Preparation of fatty hydroxamic acids for spodumene collectors, collectors and use thereof

Abstract

The application discloses a preparation of a fatty hydroxamic acid for spodumene collector and the collector and application thereof, wherein a carboxylic acid compound and anhydrous ethanol are stirred and mixed at normal temperature, concentrated sulfuric acid is added dropwise under the stirring condition at normal temperature, the reaction is carried out after the concentrated sulfuric acid is added dropwise, and oil-water separation is carried out after the reaction is completed to obtain a carboxylic acid ester compound; hydroxylamine sulfate and water are added to the carboxylic acid ester compound, the mixture is stirred and dissolved at normal temperature, and then alkali is slowly added under the stirring condition at normal temperature, after which the reaction is carried out after being heated, the reaction is neutralized to weak acidity by using dilute hydrochloric acid after being completed, and the water phase is separated to obtain a brown solution, which is the fatty hydroxamic acid. The fatty hydroxamic acid, a fatty acid soap, a polyethylene glycol antifreezing agent and an emulsifier are obtained according to a proportion to obtain the spodumene collector. The spodumene collector has good selectivity for spodumene ore and strong collecting capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and in particular to a fatty hydroxamic acid used as a spodumene collector, a preparation method thereof and application thereof in the spodumene collector. Background Art

[0002] Lithium is a key strategic resource, widely used in industries such as batteries, ceramics, glass, aluminum products, lubricants, refrigerants, and the nuclear industry. With the rapid development of strategic emerging industries such as new energy and new materials, the demand for lithium resources has become increasingly prominent.

[0003] Currently, the raw material for producing high-quality lithium products in my country primarily comes from hard-rock spodumene ore, with flotation being the primary separation method. Because spodumene often coexists with silicate minerals such as feldspar, quartz, and beryl in the ore, and these minerals share similar surface chemical properties, separating spodumene from these other silicate minerals is difficult. Spodumene flotation collectors are primarily categorized as anionic, cationic, and combined. Anionic collectors primarily include fatty acids and soaps such as oleic acid, paraffin oxide soaps, tall oil, and naphthenic acid soaps; cationic collectors primarily include fatty amines such as dodecylamine and octadecylamine; and combined collectors primarily include anionic and cationic combinations. However, these collectors also suffer from poor collection capacity and selectivity, and the coarse-grained spodumene tends to drop out of the flotation tank. Furthermore, closed-circuit flotation processes for spodumene oxide ore can present challenges such as high flotation froth viscosity, poor concentrate quality stability, and difficult on-site operations. Therefore, developing a collector with high selectivity and strong collection ability that can efficiently float coarse-grained spodumene is of great significance and value for achieving efficient utilization of hard rock lithium mineral resources. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention aims to provide a preparation method of fatty hydroxamic acid for spodumene collector, a collector thereof and applications thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing fatty hydroxamic acid used in a spodumene collector comprises the following steps:

[0007] S1, stirring and mixing a carboxylic acid compound and anhydrous ethanol at room temperature, then adding concentrated sulfuric acid dropwise under stirring at room temperature, heating to react after the addition of concentrated sulfuric acid, and separating oil and water after the reaction to obtain a carboxylate compound;

[0008] S2. Add hydroxylamine sulfate and water to the carboxylate compound prepared in step S1, stir and dissolve at room temperature, then slowly add alkali under stirring at room temperature, then raise the temperature to react, and after the reaction is completed, neutralize with dilute hydrochloric acid to weak acidity, and remove the aqueous phase to obtain a brown solution that is fatty hydroxamic acid.

[0009] Furthermore, in step S1, the ratio of the carboxylic acid compound, anhydrous ethanol and concentrated sulfuric acid is 0.1 mol: 10 mL: 0.1 mL, and the mass concentration of the concentrated sulfuric acid is 98%; after the concentrated sulfuric acid is added dropwise, the temperature is raised to 60-80° C. and the reaction is carried out for 2-4 hours.

[0010] Furthermore, in step S1, the carboxylic acid compound includes at least one of cycloalkane acid and lauric acid.

[0011] Furthermore, in step S2, the molar ratio of the carboxylate compound, hydroxylamine sulfate, and base is 1:0.5:0.55-1.2; and the base is at least one of anhydrous sodium carbonate and sodium hydroxide.

[0012] Furthermore, in step S2, the reaction temperature is 50-70°C, and the reaction time is 4-8 hours; after the reaction is completed, it is neutralized with 5% dilute hydrochloric acid to a pH of 5-6.

