Mining

17 pages, 1837 KiB

Open AccessArticle

Safe Mining Assessment of Artisanal Barite Mining Activities in Nigeria

by David Oluwasegun Afolayan, Azikiwe Peter Onwualu, Carrick McAfee Eggleston, Adelana Rasak Adetunji, Mingjiang Tao and Richard Kwasi Amankwah

Mining 2021, 1(2), 224-240; https://doi.org/10.3390/mining1020015 - 18 Sep 2021

Cited by 3 | Viewed by 6405

Abstract

Barite, used in mud formulation, is mined in several places to support the industry. However, there is insufficient literature on the downside of mining and associated hazards, especially in the artisanal barite mining sector. This paper contains three parts. The initial section reviews [...] Read more.

Barite, used in mud formulation, is mined in several places to support the industry. However, there is insufficient literature on the downside of mining and associated hazards, especially in the artisanal barite mining sector. This paper contains three parts. The initial section reviews major causes of mining accidents and health hazards in Nigeria. The second section examines existing but weak institutional frameworks and policies for artisanal and small-scale mining (ASM) in Nigeria. In the third part, data from questionnaires and heavy metal contamination assessment are compared with health and environmental standards to identify and characterize hazards. It was observed that 54% had health challenges traceable to illicit drugs, and 54% were ignorant about the use of safety kits. The UV-Vis, AAS, and ICP-MS analyses confirmed lead, barium, zinc, copper, and iron in the water samples. Index of geoaccumulation (Igeo) and contamination factor (CF) show that water samples are moderate to highly polluted by Pb²⁺, Ba²⁺, and highly contaminated. The chronic daily intake assessment and health quotient analysis revealed that the accumulation of lead and barium is possible and can initiate chronic diseases in humans over a long time. Certain safe mining protocols and controls are recommended. Full article

(This article belongs to the Special Issue Envisioning the Future of Mining)

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14 pages, 10630 KiB

Open AccessArticle

Communication of Sensor Data in Underground Mining Environments: An Evaluation of Wireless Signal Quality over Distance

by Hajime Ikeda, Oluwafemi Kolade, Muhammad Ahsan Mahboob, Frederick Thomas Cawood and Youhei Kawamura

Mining 2021, 1(2), 211-223; https://doi.org/10.3390/mining1020014 - 14 Sep 2021

Cited by 10 | Viewed by 5111

Abstract

The technologies of the fourth industrial revolution have the potential to make zero harm possible for the first time in the history of mining. In the journey toward zero harm, rock stress monitoring systems are important for the risk management process. Although communication [...] Read more.

The technologies of the fourth industrial revolution have the potential to make zero harm possible for the first time in the history of mining. In the journey toward zero harm, rock stress monitoring systems are important for the risk management process. Although communication systems for underground mining have improved significantly over the past two decades, it remains difficult to achieve reliable-all-the-time wireless communication in ultra-deep level underground mines. The aim of this study is to explore and test a smart phone network for communicating sensor data from the underground production environment to the surface. In this paper, the evaluation and performance over distance of a wireless communication system is performed in underground mining environments. The wireless system transmits the data collected from a sensor installed in a narrow reef stope, horizontal tunnel, and vertical shaft area of a mock underground mine. The evaluation was performed using the received signal strength of a mobile receiver over distance. The path loss coefficients of the underground mining environment were then derived for the measurement areas. The results show that a communication speed of 80 Mbps was achieved in a 60 m range, thus, indicating the potential for the support of applications requiring higher data rates. Full article

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20 pages, 8937 KiB

Open AccessArticle

Precision Rock Excavation: Beyond Controlled Blasting and Line Drilling

by Marilena Cardu, Simone Saltarin, Carmine Todaro and Chiara Deangeli

Mining 2021, 1(2), 192-210; https://doi.org/10.3390/mining1020013 - 09 Sep 2021

Cited by 3 | Viewed by 9115

Abstract

The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by its objective and, therefore, by the type of technique applied to achieve it. To attain the best results in terms of rock breakage, and [...] Read more.

The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by its objective and, therefore, by the type of technique applied to achieve it. To attain the best results in terms of rock breakage, and with respect to the final profile, it is important to evaluate the specific excavation energy and its optimization. This study, being a revision of different techniques to achieve good quality of the final walls, focuses on evaluating the effects of those techniques on the quality of the result, in both open-pit and underground operations. Different geometries and configurations can be applied to both quarrying and tunneling blasts. This study aims to push contour blasts to their limits, and the main aspects are discussed in order to improve the blast parameters in daily practice. Full article

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12 pages, 1000 KiB

Open AccessReview

Mathematical Programming Application in Sublevel Caving Production Scheduling

by Soroush Khazaei and Yashar Pourrahimian

Mining 2021, 1(2), 180-191; https://doi.org/10.3390/mining1020012 - 09 Aug 2021

Cited by 3 | Viewed by 7294

Abstract

Production scheduling determines the most beneficial mining sequence over the life of a mine. Developing a schedule that meets all mining aspects can substantially reduce mining costs and increase profitability. Among all underground mining methods, the sublevel caving method is a common method [...] Read more.

