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By M. A. Alan

The Bellavista Gold Deposit lies 75 Kms north west of San Jose, the capital of Costa Rica, Central America and 3 Kms north east of Miramar, in the Province of Puntarenas. The total road distance from San Jose to the deposit is 120 Kms all paved road except for a 2.5 Km graded, gravel road on the property (Figure 1). Infrastructure services in the Miramar-Puntarenas area are well developed with electrical power distribution, a modern port facility and community services being available. The deposit lies on the south west flank of the Tilaran Mountain Range between an elevation of 550 and 800 meters above sea level. The local topography is steep, originally covered with pre-montaine, tropical wet forest vegetation which has been largely destroyed due to clearing for cattle grazing. The annual rainfall is approximately 2,950 mms, 90% of which occurs between May and October.

Jan 1, 1992

By D. R. Wilburn

This summary of international mineral exploration activities for the year 2009 draws upon information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on industry exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities by the mineral industry based upon these data. Two types of information are reported and analyzed in this annual review of international exploration for the year 2009: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia, and 2) information on regional and site-specific exploration activities that took place in 2009 and were compiled by the USGS. The MEG information summarizes planned company budgets for worldwide exploration activities in 2009, primarily for base metals (copper, lead, nickel and zinc), diamond and precious metals (gold, platinum-group metals and silver). Information on uranium exploration was included in the MEG overview for the first time in 2007, although this information was not included in the USGS analysis prior to 2008. The MEG survey methodology was changed in 1999 to include companies with exploration budgets greater than $100,000, as well as those companies included in prior studies whose anticipated budgets were above $2.9 million. MEG estimates that its post-1999 surveys cover at least 90 percent of world nonferrous nonfuel mineral exploration budgets. The 2009 survey is reported by MEG to cover an estimated 95 percent. Companies who chose not to participate in the MEG study, private companies that do not publish data and government-funded exploration activities make up the majority of the remaining 5 percent. MEG included 86 more companies in its 2009 survey than it did in 2008.

May 1, 2010

By Ali Ahmadi, Andreas Rausch, Angela Binder, Stefan von der Mark, Dhananjeyan Jeyaraj, Jana Thomas, Nils Nöther, Stefan Wittek, Thomas Ulrich, Eleni Gerolymatou, Mario Kolling, Helmut Mischo, Michael D. Martin, Tugba Sen, Jens-André Paffenholz, Erik Farys, Oliver Langefeld, Wilfried Ließmann

This paper outlines the MOVIE project, which is dedicated to the development of a digital twin for an underground laboratory at the research and education mine “Forschungs- und Lehrbergwerk Reiche Zeche” in Freiberg (Germany). Data from induced rock deformations and temperature fluctuations is collected using fiber-optic sensors. The objective of the project is to establish a virtual laboratory for real-time analysis of the interactions between geology, geomechanics, geometry and ventilation. This will be achieved by integrating models from these disciplines with artificial intelligence, creating a sophisticated hybrid model. The insights gained will enhance safety and efficiency in mining through improved digital planning options, ultimately contributing to more effective resource management and operational decision-making in different mining environments.

Feb 1, 2025

By R. J. Hickson

From 1993 through 1999 Cyprus Amax Minerals Company successfully completed eight major construction projects around the world. Six greenfield mines were brought into production, an ongoing operation was completely modernized, and an environmental issue was appropriately remediated. The projects stretched over three continents, from arctic Russia to the Atacama Desert, from 16,000feet to sea level, from city suburbs to remote wilderness, from a low of $130 million to over $1 billion. Open pit and underground; mill and leach; gold, copper, molybdenum, and coal were all encompassed. The breadth of diversity experience from these projects inspired Cyprus Amax to create a “best practices” project management protocol, to steer corporate expansion into the next millenium. This paper summarizes those best practices, while high-lighting project management pitfalls to avoid.

