Preparation process of a flotation reagent for lepidolite ore

Abstract

The present invention relates to the technical field of flotation, and specifically to a preparation process of a flotation reagent for lepidolite ore. In the present invention, epoxidized soybean oil and N-methyltaurine are reacted, and then reacted with an alkyl bromide to obtain a flotation reagent for lepidolite ore. This flotation reagent for lepidolite ore contains a large number of hydroxyl groups, as well as quaternary ammonium salt cations and sulfonate anions, forming a unique betaine zwitterionic group, which has stronger hydrogen bond, electrostatic and other adsorption effects with the surface of lepidolite ore, enabling the flotation agent to be tightly and firmly adsorbed on the surface of lepidolite ore. At the same time, the flotation agent contains a hydrophobic soybean oil molecular chain, thereby making the lepidolite ore have better hydrophobic flotation properties and significantly improving the recovery rate of lepidolite minerals.

Description

Technical Field

[0001] The present invention relates to the technical field of flotation, and specifically to a preparation process of a flotation reagent for lepidolite ore. Background Art

[0002] Lithium and its compounds are widely used in fields such as glass, alloys, batteries, and new energy vehicles. In recent years, the batteries and new energy vehicles in China have developed rapidly, and the demand for lithium resources has also been continuously increasing. Lithium resources mainly come from spodumene ore, lepidolite ore, etc. Among them, lepidolite ore usually exists in the form of associated resources, with a low grade and low utilization rate. Flotation pre-concentration technology is the main treatment technology and recovery method for lepidolite. Traditional flotation reagents mainly include dodecylamine, cetyltrimethylammonium chloride, sodium oleate, sodium dodecylsulfonate, etc. These reagents have poor flotation effects on lepidolite ore and low recovery rates.

[0003] Betaine is an amphoteric ionic substance with high surface activity and good foaming performance, and is an excellent collector for flotation. Epoxidized soybean oil is a cheap and easily available biomass resource, and has broad application prospects in flotation and mineral processing processes. Chinese patent application documents with publication numbers CN103721862A, CN119263329A, CN110681493A, etc. have all reported that using epoxidized soybean oil, etc. as raw materials has good practical applications in the flotation agents for sulfide copper ore, wulfenite, coal mine, etc. However, none of these patents have reported the use of epoxidized soybean oil in the mineral processing process of lepidolite. Summary of the Invention

[0004] The present invention solves the problem that the existing cationic and anionic capture agents have poor flotation effects on lepidolite ore.

[0005] The technical solution of the present invention:

[0006] A preparation process of a flotation reagent for lepidolite ore, comprising the following steps:

[0007] S1: Add epoxidized soybean oil and N-methyltaurine to tetrahydrofuran, react at 50 - 60 °C for 3 - 6 h, with condensation reflux during the reaction, add water for dilution, dropwise add sodium hydroxide solution to adjust the pH to 8 - 9, dry to remove tetrahydrofuran and water, wash the product with ethanol, and dry to obtain sulfonated soybean oil.

[0008] S2: Add distilled water, sulfonated soybean oil, and alkyl bromide to isopropanol, react at 90 - 100 °C for 24 - 48 h, with condensation reflux during the reaction, dry to remove isopropanol and water, wash successively with saturated sodium chloride solution and ethanol, and dry to obtain the flotation reagent for lepidolite ore.

[0009] The chemical reaction process for the preparation of the flotation reagent for lepidolite ore is as follows:

[0010]

[0011] Preferably, the mass of N-methyltaurine in S1 is 43-72% of the mass of epoxidized soybean oil.

[0012] Preferably, the volume of distilled water used in S2 is 30-50% of that of isopropanol.

[0013] Preferably, the mass of alkyl bromide in S2 is 30-34% of the mass of sulfonated soybean oil.

[0014] Preferably, the alkyl bromide is 1-bromoethane, 1-bromopropane, 1-bromobutane or 1-bromopentane.

[0015] Advantageous technical effects of the present invention:

[0016] The present invention uses bio-based epoxidized soybean oil, N-methyltaurine and alkyl bromide as raw materials to prepare a flotation reagent for lepidolite ore. The flotation reagent for lepidolite ore contains a large number of hydroxyl groups, quaternary ammonium salt cations and sulfonate anions, forming a unique betaine zwitterionic group, which has stronger hydrogen bond, electrostatic and other adsorption effects with the surface of lepidolite ore, enabling the flotation agent to be tightly and firmly adsorbed on the surface of lepidolite ore. At the same time, the flotation agent contains a hydrophobic soybean oil molecular chain, so that the lepidolite ore has better hydrophobic flotation properties, significantly improving the recovery rate of lepidolite minerals. Specific embodiments

[0017] The following specific examples illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0018] Example 1:

[0019] (1) Add 20 g of epoxidized soybean oil and 11.6 g of N-methyltaurine to 40 mL of tetrahydrofuran, react at 55 °C for 5 h, carry out condensation reflux during the reaction, add 120 mL of water for dilution, dropwise add sodium hydroxide solution to adjust the pH to 8, dry to remove tetrahydrofuran and water, and wash the product with ethanol. After drying, sulfonated soybean oil is obtained.

