Dirk Van Zyl

Professor

Relevant Degree Programs

 

Graduate Student Supervision

Doctoral Student Supervision (Jan 2008 - Mar 2019)
The use of geothermal energy in mining : a decision-making framework (2018)

This thesis aims to support the uptake of geothermal energy by the mining industry by developing a decision-making framework that when applied, will allow decision makers to quickly and inexpensively assess whether geothermal merits further consideration as a potential source of energy for a given mining project. The intent was to demonstrate that such an assessment could be made by non-experts, without having to resort to more complex, specialist analysis that is typically part of traditional geothermal exploration. To this end, a 3-step approach was adopted: a) identify, rank, and map indicators of worldwide geothermal potential; b) identify, rank, and map indicators of worldwide mineral potential; c) combine geothermal and mineral potential and map to identify areas of significant overlap. The calculation of geothermal potential necessitated the creation of a comprehensive listing of geothermal power plants, which were individually verified for location accuracy — associated maps of current geothermal production were also created for select areas of interest. Geothermal potential was represented by 5 indicators, namely volcanos, earthquakes, tectonic plate boundaries, heat flow, and thermal springs. Geo-indicator subtypes were ranked with respect to their proximity to active geothermal production, and were subsequently classified as either Primary or Secondary, and used to derive a rough estimate of geothermal potential, even in areas with no current geothermal production. An Analytic Hierarchy Process-based model used to calculate the relative geo-indicator importance weights was presented, and it can be extended to include additional indicators of geothermal potential to the ones used in this research with future releases of exploration data. A comprehensive map of mineral potential was also produced, using a combination of publicly-available and proprietary data, for a total of 148 distinct commodities. Mineral potential indicator importance weights were calculated based on a combination of attributes, including resource size, development stage, activity state, resource value, and commodity listing order. Those were subsequently ranked based on their proximity to geothermal potential, and used to produce worldwide maps of geomine potential.

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Framework and maturity model to guide and evaluate corporate contributions to sustainable development of neighbouring communities : specific focus on geothermal power projects (2017)

The goal of this research is to present a new way of thinking (in the form of a framework) about how geothermal power projects can contribute to sustainable development (SD) in a way that harmonizes these projects with SD plans of their neighbouring communities. The research aims to create a SD approach for the greater geothermal power industry that is consistent with the expectations and values of today’s society. A framework, referred to as the Geothermal Sustainable Development (GSD) framework, is proposed aiming to guide and evaluate the contributions of a geothermal power project to SD in the local and regional communities. After developing the framework, to help companies and other interested parties to track and evaluate the progress of the project with respect to its approach towards SD, an evaluation strategy in the form of a maturity model is proposed. The maturity model aims to highlight the depth and quality of SD-thinking and its influence within a company/project development paradigm. The research is based on a combination of quantitative and qualitative research approaches to evaluate and test these outcomes. A survey was used that represents the quantitative research approach. This survey set out to assess whether the identified objectives presented in the framework are indeed suitable and effective as tools for the intended purposes of the framework. A second part of the research consisted of interviews (qualitative research approach) to evaluate the maturity model and its applications. Six case studies were discussed with interviewees.The developed framework can be used by the industry, communities, NGOs, and government as a starting-point to establish common ground in the development of geothermal power projects to focus the attention of everyone. It also provides the industry with an opportunity to assess their performance and communicate their approaches, contributions, and progress to the stakeholders and (possible) investors consistently and clearly. The combination of a GSD framework and the proposed SD maturity model could be used by any company at project and corporate levels that have already committed or are willing to commit to SD to evaluate their performance.

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Testing protocol for evaluating amenability of ores to HPGR crushing for heap leaching (2017)

