Eva copper project (formerly known as the Cloncurry copper project) is a copper-gold mining project located 95km north-east of Mount Isa, Queensland, Australia.
Copper Mountain Mining Corporation acquired the mine from Altona Mining in November 2017 and completed a bankable feasibility study on its development in October 2018.
The Eva copper project encompasses the development of five deposits, namely Little Eva, Turkey Creek, Bedford, Lady Clayre, and Ivy Ann. Little Eva and Turkey Creek are the main deposits accounting for more than 90% of the mineral reserves at the project.
A positive feasibility study for the Little Eva deposit was completed by GR Engineering Services for Altona Mining in 2012.
The recent feasibility study on the project forecasts annual average production of 90 million pounds (Mlbs) of copper and 19,000 ounces (oz) of gold over an estimated mine life of 12 years. The capital expenditure is estimated to be $350m.
The final investment decision (FID) on the project is expected by the end of 2018, while construction is expected to start in 2019.
Geology and mineralisation
The ore bodies of Eva copper project are hosted in Proterozoic rocks within the Mount Isa mineral province of Queensland.
The Eva ore deposits are associated with (IOGC) style hydrothermal mineralisation manifested in vein networks, breccias, disseminations, and replacements.
Eva copper and gold reserves
The Eva copper mine was estimated to hold 117 million tonnes (Mt) of proven ore reserves grading 0.40% copper and 0.07g/t of gold and containing 1,031Mlbs of copper and 260,000oz of gold, as of September 2018.
Mining at Eva copper-gold project
Conventional open-pit mining method involving moderate-sized truck and shovel operation will be employed for all five deposits of the Eva Copper project.
The biggest deposit, Little Eva, will be mined in six push-back phases during the first nine years of mine life, whereas the mining at Turkey Creek pit will be carried out in two push-back phases.
The Bedford, Lady Clayre and Ivy Ann smaller satellite pits will be mined in single push-back phases.
A total of 334Mt of rocks are to be excavated from the five pits over the 12 year-mine life, out of which 117Mt will be ore material and 217Mt will be waste rocks.
The run-of-mine ore will be sent to the on-site processing facility where it will undergo crushing, two-stage grinding (SAG-ball mill circuit), and flotation for the production of copper and gold concentrates.
The resultant tailings will be sent to the on-site tailings management facility. The recovered concentrates will be thickened, filtered and stockpiled before being trucked to Glencore’s Mt. Isa Smelter located 195km away from the Eva mine site.
The mill throughput for the first five years of mining will be 28,000 tonnes per day (tpd), which will be reduced to 25,500tpd for the remaining mine life.
Infrastructure facilities for Eva copper project
The Eva copper-gold mine will be supplied with electricity from the existing transmission infrastructure through a 220kV power line.
The water requirement for the project will be met through a well field near the processing facility as well through water from pit dewatering and the recycled water from the tailings facility.