A low-temperature reverse flotation collector for collophane and its preparation method

Abstract

This invention discloses a low-temperature reverse flotation collector for collophane and its preparation method, belonging to the field of collophane flotation technology. The low-temperature reverse flotation collector for collophane of this invention is prepared from the following raw materials: linoleic acid, linolenic acid, and gallic acid. This invention generates a low-temperature reverse flotation collector for collophane containing two OH groups and one COOH group through an esterification reaction of linoleic acid, linolenic acid, and gallic acid. In acidic pulp, the flotation recovery rate is 20-50% lower than before the esterification reaction, and the dosage is significantly improved, resulting in a substantial increase in concentrate P2O5 grade and recovery rate. Furthermore, the low-temperature reverse flotation collector for collophane can be used for flotation at a low temperature of 5-10℃. The flotation foam generated during the flotation process has a short duration, low foam stability, and is easily defoamed, which is beneficial for continuous operation and tailings recovery.

Description

Technical Field

[0001] This invention belongs to the field of collophane flotation technology, specifically relating to a low-temperature reverse flotation collector for collophane and its preparation method. Background Technology

[0002] The reverse flotation of collophane involves using sulfuric acid and phosphate to suppress apatite, and then using fatty acids to reverse-flotate dolomite. A highly efficient fatty acid collector is the core factor affecting separation efficiency. Currently, reverse flotation of collophane rarely uses a single fatty acid collector; instead, it uses mixed fatty acids, such as oleic acid and other fatty acids, including vegetable oil and waste cooking oil. These mixed fatty acids present two problems: first, the mixed fatty acids dissociate weakly under acidic conditions, leading to excessive collector dosage; second, excessive collector dosage results in overly viscous foam that is difficult to defoam, hindering the circulation of recycled water. Summary of the Invention

[0003] To address the shortcomings of the existing technology, this invention provides a low-temperature reverse flotation collector for collophane and its preparation method. This invention uses a mixture of linoleic acid and linolenic acid as the main raw material for the esterification reaction, forming a low-temperature reverse flotation collector for collophane containing 2-3 OH groups and one COOH group. The flotation recovery rate in acidic slurry is reduced by 20-50% compared to before the esterification reaction.

[0004] A low-temperature reverse flotation collector for collophane is prepared from the following raw materials: linoleic acid, linolenic acid and gallic acid.

[0005] In a preferred embodiment of the present invention, the volume ratio of linoleic acid, linolenic acid and gallic acid is 60-80:20-40:50-70.

[0006] As a preferred embodiment of the present invention, the low-temperature reverse flotation collector for collophane contains 2-3 OH groups and 1 COOH group; wherein the 2-3 OH groups in the low-temperature reverse flotation collector for collophane can be linked by hydrogen bonding between the OH groups, thereby increasing the adsorption density of the low-temperature reverse flotation collector for collophane on the mineral surface.

[0007] As a preferred embodiment of the present invention, the preparation method of the low-temperature reverse flotation collector for collophane ore includes the following steps:

[0008] (1) Mix linoleic acid and linolenic acid to obtain mixed fatty acids;

[0009] (2) Add mixed fatty acids to carbon tetrachloride and gallic acid, and react at 50-90℃ to obtain a low-temperature reverse flotation collector for phosphate rock.

[0010] Linoleic acid and linolenic acid are the main components of currently used mixed oils. Compared with oleic acid, a traditional reagent, they have the characteristics of high solubility and good dissociation under acidic conditions. This invention uses linoleic acid and linolenic acid as raw materials, and then adds gallic acid for esterification reaction to obtain a high-performance low-temperature reverse flotation collector for collophane. The specific reaction mechanism of linoleic acid and linolenic acid with gallic acid is as follows:

[0011]

[0012] In formulas (1)-(2), R1COOH is linoleic acid, R2COOH is linolenic acid, R1 is CH3(CH2)4CH=CHCH2CH=CH(CH2)7, and R2 is CH3(CH2CH=CH)3(CH2)7.

[0013] In a preferred embodiment of the present invention, the reaction time in step (2) is 30-45 minutes.

[0014] As a preferred embodiment of the present invention, in step (2), the amount of carbon tetrachloride added is 50-70% of the total mass of linoleic acid and linolenic acid. After the reaction is completed, the carbon tetrachloride is removed by distillation at 70-100°C.

[0015] In a preferred embodiment of the present invention, the collophane low-temperature reverse flotation collector is used for flotation at 5-10°C. The collophane low-temperature reverse flotation collector does not affect the flotation performance of the reagent in a low-temperature environment (5-10°C), and the foam generated using the collophane low-temperature reverse flotation collector has low viscosity and is easy to defoam.

