Method for rapidly detecting content of aluminum oxide

Abstract

The invention relates to the technical field of detection, in particular to a method for rapidly detecting the content of aluminum oxide, which comprises the following steps: S1, dissolving a material to be detected in hydrochloric acid, and then completely removing carbon dioxide; s2, carrying out spectrum determination; and S3, calculating the content of aluminum trioxide in calcium carbonate.

Description

Technical Field

[0001] The invention relates to the field of detection technology, and in particular to a method for quickly detecting aluminum oxide content. Background Art

[0002] In the rare earth extraction and separation process, the mixed rare earth chloride is extracted, washed, and stripped to obtain the praseodymium-neodymium chloride solution, which will form Al 3+ enrichment, so that the Al in the stripped praseodymium-neodymium solution 2 O 3 / REO reaches more than 0.050%, high content Al 3+ The praseodymium-neodymium solution is then used to obtain Al(OH) 3 The precipitate is colloidal and large in size, with poor flocculation and filtration performance, and difficult solid-liquid separation. 3+ The precipitation rate of rare earth in the hydrolysis process is large, making solid-liquid separation more difficult, resulting in the product Cl - , Ca 2+ 、Na + Impurities seriously affect product quality, causing the non-rare earth impurity alumina in praseodymium-neodymium carbonate and praseodymium-neodymium oxide to seriously exceed the standard, which cannot meet market requirements.

[0003] Al is obtained by multi-stage saponification, extraction, washing and stripping of organic cyclopentane acid 2 O 3 / REO is less than 0.025% of the praseodymium-neodymium liquid. The product quality of this process is stable and reliable, but there are also some problems. First, a set of special extraction and separation lines must be established, which increases fixed asset investment. Secondly, organic cyclohexane acid needs to be saponified and stripped, which consumes the corresponding alkali and acid. At the same time, 10% of the praseodymium and neodymium will enter the Al 3+ In the stripping solution, it is necessary to use oxalic acid precipitation, which is more expensive, to recover Al 3+ The praseodymium and neodymium in the stripping solution increase production costs.

[0004] Based on the above influencing factors, there are two sources of alumina: one is from the raw material mixed rare earth chloride, which can be controlled by pre-treatment aluminum removal process; the other is from the Al in the extracted saponifier. 2 O 3 Impurities, control Al in saponification raw materials 2 O 3 Therefore, the amount of Al in the saponifier raw material is controlled 2 O 3 The content of Al in saponifier raw materials is particularly important. 2 O 3 There is no relevant rapid and accurate instrument detection method for content determination, which cannot provide timely control for raw material quality. Summary of the invention

[0005] The purpose of the present invention is to provide a method for quickly detecting the content of aluminum oxide, so as to solve the problem that the content of aluminum oxide in the saponifier raw material is not high. 2 O 3 There is no rapid and accurate means to determine the content, and it is impossible to provide timely technical support for raw material quality control.

[0006] The invention discloses a method for quickly detecting aluminum oxide content, comprising the following steps:

[0007] S1. Dissolve the material to be tested in hydrochloric acid and then remove carbon dioxide;

[0008] S2. Perform spectral measurement;

[0009] S3. Calculate the content of aluminum oxide in calcium carbonate.

[0010] Furthermore, the spectral measurement is sub-plasma spectral measurement.

[0011] Furthermore, the sub-plasma spectrum measurement power is 1000W±50W.

[0012] Furthermore, the spectral measurement sets up an analysis group, a blank experiment group and a standard group. The analysis group uses a solution containing the material to be tested for measurement, the blank experiment group uses a solution without the material to be tested in the analysis group for measurement, and the standard group uses a calcium carbonate matrix solution and an aluminum standard solution for measurement.

[0013] Furthermore, the acidity of the solutions in the blank analysis group, the blank experimental group and the standard group were all between 1:19 and 1:9.

[0014] Furthermore, a standard curve is drawn through the standard group, and the concentration of the element to be measured in the analysis group is obtained according to the standard curve.

[0015] Furthermore, the calcium carbonate matrix solution and the aluminum standard solution are mixed with hydrochloric acid and then measured. After mixing, the acidity is between 1:19 and 1:9, and the matrix concentration is 10±1 mg / mL.

[0016] Furthermore, the calcium carbonate matrix solution is prepared by dissolving dried anhydrous calcium carbonate in hydrochloric acid, then removing carbon dioxide, and diluting the solution to contain 100 mg of calcium carbonate per mL after cooling.

