Acyl-containing quaternary ammonium salt compound, phosphorite reverse flotation collector and reverse flotation method
By using acyl quaternary ammonium salt compounds as collectors in the reverse flotation of phosphate rock, combined with demagnesification and desilication collectors, the problems of low phosphate rock separation efficiency and water waste have been solved, achieving efficient and water-saving phosphate concentrate production.
Patent Information
- Application Number
- CN202610152075.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-01
AI Technical Summary
Existing phosphate rock sorting processes suffer from low efficiency, difficulty in operation, sticky foam and equipment scaling due to the use of water glass, and alkali metal impurities affecting product quality. The processes are also complex and result in significant water waste.
Acyl quaternary ammonium salt compounds were used as collectors for reverse flotation of phosphate rock. Combined with demagnesification and desilication collectors, the rock was separated by reverse flotation. The desilication and demagnesification collectors were prepared by reacting acyl quaternary ammonium salt compounds with halogenated ethane under specific conditions. The pH value was adjusted for multi-stage cleaning.
It improves foam properties, reduces flushing water consumption, enhances equipment processing capacity and sorting efficiency, reduces equipment scaling risk, lowers costs, increases phosphate concentrate grade and recovery rate, reduces alkali metal impurities, and achieves water-saving effects.
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Figure CN121945299A_ABST
Abstract
Description
Acyl quaternary ammonium salt compounds, phosphate rock reverse flotation collectors and reverse flotation methods Technical Field
[0001] This invention belongs to the field of mineral processing technology, and particularly relates to an acyl quaternary ammonium salt compound, a phosphate rock reverse flotation collector, and a reverse flotation method. Background Technology
[0002] Phosphate rock contains various gangue minerals, often including both magnesian and siliceous gangue. High-silica, low- to medium-grade phosphate rock rich in potassium feldspar (KAlSi3O8) or sodium feldspar (NaAlSi3O8) faces the following challenges in effective separation: High siliceous gangue content: Traditional desilication processes heavily rely on water glass as an inhibitor, resulting in high reagent costs and a tendency for foam to become sticky and for equipment to scale. The consumption of water glass is enormous to suppress the large amount of siliceous gangue. The addition of water glass causes the foam to become sticky and tough, making defoaming difficult. This not only requires large amounts of water rinsing but also clogs pipes and foam tanks, severely limiting the equipment's processing capacity and reducing separation efficiency.
[0003] Alkali metal impurities pose significant hazards: Potassium and sodium feldspar, as aluminosilicates, are major sources of harmful alkali metals (K, Na) in phosphate concentrates. In subsequent thermal phosphate chemical processes, these alkali metals can cause equipment corrosion, furnace lining damage, and product quality degradation. Particularly in the new energy sector, potassium and sodium significantly impact conversion rates and battery energy storage during the synthesis of ferric phosphate and its physical processes, requiring strict control. Conventional flotation processes struggle to effectively remove these minerals and lack specific control indicators.
[0004] Complex process and difficulty in water reuse: Frequent pH adjustments and the use of water glass between multiple flotation stages lead to incompatibility of process water components in different operating stages, making it impossible to mix and reuse water resources, resulting in water waste and putting pressure on the ecological environment.
[0005] Therefore, developing a simplified process that can simultaneously and efficiently remove magnesium and silicon, effectively remove potassium and sodium feldspar, and also has the advantages of water saving and energy reduction has become an urgent need in this field. Summary of the Invention
[0006] To address the shortcomings of existing technologies, the present invention aims to provide an acyl quaternary ammonium salt compound, a phosphate rock reverse flotation collector, and a reverse flotation method to solve the technical problems of low phosphate rock separation efficiency and difficult operation.
[0007] The objective of this invention is achieved through the following technical solution: an acyl quaternary ammonium salt compound having the following structural formula: , where m = 8~16, and X is F, Cl, Br or I.
[0008] Preferably, the acyl-containing quaternary ammonium salt compound is selected from one of the following structural formulas: , and .