[0013] The present invention also provides a fatty hydroxamic acid prepared according to the above preparation method and used in a spodumene collector.

[0014] The present invention provides a spodumene collector, which comprises the following components, calculated by mass percentage: 40-60% of fatty hydroxamic acid, 20-40% of fatty acid soap, 15-20% of polyethylene glycol antifreeze, and 2-5% of emulsifier; the fatty hydroxamic acid is prepared according to the above preparation method.

[0015] Furthermore, the fatty acid soap is one of oxidized paraffin soap and sodium oleate.

[0016] Furthermore, the polyethylene glycol antifreeze includes at least one of polyethylene glycol-200 and polyethylene glycol-400.

[0017] Furthermore, the emulsifier includes at least one of dodecylphenol polyoxyethylene ether OP-10 and nonylphenol polyoxyethylene ether NP-10.

[0018] The present invention also provides an open circuit flotation method for spodumene, which specifically comprises the following steps:

[0019] A1. Grind spodumene to a fineness of -0.074mm (65%) per ton of dry ore using a mill, and adjust the flotation slurry concentration to 30%.

[0020] A2. First, a roughing operation is carried out. The resulting roughing concentrate enters the third-stage concentrating operation, and the roughing tailings enter the two-stage scavenging operation. The concentrated concentrate obtained from each stage of concentrating operation enters the next stage of concentrating operation. The concentrated concentrate obtained from the third stage of concentrating operation is concentrate 1. The scavenging tailings obtained from each stage of scavenging operation enter the next stage of scavenging operation. The scavenging tailings obtained from the last scavenging operation are the final tailings.

[0021] In the roughing operation, Na2CO3, NaOH, CaCl2 and the above-mentioned spodumene collector are sequentially added to prepare the slurry; in the scavenging operation 1 and scavenging operation 2, CaCl2 and the above-mentioned spodumene collector are sequentially added; in the cleaning operation 1, cleaning operation 2 and cleaning operation 3, Na2CO3 is added;

[0022] A3. The selected tailings obtained from each level of concentration operation and the scavenged concentrate obtained from each level of scavenging operation are combined and then subjected to a three-level fine scavenging operation. The fine scavenging concentrate obtained from each level of fine scavenging operation enters the next level of fine scavenging operation; Na2CO3 is added in the fine scavenging operation 1, fine scavenging operation 2 and fine scavenging operation 3.

[0023] Furthermore, based on the dry weight of each ton of raw ore, 800 g / t Na2CO3, 700 g / t NaOH, 150 g / t CaCl2 and 1500 g / t of the above-mentioned spodumene collector were added in sequence during the roughing operation, and the slurry mixing times were 5 min, 15 min, 5 min and 5 min, respectively;

[0024] In the scavenging operation 1 and scavenging operation 2, the amount of CaCl2 added was 75g / t and 30g / t respectively, the amount of spodumene collector added was 300g / t and 100g / t respectively, and the slurry mixing time was 5min;

[0025] In the first, second and third selection operations, the amount of Na2CO3 added was 400g / t, 200g / t and 100g / t respectively, and the slurry mixing time was 5min.

[0026] In the fine sweeping operation 1, fine sweeping operation 2 and fine sweeping operation 3, the amount of Na2CO3 added was 150g / t, 100g / t and 50g / t respectively, and the slurry mixing time was 5min.

[0027] The beneficial effects of the present invention are:

[0028] (1) The spodumene collector of the present invention has good selectivity for spodumene ore and strong collecting ability, and at the same time has good flotation recovery of coarse-grained spodumene, thereby achieving efficient flotation recovery of spodumene ore.

[0029] (2) The raw materials of the spodumene collector of the present invention are cheap and easily available, the preparation method is simple, and it is suitable for large-scale production, and has high promotion and application value.

[0030] (3) The open-circuit flotation method of spodumene collector of the present invention can solve the problems of poor concentrate quality stability and difficult on-site operation existing in the commonly used closed-circuit flotation process of oxide ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 4 is a flotation process flow chart of Example 4 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to this embodiment. Example 1

