GB/T 14506.6-1993 Chemical analysis methods for silicate rocks - Determination of calcium oxide
Some standard content:
National Standard of the People's Republic of China
Chemical Analysis Methods for Silicate Rocks
Determination of Calcium Oxide
Silicate Rocks Determination of Caleium Oxide1 Subject Content and Scope of Application
GB/T14506.6-93
This standard applies to the determination of calcium oxide in biotite granite, rhyolite, granodiorite, quartz hornblende andesite, olivine basalt, gabbro, trachyandesite, neon syenite, sandstone, shale and other silicate rocks with similar composition. The EGTA complexometric titration method is not applicable to rock samples with a total amount of strontium greater than 0.4%.
Determination range: EGTA complexometric titration method, 1% to 15% calcium oxide. Flame atomic absorption spectrophotometry, 0.1% to 5% calcium oxide. This standard complies with the provisions of GB/T14505.
2 Reference standards
GB/T14505 General principles and general provisions for chemical analysis of rocks and ores GB/T14506.1 Chemical analysis methods for silicate rocks Gravimetric determination of adsorbed water content Part I EGTA complexometric titration
3 Summary of the method
After separating silica, the filtrate is masked with triethanolamine to block interfering elements such as iron and aluminum. Nickel, copper, etc. are masked with potassium cyanide, or after separating interfering elements with hexamethylenetetramine and copper reagent, at pH ≥ 12, calcein-thymol acid complexing agent is used as an indicator and titrated with EGTA standard solution.
4 Reagents
4.1 Hydroxylamine hydrochloride.
4.2 Hexamethylenetetramine.
4.3 Potassium hydroxide (superior purity).
4.4 Potassium hydroxide solution (50%). Store in a plastic bottle. 4.5 Ethanol.
4.6 Hydrochloric acid (1+1).
4.7 Ammonium hydroxide (1+1).
4.8 Triethanolamine (1+1).
4.9 Potassium cyanide solution (5%).
Note: This is a highly toxic reagent and must be used with caution and kept strictly. Potassium cyanide cannot be added under acidic conditions. After use, it should be treated with Mo's salt before pouring into the sewer.
Approved by the State Administration of Technical Supervision on June 19, 1993, 22
Implemented on February 1, 1994
4.10 Sucrose solution (2%).
GB/T14506.6-93
4.11 Sodium diethyldithiocarbamate (copper reagent) solution (2%): Prepare it before use. 4.12 Calcium oxide standard solution: Weigh 0.8924g of high-purity calcium carbonate (CaCO) that has been dried at 120℃ for 2h, place in a 400mL beaker, add 10mL of water, cover the surface, slowly add 30mL of hydrochloric acid (4.6) from the beaker mouth, after complete dissolution, heat and boil for 1-2min, remove, rinse the surface III and the beaker wall with water, cool to room temperature, transfer to a 1000mL volumetric flask, dilute to scale with water, and shake well. This solution contains 0.50mg calcium oxide in 1mL.
4.13 EGTA standard titration solution [c(EGTA)=0.010mol/L): 4.13.1 Preparation of EGTA standard titration solution Place 7.6g EGTA (ethylene glycol diethyl ether diamine tetraacetic acid) in a 1000mL beaker containing 400mL water, add solid potassium hydroxide (4.3) while stirring until it is completely dissolved. Dilute to 2000mL with water and shake well. 4.13.2 Calibration of EGTA standard titration solution Take 20.0mL calcium oxide standard solution (4.12) and place it in a 200mL beaker. Add water to about 50mL, and proceed according to the analysis steps in Section 6.5.1.