[0009] The preparation method of the above-mentioned acyl quaternary ammonium salt compound includes the following steps: (1) Add fatty acyl chloride to an organic solution of N,N-dimethyl-1,4-butanediamine and react under ice bath conditions. After the reaction is completed, wash with saturated NaHCO3 aqueous solution and separate the liquid. Dry the obtained organic phase and remove the solvent to obtain an intermediate; (2) Dissolve the intermediate in ethyl acetate and mix it with haloethane. Stir and reflux the reaction under nitrogen atmosphere and at 40~60℃. After the reaction is completed, filter and wash to obtain the acyl quaternary ammonium salt compound.
[0010] Preferably, the molar ratio of N,N-dimethyl-1,4-butanediamine to fatty acyl chloride in the organic solution of N,N-dimethyl-1,4-butanediamine in step (1) is 1~1.2:0.8~1.
[0011] Preferably, the structural formula of the fatty acyl chloride in step (1) is as follows: , where m = 8~16.
[0012] Preferably, the solvent of the organic solution of N,N-dimethyl-1,4-butanediamine is at least one selected from dichloromethane, propylene glycol methyl ether, DMF, and chloroform.
[0013] Preferably, the reaction time under the ice bath conditions in step (1) is 0.5 to 1 h.
[0014] Preferably, the structural formula of the intermediate in step (1) is as follows: , where m = 8~16.
[0015] Preferably, the molar ratio of the intermediate and the haloethane in step (2) is 1:1.4~1.8.
[0016] Preferably, the chemical formula of the haloethane in step (2) is CH3CH2X, where X is F, Cl, Br or I.
[0017] Preferably, the reflux reaction time in step (2) is 6 to 8 hours.
[0018] A reverse flotation collector for phosphate rock includes a magnesium removal collector and a silicon removal collector, wherein the silicon removal collector comprises the aforementioned acyl quaternary ammonium salt compound.
[0019] Preferably, the desilication collector comprises, by weight, the following components: 40-60 parts of an acyl quaternary ammonium salt compound, 10-20 parts of a foaming agent, and 30-40 parts of a modifier.
[0020] Preferably, the foaming agent is at least one of a mixed alcohol with 8 to 12 carbon atoms, No. 2 oil, methyl isobutyl methanol, diethyl phthalate, dibutyl phthalate and dihexyl phthalate.
[0021] Preferably, the modifier is at least one selected from methanol, ethanol, n-propanol, and isopropanol.
[0022] Preferably, the magnesium-removing collector comprises, by mass parts, the following components: 50-60 parts fatty acid, 10-20 parts foaming agent, and 30-40 parts modifier.
[0023] Preferably, the fatty acid is at least one of saturated fatty acids and unsaturated fatty acids having 10 to 18 carbon atoms.
[0024] Preferably, the unsaturated fatty acid is at least one of oleic acid and linoleic acid.
[0025] Preferably, the foaming agent is at least one of a mixed alcohol with 8 to 12 carbon atoms, No. 2 oil, methyl isobutyl methanol, diethyl phthalate, dibutyl phthalate and dihexyl phthalate.
[0026] Preferably, the modifier is at least one of water, sodium hydroxide, and potassium hydroxide.
[0027] A reverse flotation method for phosphate rock includes the following steps: S1, mixing phosphate rock and water evenly to prepare a slurry with a concentration of 30-40 wt%; S2, taking the slurry and adding the above-mentioned demagnesizing collector at a ratio of 0.5-1.0 kg / t, adjusting the pH to 4.5-4.7 for roughing demagnesification, the material in the tank being the roughing concentrate; S3, taking the roughing concentrate and adding the above-mentioned desilication collector at a ratio of 0.3-1.0 kg / t, adjusting the pH to 5-5.5 for primary cleaning, the material in the tank being the primary cleaning concentrate; taking the primary cleaning concentrate and adding the above-mentioned desilication collector at a ratio of 0.2-0.4 kg / t, adjusting the pH to 5-5.5 for secondary cleaning, the secondary cleaning concentrate being the phosphate concentrate.
[0028] Preferably, step S2 further includes the following: after the froth product from the roughing demagnesification is subjected to the first scavenging, the scavenged concentrate is returned to the roughing feed end and mixed with the original ore slurry to participate in the roughing again; the pH of the first scavenging is 3.8~4.2.
