CN107037038A - The method of each element content in simultaneous determination aluminium electrolyte - Google Patents

Abstract

A joint determination of the content of each element in an aluminum electrolyte, involving the field of chemical analysis of aluminum smelting, the method first uses an inductively coupled plasma emission spectrometer to measure the emission intensity of a plurality of standard solutions with different solution concentrations of each element, and draws a standard curve. Add perchloric acid to the aluminum electrolyte sample, heat until the white smoke clears, cool, dissolve and filter with hydrochloric acid and water to obtain a sample solution, add perchloric acid to aluminum, heat, cool, dissolve and filter to obtain Blank reagent; then measure the emitted light intensity of the sample solution and the emitted light intensity of the blank test solution, check the detection concentration and blank concentration through the standard curve, and finally calculate the mass concentration of each element in the aluminum electrolyte sample. The method utilizes inductively coupled plasma atomic emission spectrometry to realize rapid, simple and accurate joint determination of the contents of K, Na, Ca, Mg and Li in aluminum electrolytes. The method has strong operability and low analysis cost.

Description

Method for joint determination of each element content in aluminum electrolyte

technical field

The invention relates to the field of chemical analysis for aluminum smelting, and in particular to a method for jointly measuring the contents of K, Na, Ca, Mg and Li in aluminum electrolytes.

Background technique

Aluminum electrolyte is the core part of aluminum smelting, its position is between the anode and cathode. Industrial aluminum electrolytes usually contain cryolite, alumina, and additives such as aluminum fluoride, calcium fluoride, magnesium fluoride, and lithium fluoride. Among them, cryolite and aluminum fluoride are fluxes, alumina is the raw material for aluminum smelting, and other fluoride salt additives are used to ensure the quality and current efficiency of aluminum, and improve the physical and chemical properties of cryolite-alumina melt, such as reducing its Melting point, or increase its conductivity, reduce the solubility of aluminum, etc. However, the addition of additives complicates the composition of the aluminum electrolyte, and Al, K, Na, Ca, Mg, and Li elements become important constituent elements in the aluminum electrolyte. Determination of the content of each element in the electrolyte melt can be used as a necessary detection method to control the content of elements in the electrolyte, that is, if the content of K, Na, Ca, Mg, and Li in the aluminum electrolyte can be quickly and accurately analyzed, it can be Adjust the amount of various additives in the aluminum electrolyte in time. Therefore, it is more necessary to standardize the determination of the content of each element in the electrolyte melt, which has important theoretical significance and application value for the aluminum smelting industry.

At present, the chemical methods used to determine the content of elements in aluminum electrolyte mainly include titration and atomic absorption spectroscopy, etc., but the analysis steps of titration are cumbersome, inefficient, and time-consuming; atomic absorption spectroscopy can only measure each element individually. The analysis time is longer and the linear range is narrow. The specific standards for detecting the element content in aluminum electrolyte are: YS/T739 "Determination of Molecular Ratio and Main Components of Aluminum Electrolyte X-ray Fluorescence Spectrometry" is the current method for analyzing element content and molecular ratio in aluminum electrolyte. The analysis speed is fast, which can meet the requirements of batch testing of main components in aluminum electrolyte during production. However, when this method uses an X-ray fluorescence spectrometer to measure the main components in the aluminum electrolyte, the curve often drifts, resulting in inaccurate measurement results; and this method can only analyze calcium fluoride CaF ₂ and magnesium fluoride MgF ₂ Two kinds of aluminum electrolytes with fluoride salt additives, when testing aluminum electrolytes with more complex components, the analysis results will be inaccurate and the reliability is low. YS/T768 "Determination of Lithium Content in Aluminum Electrolyte by Flame Atomic Absorption Spectrometry" is a method for analyzing Li content in electrolyte, but there is no analysis of Na, Ca, Mg, K and other elements in this standard.

Therefore, there is a need for a fast, simple and accurate method for the combined determination of the contents of K, Na, Ca, Mg and Li in aluminum electrolytes.

