Large-scale Mining Operations Research Articles

Predicting the Geomechanical Properties of Hard Rocks Using Analysis of the Acoustic and Vibration Signals During the Drilling Operation

Evaluating the physical and mechanical properties of materials such as rock or concrete is among the most significant issues in engineering studies. Measurement of the properties of the rocks either in the laboratory or in the field needs the standards and specific methods. Also, most of these tests need time and a large number of rock samples. Therefore, finding a method that can be accurately, quickly, and reliably predict the properties of rocks will provide a great advance in the quality of studies before or during the projects. The purpose of this paper is to find a method for predicting and determining the geomechanical properties of hard rocks during the drilling operation. For this purpose, after the preparation of the rock samples, acoustic and vibration signals propagated during the drilling process were recorded and processed. After analysing the acoustic and vibration signals, statistical analysis for investigation of the relationship between the properties of the rocks and the acoustic parameters was performed. Sound Pressure Level (SPL), First Dominant Frequency (FDF), and Vibration Level (VL) were selected as predictor variables for measuring and predicting Uniaxial Compressive Strength (UCS), Brazilian Tensile strength (BTS) and Schmidt rebound number (SRN) by multivariable regression. Results of statistical analysis show that there is an acceptable correlation coefficient between rock properties and properties of acoustic and vibration signals of the rock drilling operation. Hence, this method can be used as a relatively inexpensive, non-destructive, reliable and real-time method in large-scale mining or civil operation for predicting the rock properties.

Artisanal Gold mining in Las juntas de Abangares, Costa Rica: Approaches and barriers to achieving sustainability objectives

Gold has been mined in the area surrounding the small town of Las Juntas de Abangares in Northwestern Costa Rica for over 100 years. Originally through large-scale foreign-based industrial mining operations, now gold is exclusively mined and processed by local, artisanal small-scale gold miners. With the increasing price of gold and the lack of alternative income generating activities over the past 20 years now more than 400 families in this region depend on artisanal gold mining as their only source of income. In this paper, I explore historical and current practices; and opportunities and barriers to achieving sustainability objectives regarding this mining activity within the context of the Sustainable Development Goals. Potential policy, technical, and community development efforts that protect the environment and public health while maintaining or improving income generation for this impoverished community are explored. These include the introduction of mercury-free processing techniques that also increase yield, the formation of cooperatives, vertical integration and product development, the development of gold related tourism, and sustainability certification programs.

Brown Coal in Victoria, Australia and Maddingley Brown Coal Open Cut Mine Batter Stability

Brown coal is young, shallowly deposited, and widely distributed in the world. It is a fuel commonly used to generate electricity. This paper first reviews the resources and characteristics of brown coal in Victoria, Australia, and its exploitation and contribution to the economy or power supply in Victoria. Due to the shallow depth of the brown coal seam, e.g. very favorable stripping ratio, open pit mining is the only mining method used to extract the coal at low cost for power generators. With the large-scale mining operations, cases of batter failure were not rare in the area. From the comprehensive review of past failures, overburden batter tends to fail by circular sliding, coal batter tends to fail by block sliding after the overburden is stripped due to a weak water-bearing layer underneath the coal seam and tension cracks developed at the rear of the batter, and batter failure is typically coincided with peak raining seasons. Secondly, the paper reviews the case study of Maddingley Brown Coal (MBC) Open Cut Mine batter stability, including geology, hydrogeology, and hydro-mechanically coupled numerical modelling. The modelling employs three-dimensional finite element method to simulate the MBC northern batter where cracks were observed in November 2013. The comprehensive simulation covers an overburden batter, a brown coal batter, two rainfall models, and a buttressed batter. The simulated results agree well with observed data, and it is found that the rainfall at the intensity of 21mm substantially lowered the factor of safety of the coal batter.

