ISO/TR 4688-1:2017 – Iron ores – Determination of aluminium – Part 1: Flame atomic absorption spectrometric method has been released. This technical report describes a means to determine the mass fraction of aluminum in iron ores through the use of a flame atomic absorption spectrometric method.
Atomic absorption spectrometry, or atomic absorption spectroscopy (AAS), involves the atomization of a sample and the absorption of radiation from a light source by the free atoms to determine the elemental composition of a metallic portion. With the inclusion of flames into the atomic absorption spectrometric method, AAS can be used for determining the presence of a wider range of metals.
The flame atomic absorption spectrometric method addressed in ISO/TR 4688-1:2017 begins with a test portion being decomposed through treatment with hydrochloric acid and some nitric acid. The mixture is then evaporated into dehydrate silica, which undergoes dilution and filtration. After this, the residue is ignited, and, after the silica is removed, it is fused with sodium carbonate and, after cooling, is dissolved in the filtrate. The resulting solution is aspirated into the flame of an atomic absorption spectrometer using a dinitrogen oxide/acetylene burner.
The absorbance values gathered for aluminum from this method should be compared with those obtained from the calibration solutions.
The animation below gives a demonstration of a flame atomic absorption spectrometric method.
While the method seen above is not exactly identical to every guideline detailed in the technical report, it does provide a helpful visualization to the procedure. The flame atomic absorption spectrometric method addressed in ISO/TR 4688-1:2017 is applicable to mass fractions of aluminum between 0.1 % and 5.0 % in natural iron ores, iron ore concentrates, and agglomerates, including sinter products.
ISO/TR 4688-1:2017 – Iron ores – Determination of aluminium – Part 1: Flame atomic absorption spectrometric method is available on the ANSI Webstore.