X-ray Techniques for Process Control in the Mineral Industry

Abstract

In any mineral processing plant, automatic control demands information on the behaviour of the system from sensors measuring the required parameters. In most processes the concentrations of certain elements or crystalline materials must be known at a number of points in the plant, and these can be obtained by X-ray fluorescence and X-ray diffraction analysis respectively. The concentrations can be monitored by either on-line or on-stream analysis, where an on-line analyser automatically takes a discrete sample, prepares it, delivers it to an instrument which carries out the required measurement, and then subsequently communicates the data to the control computer, while an on-stream analyser has all or part of the process stream continually flowing through it and it carries out its measurement also continuously, the output being available when required. X-ray methods are well suited to on-stream as well as to on-line analysis, having high selectivity, large sample throughput, the ability to examine liquids, slurries and powders in an ‘as-received’ form, and true digital outputs.