Method for rapidly determining content of silicon and zinc elements in molybdenum concentrate

Abstract

The invention discloses a method for rapidly determining the content of silicon and zinc elements in molybdenum concentrate, which comprises the following steps: weighing molybdenum concentrate and sodium hydroxide, and heating and melting in a crucible to obtain a molybdenum concentrate melt; leaching the molybdenum concentrate melt with hot water to obtain a mixed solution A; dropwise adding hydrochloric acid into the mixed solution A to obtain a mixed solution B; transferring the mixed solution B into a volumetric flask, carrying out constant volume, and then carrying out dry filtration to obtain a mixed solution C; preparing a blank control solution and a standard measurement solution; setting an inductively coupled plasma spectrometer, drawing a calibration curve of the standard solution and a working curve of the blank control solution and the mixed solution C, respectively obtaining the concentrations of silicon and zinc in the blank control solution and the mixed solution C, and calculating the contents of silicon and zinc elements. The method has the advantages of simplicity and convenience in operation, high efficiency, good effect and small pollution, can be used for production process control and finished product detection, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing methods, and relates to a method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate. Background Art

[0002] Molybdenum concentrate mainly refers to molybdenite (MoS2), which is often produced in the contact zone of granite and limestone to form ore deposits. Approximately 99% of molybdenum ores are mined in the form of molybdenite. Molybdenite is the most important mineral raw material for extracting molybdenum. Mineral raw materials are used to produce ferro-molybdenum alloy, metallic molybdenum, calcium molybdate, ammonium molybdate, lubricants, etc. In molybdenum concentrate products and the production process, it is necessary to determine the contents of silicon and zinc elements before judging their grade levels, and rapid test results are required.

[0003] At present, the sample treatment process of the detection method for the contents of silicon and zinc elements in molybdenum concentrate adopts the sodium peroxide melting method, which requires reduction and complexation reactions, and finally uses spectrophotometry to measure absorbance. In this series of detection methods, nitric acid, hydrochloric acid, hydrofluoric acid, and perchloric acid are added during the sample treatment process. In addition, the residue needs to be calcined. Hydrofluoric acid has high requirements for detection equipment, experimental utensils, and reagents, and is very harmful to human health. A large amount of smoke is generated when hydrofluoric acid and perchloric acid dissolve the sample, causing environmental protection pressure. The overall acid consumption for dissolving the sample in this standard is large, the digestion time is long, the efficiency is low, and it cannot guide production in a timely manner. The methods reported in the literature use reagents that are not easy to store and stably store. It takes at least 2 - 3 hours to complete the reduction, complexation, color development process, and extraction operation, which is not suitable for the detection of industrial production samples and cannot meet the requirements for rapid detection of a large number of samples. The methods reported in the literature have the defects of cumbersome determination steps, difficult accurate control during the determination process, many determination interference factors, long determination time, and high determination cost, and cannot achieve the goals of rapid and low-cost detection.

[0004] Inductively coupled plasma atomic emission spectrometry (ICP - AES) is an efficient and accurate multi-element analysis method with the characteristics of being simple and easy to operate. Using inductively coupled plasma atomic emission spectrometry to determine the contents of silicon and zinc can meet the requirements for rapid and accurate detection of molybdenum concentrate, achieving the characteristics of simple operation, low detection limit, accurate results, and high precision. Applying inductively coupled plasma spectrometry can achieve rapid determination of the contents of silicon and aluminum elements in molybdenum concentrate, and has the advantages of accuracy, low cost, and environmental protection. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate, which solves the problems of long determination time and inaccurate determination caused by many determination interference factors in the prior art.

[0006] The technical solution adopted by the present invention is a method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate, which is determined by inductively coupled plasma spectrometry. The specific steps are as follows: Step 1, weigh molybdenum concentrate and sodium hydroxide and place them in a crucible for heating and melting to obtain a molten molybdenum concentrate. Step 2, leach the molten molybdenum concentrate with hot water to obtain a mixed solution A. Step 3, add hydrochloric acid dropwise to the mixed solution A to obtain a mixed solution B. Step 4, transfer the mixed solution B to a volumetric flask and make up the volume, then perform dry filtration to obtain a mixed solution C. Step 5, prepare a blank control solution and a standard measurement solution. Step 6, set the inductively coupled plasma spectrometer, draw the calibration curve of the standard solution and the working curve of the blank control solution and the mixed solution C, respectively obtain the concentrations of silicon and zinc in the blank control solution and the mixed solution C, and calculate the contents of silicon and zinc elements.