Finer particle size distribution (PSD) and generation of more microcracks obtained by the use of high pressure grinding rolls (HPGR) are believed to be the major reasons for metal recovery improvement by heap leaching. Finer PSD increases the surface area of the particles, which are in contact with the leach solution and improves recovery. Microcracks in HPGR materials result in improved penetration of leach solution into the grains and thus metal recovery. The objective of this work is to develop a better understanding of ores crushed by HPGR and cone crusher, in terms of microcracks and PSD, and assess the benefits of using HPGR for heap leach projects. The test results can be used in the early stages of the project to develop an initial understanding of the benefits of utilizing HPGR in the comminution circuits for heap leaching.Gold oxide, copper sulfide and copper/gold sulfide samples were used in this research. Laboratory tests including PSD analysis, scanning electron microscope (SEM), slake durability, Helium (He) pycnometry, nitrogen gas adsorption, water absorption and column tests were used to evaluate the changes in the PSD, microcracks morphology, mechanical stability, porosity, exposed surface area, water absorption capacity and unsaturated flow behavior of the samples. Finally, modeling by HYDRUS was conducted to investigate the hydraulic behavior of the crushed ores.PSD analysis showed finer size distribution for HPGR materials, independent of the ore types. Lower slake durability indices, higher porosities, larger surface areas, higher water absorption values and residual water degree were obtained for HPGR’s materials in comparison with the cone crusher’s. Computer modeling showed lower unsaturated hydraulic conductivity for HPGR samples. Estimation of the microcracks percentage over the total porosity indicated higher values for HPGR samples. Percentage of water inside microcracks and on particle surfaces over the water remaining between particles was higher in most HPGR crushed samples. Finally, a time efficient testing protocol for evaluating the amenability of HPGR to provide ore having the preferred characterization for heap leaching is designed.

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The impact of fabric and surface characteristics on the engineering behavior of polymer-amended mature fine tailings (2016)

Management and reclamation of large inventories of legacy and fresh mature fine tailings (MFT) represent a continuing and significant challenge to surface mine operators in the Alberta Oil Sands because of the complex chemical and physical behavior of these tailings. Suncor’s tailings recovery operations (TRO™) and Shell Canada’s atmospheric fines drying (AFD) use anionic polymers to flocculate MFT to remove fine tailings solids from aqueous suspension. Addition of anionic polyacrylamide polymer to MFT results in the creation of a complex synthetic material, polymer-amended MFT (PA-MFT).This research investigates the fundamental properties and characteristics governing PA-MFT dewatering in an effort to better understand how these factors contribute to overall material behavior including strength development and consolidation. This work confirms that the addition of anionic polyacrylamide polymer does little to change the zeta potential of the input raw MFT as the resulting material is colloidally stable. The work also indicates how residual bitumen and fabric act independently and in combination to reduce the permeability of PA-MFT and enable retention of water within the material’s fabric especially when it is stored in lifts that exceed the depth at which the combination of evaporative drying and underdrainage are effective. It is concluded that PA-MFT fabric includes abundant micropores with tortuous flow paths with little connectivity between pores. The size and configuration of the pores effectively traps water within the PA-MFT fabric. Residual bitumen may also block pore throats or form a hydrophobic barrier that limits both the effectiveness of evaporation for material deposited below a depth of 15 cm in thick lift deposits. Residual bitumen may also prevent diffusion of trapped water upward through deposited material and contributes to the plasticity and compressibility exhibited by PA-MFT when it is deposited in lifts thicker than 20 cm.

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Socio-Economic Mine Closure (SEMC) framework : a comprehensive approach for addressing the socio-economic challenges of mine closure (2014)

This thesis seeks to investigate the initiatives that address the socio-economic implications of mine closure that have been implemented by three mining companies which are located in Mongolia, Argentina and Canada. It further addresses the perceptions of stakeholders, specifically community members, local government representatives and mining company employees regarding the initiatives that have been implemented by three mining companies. Additionally, the research examines six mining industry-related frameworks/guidelines, and explores the ways in which these documents interpret the socio-economics of mine closure. Finally, this thesis introduces and evaluates the Socio-Economic Mine Closure (SEMC) Framework, which was originally developed as part of this PhD investigation. There are 10 elements in the Framework: Policy, Presence, Participation, Planning, Performance, Promotion, Perseverance, Patience, Passion, and Personality.The SEMC Framework is assessed in multiple ways: a) against the current literature on mine closure; b) through an online survey in which 151 experts were invited to provide feedback on the elements and sub-element constituents of the Framework and c) by its utility in constructing the fieldwork survey and the feedback of survey participants indicating the appropriateness of the framework.The study indicates that it would be relevant, timely and appropriate for the mining industry to introduce, discuss and adopt the proposed SEMC Framework.The case study analyses, all of which employed interviews, group sessions, and distribution of survey material as part of their methodological approaches, reveal that each case has unique characteristics and that all are context-based. The case studies also indicate that all three situations reveal the presence of some common issues. For instance, the results of the study suggest that, in all three cases, communication levels need to be improved and augmented.An important finding of the overall study concerns the element Personality within the SEMC Framework. Although in both the online survey and in the survey distributed to study participants, this element was ranked as one of low importance, through the interviews, group sessions and researcher observations it became clear that the Personality of the company community liaison does play a significant role in maintaining and fostering relationships between mining companies and local stakeholders.