[0033] Add 0.1 mol of cycloalkane acid and 10 mL of anhydrous ethanol to a 150 mL three-necked flask and stir at room temperature for 10 minutes. Then, add 0.1 mL of 98% concentrated sulfuric acid dropwise while stirring at room temperature. After the addition is complete, heat the mixture to 60°C and react for 4 hours. After the reaction is complete, separate the oil and water to obtain the cycloalkane ester compound. Add 0.1 mol of the cycloalkane ester compound to a 150 mL three-necked flask, add 0.05 mol of hydroxylamine sulfate and 10 mL of water and stir at room temperature to dissolve. Then, slowly add 0.055 mol of anhydrous sodium carbonate while stirring at room temperature. After the addition is complete, heat the mixture to 70°C and react for 4 hours. After the reaction is complete, neutralize with 5% dilute hydrochloric acid to pH = 5. Separate the aqueous phase to obtain a brown solution, which is the cycloalkane hydroxamic acid. Calculated by mass percentage, 40% cycloalkanehydroxamic acid, 40% oxidized paraffin soap, 15% polyethylene glycol-400 antifreeze agent, and 5% OP-10 emulsifier are mixed uniformly at room temperature to obtain a viscous liquid that is a spodumene collector. Example 2

[0034] Add 0.1 mol of cycloalkane acid and 10 mL of anhydrous ethanol to a 150 mL three-necked flask and stir at room temperature for 10 minutes. Then, add 0.1 mL of 98% concentrated sulfuric acid dropwise while stirring at room temperature. After the addition is complete, heat the mixture to 70°C and react for 3 hours. After the reaction is complete, separate the oil and water to obtain the cycloalkane ester compound. Add 0.1 mol of the cycloalkane ester compound to a 150 mL three-necked flask, add 0.05 mol of hydroxylamine sulfate and 10 mL of water and stir at room temperature to dissolve. Then, slowly add 0.060 mol of anhydrous sodium carbonate while stirring at room temperature. After the addition is complete, heat the mixture to 50°C and react for 8 hours. After the reaction is complete, neutralize with 5% dilute hydrochloric acid to a pH of 5.5. Separate the aqueous phase to obtain a brown solution, which is the cycloalkane hydroxamic acid. Calculated by mass percentage, 60% cycloalkanehydroxamic acid, 20% sodium oleate, 17% polyethylene glycol-200 antifreeze agent, and 3% NP-10 emulsifier are mixed uniformly at room temperature to obtain a viscous liquid that is a spodumene collector. Example 3

[0035] Add 0.1 mol of lauric acid and 10 mL of anhydrous ethanol to a 150 mL three-necked flask and stir at room temperature for 10 minutes. Then, add 0.1 mL of 98% concentrated sulfuric acid dropwise under room temperature stirring. After the addition is complete, heat the mixture to 80°C and react for 2 hours. After the reaction is complete, separate the oil and water to obtain a lauric acid ester compound. Add 0.1 mol of lauric acid ester compound to a 150 mL three-necked flask, add 0.05 mol of hydroxylamine sulfate and 10 mL of water at room temperature and stir to dissolve. Then, slowly add 0.12 mol of sodium hydroxide under room temperature stirring. After the addition is complete, heat the mixture to 60°C and react for 6 hours. After the reaction is complete, neutralize with 5% dilute hydrochloric acid to pH = 6. Separate the aqueous phase to obtain a brown solution, which is lauric acid hydroxamic acid. Calculated by mass percentage, the viscous liquid obtained by uniformly mixing 50% lauric acid, 28% oxidized paraffin soap, 20% polyethylene glycol-200 antifreeze agent, and 2% NP-10 emulsifier at room temperature is the spodumene collector. Example 4

[0036] A hard rock type spodumene ore contains Li2O grade of 1.53%, and the main impurities are feldspar and quartz, with contents of 39.11% and 33.74% respectively. According to the dry weight of raw ore per ton, the spodumene is ground to a fineness of -0.074mm by a grinding mill, accounting for 65%, and regulating the flotation pulp concentration to 30%. Then flotation is carried out by the process of "one roughing, three cleanings, two sweepings, and three fine sweeps". In the roughing, 800g / t Na2CO3 is added successively, and the slurry mixing time is 5min, 700g / t NaOH, and the slurry mixing time is 15min, 150g / t CaCl2 and the spodumene collector obtained by 1500g / t embodiment 1, the slurry mixing time is 5min. In scavenging 1 and scavenging 2, the amount of CaCl2 added was 75g / t and 30g / t respectively, the amount of spodumene collector added obtained in Example 1 was 300g / t and 100g / t respectively, and the slurry mixing time was 5min; in selecting 1, selecting 2 and selecting 3, the amount of Na2CO3 added was 400g / t, 200g / t and 100g / t respectively, and the slurry mixing time was 5min; in fine sweeping 1, fine sweeping 2 and fine sweeping 3, the amount of Na2CO3 added was 150g / t, 100g / t and 50g / t respectively, and the slurry mixing time was 5min. In the lithium oxide concentrate (concentrate 1 + concentrate 2) finally obtained, the Li2O grade was 6.30% and the Li2O recovery rate was 88.12%. See flotation process Figure 1 The selection results are shown in Table 1.