[0007] The characteristics of the present invention also lie in: Step 1 specifically includes the following steps: Step 101, weigh sodium hydroxide with a mass of 0.2 g to 0.4 g, denoted as pre-loaded sodium hydroxide A, and spread it flat in a silver crucible. Step 102, weigh molybdenum concentrate with a mass of 0.1 g to 0.2 g and spread it flat on the pre-loaded sodium hydroxide A. Step 103, weigh sodium hydroxide with a mass of 0.5 g to 1.0 g, denoted as covering sodium hydroxide A, and spread it flat on the molybdenum concentrate in the silver crucible to form a structure of "pre-loaded sodium hydroxide A - molybdenum concentrate - covering sodium hydroxide A". Step 104, place the silver crucible containing "pre-loaded sodium hydroxide A - molybdenum concentrate - covering sodium hydroxide A" in a muffle furnace for heating and melting to obtain a molten molybdenum concentrate, where the temperature of the muffle furnace is 500 °C to 600 °C; the heating and melting time is 10 min to 20 min.

[0008] Step 2 is specifically to take out the heated and melted silver crucible, cool it to room temperature, and leach the molten molybdenum concentrate with hot water in small amounts several times to obtain a leaching solution, denoted as mixed solution A.

[0009] Step 3 is specifically to add hydrochloric acid with a volume of 10 mL to 20 mL and a concentration of 1.18 g / mL dropwise to the mixed solution A to obtain a mixed solution B.

[0010] Step 4 is specifically to transfer the mixed solution B to a 100 mL volumetric flask, add water to the volumetric flask until the liquid level in the volumetric flask reaches the calibration line, shake the volumetric flask and then perform dry filtration to obtain a mixed solution C.

[0011] The preparation of the blank control solution specifically includes the following steps: Step 501: Weigh 0.2 g to 0.4 g of sodium hydroxide, denoted as pre-loaded sodium hydroxide B, and spread it flat in a silver crucible. Step 502: Weigh 0.5 g to 1.0 g of sodium hydroxide, denoted as covering sodium hydroxide B, and spread it flat on the pre-loaded sodium hydroxide B to form a structure of "pre-loaded sodium hydroxide B - covering sodium hydroxide B". Step 503: Place the silver crucible containing "pre-loaded sodium hydroxide B - covering sodium hydroxide B" in a muffle furnace for heating and melting to obtain a blank test melt, where the temperature of the muffle furnace is 500 °C to 600 °C; the heating and melting time is 10 min to 20 min. Step 504: After taking out the heated and melted silver crucible and cooling it to room temperature, extract and wash the blank test melt with hot water in small amounts multiple times to obtain a leaching solution. Add 10 mL to 20 mL of hydrochloric acid with a concentration of 1.18 g / mL to the leaching solution, then transfer it to a 100 mL volumetric flask and make up the volume. Shake the volumetric flask and then perform dry filtration to obtain the blank control solution.

[0012] Step 6 specifically includes the following steps: Step 601: Set the measurement spectral lines of the inductively coupled plasma spectrometer. The analysis line wavelength for standard silicon element is 252.851 nm, and the analysis line wavelength for standard zinc element is 202.548 nm. Set the power parameter range of the inductively coupled plasma spectrometer to 1000 W to 1100 W. Step 602: Measure the emission intensity of the standard measurement solution when the wavelengths of the inductively coupled plasma emission spectrometer are 252.851 nm and 202.548 nm respectively. Draw a calibration curve with the mass concentration of silicon and zinc as the abscissa and the emission intensity as the ordinate. Step 603: Measure the emission intensity of the blank control solution and the mixed solution C respectively when the wavelengths of the inductively coupled plasma emission spectrometer are 252.851 nm and 202.548 nm, and calculate the concentrations of silicon and zinc corrected by the blank control solution from the corresponding working curves. Step 604: Calculate the contents of silicon and zinc elements.

[0013] The calculation method for the contents of silicon and zinc elements is as follows: (1) In the formula, is the mass fraction of silicon and zinc, expressed in %; - the concentration of silicon and zinc elements in the mixed solution C on the working curve, with the unit of μg / mL; - Concentration of silicon and zinc elements in the blank control solution on the working curve, in μg / mL; V - Total volume of the mixed solution C, in mL; m - Mass of molybdenum concentrate, in g.

