| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2954 | Biochemical Engineering Journal | 2015 | 12 Pages |
•Design of multiple, mini-column reactors to simulate grab samples from a heap bioleach.•Sacrifice of a mini-column in test represents a time point in data series for microbial growth.•Independently quantify microorganisms in flowing and stagnant solution and on ore.
Heap bioleaching systems are complex, with multiple sub-processes interacting at various scales within the heterogeneous reaction environment. 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.