Contents of the invention

The object of the present invention is to provide a method for joint determination of the content of each element in the aluminum electrolyte, which utilizes inductively coupled plasma atomic emission spectrometry to realize fast, simple and accurate joint determination of K, Na, Ca, Mg, The content of each element of Li, the method has strong operability and low analysis cost.

The present invention solves its technical problems by adopting the following technical solutions.

The present invention proposes a method for jointly determining the content of each element in an aluminum electrolyte, which comprises the following steps:

Using an inductively coupled plasma emission spectrometer to measure the emission intensity of standard solutions of multiple different solution concentrations of each element in K, Na, Ca, Mg, and Li under the optimal analysis line of the corresponding element, and plot K, Na , the standard curve between the solution concentration of each element in Ca, Mg and Li and the intensity of emitted light, wherein the standard solution also contains perchloric acid and hydrochloric acid;

Add perchloric acid to the aluminum electrolyte sample, heat until the white smoke clears, cool, then add hydrochloric acid and water to dissolve, filter to obtain a sample solution; add perchloric acid to the aluminum, heat until the white smoke clears, Cooling, then add hydrochloric acid and water to dissolve, filter to obtain a blank reagent, the concentration of perchloric acid and hydrochloric acid in the blank reagent and the sample solution is correspondingly equal to the concentration of perchloric acid and hydrochloric acid in the standard solution;

Using an inductively coupled plasma emission spectrometer, respectively measure the emission light intensity of the sample solution and blank reagent under the optimal analysis line of each element in K, Na, Ca, Mg, Li, and obtain K, The detection concentration and blank concentration of each element in Na, Ca, Mg and Li;

Calculate the mass concentration of each analyte element in the aluminum electrolyte sample according to the detected concentration of each element in K, Na, Ca, Mg, Li, the blank concentration, and the aluminum electrolyte sample concentration of the sample solution.

Further, in a preferred embodiment of the present invention, the mass concentration w(x) of each analyte element in the aluminum electrolyte sample is calculated according to the following formula: Among them, c is the detected concentration of the element to be measured, c0 is the blank concentration of the element to be measured, V is the volume of the sample solution, R is the dilution factor of a standard solution of a plurality of different solution concentrations of the element to be measured, and _{m0 is} The mass of the aluminum electrolyte sample.

Further, in a preferred embodiment of the present invention, m ₀ =0.1000-0.5000g.

Further, in a preferred embodiment of the present invention, the preparation method of the aluminum electrolyte sample is as follows: pass the aluminum electrolyte block through a 0.074mm standard sieve, dry it at 100-110°C, and transfer it to a desiccator to cool to room temperature.

Further, in a preferred embodiment of the present invention, the heating method is as follows: first place the aluminum electrolyte sample or aluminum in a polytetrafluoroethylene beaker, add water to make it uniformly dispersed, then add perchloric acid, and place at 150-200 ℃ on the electric heating plate until the white smoke dissipates completely, and the sample is obtained.

Further, in a preferred embodiment of the present invention, the method of dissolving and filtering is as follows: add hydrochloric acid and water into a polytetrafluoroethylene beaker, heat until the sample is completely dissolved, and then filter with filter paper.

Further, in a preferred embodiment of the present invention, the matrix solution is first prepared in the same way as the preparation of the blank reagent, and then the matrix solution is used to prepare the blank reagent and multiple standard solutions with different concentrations of each element.

Further, in a preferred embodiment of the present invention, the best analysis line of K is 766.491nm, the best analysis line of Na is 588.995nm and 589.592nm, the best analysis line of Ca is 317.933nm, the best analysis line of Mg The best analytical line is 285.213nm, and the best analytical line for Li is 670.784nm.

Further, in a preferred embodiment of the present invention, in the aluminum electrolyte sample, the measurement range of K is 0.05% to 5%, the measurement range of Na is 20% to 35%, and the measurement range of Ca is 0.5% to 10%, The measurement range of Mg is 0.1% to 5%, and the measurement range of Li is 0.05% to 5%.

