Abstract

Claims about resource sustainability abound in business communications. Yet, little do we know about how such claims are enabled amidst ongoing controversy of industrial and organizational benefits. Here, we propose to approach these claims through the concept of organizational sustainability identities (OSIs), which are claims serving as sustainable identifiers, and whose meanings are co-constructed by stakeholders. We assess how a new voluntary sustainability standard (VSS) of the metals industry is driven by a mission to enable an OSI for the product of its members, such as that their metal ‘is’ ‘responsible’, and how the members attain this through the structural conditions set by the new scheme. We present an exploratory case study that is based on data from a content analysis of standards texts and thematic analysis of stakeholder interviews. We find that VSS enable OSIs through a) an advanced performance rationale, b) the creation of a community of practice, c) members’ perceptions of altered power relations among value chain stakeholders, and d) the facilitation of a platform to keep defining the ‘responsible metal’. We contribute to the discussions of VSS emergence and their effectiveness, for which we highlight the prolificness of the OSI concept and introduce a novel comparative method of provision type analysis to capture the developments of performance rationales.

Introduction

Claims about natural resources ‘being’, for instance, ‘responsible’ abound as a part of the public relation strategies of contemporary business. Examples of such claims are descriptions of metals as ‘green’, ‘eco-friendly’, ‘responsible’, or ‘sustainable’. The making of such claims usually presupposes that businesses follow practices understood by stakeholders to represent a state-of-the-art for social and/or environmental engagement (Tröster and Hiete, 2019). There is also widespread acknowledgement that claims about the responsible nature of business result from negotiations and contestations between stakeholders (Azevedo, in press; Frostenson et al., 2022; Hatch and Schultz, 1997, 2002; Kennedy et al., 2012; Kouamé et al., 2022; Levy et al., 2016; Scott and Lane, 2000), while such claims affect an organization’s strategy and legitimacy building (Huemer, 2010; Napier et al., 2023). What is further noteworthy is that there has been a change regarding the foci of such claims; from an emphasis on major upstream resource producers to a value chain perspective that includes also downstream processors and traders (Bleischwitz et al., 2012; Deberdt, 2022; Liu et al., 2022; Mancini et al., 2021; Sauer and Seuring, 2017; Tröster and Hiete, 2019). Yet, what has remained so far underexplored is the role of mediators among stakeholders, such as voluntary sustainability standards (VSS), in the enabling of claims of ‘being’ ‘responsible’ of natural resources, and how that enabling role constitutes the added value of a new VSS for its adopters.

In this article, we approach the phenomenon of claims about metals ‘being’ ‘responsible’, and their enabling by VSS, through the conceptual lens of organizational sustainability identities (OSIs). OSIs are a recent emerging concept within management and organization studies (Bouncken et al., 2022; Frostenson et al., 2022; Hamilton and Gioia, 2009; Imbrogiano and Steiner, 2022), that directs scholarly attention to the understanding of ‘sustainable’ ‘being’. OSIs are presented as a positive state of an organization regarding perceived or actual environmental or social effects of operations or products (Imbrogiano and Steiner, 2022). OSIs are thus focused on the organizational level, yet also apply to statements about a state of ‘being’ of an organization’s product(s), as these statements principally serve to respond to questions about ‘Who are we as an organization?’ or ‘(As) Who do we want to be (seen) as an organization?’ (Albert and Whetten, 1985; Gioia et al., 2000). As we will highlight in this study, VSS are indispensable for metals ‘being’ (seen as) ‘responsible’. While VSS and reasons of their emergence have been studied from multiple angles in the governance literature, their centrality in providing the grounds to enable ambiguous OSI claims has not yet been raised.

Conclusion

This paper set out to explore how VSS enable the use of OSIs for business communication, in spite of a diversified field of already existing standards with a similar portfolio of sustainability ambitions. Our study of a new VSS in the metals industry reveals four structural conditions that enable OSIs: the support for industry stakeholders in creating a community of practice; the perceived alterations of power relations within the value chain; the promotion of a renewed performance rationale for the sustainability ambitions of the industry; and the provision of a discursive platform that supports the ongoing translation of OSI into business practices. These findings are important for any new attempt of VSS emergence, as leaving one of these structural conditions apart could undermine the effective establishment of OSIs for industry.