Production scheduling determines the most beneficial mining sequence over the life of a mine. Developing a schedule that meets all mining aspects can substantially reduce mining costs and increase profitability. Among all underground mining methods, the sublevel caving method is a common method with moderate development requirements, a high production rate, and a high degree of mechanization and flexibility. None of the manual planning methods and heuristic algorithms used in commercial software will lead to a truly optimal schedule. Mathematical programming models, particularly mixed-integer programming (MIP), have been applied to provide an operationally feasible multi-time-period schedule in sublevel caving. However, confined blasting conditions, chaotic material flow, and frequent mixing of ore and waste while loading broken ore at the drawpoint make the sublevel caving method unique when producing a holistic plan. This paper reviews all mathematical programming models presented in sublevel caving production scheduling, highlights the inherent characteristics of the sublevel caving that affect production, and puts forward some promising ideas for future works. Full article

(This article belongs to the Special Issue Recent Advances in Underground Mine Planning, Scheduling, and Optimization: Theory and Applications)

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13 pages, 4435 KiB

Open AccessArticle

Optimising Productivity and Safety of the Open Pit Loading and Haulage System with a Surge Loader

by Ignacio Andrés Osses Aguayo, Micah Nehring and G. M. Wali Ullah

Mining 2021, 1(2), 167-179; https://doi.org/10.3390/mining1020011 - 02 Aug 2021

Cited by 5 | Viewed by 9849

Abstract

The open pit mining load and haul system has been a mainstay of the mining industry for many years. While machines have increased in size and scale and automation has become an important development, there have been few innovations to the actual load [...] Read more.

The open pit mining load and haul system has been a mainstay of the mining industry for many years. While machines have increased in size and scale and automation has become an important development, there have been few innovations to the actual load and haul process itself in recent times. This research highlights some of the potential productivity and safety benefits that the incorporation of a surge loader may bring to the load and haul system through an analysis of the system, discussion of component characteristics, and mine planning aspects. The incorporation of the surge loader into open pit loading and haulage operations also enables improved safety. This is a result of a reduction in shovel–truck interactions and the reduced likelihood of truck overfilling and uneven loading. This paper details the number of mine worker deaths that a surge loader may have prevented within the Peruvian and Chilean mining industries. Full article

(This article belongs to the Special Issue Envisioning the Future of Mining)

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12 pages, 2981 KiB

Open AccessFeature PaperArticle

Investigation of Backfilling Step Effects on Stope Stability

by Huawei Xu, Derek B. Apel, Jun Wang, Chong Wei and Yashar Pourrahimian

Mining 2021, 1(2), 155-166; https://doi.org/10.3390/mining1020010 - 29 Jul 2021

Cited by 5 | Viewed by 3192

Abstract

Cemented rock fill (CRF) is commonly used in cut-and-fill stoping operations in underground mining. This allows for the maximum recovery of ore. Backfilling can improve stope stability in underground workings and then improve ground stability of the whole mine site. However, backfilling step [...] Read more.

Cemented rock fill (CRF) is commonly used in cut-and-fill stoping operations in underground mining. This allows for the maximum recovery of ore. Backfilling can improve stope stability in underground workings and then improve ground stability of the whole mine site. However, backfilling step scenarios vary from site to site. This paper presents the investigation of five different backfilling step scenarios and their impacts on the stability of stopes at four different mining levels. A comprehensive comparison of displacements, major principal stress, and Stress Concentration Factor (SCF) was conducted. The results show that different backfilling step scenarios have little influence on the final displacement for displacement in the stopes. Among the five backfilling scenarios, the major principal stress and stress concentration factor (SCF) have almost the same final results. The backfilling scenario SCN-1 is the optimum option among these five backfilling scenarios. It can immediately prevent the increase of the displacement and reduce the sidewall stress concentration, thereby preventing possible failures. Using the same strength of CRF can achieve the same effects among the four mining levels. Applying backfilling CRF of the same strength at different mining depths is acceptable and feasible to improve the stability of the stopes. Full article

(This article belongs to the Special Issue Recent Advances in Underground Mine Planning, Scheduling, and Optimization: Theory and Applications)

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20 pages, 6794 KiB

Open AccessArticle

Rock Fall Hazard Analysis for In-Pit Operations Potentially Impacting External Sensitive Areas

by Renato Macciotta, Frank Altamirano, Lachlan Gibbins, Marco Espezua, Rubén Fernández and Javier Maguiña

Mining 2021, 1(2), 135-154; https://doi.org/10.3390/mining1020009 - 23 Jun 2021

Cited by 1 | Viewed by 4525

Abstract

Controlling rockfall-related risks is a requirement for safe pit operations and primarily mitigated through adequate bench geometry design and implementation. This paper presents a method for rockfall hazard analysis for in-pit operations potentially impacting external sensible areas, adapted from natural rockfall hazard analyses. [...] Read more.

Controlling rockfall-related risks is a requirement for safe pit operations and primarily mitigated through adequate bench geometry design and implementation. This paper presents a method for rockfall hazard analysis for in-pit operations potentially impacting external sensible areas, adapted from natural rockfall hazard analyses. The method considers the natural susceptibility to rockfalls pre-mining, rockfalls originated from bench failures, and those initiated as flyrock. Rockfall trajectory models are used to estimate the potential for blocks reaching exposed elements. Natural susceptibility to rockfalls and trajectories are used as a baseline on which to evaluate the potential effects of open pit operations on the environment and perceptions of communities in the area. The method is illustrated for an open pit in steep terrain in the Peruvian Andes at a feasibility level of study. The paper illustrates the flexibility for including considerations of pre-mining rockfall impacts on the external elements of interest, and for developing rockfall mitigation strategies that consider rock block velocities, heights, energies and the spatial distribution of trajectories. The results highlight the importance of considering the three-dimensional effects of the terrain on block trajectories, and how such insights allow for increasing the efficiency of resources available for rockfall protection structures. Full article

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Mining, Volume 1, Issue 2 (September 2021) – 7 articles

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