Further, in a preferred embodiment of the present invention, the volume percentage concentration of perchloric acid in the sample solution, blank reagent and standard solution is all 0.75%-1.25%, and the volume percentage concentration of hydrochloric acid is 3%-3.5%.

The beneficial effect of the method for jointly determining the content of each element in the aluminum electrolyte in the embodiment of the present invention is: firstly, the method uses an inductively coupled plasma emission spectrometer to measure the emitted light intensity of a plurality of standard solutions with different solution concentrations of each element, and draws a standard curve , followed by adding perchloric acid to the aluminum electrolyte sample, heating until the white smoke clears, cooling, dissolving and filtering with hydrochloric acid and water to obtain a sample solution, adding perchloric acid to the aluminum, heating until the white smoke clears, Cool, dissolve and filter with hydrochloric acid and water to obtain a blank reagent; then measure the emitted light intensity of the sample solution and the emitted light intensity of the blank test solution, check the detection concentration and blank concentration through the standard curve, and finally calculate the concentration in the aluminum electrolyte sample. The mass concentration of each element. The method uses inductively coupled plasma atomic emission spectrometry, and the relative standard deviation of each element is measured in the range of 0.03% to 0.90%, with high accuracy, good stability and high precision, and realizes fast, simple and accurate joint determination The contents of K, Na, Ca, Mg and Li elements in the aluminum electrolyte. This method has strong operability and low analysis cost, and can be used for the analysis of standard samples and production samples.

detailed description

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 will be clearly and completely described below. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

The method for jointly determining the content of each element in the aluminum electrolyte in the embodiment of the present invention will be described in detail below.

An embodiment of the present invention provides a method for jointly determining the content of each element in an aluminum electrolyte, which uses inductively coupled plasma emission spectrometry to jointly determine the content of K, Na, Ca, Mg, and Li in an aluminum electrolyte, wherein K The measuring range of Na is 10%-20%, the measuring range of Na is 20%-35%, the measuring range of Ca is 0.5%-10%, the measuring range of Mg is 0.1%-5%, and the measuring range of Li is 0.05%. ~5%. The method specifically includes the following steps:

(1) Configure a series of standard solutions: Prepare K, Na, Ca, Mg, Li, respectively, a plurality of standard solutions with different solution concentrations of each element, that is, a series of standard solutions, which also contain perchloric acid and hydrochloric acid. In this embodiment, the standard solution of each element is preferably diluted step by step according to the dilution factor R, and the concentration of the standard storage solution of each element is 1.0 mg/mL, which is convenient to prepare different The standard solution of solution concentration; the volume percentage concentration of perchloric acid in the standard solution is 0.75%～1.25%, and the volume percentage concentration of hydrochloric acid is 3%～3.5%.

(2) Draw a standard curve:

First of all, according to the composition of the aluminum electrolyte sample, the best analytical spectral line for each element in K, Na, Ca, Mg, and Li is selected. There is a lot of interference between the lines, not only between different analytical spectral lines of the same element, but also between the analytical spectral lines of different elements, and the intensity of different analytical spectral lines is also different. Therefore, the present invention has screened the analysis lines of each element. In the present embodiment, the best analysis line of K is 766.491nm, the best analysis line of Na is 588.995nm and 589.592nm, and the best analysis line of Ca is The best analysis line of Mg is 285.213nm, and the best analysis line of Li is 670.784nm.

Next, use an inductively coupled plasma emission spectrometer to measure the emission light intensity of the standard solution of each element in the above-mentioned K, Na, Ca, Mg, and Li under the optimal analysis line of the corresponding element, specifically, pass the standard solution through The sampling system is introduced into an inductively coupled plasma emission spectrometer for detection, and a standard curve between the solution concentration of each element in K, Na, Ca, Mg, and Li and the emission light intensity is drawn.

