Quantitative testing method for adsorbing capacity of benzyl ammonium chloride collecting agent on surface of mineral in flotation process

Abstract

The invention relates to a method for quantitatively testing the adsorption capacity of a benzyl ammonium chloride collecting agent on the surface of a mineral in a flotation process, which comprises the following steps: preparing a background solution and a sample to be tested; establishing a trace benzyl ammonium chloride collecting agent standard curve and a trace benzyl ammonium chloride collecting agent standard curve; and detecting the sample and calculating the adsorption quantity. According to the testing method provided by the invention, photometric measurement errors caused by metal ions and anions such as Ca < 2 + > and F <-> dissolved out of minerals are avoided, trace and trace components can be detected at the same time, the detection range is widened, operation errors caused by a dilution or concentration step in the collecting agent detection process are avoided, additional agents such as an extracting agent do not need to be introduced, and the method is simple and convenient to operate. And the method has the advantages of simplicity and convenience in operation, high analysis speed, good accuracy and the like.

Description

Technical Field

[0001] The invention relates to the technical field of collophanite flotation, in particular to a method for detecting the adsorption amount of benzyl ammonium chloride collector on a mineral surface, and in particular to a method for quantitatively testing the adsorption amount of benzyl ammonium chloride collector on a mineral surface during a flotation process. Background Art

[0002] 70% of my country's phosphate resources belong to sedimentary rock type phosphorite. In phosphorus-rich sedimentary deposits, useful mineral apatite is often associated with gangue minerals such as potassium feldspar and dolomite. The average grade of P2O5 is low, mainly collophanite, the ore is finely embedded, and the separation is difficult. Collophanite flotation technology is a process of enriching concentrates by froth flotation using the adsorption differences between different ores and collectors. It is an important way to achieve phosphate recovery. Benzyl ammonium chloride collector has received widespread attention as an important collector for reverse flotation of collophanite. The flotation effect is directly related to the adsorption amount of the collector on the mineral surface. Excessive use of collectors will cause a series of problems such as reagent waste, abnormal fluctuations in mineral processing indicators, poor precision selectivity and phosphorus loss; too little collector will cause phosphorus loss. Therefore, in order to effectively control the amount of collectors and avoid black box operations, it is particularly important to accurately analyze the adsorption amount on the mineral surface.

[0003] Wang Dianzuo et al. disclosed the determination of adsorption amount in the flotation process by ultraviolet absorption spectroscopy in "Application of Absorption Spectroscopy in Flotation Research". During the determination, the reagent solution is usually brought into contact with the mineral, and the concentration of the equilibrium solution is measured. The adsorption amount is calculated based on the difference with the initial concentration, or the mineral is treated with an appropriate solvent to desorb the adsorbed reagent, and then its concentration is measured to calculate the adsorption amount.

[0004] CN113834890B discloses a method for accurately and quantitatively analyzing the amount of sodium oleate collector adsorbed on the surface of a mineral during flotation. The method comprises the following steps: (1) adding sodium oleate to a mineral pulp, shaking, and after the adsorption reaches equilibrium, centrifuging, and taking the supernatant as a test liquid; (2) adding an excess of concentrated H2SO4 to the test liquid to convert the sodium oleate into oleic acid, and then extracting and separating to obtain an oil phase containing oleic acid; (3) methylating the oleic acid to obtain methyl oleate; (4) detecting and analyzing the methyl oleate organic phase containing methyl heptadecanoate as an internal standard by a gas chromatography-mass spectrometer, and then calculating the amount of sodium oleate adsorbed on the surface of the mineral according to the detection and analysis results.

