Rehabilitation of co-disposed kimberlite tailings: Quantifying physical and chemical properties from a rehabilitation perspective

Abstract

Mine rehabilitation is a complex process and the potential of revegetating kimberlite tailings (after being co-disposed) was evaluated in this study, with regard to physical and chemical properties. High water soluble Na concentrations (8.22 mmol ^-1) represent the most serious challenge for successful vegetation establishment, as well as low Ca (0.27 mmol l^-1) and Mg (0.44 mmol l^-1). Potentially chelatable manganese Mn (0.43 mmol l^-1) poses slight limitations that can be overcome by means of inorganic ameliorant application. The co-disposed material does not pose any serious health risks, despite slightly elevated Al (2.89 mmol l^-1), Se (1.56 mmol l^-1) and As (1.15 mmol l^-1) concentrations. Another concern is the expansive and shrinking properties of the high smectite clay fraction (81%) of the tailings. It was concluded that, with the exception of certain chemical difficulties that can be addressed, the tailings material constitutes a growth medium that can be rehabilitated to sustain vegetation over the long term.

Keywords:

• Co-disposed material
• diamond tailings
• kimberlite tailings
• mine rehabilitation