[0014] The beneficial effects of the present invention are as follows: In the method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate of the present invention, the method for sample dissolution treatment uses the sodium hydroxide melting method, avoiding the use of highly dangerous chemical reagent hydrofluoric acid; the method for rapidly determining the contents of silicon and zinc in molybdenum concentrate by inductively coupled plasma spectrometry of the present invention can rapidly and accurately determine the contents of silicon and zinc, and the determination range can reach Si 0.050% - 5.00%, Zn 0.0050% - 1.00%. The precision of the determination result of the method of the present invention can reach an RSD of less than 5%, and both the accuracy and precision are relatively high. The method for rapidly determining the contents of silicon and zinc in molybdenum concentrate of the present invention has the advantages of simple operation, high efficiency, good effect and small pollution, can be used for production process control and finished product detection, has a wide application prospect, and can meet the requirements of scientific research and production for the rapid detection of the contents of silicon and zinc in molybdenum concentrate products. Specific embodiments

[0015] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0016] Reagents: Molybdenum concentrate GBW07144; 100 mg / L silicon element standard solution (National Nonferrous Metals and Electronic Materials Analysis and Testing Center, national standard sample); 100 mg / L zinc element standard solution (National Nonferrous Metals and Electronic Materials Analysis and Testing Center, national standard sample); hydrochloric acid (GR); sodium hydroxide (GR); water is deionized water or distilled water; pre-installed sodium hydroxide includes pre-installed sodium hydroxide A and pre-installed sodium hydroxide B; covering sodium hydroxide includes covering sodium hydroxide A and covering sodium hydroxide B.

[0017] The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate is determined by inductively coupled plasma spectrometry, and specifically includes the following steps: Step 1, weigh molybdenum concentrate and sodium hydroxide and place them in a crucible for heating and melting to obtain a molybdenum concentrate melt; Step 101, weigh 0.2 g - 0.4 g of sodium hydroxide, denoted as pre-installed sodium hydroxide A, and spread it evenly in a silver crucible; Step 102, weigh 0.1 g - 0.2 g of molybdenum concentrate and spread it evenly on the pre-installed sodium hydroxide A; Step 103, weigh 0.5 g - 1.0 g of sodium hydroxide, denoted as covering sodium hydroxide A, and spread it evenly on the molybdenum concentrate in the silver crucible to form a structure of "pre-installed sodium hydroxide A - molybdenum concentrate - covering sodium hydroxide A"; Step 104: Place the silver crucible containing "preloaded sodium hydroxide A - molybdenite concentrate - covering sodium hydroxide A" in a muffle furnace for heating and melting to obtain a molten molybdenite concentrate, where the temperature of the muffle furnace is 500°C to 600°C; the heating and melting time is 10 min to 20 min. Step 2: Leach the molten molybdenite concentrate with hot water to obtain mixed solution A; after taking out the silver crucible after heating and melting and cooling it to room temperature, leach and wash the molten molybdenite concentrate with hot water in small amounts multiple times to obtain a leaching solution, denoted as mixed solution A. Step 3: Add hydrochloric acid dropwise to mixed solution A to obtain mixed solution B; add 10 mL to 20 mL of hydrochloric acid with a concentration of 1.18 g / mL dropwise to mixed solution A to obtain mixed solution B. Step 4: Transfer mixed solution B to a volumetric flask and make up the volume, then perform dry filtration to obtain mixed solution C; transfer mixed solution B to a 100 mL volumetric flask, add water to the volumetric flask until the liquid level in the volumetric flask reaches the calibration line, shake the volumetric flask and then perform dry filtration to obtain mixed solution C. The present invention adopts a dry filtration technique, directly measures the stock solution without dilution, and obtains highly accurate results. The contribution value of the measured value of the filter residue generated by the dry filtration technique to the relative error of the direct measurement result is less than 0.5%. The main component of molybdenite concentrate is MoS2. Taking a sample weight of 0.1 g and a fixed volume of 100 g as an example, the dry filtration operation has no significant impact on the accuracy of the detection result, as shown in the following table: Measured results of the filter residue after dry filtration

[0018] Step 5: Prepare a blank control solution and a standard measurement solution. The preparation of the blank control solution specifically includes the following steps: Step 501: Weigh 0.2 g to 0.4 g of sodium hydroxide, denoted as preloaded sodium hydroxide B, and spread it flat in the silver crucible. Step 502: Weigh 0.5 g to 1.0 g of sodium hydroxide, denoted as covering sodium hydroxide B, and spread it flat on the preloaded sodium hydroxide B to form a structure of "preloaded sodium hydroxide B - covering sodium hydroxide B". Step 503: Place the silver crucible containing "preloaded sodium hydroxide B - covering sodium hydroxide B" in a muffle furnace for heating and melting to obtain a blank test melt, where the temperature of the muffle furnace is 500°C to 600°C; the heating and melting time is 10 min to 20 min. Step 504: After taking out the heated and melted silver crucible and cooling it to room temperature, leach and wash the blank test melt with hot water in small amounts multiple times to obtain a leaching solution. Add hydrochloric acid with a volume of 10 mL to 20 mL and a concentration of 1.18 g / mL to the leaching solution, then transfer it to a 100 mL volumetric flask and make up the volume. Shake the volumetric flask and then perform dry filtration to obtain a blank control solution. A method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate. In the process of accurately analyzing and detecting samples, in order to construct a standard curve to achieve accurate determination of the content of the target substance, the preparation of a series of standard measurement solutions with different concentration gradients is as follows: Prepare seven clean and calibrated 100 mL volumetric flasks, and clearly label them as volumetric flask A, volumetric flask B, volumetric flask C, volumetric flask D, volumetric flask E, volumetric flask F, and volumetric flask G respectively. Preparation of standard measurement solution A: Use a pipette to measure 2 mL of nitric acid, slowly add it to volumetric flask A, add water to volumetric flask A until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and gently shake it to form standard measurement solution A.

