Kwame Awuah-Offei

Missouri University of Science and Technology | Missouri S&T · Department of Mining Engineering

On August 9-10, 2023, the Thomas J. O’Keefe Institute for Sustainable Supply of Strategic Minerals at Missouri University of Science and Technology (Missouri S&T) hosted the third annual workshop on ‘Resilient Supply of Critical Minerals’. The workshop was funded by the National Science Foundation (NSF) and was attended by 218 participants. 128 par...

Local community acceptance, a key indicator of the socio-political risk of a project, is addressed through good stakeholder (community) engagement. Discrete choice modeling (DCM) enhances stakeholder analysis and has been widely applied to encourage community engagement in energy projects. However, very little detail is provided on how researchers...

Workshop Proceedings for the 2nd Annual National Workshop on the Resilient Supply of Critical Minerals hosted by Missouri University of Science and Technology on August 4-5, 2022.

This research sought to facilitate improved stakeholder analysis in mining by providing further insights into the preferences of local community members using discrete choice theory. While recent research has demonstrated the usefulness of discrete choice theory in mining stakeholder analysis, no previous work has examined which discrete choice mod...

The topic of economics of critical minerals production has received little attention in the economics literature. This study presents a two-stage optimization model to frame the economics of critical minerals. In the first- stage, firms minimize cost to choose input levels, including the extraction of a common ore to produce a critical mineral with...

Several underground coal mining disasters, such as Upper Big Branch in 2010, have revealed technological and organizational shortcomings related to self-escape. Efforts to address these gaps have primarily been top-down, that is, identified and implemented by upper management or external governing bodies. In contrast, this study employs a novel min...

Investors and other stakeholders are increasingly concerned about the quality and quantity of sustainability disclosures as well as the extent to which such disclosures correlate with sustainability practices of mining firms. This is because disclosure policies vary widely across firms in terms of extensiveness, materiality, and disclosed topic. In...

The work applies discrete element modelling (DEM) and similitude theory to predict draft on a rubber tyre loader bucket. A DEM model is calibrated and validated using a 1:16 scale model of a rubber tyre loader, followed by simulations at three different speeds (60 mm s⁻¹, 70 mm s⁻¹, and 80 mm s⁻¹) and two different rake angles (5° and 7.5°). The wo...

This paper examines the effect of bucket geometry (cutting blade profile, floor profile, and blade thickness), speed, motor power output, and muckpile particle sizes on bucket penetration and draft for rubber tire loaders. The work uses a 1:16 scaled model of a load-haul-dump in full factorial experiments to examine the effect of the variables on p...

On August 2-3, 2021, the Thomas J. O’Keefe Institute for Sustainable Supply of Strategic Minerals at Missouri University of Science and Technology (Missouri S&T) hosted the NSF-funded virtual workshop ‘Resilient Supply of Critical Minerals’. The workshop was convened via Zoom and attracted 158 registrants, including 108 registrants from academia (6...

This paper evaluates the effectiveness of similitude theory in predicting the draft of a rubber tire loader’s bucket during initial penetration. The work uses 1:16 and 1:8 scale models of an 18-t capacity load haul dump, scaled with the Buckingham Pi Theorem, to evaluate the prediction of draft and penetration under different operating and differen...

Mining is one of the most energy-intensive industries worldwide. It also provides a critical source of raw materials for the manufacturing, transportation, construction, and energy sectors. Demand for raw materials is projected to increase as the world population grows and many low-income economies become middle-income countries. This growth in min...

This study examined whether individual preferences for mining projects vary with cultural, regulatory, socio-economic, and historical context. The same discrete choice experiment was conducted in the United States and China to: (1) identify differences in the relative importance of various mining project attributes in predicting individual preferen...

As with other engineering design tasks, mine design involves setting design objectives and constraints (the feasible solution space) and finding the optimal design alternative. Mine engineers often struggle to incorporate the preferences of local community members into their evaluation of mine design alternatives because the mining literature lacks...

The highly specialized materials needed for the de-carbonization of energy, smart devices and the internet of things have created supply concerns of critical elements used in these applications. Several critical elements are produced as by-products from base metal mining and processing. Increasing the capture of critical elements from existing oper...

