotation process.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides an ilmenite flotation process, characterized by comprising: Roughing: Place the mineral in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 7-9, add a composite collector, and perform roughing flotation to obtain roughing titanium concentrate and roughing tailings; Concentration: placing the rough titanium concentrate in a flotation tank, adding water to slurry, stirring evenly, adjusting the pH value to 7-9, adding a composite collector, and performing concentration flotation to obtain titanium concentrate; Wherein, the composite collector comprises citric acid hydroxamic acid and sodium oleate.

[0006] In some embodiments, the amount of composite collector added per ton of mineral is 0.5 kg to 2 kg.

[0007] In some embodiments, in the composite collector, the mass ratio of citric acid hydroxamic acid to sodium oleate is 2:1-2.

[0008] In some embodiments, the citric acid hydroxamic acid is prepared by reacting a citrate ester and hydroxylamine hydrochloride, and the preparation method of the citric acid hydroxamic acid comprises: Add hydroxylamine hydrochloride to methanol, add sodium hydroxide, and stir at 20°C-30°C for 30min-40min to obtain a hydroxylamine solution; Add citrate to the hydroxylamine solution, heat in a water bath at 50°C-60°C for 4h-8h, adjust the pH to 4-5 after the reaction, let stand for 20h-30h, vacuum filter, and dry to obtain citric acid hydroxamic acid.

[0009] In some embodiments, the molar ratio of hydroxylamine hydrochloride to sodium hydroxide is 1:2-3.

[0010] In some embodiments, the molar ratio of hydroxylamine hydrochloride to citrate is 1:1-3.

[0011] In some embodiments, the method for preparing the citrate ester comprises: Take citric acid and acetic anhydride and add them to acetic acid, stir evenly, raise the temperature to 30-40°C, react for 1-3 hours, and obtain citric anhydride; Place a higher fatty alcohol in a flask, heat to melt, add citric anhydride, raise the temperature to 80°C-100°C, react for 3h-5h, and obtain citrate ester.

[0012] In some embodiments, the molar ratio of citric acid to acetic anhydride is 1:1-2.

[0013] In some embodiments, the molar ratio of the higher fatty alcohol to citric anhydride is 1:1.2-1.8.

[0014] In some embodiments, the higher fatty alcohol is one of n-decanol, n-dodecanol, and n-tetradecanol.

[0015] The beneficial effects achieved by the present invention are as follows: Citric acid hydroxamic acid prepared from citrate and hydroxylamine hydrochloride is compounded with sodium oleate to obtain a composite collector. The composite collector is used as a collector in the ilmenite flotation process, which can achieve efficient separation of ilmenite from titanopyroxene and olivine and is relatively environmentally friendly, thereby enabling green and efficient flotation of ilmenite. DETAILED DESCRIPTION

[0016] The technical solutions in 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 part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0018] In view of the deficiencies in the prior art mentioned in the background technology, the embodiment of the present invention proposes an ilmenite flotation process, comprising: Roughing: Place the mineral in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 7-9, add a composite collector, and perform roughing flotation to obtain roughing titanium concentrate and roughing tailings; Concentration: Place the rough titanium concentrate in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 7-9, add a composite collector, and perform concentrating flotation to obtain titanium concentrate; Wherein, the composite collector comprises citric acid hydroxamic acid and sodium oleate.

[0019] Due to the complex mineral composition of ilmenite, there are both easily selected minerals (such as kaolinite and quartz) and difficult-to-select gangue minerals (such as titanite and olivine). Through the two stages of roughing and fine selection, these minerals with different properties are gradually separated to obtain higher-grade ilmenite concentrate.

[0020] The citric acid hydroxamic acid in the composite collector retains the advantage of high selectivity of hydroxamic acid collectors, while the carbon chain structure avoids the harm of aromatic groups to the environment. In addition, the combined use of sodium oleate and hydroxamic acid can further improve the foaming property of the composite collector, thereby improving the collection capacity of the composite collector.

[0021] It should be noted that the pH value of the slurry after slurry adjustment has a great influence on the flotation behavior of the composite collector. Since the hydroxyoxime group is a group with high coordination activity, it can form a stable chelate with the metal ions on the surface of the mineral and adsorb on the surface of the mineral. The pH value of the slurry will affect the ionization degree of hydroxamic acid, thereby affecting the selectivity of the collector. Therefore, the pH value of the slurry is adjusted to 7-9.

[0022] In some embodiments, the amount of the composite collector added per ton of mineral is 0.5kg-2kg. Excessive addition of the composite collector will lead to excessive stability of the mineral bubbles, which will reduce the floatability of the mineral and affect the flotation effect; if the amount of the composite collector added is too little, the composite collector cannot fully interact with the mineral surface, reducing the capture capacity of the composite collector. Therefore, the amount of the composite collector added per ton of mineral needs to be set to 0.5kg-2kg.

