Method for detecting content of tungsten element in bauxite

Abstract

The invention relates to the technical field of chemical detection, in particular to a method for detecting the content of a tungsten element in bauxite. The method comprises the following steps: (1) sequentially adding hydrochloric acid and nitric acid into a to-be-tested sample, and adding hydrofluoric acid for digestion; (2) adding a tartaric acid solution, heating until the to-be-tested sample is completely dissolved, then adding perchloric acid, heating until smoking to remove hydrofluoric acid, cooling to room temperature, and fixing the volume of the obtained solution to obtain a to-be-tested solution; (3) preparing a standard series solution with gradient concentration, measuring the emitted light intensity of tungsten in the standard series solution at the wavelength of 207.91 nm by using an inductively coupled plasma emission spectrometer, and drawing a working curve; and (4) measuring the intensity of emitted light of the to-be-tested liquid at the wavelength of 207.91 nm by using an inductively coupled plasma emission spectrometer. The detection method disclosed by the invention has the advantages of simplicity and convenience in operation, high sensitivity, good reproducibility and the like, and is suitable for analysis and detection of various types of bauxite samples.

Description

Technical Field

[0001] The present invention relates to the field of chemical detection technology, and in particular to a method for detecting the content of tungsten in bauxite. Background Art

[0002] As an important mineral resource, bauxite demonstrates broad application value and profound research significance in multiple fields. Its unique physical and chemical properties make it irreplaceable in fields such as refractories, ceramics, metallurgy, chemicals, and environmental protection.

[0003] In the field of refractory materials, bauxite, due to its high melting point, excellent refractory properties, and thermal shock resistance, has become an important raw material for the manufacture of various refractory bricks, refractory castables, and refractory fibers. In the field of metallurgy, bauxite is a key raw material for aluminum smelting. Through refining and processing, it can be used to obtain metallic aluminum and other aluminum compounds, which are widely used in industries such as aerospace, automobile manufacturing, and electronic communications. Bauxite is also widely used in the ceramic industry, and can be used to manufacture high-end ceramic products such as high-aluminum porcelain and bone china. Its excellent physical properties and chemical stability make ceramic products more durable and beautiful. Bauxite also has important applications in the chemical industry, and can be used to produce various aluminum salts, aluminum oxide, and other products. These products play an important role in papermaking, water treatment, catalysts, and other fields.

[0004] Tungsten is generally present as an impurity in bauxite. Excessive tungsten content can have negative effects, such as altering the chemical and phase composition of the bauxite, causing changes in its original properties and even reducing its quality and performance in certain applications. Therefore, it is important to develop a method for detecting tungsten content in bauxite. Summary of the Invention

[0005] The present invention aims to provide a method for detecting the tungsten content in bauxite, thereby improving the detection speed, accuracy, and precision of tungsten in bauxite and providing technical support for steel metallurgical production. To achieve the above-mentioned purpose, the technical solution of the present invention is as follows:

[0006] The present invention provides a method for detecting the content of tungsten in bauxite, the method comprising the following steps:

[0007] (1) Hydrochloric acid, nitric acid, and hydrofluoric acid are added to the sample to be tested in sequence for digestion;

[0008] (2) adding tartaric acid solution and heating until the sample to be tested is completely dissolved, then removing hydrofluoric acid by adding perchloric acid and heating until smoking, cooling to room temperature, and fixing the resulting solution to obtain a test solution;

[0009] (3) preparing a series of standard solutions with gradient concentrations, measuring the emission light intensity of tungsten in the standard solutions at a wavelength of 207.91 nm using an inductively coupled plasma emission spectrometer, and plotting a working curve with the emission light intensity as the ordinate and the tungsten concentration as the abscissa;

[0010] (4) The emission light intensity of the test liquid was measured at a wavelength of 207.91 nm using an inductively coupled plasma emission spectrometer. The tungsten content in the test sample was calculated according to formula (1) and expressed as mass fraction:

[0011]

[0012] Where:

[0013] W w —The content of tungsten in the sample to be tested, %;

[0014] C w —The concentration of tungsten in the test solution is obtained from the working curve, μg / mL;

[0015] V—volume of the test solution, mL;

[0016] m—mass of the sample to be tested, g.

[0017] In the above technical solution, further, in step (1), the method for digesting the test sample is: weighing 0.050-2.00 g of the test sample into a polytetrafluoroethylene beaker, adding 3-25 mL of hydrochloric acid and 3-25 mL of nitric acid in sequence and reacting for 5-10 minutes, adding 3-15 mL of hydrofluoric acid dropwise, and heating to 250-350° C. for digestion.

