Estimation of Ionic Load Effect on the Oxidizing Activity of the Microbial Population in the Heap Bioleaching Process at Escondida Mine

Abstract:

The design of the industrial copper bioleaching plant at Escondida mine involves the recycling of the solutions in the system, with a consequent increase of ionic solutes in the raffinate solution and Pregnant Leach Solution (PLS). It is known that elevated concentrations of solutes in these solutions have a negative effect on the microbial population leading to decrease the dissolution of copper containing ore. To study the effect of the ionic load on the microbial oxidizing activity, a regression model was built using the systematic data obtained for the concentrations of sulfate, aluminum, chloride and manganese in solutions, during five years of operation. Then, this model was used to support a design of experiment (DOE). The DOE revealed an important effect on the microbial activity produced by sulfate and/or aluminum, decreasing the activity to minimum values, but the effect of chloride and manganese were not significant on the microbial oxidizing activity. This work highlights the importance of determining operational limits for the ionic load of biomining solutions in order to prevent future inhibitions of the microbial oxidizing-activity.

• Periodical: Advanced Materials Research (Volume 825)
• Pages: 219-222
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.825.219
• Online since: October 2013
• Authors: Dina Cautivo, Pamela Soto, Victor J. Zepeda, Pedro A. Galleguillos, Antonio Velásquez, Carlos Pinilla, Cecilia Demergasso
• Keywords: Bioleaching, Ionic Load, Regression Models

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