[0005] As mentioned above, the commonly used methods for measuring adsorption include extraction, high performance liquid chromatography, infrared spectroscopy, ion chromatography, etc. These methods use toxic reagents such as benzene, the peak display is not obvious due to the low concentration of trace collector, and the water environment contains various anions and cations (such as Ca 2+ / Mg 2+ / F- / Cl - / K - / PO4 3- / SO4 2- etc.), other ion interferences make it impossible to define the adsorption amount of benzyl ammonium chloride collector by measuring chlorine content. In addition, benzyl ammonium chloride collector has both hydrophilic and hydrophobic ends, which cannot achieve complete extraction and affect the measurement accuracy, and the extraction process is complicated to operate, and it is necessary to introduce additional solvents, which leads to environmental pollution and increases the measurement cost; the degree of ore adsorption is different at different times during the flotation process, and the concentration of benzyl ammonium chloride collector remaining in the water body spans a large range, which directly affects the measurement accuracy through dilution or concentration. Therefore, it is urgent to develop a method for accurately measuring the adsorption amount of benzyl ammonium chloride collector during flotation. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a method for quantitatively testing the adsorption amount of benzyl ammonium chloride collector on the surface of minerals during flotation. The method adopts an ultraviolet-visible spectrophotometer, uses a pulp clear liquid without adding benzyl ammonium chloride collector as the background solution, and directly detects the residual content of benzyl ammonium chloride collector in the pulp clear liquid. The method of the present invention avoids the dissolution of metal ions and anions such as Ca2+ from minerals. 2+ 、F - The method can reduce the photometric measurement errors caused by the dilution or concentration steps during the detection of benzyl ammonium chloride collector, and has the advantages of simple operation, fast analysis speed and good accuracy, which meets the needs of simultaneously detecting trace and trace amounts of benzyl ammonium chloride collector content using ultraviolet detection methods.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for quantitatively testing the adsorption amount of benzyl ammonium chloride collector on the surface of a mineral during a flotation process, the method comprising the following steps:

[0009] After the mineral is prepared into slurry, it is stirred and the solid and liquid are separated, and the clear liquid is taken as the background solution for UV detection;

[0010] After the ore pulp is mixed with the benzyl ammonium chloride collector, the solid and liquid are separated, and the clear liquid is taken as the sample to be tested;

[0011] Establish a standard curve for micro and trace amounts of benzyl ammonium chloride collector;

[0012] Using an ultraviolet-visible spectrophotometer to perform photometric measurement on the background solution of ultraviolet detection and the sample to be tested, respectively, to obtain the content of the benzyl ammonium chloride collector in the sample to be tested;

[0013] The adsorption amount of the 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.

[0014] The test method of the present invention uses a pulp clear liquid to which a benzyl ammonium chloride collector is not added as a background solution, and uses an ultraviolet-visible spectrophotometer to test the content of the residual benzyl ammonium chloride collector in the pulp clear liquid, thereby eliminating the interference of other ions on the test result, avoiding the measurement error usually caused by using water as the background, and also avoiding the process of separating ions and the collector to be tested during measurement; in addition, two absorption wavelengths are selected as detection wavelengths for trace and trace detection according to the unique ultraviolet spectrum characteristics of the benzyl ammonium chloride collector, and a standard curve of the relationship between the concentration and absorbance of the trace and trace benzyl ammonium chloride collector is established, thereby avoiding the problem that the detection concentration does not match the standard curve when using a single wavelength for detection, and the content of the trace and trace benzyl ammonium chloride collector cannot be measured simultaneously; without diluting or concentrating the test sample, the simultaneous detection of the trace and trace benzyl ammonium chloride collector is achieved, the operation error is effectively reduced, the accuracy of the measurement result is improved, and the operation process is simple without introducing additional reagents.

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

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

[0017] Preferably, the concentration of the slurry is 100-500 g / L, for example 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, and other unlisted values ​​within the above numerical range are also applicable.

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

[0019] Preferably, the stirring time is 10-30 min, for example 10 min, 15 min, 20 min, 25 min, 30 min, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0020] As a preferred technical solution of the present invention, the solid-liquid separation is carried out using an aqueous filter membrane, and the membrane pore size of the aqueous filter membrane is 0.1-1μm, for example, 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, and other unlisted values ​​within the above numerical range are also applicable.

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

[0022] As a preferred technical solution 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 are not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0023] Preferably, the mixing is carried out so that the benzyl ammonium chloride collector is gradually adsorbed onto the mineral surface to reach adsorption equilibrium.