[0017] Furthermore, the anhydrous calcium carbonate ω (CaCO 3 )≥99.99%,ω(Al 2 O 3 )≤5ppm.

[0018] Furthermore, the aluminum standard solution is prepared by pre-immersing aluminum foil in dilute hydrochloric acid, washing with anhydrous ethanol, drying, adding water, hydrochloric acid and nitric acid, dissolving at low temperature, cooling to room temperature, and then diluting to 1 mL of solution containing 1 mg of aluminum.

[0019] Furthermore, the metal aluminum foil w(Al)≥99.9%.

[0020] Furthermore, the nitric acid is added dropwise.

[0021] Furthermore, the blank group

[0022] Furthermore, the content of aluminum oxide ωAl 2 O 3 %The calculation method is:

[0023]

[0024] Where:

[0025] ρ0—the concentration of the element to be tested in the blank test solution output by the computer, in nanograms per milliliter;

[0026] ρ1—the concentration of the element to be measured in the analysis group output by the computer, in nanograms per milliliter;

[0027] V—total volume of test solution, in milliliters;

[0028] m—mass of the sample, in grams.

[0029] Furthermore, the carbon dioxide is removed by boiling.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. A breakthrough in the instrumental detection method of aluminum oxide content in the raw materials of extraction saponifiers has been achieved

[0032] The method utilizes the high-precision characteristics of the plasma emission spectrometer to achieve accurate detection of the aluminum oxide content in the extraction saponifier, thereby improving the detection limit of the aluminum oxide impurity content.

[0033] 2. Improve detection efficiency

[0034] Through this method, the detection of alumina content can be completed in a shorter time, greatly improving production efficiency. This helps companies reduce production costs and improve market competitiveness. In addition, this method has a high degree of automation and can be seamlessly connected with other production processes to achieve intelligent and automated production lines.

[0035] 3. Technological innovation and market advantages

[0036] Owning this patent means that a technological breakthrough has been made in the relevant technical field, which can give enterprises an advantage in market competition. In addition, the method may be original, which can help enterprises form a differentiated competitive strategy in the market and increase market share.

[0037] 4. Economic and social benefits

[0038] Economic benefits: Accurate testing can ensure the quality control of saponifier products, thereby improving the market acceptance of products and bringing higher economic benefits to enterprises. In addition, the improvement of production efficiency and product quality also helps to reduce the scrap rate in the production process and further reduce costs.

[0039] Social benefits: The application of this invention can promote the development of related industries and improve the technical level of the entire industrial chain. At the same time, the precise detection method can also help protect the rights and interests of consumers and improve the public's trust in products.

[0040] 5. Specific benefit examples

[0041] For the manufacturing industry: Accurate alumina content testing helps manufacturers produce products that better meet specifications and requirements, reduce the proportion of unqualified products, and reduce production risks.

[0042] For consumers: Consumers can buy products with more reliable quality, which increases their trust and loyalty to the brand.

[0043] For the environment: Accurate testing helps ensure the safety and environmental friendliness of saponifiers during use and reduces adverse impacts on the environment.

[0044] In summary, the method of using patented plasma emission spectrometer to detect the content of aluminum oxide in extraction saponifiers has significant benefits, including improving detection accuracy and production efficiency, promoting technological innovation and market development, and protecting consumer rights and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only represent some embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 , Figure 2 This is a screenshot of the precision experimental test results of standard sample 1# of the present invention.

[0047] Figure 3 , Figure 4This is a screenshot of the precision test results of the 2# standard sample of the present invention.

[0048] Figure 5 , Figure 6 This is a screenshot of the precision test results of the 3# standard sample of the present invention.

[0049] Figure 7 , Figure 8 This is a screenshot of the precision test results of the 4# standard sample of the present invention.

[0050] Fig. 9 , Fig.10 This is a screenshot of the precision test results of the 5# standard sample of the present invention.

[0051] Fig.11 This is a screenshot of the spectrum interference situation of the spectrum line tracing test at 396.152nm of the present invention.

[0052] Fig.12 This is a screenshot of the spectrum interference situation of the spectrum line tracing test at 309.271nm of the present invention.

[0053] Fig.13 This is a screenshot of the spectrum interference situation of the spectrum line tracing test at 257.509nm of the present invention.

