Apatite positive flotation collector and its application

Abstract

The present invention discloses an apatite positive flotation collector and its application, belonging to the field of mineral processing technology. The apatite positive flotation collector comprises the following raw materials: an esterified collector and hexadecylphenol. The esterified collector is prepared from the following raw materials: ricinoleic acid and p-hydroxybenzoic acid. The present invention utilizes an esterification reaction of ricinoleic acid and p-hydroxybenzoic acid to produce an esterified collector containing multiple functional groups. Hydrogen bonds are formed between the molecules, enhancing the adsorption of the apatite positive flotation collector on the apatite surface and increasing the surface adsorption density of the apatite positive flotation collector. The hydrogen bonds produce excellent flotation efficiency for the mineral, thereby improving the grade and recovery rate of the apatite concentrate. Furthermore, the present invention combines the esterified collector with hexadecylphenol to produce the apatite positive flotation collector. The apatite positive flotation collector can be used in both neutral and alkaline environments. The present invention is low-cost, simple to prepare and operate, and has excellent flotation performance, resulting in high apatite concentrate grade and recovery rate.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing, and particularly relates to an apatite positive flotation collector and application thereof. Background Art

[0002] Phosphate rock is a vital non-metallic mineral resource. Most of my country's phosphate resources consist of medium- to low-grade phosphate rock, mostly collophosphate, which is challenging to separate and expensive to enrich. Flotation is the primary method for phosphate separation. Based on the principle of "suppressing more and floating less," processes such as direct flotation for phosphorus desiliconization, reverse flotation for desiliconization, and reverse flotation for magnesium or calcium removal are commonly used. Currently, the most critical issue in phosphate flotation is flotation reagents. Traditional fatty acid reagents have low solubility, are difficult to disperse, are sensitive to ore slimes and ions, and exhibit poor selectivity. This results in high dosages or the need for slurry heating, increasing production costs. Summary of the Invention

[0003] In view of the above shortcomings of the prior art, the present invention provides an apatite positive flotation collector and application thereof.

[0004] An apatite positive flotation collector comprises the following raw materials: an esterified collector and hexadecylphenol. The esterified collector is prepared from the following raw materials: ricinoleic acid and p-hydroxybenzoic acid.

[0005] As a preferred embodiment of the present invention, the mass of the hexadecylphenol is 10-30% of the total mass of the apatite positive flotation collector.

[0006] As a preferred embodiment of the present invention, the esterified collector is prepared from raw materials comprising the following mass percentages: 50-80% ricinoleic acid and 20-40% p-hydroxybenzoic acid.

[0007] As a preferred embodiment of the present invention, the esterified collector contains one hydroxyl group and one carboxyl group.

[0008] As a preferred embodiment of the present invention, the preparation method of the esterified collector comprises the following steps: adding ricinoleic acid to acetone and stirring until dissolved, then adding p-hydroxybenzoic acid, and then adding phosphorus chloride to react to obtain the esterified collector.

[0009] After adding phosphorus chloride for reaction, the acetone solvent is removed by distillation to obtain a high-purity esterified collector.

[0010] The esterified collector contains a hydroxyl group and a carboxyl group, which can form intermolecular hydrogen bonds, thereby increasing the viscosity of the esterified collector and improving the adsorption density of the esterified collector on the mineral surface.

[0011] The reaction equation of esterification collector is as follows:

[0012]

[0013] Wherein RCOOH is ricinoleic acid.

[0014] As a preferred embodiment of the present invention, the reaction temperature is 20-60° C. and the reaction time is 0.5-2 hours.

[0015] As a preferred embodiment of the present invention, the amount of acetone added is 2-3 times the mass of ricinoleic acid, and the amount of phosphorus chloride added is 5-10% of the mass of ricinoleic acid.

[0016] The apatite positive flotation collector is obtained by mixing an esterified collector and hexadecylphenol.

[0017] Application of the apatite positive flotation collector in apatite positive flotation.

[0018] As a preferred embodiment of the present invention, the pH of the apatite positive flotation collector during apatite positive flotation is neutral or alkaline. Preferably, the pH of the apatite positive flotation collector during apatite positive flotation is 7-11.

