Quantification of uncertainty of geometallurgical variables for mine planning optimisation

Interest in geometallurgy has increased significantly over the past 15 years or so because of the benefits it brings to mine planning and operation. Its use and integration into design, planning and operation is becoming increasingly critical especially in the context of declining ore grades and increasing mining and processing costs. This thesis, comprising four papers, offers methodologies and methods to quantify geometallurgical uncertainty and enrich the block model with geometallurgical variables, which contribute to improved optimisation of mining operations. This enhanced block model is termed a geometallurgical block model. Bootstrapped non-linear regression models by projection pursuit were built to predict grindability indices and recovery, and quantify model uncertainty. These models are useful for populating the geometallurgical block model with response attributes. New multi-objective optimisation formulations for block caving mining were formulated and solved by a meta-heuristics solver focussing on maximising the project revenue and, at the same time, minimising several risk measures. A novel clustering method, which is able to use both continuous and categorical attributes and incorporate expert knowledge, was also developed for geometallurgical domaining which characterises the deposit according to its metallurgical response. The concept of geometallurgical dilution was formulated and used for optimising production scheduling in an open-pit case study.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 201

General Equilibrium Models: An Overview

This article reviews the literature on general equilibrium models, relevant to the Chilean economy, and revised versions of the papers presented at the Conference of General Equilibrium Models for the Chilean Economy organized by the Central Bank of Chile, that will be published in a book by the same name (edited by Rómulo Chumacero and Klaus Schmidt-Hebbel, 2005). This introductory chapter provides a brief overview of the development and application of three families of GEMs: macroeconomic GEMs, computable general equilibrium models, and overlapping generations models. We also summarize the scope and main results of the twelve GEMs that comprise the volume.

Master of Science

thesisMining and the related industries play an important role in the Korean economy. The Korean mining industry is relatively small. There are several mines in Korea but they are very small, and production is low in comparison with other countries' mines. Thus Korea must take part in mineral projects all over the world to secure essential minerals such as coal, copper, uranium, iron ore, zinc, and nickel to support its manufacturing industries. For that reason, the Korean government established K Company1 as a government corporation to invest in mineral deposits throughout the world. However there are several major entities, including BHP Billiton, Rio Tinto, Anglo American, Xstrata, Freeport McMoRan, Chinese government-run companies, and Japanese trading companies that have large foreign holdings, controlling deposits in most of the world's established and productive mining districts. As a relative newcomer, K Company is having difficulty breaking into these markets. In general, the mining industry considers the United States, Canada, Australia, and European countries to have good mining investment environments, but because the major companies have already achieved market dominance in those countries large investments are required. Thus K Company is increasingly turning to new areas like South America (Peru and Bolivia) and Africa. The competition among businesses to secure a share of the new market is intense but there are still good investment opportunities. However, because most of the countries in these areas are not well developed, there are several additional risks associated with participation in mining projects there. Risk is a major factor in all mining activities, arising from many internal and external variables. In this thesis, those variables are identified, and their effects evaluated, based on a survey of 31 experts. A statistical model to analyze the effect of risk on the economic feasibility of mine development and operation at a given location is presented, and validated using analysis from projects at K Company. The guidelines and model, as presented here, will enable K Company and other investors to make better investment decisions in the future

Managing End-of-Life Lithium-ion Batteries: an Environmental and Economic Assessment

The growing market for lithium-ion batteries raises concerns about sustainable management of those batteries at end of life. Launching relevant policies requires a comprehensive understanding of potential economic values as well as environmental performance of end-of-life lithium-ion batteries. However, both recyclers and policymakers are facing a number of unanswered questions, including 1) how battery technology trajectory would affect the incentives for recycling? 2) what strategies are available to improve material recovery efficiency? and 3) what is the potential for nanoparticle release during end-of-life processing, particularly for next-generation lithium-ion batteries who contain nano-scale cathode materials? This dissertation aims to fill these research gaps. Multi-criteria optimization modeling and fundamental material characterization methods were used to quantify environmental and economic trade-offs for end-of-life lithium-ion batteries. Results show that potential material recovery values decrease as battery cathode chemistry transitions to low-cost cathode materials, as a majority of potentially recoverable value resides in the base metals contained in the cathode. Cathode changes over time will result in a heavily co-mingled waste stream, further complicating waste management and recycling processes. An optimization model was developed to analyze the economic feasibility of recycling facilities under possible scenarios of waste stream volume and composition. Sensitivity analysis shows that the profitability is highly dependent on the expected mix of cathode chemistries in the waste stream and resultant variability in material mass and value. Estimated current collection rate of end-of-life lithium-ion batteries turned out to be extremely low, indicating more opportunities and higher profitability for local recycling facilities if this rate can be improved. Aiming to achieve segregation of high value metallic materials in lithium-ion batteries, a pre-recycling process, including mechanical shredding and size-based sorting steps, which can be easily scaled up to the industrial level, has been proposed. Sorting results show that contained metallic materials can be effectively segregated into size fractions at different levels. In addition, using this pre-recycling process as a case study, the nanoparticle exposure potential during mechanical processing has been proactively investigated by using both traditional and nano-enabled lithium-ion batteries. Results show that a substantial amount of nanoparticles released during the mechanical shredding but not the size-based sorting process. Additionally, shredding nano-scale LiFePO4 cathode batteries may have a higher potential for nanoparticle exposure. Facing the rapidly growing volume of spent lithium-ion batteries, the results suggest policy or other incentives may be necessary to promote a robust collection and recycling infrastructure as the economic incentives will likely decrease as the chemistry transitions away from cobalt-based cathodes. This dissertation also demonstrates the importance of implementing a battery labeling system as recyclers will likely face a co-mingled waste stream. Specifying recycling-relevant information would increase the effectiveness of the pre-recycling system

