A method for quantitatively testing the adsorption amount of benzyl ammonium chloride collector on the surface of minerals in a flotation process

Abstract

The present application relates to a kind of mineral surface benzyl ammonium chloride collector adsorption quantity quantitative test method in flotation process, comprising, preparation background solution and sample to be measured;Establish trace and trace benzyl ammonium chloride collector standard curve;Test sample and calculate adsorption quantity.The test method provided by the present application avoids the photometric error caused by the metal ion and anion such as Ca 2+ 、F ‑ Dissolved by mineral, can detect trace component simultaneously, widen detection range, avoid the operation error caused by dilution or concentration step in the process of collector detection, and need not introduce extractant and other additional medicament, avoid the adsorption quantity calculation error caused by incomplete extraction, with the advantages of simple operation, analysis speed is fast, accuracy is good etc..

Description

Technical Field

[0001] This invention relates to the field of phosphate rock flotation technology, and in particular to a method for detecting the amount of benzyl ammonium chloride collector adsorbed on the mineral surface, especially a quantitative testing method for the amount of benzyl ammonium chloride collector adsorbed on the mineral surface during flotation. Background Technology

[0002] 70% of my country's phosphate rock resources are sedimentary phosphate rock. In phosphate-rich sedimentary deposits, the valuable mineral apatite is often associated with gangue minerals such as potassium feldspar and dolomite. The average P2O5 grade is low, with collophane being the dominant mineral. The ore has a fine grain size, making beneficiation difficult. Collophane flotation technology utilizes the adsorption differences between different ores and collectors to achieve concentrate enrichment through froth flotation, which is an important way to recover phosphate ore. Benzyl ammonium chloride collector has received widespread attention as an important collector in collophane reverse flotation. The flotation effect is directly related to the amount of collector adsorbed on the mineral surface. Excessive collector dosage will cause a series of problems such as reagent waste, abnormal fluctuations in beneficiation indicators, poor precision selectivity, and phosphorus loss; insufficient collector dosage will result in phosphorus loss. Therefore, to effectively control the amount of collector used and avoid opaque operations, accurate analysis of the adsorption amount on the mineral surface is particularly crucial.

[0003] In their paper "Application of Absorption Spectroscopy in Flotation Research," Wang Dianzuo et al. disclosed the determination of adsorption amount in the flotation process using ultraviolet absorption spectroscopy. The determination usually involves contacting the reagent solution with the mineral, measuring the concentration of the equilibrium solution, and calculating the adsorption amount based on the difference from the initial concentration. Alternatively, the mineral that has been treated with an appropriate solvent is treated to desorb the adsorbed reagent, and then its concentration is measured to calculate the adsorption amount.

[0004] CN113834890B discloses a method for accurately quantitatively analyzing the adsorption amount of sodium oleate collector on the surface of minerals during flotation. The method includes the following steps: (1) Add sodium oleate to the slurry, shake, and after the adsorption reaches equilibrium, centrifuge and take the supernatant as the test solution; (2) Add excess concentrated H2SO4 to the test solution to convert sodium oleate into oleic acid, and then extract and separate to obtain an oil phase containing oleic acid; (3) Perform methyl esterification on oleic acid to obtain methyl oleate; (4) Detect and analyze the methyl oleate organic phase containing heptadecanoate internal standard by gas chromatography-mass spectrometry, and then calculate the adsorption amount of sodium oleate on the surface of minerals based on the detection and analysis results.