[0023] In some embodiments, in the composite collector, the mass ratio of citric acid hydroxamic acid to sodium oleate is 2:1-2. The larger the mass ratio of citric acid hydroxamic acid to sodium oleate, the more citric acid hydroxamic acid accounts for in the composite collector, the less sodium oleate accounts for, the better the selectivity of the composite collector, and the worse the foaming property; the smaller the mass ratio of citric acid hydroxamic acid to sodium oleate, the less citric acid hydroxamic acid accounts for in the composite collector, the more sodium oleate accounts for, the worse the selectivity of the composite collector, and the better the foaming property. By limiting the mass ratio of citric acid hydroxamic acid to sodium oleate to 2:1-2, the composite collector can have better selectivity and foaming property.

[0024] In some embodiments, citric acid hydroxamic acid is prepared by reacting a citrate ester and hydroxylamine hydrochloride, and the preparation method of citric acid hydroxamic acid comprises: Add hydroxylamine hydrochloride to methanol, add sodium hydroxide, and stir at 20°C-30°C for 30min-40min to obtain a hydroxylamine solution; Add citrate to the hydroxylamine solution, heat in a water bath at 50°C-60°C for 4h-8h, adjust the pH to 4-5 after the reaction, let stand for 20h-30h, vacuum filter, and dry to obtain citric acid hydroxamic acid.

[0025] Methanol is used as a solvent, sodium hydroxide is added to adjust the pH value, and hydroxylamine hydrochloride is promoted to dissolve in methanol to form a hydroxylamine solution containing free hydroxylamine, so that citrate can undergo an oximation reaction with hydroxylamine hydrochloride to obtain an oximation product, and finally the oximation product is acidified to obtain citric acid hydroxamic acid.

[0026] In some embodiments, the molar ratio of hydroxylamine hydrochloride to sodium hydroxide is 1:2-3. Sodium hydroxide is mainly used to neutralize the hydrochloric acid part in hydroxylamine hydrochloride to generate free hydroxylamine. By setting the molar ratio of hydroxylamine hydrochloride to sodium hydroxide to 1:2-3, the amount of sodium hydroxide added is slightly excessive, thereby ensuring that the hydroxylamine hydrochloride reacts completely.

[0027] In some embodiments, the molar ratio of hydroxylamine hydrochloride to citrate is 1:1-3. In order to completely carry out the reaction of hydroxylamine hydrochloride and citrate and obtain a higher yield, it is necessary to control the molar ratio of hydroxylamine hydrochloride to citrate to be 1:1-3. In some embodiments, the method for preparing a citrate ester comprises: Take citric acid and acetic anhydride and add them to acetic acid, stir evenly, raise the temperature to 30-40°C, react for 1-3 hours, and obtain citric anhydride; Place a higher fatty alcohol in a flask, heat to melt, add citric anhydride, raise the temperature to 80°C-100°C, react for 3h-5h, and obtain citrate ester.

[0028] Wherein, citric acid and acetic anhydride undergo a dehydration reaction with acetic acid as a catalyst and solvent to generate citric anhydride, and the citric anhydride further undergoes an esterification reaction with a higher fatty alcohol to obtain a citrate ester.

[0029] In some embodiments, the molar ratio of citric acid to acetic anhydride is 1: 1-2. Too large a molar ratio of citric acid to acetic anhydride will result in acetylation of excess acetic anhydride with citric acid or citric anhydride, resulting in a decrease in yield, while too small a molar ratio of citric acid to acetic anhydride will result in incomplete reaction of citric acid, resulting in a decrease in the conversion rate of citric acid, and therefore, the molar ratio of citric acid to acetic anhydride needs to be set to 1: 1-2.

[0030] In some embodiments, the molar ratio of the higher fatty alcohol to citric anhydride is 1:1.2-1.8. If the molar ratio of the higher fatty alcohol to citric anhydride is too large, the acid value of the reaction system will be too large, and the conversion rate of the esterification reaction will be too low. If the molar ratio of the higher fatty alcohol to citric anhydride is too small, the higher fatty alcohol and citric anhydride will not react completely. Therefore, it is necessary to set the molar ratio of the higher fatty alcohol to citric anhydride to 1:1.2-1.8.

[0031] In some embodiments, the higher fatty alcohol is one of n-decanol, n-dodecyl alcohol, and n-tetradecanol. The hydroxyl reactivity of n-decanol, n-dodecyl alcohol, and n-tetradecanol is moderate, neither too active nor too inert, which is conducive to the esterification reaction.

[0032] The present invention will be further described below by way of specific embodiments.

