A method for detecting impurity content in scandium fluoride

Abstract

The present invention relates to the field of chemical detection technology, and in particular to a method for detecting impurity content in scandium fluoride. A method for detecting impurity content in scandium fluoride comprises the following steps: (1) weighing an appropriate amount of scandium fluoride as a sample, mixing and melting the scandium fluoride with sodium hydroxide, sodium carbonate and sodium bicarbonate, and adding water to form a mixed solution after cooling; (2) adding hydrochloric acid and boric acid to the mixed solution to obtain a clear solution; (3) using ICP-OES to detect the spectral intensity of different impurities in the clear solution, and calculating the impurity content in scandium fluoride according to a standard curve. The detection method of the present invention has reasonable process, safety and reliability, simple operation, low cost, and meets production needs.

Description

Technical Field

[0001] The invention relates to the technical field of chemical detection, and in particular to a method for detecting impurity content in scandium fluoride. Background Art

[0002] Scandium fluoride is an important intermediate product in the production of high-purity metallic scandium. The impurity content in scandium fluoride affects the quality of high-purity metallic scandium. Therefore, it is particularly important to accurately detect the impurity content in scandium fluoride. The impurity content in scandium fluoride is generally at the ppm level. The existing detection methods have a long sample dissolution time, which has the risk of introducing contamination, and the amount of perchloric acid reagent added continuously during the process is large, and the detection cost is high. Traditional detection methods require the solid sample to be converted into a solution. For example, after using perchloric acid to smoke and remove fluorine, the solid scandium fluoride is converted into an aqueous solution for detection; existing detection methods (such as Figure 1 As shown in the figure, it takes 32-40 hours of continuous perchloric acid fuming to dissolve the solid scandium fluoride into a clear aqueous solution. This method has the disadvantages of long dissolution time, risk of introducing impurity contamination, high consumption of perchloric acid reagent, and high detection cost. In addition, there is the problem of poor solubility of scandium fluoride samples. It is difficult to completely convert it into a solution by traditional methods, making traditional detection methods impossible to carry out.

[0003] Traditional detection methods for solid samples include direct instrument detection methods such as XRF, GD-OES or GD-MS. Although these methods can directly test the impurity content in solid samples, they have problems such as expensive equipment, difficult sample preparation and difficulty in obtaining standard samples. Summary of the invention

[0004] The invention uses a small amount of reagent to dissolve the scandium fluoride solid into a clear aqueous solution, and then uses ICP-OES (inductively coupled plasma emission spectrometer) to directly detect the content of impurities in the scandium fluoride. The dissolution time is short, the amount of reagent used is small, the detection efficiency is high, and the cost is low.

[0005] To solve the above problems, the technical solution of the present invention is as follows:

[0006] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0007] (1) Weighing an appropriate amount of scandium fluoride as a sample, mixing and melting the scandium fluoride with sodium hydroxide, sodium carbonate and sodium bicarbonate, and adding deionized water to form a mixed solution after cooling;

[0008] (2) adding hydrochloric acid and boric acid to the mixed solution to obtain a clear solution;

[0009] (3) The spectral intensity of different impurities in the clear solution was detected by ICP-OES, and the impurity content in scandium fluoride was calculated based on the standard curve.

[0010] In this method, the key point is to use sodium hydroxide, sodium carbonate, and sodium bicarbonate reagents to convert the scandium fluoride sample into the hydroxide of scandium, and then use hydrochloric acid to acidify and dissolve the hydroxide of scandium into a scandium chloride solution. In this process, each impurity element also changes its ion form for easy testing. The generated fluoride ions are complexed with boric acid to eliminate their interference, while avoiding the corrosion of fluoride ions on glass equipment and ICP-OES instrument injection system; when selecting the test wavelength of each impurity element, the instrument test background is fully considered to eliminate its interference with the test results. Finally, the content of each impurity element is calculated based on the working curve fitted by the standard solution tested by the ICP-OES instrument and the measured value of the sample solution.

[0011] Hydrochloric acid is added to the mixed solution, part of the hydrochloric acid reacts with scandium hydroxide, and part of the hydrochloric acid neutralizes sodium hydroxide, sodium carbonate and sodium bicarbonate, and ensures that the solution has a 5% acidity medium to meet the requirements of ICP-OES testing.