[0005] As mentioned earlier, common methods for measuring adsorption capacity include extraction, high-performance liquid chromatography, infrared spectroscopy, and ion chromatography. However, these methods have limitations: some use toxic reagents such as benzene, others have issues with low concentrations of trace collectors resulting in indistinct peaks exceeding the measurement range, and still others involve water environments containing various anions and cations (such as Ca2+). 2+ / Mg 2+ / F- / Cl - / K - / PO4 3- SO4 2- Other ions, such as chlorine content, interfere with the measurement of the adsorption amount of benzyl ammonium chloride collector, making it impossible to define the adsorption amount by measuring the chlorine content. Furthermore, the benzyl ammonium chloride collector has both hydrophilic and hydrophobic ends, making complete extraction impossible and affecting measurement accuracy. The extraction process is also complex, requiring the introduction of additional solvents, leading to environmental pollution and increased measurement costs. Additionally, the degree of ore adsorption varies at different times during flotation, resulting in a wide range of benzyl ammonium chloride collector concentrations remaining in the water. Dilution or concentration directly affects measurement accuracy. Therefore, there is an urgent need to develop a method for accurately measuring the adsorption amount of benzyl ammonium chloride collector during flotation. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for quantitatively testing the adsorption amount of benzyl ammonium chloride collector on the mineral surface during flotation. The method employs a UV-Vis spectrophotometer, using a clarified pulp solution without added benzyl ammonium chloride collector as the background solution, and directly detects the residual content of benzyl ammonium chloride collector in the clarified pulp solution. This method avoids the problem caused by the dissolution of metal ions and anions such as Ca from the minerals. 2+ F - It eliminates photometric measurement errors caused by factors such as dilution or concentration during the detection of benzyl ammonium chloride collector, and also mitigates operational errors caused by dilution or concentration steps. It boasts advantages such as ease of operation, fast analysis speed, and good accuracy, meeting the need for simultaneous detection of trace and ultraviolet benzyl ammonium chloride collector content using ultraviolet detection methods.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] This invention provides a method for quantitatively testing the adsorption capacity of benzyl ammonium chloride collector on the surface of minerals during flotation, the method comprising the following steps:

[0009] After the minerals are prepared into a slurry, they are stirred and the solid and liquid are separated. The clear liquid is used as the background solution for ultraviolet detection.

[0010] After the slurry is mixed with benzyl ammonium chloride collector, solid-liquid separation is performed, and the clear liquid is taken as the sample to be tested.

[0011] Establish standard curves for trace and ultra-trace amounts of benzylammonium chloride collector;

[0012] The background solution for ultraviolet detection and the sample to be tested were measured photometrically using an ultraviolet-visible spectrophotometer to obtain the content of benzyl ammonium chloride collector in the sample to be tested.

[0013] The amount of benzyl ammonium chloride collector adsorbed on the mineral surface is calculated by the difference between the initial concentration of the benzyl ammonium chloride collector and the residual concentration in the sample to be tested.

[0014] The testing method described in this invention uses a mineral slurry without added benzyl ammonium chloride collector as the background solution and employs a UV-Vis spectrophotometer to test the content of residual benzyl ammonium chloride collector in the slurry. This eliminates interference from other ions on the test results, avoids measurement errors caused by using water as a background, and also avoids the process of separating ions from the collector during measurement. Furthermore, based on the unique UV spectral characteristics of benzyl ammonium chloride collector, two absorption wavelengths are selected as detection wavelengths for trace and ultra-trace amounts, establishing standard curves relating the concentration of trace and ultra-trace benzyl ammonium chloride collector to absorbance. This avoids the problem of mismatch between the detected concentration and the standard curve when using a single wavelength for detection, which prevents simultaneous measurement of trace and ultra-trace benzyl ammonium chloride collector content. This method achieves simultaneous detection of trace and ultra-trace benzyl ammonium chloride collector without diluting or concentrating the test sample, effectively reducing operational errors, improving the accuracy of measurement results, and simplifying the operation process without the need for additional reagents.

[0015] As a preferred technical solution of the present invention, the stirring is based on the principle that the free ions on the surface of the mineral are fully dissolved into the water to achieve dissolution equilibrium;

[0016] Preferably, the mineral is collophane, such as potassium feldspar, apatite, etc.

[0017] Preferably, the concentration of the slurry is 100-500 g / L, such as 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, 200 g / L, 300 g / L, 400 g / L, 500 g / L, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0018] Preferably, the stirring is carried out in a stirring tank, and the stirring speed of the stirring tank is 200-1200 r / min, such as 200 r / min, 400 r / min, 600 r / min, 800 r / min, 1000 r / min, 1100 r / min, 1200 r / min, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0019] Preferably, the stirring time is 10-30 min, such as 10 min, 15 min, 20 min, 25 min, 30 min, etc., but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0020] As a preferred technical solution of the present invention, the solid-liquid separation is performed using an aqueous filter membrane. The pore size of the aqueous filter membrane is 0.1-1μm, such as 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0021] Preferably, the solid-liquid separation is performed at least twice to remove fine particles.