[0019] As a preferred embodiment of the present invention, the positive flotation temperature is room temperature.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention adopts the esterification reaction of ricinoleic acid and p-hydroxybenzoic acid to obtain an esterified collector. Unlike other mixed collectors prepared by compounding saturated fatty acids and unsaturated fatty acids, the esterified collector contains multiple functional groups and forms hydrogen bonds between molecules, thereby strengthening the adsorption of the apatite positive flotation collector on the apatite surface and improving the surface adsorption density of the apatite positive flotation collector. Compared with other reagents, the dosage is small; the appearance of hydrogen bonds will produce excellent flotation efficiency for minerals, thereby improving the grade and recovery rate of apatite concentrate.

[0022] (2) The present invention combines an esterified collector with hexadecylphenol to obtain an apatite positive flotation collector. The OH group in the hexadecylphenol can form a hydrogen bond with the CO group in the esterified collector, thereby co-adsorbing on the apatite surface, thereby increasing the adsorption density of the agent on the mineral surface, thereby expanding the application range of the collector. In addition, hexadecylphenol has high solubility and can exist stably within the pH range of 7-11. Therefore, the apatite positive flotation collector has strong environmental adaptability. The present invention is low in cost, simple in preparation and operation, has good flotation effect, and has high apatite concentrate grade and recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1Schematic diagram of the contact angle of a mineral whose surface is impregnated with apatite positive flotation collector. In the figure, 1 is the mineral whose surface is impregnated with apatite positive flotation collector, and 2 is deionized water. DETAILED DESCRIPTION

[0024] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0025] Example 1

[0026] The apatite positive flotation collector comprises raw materials in percentage by mass: 70% esterified collector and 30% hexadecylphenol. The esterified collector is prepared from raw materials in percentage by mass: 60% ricinoleic acid and 40% p-hydroxybenzoic acid.

[0027] The preparation method of the apatite positive flotation collector comprises the following steps:

[0028] (1) Ricinoleic acid is added to acetone in an amount 2.5 times the mass of ricinoleic acid and stirred until dissolved, and then p-hydroxybenzoic acid is added, followed by addition of phosphorus chloride in an amount 12% of the mass of ricinoleic acid, and the mixture is reacted at 45° C. for 1 hour. After the reaction is completed, the acetone solvent is removed by distillation to obtain a high-purity esterified collector.

[0029] (2) The esterified collector is combined with hexadecylphenol to prepare an apatite positive flotation collector.

[0030] Example 2

[0031] The apatite positive flotation collector comprises raw materials in percentage by mass: 90% of an esterified collector and 10% of hexadecylphenol. The esterified collector is prepared from raw materials in percentage by mass: 65% of ricinoleic acid and 35% of p-hydroxybenzoic acid.

[0032] The preparation method of the apatite positive flotation collector comprises the following steps:

[0033] (1) Ricinoleic acid is added to acetone in an amount twice the mass of ricinoleic acid and stirred until dissolved, and then p-hydroxybenzoic acid is added, followed by addition of phosphorus chloride in an amount 10% of the mass of ricinoleic acid, and the mixture is reacted at 60° C. for 2 hours. After the reaction is completed, the acetone solvent is removed by distillation to obtain a high-purity esterified collector.

[0034] (2) The esterified collector is combined with hexadecylphenol to prepare an apatite positive flotation collector.

[0035] Example 3

[0036] The apatite positive flotation collector comprises raw materials in percentage by mass: 74% esterified collector and 26% hexadecylphenol. The esterified collector is prepared from raw materials in percentage by mass: 80% ricinoleic acid and 20% p-hydroxybenzoic acid.

[0037] The preparation method of the apatite positive flotation collector comprises the following steps:

[0038] (1) Ricinoleic acid is added to acetone in an amount 3 times the mass of ricinoleic acid and stirred until dissolved, and then p-hydroxybenzoic acid is added, followed by addition of phosphorus chloride in an amount 5% of the mass of ricinoleic acid, and the mixture is reacted at 20° C. for 0.5 hour. After the reaction is completed, the acetone solvent is removed by distillation to obtain a high-purity esterified collector.

[0039] (2) The esterified collector is combined with hexadecylphenol to prepare an apatite positive flotation collector.

[0040] Comparative Example 1

[0041] The apatite positive flotation collector is an esterified collector; the esterified collector is prepared from raw materials having the following mass percentages: 60% ricinoleic acid and 40% p-hydroxybenzoic acid.