(3) Preparation of sample solution:

First, pre-treat the aluminum electrolyte block: sieve, dry, and cool the aluminum electrolyte block, preferably through a 0.074mm standard sieve, dry it in an oven at 100-110°C, transfer it to a desiccator and cool it to room temperature, and obtain Aluminum electrolyte samples.

Then, weigh an aluminum electrolyte sample with a mass m ₀ =0.1000～0.5000g, add perchloric acid, heat until the white smoke disperses, cool, add hydrochloric acid and water to dissolve, and filter to obtain a sample solution, sample solution The concentration of perchloric acid and hydrochloric acid in the medium is equal to the concentration of perchloric acid and hydrochloric acid in the standard solution. The volume percentage concentration of perchloric acid in the sample solution is 0.75% to 1.25%, and the volume percentage concentration of hydrochloric acid is 3% to 3.5%. Among them, the heating method is: first place the aluminum electrolyte sample in a polytetrafluoroethylene beaker of a digester, add water to make it evenly dispersed, then add perchloric acid, and heat it on an electric heating plate at 150-200°C until the white smoke is scattered. As much as possible, get a sample. The method of dissolving and filtering is as follows: add hydrochloric acid and water into a polytetrafluoroethylene beaker, and heat until the sample is completely dissolved, and filter with filter paper until the sample is completely dissolved; then dilute the filtrate with hydrochloric acid and water, and dilute to a volume of V, to obtain the sample solution. This process does not need to be melted in a high-temperature furnace, but only needs to be heated on an electric heating plate, which has the advantages of saving energy and reducing consumption.

(4) Configure a blank reagent, add perchloric acid to the aluminum in the same way as the preparation of the sample solution, heat until the white smoke disperses, cool, then add hydrochloric acid and water to dissolve, filter to prepare a blank reagent, blank The concentration of perchloric acid and hydrochloric acid in the reagent is equal to the concentration of perchloric acid and hydrochloric acid in the standard solution. The volume percentage concentration of perchloric acid in the blank reagent is 0.75% to 1.25%, and the volume percentage concentration of hydrochloric acid is 3% to 3.5%. .

In this embodiment, in order to ensure that the concentrations of perchloric acid and hydrochloric acid in the sample solution, blank reagent and standard solution are equal, the matrix solution can be prepared in the same way as the preparation of the blank reagent, and then the matrix solution can be prepared separately to obtain Reagent blanks and standard solutions of multiple different solution concentrations for each element.

(5) Detect sample solution: adopt inductively coupled plasma emission spectrometer, measure the sample solution of step (3) preparation respectively under the optimal analysis spectral line of each element in K, Na, Ca, Mg, Li Emit light intensity, and according to the standard curve of corresponding element, find detection concentration to be c; The blank test solution of measuring step (4) is prepared respectively in K, Na, Ca, Mg, the optimal analytical spectral line of each element in Li Under the emission light intensity, and according to the standard curve of the corresponding element, the blank concentration was found to be c ₀ .

Inductively coupled plasma atomic absorption spectrometry is widely used in various fields because of its high sensitivity, good precision, no need for chemical separation, simultaneous determination of multiple elements in one sample injection, wide range of standard curves, and fast testing speed. The analysis of material composition has a good application prospect. The used inductively coupled plasma emission spectrometer of the present invention is IRIS1000 type full-spectrum direct-reading inductively coupled plasma emission spectrometer (American thermoelectric), and the working condition of this inductively coupled plasma emission spectrometer is: RF power is 1150W, and auxiliary device flow rate is 0.5 L/min, the pump speed is 80~130r/min, the atomizer flow rate is 0.65L/min, and the integration time is 15s.

(6) Calculate the content of each element: calculate the aluminum electrolyte sample according to the detected concentration of each element in K, Na, Ca, Mg, Li, the blank concentration, and the aluminum electrolyte sample concentration of the sample solution The mass concentration of each analyte element in . Preferably, the mass concentration w(x) of each analyte element in the aluminum electrolyte sample is calculated according to the following formula: Among them, c is the detected concentration of the element to be measured, c0 is the blank concentration of the element to be measured, V is the volume of the sample solution, R is the dilution factor of a standard solution of a plurality of different solution concentrations of the element to be measured, and _{m0 is} The mass of the aluminum electrolyte sample.