[0022] As a preferred embodiment of the present invention, the concentration of the benzyl ammonium chloride collector after mixing with the slurry is 10. -6 -10 -3 g / mL, for example 1×10 -6 g / mL, 5×10 -6 g / mL, 1×10 -5 g / mL, 5×10 -5 g / mL, 1×10 -4 g / mL, 5×10 -4 g / mL, 1×10 -3 g / mL, etc., but not limited to the listed values; other unlisted values ​​within the above range also apply.

[0023] Preferably, the mixture is prepared by gradually adsorbing benzyl ammonium chloride collector onto the mineral surface until adsorption equilibrium is reached.

[0024] As a preferred embodiment of the present invention, the step of establishing standard curves for trace and ultra-trace amounts of benzyl ammonium chloride collector includes:

[0025] Trace and ultra-trace benzyl ammonium chloride collector standard solutions were prepared, and the spectra of the trace and ultra-trace benzyl ammonium chloride collector standard solutions were scanned in the wavelength range of 185-800 nm using a UV-Vis spectrophotometer with ultrapure water as the background.

[0026] Select appropriate absorption wavelengths as the UV detection wavelengths for trace and ultra-trace benzyl ammonium chloride collectors, fix different detection wavelengths to perform photometric measurements of trace and ultra-trace solutions, establish the relationship between the concentration and absorbance of trace and ultra-trace benzyl ammonium chloride solutions, and plot standard curves.

[0027] Preferably, the concentration of the trace benzyl ammonium chloride collector standard solution is 5-100 ppm, such as 5 ppm, 10 ppm, 20 ppm, 40 ppm, 60 ppm, 80 ppm, 100 ppm, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0028] Preferably, the concentration of the trace benzyl ammonium chloride collector standard solution is 0.1-5 ppm, such as 0.1 ppm, 0.2 ppm, 0.4 ppm, 0.6 ppm, 0.8 ppm, 1 ppm, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0029] Preferably, the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 200-220nm, such as 200nm, 205nm, 210nm, 215nm, 220nm, etc., but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0030] More preferably, when the trace benzyl ammonium chloride collector is tetradecyl dimethyl benzyl ammonium chloride, its ultraviolet detection wavelength is 208.5 nm.

[0031] Preferably, the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 185-200nm, such as 185nm, 190nm, 195nm, 200nm, etc., but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0032] More preferably, when the trace benzyl ammonium chloride collector is tetradecyl dimethyl benzyl ammonium chloride, its ultraviolet detection wavelength is 190.5 nm.

[0033] As a preferred technical solution of the present invention, the formula for calculating the amount of adsorption on the mineral surface is as follows:

[0034]

[0035] Where Γ represents the adsorption capacity, in kg / m³. 2 ;c m0 With c m1 , respectively, represent the initial and residual concentrations of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the mineral sample, g; S is the specific surface area of ​​the pure mineral, m². 2 / Kg.

[0036] As a preferred technical solution of the present invention, the method includes the following steps:

[0037] After the minerals are prepared into a slurry, they are stirred to fully dissolve the free ions on the mineral surface into the water. After reaching dissolution equilibrium, solid-liquid separation is performed using an aqueous filter membrane with a pore size of 0.1-1 μm. The clear liquid is then used as the background solution for ultraviolet detection.

[0038] The slurry is mixed with benzyl ammonium chloride collector, allowing the benzyl ammonium chloride collector to gradually adsorb onto the mineral surface. After adsorption equilibrium is reached, solid-liquid separation is performed using an aqueous filter membrane with a pore size of 0.1-1 μm, and the clear liquid is used as the test solution. The concentration of the benzyl ammonium chloride collector after mixing with the slurry is 10%. -6 -10 -3 g / mL;

[0039] Establish standard curves for trace and ultra-trace benzyl ammonium chloride collectors: prepare standard solutions of trace and ultra-trace benzyl ammonium chloride collectors, and use a UV-Vis spectrophotometer with ultrapure water as background to perform spectral scanning of the standard solutions of trace and ultra-trace benzyl ammonium chloride collectors in the wavelength range of 185-800 nm.