Identification of digital technologies and digitalisation trends in the mining industry

Digitalisation in mining refers to the use of computerised or digital devices or systems and digitised data that are to reduce costs, improve business productivity, and transform mining practices. However, it remains increasingly difficult for mining companies to decide which digital technologies are most relevant to their needs and individual mines. This paper provides an overview of digital technologies currently relevant to mining companies as presented and discussed by mining journals, the media and insight reports of leading consultancy agencies. Relevant technologies were systematically identified using text-mining techniques, and network analyses established the relations between significant technologies. Results demonstrated that currently 107 different digital technologies are pursued in the mining sector. Also, an analysis of the actual implementation of digital technologies in 158 active surface and underground mines reveals a limited uptake of digital technologies in general and that the uptake increases with the run-of-mine production. Large-scale mining operations appear to select and apply digital technologies suitable to their needs, whereas operations with lower production rates do not implement the currently available digital technologies to the same extent. These minor producers may require other digital transformation solutions tailored to their capabilities and needs and applicable to their scale of operations.

Cajamarca: Mapping (Post)Mining Palimpsests of the Peruvian Andes

Mining, in addition to other human activities and natural phenomena, has repeatedly reshaped the landscapes of the Peruvian Andes. Long-standing, significantly modified and new Andean landscapes have resulted in a complex reading of the ‘land as palimpsest’ (Corboz, 1983). In recent decades, large-scale modern mining has disturbed headwater landscapes and broader Andean ecologies, as exemplified in Cajamarca’s gold mines. This article critically reads past and present spatial transformations induced by gold mining in the headwaters of the Cajamarca Basin. Through archival documentation, fieldwork and interpretative cartography, it analyses the large-scale surface mining operations in Cajamarca from 1993 to 2020, as well as their impact on downstream rural and urban ecologies. A cross-scalar mapping investigation discloses the spatial-ecological outcomes of twenty-seven years of mining (and closure) operational procedures. As a conclusion of the palimpsest reading, a design-research question is posed as to how Cajamarca’s post-mining landscapes can be opportunely premeditated. It hypothesizes that, already during exploitation, the post-mining landscapes can be consciously constructed by an intelligent manipulation of mining procedures and create a layer of the territory that is more robust. Environmental reconstruction after mining closure recreates a pseudo-natural environment that supposedly erases the traces of mining and restores natural condition—literally back to nature, with no cultural trace. In this regard, reconstruction is merely theoretical since the repairing to a natural state would mean no palimpsests. However, despite the most imaginative and ecological repair, the territory remains a mega palimpsest, cruelly violated and disrupted. Therefore, at best, the proposition can be to build a cultural, consciously conceived and tailored post-mining landscape, merging mining and post-mining landscape construction into one movement, where the remaining (palimpsest) is part-and-parcel of the newly constructed.

Corporate human rights due diligence and assessing risks of sexual violence in large-scale mining operations

ABSTRACT A growing body of literature associates large-scale mining with specific impacts on and risks for women, including systemic sexual violence. Mining companies themselves have been accused of involvement in rape and sexual assault in their operations. I focus on two international instruments developed to regulate the human rights impacts of business activities, and analyse whether the notion of human rights due diligence upon which they rest constitutes an effective tool to identify and prevent mining-related risks of sexual violence. I contend that both instruments portray sexual violence as an exceptional risk, thus discouraging mining companies from considering it in their due diligence processes. I ultimately argue that a gender approach to human rights due diligence, stronger international guidance and better stakeholder engagement would allow mining companies to develop due diligence strategies that effectively consider the specific experiences of women.

The land reclamation concept as a key factor in solving the environmental problems of coal mining regions

The impact of coal mining in Kuzbass on the ecosystem of the region is studied in the article. Large-scale mining operations have led to land disturbance over large areas. The coal industry development program, which provides for a significant increase in production, will further aggravate the identified problem. There are a lot of reclamation mechanisms, they must be implemented comprehensively, be high-tech. Large-scale disturbance of land resources, and land retirement, its pollution and littering are the most significant problems requiring a primary solution. The mechanism of state and regional legal regulation of disturbed land reclamation is proposed. Improving the quality of reclamation will be facilitated by the development of a strategy for the environmental remediation, which would be included into the Concept for reclamation of disturbed lands.

