Octylphenoxyacetic acid compound as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of mineral processing, and particularly relates to an octylphenoxyacetic acid compound as well as a preparation method and application thereof. The chemical structure of the octylphenoxyacetic acid compound provided by the invention contains ether groups, and the octylphenoxyacetic acid compound has stable low-temperature flotation performance, has the advantages of strong collecting capacity and good selectivity, and can obtain good beneficiation indexes when being used for oxidized ore flotation. When being matched with the fatty acid saponified matter and the oxidized paraffin soap for use, the high-efficiency collecting agent can also achieve the excellent effects of lower dosage and better collecting performance.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, specifically relating to an octylphenoxyacetic acid compound, its preparation method, and its application. Background Technology

[0002] Fatty acids consist of a long hydrocarbon chain and a terminal carboxyl group (-COOH), with the general formula R-COOH. In flotation, they typically function in the form of their salts. The carboxyl ions of fatty acids react with Ca2+ on the mineral surface. 2+ Al 3+ Fe 3+ By chelating with metal cations, the nonpolar, hydrophobic hydrocarbon chains of fatty acids are fixed to the mineral surface, changing it from hydrophilic to hydrophobic. This makes the mineral surface more easily adhered when colliding with air bubbles in the flotation cell. Using the buoyancy of the bubbles, the mineral particles transfer to the surface of the pulp, forming a foam layer that is scraped off, achieving separation from the hydrophilic gangue minerals. Therefore, fatty acid collectors have good collecting ability for metal oxide ores and are used in the flotation of minerals such as scheelite (which contains both recoverable wolframite and scheelite), bauxite, and ilmenite.

[0003] However, the inherent drawbacks of fatty acid collectors limit their application in high-efficiency, energy-saving flotation. Specifically: First, they have poor selectivity. Due to the non-specificity of their mechanism of action, fatty acids often collect other gangue minerals with the same metal cations as the target mineral. Fatty acids and their micelles can also be physically adsorbed onto the surfaces of various minerals (including silicate gangues) through electrostatic or van der Waals forces, leading to non-selective physical adsorption. Second, fatty acids exist in various forms in the pulp (ions, molecules, dimers, micelles), and different forms have different activities on different minerals, resulting in high uncontrollability and hindering selective separation. Finally, fatty acid collectors are not resistant to low temperatures. Below 10-15℃, the solubility of fatty acid soaps in water decreases, the diffusion rate of fatty acid ions / molecules to the mineral surface slows down, and the collision and reaction rate with active sites on the mineral surface decreases. At low temperatures, the pulp viscosity increases, further reducing bubble dispersion and the collision efficiency between mineral particles and bubbles. More importantly, the long hydrocarbon chains of fatty acids are more prone to solidification or crystallization at low temperatures. The fatty acid layer adsorbed on the mineral surface transforms into a rigid, discontinuous "solid" film with poor hydrophobicity. Therefore, the use of fatty acid collectors at low temperatures leads to a deterioration in flotation performance, and traditionally, heating the pulp is relied upon to maintain the effect, resulting in high energy consumption.

[0004] Currently, oleic acid and linoleic acid, commonly used in flotation technology, are unsaturated fatty acids, while 731 and 733 are saturated fatty acids. For the reasons mentioned above, these fatty acids are used in large quantities as collectors in practical applications, leading to increased production costs per unit concentrate, increased gangue mineral inclusions, and reduced concentrate grade. Furthermore, large amounts of fatty acid collectors can affect the stability of the flotation process, reduce operational efficiency, and leave excessive fatty acid residues on the surface of the concentrate after flotation, which can adversely affect subsequent smelting and purification processes.

[0005] Therefore, there is a need to invent a fatty acid collector that has good selectivity, strong low-temperature adaptability, and low dosage to improve flotation performance. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an octylphenoxyacetic acid compound, its preparation method, and its application. The octylphenoxyacetic acid compound provided by this invention exhibits good selectivity and requires a small dosage in mineral flotation, thus offering more and better reagent options for mineral flotation.

