Rapid ore breakage parameter estimation from a laboratory crushing test Fernando N. de Magalhães, Luís Marcelo Tavares ⁎ Department of Metallurgical and Materials Engineering, Universidade Federal do Rio de Janeiro, COPPE/UFRJ, Cx. Postal 68505, CEP 21941-972, Rio de Janeiro, RJ, Brazil abstract article info Article history: Received 2 August 2013 Received in revised form 7 November 2013 Accepted 17 November 2013 Available online 26 November 2013 Keywords: Breakage parameters Crushing Power Particle breakage Geometallurgy Drop weight testers have been widely and successfully used to characterize ore breakage parameters for simulation of crushers and mills. In some cases, limitations of time, sample availability, and even cost, can prevent the conduc- tion of these tests when preparing samples for chemical analysis and/or grindability and flotation/concentration testing. The present work demonstrates how a laboratory cone crusher equipped with a power meter, in conjunc- tion with Whiten–Awachie crusher model, has been used to quickly estimate the A * b breakage parameters. With an average absolute error of 36% when applied to a variety of materials, it is demonstrated that the method is not a priori restricted to the particular crusher used, neither to the crushing conditions employed. It is discussed that the method, when part of a variability study, can be used as a convenient tool for geometallurgical mapping of ore de- posits regarding ore breakage response. © 2013 Elsevier B.V. All rights reserved. 1. Introduction A number of questions should be answered when selecting the ap- propriate crusher to an application, which include crusher capacity, power consumption, product size distribution and wear rate of liners, amongst others (Bearman et al., 1997; Tavares and da Silveira, 2008). In estimating the product size and the corresponding specific energy consumption, a number of options exist, although it is not uncommon to solely rely on data provided by crusher manufacturers or to use data from other plants that processes similar ores. Throughout the life of a mine, crushers may be fed with ores with highly variable crushing responses, so that characterizing the amenabil- ity of ores contained in different parts of a deposit to crushing is worth- while. This requires, however, proper crushability tests as well as mathematical expressions that can use characterization data to predict equipment performance. Briefly, two main indices have been used to access the response of ores to crushing (Tavares, 2007; Tavares and da Silveira, 2008). The crushing work index (CWi), estimated on the basis of the twin- pendulum test, has been proposed by Fred Bond and accumulates a long track record in predicting the performance of crushing operations, although with several cases of poor performance. On the other hand, the A * b breakage parameters, obtained using the drop weight test (Napier-Munn et al., 1996) and, more recently, the rotary breakage tester (Shi et al., 2009), has been used with reasonable success in conjunction with Whiten's model of compression crushers (Whiten, 1972) to predict the performance of full-scale machines. The A * b breakage parameters are calculated on the basis of impact tests on individual particles contained in five standard size classes, rang- ing from 63–53 mm down to 16.0–13.2 mm. In several instances, however, sample availability and even cost represent challenges to conducting the test, so that it may not be included in the suite of tests that are carried out when processing drill core samples, especially when preparing samples for assaying. Although alternative tests have been proposed that use more limited sample volumes (Chieregati and Delboni, 2002; Morrell, 2004) there are instances that not even these tests are used. In all cases, however, laboratory crushers are invariably used to prepare the sample for grindability or concentration tests or, at least, for assaying or mineralogical analyses. Indeed, some researchers (Kojovic et al., 2010) have identified that the response of the samples, normally diamond drill cores, to this crushing operation could provide in- formation on breakage response of ores to size reduction, and proposed an additional comminution index, the Ci. Evidently, a number of measures of breakage response of ores have some degree of correlation with the A * b breakage parameters. For in- stance, Kojovic et al. (2010) show that it is correlated to the Ci. Napier- Munn et al. (1996) show the correlation between A * b and the Bond ball mill work index, whereas Tavares and da Silveira (2008) demon- strates that it is correlated with the Bond crushing work index (CWi) and even the Los Angeles index, more commonly used to characterize the amenability of a rock to be used in pavements. However, empirical correlations with no physical background carry the risk of only being valid for the cases for which they were developed, besides requiring strict adherence to the standard used in the test. The present paper demonstrates that the laboratory crushing opera- tion that is used to prepare drill core samples for grindability or concen- tration tests, or even assaying, can be, after proper calibration, used to estimate the breakage indices A * b of ores. International Journal of Mineral Processing 126 (2014) 49–54 ⁎ Corresponding author. Tel.: +55 21 2562 8538. E-mail address: tavares@ufrj.br (L.M. Tavares). 0301-7516/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.minpro.2013.11.007 Contents lists available at ScienceDirect International Journal of Mineral Processing journal homepage: www.elsevier.com/locate/ijminpro