The nature of our study also provides opportunities for researchers and practitioners to revisit and expand its findings. Firstly, due to this research being focused on a singular case, there is value in taking a broader look at the continuing fragmentation of VSS in the metals and other industries. Secondly, we have focused our analysis of stakeholder perceptions and experiences mainly on the context of European businesses of the metal value chain. Samples with more intercontinental representation, or foci on other regions of the world, could add further novelties to apprehending standard emergence and their OSI enabling role amidst crowded standard fields, as well as the dynamics these amidst public pressure. Thirdly, in terms of the interpretation of the data, we remained concentrated on the data and its applicability to the MSS case in the analysis of stakeholder perceptions. Regarding the findings of changing performance rationales and MSS constituting a discursive platform for the industry, there are potential opportunities in taking rather sociological perspectives on the creations of OSI meanings for sustainable development and the altering of performance rationales globally (Imbrogiano, 2021). Lastly, we see also, a need for ethnographic insights on VSS emergence, as such observer and participant accounts are scarce (e.g., Hopkins and Kemp, 2021), yet it would help us further in understanding the internal dynamics behind the formulation of provisions, their implementation, and verification of OSIs.

Abstract

     The use of renewable energy technologies is a key factor for sustainable development but their selection from several alternatives is a difficult task that relies on the careful assessment of relevant criteria. While Multiple Criteria Decision Making (MCDM) methods have been used successfully in various renewable energy technology selection problems, the decision process becomes more challenging when preferential judgements are made on the basis of non-homogenous and imprecise input data, and when there is uncertainty due to disparities among decision makers. This paper presents a hybrid MCDM method capable of overcoming these problems by taking into account quantitative and qualitative data under a probabilistic environment in the context of group decision making. In this method, qualitative data is fuzzified and used along with quantitative data to develop a hybrid model. A coefficient factor allows decision makers to vary the weight of each quantitative model so that the resultant criteria weights and overall alternatives’ scores consider both subjective considerations and objective information. An example is presented to showcase the usability of the method developed for ranking and evaluating renewable energy technologies in the mining industry. In addition, the impact of different coefficient factors on the final results was assessed by means of sensitivity analysis. The results indicate that the method developed is able to minimise the loss of valuable objective information, caused by the subjective bias of qualitative weights during the evaluations, by adjusting the coefficient factors of the hybrid model during the calculations.

Introduction

     Energy-generating technologies that depend on non-renewable fossil fuels result in significant environmental challenges, such as increasing greenhouse gas (GHG) emissions, which lead to climate change (Disli et al., 2016, Li et al., 2020). In response to these challenges, it is important to better exploit renewable energy technologies (e.g. wind and solar), which are low-cost, clean and sustainable (Cunden et al., 2020, Dincer, 2000).

     The selection of renewable energy technologies is a complex and multidisciplinary problem that mainly refers to the performance of the technologies concerning multiple criteria such as environmental, social, technical and economic (Wu et al., 2018). In order to evaluate holistically and select the technologies that have a higher performance appropriately, decision makers need to have methodological tools that incorporate both quantitative and qualitative analyses of the multiple criteria. Decision makers should, therefore, make use of the best tools available to evaluate the performance criteria of renewable energy technologies. Choosing the best renewable energy technology to use among various alternatives considering conflicting criteria is thus considered a Multiple Criteria Decision Making (MCDM) problem (Büyüközkan & Güleryüz, 2017).

Conclusions

     A hybrid MCDM method was proposed and was applied to the selection of renewable energy technologies in the mining industry, which faces an increase in energy demand as high grade ores are depleted and the demand for metals and minerals, including those required for renewable energy technologies, increases. The large scale of mining operations makes it very important to consider renewable energy options in order to contribute to the sustainability of the operations.

     Three renewable technology alternatives, namely onshore wind, concentrated solar power, and solar photovoltaic, were assessed taking into account both subjective considerations and objective information with respect to five sustainability criteria. The selected criteria were potential total power generation, GHG emissions, area requirement, levelised energy cost, and prospective jobs creation. An objective weight was obtained using data compiled from the literature, whereas a subjective weight was obtained from the judgements and preferences of four experts. The proposed method was then employed to compute the criteria weights and the alternatives’ scores.

Highlights

Abstract

Graphical abstract

Keywords

1. Introduction

2. Materials and methods

3. Results

4. Discussion

5. Conclusion

CRediT authorship contribution statement

Declaration of competing interest

Acknowledgments

References

Abstract

Coal is not only the main fossil fuel in China but also a pollution source. To evaluate the impact of coal production on the environment, a life cycle assessment (LCA) was conducted on the mining process of a typical coal mine in China by using the SimaPro 9.0.0 software. The Ecoinvent v3 database was used to provide the background data, and midpoint results with uncertainty information were calculated using the ReCiPe Midpoint (H) method. After normalising the midpoint results, fossil depletion was identified as the most predominant environmental impact category, followed by marine ecotoxicity, freshwater ecotoxicity, climate change, freshwater eutrophication, and human toxicity. The contribution analysis indicates that coal mining activities, consumption of steel and electricity, and mine ventilation are the key processes causing the above-mentioned environmental impact categories, which should be paid special attention. According to the sensitivity analysis, the primary countermeasures for addressing the environmental issues are to reduce the mining activities and improve the efficiency of coal mining and utilisation. In addition, the quantitative and comparative analyses show that the gas extraction production mode is beneficial to the environment. Finally, technical measures were proposed to promote green and sustainable development of the coal industry. This research can provide guidance for ensuring national energy security and promoting healthy development of the national economy.

