X-Ray Fluorescence of Suspended Particles in a Liquid Hydrocarbon

Abstract

AbstractIn the application of X-ray fluorescence to the inspection of petroleum or petrochemical products, the measured element may not be ideally dispersed in the organic substrate but may exist as suspended particles. A question naturally arising is how small the particles must be to approximate the fluorescent intensity level of the true solution. The fluorescent emissions of suspensions of particles in a viscous hydrocarbon were measured and the intensities compared with true solutions of zinc, iron, and silicon, respectively. Particle segregates were classified by raicrosieve and photomiorographic inspection. Iron or zinc particles of 8-μ size yield 65% of the intensity of the solution state. Increase of particle size to 70 μ reduces intensity by several fold. Silicon, dispersed as porous silicon dioxide particles of 28-μ size, yields 80% of the intensity of the solution form. Reliable measurement of a suspension can be made provided it is stable and a standard closely simulating it is available for reference or if proper intensity corrections are applied for a known particle size in suspension. Comparisonsof experiment with theory for the particle size-intensity effect agree only moderately well. This is attributed to uncertainties in the parameters relating the two. Theory indicates that zinc or iron in suspended form should be less than 1 μ in size to approximate the intensity of the elements in solution. Additional research aspects of particles in suspension are suggested.