Abstract Revolutionary advances in extractive metallurgy and mineral processing and their evolutionary application have significantly altered the processing operations of mining companies over time by increasing productivity and reducing costs. Some developments have had such an impact on the industry that new types of mineral deposits can be developed and waste becomes ore. Historically, it has taken years, in some cases decades, for metallurgical developments to affect exploration strategies, largely because of limited communications between geologists and metallurgists. Seven significant advances in the extractive sciences are viewed as having the highest impact on mineral exploration and mining. These are solvent extractionelectrowinning, leach processing, bioprocessing, flash smelting, geometallurgy, energy-efficient fine grinding, and underground processing. Developments in these fields have resulted in commercialized or piloted processes that demonstrably reduce capital and operating costs and thereby increase shareholder value. Two process developments with the potential to significantly affect the industry in the future are breaking rock in tension and in situ leach of metals. The benefits of metallurgical advances to exploration include reduced processing and capital costs, as well as elimination of repeat characterizations through improved analytical instrumentation and data transfer capabilities. New ore deposits are less likely to be overlooked or underappreciated when metallurgical and processing developments are integrated into team-based exploration planning. An example of new target generation is zinc oxide ore, such as that from Skorpion, Namibia, that has been made economic by hydrometallurgical techniques. As exploration targets and discoveries become increasingly deep, the successful development of orebodies will depend in part on the ability of metallurgists to develop innovative processing methods, such as pressure leach and bioleach hydrometallurgical technologies, or developments in mineral processing. To some extent, the ore geology of a deposit may predetermine the processing methods to be applied. However, the complex relationships of mineralogy, grade, and location, plus energy, capital, and other costs make the development of new extractive techniques a virtual necessity for exploration success.

Abstract Redox-reactive minerals can serve as electron donors or acceptors for abiotic reactants or microbial metabolic processes, and hence can play important roles in terrestrial and aquatic environments, particularly if their reaction rates are comparable to those of other biogeochemical processes. Under such circumstances, their reactions can control metal and contaminant bioavailability and change the permeability of soils and sediments. While the thermodynamic driving force for a mineral redox reaction is frequently a good predictor of relative rates of reaction, there are many examples in which kinetic factors limit reaction rate. Understanding the thermodynamic and kinetic aspects of mineral reaction rates, and their sensitivity to environmental conditions such as temperature or pH, is important for anticipating the biogeochemical evolution of natural environments subjected to change. Achieving this goal requires knowledge of the reaction pathway, the timescales of intermediate steps, and the lifetimes of metastable reaction states. Mineral redox reactions proceed through a combination of steps that can include electron and proton transfer, the breaking or formation of bonds, and mineral dissolution or phase transformation. The combination of conventional kinetics approaches, newly-developed ultrafast time-resolved methods and molecular simulation can provide elucidation of such complex reaction pathways. This chapter summarizes key concepts in mineral and interfacial redox reactions with illustrations from the rich geochemistry of iron and iron-bearing minerals.