[0040] Select appropriate absorption wavelengths as the UV detection wavelengths for trace and ultra-trace benzyl ammonium chloride collectors, fix different detection wavelengths to perform photometric measurements of trace and ultra-trace solutions, establish the relationship between the concentration and absorbance of trace and ultra-trace benzyl ammonium chloride solutions, and plot standard curves;

[0041] The concentration of the trace benzyl ammonium chloride collector standard solution is 5-100 ppm; the concentration of the ultraviolet (UV) detection wavelength of the trace benzyl ammonium chloride collector is 0.1-5 ppm; the UV detection wavelength of the trace benzyl ammonium chloride collector is 200-220 nm; and the UV detection wavelength of the ultraviolet (UV) ...

[0042] The background solution for ultraviolet detection and the sample to be tested were measured photometrically using an ultraviolet-visible spectrophotometer to obtain the content of benzyl ammonium chloride collector in the sample to be tested.

[0043] The adsorption amount of benzyl ammonium chloride collector on the mineral surface is calculated by the difference between the initial concentration of the benzyl ammonium chloride collector and the residual concentration in the sample to be tested. The calculation formula is as follows:

[0044]

[0045] Where Γ represents the adsorption capacity, in kg / m³. 2 ;c m0 With c m1 , respectively, represent the initial and residual concentrations of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the mineral sample, g; S is the specific surface area of ​​the pure mineral, m². 2 / Kg.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] (1) This invention provides a method for quantitatively testing the adsorption capacity of benzyl ammonium chloride collector on the surface of minerals during flotation. The method uses the clarified slurry without added collector as the background solution, thus eliminating the possibility of metal ions and anions such as Ca dissolving from the minerals. 2 + F - This method eliminates interference with the test results, avoids measurement errors caused by the usual water background, and also avoids the process of separating ions from the analyte during measurement.

[0048] (2) Based on the unique ultraviolet spectral characteristics of benzyl ammonium chloride collector, this invention selects two absorption wavelengths as the detection wavelengths for trace and ultra-trace detection, avoiding the problem of mismatch between the detection concentration and the standard curve when using a single wavelength for detection, which makes it impossible to simultaneously measure the content of trace and ultra-trace benzyl ammonium chloride collector; at the same time, without the need to dilute or concentrate the test sample, it realizes the simultaneous detection of trace and ultra-trace benzyl ammonium chloride collector, broadens the detection range, effectively reduces operational errors, and improves the accuracy of measurement results; and there is no need to introduce additional reagents such as extractants, avoiding the error in adsorption calculation caused by incomplete extraction, which has the advantages of simple operation, fast analysis speed, and good accuracy. Attached Figure Description

[0049] Figure 1 The ultraviolet spectra of trace and ultra-trace amounts of tetradecyl dimethyl benzyl ammonium chloride are shown.

[0050] Figure 2 Standard curves for trace and ultra-trace amounts of tetradecyl dimethyl benzyl ammonium chloride.

[0051] Figure 3 The results show the adsorption capacity of tetradecyl dimethyl benzyl ammonium chloride collector on potassium feldspar.

[0052] Figure 4 The results show the adsorption capacity of tetradecyl dimethyl benzyl ammonium chloride collector on apatite.

[0053] Figure 5 The UV spectra are shown against the background of slurry clear liquid without collector and against the background of pure water. Detailed Implementation

[0054] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0055] Instruments and working conditions

[0056] Instrument used: UV-2600i UV-Vis spectrophotometer

[0057] Instrument operating conditions: temperature 15-35℃, humidity 30-80%, power supply AC100V-240V, 50 / 60Hz. In a dim and quiet environment, avoid sunlight and other strong light interference.

[0058] Example 1

[0059] This embodiment uses tetradecyl dimethyl benzyl ammonium chloride as the collector and selects potassium feldspar ore to provide a method for quantitatively testing the adsorption capacity of benzyl ammonium chloride collector on the mineral surface during flotation. The method includes the following steps:

[0060] (1) Sample preparation

[0061] Weigh 50.00g of potassium feldspar into a 1L beaker using an electronic balance, add 500mL of deionized water, adjust the pH to 9, and stir at 250r / min for 30min to allow the potassium feldspar to reach dissolution equilibrium. After standing for 6min, take 20mL of the supernatant and filter it twice through a 0.2μm pore size aqueous filter membrane to completely remove the potassium feldspar minerals, so as to avoid the solid residue from affecting the subsequent absorbance detection. The filtered clear liquid is used as the background solution for ultraviolet detection.

