CN114674856A - Method for detecting nickel in nickel iron - Google Patents

Method for detecting nickel in nickel iron Download PDF

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CN114674856A
CN114674856A CN202210307073.XA CN202210307073A CN114674856A CN 114674856 A CN114674856 A CN 114674856A CN 202210307073 A CN202210307073 A CN 202210307073A CN 114674856 A CN114674856 A CN 114674856A
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nickel
ferronickel
sample
detecting
nitric acid
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肖星
郭妙妙
吴圆
彭明耀
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Hunan Valin Lianyuan Iron & Steel Co Ltd
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Hunan Valin Lianyuan Iron & Steel Co Ltd
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    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/22Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
    • G01N23/223Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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    • G01N2223/076X-ray fluorescence

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Abstract

The invention belongs to the technical field of alloy detection, and particularly discloses a method for detecting nickel in ferronickel; dissolving, namely adding a nitric acid solution and a hydrofluoric acid solution into a nickel iron sample, heating and dissolving to obtain a clear solution, and keeping the volume of the solution concentrated at low temperature to be nearly dry; tabletting: adding a fusing agent and a release agent into the heated product obtained in the step S1, melting 5-25min at 1040-1060 ℃, and casting the molten liquid into a sample wafer; and (3) detection: detecting the sample wafer obtained in the step S2 by using an X fluorescent agent analyzer to obtain the content of nickel in the ferronickel; the method has the advantages that nickel iron oxide samples are quickly dissolved by nitric acid-hydrofluoric acid, alloy metal effects are removed, direct solute sample preparation is realized, and the glass sheet for X fluorescence analysis is prepared; the analysis period can be shortened to 1.5 hours from 4-6 hours of the original chemical wet method, and the batch detection of nickel in the nickel iron can be realized.

Description

Method for detecting nickel in nickel iron
Technical Field
The invention relates to the technical field of alloy detection, in particular to a method for detecting nickel in ferronickel.
Background
The ferronickel is an alloy of nickel and iron, contains elements such as carbon, silicon, phosphorus, cobalt, chromium, copper, molybdenum and the like, and is a common alloying agent for smelting stainless steel. The quality of the ferronickel mainly depends on the content of nickel, generally 20-60%, the nickel element in the ferronickel is generally analyzed by a chemical wet method, the interference of coexisting elements in the ferronickel needs to be considered in the existing national standard GB/T30072-2013 nickel-iron content determination and EDTA titration method, hydroxylamine hydrochloride and ammonium fluoride are respectively used for masking iron, aluminum and titanium, sodium hexametaphosphate is used for masking manganese, and simultaneously copper and cobalt need to be separately determined, and the influence of the copper and cobalt is corrected and eliminated by a mathematical correction method; in the national standard GB/T21933.1-2008 weight method for measuring nickel, iron and nickel contents in the nickel-dimethylglyoxime, firstly, silicon is dehydrated and separated out, then, the silicon is filtered and removed, then, under the action of a masking agent, nickel is separated by twice precipitation with dimethylglyoxime, and finally, the nickel in the filtrate is measured by an atomic absorption method for correction.
Both methods need a plurality of chemical reagents, the operation steps are complex and tedious, the analysis period is long, and the requirements of the existing rapid detection cannot be met. No acid-soluble pretreatment sample is found, and the nickel content in the nickel iron is measured by a melting sample preparation-X fluorescence method.
Disclosure of Invention
The invention aims to provide a method for detecting nickel in ferronickel, which solves the following technical problems:
the prior art adopts a chemical method to detect the nickel content, iron and nickel, and has the problems of complicated steps and long period.
