The field of geometallurgy includes aspects of geotechnical engineering, process mineralogy, geology, metallurgy, resource modelling, geostatistics and mine planning (Bye, 2010). Typically, geometallurgical characterizations are carried out using core samples and the results are used to quantify the value associated with including an individual block in the mining footprint.
The majority of reviewed geometallurgical studies involved the process of defining geometallurgical domains or units. Lotter (2011), describes a geometallurgical unit as an individual or group of ore types that possess a unique set of textural or compositional properties from which it can be predicted that a similar metallurgical performance will result.
Bye (2010) mentions that in order to define the inherent variability of an orebody, coordinating smaller volume tests, rather than compositing of core samples, is a dominant trend in the field of geometallurgy. A challenge associated with handling geometallurgical data is the fact that not all geometallurgical characteristics are additive. For example, Bond ball mill work indices are not additive and need to be converted into alternative units through simulation if they are to be used with kriging or inverse distance methods to populate a block model (Barratt et al., 2008). Alternatively, blend-response models, as proposed by Bye (2011), have been identified as a solution to modelling mill performance for a variety of ore types.
Many geometallurgical studies have shown strong correlations between geotechnical test data and crushing/grinding indices. Burger et al. (2006) found good correlations between the Point Load Index Is(50) and DropWeight Indices for certain ore types. Advantages of the Point Load Index (PLI) test are the relatively low test costs and short turn-around time in comparison to DropWeight type breakage tests. Proper geotechnical characterization of ore bodies is critical for caving projects, resulting in an abundance of geotechnical data that is available for consideration in a Cave-to-Mill approach.