[0062] Add a certain concentration of tetradecyl dimethyl benzyl ammonium chloride collector solution, and stir with an electric motor at 250 r / min for 10 min to ensure that the tetradecyl dimethyl benzyl ammonium chloride collector is in full contact with the potassium feldspar mineral and reaches adsorption equilibrium. After standing for 6 min, take 10 mL of the supernatant and filter it twice with a water-based filter membrane. The filtered clear liquid is used as the sample to be tested.

[0063] (2) Establish standard curves for trace and ultra-trace amounts of benzyl ammonium chloride collector.

[0064] Trace standard solutions of tetradecyl dimethyl benzyl ammonium chloride collector with known concentrations of 5 ppm, 10 ppm, 20 ppm, 40 ppm, 60 ppm, 80 ppm, and 100 ppm, and ultra-trace standard solutions of tetradecyl dimethyl benzyl ammonium chloride collector with concentrations of 0.1 ppm, 0.2 ppm, 0.4 ppm, 0.6 ppm, 0.8 ppm, and 1 ppm were prepared. A UV-Vis spectrophotometer was used with ultrapure water as a background to perform spectral scanning of the standard solutions in the wavelength range of 185–800 nm. The UV spectra are shown below. Figure 1 As shown. Considering factors such as baseline, peak stability, sensitivity, and detection limit, 208.5 nm was selected as the UV detection wavelength for trace amounts of tetradecyl dimethyl benzyl ammonium chloride collector, and 190.5 nm was selected as the UV detection wavelength for ultraviolet (UV) amounts of tetradecyl dimethyl benzyl ammonium chloride collector.

[0065] Standard curves for trace and ultra-trace amounts of benzyl ammonium chloride collector were established at 208.5 nm and 190.5 nm, respectively. The results are as follows: Figure 2 As shown.

[0066] (3) Detection of adsorption capacity on mineral surface

[0067] The UV-Vis spectrophotometer was used to measure the photometric properties of the background solution and the sample to be tested under UV detection, and the concentration of residual collector in the sample to be tested was calculated based on the standard curve.

[0068] The adsorption capacity of tetradecyl dimethyl benzyl ammonium chloride collector on the surface of potassium feldspar minerals is calculated by the difference between the initial concentration of tetradecyl dimethyl benzyl ammonium chloride collector and the residual collector concentration in the sample. The calculation formula is as follows:

[0069]

[0070] Where Γ represents the adsorption capacity, in kg / m³. 2 ;c m0 With c m1 , respectively, represent the initial and residual concentrations of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the mineral sample, g; S is the specific surface area of ​​the pure mineral, m². 2 / Kg. The measured specific surface area of ​​potassium feldspar is 121.1m². 2 / kg. The adsorption capacity of potassium feldspar on tetradecyl dimethyl benzyl ammonium chloride collector was measured as follows: Figure 3 As shown.

[0071] from Figure 1 It can be seen that the UV spectrum of the tetradecyl dimethyl benzyl ammonium chloride collector shows two characteristic peaks, corresponding to wavelengths of 190.5 nm and 208.5 nm, respectively. These peaks exhibit high sensitivity and are unaffected by other interferences. However, within the concentration range tested in this experiment, a concentration-absorbance standard curve established using a fixed wavelength cannot predict the supernatant concentration. This is because at high concentrations, surfactant molecular aggregation can form supramolecular structures, or hydrogen bonding can cause a shift in the 190.5 nm peak; at low concentrations, noise is significant, causing the peak at 208.5 nm to disappear, thus making it impossible to establish a linear concentration-absorbance curve within the tested concentration range. Therefore, 190.5 nm was chosen as the UV detection wavelength for trace amounts of the tetradecyl dimethyl benzyl ammonium chloride collector, and 208.5 nm was chosen as the UV detection wavelength for micro amounts.