[0037] Comparative Example 1

[0038] The only difference between Comparative Example 1 and Example 4 is the collector. The collector used in Comparative Example 1 is a combination of naphthenic acid and oxidized paraffin soap in a weight ratio of 1:1. Other than this, the other flotation conditions are the same. The lithium oxide concentrate (concentrate 1 + concentrate 2) finally obtained in this comparative example has a Li2O grade of 5.94% and a Li2O recovery rate of 82.80%. See the flotation process. Figure 1 , the test results are shown in Table 1.

[0039] Table 1

[0040]

[0041] As shown in the flotation results in Table 1, the modified spodumene collector provided in Example 1 achieved superior flotation results for hard rock spodumene ore compared to a conventional unmodified naphthenic acid + oxidized paraffin soap combination collector. Furthermore, using the spodumene collector provided in Example 1, an open-circuit flotation process consisting of one roughing, three cleaning, two scavenging, and three fine scavenging steps was employed to obtain a spodumene concentrate with a Li₂O₂ grade of 6.30% and a Li₂O recovery rate of 88.12%, achieving excellent results. Example 5

[0042] A pegmatite spodumene ore with a LiO grade of 1.43% was used. The main impurities were quartz and feldspar, with contents of 15.01% and 27.90%, respectively. A primary roughing flotation test at room temperature was conducted on this ore using the spodumene collectors prepared in Examples 1-3. The results were also compared with those of a conventional anionic combination collector consisting of "oxidized paraffin soap + sodium oleate" and a cationic combination collector consisting of "oxidized paraffin soap + dodecylamine."

[0043] The spodumene was ground to a fineness of -0.074 mm (70% of the original ton dry weight) using a mill. The flotation slurry concentration was adjusted to 30%. During the roughing process, 800 g / t NaCO was added for 5 minutes, followed by 600 g / t NaOH for 15 minutes, 150 g / t CaCl for 5 minutes, and 1000 g / t collector for 5 minutes. The test results are shown in Table 2.

[0044] Table 2

[0045]

[0046] It can be seen from the flotation results in Table 2 that the spodumene collectors of Examples 1-3 have good collecting ability and selectivity for pegmatite spodumene ore, and their flotation effects are better than those of the conventional "oxidized paraffin soap + sodium oleate" anionic combination collector and "oxidized paraffin soap + dodecylamine" cationic combination collector. Example 6

[0047] For -0.2+0.1mm coarse particle size spodumene pure mineral, a roughing flotation test was carried out using the spodumene collectors of Examples 1-3, respectively, and compared with the conventional "oxidized paraffin soap + sodium oleate" anionic combination collector and "oxidized paraffin soap + dodecylamine" cationic combination collector.

[0048] Pure spodumene with a coarse particle size of -0.2 + 0.1 mm was used to adjust the flotation slurry concentration to 20%. The pH of the flotation slurry was adjusted to 11.5 using NaOH for 15 minutes. 20 mg / L CaCl₂ was then added for 5 minutes, and 200 mg / L collector was added for 5 minutes. The test results are shown in Table 3.

[0049] Table 3

[0050]

[0051] From the flotation results in Table 3, it can be seen that the spodumene collector has a good collection ability for -0.2+0.1mm coarse particle size spodumene pure minerals, and its flotation effect is better than that of the conventional "oxidized paraffin soap + sodium oleate" anionic combination collector and "oxidized paraffin soap + dodecylamine" cationic combination collector.

[0052] Those skilled in the art can make various corresponding changes and modifications based on the above technical solutions and concepts, and all of these changes and modifications should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for preparing fatty hydroxamic acid used in a spodumene collector, characterized in that: The steps include: S1, stirring and mixing a carboxylic acid compound and anhydrous ethanol at room temperature, then adding concentrated sulfuric acid dropwise under stirring at room temperature, heating to react after the addition of concentrated sulfuric acid, and separating oil and water after the reaction to obtain a carboxylate compound; S2. Add hydroxylamine sulfate and water to the carboxylate compound prepared in step S1, stir and dissolve at room temperature, then slowly add alkali under stirring at room temperature, then raise the temperature to react, and after the reaction is completed, neutralize with dilute hydrochloric acid to weak acidity, and remove the aqueous phase to obtain a brown solution that is fatty hydroxamic acid.

