The Cerro Casale gold–copper deposit is located in the Aldebarán sub-district of the Maricunga Volcanic Belt in northern Chile. The Maricunga belt is made up of a series of coalescing composite, Miocene andesitic to rhyolitic volcanic centres that extend for 200 km along the western crest of the Andes. Reverse faults parallel to the axis of the Andes have uplifted hypabyssal intrusive rocks beneath the extrusive volcanics, exposing porphyry-hosted gold-copper deposits in the Aldebarán area. In addition to Cerro Casale, the Aldebarán property is host to several, less-explored, satellite deposits including Zona de Vetas, Eva, Cerro Roman, Estrella, Anfiteatro, Jotabeche, and Romancito Sur.

At Cerro Casale, gold–copper mineralization occurs in quartz–sulphide and quartz–magnetite–specularite veinlet stockworks developed in the dioritic to granodioritic intrusives and in adjacent volcanic wall rocks. Stockworks are most common in two dioritic intrusive phases, particularly where intrusive and hydrothermal breccias are developed. Mineralization has been encountered to at least 1,450 m vertically and 850 m along strike. The strike of mineralization follows west–northwest fault and fracture zones, and is open at depth along this strike. The main zone of mineralization pinches and swells from 250 m to 700 m along strike, and down dip steeply to the southwest. The highest grade mineralization is coincident with well-developed quartzsulphide stockworks in strongly pota ........

Open pit mining will be carried out with haul trucks and a combination of electric shovels, hydraulic excavators, and large front-end loaders. All rock will require drilling for sampling and blasting purposes.

Mine design and production schedules were developed for a nominal mining rate of 225 Mt/a, smoothed for truck requirements. Mine production and processing facilities will operate 24 h/d, 7 d/wk, 365 d/a.

The optimized Cerro Casale final pit limit was divided into a sequence of nine pit phases of decreasing profitability in order to facilitate an efficient mining schedule and realize the highest project NPV. The last two of these phases were split into east and west sub-phases in order to defer waste mining and keep the peak mining rate as low as possible.

Considerable pre-stripping will be required to access the deeper, more profitable sulphide ore in the early stages of production. The primary crusher is located 500 m south of the ultimate pit limit, although a 2 km haul road is required out of the Stage 1 pit around the east side of Cerro Casale. Waste dumps and low-grade stockpiles are located within 500 m of the pit entrance.

All mining will be carried out on 16 m benches, with final pit wall berms at 32 m intervals. The overall wall slope angles vary from 34° to 47°. Haulage ramps are designed to a maximum grade of 10% and to a width of 40 m.

Approximately 2,231 Mt of waste will be mined over the 20 year li ........

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