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By Peter Zhang, I. BERK TULU, Morgan M. Sears, Heather Dougherty, Ted Klemetti, DYKE MARK VAN, Gabriel S. Esterhuizen

Ground falls in longwall gateroad entries remain a concern in modern longwall operations. The gateroads are subject to changing horizontal and vertical ground stress induced by longwall extraction. These stress changes can result in failure of the strata around an entry leading to large deformations of the entry roof, floor and ribs. The gateroad support systems are required to control the failed strata while maintaining safe access to the longwall face and unimpeded ventilation. This paper presents research conducted to better understand the stability issues in gateroad excavations and to develop procedures for evaluating support and layout alternatives for longwall gateroads. Using the results of a field-monitoring program and numerical model analysis of case histories, a conceptual model of gateroad support needs was developed. The conceptual model formed the basis for developing a set of equations that can be used to estimate likely roof sag and support loading for given roof geology and longwall-induced loading conditions. The developed equations were used to compare predicted gateroad stability to field study results, showing satisfactory agreement. The calculation procedures are used to demonstrate their application in assessing support alternatives at a case study mine. It is concluded that the developed analysis procedures provide realistic assessments of likely ground stability and can be used to evaluate alternative gateroad support systems at operating longwall mines.

By Ari Glazer

"Every year the tunneling business is expanding and collaboration with the International Society of City and Regional Planners (ISOCARP) for the future design of cities and urban communities is in the making. During the last half of this century, billions of people migrated to cities, and it is estimated that by 2030 almost five billion people worldwide will reside in urban communities. Hence, “Underground development will be an important tool in reshaping our urban areas to meet the challenges of the future without destroying their heritage or worsening their surface environment” (Esaki, 2005). In 2013, the Organization for Economic Co-operation and Development (OECD) estimated life expectancy to be around 80 years, meaning that in less than a decade we will need to bury billions of people in cities and urban communities, while trying to retain the deceased’s beliefs and customs. Religion plays a major role in our lives, and many people worldwide still decline to cremate their body after their death; therefore, cemeteries are essential for city inhabitants. Rites and traditions usually call for burials to be near the place of residence, which allows the remaining family members and friends to visit the grave frequently, at least in the first years. This is a challenge that urban designers and architects must confront while trying to solve the problems of future urbanization. In recent years, population growth, the rising cost of land and the extensive preservation of green areas have made cemeteries a burden and a nuisance, particularly for large cities and communities. Many graveyards that were once on the city's outskirts have become lifeless islands in populated areas (Fig. 1), rarely visited by the second and later generations. Cities worldwide face the challenge of allocating less land to maintain current burial practices. In response, some cities have begun to bury their dead at a great distance from the community; others have started to stacked burials, one on top of the other, while still others are constructing buildings and even skyscrapers for the practice of burial (Fig. 2)."

Jan 1, 2016

By E.C. Jong

Resumen ¦ Un sistema de comunicaciones “a través del suelo” (TTE) comercial y disponible fue evaluado en una mina de carbón subterránea en la zona Este del Estado de Kentucky. Este estudio de campo fue realizado como parte de una evaluación multisitio mayor de sistemas TTE disponibles. La mina detallada en este estudio se encontraba paralizada al momento de la evaluación, lo que proporcionó la representación más cercana a la realidad del medio ambiente en una mina luego de una operación de cierre. Para este estudio se probaron las comunicaciones superficie a subterráneo y subterráneo a superficie. El despliegue estándar del sistema TTE usando los procedimientos recomendados por el fabricante logró obtener comunicaciones claras y nítidas entre el socavón y la superficie. Otras disposiciones de las unidades arrojaron resultados mixtos. Existen planes para examinar más los fenómenos observados en esta mina.

Apr 1, 2016

By R. H. Kuhlman

The purpose of this paper is to describe the roles of cement and concrete in construction in general and, more specifically, as construction materials of the Southeast. For purpose of this discussion, the Southeast will include the geographic area composed. of the following 13 states: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, Virginia and West Virginia. In one sense, cement by itself is not a construction material. It is a finely ground manufactured mineral product, usually gray in color. Cement is mixed with water and sand, gravel, crushed stone, or other aggregate to form concrete, the rock-like substance that is the most widely used construction material in the world. Because cement is seldom used by itself for construction but is usually a component of concrete, there is no such thing. as a "cement" sidewalk, a "cement" highway, or "cement" building. Neither is "portland" a brand name. It is a generic term used to describe any cement that hardens in the presence of water and is made to standard specifications .. For all practical construction purposes, therefore, all cement is "portland." The name "port-land" was selected by the English inventor of the product in 1824 because concrete made with his product resembled natural building stone quarried on Portland, an English island. Although portland cement is not the final material which finds its way into completed construction, as the principal component of the most widely used construction material in the world, the location and process of its manufacture warrant some discussion