This article examines whether the U.S. government's policy to require mining firms to disclose specified mine safety incidents produced the desired policy outcomes. This is accomplished by examining whether investors respond to mandatory periodic disclosures by coal mining firms as well as mine fatality incidents. Our results show that the market d...

This work evaluated the effect of bucket orientation and operating parameters on resistive forces and penetration for rubber tire loaders. The work used a 1:16 scale LHD model to test a rubber tire loader (RTL) bucket operating at different levels of tractive effort, speed, digging height, and rake angles in a full factorial design experiment. The...

Rubber tire loaders are key loading equipment for surface and underground mines and can load up to 35 t of material in a pass. Efficient initial penetration into the pile improves the overall efficiency of the loading operation. For efficient design for good initial penetration, we need to predict accurately the resistive forces encountered by thes...

One of the main limitations of discrete element modeling for understanding excavation is the large number of particles required to model any realistic problem. This means models require significant computational power to solve. One approach to solving such problems is to use scaled numerical models to study larger physical problems. This work studi...

The global transition to a low-carbon economy will involve changes in material markets and supply chains on a hitherto unknown scale and scope. With these changes come numerous challenges and opportunities related to supply chain security and sustainability. To help support decision-making as well as future research, this study employs a problem-or...

Discrete choice theory has been shown to be a viable way to study individual preferences for resource development. However, only a limited amount of literature assesses the effect of culture, socio-economic, historical, and regulatory factors on the classification of factors that are important to individual preferences for resource development used...

The social responsibility of corporate mining has been challenged by a significant socio-political risk from local communities. These issues reduce shareholder value by increasing costs and decreasing the market perception of corporate social responsibility. Community engagement is the process of understanding the behavior and interests of a group...

While a body of work exists on intelligent systems for guiding occupants out of buildings during an emergency, the problem of guiding miners out of a mine during an underground emergency has not been explored. Underground evacuation fundamentally differs from building evacuation because of differences in the regulatory regime and uncertainty regar...

Increasingly, underground miners have access to personal transponders capable of two-way text messaging. However, we could find no previous work that evaluates how effective text messages could be in providing early guidance to miners during an emergency. This preliminary work evaluates the effectiveness of text message guidance on miners’ evacuati...

Mineral products provide essential fuels and raw materials for industrialization and our daily life, but their influences on other aspects of life need to be taken into consideration. While the whole world benefits from mining’s contributions, most of the resulting detrimental impacts on the environment and society fall on the local communities. Th...

The objective of this research is to determine if information provided to miners during an emergency will help an individual miner make safer decisions. The objective was achieved through surveys that obtained information from miners about what they will do in various circumstances. Respondents are presented with real-life scenarios of emergency an...

The literature on mining community preferences for mineral development, which is the basis for engaging local communities, mainly focuses on rural communities, and may not provide enough insight into an urban community's needs, concerns, and preferences. To bridge this gap, this work uses Salt Lake City, Utah in the United States of America (USA) a...

Information diffusion potential of a social media user affects how quickly information about a mineral project can diffuse through that user. If management can use social media and network analysis, in community engagement program, to understand how fast and how far information will diffuse to communities and followers of particular social media us...

Information diffusion potential of a social media user affects how quickly information about a mineral project can diffuse through that user. If management can use social media and network analysis, in community engagement program, to understand how fast and how far information will diffuse to communities and followers of particular social media us...

This chapter seeks to establish the current knowledge on energy efficiency of cable shovel operations. Additionally, the chapter uses a review of the literature to make recommendations for industrial best practices and for future research to address identified gaps in the literature. The chapter first presents the fundamentals of cable shovel opera...

Dragline operators, as controllers of one the most energy-intensive equipments in surface coal mines, play a significant role in dragline energy efficiency and thus mine profitability. The literature lacks work that explores monitoring system data and applies data-driven methods to gain a better understanding of dragline operation and develop more...

