Decommission of Potash Mine Shaft

Esterhazy, SK, Canada
Mosaic Company, LLC

RESPEC was involved in the design for decommissioning the Mosaic K1 and K2 potash mine. This is the first potash mine in the province of Saskatchewan to be decommissioned. The Mosaic K1 and K2 potash mine is an area with complex hydrogeology and has had mine inflows since late 1985. This complex hydrogeology resulted in unique conditions that had to be accounted for in the design. RESPEC conducted geomechanical and hydrogeological modelling to aid in the design. RESPEC consulted with subcontractors on the concrete mix design for the shaft plug system, grouting of the interface between the existing liner and plug system, grouting of the surrounding geological formation and backfill design from shaft plug to surface. The design included the development of QAQC programs, pre-construction activities, site inspections and the implementation of the shaft plugs with the mining construction contractor. RESPEC has developed, in conjunction with Mosaic, long-term monitoring plans for tracking and assessing the implemented design functions as expected.