Jan 1, 1977

By Marie-Josée Banwell, Cyriac Sebastian, Giacomo Falorni, Sara Del Conte

Interferometric Synthetic Aperture Radar (InSAR) is a satellite-based monitoring technique that complements other in-situ methods for detecting and measuring surface displacement. Recent advances in data processing algorithms, coupled with the use of high-resolution satellite systems, make it possible to now provide high-frequency InSAR monitoring services, with updated results delivered every time a new satellite image is acquired. The advent of large, continuously updated data sets, however, brings new challenges, including the need to rapidly sift through the data to identify only those points showing relevant ground displacement information. This has been achieved by using trend variation analysis tools, that quickly isolate and highlight only areas of anomalous behavior. The paper focuses on project case studies where continuous InSAR monitoring has proven to be key in identifying displacement trend changes near tunnel alignments.

Jun 13, 2021

By J. S. Walstrom

Debate on an appropriate, acceptable method of regulating mine and mineral processing wastes has been ongoing since Congress passed the Resource Conservation and Recovery Act (RCRA) on October 21. 1976. Final regulatory determination on which mineral processing wastes are excluded from the RCRA hazardous waste regulations under the Bevill amendment was made by the U.S. Environmental Protection Agency on June 13, 1991. Regardless of whether a mining or mineral processing facility?s waste stream(s) lost or maintained its exclusion status under the Bevill amendment, that facility can expect more stringent regulation of affected waste streams. These more stringent regulations will be added to an already complex regulatory maze, which includes the Clean Air Act (CAA), Clean Water Act (CWA), Safe Drinking Water Act (SDWA), Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), Superfund Amendments and Reauthorization Act (SARA), and Toxic Substances Control Act (TSCA), as well as state and municipal environmental regulations.

Jan 1, 1992

By M. Murillo, J. Botín

"Mining has always played a key role in the improvement of the quality of life, but also, it has been a source of environmental and social conflict. Despite the great progress in social responsibility and sustainability experienced in recent decades, the public image of mining remains low and mining projects and operations must face growing difficulties and demands, which results in increasing capital and operating costs. In practice, the objective of a mining company is to create value for its shareholders and therefore, the best approach to Sustainability would be to foster those drivers aligning sustainability and shareholders value, this is, the “Business Case for Sustainability” (BCS). Only under this assumption, convergence of corporate strategy and sustainability may be assured. This paper discusses partial results of a Research Project being carried out at the Catholic University of Chile, aiming to develop a social and economic model for the effective integration of the values of sustainable development in the strategy of mining companies and their stakeholders. INTRODUCTION Mining is fundamental for the wellbeing of our everyday life. But as important as these benefits are for humanity, the mining Industry has had negative environmental and social impacts. For these reasons, a closer relationship between “Sustainable Development and Mining” is more necessary than ever. The Brundtland definition of Sustainable development does not have a clear relationship with mining, but it provides the context. Under a strict interpretation of the Bruntlandt definition, stating that “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [10], mining would not be sustainable because the minerals are non-renewable resources. However, this research focuses on how mining can contribute to the sustainable development in the territories where the projects take place. In other words, this research follows the publication titled “Berlin II Guidelines for Mining and Sustainable Development” [9], which stated that “A mining project that is developed, operated and closed in an environmentally and socially acceptable manner could contribute to sustainable development. Critical to this goal is ensuring that benefits of the project are employed to develop the region in a way that will survive long after the mine is closed”. The potential conflicts between mining stakeholders arises from the interpretation of the concept “developing, operating and closing a project in an environmentally and socially acceptable manner”, and the impact on the economic objectives of mining companies. Nevertheless, the ability of mining companies to control new demands and expectations of stakeholders has threatened the implementation and continuity of their projects and operations. To deal with these issues this research analyses the “Business Case for Sustainability” (BCS). It refers to the process leading to a business and social-economic environment whereby shareholders value may only be optimum under a business strategy which fully integrates the values of sustainability. In the model proposed, the Business Case will start when the benefits are higher than the costs. Benefits not only associated with efficient use of resources, also benefits associated with avoiding difficulties to continue with the mining projects such as strikes, heavy penalties, loss of investment, and so on."