[0020] (2) Add 80 mL of distilled water, 30 g of sulfonated soybean oil and 9.7 g of 1-bromopropane to 200 mL of isopropanol, react at 90 °C for 36 h, carry out condensation reflux during the reaction, dry to remove isopropanol and water, wash successively with saturated sodium chloride solution and ethanol, and obtain a flotation reagent for lepidolite ore after drying.

[0021] Example 2:

[0022] (1) Add 20 g of epoxidized soybean oil and 8.6 g of N-methyltaurine to 40 mL of tetrahydrofuran, react at 50 °C for 6 h with reflux condensation during the reaction, add 120 mL of water for dilution, adjust the pH to 8 by dropping sodium hydroxide solution, dry to remove tetrahydrofuran and water, wash the product with ethanol, and obtain sulfonated soybean oil after drying.

[0023] (2) Add 60 mL of distilled water, 30 g of sulfonated soybean oil, and 10.1 g of 1-bromopentane to 200 mL of isopropanol, react at 90 °C for 48 h with reflux condensation during the reaction, dry to remove isopropanol and water, wash successively with saturated sodium chloride solution and ethanol, and obtain a flotation reagent for lepidolite ore after drying.

[0024] Example 3:

[0025] (1) Add 20 g of epoxidized soybean oil and 14.4 g of N-methyltaurine to 50 mL of tetrahydrofuran, react at 60 °C for 3 h with reflux condensation during the reaction, add 120 mL of water for dilution, adjust the pH to 9 by dropping sodium hydroxide solution, dry to remove tetrahydrofuran and water, wash the product with ethanol, and obtain sulfonated soybean oil after drying.

[0026] (2) Add 100 mL of distilled water, 30 g of sulfonated soybean oil, and 10.2 g of 1-bromoethane to 200 mL of isopropanol, react at 100 °C for 24 h with reflux condensation during the reaction, dry to remove isopropanol and water, wash successively with saturated sodium chloride solution and ethanol, and obtain a flotation reagent for lepidolite ore after drying.

[0027] Example 4:

[0028] (1) Add 20 g of epoxidized soybean oil and 8.6 g of N-methyltaurine to 40 mL of tetrahydrofuran, react at 50 °C for 5 h with reflux condensation during the reaction, add 120 mL of water for dilution, adjust the pH to 8 by dropping sodium hydroxide solution, dry to remove tetrahydrofuran and water, wash the product with ethanol, and obtain sulfonated soybean oil after drying.

[0029] (2) Add 60 mL of distilled water, 30 g of sulfonated soybean oil, and 9 g of 1-bromobutane to 200 mL of isopropanol, react at 100 °C for 36 h with reflux condensation during the reaction, dry to remove isopropanol and water, wash successively with saturated sodium chloride solution and ethanol, and obtain a flotation reagent for lepidolite ore after drying.

[0030] Comparative Example 1:

[0031] (1) Add 20 g of epoxidized soybean oil and 11.6 g of N-methyltaurine to 40 mL of tetrahydrofuran, react at 55 °C for 5 h with reflux condensation during the reaction, add 120 mL of water for dilution, adjust the pH to 8 by dropping sodium hydroxide solution, dry to remove tetrahydrofuran and water, wash the product with ethanol, and obtain sulfonate soybean oil after drying, which is used as a flotation reagent.

[0032] Comparative Example 2:

[0033] (1) Add 20 g of epoxidized soybean oil and 11.6 g of N-ethylmethylamine (structural formula is ) to 40 mL of tetrahydrofuran, react at 55 °C for 5 h with reflux condensation during the reaction, add 120 mL of water for dilution, adjust the pH to 8 by dropping sodium hydroxide solution, dry to remove tetrahydrofuran and water, wash the product with ethanol, and obtain tertiary amine soybean oil after drying.

[0034] (2) Add 80 mL of distilled water, 30 g of tertiary amine soybean oil, and 9.7 g of 1-bromopropane to 200 mL of isopropanol, react at 90 °C for 36 h with reflux condensation during the reaction, dry to remove isopropanol and water, wash successively with saturated sodium chloride solution and ethanol, and obtain a flotation reagent after drying.

[0035] Comparative Example 3 uses a composition of dodecylamine and sodium dodecylsulfonate with a molar ratio of 1:1 as a flotation reagent.