The purpose of the invention can be realized by the following technical scheme:
a detection method for nickel in ferronickel comprises the following steps:
s1, dissolving, namely adding a nitric acid solution and a hydrofluoric acid solution into a nickel iron sample, heating and dissolving to obtain a clear solution, and keeping the heating temperature and concentrating the volume until the volume is nearly dry;
s2, tabletting: adding a fusing agent and a release agent into the heated product obtained in the step S1, melting for 5-25min at 1040-1060 ℃, and casting the molten liquid into an analysis sample wafer;
s3, detection: and (4) detecting the analysis sample wafer obtained in the step S2 by using an X fluorescent agent analyzer to obtain the content of nickel in the ferronickel.
As a further scheme of the invention: in step S1, the nitric acid solution is prepared from analytically pure, concentrated nitric acid having a density of 1.42g/mL and has a volume ratio to water of 1:1, the adding mass of the nitric acid solution is 24-36 times of that of the ferronickel, the hydrofluoric acid is analytically pure, the density is 1.15g/mL, the concentration is 40 wt%, and the adding mass is 5.7-11.4 times of that of the ferronickel.
As a further scheme of the invention: the clear solution in step S1 is concentrated to a volume of 0.4-0.6 mL.
As a further scheme of the invention: the heating temperature in step S1 was 120 ℃.
As a further scheme of the invention: the flux in step S2 is 67Li2B4O7:33LiBO2High purity mixed flux.
As a further scheme of the invention: the release agent in the step 1 is analytically pure potassium iodide.
As a further scheme of the invention: the mass ratio of the nickel iron sample to the release agent to the solvent is 1:6: 70.
As a further scheme of the invention: and (3) comparing the X-ray fluorescence intensity obtained by the X fluorescent agent analyzer in the step (3) with a function model established by a standard sample to obtain the nickel content, wherein the function model is a linear equation established by a high-purity iron-high-purity nickel mixture with gradient nickel content.
As a further scheme of the invention: in the process of establishing the linear equation, high-purity iron with different weights is respectively dissolved in the nitric acid solution in the step S1 at 120 ℃, 40 wt% of hydrofluoric acid is added after high-purity nickel with corresponding weight is added, the solution is steamed at 120 ℃ until the volume of the residual solution is 0.4-0.6mL, the obtained heating product is subjected to sheet making according to the step S2, X-fluorescence intensity detection is carried out on a sample sheet, the linear equation is established between the calculated nickel content and the X-fluorescence intensity, and X-fluorescence analysis detection parameters are adjusted to enable the correlation coefficient of a calibration curve to be larger than 0.999.
As a further scheme of the invention: the X-fluorescence analysis detection parameters are as follows:
spectral line: Ni-K alpha; crystal: LiF 200; a collimator: s2; a detector: SC; 2 theta DEG: 48.648, respectively; the detection time is 20 s; voltage: 50 KV; current: 60 mA; pulse height: 100-300.
The invention has the beneficial effects that:
(1) the application can rapidly dissolve the nickel iron oxide sample through nitric acid-hydrofluoric acid, remove the alloy metal effect, realize direct solute sample preparation, and be easier to obtain the glass sheet for X fluorescence analysis.
(2) The glass sheet is prepared by melting lithium tetraborate-lithium metaborate, so that the uniformity of sample components is ensured, the granularity effect is effectively eliminated, the matrix effect is weakened, the nickel content in the nickel iron is determined by an X fluorescence method, the detection range is wide, the method is suitable for determining the nickel content of 20-60% in the nickel iron, and the accuracy can be comparable to a chemical wet method.
(3) The analysis period can be shortened to 1.5 hours from 4-6 hours of the original chemical wet method, and the batch detection of nickel in the nickel iron can be realized.
Drawings
The invention is further described below with reference to the accompanying drawings.