[0072] like Figure 2 As shown, when the concentration is 0.5-5 ppm, the standard curve of the tetradecyl dimethyl benzyl ammonium chloride collector is y = 131050.43x, and the coefficient of determination R0 is... 2The coefficient of determination is 0.99936; when the concentration is 5-100 ppm, the standard curve of the tetradecyl dimethyl benzyl ammonium chloride collector is y = 20075.78x, and the coefficient of determination R is 0.99936. 2 The value is 0.99994. The R-values ​​of the two standard curves are... 2 The values ​​all reached 0.999 or higher, indicating that the concentration of tetradecyl dimethyl benzyl ammonium chloride collector and absorbance showed a good linear relationship, which can be used as a standard curve for ultraviolet detection.

[0073] from Figure 3 As can be seen, with the increase of the concentration of tetradecyl dimethyl benzyl ammonium chloride collector, the adsorption capacity on the surface of potassium feldspar minerals first increases and then remains constant, reaching adsorption equilibrium, i.e., adsorption saturation, which is consistent with conventional understanding in the field and conforms to adsorption laws; in addition, Figure 3 The curve changes very regularly, which shows that the present invention can indeed detect the concentration of trace amounts of tetradecyl dimethyl benzyl ammonium chloride collector, thereby achieving highly sensitive detection of the amount of tetradecyl dimethyl benzyl ammonium chloride collector adsorbed on the surface of potassium feldspar minerals.

[0074] Example 2

[0075] This embodiment uses tetradecyl dimethyl benzyl ammonium chloride as a collector and apatite ore to provide a method for quantitatively testing the adsorption capacity of benzyl ammonium chloride collector on the mineral surface during flotation. The method includes the following steps:

[0076] (1) Sample preparation

[0077] Weigh 50.00g of apatite into a 1L beaker using an electronic balance, add 500mL of deionized water, adjust the pH to 9, and stir the mixture at 300r / min for 25min to allow the apatite to reach dissolution equilibrium. After standing for 6min, take 20mL of the supernatant and filter it twice through a 0.2μm pore size aqueous filter membrane to completely remove the apatite minerals and avoid the solid residue from affecting the subsequent absorbance detection. The filtered clear liquid is used as the background solution for ultraviolet detection.

[0078] Add a certain concentration of tetradecyl dimethyl benzyl ammonium chloride collector solution, and stir with an electric motor at 300 r / min for 12 min to ensure that the tetradecyl dimethyl benzyl ammonium chloride collector is in full contact with the apatite mineral and reaches adsorption equilibrium. After standing for 6 min, take 10 mL of the supernatant and filter it twice with a water-based filter membrane. The filtered clear liquid is used as the sample to be tested.

[0079] (2) Establish standard curves for trace and ultra-trace amounts of benzyl ammonium chloride collector.

[0080] Trace tetradecyl dimethyl benzyl ammonium chloride collector standard solutions with known concentrations of 20 ppm, 40 ppm, 60 ppm, 80 ppm, and 100 ppm, and ultra-trace tetradecyl dimethyl benzyl ammonium chloride collector standard solutions with concentrations of 0.2 ppm, 0.4 ppm, 0.6 ppm, 0.8 ppm, and 1 ppm were prepared. Using a UV-Vis spectrophotometer with ultrapure water as the background, the standard solutions were spectrally scanned in the wavelength range of 185–800 nm. Considering factors such as baseline, peak stability, sensitivity, and detection limit, 208.5 nm was selected as the UV detection wavelength for the trace tetradecyl dimethyl benzyl ammonium chloride collector, and 190.5 nm was selected as the UV detection wavelength for the ultraviolet detection wavelength for the ultraviolet detection wavelength for the ultraviolet-visible collector.

[0081] Standard curves for trace amounts of benzyl ammonium chloride collector were established at 208.5 nm and 190.5 nm, respectively.

[0082] (3) Detection of adsorption capacity of mineral surface collectors

[0083] The UV-Vis spectrophotometer was used to measure the photometric properties of the background solution and the sample to be tested under UV detection, and the concentration of residual collector in the sample to be tested was calculated based on the standard curve.

