Material contained in the Tailings Storage Facilitys (TSF) and Waste Rock Dumps (WRD) predominantly originates from deep level gold mines, operated by Harmony and others, mostly located in Klerksdorp and Carletonville. The West Wits mining operations predominantly extract tabular goldbearing conglomeratic reefs, namely the Carbon Leader Reef (CLR) and Ventersdorp Contact Reef (VCR). The Mine Waste Solutions (MWS) Operation, however, mainly exploits TSFs and WRD derived from the VR. The Witwatersrand reefs occur within the Archean Witwatersrand Basin which hosts the Witwatersrand Supergroup succession. The VCR horizon is located at the top of the Turffontein Subgroup of the Central Rand Group (CRG), capping the Witwatersrand Supergroup. The Vaal Reef (VR) horizon is situated within the Krugersdorp Formation, in the Johannesburg Subgroup of the CRG. The CLR is situated near the base of the Johannesburg Subgroup. The TSF material comprises previously treated residues of gold-bearing conglomeratic reefs processed by CIL. They are man-made “deposits” and are not the result of natural sedimentary processes. The grade of the TSFs is determined by the grade of the ore source at the time that they were processed, and the processing efficiency. The WRDs are unconsolidated and are comprised of untreated, low grade, gold-bearing material from underground workings. The WRDs are also man-made deposits, with very little structure or continuity, and one in which the grade does not behave ........

The mining methodologies adopted at Mine Waste Solutions entail the hydro-mining of the TSFs and reclamation of WRDs using FELs. The TSF material is reclaimed using several hydraulic monitoring guns which deliver high-pressure water to the face. High pressure water is transferred to the monitoring guns observing the maximum design capacity of the equipment, limited to 40 bars (“b”). The tailings are reclaimed using several hydraulic (high-pressure water) monitoring guns to deliver water at pressure, typically 27-30 bar, to the face. The tailings material is reclaimed by blasting the TSF face with the high-pressure water, resulting in the slurry gravitating towards pumping stations. These monitoring guns can be positioned to selectively reclaim required areas from the TSFs. Bench heights are constrained by the force delivered from the monitoring gun nozzle and safety constraints. With enough pressure, face advance of up to 25m can be reclaimed per cut. Typical bench heights are between 10 and 15 metres. The pump stations are located at the lowest point of the dams to ensure that the slurry from the dams will gravitate towards the pump station from where the slurry will be pumped to the processing plants. The tailings material can be selectively mined based on the positioning of the monitoring guns. The TSF face is broken by the water pressure, resulting in the slurry gravitating towards the collection sumps that deliver the slurry to the pumping stations, which is then pu ........

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