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Master's Student Supervision (2010-2017)
Study on financial assurance and closure cost for mine reclamation (2017)

Financial assurance for mine closure has been widely adopted by governments and companies internationally. Concern has grown in and around the global mining and mineral processing industry over potential risks associated with insufficient funding for mine closure.The motivation of this research is to review financial assurance information from several jurisdictions and to quantitatively assess closure cost for a specific example. This research address the following four objectives:1. To carry out a literature review on financial assurance for mine reclamation.2. To compare present regulations and policies on financial assurance for mine closure in Canada, United States and Western Australia.3. To identify expectations for different types of mining.4. To develop the closure approaches and apply a method to estimate and calculate the closure cost for a mine site.Main research results are as follow:a. Significant reclamation financial assurance information is highlighted, and the expectations of various stakeholder are identified for different types of mines in various jurisdictions across the world.b. Mine reclamation laws in selected jurisdictions of the Canada, United States, Western Australia have some differences and similarities in regulating agency, closure legislation, guidelines and other aspects. Regulations and policies on financial assurance for mine reclamation in the United States and Canada can be classified into prescriptive and performance-based approaches. The performance-based approach is preferred by mining companies for mine reclamation regulations.c. Developing a mine closure cost estimate requires an understanding of the site-specific closure requirements and available software can be used to perform the closure cost estimates. This study applies the Sherpa software to calculate the closure cost of a conceptual gold mine near Winnemucca, Humboldt County, Nevada. ArcGIS Software is used for calculating the size of each small surface water catchment areas for this mine.The final cost estimate for the total closure cost for the gold mine near Winnemucca, Humboldt County, Nevada is $32,417,400 including $22,574,400 direct cost and $9,843,000 of indirect cost. Considering the Gross Receipt Tax of $677,200, the total financial assurance for this project is $33,094,600. The total overhead costs account for 30.4% of the direct project costs.

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The role of policies and regulations in expanding local procurement in the mining industry in Sub-Saharan Africa (2017)

The aim of this research is to study the role of policies and regulations in expanding local procurement as a socio-economic development tool in two countries of Sub-Saharan Africa, namely South Africa, which has a strong and well-structured regulatory framework and Namibia, which has a weak one. The concept of local procurement has become very relevant, mostly in resource-rich countries where a strong mining sector represents an important part of the national economy. Whereas governments perceive local procurement as a poverty-reduction tool and as a medium to correct previous inequalities by enabling economic development, private industry sees it from the perspective of securing its social license to operate, thus running smoothly through their life cycle with a reduced likelihood of conflicts with regional stakeholders.During the course of this research, social, economic, and political indicators were analyzed, legal frameworks were compared and contrasted, interviews were carried out, information from the interviews was examined using data analysis software to help find main themes and patterns among the interviews with the participants, and finally a discussion was carried out to address both, the question and the research objectives of this thesis. The research included a historical document review and field work in both countries.In conclusion, this study finds that policies and regulations play a paramount role in expanding local procurement in both countries. Furthermore, for local procurement to support long-term economic growth; public, private and advocacy stakeholders need to continuously engage through reviewing their policies and regulations ensuring their legal framework is inclusive and its goals and objectives are aligned to the goals and objectives of the host country.

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Water balance of metal mining tailings management facilities : influence of climate conditions and tailings management options (2017)