[0007] The first aspect of this invention provides an octylphenoxyacetic acid compound, as shown in formula (I) or (II): (I); (II); The compound of formula (I) is octylphenoxyacetic acid, wherein -C8H 17 It is a straight chain or its isomer; The compound of formula (II) is an octylphenoxyacetic acid coupling compound, wherein -C8H 17 It can be a straight chain or its isomer.

[0008] Another aspect of the present invention provides a method for preparing the octylphenoxyacetic acid or the coupling compound, specifically comprising the following steps: S1. Mix octylphenol compounds and chloroacetic acid, add an alcoholic solution containing alkali, adjust the pH to 11-12, and react. When preparing octylphenoxyacetic acid as shown in formula (I), the octylphenol compound is selected from octylphenol as shown in formula (III): (III); -C8H in formula (III) 17 It is a straight chain or its isomer; When preparing the coupling compound of formula (II), the octylphenol compound is selected from the dimer of octylphenol as shown in formula (IV): (IV); -C8H in formula (IV) 17 It is a straight chain or its isomer; S2. The solution after the reaction in step S1 is subjected to vacuum distillation, and then neutralized with acid to obtain the final product.

[0009] Preferably, the reaction temperature in step S1 is 70–100°C.

[0010] Preferably, the molar ratio of the hydroxyl group, chloroacetic acid and base in the octylphenol compound of step S1 is 1:(1-1.5):(1-4).

[0011] Preferably, the alcohol in step S1 is one of methanol or ethanol.

[0012] Preferably, the alkali in step S1 is one or a combination of sodium hydroxide or potassium hydroxide.

[0013] Preferably, the reaction time in step S1 is 4 to 8 hours.

[0014] Preferably, the acid in step S2 is one or a combination of sulfuric acid or hydrochloric acid.

[0015] Preferably, the method for preparing the dimer of octylphenol is as follows: octylphenol, formaldehyde and sulfuric acid as shown in formula (III) are added to a reactor, the temperature is raised to the melting point and stirred to obtain the product.

[0016] Preferably, the acid neutralization in step S2 involves adjusting the pH to 4-6.

[0017] Another aspect of the present invention provides the application of the aforementioned octylphenoxyacetic acid compounds in mineral flotation.

[0018] Preferably, the mineral is an oxide mineral.

[0019] Preferably, the octylphenoxyacetic acid compound is used to prepare a collector.

[0020] Preferably, the collector comprises, by mass percentage, 40% to 100% of octylphenoxyacetic acid compounds, 0% to 30% of fatty acid saponifications, and 0% to 30% of oxidized paraffin soap.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The octylphenoxyacetic acid compounds provided by the present invention contain an ether group in their chemical structure, which gives them stable low-temperature flotation performance, while also having the advantages of strong collection ability and good selectivity.

[0022] (2) Through mineral processing experiments, it was found that the octylphenoxyacetic acid compounds provided by the present invention can obtain good mineral processing indicators when used as mineral flotation collectors and further used in the flotation of oxidized minerals. Attached Figure Description

[0023] Figure 1This is the infrared spectrum of octylphenoxyacetic acid obtained in Example 1 of this invention; Figure 2 This is the LC-MS spectrum of octylphenoxyacetic acid obtained in Example 1 of this invention; Figure 3 This is the infrared spectrum of the coupling compound (named (2,2'-{[(4-octyl-1,3-phenylene)dimethyl]bis(oxy)}diacetic acid) obtained in Example 2 of this invention) by ChemDraw; Figure 4 This is the LC-MS spectrum of the coupling compound (named (2,2'-{[(4-octyl-1,3-phenylene)dimethyl]bis(oxy)}diacetic acid) obtained in Example 2 of this invention) by ChemDraw; Figure 5 This is a flow chart of the flotation process used in Experimental Example 1 of the present invention; Figure 6 This is a flow chart of the flotation process used in Experimental Example 2 of the present invention; Figure 7 A is a schematic diagram of the chemical structure of octylphenoxyacetic acid of the present invention; B is a schematic diagram of the chemical structure of the octylphenoxyacetic acid coupling compound. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments. These embodiments are merely typical examples of the present invention and not all embodiments thereof. Various modifications, substitutions, and variations made to the present invention by those skilled in the art without creative effort and without departing from the basic idea or principle of the present invention fall within the protection scope of the present invention.

