Treatment of mine water with colloidal suspensions

Abstract

Groote Eylandt Mining Company (GEMCO) mines manganese from leases of land with Arhnem Land’s traditional owners. The open cut mining operation requires dewatering of quarries, with some of the quarries being located in areas of montmorillonite (commonly known as smectite) clay. Through the action of groundwater infiltration through, and stormwater runoff over the exposed clay surface surrounding the quarry, the clay becomes finely dispersed which results in highly turbid quarry water. This colloidal suspension of clay in the water is attributed to the surface of the clay particles carrying a negative surface charge leading to a stable colloidal system of ultra fine particles. The particles do not settle out over time.