OMC’s scope of work was to facilitate the ramp up of the production rate to 4.5 Mtpa. This involved a desk top audit of the design, site audit and data collection, site commissioning / optimisation and training services, modelling of design improvements.
The Varvarinskoye plant comprises a 1.25 Mtpa copper gold flotation concentrator and a 3.25 Mtpa gold CIP circuit. The plant has a common crusher for the Cu/Au and Au circuit stockpiles. Each circuit has a SAG Ball circuit. The Cu/Au circuit has 1.5 MW mills and the Au circuit 4.5 MW units.
The combined capacity of the plant was approximately 250 tph when OMC began work on the project. During a 6 month period the plant production was increased to 450tph through improved use of the crushing circuit, stockpile and blend management, reconfiguration of the cyclones, implementation of a control philosophy and process control.
Due to the ore characteristics the plant production was still shy of the target 540 tph at the end of 6 month period. Using survey data, modeling was undertaken to determine the best means to achieve the production target. Through the use of modeling techniques (Bruno, JKSimMet & HelpSAG) and consultation with the client, a partial secondary crushing was selected. Major equipment selection and mass balance data from the upgrade was packaged for use by an engineer in the design and implementation of the project.