Jan 1, 2000

By T. Mudder

The objectives for closure of a hard rock mine include minimizing long term environmental liability, attaining regulatory compliance, and maintaining geotechnical stability, while closing as cost-effectively as possible. Proper planning for closure should come during the feasibility study, design and permitting phases, and during operations as updates. The lack of a proper or updated closure plan can result in severe environmental and economic consequences. Effective mine closure is the result of a combination of innovative concepts, long-term commitments, and multi-party cooperation. The purpose of this paper is to discuss concepts, commitments, and cooperation as they relate to an effective closure plan.

Jan 1, 1999

By JIACHENG XIE, Juanli Li, Wenyong Du, Tao Cui, Mengyao Dong, Pengfei Huo

The operation of intelligent coal mining in complex geological environment is still unable to realize automation. In order to realize the autonomous cutting of fully mechanized mining equipment and improve coal production, a mining and transportation equipment dynamic advancement path planning method based on spatial kinematics coordinate deduction prediction and real-time correction prediction of coal-rock state identification of equipment cutting current index are proposed. Firstly, the spatial motion law of the mining and transportation equipment is analyzed, and the mathematical model of the spatial motion of the mining and transportation equipment is established. The relationship between the adjustment of the shearer rocker arm and the pose change of the scraper conveyor is determined, and the coordinate deduction model of the spatial advancement position of the equipment is determined, which provides a theoretical basis for the advancement path planning of the mining and transportation equipment. Then, on the basis of the mathematical model construction, combined with real geological data and equipment information, the three-dimensional dynamic planning of the advancement path of the mining and transportation equipment is carried out from the two dimensions of the horizontal advancement direction and the shearer walking direction. At the same time, the relationship between the cutting current index of shearer and the state recognition of coal-rock mass is analyzed, and the coal-rock mass state identification of cutting current and the adjustment of rocker arm model is constructed, and the real-time dynamic correction of three-dimensional path is carried out, so that the planned path can better adapt to the sudden change of real geological environment. Then, using the unity3d virtual reality technology, a simulation system for the horizontal advancement path planning of the virtual mining and transportation equipment is constructed, which simulates the real advancement operation process of the mining and transportation equipment and conducts advancement training. Finally, the dynamic advancement scheme update prediction based on the existing actual cutting but ahead of the actual cutting is realized in the virtual scene, and the optimal scheme is transmitted into the existing prediction cutting system to guide the actual physical equipment mining. The path planning method can control the coordinate position error of the advancing cutting path within 15 mm, which provides ideas for the research on the advancing path planning of fully mechanized equipment.

Nov 22, 2022

By Stephen Semeniuk

Working with junior mining companies as a valuer, my experience with regulators is that simplicity works and the sales comparison method is the way to go. What I like about Mr. Ellis?s approach (as in his Table 7) is the integration of commodity prices with the timing of acquisitions and the implication of price changes in gold on the adjustment of individual project valuations. However, the sample gold-related appraisals in Ellis?s paper are pre-2008 transactions and readers should be made aware of the current market for such projects. Before moving on, to be noted is that the effective date of the Las Brisas appraisal (Ellis?s sample Appraisal 3) is Feb. 10, 2006; given that the subject value of Transaction 9, Choco 10 in Ellis?s Table 6 was listed as $353 million for a 95% interest in the con-cession, I am uncomfortable accepting that the acquisition was suddenly worth the adjusted value of $1,205 million (as given in Ellis?s Table 7). In some cases, illiquidity discounts can apply, and commodity-wise, in the one-month period between the acquisition in January 2006 and the adjustment to the Las Brisas conditions as of February 10, 2006, the indicated gold price change was only 41 cents/g ($12.60/oz); i.e., from $17.50/g to $17.91/g ($544.40/oz to $557/oz).