[0084] The adsorption capacity of tetradecyl dimethyl benzyl ammonium chloride collector on the surface of apatite minerals is calculated by the difference between the initial concentration of tetradecyl dimethyl benzyl ammonium chloride collector and the residual collector concentration in the sample. The calculation formula is as follows:

[0085]

[0086] Where Γ represents the adsorption capacity, in kg / m³. 2 ;c m0 With c m1 , respectively, represent the initial and residual concentrations of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the mineral sample, g; S is the specific surface area of ​​the pure mineral, m². 2 / Kg. The measured specific surface area of ​​apatite is 228.7m². 2 / kg. The adsorption capacity of tetradecyl dimethyl benzyl ammonium chloride collector on apatite was determined as follows: Figure 4 As shown.

[0087] from Figure 4 As can be seen, with the increase of the concentration of tetradecyl dimethyl benzyl ammonium chloride collector, the adsorption capacity on the surface of apatite minerals first increases and then remains constant, reaching adsorption equilibrium, i.e., adsorption saturation, which is consistent with conventional understanding in the field and conforms to adsorption laws; in addition, Figure 3The curve changes very regularly, which shows that the present invention can indeed detect the concentration of trace amounts of tetradecyl dimethyl benzyl ammonium chloride collector, thereby achieving highly sensitive detection of the amount of tetradecyl dimethyl benzyl ammonium chloride collector adsorbed on the surface of apatite minerals.

[0088] Comparative Example 1

[0089] This comparative example provides a method for quantitatively testing the adsorption amount of benzyl ammonium chloride collector on the mineral surface during flotation. Based on the method described in Example 2, the only difference is that a pulp slurry without added benzyl ammonium chloride collector is not used as a background solution for UV detection; instead, the concentration of residual benzyl ammonium chloride collector in the sample is directly tested. Figure 5 The UV spectra are shown against the background of slurry clear liquid without collector and against the background of pure water.

[0090] from Figure 5 It can be seen that after apatite adsorbs tetradecyl dimethyl benzyl ammonium chloride, absorbance measurements were performed against the background of slurry without collector and against the background of pure water. It can be seen that the baseline of the spectrum obtained against the background of pure water deviates from 0. This is because ions in the slurry contribute to the absorbance, which is inconsistent with the actual value, resulting in a large error in the actual measurement results of the tetradecyl dimethyl benzyl ammonium chloride collector.

[0091] In summary, this invention provides a quantitative test method for the adsorption amount of benzyl ammonium chloride collector on the mineral surface during flotation. It uses a UV-Vis spectrophotometer to measure the photometric value of residual collector in the clarified slurry, using a clarified slurry without added collector as the background solution to eliminate interference from other ions and avoid measurement errors caused by using water as a background solution. It also avoids the process of separating ions from the collector during measurement. Standard curves for trace and ultra-trace amounts of benzyl ammonium chloride collector are established, enabling simultaneous detection of trace and ultra-trace collectors without diluting or concentrating the test sample. This effectively reduces operational errors and improves the accuracy of measurement results, offering advantages such as simple operation, fast analysis speed, and good accuracy.

[0092] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for quantitatively testing the adsorption capacity of benzyl ammonium chloride collector on the mineral surface during flotation, characterized in that, The method includes the following steps: After the minerals are prepared into a slurry, they are stirred and subjected to solid-liquid separation. The clear liquid is used as the background solution for ultraviolet detection. The solid-liquid separation is performed using an aqueous filter membrane with a pore size of 0.1-1 μm. After the slurry is mixed with benzyl ammonium chloride collector, solid-liquid separation is performed, and the clear liquid is taken as the sample to be tested. The steps for establishing standard curves for trace and ultra-trace benzyl ammonium chloride collectors include selecting appropriate absorption wavelengths as the ultraviolet detection wavelengths for trace and ultra-trace benzyl ammonium chloride collectors; The ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 200-220 nm; the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 185-200 nm. The background solution for UV detection and the sample to be tested were measured using a UV-Vis spectrophotometer. Based on the established standard curves for trace and ultraviolet-visible benzyl ammonium chloride collector, the content of benzyl ammonium chloride collector in the sample to be tested was determined. The amount of benzyl ammonium chloride collector adsorbed on the mineral surface is calculated by the difference between the initial concentration of the benzyl ammonium chloride collector and the residual concentration in the sample to be tested.

2. The method according to claim 1, characterized in that, The stirring is performed until the free ions on the mineral surface are fully dissolved into the water, reaching a dissolution equilibrium.