[0019] Preparation of standard measurement solution B: Measure 0.50 mL of silicon standard solution, carefully transfer it into volumetric flask B, then measure 0.10 mL of zinc standard solution into volumetric flask B. Subsequently, add 2 mL of nitric acid into volumetric flask B, and finally add water to volumetric flask B until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and gently shake it to form standard measurement solution B.

[0020] Preparation of standard measurement solution C: Measure 1.0 mL of silicon standard solution, carefully transfer it into volumetric flask C, then measure 0.50 mL of zinc standard solution into volumetric flask C. Subsequently, add 2 mL of nitric acid into volumetric flask C, and finally add water to volumetric flask C until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and gently shake it to form standard measurement solution C.

[0021] Preparation of standard measurement solution D: Measure 5.0 mL of silicon standard solution, carefully transfer it into volumetric flask D, then measure 1.0 mL of zinc standard solution into volumetric flask D. Subsequently, add 2 mL of nitric acid into volumetric flask D, and finally add water to volumetric flask D until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and gently shake it to form standard measurement solution D.

[0022] Preparation of standard measurement solution E: Measure 10.0 mL of the silicon standard solution, carefully transfer it into volumetric flask E, then measure 2.0 mL of the zinc standard solution into volumetric flask E, subsequently add 2 mL of nitric acid into volumetric flask E, and finally add water into volumetric flask E until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and shake gently to form standard measurement solution E.

[0023] Preparation of standard measurement solution F: Measure 3.0 mL of the silicon standard solution, carefully transfer it into volumetric flask F, then measure 5.0 mL of the zinc standard solution into volumetric flask F, subsequently add 2 mL of nitric acid into volumetric flask F, and finally add water into volumetric flask F until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and shake gently to form standard measurement solution F.

[0024] Preparation of standard measurement solution G: Measure 5.0 mL of the silicon standard solution, carefully transfer it into volumetric flask G, then measure 10.0 mL of the zinc standard solution into volumetric flask G, subsequently add 2 mL of nitric acid into volumetric flask G, and finally add water into volumetric flask G until the lowest point of the concave liquid surface just touches the 100 mL graduation line, and shake gently to form standard measurement solution G; Step 6: Set up the inductively coupled plasma spectrometer, and plot the calibration curve of the standard solution and the working curves of the blank control solution and mixed solution C, respectively obtain the concentrations of silicon and zinc in the blank control solution and mixed solution C, and calculate the contents of silicon and zinc elements; Step 601: Set the determination spectral lines of the inductively coupled plasma spectrometer. The analytical line wavelength used for standard silicon element is 252.851 nm, and the analytical line wavelength used for standard zinc element is 202.548 nm. Set the power parameter range of the inductively coupled plasma spectrometer to be 1000 W - 1100 W; Step 602: Measure the emission intensities of the standard measurement solutions when the wavelengths of the inductively coupled plasma emission spectrometer are 252.851 nm and 202.548 nm respectively, and plot the calibration curve with the mass concentrations of silicon and zinc as the abscissa and the emission intensity as the ordinate; Step 603: Measure the emission intensities of the blank control solution and mixed solution C respectively when the wavelengths of the inductively coupled plasma emission spectrometer are 252.851 nm and 202.548 nm, and calculate the concentrations of silicon and zinc corrected by the blank control solution from the corresponding working curves; Step 604: Calculate the contents of silicon and zinc elements.

[0025] The calculation method for the contents of silicon and zinc elements is as follows: (1) In the formula, are the mass fractions of silicon and zinc, expressed in %; - The concentrations of silicon and zinc elements in the mixed solution C on the working curve, in μg / mL; - The concentrations of silicon and zinc elements in the blank control solution on the working curve, in μg / mL; V - The total volume of the mixed solution C, in mL; m - The mass of the molybdenum concentrate, in g.

[0026] The selection basis for the pre-loaded sodium hydroxide dosage, covering sodium hydroxide dosage, melting temperature, melting time, and hydrochloric acid dosage in the present invention is as follows: Selection of the pre-loaded sodium hydroxide dosage: Under the condition that other test conditions remain unchanged, different dosages of pre-loaded sodium hydroxide were selected to treat molybdenum concentrate samples (Mo content 45%), and the emission intensity was measured. Taking a sample weight of 0.1 g, a muffle furnace temperature of 500 °C, a melting time of 10 min, a hydrochloric acid addition amount of 10 mL, and a constant volume of 100 mL as an example, the data are shown in the following table.