FIG. 1 is an analysis flow chart of an embodiment of a method for detecting nickel in ferronickel of the present invention;
FIG. 2 is a linear equation working curve established by high-purity iron powder and a high-purity nickel standard sample according to the method for detecting nickel in ferronickel.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Reagent:
a) and a solvent 1: HNO3The volume ratio is 1+1 (the volume ratio of the concentrated nitric acid to the water is 1:1), and the analysis is pure;
b) and a solvent 2: HF, density about 1.15g/mL, analytically pure;
c) and the release agent KI is solid and analytically pure.
d) Flux Li2B4O7+LiBO267% + 33%, high purity.
e) Standard substance 1: ni, high purity > 99.99%, flake or <0.3mm fine particle.
f) Standard substance 2: fe, high purity, purity > 99.99%, and particle size <0.1 mm.
The instrument equipment comprises:
the detector of the wavelength dispersion X-fluorometer (meeting the requirements of JJG810 verification regulations) is a scanning type gas flow proportional counter and a scintillation counter, and the maximum power: 4 kW;
sample preparation equipment: the electric heating melting equipment, the high-frequency melting furnace or the infrared melting furnace can maintain the temperature of 1100 ℃, and can realize the functions of automatic temperature rise, temperature selection, swinging in the melting process, automatic casting and the like;
a low-temperature electric furnace of 500W, the temperature is adjustable;
sample weighing equipment: an electronic balance, the precision is 0.1mg, and the maximum weighing is not less than 120 g;
sample dissolving/melting equipment: pt 95% -Au 5% X fluorescence analysis melting applicable crucibles and/or sets of crucibles and matched moulds are counted; the crucible volume is not less than 35 mL.
Scanning a conventional sample, and determining analysis conditions:
selecting a conventional sample with higher chemical components for scanning, wherein a generally non-interference k alpha 1 line is used as an analysis spectral line, and the maximum peak position is an actual detection peak position; the light splitting crystal selects LiF which is suitable for most elements in the range of Ni-Te, and factors such as light tube voltage, current, collimator slit and the like are comprehensively considered, so that the intensity of photons received by the detector is not higher than 1000 kcps; PHA window analysis can enlarge the window as much as possible while introducing no other spectral line signals; the intensity of the signal to be detected is more than 10 times higher than that of the background signal, so that the background intensity is ignored, and the scanning time is shortened; the analysis time is set as the analysis end time when the scanning signal deviation is less than 0.3%.
In the following examples, 0.1000g of ferronickel analysis sample with the granularity of less than or equal to 0.125mm is prepared according to the national standard GB/T4010-20125 sample for ferroalloy chemical analysis and preparation.
Example 1
Referring to fig. 1, the present invention is a method for detecting nickel in ferronickel, including the following steps:
s1, dissolving, namely putting a ferronickel analysis sample into a Pt 95% -Au 5% platinum yellow crucible, adding 3.0mL of 1+1 (the volume ratio of concentrated nitric acid to water is 1:1) nitric acid solution, shaking the crucible to disperse the ferronickel analysis sample, slowly and dropwise adding 1.0mL of 40 wt% hydrofluoric acid solution along the edge of the crucible under continuous shaking, heating and dissolving at 120 ℃ after the reaction is stable, completely clearing and removing residues, keeping the temperature, continuously steaming until the volume of the nearly dry residual solution is 0.5mL, cooling to room temperature to obtain a target sample, wherein the nitric acid solution and the hydrofluoric acid solution can be properly increased and decreased according to the sample dissolving condition, and the standard that the final solid phase is completely dissolved and has no residues is adopted;
s2, tabletting: 7.0000g67Li2B4O7:33LiBO2Adding the high-purity mixed flux and 0.600g of release agent into the platinum yellow crucible in the step S1, transferring the mixture to an electric heating melting sample machine, standing and melting the mixture for 5min at 1050 ℃, then shaking the crucible to heat the mixture for 10min, cooling or casting the molten liquid into a sample wafer after the melting is finished, and checking whether the sample wafer has no defects such as non-melt, cracks, bubbles or segregation and the like after the preparation of the sample wafer is finished to obtain an analysis sample wafer;
