[RESOURCE] Geological optimisation for sustainable copper-gold mining

Porphyry deposits, formed in association with igneous rocks, are major sources of the world's copper, gold and molybdenum. Clay minerals are a common alteration product in these systems and although conventional geological models describe the general distribution of clays, in detail these zones are complex and highly varied. The distribution and character of clays is particularly important when they occur in ore zones because they impact on the efficiency of mineral processing. Optimising processing by understanding clay distributions and chemistry can reduce energy use. Furthermore, if it has suitable properties, the waste clay product could be reused in tailings dam construction - a novel concept - thereby helping to achieve sustainability of mineral extraction. The principal aim of the research is to develop a predictive model for the distribution of clay minerals at the Cerro Corona copper-gold mine, Peru, that will help to optimise mining and processing efficiency for the life of mine. The proposal is timely as Cerro Corona is a new mine so that research can feed directly into daily mine geology, mill optimisation, and future planning. We expect to produce generic outcomes that will be more widely applicable in large tonnage, low grade porphyry deposits, in particular the potential reuse of clay for tailings dam construction. In addition, we will investigate the underlying geological controls of alteration style and distribution to provide a scientific framework. This will involve testing of competing hypotheses of argillic alteration using both novel and conventional methods. A secondary aim is to determine why approximately 20% more gold is being produced than expected, to avoid loss of ore to the waste dump. It is suspected that the difference is due to low temperature epithermal veins that are not sampled in the grade control drilling. Here, the underlying scientific question is how the cool hydrothermal fluids responsible for these veins relate to the high temperature porphyry stage. Although porphyry-epithermal transitions are documented in many systems and theoretical models exist for fluid evolution pathways and copper-gold transport, these have yet to be rigorously tested. The student will receive training in relevant research and transferable skills from the CASE supervisor, company staff on site in Peru, the academic supervisors at Imperial College and by attendance at internal and external taught courses and workshops. In addition, the student will benefit from the in-house expertise in socio-economic and environmental impacts of mining within the CASE partner organization. The CASE partner has defined clear practical objectives for the project that will deliver direct economic benefits to the company, and socio-economic benefits to the local population and society at large, both by supporting the development of more sustainable mining practices and by reducing its own carbon footprint. As a consequence, they have agreed to commit significant cash and in-kind resources. The student will benefit by developing an in-depth understanding of the geology and geochemistry of a major ore system, and the practical issues underpinning the sustainable development of such resources. The student will also be trained in cutting-edge analytical techniques and transferable skills. It will provide a rare opportunity to work in a major modern open pit copper-gold mine in collaboration with a leading minerals company that pioneers socially and environmentally responsible mining and that is a member of the International Council on Mining and Metals, committed to the United Nations Global Compact and its supporting principles. A major element in the NERC 2007-2012 Strategy is 'enabling society to respond urgently to the increasing pressures on natural resources'. To meet this challenge, society must develop resources in a sustainable way and our proposal aims to make a contribution to this important goal.