• Hill, Anita
• Mardel, James

Abstract

The durability of critical wear components, the ability to predict their remaining life and their improved operating efficiency was identified by the Australian coal industry to be a long term strategic objective. Polymer screen panels used in high capacity multi-sloped screens (banana screens) are a critical wear component that can affect both availability of the plant and plant performance. As a screen panel wears more oversize material is presented to down stream processing unit operations such as spirals and flotation plants, this oversize material has detrimental affects on the operating efficiency of these unit operations and can result in considerable yield losses.I addition the maintenance of the screen panels is often done on a reactive basis or carried out at times when it is not needed resulting in unnecessary stoppages to the plant. If the plant operators can predict when the screen apertures/misplaced material reaches a point where yield loss is excessive and screen maintenance is required then reactive screen maintenance can be eliminated. This paper describes the plant work undertaken during the course of the project, the results of the plant work and the next steps towards developing a model describing the wear and the effect this wear has on downstream processing. Two plants were chosen for the test work; the first a plant with desliming banana screens cutting at nominally 1.8mm with the oversize (30mm by 1.8mm) reporting to a primary 1m DMC and the undersize to classifying cyclones and spirals. The second plant was desliming the 50mm topsize feed again using banana screens at a cut point of nominally 0.4mm,the 50mm by 0.4mm was cleaned using a primary 1m dense medium cyclone and the desliming screen undersize nominally 0.4mm by 0 was treated using column flotation. Both these circuits incorporated secondary processing of the primary DMC rejects using secondary DMCs to produce a thermal coal. Screen apertures were measured over a period of 10 to 12 weeks using an optical image analysis technique and samples taken of the screen products either just prior to the aperture measurement or immediately after.

Topics

• impedance spectroscopy
• polymer
• reactive
• durability