[0042] The preparation method of the apatite positive flotation collector comprises the following steps: adding ricinoleic acid to acetone in an amount 2.5 times the mass of the ricinoleic acid and stirring until dissolved; then adding p-hydroxybenzoic acid; and then adding phosphorus chloride in an amount 12% of the mass of the ricinoleic acid, and reacting at 45°C for 1 hour. After the reaction is completed, the acetone solvent is removed by distillation to obtain a high-purity esterified collector.

[0043] Comparative Example 2

[0044] The apatite positive flotation collector is hexadecylphenol.

[0045] Comparative Example 3

[0046] The apatite positive flotation collector comprises raw materials in the following mass percentages: 70% mixed acid and 30% hexadecylphenol, and the mixed acid comprises raw materials in the following mass percentages: 60% ricinoleic acid and 40% p-hydroxybenzoic acid.

[0047] The preparation method of the apatite positive flotation collector comprises the following steps:

[0048] (1) mixing ricinoleic acid and p-hydroxybenzoic acid to obtain a mixed acid;

[0049] (2) The mixed acid and hexadecylphenol are combined to prepare an apatite positive flotation collector.

[0050] Comparative Example 4

[0051] The apatite positive flotation collector comprises raw materials in percentage by mass: 60% ricinoleic acid and 40% p-hydroxybenzoic acid.

[0052] The preparation method of the apatite positive flotation collector comprises the following steps: mixing ricinoleic acid and p-hydroxybenzoic acid to obtain the apatite positive flotation collector.

[0053] Effect Example 1

[0054] Collector samples: the apatite positive flotation collector described in Examples 1-3, the apatite positive flotation esterified collector described in Comparative Examples 1-4, and ricinoleic acid.

[0055] Mineral 1 is selected from apatite from Baiquan Iron Mine of Hebei Iron and Steel Group.

[0056] The contact angle test includes: cutting mineral 1 into 2 mm x 10 mm x 10 mm flakes, grinding and polishing, cleaning with deionized water, soaking in 100 mL of a collector sample with a concentration of 300 mg / L for 10 min, pH = 7 or 10 (see Table 1 for details), drying the sample at low temperature, placing it on a measuring water platform, releasing deionized water vertically at a distance of 10 mm from the sample, and measuring the contact angle of the sample surface. The results are shown in Table 1.

[0057] Table 1

[0058]

[0059]

[0060] According to Table 1, compared with Comparative Examples 1-4 and other collector samples, the contact angle of the apatite positive flotation collector described in Examples 1-3 can be maintained at 75° under both neutral and alkaline conditions, and the reaction time of the contact angle is faster.

[0061] According to embodiment 1, compare with comparative example 1-2, esterification collector can improve the hydrophobicity on apatite surface, makes apatite surface modification, thereby improves the flotation recovery of apatite.But the adsorption capacity of hexadecylphenol on apatite surface is poor, and can't effectively improve apatite surface hydrophobicity when used alone, and apatite contact angle only has 33 °.When esterification collector and hexadecylphenol are mixed as apatite positive flotation collector, apatite contact angle rises to 75 ° from 60 °, and the hydrophobicity of apatite increases, and flotation recovery improves. The solubility of hexadecylphenol is high, and can stably exist in neutral to alkaline solution, but collecting ability is weak, and after being used in conjunction with esterification collector, the OH group in hexadecylphenol can form hydrogen bond with the CO group of esterification agent and be co-adsorbed on apatite surface, thereby increase the adsorption capacity of medicament on apatite surface, and improve the hydrophobicity on apatite surface.