4.13.3 Calculate the calcium oxide titration degree of EGTA standard titration solution according to formula (1): T-
Where: T--the titration degree of EGTA standard titration solution on calcium oxide, mg/mL; m
the standard amount of calcium oxide, mg;
-the volume of EGTA standard titration solution consumed, mL. (1)
4.14 Calcein-thymol acid complexing agent indicator: 0.2g calcein and 0.1g thymol acid complexing agent are finely ground and mixed, and stored in a ground-mouth bottle. Take a small amount and dissolve it in water when using, and prepare it when used. 4.15 Methyl red indicator (0.1%): ethanol (4.5) solution. 5 Sample
5.1 The particle size of the sample should be less than 74μm.
5.2 The sample should be pre-dried at 105℃ for 2-4h, placed in a desiccator, and cooled to room temperature. 5.3 For rocks that easily absorb water, air-dried samples should be taken. While weighing the sample Determine the adsorbed water according to GB/T14506.1. Calculate the result in the final state.
6 Analysis steps
6.1 Determination quantity
The same sample should be measured 2 to 4 times in the same laboratory by the same operator at different times. 6.2 Test volume
Direct titration: Take 25.0mL of the filtrate after separating the silica (equivalent to 100mg of sample) for titration. Separation: Take 50.0mL of the filtrate after separating the silica for separation, and then take a solution equivalent to 100mg of sample for titration.
6.3 Blank test
Carry out double blank tests together with the sample, and the reagents used must be taken from the same reagent bottle. 6.4 Calibration testwww.bzxz.net
Analyze the same type of sample together 6.5 Determination
6.5.1 Direct titration
According to 6.2, transfer the filtrate A after the determination of silicon dioxide, place it in a 200mL beaker, add water to about 50mL, add 0.5~1g of salt 23
GB/T14506.6-93
acid hydroxylamine (4.1) and 2~3mL of triethanolamine (4.8), 2 drops of methyl red indicator solution (4.15), adjust it with ammonium hydroxide (4.7) until it turns yellow, add 5mL of potassium hydroxide solution (4.4), add 3~5 drops of potassium cyanide solution (4.9), add a few drops of calcein-thymolphthalein complex indicator (4.14), put black paper on the bottom of the cup as the background, and titrate with EGTA standard titration solution (4.13.1) until the green fluorescence disappears as the end point. Note: If the sample has a high modulus content, add water to a volume of 100 mL, add 1~2 mL of sucrose solution (4.10) to prevent magnesium hydroxide precipitation from affecting the determination results.
6.5.2 Separation of interference and determination of solution
6.5.2.1 Separation of interference
According to Article 6.2, transfer the filtrate A obtained after the determination of silicon dioxide, place it in a 200 mL beaker, heat and evaporate it to a wet salt state, remove it and cool it, add 2~3 g of hexamethylenetetramine (4.2), and stir it well. Add 20 mL of copper reagent solution (4.11), stir it well, add water to about 50 mL, stir to dissolve the soluble salt, transfer it to a 100 mL volumetric flask, dilute it to the scale with water, and shake it well. Note: When the direct titration endpoint is difficult to judge, and the content of iron, manganese and non-ferrous metal ions in the sample is high and difficult to mask, it is necessary to separate the interference before determination. 6.5.2.2 Determination of aliquots
After dry filtration, take 50.0 mL of the solution equivalent to 25.0 mL of filtrate A (6.5.2.1) and place it in a 200 mL beaker. The following analysis steps are carried out according to Section 6.5.1.
7 Calculation of analysis results
7.1 Calculate the content of calcium oxide according to formula (2): CaO (%) = (Vi-Vo) · T : V× 10-*m·V.
Where: V, — volume of EGTA standard titration solution consumed in titrating the sample solution, mL; × 100
V. -- volume of EGTA standard titration solution consumed in titrating the sample blank solution, mL; T-
- titer of EGTA standard titration solution on calcium oxide, mg/mL; V-total volume of sample solution, mL;
m sample volume, g;
V. —Volume of sample solution, mL.
7.2 Analytical results are expressed to the second decimal place. 8 Precision
Precision table
Horizontal range, %
Repeatability T
rm= 0. 167 7 mo. 280 8
Reproducibility R
R=0.188 7 mo. 306 4
This precision data was determined in experiments conducted by eight laboratories on ten levels of samples in 1988-1989. Part II Flame Atomic Absorption Spectrophotometry 9 Method Summary
(2)
The filtrate after separation of silica is made into a 2% hydrochloric acid solution, and strontium salt is added as a release agent to eliminate interference. The background is corrected by Zeeman effect correction method or continuous spectrum lamp background correction method on the atomic absorption spectrophotometer, and atomized in an air-acetylene flame, and calcium 422 is measured by direct determination method.7nm atomic absorption.