[0012] Boric acid is added to a mixed solution containing hydrochloric acid, and the boric acid reacts with fluoride ions to generate BF4 -1 Complex ion, BF4 -1 The complex ions exist in ionic form and will not form precipitation, eliminating the corrosion of F ions on the ICP-OES injection system.

[0013] Preferably, the mass ratio of scandium fluoride to sodium hydroxide, sodium carbonate and sodium bicarbonate is 1:5:3:3.

[0014] Preferably, weigh 0.1 g of the scandium fluoride sample.

[0015] Preferably, 10 mL of deionized water is added to the mixed solution in step (1).

[0016] The addition of deionized water in this process does not need to be strictly controlled, and about 10 mL is sufficient; the purpose of adding water is to fully mix the scandium fluoride sample with sodium hydroxide, sodium carbonate, and sodium bicarbonate.

[0017] Preferably, the melting is carried out at 180-220°C with continuous stirring for 30-60 minutes.

[0018] Scandium fluoride does not react with sodium hydroxide, sodium carbonate, and sodium bicarbonate at room temperature. It must react evenly at a high temperature of 180-220°C to form a uniform reactant.

[0019] Preferably, in step (2), 5-10 mL of 40 g / L boric acid solution is added, shaken and allowed to stand for 30 min.

[0020] Preferably, in step (2), deionized water is added to make the volume to 100 mL.

[0021] Preferably, the ICP-OES instrument setting parameters are: injection speed 30r / min, plasma power 1200W.

[0022] Both the injection speed and the plasma power will significantly affect the detection sensitivity. In the present invention, the injection speed and the plasma power will obtain the best sensitivity.

[0023] Preferably, the test method of the standard curve is: respectively introducing the prepared standard solutions into ICP-OES to test the emission intensity of the elements to be tested, and obtaining a working curve fitted by the ICP-OES standard solution, that is, the standard curve.

[0024] Preferably, the standard solutions are respectively magnesium solution with C(Mg)=1000μg / mL, bismuth solution with C(Bi)=1000μg / mL, barium solution with C(Ba)=1000μg / mL, holmium solution with C(Ho)=100μg / mL, samarium solution with C(Sm)=100μg / mL, thulium solution with C(Tm)=100μg / mL, vanadium solution with C(V)=1000μg / mL, and selenium solution with C(Se)=1000μg / mL.

[0025] The test sample is then introduced into the ICP-OES test to obtain the test value; the impurity content is calculated based on the working curve fitted by the ICP-OES standard solution and the test value.

[0026] Preferably, ICP-OES is used to detect the spectral intensity of different impurities, the concentration value x of the impurity element is calculated according to the linear least squares method, and the impurity content in the sample is calculated according to the weighed scandium fluoride sample amount and the dilution factor.

[0027] The impurity content concentration value is calculated by the linear least squares method:

[0028] y=k·x+b

[0029] Where:

[0030] y——Emission intensity of the element to be measured, in CPS;

[0031] x——the test concentration value of the impurity element in the sample solution, in micrograms per milliliter;

[0032] k, b——constants;

[0033] Preferably, the test wavelengths of each impurity element are shown in the following table:

[0034] Table 1 Test wavelengths of various impurity elements

[0035]

[0036] Preferably, the standard solution preparation method for ICP-OES instrument calibration is:

[0037] Different single-element reagents were prepared into single-element standard solutions with a concentration of 10 μg / mL: 1.00mL, 1.00mL, 1.00mL, 1.00mL, 10.00mL, 10.00mL, 10.00mL, 1.00mL, 1.00mL of each single-element standard solution of C(Mg)=1000μg / mL, C(Bi)=1000μg / mL, C(Ba)=1000μg / mL, C(Ho)=100μg / mL, C(Sm)=100μg / mL, C(Tm)=100μg / mL, C(V)=1000μg / mL, and C(Se)=1000μg / mL were accurately taken in a 100mL volumetric flask. Each element exists in the form of ions. 5mL of hydrochloric acid was added to ensure that the standard solution was a 5% acid medium. The volume was made up to 100mL with deionized water and shaken well.

