Method for simultaneously determining contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by ICP-AES (Inductively Coupled Plasma-

Abstract

The invention relates to the technical field of analysis and testing, in particular to a method for simultaneously determining the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate through inductively coupled plasma-atomic emission spectrometry (ICP-AES). According to the method, the contents of 13 elements in the germanium concentrate are measured by adopting lithium metaborate decomposition, nitric acid leaching and inductively coupled plasma atomic emission spectrometry. A sample dissolving method, digestion conditions and matrix interference conditions are investigated and researched, and the interference degree is reduced to the minimum by adopting a matrix matching method. The measurement range is as follows: omega (GE) is 1.00%-6.00%; and omega (Pb, Zn, Ca, Mg, Al, Fe, Mn, K, Na, As, Sb and Si): 0.20%-6.00%. A standard recovery experiment shows that the recovery rate is between 92.8% and 105.5%. The method is accurate and simple, and is suitable for rapidly determining the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in the germanium concentrate.

Description

Technical Field

[0001] The invention relates to the technical field of analysis and testing, and in particular to a method for simultaneously determining the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by using inductively coupled plasma atomic emission spectrometry (ICP-AES). Background Art

[0002] Germanium is a scarce strategic mineral resource, and is widely used in aerospace, nuclear physics detection, optical fiber communication, infrared optics, biomedicine, new energy and other fields. The content of germanium in germanium concentrate directly affects its grade and is a key element of concern; in the production process of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate are the main impurity elements, and accurate determination of their content is of great significance for quality control in the process.

[0003] At present, in the existing standard analysis method for germanium concentrate GB / T 21513, the determination of germanium and arsenic mainly adopts the titration method, and the determination of silicon adopts the weight method. These methods have the following shortcomings in the process of use in recent years: germanium needs to be distilled during its pre-treatment process to separate and enrich germanium; arsenic also needs to be reduced to a single substance before filtering and separation; silicon adopts the animal glue weight method. These methods have complex experimental operations and long processes. As the complexity of germanium concentrate materials increases, they are easily affected by interfering elements, affecting the accuracy and stability of the determination results. In addition, there are no analysis methods for lead, zinc, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, and sodium. Summary of the invention

[0004] In view of this, in order to solve the problem, the present invention provides a method for simultaneously determining the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method has the advantages of simple sample processing and accurate analysis results, and can quickly and simultaneously determine the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate.

[0005] It should be noted that the inductively coupled plasma atomic emission spectrometry is a mature technology with the characteristics of high sensitivity, good stability, low interference, fast detection speed and simultaneous determination of multiple elements. It is now planned to establish a lithium metaborate-inductively coupled plasma atomic emission spectrometry method to simultaneously detect low-content germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium, silicon and other elements in germanium concentrate, so as to achieve high-throughput, rapid and accurate determination of multiple elements in germanium concentrate.

[0006] The invention adopts lithium metaborate to completely dissolve germanium concentrate, which can ensure that germanium and silicon elements are not easy to volatilize and avoid the influence of potassium and sodium salt flux on the simultaneous determination of potassium and sodium elements.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A method for determining the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by ICP-AES, comprising the following steps:

[0009] (1) Place 0.2000g of germanium concentrate sample (grade of 1%-6%) in a platinum crucible pre-added with 1g of lithium metaborate, then cover it with 1g of lithium metaborate, move the platinum crucible into a muffle furnace at 300℃~400℃, heat it to 900℃, melt it for 30 minutes, take it out, and cool it; place the platinum crucible in a 250mL beaker, add nitric acid to completely soak it, oscillate it with an ultrasonic instrument for 30 minutes, wash the crucible with dilute nitric acid, and wash the crucible with water 2 to 3 times. Cool to room temperature, transfer it to a 100mL volumetric flask, dilute it to the scale with water, and mix it well; take 10mL of the test solution, transfer it to a 100mL volumetric flask, add 10mL of nitric acid, dilute it to the scale with water, mix it well, and prepare the test solution;

[0010] (2) Preparation of standard solution working curve: Weigh 2 g of lithium metaborate and prepare a sample blank solution according to the above method for later use; take 6 100 mL volumetric flasks, add the mixed standard solution, add 10 mL of blank solution, add 10% nitric acid, dilute to the scale, and shake well;

[0011] (3) Turn on the ICP, wait until all instrument indicators meet the requirements and the ignition is stable for half an hour, then establish the sample analysis method according to the working conditions of the ICP, select the optimal wavelength under the optimal instrument conditions, and measure the blank solution, standard solution and test solution in sequence. Fit a linear curve with the concentration value as the horizontal axis and the signal intensity value as the vertical axis to calculate the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon.

[0012] Furthermore, in step (1), the parameters of nitric acid leaching are: 40 mL of nitric acid (1+1).