[0025] All reagents and instruments used in the following examples are commercially available products. Unless otherwise specified, all percentages in the following examples are mass percentages.

[0026] Example 1: Octylphenoxyacetic acid (tert-octylphenoxyacetic acid) The structural formula of terocinolone acetic acid is shown in formula (I): (I); The specific steps of the preparation method are as follows: S1. Take a 250mL three-necked reactor equipped with a condenser, stirrer and thermometer, add teroctylphenol and chloroacetic acid in a 1:1 molar ratio, heat to 80℃, add a methanol solution containing NaOH in a molar ratio of teroctylphenol, chloroacetic acid and NaOH of 1:1:2.5, control the pH value in the range of 11 to 12, and then saponify at 80℃ for 8 hours to obtain a reaction system containing sodium teroctylphenoxyacetate. S2. Add concentrated sulfuric acid dropwise to the reaction system obtained in step S1 to adjust the pH to 5.5, and obtain the reaction product containing terocene phenoxyacetic acid (the compound shown in formula (I)), which is a red liquid.

[0027] The synthetic route for the above reaction is shown below: .

[0028] The infrared spectrum of terocinolone acetic acid is shown below. Figure 1 As shown, the LC-MS chromatogram of terocinoxyacetic acid is as follows. Figure 2 As shown.

[0029] Example 2: Octylphenoxyacetic acid (n-octylphenoxyacetic acid) The structural formula of n-octylphenoxyacetic acid is shown in formula (I): (I); The specific steps of the preparation method are as follows: S1. Take a 250mL three-necked reactor equipped with a condenser, stirrer and thermometer, add n-octylphenol and chloroacetic acid in a 1:1 molar ratio, heat to 90℃, add a methanol solution containing NaOH in a molar ratio of n-octylphenol, chloroacetic acid and NaOH of 1:1:2.5, control the pH value in the range of 11 to 12, and then saponify at 90℃ for 8 hours to obtain a reaction system containing sodium n-octylphenoxyacetate. S2. Add concentrated sulfuric acid dropwise to the reaction system obtained in step S1 to adjust the pH to 5.5, and obtain a reaction product containing n-octylphenoxyacetic acid (the compound shown in formula (I)), which is a red liquid.

[0030] The synthetic route for the above reaction is shown below: .

[0031] Example 3: Octylphenoxyacetic acid coupling compound ((2,2'-{[(4-octyl-1,3-phenylene)dimethyl]bis(oxy)}diacetic acid) The structural formula of 2,2'-{[(4-octyl-1,3-phenylene)dimethyl]bis(oxy)}diacetic acid is shown in formula (II): (II); The specific steps of the preparation method are as follows: S1. Take a 250mL three-necked reactor equipped with a condenser, stirrer and thermometer, add tert-octylphenol and formaldehyde in a molar ratio of 1:3.74, then add concentrated sulfuric acid to adjust the pH to pH=6, and react at 80℃ for 24h to obtain intermediate product T1 (dimer of tert-octylphenol); then add chloroacetic acid (molar ratio of 1:1 with tert-octylphenol), add dropwise an ethanol solution containing KOH, control the pH value range at 11-12, and saponify at 90℃ for 4h. S2. Add concentrated hydrochloric acid dropwise to the reaction system obtained in step S1 to adjust the pH to 5.8, and obtain the reaction product containing (2,2'-{[(4-octyl-1,3-phenylene)dimethylene]bis(oxy)}diacetic acid (the compound shown in formula (II)), which is a yellow liquid.

[0032] The synthetic route for the above reaction is shown below: .

[0033] The infrared spectrum of (2,2'-{[(4-octyl-1,3-phenylene)dimethyl]bis(oxy)}diacetic acid is shown below. Figure 3 As shown, the LC-MS plot is as follows Figure 4 As shown.