[0029] Preferably, step S2 further includes a second sweep after the first-stage selected foam product and the second-stage selected foam product are combined, wherein the pH of the second sweep is 5~5.5.
[0030] Compared with the prior art, the beneficial effects of the present invention include: (1) fundamentally improving the operating environment: excellent foam properties: the reverse flotation foam of the present invention is non-sticky and easy to defoam, which greatly reduces the amount of rinsing water used (saving more than 30%), avoids pipe blockage, and improves production continuity.
[0031] (2) Significantly improved system processing capacity and efficiency: smooth circulation of middlings: good foam properties make middlings return processing smoother, middlings circulation volume can be increased by more than 30%, and the system is more stable.
[0032] Significantly improved flotation rate: Due to the good fluidity and rapid defoaming of the foam, the processing capacity of the flotation machine per unit time is enhanced, and the overall flotation rate of the equipment can be increased by 10-30%, which means that a concentrator of the same scale can obtain a higher concentrate output.
[0033] (3) Excellent sorting indicators: While achieving the above-mentioned operational advantages, it can stably obtain high-quality phosphate concentrate with a P2O5 grade of 28~36% and a recovery rate of over 80%, in which the potassium and sodium feldspar content is reduced by more than 40% compared with the original ore.
[0034] (4) Cost and environmental advantages: Waterless glass does not require adjusting the acidic crude concentrate slurry after magnesium removal to alkaline. It can be directly desiliconized in an acidic environment. In addition, the recycled water from the desiliconization section can be used throughout the process, which reduces the process burden and brings about a comprehensive reduction in cost and improvement in efficiency. Attached Figure Description
[0035] Figure 1 is a schematic flowchart of the phosphate rock reverse flotation method described in Example 3.
[0036] Figure 2 shows the infrared spectrum of the acyl quaternary ammonium salt compound prepared in Example 1. Detailed Implementation
[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0038] Example 1: An acyl quaternary ammonium salt compound having the following structural formula: .
[0039] The preparation method of the above-mentioned acyl quaternary ammonium salt compound is as follows: (1) Add dodecyl chloride to the dichloromethane solution of N,N-dimethyl-1,4-butanediamine and react for 0.5 h under ice bath conditions. After the reaction is completed, wash with saturated NaHCO3 aqueous solution and separate the liquid. The obtained organic phase is dried with anhydrous magnesium sulfate and the solvent is evaporated to obtain the intermediate. The molar ratio of N,N-dimethyl-1,4-butanediamine to fatty acyl chloride in the organic solution of N,N-dimethyl-1,4-butanediamine is 1.2:1. (2) Add the intermediate in step (2) to the reaction, add ethyl acetate, and add haloethane (specifically CH3CH2Br) under nitrogen atmosphere protection. Stir and reflux at 40~60℃ for 8 h. After the reaction is completed, filter and wash with ethyl acetate to obtain the acyl quaternary ammonium salt compound. The molar ratio of the intermediate to halogenated ethane is 1:1.6.
[0040] The infrared spectrum of the acyl quaternary ammonium salt compound prepared in Example 1 is shown in Figure 2. From Figure 2, it can be seen that: 1639.28 cm⁻¹ -1 The peak at 3322.6 cm⁻¹ represents the stretching vibration absorption peak of the carbonyl group (C=O) in the amide group. -1 1548.22 cm -1 These are the stretching and bending vibration peaks of the (-NH) group in the acyl group, respectively, at 1248.41 cm⁻¹. -1 1019.67cm -1 The characteristic absorption peak of (CN) is at 975.25 cm⁻¹. -1 684.33 cm -1 It is (-N) + The characteristic absorption peak of R3 is at 2916.24 cm⁻¹. -1 2847.40 cm -1 The peak represents the stretching vibration of (-CH2, -CH3), at 1470.49 cm⁻¹. -1 These are absorption peaks representing the bending vibrations of (-CH). The structures represented by these peaks are basically consistent with the structure of the target product.
[0041] Example 2: A reverse flotation collector for phosphate rock, composed of a magnesium removal collector and a desilication collector; wherein, the desilication collector, by mass parts, comprises the following components: 50 parts of the acyl quaternary ammonium salt compound prepared in Example 1, 15 parts of a foaming agent (methyl isobutyl methanol) and 35 parts of a modifier (methanol).