The objective of this research was done to review and compare available methods for Tailings Management Facilities (TMFs) water balance; to develop deterministic and probabilistic models; and to compare the impacts of different tailings management options and climate conditions.The developed models were spreadsheet based. Mount Polley operational data were used. Water balance models were created for lined and unlined impoundments in both wet and dry climates. Wet condition climate data were extracted from ClimateBC (a University of British Columbia Software Program) using the location of the Kerr-Sulphurets-Mitchell (KSM) project in British Columbia. Climatic data from the Cerro Negro mine site in Argentina were used to simulate the dry condition. After developing a deterministic model, Monte Carlo simulation computational algorithm was used to develop the probabilistic evaluations. Simulations were carried out using the Oracle Crystal Ball Excel add-in. Evaluations were done on four management options (slurry, thickened, paste, and filtered tailings) by changing the tailings solids content. Results confirmed that entrainment and evaporation were the biggest water losses in TMF. For slurry tailings, entrainment loss was more than 80% of the total water loss in the wet condition and more than 50% of the total water loss in the dry condition.The reported average mine water consumption for slurry tailings in arid climate is between 0.4 and 0.7 m³/tonne. The estimated mean required make up water from the developed model in this reaserch was 0.70 m³/tonne. Water withdrawal in dry climate conditions can decrease to 0.18m³/tonne when a filtered tailings option is implemented. The average water surplus in wet climate conditions for an unlined impoundment varied between 0.83 and 1.12 m³/tonne for solids contents between 45% (slurry tailings) and 80% (filtered tailings). The corresponding values for a lined impoundment were 0.86 and 1.16 m³/tonne.Implementing dewatered tailings is not recommended in wet climates. In contrast, paste tailings and filtered tailings are good options in arid areas for proper-size operations.TMFs are site-specific complex systems. Results presented here are only examples to outline how the mining industry can work toward reducing water losses by using dewatering and tailings management technologies.

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Education, community engagement and oil and gas development : northeast British Columbia (2016)

Resource development projects offer economic opportunities to communities near operations, through the provision of jobs and corporate social responsibility (CSR) initiatives. When the local labour pool is not prepared, or lacks appropriate skills or education avenues for upgrades, labour demands will be filled by a fly-in-fly-out workforce. This system both draws resource benefits away from impacted communities, and incurs high transportation and lodging costs to the company. Improving labour-force quality will require upgrading education resources necessary for acquiring the appropriate post-secondary degrees and certificates for employment in the industry. Before planning education programs, it is important to have an acute understanding of the population’s history, socio-economy, regional education resources, and perspective on local education and employment. This research study examined the Northeastern, British Columbia (NEBC) region, where oil and gas (OAG) development is expected to increase exponentially in the near future with the use of hydraulic fracturing. Due to the specialized skills required for this industry, the local communities are currently ill equipped to participate in the labour boom. An education gap analysis was performed to examines the education disparities and obstacles for varying communities in NEBC. The study used a geographic analysis of regional education opportunities to identify community needs, followed by field work where in-depth interviews and focus groups brought to light local thoughts and perceptions on education, employment and community development. This information can be used by OAG companies to invest in socially responsible programs, that benefit regional communities as they develop the resource.

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Management of socio-political risk arising from corporate transitions : the Mt. Milligan experience (2016)

Changes in management and/or ownership at mineral exploration and mining projects can cause a regression in corporate-stakeholder relationships, as the changing faces and attitudes can lead to breakdowns in communication, misunderstandings, and heightened risk of conflict. Failure to maintain positive relationships with stakeholders can lead to significant costs for proponents, and is frequently cited as one of the most pressing issues facing the mining industry. By examining the Mt. Milligan mine in central British Columbia, Canada, as a case-study, this thesis provides an analysis of how successive management teams endeavored to mitigate socio-political risk by building relationships with local stakeholders, and specifically how these relationships were impacted by successive changes in management and ownership.Interviews with managers from the three most recent proponents of Mt. Milligan were conducted to collect data on perceptions of socio-political risk and the execution of corporate transitions. The study also incorporates perceptions of the Mt. Milligan experience drawn from interviews with local and regional stakeholders, including First Nations groups and neighboring municipalities. Information from the interviews was scrutinized using data analysis software, and collectively reviewed for main themes and patterns over time. The research also included a historical document review, and a field visit to the mine region.This study finds that the levels of socio-political risk arising from a transition are linked to: effective due-diligence, corporate culture and experience of the proponent, and community experience and capacity. Effective mitigation of this risk is linked to: transfer of personal relationships, quality and frequency of communication, creation of institutionalized stakeholder engagement mechanisms, and preserving an institutional record of social engagement and commitments to communities. A strong relationship is noted between the experience of managers and community members during Mt. Milligan's development history, and the ideas conveyed by the current literature on socio-political risk management in the mining industry. In summary, this study delivers a review of the historic mitigation of socio-political risk at Mt. Milligan arising from multiple changes in management and ownership. Lessons drawn from this review inform key strategies that can be employed in the management and mitigation of socio-political risk at future projects. The study advances the current dialogue surrounding stakeholder relations in the mining industry, and contributes to an improvement of industry practices addressing the management of socio-political risk through transitions in the management and ownership of mining projects.

