SENTINEL MINE
The Sentinel open-pit copper mine, 150km west of Solwezi in North Western Province of Zambia, is at the forefront of mining technology.
Overview
Constructed over four years from 2012, Sentinel represents US$2.1 billion of investment - Zambia's largest infrastructure investment since the Kariba Dam was constructed in 1959. The operation is based on sophisticated technology – including the world's largest steel-ball mills and the world’s largest semi-mobile rope shovels.
Mining capacity will eventually extend to around 65 million bulk cubic metres of ore and waste mined per annum. The plant has capacity to treat 55 million tonnes of ore to produce 300,000 tonnes of copper per annum.
The workforce at Sentinel is greater than 6,000, predominantly Zambian nationals.
In 2010, First Quantum acquired 100 per cent of Kiwara plc and its main asset - a controlling interest in the prospecting license on the periphery of the Kabombo Dome, which included the Kalumbila copper deposit (now Sentinel) and the Kawako nickel deposit (now Enterprise.) The combined project was renamed Trident after the acquisition. Sentinel and Enterprise will ultimately share processing infrastructure and tailings facilities.
Mining and Processing
Sentinel is a sediment-hosted stratiform copper deposit, with predominantly primary chalcopyrite copper mineralisation.
Open pit mining is carried out using conventional methods, with large-scale electric face shovels and hydraulic excavators, and a fleet of ultraclass haul trucks. The three 57m3 bucket capacity rope shovels are electric rather than diesel-powered, and we use electrical trolley assist for waste haulage. Ore is crushed in-pit, in three semi-mobile gyratory crushers. Overland conveyors feed two secondary crushers, and two mill trains each consisting of a 40 foot diameter 28 megawatt SAG mill twinned with a 44 foot length 22 megawatt Ball mill. The grinding mills are amongst the largest of their type currently operating in the world. Chalcopyrite is recovered in flotation and delivered to the dedicated concentrate handling facility where it is thickened and filtered.
The process plant is designed to treat 55 million tonnes per annum of copper ore from Sentinel mine, with a separate 4 million tonnes per annum circuit designed to process nickel ore feed from the Enterprise project or additional copper ore feed from Sentinel.
Sentinel production was 3% higher than the first quarter of 2020 due to higher grades, despite the repair work to the Train 1 ball mill trunnion in February, as well as higher rainfall.