Bisha Mine | Copper Expansion Project
The Bisha copper expansion project will increase ore throughput from 2.0 to 2.4 million tonnes per year and convert from gold/silver doré to copper concentrate production. The Bisha and Harena open pit mines, crusher and grinding circuit remain unchanged. The bulk of the capital cost is constructing a copper flotation plant and copper concentrate load out facilities. The existing carbon-in-leach (CIL) processing plant will be on care and maintenance in a condition so that it could be re-commissioned if additional gold oxides at or near Bisha are found.
The project budget is $100 million for on-site facilities and $25 million for off-site concentrate export infrastructure. Production is scheduled for mid-2013. See the copper expansion photo gallery for recent images of the project progress. The project is being built under EPCM contract by SENET of South Africa. SENET was the same contractor who successfully built the original Bisha plant on-time and under budget.
Copper Flotation Plant Process
The copper flotation plant is a conventional circuit with rougher plus cleaner stages and regrinding. See flowsheet to the right or click here. Ground ore from the existing SAG mill and ball mill is fed to the rougher flotation circuit. Rougher concentrate is sent to the primary cleaner flotation cells and rougher tailing goes to final tailing. Primary cleaner concentrate is sent to the final concentrate thickener while primary cleaner tailing goes to the regrind circuit to increase mineral liberation. The reground material is delivered to the secondary cleaner flotation cells. Tailings from secondary cleaner flotation goes to final tailing cleaner and overflow to the final concentrate thickener. Thickened concentrate is dewatered and stockpiled.
The new facilities are being constructed north of the current CIL plant. See layout to the right or click here. The facilities being constructed include the flotation plant described above, reagent handling area, workshops, concentrate thickening and storage, concentrate load-out and related support infrastructure.
Concentrate Export Infrastructure
Concentrate is being exported using a proven system with industry leading environmental controls. Concentrate is loaded and sealed in custom half-height shipping containers and transported to the port of Massawa by regular container trucks. The sealed containers are stockpiled in Massawa at the existing container port facilities. The Rotainer crane system then discharges the containers into bulk vessels. The bulk vessels deliver the concentrate to copper smelters worldwide and the containers are returned to Bisha for re-loading.