[0042] The magnesium removal collector comprises the following components by mass: 60 parts fatty acid (hexadecanoic acid), 10 parts foaming agent (No. 2 oil), and 30 parts modifier (40wt% sodium hydroxide aqueous solution).
[0043] Example 3: A reverse flotation method for phosphate rock, comprising the following steps: S1: Mixing phosphate rock (from a phosphate mine in Guizhou) and water evenly to prepare a slurry with a concentration of 36 wt%; S2: Taking the slurry, adding the magnesium removal collector described in Example 2 at a ratio of 0.6 kg / t, adjusting the pH to 4.7 for roughing magnesium removal, the material in the tank is the roughing concentrate; the froth product from the roughing magnesium removal, after the first scavenging, the scavenging concentrate (denoted as middlings) is returned to the roughing feed end, mixed with the original slurry and re-participated in roughing, the scavenging tailings are denoted as magnesium removal tailings; the pH of the first scavenging is 4.0; S3: Taking the roughing concentrate, adding the desilication collector described in Example 2 at a ratio of 0.5 kg / t, adjusting the pH to 5.2 for primary cleaning, the material in the tank is the primary cleaning concentrate; taking the primary cleaning concentrate, then adding 0.3 kg / t... The above-mentioned desilication collector is added at a ratio of kg / t, and the pH is adjusted to 5.2 for two-stage cleaning. The concentrate from the two-stage cleaning is the phosphate concentrate. The foam products from the first-stage cleaning and the foam products from the second-stage cleaning are combined and then subjected to a second scavenging. The scavenging concentrate is returned to the feed end of the first-stage cleaning. The scavenging tailings are recorded as desilication tailings. The pH of the second scavenging is 5.2.
[0044] The main mineral composition of a phosphate mine in Guizhou described in Example 3 is shown in Table 1.
[0045] Table 1. Main mineral composition of a phosphate mine in Guizhou
[0046] After multiple cycles of middlings return and circulation, once the flotation system reaches a balance between materials and indicators (with fluctuations in each product indicator less than ±0.5%), the indicators obtained from the closed-circuit test are shown in Table 2.
[0047] Table 2 Results of Closed-Circuit Samples in Example 3
[0048] Referring to Table 2, we can see that after the double reverse flotation process, the raw ore with a P2O5 grade of 19.06%, MgO content of 6.23%, and SiO2 content of 16.12% was transformed into a phosphate concentrate product with a P2O5 grade of 30.38%, MgO content of 0.39%, and SiO2 content of 14.51%. The phosphate concentrate yield was 48.68%, the phosphorus recovery rate was 78.72%, the phosphorus grade of the demagnesium tailings was only 3.85%, and the phosphorus grade of the desiliconization tailings was 14.30%.
[0049] Example 4: A reverse flotation method for phosphate rock, comprising the following steps: S1: Mixing phosphate rock (from a phosphate mine in Sichuan) and water evenly to prepare a slurry with a concentration of 30 wt%; S2: Taking the slurry, adding the magnesium removal collector described in Example 2 at a ratio of 1.0 kg / t, adjusting the pH to 4.7 for roughing magnesium removal, the material in the tank is the roughing concentrate; the froth product from the roughing magnesium removal is returned to the roughing feed end after the first scavenging, mixed with the original slurry and re-participated in roughing, the scavenging tailings are recorded as magnesium removal tailings; the pH of the first scavenging is 4.2; S3: Taking the roughing concentrate, adding the desilication collector described in Example 2 at a ratio of 0.3 kg / t, adjusting the pH to 5.0 for primary cleaning, the material in the tank is the primary cleaning concentrate; taking the primary cleaning concentrate, then adding 0.2 kg / t... The above-mentioned desilication collector is added at a ratio of kg / t, and the pH is adjusted to 5.0 for two-stage cleaning. The concentrate from the two-stage cleaning is the phosphate concentrate. The foam products from the first-stage cleaning and the foam products from the second-stage cleaning are combined and then subjected to a second scavenging. The scavenging concentrate is returned to the feed end of the first-stage cleaning. The scavenging tailings are recorded as desilication tailings. The pH of the second scavenging is 5.5.