[0018] In the above technical solution, further, in step (2), the amount of tartaric acid solution added is 5-25 mL, the concentration of the tartaric acid solution is 30-70 g / L, and the heating temperature is 250-350°C.

[0019] In the above technical solution, further, in step (2), the method for removing hydrofluoric acid is: after the test sample is completely dissolved, 5 to 15 mL of perchloric acid is added, and heated at 350 to 400° C., and the perchloric acid smokes to drive out the hydrofluoric acid.

[0020] In the above technical solution, further, the bauxite contains tungsten in an amount of 0.001% to 1.00% by mass.

[0021] In the above technical solution, further, the preparation method of the standard series solution is: take 0.00mL, 0.50mL, 1.00mL, 3.00mL, and 5.00mL of a tungsten standard solution with a concentration of 10μg / mL into a 100mL volumetric flask, dilute to volume with water, and prepare the standard series solution.

[0022] In the above technical solution, further, the inductively coupled plasma emission spectrometer is preheated for 0.5 to 1.5 hours before starting.

[0023] The beneficial effects of the present invention are:

[0024] The method of the present invention can accurately determine trace tungsten in bauxite, providing a scientific basis for the development and utilization of bauxite resources. The detection method of the present invention has the advantages of simple operation, high sensitivity, and good reproducibility, and is suitable for the analysis and detection of various types of bauxite samples. DETAILED DESCRIPTION

[0025] The following examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0026] Unless otherwise specified, the materials used in the examples of the present invention can be obtained from commercial sources or prepared according to conventional methods well known to those skilled in the art.

[0027] Example 1

[0028] 1. Reagents: Unless otherwise specified, only purified reagent water was used in the analysis.

[0029] 1.1. Hydrochloric acid, ρ = 1.19 g / mL; purify the hydrochloric acid at 90°C using a CIF-AP1000L sub-boiling acid purifier, and perform a secondary purification on the purified hydrochloric acid at a rate of 5-6 drops / minute;

[0030] 1.2, nitric acid, ρ is 1.42g / mL; use CIF-AP1000L sub-boiling acid purifier to purify nitric acid at 100 ° C, and the purified nitric acid is purified twice, controlling the purification rate to 5-6 drops / minute;

[0031] 1.3, tartaric acid solution, concentration is 50g / L;

[0032] 1.4, hydrofluoric acid, ρ is 0.988 g / mL;

[0033] 1.5, perchloric acid, ρ is 1.67 g / mL;

[0034] 1.6. Water: Use CIF-AP1000L sub-boiling acid purifier to purify the pure water twice at 90℃, and control the purification speed to 5-6 drops / minute;

[0035] 2. Instruments and equipment: Inductively coupled plasma optical emission spectrometer, manufactured by Thermo Fisher Scientific, USA.

[0036] 3. Test steps: The method for detecting the tungsten content in bauxite in this embodiment includes the following steps:

[0037] (1) Weigh 0.5 g (accurate to 0.0001 g) of No. 1 bauxite sample and place it in a 200 mL polytetrafluoroethylene beaker. Add 10 mL of hydrochloric acid and 10 mL of nitric acid in sequence and react for 1.5 h. Then, add 5 mL of hydrofluoric acid dropwise and heat to 300 °C for digestion.

[0038] (2) Add 5 mL of tartaric acid solution and heat at 300°C until the sample to be tested is completely dissolved. Then add 5 mL of perchloric acid and heat at 370°C until the perchloric acid smokes to remove hydrofluoric acid. After cooling to room temperature, transfer the resulting solution into a 100 mL volumetric flask and add water to make up to volume to obtain the test solution.

[0039] (3) Take 0.00mL, 0.50mL, 1.00mL, 3.00mL, and 5.00mL of a 1.00μg / mL tungsten standard solution in a 100mL volumetric flask, add water to the volume to prepare a gradient concentration standard series solution, start the inductively coupled plasma optical emission spectrometer, and preheat it for 1h before measurement. Measure the emission light intensity at a wavelength of 207.91nm, and draw a working curve with the emission light intensity as the ordinate and the tungsten concentration as the abscissa;

[0040] (4) The emission light intensity of the test solution was measured at a wavelength of 207.91 nm using an inductively coupled plasma emission spectrometer. The tungsten content in the test sample was calculated according to formula (1) and expressed as mass fraction:

[0041]

[0042] Where:

[0043] W w —The content of tungsten in the sample to be tested, %;

[0044] C w —The concentration of tungsten in the test solution is obtained from the working curve, μg / mL;

[0045] V—volume of the test solution, mL;

[0046] m—mass of the sample to be tested, g.

