GB/T 14949.7-1994 Chemical analysis methods for manganese ores - Determination of sodium and potassium content

This standard specifies the determination of sodium and potassium by flame atomic absorption spectrometry. This standard is applicable to the determination of sodium and potassium in manganese ore. The determination range is: sodium 0.02% to 0.90%, potassium 0.05% to 3.00%. GB/T 14949.7-1994 Chemical analysis method for manganese ore - determination of sodium and potassium content. GB/T14949.7-1994 Standard download decompression password: www.bzxz.net

Method".
National Standard of the People's Republic of China
Chemical analysis method of manganese ore
Determination of sodium and potassium contents
Manganese ores--Determination of sodium and potassium contentsGB/T 14949.7 94
This standard is equivalent to IS079691985 "Manganese ore and manganese concentrate---Determination of sodium and potassium contents-Flame atomic absorption spectrometry 1 Subject content and scope of application
This standard specifies the determination of sodium and potassium contents by flame atomic absorption spectrometry. This standard is applicable to the determination of sodium and potassium in manganese ore. The determination range is: sodium 0.02%~0.90% potassium 0.05%~3.00% 2 Method Summary
The sample is dissolved with nitric acid, hydrofluoric acid and sulfuric acid (the insoluble sample is dissolved with hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid). After the test solution is fixed to volume, it is sprayed into the acetylene flame with air. Steel and potassium hollow cathode lamps are used as light sources respectively. The absorbance of sodium and potassium is measured at the wavelength of 589.0nm and 766.5nm of the atomic absorption spectrometer. In order to eliminate the influence of matrix elements, manganese and iron in an amount similar to that of the sample must be added when drawing the standard curve. 3 Reagents
The water used in this method is double distilled water and high-grade pure reagents. 3.1 Hydrochloric acid (p1.19g/mL).
3.2 Hydrochloric acid (1+2).
3.3 Nitric acid (pl.42g/ml).
3.4 ​​Sulfuric acid 1+1).
3.5 Hydrofluoric acid (pl.14g/ml).
3.6 Perfluoric acid (pl.51g/ml.).
3.7 Hydrogen peroxide 130% (m/m)) (does not contain alkali metals). 3.8 Nitric acid solution (15g/1).
3.9 Iron solution
Weigh 2.5g of high-purity iron (99.99%) and place it in a 400ml beaker. Add 30ml of water and slowly add 15ml of nitric acid (3.3). Heat at low temperature to dissolve, then add 15mL of sulfuric acid (3.4). Evaporate the solution until sulfuric acid fumes appear. After cooling, transfer it to a 250ml volumetric flask, dilute to the mark with water and mix well. This solution contains 10mg of iron in 1mL. Store this solution in a polyethylene bottle. 3.10 Manganese solution
Weigh 6.25g of high-purity electrolytic manganese (99.95%) into a 400ml beaker (the surface oxides of electrolytic manganese can be removed by washing with dilute hydrochloric acid and distilled water, then put into acetone, take out and dry before weighing), add 30ml of water, slowly add 30ml of hydrochloric acid (3.1) and 35ml of sulfuric acid (3.4), dissolve and evaporate the solution at low temperature until sulfuric acid smoke appears, and cool. After rinsing, transfer to a 250ml volumetric flask, dilute with water to full scale and mix well. 1ml of this solution contains 25mg of manganese. Store this solution in a polyethylene bottle. 3.11 Sodium standard solution
Approved by the State Administration of Technical Supervision on January 18, 1994 and implemented on October 1, 1994
GB/T14949.7-94
3.11.1 Weigh 0.2542g of sodium chloride (reference reagent) dried to constant weight at 110℃, place it in a 400mL beaker, dissolve it in 200mL water, transfer it to a 1000ml volumetric flask, dilute it to the mark with water, and mix it. 1mL of this solution contains 0.1000mg of sodium. Store this solution in a polyethylene bottle.
3.11.2 Transfer 10.00ml of sodium standard solution (3.11.1) to a 100mL volumetric flask, dilute it to the mark with water, and mix it. 1mL of this solution contains 0.0100mg of sodium. Store this solution in a polyethylene bottle. 3.12 Potassium standard solution
3.12.1 Weigh 0.1907g of potassium chloride (reference reagent) dried to constant weight at 110℃, place in a 400ml beaker, dissolve in 200ml water, transfer to a 1000ml volumetric flask, dilute to scale with water, and mix. 1mL of this solution contains 0.1000mg potassium. Store this solution in a butyl polyethylene bottle.