[0050] The main mineral composition of a phosphate mine in Sichuan described in Example 4 is shown in Table 3.
[0051] Table 3. Main mineral composition of a phosphate mine in Sichuan
[0052] After multiple cycles of middlings return and circulation, once the flotation system reaches a balance between materials and indicators (with fluctuations in each product indicator less than ±0.5%), the indicators obtained from the closed-circuit test are shown in Table 4.
[0053] Table 4 Results of Closed-Circuit Test Samples in Example 4
[0054] Referring to Table 4, we can see that after the double reverse flotation process, the raw ore with a P2O5 grade of 18.30%, MgO content of 6.38%, and SiO2 content of 19.12% was transformed into a phosphate concentrate product with a P2O5 grade of 32.37%, MgO content of 0.81%, and SiO2 content of 12.76%. The phosphate concentrate yield was 49.82%, the phosphorus recovery rate was 86.47%, the phosphorus grade of the demagnesium tailings was only 4.39%, and the phosphorus grade of the desiliconization tailings was 6.77%.
[0055] Example 5: A reverse flotation method for phosphate rock, comprising the following steps: S1: Mixing phosphate rock (from a phosphate mine in Hubei Province) and water evenly to prepare a slurry with a concentration of 34 wt%; S2: Taking the slurry, adding the magnesium removal collector described in Example 2 at a ratio of 0.6 kg / t, adjusting the pH to 4.5 for roughing and magnesium removal, the material in the tank being the roughing concentrate; performing a first scavenging on the froth product from the roughing and magnesium removal, the scavenging pH being 4.0; obtaining a first scavenging concentrate and a first scavenging tailings; the first scavenging tailings being designated as magnesium removal tailings; S3: Taking the roughing concentrate, adding the desilication collector described in Example 2 at a ratio of 0.5 kg / t, adjusting the pH to 5.0 for a first-stage cleaning, the material in the tank being the first-stage clean concentrate; taking the first-stage clean concentrate, then adding 0.2 kg / t... The above-mentioned desilication collector is added at a ratio of kg / t, and the pH is adjusted to 5.0 for two-stage cleaning. The concentrate from the two-stage cleaning is the phosphate concentrate. The foam products from the first-stage cleaning and the foam products from the second-stage cleaning are then combined for a second scavenging process. The pH of the second scavenging process is 5.0, resulting in a second scavenging concentrate and a second scavenging tailings. The second scavenging tailings are referred to as desilication tailings.
[0056] The main mineral composition of a phosphate mine in Hubei Province described in Example 5 is shown in Table 5.
[0057] Table 5. Main mineral composition of a phosphate mine in Hubei Province
[0058] The indicators obtained from the above open-circuit test are shown in Table 6.
[0059] Table 6 Results of Closed-Circuit Samples in Example 5
[0060] Referring to Table 6, we can see that after the double reverse flotation process, the raw ore with a P2O5 grade of 27.75%, MgO content of 3.57%, and SiO2 content of 13.62% yielded a phosphate concentrate product with a P2O5 grade of 33.38%, MgO content of 0.75%, and SiO2 content of 9.49%. The phosphate concentrate yield was 67.97%, the phosphorus recovery rate was 89.71%, the phosphorus grade of the demagnesium tailings was only 4.17%, and the phosphorus grade of the desilication tailings was 8.85%. The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made according to the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A compound containing an acyl quaternary ammonium salt, characterized in that, It has the following structural formula: , where m = 8~16, and X is F, Cl, Br or I.
2. The acyl-containing quaternary ammonium salt compound according to claim 1, characterized in that, The acyl-containing quaternary ammonium salt compound is selected from one of the following structural formulas: 、 and 。 3. The method for preparing the acyl-containing quaternary ammonium salt compound according to any one of claims 1 to 2, characterized in that, The process includes the following steps: (1) Adding fatty acyl chloride to an organic solution of N,N-dimethyl-1,4-butanediamine and reacting it under ice bath conditions. After the reaction is completed, the mixture is washed with saturated NaHCO3 aqueous solution and separated. The resulting organic phase is dried and the solvent is removed to obtain an intermediate. (2) Dissolving the intermediate in step (2) in ethyl acetate and mixing it with haloethane, stirring and refluxing it under a nitrogen atmosphere and at 40~60℃. After the reaction is completed, the mixture is filtered and washed to obtain the acyl quaternary ammonium salt compound.