Voces Mineras: Clarifying the future of artisanal and small-scale mining collaborations

Using a creative capacity building (CCB) framework, co-design workshops among artisanal and small-scale gold miners, government officials, NGO representatives, and academics can provide an effective mechanism to identify pressing needs and desires of miners and operators towards formalization. As recently implemented in Peru, one of these workshops identified the need for a single forum (association) to allow artisanal and small-scale miners to represent their voice in front of government and large-scale mining operations and the need for a streamlined simple process for formalization that included mining, environment, health, safety, and employment considerations. A first step towards the single forum was taken with the creation of a social media outlet that allows participants to voice their concerns and share information. Future workshops are needed to cement the creation of the forum and provide specific recommendations for the streamlining of the formalization process.

Development of cemented paste backfill based on the addition of three mineral additions using the mixture design modeling approach

Large-scale mining operations have produced large amounts of iron ore tailings (IOT) and stopes. IOT will cause air and water pollution, and open stopes may lead to surface subsidence or even geological disasters. Using cemented paste backfill (CPB) which is composed of IOT and binders to fill stopes can well solve the above two problems. Based on the alkali-activated theory, slag and desulfurized gypsum are selected as basic materials, cement (C), lime (L) and silica fume (SF) are chosen as mineral activators. Mixture design, an experimental design method, is used to model the effect of C, L, and SF on the spread, compressive strength and shrinkage ratio of CPB. The models are helpful to know the interaction between three mineral additions. Results show that the optimal spread is reached when the content of C and SF are 8% and 5%, respectively in C-SF binary system. The compressive strength at 3,7,28 days increase and then decrease with the increase of each admixture in L-SF and C-SF binary system. The maximum compressive strength at 28 days is 0.83 MPa, which can provide support for the adjacent mine structure and keep a stable working platform for miners. The shrinkage ratio decreases with the increase of SF content and increases with the increase of C content in C-SF binary system. However, in C-L binary system, the shrinkage ratio increases with the increase of L or C content. The minimum shrinkage ratio is 1.16% (corresponding to the proportion of 7% of C, 3% of L and 5% of SF). Finally, the morphology of hydration products at different ages are compared by scanning electron microscopy (SEM). The results show that the derived models are very effective in explaining the influence of three mineral admixtures on the workability and mechanical property of CPB. This design method is a useful tool to select the optimal mix proportions to achieve engineering objectives and reduce cost.

Terrestrial Ecosystem Impacts of Sulfide Mining: Scope of Issues for the Boundary Waters Canoe Area Wilderness, Minnesota, USA

Large-scale metal mining operations are planned or underway in many locations across the boreal forest biome in North America, Europe, and Asia. Although many published analyses of mining impacts on water quality in boreal landscapes are available, there is little guidance regarding terrestrial impacts. Scoping of potential impacts of Cu-Ni exploration and mining in sulfide ores are presented for the Boundary Waters Canoe Area Wilderness (BWCAW), Minnesota USA, an area of mostly boreal forest on thin soils and granitic bedrock. Although the primary footprint of the proposed mines would be outside the BWCAW, displacement and fragmentation of forest ecosystems would cause spatial propagation of effects into a secondary footprint within the wilderness. Potential negative impacts include disruption of population dynamics for wildlife species with migration routes, or metapopulations of plant species that span the wilderness boundary, and establishment of invasive species outside the wilderness that could invade the wilderness. Due to linkages between aquatic and terrestrial ecosystems, acid mine drainage can impact lowland forests, which are highly dependent on chemistry of water flowing through them. The expected extremes in precipitation and temperature due to warming climate can also interact with mining impacts to reduce the resilience of forests to disturbance caused by mining.