[0034] Example 4: A mineral flotation collector Specifically, it comprises the following components: octylphenoxyacetic acid (50%) prepared in Example 1, fatty acid saponification (25%), and oxidized paraffin soap (25%), by mass percentage. The fatty acid saponification consists of 0.87% dodecanoic acid, 3.23% myristic acid, 15.67% hexadecanoic acid, and 80.23% oleic acid.

[0035] Example 5: A mineral flotation collector Specifically, it comprises the following components: 50% by mass of 2,2'-{[(4-octyl-1,3-phenylene)dimethylene]bis(oxy)}diacetic acid prepared in Example 2, and fatty acid saponification (25%) and oxidized paraffin soap (25%). The fatty acid saponification consists of 0.87% dodecanoic acid, 3.23% myristic acid, 15.67% hexadecanoic acid, and 80.23% oleic acid.

[0036] Comparative Example 1: A mineral flotation collector Specifically, it contains the following components: fatty acid saponifications, which, by mass percentage, consist of dodecanoic acid (0.87%), tetradecanoic acid (3.23%), hexadecanoic acid (15.67%) and oleic acid (80.23%).

[0037] Comparative Example 2: A mineral flotation collector Specifically, it contains the following ingredients: by weight percentage, benzoic acid (50%), methyl benzoate (30%), and benzoic acid (20%).

[0038] Experimental Example 1 Using a high-calcium scheelite ore in Hunan Province as the flotation target, mineral processing tests were conducted using Examples 1-3 and Comparative Examples 1-2 as collectors, respectively.

[0039] The raw scheelite ore has a WO3 grade of 0.50%, a calcite grade of 25.23%, and a fluorite grade of 21.19%. In the flotation tests, the dosage of sodium carbonate was fixed at 1000 g / t, lead nitrate at 500 g / t, total collector at 800 g / t, modified water glass at 6000 g / t, and frother (No. 2 oil) at 25 g / t. A closed-circuit test of the scheelite ore was conducted, consisting of one roughing, three cleaning, and two scavenging processes. The flotation process flow is shown below. Figure 5 As shown in Table 1 below, the experimental results are as follows.

[0040] Table 1. Results of beneficiation of scheelite ore with different collectors.

[0041] As shown in the table above, when flotating scheelite, under the same dosage, the flotation indicators obtained in Examples 1-3 of this invention are superior to those in Comparative Examples 1 and 2. The WO3 grades in Examples 1-3 are 23.72%, 19.95%, and 20.23%, respectively, significantly higher than the 7.35% in Comparative Example 1 and 17.39% in Comparative Example 2, demonstrating that the octylphenoxyacetic acid or its coupling compounds of this invention have better selectivity. Based on higher specificity, the recoveries of this invention can reach 84.44%, 85.20%, and 86.58%, comparable to the lowest selectivity in Comparative Example 1 (84.67%), and far exceeding that of Comparative Example 2 (80.69%), proving that the octylphenoxyacetic acid or its coupling compounds of this invention have excellent collecting ability in mineral flotation, possessing both better selectivity and high collecting efficiency.

[0042] Experimental Example 2 Using a certain black and white tungsten ore as the flotation target, beneficiation tests were conducted using Examples 1-5 and Comparative Examples 1-2 of this invention as collectors. The raw ore of this black and white tungsten ore had a WO3 grade of 0.35%, and scheelite accounted for 77.56% of the tungsten minerals. The main gangue minerals were quartz, mica, and feldspar. In the flotation tests, the dosage of sodium carbonate was fixed at 800 g / t, water glass at 3000 g / t, and frother (No. 2 oil) at 20 g / t. The collector was a variable. Closed-circuit tests of the black and white tungsten ore were conducted, including one roughing, two cleaning, and two scavenging processes. The flotation process flow is shown below. Figure 6 As shown in Table 2 below, the experimental results are as follows.