4. The method for preparing the acyl-containing quaternary ammonium salt compound according to claim 3, characterized in that, The molar ratio of N,N-dimethyl-1,4-butanediamine to fatty acyl chloride in the organic solution of N,N-dimethyl-1,4-butanediamine in step (1) is 1~1.2:0.8~1; and / or the molar ratio of intermediate to haloethane in step (2) is 1:1.4~1.8; and / or the reaction time under ice bath conditions in step (1) is 0.5~1 h; and / or the reflux reaction time in step (2) is 6~8 h.
5. The method for preparing the acyl-containing quaternary ammonium salt compound according to claim 3, characterized in that, The structural formula of the fatty acyl chloride in step (1) is as follows: Where m = 8~16; and / or the solvent of the organic solution of N,N-dimethyl-1,4-butanediamine is at least one of dichloromethane, propylene glycol methyl ether, DMF and chloroform; and / or the structural formula of the intermediate in step (1) is as follows: , where m = 8~16; and / or the chemical formula of the haloethane in step (2) is CH3CH2X, where X is F, Cl, Br or I.
6. A reverse flotation collector for phosphate rock, characterized in that, It includes a magnesium-removing collector and a silicon-removing collector, wherein the silicon-removing collector comprises the acyl quaternary ammonium salt compound as described in any one of claims 1 to 2.
7. The phosphate rock reverse flotation collector according to claim 6, characterized in that, The desilication collector comprises, by weight, the following components: 40-60 parts of an acyl quaternary ammonium salt compound, 10-20 parts of a foaming agent, and 30-40 parts of a modifier; the foaming agent is at least one selected from a mixture of alcohols with 8-12 carbon atoms, No. 2 oil, methyl isobutyl methanol, diethyl phthalate, dibutyl phthalate, and dihexyl phthalate; the modifier is at least one selected from methanol, ethanol, n-propanol, and isopropanol.
8. The phosphate rock reverse flotation collector according to claim 6, characterized in that, The magnesium removal collector comprises, by weight, the following components: 50-60 parts fatty acid, 10-20 parts foaming agent, and 30-40 parts modifier; the fatty acid is at least one of saturated fatty acid and unsaturated fatty acid with 10-18 carbon atoms; the foaming agent is at least one of mixed alcohol with 8-12 carbon atoms, No. 2 oil, methyl isobutyl methanol, diethyl phthalate, dibutyl phthalate, and dihexyl phthalate; and the modifier is at least one of water, sodium hydroxide, and potassium hydroxide.
9. A method for reverse flotation of phosphate rock, characterized in that, The process includes the following steps: S1, mixing phosphate rock and water evenly to prepare a slurry with a concentration of 30-40 wt%; S2, taking the slurry and adding the demagnesifying collector according to any one of claims 6-8 at a ratio of 0.5-1.0 kg / t, adjusting the pH to 4.5-4.7 for roughing demagnesification, with the residue in the tank being the roughing concentrate; S3, taking the roughing concentrate and adding the desilication collector according to any one of claims 6-8 at a ratio of 0.3-1.0 kg / t, adjusting the pH to 5-5.5 for primary cleaning, with the residue in the tank being the primary cleaning concentrate; taking the primary cleaning concentrate and adding the aforementioned desilication collector at a ratio of 0.2-0.4 kg / t, adjusting the pH to 5-5.5 for secondary cleaning, with the secondary cleaning concentrate being the phosphate concentrate.
10. The phosphate rock reverse flotation method according to claim 9, characterized in that, Step S2 further includes that, after the froth product from the roughing demagnesification is subjected to the first scavenging, the scavenged concentrate is returned to the roughing feed end and mixed with the original ore slurry to participate in the roughing again; the pH of the first scavenging is 3.8~4.2; And / or step S2 further includes a second sweep after the first-stage selected foam product and the second-stage selected foam product are combined, wherein the pH of the second sweep is 5~5.5.