Solution Mining Technology

HPC estimates mining in the Manenga exploration license will be entirely by solution mining technology. In the Tchitondi area the western outboard of the permit may be amenable to solution mining. Solution mining technology has been in existence for over 30 years, it is proven and tested technology for the mining of deep salt deposits and is currently successfully applied in potash production projects in the USA, Canada, Germany, Holland and Thailand. Solution mining implies the use of solvents (water or weak brine) to dissolve the ore material. The process starts with the drilling of one or several wells down to the target mineable salt horizons and the Injection of the solvent which in turn dissolves the ore and creates a brine that is pumped to surface for processing. This creates caverns that require management with respect to their stability and decommissioning by backfilling the residual salts and purges from evaporators or are elsewhere used for gas or oil storage. Recoverable resources per area from solution mining operations are estimated by industry between 20 and 40%. Solution mining presents the following advantages:

  • Low upfront Capex and overall less expensive than conventional mine development operations.
  • Reduced construction time of 4-5 years compared with 5-8 years for conventional mining.
  • Flexible allowing for incremental and modular project expansion
  • Sustainable and environmentally responsible mining method when carefully implemented, allowing for a small footprint on the environment and a clean rapid reclamation and rehabilitation. All wastes can potentially be backfilled in caverns and area can thus safely be decommissioned.