Patent Number: 050200844
Section: abstract

A method for the rapid and sensitive analysis of heavy metal ores, especially those of gold and uranium, uses high-engery X-ray fluorescence spectroscopy. The invention is of particular interest for the measurement of samples from gold or bodies which typically have concentrations up to 10 ppm by mass. Preferred features include the use of an X-ray tube as a source, the counting of emitted fluorescence photons in energy bands selected to correlate with the characteristic x-ray fluorescence emissions of elements of interest, the excitement of the ore sample by irradiation with high energy bremsstrahlung radiation filtered through tin, the exploitation of polarization in analysis for uranium, the interposition of a platinum-group metal filter between the sample and the detector, and the use of high-purity germanium detectors. Techniques are described for the detection and elimination of inaccuracies due to the presence of certain interfering metals and correction for variations in sample density. Apparatus for use in the method of the invention is also disclosed and claimed.