10 Reagents
10.1 Hydrochloric acid (1+1).
GB/T14506.6—93
10.2 Strontium fluoride solution: 152g strontium chloride (SrCl·6H,0) is dissolved in water, then water is added to 1000mL, and shake well. This solution contains 50mg strontium in 1mL.
Note: If it is not a special reagent for atomic absorption determination of calcium and magnesium, it must be recrystallized. It can be purified as follows: Take about 200g strontium chloride, dissolve it in as little 60℃ water as possible, filter it with medium-speed filter paper, wash it slightly, and place it until a small amount of crystals are precipitated. Add 100mL of anhydrous ethanol while stirring, and a large amount of strontium chloride will precipitate. Filter it under reduced pressure, wash it with anhydrous ethanol several times, and use it after air drying. 10.3 Calcium oxide standard solution
10.3.1 Weigh 0.8924g of high-purity calcium carbonate (CaCO) dried at 120℃ for 2h, place in a 400mL beaker, add 10mL of water, cover with a watch glass, slowly add 30mL of hydrochloric acid (10.1) from the beaker mouth, and after complete dissolution, heat and boil to remove all carbon dioxide, remove and cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and shake well. This solution contains 0.50mg calcium oxide in 1mL. 10.3.2 Transfer 10.0mL of calcium oxide standard solution (10.3.1) to a 100mL volumetric flask, dilute to scale with water, and shake well. This solution contains 50.0μg calcium oxide in 1mL.
11 Instruments
Atomic absorption spectrophotometer, equipped with calcium hollow cathode lamp, air-acetylene premixed burner, Zeeman effect or continuous spectrum lamp background corrector (this standard recommends the use of Zeeman effect background corrector), printer or recorder. The atomic absorption spectrophotometer used should meet the following indicators: 11.1 Detection limit: In a solution consistent with the matrix of the final measured sample solution, the detection limit of calcium should be less than 0.1ug/ml. 11.2 Linearity of working curve: The ratio of the slope (expressed as the change in absorbance) in the upper 20% concentration range of the working curve to the slope in the lower 20% concentration range should be less than 0.7. 11.3 Minimum precision requirement: The standard deviation of the 10 absorbances of the highest concentration standard solution in the working curve should not exceed 1.5% of its average absorbance; the standard deviation of the 10 absorbances of the lowest concentration standard solution (not the zero concentration solution) should not exceed 0.5% of the average absorbance of the highest concentration standard solution. 12 Sample
12.1 The particle size of the sample should be less than 74um.
12.2 The sample should be pre-dried at 105℃ for 2 to 4 hours, placed in a desiccator, and cooled to room temperature. 12.3 For rocks that easily absorb water, air-dried samples should be taken. While weighing the sample, the adsorbed water should be determined according to GB/T14506.1. The final result is calculated in dry state.
13 Analysis steps
13.1 Quantity of determination
The same sample should be determined 2 to 4 times by the same operator in the same laboratory at different times. 13.2 Sample quantity
According to the calcium oxide content, 0.1% to 1% Ca0 should be measured in a solution equivalent to 100mg of the sample; 1% to 2% Ca0 should be measured in a solution equivalent to 50mg of the sample; 2% to 4% Ca0 should be measured in a solution equivalent to 25mg of the sample; 5% Ca0 should be measured in a solution equivalent to 20mg of the sample.
