The following basic design assumptions have been made:
• There is no overlying aquifer and no water occurs in the potash seam;
• No flammable gas occurs in the potash seam;
• Geotechnical design can be based upon general geotechnical parameters derived from existing potash operations;
• The salt beam (Lower Salt Formation) between the potash horizon and overlying Basalt Unit is contiguous with the basalt and can be supported through appropriate room sizing with systematic roof bolting in main roadway developments only;
• The potash horizon floor elevation is relatively planar and does not compromise the mine design in terms of access and mineral recoveries;
• No major faulting occurs across the deposit area;
• Panel room orientation is not affected by in-situ stress fields;
• Selective mining of sylvite is not proposed;
• Backfill is not proposed nor required in Morocco;
• The production target is approximately 6.0 Mtpa ROM which will allow for a 19-year life of mine.
The Company has elected to use contract mining for both production and development.
The mine is proposed to be accessed via twin declines from the surface which will enable ore to be extracted using a conventional room and pillar mining methodology using continuous miners.
The decline will be driven through three key lithologies: minor clay formation (~10m thick); primary massive salt horizon (~320m thick); and an overlying basalt ........