Jan 1, 2016

By T. Lupek, S. Plaum

"The execution of classical building services in underground mining operations is more truth than myth. From small concrete foundations for conveyor belts to the construction of huge workshops for large machinery maintenance, nearly every operation requires building services. By creating such fixed facilities, these services ensure the efficiency of the production. A distinction must be made between fixed facilities which directly enable the production and auxiliary facilities which only indirectly support the production. The construction costs of such auxiliary facilities are often roughly estimated because they do not immediately contribute to mineral extraction. The research project ‘Development of a systematic cost-calculation method for building services in underground mines’ seeks to address the question: ‘Can the construction costs concerning fixed auxiliary facilities be neglected e.g. within a prefeasibility study?’ The presentation will show the monetary relevance and significance of these auxiliary facilities and introduce a guideline for cost estimators. PROBLEM DEFINITION The overriding interest of an underground mining operator is to exploit the commodity with the maximal quality by minimum cost and time expenditure. If a new operation shall be installed, it has to promise profitability. Therefore, predictive economic feasibility studies are performed in advance of installation. Herein, all cost expenditure for installation and operation of the future underground mine is determined and compared to the expected income by selling the raw material. The described interest of the mining operator is the starting point of the research project ‘Development of a systematic cost-calculation method for building services in underground mines’. While economic feasibility studies for future operations are focused on the profitable exploitation of raw materials and the efficiency of the accompanying necessary production processes, auxiliary actions are only considered rudimentary. Necessary production processes, as well as auxiliary actions regularly require classical building services, which are normally performed in construction business on the surface in the same manner. By performing building services like masonry or concrete works in underground mines, fixed facilities shall be set up in order to enable or support the raw material production. Production enabling fixed facilities are varying from small concrete foundations for conveyor belts or other infrastructural elements to upstream processing plants situated in the mine workings. While such fixed facilities are essential parts of the production process chain, supporting facilities underground shall increase the efficiency of the mining operation. Workshops, control rooms and social installations are only a few examples for supporting facilities. Those could be situated on the surface as well, but the efficiency increases significantly by installing them underground. Especially supporting facilities are evading from the main interest of the mine operator, since they are only indirectly connected to the production process. The building costs are oftentimes only roughly assumed."

Jan 1, 2017

"A commercially available through-the-earth (TTE) communications system was evaluated at an underground coal mine in eastern Kentucky. This field study was conducted as part of a larger multisite evaluation of available TTE systems. The mine detailed in this paper was idled at the time of the study, which provided the nearest practical representation of a postevent mine shutdown environment. For this study, surface-to-underground and undergroundto- surface communications were tested. Standard deployments of the TTE system using the manufacturer’s recommended procedures were able to achieve clear communications between underground and surface locations. Other arrangements of the units yielded mixed results. Future experimentation is planned to further examine the phenomena observed at this mine IntroductionThe ability to establish effective communication between surface and underground personnel after a mine event is essential for both evacuation and rescue efforts. Current wireless underground communication technologies are reliant on intermediary physical infrastructure, such as antennas and repeaters, to enable underground communications. As such, communications are easily disabled during a mine event because of the inherent vulnerabilities to physical damage (Damiano, 2012; National Academy of Engineers, 1970; Yenchek et al., 2011). A true emergency communications system would function regardless of a mine’s physical state. Through-the-earth (TTE) wireless communication technology only requires the use of a single transmitter and a single receiver to achieve point-to-point communication through solid strata. With this capability, TTE systems have the potential to serve as a true emergency communications platform."