s3, modeling: 0.070g, 0.060g, 0.050g, 0.040g, 0.035g and 0.030g of high-purity iron are respectively weighed and dissolved in 3mL of 1+1 (the volume ratio of concentrated nitric acid to water is 1:1) nitric acid at the temperature of 120 ℃, 0.020g, 0.030g, 0.040g, 0.050g, 0.055g and 0.060g of high-purity nickel are added to each group of high-purity iron, continuously shaking the crucible edge, slowly and dropwise adding 1mL of 40 wt% hydrofluoric acid, after the reaction is stable, heating at 120 deg.C for dissolving completely, removing residue, steaming at low temperature until the volume of the residual solution is 0.5mL (the volume of the residual solution is not critical, and excessive liquid phase is evaporated during tabletting step), tabletting the obtained solution according to step S2 to obtain standard sample tablet, performing X-fluorescence intensity detection on the standard sample, establishing a linear equation between the calculated nickel content and the X-fluorescence intensity, and adjusting X-fluorescence analysis detection parameters to calibrate the curve correlation coefficient to be greater than 0.999;
the resulting X-fluorescence assay detection parameters are as follows:
Figure BDA0003565905240000051
under the determined analysis condition, scanning a standard sample, automatically making a working curve by a data processor, wherein the nickel content in the nickel iron is generally 20-60%, so that the working curve only covers 30-60% in the experiment, and correcting by adopting a fixed alpha coefficient; the sample is made into glass sheets by a melting method, the matrix effect is small, and no interference element exists.
S4, detection: and (4) detecting the analysis sample wafer obtained in the step (S2) by using an X fluorescent agent analyzer, and comparing the X-ray fluorescence intensity obtained by the X fluorescent agent analyzer with a function model established by a standard sample to obtain the nickel content.
The working principle of the invention is as follows:
analyzing the mass of the sample, and accurately weighing 0.1000g of the sample; the amount of the reagent can vary from 0.0900g to 0.1100g, but is accurately weighed to 0.0001g and converted to 0.1000g after measurement.
Concentration and dosage of nitric acid and hydrofluoric acid: (1+1) 2.0-3.0 mL of nitric acid, shaking up the sample, and slowly dropwise adding 0.5ml-1 mL of HFH along the edge of the crucible under continuous shaking; can be properly increased or decreased according to the dissolution condition of the sample, and the final solid phase is completely dissolved without residue as a standard.
The amount of mixed flux and mold release agent, 7.0000g (to the nearest 0.0005g)67Li2B4O7:33LiBO2Mixing the flux, and adding 0.600g of potassium iodide solid which is accurately weighed; the glass wafer with the diameter of 32mm +/-2 mm suitable for X-fluorescence analysis can be obtained according to the proportion, and the diameter of the glass wafer can be increased or decreased in equal proportion if a fluorescence instrument is suitable for analyzing different diameters of the glass wafer.
The recommended measurement conditions for X-fluorescence can be optimized for different X-fluorescences.
The number of control points of a calibration curve is established, and the 6 control points adopted by the method are suitable for the nickel content range of 20% -60% in the ferronickel; the control point may be appropriately adjusted or increased according to the range of the sample to be analyzed.
Accuracy experiment:
a) accuracy test
According to the sample melting method and the analysis conditions, the existing samples are analyzed and compared with the dimethylglyoxime precipitation-EDTA titration method for determination, wherein each group of samples are only used for comparing the difference value between the titration method and the determination value, the specific composition ratio is not critical, and the comparison data is as follows:
comparison data with dimethylglyoxime precipitation-EDTA titration (%)
Figure BDA0003565905240000071
In the accuracy test, the nickel content of the nickel-iron alloy is detected by adopting the independent nickel-iron alloy, the nickel content is measured by a dimethylglyoxime precipitation-EDTA titration method, and the result obtained by the detection method is compared with the measured value of the dimethylglyoxime precipitation-EDTA titration method to obtain a difference value, so that the detection accuracy is sequentially measured.
b) Standard addition recovery test
Adding high-purity nickel into the existing sample according to the sample melting method and the analysis conditions to carry out standard addition recovery test analysis, wherein the data is as follows:
test data (%)
Figure BDA0003565905240000072
c) Precision experiment
6 independent melting samples of the sample SY002109088819 are respectively carried out and analyzed, and the data are calculated as follows:
precision test data (%)
Figure BDA0003565905240000073
The data show that the analysis method has higher accuracy and precision, and the repeatability and the reproducibility can be comparable to those of the traditional chemical method.