1. Introduction

Since 2012, the annual output of raw coal in China has remained at 3.41 to 3.97 billion tonnes (SCIO, 2020). In 2020, coal accounted for 56.8% of the primary energy consumption (NBSPRC, 2021). In the next five years, coal is still expected to account for more than half of the primary energy consumption in China. It is estimated that by 2025, the coal consumption will be approximately 4.1 billion tonnes, accounting for approximately 52% (Kang, 2019). With the implementation of reforms in the energy structure, the proportion of coal consumption in China has declined, but the coal-based energy structure is expected to remain for a long time (Yuan et al., 2016). This huge energy consumption will result in a series of environmental problems, seriously threatening the ecological environment and human health. Life cycle assessment (LCA) is an effective tool for quantifying product sustainability. Because it can quantitatively describe the burden of production on the environment (ISO 14040, 2006), it has been widely used in the industrial, agricultural, and other fields, as indicated in the studies by Nabavi-Pelesaraei et al. (2019), Khanali et al. (2021), Hou et al. (2016), and Saber et al. (2021). These studies have provided important theoretical support for sustainable development. By reviewing the literature, it was found that most LCA studies on coal focused on the consumption scenario, and there were only few studies concerning production processes. Peng et al. (2021) adopted the LCA method to assess volatile organic compound emissions from coal-fired power plants in China. Tong et al. (2021) conducted a LCA on three different technical coal-to-liquid routes. Li et al. (2019) studied the impact of greenhouse gases on the life cycle of direct chemical recycling of coal for hydrogen production. Some scholars have analysed the environmental pollution caused by coal tailings (Adiansyah et al., 2017; Peng et al., 2020). The above-mentioned studies obtained many useful conclusions. Because coal production is the second largest source of emissions after coal consumption (Aguirre-Villegas and Benson, 2017), the environmental pollution due to coal production cannot be ignored.

Abstract

     Since the UN Guiding Principles on Business and Human Rights (UNGPs) were adopted by the UN Human Rights Council in 2011, they have diffused into policy frameworks, laws, and regulations across the globe. This special issue seeks to advance the interdisciplinary field of human rights research by examining key elements of the emerging transnational regime for the regulation of business and human rights. In seven original contributions, scholars from political science, law, accounting, and philosophy critically reflect on the theoretical foundations of the UNGPs, they analyze the effectiveness of implementation mechanisms and current regulatory practice, and they advance proposals for the future development of the business and human rights regime. In this introduction, we prepare the ground for these analyses, proceeding in three steps. Firstly, we argue that the adoption of the UNGPs has triggered a norm cascade which requires a distinctive, empirically oriented research agenda focusing on the scope, governance, and effectiveness of corporate human rights accountability norms and instruments. Secondly, we explain how the articles in this special issue contribute to that research agenda by addressing these themes. Thirdly, we provide an overview of the individual contributions and point out avenues for future research.

Introduction

     Following the endorsement of the Guiding Principles on Business and Human Rights (UNGPs) by the UN Human Rights Council (UNHRC) in 2011, they have become widely regarded as “the most authoritative statement of the human rights duties or responsibilities of states and corporations adopted at the UN level” (De Schutter 2013: xvii).Footnote1 Developed in a worldwide consultation process by the Special Representative of the UN Secretary-General (SRSG), John Ruggie, the UNGPs were aimed at tackling and preventing business-related human rights abuses by closing governance gaps in the largely unrestrained global market economy (Ruggie 2013: xxiii).

     Although many corporations contribute positively to realizing human rights, e.g., through job creation, the production and distribution of goods, services, and infrastructure, business activities also impact negatively on human rights. Some of the most severe and widespread forms of corporate human rights abuse include the dislocation of indigenous communities without compensation or consultation, the impairment of people’s health and safety due to unfit working conditions and destruction of the environment, the leaking of individuals’ data to government agents, the denial of freedom of expression and of association, discrimination and sexual harassment at the workplace, and sweatshops, bonded labor, and child labor in the transnational supply chains of global brands (see Bernaz 2017: 1–2; Ruggie 2013: xv-xvi; ILO 2017). However, it is rather difficult to hold business enterprises to account for human rights abuses, for various reasons.

