Geometallurgy

To maximise the value of a mining operation and minimise its environ- mental and social impacts, all processes—from the ore deposit to the final product and waste streams—should be optimised together. However, mining and metallurgical processes are inherently variable and uncertain due to the natural heterogeneity of ore deposits and the limited information and incomplete models available on ore behaviour throughout the process chain. Propagating these effects to geometallurgical models is important because they are used to make decisions with potentially large environmental and economic impacts. In this paper, we describe the need for geometallurgical optimisation routines to account for the effects of uncertainties, and the tools needed to manage them, by summarising the routines that already exist and those that are still missing.

The raw materials industry produces billions of tonnes of mine waste per year. Given increasing metal demand and the global appetite for waste reduction, strategic opportunities to minimise its production must be embedded across the life-of-mine. Adopting a geometallurgical approach to total deposit characterisation—where mineralogical and geochemical data are routinely collected and used to model geoenvironmental domains—offers profound benefits for improving the understanding of the composition and environmental impact of different residues. Using established and emerging technologies, from handheld instruments and core scanners to synchrotrons, throughout a mine’s life—starting already during exploration—may assist the raw materials industry to reduce their waste footprint and adopt circular economy principles.

There is no doubt that mineralogy, texture, and microfabric, as primary characteristics of an ore, affect mineral processing operations. Their direct effects on extractive metallurgical processes and the associated optimization potential, however, are less well documented. Here, we examine the status of geometallurgical approaches in extractive metallurgy by focusing on the effects of primary ore characteristics in hydrometallurgical and pyrometallurgical processes. Two selected case studies illustrate the linkages. Using quantitative data analytics on ores and concentrates, the possibilities for optimized and sustainable metal extraction and waste valorization are discussed.

Mineral processing encompasses the series of operations used to first liberate the valuable minerals in an ore by comminution, and then separate the resulting particles by means of their geometric, compositional, and physical properties. From a geometallurgical perspective, it is fundamental to understand how ore textures influence the generation of ore particles and their properties. This contribution outlines the processes used to generate and concentrate ore particles, and how these are commonly modelled. A case study illustrates the main ideas. Finally, a brief outlook on the most important research challenges remaining in this branch of geometallurgy is presented.

The successful implementation of geometallurgy largely depends on the continuous collection of high-quality, multi-scale, multi-dimensional quantitative data on the geology, geochemistry, mineralogy, texture, and physical properties of an orebody. This can then be used to build and improve, amongst other things, ore deposit models, comminution strategies, waste management, and downstream mineral processing and extractive metallurgy routes. The present contribution provides a brief overview of the key types of data collected, and analytical techniques used, in geometallurgical programs. It also highlights important developments that are currently underway, which may generate a significant impact in the near future.

Geometallurgy is an interdisciplinary research field concerned with the planning, monitoring, and optimisation of mineral resource extraction and beneficiation. Geometallurgy relies on a quantitative under- standing of primary resource characteristics such as mineralogical composition and texture, the spatial distribution and variability of these characteristics, and how they interact with mining and beneficiation processes. Thus, geometallurgy requires accurate analytical data for resource characterisation and detailed models of orebody geology, mining and processing technologies, mineral economics, and the often-complex interactions between them. Here, we introduce the fundamental concepts relevant to the field, with particular emphasis on the current state-of-the-art and some notes on potential future developments.