Although one embodiment of the present invention has been described in detail, the description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims (10)

1. A detection method for nickel in ferronickel is characterized by comprising the following steps:
s1, dissolving, namely adding a nitric acid solution and a hydrofluoric acid solution into a nickel iron sample, heating and dissolving to obtain a clear solution, and keeping the heating temperature and concentrating the volume until the volume is nearly dry;
s2, tabletting: adding a fusing agent and a release agent into the heated product obtained in the step S1, melting for 5-25min at 1040-1060 ℃, and casting the molten liquid into an analysis sample wafer;
s3, detection: and (4) detecting the analysis sample wafer obtained in the step S2 by using an X fluorescent agent analyzer to obtain the content of nickel in the ferronickel.
2. The method for detecting nickel in ferronickel according to claim 1, wherein the nitric acid solution prepared in step S1 is concentrated nitric acid with an analytical purity and a density of 1.42g/mL, and the volume ratio of the nitric acid solution to water is 1:1, the adding mass of the nitric acid solution is 24-36 times of that of the ferronickel, the hydrofluoric acid is analytically pure, the density is 1.15g/mL, the concentration is 40 wt%, and the adding mass is 5.7-11.4 times of that of the ferronickel.
3. The method for detecting nickel in ferronickel according to claim 1, wherein the concentrated volume of the cleaning solution in step S1 is 0.4-0.6 mL.
4. The method for detecting nickel in ferronickel according to claim 2, wherein the heating temperature in step S1 is 120 ℃.
5. The method for detecting nickel in ferronickel according to claim 1, wherein the flux in step S2 is 67Li2B4O7:33LiBO2High purity mixed flux.
6. The method for detecting nickel in ferronickel according to claim 5, wherein the release agent in step 1 is analytically pure potassium iodide.
7. The method for detecting nickel in ferronickel according to claim 6, wherein the mass ratio of the ferronickel sample, the mold release agent and the solvent is 1:6: 70.
8. The method for detecting nickel in ferronickel according to claim 5, wherein the X-ray fluorescence intensity obtained by the X-ray fluorescence analyzer in the step 3 is compared with a function model established by a standard sample to obtain the nickel content, and the function model is a linear equation established by a high-purity iron-high-purity nickel mixture with a gradient nickel content.
9. The method for detecting nickel in ferronickel according to claim 8, wherein in the equation of equations establishing process, different weights of high purity iron are respectively dissolved in the nitric acid solution in the step S1 at 120 ℃, 40 wt% hydrofluoric acid is added after the corresponding weight of high purity nickel is added, the solution is steamed at 120 ℃ until the volume of the remaining solution is 0.4-0.6mL, the obtained heated product is subjected to sheet preparation according to the step S2, the sample piece is subjected to X-fluorescence intensity detection, the calculated nickel content and the X-fluorescence intensity are established into an equation of equations, and the X-fluorescence analysis detection parameters are adjusted to make the correlation coefficient of the calibration curve be greater than 0.999.
10. The method for detecting nickel in ferronickel according to claim 9, wherein the X-fluorescence analysis detection parameters are:
spectral line: Ni-K alpha; crystal: LiF 200; a collimator: s2; a detector: SC; 2 theta DEG: 48.648, respectively; the detection time is 20 s; voltage: 50 KV; current: 60 mA; pulse height: 100-300.
CN202210307073.XA 2022-03-25 2022-03-25 Method for detecting nickel in nickel iron Pending CN114674856A (en)

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