Investigation of Recently Developed Monitoring Instruments for DMC Circuits at New Acland

Abstract

The objective of this Australian Coal Association Research Programme (ACARP) supported project was to bring together at a single site the two research groups involved in dense medium cyclone (DMC) instrumentation and software development to demonstrate the following: the long-term capability of the instruments in a coal preparation plant environment, a comprehensive DMC monitoring and measurement reporting capability, and the application of smart sensors to maximize the utility of measurements of this nature. The instruments were deployed for a minimum of 12 months and, apart from some initial issues, were shown to operate effectively in the robust environment of an operating plant. These instruments included motion analyzers on the desliming, product and reject drain and rinse screens, electrical impedance spectroscopes (EIS) for measuring the medium densities of the correct, DMC feed, overflow and underflow streams, a through tile density meter, and in-stream density meter provided measurements of the amount of magnetite in the medium at the DMC vortex finder and underneath the product drain screen. The motion analyzers were calibrated to link the stroke of the screens with the tonnes per hour of the oversize stream reporting from the screens. This meant that the mass flow of feed to the DMC and the product and reject streams was now available dynamically. From this data, an estimate, for the first time, of the on-line yield could be calculated.