The characteristics and performance of the present invention will be described in further detail below in conjunction with the examples.

Test equipment and working conditions used in the embodiment of the present invention:

IRIS1000 full-spectrum direct-reading inductively coupled plasma emission spectrometer (Thermoelectricity of the United States), working conditions: RF power is 1150W, auxiliary flow rate is 0.5L/min, pump speed is 80-130r/min, atomizer flow rate is 0.65L /min, the integration time is 15s; 250mL polytetrafluoroethylene beaker, soaked in nitric acid, the required use temperature is lower than 200 ℃; electronic balance, sensitivity 0.1mg; electric heating plate.

Test main reagent in the embodiment of the present invention:

Perchloric acid (ρ=1.67g/mL), superior grade; hydrochloric acid (1+1), superior grade; aluminum metal (Al≥99.99%); sodium chloride (reagent); calcium carbonate (reagent) ; Magnesium metal (Mg≥99.99%); Potassium chloride (reagent); Lithium carbonate (reagent); Test water is laboratory first-grade water.

Example 1

Embodiment 1 provides a method for joint determination of the content of each element in the aluminum electrolyte. The method uses an inductively coupled plasma emission spectrometer to jointly detect the content of K, Na, Ca, Mg, and Li elements in the aluminum electrolyte sample. The aluminum electrolyte sample The aluminum electrolyte standard sample GDJ-1 produced by Zhengzhou Light Metal Research Institute was selected. The method specifically includes the following steps:

Weigh 0.0750g of metallic aluminum and place it in a polytetrafluoroethylene beaker, add 10mL of perchloric acid, place it on a 180°C electric heating plate, heat until the white smoke clears, and cool to room temperature; add 12.5 mL of hydrochloric acid and an appropriate amount of water, heated until the sample is completely dissolved, transferred to a 200mL volumetric flask, diluted with water to the mark, and mixed to obtain a matrix solution. The volume percentage concentration of perchloric acid in the matrix solution is 5%, and the volume percentage concentration of hydrochloric acid is 6.75%.

Prepare standard storage solutions of K, Na, Ca, Mg, and Li elements with a concentration of 1.0 mg/mL:

a. Sodium standard storage solution: Accurately weigh 2.540g of sodium chloride (fired at 500°C to 600°C to constant weight in advance) in a 400mL beaker, add 20mL of hydrochloric acid and slightly heat to dissolve. After cooling, transfer the solution into a 1000mL PFA volumetric flask, dilute to the mark with water, and mix well. 1mL of this solution contains 1.0mg of sodium.

b. Calcium standard storage solution: Accurately weigh 2.4971g of calcium carbonate pre-dried at 105°C, put it in a beaker, cover with a watch glass, add 10mL of water, add hydrochloric acid drop by drop until completely dissolved, then add 20mL of hydrochloric acid, boil Remove carbon dioxide, take it off and cool it, transfer it into a 1000mL volumetric flask, dilute to the mark with water, shake well, 1mL of this solution contains 1.0mg of calcium.

c. Magnesium standard storage solution: Accurately weigh 1.0000g of metallic magnesium, place it in a 400mL beaker, add 40mL of hydrochloric acid, cover the watch glass, heat slowly until completely dissolved, cool, transfer the solution into a 1000mL volumetric flask, and dilute with water to the mark , Mix well, 1mL of this solution contains 1.0mg of magnesium.

d. Potassium standard storage solution: Accurately weigh 1.9067g of potassium chloride (burned at 500°C to 600°C to constant weight in advance) in a 400mL beaker, add 20mL of hydrochloric acid and slightly heat to dissolve. After cooling, transfer the solution into a 1000mL volumetric flask, dilute to the mark with water, and mix well. 1mL of this solution contains 1.0mg of potassium.

e. Lithium standard storage solution: Accurately weigh 5.3228g lithium carbonate (pre-dried at 280°C±10°C for 2h and cool to room temperature in a desiccator), put it in a 200mL beaker, add 20mL hydrochloric acid to dissolve, heat to drive off carbon dioxide After cooling, transfer the gas into a 1000mI volumetric flask, dilute to the mark with water, and shake well. 1mL of this solution contains 1.0mg lithium.