Jan 1, 2012

By Richard L. Stein

INTRODUCTION Increasing a miner's chance of surviving a disaster requires advance planning for emergencies, adequate training of personnel, and the provision of proper survival equipment. It is extremely important that fires and toxic gases be detected early, and that warning systems such as stench, audible and visual alarms, and communications systems be provided to allow timely escape. However, situations do occur where timely warning is not provided and immediate escape is not possible, regardless of the precautions that are taken. Under such circumstances, a combination of new per¬sonal protective devices and old techniques can provide protection that is adequate to save a miner's life. SELF-RESCUE EQUIPMENT Self-rescuers are devices which provide a short-term supply of respirable air under the potentially lethal con¬ditions following a mine disaster. Functioning either as filtration devices for the elimination of carbon monoxide (CO) or as oxygen supplies, self-rescuers allow an endangered miner a limited amount of time in which to effect an escape or reach a place of temporary safety. Carbon-Monoxide Self-Rescuers For almost 50 years, filtration self-rescuers have protected miners' lives following explosions or fires. Designed to eliminate carbon monoxide from inhaled air, the first of these devices was approved in the 1920s and has evolved into the two units that are approved today-the Mine Safety Appliance (MSA) W-65 and the Draeger 810. Both of these units rely on the cata¬lytic conversion of very toxic carbon monoxide to rela¬tively safe levels of carbon dioxide (CO,). As shown in Figs. 1 and 2, both of these filtration self-rescuers operate in the same manner. On inhalation, the mine air passes through both coarse and fine filters that remove the dust, preventing the dust from coating the chemical beds or entering the miner's mouth. The air then passes over a drying agent that removes water vapor; this is required to prevent the water vapor from poisoning the catalyst. Subsequently, the dried air passes over the Hopcalite catalyst, where carbon monoxide is converted to carbon dioxide. Then, the air passes through a heat exchanger that reduces the temperature of the inhaled air. Finally, the air is inhaled by the user. Air exhaled by the user passes through the heat ex¬changer and exits the device through an expiratory valve. Both units of this type are subject to certain limita¬tions: 1) The units do not protect the user against oxygen¬deficient air; when air is inhaled through this type of self-rescuer, the device only removes the carbon mon¬oxide. If the mine air contains less than 15% oxygen, anoxia is inevitable. Symptoms of anoxia include dizzi¬ness, shortness of breath, quickened pulse, and deeper and more rapid respiration while the victim is at rest. During heavy exertion such as would be expected dur¬ ing escape efforts, a 15% oxygen level can cause loss of consciousness. 2) The units do not protect against excessive levels of carbon dioxide. Available data on carbon monoxide and carbon dioxide concentrations following explosions or fires are limited, but there are indications that the carbon monoxide concentration can rise to 2% and the carbon dioxide concentration can reach 5 or 6% of the mine air (by volume). In some situations, the in¬haled air could contain up to 6 or 7% carbon dioxide. At a carbon dioxide concentration higher than 2%, breathing patterns can be affected adversely. At a con¬centration of 6 or 7%, the effects include severe respira¬tory distress, with unconsciousness resulting from exer¬tion such as that needed for escape activities. 3) The units do not protect against high inhalation temperatures. The catalytic oxidation of carbon mon¬oxide to carbon dioxide is an exothermic reaction that evolves a large amount of heat. As the carbon monoxide concentration increases, the temperature of the inhaled air also increases. Available data show that above 1.5% carbon monoxide, the air inhaled through some self¬rescuers can be as high as 90°C (194°F). At those

Jan 1, 1982

By A. V. Castelli

Weighting materials as we know them today were first recognized in 1922 by B. K. Stroud1. Stroud, who was supervisor or the Mineral Division of the Louisiana Department of Conservation, tested galena, cement and hematite as weighting materials and successfully used hematite to make a "heavy mud". The first use of barite was in the fall of 19222 . The process of adding heavy minerals in mud was patented in 1926 by Stroud and National Pigments and Chemical Company, a subsidiary of National Lead Company now NL Industries, Inc. The ground barite was marketed as BAROIDR barite.