[0038] Furthermore, different single-element reagents were prepared into single-element solutions with concentrations of 0.00, 0.01, 0.02, 0.03, 0.05, 0.1, 0.4, 0.6, and 1.0 μg / mL: 0.0, 0.1, 0.2, 0.3, 0.5, 1.0, 4.0, 6.0, and 10 mL of each single-element standard solution were accurately taken into a 100-mL volumetric flask, 5 mL of hydrochloric acid was added to ensure that the standard solution was a 5% acid medium, and the volume was made up to 100 mL with deionized water and shaken well.

[0039] The present invention also conducts precision and spike recovery experiments, which show that the detection method of the present invention is easy to operate, the results are accurate, and the stability and accuracy of the detection results meet the relevant requirements. In addition, the detection method of the present invention has reasonable process, safety and reliability, simple operation, low cost, and meets production needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The following is a detection flow chart of the prior art.

[0041] Figure 2 It is a detection flow chart of the present invention.

[0042] Figure 3 This is a diagram of Example 1 after dissolution;

[0043] Figure 4 is the standard curve of each element;

[0044] Figure 5 This is a diagram of Example 3-10 after dissolution;

[0045] Figure 6 It is the detection flow chart of Example 3-10. DETAILED DESCRIPTION

[0046] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0048] Example 1

[0049] 1. Main instruments and equipment: ICP-OES, graphite furnace

[0050] 2. Reagents: hydrochloric acid (GR), nitric acid (GR), sodium hydroxide (GR), sodium carbonate (GR), sodium bicarbonate (GR), boric acid (AR), standard solution (Mg, Bi, Ba, V, Se = 1000ug / mL), standard solution (Ho, Sm, Tm, = 100ug / mL);

[0051] 3. Experimental process

[0052] according to Figure 2 As shown, the contents of different impurity elements in scandium fluoride are detected respectively:

[0053] 3.1 Accurately weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample into a 250 mL polytetrafluoroethylene beaker;

[0054] 3.2 Add 0.5g (accurate to 0.01g) sodium hydroxide, 0.3g (accurate to 0.01g) sodium carbonate, and 0.3g (accurate to 0.01g) sodium bicarbonate;

[0055] 3.3 Add 10 mL of deionized water to the above reagents and shake gently;

[0056] 3.4 Place the above mixture on an electric furnace for heating and digestion, and heat to dryness at 180-220℃;

[0057] 3.5 Remove and cool to room temperature, add 30mL hydrochloric acid, and heat at 180-220℃ for 30-60min;

[0058] 3.6 After cooling to room temperature, add 5-10 mL of 40 g / L boric acid solution, shake well and let stand for 30 minutes

[0059] 3.7 Add deionized water to make the solution 100 mL, shake well, and cool to room temperature. The solution is a clear aqueous solution. Figure 3.

[0060] 3.8ICP test, plasma settings: flushing pump speed 45rpm, analysis pump speed 30rpm, RF power 1200W, pump stabilization time 5s, auxiliary gas flow 0.5L / min, vertical observation height 12.0mm;

[0061] The test wavelengths of each impurity element are shown in the table below:

[0062] Table 2 Test wavelengths of various impurity elements

[0063]

[0064] 3.9 Add Sc standard and use ICP-OES to detect the emission intensity of impurity elements to confirm the interference of Sc on impurity elements, see the table below:

[0065] Table 3 Emission intensity of impurity elements detected by ICP-OES with Sc standard

[0066]

[0067] It can be seen from the above table that as the Sc content increases, the intensity of the impurity elements tested by ICP-OES does not change much, which means that the Sc element has little interference with the test of the impurity elements of the present invention.

[0068] 3.10 Prepare standard solution:

[0069] Different single element reagents were prepared into mixed element standard solutions with a concentration of 10 μg / mL: accurately take 1.00mL, 1.00mL, 1.00mL, 1.00mL, 10.00mL, 10.00mL, 10.00mL, 1.00mL, 1.00mL of C(Mg)=1000μg / mL, C(Bi)=1000μg / mL, C(Ba)=1000μg / mL, C(Ho)=100μg / mL, C(Sm)=100μg / mL, C(Tm)=100μg / mL, C(V)=1000μg / mL, C(Se)=1000μg / mL single element standard solutions and put them in the same 100mL volumetric flask. Each impurity element exists in the form of ions. Add 5mL of hydrochloric acid to ensure that the standard solution is a 5% acidity medium, add deionized water to make up to 100mL, and shake well.

