Assessing the concentration of mineral matter in coal-derived liquids

Mineral matter in coal-derived liquids such as coal extracts can be assessed on-line by passing an X-ray beam having as a predominant component wavelengths in the range 0.6 to 0.8 Angstrom units through the liquid and detecting the intensity of the transmitted radiation. X-ray wavelengths in this range permit adequate discrimination between attenuation caused by mineral matter and that caused by the liquid, without having very poor transmission. The source may be an X-ray tube or a Pm 147/Zr source having a shutter which automatically closes on removal from a lead container. A proportional counter is positioned opposite the source on a pipe carrying the coal solution. The X-rays are collimated by a lead ring and pass through graphite windows. (author)