This book presents a state-of-the-art analysis of energy efficiency as applied to mining processes. From ground fragmentation to mineral processing and extractive metallurgy, experts discuss the current state of knowledge and the nagging questions that call for further research. It offers an excellent resource for all mine managers and engineers wh...

This paper presents an approach, based on input-output analysis, for identifying critical commodities in a supply chain to guide a local procurement supply chain management strategy aimed at creating shared value and more sustainable outcomes. The Missouri stone mining and quarrying industry is used to illustrate the approach. The work shows that t...

It is necessary to validate discrete choice experiments to ensure they will lead to reasonable responses and, consequently, to valid modeling results. While some researchers have started to consider the validity of their discrete choice experiments, the approaches used for such validation are not widely reported in the literature. This paper addres...

Mine managers find it challenging to predict changes in the level of acceptance of their mining projects due to changes in associated social, environmental and technological factors. To address this challenge, this study presents a: (i) framework for modeling the effect of information diffusion on community acceptance of mining using agent-based mo...

The mining industry has difficulties predicting changes in the level of community acceptance of its projects over time. These changes are due to changes in the society and individual perceptions around these mines as a result of the mines’ environmental and social impacts. Agent-based modeling can be used to facilitate better understanding of how c...

Sustainable mining has received much attention in recent years as a consequence of the negative impacts of mining and public awareness. The aim of this paper is to provide mining companies guidance on improving the sustainability of their sites through effective community engagement based on recent advances in the literature. It begins with a revie...

A key design aspect of room-and-pillar coal mines is the panel width (or number of entries in a panel), which affects unit mining costs and productivity. Traditional mine design approaches do not facilitate optimisation of unit mining costs and productivity as a function of the panel width. Discrete event simulation can be used to facilitate optima...

Recent incidents of hazardous accumulations of CO2 in homes on or adjacent to reclaimed mine land have been shown to be linked to neutralization reactions between acidic mine drainage and carbonate material. An efficient and economic method is necessary to identify the presence of acid mine drainage- (AMD-) derived CO2 on reclaimed mine land, prior...

Incidents of hazardous accumulations of CO2 in homes built on or near reclaimed mine land, in the last decade, have been shown to be linked to neutralization reactions between acidic mine drainage and carbonate material. Recent research has shown that CO2 fluxes on reclaimed mine land with this hazard are, sometimes, spatially autocorrelated (i.e.,...

This paper presents an approach for handling correlated input variables in discrete event simulation (DES) modelling of truck–shovel systems using commercial DES software and uses a case study to investigate the effect of ignoring correlation between input variables. Multivariate random vectors, instead of independent probability distributions, are...

The ground articulating pipeline (GAP) system was developed to transport oil sand using a continuous transport system. This paper proposes a simulation-based optimisation approach to improve the efficiency of oil sand continuous transport systems at the operational level. Based on the analysis of shovel capacity, the authors recommend that this GAP...

Abstract Recent evidence has shown that CO2 emissions from reclaimed mine soil with acid mine drainage and carbonate material is an emerging geohazard. Surface CO2 flux measurements can be a cheap and effective way to delineate such hazards and avoid residential and commercial real-estate development on high-risk zones. Very little work has been do...

Material handling (including digging) is one of the most energy-intensive processes in mining. Operators’ skills and practices are known to be some of the major factors that affect energy efficiency of digging operations. Improving operators’ skills through training is an inexpensive and effective method to improve energy efficiency. The method pro...

Cable shovel excavation in the Athabasca oil sands is vital given the in-situ excavation of formation. Random occurrence of boulders in the oil sands formation results in varying mechanical energy input and stress loading of the shovel handle-dipper-tooth assembly. These problems pose significant failure threat to the shovel handle-dipper-teeth ass...

Recently, incidents of hazardous accumulations of CO2 in homes built on or near reclaimed mine land have been shown to be linked to neutralization reactions between acidic mine drainage and carbonate material. Surface CO2 flux measurements have been proposed as a potentially cheap and effective strategy to monitor and delineate such hazards to avoi...

Local community acceptance is a key indicator of the socio-political risk associated with a mining project. Discrete choice modeling could enhance stakeholder analysis, a critical step in community engagement. This paper seeks to identify and classify key mining project characteristics and demographic factors that influence individual acceptance of...

