X-ray fluorescence determination of magnetite iron in iron ores after preliminary magnetic separation

The technique for determining the magnetite iron content in iron ores by X-ray fluorescence after preliminary extraction of magnetic fraction by using a magnetic separator is proposed. Separation of the magnetic and nonmagnetic fractions occurs with sufficient completeness and accuracy at a particle size in the sample in the range of–0.074 to +0.044 mm. At smaller grain size, the quality of separation sharply worsens. Mixing of a weighed sample with nonmagnetic powder before separation provides satisfactory accuracy of recovery of the magnetic fraction even in the case of a very finely powdered sample. Application of an X-ray fluorescence energy dispersion spectrometer makes it possible to perform a qualitative assessment of separation by comparison of spectra of scattered and fluorescent radiation after each separation cycle.