The Aktogay open-pit copper mine being developed by Kazakhmys, the largest copper producer in Kazakhstan, is located in the eastern region of Kazakhstan about 250km from the border with China.
The project includes the development of an open-pit mine and construction of an on-site concentrator to produce copper cathode from oxide ore and copper concentrate from the sulphide ore. Molybdenum will also be produced as a by-product.
Approval for the copper project was issued by the board of Kazakhmys in December 2012 and construction works began in 2013. The Aktogay mining operation is expected to start oxide copper cathode production in the last quarter of 2015 and sulphide copper concentrate production in 2017.
The $2.3bn copper project is anticipated to have a production life of more than 50 years and is expected to produce 104,000t of copper cathode, equivalent per annum during the first 10 years of operation.
Aktogay copper mine geology, mineralisation and reserves
The Aktogay copper-molybdenum porphyry deposit lies on the southern border of East Kazakhstan Oblast along the west-northwest-striking Aktogai fault zone. The ore body consists of a copper oxide deposit sitting atop a larger sulphide deposit that also contains molybdenum.
Copper is mostly contained in the form of chalcopyrite and mineralisation occurs in quartz-carbonate filled stockwork fractures. Mineralisation is present in the form of a compact body within the rocks of the first intrusive phase and the volcanogenic-sedimentary rocks of the Keregetas Formation. Approximately 70% of the mineralisation is hosted by intrusive rocks, mainly diorites and granodiorites, and the remaining by the volcanogenic-sedimentary rocks of the Keregetas Formation.
The mine is estimated to contain JORC-compliant measured and indicated oxide mineral resources of approximately 122.8 million tonnes, at an average copper grade of 0.37%, and 2,063.6 million tonnes of sulphide resources grading at 0.33% Cu.
Mining and processing of ore at Aktogay mine
Conventional drill and blast method of mining using trucks and excavators will be adopted for the Aktogay open-pit mining operation. The extracted ore will be crushed in a primary crusher at the mine site before being taken to the concentrator stockpile.
The stockpiled ore will be reclaimed by the underground feeders and delivered to the grinding section of the concentrator that houses a 28MW semi autogenous grinding (SAG) mill. Ore will then be processed into slurry by the drive ball mills before being delivered to the flotation section of the concentrator plant.
Copper concentrate will be separated from the waste tailings as it passes through the floatation circuit and molybdenum will be extracted as a separate product at the end of the floatation process. The obtained copper concentrate will be de-watered and stockpiled in powder form at the filter facility before being loaded into rail wagons for shipping to smelters.
The oxide processing facility for the mine will feature a dump leach facility to produce copper rich pregnant leach solution (PLS) using sulphuric acid as the leaching agent, as well as a solvent extraction-electro winning plant to recover the dissolved copper from the PLS.
Infrastructure facilities at Aktogay copper mine
Power supply for the mine will be provided by the Karaganda GRES-2 power plant through an 110kV overhead transmission line. Water will be supplied from a borefield development in the Zhuzagash reservoir through a 27km long underground pipeline.
Other infrastructure facilities will comprise of a 60-person accommodation camp, three warehouses, and associated utilities
Financing of the Aktogay project
The Aktogay copper project is funded by a $1.5bn loan facility from China Development Bank. The loan facility, signed in December 2011, comprises of two separate agreements including a USD agreement for up to $1.34bn and an RMB agreement for up to RMB1.0bn (approximately $160m).
Alarko is the engineering, procurement, and construction (EPC) contractor for the processing plant at Aktogay.
ABB provides complete electrification and automation solutions for the Aktogay copper plant under a contract awarded in December 2012. ABB was also awarded a contract worth $44m earlier in May 2012 to provide three gearless mill drive systems including the 28MW semi-SAG mill and two 22MW ball mills.
Ausenco was awarded a $30m engineering services contract for the open-pit mine in October 2011.
BIR provides engineering and consultancy services for architectural, civil, mechanical and electrical works for the Aktogay copper processing plant.
In September 2014, Non Ferrous China (NFC) was awarded the contract for the construction of the sulphide concentrator.