Hirashasan: Governing diamonds in Central India

Hirashasan is the term used for governance of diamond mining and trade – with a small bureaucracy and an exclusive set of rules and regulations – by the district administration of Panna in the state of Madhya Pradesh in India. Diamond mining in Panna encompasses diverse extractive practices that range from fully mechanised large-scale mining operations owned by the state, to small-scale and semi-mechanised mining carried out by farmers and landowners in groups, to individuals carrying out seasonal and part-time mining of diamonds in an artisanal manner. Based on an ethnographic study was undertaken from September 2016 to April 2017, we argue that Hirashasan has created an “extractive assemblage” that comprises four genres of mining and production systems: large-scale, small-scale, licensed artisanal and unlicensed artisanal. This assemblage is a product of historical, cultural and geographical contingencies as much as place-specificities, and does not lend itself to a single mode of governance. Mineral resource governance in a particular place, therefore, necessitates understanding and internalising the variegated and pluri-form extractive assemblages, such as that of the diamond economy in Panna.

Flexible Corporate Social Responsibility: Evidence from A Chinese Company in Africa

In the emergent field of corporate social responsibility (CSR) studies, there has been growing interest in understanding and practice in particular sociocultural contexts in developing countries. As a rising force of overseas investment, Chinese enterprises are increasingly encountering local challenges stemming from CSR. This paper is an ethnographic study of a Chinese gold mining company in contemporary Ghana in regard to CSR knowledge and practice. It investigates how multiple actors negotiate understandings of CSR in a Chinese gold mining company as compared with an American gold mining company. The research was conducted near the mining sites located in Odumase of Eastern region and Juaso of Ashanti region of Ghana during 2016. Its CSR practice was compared with that of the Akyem mining site operated by an American mining corporation. Through ethnographic fieldwork, this paper contextualizes the construction of diverse understandings of CSR among multiple actors in this Chinese investment project. It also demonstrates how both formal and informal engagements with affected communities constitute its CSR practice. Based on a case study and comparison with an American mining company, this paper finds that large-scale Chinese mining operation in Africa is receptive of the concept of CSR but its practice is very unique.

Gold in Ghana: The effects of changes in large-scale mining on artisanal and small-scale mining (ASM)

Two scales of gold mining operations, artisanal and small-scale mining (ASM) and large-scale mining, have operated side by side in Ghana for decades. In the past, the two co-existed on the same mineralised land without much contact or conflict, as large-scale mining occurred underground and ASM operated mainly on the surface. With the former’s transition from an underground labour-intensive mining operation to capital-intensive surface activity, however, opportunities for wage employment have reduced leading to labour retrenchment. Using an informalisation theoretical framework, and drawing on fieldwork conducted in the three gold mining towns of Obuasi, Prestea and Kenyasi, this paper explores how the interface between large-scale mining and ASM has evolved. It is shown how the loss of wage employment opportunities in large-scale mining has contributed to the proliferation of illegal ASM operations. As large-scale surface mining operations have reduced access to mineralised land by ASM, the latter have encroached on to the concessions of the former resulting in conflicts between these parties. It is ASM rather than large-scale mining, however, that is sustaining local economies in Ghana. As the economic well-being of mining towns is linked largely to the fortune of their mining economies, it is imperative that an innovative approach is adopted by the state in addressing the need for ASMs to access mineralised land.

Zones of entanglement: Researching mining arenas in Melanesia and beyond

The social relations of resource extraction and the settings where these activities occur can be understood as ‘zones of entanglement’. Our notion of entanglement draws upon two interrelated bodies of thought on interfaces and conjunctures that allows us to emphasise certain material, historical and relational qualities found in contemporary mining arenas. This is no easy terrain for researchers, and engagement is fraught with difficult ethical, methodological and ontological challenges. In this paper we reflect on a selection of ‘positional’ alternatives from recent studies of large-scale mining. We argue that the complexity of the social landscape that individuals and institutions encounter when they become involved in research, advocacy or consultancy around large-scale mining operations demands a set of reflexive dialogical strategies that favour the voices of a diverse cast of actors and their conflicting interests, and avoids portraying local encounters in simple, binary terms. We also highlight the value of mobility as a strategic resource for anthropologists and other social scientists: unpacking, or unravelling the elements contained within these zones of entanglement will require openness to ethically grounded and serially positioned forms of engagement over time.