Jan 1, 1983

By Nicholas Chlumecky

A practical method is described for determining or checking whether underground supports such as props, posts and mechanized longwall supports have bearing areas of proper size in relation to the type of ground or floor strata on which they are standing, It is felt that this information provides an approach to eliminate, as much as possible, a potential grave source of error during the selection of roof supports. This would also affect the choice of costly mechanized longwall equipment where it is possible that the size of the bearing area is not as carefully determined as, for instance, the design strength of structural components.

Jan 1, 1967

By D. E. Hulse

"Social License, the consent of the neighbors and community to develop and operate a mine, has received little attention until recently. Though social license is intangible, not having this relationship with the community carries operational and economic risk to a project, potentially including future impairment of the asset. Acquiring and maintaining social license is a long term personal relationship. It requires communication, commitment, consistency, and transparency. This presentation will review the building blocks to acquire and maintain a social license based on experiences with mining projects in Mexico. INTRODUCTION Mining has been a source of controversy for at least 500 years. “Since there has always been the greatest disagreement amongst men concerning metals and mining, some praising, others utterly condemning them” (Agricola 1556). In 2015 it is widely recognized that mineral resources and reserves must give due regard to the social license in order to operate. “Most commonly, the SLO is understood to refer to ‘the ongoing acceptance and approval of a [project] by local community members and other stakeholders that can affect its profitability’ (Moffat 2014).” “Social License to Operate has gained traction, in part, because it is also a concept which – while remaining poorly, technically defined – is generally easily and widely understood by community stakeholders.” (Bice 2014) A generation ago I learned that mining is based on a stable platform supported by three pillars, geology, mining and metallurgy. The three legged stool is a very stable structure.In 2015 it seems that we have added some other legs to the stool. The JORC code addresses “social, and governmental factors” (JORC 2012), and refers specifically to social license in Section 4 of the Report Template “Estimation and Reporting of Ore Reserves”. The Canadian CIM Guidelines refer to “environmental, legal and social data” (CIM 2003).Compared to these the 2014 SME Guide is positively verbose stating “a discussion of any potential social or community related requirements and plans for the project and the status of any negotiations or agreements with local communities,” (SME 2014) although in all cases the scope of this disclosure is left at the discretion of the Competent Person."

Jan 1, 2016

By W. C. Painter

In 30 years of experience in Western Mines as Master Mechanic, Chief Electrician and Field Service Representative of Joy Manufacturing Company, I have seen a steady rise in the acceptance of A-C powered equipment for underground use in coal mines. This is also true for potash, gypsum and trona mines where coal mine type equipment and methods are used. This paper covers a large section of actual western mining practice with no theoretical calculations or predictions.

Jan 1, 1959

By J. K. Grunig

A process consisting of leach, continuous countercurrent decantation, resin-in-column ion exchange, evaporative crystallization of beryllium sulfate, and decomposition of the sulfate was developed for Spor Mountain, Utah, ores. The process is metallurgically sound, has a minimum of process steps, and is applicable to a wide variety of beryllium ores. The most novel aspect of the process is a resin system of ion exchange which is highly selective for beryllium and which rejects substantially all impurities except for minor amounts of aluminum, magnesium, fluorine, and sulfate in addition to beryllium. The oxide from sulfate decomposition meets specifications of potential users.

Jan 1, 1982

By H. W. Hintze

Coal handling facilities, such as utility plants, coal terminals, ports, manufacturing, processing, etc. Protect themselves against interruptions in coal receipts by maintaining a 60 to 90 day supply in storage. Not too long ago, these storage piles were referred in terms of hundreds or thousands of tons. Today, it is not unusual to have hundreds of thousands or millions of tons in storage. Burn, or shipping and receiving, rates have increased dramatically and storage piles have grown in horizontal as well as vertical dimensions. Fixed systems for delivering and retrieving coal from storage have increased in length and operating capacity and have become highly sophisticated in their operation. With few exceptions, mobile material handling equipment is used to handle all coal beyond the reach of these systems. These machines take excess loose coal from the fixed system to the storage area, place it on the storage pile, compact it, maintain the pile, protect against spontaneous combustion, the spread of fires if they occur, and return the coal to the reclaim system as required, plus many of the small chores around the facility.