[0047] The test results are shown in Table 1.

[0048] Example 2

[0049] The difference between this embodiment and embodiment 1 is that in step (1), 0.5 g of No. 2 bauxite sample is weighed, and the remaining steps are the same as those in embodiment 1. The test results are shown in Table 1.

[0050] Example 3

[0051] The difference between this embodiment and embodiment 1 is that in step (1), 0.1 g of No. 3 bauxite sample is weighed, and the remaining steps are the same as those in embodiment 1. The test results are shown in Table 1.

[0052] Example 4

[0053] The difference between this embodiment and embodiment 1 is that in step (1), 0.1 g of No. 4 bauxite sample is weighed, and the remaining steps are the same as those in embodiment 1. The test results are shown in Table 1.

[0054] Example 5

[0055] The difference between this embodiment and embodiment 1 is that in step (1), 0.1 g of No. 5 bauxite sample is weighed, and the remaining steps are the same as those in embodiment 1. The test results are shown in Table 1.

[0056] Table 1 Mass percentage of tungsten element / %

[0057] Test results Example 1 Example 2 Example 3 Example 4 Example 5 1 0.00121 0.0032 0.92 0.030 0.38 2 0.0012 0.0033 0.91 0.031 0.39 3 0.0013 0.0032 0.91 0.029 0.38

[0058] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Other variations or modifications may be made based on the above description. Obvious variations or modifications derived therefrom shall remain within the scope of protection of the present invention.

Claims

1. A method for detecting the content of tungsten in bauxite, characterized in that: The method comprises the following steps: (1) Hydrochloric acid, nitric acid, and hydrofluoric acid are added to the sample to be tested in sequence for digestion; (2) adding tartaric acid solution and heating until the sample to be tested is completely dissolved, then removing hydrofluoric acid by adding perchloric acid and heating until smoking, cooling to room temperature, and fixing the resulting solution to obtain a test solution; (3) preparing a series of standard solutions with gradient concentrations, measuring the emission light intensity of tungsten in the standard solutions at a wavelength of 207.91 nm using an inductively coupled plasma emission spectrometer, and plotting a working curve with the emission light intensity as the ordinate and the tungsten concentration as the abscissa; (4) The emission light intensity of the test liquid was measured at a wavelength of 207.91 nm using an inductively coupled plasma emission spectrometer. The tungsten content in the test sample was calculated according to formula (1) and expressed as mass fraction: Where: W w —The content of tungsten in the sample to be tested, %; C w —The concentration of tungsten in the test solution is obtained from the working curve, μg / mL; V—volume of the test solution, mL; m—mass of the sample to be tested, g.

2. The method for detecting the tungsten content in bauxite according to claim 1, characterized in that: In step (1), the method for digesting the test sample is as follows: weigh 0.050-2.00 g of the test sample into a polytetrafluoroethylene beaker, add 3-25 mL of hydrochloric acid and 3-25 mL of nitric acid in sequence and react for 5-10 minutes, add 3-15 mL of hydrofluoric acid dropwise, and heat to 250-350° C. for digestion.

3. The method for detecting the content of tungsten in bauxite according to claim 1, characterized in that: In step (2), the amount of tartaric acid solution added is 5 to 25 mL, the concentration of the tartaric acid solution is 30 to 70 g / L, and the heating temperature is 250 to 350°C.

4. The method for detecting the content of tungsten in bauxite according to claim 1, characterized in that: In step (2), the method for removing hydrofluoric acid is as follows: after the test sample is completely dissolved, 5 to 15 mL of perchloric acid is added, and the mixture is heated at 350 to 400° C., and the perchloric acid smokes to drive out the hydrofluoric acid.

5. The method for detecting the content of tungsten in bauxite according to claim 1, characterized in that: The bauxite contains tungsten in an amount of 0.001% to 1.00% by mass.

6. The method for detecting the content of tungsten in bauxite according to claim 1, characterized in that: The preparation method of the standard series solution is as follows: take 0.00mL, 0.50mL, 1.00mL, 3.00mL, and 5.00mL of a 10μg / mL tungsten standard solution into a 100mL volumetric flask, dilute to volume with water, and prepare the standard series solution.

7. The method for detecting the content of tungsten in bauxite according to claim 1, characterized in that: Preheat the inductively coupled plasma optical emission spectrometer for 0.5 to 1.5 hours before starting.

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