2. The preparation method according to claim 1, characterized in that In step S1, the ratio of the carboxylic acid compound, anhydrous ethanol and concentrated sulfuric acid is 0.1 mol: 10 mL: 0.1 mL, and the mass concentration of the concentrated sulfuric acid is 98%. After the concentrated sulfuric acid is added dropwise, the temperature is raised to 60-80° C. and the reaction is carried out for 2-4 hours. The carboxylic acid compound includes at least one of cyclohexane acid and lauric acid.

3. The preparation method according to claim 1, characterized in that In step S2, the molar ratio of the carboxylate compound, hydroxylamine sulfate, and base is 1:0.5:0.55-1.2; the base is at least one of anhydrous sodium carbonate and sodium hydroxide; the reaction temperature is 50-70°C, and the reaction time is 4-8 hours; after the reaction is completed, the solution is neutralized with 5% dilute hydrochloric acid to a pH of 5-6.

4. A fatty hydroxamic acid used in a spodumene collector prepared by the preparation method according to any one of claims 1 to 3.

5. A spodumene collector, characterized in that, The invention comprises the following components calculated by mass percentage: 40-60% fatty acid hydroxamic acid, 20-40% fatty acid soap, 15-20% polyethylene glycol antifreeze, and 2-5% emulsifier; the fatty hydroxamic acid is prepared according to the preparation method according to any one of claims 1-3.

6. spodumene collector according to claim 5, is characterized in that, The fatty acid soap is one of oxidized paraffin soap and sodium oleate.

7. spodumene collector according to claim 5, is characterized in that, The polyethylene glycol antifreeze agent includes at least one of polyethylene glycol-200 and polyethylene glycol-400.

8. spodumene collector according to claim 5, is characterized in that, The emulsifier includes at least one of dodecylphenol polyoxyethylene ether OP-10 and nonylphenol polyoxyethylene ether NP-10.

9. An open circuit flotation method for spodumene, characterized in that: The specific steps include: A1. Grind spodumene to a fineness of -0.074mm (65%) per ton of dry ore using a mill, and adjust the flotation slurry concentration to 30%. A2. First, a roughing operation is carried out. The resulting roughing concentrate enters the third-stage concentrating operation, and the roughing tailings enter the two-stage scavenging operation. The concentrated concentrate obtained from each stage of concentrating operation enters the next stage of concentrating operation. The concentrated concentrate obtained from the third stage of concentrating operation is concentrate 1. The scavenging tailings obtained from each stage of scavenging operation enter the next stage of scavenging operation. The scavenging tailings obtained from the last scavenging operation are the final tailings. In the roughing operation, Na2CO3, NaOH, CaCl2 and the spodumene collector described in any one of claims 5-8 are sequentially added to prepare the slurry; in the scavenging operation 1 and the scavenging operation 2, CaCl2 and the spodumene collector described in any one of claims 5-8 are sequentially added; in the cleaning operation 1, the cleaning operation 2 and the cleaning operation 3, Na2CO3 is added; A3. The selected tailings obtained from each level of concentration operation and the scavenged concentrate obtained from each level of scavenging operation are combined and then subjected to a three-level fine scavenging operation. The fine scavenging concentrate obtained from each level of fine scavenging operation enters the next level of fine scavenging operation; Na2CO3 is added in the fine scavenging operation 1, fine scavenging operation 2 and fine scavenging operation 3.

10. The open circuit flotation method according to claim 9, characterized in that: Based on the dry weight of each ton of raw ore, 800g / t Na2CO3, 700g / t NaOH, 150g / t CaCl2 and 1500g / t of the spodumene collector according to any one of claims 5 to 8 are added in sequence during the roughing operation, and the slurry mixing times are 5min, 15min, 5min and 5min respectively; In the first scavenging operation and the second scavenging operation, the amount of CaCl2 added is 75g / t and 30g / t respectively, the amount of spodumene collector added according to any one of claims 5 to 8 is 300g / t and 100g / t respectively, and the slurry mixing time is 5min; In the first, second and third selection operations, the amount of Na2CO3 added was 400g / t, 200g / t and 100g / t respectively, and the slurry mixing time was 5min. In the fine sweeping operation 1, fine sweeping operation 2 and fine sweeping operation 3, the amount of Na2CO3 added was 150g / t, 100g / t and 50g / t respectively, and the slurry mixing time was 5min.

Images