[0036] Crush, ball-mill, and screen the original lepidolite ore, and control the particle size of the ore powder to be between 0.074 - 0.150 mm. Weigh 5 g of lepidolite ore powder and add it to the flotation cell of a flotation machine, add 150 mL of distilled water, stir and adjust the pulp for 2 min, adjust the pH to 7, then add a flotation reagent, control the addition amount to be 100 mg / L, stir for 2 min, carry out flotation and foam scraping for 3 min, collect the foam product after flotation and filter, dry, weigh, and calculate the mineral recovery rate.

[0037] Table 1 Mineral Recovery Rate Test

[0038]

[0039] After testing, the flotation reagents for lepidolite ore prepared in Examples 1 - 4 have a mineral recovery rate of 54.6 - 61.5% after flotation of lepidolite ore. The main reason is that the flotation reagent contains quaternary ammonium salt cations and sulfonate anions, forming a unique betaine zwitterionic group and having a stronger electrostatic adsorption effect with the surface of lepidolite ore, making the flotation agent adsorb tightly and firmly on the surface of lepidolite ore. At the same time, the flotation agent contains a hydrophobic soybean oil molecular chain, so that lepidolite ore has better hydrophobic flotation properties, significantly improving the recovery rate of lepidolite minerals.

[0040] In Comparative Example 1, sulfonated soybean oil was used as a flotation reagent, which only contained sulfonate cationic groups. The flotation reagent prepared in Comparative Example 2 only contained quaternary ammonium salt cationic groups, and neither of them contained betaine zwitterionic groups. The adsorption effect on the surface of lepidolite ore was relatively low, and it could not improve the hydrophobic flotation property of lepidolite ore well, resulting in a relatively low recovery rate. In Comparative Example 3, a composition of conventional dodecylamine and sodium dodecylsulfonate was used as a flotation reagent, and the mineral recovery rate was only 45.3%, which was significantly lower than that of each example.

[0041] The original lepidolite ore was crushed, ball-milled, and sieved to control the particle size of the ore powder between 0.074 - 0.150 mm. Weigh 5 g of lepidolite ore powder (prepared in Example 3) and add it to the flotation cell of a hanging cell flotation machine. Add 150 mL of distilled water, stir and adjust the pulp for 1 min, adjust the pH to 7, then add the flotation reagent, control the addition amount to be 20 - 70 mg / L, stir for 2 min, carry out flotation and foam scraping for 3 min. After flotation, collect the foam product, filter, dry, weigh, and calculate the mineral recovery rate.

[0042] Table 2 Mineral recovery rate test with different addition amounts of flotation reagents

[0043]

[0044] After testing, when the addition amount of the flotation reagent was 20 - 70 mg / L, the lepidolite mineral recovery rate reached 61.5 - 87.2%, and the flotation effect was excellent.

Claims

1. A preparation process for a lepidolite ore flotation agent, characterized in that: The preparation process comprises the following steps: S1: Add epoxidized soybean oil and N-methyltaurine to tetrahydrofuran, add water to dilute after the reaction, add sodium hydroxide solution dropwise to adjust the pH, dry to remove tetrahydrofuran and water, wash the product with ethanol, and dry to obtain sulfonate soybean oil; S2: Add distilled water, sulfonate soybean oil and alkyl bromide to isopropanol, dry to remove isopropanol and water after reaction, wash with saturated sodium chloride solution and ethanol in turn, and obtain a lepidolite ore flotation agent after drying.

2. The preparation process of the lepidolite ore flotation reagent according to claim 1, characterized in that: The mass of N-methyltaurine in S1 is 43-72% of the mass of epoxidized soybean oil.

3. The preparation process of the lepidolite ore flotation reagent according to claim 1, characterized in that: The reaction temperature in S1 is 50-60°C and the reaction time is 3-6h.

4. The preparation process of the lepidolite ore flotation reagent according to claim 1, characterized in that: The pH of S1 was adjusted to 8-9.

5. The preparation process of the lepidolite ore flotation reagent according to claim 1, characterized in that: The reaction temperature in S2 is 90-100°C and the reaction time is 24-48h.

6. The preparation process of the lepidolite ore flotation reagent according to claim 1, characterized in that: The volume usage of distilled water in S2 is 30-50% of isopropanol.

7. The preparation process of the lepidolite ore flotation reagent according to claim 1, characterized in that: The mass of the alkyl bromide in S2 is 30-34% of the mass of the sulfonate soybean oil.

8. The preparation process of the lepidolite ore flotation reagent according to claim 7, characterized in that: The alkyl bromide is 1-bromoethane, 1-bromopropane, 1-bromobutane or 1-bromopentane.

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