Research has recognised operators' skill as important factors affecting performance and energy efficiency of mining equipment. Modern monitoring tools generate large, highly variable, and, often, skewed energy efficiency data sets. Well-conceived statistical tests should be used to assess the effect of operators on energy efficiency in such situati...

Draglines are dominant machines and the most electricity consumers in surface coal mines. With the growing price of energy, environmental concerns, and the high sensitivity of mine profitability to dragline productivity, any improvement in efficiency of draglines can be beneficial for mines. Research has shown that operator skills have a significan...

The significance of local community acceptance to the success of a mine cannot be over-stated. Project sustainability has implications for local community acceptance as the development and operation of a mine can be viewed as a development intervention with concrete social, economic and environmental impacts. Although, some work has been done to un...

The goal of hot mix asphalt (HMA) design is optimal material blending to meet Superpave specifications. HMA cost minimization has being modeled as linear programing (LP) (Awuah-Offei et al 2011) and mixed integer LP problems (Brown et al, 2012) and solved with commercial software such as LINDO and CPLEX. Often these software, which are designed to...

Local community acceptance is a key aspect of planning and managing mining projects, whether through sustainability assessment and reporting or corporate social responsibility programs. However, there has been very little research to understand the determinants of community acceptance. This paper seeks to identify key mine characteristics and demog...

Draglines are the main energy consumers in strip mines. Given the growing cost of energy and environmental concerns, it is important to properly understand dragline energy efficiency. The goal of current research at Missouri University of Science & Technology is to account for operator practice and operating conditions in modeling dragline energy e...

In oil sands mining, timely provisions of ore and tailings containment with less environmental footprints are the main drivers of profitability and sustainability. The recent Alberta Energy Resources Conservation Board Directive 074 requires oil sands waste disposal planning to be an integral part of mine planning. This requires the development of...

Purpose This study’s aim was to understand the effect of mine characteristics on cradle-to-gate life cycle impacts of surface coal mining in the USA. Five bituminous coal strip mines were used as case studies. The study assessed the life cycle water use, land use, energy use, abiotic resource depletion, and climate change impacts. Methods The stud...

Energy efficiency has become significant due to cost and environmental considerations. Comminution and material handling have been identified as the two most energy intensive processes in mining. The objective of this work was to evaluate truck-shovel energy efficiency strategies using discrete event modeling. Energy audits and time and motion stud...

The use of quality materials (aggregates and asphalt binder) in optimal proportions is the key to producing optimally performing hot mix asphalt (HMA). The Superpave mix design standard in the US introduced specific volumetric and binder property requirements in HMA design. Different methods for HMA constituent proportioning have been proposed in v...

The cable shovel is widely used in surface mining. High operating and ownership costs necessitate efficient use of the cable shovel. Operator practices have long been suspected to contribute towards the inefficient use of the shovel. Crowd arm and hoist rope speeds are key measures of operator practices. The objective of this work is to find the cr...

The feasibility of Small Modular Reactors (SMR) in providing a lower-cost power-generation alternative to large nuclear power plants has been suggested widely in recent years, but remains a largely undeveloped technology. Published reports have identified many of the challenges of building SMR technology, with the major ones being industrial capaci...

The US coal mining industry consumes approximately 142 billion kWh per year of energy. The US Department of Energy estimates that the industry's annual energy consumption can be reduced by 49% (24.6 billion kWh/year by using currently available best practices and a further 44.8 billion kWh/year with more research). This constitutes nearly $3.7 bill...

Hot-mix asphalt is a mixture of aggregates and asphalt binder in appropriate ratios to produce a high-performing material for asphalt pavements. The aggregate structure, which depends on the gradation, is an important factor in determining the volumetric properties of HMA. The design process to determine the optimal aggregate blend is currently ite...

Research to evaluate possible metrics for predicting dredgeability of compact aggregates, by hydraulically actuated clamshell dredges, shows work done by the pistons as a viable metric. Analysis of field data shows that there is a low, positive, correlation between cycle time (CT) and work done. If this correlation exists, then CT has to be conside...

