Methods for chemical analysis of laterite nickel ores―Part 19:Determination of aluminum,chromium,iron,magnesium,manganese,nickel and silicon contents―Energy-dispersive X-ray fluorescence spectrometry
Methods for chemical analysis of laterite nickel ores — Part 19: Determination of aluminum, chromium, iron, magnesium, manganese, nickel and silicon contents — Energy-dispersive X-ray fluorescence spectrometry
1 Scope
This part of YS/T 820 specifies methods for the determination of aluminum, chromium, iron, magnesium, manganese, nickel and silicon contents in laterite nickel ores by energy-dispersive X-ray fluorescence spectrometer.
This part is applicable to the determination of aluminum, chromium, iron, magnesium, manganese, nickel and silicon contents in laterite nickel ores. See Table 1 for the determination range.
Note: The contents of aluminum, chromium, iron, magnesium, manganese, nickel and silicon contents in laterite nickel ores can also be determined using the method in Annex A.
Table 1 Element and its determination range
2 Method summary
The powder specimen is pressed or prepared into glass melt piece, which is placed in the ray beam emitted by the X-ray source. When the sample is excited, the fluorescent X-ray intensity generated is measured by the analysis device, and the content of the element to be measured is calculated through the calibration curve.
3 Interferences
3.1 When each element in the laterite nickel ore sample emits X-ray and produces spectral interference, the detector cannot correctly detect the X-ray emitted by the element to be detected, resulting in spectral superposition and spectral interference. Calibrate the instrument according to the operating instructions of the instrument manufacturer to eliminate interference.
3.2 The change of element content in the sample may change the matrix and directly affect the X-ray absorption, thus changing the measurement results of each element. This interference usually occurs in X-ray fluorescence analysis, but it is not the spectral interference.
3.3 Some instruments are equipped with interference reduction software, which can automatically check and reduce interference.
4 Instruments and equipment
4.1 Energy-dispersive X-ray fluorescence spectrometer: Any energy-dispersive X-ray fluorescence spectrometer that can be used in this test method and meets the following conditions may be used.
4.1.1 X-ray excitation source: molybdenum target, antimony target, palladium target, silver target, gadolinium target, tungsten target or gold target X-ray tubes. The excitation energy is 4keV ~ 50keV or higher. Programmable control can be used to selectively excite the sample and simplify the sample spectrum.
Note: When using X-rays for testing, analysts shall comply with the safety instructions of the instrument manufacturers as well as national and local safety regulations.
4.1.2 X-ray detector with resolution below 155eV (Mn-Kα).
Foreword i
1 Scope
2 Method summary
3 Interferences
4 Instruments and equipment
5 Preparation of specimen
6 Calibration and standardization
7 Analytical procedures
8 Expression of results
9 Precision
10 Test report
Annex A (Informative) Molten slide method
Annex B (Informative) Working conditions for instruments