[0054] Fig.14 This is a screenshot of the spectrum interference situation of the spectrum line tracing test at 237.312nm of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0056] Example 1

[0057] This embodiment discloses a method for quickly detecting the content of aluminum oxide, comprising the following steps:

[0058] The following steps are involved:

[0059] S1. Place the material to be tested in a 100mL beaker, add a small amount of water to moisten it, slowly add 10mL of hydrochloric acid to dissolve until it is clear, boil to remove all carbon dioxide, cool to room temperature, transfer the solution into a 1000mL volumetric flask, dilute to the scale with water, mix well, and test;

[0060] S2. Perform sub-plasma spectrum measurement using an inductively coupled plasma emission spectrometer: resolution <0.006nm (at 200nm), light source: argon plasma light source, power: 1000W±50W;

[0061] An analysis group, a blank experimental group and a standard group are set, wherein the analysis group is measured using a solution containing the material to be measured, the blank experimental group is measured using a solution in the analysis group without the material to be measured, and the standard group is measured using a calcium carbonate matrix solution and an aluminum standard solution;

[0062] Calcium carbonate matrix solution: weigh 20.000 g of anhydrous calcium carbonate [ω(CaCO 3 )≥99.99%,ω(Al 2 O 3 )≤5ppm] in a 200ml beaker, add 40mL hydrochloric acid to dissolve, boil to remove all carbon dioxide. Cool to room temperature, transfer the solution into a 1000mL volumetric flask, dilute to scale with water, mix well, and 1mL of this solution contains 100mg calcium carbonate.

[0063] Aluminum standard storage solution: accurately weigh 0.2000g of aluminum foil [w(Al)≥99.9%] (pre-soaked in dilute hydrochloric acid, cleaned with anhydrous ethanol, and dried with an infrared lamp) in a 200mL beaker, add 10mL of water, add 20mL of hydrochloric acid, drop 2mL of nitric acid, dissolve at low temperature, cool to room temperature, transfer the solution to a 200mL volumetric flask, dilute to scale with water, and shake well. This solution contains 1mg aluminum in 1mL;

[0064] Aluminum standard stock solution (100 μg / mL): Pipette 10.00 mL of aluminum standard solution into a 100 mL volumetric flask, dilute to scale with water, and mix. 1 mL of this solution contains 100 μg aluminum;

[0065] According to Table 1, transfer the corresponding contents of calcium carbonate matrix solution and aluminum standard solution into 5 100mL volumetric flasks, add 5mL of hydrochloric acid to ensure that the acidity is 1+19 and the matrix concentration is 10mg / mL, dilute to the scale with water, mix well, and set aside.

[0066] Table 1

[0067]

[0068] Preparation of blank experimental group solution

[0069] According to Table 2, transfer aluminum standard solution into three 100mL volumetric flasks, add 5mL hydrochloric acid to ensure the acidity is 1+19, dilute to the scale with water, mix well, and set aside.

[0070] Table 2

[0071]

[0072]

[0073] Determination

[0074] Select the analytical lines 237.312nm and 257.509nm to draw the standard curve, see Table 3

[0075] Table 3

[0076] element Analysis line 1(nm) Analysis line 2 (nm) Al 237.312 257.509

[0077] S3. Calculate the content of aluminum oxide in calcium carbonate ωAl 2 O 3 %count:

[0078]

[0079] Where:

[0080] ρ0—the concentration of the element to be tested in the blank experimental group solution output by the computer, in nanograms per milliliter (μg / mL);

[0081] ρ1—the concentration of the element to be measured in the analysis group output by the computer, in nanograms per milliliter (μg / mL);

[0082] V—total volume of test solution, in milliliters (mL);

[0083] m—mass of the sample, in grams (g);

[0084] 1.8895—Conversion factor between alumina and elemental aluminum.

[0085] The above analysis method and the detection method specified in GB / T19281-2014 "The sample is masked with ascorbic acid to prevent the interference of iron. In a hexamethylenetetramine medium with a pH value of 5.5 to 6.1, aluminum and chrome azuro-S generate a purple-red complex. The absorbance is measured at a wavelength of 545nm by a spectrophotometer" were compared with a series of standard samples. The experimental results show that the accuracy and reproducibility of the instrument method can meet the detection requirements. The details are as follows:

[0086] 1. Accuracy experiment

[0087] Two detection methods were used to test the Al content of 1#~5# standard samples. 2 O 3 Content detection, such as Figure 1-Figure 10 The test results are shown in Table 4.