Variation in microbial community structure correlates with heavy-metal contamination in soils decades after mining ceased

Microorganisms play vital roles in Earth's biogeochemical cycles. Identifying disturbances in microbial communities due to anthropogenic contamination can provide insights into the health of ecosystems. Picher, Oklahoma, was the site of large-scale mining operations for Pb, Zn, and other heavy metals until the mid-1950s, operating within the Tri-State Mining District (TSMD) of Missouri, Kansas and Oklahoma. Although mining ceased decades ago, high concentrations of heavy metals (>1000 ppm) remain in area soil and water systems. Previously, we mapped metal concentrations on samples collected from mine tailings in Picher and along cardinal-direction transects within an 8.05-km radius of the town. To elucidate changes in microbial community structure due to regional metal contamination, 16S rRNA gene sequences and qPCR calculations of total Bacteria and Archaea were analyzed against these metal concentrations. Bacteria were negatively and significantly correlated with Pb, Cd, Zn, and Mg; however, Archaea was only significantly and positively correlated with pH. Illumina sequencing of 16S rRNA genes showed significant differences in microbial communities of chat and west transect samples. Comparison of soil chemistry with community structure indicated that Al, Pb, Cd, and Zn significantly impacted community composition and distribution of individual OTUs. Mapping the distribution of heavy-metal contamination and microbial communities in these soils represents the first step in understanding effects of long-term, heavy-metal contamination at a basic trophic level.

Locals’ attitudes toward artisanal and large-scale mining—A case study of Tambogrande, Peru

The recent unopposed proliferation of artisanal gold mining (AGM) in towns that previously rejected large-scale mining (LSM) in Andean countries poses a thorny question: Why do locals respond differently to mining activities at different scales? To explain the basis for opposition or tolerance to mining activities, the paper develops a comparative study of local communities’ perceptions of LSM and AGM. Through extensive fieldwork in the area and collection of qualitative evidence from surveys, interviews, and ethnographies, the paper revisits the case of Tambogrande (Peru) 15 years after the resistance against LSM operations in the light of the recent proliferation of AGM in the same area. The paper finds that AGM faces less resistance because it is considered more compatible with the existing social order, which hinges on personal ties and strong relationships of trust. By contrast, LSM is far removed from local dynamics and it is perceived as an imposition that would divide and displace the community. Although economic and environmental factors are in fact a cause for concern for local communities, social considerations usually take priority.

A community-based intervention to build community harmony in an Indigenous Guatemalan Mining Town

ABSTRACTThe presence of large-scale mining operations poses many threats to communities. In a rural community in Guatemala, community leaders were motivated to address divisiveness and local conflict that have been exacerbated since the arrival of a mining company in the region. Prior research by our team identified spiritual and cultural strengths as important sources of strength and resilience in the community. We piloted a community-based intervention centred on spiritual and cultural practices in the region, to address divisiveness and build community harmony. One hundred and seventeen participants from over 18 villages in the municipality participated in the workshops and follow-up focus groups. Community leaders facilitated the intervention and partnered with the academic researcher throughout the research process. Overall, community members and facilitators expressed satisfaction with the workshop. Further, our analysis revealed three important processes important to the development of community harmony in the region: (a) mutual recognition and collectivisation; (b) affirmation of ancestral roots and connections to Mother Earth and (c) inspiring action and momentum towards solutions. These mechanisms, and the socio-political contexts that undermine them, have important implications for how global health programmes are developed and how collective processes for well-being are understood within an inequitable, conflict-laden world.