[0016] As a preferred embodiment of the present invention, the low-temperature reverse flotation collector for collophane flotation floats dolomite within a pH range of 4-6, while avoiding interference from calcium and magnesium ions in the pulp. Compared with linoleic acid, linolenic acid, or a mixture of linoleic and linolenic acid fatty acids, the dosage of the low-temperature reverse flotation collector for collophane can be reduced by 30-40%.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) The present invention generates a low-temperature reverse flotation collector for collophane containing two OH and one COOH by esterification reaction of linoleic acid, linolenic acid and gallic acid. The flotation recovery rate in acidic slurry is 20-50% lower than before esterification reaction, and the amount of collophane used is significantly improved, and the P2O5 grade and recovery rate of the concentrate are significantly improved.

[0019] (2) The low-temperature reverse flotation collector for collophane can be used for flotation at a low temperature of 5-10℃. Furthermore, the flotation foam generated during the flotation process by the low-temperature reverse flotation collector for collophane has a short duration, low foam stability, and is easy to defoam, which is beneficial for continuous operation and tailwater recovery. Attached Figure Description

[0020] Figure 1 This is a comparison chart showing the change in flotation foam layer thickness over time under the action of the low-temperature reverse flotation collector for collophane prepared in Example 1 or a mixture of fatty acids of linoleic acid and linolenic acid. Detailed Implementation

[0021] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0022] Example 1

[0023] The preparation method of the low-temperature reverse flotation collector for collophane ore includes the following steps:

[0024] (1) Mix 6 mL of linoleic acid and 4 mL of linolenic acid to obtain mixed fatty acids;

[0025] (2) Add the mixed fatty acids to 5 mL of carbon tetrachloride and 5 mL of gallic acid. React at 50 °C for 45 minutes. After the reaction is complete, distill at 100 °C to remove carbon tetrachloride and obtain the low-temperature reverse flotation collector for phosphate rock.

[0026] Example 2

[0027] The preparation method of the low-temperature reverse flotation collector for collophane ore includes the following steps:

[0028] (1) Mix 8 mL of linoleic acid and 2 mL of linolenic acid to obtain mixed fatty acids;

[0029] (2) Add the mixed fatty acids to 7 mL of carbon tetrachloride and 7 mL of gallic acid. React at 90 °C for 30 minutes. After the reaction is complete, distill at 70 °C to remove carbon tetrachloride and obtain the low-temperature reverse flotation collector for phosphate rock.

[0030] Comparative Example 1

[0031] The low-temperature reverse flotation collector for collophane described in this comparative example is a mixture of 6 mL of linoleic acid and 4 mL of linolenic acid to obtain a mixed fatty acid.

[0032] Example of effect 1

[0033] This example demonstrates the foam stability of a collector sample.

[0034] Collector samples: Low-temperature reverse flotation collectors for phosphate rock described in Examples 1-2, and mixed fatty acids described in Comparative Example 1.

[0035] The foam stability test in this example includes the following steps: 200 mL of deionized water is added to a 1000 mL graduated cylinder, 300 mg / L of collector sample is added, and air is used to aerate the foam layer at a flow rate of 1.2 L / min to generate a foam layer. The change in foam layer thickness over time is observed to reflect the stability of the foam layer during the flotation process.

[0036] like Figure 1 As shown, the foam layer thickness is extremely stable under the action of mixed fatty acids, maintaining a thickness of 25-30 cm within the measured 10 minutes; however, the foam layer stability of the collophane low-temperature reverse flotation collector described in Examples 1-2 after the mixed fatty acids undergo esterification reaction drops sharply, decreasing from 33 cm to below 10 cm within 10 minutes, exhibiting a more significant defoaming effect. This indicates that the foam of the collophane low-temperature reverse flotation collector obtained after esterification reaction is easy to defoam, has lower viscosity, and enhances the flowability of the foam product.

[0037] Example 2

[0038] This example demonstrates the effect of a collector sample on the grade and recovery rate of P2O5 in a flotation process.

[0039] The raw ore was selected from phosphate rock in Jinning area of ​​Yunnan Province. It is characterized by high phosphorus, low magnesium and high sesquioxide (R2O3) content. It does not meet the quality standard requirements for phosphate rock for acid processing and is difficult to use directly. Therefore, it is a difficult-to-process phosphate rock with a P2O5 grade of 18.66%.

[0040] Collector samples: the low-temperature reverse flotation collector for collophane described in Examples 1-2, and the mixed fatty acids, linoleic acid, linolenic acid, and gallic acid described in Comparative Example 1.