[0043] Table 2. Beneficiation results of black and white tungsten ore with different collectors

[0044] As shown in the table above, compared with Comparative Example 1, the yields of Examples 1-3 of the present invention are lower under the same dosage, indicating that the collector has better selectivity. Judging from the tungsten concentrate grades obtained, Examples 1-3 are 14.59%, 12.99% and 13.27% respectively, which are higher than 8.80% of Comparative Example 1. In terms of recovery rate, Examples 1 and 2 are also higher than Comparative Example 1.

[0045] The performance of a collector needs to be comprehensively evaluated based on three major indicators: yield, grade, and recovery rate. Although the yield of Comparative Example 2 is lower than that of Examples 1-3 of this invention, its grade (10.35%) and recovery rate (56.98%) are significantly lower than those of this invention. The recovery rates of Examples 1-3 of this invention reach 73.62%, 74.85%, and 75.15%, respectively. Therefore, compared with the highly selective fatty acid collectors in the prior art, this invention can efficiently and specifically collect ores by flotation at a lower dosage (the dosage of Comparative Example 2 is 1.5 times that of Examples 1-3).

[0046] This invention, when used alone, already achieves good flotation results. However, data from Examples 4 and 5 show that when octylphenoxyacetic acid or its coupling compounds are used in combination with fatty acid saponifiers and oxidized paraffin soaps, an even better synergistic effect is achieved. Only 450 g / t is needed to achieve better results than Examples 1-3 and Comparative Examples 1-2, with recoveries reaching 81.02% and 83.45%, respectively. All of the above demonstrates that this invention effectively reduces the amount of fatty acid collectors used while improving their selectivity and efficiency.

[0047] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. It is impossible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Octylphenoxyacetic acid compounds, characterized in that, As shown in equation (I) or (II): (AND); (II); The compound of formula (I) is octylphenoxyacetic acid, wherein -C8H17 is a straight chain or its isomer; The compound of formula (II) is an octylphenoxyacetic acid coupling compound, wherein -C8H17 is a straight chain or its isomer.

2. The method for preparing octylphenoxyacetic acid compounds as described in claim 1, characterized in that, Specifically, the following steps are included: S1. Mix octylphenol compounds and chloroacetic acid, add an alcoholic solution containing alkali, adjust the pH to 11-12, and react. When preparing octylphenoxyacetic acid as shown in formula (I), the octylphenol compound is selected from octylphenol as shown in formula (III); (III); In formula (III), -C8H17 is a straight chain or its isomer; When preparing the octylphenoxyacetic acid coupling compound of formula (II), the octylphenol compound is selected from the dimer of octylphenol as shown in formula (IV); (IV); In formula (IV), -C8H17 is a straight chain or its isomer; S2. The solution after the reaction in step S1 is subjected to vacuum distillation, and then neutralized with acid to obtain the final product.

3. The preparation method according to claim 2, characterized in that, The reaction temperature in step S1 is 70–100°C.

4. The preparation method according to claim 2, characterized in that, The molar ratio of the hydroxyl group, chloroacetic acid and base in the octylphenol compound described in step S1 is 1:(1-1.5):(1-4).

5. The preparation method according to claim 2, characterized in that, The alkali mentioned in step S1 is one or a combination of sodium hydroxide or potassium hydroxide; the alcohol mentioned in step S1 is methanol or ethanol.

6. The preparation method according to claim 2, characterized in that, The acid mentioned in step S2 is one or a combination of sulfuric acid or hydrochloric acid.

7. The preparation method according to claim 2, characterized in that, The method for preparing the dimer of octylphenol is to add octylphenol with the structure of formula (III), formaldehyde and sulfuric acid to a reactor, raise the temperature to the melting point, and stir to obtain the product.

8. The application of the octylphenoxyacetic acid compounds as described in claim 1 in mineral flotation.

9. The application according to claim 8, characterized in that, The mineral in question is an oxide mineral.

10. The application according to claim 8, characterized in that, When used in mineral flotation, the collector, by mass percentage, comprises 40%–100% of the octylphenoxyacetic acid compounds, 0%–30% of fatty acid saponifications, and 0%–30% of oxidized paraffin soap.

Images