Use matrix solution and water to dilute the standard storage solution step by step according to the dilution factor R. Specifically, pipette different amounts of the standard storage solutions of the above elements and place them in a group of 100mL volumetric flasks with 20mL of matrix solution added in advance. Add 2mL of hydrochloric acid, dilute to the mark with water, and mix well to obtain a series of standard solutions of each element. The volume percentage concentration of perchloric acid in the series of standard solutions is 1%, and the volume percentage concentration of hydrochloric acid is 3.25%. The element content should be within the range of its corresponding working curve. The number of series standard solutions is determined by the accuracy requirements. The series of standard solutions for each element includes at least 6 different standard solutions.

According to the composition of the aluminum electrolyte sample, the best analytical lines of each element are selected, and the recommended best analytical lines of each element are as follows:

Table 1 Recommended optimal analytical lines for each element

element Analysis line/nm Na 588.995, 589.592 Ca 317.933 Mg 285.213 K 766.491 Li 670.784

The prepared series of standard solutions are introduced into the inductively coupled plasma emission spectrometer through the sampling system for detection, and the emission intensity of the series of standard solutions of each element under the optimal analysis line of the element is measured, and the concentration of each element is plotted against the Standard curves between emitted light intensities were used to obtain standard curves for K, Na, Ca, Mg, and Li, respectively.

After grinding the aluminum electrolyte sample, pass it through a 0.074mm standard sieve, dry it in an oven at 100-110°C, and then transfer it to a desiccator to cool to room temperature; weigh the above-mentioned aluminum electrolyte sample with a mass of m ₀ =0.2g, and accurately to 0.0001g, put it in a polytetrafluoroethylene beaker, add 1mL of water to make it evenly dispersed, then add 4mL of perchloric acid, place it on a 180°C electric heating plate and heat until the white smoke disappears, then cool to room temperature; Add 5mL of hydrochloric acid and 20mL of water into an ethylene beaker, heat until completely dissolved; filter through a medium-speed filter paper into a 200mL volumetric flask, dilute with water to the mark, and mix well to obtain a test solution; divide 50mL of the above test solution into a 100mL volumetric flask, Add 2 mL of hydrochloric acid, dilute to the mark with water, and mix uniformly to obtain a sample solution. The volume percentage concentration of perchloric acid in the sample solution is 1%, and the volume percentage concentration of hydrochloric acid is 3.25%.

Take 20mL of matrix solution and add it to a 100mL volumetric flask, add 2mL of hydrochloric acid, dilute to the mark with water, and mix to obtain a blank reagent. The volume percentage concentration of perchloric acid in the blank reagent is 1%, and the volume percentage concentration of hydrochloric acid is 3.25%.

When the linear correlation coefficient of the working curve is greater than or equal to 0.999, the sample solution is introduced into the inductively coupled plasma emission spectrometer through the sample introduction system, and the emission light intensity of the sample solution under the optimal analysis line of the element to be measured is measured, and the The detection concentration found on the standard curve of the analyte is c; the blank test solution is introduced through the sampling system to measure the emission intensity of the blank test solution under the optimal analysis line of the analyte, and the intensity of the emitted light is measured on the standard curve of the analyte. Check the blank concentration on the c ₀ .

Calculation of mass percent concentration of analyte elements in aluminum electrolyte samples Until the mass concentrations of K, Na, Ca, Mg, and Li in the aluminum electrolyte samples are determined and calculated respectively.