[0024] As a preferred technical solution of the present invention, the step of establishing a standard curve of trace benzyl ammonium chloride collector comprises:

[0025] Prepare a trace and micro amount of benzyl ammonium chloride collector standard solution, use a UV-visible spectrophotometer, use ultrapure water as the background, and perform spectral scanning of the trace and micro amount of benzyl ammonium chloride collector standard solution in the wavelength range of 185 to 800 nm;

[0026] Select a suitable absorption wavelength as the ultraviolet detection wavelength of trace and micro-benzyl ammonium chloride collector, fix different detection wavelengths to perform photometric determination of trace and micro-amount solutions respectively, establish the relationship between the concentration and absorbance of trace and micro-benzyl ammonium chloride solutions, and draw a standard curve.

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

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

[0030] Further 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 185-200 nm, such as 185 nm, 190 nm, 195 nm, 200 nm, etc., but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0032] Further 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 calculation formula for calculating the amount of adsorption on the mineral surface is:

[0034]

[0035] Where Γ is the adsorption capacity, Kg / m 2 ;c m0 With c m1 are the initial concentration and residual concentration of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the ore sample, g; S is the specific surface area of ​​the pure mineral, m 2 / Kg.

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

[0037] After the mineral is prepared into slurry, it is stirred to allow the free ions on the surface of the mineral to fully dissolve into the water body. After reaching the dissolution equilibrium, a water filter with a pore size of 0.1-1μm is used for solid-liquid separation, and the clear liquid is taken as the background solution for UV detection;

[0038] The ore pulp is mixed with the benzyl ammonium chloride collector, and the benzyl ammonium chloride collector is gradually adsorbed onto the mineral surface. After reaching adsorption equilibrium, a water filter with a membrane pore size of 0.1-1 μm is used for solid-liquid separation, and the clear liquid is taken as the test solution; the concentration of the benzyl ammonium chloride collector after mixing with the ore pulp is 10 -6 -10 -3 g / mL;

[0039] Establishing a standard curve of trace benzyl ammonium chloride collector: preparing a trace benzyl ammonium chloride collector standard solution, using a UV-visible spectrophotometer, using ultrapure water as the background, and performing a spectral scan of the trace benzyl ammonium chloride collector standard solution in the wavelength range of 185 to 800 nm;

[0040] Select appropriate absorption wavelength as the ultraviolet detection wavelength of trace benzyl ammonium chloride collector, fix different detection wavelengths to respectively carry out the photometric determination of trace and micro solutions, establish the relationship between the concentration and absorbance of trace and micro benzyl ammonium chloride solution, and draw a standard curve;

[0041] Wherein, the concentration of the trace benzyl ammonium chloride collector standard solution is 5-100ppm; the concentration of the trace benzyl ammonium chloride collector standard solution is 0.1-5ppm; the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 200-220nm; the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 185-200nm;

[0042] Using an ultraviolet-visible spectrophotometer to perform photometric measurement on the background solution of ultraviolet detection and the sample to be tested, respectively, to obtain the content of the benzyl ammonium chloride collector in the sample to be tested;

[0043] The adsorption amount of the 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, and the calculation formula is:

[0044]

[0045] Where Γ is the adsorption capacity, Kg / m 2 ;c m0 With c m1 are the initial concentration and residual concentration of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the ore sample, g; S is the specific surface area of ​​the pure mineral, m 2 / Kg.

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

[0047] (1) The present invention provides a quantitative test method for the adsorption of benzyl ammonium chloride collector on the surface of minerals during flotation, using the clear liquid of the slurry without the addition of collector as the background solution, excluding the metal ions and anions such as Ca2+ dissolved in the minerals. 2 + 、F - It avoids the interference of the test results with water as the background, and also avoids the process of separating ions and the collector to be measured during the measurement.

[0048] (2) The present invention selects two absorption wavelengths as the detection wavelengths for trace and micro-amount detection according to the unique ultraviolet spectrum characteristics of the benzyl ammonium chloride collector, thereby avoiding the problem that when a single wavelength is used for detection, the detection concentration does not match the standard curve and the trace and micro-amount contents of the benzyl ammonium chloride collector cannot be measured simultaneously; at the same time, without the need to dilute or concentrate the test sample, the simultaneous detection of trace and micro-amounts of the benzyl ammonium chloride collector is achieved, the detection range is broadened, the operation error is effectively reduced, and the accuracy of the measurement result is improved; and there is no need to introduce additional reagents such as extractants, thereby avoiding the calculation error of the adsorption amount caused by incomplete extraction, and the method has the advantages of simple operation, fast analysis speed, good accuracy, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is the UV spectrum of trace and trace amounts of tetradecyldimethylbenzylammonium chloride.