Conclusion and Avenues for Future Research

     Taken together, the contributions to this special issue offer a rich multi-dimensional and transdisciplinary analysis of key elements of the business and human rights regime. On the one hand, they enhance our understanding of different conceptions of corporate human rights accountability, of the role and functions, the impact but also the limitations of important actors and governance instruments of that regime. On the other hand, the articles engage with these limitations in a critical yet constructive fashion, making proposals for resolving misalignments in the governance architecture and improving the effectiveness of specific instruments. In so doing, all contributions are driven by a normative commitment to strengthen corporate human rights accountability, help prevent business-related human rights abuses, and improve access to effective remedies for victims.

     Building on the insights provided by the analyses in this special issue, as well as on the research agenda set out above, we identify three main tasks for future research in the business and human rights field. Firstly, scholarship needs to further investigate the scope and substance of changes in corporate human rights conduct in response to regulatory initiatives. This is not only to differentiate good corporate practice from rhetorical adaptation or strategic attempts to co-opt the human rights discourse but also to identify the underlying conditions for the effective socialization of business actors into norm acceptance and compliant behavior. Secondly, researchers need to keep pace with the evolution of, and changing trends in, the business and human rights regime. This implies the close monitoring and critical assessment of the construction, contestation, and transformation of human rights and accountability norms, as well as of the emergence and performance of actors and governance instruments, such as National Contact Points, National Action Plans, corporate reporting standards, and due diligence laws. Here, it is important to move beyond dominant perspectives on the Global North and extend the research focus to regulatory frameworks and corporate conduct at the starting point of transnational supply chains, especially in countries of the Global South. Finally, business and human rights scholars should continue to feed their academic expertise into the policy process and public debate at the local, national, and transnational levels. With their privileged access to the insights of multidisciplinary human rights scholarship, business and human rights scholars are in an ideal position to create awareness for the complexity of the issues at stake, help building bridges between opposing actors, and contribute to the enhancement of corporate human rights accountability.

Abstract

     Although the extractive industry has contributed to the socio-economic development of many African countries, it has also led to incidences of human rights violations in many rural communities. However, the use of an evidence-based approach to search, locate, explore and synthesize the literature systematically in order to understand the nature and pattern of human rights violations within the extractive industry remains limited. Consequently, this study employs the systematic review method to determine the nature and drivers of human rights abuses within the extractive industry in Africa. Of the 791 articles retrieved from the search of the databases, 58 articles met the inclusion criteria and were included in evidence synthesis. Based on the thematic analysis conducted on the articles that met the inclusion criteria, we find that human rights abuses tend to be associated with the violation of economic, social, and cultural rights, tensions over land ownership, the loss of livelihood, and community marginalization. We conclude the study with some policy implications and suggest avenues for future research.

Introduction

     The relationship between resource extraction and sustainable development in Africa has largely remained contested. Indeed, while the World Bank and African governments/elites are often quick to point out that resource extraction contributes to the economic development of African countries, others have emphasized the negative socio-economic impacts of the extractive industry on the poor and marginalized communities (Akabzaa and Darimani, 2001; 1demudia, 2007; Tuokuu et al., 2018). As primarily an exporter of primary commodities, African governments pursuit of economic development through resource extraction with the adoption of neoliberal economic policies like the structural adjustment programs (SAPs) in the 1980s resulted in the liberalization of codes and laws that also allowed for the influx of foreign multinational corporations (MNCs) into rural communities where resource extraction tends to take place (Campbell, 2003, 2010; Tuokuu et al., 2019). As a result, in contrast to the 1960s that was dominated by African governments’ pursuit of nationalization of economic policies, the domain of opposition to MNC activities in the 1990s invariably shifted from host governments to local communities (Harvey, 2006). These contestations over the activities of MNCs in rural communities often resulted in a widespread incidence of corporate-community conflict and associated human rights violations. For example, local protests over incidences of environmental degradation associated with the operation of Shell in the Niger Delta area of Nigeria led to the displacement of the Ogoni people and the violations of their human rights (Obi, 2009). These kinds of incidences resulted in reputational damage, increased social risks, and associated costs for MNCs.