[0041] Reverse flotation process: Under the conditions of reverse flotation temperature of 10℃, grinding fineness of -0.074mm, mass fraction of 83.6%, collector sample dosage of 1kg / t for reverse flotation roughing and 0.5kg / t for reverse flotation scavenging, and with raw ore P2O5 grade of 18.66%, a closed-circuit process of reverse flotation 1 roughing 1 scavenging - 1 concentrate middlings sequential return was adopted to obtain phosphate concentrate. The results are shown in Table 1.

[0042] Table 1

[0043]

[0044]

[0045] The results in Table 1 show that using the low-temperature reverse flotation reagents of Examples 1 and 2, the grade of phosphate concentrate reached 28-29%, and the recovery rate was between 86-87%. However, using the collector of Comparative Example 1 (a mixture of linoleic acid and linolenic acid), the grade of phosphate concentrate was only 25.22%, indicating that the gangue minerals were not fully floated and the concentrate grade was not significantly improved; using linoleic acid, linolenic acid, and gallic acid alone could not effectively improve the P2O5 grade in the concentrate. The reverse flotation reagents in Examples 1 and 2 have significant collecting ability and are suitable for reverse flotation of phosphate rock. This is because the esterified reagents formed by the reaction of linoleic acid and linolenic acid with gallic acid contain COOH groups, which can collect dolomite and calcite gangue. Moreover, the benzene ring of the esterified reagent contains two OH groups. When the reagent is adsorbed on the surface of dolomite, adjacent reagent molecules can form intermolecular hydrogen bonds through the OH groups, thereby strengthening the aggregation of the reagent, increasing the adsorption density of the reagent on the mineral surface, and improving the flotation efficiency. In addition, the introduction of COC ether groups into the molecule increases the solubility of the reagent, making the reagent adaptable to acidic environments. At the same time, the ether groups have a certain degree of hydrophilicity, which can reduce the viscosity of foam and facilitate defoaming.

[0046] Example 3

[0047] This example demonstrates the effect of collector samples on the grade and recovery rate of P2O5 in concentrate at different flotation temperatures.

[0048] The raw ore was selected from the flotation test of medium-low grade collophane ore in three layers of Fangmashan, Hubei Province. The raw ore has a P2O5 grade of 20.14% and high contents of SiO2, MgO and CaO. The main gangue minerals are quartz, dolomite and albite.

[0049] Collector samples: Low-temperature reverse flotation collector for phosphate rock described in Examples 1-2, and mixed fatty acids, linoleic acid, and linolenic acid described in Comparative Example 1.

[0050] Flotation process: Each test was conducted using 500g of raw ore. Flotation was carried out at a grinding fineness of 85%-200 mesh. The rougher collector dosage was 500g / t, and the sulfuric acid depressant dosage was 18kg / t. The flotation process was 1 rougher-1 cleaner-1 scavenger. The middlings were returned sequentially. For the cleaner, 2kg / t of sulfuric acid and 200g / t of collector were added. The results are shown in Table 2.

[0051] Table 2

[0052]

[0053] The results in Table 2 show that for the low-grade phosphate rock in the three layers of Fangmashan, Hubei, the reagents used in Implementation Cases 1 and 2 can yield phosphate concentrate with a P2O5 grade >28% and a recovery rate of over 80% at 5℃ and 10℃. However, when using Comparative Example 1, linolenic acid, and linoleic acid, the grade of the phosphate concentrate is difficult to improve at 5℃, 10℃, and 20℃, with the P2O5 grade between 20-24%, making it impossible to obtain high-grade phosphate concentrate.

[0054] 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 modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A low-temperature reverse flotation collector for collophane, characterized in that, It is prepared from the following raw materials: linoleic acid, linolenic acid and gallic acid; the volume ratio of linoleic acid, linolenic acid and gallic acid is 60-80:20-40:50-70; The preparation method of the low-temperature reverse flotation collector for collophane ore includes the following steps: (1) Mix linoleic acid and linolenic acid to obtain mixed fatty acids; (2) Add the mixed fatty acids to carbon tetrachloride and add gallic acid, and react at 50-90℃ for 30-45 minutes to obtain the low-temperature reverse flotation collector for phosphate rock.

2. The low-temperature reverse flotation collector for phosphate rock as described in claim 1, characterized in that, The low-temperature reverse flotation collector for collophane contains 2-3 OH radicals and 1 COOH radical.

3. The low-temperature reverse flotation collector for collophane as described in claim 1 or 2, characterized in that, The collophane low-temperature reverse flotation collector is used for flotation at 5-10℃.

4. The low-temperature reverse flotation collector for collophane as described in claim 1 or 2, characterized in that, The low-temperature reverse flotation collector for collophane ore is used to float dolomite within a pH range of 4-6.

5. The low-temperature reverse flotation collector for phosphate rock as described in claim 1, characterized in that, In step (2), the amount of carbon tetrachloride added is 50-70% of the total mass of linoleic acid and linolenic acid.

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