13.3 Blank test
Carry out a double blank test with the sample, and the reagents used must be taken from the same reagent bottle. 13.4 Calibration test
Analyze the same type of standard sample with the sample. 13.5 Determination
13.5.1 Treatment of test solution
According to (13.2), take the filtrate A obtained after the determination of silicon dioxide, place it in a 100mL volumetric flask, add hydrochloric acid (10.1) to an acidity of 25
GB/T14506.6-93
2%, add water to 50~60mL, add 10mL strontium chloride solution (10.2), dilute with water to the scale, and shake well. Note: For filtrate A containing 1%~5% Ca0, take 25.0mL and dilute to 100mL, then take the required amount for treatment and determination. 13.5.2 Measurement of absorbance
On the atomic absorption spectrophotometer, adjust the wavelength to 422.7nm and the spectral bandwidth to 0.7~1.3nm, ignite the air-acetylene flame, adjust the zero value with water, and measure the absorbance of calcium. First, use the solution with the highest concentration in the working curve series to spray and measure, and adjust the flame state and the position and height of the burner to make the measured absorbance the largest. Then, spray the calcium working curve series solution and the sample solution to be tested (including blank and standard sample) in order from low to high concentration. When spraying the solution, adjust the zero value with water. Spray each solution at least twice, record the stable readings obtained, and calculate the average absorbance of each.
During the process of spraying the sample solution, it is necessary to spray a portion of the working curve series solution frequently to understand whether the working condition of the instrument has changed. If the reading of the solution has changed significantly, it is necessary to spray all the working curve series solutions again before continuing the measurement. 13.6 Drawing of working curve
13.6.1 Preparation of working curve series solution Take 0.00, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00, 12.00, 16.00, 20.00mL of calcium oxide standard solution (10.3.2); add water to 50~60mL in a series of 100mL volumetric flasks, add 4mL of hydrochloric acid (10.1) and 10mL of chlorination solution (10.2), dilute with water to the scale, and shake well.
13.6.2 Drawing of working curve
The average absorbance of each solution in the working curve series minus the average absorbance of the zero concentration solution is the net absorbance of the calcium oxide working curve series solution. Draw the working curve with the amount of calcium oxide as the horizontal axis and the net absorbance as the vertical axis. 13.7 Take the average absorbance of the sample solution and the average absorbance of the blank sample solution accompanying the sample, and find out the amount of calcium oxide in the sample solution and blank solution from the working curve respectively. 14 Calculation of analysis results
14.1 Calculate the content of calcium oxide according to formula (3): CaO(%) = (m - mo): V× 10-cm.V.
Wherein: m1-the amount of calcium oxide in the sample solution found from the working curve, ug; mo——the amount of calcium oxide in the blank sample solution found from the working curve, μg; V.---the total volume of the sample solution, mL;
m—the amount of sample, g;
V,——the volume of the sample solution taken, mL. 14.2 The analysis results are expressed to the second decimal place. 15 Precision
Precision table
Horizontal range, %
0.28~9.74
Repeatability r
r=0.0876+0.0562m
Reproducibility R
Rm0.1318+0.0651m
This precision data was determined in experiments conducted by eight laboratories on ten horizontal specimens from 1988 to 1989. 26
(3)
Additional notes:
GB/T14506.6-93
This standard was proposed by the Ministry of Geology and Mineral Resources of the People's Republic of China. This standard is under the jurisdiction of the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. This standard was drafted by the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. The main drafters of this standard are Zhang Zongchun, Yan Maohong, Xiao Huixiang and Chen Jinwu. 270μg calcium oxide.