The lack of metrics to assess clamshell formation dredgeability limits the ability of engineers to predict the dredgeability of compact material and increases the risks associated with clamshell selection. Work done and motor energy are possible dredgeability metrics that can be estimated using micro-processor based machine monitoring. The objectiv...

Background, aim, and scopeIn spite of the increasing application of life cycle assessment (LCA) for engineering evaluation of systems and products, the application of LCA in the mining industry is limited. For example, a search in the Engineering Compendex database using the keywords “life cycle assessment” results in 2,257 results, but only 19 are...

The U.S. coal mining industry consumes approximately 142 billion kWh/a of energy. The U.S. Department of Energy estimates that the industry's annual energy consumption could be reduced by 49%. This constitutes nearly $3.7 billion of potential savings on coal production costs at 5.3¢/kWh of energy. Additionally, with climate change regulation on the...

Research to evaluate possible metrics for predicting dredgeability of compact aggregates, by hydraulically actuated clamshell dredges, shows work done by the pistons as a viable metric. Analysis of field data shows that there is a low, positive, correlation between cycle time (CT) and work done. If this correlation exists, then CT has to be conside...

Hot-mix asphalt (HMA) is a mixture of aggregates and asphalt binder in appropriate ratios to produce a high performing material for asphalt pavements. The aggregate structure, which depends on the gradation, is an important factor in determining the volumetric properties of HMA. The design process of determining the optimal aggregate blend is curre...

In order to optimize the hydraulic transportation system efficiency and cost in the surface extraction of Athabasca oil sand deposits in Canada, there is a desire to extend the hydraulic transport system to production faces in oil sands mines using mobile train of Flex-Rite-based flexible pipelines. Hydraulic transportation system based on flexible...

One of the main obstacles in using Mixed Integer Linear Programming (MILP) formulations for open pit production scheduling is the size of the problem. The main objective of this paper is to present and implement a practical MILP formulation for open pit production scheduling problem. To reduce the number of binary integer variables in the formulati...

Coal plays an important role in the energy needs of the World. Given its wide abundance and low cost, coal use is bound to increase with the growing energy demand. Despite its importance, there are growing concerns over coal's environmental burdens, especially its contribution to greenhouse gas emissions. To ensure sustainable extraction and use of...

High CO2 fluxes associated with reclaimed coal mine spoils pose an environmental hazard where such sites are used for building. CO2 concentrations in excess of 25% have been reported in homes constructed on or down gradient of such spoils. The objective of this study was to investigate the effect of a mitigation trench used at one mine site on CO2...

The role of aggregate gradation in hot-mix asphalt performance is well documented in the literature. Yet the Bailey method is the only tool available for guidance on aggregate gradation selection for optimal performance. Also, there is a lack of tools for design engineers and plant managers of quarry sites to manage stockpile inventory levels and c...

Various mixed integer linear programming (MILP) formulations have been used for production scheduling of open pit mines. Every orebody is different, but for a typical open pit long-term scheduling problem numbers of blocks are in the order of couple of hundred thousands to millions and the number of scheduling periods are twenty years and more for...

We have proposed two mixed integer linear programming (MILP) formulations for large-scale long-term open pit production scheduling problem. We developed, implemented, and tested the proposed MILP theoretical frameworks for large-scale open pit production scheduling.

Development of new optimization techniques and uncertainty quantification for long-term mine planning plays a vital role in reducing environmental footprint and financial risk of mining projects. Deviations from optimal plans in mega mining projects will result in huge financial losses, delayed reclamation, and resource sterilization. In this resea...

Open pit mine plans define the complex strategy of displacement of ore and waste over the mine life. The objective of the mine plan is to maximize the future cash flows within the technical and physical constraints. Various mixed integer linear programming (MILP) formulations have been used for production scheduling of open pit mines. In the MILP f...

Strategic mine planning and the management of the future cash flows are a vital core of surface mining operations. The time dimension, which is an integral part of the scheduling problem, is not embedded in traditional ultimate pit outline optimisation algorithms. This study explores the validity of the theorem that a pit outline determined by an o...