[0070] Furthermore, different single-element reagents were prepared into single-element standard solutions with concentrations of 0.00, 0.01, 0.02, 0.03, 0.05, 0.1, 0.4, 0.6, and 1.0 μg / mL: Accurately take appropriate single-element standard solutions, put them in a 100-mL volumetric flask, add 5 mL of hydrochloric acid to ensure that the standard solution is a 5% acid medium, make up to 100 mL with deionized water, and shake well.

[0071] 3.11 Drawing of standard curve: Under the same conditions as the sample solution, measure the absorbance of the standard solution series, deduct the standard blank, and draw the standard curve with the mass concentration of each element as the horizontal axis and the emission intensity as the vertical axis. The obtained curve is as follows: Figure 4 shown.

[0072] 3.12 Complete the standard curve test of impurity elements, introduce the sample into ICP-OES to obtain the test value; calculate the concentration value x of the element to be tested according to the linear least squares method, and finally calculate the content of impurity elements in the sample according to the sample weight and dilution multiple.

[0073] The impurity element content concentration value is calculated using the linear least squares method:

[0074] y=k·x+b

[0075] Where:

[0076] y——Emission intensity of the element to be measured, in CPS;

[0077] x——the test concentration value of the impurity element in the sample solution, in micrograms per milliliter;

[0078] K, b——constants;

[0079] 4. Results:

[0080] The precision of the detection method of the present invention

[0081] Weigh 1 sample and test it according to the detection method of the present invention. The results are as follows:

[0082] Table 4 Test results and precision of 10 parallel measurements of the same sample

[0083]

[0084] The calculation formula of standard deviation SD is:

[0085]

[0086] The calculation formula of relative standard deviation RSD is:

[0087]

[0088] The precision of the samples tested according to the present invention complies with Table F.2 (coefficient of variation within the laboratory) in GB / T27404-2008.

[0089] 4.2 Recovery rate of the present invention

[0090] A scandium fluoride sample was selected and treated according to the detection method of the present invention. The results were measured. A certain weight of the sample and the corresponding element standard to be measured were weighed and recorded as the nominal value. A recovery rate experiment was performed. The results are as follows:

[0091] Table 5 Recovery of Example 1

[0092]

[0093] As can be seen from the above table, the recovery rate of the method for determining the impurity content in scandium fluoride using the detection method of the present invention is 85.6 to 100.1, which meets the requirements of the recovery rate test in the national standard GB / T27404-2008 "Laboratory Quality Control Specifications for Physical and Chemical Testing of Food".

[0094] Example 2

[0095] A test reagent for the impurity content in scandium fluoride comprises: hydrofluoric acid (GR), nitric acid (AR), deionized water, and impurity element standard solution.

[0096] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0097] Weigh 0.1g (accurate to 0.0001g) of sample into a polytetrafluoroethylene beaker, add 10mL hydrofluoric acid and 20mL nitric acid, heat on an electric stove at 180-220℃ for 2 hours, remove and cool to room temperature, add 5mL boric acid (40g / L), shake well and let stand for 30min, dilute to 100mL, shake well, cool to room temperature, and the turbid aqueous solution is visible. Figure 5 After filtration, the content of impurity elements is accurately detected according to steps 3.8 to 3.12 of the first implementation scheme.

[0098] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 2, respectively, and the results were as follows:

[0099] Table 5 Test results comparison 1

[0100]

[0101] It can be seen from the above table that the detection result of Example 2 is significantly lower than that of the method of Example 1, and the method of Example 2 is an unclear aqueous solution after digestion; the precision and the spiked recovery rate cannot meet the requirements, so the method of Example 1 is more accurate than the method of Example 2.

[0102] Example 3

[0103] A method for detecting impurity content in scandium fluoride, the test reagents include: perchloric acid (GR), boric acid (AR), deionized water

[0104] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0105] Weigh 0.1g (accurate to 0.0001g) of scandium fluoride sample, add 5mL of deionized water to a 250mL polytetrafluoroethylene beaker, add 5mL of perchloric acid in portions, and continue to heat and smoke on an electric furnace for 32-40 hours. During the process, perchloric acid is continuously added until it becomes a clear aqueous solution. Add 5-10mL of boric acid (40g / L), shake well and place for 30min, transfer to a 100mL volumetric flask, make up to volume and shake well; accurately detect the impurity content according to steps 3.8 to 3.12 in Implementation Plan 1.