3.12.2 Transfer 10.00mL of potassium standard solution (3.12.1) to a 100mL volumetric flask, dilute to scale with water, and mix. 1mL of this solution contains 0.0100mg potassium. Store this solution in a polyethylene bottle. 4 Instruments and Equipment
Instruments and Equipment Commonly Used in the Laboratory
4.1 Platinum III, polytetrafluoroethylene beaker, etc.
The utensils used should be cleaned with hydrochloric acid (3.2) and heated for 15 minutes, and cleaned repeatedly until the blank value drops to the minimum. 4.2 Atomic absorption spectrometer, equipped with air-acetylene burner, sodium and potassium hollow cathode lamps. The atomic absorption spectrometer used should meet the following indicators: 4.2.1 Minimum Sensitivity
The absorbance of the highest concentration calibration solution in the calibration curve should not be less than 0.3. 4.2.2 Minimum Stability
Measure the absorbance of the highest calibration solution 10 times, and calculate the average value and standard deviation of its absorbance. The standard deviation should generally not exceed 1.0% of the average absorbance of the highest calibration solution. Measure the absorbance of the lowest calibration solution (not the "zero" calibration solution) 10 times, and calculate the average value and standard deviation of its absorbance. The standard deviation should not exceed 0.5% of the average absorbance of the highest calibration solution. 4.2.3 Linearity of calibration curve
The ratio of the slope of the calibration curve in the upper 20% concentration range (expressed as the change in absorbance) to the slope in the lower 20% concentration range should be not less than 0.7.
5 Sample
The sample should pass through a 0.100mm sieve and be aired under laboratory conditions. 6 Analysis steps
6.1 Sample quantity
Weigh about 0.25g of sample to an accuracy of 0.0001g. While measuring, weigh the sample to determine the mass percentage of wet water (A). When calculating the results of sodium and potassium, the obtained results (mass percentage) should be multiplied by the conversion factor K, which is the mass percentage of the measured sodium and potassium in the completely dry sample. Conversion factor K = 100A
6.2 Blank test
Carry out a blank test with the sample. In all cases, except for adding 1mL of iron solution (3.9) and 2mL of manganese solution (3.10), follow the analysis steps 6.3.
6.3 Determination
6.3.1 Easily decomposable samples
GB/T14949.7-94
Put the sample (6.1) in platinum III, add 3mL of nitric acid (3.3), 5mL of hydrofluoric acid (3.5) and 5mL of sulfuric acid (3.4), heat at low temperature to dissolve, evaporate the solution until sulfuric acid fumes appear, and cool. Rinse the III wall with water and evaporate again until sulfuric acid fumes disappear, and cool. Wash the wall of the beaker with 10-15 ml of water, add 0.5 ml of sulfuric acid (3.4), add 10 drops of hydrogen peroxide (3.7) drop by drop, heat to dissolve the manganese oxide, and completely decompose the excess cyanogen peroxide, and cool.
6.3.2 Difficult to decompose samples
Put the sample (6.1) in a 250 ml polytetrafluoroethylene beaker, add 10 ml of hydrochloric acid (3.1) to dissolve the sample, then add 2 ml of nitric acid (3.3), 5 ml of hydrofluoric acid (3.5) and 5 ml of perchloric acid (3.6), heat the solution until white perferric acid smoke appears, continue for 2 min. Cool, rinse the beaker wall with distilled water, heat again until the perchloric acid smoke is gone, and cool. Add 10.0 ml of hydrochloric acid (3.1) to dissolve the residue, add 15 ml of water while heating, heat to dissolve the salts, and cool.
6.3.3 Preparation of test solution
Place the test solution (6.3.1) or the test solution (6.3.2) into a 250 ml volumetric flask, add 5 ml of nitric acid solution (3.8), dilute to the mark with water, and mix. If the solution is turbid, dry filter it. 6.3.3.1 When the sodium and potassium content is between 0.02% and 0.2%, use the test solution (6.3.3) to measure according to 6.3.4. 6.3.3.2 When the sodium and potassium content is greater than 0.2%, take the test solution according to Table 1, add the matrix solution to a 100 ml volumetric flask, and then add 2 ml of nitric acid solution (3.8). If the test solution (6.3.2) is a difficult-to-decompose sample, add hydrochloric acid (3.1) to 4% acidity, dilute to the mark with water, and mix. The following measurements are made according to 6.3.4.