[0050] Figure 2 It is a standard curve for micro and trace amounts of tetradecyldimethylbenzylammonium chloride.

[0051] Figure 3 This is the test result of the adsorption amount of tetradecyl dimethyl benzyl ammonium chloride collector on potassium feldspar.

[0052] Figure 4 This is the test result of the adsorption amount of tetradecyl dimethyl benzyl ammonium chloride collector on apatite.

[0053] Figure 5 These are UV spectra with the slurry without collector added as the background and pure water as the background. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only 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 shall be subject to the claims.

[0055] Instruments and working conditions

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

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

[0058] Example 1

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

[0060] (1) Sample preparation

[0061] Use an electronic balance to weigh 50.00g of potassium feldspar in a 1L beaker, add 500mL of deionized water, adjust the pH to 9, stir at 250r / min for 30min to allow the potassium feldspar to reach dissolution equilibrium, let it stand for 6min, take 20mL of the supernatant, filter it twice with a 0.2μm pore size water filter membrane to completely remove the potassium feldspar minerals to avoid the influence of solid residues on the subsequent absorbance detection, and use the filtered clear solution as the background solution for UV detection;

[0062] Add a certain concentration of tetradecyl dimethyl benzyl ammonium chloride collector solution, stir it electrically at a speed of 250r / min for 10 minutes to allow the tetradecyl dimethyl benzyl ammonium chloride collector to fully contact with the potassium feldspar mineral and reach adsorption equilibrium. After standing for 6 minutes, take 10mL of the supernatant, filter it twice with a water filter membrane, and use the filtered clear liquid as the sample to be tested.

[0063] (2) Establishing a standard curve for trace benzyl ammonium chloride collector

[0064] Prepare trace tetradecyl dimethyl benzyl ammonium chloride collector standard solutions with known concentrations of 5ppm, 10ppm, 20ppm, 40ppm, 60ppm, 80ppm and 100ppm and trace tetradecyl dimethyl benzyl ammonium chloride collector standard solutions with known concentrations of 0.1ppm, 0.2ppm, 0.4ppm, 0.6ppm, 0.8ppm and 1ppm. Use a UV-visible spectrophotometer and ultrapure water as the background to perform spectral scanning of the standard solutions in the wavelength range of 185-800nm. The UV spectrum is as follows: Figure 1 Considering the factors such as baseline, peak stability, sensitivity, and detection limit, 208.5 nm was selected as the UV detection wavelength of trace tetradecyl dimethyl benzyl ammonium chloride collector, and 190.5 nm was selected as the UV detection wavelength of trace tetradecyl dimethyl benzyl ammonium chloride collector.

[0065] The standard curves of trace and micro amounts of benzyl ammonium chloride collector were established at 208.5 nm and 190.5 nm, respectively. Figure 2 shown.

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

[0067] The background solution and the sample to be tested are photometrically measured by UV-visible spectrophotometer, and the concentration of the residual collector in the sample to be tested is calculated according to the standard curve;

[0068] The adsorption amount of tetradecyl dimethyl benzyl ammonium chloride collector on the surface of potassium feldspar mineral is calculated by the difference between the initial concentration of tetradecyl dimethyl benzyl ammonium chloride collector and the residual collector concentration in the sample to be tested. The calculation formula is:

[0069]

[0070] Where Γ is the adsorption capacity, Kg / m 2 ;c m0 With c m1 are the initial concentration and residual concentration of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the ore sample, g; S is the specific surface area of ​​the pure mineral, m 2 / Kg. The measured specific surface area of ​​potassium feldspar is 121.1m 2 / kg. The adsorption test results of tetradecyl dimethyl benzyl ammonium chloride collector on potassium feldspar are as follows Figure 3 shown.

