Drilling Specific Energy Application to Estimate SAG TPH in Short Term Planning, Teck Carmen de Andacollo

摘要

Carmen de Andacollo (CDA) is a copper porphyry deposit, located near the town of Andacollo, in the Region of Coquimbo, Chile. Its main business is the copper concentrate production in a plant designed to process 55,000 tons/day. To date, more than 50,000 Drilling Specific Energy (EEP, in Spanish) data have been collected in CDA from a combination of automated readings performed on blast-hole drilling machines (Teale, 1964). The EEP expresses the intrinsic rock resistance to the drop and rotation of the drill. Thus, rocks and "hard" alteration zones (e.g., porphyry with albite alteration) present high EEP values, whereas "soft" alteration zones (e.g., breccias with argillic alteration) show low EEP values. Considering the amount of data obtained and its correlation with the metallurgical parameter DWi, a monitoring program was carried out of the plant's operational parameters and the mine's geometallurgic variables, to identify and correlate the ore characteristics with its response to the industrial milling process. The successful results led to the development of a TPH Model based on a Multiple Linear Regression, which includes, among its most important predictors, the variables of F80 for SAG Feed, DWi, and EEP. The TPH Model has been subjected to validation since its implementation, presenting a relative difference of 6% to date, between the estimated and the actual throughput. The Short-Term Planning area has developed a script in Vulcan?, which allows applying the TPH model as a block model variable, assigning each block the maximum performance achieved by the SAG mill. With this we can predict the plant throughput according to its operational parameters and the geometallurgic variables of the ore. Now the planning engineer can develop different options for mining plans in a shorter time, improving the level of reliability in the plant throughput estimation and maximizing the production of fine copper.