Conclusion and future directions

     The aim of this systematic review was to synthesize available evidence in the literature on the drivers and patterns of human rights abuses in the extractive industry as well as identify the common suggestions on how to address these abuses. Our analysis showed that the pattern of abuse is often in terms of the violation of economic, social, and cultural rights and the core drivers of human rights abuses are contestations over land ownership, the associated loss of livelihood, and the marginalization of communities in decision-making. Much of the suggestions on efforts to address human rights abuses in the sector focused on CSR programs, formalization of ASM, and active community engagement. The implication is that the literature on business and human rights within the extractive industry in Africa tend to focus on document incidence of human rights abuses as opposed to analyzing how MNCs seek to address their human rights obligations. Indeed, while the extant works are critical for better understanding of the nature of the human rights problems in the sector, there is a need to move towards examining the effectiveness of the different processes and practices that MNCs are putting in place to address their human rights obligations. This is particularly important given that several MNCs are increasingly signing up to global initiatives such as the UN global compact and the voluntary principles of security and human rights as means to demonstrate their commitments to become corporate human rights defenders. Put differently, future research can usefully examine the extent to which corporate commitment to such global initiatives have necessarily yielded positive human rights dividend for local communities on the ground. There is the need for future research to probe how corporate commitments to global initiatives have yielded human rights outcomes within the extractive industry in Africa. Similarly, a crucial assumption underpins the idea that it is in the best interest of MNCs to respect human rights and rely on the notion that they require social licenses to operate. While the concept of social licenses to operate has been a subject of various critiques (see Owen and Kemp, 2013), we still do not know whether and how poor communities can enforce social license to operate or what other effective alternative corporate accountability strategies that local communities might be deploying to ensure MNCs respect their human rights.

Abstract

Keywords

1. Introduction

2. Site characterization

3. Methods

4. Results

5. Conclusions

Declaration of competing interest

Acknowledgments

Nomenclature

References

Vitae

Abstract

Characterizing the permeability variation in fractured rocks is important in various subsurface applications, but how the permeability evolves in the foundation rocks of high dams during operation remains poorly understood. This permeability change is commonly evidenced by a continuous decrease in the amount of discharge (especially for dams on sediment-laden rivers), and can be attributed to fracture clogging and/or hydromechanical coupling. In this study, the permeability evolution of fractured rocks at a high arch dam foundation during operation was evaluated by inverse modeling based on the field time-series data of both pore pressure and discharge. A procedure combining orthogonal design, transient flow modeling, artificial neural network, and genetic algorithm was adopted to efficiently estimate the hydraulic conductivity values in each annual cycle after initial reservoir filling. The inverse results show that the permeability of the dam foundation rocks follows an exponential decay annually during operation (i.e. K/K0 = 0.97e−0.59t + 0.03), with good agreement between field observations and numerical simulations. The significance of the obtained permeability decay function was manifested by an assessment of the long-term seepage control performance and groundwater flow behaviors at the dam site. The proposed formula is also of merit for characterizing the permeability change in riverbed rocks induced by sediment transport and deposition.

1. Introduction

Characterizing the permeability of fractured rock formations is crucial to various subsurface applications, such as groundwater modeling (Chen et al., 2016a), oil and gas production (Mohamadi-Baghmolaei et al., 2016), thermal energy extraction (Sun et al., 2017), contaminant transport simulation (Carrera, 1993), hyporheic exchange characterization (Rozemeijer et al., 2010; Barlow and Coupe, 2012; Kiel and Cardenas, 2014), and optimization design of impervious barriers in dam engineering (Li et al., 2014, 2017; Chen et al., 2015). It has been well understood that the permeability of rocks is determined by the geometries (e.g. size, roughness and interconnectivity) of the void space consisting of pores and fractures through which the fluid transmits. The permeability could hence be highly anisotropic, heterogeneous, and scale-dependent (Snow, 1969), and varies with time as the flow geometries change. This could be induced by various processes such as rock deformation (Chen et al., 2007), damage (Chen et al., 2014), erosion (Sadhukhan et al., 2007), and particle clogging (Nowinski et al., 2011).