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Materials for manufacturing low-tech, low-cost ceramic water filters and the business models for their distribution in Central America (2016)

Water is a critical resource to the human race, yet half the planet's population experiences water scarcity and 780 million people do not have access to clean water sources year round. For those with no other choice but to drink from contaminated water sources, they are at risk of contracting a broad range of diseases, most commonly diarrhoea, which the second largest killer of children under the age of five. Residents living in rural areas of developing countries are primarily at risk, lacking access to basic water infrastructure and medical services. To provide clean water to those in need requires culturally appropriate technology that is simple to construct and local made. Ceramic Water Filter Pots (CWFPs) consist of porous clay that acts as a filter, which is coated with silver nanoparticles creating a system capable of removing 99.995% of bacterial pathogens from drinking water and built in any community in the world. Working with a nationally recognized NGO based in Nicaragua, Potters for Peace (PfP), this study aimed to determine the limiting factors of production of CWFP by examining the materials used in three factories in Nicaragua, and the business model used in Guatemala based EcoFiltro. Field work was conducted in three factories in Nicaragua, and one factory in Guatemala. Visual observations of the production methods, testing protocols and business practices were documented visually and used to contrast the facilities production and businesses practices. Clay samples were collected from the Maysuta (n=2) and Filtron (n=3) factories to be analyzed at the University of British Columbia. The Atterberg limits were determined on the samples and X-ray diffraction analysis was used to determine the mineral makeup of the five samples and the percentage and type of clay in each. This study outlines the limits of clay composition, specifically montmorillonite, which can be used to manufacture ceramic water filters that make a viable ceramic filter, and contrasts the business models of two ceramic water manufacturers.

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Fundamental study of the sedimentation of copper tailings with Kynch theory (2015)

The management of tailings is a significant issue within the mining industry worldwide. An understanding of sedimentation and consolidation of tailings provides a solid foundation for the management of tailings. Kynch theory, the first mathematical formulation of sedimentation theory, is widely used as a tool in the analysis of batch sedimentation. However, due to various idealized assumptions within Kynch theory, the application of this theory to describe and analyze tailings sedimentation in the laboratory setting has not been well developed. For the purpose of this research, a new apparatus was designed and constructed to carry out column settling tests and to remove and collect samples of water and suspensions in thin layers. Tests conducted with this apparatus aim at investigating the settling behavior and the internal changes in the suspension during the process of sedimentation. Solid content and particle size were selected as the main parameters. Benchmark tests were first conducted to determine the general range of the two parameters. Solid contents of 35% and 40% were selected for the column settling tests. Tests were carried out on total copper tailings as well as fine portions of copper tailings with a particle size smaller than 37 µm. The experimental data collected from these tests was analyzed with Kynch theory. Total copper tailings, with a large range of particle sizes could not satisfy the assumptions of Kynch theory on particle size, and failed to conform to Kynch theory. In the tests of fines from copper tailings, the influence of segregation decreased as the coarse particles in the copper tailings were removed. Based on Kynch theory and some laboratory data, a prediction curve was developed and compared with the results of the column settling tests. Changes in the internal attractive force, and the influence of compaction settling were found to be reasons why the prediction curve was unable to completely match the experimental data.

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Mine closure planning with First Nations communities : the Stk'emlupsemc te Secwepemc Nation and the New Afton Mine (2015)

