Method for simultaneously measuring total barium and sulfur in barite by acid dissolution-inductively coupled plasma emission spectrometry

Abstract

The invention relates to the technical field of mineral content detection, in particular to a method for simultaneously determining total barium and sulfur in barite through acid dissolution-inductively coupled plasma emission spectrometry. The method comprises the following steps: adding nitric acid and hydrochloric acid into barite, heating on an electric heating plate, adding a chromium internal standard solution and a nitric acid solution, heating, cooling, and determining by using an inductively coupled plasma emission spectrometer. According to the method, simultaneous determination is achieved in an acid dissolution mode, the detection efficiency is improved, time and cost are saved, the whole test solution preparation process is relatively simple, accurate volume determination is not needed, sample digestion treatment can be completed through common means such as electric hot plate heating under conventional laboratory conditions, and the method is more stable, easy and convenient to operate, easy to master and suitable for large-scale popularization and application. The reproducibility is good, and popularization and application are convenient. Meanwhile, the method can improve the accuracy and precision of a measurement result, so that the measurement result is more reliable.

Description

Technical Field

[0001] This invention relates to the field of mineral content detection technology, specifically a method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry. Background Technology

[0002] Barite's main component is BaSO4. Pure barite is white and lustrous, chemically stable, and has a high specific gravity. These physicochemical properties lead to its widespread use as a weighting agent in oil drilling, as well as in pigments, paints, papermaking, and the chemical industry. In recent years, the mining and processing of barite has gained increasing attention. Natural barite typically occurs in nature alongside gangue minerals such as calcite, dolomite, and quartz, exhibiting complex occurrences. Therefore, the determination of barium and sulfur content in barite ore has become a focus of research.

[0003] Existing methods for determining the total barium and sulfur content in barite mainly include gravimetric methods, volumetric methods, high-frequency infrared carbon-sulfur analyzers, inductively coupled plasma atomic emission spectrometry (ICP-AES) (with other pretreatment methods), and X-ray fluorescence spectrometry (XRF). Traditional analytical methods such as gravimetric and volumetric methods are cumbersome, have long analysis cycles, and require multiple precipitation, filtration, and drying operations, demanding high experimental conditions and operator skills. Furthermore, they cannot simultaneously determine the content of barium and sulfur. High-frequency infrared carbon-sulfur analyzers determine sulfur content through an infrared detection system, but this instrument typically cannot directly measure barium. ICP-AES (with other pretreatment methods) usually involves high-temperature melting of the sample using sodium carbonate, which may lead to more thorough decomposition of some samples. However, the operation is relatively complex, requiring high-temperature melting equipment, and the introduced sodium salt may affect subsequent measurements. Moreover, this method typically does not use an internal standard, and barium, with its high sensitivity, requires a large dilution ratio, has a narrow linear range, and poor precision, making it difficult to meet the requirements for determining the purity of barite. X-ray fluorescence spectrometry (XRF) can simultaneously determine total barium and sulfur in barite. However, for samples containing sulfides and polymetallic materials such as iron, the platinum crucible is significantly corroded during the fusing process. Furthermore, the results are greatly affected by the type of mineral. In addition, XRF spectrometers are more expensive than inductively coupled plasma atomic emission spectrometers (ICP-AES), have higher maintenance and operating costs, and require more specialized skills from operators, which greatly limits their practical application.

[0004] Inductively Coupled Plasma Emission Spectrometry (ICP-ESI) (with other pretreatment methods) discloses a method for simultaneously determining total barium and sulfur in barite using ICP-ESI, as disclosed in the inventor's prior patent application CN115950876 A. This method involves melting and decomposing the sample with sodium carbonate and sodium hydroxide, extracting the slag with hot water, adding nitric acid and chromium internal standard solution, washing the crucible and beaker with dilute hydrochloric acid, adding water and shaking, heating on a hot plate until slightly boiling, removing and shaking again, and then measuring on an ICP-ESI spectrometer after cooling. This method effectively solves the technical problem of traditional methods for determining total barium and sulfur in barite, where sulfur and barium are difficult to coexist in solution, usually requiring two different methods or even pre-separation of barium and sulfur, resulting in a long process and low detection efficiency. However, it still has technical problems such as high salt content, slightly lower precision and accuracy, and slightly longer detection time. Building on the original research, the inventor conducted further research, adopting an acid dissolution method to achieve simultaneous determination, improving detection efficiency, saving time and cost, and providing more accurate and reliable results. Summary of the Invention