1- Introduction

2- Field investigation and analysis of tunnel damage through fault zone

3- Design idea of sectional tunnel lining with flexible joints through fault

4- Experimental method and apparatus

5- Model test results and discussion

6- Conclusions

References

Abstract

Tunnels often suffered severe seismic damage when passing through the active fault in high intensity earthquake area. The fault movement might be divided into fault movement and seismic motion under the strong earthquake action, and both of them could have the significant influence on the stability of tunnel structure. To improve the seismic performance of the mountain tunnel through fault, a design idea or method of the between sectional tunnel structures with the flexible joint were put forward to run through the active fault and verified or analyzed by using the shaking table test. Firstly, the typical seismic damage characteristics of the tunnel passing through the fault were analyzed after Wenchuan earthquake; secondly, the sectional tunnel linings with the flexible joint were designed in the active fault zone under the strong seismic motion, and the basic theory of this design method was presented in detail. Thirdly, the scaled model shaking table test was carried out to study the seismic performance of flexible joints of tunnels under the normal fault action, and some key parameters of the test was designed, including similarity relationship, boundary condition, sensor layout, input earthquake wave and flexible joint design. The test results showed that the joints between sectional linings could make structure localize damage rather than global damage, and compared to seismic motion, the fault movement suffered more serious damage for the tunnel structure. The tunnel lining at hanging wall was more susceptible to damage or destroy than that at the footwall under the normal fault action, and the flexible joint could adapt to the differential deformation of fault during the strong earthquake. Lastly, the dynamic response of the tunnel lining demonstrated that the upper-structure of the tunnel mainly suffered the severe seismic load, while the lower-structure might experiences the imposed deformation of fault movement under strong earthquake motion. So the design method of the sectional tunnel lining with the flexible joint would be applied to tunnel structure design to improve the adaptive deformation ability of tunnel structure through active fault.

Introduction

For a long time, the underground structure has been generally considered to suffer a lower level of damage in comparison with the surface structure during an earthquake (Asakura et al., 2007). The tunnel engineering project will be prior to be recommended due to the advantages of shortening lines, smoothing the curve of traffic lines and resisting geological hazards and earthquake disaster (Yan et al., 2020a, 2020b). However, tunnels located in the active fault area are easily vulnerable to damage by shear deformation under strong ground motion (Kun and Onargan, 2013). A lot of tunnels are designed or constructed in China Western and inevitably cross through active fault zones in mountainous area with some disasters. Therefore, the damage mechanism of the tunnel through fracture zone should be firstly demonstrated under the strong ground motion, and some seismic design method need to be studied to improve the seismic performance of the tunnel running through fault zone in the high intensity earthquake area. A number of related researches have been carried out to investigate the damage mechanism and seismic design method for tunnels crossing the fault section including numerical simulation (Anastasopoulos et al., 2008; Wang and Zhang, 2013), theoretical analysis (Zhang et al., 2018) and model tests (Su et al., 2019; Wang et al., 2019a, 2019b). Researches have shown that the most severe earthquake damage occurs in fault fracture zones, followed by tunnel entrances and public road sections (Lai et al., 2017; Yu et al., 2016).

Due to the decline of resources and a lack of motivation for development, coal cities encounter problems related to sustainable development. This paper focuses on the analysis of the capability of different types of coal cities for sustainable development. We synthetically evaluated this capability for four typical coal cities (in terms of growth, maturity, recession, and regeneration) in China from 2012 to 2016 by using the Super-SBM model. The Malmquist index is used to dynamically decompose changes in the capability for sustainable development. We also analyze the ineffectiveness distribution of the input and output indicators, and suggest directions for optimization. The results show the following: (1) the capability for sustainable development of coal cities in China was low (0.6704) and unstable overall. Major inefficiencies persist in resource allocation and utilization. (2) The four coal cities were ranked in the order of growth > regeneration > maturity > recession. (3) Technological progress was the main factor affecting changes in the capability for sustainable development of China’s coal cities. (4) Inefficiency was mainly distributed over the economic output, and inadequate economic output capability was the main factor hindering the sustainable development of most coal cities in China.

Introduction

With aims of the exploration and exploitation of coal, a number of coal cities have been established in China. They have provided rich mineral resources and raw materials for national economic construction, and have promoted local economic development and enhanced China’s regional economic strength. Of the 118 resource-based cities in the country, 63 are coal cities, accounting for 53%. Coal accounts for more than 90% of China’s primary source of energy and its proportion of consumption is over 60% (Hou et al., 2018). Coal endowment determines the importance of the coal industry in the social and economic development of China. In the foreseeable future, coal will continue to dominate the primary energy structure (Fig. 1). Coal cities play an important role in the construction of urban areas in China. They have unique laws of development in terms of the orientation, mechanism of growth, and industrial structure of cities. However, owing to the excessive economic development of coal cities in the early stages of China’s growth, the lack of scientific planning and reasonable guidance for urban development have led to conflicts among resource systems, socio-economic systems, and ecological and environmental systems that have become increasingly prominent in recent years. This has rendered the development of coal cities difficult to sustain. The serious challenges faced by these cities include a single industrial structure and lack of driving forces for economic development (Ye et al., 2011). These cities have large numbers of unemployed people and attendant pressures, which lead to low standards of living among residents and social strife. The ecology in these cities has been seriously damaged, and some mining areas also pose geological hazards.