[0013] Furthermore, in step (2), 0.00, 0.50, 1.00, 5.00, 10.00 mL, and 20.00 mL of a mixed standard solution (100 μg / mL) of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium, and silicon were respectively transferred into a 100 mL volumetric flask to prepare a series of standard working solutions with concentrations of 0.00, 0.50, 1.00, 5.00, 10.00 mL, and 20.00 μg / mL, 10 mL of the sample blank solution was added, 10% HNO3 was added, the solution was diluted to the scale, and shaken well.

[0014] Furthermore, the working conditions of the inductively coupled plasma atomic emission spectrometer in step (3) are as follows: RF power 1000 W, plasma gas flow 15.0 L / min, auxiliary gas flow 1.50 L / min, atomizing gas flow 0.60 L / min, observation height 6 mm, and reading time 5 s.

[0015] The wavelengths of the analyzed elements are: Ge: 209.426nm, Pb: 220.353nm, Zn: 206.200nm, Ca: 422.673nm, Mg: 285.213nm, Al: 396.152nm, Fe: 259.904nm, Mn: 257.610nm, K: 766.491nm, Na: 589.592nm, As: 188.980nm, Sb: 206.834nm, Si: 251.611nm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1) The contents of 13 elements in germanium concentrate were determined by using lithium metaborate to decompose the sample, nitric acid leaching, and inductively coupled plasma atomic emission spectrometry. The sample dissolution method, digestion conditions, and matrix interference were investigated and studied, and the matrix matching method was used to minimize the interference. Determination range: ω (Ge): 1.00% ~ 6.00%; ω (Pb, Zn, Ca, Mg, Al, Fe, Mn, K, Na, As, Sb, Si): 0.20% ~ 6.00%. After the spike recovery experiment, the recovery rate was between 92.8% and 105.5%.

[0018] 2) The present invention is fast and simple, and can efficiently and accurately detect the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate, providing a new reference for the simultaneous analysis of other elements in similar samples. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0021] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0022] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0023] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.

[0024] The invention discloses a method for simultaneously determining the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by using an ICP-AES method.

[0025] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0026] The equipment used in the experiment was Agilent ICP-OES 725 inductively coupled plasma spectrometer (Agilent Technologies, USA).

[0027] Reagents used in the experiment: sodium peroxide (analytical grade); nitric acid (analytical grade); ultrapure water (homemade); standard stock solutions: standard stock solutions of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium, and silicon were provided by the National Iron and Steel Research Institute, and the concentration values ​​were all 1000 μg / mL.

[0028] In order to verify the accuracy of the measurement results of the method of the present invention, 10 such samples were selected as examples, marked as Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, Example 8, Example 9, and Example 10.

[0029] The method for determining the contents of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in the samples of Examples 1-10 comprises the following steps:

[0030] (1) Sample decomposition: Place 0.2000g of the sample in a platinum crucible that has been pre-added with 1g of lithium metaborate, then add 1g of lithium metaborate to cover it. Move the platinum crucible into a muffle furnace at 300℃~400℃, heat it to 900℃, melt it for 30 minutes, take it out, and cool it. Place the platinum crucible in a 250mL beaker, add nitric acid to completely soak it, oscillate it with an ultrasonic device for 30 minutes, clean the crucible with dilute nitric acid, and wash the crucible with water 2 to 3 times. Cool to room temperature, transfer it to a 100mL volumetric flask, dilute it to the mark with water, and mix it. Take 10mL of the test solution, transfer it to a 100mL volumetric flask, add 10mL of nitric acid, dilute it to the mark with water, and mix it.

[0031] (2) Preparation of standard solution working curve: Pipette 0.00, 0.50, 1.00, 5.00, 10.00, and 20.00 mL of a mixed standard solution (100 μg / mL) of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium, and silicon into a 100-mL volumetric flask to prepare a series of standard working solutions with concentrations of 0.00, 0.50, 1.00, 5.00, 10.00, and 20.00 μg / mL, add 10 mL of sample blank solution, add 10% HNO3, dilute to the scale, and shake well.

[0032] (I) Determination of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon content

[0033] The instrument parameters were optimized to make the instrument in the best state: RF power 1000W, plasma gas flow 15.0L / min, auxiliary gas flow 1.50L / min, nebulizer gas flow 0.60L / min, observation height 6mm, reading time 5s, and the wavelengths of analyzed elements were: Ge: 209.426nm, Pb: 220.353nm, Zn: 206.200nm, Ca: 422.673nm, Mg: 285.213nm, Al: 396.152nm, Fe: 259.904nm, Mn: 257.610nm, K: 766.491nm, Na: 589.592nm, As: 188.980nm, Sb: 206.834nm, Si: 251.611nm. Turn on ICP, and after all instrument indicators meet the requirements and the ignition is stable for half an hour, establish the sample analysis method according to the working conditions of ICP, select the optimal wavelength under the best instrument conditions, and measure the blank solution, standard solution and test solution in sequence. Fit a linear curve with the concentration value as the horizontal axis and the signal intensity value as the vertical axis to calculate the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon.