11 Instruments
Atomic absorption spectrophotometer, equipped with a calcium hollow cathode lamp, air-acetylene premixed burner, Zeeman effect or continuous spectrum lamp background corrector (this standard recommends the use of Zeeman effect background corrector), printer or recorder. The atomic absorption spectrophotometer used should meet the following indicators: 11.1 Detection limit: In a solution consistent with the matrix of the final measured sample solution, the detection limit of calcium should be less than 0.1ug/ml. 11.2 Linearity of working curve: The ratio of the slope (expressed as the change in absorbance) within the upper 20% concentration range of the working curve to the slope within the lower 20% concentration range should be less than 0.7. 11.3 Minimum precision requirement: The standard deviation of the 10 absorbances of the standard solution with the highest concentration in the working curve should not exceed 1.5% of its average absorbance; the standard deviation of the 10 absorbances of the standard solution with the lowest concentration (not the zero concentration solution) should not exceed 0.5% of the average absorbance of the standard solution with the highest concentration. 12 Sample
12.1 The particle size of the sample should be less than 74um.
12.2 The sample should be pre-dried at 105℃ for 2 to 4 hours, placed in a dryer, and cooled to room temperature. 12.3 For rocks that easily absorb water, air-dried samples should be taken. While weighing the sample, the adsorbed water should be determined according to GB/T14506.1. The results are finally calculated in dry state.
13 Analysis steps
13.1 Number of measurements
The same sample should be measured 2 to 4 times in the same laboratory by the same operator at different times. 13.2 Sample volume
According to the calcium oxide content, 0.1% to 1% CaO is equivalent to 100 mg of sample solution; 1% to 2% CaO is equivalent to 50 mg of sample solution; 2% to 4% CaO is equivalent to 25 mg of sample solution; 5% CaO is equivalent to 20 mg of sample solution for measurement.
13.3 Blank test
Carry out double blank test with the sample, and the reagents used must be taken from the same reagent bottle. 13.4 Calibration test
Analyze the same type of standard sample with the sample. 13.5 Determination
13.5.1 Treatment of test solution
According to (13.2), take the filtrate A obtained after the determination of silicon dioxide, place it in a 100mL volumetric flask, add hydrochloric acid (10.1) to an acidity of 25
GB/T14506.6-93
2%, add water to 50-60mL, add 10mL strontium chloride solution (10.2), dilute to the scale with water, and shake well. Note: For filtrate A containing 1%~5% Ca0, take 25.0mL and dilute to 100mL, then take the required amount for treatment and determination. 13.5.2 Measurement of absorbance
On the atomic absorption spectrophotometer, adjust the wavelength to 422.7nm and the spectral bandwidth to 0.7~1.3nm. Light the air-acetylene flame, adjust to zero with water, and measure the absorbance of calcium. First, spray the solution with the highest concentration in the working curve series, and adjust the flame state and the position and height of the burner to maximize the measured absorbance. Then, spray the calcium working curve series solution and the sample solution to be tested (including blank and standard samples) in order from low to high concentration. When spraying the solution, adjust to zero with water. Spray each solution at least twice, record the stable readings obtained, and calculate the average absorbance of each.
During the process of spraying the sample solution, it is necessary to spray a portion of the working curve series solution frequently to understand whether the working condition of the instrument has changed. If the reading of the solution changes significantly, it is necessary to spray all the working curve series solutions again before continuing the measurement. 13.6 Drawing of working curve
13.6.1 Preparation of working curve series solution Take 0.00, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00, 12.00, 16.00, 20.00mL of calcium oxide standard solution (10.3.2); add water to 50~60mL in a series of 100mL volumetric flasks, add 4mL of hydrochloric acid (10.1) and 10mL of chlorination solution (10.2), dilute with water to the scale, and shake well.
13.6.2 Drawing of working curve
The average absorbance of each solution in the working curve series minus the average absorbance of the zero concentration solution is the net absorbance of the calcium oxide working curve series solution. Draw the working curve with the amount of calcium oxide as the horizontal axis and the net absorbance as the vertical axis. 13.7 Take the average absorbance of the sample solution and the average absorbance of the blank sample solution accompanying the sample, and find out the amount of calcium oxide in the sample solution and blank solution from the working curve respectively. 14 Calculation of analysis results
