A systematic approach of sample selection to predict processing performance of an ore body

摘要

The depletion of easily mined high-grade ore bodies resulted in the industry having to exploit lower grade, complex resources (Albanese and McGagh, 2011; Darling, 2011; Randolph, 2011). The trend is now towards mining and processing of low-grade and complex ores (Darling, 2011; Yingling, 1990). Variable geological and mineralogical characteristics, and complex mineralogy and texture can result in large variations in metallurgical response and also cause challenges in processing. (Carson, 1995; Lorenzen and Barnard, 2011; Yingling, 1990). Variability and the complex nature of ores are fundamental sources of risk that often cause the greatest economic impact (Dusci et al., 2007; Williams and Richardson, 2004). Hence it is important to effectively characterise these types of ore bodies and assess their processing performance (ie recovery, grade). To enable this, there is a need for the following:i) characterisation of geological, mineralogical and metallurgical variability in the ore body;ii) effective selection of drill core with characteristics that represent the range of ores in the entire ore body.Despite the established Gy's theory of representative sampling and the several techniques of correct sampling (Wills & Napier-Munn, 2006; Pitard, 1993), ensuring a representative sample remains a challenge, especially when sampling an entire ore body. Unrepresentative samples may provide inaccurate information that can cause inaccurate assessment. More often, testing is carried out on a small number of composite samples to assess the processing response of the ore body (Lorenzen and Barnard, 2011, Hanks and Barratt, 2002, Scott and Johnston, 2002). Because of the variability in ore characteristics, the use of a limited number of composite samples can result in technical errors.