RE: Last Mondays RNS27 Feb 2021 20:05
Not sure about open pit, Turner and pope wrote in their synopsis of the rns : Favouring underground mining for APTA
Possibly one of APTA’s key planning takeaways is that it needs to demonstrate a high enough metal value/tonne to support underground mining, as it is considered that an open pit is now unlikely to be successfully permitted on Colombia’s Mid-Cauca belt. This has already been demonstrated with major low-grade porphyry projects like, for example, AngloGold Ashanti’s La Colosa that is ultimately likely be abandoned on such grounds, as was Greystar Resources’ seemingly ill-fated Angostura gold deposit which similarly stalled a decade or so back. Contrasting with the relatively dry condition of the naturally draining Altiplano region of Chile, these projects found themselves located in a rugged, hot and wet part of Colombia, meaning that not only would the ‘scar’ that such surface mining creates on the landscape raise the hackles of environmentalists, but they also create complex and expensive problems when dealing with waste and tailings disposal in an ecological manner. Moreover, APTA’s ore has a high sulphide content which becomes mixed with rainfall in the region’s ambient temperatures, suggests acid drainage could also become an issue. Such problems of course do not arise when working underground, given that there is little surface footprint and little or no waste given that all tailings are simply pumped back underground as backfill.