Mining, Volume 1, Issue 1 (June 2021) – 8 articles

It is important that the strategic mine plan makes optimum use of available resources and provides continuous quality ore to drive sustainable mining and profitability. This requires the development of a well-integrated strategy of mining options for surface and/or underground mining and their interactions. Understanding the current tools and methodologies used in the mining industry for surface and underground mining options and transitions planning are essential to dealing with complex and deep-seated deposits that are amenable to both open pit and underground mining. In this study, extensive literature review and a gap analysis matrix are used to identify the limitations and opportunities for further research in surface-underground mining options and transitions optimization for comprehensive resource development planning. Full article

This paper proposes a stochastic frontier model for measuring both technical and environmental performance at the mine level by using a translog production function. The Kardia Field opencast lignite mine of the Greek Public Power Corporation (PPC), S.A. is the topic of the case study. Efficiency ratings are derived over a long period of time using annual operating data, and in addition, the determinants of inefficiency are established by means of the technical inefficiency effects model. In the light of the results, there is a strong correlation between technical and environmental efficiency; the results are validated by those produced by data envelopment analysis (DEA). In addition, the stripping ratio is identified as the statistically significant determinant of performance. The proposed framework could be used as an instrument to measure the efficiency of lignite mining operations and to identify the drivers of performance. Full article

Continuously poured paste backfill dramatically improves underground mining efficiency through reduced stope cycle time and simplified logistics. For longhole stopes, a backfill “plug” is poured to a few meters above the undercut brow and must gain sufficient strength to prevent failure through the plug when the “main” pour begins. A novel, rational engineering design approach that determines the required plug strength is developed. The potential failure mechanism during continuous pouring is identified and the theoretical solution and its numerical validation/calibration are discussed. Four field case histories are then used, three of them involving continuous pours, to demonstrate the theoretical solution’s validity in back-analysis. These case studies are unique in the extent and quality of total stress and water pressure measurements made throughout backfilling. Additionally, comprehensive laboratory data are available to characterize strength development during binder hydration in the first few days, which are critical to the back-analyses. Results indicate that continuous backfilling is feasible with reasonably attainable backfill strengths at most mines. However, mines must undertake comprehensive early strength laboratory testing, and must carry out field measurements during the pour to ensure the placed backfill behaviour is consistent with the analysis assumptions. Full article

In-pit crushing and conveying (IPCC) systems have drawn attention to the modern mining industry due to the numerous benefits than conventional truck-and-shovel systems. However, the implementation of the IPCC system can reduce mining flexibility and introduce additional mining sequence requirements. This paper investigates the long-term production scheduling and the crusher relocation plan of open-pit mines using a semi-mobile IPCC system and high-angle conveyor. A series of candidate high-angle conveyor locations is generated around the pit limit, with a crusher located along each conveyor line. Each conveyor location is solved independently by an integer linear programming model for making production scheduling and crushing station decisions, aiming to maximize the net present value (NPV) considering the material handling and crushing station relocation costs. The production schedule with the highest NPV and the associated conveyor and crusher location is considered the optimum or near-optimum solution. Full article

In terms of its history and complexity, the Lugau/Oelsnitz mining area is a representative example of many hard coal fields in Europe. The special characteristic, however, is the low water inflow and the associated long flooding process with corresponding low and long-ongoing ground movements. In order to ensure the long-term monitoring of ground movements in the future, an adapted and cost-effective concept based on modern methods should be implemented. The today widely used radar interferometry, is well established as a method but the results offer many possibilities for interpretation, which one should be aware of in order to derive reliable information. Presented are the results of a complex interferometric evaluation, based on Sentinel-1 data from different orbits, and an analysis of the spatiotemporal characteristic of ground movements. The focus of this paper is a detailed presentation of the workflow and an application-related interpretation of the results. The pool of methods used includes radar interferometry, but also spatiotemporal analysis and modeling. The overall objective of this comprehensive case study is to present the possibilities but also the limitations of the application of radar interferometry and to provide a perspective for future monitoring in post-mining areas. Full article

In the recent years, there has been a surge in artisanal and small-scale gold mining (ASGM) in various districts of Malawi. Reports of a gold rush have emerged in various districts, including Mangochi, Lilongwe, Balaka, and lately in Kasungu. There has been persistence by many indigenous communities participating in ASGM activities, yet little is being done by the government to formalize and support the sub-sector. The purpose of this study was to investigate the benefits of artisanal small-scale gold mining in Malawi and expose the shortfalls so that key stakeholders and policy makers are well informed. A quantitative approach which used semi-structured questionnaires was used and the data was analyzed using Microsoft excel and Statistical Packages for the Social Sciences (SPSS). The study shows that ASGM is characterized by people with low literacy levels, who use traditional tools (low-tech) and use methods fueled by lack of capital, and deficiency of basic knowledge of mining and geology. The study found that the government could achieve substantial socio-economic development from the sector by: (1) revising the current artisanal and small-scale mining (ASM) legislation so that it embraces the customary practices whilst safeguarding the environment and improving the tax collection base; (2) providing support in form of mining related training and education to these communities; (3) leading in transfer of modern technologies for improved extraction; (4) supporting ASM cooperatives in securing credit facilities from financial institutions; and (5) closing the existing knowledge gap for ASM related issues through introduction of mining desk officers in district councils. Full article

This study analyzes various regulatory framework mechanisms applied to prevent, minimize, and mitigate environmental accidents and disasters, within the extractive mining industry, in seven Latin American countries. The selected countries offer an ample view of the mining industry specter since each one of them is at the different development stages, such as Chile, Bolivia, Mexico, and Brazil. Nevertheless, some of the countries have similar technical characteristics, as is the case of Peru, Colombia, and Ecuador. Controls and regulations employed in each of the countries reveal particularities that should be appreciated and understood. In conclusion, the existence of mining regulations has not diminished the occurrence of environmental accidents in those countries. However, the existing environmental controls allow authorities to quantify with substantial precision the degree of impact coming from Latin America’s mining industry. Furthermore, for more than a decade, mining industries have been subjected to several global initiatives to integrate elements of corporative social responsibility into their management systems—mainly in strong cooperation with different governmental formalization programs. The key focus is, cooperation among different scales (industry and small-scale and artisanal mining) which challenged, but also improved the capacities of environmental authorities and the effectiveness of different legal frameworks. Full article