[0062] According to Example 1 and Comparative Examples 3-4, when ricinoleic acid and p-hydroxybenzoic acid are directly mixed, the contact angle of apatite is very low and the hydrophobicity is weak. The ricinoleic acid molecule has only one COOH group that can interact with the calcium on the apatite surface, but its own solubility is weak. The p-hydroxybenzoic acid itself has a short carbon chain length, and the OH and COOH groups are in the opposite position of the molecule. When the COOH group interacts with the apatite, the OH group faces the solution and cannot produce a hydrophobic surface. However, when ricinoleic acid and p-hydroxybenzoic acid react, the esterified agent formed has a longer hydrophobic group than ricinoleic acid, and has a stronger ability to enhance the hydrophobicity of the apatite. Secondly, in addition to the COOH group in the molecule that can react with the apatite surface, the CO group can increase the solubility of the molecule and can also interact with the calcium on the apatite surface, thereby increasing the adsorption capacity of the agent. Moreover, the benzene ring in the molecule occupies a larger space on the apatite surface, which can also improve the hydrophobicity of the apatite surface. Although the contact angle of apatite is 76° or 77° when ricinoleic acid, p-hydroxybenzoic acid and hexadecylphenol are mixed, the reaction time of the contact angle is much longer than that of the apatite positive flotation collector of the present invention.

[0063] Effect Example 2

[0064] Collector samples: the apatite positive flotation collector described in Examples 1-3, the apatite positive flotation collector described in Comparative Examples 1-4, and oleic acid.

[0065] Mineral 2 is selected from a mixed phosphate mine in Dongchuan, Yunnan. The ore grade of the mixed phosphate mine in Dongchuan, Yunnan is 21%. The main gangue minerals are sesquioxides and silicate minerals. The mineral embedding particle size is uneven and the embedding relationship is complex. It is a low-grade phosphate mine.

[0066] The flotation process of oleic acid collector is the original flotation process test: a flotation test process of one coarse and one fine is adopted. The test uses sodium carbonate with a concentration of 2.0kg / t, water glass with a concentration of 0.90kg / t as an inhibitor, and oleic acid with a concentration of 2.5kg / t as a collector. Finally, a concentrate with a grade of 28.03% and a recovery rate of 78.77% can be obtained.

[0067] Flotation process of other collector samples: grinding fineness -0.074mm accounts for 83%. 500g of mineral 2 was added to a 1.5L flotation cell. No inhibitor or frother was added. Only 1.0kg / t of collector sample was added. Under the condition of pH = 10, stirring was carried out at a speed of 1800 rpm for 3min and scraping was carried out for 4min to obtain apatite concentrate. The concentrate grade and recovery rate are shown in Table 2.

[0068] Table 2

[0069]

[0070]

[0071] According to embodiment 1 and comparative example 1-2 experimental results, show, collector dosage is identical, for the apatite of complex composition, containing a large amount of gangue minerals, the apatite positive flotation collector of the present invention has better selectivity to apatite than single esterified collector or hexadecylphenol, and obtains high-grade phosphate rock.Esterified collector can improve the hydrophobicity of apatite surface, makes apatite surface modification, thereby improves the flotation recovery of apatite.Hexadecylphenol has high solubility and can stably exist in neutral to alkaline water, but its collecting ability is weak.Therefore, after hexadecylphenol is used in conjunction with esterified collector, the OH group in hexadecylphenol can form hydrogen bond with the CO group of esterified collector and be co-adsorbed on the apatite surface, thereby increases the adsorption amount of the agent on the apatite surface, and improves the phosphate rock concentrate grade and recovery.

[0072] According to Example 1 and Comparative Examples 3-4, when ricinoleic acid and p-hydroxybenzoic acid are directly mixed, the apatite contact angle is very low and the hydrophobicity is weak. The ricinoleic acid molecule has only one COOH group that can interact with the calcium on the apatite surface, but its own solubility is weak. P-hydroxybenzoic acid itself has a short carbon chain length, and the OH and COOH groups are in the para position of the molecule. When the COOH group interacts with the apatite, the OH group faces the solution, failing to produce a hydrophobic surface. Therefore, when ricinoleic acid and p-hydroxybenzoic acid are directly mixed, the apatite concentrate grade and recovery rate are significantly reduced. Since the OH group in hexadecylphenol can form a hydrogen bond with the CO group of the esterified collector, the OH groups are co-adsorbed on the apatite surface, thereby increasing the adsorption density of the agent on the mineral surface. Therefore, compared with the collector formed by mixing ricinoleic acid, p-hydroxybenzoic acid and hexadecylphenol, the apatite positive flotation collector formed by the esterified collector and hexadecylphenol has a higher apatite concentrate grade and recovery rate.

[0073] Compared with the original flotation process test (oleic acid as collector), the flotation of apatite positive flotation collector described in this embodiment uses a lower collector dosage, and the various indicators of the obtained concentrate are also better than those of the original test concentrate.