Example 2

Embodiment 2 provides a method for jointly determining the content of each element in the aluminum electrolyte. The aluminum electrolyte sample is the aluminum electrolyte standard sample GDJ-2 produced by Zhengzhou Light Metal Research Institute. This method is the same as the method in embodiment 1.

Example 3

Example 3 provides a method for jointly determining the content of each element in the aluminum electrolyte. The aluminum electrolyte sample is the aluminum electrolyte standard sample GDJ-3 produced by the Zhengzhou Light Metal Research Institute. This method is roughly the same as the method in Example 1, except that In that: the volume percent concentration of perchloric acid in the sample solution, the blank reagent and the standard solution is 0.75%, and the volume percent concentration of hydrochloric acid is 3%.

Example 4

Embodiment 4 provides a method for jointly determining the content of each element in the aluminum electrolyte. The aluminum electrolyte sample is the aluminum electrolyte standard sample GDJ-4 produced by Zhengzhou Light Metal Research Institute. This method is the same as the method in embodiment 3.

Example 5

Example 5 provides a method for jointly determining the content of each element in the aluminum electrolyte. The aluminum electrolyte sample is the aluminum electrolyte standard sample GDJ-5 produced by the Zhengzhou Light Metal Research Institute. This method is roughly the same as the method in Example 1, except that In that: the volume percent concentration of perchloric acid in the sample solution, the blank reagent and the standard solution is 1.25%, and the volume percent concentration of hydrochloric acid is 3.5%.

Example 6

Example 6 provides a method for joint determination of the content of each element in the aluminum electrolyte. The aluminum electrolyte sample is the aluminum electrolyte standard sample GDJ-6 produced by Zhengzhou Light Metal Research Institute. This method is the same as the method in Example 5.

The accuracy and precision of embodiment 1-6 are tested:

The specific content of each aluminum electrolyte standard sample in embodiment 1-6 is as shown in table 2:

Table 2 The content of each element in the aluminum electrolyte standard sample

A. Precision test: Utilize 6 aluminum electrolyte standard samples of Zhengzhou Light Metal Research Institute, 6 parallel measurement results of each aluminum electrolyte standard sample, evaluate the relative standard deviation of each aluminum electrolyte standard sample, the embodiment of the present invention 1 The precision results of the -6 detection method are shown in Table 3.

Table 3 precision test results

From the measurement results in Table 3, it can be seen that the relative standard deviation range of 6 parallel determinations of K element is 0.12%-0.33%; the relative standard deviation range of Na element is 0.05%-0.24%; the relative standard deviation range of Ca element is 0.50% ～1.12%; the relative standard deviation range of Mg element is 0.43%～0.86%; the relative standard deviation range of Li element is 0.39%～0.94%. The standard deviations of the above elements are completely within the national standard error range, therefore, the accuracy of the detection method of the present invention can meet the needs of actual analysis.

B. Accuracy test: The accuracy of the detection method of the present invention is evaluated by the recovery rate of the measurement results of 6 aluminum electrolyte standard samples of Zhengzhou Light Metal Research Institute, and the test results are shown in Table 4.

Table 4 recovery test results

As can be seen from the test data in Table 4, when using the detection method of the present invention to jointly measure the contents of five elements K, Na, Ca, Mg and Li in the aluminum electrolyte, the recovery rate ranges from 96.62% to 102.32%, which can accurately The content of above-mentioned five kinds of elements is determined accurately, further proves that the detection method of the present invention has very high accuracy.

In summary, the method for the joint determination of the contents of each element in the aluminum electrolyte in the embodiment of the present invention uses inductively coupled plasma atomic emission spectrometry to realize a fast, simple and accurate joint determination of K, Na, Ca, The content of each element of Mg and Li, this method has strong operability and low analysis cost.