An aggregate plant may have difficulty balancing product stockpile inventories if hot mix asphalt (HMA) design engineers do not account for aggregate inventory during mix design. Yet HMA design engineers do not, often, take this into consideration during asphalt mix design. This is due to the lack of tools that enable the lab technician or engineer...

Modelling and simulation of formation resistance to excavation has become important in evaluating performance and designing efficient earthmoving equipment. Previous attempts at extending the passive earth theory to excavator dippers have only covered snap-shot estimates for a right-angled framed assembly. This work applies cable shovel kinematics...

The objective of asphalt mix design is to produce a mix with optimal performance using available aggregate stockpiles. Often, this process does not take into consideration aggregate plant stockpile inventories or the cost of aggregate in the mix. This is due to the lack of tools that enable the lab technician or the engineer to optimize the mix for...

An aggregate plant may have difficulty balancing product stockpile inventories if hot mix asphalt (HMA) design engineers do not account for aggregate inventory during mix design. Yet HMA design engineers do not, often, take this into consideration during asphalt mix design. This is due to the lack of tools that enable the lab technician or engineer...

Life Cycle Assessment (LCA) is an emerging environmental management tool for examining environmental impact from cradle-to-grave. In this paper, LCA is used to evaluate the acidification potential (AP) and global warming potential (GWP) of belt conveyor and truck haulage systems in a surface gold mine using the ISO 14040 standards. The results show...

Cable shovel excavation in the Athabasca oil sands formation is carried out with little or no pre-fragmentation. The stress loading of a shovel's front-end assembly must continually be monitored and managed to prevent fatigue failure. In this paper, the authors advance the reliability of the cable shovel boom through dynamic and stress modelling us...

Operator practices have long been suspected to contribute towards the inefficient use of cable shovels. The objective of this work is to find the optimal crowd arm and hoist rope speeds for given initial conditions, material properties and uncertain bulk densities. The excavation process has been modeled using shovel kinematics and dynamics and inc...

Classical optimal hedge ratio concentrates on risk reduction and neglects strategic value maximisation. In this study, the authors use stochastic optimisation theories to formulate an optimal, short-term hedging scheme to mitigate risks while maximising portfolio value. Stochastic spot and futures price models are used to simulate prices. The perio...

The cable shovel is an important primary excavator in surface mining operations. The production function of this shovel becomes more critical in the Athabasca oil sands formation with little or no pre-production blasting. The random occurrence of shales, dolomites and limestones in this formation causes a high digging resistance, mechanical wear, t...

Cable shovel ownership and operating costs are major cost centers in surface mining operations. In the Athabasca oil sands formation, excavation is carried out with little or no pre-fragmentation. Random occurrence of shales and limestones results in varying shovel diggability and stress loading of the boom-crowd-dipper-teeth assembly with correspo...

Long-term production scheduling and sequencing are the focal keys to attain the economical objectivesinsurfacemining.Determinationofoptimalproductionschedulesforopenpitminesrequirescomplex modeling and computational tasks. A realistic model should incorporate mathematical rigors, technical and economical constraints. The extensive search domain for...

Long-term production scheduling and sequencing are the focal keys to attain the economical objectives in surface mining. Determination of optimal production schedules for open pit mines requires complex modeling and computational tasks. A realistic model should incorporate mathematical rigors, technical and economical constraints. The extensive sea...

The cable shovel excavator is used for primary production in many surface mining operations. A major problem in excavation is the variability of material diggability, resulting in varying mechanical energy input and stress loading of shovel dipper-and-tooth assembly across the working bench. This variability impacts the shovel dipper and tooth asse...

Material scheduling, sequencing planning and execution are the core tactical mine plan for achieving production targets that maximize the objective function of any mine production entity. This objective function is constrained by several exogenous and endogenous constraints including geological, operating, technological, marketing, financial, polit...

A mining contractor is expected to provide equipment flexibility in spite of the fact that haulage unit production varies as mining progresses. Consequently, predicting the equipment needs well in advance is important for the mining contractor. African Mining Services (Ghana) Limited (AMS) is a mining contractor, responsible for the loading and hau...