[0027]

[0028] The data show that the dosage of pre-loaded sodium hydroxide has a certain influence on the emission intensity of Si and Zn element determinations. Therefore, the preferred dosage of pre-loaded sodium hydroxide for Si and Zn element determinations in the present invention is 0.2 g to 0.4 g.

[0029] Selection of the covering sodium hydroxide dosage: Under the condition that other test conditions remain unchanged, different dosages of covering sodium hydroxide were selected to treat molybdenum concentrate samples (Mo content 45%), and the emission intensity was measured. Taking a sample weight of 0.1 g, a muffle furnace temperature of 500 °C, a melting time of 10 min, a hydrochloric acid addition amount of 10 mL, and a constant volume of 100 mL as an example, the data are shown in the following table.

[0030]

[0031] The data show that the dosage of covering sodium hydroxide has a certain influence on the emission intensity of Si and Zn element determinations. Therefore, the present invention selects the covering sodium hydroxide dosage of 0.5 g to 1.0 g for Si and Zn element determinations.

[0032] Selection of the melting temperature: The melting temperature affects the dissolution effect of the sample. Under the condition that other test conditions remain unchanged, different melting temperatures were selected to treat molybdenum concentrate samples (Mo content 45%), and the emission intensity was measured. Taking a sample weight of 0.1 g, a pre-loaded sodium hydroxide addition amount of 0.2 g, a covering sodium hydroxide addition amount of 0.5 g, a hydrochloric acid addition amount of 10 mL, and a constant volume of 100 mL as an example, the data are shown in the following table.

[0033]

[0034] Data shows that the melting temperature has a certain impact on the emission intensity of Si and Zn element determination. Therefore, for the determination of Si and Zn elements in the present invention, the melting temperature is selected to be 500°C - 600°C.

[0035] Selection of melting time: The melting time affects the dissolution effect of the sample. Under the condition that other test conditions remain unchanged, different melting times were selected to treat molybdenum concentrate samples (Mo content 45%), and the emission intensity was measured. Taking the sample weighing 0.1 g, the pre-loaded sodium hydroxide addition amount of 0.2 g, the covering sodium hydroxide addition amount of 0.5 g, the hydrochloric acid addition amount of 10 mL, and the constant volume of 100 mL as an example, the data are shown in the following table.

[0036]

[0037] Data shows that the melting time has a certain impact on the emission intensity of Si and Zn element determination. Therefore, for the determination of Si and Zn elements in the present invention, the melting time is selected to be 10 min - 20 min.

[0038] Selection of hydrochloric acid dosage: Hydrochloric acid is used as an acidic medium to neutralize alkalinity and the sample solution. Under the condition that other test conditions remain unchanged, different dosages of hydrochloric acid were selected to treat molybdenum concentrate samples (Mo content 45%), and the emission intensity was measured. Taking the sample weighing 0.1 g, the pre-loaded sodium hydroxide addition amount of 0.2 g, the covering sodium hydroxide addition amount of 0.5 g, the muffle furnace temperature of 500°C, and the melting time of 10 min as an example, the data are shown in the following table.

[0039]

[0040] The data in the table shows that the dosage of hydrochloric acid has little impact on the emission intensity of Si and Zn element determination. For the determination of Si and Zn elements in the present invention, the hydrochloric acid dosage is selected to be 10 mL.

[0041] Example 1 In this example, the emission intensity of standard measurement solutions A - F was measured.

[0042] The spectral lines for determination were selected. The analytical line wavelength for standard silicon element is 252.851 nm, and the analytical line wavelength for standard zinc element is 202.548 nm. Subsequently, the inductively coupled plasma spectrometer was set. The power of the inductively coupled plasma spectrometer is 1000 W. The emission intensity of standard measurement solutions A - F was measured. Taking the mass concentration of silicon and zinc as the abscissa and the emission intensity as the ordinate, the working curves were plotted. The emission intensity, linear equation, and linear correlation coefficient of the plotted working curves are as shown in the following table:

[0043] Example 2 The mixed solutions C-1, C-2, C-3 and the blank control solution 1 required in the method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate in this embodiment.

