Parameters influencing full scale sublevel caving material recovery at the Ridgeway gold mine

The literature discusses a number of theoretical, small, and full scale experimental programs, which have aimed at identifying parameters influencing sublevel caving (SLC) material flow behaviour, and therefore ore recovery and dilution. Historically, parameters directly influencing flow behaviour have been found to include the geometry of the extraction layout and drives, sublevel height, blast ring design, material characteristics of the blasted and waste material, and draw control methodology. To date, no detailed analysis of parameters influencing full scale material flow behaviour and recovery in modern SLC mines has been documented in the literature. This paper outlines the analysis undertaken to identify parameters which influence material recovery at the Ridgeway SLC operation. Parameters analysed included those related to drawpoint location, drill and blast design, geology, drawpoint geometry, and draw control. To identify parameters influencing recovery, a Self-Organising Map (SOM) technique was adopted. SOM is considered an ideal tool for analysing complex geological and mining datasets, and for extracting relationships and patterns that typically are not evident by other means. The SOM analysis indicated that a number of drill and blast design parameters were directly or inversely correlated to material recovery at the Ridgeway SLC operation. Blasting parameters dominated correlations with recovery when compared to drawpoint and geological parameters.