14.1 Calculate the content of calcium oxide according to formula (3): CaO(%) = (m - mo): V× 10-cm.V.
Wherein: m1-the amount of calcium oxide in the sample solution found from the working curve, ug; mo——the amount of calcium oxide in the blank sample solution found from the working curve, μg; V.---the total volume of the sample solution, mL;
m—the amount of sample, g;
V,——the volume of the sample solution taken, mL. 14.2 The analysis results are expressed to the second decimal place. 15 Precision
Precision table
Horizontal range, %
0.28~9.74
Repeatability r
r=0.0876+0.0562m
Reproducibility R
Rm0.1318+0.0651m
This precision data was determined in experiments conducted by eight laboratories on ten horizontal specimens from 1988 to 1989. 26
(3)
Additional notes:
GB/T14506.6-93
This standard was proposed by the Ministry of Geology and Mineral Resources of the People's Republic of China. This standard is under the jurisdiction of the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. This standard was drafted by the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. The main drafters of this standard are Zhang Zongchun, Yan Maohong, Xiao Huixiang and Chen Jinwu. 270μg calcium oxide.
11 Instruments
Atomic absorption spectrophotometer, equipped with a calcium hollow cathode lamp, air-acetylene premixed burner, Zeeman effect or continuous spectrum lamp background corrector (this standard recommends the use of Zeeman effect background corrector), printer or recorder. The atomic absorption spectrophotometer used should meet the following indicators: 11.1 Detection limit: In a solution consistent with the matrix of the final measured sample solution, the detection limit of calcium should be less than 0.1ug/ml. 11.2 Linearity of working curve: The ratio of the slope (expressed as the change in absorbance) within the upper 20% concentration range of the working curve to the slope within the lower 20% concentration range should be less than 0.7. 11.3 Minimum precision requirement: The standard deviation of the 10 absorbances of the standard solution with the highest concentration in the working curve should not exceed 1.5% of its average absorbance; the standard deviation of the 10 absorbances of the standard solution with the lowest concentration (not the zero concentration solution) should not exceed 0.5% of the average absorbance of the standard solution with the highest concentration. 12 Sample
12.1 The particle size of the sample should be less than 74um.
12.2 The sample should be pre-dried at 105℃ for 2 to 4 hours, placed in a dryer, and cooled to room temperature. 12.3 For rocks that easily absorb water, air-dried samples should be taken. While weighing the sample, the adsorbed water should be determined according to GB/T14506.1. The results are finally calculated in dry state.
13 Analysis steps
13.1 Number of measurements
The same sample should be measured 2 to 4 times in the same laboratory by the same operator at different times. 13.2 Sample volume
According to the calcium oxide content, 0.1% to 1% CaO is equivalent to 100 mg of sample solution; 1% to 2% CaO is equivalent to 50 mg of sample solution; 2% to 4% CaO is equivalent to 25 mg of sample solution; 5% CaO is equivalent to 20 mg of sample solution for measurement.
13.3 Blank test
Carry out double blank test with the sample, and the reagents used must be taken from the same reagent bottle. 13.4 Calibration test
Analyze the same type of standard sample with the sample. 13.5 Determination
13.5.1 Treatment of test solution
According to (13.2), take the filtrate A obtained after the determination of silicon dioxide, place it in a 100mL volumetric flask, add hydrochloric acid (10.1) to an acidity of 25
GB/T14506.6-93
2%, add water to 50-60mL, add 10mL strontium chloride solution (10.2), dilute to the scale with water, and shake well. Note: For filtrate A containing 1%~5% Ca0, take 25.0mL and dilute to 100mL, then take the required amount for treatment and determination. 13.5.2 Measurement of absorbance
On the atomic absorption spectrophotometer, adjust the wavelength to 422.7nm and the spectral bandwidth to 0.7~1.3nm. Light the air-acetylene flame, adjust to zero with water, and measure the absorbance of calcium. First, spray the solution with the highest concentration in the working curve series, and adjust the flame state and the position and height of the burner to maximize the measured absorbance. Then, spray the calcium working curve series solution and the sample solution to be tested (including blank and standard samples) in order from low to high concentration. When spraying the solution, adjust to zero with water. Spray each solution at least twice, record the stable readings obtained, and calculate the average absorbance of each.