[0005] This invention addresses the technical problems existing in the background art by providing a method for the simultaneous determination of total barium and sulfur in barite using acid dissolution-inductively coupled plasma atomic emission spectrometry. The method of this invention uses acid dissolution to achieve simultaneous determination, improving detection efficiency and saving time and cost. The entire sample preparation process is relatively simple, requiring no precise volume determination. Under conventional laboratory conditions, sample digestion can be completed using common methods such as hot plate heating. The method is more stable, easy to operate and master, has good reproducibility, and is easy to promote and apply. Simultaneously, this invention improves the accuracy and precision of the determination results, making the results more reliable, and solves the technical problems of high salt content and poor precision and accuracy in alkali fusion determination.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: A method for simultaneously determining total barium and sulfur in barite using acid-soluble inductively coupled plasma atomic emission spectrometry, characterized by comprising the following steps: (1) Sample preparation: The barite sample was crushed to a particle size of less than 0.097 mm, dried at 105℃ for 2 hours, and then cooled for later use. (2) Preparation of test solution: Take 0.1 g (accurate to 0.00001 g) of barite sample into a 250 mL Erlenmeyer beaker, add glass beads, add 5 mL of nitric acid solution, shake well, let stand for 5 min, add 2 mL of hydrochloric acid, heat on a hot plate until it boils slightly, remove, add water to 100 mL, add 10 mL of chromium internal standard solution (added by weighing, accurate to 0.001 g, solution specific gravity is 1 g / mL), 35 mL of nitric acid, cover with a watch glass, place on a hot plate and heat until it boils slightly for 15 min, remove the watch glass and add water to 240 mL, shake well, cover with a watch glass, continue heating until the solution is in a state of slight boiling, keep warm for 40 min, remove, shake well, cool to room temperature and then use an inductively coupled plasma atomic emission spectrometer for determination; (3) Plotting working curves: Accurately weigh a certain amount of superior grade barium carbonate (accurate to 0.00001g) and a series of high-purity potassium sulfate (accurate to 0.00001g) into 250mL Erlenmeyer beakers, prepare the corresponding standard solutions according to step (2), shake well, and measure on an inductively coupled plasma atomic emission spectrometer. Plot the working curves of barium and sulfur with relative concentration as the abscissa and the ratio of analytical spectral lines to internal standard spectral lines as the ordinate. (4) Sample determination: The barite sample was processed according to the steps in step (2), and the emission intensity counts of barium and sulfur were measured using an inductively coupled plasma atomic emission spectrometer. The emission intensity counts were substituted into the working curve to obtain the content of barium and sulfur in the solution. (5) Verification and comparison of working curves: Select 2-6 barite national first-class standard materials, prepare the corresponding solutions according to the steps in (2), and prepare a sample blank solution at the same time. Under the same conditions, use an inductively coupled plasma atomic emission spectrometer to measure and verify and compare with the standard values ​​of each standard material. (6) Analysis results: The contents of barium and sulfur in the barite sample were calculated by the following formula as mass fraction w(B), and the unit was expressed as (%). The contents of barium and sulfur were determined by comparing the contents of barium and sulfur obtained in step (4) with the contents of barium and sulfur calculated in step (6). Where: ρ—the relative concentration of the element to be measured in the sample solution, in milligrams per milliliter (mg / mL); ρ0—The relative concentration of the element to be tested in the blank test solution, in milligrams per milliliter (mg / mL). m — Sample mass, in grams.

[0007] As a preferred technical solution of the present invention: the nitric acid in step (2) contains 8 g / L of potassium chlorate.

[0008] As a preferred technical solution of the present invention: the mass concentration of nitric acid in step (2) is 68%.

[0009] As a preferred technical solution of the present invention: the mass concentration of hydrochloric acid in step (2) is 36%.

[0010] As a preferred technical solution of the present invention: the concentration of the chromium internal standard solution in step (2) (calculated as chromium) is 1 mg / mL.

[0011] As a preferred technical solution of the present invention: the working environment measured by the inductively coupled plasma atomic emission spectrometer: As a preferred technical solution of the present invention: the determination range of the method of the present invention is 0.02%~66% for BaO and 0.3%~40% for SO3 in barite.