The embodiments described above are some, not all, embodiments of the present invention. The detailed description of the embodiments of the invention is not intended to limit the scope of the claimed invention but to represent only selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Claims (10)

1. a kind of method of each element content in simultaneous determination aluminium electrolyte, it is characterised in that it comprises the following steps：

The multiple different solutions for determining each element in K, Na, Ca, Mg, Li using inductive coupling plasma emission spectrograph are dense Emitted luminescence intensity of the standard liquid of degree under the optimized analysis spectral line of the correspondence element, and draw in K, Na, Ca, Mg, Li Standard curve between the solution concentration and emitted luminescence intensity of each element, wherein, also contain perchloric acid in the standard liquid And hydrochloric acid；

Perchloric acid is added in aluminium electrolyte sample, white cigarette is heated to and disperses, cools down, then adds hydrochloric acid and water to be dissolved, is filtered, Sample solution is made；Perchloric acid is added in aluminium, white cigarette is heated to and disperses, cools down, then adds hydrochloric acid and water to be dissolved, is filtered, Perchloric acid, the concentration of hydrochloric acid and height in the standard liquid in blank reagent, the blank reagent and the sample solution is made The concentration correspondent equal of chloric acid, hydrochloric acid；

Using inductive coupling plasma emission spectrograph, determine respectively the sample solution and the blank reagent K, Na, Emitted luminescence intensity under the optimized analysis spectral line of each element in Ca, Mg, Li, and according to the standard curve obtain K, Na, The detectable concentration and blank concentration of each element in Ca, Mg, Li；

The detectable concentration of each element in K, Na, Ca, Mg, Li, the blank concentration and the sample solution Aluminium electrolyte sample concentration calculate the mass concentration of each element to be measured in the aluminium electrolyte sample.

2. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that according to Lower formula, calculates the mass concentration w (x) of each element to be measured in the aluminium electrolyte sample：

Wherein, c is the detectable concentration of element to be measured, c₀To treat The blank concentration of element is surveyed, V is the volume of sample solution, and R is the standard liquid of multiple different solutions concentration of element to be measured The coefficient of dilution, m₀For the quality of aluminium electrolyte sample.

3. the method for each element content in simultaneous determination aluminium electrolyte according to claim 2, it is characterised in that m₀= 0.1000~0.5000g.

4. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that the aluminium The preparation method of electrolyte sample is：Aluminium electroloysis mass is crossed into 0.074mm standard screens, in 100~110 DEG C of drying, is transferred to dry Room temperature is cooled in dry device.

5. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that described to add Heat method be：First aluminium electrolyte sample or aluminium are placed in polytetrafluoroethylene beaker, adding water makes its dispersed, add institute Perchloric acid is stated, being heated to white cigarette on the electric hot plate for being placed in 150~200 DEG C disperses, and obtains sample.

6. the method for each element content in simultaneous determination aluminium electrolyte according to claim 5, it is characterised in that described molten Solution and the method for filtering are：Hydrochloric acid and water are added into the polytetrafluoroethylene beaker, the sample is heated to and is completely dissolved, then Filtered with filter paper.

7. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that first according to With preparing the blank reagent identical method, preparation obtains Matrix Solution, reuses Matrix Solution and prepares respectively and obtains described The standard liquid of blank reagent and multiple different solutions concentration of each element.

8. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that K is most Good analysis spectral line is 766.491nm, and Na optimized analysis spectral line is 588.995nm and 589.592nm, Ca optimized analysis spectral line For 317.933nm, Mg optimized analysis spectral line is 285.213nm, and Li optimized analysis spectral line is 670.784nm.

9. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that the aluminium In electrolyte sample, the measurement range that the measurement range that K measurement range is 0.05%~5%, Na is 20%~35%, Ca is The measurement range that 0.5%~10%, Mg measurement range are 0.1%~5%, Li is 0.05%~5%.

10. the method for each element content in simultaneous determination aluminium electrolyte according to claim 1, it is characterised in that described In sample solution, the blank reagent and the standard liquid concentration of volume percent of perchloric acid be 0.75%~ 1.25%, the concentration of volume percent of hydrochloric acid is 3%~3.5%.