Extraction and Processing
Mining operations at Kinsevere
Conventional mining methods are used to remove waste material and extract ore at the Kinsevere open pit mine. Most areas can be mined without blasting due to favourable ground conditions.
Ore is hauled to the run of mine (ROM) stockpile while waste material is stockpiled on the surface or used on walls of the tailings storage facility (TSF).
Processing plant at Kinsevere
After mining, Copper Oxide ore delivered to the ROM stockpiles is fed into the processing plant through a mineral sizer followed by a semi-autogenous grinding mill (SAG mill).
Copper is produced primarily by an agitated leach, counter current decantation and solvent extraction and electrowinning (SX-EX) process. The agitated leach plant is partially supplemented by additional copper from a heap leach operation.
The leaching process uses a sulphuric acid solution to extract copper from its solid copper oxide form into a solution referred to as PLS.
After separating the copper containing solution (PLS) from the slurry, the copper is sent to the solvent extraction plant (SX). The SX process uses mixing and settling tanks to transfer copper from the PLS into a solvent solution. The density difference between PLS and the solvent is used to separate the two solutions after the copper has been transferred. The copper in the solvent solution is then transferred to an acidic high copper containing electrolyte, using similar mixing and settling tanks.
The high copper containing electrolyte is sent to the electrowinning process where it is exposed to the electrolytic processes (similar to a battery). In transferring electrical charge from anode to cathode, copper is brought out of solution and deposited onto stainless steel cathode plates.
It takes six days for sufficient copper to deposit and form a sheet on the cathode plate. At this time, the copper sheets are harvested and are weighed and bundled for transport and sale.
Bundled copper sheets.