[0012] Compared with the prior art, the advantages and beneficial effects of the present invention include: This invention employs acid dissolution for simultaneous determination, improving detection efficiency and saving time and costs. The entire sample preparation process is relatively simple, requiring no precise volume determination. Under conventional laboratory conditions, sample digestion can be completed using common methods such as hot plate heating. The method is more stable, easy to operate and master, exhibits good reproducibility, and is easy to promote and apply. Furthermore, this invention improves the accuracy and precision of the determination results, making them more reliable and solving the technical problems of high salt content and poor precision and accuracy in alkali fusion determination. Attached Figure Description

[0013] Figure 1 A standard curve for barium; Figure 2 This is a standard curve diagram for sulfur. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0015] Example 1 A method for simultaneously determining total barium and sulfur in barite using acid-soluble inductively coupled plasma atomic emission spectrometry, characterized by comprising the following steps: (1) Sample preparation: The barite sample was crushed to a particle size of less than 0.097 mm, dried at 105℃ for 2 hours, and then cooled for later use. (2) Preparation of test solution: Take 0.1 g (accurate to 0.00001 g) of barite sample into a 250 mL Erlenmeyer beaker, add glass beads, add 5 mL of nitric acid solution (containing 8% potassium chlorate), shake well, let stand for 5 min, add 2 mL of 36% concentrated hydrochloric acid, heat on a hot plate until it boils slightly, remove, add water to 100 mL, add 10 mL of chromium internal standard solution (added by weighing, accurate to 0.001 g, the specific gravity of the solution is 1 g / mL), 35 mL of 68% concentrated nitric acid, cover with a watch glass, place on a hot plate and heat until it boils slightly for 15 min, remove the watch glass and add water to 240 mL, shake well, cover with a watch glass, continue heating until the solution is in a state of slight boiling, keep warm for 40 min, remove, shake well, cool to room temperature and then use an inductively coupled plasma atomic emission spectrometer for determination.

[0016] Operating environment of inductively coupled plasma atomic emission spectrometer: (3) Plotting the working curves: Accurately weigh a certain amount of superior grade barium carbonate (accurate to 0.00001 g) and a series of high-purity potassium sulfate (accurate to 0.00001 g) into 250 mL Erlenmeyer beakers, prepare the corresponding standard solutions according to step (2), shake well, and measure on an inductively coupled plasma atomic emission spectrometer. Plot the working curves of barium and sulfur with the relative concentration (the concentration of the analyte in the standard solution in the volume of the added internal standard solution) as the abscissa and the ratio of the analytical spectral line to the internal standard spectral line as the ordinate. The measurement results are shown in Table 1, Table 2 and Table 3 respectively. Figure 1 , Figure 2 As shown.

[0017] Table 1: Results of Barium Oxide Working Curve Measurement Table 2: Results of sulfur working curve determination from Figure 1 and Figure 2 It can be seen that the working curve for barium oxide plotted using this method is y=0.1222946x, R. 2 =0.99999912, the working curve for sulfur is y=0.0065114x, R 2 =0.9999918.

[0018] (4) Sample determination: The barite sample was processed according to the steps in step (2), and the emission intensity counts of barium and sulfur were measured using an inductively coupled plasma atomic emission spectrometer. The emission intensity counts were then substituted into the working curve to obtain the content of the barium and sulfur elements in the solution.

[0019] Limit of detection determination In 12 250 mL Erlenmeyer beakers without weighing the samples, the corresponding solutions were prepared according to step (2). The detection limits of the solutions were determined by inductively coupled plasma atomic emission spectrometry under the same conditions. The results of the detection limit determination are shown in the table below.

[0020] The test results show that the detection limit for barium by the method of the present invention is 0.0025% and the detection limit for sulfur is 0.05%, while the detection limit for barium by the alkali fusion method is 0.0005% and the detection limit for sulfur is 0.1%, which indicates that the detection limit of the present method is even lower.

[0021] Precision determination Weigh 12 samples of 0.1g (accurate to 0.00001g) barite national first-grade standard material into 250mL Erlenmeyer beakers, prepare the corresponding solutions according to step (2), and determine the precision of the solutions using inductively coupled plasma atomic emission spectrometry under the same conditions. At the same time, the precision of barite was determined by the alkaline fusion method 202310033548.5, and the results are shown in the table below.