‘The miskeet tree doesn't belong here': shifting land values and the politics of belonging in Um Doum, central Sudan

The new-yet-old phenomenon of ‘land grabbing’ is often characterized in media and NGO reports as an unstoppable tidal wave hitting the African continent. Yet, as Anna Tsing reminds us, global power rarely operates without friction (2005). From the negotiation of deals that give investors access to land, to its transformation for use in large-scale agribusiness or mining operations, the process of ‘grabbing land’ is rarely unilinear and always historically situated. While some land investments materialize, others run into crisis. In April of 2013, a deal was struck between government elites and a Saudi businessman over customary land in Um Doum – a peri-urban community in central Sudan – that had been utilized by local families for generations. Community members immediately mobilized against the deal using civil disobedience tactics and media advocacy, forcing government officials to reverse the land deal and to initiate negotiations aimed at locally redistributing the land through registration and titling. Despite the apparent success of this resistance to a large-scale land deal, this article argues that the subsequent programme of land titling nevertheless represented the extension of state control over land tenure and generated profound change in gendered and ethnic social relations and land values. As such, the Um Doum negotiations served to restructure, rather than reverse, the process of land dispossession. It concludes that even when large-scale land deals are renegotiated in favour of those dispossessed, it is important to consider the ways in which ‘negotiability’ in land rights (Peters, 2004) can benefit elites and exacerbate existing social divisions by intensifying forms of inequality in land access.

Brazil's worst mining disaster: Corporations must be compelled to pay the actual environmental costs.

In November 2015, a large mine-tailing dam owned by Samarco Corporation collapsed in Brazil, generating a massive wave of toxic mud that spread down the Doce River, killing 20 people and affecting biodiversity across hundreds of kilometers of river, riparian lands, and Atlantic coast. Besides the disaster's serious human and socioeconomic tolls, we estimate the regional loss of environmental services to be ~US$521 million per year. Although our estimate is conservative, it is still six times higher than the fine imposed on Samarco by Brazilian environmental authorities. To reduce such disparities between estimated damages and levied fines, we advocate for an environmental bond policy that considers potential risks and environmental services that could possibly be impacted by irresponsible mining activity. Environmental bonds and insurance are commonly used policy instruments in many countries, but there are no clear environmental bond policies in Brazil. Environmental bonds are likely to be more effective at securing environmental restitution than post-disaster fines, which generally are inadequate and often unpaid. We estimate that at least 126 mining dams in Brazil are vulnerable to failure in the forthcoming years. Any such event could have severe social-environmental consequences, underscoring the need for effective disaster-management strategies for large-scale mining operations.

Quantitative analysis of the extent of heavy-metal contamination in soils near Picher, Oklahoma, within the Tar Creek Superfund Site

The Tri-State Mining District of Missouri, Kansas and Oklahoma was the site of large-scale mining operations primarily for lead and zinc until the mid-1950s. Although mining across the area has ceased, high concentrations of heavy metals remain in the region's soil and water systems. The town of Picher, Ottawa County, OK, lies within this district and was included in the Tar Creek Superfund Site by the U.S. Environmental Protection Agency in 1980 due to extensive contamination. To elucidate the extent of heavy-metal contamination, a soil-chemistry survey of the town of Picher was conducted. Samples (n = 111) were collected from mine tailings, locally known as chat, in Picher and along cardinal-direction transects within an 8.05-km radius of the town in August 2015. Samples were analyzed for soil pH, moisture, and metal content. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analyses of 20 metals showed high concentrations of lead (>1000 ppm), cadmium (>40 ppm) and zinc (>4000 ppm) throughout the sampled region. Soil moisture content ranged from 0.30 to 35.9%, and pH values ranged from 5.14 to 7.42. MANOVA of metal profiles determined that soils collected from the north transect and chat were significantly different (p < 0.01) than other sampled directions. Lead, cadmium and zinc were correlated with one another. These data show an unequal distribution of contamination surrounding the Picher mining site. Mapping heavy-metal contamination in these soils represents the first step in understanding the distribution of these contaminants at the Picher mining site.