[0071] from Figure 1 It can be seen that the ultraviolet spectrum of tetradecyl dimethyl benzyl ammonium chloride collector will form two characteristic peaks, corresponding to wavelengths of 190.5nm and 208.5nm, with high sensitivity and not affected by other interferences. However, within the concentration test range of this experiment, it is impossible to use a concentration-absorbance standard curve established with a fixed wavelength to predict the concentration of the supernatant. This is because at high concentrations, the aggregation of surfactant molecules will form a supramolecular structure or the influence of hydrogen bonds will cause 190.5nm to shift; at low concentrations, the noise effect is large, and the peak corresponding to 208.5nm disappears, so that the concentration-absorbance linear relationship curve cannot be established within the test concentration range. Therefore, 190.5nm is selected as the ultraviolet detection wavelength of trace tetradecyl dimethyl benzyl ammonium chloride collector, and 208.5nm is selected as the ultraviolet detection wavelength of trace tetradecyl dimethyl benzyl ammonium chloride collector.

[0072] like Figure 2 As shown, when the concentration is 0.5-5ppm, the standard curve of tetradecyl dimethyl benzyl ammonium chloride collector is y=131050.43x, and the determination coefficient R 2is 0.99936; when the concentration is 5-100ppm, the standard curve of tetradecyl dimethyl benzyl ammonium chloride collector is y=20075.78x, and the determination coefficient R 2 The R of the two standard curves is 0.99994. 2 All reached 0.999 and above, indicating that the concentration of tetradecyldimethylbenzylammonium chloride collector and the absorbance showed a good linear relationship and could be used as a standard curve for UV detection.

[0073] from Figure 3 It can be seen that with the increase of the concentration of tetradecyl dimethyl benzyl ammonium chloride collector, the adsorption amount on the surface of potassium feldspar mineral increases first and then remains unchanged, reaching adsorption equilibrium, that is, adsorption saturation, which is consistent with the conventional knowledge in this field and conforms to the adsorption law; in addition, Figure 3 The change of the middle curve is very regular, which can indicate that the present invention can indeed detect the concentration of trace and trace tetradecyl dimethyl benzyl ammonium chloride collectors, thereby achieving highly sensitive detection of the adsorption amount of tetradecyl dimethyl benzyl ammonium chloride collectors 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 amount of benzyl ammonium chloride collector on the mineral surface during flotation. The method comprises the following steps:

[0076] (1) Sample preparation

[0077] Use an electronic balance to weigh 50.00g of apatite in a 1L beaker, add 500mL of deionized water, adjust the pH to 9, stir at 300r / min for 25min to allow the apatite to reach dissolution equilibrium, let stand for 6min, take 20mL of the supernatant, filter twice with a 0.2μm pore size water filter membrane to completely remove the apatite minerals to avoid the influence of solid residues on the subsequent absorbance detection, and use the filtered clear solution as the background solution for UV detection;

[0078] A certain concentration of tetradecyl dimethyl benzyl ammonium chloride collector solution was added, and the mixture was stirred electrically at a speed of 300 r / min for 12 min to allow the tetradecyl dimethyl benzyl ammonium chloride collector to fully contact with the apatite mineral and reach adsorption equilibrium. After standing for 6 min, 10 mL of the supernatant was taken and filtered twice with a water-based filter membrane. The filtered clear liquid was used as the sample to be tested.

[0079] (2) Establishing a standard curve for trace benzyl ammonium chloride collector

[0080] Prepare trace tetradecyldimethylbenzyl ammonium chloride collector standard solutions with known concentrations of 20ppm, 40ppm, 60ppm, 80ppm and 100ppm and trace tetradecyldimethylbenzyl ammonium chloride collector standard solutions with concentrations of 0.2ppm, 0.4ppm, 0.6ppm, 0.8ppm and 1ppm. Use a UV-visible spectrophotometer and ultrapure water as the background to perform spectral scanning of the standard solutions in the wavelength range of 185-800nm. Considering factors such as baseline, peak stability, sensitivity, and detection limit, 208.5nm is selected as the ultraviolet detection wavelength of the trace tetradecyldimethylbenzyl ammonium chloride collector, and 190.5nm is selected as the ultraviolet detection wavelength of the trace tetradecyldimethylbenzyl ammonium chloride collector.