[0044] Weigh three portions of sodium hydroxide with a mass of 0.20 g and lay them in three silver crucibles respectively. Then weigh 0.1000 g of molybdenum concentrate 1 # 、0.1000 g of molybdenum concentrate 2 # 、0.1000 g of the certified reference material GBW07144 molybdenum concentrate 1, and lay them on the sodium hydroxide in the silver crucibles respectively. Finally, weigh three portions of sodium hydroxide with a mass of 0.20 g and lay them on molybdenum concentrate 1 # 、molybdenum concentrate 2 # and the certified reference material molybdenum concentrate 1 in the silver crucibles respectively. Place the three silver crucibles in a muffle furnace at 500 °C and heat them for melting for 20 min to obtain molybdenum concentrate melt 1, molybdenum concentrate melt 2 and standard molybdenum concentrate melt 1 respectively. Leach molybdenum concentrate melt 1, molybdenum concentrate melt 2 and standard molybdenum concentrate melt 1 successively in small amounts with hot water for multiple times. Place the leaching solution in a quartz beaker, add 10 mL of hydrochloric acid with a concentration of 1.18 g / mL respectively, then transfer them to three 100 mL volumetric flasks and make up the volume. After dry filtration, form molybdenum concentrate-hydrochloric acid mixed solutions C-1, C-2, C-3.

[0045] Weigh sodium hydroxide with a mass of 0.20 g and lay it in a silver crucible. Then weigh sodium hydroxide with a mass of 0.50 g and lay it on the sodium hydroxide in the silver crucible. Place the silver crucible in a muffle furnace at 500 °C and heat it for melting for 20 min to obtain blank test melt 1. Leach blank test melt 1 successively in small amounts with hot water for multiple times. Place the leaching solution in a quartz beaker, add 10 mL of hydrochloric acid with a concentration of 1.18 g / mL respectively, then transfer it to a 100 mL volumetric flask and make up the volume. After dry filtration, form blank control solution 1.

[0046] Example 3 On the basis of Examples 1 and 2, measure the emission intensities of blank control solution 1 and mixed solutions C-1, C-2, calculate the concentrations of silicon and zinc corrected by blank control solution 1 from the corresponding working curves, and calculate the contents of silicon and zinc elements. For each of molybdenum concentrate 1# and molybdenum concentrate 2#, 11 groups of parallel determinations are carried out to reduce experimental errors. The sample test results and precision results of molybdenum concentrate 1# and molybdenum concentrate 2# are as follows in the table:

[0047] The comparison between the test results of the certified reference material 1 of molybdenum ore (GBW07144) and the standard values in the standard sample certificate is as follows in the table:

[0048] The precision of the measurement results of the method of the present invention can reach an RSD of less than 5%, fully meeting the analysis requirements and enabling the requirements for large - batch detection and analysis.

[0049] Example 4 The mixed solutions C - 4, C - 5, C - 6 and the blank control solution 2 required in the method for rapidly determining the contents of silicon and zinc in molybdenum concentrate prepared in this example.

[0050] Weigh three portions of sodium hydroxide with a mass of 0.30 g and lay them in three silver crucibles respectively. Then weigh 0.1500 g of molybdenum concentrate 3 # 、0.1500 g of molybdenum concentrate 4 # 、0.1500 g of the certified reference standard sample of molybdenum concentrate GBW07144, and lay them respectively on the sodium hydroxide in the silver crucibles. Finally, weigh three portions of sodium hydroxide with a mass of 0.70 g and lay them respectively on molybdenum concentrate 3 # 、molybdenum concentrate 4 # and the standard sample of molybdenum concentrate 2. Place the three silver crucibles in a muffle furnace at 550 °C and heat - melt them for 15 min to obtain molybdenum concentrate melt 4, molybdenum concentrate melt 5 and standard molybdenum concentrate melt 2 respectively. Leach molybdenum concentrate melt 1, molybdenum concentrate melt 2 and standard molybdenum concentrate melt 2 successively with hot water in small amounts and multiple times. Place the leaching solution in a quartz beaker, add 15 mL of hydrochloric acid with a concentration of 1.18 g / mL respectively, then transfer them to three 100 - mL volumetric flasks and make up the volume. After dry - filtration, form molybdenum concentrate - hydrochloric acid mixed solutions C - 4, C - 5, C - 6.

[0051] Weigh 0.30 g of sodium hydroxide and lay it in a silver crucible. Then weigh 0.70 g of sodium hydroxide and lay it on the sodium hydroxide in the silver crucible. Place the silver crucible in a muffle furnace at 550 °C and heat - melt it for 15 min to obtain blank test melt 2. Leach blank test melt 2 successively with hot water in small amounts and multiple times. Place the leaching solution in a quartz beaker, add 15 mL of hydrochloric acid with a concentration of 1.18 g / mL respectively, then transfer it to a 100 - mL volumetric flask and make up the volume. After dry - filtration, form blank control solution 2.