Expected sodium
or potassium in sample, %
(m/n）
0-2 ~ 0. 8
>0.8~1. 5
>1.5～3. 0bZxz.net
Solution aliquot
6.3.4 Atomic absorption spectrometry
Add matrix solution, mL
Manganese solution
Iron solution
Amount of sodium or potassium in the solution to be tested
0. 4-~ 1. 6
0. 8~~1. 5
0. 75~~ 1.5
Put the test solution on the atomic absorption spectrometer at wavelengths of 589.0nm and 766.5nm, respectively, with air-acetylene flame, sodium or potassium hollow cathode lamp, adjust the instrument to the best state, and then use water to zero to measure the absorbance of sodium and potassium respectively (repeat the spray measurement 3 times), and calculate the corresponding element concentration from the calibration curve.
6.4 Drawing of calibration curve
6.4.1 Pipette 0, 2.00, 5.00, 10.00, 15.00, 20.00mL of sodium standard solution (3.11.2) or potassium standard solution (3.12.2) into a set of platinum III (operate according to 6.3.1) or a set of polytetrafluoroethylene beakers (operate according to 6.3.2) and add 1ml of iron solution (3.9) and 2ml of manganese solution (3.10) respectively.
If the operation is carried out according to 6.3.1, the amount of sulfuric acid (3.4) added at the end is reduced from 0.5ml to (.2mL, and the amount of hydrogen peroxide (3.7) is reduced from 10 drops to 4 drops;
If the operation is carried out according to 6.3.2, the amount of hydrochloric acid (3.1) added at the end is reduced from 10mL to 4.0mL. 6.4.2 Transfer the solution (6.4.1) to a group of 100ml volumetric flasks, and then add 2ml of saturated nitric acid solution (3.8) in turn. Dilute to the scale with water and mix well. The following is carried out according to 6.3.4. 6.4.3 Draw a calibration curve with the concentration (μg/mL) of the sodium or potassium calibration solution series as the horizontal axis and the average absorbance of each calibration solution as the vertical axis.
Calculation of analysis results
Calculate the percentage of sodium or potassium according to the following formula: GB/T 14949.7--94
Na(K)(%) --
(c - c)).V × 100
m × 10
Wherein: (---the concentration of sodium or potassium in the blank solution accompanying the sample is obtained from the calibration curve, μg/ml; the concentration of sodium or potassium in the test solution is obtained from the calibration curve, μg/ml.; V—-total volume of the test solution, ml.;
-dilution multiple, when the sample contains less than 0.2% sodium or potassium, K--conversion coefficient of the amount of sodium or potassium in the completely dried sample, m The mass of the sample + g.
8 Precision
The precision listed in this standard is the repeatability obtained by statistical analysis of 8 laboratories in 1990 on 4 uniform samples evenly distributed in the range of this method, according to the analysis steps of this standard, and after jointly conducting the test, the data were summarized and followed the national standard GB6379 "Precision of test methods, repeatability or reproducibility of standard methods determined by inter-laboratory tests". The reproducibility R is shown in Table 2 and Table 3. The original data is shown in Appendix A (Supplement).
Level range, %
0. 021~0.88
Level range. %
0.052-~3.2
Repeatability
= 0. 004 5 / 0. 051 7 m
Repeatability,
=0.00570.0315m
ReproducibilityR
R 0. 004 9- 0. 065 5 m
Reproducibility scale
1. 133 1 0. 798 3 gm
Repeatability is the maximum difference between two independent test results at a 95% probability level, which are obtained by the same operator, in the same laboratory, using an instrument, and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level, which are obtained by two operators, in different laboratories, on the same sample under normal and correct operation conditions. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Data
Laboratory
GB/T 14949.7-94
Appendix A
Precision test raw data
(Supplement)
Table A1 Sodium content raw data
Laboratory
Additional notes:
GB/T14949.7--94
Table A2 Potassium content raw data
This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. K-3
3, 235
This standard was issued by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by Xinyu Ganggang Guang.
The main drafters of this standard are Long Qishen, Ren Shuying, Chen Meiying and Fu Tao. 427-94
Appendix A
Precision test raw data
(Supplement)
Table A1 Sodium content raw data
Laboratory
Additional notes:
GB/T14949.7--94
Table A2 Potassium content raw data
This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. K-3
3, 235
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by Xinyu Ganggangguang.
The main drafters of this standard are Long Qishen, Ren Shuying, Chen Meiying and Fu Tao. 427-94
Appendix A
Precision test raw data
(Supplement)
Table A1 Sodium content raw data
Laboratory
Additional notes:
GB/T14949.7--94
Table A2 Potassium content raw data
This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. K-3
3, 235
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by Xinyu Ganggangguang.
The main drafters of this standard are Long Qishen, Ren Shuying, Chen Meiying and Fu Tao. 42
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