1- Introduction

2- Project overview

3- Establishment of microseismic monitoring system

4- Analysis of microseismic activity characteristics

5- Conclusions

References

Abstract

The access tunnel in the main powerhouse of the Shuangjiangkou hydropower station in China has complex geological conditions and is subject to high in situ stress in deep buried sections. Microseismic activity in the surrounding rock mass of the tunnel was monitored by a microseismic monitoring system, and rockburst was effectively predicted. Based on abundant data obtained from the microseismic monitoring, statistical parameters, which include cumulative apparent volume, the energy index, cumulative released energy and the Es/Ep value, were used to analyze the microseismic activity before and after rockburst to determine a more accurate early warning period and construction safety period. A sharp decrease in the energy index and a rapid increase in the cumulative apparent volume indicated a deterioration of the surrounding rock mass stability. The change characteristics of Es/Ep values revealed that the rockburst process underwent a transformation of compression-shear damage, tension-shear mixed damage and tension damage. Finally, based on the number of daily events N and the b value of the microseismic events, lgN/b was first established to evaluate the rockburst risk of tunnels. When the value of lgN/b was greater than 1, rockburst was more likely to occur; the larger the lgN/b value, the more severe the rockburst was. The research results provide an important reference value for the prediction of rockbursts in deep tunnels and the regulation of site construction progress.

Introduction

Rockburst is a special failure pattern that occurs during excavation in a high-stress environment, accompanied by the sudden release of strain energy, and it can pose a considerable threat to on-site workers and engineering equipment. Therefore, research on rockburst mechanisms and predictions has become a key scientific and technical pursuit in rock mechanics to reduce and control rockbursts.1 Detailed analysis of the occurrence process of rockburst and revealing rockburst mechanisms are the keys to accurately predicting rockbursts. Extensive theoretical and experimental studies have been conducted on failure mechanisms, forecasting methods, and prevention technologies. Ortlepp and Stacey2 distinguished several different rockburst mechanisms in tunnels and shafts, drew a distinction between source and damage mechanisms, and suggested five rockburst types in tunnels and shafts, namely, strain burst, buckling, face crush burst, shear rupture, and fault slip burst. Their research results form a good foundation for further analysis of rockburst mechanisms and rockburst prediction in underground engineering in the future. Based on research findings from other researchers, Kaiser et al.3 proposed three rockburst types (strain burst, pillar burst, and fault slip burst). Frid4 established the electromagnetic radiation criterion for rockburst prediction in coal mines. The antenna that captured signals was normally located 1 m from the mine working face. Therefore, this method of predicting rockbursts cannot be applied to general tunnel excavation. Romashov5 first proposed a generalized model of rockbursts that was in accordance with the general character of deformations in rock masses and physical representations of many phenomena. Their research results form a good foundation for creating a rockburst model of specific rock masses and developing new more reliable methods of estimating their rockburst hazard. Liu et al.6 used cloud models and the attribution weight method to predict rockburst classifications. The data collection is an enormous challenge for their applicability. Gong and Li7 established a distance discriminant analysis method for rockburst prediction. In the research, the parameters used to build the model are difficult to be obtained on site, so it is an enormous challenge for applications in the tunnel with complex geological environments.

1- Introduction

2- Exploration information systems (EIS)

3- Discussion

4- Concluding remarks

References

Abstract

The advent of modern data collection and storage technologies has brought about a huge increase in data volumes with both traditional and machine learning tools struggling to effectively handle, manage and analyse the very large data quantities that are now available. The mineral exploration industry is by no means immune to this big data issue. Exploration decision-making has become much more complex in the wake of big data, in particular with respect to questions about how to best manage and use the data to obtain information, generate knowledge and gain insight. One of the ways in which the mineral exploration industry works with big data is by using a geographic information system (GIS). For example, GIS platforms are often used for integration, interrogation and interpretation of diverse geoscience and mineral exploration data with the goal of refining and prioritising known and identifying new targets. Here we (i) briefly discuss the importance of carefully translating conceptual ore deposit models into effective exploration targeting maps, (ii) propose and describe what we term exploration information systems (EIS): a new idea for an information system designed to better integrate the conceptual mineral deposit model (i.e., the critical and constituent processes of the targeted mineral system) with data available to support exploration targeting, and (iii) discuss how best to categorise mineral systems in an EIS as scale-dependent subsystems to form mineral deposits. Our vision for the future use of EIS in exploration targeting is one whereby the mappable ingredients of a targeted mineral system are translated and combined into a set of weighted evidence (or proxy) maps automatically, resulting in an auto-generated mineral prospectivity map and a series of ranked exploration targets. We do not envisage the EIS replacing human input and ingenuity; rather we envisage the EIS as an additional tool in the exploration toolbox and as an intelligence amplifying system in which humans are making use of machines to achieve the best possible results.