[0088] Table 4 Comparison of analysis results

[0089] Standard sample serial number Example 1 Test results (%) GB / T19281 test results (%) 1#(Al2O3=0.015%) 0.0145 0.0146 2#(Al2O3=0.042%) 0.0421 0.0418 3#(Al2O3=0.086%) 0.085 0.086 4#(Al2O3=0.126%) 0.126 0.123 5#(Al2O3=0.198%) 0.194 0.199

[0090] Precision experiment

[0091] The Al in 1#~5# standard samples was quantified by the method in Example 1. 2 O 3 Eleven repeatability tests were performed to verify the precision of the method.

[0092] Table 5 Precision experimental data

[0093]

[0094] Comparative Example 1

[0095] The use of Al395.152nm and 309.271nm as analytical spectral lines resulted in poor linearity and a large deviation between the test results and the actual content. The standard curve drawn using 395.152nm was not linear, and the linear R 2 The value is 0.8125, which cannot be used as a spectrum line for analysis and testing; 309.271nm has linearity, R 2 The value is 0.9995, but the test standard 1# sample (Al 2 O 3 : 0.015%) the result was 0.028%.

[0096] Comparative Example 2

[0097] A method for rapidly and accurately detecting the content of aluminum oxide in a raw material for rare earth extraction and saponification comprises the following steps:

[0098] S1. Confirm the basic composition of the main chemical components of rare earth extraction and saponification raw materials

[0099] Using X-ray fluorescence spectrometry (XRF) semi-quantitative analysis, the main element was determined to be CaCO3; the trace impurity elements were determined to be Al, Mg, Fe, Mn, Cu, and Ba.

[0100] S2. Select the analysis line of Al element according to the detection requirements. Draw the profile spectrum of the emission spectrum of the measured element at a matrix concentration of 10 mg / mL, and observe in detail the interference of the matrix line on the high-sensitivity analysis line of the measured element:

[0101] from Figure 11-Figure 14 It can be seen that the analysis line of the measured element is seriously affected by the matrix background and cannot be selected.

[0102] S3. Interference experiment of coexisting elements. The matrix matching method is used to correct the matrix interference, so as to carry out the interference experiment of the measured element:

[0103] The matrix matching method was used to correct the matrix interference. For the interference test of the measured elements, 10 μg / mL of coexisting elements Mg, Fe, Mn, Cu, and Ba were added to 5 samples of the same CaCO3 10 mg / mL for determination. Among them, Al (257.509 nm) and Al (237.312 nm) did not interfere with each other at this concentration.

[0104] Table 6 Unit: μg / g

[0105]

[0106]

[0107] S4. Experiment on the influence of acidity determination:

[0108] Test solutions with acidity of 1+99, 1+49, 1+19, 2+23, and 1+9 were prepared. They all contained Ca10mg / mL and Al2O3 impurity content of 2.10μg / mL. The signal intensity of each element was detected under the same instrument test conditions. The signal value under 1+19 acidity was used as the reference signal value to obtain the signal intensity ratio between the acidities. It was observed that: with the increase of acidity, the signal value of each element decreased slightly. If the acidity is too high, the signal value will decrease. However, if low acidity is used, it is easy to induce precipitation and block the pipeline, see Table 7.

[0109] Table 7 Effect of acidity in hydrochloric acid medium on determination (signal intensity)

[0110]

[0111] S5. Experiment on power conditions of plasma emission spectrometer:

[0112] Prepare a test solution with an acidity of 1+19 hydrochloric acid, containing CaCO3 10mg / mL and Al2O3 impurity content of 2.10μg / mL. Under the same instrument and different power test conditions, the signal intensity and background intensity of each element were detected to obtain the signal-to-background ratio of each element. Through observation and comparison, it was found that increasing the power can increase the signal value, the background value also increases, and the signal-to-background ratio decreases with the increase of power, see Table 8.

[0113] Table 8 Effect of power on measurement

[0114]

[0115]

[0116] S6. Matrix concentration condition experiment:

[0117] Test solutions with matrix concentrations of 0g / L, 2g / L, 4g / L, 8g / L, 10g / L, 12g / L, 14g / L, and 16g / L were prepared, and the Al2O3 impurity content was 2.10μg / mL. The signal values ​​of each element were detected under the same instrument and the same test conditions. The signal value measured by the 0g / L sample solution was used as the reference signal value, and the signal intensity ratio between the matrix concentrations was obtained.