[0033] The experimental methods in the following examples are conventional methods unless otherwise specified; the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

[0034] Example 1 Preparation of composite collector: Take citric acid and acetic anhydride and add them to acetic acid, the molar ratio of citric acid to acetic anhydride is 1:1, stir evenly, heat to 30°C, react for 1h, and obtain citric anhydride; Place n-decanol in a flask, heat to melt, add citric anhydride, the molar ratio of n-decanol to citric anhydride is 1:1.2, heat to 80°C, react for 3h, and obtain citrate; Add hydroxylamine hydrochloride to methanol, add sodium hydroxide, the molar ratio of hydroxylamine hydrochloride to sodium hydroxide is 1:2, stir at 20°C for 30 minutes to obtain a hydroxylamine solution; Add citrate to the hydroxylamine solution, the molar ratio of hydroxylamine hydrochloride to citrate is 1:1, heat in a water bath at 50°C for 4 hours, adjust the pH value to 4 after the reaction is completed, let stand for 20 hours, vacuum filter, and dry to obtain citric acid hydroxamic acid.

[0035] Ilmenite flotation: Roughing: Place the mineral in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 7, add a composite collector, and perform roughing flotation to obtain roughing titanium concentrate and roughing tailings; Concentration: placing the rough titanium concentrate in a flotation tank, adding water to slurry, stirring evenly, adjusting the pH value to 7, adding a composite collector, and performing concentration flotation to obtain titanium concentrate; The amount of the composite collector added to each ton of mineral is 0.5 kg, and the mass ratio of citric acid hydroxamic acid to sodium oleate in the composite collector is 2:1.

[0036] Example 2 Preparation of composite collector: Take citric acid and acetic anhydride and add them to acetic acid, the molar ratio of citric acid to acetic anhydride is 1:2, stir evenly, heat to 40°C, react for 3h, and obtain citric anhydride; Place n-dodecyl alcohol in a flask, heat to melt, add citric anhydride, the molar ratio of n-dodecyl alcohol to citric anhydride is 1:1.8, heat to 100°C, react for 5 hours, and obtain citrate; Add hydroxylamine hydrochloride to methanol, add sodium hydroxide, the molar ratio of hydroxylamine hydrochloride to sodium hydroxide is 1:3, stir at 30°C for 40 minutes to obtain a hydroxylamine solution; Add citrate to the hydroxylamine solution, the molar ratio of hydroxylamine hydrochloride to citrate is 1:3, heat in a water bath at 60°C for 8 hours, adjust the pH value to 5 after the reaction is completed, let stand for 30 hours, vacuum filter, and dry to obtain citric acid hydroxamic acid.

[0037] Ilmenite flotation: Roughing: Place the mineral in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 9, add a composite collector, and perform roughing flotation to obtain roughing titanium concentrate and roughing tailings; Concentration: placing the rough titanium concentrate in a flotation tank, adding water to slurry, stirring evenly, adjusting the pH value to 9, adding a composite collector, and performing concentration flotation to obtain titanium concentrate; The amount of the composite collector added to each ton of mineral is 2 kg, and the mass ratio of citric acid hydroxamic acid to sodium oleate in the composite collector is 1:1.

[0038] Example 3 Preparation of composite collector: Take citric acid and acetic anhydride and add them to acetic acid, the molar ratio of citric acid to acetic anhydride is 1:1.5, stir evenly, heat to 35°C, react for 2h, and obtain citric anhydride; Place n-tetradecanol in a flask, heat to melt, add citric anhydride, the molar ratio of n-tetradecanol to citric anhydride is 1:1.5, heat to 90°C, react for 4h, and obtain citrate; Add hydroxylamine hydrochloride to methanol, add sodium hydroxide, the molar ratio of hydroxylamine hydrochloride to sodium hydroxide is 1:2.5, stir at 25°C for 35 minutes to obtain a hydroxylamine solution; Add citrate to the hydroxylamine solution, the molar ratio of hydroxylamine hydrochloride to citrate is 1:2, heat in a water bath at 55°C for 6 hours, adjust the pH to 5 after the reaction is completed, let stand for 25 hours, vacuum filter, and dry to obtain citric acid hydroxamic acid.

[0039] Ilmenite flotation: Roughing: Place the mineral in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 8, add a composite collector, and perform roughing flotation to obtain roughing titanium concentrate and roughing tailings; Concentration: placing the rough titanium concentrate in a flotation tank, adding water to slurry, stirring evenly, adjusting the pH value to 8, adding a composite collector, and performing concentration flotation to obtain titanium concentrate; The amount of the composite collector added to each ton of mineral is 1.5 kg, and the mass ratio of citric acid hydroxamic acid to sodium oleate in the composite collector is 2:1.5.

