Preliminary Evaluation, Solution Mining Potash
Agapito Associates, Inc. (AAI) was commissioned to prepare a preliminary evaluation of the potential for solution mining an offshore occurrence of deep, thick, high-grade potash consisting of a mixture of sylvinite and carnallite with associated langbeinite and polyhalite for a prospect in northern Africa. The Scope of Work consisted of the development of a preliminary study to extract and treat brine followed by solar evaporation and concentration, for production of granular potash at a rate of 2 million tonnes of potash (95% pure KCl) per year.
The deposit was characterized as having an ore grade of 20 percent (%) potassium oxide (K2O) and height of 80 meters. The number of caverns at startup was estimated at approximately 68 with cavern replacement of seven caverns per year. Initial capital costs for the mine including cavern development, evaporative ponds plant, and infrastructure were estimated. Operating costs including energy costs, well replacement, cavern operations, pond, plant, and transport to the built-for-purpose port were prepared. Risks to the success of the project and recommendations for additional studies were identified.