The goal of this research is to understand how the traditional knowledge of the Stk’emlupsemc te Secwepemc Nation can be used to improve reclamation and closure planning of the New Afton mine. Furthermore, this research will provide insight into consultation with First Nation communities for closure and reclamation planning. The New Afton Mine site, located ten kilometers west of Kamloops, BC is on the traditional territory of the Tk’emlúps te Secwepemc and Skeetchestn Indian Bands. The application of traditional knowledge for closure is a relatively new field. As such, the application of the findings of this research are at a conceptual level. Interviews with traditional knowledge keepers were conducted to understand the relationship between plant life, wildlife, water sources and the traditional use pattern in the area. Site visits to both the Stk’emlupsemc te Secwepemc Nation and New Afton Mine site have taken place during this research study. Visits to the New Afton property focused on determining and understanding the different areas of disturbance. Visits with the Stk’emlupsemc te Secwepemc members were aimed at engaging, recognizing, and understanding their objectives for the long term post-closure use of the mine site. This research found an extremely strong connection between the community’s culture and natural environment. In addition, hunting, fishing, medicinal and nutritional plant gathering were considered as the key traditional land uses in the area. The New Afton Mine was known as an old stop-over ground for travelers in the region. Concerns relating to the impacts of tailings and possible contaminants to the environment (water, wildlife and plant life) were indicated. Reclaiming the land to a natural state was outlined as the most desirable outcome for closure. The technical constraints of the property were also discussed (subsidence zones, semi-arid conditions, etc.) and how the property, considered as a brownfield development, impacts the closure and reclamation outcomes. Finally, through the interviews and field notes, it was found that successful consultation and collaboration with First Nations communities requires: respect and understanding of the community’s culture and history, well established trust, and an ability to be flexible to the needs of the community.

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Stakeholders' perception on the applicability of shared value creation in Mongolian mining development (2015)

In recent decades, world population growth has resulted in an unprecedented rise in consumer demand for goods and commodities, and has resultantly triggered the rapid development of relevant industries, including the mining sector. Site-specific effects of the rapid industrial development have led to environmental issues and mounting social dissatisfaction, and have created major obstacles for the industry. Weak governance, an unstable regulatory environment and ill-defined public expectations are considerations that should all be taken into account in order to better understand the current dynamics. Researchers, scientists and business owners are looking for ways to effectively mitigate some of the non-technical challenges facing the industry, proposing various tools, approaches and innovative ideas to moderate risks and to assist with collaboration. One idea gaining momentum is the “Shared Value” approach, which is the subject of this thesis. This research explores the applicability of the Shared Value approach within the Mongolian context. This research focuses on the mining industry’s impact on Mongolia’s development, the negative effects of which have mainly been caused by the unequal distribution of the mining wealth over the last 25 years, analyzes and identifies factors which have led to current social and political issues faced within Mongolia, and which can be traced back to the development of the mining sector.The current situation regarding public perceptions and expectations in Mongolia are based on a survey of the major mining stakeholders. The results of this survey will help us understand the public expectations held in Mongolia with respect to mining development, and these considerations will be taken into account in the development of future strategies.The case study of the situation in Mongolia offers us a unique opportunity to study the development of the mining industry in a country with a highly educated population that is endowed with vast untapped natural resources, and yet which is unable to fully benefit from these advantages because of weak governance, appropriate or inappropriate governmental regulations, mining projects with disastrous environmental and social impacts, and the often one-sided and polarized involvement of civil societies.

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Fault tree analysis of slurry and dewatered tailings management: A framework (2014)

No abstract available.

Seepage Induced Consolidation Test : characterization of mature fine tailings (2014)

Managing oil sand slurry tailings waste is a significant issue in the oil sands industry and thus accurate characterization of the tailings is required. Conventional soil characterization tests usually involve one or more limiting assumptions such as small strains and constant coefficients of consolidation and hydraulic conductivity. These limitations are significant when testing low density slurries such as dredged soils and mining waste. One unconventional test in particular, the Seepage Induced Consolidation Test (SICT) has been shown to accurately determine compressibility and permeability relations for low density slurries. The SICT was first constructed at the Colorado University (CU) in Boulder, Colorado and has been used for the past two decades to characterize phosphate slurry tailings. Over the last two years a SICT was constructed at the University of British Columbia to provide accurate consolidation characterization of oil sand waste, in particular, mature fine tailings (MFT). Benchmark testing was initially performed on kaolinite clay at the UBC laboratory and results showed the test was repeatable and comparable to results obtained at CU. Test results on MFT at UBC also proved to be in agreement with published data from CU. The use of the SICT helps in the understanding of MFT and the characterization results can be directly used in into large strain consolidation modeling such as CONDES0 1D and SoilVision’s SVOffice 1D, 2D, and 3D software programs. These and other similar models, which are dependent on the compressibility and permeability relations from the SICT, can be used in the design of waste disposal strategies at every stage of a mining project.