[0052] Example 5 On the basis of Examples 1 and 4, measure the emission intensities of blank control solution 2 and mixed solutions C - 4, C - 5. Calculate the concentrations of silicon and zinc corrected by blank control solution 2 from the corresponding working curves, and calculate the contents of silicon and zinc elements. For each of molybdenum concentrate 3# and molybdenum concentrate 4#, 11 groups of parallel determinations are carried out to reduce experimental errors. The sample detection results and precision results of molybdenum concentrate 3# and molybdenum concentrate 4# are as follows in the table:

[0053] The test results of the certified reference material of molybdenum ore 2 (GBW07144) are compared with the certified values in the certificate of the reference material as shown in the following table:

[0054] The precision of the determination results by the method of the present invention can reach an RSD of less than 5%, fully meeting the analysis requirements and enabling the requirements for large - batch detection and analysis.

[0055] Example 6 Prepare the mixed solutions C - 7, C - 8, C - 9 and the blank control solution 3 required in the method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate in this example.

[0056] Weigh three portions of sodium hydroxide with a mass of 0.40 g and lay them in three silver crucibles respectively. Then, weigh 0.2000 g of molybdenum concentrate 5 # 、0.2000 g of molybdenum concentrate 6 # 、0.2000 g of the certified reference material of molybdenum concentrate GBW07144, lay them on the sodium hydroxide in the silver crucibles respectively. Finally, weigh three portions of sodium hydroxide with a mass of 1.00 g and lay them on molybdenum concentrate 5 # 、molybdenum concentrate 6 # and the certified reference material of molybdenum concentrate 3 respectively. Place the three silver crucibles in a muffle furnace at 600 °C and heat - melt them for 10 min to obtain molybdenum concentrate melt 7, molybdenum concentrate melt 8 and standard molybdenum concentrate melt 3 respectively. Leach molybdenum concentrate melt 7, molybdenum concentrate melt 8 and standard molybdenum concentrate melt 3 successively in small amounts with hot water for multiple times. Place the leaching solutions in quartz beakers, add 15 mL of hydrochloric acid with a concentration of 1.18 g / mL respectively, then transfer them to three 100 - mL volumetric flasks and make up to the mark. After dry - filtering, form molybdenum concentrate - hydrochloric acid mixed solutions C - 7, C - 8, C - 9.

[0057] Weigh sodium hydroxide with a mass of 0.40 g and lay it in a silver crucible. Then, weigh sodium hydroxide with a mass of 1.00 g and lay it on the sodium hydroxide in the silver crucible. Place the silver crucible in a muffle furnace at 600 °C and heat - melt it for 10 min to obtain the blank test melt 3. Leach the blank test melt 3 successively in small amounts with hot water for multiple times. Place the leaching solution in a quartz beaker, add 15 mL of hydrochloric acid with a concentration of 1.18 g / mL, then transfer it to a 100 - mL volumetric flask and make up to the mark. After dry - filtering, form the blank control solution 3.

[0058] Example 7 On the basis of Examples 1 and 6, the emission intensities of the blank control solution 3 and the mixed solutions C-7 and C-8 were measured. The concentrations of silicon and zinc corrected by the blank control solution 3 were calculated from the corresponding working curves, and the contents of silicon and zinc elements were calculated. For each of molybdenum concentrate 5# and molybdenum concentrate 6#, 11 groups of parallel determinations were carried out to reduce experimental errors. The sample test results and precision results of molybdenum concentrate 5# and molybdenum concentrate 6# are as follows in the table:

[0059] The comparison between the test results of the certified reference material of molybdenum ore 3 (GBW07144) and the standard values in the standard sample certificate is as follows in the table:

[0060] The precision of the determination results by the method of the present invention can reach an RSD of less than 5%, fully meeting the analysis requirements and enabling the requirements for large-scale detection and analysis.

[0061] The determination range of the method of the present invention can reach Si 0.050% - 5.00% and Zn 0.0050% - 1.00%. The precision of the determination results can reach an RSD of less than 5%, fully meeting the analysis requirements and enabling the requirements for large-scale detection and analysis.

Claims

1. A method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate, characterized in that, Determination is carried out by inductively coupled plasma spectrometry, specifically including the following steps: Step 1, Weigh molybdenite concentrate and sodium hydroxide and place them in a crucible for heating and melting to obtain a molten molybdenite concentrate; Step 2, Leach the molten molybdenite concentrate with hot water to obtain a mixed solution A; Step 3, Add hydrochloric acid dropwise to the mixed solution A to obtain a mixed solution B; Step 4, Transfer the mixed solution B to a volumetric flask and make up the volume, then carry out dry filtration to obtain a mixed solution C; Step 5, Prepare a blank control solution and a standard measurement solution; Step 6, Set up the inductively coupled plasma spectrometer, draw the calibration curve of the standard solution and the working curve of the blank control solution and the mixed solution C, respectively obtain the concentrations of silicon and zinc in the blank control solution and the mixed solution C, and calculate the contents of silicon and zinc elements.

2. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 1, characterized in that, The specific steps of Step 1 include the following steps: Step 101, Weigh sodium hydroxide with a mass of 0.2 g to 0.4 g, denoted as pre-loaded sodium hydroxide A, and spread it flat in a silver crucible; Step 102, Weigh molybdenite concentrate with a mass of 0.1 g to 0.2 g and spread it flat on the pre-loaded sodium hydroxide A; Step 103, Weigh sodium hydroxide with a mass of 0.5 g to 1.0 g, denoted as covering sodium hydroxide A, and spread it flat on the molybdenite concentrate in the silver crucible to form a structure of "pre-loaded sodium hydroxide A - molybdenite concentrate - covering sodium hydroxide A"; Step 104, Place the silver crucible containing "pre-loaded sodium hydroxide A - molybdenite concentrate - covering sodium hydroxide A" in a muffle furnace for heating and melting to obtain a molten molybdenite concentrate, where the temperature of the muffle furnace is 500 °C to 600 °C; the heating and melting time is 10 min to 20 min.

3. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 1, characterized in that, The specific operation of Step 2 is to take out the heated and melted silver crucible, cool it to room temperature, and leach the molten molybdenite concentrate with hot water in small amounts multiple times to obtain a leaching solution, denoted as mixed solution A.

4. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 1, characterized in that, The specific operation of Step 3 is to add hydrochloric acid with a volume of 10 mL to 20 mL and a concentration of 1.18 g / mL dropwise to the mixed solution A to obtain a mixed solution B.

5. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 1, wherein The specific operation of Step 4 is to transfer the mixed solution B to a 100 mL volumetric flask, add water to the volumetric flask until the liquid level in the volumetric flask reaches the calibration line, shake the volumetric flask and then carry out dry filtration to obtain a mixed solution C.

6. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 1, characterized in that, The preparation of the blank control solution specifically includes the following steps: Step 501, Weigh sodium hydroxide with a mass of 0.2 g to 0.4 g, denoted as pre-loaded sodium hydroxide B, and spread it flat in a silver crucible; Step 502, Weigh sodium hydroxide with a mass of 0.5 g to 1.0 g, denoted as covering sodium hydroxide B, and spread it flat on the pre-loaded sodium hydroxide B to form a structure of "pre-loaded sodium hydroxide B - covering sodium hydroxide B"; Step 503, Place the silver crucible containing "pre-loaded sodium hydroxide B - covering sodium hydroxide B" in a muffle furnace for heating and melting to obtain a blank test melt, where the temperature of the muffle furnace is 500 °C to 600 °C; the heating and melting time is 10 min to 20 min; Step 504: After taking out the heated and melted silver crucible and cooling it to room temperature, leach and wash the molten material of the blank test with hot water in small amounts multiple times to obtain a leaching solution. Add hydrochloric acid with a volume of 10 mL to 20 mL and a concentration of 1.18 g / mL to the leaching solution, then transfer it to a 100 mL volumetric flask and make up the volume. Shake the volumetric flask and then perform dry filtration to obtain a blank control solution.

7. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 1, characterized in that, Step 6 specifically includes the following steps: Step 601: Set the measurement spectral lines of the inductively coupled plasma spectrometer. The analysis line wavelength for standard silicon element is 252.851 nm, and the analysis line wavelength for standard zinc element is 202.548 nm. Set the power parameter range of the inductively coupled plasma spectrometer to be 1000 W to 1100 W. Step 602: Measure the emission intensity of the standard measurement solution when the wavelengths of the inductively coupled plasma emission spectrometer are 252.851 nm and 202.548 nm respectively. Draw a calibration curve with the mass concentration of silicon and zinc as the abscissa and the emission intensity as the ordinate. Step 603: Measure the emission intensity of the blank control solution and the mixed solution C when the wavelengths of the inductively coupled plasma emission spectrometer are 252.851 nm and 202.548 nm respectively. Calculate the concentrations of silicon and zinc corrected by the blank control solution from the corresponding working curves. Step 604: Calculate the contents of silicon and zinc elements.

8. The method for rapidly determining the contents of silicon and zinc elements in molybdenum concentrate according to claim 7, wherein, The calculation method for the contents of silicon and zinc elements is as follows: (1) In the formula, is the mass fraction of silicon and zinc, expressed in %; - the concentrations of silicon and zinc elements in the mixed solution C on the working curve, with the unit of μg / mL; - the concentrations of silicon and zinc elements in the blank control solution on the working curve, with the unit of μg / mL; V - the total volume of the mixed solution C, with the unit of mL; m - the mass of molybdenum concentrate, with the unit of g.

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