Search

The mining sector faces some of the most difficult sustainability challenges of any industrial sector. The mining sector is remarkably significant to the development of the Asia-Pacific Economic Cooperation (APEC) region, because the majority of global trade and investment in this region depends on this sector. Therefore, the assessment of mining sector sustainability at national and global scales in APEC economies is an important task. So far, however, mining sector sustainability assessment frameworks have only been developed at small scales, such as companies and cities. In this study, therefore, it is proposed an indicator-based sustainability assessment framework (iSAF) to assess mining sector sustainability at national and global scales. In this framework, fuzzy logic was utilized to adequately deal with the uncertainty and vagueness of human expressions. The conventional fuzzy scales were suitably modified in the proposed framework to facilitate confident decision-making by the relevant stakeholders. In order to avoid repeatedly conducting the judgment until the acceptable consistency was obtained, iSAF implemented an innovative theory to deal with unacceptable consistencies in judgment. The proposed iSAF was applied to the mining sector of APEC economies using data from the APEC 2010 Project. As for the results, three important criteria including economic, environmental, and social criteria and twenty significant indicators were appropriately selected to cover the actual situation in the sector. The results showed that iSAF was a suitable framework for preventing uncertainty and vagueness in decision-making. iSAF was found to provide crucial support to decision-makers, not only in identifying and structuring the main components contributing to sustainability, but also in pointing out the factors in which significant investment should be made to effectively improve sustainability.

We experimentally analyzed two different nonlinear fitting methods for a Brillouin optical time domain reflectometery (BOTDR) system. By measuring the spontaneous Brillouin frequency and comparing a Lorentzian fit with a Voigt fit, we confirmed that the accuracy of the Lorentzian fit was higher than that of the Voigt fit. We also performed long-range distributed measurements using coherent detection system with a 36 km long-range optical fiber. The extinction ratio of optical pulse was improved by employing an acousto-optic modulator (AOM). As a result, we could successfully measure the Brillouin frequency shift (BFS) using a Lorentzian fit algorithm in order to calculate applied temperature and strain in the optical fiber.

Coal ash generated from thermal power plants is planned to use for mine filling in order to prevent subsidence of the ground. In according, the basic physical properties and flow characteristics were grasped using coal ash from generated Yeongdong thermal power plant, and hydraulic filling experiments were performed a total of eight times by manufacturing the model of 1 inclined shaft in Hanbo coal mine. The specific gravity of coal ash is 2.34, and the result of particle size analysis belongs to silty sand (SM). Coal ash of weight ratio of 60% was used in the filling experiments of the model, since liquefaction have shown in coal ash less than weight ratio of 70% from the result of slump and flow test. The outlet should be located at the bottom of the inclined and vertical shaft, this was favorable way in improving the filling efficiency from the experiment results regardless of groundwater exists.

The aim of this study is to develop eco-friendly, fundamental technology for vegetative restoration of barren lands using green rehabilitation material, for the stabilization of abandoned mine debris slopes and depository slopes composed of rock fragments. It is expected that such methods would help to improve the negative view of artificial slopes that remain following mining activity, while also contributing to slope stabilization and prevention of the loss of rock fragments and the dispersion of tailings. We tested the tensile strength and tear strength of various materials, including commonly used natural coir material, natural fibers, and synthetic textile materials with enhanced durability. In conclusion, there is the possibility that natural coir can be used as an eco-friendly material in vegetation restoration, while its durability in natural conditions can be improved by controlling the degree of knot convolution and by antibacterial treatment against biodegradation.

In recent, the using of the hydraulic filling method has increased on the underground reinforcement of the abandoned mine in Korea, however it is the lack of research on the efficient filling method. In this study, tank model tests and field tests were conducted for development of tip device for filling efficiency improvements on the hydraulic filling method. In tank model experiments, the filling efficiency was evaluated according to the form and angle of the nozzle on tip device in the same condition. Then tip device model designed by tank model tests was applied to the field experiment. As a result, the amount of filling of nozzle 90° tube is increased by approximately 18% compared to the common vertical injection pipe. The angle of repose was 30.82°. Filling hole spacing in the field is usually designed from 5m up to 10m assumed to be 40° of the angle of repose. According to the results of this study, it is possible that the filling hole spacing expands at least 10m up to 15m applied to be 30°~35° of the angle of repose. Therefore, it is expected to be economical and efficient mine filling.