Net Zero Roadmap for Copper and Nickel

As we seek to meet the challenges of climate change impacts, many commodities will play an increasing role in decarbonizing economies. There are increasing challenges of addressing the emissions from extraction of these commodities needed to support the zero-carbon transition. CCSI, in a consortium with Carbon Trust, RMI, and the Payne Institute for Public Policy at the Colorado School of Mines, developed the Net Zero Roadmap to 2050 for Copper and Nickel Value Chains to support the copper and nickel mining sectors in taking collective, coordinated action by providing a clear, approachable, and accepted roadmap for decarbonization. Our key messages to mining CEOs are as follows: Demand for Energy Transition Metals (ETMs) doubles GHG emissions. To reach net zero, ETM emissions will need to reduce by 90%. Technological solutions are already or soon will be available. Three waves of technology deployment: (i) Renewable energy, site operational energy efficiency improvements, and process optimization; (ii) zero-emissions haulage trucks; (iii) process heat electrification and green hydrogen. Enormous ESG risks associated with rising ETM demand. For example, many copper and nickel reserves are located in high water risk and high biodiversity areas respectively, necessitating proactive and responsible management. Just Transition. Mining companies, governments and other actors have an important role in enabling communities to reimagine their future at the center of a new climate economy and in the process build community resilience. Collaboration is key to achieving net zero. Mining companies, value chain actors, and policymakers must work together to accelerate the development, deployment, and co-investment in the technological innovations required for the mine of the future, and to develop net zero industry standards, regulations, and frameworks. The project was commissioned by the International Finance Corporation (IFC) and the International Council on Mining and Metals (ICMM), as part of the World Bank Group’s Climate-Smart Mining initiative

Technology and Management Applied in Construction Engineering Projects

This book focuses on fundamental and applied research on construction project management. It presents research papers and practice-oriented papers. The execution of construction projects is specific and particularly difficult because each implementation is a unique, complex, and dynamic process that consists of several or more subprocesses that are related to each other, in which various aspects of the investment process participate. Therefore, there is still a vital need to study, research, and conclude the engineering technology and management applied in construction projects. This book present unanimous research approach is a result of many years of studies, conducted by 35 well experienced authors. The common subject of research concerns the development of methods and tools for modeling multi-criteria processes in construction engineering

Techniques for Analysing and Reconciling the Progressive Mineral Taxation Regime of Papua New Guinea

The study investigated how progressive tax instruments behave to raise revenues from the mining industry without distorting the investment decision-making. The study used real option and Monte Carlo simulation cash flow tax models and historical data to investigate the revenue collecting potentials of Papua New Guinea’s (PNG) progressive mineral taxation regime. The results show that PNG and mineral endowed nations can successfully capture high magnitude of revenues from the resources sector by making tax instruments more progressive

Determination of an Ultimate Pit Limit Utilising Fractal Modelling to Optimise NPV

The speed and complexity of globalisation and reduction of natural resources on the one hand, and interests of large multinational corporations on the other, necessitates proper management of mineral resources and consumption. The need for scientific research and application of new methodologies and approaches to maximise Net Present Value (NPV) within mining operations is essential. In some cases, drill core logging in the field may result in an inadequate level of information and subsequent poor diagnosis of geological phenomenon which may undermine the delineation or separation of mineralised zones. This is because the interpretation of individual loggers is subjective. However, modelling based on logging data is absolutely essential to determine the architecture of an orebody including ore distribution and geomechanical features. For instance, ore grades, density and RQD values are not included in conventional geological models whilst variations in a mineral deposit are an obvious and salient feature. Given the problems mentioned above, a series of new mathematical methods have been developed, based on fractal modelling, which provide a more objective approach. These have been established and tested in a case study of the Kahang Cu-Mo porphyry deposit, central Iran. Recognition of different types of mineralised zone in an ore deposit is important for mine planning. As a result, it is felt that the most important outcome of this thesis is the development of an innovative approach to the delineation of major mineralised (supergene and hypogene) zones from ‘barren’ host rock. This is based on subsurface data and the utilisation of the Concentration-Volume (C-V) fractal model, proposed by Afzal et al. (2011), to optimise a Cu-Mo block model for better determination of an ultimate pit limit. Drawing on this, new approaches, referred to Density–Volume (D–V) and RQD-Volume (RQD-V) fractal modelling, have been developed and used to delineate rock characteristics in terms of density and RQD within the Kahang deposit (Yasrebi et al., 2013b; Yasrebi et al., 2014). From the results of this modelling, the density and RQD populations of rock types from the studied deposit showed a relationship between density and rock quality based on RQD values, which can be used to predict final pit slope. Finally, the study introduces a Present Value-Volume (PV-V) fractal model in order to identify an accurate excavation orientation with respect to economic principals and ore grades of all determined voxels within the obtained ultimate pit limit in order to achieve an earlier pay-back period.Institute of Materials, Minerals and Mining, the global network IOM3Cornish Institute of EngineersWhittle Consulting (Business Optimisation for the Mining Industry