3. The method according to claim 1, characterized in that, The concentration of the benzyl ammonium chloride collector after mixing with the slurry is 10. -6 -10 -3 g / mL.

4. The method according to claim 1, characterized in that, The mixture is gradually adsorbed onto the mineral surface by benzyl ammonium chloride collector until adsorption equilibrium is reached.

5. The method according to claim 1, characterized in that, The steps for establishing standard curves for trace and ultra-trace amounts of benzyl ammonium chloride collector include: Trace and ultra-trace benzyl ammonium chloride collector standard solutions were prepared, and the spectra of the trace and ultra-trace benzyl ammonium chloride collector standard solutions were scanned in the wavelength range of 185~800 nm using a UV-Vis spectrophotometer with ultrapure water as the background. Select appropriate absorption wavelengths as the UV detection wavelengths for trace and ultra-trace benzyl ammonium chloride collectors, fix different detection wavelengths to perform photometric measurements of trace and ultra-trace solutions, establish the relationship between the concentration and absorbance of trace and ultra-trace benzyl ammonium chloride solutions, and plot standard curves.

6. The method according to claim 5, characterized in that, The concentration of the trace benzyl ammonium chloride collector standard solution is 5-100 ppm; the concentration of the ultra-trace benzyl ammonium chloride collector standard solution is 0.1-5 ppm.

7. The method according to claim 1, characterized in that, The formula for calculating the amount of adsorption on the mineral surface is as follows: ； Where Γ represents the adsorption capacity, in kg / m³. 2 c m0 With c m1 , respectively, represent the initial and residual concentrations of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the mineral sample, g; S is the specific surface area of ​​the pure mineral, m². 2 / Kg.

8. The method according to claim 1, characterized in that, The method includes the following steps: After the minerals are prepared into a slurry, they are stirred to fully dissolve the free ions on the mineral surface into the water. After reaching dissolution equilibrium, solid-liquid separation is performed using an aqueous filter membrane with a pore size of 0.1-1 μm. The clear liquid is then used as the background solution for ultraviolet detection. The slurry is mixed with benzyl ammonium chloride collector, allowing the benzyl ammonium chloride collector to gradually adsorb onto the mineral surface. After adsorption equilibrium is reached, solid-liquid separation is performed using an aqueous filter membrane with a pore size of 0.1-1 μm, and the clear liquid is used as the test solution. The concentration of the benzyl ammonium chloride collector after mixing with the slurry is 10%. -6 -10 -3 g / mL; Establish standard curves for trace and ultra-trace benzyl ammonium chloride collectors: Prepare standard solutions of trace and ultra-trace benzyl ammonium chloride collectors, and use a UV-Vis spectrophotometer with ultrapure water as the background to perform spectral scanning of the standard solutions of trace and ultra-trace benzyl ammonium chloride collectors in the wavelength range of 185~800 nm. Select appropriate absorption wavelengths as the UV detection wavelengths for trace and ultra-trace benzyl ammonium chloride collectors, fix different detection wavelengths to perform photometric measurements of trace and ultra-trace solutions, establish the relationship between the concentration and absorbance of trace and ultra-trace benzyl ammonium chloride solutions, and plot standard curves; The concentration of the trace benzyl ammonium chloride collector standard solution is 5-100 ppm; the concentration of the ultraviolet (UV) detection wavelength of the trace benzyl ammonium chloride collector is 0.1-5 ppm; the UV detection wavelength of the trace benzyl ammonium chloride collector is 200-220 nm; and the UV detection wavelength of the ultraviolet (UV) ... The background solution for UV detection and the sample to be tested were measured using a UV-Vis spectrophotometer. Based on the established standard curves for trace and ultraviolet-visible benzyl ammonium chloride collector, the content of benzyl ammonium chloride collector in the sample to be tested was determined. The adsorption amount of benzyl ammonium chloride collector on the mineral surface is calculated by the difference between the initial concentration of the benzyl ammonium chloride collector and the residual concentration in the sample to be tested. The calculation formula is as follows: ； Where Γ represents the adsorption capacity, in kg / m³. 2 c m0 With c m1 , respectively, represent the initial and residual concentrations of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the mineral sample, g; S is the specific surface area of ​​the pure mineral, m². 2 / Kg.

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