[0074] Effect Example 3

[0075] Ore 3, sourced from Leshan City, Sichuan Province, is dark gray in color and contains 13.18% P₂O₅. Phosphorus primarily exists as Ca₅(PO₄)₃F. The ore also contains a significant amount of quartz gangue and a small amount of dolomite. Ore 3 is a low-grade siliceous phosphate rock.

[0076] Collector samples: the apatite positive flotation collectors described in Examples 1-3 and the apatite positive flotation collectors described in Comparative Examples 1-4.

[0077] Flotation process: grinding fineness -0.074mm accounts for 75%. In a 1.5L flotation cell, 500g of mineral 3, 300g / t of water glass to suppress quartz gangue, 50g / t of terpineol frother, and only 400g / t of collector sample were added. Under the condition of pH = 9, stirring was carried out at a speed of 1800 rpm for 3min, and scraping was carried out for 4min to obtain apatite concentrate. The concentrate grade and recovery are shown in Table 3.

[0078] Conventional flotation process: Under the same experimental conditions, a calcination-leaching-acid activation process was used to extract apatite ore. The collector sample was 800 g / t of the apatite positive flotation collector described in Example 1. The calcination temperature was 793°C, and the leaching was carried out with NH4NO3 and the acid activation was carried out with sulfuric acid (10%). Finally, the apatite concentrate with a grade of 20% and a recovery rate of 53% was obtained.

[0079] Table 3

[0080] Collector samples Concentrate grade / % Recovery rate / % Example 1 27.93 85.34 Example 2 28.31 82.31 Example 3 28.45 83.25 Comparative Example 1 25.34 64.22 Comparative Example 2 24.49 63.28 Comparative Example 3 27.66 80.38 Comparative Example 4 25.21 55.32

[0081] According to the experimental results of Example 1 and Comparative Examples 1-2, the same collector dosage is shown. For low-grade carbonate phosphate ore, the apatite positive flotation collector of the present invention has better selectivity for apatite than a single esterified collector or hexadecylphenol, and high-grade phosphate ore is obtained. According to Example 1 and Comparative Examples 3-4, when ricinoleic acid and p-hydroxybenzoic acid are directly mixed and used, the apatite concentrate grade and recovery rate are significantly reduced. Since the OH group in hexadecylphenol can form a hydrogen bond with the CO group of the esterified collector, the apatite concentrate grade and recovery rate of the apatite positive flotation collector formed by the esterified collector and hexadecylphenol are higher than those formed by the mixed collector of ricinoleic acid, p-hydroxybenzoic acid and hexadecylphenol.

[0082] The traditional flotation method has a complicated process and the obtained apatite has a low grade. The flotation process of the apatite positive flotation collector has a simple process and a good flotation effect, and can obtain high-grade phosphate ore. It can be used as a good collector for apatite.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A collector for positive flotation of apatite, characterized in that: The method comprises the following raw materials: an esterified collector and hexadecylphenol; The preparation method of the esterified collector comprises the following steps: adding ricinoleic acid into acetone and stirring until dissolved, then adding p-hydroxybenzoic acid, and then adding phosphorus chloride to react to obtain the esterified collector.

2. The apatite positive flotation collector according to claim 1, characterized in that: The mass of the hexadecylphenol is 10-30% of the total mass of the apatite positive flotation collector.

3. The apatite positive flotation collector according to claim 1, characterized in that: The esterified collector is prepared from raw materials having the following mass percentages: 50-80% ricinoleic acid and 20-40% p-hydroxybenzoic acid.

4. The apatite positive flotation collector according to claim 1, characterized in that: The reaction temperature is 20-60° C., and the reaction time is 0.5-2 hours.

5. The apatite positive flotation collector according to claim 1, characterized in that: The amount of acetone added is 2-3 times the mass of ricinoleic acid, and the amount of phosphorus chloride added is 5-10% of the mass of ricinoleic acid.

6. Use of the apatite positive flotation collector according to any one of claims 1 to 5 in apatite positive flotation.

7. The use according to claim 6, characterized in that During the positive flotation, the pH is 7-11.

8. The use according to claim 6, characterized in that During the positive flotation, the temperature is room temperature.

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