Apr 1, 2016

By C. V. Deutsch, J. B. Boisvert, M. A. Cuba

The amount of information available for characterizing a deposit increases over time due to the continuous acquisition of data during mining. This additional information is collected from different sources, including geologic mapping, production data and infill drilling. Throughout the lifetime of a mining project, the block model and the mining sequence are periodically updated to account for this new data. In general, the acquisition of additional data increases the accuracy of the block model, reduces uncertainty in ore/waste limits and clarifies the optimal mining sequence. There has been extensive research on mine planning, but current techniques do not consider the decrease in uncertainty as additional information becomes available. Conventional paradigms assume either 1) the kriged model is correct and uncertainty due to multiple realizations does not change the mining sequence, or 2) the mining sequence is unrealistically adapted to each realization. A new paradigm is proposed for evaluating minable reserves of surface mining projects, which accounts for the acquisition of additional information in the design of the long term mine plan. Multiple scenarios characterizing the dynamic nature of mining and data collection are created. In the proposed methodology, the performance of the long-term mine plan depends on both mining and data acquisition strategies. Each scenario considers the same extracted volume for the first period, resulting in a set of scenarios that diverge from a common initial period, accounting for how the mine may develop over time as new data are acquired and provide a more realistic evaluation of reserves with an appropriate level of uncertainty. A synthetic example is presented to illustrate the implementation of the methodology and the benefits over conventional paradigms.

Jan 1, 2013

By J. M. Gambogi

Demand for titanium minerals and pigments was nearly unchanged in 1996 compared with 1995. However, through mine expansions and process optimization by the TiO, pigment industry, the available supply of titanium minerals and pigments increased moderately. At the end of 1996, exploration, development and expansion programs were ongoing in the mining sector. But expansion projects in the pigment sector were delayed pending increased demand.

Jan 1, 1997

By Jerry Harrington, Brad Wigglesworth, David C. Beling

Commercial operations at the open pit, heap leach Crofoot Mine commenced in April, 1988. Approximately 13,600 tonnes (15,000 st) of low grade pregnant solution are treated daily using a Merrill-Crowe circuit. Acceptable gold recoveries from these low grade solutions can be obtained by optimizing solution pre-treatment prior to zinc addition.

Jan 1, 1990

By Peniti Niskanen

Outokumpu metals & Resources (OMR) is a sub-group of Outokumpu Oy. OMR is a Mining and Metallurgy group of about 75 companies in 16 countries. The main activities are exploration, mine development and, mining and metallurgical processing of base metals.

Jan 1, 1996

By Deepak Malhotra

Is operator training necessary for optimization of flotation plants? The answer is obvious-Yes. The author suggests a three-phase program for operators when new plants are built or new crews are hired in existing operations. Case examples are discussed to illustrate the benefits of operator training.

Jan 1, 1999

By J. Changsheng, Z. Youdi

Based on the criteria of maximum net present value per ton of reserves and on the optimum matching of some other essential parameters, a comprehensive optimization model of surface-mine production rate is developed using system- engineering approaches and using the theory of economy of scale. A mine is then selected to demonstrate the application of the model.

Jan 1, 2000

By M. A. Bothwell

The purpose of this paper is to describe the methods used to select mill discharge screens, and to outline factors which should be taken into consideration when choosing screens for this application.

Jan 1, 2001

By Robert L. Bates

The field of industrial minerals and rocks includes such a wide diversity of materials and occurrences that communication is essential to foster a sense of "belonging? among geologists and other professionals. Besides, exchange of ideas and information is essential in meeting the needs of an ever-expanding world economy. A survey of the field shows to what an extent such communication--especially in the form of conferences and their proceedings--has increased during the past 25 years.

Jan 1, 1995

By V. Nemec

The paper deals with further progress of the space and time models achieved since some of the previous APCOM symposia (1970, 1975, 1980) where original methodology was presented. Various transformations, de- and retectonization of space models, transfer of patterns, interactive time models are among the most important improvements. Enlarged possibilities of practical applications of the developed system are shown.

Jan 1, 1986

By William L. Hodgson

HOARDS was written to fill the needs of an active minerals explorer. It permits retrievals using a number of spatial functions as well as direct relational logic, and enables statistical analysis within the system. Specified for use by non-EDP oriented staff, HOARDS also offers functions to subset, transform points to polygons of influence, and to calculate polygon overlap, enabling ready and efficient conversion of databases containing point oriented sample data to area/volume mine planning format. Both the design and implementation to date, and proposed enhancements are discussed.

Jan 1, 1979

By David M. Shaw, John C. Franklin

A 32-channel warning system for high working level, fan operation, and airlock-doors has been constructed. The working level monitors have a microcomputer for accumulating the pulses, converting to working level, and triggering an alarm at a variable set point and at one working level. The system also detects when underground fans lose power or air doors are open. The system can detect changes in air velocity which indicate surface fan failures or changes in the ventilation system. Using this alarm system, the ventilation engineer will be alerted prior to excessive levels of radon daughters being reached so corrective action can be taken.

Jan 1, 1981