Testing
GeoBiotics conducts testwork to demonstrate the application of the GEOCOAT® or GEOLEACH™ processes to treatment of project-specific sulfide concentrates and ores, and to collect the metallurgical and chemical process data necessary for plant design.
GeoBiotics will design a testwork program in consultation with the mine owner, and will determine the quantities of ore or concentrate, support rock, and site water required for the program. Depending on the material to be tested, ongoing testwork program schedules, and client preferences, GeoBiotics will suggest that testwork be carried out at either its own facility or at a third-party lab.
The purposes of the testwork program are to:
- investigate the applicability of GeoBiotics' Technologies for the treatment of client's sulfide ore or concentrate
- determine the metal extraction as a function of sulfide oxidation
- investigate process variables such as heap height
- determine the chemical reagent consumptions
- determine the leach kinetics
- refine heat balance models
- determine the microbiological operating regime
- determine efficiency of arsenic removal and stability of residues
A complete testwork program typically consists of three phases:
- Scoping level tests
- mineralogical and chemical analyses
- microbial adaptation
- diagnostic leach
- batch amenability testing
- solution analyses
- biooxidation product analyses
- Kinetic (short) column testing
- leach kinetics at various temperatures
- support rock testing (for GEOCOAT®)
- coating ratio and slurry density (for GEOCOAT®)
- acid consumption
- Tall column testing
- biooxidation 5-6 meter column tests on owner-supplied support and inert support rock (for GEOCOAT®)
- short sacrificial columns terminated at varying times
- neutralization tests
- liquid/solids separation and viscosity tests
At the conclusion of each phase of the test program, GeoBiotics will prepare a report that includes descriptions of the test procedures, presentation of results and operating data, and analyses of the results.
In some cases, construction and operation of a demonstration heap is desired or required to prove the technology at site-specific production conditions.
The demonstration plant will provide critical information on several design variables, including:
- Bioleach performance – metal extraction and leach rates
- Control and instrumentation system
- Temperature measurement
- Oxygen measurement
- Control philosophy
- Heap construction variables
- Aeration design
- Irrigation design
- Drainage design
- Inoculation techniques
- Coating performance (for GEOCOAT®)
- Solar heating of heap using new mat technology
- Site investigations of existing heap design
The data collected during the trial is then used for process and engineering design of a commercial-scale operation.