During the process of spraying the sample solution, it is necessary to spray a portion of the working curve series solution frequently to understand whether the working condition of the instrument has changed. If the reading of the solution changes significantly, it is necessary to spray all the working curve series solutions again before continuing the measurement. 13.6 Drawing of working curve
13.6.1 Preparation of working curve series solution Take 0.00, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00, 12.00, 16.00, 20.00mL of calcium oxide standard solution (10.3.2); add water to 50~60mL in a series of 100mL volumetric flasks, add 4mL of hydrochloric acid (10.1) and 10mL of chlorination solution (10.2), dilute with water to the scale, and shake well.
13.6.2 Drawing of working curve
The average absorbance of each solution in the working curve series minus the average absorbance of the zero concentration solution is the net absorbance of the calcium oxide working curve series solution. Draw the working curve with the amount of calcium oxide as the horizontal axis and the net absorbance as the vertical axis. 13.7 Take the average absorbance of the sample solution and the average absorbance of the blank sample solution accompanying the sample, and find out the amount of calcium oxide in the sample solution and blank solution from the working curve respectively. 14 Calculation of analysis results
14.1 Calculate the content of calcium oxide according to formula (3): CaO(%) = (m - mo): V× 10-cm.V.
Wherein: m1-the amount of calcium oxide in the sample solution found from the working curve, ug; mo——the amount of calcium oxide in the blank sample solution found from the working curve, μg; V.---the total volume of the sample solution, mL;
m—the amount of sample, g;
V,——the volume of the sample solution taken, mL. 14.2 The analysis results are expressed to the second decimal place. 15 Precision
Precision table
Horizontal range, %
0.28~9.74
Repeatability r
r=0.0876+0.0562m
Reproducibility R
Rm0.1318+0.0651m
This precision data was determined in experiments conducted by eight laboratories on ten horizontal specimens from 1988 to 1989. 26
(3)
Additional notes:
GB/T14506.6-93
This standard was proposed by the Ministry of Geology and Mineral Resources of the People's Republic of China. This standard is under the jurisdiction of the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. This standard was drafted by the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. The main drafters of this standard are Zhang Zongchun, Yan Maohong, Xiao Huixiang and Chen Jinwu. 27Ignite the air-acetylene flame at 3nm, adjust to zero with water, and measure the absorbance of calcium. First, spray the solution with the highest concentration in the working curve series, and adjust the flame state and the position and height of the burner to maximize the measured absorbance. Then spray the calcium working curve series solution and the sample solution to be tested (including blank and standard samples) in order from low to high concentration. When spraying the solution, adjust to zero with water. Spray each solution at least twice, record the stable readings obtained, and calculate the average absorbance of each.
During the process of spraying the sample solution, it is necessary to spray a portion of the working curve series solution frequently to understand whether the working condition of the instrument has changed. If the reading of the solution changes significantly, it is necessary to re-spray all the working curve series solutions before continuing the measurement. 13.6 Drawing of working curve
13.6.1 Preparation of working curve series solution Take 0.00, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00, 12.00, 16.00, 20.00mL of calcium oxide standard solution (10.3.2); add water to 50~60mL in a series of 100mL volumetric flasks, add 4mL of hydrochloric acid (10.1) and 10mL of chlorination solution (10.2), dilute with water to the scale, and shake well.