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Calibration of a mixing model for sublevel caving (2013)

Sublevel caving (SLC) is an underground mass mining method where the orebody is divided into a regular network of tunnels. The ore is extracted by level working downwards through the orebody. The caved waste from the overlying rock mass fills the void created by ore extraction generating a dynamic mixing situation between the broken ore and the waste (dilution) from upper levels. The dynamic process of mixing creates a significant challenge in the SLC project to estimate grades reliably. PCSLC is an application developed by Gemcom Software specifically designed for the mine planning of Sub Level Caving projects and operations. It incorporates a rich set of tools to assist with the whole design and planning process including a sophisticated mixing models, it can simulates the material flow observed in caving mines using a technique known as Template Mixing, but due to the complexity that it represents, it is extremely necessary to calibrate its results against real data. The main purpose of this study was to calibrate the mixing model implemented in PCSLC using real data from Newcrest Ridgeway Gold Mine to provide guidelines for SLC project to forecast grade reliably.The methodology used was to collect historical information provided by Ridgeway to reproduce its design and result in PCSLC and then be capable to understand the complexity of gravity flow in SLC. Key information for this purpose was the utilization of the trial marker scale experiments applied at the mine, since it creates the concept of material recovery curve per level. This was fundamental to create a PCSLC model and be able to replicate the tonnage extracted and the grades reported at the mine.One of the main results in this thesis is the understanding of the gravity flow in SLC method and the demonstration of the benefit to use a recovery curve per level as a main driver for mixing modeling. The calibration of the mixing model in PCSLC was successful and the most important part is the guideline created to use in PCSLC to get reliable results in the prediction of grades and dilution for production scheduling purposes.

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On the flow and beaching behaviour of sub-aerially deposited, polymer-flocculated oil sands tailings : a conceptual and energy-based model (2013)

This thesis presents the background, observations, and analyses performed during an investigation of the flocculated mature fine tailings (MFT) technology at the Suncor Energy Oil Sands Tailings Reduction Operation (TRO) in Fort McMurray, Alberta, Canada.The sub-aerial flow and deposition of flocculated MFT on a sloping beach can be described in the context of a rheology-energy conceptual model. The conceptual model, or flow map, can provide deposition cell designers and operators with a useful framework for managing beach development in a sub-aerial deposition cell. Observations during field work resulted in the development of the flow map and the establishment of numerical boundaries for the transitions between flow types. Practical applications for this new conceptual model are provided.The database of fully-developed beach surveys presented in this thesis demonstrates the trend of strongly concave profiles. This concavity has significant repercussions for tailings management and cell design, and cannot be ignored when calculating storage volumes. Furthermore, it is shown that the McPhail (1995) stream power model provides a robust tool for estimating ultimate beach profiles developed from the sub-aerial discharge of polymer-flocculated MFT. The model has been validated against field-scale measurements and is consistent with the rheology-energy conceptual model developed to describe the flocculated MFT flow behaviour.

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Foundations in the mining industry : characteristics, structure and exit strategies (2012)

Community social investment (CSI) is often part of the sustainable development efforts for mining companies, especially in remote areas or in developing countries. One vehicle for CSI is to establish a foundation, trust or fund (FTF). This thesis explores the FTF structures, with specific focus on exit strategies. Research focused on questionnaire respondents from twelve mining companies or foundations, twelve interviews conducted with representatives of companies, foundations and industry, and various public documents. A mixed-method qualitative approach was taken in analysis, focusing on trends emerging from the data, especially in the interviews conducted by the researcher.There are various types of FTFs, with existing typologies defined by programmatic method, focus or key attributes. In this research, the author focused on considering FTF types by closure or exit strategy, and presenting some of the key attributes in relation to these exit strategies. The key attributes that should be aligned with the exit strategy include the financing mechanism, the project selection method, and the governance and management functions. Although it is not yet standard practice within the industry, designing the FTF structure for closure is considered leading practice. Currently FTFs tend to plan for closure on a project-by-project basis.Transition is a natural feature of FTFs, whether due to the progression of mine life cycle stages, changes in government, local capacity, or other factors. Strategic plans help to smooth these transitions and facilitate the closure process. Foundations, trusts and funds provide a unique opportunity to build specialized expertise in an independent structure from the supporting mining companies. This independent structure can facilitate the development of partnerships with multiple stakeholders, an area which was identified as significantly contributing to sustainable results as the partners pool resources and expertise. The independent structure of an FTF also tends to facilitate the involvement of the community, without which community social investment struggles to find true ownership and sustainability.While mining companies should consider the pros and cons of the FTF structure relevant to the local context and business objectives, the FTF structure offers distinct advantages as a vehicle for CSI.

