Presented paper

IMWA2019 Students work

Geochemical And Mineralogical Characterisation Of Precipitates From Sabie-Pilgrim’s Rest Goldfields For The Potential Of Acid Mine Drainage

Lusunzi, Rudzani; Novhe, Obed; Mashalane, Tlou
Council for Geoscience, South Africa

Geochemical And Mineralogical Characterisation Of Precipitates From Sabie-Pilgrim’s Rest Goldfields For The Potential Of Acid Mine Drainage

Lusunzi Rudzani1, Tlou Mashalane2, Obed Novhe2

1Council for Geoscience, Economic Geology & Geochemistry Unit, 280 Pretoria Road, Silverton, 0184, South Africa

2(Tribute to my colleagues)


Decades of mining in South Africa had resulted in acid mine drainage problem for certain regions. Geochemical characterization of mine waste impoundments is crucial in order to rehabilitate or remediate and protect the surrounding environment.

Two tailings storage facilities within the Sabie-Pilgrim’s Rest Goldfields had been studied. The study focused on characterizing geochemistry and mineralogy of two tailings storage facilities currently not in use.

The novelty of this study showed that occurrence of acid neutralising dolomite, material was available at Glynn’s mine tailings and can be used to neutralise acid generation capability of Nestor’s mine tailings. The acid neutralizing material would improve the acidic Nestor’s mine tailings almost neutral pH which is conducive for the growth of plants, necessary for phytoremediation efforts.

Quartz and mica are the most dominant primary minerals respectively in both tailings storage facilities from the XRD results. Dolomite is the principal primary mineral present in the Glynn’s Lydenburg tailings storage facility and absent in the Nestor tailings storage facility. Secondary clay minerals smectite and kaolinite were only found in soil samples collected around the respective tailings storage facilities. The principal secondary mineral at both sites is gypsum. Other secondary acid-producing minerals found in Nestor tailings include ferricopiapite, fibroferrite, gibbsite and jarosite.

The X-Ray Fluorescence results show that in both Nestor and Glynn’s Lydenburg tailings storage facilities the most abundant major elements are Si, Fe and Al; the decreasing sequence of abundance is the following: Si>Fe>Al>K>Mg>Mn>Ti>Na. The most abundant minor elements also found within the respective tailings storage facilities are As, Cu, Co, Cr, Ni, Pb and Zn, whom sequence of abundance is As>Zn>Cr>Cu>V>Ni>Pb>Co.

The study however, noted that phytoremediation of Nestor mine tailings would not succeed because the plants could not grow in acidic soils. However, the presence of acid neutralising material within Glynn’s mine tailings can be used to neutralise the acid generation capability of Nestor mine tailings. Thus, the presence of acid neutralising material at a location less than a distance of 6 km would reduce transportation and material costs. This would ensure the success of phytoremediation efforts in saving the environment and the overall prevention of acid mine drainage.