[0034] Detection limit: The sample blank solution was measured 11 times, the standard deviation was calculated, 3 times the standard deviation was taken as the detection limit, and 5 times the detection limit was taken as the lower limit of determination. The results are shown in Table 1.

[0035] Table 1 Instrument detection limit and method detection limit

[0036] element Detection limit (μg / mL) Determination limit (μg / mL) Ge 0.024 0.080 Pb 0.037 0.123 Zn 0.010 0.033 Ca 0.011 0.037 Mg 0.007 0.023 Al 0.006 0.020 Fe 0.006 0.020 Mn 0.006 0.020 K 0.004 0.013 Na 0.008 0.027 As 0.019 0.063 Sb 0.015 0.050 Si 0.013 0.043

[0037] Precision and accuracy: The accuracy of the method was verified using samples from Examples 1-10. The results are shown in Table 2.

[0038] Table 2 Precision test results (n = 11)

[0039]

[0040]

[0041]

[0042]

[0043] Recovery rate: Select the corresponding samples, add a certain amount of standard solution, treat the samples according to the provisions of this standard, and conduct spiked recovery experiments. The results are shown in Table 3.

[0044] Table 3 Spike recovery test

[0045]

[0046]

[0047] The test results show that the standard curves corresponding to the determination of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon have good linear relationships. The detection limit of this method is 0.010-0.10 μg / mL, the precision is <5%, and the recovery rate is 92.8-105.5%, which shows that the method of the present invention has high precision, the determination results are stable and reliable, and the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate can be quickly and accurately detected.

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by ICP-AES, characterized in that: The steps include: (1) 0.2000 g of germanium concentrate sample is placed in a platinum crucible pre-added with 1 g of lithium metaborate, and then 1 g of lithium metaborate is added to cover it. The platinum crucible is moved into a muffle furnace at 300° C. to 400° C., heated to 900° C., melted for 30 min, taken out, and cooled; the platinum crucible is placed in a 250 mL beaker, leached completely with nitric acid, oscillated with an ultrasonic instrument for 30 minutes, cleaned with dilute nitric acid, and washed with water 2 to 3 times; cooled to room temperature, moved into a 100 mL volumetric flask, diluted to scale with water, and mixed; 10 mL of the test solution is taken, moved into a 100 mL volumetric flask, 10 mL of nitric acid is added, diluted to scale with water, and mixed to prepare a test solution; (2) Weigh 2 g of lithium metaborate and prepare a sample blank solution according to the method described in step (1) for later use; take 6 100 mL volumetric flasks, add the mixed standard solution, add 10 mL of the sample blank solution, add 10% nitric acid, dilute to the scale, and shake well; (3) Turn on the ICP, wait until all instrument indicators meet the requirements and the ignition is stable for half an hour, then establish the sample analysis method according to the working conditions of the ICP, select the optimal wavelength under the optimal instrument conditions, and measure the blank solution, standard solution and test solution in sequence. Fit a linear curve with the concentration value as the horizontal axis and the signal intensity value as the vertical axis to calculate the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon.

2. The method for determining the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by ICP-AES according to claim 1, characterized in that: In step (1), the parameters of nitric acid leaching are: 40 mL of nitric acid (1+1).

3. The method for determining the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by ICP-AES according to claim 1, characterized in that: In step (2), 0.00, 0.50, 1.00, 5.00, 10.00 mL, and 20.00 mL of a mixed standard solution (100 μg / mL) of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium, and silicon were respectively transferred into a 100 mL volumetric flask to prepare a series of standard working solutions with concentrations of 0.00, 0.50, 1.00, 5.00, 10.00 mL, and 20.00 μg / mL, add 10 mL of the sample blank solution, add 10% HNO3, dilute to the scale, and shake well.

4. The method for determining the content of germanium, lead, zinc, arsenic, antimony, calcium, magnesium, aluminum, iron, manganese, potassium, sodium and silicon in germanium concentrate by ICP-AES according to claim 1, characterized in that: The working conditions of the inductively coupled plasma atomic emission spectrometer in step (3) are as follows: RF power 1000 W, plasma gas flow 15.0 L / min, auxiliary gas flow 1.50 L / min, atomizing gas flow 0.60 L / min, observation height 6 mm, and reading time 5 s. The wavelengths of the analyzed elements are: Ge: 209.426nm, Pb: 220.353nm, Zn: 206.200nm, Ca: 422.673nm, Mg: 285.213nm, Al: 396.152nm, Fe: 259.904nm, Mn: 257.610nm, K: 766.491nm, Na: 589.592nm, As: 188.980nm, Sb: 206.834nm, Si: 251.611nm.

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