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

[0082] (3) Detection of collector adsorption on mineral surface

[0083] The background solution and the sample to be tested are photometrically measured by UV-visible spectrophotometer, and the concentration of the residual collector in the sample to be tested is calculated according to the standard curve;

[0084] The adsorption amount of tetradecyl dimethyl benzyl ammonium chloride collector on the surface of apatite mineral is calculated by the difference between the initial concentration of tetradecyl dimethyl benzyl ammonium chloride collector and the residual collector concentration in the sample to be tested. The calculation formula is:

[0085]

[0086] Where Γ is the adsorption capacity, Kg / m 2 ;c m0 With c m1 are the initial concentration and residual concentration of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the ore sample, g; S is the specific surface area of ​​the pure mineral, m 2 / Kg. The measured specific surface area of ​​apatite is 228.7m 2 / kg. The adsorption test results of tetradecyl dimethyl benzyl ammonium chloride collector on apatite are as follows Figure 4 shown.

[0087] from Figure 4 It can be seen that with the increase of the concentration of tetradecyl dimethyl benzyl ammonium chloride collector, the adsorption amount on the surface of apatite mineral increases first and then remains unchanged, reaching adsorption equilibrium, that is, adsorption saturation, which is consistent with the conventional knowledge in this field and conforms to the adsorption law; in addition, Figure 3The change of the middle curve is very regular, which can indicate that the present invention can indeed detect the concentration of trace and trace tetradecyl dimethyl benzyl ammonium chloride collectors, thereby achieving highly sensitive detection of the adsorption amount of tetradecyl dimethyl benzyl ammonium chloride collectors on the surface of apatite minerals.

[0088] Comparative Example 1

[0089] This comparative example provides a quantitative test method for the adsorption of benzyl ammonium chloride collector on the surface of minerals during flotation, which is based on the method described in Example 2, except that: the slurry clear liquid without benzyl ammonium chloride collector is not set as the background solution for ultraviolet detection, and the concentration of residual benzyl ammonium chloride collector in the sample to be tested is directly tested. Figure 5 These are UV spectra with the slurry without collector added as the background and pure water as the background.

[0090] from Figure 5 It can be seen that after apatite adsorbed tetradecyl dimethyl benzyl ammonium chloride, the absorbance was measured with the slurry clear liquid without adding collector as the background and pure water as the background. It can be seen that the baseline of the spectrum obtained with pure water as the background deviates from 0. This is because the ions in the slurry contribute to the absorbance, which is inconsistent with the actual situation, resulting in a large error in the actual measurement results of the tetradecyl dimethyl benzyl ammonium chloride collector.

[0091] In summary, the present invention provides a quantitative test method for the adsorption amount of benzyl ammonium chloride collector on the surface of a mineral during a flotation process, wherein an ultraviolet-visible spectrophotometer is used to perform photometric measurement of the residual collector in the slurry clear liquid, and the slurry clear liquid without the collector added is used as the background solution, thereby eliminating the interference of other ions on the test result, avoiding the measurement error usually caused by using water as the background, and also avoiding the process of separating ions and the collector to be measured during the measurement; standard curves of trace and trace benzyl ammonium chloride collectors are respectively established, and the simultaneous detection of trace and trace collectors is achieved without diluting or concentrating the test sample, thereby effectively reducing the operation error, improving the accuracy of the measurement result, and having the advantages of simple operation, fast analysis speed, good accuracy, etc.

[0092] The applicant declares that the above is only a specific implementation mode 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 thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A quantitative test method for the adsorption of benzyl ammonium chloride collector on the surface of minerals during flotation, characterized in that: The method comprises the following steps: After the mineral is prepared into slurry, it is stirred and the solid and liquid are separated, and the clear liquid is taken as the background solution for UV detection; After the ore pulp is mixed with the benzyl ammonium chloride collector, the solid and liquid are separated, and the clear liquid is taken as the sample to be tested; Establish a standard curve for micro and trace amounts of benzyl ammonium chloride collector; Using an ultraviolet-visible spectrophotometer to perform photometric measurement on the background solution of the ultraviolet detection and the sample to be tested, respectively, and determining the content of the benzyl ammonium chloride collector in the sample to be tested according to the standard curve of the trace and trace benzyl ammonium chloride collector established; The adsorption amount of the 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.

