CIM Bulletin, Vol. 1, No. 4, 2006
P.P. Rosario, R.A. Hall and D.M. Maijer
The file is a zipped PDF document.The primary crusher is a key component in comminution processes and its optimization provides a great opportunity to enhance the overall operational efficiency in high-tonnage mines. Increasing throughput and product quality at the primary crushing phase can increase the productivity throughout the rest of the plant. A collaborative research project between the University of British Columbia and Highland Valley Copper (HVC) was conducted, aiming at understanding gyratory crusher liner wear in the overall context of the crushing process. Improvements in crushing product quality in the three gyratory crushers used for primary size reduction at HVC were expected, as well as reductions in maintenance costs through the development and application of proper liner designs and materials.This paper presents an analysis methodology applied to data collected using a laser-based tool for assessing wear in gyratory crushers. During two years, chamber profiles were collected using a unique laser profiler device (LPD) for the two in-pit 1.52 by 2.26 m (60 by 89 in.) Metso Superior Gyratory crushers in operation at HVC. Chamber design, or cavity design, is considered a key parameter in crushing performance and it is expected that with the right design of the liners, wear can be minimized. Concurrent with the wear measurement program, improvements were made to the laser device and a methodology to analyze the geometry of the crushing chamber using LPD’s data was developed. An Excel-based tool was developed and provided additional functionality to the laser-based methodology. This new application included several analytical features, such as wear calculations, close-side setting (CSS) estimation by mantle position, and a graphical representation of chamber volume by concave height.Data from the wear measurements were correlated with crusher production information, such as current draw, product size distribution, and production rate. Graphical analyses of these crushing parameters were applied. One of the significant outcomes of these analyses was the ability to assess the crushing performances of several different types of mantles over the life of various concaves.The data analyses served to correlate particular chamber geometry characteristics with distinct periods of crushing performance. Of main interest for the investigation of chamber characteristics were operational periods that varied significantly from the norm. These distinct periods were those when the crusher was operating very well, as indicated by a stable current draw, good product quality, and high-mantle tonnage, and the periods when issues occurred, such as high current spikes, poor product quality, or low mantle throughput.From the data analyses, an understanding of crushing chamber characteristics and their impact on crushing performance was achieved. In addition, wear rate as a function of production was determined for the concaves, which enabled wear prediction for the bottom part of the concave.As a result of the knowledge developed during this work, an innovative way to evaluate crusher liner profiles was created and applied in the design of new mantle profiles. In addition, this understanding helped in a thorough evaluation of the current liner management policy at the mine.The evaluation resulted in a revised maintenance schedule based on the use of two new mantle profiles specially designed for this application. This led to a reformulation of HVC’s standard liner management policy, with a resulting estimated annual savings of 13% in total crusher liner cost and a 15% reduction in liner replacement downtime.