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Modeling multidimensional large strain consolidation of tailings (2012)

Mine sites generate large volumes of tailings materials, requiring storage in tailings impoundments. Large strain consolidation of tailings materials represents a major factor in determining how a tailings impoundment will behave over time. Being able to accurately model these phenomena ensures that the effects of long term consolidation may be considered in the design of future tailings impoundments. SoilVision Systems has created an internal version of the SVOFFICE 2009 finite element modeling software capable of evaluating these scenarios. Prior to this research, preliminary benchmarks have been established, but the software had not yet been applied to multidimensional scenarios to benchmark the results. The goal of this research was to first benchmark the software against literature case studies. Following this, the software could then be applied to multidimensional tailings impoundments to study how the modeling could be performed and what factors require further consideration. Benchmarking of the software showed that the software is capable of recreating a wide variety of case studies from the literature. Further test were used to determine the effects of various material parameters on the material. Applications to multidimensional scenarios show that the software is capable of analyzing a wide variety of scenarios and considering numerous factors not found in other software packages. While the software does require additional functionality, it has been found to be a viable tool for examining multidimensional consolidation effects in tailings impoundments.

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The role of employee capacity building in reducing mining company-community conflicts in Peru (2011)

Based on expenditure, Peru is the third destination worldwide in exploration. Peru is also the world’s leading producer of silver, second in copper and zinc, and sixth in gold. However, mining conflicts in Peru have spread considerably over the last decade. The Peruvian government has not been able to successfully promote the benefits of the industry to local communities, nor has it been able to effectively address grievances. Mining companies will need to explore new initiatives to acquire and retain the social license to operate, as well as strengthening the social capital needed to keep mining in a country with proven mineralogical riches and a historic mining culture. This research project explores the opinions and experiences surrounding a resource often overlooked by companies: the human resource. In order to gather information regarding initiatives to improve company-community relations, more than 30 surveys were conducted among professionals working at mines in the Peruvian mining industry. This research project also explored the effectiveness of training mining personnel in community affairs as an initiative to improve relations with local communities. The results showed that mining company employees acknowledge that they play an important role in the development of company-community relations. They consider that the deterioration of such relations may also originate in the way employee-community relations are managed. The research also showed that employees are willing to develop capacities to effectively interact with local communities. Mining company employees provided their recommendations in order to contribute to success in a location where cultural differences have not been properly considered. Finally, participants also expressed their opinions regarding organizational cultures and the impact of management commitment (or lack thereof) on community affairs.

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The application of social media in the mining industry (2010)

The current discourse on public engagement in the mining industry revolves around legislated processes that drive communication and information sharing with interested parties. This discourse neither aligns with modern tools for communication nor with the reality of a highly networked society that use social media to facilitate dialogue. This thesis addresses the gap between traditional communication processes in the mining industry and social media tools that create opportunities for dialogue and information sharing. The research used a qualitative and mixed method approach to data collection. Twelve social media websites were observed to assess the extent of mining-related dialogue, and 41 interviews were conducted with representatives from the public, private, academic and civil sectors to learn about the challenges and opportunities of using social media. The interviews found that 62% of respondents were using social media tools; the most popular applications were blogs, followed by social networking platforms. These platforms are being used for outreach to established supporters and networks. Industry’s use of these platforms mimics their public relations and marketing messaging approaches, whereas civil society is able to generate dialogue on a number of topics through authentic disclosure of information. Government departments have been hesitant to incorporate social media tools as they struggle to align them with regulatory structures while also presenting an authentic and credible voice. Many respondents were using a trial and error approach to implement social media, despite having identified risks of using them. Risks and challenges include the possibility of losing control of messaging and wasting time on unproven communications technology. While some mining companies are adopting social media applications to conduct public outreach, these tools have not been explicitly used for stakeholder engagement. Case studies show how mining stakeholders use social media tools and their experience provides a foundation for strategic recommendations. This research demonstrates that social media is being used for specific purposes by mining stakeholders, although there is hesitancy around perceived risks of online dialogue.

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