13.6.2 Drawing of working curve
The average absorbance of each solution in the working curve series minus the average absorbance of the zero concentration solution is the net absorbance of the calcium oxide working curve series solution. Draw the working curve with the amount of calcium oxide as the horizontal axis and the net absorbance as the vertical axis. 13.7 Take the average absorbance of the sample solution and the average absorbance of the blank sample solution accompanying the sample, and find out the amount of calcium oxide in the sample solution and blank solution from the working curve respectively. 14 Calculation of analysis results
14.1 Calculate the content of calcium oxide according to formula (3): CaO(%) = (m - mo): V× 10-cm.V.
Wherein: m1-the amount of calcium oxide in the sample solution found from the working curve, ug; mo——the amount of calcium oxide in the blank sample solution found from the working curve, μg; V.---the total volume of the sample solution, mL;
m—the amount of sample, g;
V,——the volume of the sample solution taken, mL. 14.2 The analysis results are expressed to the second decimal place. 15 Precision
Precision table
Horizontal range, %
0.28~9.74
Repeatability r
r=0.0876+0.0562m
Reproducibility R
Rm0.1318+0.0651m
This precision data was determined in experiments conducted by eight laboratories on ten horizontal specimens from 1988 to 1989. 26
(3)
Additional notes:
GB/T14506.6-93
This standard was proposed by the Ministry of Geology and Mineral Resources of the People's Republic of China. This standard is under the jurisdiction of the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. This standard was drafted by the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. The main drafters of this standard are Zhang Zongchun, Yan Maohong, Xiao Huixiang and Chen Jinwu. 27Ignite the air-acetylene flame at 3nm, adjust to zero with water, and measure the absorbance of calcium. First, spray the solution with the highest concentration in the working curve series, and adjust the flame state and the position and height of the burner to maximize the measured absorbance. Then spray the calcium working curve series solution and the sample solution to be tested (including blank and standard samples) in order from low to high concentration. When spraying the solution, adjust to zero with water. Spray each solution at least twice, record the stable readings obtained, and calculate the average absorbance of each.
During the process of spraying the sample solution, it is necessary to spray a portion of the working curve series solution frequently to understand whether the working condition of the instrument has changed. If the reading of the solution changes significantly, it is necessary to re-spray all the working curve series solutions before continuing the measurement. 13.6 Drawing of working curve
13.6.1 Preparation of working curve series solution Take 0.00, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00, 12.00, 16.00, 20.00mL of calcium oxide standard solution (10.3.2); add water to 50~60mL in a series of 100mL volumetric flasks, add 4mL of hydrochloric acid (10.1) and 10mL of chlorination solution (10.2), dilute with water to the scale, and shake well.
13.6.2 Drawing of working curve
The average absorbance of each solution in the working curve series minus the average absorbance of the zero concentration solution is the net absorbance of the calcium oxide working curve series solution. Draw the working curve with the amount of calcium oxide as the horizontal axis and the net absorbance as the vertical axis. 13.7 Take the average absorbance of the sample solution and the average absorbance of the blank sample solution accompanying the sample, and find out the amount of calcium oxide in the sample solution and blank solution from the working curve respectively. 14 Calculation of analysis results
14.1 Calculate the content of calcium oxide according to formula (3): CaO(%) = (m - mo): V× 10-cm.V.
Wherein: m1-the amount of calcium oxide in the sample solution found from the working curve, ug; mo——the amount of calcium oxide in the blank sample solution found from the working curve, μg; V.---the total volume of the sample solution, mL;
m—the amount of sample, g;
V,——the volume of the sample solution taken, mL. 14.2 The analysis results are expressed to the second decimal place. 15 Precision
Precision table
Horizontal range, %
0.28~9.74
Repeatability r
r=0.0876+0.0562m
Reproducibility R
Rm0.1318+0.0651m
This precision data was determined in experiments conducted by eight laboratories on ten horizontal specimens from 1988 to 1989. 26
(3)
Additional notes:
GB/T14506.6-93
This standard was proposed by the Ministry of Geology and Mineral Resources of the People's Republic of China. This standard is under the jurisdiction of the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. This standard was drafted by the Rock and Mineral Testing Technology Research Institute of the Ministry of Geology and Mineral Resources. The main drafters of this standard are Zhang Zongchun, Yan Maohong, Xiao Huixiang and Chen Jinwu. 27
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