[0106] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 3, respectively. The results are as follows:

[0107] Table 6 Test results comparison 2

[0108]

[0109]

[0110] It can be seen from the above table that the result of Mg tested in Example 3 is slightly higher than that in Example 1, and the results of other elements are not much different from those in Example 1.

[0111] The test cost comparison between the method of Example 1 and the method of Example 3 is as follows:

[0112] Table 7 Cost comparison

[0113]

[0114] The detection cost of the method in Example 1 is about RMB 7.5, and the detection cost of the method in Example 3 is about RMB 46. The detection cost of the method in Example 1 is significantly lower than that in Example 3.

[0115] Example 4

[0116] A reagent for detecting impurity content in scandium fluoride includes: hydrochloric acid (GR), nitric acid (GR), boric acid (AR), deionized water

[0117] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0118] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample into a 250 mL polytetrafluoroethylene beaker, add 5 mL of deionized water, add 9 mL of hydrochloric acid and 3 mL of nitric acid in portions, heat on an electric furnace at 180-220° C. for 2 hours, remove and cool to room temperature, add 5 mL of boric acid (40 g / L), shake well and let stand for 30 minutes, transfer to a 100 mL volumetric flask, make up to volume and shake well to obtain a turbid aqueous solution; after filtering, accurately detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0119] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 4, respectively. The results are as follows:

[0120] Table 8 Test results comparison 3

[0121]

[0122]

[0123] It can be seen from the above table that the detection result of Example 4 is lower than that of Example 1, and Example 4 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0124] Example 5

[0125] A test reagent for the impurity content in scandium fluoride includes: sodium hydroxide, hydrochloric acid, boric acid, deionized water

[0126] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0127] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample, put it into a 50 mL platinum crucible, add 2 g of sodium hydroxide, melt it at 650 ° C for 2 hours, cool it to room temperature, add 20 mL of water, heat it at 180-220 ° C for 30 min, cool it to room temperature, add 50 mL of hydrochloric acid, heat it to dissolve, and cool it to room temperature to obtain a turbid aqueous solution; after filtering, accurately detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0128] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 5, respectively. The results are as follows:

[0129] Table 8 Test results comparison 4

[0130]

[0131] It can be seen from the above table that the detection result of Example 5 is lower than that of Example 1, and Example 5 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0132] Example 6

[0133] A test reagent for impurity content in scandium fluoride includes: borax (AR), hydrochloric acid (GR), boric acid, and deionized water. A method for detecting impurity content in scandium fluoride includes the following steps:

[0134] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample into a 100 mL polytetrafluoroethylene beaker, add 2 g of borax, heat and evaporate to dryness at 180-220° C. on an electric furnace for 1 hour, remove and cool to room temperature, add 50 mL of hydrochloric acid, heat, and cool to room temperature to form a turbid aqueous solution. After filtering, accurately detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0135] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 6, respectively. The results are as follows:

[0136] Table 9 Test results comparison 5

[0137]

[0138] It can be seen from the above table that the detection result of Example 6 is lower than that of Example 1, and Example 6 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0139] Example 7

[0140] A test reagent for impurity content in scandium fluoride includes: sodium hydroxide (AR), sodium bicarbonate (AR), hydrochloric acid (GR), boric acid, deionized water

[0141] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0142] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample, add 2 g of sodium hydroxide and 2 g of sodium bicarbonate into a 100 mL polytetrafluoroethylene beaker, heat and evaporate to dryness at 180-220° C. for 1 hour, remove and cool to room temperature, add 50 mL of hydrochloric acid, heat and dissolve, cool to room temperature to form a turbid aqueous solution. After filtering, accurately detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0143] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 7, respectively. The results are as follows:

[0144] Table 10 Test results comparison 6

[0145]

[0146] It can be seen from the above table that the detection result of Example 7 is lower than that of Example 1, and Example 7 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0147] Example 8

[0148] A reagent for testing the impurity content in scandium fluoride includes: sodium hydroxide (AR), sodium carbonate (AR), hydrochloric acid (GR), boric acid, deionized water

