This standard specifies the determination method of magnesium oxide content in copper concentrate. This standard is applicable to the determination of magnesium oxide content in copper concentrate. GB/T 3884.4-2000 Chemical analysis method for copper concentrate Determination of magnesium oxide content GB/T3884.4-2000 Standard download decompression password: www.bzxz.net

GB/T3884.4—2000
This standard is a reaffirmation of GB/T3884.5-1983 "Chemical analysis method of copper concentrate - Determination of magnesium oxide by atomic absorption spectrophotometry". Except for changing the release agent in the original standard from lanthanum salt to strontium salt, the other modifications are editorial. This standard complies with:
GB/T1.1-1993
Guidelines for Standardization
Basic provisions
Unit 1: Rules for drafting and expressing standards Provisions for the preparation of chemical analysis methods standards
Guidelines for Standardization
GB/T1.4-1988
3 General principles and general provisions for chemical analysis methods for metallurgical products GB/T1467-1978
GB/T7728—1987 General principles for flame atomic absorption spectrometry for chemical analysis of metallurgical products GB/T17433—1998 Basic terms for chemical analysis of metallurgical products This standard replaces GB/T3884.5—1983 from the date of implementation. Appendix A in this standard is a prompt appendix. This standard was proposed by the State Bureau of Nonferrous Metals Industry. This standard was drafted by Daye Nonferrous Metals Company. The main drafters of this standard are: Peng Jianjun, Feng Congxin, Ma Chenwu. 22
Part 1: Standard preparation
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of copper concentrates
Determination of magnesium oxide content
Methods for chemical analysis of copper concentrates-Determination of magnesium oxide content This standard specifies the determination method of magnesium oxide content in copper concentrates. This standard is applicable to the determination of magnesium oxide content in copper concentrates. Determination range: 0.50%~6.00%. 2 Method summary
GB/T3884.4—2000
Replaces GB/T3884.5—1983
The sample is dissolved with hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid. In the dilute hydrochloric acid medium, a certain amount of strontium chloride is added to suppress interfering elements. The absorbance of magnesium oxide is measured at a wavelength of 285.2nm using an air-acetylene flame on an atomic absorption spectrometer. 3 Reagents
3.1 Hydrochloric acid (pl.19g/mL).
3.2 Nitric acid (pl.42g/mL).
3.3 Hydrofluoric acid (pl.13g/mL).
3.4 ​​Perchloric acid (pl.67g/mL).
3.5 Hydrochloric acid (1+1).
3.6 Magnesium oxide standard solution: Pre-calculate magnesium oxide (spectrally pure) at 600℃ for 1h, place in a desiccator and cool to room temperature. Weigh 0.5000g magnesium oxide in a 250mL beaker, add a small amount of water to moisten, add 20mL hydrochloric acid (3.5) to dissolve completely, transfer to a 500mL volumetric flask, dilute to scale with water, and mix. This solution contains 1mg magnesium oxide in 1mL. 3.7 Strontium solution: weigh 30.43g strontium chloride (SrClz·6Hz0) in a 250mL beaker, add 30mL water, dissolve in 25mL hydrochloric acid (3.5), transfer to a 500mL volumetric flask, dilute to scale with water, and mix. This solution contains 20mg strontium in 1mL. 3.8 Disodium ethylenediaminetetraacetate (NaEDTA) solution [c(Na,EDTA)=0.10mol/L]: weigh 18.62g disodium ethylenediaminetetraacetate (CoHN,O.Na?2HO), place in a 250mL beaker, add hot water to dissolve, transfer to a 500mL volumetric flask, dilute to scale with water, and mix.
4 Instruments
Atomic absorption spectrometer, with magnesium hollow cathode lamp. Under the best working conditions of the instrument, those that can achieve the following indicators can be used. Sensitivity: In a solution consistent with the matrix of the measured solution (burner angle 90°), the characteristic concentration of magnesium oxide should not exceed 0.411μg/mL.
