Other Applications
Oxford Labs’ X-ray fluorescence facilities are available for use in a wide range of other applications, including:-
- analysis of metals recovered for recycling
- research in igneous, sedimentary, and metamorphic petrology
- soil surveys
- mining (e.g., measuring the grade of ore)
- cement production (e.g., quality control)
- ceramic and glass manufacturing
- metallurgy (e.g., quality control)
- environmental studies (e.g., analyses of particulate matter on air filters)
- petroleum industry (e.g., sulphur content of crude oils and petroleum products)
- field analysis in geological and environmental studies (using portable, hand-held XRF spectrometers)
Metal Recovery Applications. EDXRF is a valuable tool for the fast and accurate assessment of recovered (scrap) metals. This allows for rapid sorting into grades – for example, stainless steel, tool steels, various low-alloy steels, nickel alloys, titanium alloys, and others.
Environmental Monitoring Applications. The potential applications for portable EDXRF machines in environmental monitoring are manifold. Examples include air quality monitoring, soil remediation, plastics recycling, waste oil treatment. Current legislation regarding the disposal and handling of hazardous materials (for example, EU directive 2002/95/EC – Restriction of Hazardous Substances) makes it vital that accurate assessments are made and records maintained. Other examples of the use of XRF technology include the detection of lead in paint on children’s toys, and of hazardous pollutants in contaminated soil.
Geological and Petrological Applications. In most cases for rocks, ores, sediments and minerals, the sample is pulverized (ground to a fine powder) after which it may be analyzed directly, especially in the case of trace element analyses. However, the very wide range in abundances of different elements (especially iron) and in grain-sizes within a powdered sample, both make comparison with the proportional standards problematic. For this reason, it is common practice to mix the sample with a chemical flux and use a furnace or gas burner to melt the powder. Melting creates a homogenous ‘glass’ which can be effectively analyzed, and the proportions of the (now diluted) elements can be calculated.
Merits of the EDXRF technique. X-ray fluorescence is particularly well-suited for investigations which involve:-
- bulk chemical analyses of major elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K, P) in rock and sediment
- bulk chemical analyses of trace elements (in abundances >1 ppm; Ba, Ce, Co, Cr, Cu, Ga, La, Nb, Ni, Rb, Sc, Sr, Rh, U, V, Y, Zr, Zn) in rock and sediment – the detection limits for trace elements are typically in the order of a few parts per million (ppm)
X-ray fluorescence is limited to analysis of:-
- relatively large samples, typically > 1 gram
- materials which can be reduced to powder form and effectively homogenized
- materials for which compositionally similar, well-characterized standards are available
- materials containing high abundances of elements for which the absorption and fluorescence effects are reasonably well understood