[0022] The contents of barium and sulfur in the barite sample were calculated using the following formula as mass fraction w(B), expressed in (%). The contents of barium and sulfur were compared with those obtained in step (4) and those calculated in step (6). The results are shown in Table 3.

[0023] Where: ρ—the relative concentration of the element to be measured in the sample solution, in milligrams per milliliter (mg / mL); ρ0—The relative concentration of the element to be tested in the blank test solution, in milligrams per milliliter (mg / mL). m — Sample mass, in grams.

[0024] The above test results show that the method of the present invention uses acid melting, has a lower salt content, and has better precision than the alkali melting method.

[0025] Accuracy determination: Six samples of barite national first-class standard material were selected, and corresponding solutions were prepared according to step (2). Under the same conditions, the solutions were measured using an inductively coupled plasma atomic emission spectrometer. The results of the accuracy measurement were compared with the standard values ​​of each standard material. The results are shown in the table below. The test results show that the accuracy of the method of the present invention is better than that of the alkali fusion method.

[0026] The above description, in conjunction with specific / preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the inventive concept, and all such substitutions or modifications should be considered within the scope of protection of the present invention.

Claims

1. A method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry, characterized in that: Includes the following steps: (1) Sample preparation: The barite sample was crushed to a particle size of less than 0.097 mm, dried at 105℃ for 2 hours, and then cooled for later use. (2) Preparation of test solution: Take 0.1g of barite sample into a 250mL Erlenmeyer beaker, add glass beads, add 5mL of nitric acid solution, shake well, let stand for 5min, add 2mL of hydrochloric acid, heat on a hot plate until it boils slightly, remove, add water to 100mL, add 10mL of chromium internal standard solution and 35mL of nitric acid, cover with a watch glass, place on a hot plate and heat until it boils slightly for 15min, remove the watch glass and add water to 240mL, shake well, cover with a watch glass, continue heating until the solution is in a state of slight boiling, keep warm for 40min, remove, shake well, cool to room temperature and then use an inductively coupled plasma atomic emission spectrometer for determination; (3) Plotting working curves: Accurately weigh a certain amount of superior grade barium carbonate and a series of high-purity potassium sulfate into 250mL Erlenmeyer beakers, prepare the corresponding standard solutions according to step (2), shake well, and measure on an inductively coupled plasma atomic emission spectrometer. Plot the working curves of barium and sulfur with relative concentration as the abscissa and the ratio of analytical spectral lines to internal standard spectral lines as the ordinate. (4) Sample determination: The barite sample was processed according to the steps in step (2), and the emission intensity counts of barium and sulfur were measured using an inductively coupled plasma atomic emission spectrometer. The emission intensity counts were substituted into the working curve to obtain the content of barium and sulfur in the solution. (5) Verification and comparison of working curves: Select 2-6 barite national first-class standard materials, prepare the corresponding solutions according to the steps in (2), and prepare a sample blank solution at the same time. Under the same conditions, use an inductively coupled plasma atomic emission spectrometer to measure and verify and compare with the standard values ​​of each standard material. (6) Analysis results: The contents of barium and sulfur in the barite sample were calculated by the following formula as mass fraction w(B), expressed in %; the contents of barium and sulfur obtained in step (4) were compared with the contents of barium and sulfur calculated in step (6) for analysis. Where: ρ—the relative concentration of the element to be measured in the sample solution, in milligrams per milliliter (mg / mL); ρ0—The relative concentration of the element to be tested in the blank test solution, in milligrams per milliliter (mg / mL). m — Sample mass, in grams.

2. The method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: The nitric acid mentioned in step (2) contains 8 g / L of potassium chlorate.

3. The method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: The mass concentration of nitric acid in step (2) is 68%.

4. The method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: The mass concentration of hydrochloric acid in step (2) is 36%.

5. The method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: The concentration of the chromium internal standard solution in step (2).

6. The method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: The operating environment measured by the inductively coupled plasma atomic emission spectrometer: 。 7. A method for simultaneously determining total barium and sulfur in barite using acid-dissolution-inductively coupled plasma atomic emission spectrometry according to any one of claims 1 to 6, characterized in that: The determination range of this method is 0.02%~66% for BaO and 0.3%~40% for SO3 in barite.

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