Introduction

Mineral exploration targeting requires the compilation, integration and interrogation of diverse, multi-disciplinary data (e.g., Hronsky and Groves, 2008). In today’s world, this is commonly done using a geographic information system (GIS), the light table environment of our modern computer-age. A GIS is a powerful computer-based system designed to capture, store, manipulate, analyse, manage, and present spatial data (e.g., Groves et al., 2000) and their non-spatial attributes that can be stored in linked, interrogatable tables. In mineral exploration targeting, as in many other fields of applied geoscience, GIS has surpassed the human ability to integrate and quantitatively analyse the ever-growing amount of geospatial data available, thereby progressively replacing the traditional working methods. Over the past two decades and driven by significant improvements in soft- and hardware capabilities, powerful GIS-based, algorithm-driven methods have been developed in support of exploration targeting. These methods fall under the umbrella term of mineral prospectivity mapping (MPM), also known as mineral prospectivity analysis, spatial predictive modelling or mineral potential modelling (e.g., Bonham-Carter, 1994; Pan and Harris, 2000; Carranza, 2008; Porwal and Kreuzer, 2010; Yousefi and Nykänen, 2017; Hronsky and Kreuzer, 2019).

Flotation tests using artificial mixtures of clean coal and quartz were conducted with and without the presence of sodium hexametaphosphate (SHMP) to study the effect of polyaluminum chloride (PAC) on quartz entrainment in fine coal flotation. Comparisons of flotation results show that the degree of quartz entrainment was greatly reduced using a suitable amount (e.g., 20 mg/L) of PAC in the absence of SHMP, however, significant changes of PAC on quartz entrainment did not appear in the presence of SHMP. The possible mechanisms responsible for the reduced quartz entrainment using PAC in fine coal flotation were investigated by particle size distribution measurements, zeta potential measurements, and interaction force calculations. Analysis of particle size distribution results reveals that when SHMP was not added, quartz particles were selectively aggregated with the addition of 20 mg/L PAC and the aggregation of quartz or coal particles was negligible at a high PAC dosage (e.g., 50 mg/L). Meanwhile, the aggregation of quartz particles induced by PAC was eliminated with the presence of SHMP. The electrostatic double layer repulsive force between quartz particles was calculated using the Deyaguin-Landau-Verwey-Overbeek (DLVO) theory with incorporating the results of zeta potential measurements. At 20 mg/L of PAC, the negative surface charge of quartz particle was neutralized and the electrostatic double layer repulsive force between quartz particles reached the minimum. These findings might be reasons of the aggregation of quart particles and therefore reduce the quartz entrainment in fine coal flotation.

Introduction

Gangue entrainment is the main reason that results in the deterioration of flotation concentrate grade. The gangue entrainment problem in coal flotation has become more severe since the proportion of fine and ultrafine particles in coal flotation feed increases greatly with the popularization of mechanical mining and heavy medium cyclone separation technologies. Since China has adopted much stricter environmental regulations, the production of high quality clean coal has become a major challenge faced by the coal flotation industry today. Reducing the entrainment of fine and ultrafine gangue minerals seems to be a promising approach to improving the grade of clean coal, although, studies reported that it is very difficult to deal with [1–3]. In recent years, a number of studies have been conducted to improve the quality of flotation clean coal. Jiang et al. [4] and Peng et al. [5] applied inclined plates in the flotation column to increase the segregation rate between the rising bubbles and descending liquid by which both the capacity and the separation efficiency of the flotation column increased. Ni et al. [6] designed an unconventional flotation column by adopting the mechanism of gravity sedimentation into flotation. They found that the ash of clean coal obtained with the new column was reduced by 1.17% compared with the conventional flotation column. The successes in improving clean coal quality also have been achieved by the development of new compound collector to promote fine particle recovery [7], the uses of ultrasonic [8], and high intensity conditioning to realize surface cleaning [9]. Recently, two liquid flotation, for example the Hydrophobic-Hydrophilic Separation (HHS) technology, has been developed to remove the gangue minerals by dispersing coal in hydrocarbon phase [10,11]. The entrainment of gangue minerals such as quartz, kaolinite, and montmorillonite in fine coal flotation has been recognized since the beginning of employing flotation. However, research effort has been mainly focused on developing new processes to improve the clean coal quality as abovementioned. On the other hand, various studies have also been carried out to understand the gangue entrainment.