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Spontaneous heating in the active goaf area during normal mining processes poses increased threats to mine productivity and safety, as evidenced in events induced by spontaneous combustion of coal. To control and mitigate this engineering problem, there is a need to gain critical knowledge of spontaneous combustion in the longwall goaf area, which can be achieved through a combination of field tests and numerical modeling. This paper introduces the spontaneous combustion management system widely used in Australia and presents Computational Fluid Dynamics (CFD) models for the simulation of gas flow dynamics in the goaf area, based on the site conditions of an underground coal mine where coal seam gas is predominantly comprised of carbon dioxide. The models were validated with gas monitoring data and used to conduct parametric studies for proactive goaf inertisation optimization. Qualitative and quantitative analysis of simulation results indicated that better goaf inertisation could be achieved when nitrogen was injected via cut-through at 250 m on the maingate (MG) side and surface boreholes at 100 m and 700 m on the tailgate (TG) side, with a total injection rate greater than 1750 1/s. The oxygen concentration on the MG and TG side dropped below 5% at distances of 120 m and 75 m behind the longwall face, with an oxidation zone area of 35375 m2, which was approximately one-third of the oxidation zone area of the scenario without inert gas injection. Simulation results help shed light on improving current goaf inertisation practices to effectively reduce the risk of heating in goaf areas and improve mining process safety based on Australian conditions and practices. [ABSTRACT FROM AUTHOR]

Historically, the idea of designing and installing rockbolts in rockmasses can be traced back to the construction of the Snowy Mountain hydroelectric scheme in Australia, which was completed in 1974. The use of rockbolts as a ground support system has been widely applied to enhance the stability of structures in mining and to resist the movement of keyblocks in underground excavations. The strength of a rockbolt as a rock support tool lies in its ability to improve the tensile and shear strength needed to maintain the load-bearing capacity of a rockmass. Currently, rockbolts are extensively used as reinforcement methods in mining and civil engineering projects to support deforming rockmasses in coal and hard rock mining, tunnelling and underground openings. The performance of a rockbolt depends on the design parameters such as load-bearing capacity of the bolt, strength of the bolt, bolt diameter, length of the bolt and bolt spacing. This study provides a detailed review of the various applications of rockbolts in mining operations. In addition, the integration of smart sensors in rockbolts to enhance monitoring of displacement measurements, stresses, subsidence of pillars and ground pressure on structures are discussed in this paper. The use of smart rockbolt devices, which has improved the monitoring and evaluation of critical parameters in rockbolts such as the axial force, corrosion occurrence, grout quality and resin delamination, are also discussed. This review shows that with the numerous applications of rockbolts in mining, especially in underground excavations and tunneling engineering, rockbolts can be used as supports in rocks with different geological conditions. Nevertheless, this paper highlights that there are still some areas that need improvement in rockbolting technology. [ABSTRACT FROM AUTHOR]

The mining industry, considered a traditional and conservative industry with respect to innovation, finds itself at a turning point due to the increasingly complex challenges, such as declining ore grades. These challenges have created an imperative to innovate. Parallel to the above, several digital innovations are being implemented in many mining operations across the globe. Not only do these provide solutions to the existing problems but also radically transform mining processes, increasing efficiency, profitability, and the ability to comply with stricter regulations. The incorporation of mature and incipient technologies into the mining industry has opened up many opportunities for long-established firms as well as knowledge-based start-ups. This includes potential suppliers in countries where mining accounts for a significant share of the GDP but the development of productive linkages remains suboptimal, as in Latin American countries. While in recent years, some suppliers in Latin America have made important contributions to increasing innovation in the mining industry, most suppliers in the region have not been able to do so. This paper provides an overview of the innovation paradigm of the mining sector from a global perspective, i.e., how innovation processes take place in countries with a long-established technological leadership in the mining sector, such as Australia and Canada. Given the importance of suppliers in this process, a special attention is paid to innovation in various stages of the supply chain. This is in order to provide a departure point for identifying windows of opportunity for equipment and service suppliers in Latin America. [ABSTRACT FROM AUTHOR]

The assessment of the stope stability is of great importance in the underground mine design process. The instability of stopes leads to serious economic and safety problems in mining operations. This paper aims to assist in the prediction of stope stability by making use of machine learning algorithms. For this purpose, a hybrid grid search-based Artificial Neural Network method is proposed. In the experiments, a total of 215 stope cases which have been collected from six underground mining operations located across Australia are used to prove the validity of the proposed method. Then, the performance of the proposed method is compared with k-nearest neighbour (kNN), naive Bayes (NB), support vector machine (SVM), decision tree (DT) and the stability graph method. Furthermore, several performance measures, such as accuracy, precision, specificity, recall, f-measure, and g-mean are considered during the performance comparison of the methods. The accuracy values are obtained as 91.63%, 81.86%, 77.21%, 76.74%, 73.95%, and 69.77% with the proposed hybrid grid search-based ANN method, SVM, DT, NB, kNN, and the stability graph method, respectively. The empirical results from the experiments indicated that the proposed hybrid approach outperformed the other aforementioned methods, which confirms that the proposed method is a useful tool to predict stope stability. [ABSTRACT FROM AUTHOR]

Public and corporate policies regarding mine closure focus on bio-physical remediation and ignore the social impacts associated with the end of mine life and the legacies that mining leaves. In a departure from most existing writing on social impact assessment and extractive industry, we show that this situation does not simply reflect the disciplinary dominance of environmental science or a gap in knowledge regarding social impacts that can be addressed by allocation of additional resources and research effort. Rather it reflects the strategic application of ignorance, allowing the social impacts of mining to be ignored and extraction to continue unhindered. We use the contentious Ranger uranium mine on Mirarr Aboriginal land in the Kakadu region of the Northern Territory of Australia to illustrate our argument. Information on the negative social impacts of mining on the Mirrar has been available through the life cycle of the Ranger mine. It has been consistently ignored by the State and by the mine's corporate owners, and social impacts remain conspicuously absent in the mining company's mine closure plans and governmental assessments. In an important theoretical innovation we brings Val Plumwood's concept of "shadow places" into conversation with the ignorance studies literature to explore how the practices of ignorance do not just involve the absence of knowledge but are actively mobilised in order to obscure the social impacts of mining on Indigenous lands, and perpetuate long-standing social and environmental injustices in settler colonies such as Australia. • The Ranger Uranium Mine on the First Nations Mirarr land has recently closed. • Technical knowledges being privileged during mine closure process. • Social impact data collected during mining operations ignored during mine closure. • Ignorance strategically used to avoid complex impacts of mining on First Nations. [ABSTRACT FROM AUTHOR]