Geometallurgical analysis for increasing gold recovery - Santa Bárbara

摘要

Rio das Velhas Greenstone Belt, largely located in the Iron Quadrangle (Quadrilátero Ferrífero) region of the State of Minas Gerais, is the most important gold district in Brazil. Córrego do Sítio mines complex are gold deposits exploited by AngloGold Ashanti Brazil using the underground mining method. At these mines, besides grade variation, numerous other parameters can directly influence costs and revenues. Examples of these parameters are variation of hardness, liberation of ore minerals, mineralogy, porosity, among others. This work aims to demonstrate how these geometallurgical parameters can be used across different operating areas of an active gold mining operation, by previously identifying the variability in the metallurgical behavior of different types of ores and, in addition, assisting with process stability. Implementation of the Geometallurgical Process began in 2015 following decisions made in respect of sampling plans, types of tests and analysis and use of data in the operational routine. Its methodology consists of drill core sampling in line with the mining plan, core logging, bench tests representative of the metallurgical plant's operations and chemical and mineralogical characterization of samples before and after being tested. Through the pursuit of such knowledge, which involves a more detailed geological characterization, combined and correlating with metallurgical characteristics, a suitable ore treatment method has been obtained, increasing the efficiency of the ore - treatment - metallurgy system, as well as the predictability of metallurgical behavior.