The objectives of this study were to investigate soil chemical properties for forest rehabilitation and suggest design and management in abandoned coal mine areas in Mungyeong, Gyeongsangbuk-do. Total study sites were 10 sites, and soil analysis particular were soil pH, TOC, total-N, C/N ratio, A.v. , and CEC. Because most of study sites showed soil pH from 5.0 to 7.0, it seems that soil pH does not affect growth of vegetation. But soil pH in Danbong1 was acidic (pH 4.6), so it is needed to improve with ameliorant such as limestone. Most of study sites is necessary to manage for organic matter and Nitrogen, because there sites showed lower value of TOC and total-N than general forest. The values of A.v. and CEC were good in most of study sites, so it seems that they do not have effect on vegetation growth. All of soil factors has no regression according to elapsed time after rehabilitation. TOC, total-N and A.v. among soil properties have positive relationship between each other. It is necessary to fertilizer for organic matter and Nitroge because of value in TOC, total-N and C/N ratio. The results of this study were analyzed only one time. So, long-term monitoring for soil properties is important for the correct forest rehabilitation and management.

Surface subsidence in abandoned mine areas is a keen issue since it can cause loss of lives and serious property damage. However, the hazard of surface subsidence cannot usually be predicted in advance because surface subsidence is affected by many parameters. In this study, numerical simulation was carried out to predict the probability of surface subsidence. Many factors, such as cavity size, geometry, rock mass condition, rainfall and groundwater table, are well known for their key roles. Much research has been carried out to predict the probability of surface subsidence induced by the collapse or squeezing of a mined opening. In this study, the cavity geometry (i.e. depth, width, height and angle of cavity) and rock mass condition were selected as the key parameters for subsidence. A conceptual genetic cavity model in a horizontally layered rock mass was considered in the numerical simulation. The relationship between each of the selected factors and the hazard of subsidence was obtained. The vertical...

The objectives of this study were to investigate soil chemical characteristics for forest rehabilitation and suggest management in abandoned coal mine areas in Hwasun-gun, South Jeolla Province. Total study sites were 8 sites, and soil analysis particular were soil pH, TOC, total-N, C/N ratio, Avail. P2O5, and CEC. Average soil pH was 5.8 (4.7～6.4). Average contents of TOC, total-N and C/N ratio were 1.1% (0.2～2.0%), 0.08% (0.02～0.13%) and 15.0 (7.9～31.4), respectively. Average Avail. P2O5 was 8.3 mg kg -1 (2.7～15.0) and Average CEC was 13.7 cmolc ㎏ -1 (9.9～18.5 cmolc ㎏ -1 ). Soil pH was decreased according to elapsed time from forest rehabilitation, while TOC, total N and CEC were increased. Av. P2O5 did not show any relationship with elapsed time. Soil pH was stable comparing with general forest soil in South Jeolla Province (5.1), while contents of TOC and total N were lower than general forest soil in South Jeolla Province (4.9% and 0.18%, respectively). Therefore, sustainable managements such as fertilization for TOC and total N are necessary for good rooting and growth of vegetation.

Mining activities have not only provided positive impacts on eco-social development but also caused many adverse ones on social and environmental conditions. Measurement of sustainable development for this specific economic sector requires specific considerations and implements in a sustainable development concept. This paper provides essential information regarding sustainable development issues, sustainable development evaluation and the wide range of effective applications of the two multi-criteria approaches, analytic hierarchy process (AHP) and fuzzy AHP. The aims of this paper are to discuss the urgent tasks of sustainable development problems in the mining sector, and to suggest a potential and practical approach of fuzzy AHP in the evaluation of sustainable development for mining sector. Moreover, this paper discusses the strong possibility of fuzzy AHP approaches for designing a sustainability system in the mining sector and handling uncertainty in deriving the priorities of components i...