[0149] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0150] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample, add 2 g of sodium hydroxide and 2 g of sodium carbonate into a 100 mL polytetrafluoroethylene beaker, heat and evaporate to dryness at 180-220° C. for 1 hour, remove and cool to room temperature, add 50 mL of hydrochloric acid, heat and dissolve, cool to room temperature to obtain a turbid aqueous solution. After filtering, accurately detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0151] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 8, respectively. The results are as follows:

[0152] Table 11 Test results comparison 7

[0153]

[0154] It can be seen from the above table that the detection result of Example 8 is lower than that of Example 1, and Example 8 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0155] Example 9

[0156] A reagent for testing the impurity content in scandium fluoride includes: sodium bicarbonate (AR), sodium carbonate (AR), hydrochloric acid (GR), boric acid, deionized water

[0157] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0158] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample, add 2 g of sodium bicarbonate and 2 g of sodium carbonate into a 100 mL polytetrafluoroethylene beaker, heat and evaporate to dryness at 180-220°C for 1 hour, remove and cool to room temperature, add 50 mL of hydrochloric acid, heat and dissolve, cool to room temperature to obtain a turbid aqueous solution. After filtering, detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0159] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 9, respectively. The results are as follows:

[0160] Table 12 Test results comparison 8

[0161]

[0162]

[0163] It can be seen from the above table that the detection result of Example 9 is lower than that of Example 1, and Example 9 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0164] Example 10

[0165] A reagent for testing the impurity content in scandium fluoride comprises: sodium peroxide (AR), hydrochloric acid (GR), boric acid and deionized water.

[0166] A method for detecting impurity content in scandium fluoride comprises the following steps:

[0167] Weigh 0.1 g (accurate to 0.0001 g) of scandium fluoride sample into a 100 mL polytetrafluoroethylene beaker, add 2 g of sodium peroxide, heat at 180-220° C. to evaporate for 1 hour, remove and cool to room temperature, add 40 mL of hydrochloric acid, heat to dissolve, and cool to room temperature to form a turbid aqueous solution. After filtering, accurately detect the impurity content according to steps 3.8 to 3.12 in Example 1.

[0168] Four batches of scandium fluoride were tested using the methods of Example 1 and Example 10, respectively. The results are as follows:

[0169] Table 13 Test results comparison 9

[0170]

[0171] It can be seen from the above table that the detection result of Example 10 is lower than that of Example 1, and Example 10 is an unclear aqueous solution after digestion; the precision and spiked recovery rate cannot meet the requirements.

[0172] The invention also carries out precision and spike recovery experiments, and the stability and accuracy of the test results meet the relevant requirements. In addition, the detection method of the invention has reasonable process, is safe and reliable, is easy to operate, has low cost, and meets production needs.

[0173] The above contents are only preferred specific implementation modes of the present invention, and it cannot be determined that the specific implementation modes of the present invention are limited to these descriptions. For any technician familiar with this technical field, other implementation modes derived without departing from the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting impurity content in scandium fluoride, characterized in that: The steps include: (1) Weighing an appropriate amount of scandium fluoride as a sample, mixing and melting the scandium fluoride with sodium hydroxide, sodium carbonate and sodium bicarbonate, and adding deionized water to form a mixed solution after cooling; (2) adding hydrochloric acid and boric acid to the mixed solution to form a clear solution; (3) using ICP-OES to detect the spectral intensity of different impurities in the clarified solution, and calculating the impurity content in scandium fluoride according to the standard curve; The mass ratio of scandium fluoride to sodium hydroxide, sodium carbonate and sodium bicarbonate is 1:5:3:3; The mixing and melting is continued at 180-220°C for 30-60 minutes.

2. The detection method according to claim 1, characterized in that: In step (2), add 5-10 mL of 40 g / L boric acid solution, shake well and let stand for 30 minutes.

3. The detection method according to claim 1, characterized in that: The testing method of the standard curve is: respectively introducing the prepared standard solution into ICP-OES to test the emission intensity of the element to be tested, and obtaining the working curve fitted by the ICP-OES standard solution, that is, the standard curve.

4. The detection method according to any one of claims 1 to 3, characterized in that: The spectral intensity of different impurities was detected by ICP-OES, and the concentration value x of the impurity element was calculated according to the linear least squares method. The impurity content in the sample was calculated according to the weighed scandium fluoride sample amount and the dilution multiple.

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