MIXING OF WASTE ROCK TO LOWER THE RELEASE OF Mg+2 AND SO4-2 AT ARGYLE DIAMOND MINE
English

Sunil Samaraweera, Rich Borden, Alvin D'Almaida, Ernst Griebel
2006 Journal American Society of Mining and Reclamation  
The seepage from the Argyle mine waste dumps is mildly acidic and contains high concentrations of magnesium (1400 mg/L) and sulfate (6500 mg/L). Out of the fourteen waste rock types mined, only Pv1 (with relatively low total sulfur content of 0.1 % to 1.0 %) causes a significant release of acidity and solutes. Only Pv5 possesses abundant acid neutralizing capacity and releases significant amount of Ca +2 during neutralization reactions. Experiments conducted in the laboratory have shown that
more » ... have shown that when Pv1 is blended with Pv5 (ratio 2:1) a neutral pH solution, with about 1/10 the Mg +2 and 1/3 the SO 4 -2 is released compared to unblended Pv1 or blends made with other waste rock types. Argyle mine has recently implemented controlled co-disposal of these two rock types. The environmental and ecological benefits resulting from of these changes into the waste rock management procedures will be assessed in the coming years.
doi:10.21000/jasmr06021824 fatcat:k4sslkdjp5hovgh4s2gcf2jsqu