Precision: The standard deviation of measuring the absorbance 10 times with the highest concentration standard solution should not exceed 1.0% of the average absorbance. The standard deviation of measuring the absorbance 10 times with the lowest concentration standard solution (not the "zero" standard solution) should not exceed 0.5% of the average absorbance of the highest standard solution.
Working curve linearity: Divide the working curve into five sections according to concentration. The ratio of the absorbance difference of the highest section to the absorbance difference of the lowest section should not be less than 0.9.
Instrument working conditions are shown in Appendix A (Suggested Appendix). 5 Sample
5.1 The sample size should not be greater than 0.082mm. 5.2 The sample should be dried in an oven at 100~105℃ for 1h and placed in a desiccator to cool to room temperature for later use. 6 Analysis steps
6.1 Sample
Weigh 0.20g of sample to an accuracy of 0.0001g. Perform two independent determinations and take the average value. 6.2 Blank test
Perform a blank test along with the sample.
6.3 Determination
6.3.1 Place the sample (6.1) in a 150mL polytetrafluoroethylene beaker, add a small amount of water to moisten it, add 10mL hydrochloric acid (3.1), place it on a hot plate and heat for 5 minutes, add 10mL nitric acid, heat for 5 minutes, add 5~10mL hydrofluoric acid, heat and evaporate to a volume of about 10mL, add 5~10mL perfluoric acid, continue to heat and dissolve, evaporate until perchloric acid emits white smoke (if the carbon content is high, add 5mL peroxy acid), evaporate until it is almost dry, remove and cool.
6.3.2 Add 6mL hydrochloric acid (3.5) and 5mL water, heat to completely dissolve the salts, remove and cool to room temperature. 6.3.3 Transfer the solution to a 100mL volumetric flask, dilute to the mark with water, and mix well. 6.3.4 Take the test solution according to Table 1 and add hydrochloric acid (3.5) to a 100mL volumetric flask, add 1mL NazEDTA solution, 5mL strontium solution, dilute to the mark with water, and mix well.
Magnesium oxide content, %wwW.bzxz.Net
0.50~1.00
>2.00~3.00
Amount of test solution taken, mL
Amount of hydrochloric acid (3.5) added, mL
6.3.5 Use air-acetylene flame, at the wavelength of 285.2nm of the atomic absorption spectrometer, with the burner angle 90°, and adjust to zero with water at the same time as the standard solution series, measure the absorbance of the solution, subtract the absorbance of the blank solution accompanying the sample, and find the corresponding magnesium oxide concentration from the working curve.
6.4 Drawing of working curve
6.4.1 Take 0.00, 0.50, 1.00, 1.50, 2.00, 2.50mL of magnesium oxide standard solution and place them in a group of 100mL volumetric flasks, add about 20mL of water, 6mL of hydrochloric acid (3.5), 1mL of NazEDTA solution, 5mL of strontium solution, dilute with water to the scale, and mix. 6.4.2 Use air-acetylene flame, at the wavelength of 285.2nm of atomic absorption spectrometer, turn the burner angle 90°, adjust to zero with water, measure the absorbance of the solution, subtract the absorbance of the "zero" concentration solution, and draw the working curve with magnesium oxide concentration as the horizontal axis and absorbance as the vertical axis. 7 Description of analysis results
Calculate the percentage of magnesium oxide according to formula (1): Mgo(%) = V. V,× 10-s
?（1）
GB/T3884.4-2000
Wherein: C——the magnesium oxide concentration of the sample solution obtained from the working curve +ug/mL; V. —total volume of the test solution, mL;
Vi—the volume of the aliquoted test solution, mL;
V.——the volume of the aliquoted test solution after dilution, mL, the mass of the sample, g.
The result is expressed in two decimal places.
8Allowable Difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Magnesium oxide content
>0.50~1.00
>1.00~2.00
>2.00~4,00
>4.00~6.00
Allowance
GB/T3884,4—2000
Appendix A
(Suggested Appendix)
Working conditions of the instrument
The working conditions for measuring the magnesium oxide content using the Japanese Shimadzu AA640-13 atomic absorption spectrometer are shown in Table A1. Table A1
Harmonic passband
Observation height
Air flow cylinder
B fast flow disk
Measurement method
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