[0040] Example 4 The same as Example 1, except that the amount of the composite collector added per ton of mineral is 1 kg.

[0041] Example 5 The same as Example 1, except that the amount of the composite collector added per ton of mineral is 1.5 kg.

[0042] Example 6 The same as Example 1, except that the amount of the composite collector added per ton of mineral is 2 kg.

[0043] Example 7 The method is consistent with Example 1, except that the mass ratio of citric acid hydroxamic acid to sodium oleate in the composite collector is 2:1.

[0044] Example 8 The method is consistent with Example 1, except that the mass ratio of citric acid hydroxamic acid to sodium oleate in the composite collector is 2:1.5.

[0045] Example 9 The method is consistent with Example 1, except that the mass ratio of citric acid hydroxamic acid to sodium oleate in the composite collector is 1:1.

[0046] Comparative Example 1 The same as Example 1, the difference is that commercially available benzohydroxamic acid is used in the composite collector instead of citric acid hydroxamic acid.

[0047] Comparative Example 2 The same as Example 1, except that citric acid hydroxamic acid is used instead of the composite collector.

[0048] Recovery test: The titanium concentrate obtained by flotation is filtered, dried, weighed, sampled and tested in turn to determine the TiO2 content or the content of other target elements. The recovery rate of ilmenite is calculated based on the quality and grade of the recovered concentrate and the quality and grade of the original ore. The recovery rate is calculated as follows: Recovery rate = (mass of TiO2 in concentrate / mass of TiO2 in original ore) × 100%.

[0049] Table 1

[0050] Table 1 is the recovery test results. It can be seen from Table 1 that the recovery rate of Example 5 is higher, and the recovery rates of Comparative Example 1 and Comparative Example 2 are respectively 12.7% and 20.3% lower than those of Example 1. It can be seen that citric acid hydroxamic acid can improve the flotation recovery rate compared with commercially available benzohydroxamic acid, and adding sodium oleate to the composite collector can further improve the flotation recovery rate of citric acid hydroxamic acid.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the protection scope of the present invention.

Claims

1. A flotation process for ilmenite, characterized in that: include: Roughing: Place the mineral in a flotation tank, add water to slurry, stir evenly, adjust the pH value to 7-9, add a composite collector, and perform roughing flotation to obtain roughing titanium concentrate and roughing tailings; Concentration: placing the rough titanium concentrate in a flotation tank, adding water to slurry, stirring evenly, adjusting the pH value to 7-9, adding a composite collector, and performing concentration flotation to obtain titanium concentrate; Wherein, the composite collector comprises citric acid hydroxamic acid and sodium oleate.

2. The ilmenite flotation process according to claim 1, characterized in that: The amount of composite collector added per ton of mineral is 0.5kg-2kg.

3. The ilmenite flotation process according to claim 1, characterized in that: In the composite collector, the mass ratio of citric acid hydroxamic acid to sodium oleate is 2:1-2.

4. The ilmenite flotation process according to claim 1, characterized in that: The citric acid hydroxamic acid is prepared by reacting a citrate ester and hydroxylamine hydrochloride. The preparation method of the citric acid hydroxamic acid comprises: Add hydroxylamine hydrochloride to methanol, add sodium hydroxide, and stir at 20°C-30°C for 30min-40min to obtain a hydroxylamine solution; Add citrate to the hydroxylamine solution, heat in a water bath at 50°C-60°C for 4h-8h, adjust the pH to 4-5 after the reaction, let stand for 20h-30h, vacuum filter, and dry to obtain citric acid hydroxamic acid.

5. The ilmenite flotation process according to claim 4, characterized in that: The molar ratio of the hydroxylamine hydrochloride to the sodium hydroxide is 1:2-3.

6. The ilmenite flotation process according to claim 4, characterized in that: The molar ratio of the hydroxylamine hydrochloride to the citrate is 1:1-3.

7. The ilmenite flotation process according to claim 1, characterized in that: The preparation method of the citrate comprises: Take citric acid and acetic anhydride and add them to acetic acid, stir evenly, raise the temperature to 30-40°C, react for 1-3 hours, and obtain citric anhydride; Place a higher fatty alcohol in a flask, heat to melt, add citric anhydride, raise the temperature to 80°C-100°C, react for 3h-5h, and obtain citrate ester.

8. The ilmenite flotation process according to claim 7, characterized in that: The molar ratio of the citric acid to the acetic anhydride is 1:1-2.

9. The ilmenite flotation process according to claim 7, characterized in that: The molar ratio of the higher fatty alcohol to citric anhydride is 1:1.2-1.

8.

10. The ilmenite flotation process according to claim 7, characterized in that: The higher fatty alcohol is one of n-decanol, n-dodecanol and n-tetradecanol.

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