2. The method according to claim 1, characterized in that: The stirring is performed so that the free ions on the surface of the mineral are fully dissolved into the water body and a dissolution equilibrium is reached.

3. The method according to claim 1 or 2, characterized in that: The solid-liquid separation is performed using a water filter membrane, and the membrane pore size of the water filter membrane is 0.1-1 μm.

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

5. The method according to any one of claims 1 to 4, characterized in that: The mixing is carried out so that the benzyl ammonium chloride collector is gradually adsorbed onto the mineral surface and reaches adsorption equilibrium.

6. The method according to any one of claims 1 to 5, characterized in that: The steps of establishing a standard curve of trace benzyl ammonium chloride collectors include: Prepare a trace and micro amount of benzyl ammonium chloride collector standard solution, use a UV-visible spectrophotometer, use ultrapure water as the background, and perform spectral scanning of the trace and micro amount of benzyl ammonium chloride collector standard solution in the wavelength range of 185 to 800 nm; Select a suitable absorption wavelength as the ultraviolet detection wavelength of trace and micro-benzyl ammonium chloride collector, fix different detection wavelengths to perform photometric determination of trace and micro-amount solutions respectively, establish the relationship between the concentration and absorbance of trace and micro-benzyl ammonium chloride solutions, and draw a standard curve.

7. The method according to any one of claims 1 to 6, characterized in that: The concentration of the trace benzyl ammonium chloride collector standard solution is 5-100 ppm; the concentration of the trace benzyl ammonium chloride collector standard solution is 0.1-5 ppm.

8. The method according to any one of claims 1 to 7, characterized in that: 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.

9. The method according to any one of claims 1 to 8, characterized in that: The calculation formula for calculating the amount of adsorption on the mineral surface is: Where Γ is the adsorption capacity, Kg / m 2 ;c m0 With c m1 are the initial concentration and residual concentration of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the ore sample, g; S is the specific surface area of ​​the pure mineral, m 2 / Kg.

10. The method according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: After the mineral is prepared into slurry, it is stirred to allow the free ions on the surface of the mineral to fully dissolve into the water body. After reaching the dissolution equilibrium, a water filter with a pore size of 0.1-1μm is used for solid-liquid separation, and the clear liquid is taken as the background solution for UV detection; The ore pulp is mixed with the benzyl ammonium chloride collector, and the benzyl ammonium chloride collector is gradually adsorbed onto the mineral surface. After reaching adsorption equilibrium, a water filter with a membrane pore size of 0.1-1 μm is used for solid-liquid separation, and the clear liquid is taken as the test solution; the concentration of the benzyl ammonium chloride collector after mixing with the ore pulp is 10 -6 -10 -3 g / mL; Establishing a standard curve of trace benzyl ammonium chloride collector: preparing a trace benzyl ammonium chloride collector standard solution, using a UV-visible spectrophotometer, using ultrapure water as the background, and performing a spectral scan of the trace benzyl ammonium chloride collector standard solution in the wavelength range of 185 to 800 nm; Select appropriate absorption wavelength as the ultraviolet detection wavelength of trace benzyl ammonium chloride collector, fix different detection wavelengths to respectively carry out the photometric determination of trace and micro solutions, establish the relationship between the concentration and absorbance of trace and micro benzyl ammonium chloride solution, and draw a standard curve; Wherein, the concentration of the trace benzyl ammonium chloride collector standard solution is 5-100ppm; the concentration of the trace benzyl ammonium chloride collector standard solution is 0.1-5ppm; the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 200-220nm; the ultraviolet detection wavelength of the trace benzyl ammonium chloride collector is 185-200nm; Using an ultraviolet-visible spectrophotometer to perform photometric measurement on the background solution of the ultraviolet detection and the sample to be tested, respectively, and determining the content of the benzyl ammonium chloride collector in the sample to be tested according to the standard curve of the trace and trace benzyl ammonium chloride collector established; The adsorption amount of the 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, and the calculation formula is: Where Γ is the adsorption capacity, Kg / m 2 ;c m0 With c m1 are the initial concentration and residual concentration of benzyl ammonium chloride collector, g / mL; V is the volume of the solution, mL; m is the mass of the ore sample, g; S is the specific surface area of ​​the pure mineral, m 2 / Kg.

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