[0118] It can be seen from Table 9 that the matrix concentration has a great influence on the determination. As the matrix concentration increases, the signal-to-background ratio decreases. Considering the lower limit of the determination, comprehensive considerations should be made. Therefore, the matrix matching method is used to correct the influence of the matrix on the determination.

[0119] Table 9 Effect of matrix concentration on determination

[0120]

[0121] S7. Method determination lower limit experiment:

[0122] A standard working curve was made using a series of standard sample solutions according to the working conditions. The intensity of each spectral line in CaCO3 10 mg / mL was repeatedly measured. The concentration corresponding to 10 times the standard deviation of the intensity was taken as the lower limit of determination of this method (see Table 10).

[0123] Table 10 Determination lower limit Unit: μg / g

[0124] element Al2O3(237.312nm) Al2O3(257.509nm) Determination limit 10 12

[0125] S8. Spike recovery verification experiment:

[0126] Weigh three samples of matrix calcium carbonate, the matrix concentration is 10 mg / mL, and the amount of Al2O3 impurities added is 20 μg / g, 100 μg / g, and 200 μg / g, respectively. The recovery of the measured elements is shown in Table 11. It can be seen that the spiked recovery is between 99% and 103%.

[0127] Table 11 Recovery rate

[0128]

[0129] S9. Detection precision experiment:

[0130] The precision of the analytical data was determined by measuring 5 uniform samples under the above test conditions. The results are shown in Table 12.

[0131] Table 12 Analytical precision Unit: μg / g

[0132]

[0133] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various forms of implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the scope of protection of this embodiment. The scope of protection of this embodiment shall be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A method for quickly detecting aluminum oxide content, characterized in that: The following steps are involved: S1. Dissolve the material to be tested in hydrochloric acid and then remove carbon dioxide; S2. Perform spectral measurement; S3. Calculate the content of aluminum oxide in calcium carbonate.

2. The method for rapidly detecting aluminum oxide content according to claim 1, characterized in that: The spectroscopic measurement is subplasma spectroscopic measurement.

3. The method for rapidly detecting aluminum oxide content according to claim 1, characterized in that: The spectral measurement is set up with an analysis group, a blank experiment group and a standard group. The analysis group is measured using a solution containing the material to be measured, the blank experiment group is measured using a solution without the material to be measured in the analysis group, and the standard group is measured using a calcium carbonate matrix solution and an aluminum standard solution.

4. A method for rapidly detecting aluminum oxide content according to claim 3, characterized in that: A standard curve is drawn through the standard group, and the concentration of the element to be measured in the analysis group is obtained according to the standard curve.

5. The method for rapidly detecting aluminum oxide content according to claim 3, characterized in that: The calcium carbonate matrix solution and the aluminum standard solution are mixed with hydrochloric acid before being measured.

6. The method for rapidly detecting aluminum oxide content according to claim 3, characterized in that: The preparation method of the calcium carbonate matrix solution is as follows: dried anhydrous calcium carbonate is dissolved in hydrochloric acid, then carbon dioxide is completely removed, and the solution is cooled and diluted to contain 100 mg of calcium carbonate per 1 mL of solution.

7. A method for rapidly detecting aluminum oxide content according to claim 6, characterized in that: The anhydrous calcium carbonate ω (CaCO3) is ≥ 99.99%, and ω (Al2O3) is ≤ 5ppm.

8. The method for rapidly detecting aluminum oxide content according to claim 3, characterized in that: The aluminum standard solution is prepared by pre-immersing aluminum foil in dilute hydrochloric acid, washing with anhydrous ethanol, adding water, hydrochloric acid and nitric acid after drying, dissolving at low temperature, cooling to room temperature, and then diluting to 1 mL of solution containing 1 mg of aluminum.

9. A method for rapidly detecting aluminum oxide content according to claim 8, characterized in that: The metal aluminum foil w(Al)≥99.9%.

10. The method for rapidly detecting aluminum oxide content according to claim 3, characterized in that: The calculation method of the content of aluminum oxide ωAl2O3% is: Where: ρ0—the concentration of the element to be tested in the blank test solution output by the computer, in nanograms per milliliter; ρ1—the concentration of the element to be measured in the analysis group output by the computer, in nanograms per milliliter; V—total volume of test solution, in milliliters; m—mass of the sample, in grams.

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