A novel experimental system for the study of microbial ecology and mineral leaching within a simulated agglomerate-scale heap bioleaching system
Biochemical Engineering Journal
Reason for embargo
This provides a challenge to determining the growth characteristics of micro-organisms and reaction characteristics of the mineral ore in a representative environment. The experimental system presented in this paper was designed to simulate heap bioleaching conditions using multiple, identically constructed agglomerate-scale mini-column reactors. Ore samples were prepared representatively as grab samples of a larger heap. Particle size distributions and agglomerate masses of the prepared ore samples were shown to be similar within acceptable variance and provided comparable surface areas for microbial colonisation and chemical reaction. The microbial abundance within the whole ore system was determined from effluent sampling for the planktonic population and the systematic and sequential sacrifice of identically operated mini-column reactors to determine the change in the ore-associated microbial population with time. Microbial colonisation and growth rate kinetics were determined from analysis of these populations. The growth curves obtained for the bulk flowing solution and ore-associated populations at the base case operating conditions were reproducible, within a 95% confidence interval.
The financial assistance of the DST and the National Research Foundation (NRF) of South Africa, through the South African Research Chairs Initiative (SARChI UID64778) is hereby acknowledged. Opinions expressed and conclusions arrived, are those of the author and are not necessarily to be attributed to the NRF. The authors would like to acknowledge the assistance and expertise of Bill Randall, Granville de la Cruz and Joe Macke, who contributed to the design and commissioning of the equipment.
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.
Vol. 95, pp. 86 - 97