Jan 1, 1981

By Jeff Reid, Mohamed Maghari, Nicholas Joens

The Burnaby Mountain Tunnel was an integral part of the Trans Mountain Expansion Project. General Contractor, Kiewit Ledcor TMEP Partnership (KLTP), contracted with McNally Construction to build an underground tunnel between the Burnaby and Westridge Marine terminals under Burnaby Mountain. The pipeline was constructed within a 2.6-kilometre tunnel, eliminating the need to run the pipeline over the mountain and minimizing community impacts. The complexities of this Project led to multiple innovations, including the design of a Tunnel Boring Machine (TBM) capable of excavating through mixed-faced conditions concurrently thus allowing the Project team to complete the tunnel with limited geotechnical information.

Jun 23, 2024

By J. Navoyski, B. Macdonald, W. J. Helfrich, J. L. Bellanca, B. Demich

DISCLAIMER The findings and conclusions in this paper are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention. Mention of company names or products does not constitute endorsement by NIOSH. ABSTRACT The pervasiveness of high-fidelity video games raises expectations of quality, detail, and lighting in virtual reality (VR) applications. However, high-quality models of mining equipment and environments are often not readily available, and developers may not be familiar with the latest techniques, such as physically based rendering (PBR). Because a consistent aesthetic is critical for maintaining immersion and controlling visual stimuli in research as well as in training, researchers at the National Institute for Occupational Safety and Health (NIOSH) created an asset development workflow. This paper details this workflow, including precision modeling and PBR techniques as well as a rigorous review process. It also describes lessons learned in the creation of photorealistic VR assets. BACKGROUND Virtual reality (VR) describes the simulated experience generated by an assemblage of hardware and software that are used to immerse the user. Over many years VR developers targeted the development of virtual environments (VE) toward various purposes: entertainment, the treatment of phobias [1], rehabilitation [2], and training [3]. A large part of the VE development includes digital assets, where digital assets refer to the non-programmed elements including 3D models, audio, and user interface. Because vision provides nearly 10Mbps of data [4] and accounts for the majority of all sensory input combined [5], a focused effort on asset appearance in VEs is warranted. Furthermore, research has shown that higher-resolution imagery increases search performance and training transfer, necessitating high-fidelity assets [6, 7]. In addition to being visually appealing, it is important that the assets and environment are also dimensionally accurate and consistent in order to elicit appropriate responses from the end users as they interact with and among these items [8, 9]. Researchers at the National Institute for Occupational Safety and Health (NIOSH) have developed VEs and digital assets under several research projects over the course of the last two decades [10, 11, 12, 13]. This work has provided researchers with a strong knowledge base for digital asset development. However, the assets themselves have had limited reuse value. Due to the extended timeframes and limited scope of these projects, the previously developed assets are not consistent in visual quality and dimensional accuracy. Moving forward, researchers wanted to minimize future development time and use of resources as well as adopt new asset development tools and game engine technology. Therefore, the aim of this paper is to document a new asset development workflow including geometry, materials, UV layout, and shader implementation combined with review steps in order to produce high-fidelity simulation assets that are accurate with consistent characteristics, using repeatable methodologies that are well documented.

Jan 1, 2019

By Y. J. Wang

A critical path approach is presented for the problem of mine ventilation net- works where regulators and fans are employed to control the airflow distribution which is preassigned. The problem is a classic one which arises in mine ventilation planning. By identifying the analogy between the network for controlled flow and that for CPPI, the applications of the well known CPM technique to the ventilation network problem become straight- forward. The mathematical formulation of the problem is presented and the solutions are illustrated with examples. The effect of booster fans on the total air power consumed in a ventilation network are also discussed.

Jan 1, 1981

By LaTasha R. Swanson, Jennica L. Bellanca

Proximity detection systems (PDSs) for mobile machines have the potential to decrease injuries and fatalities. Early adopters of the technology have identified some challenges, which present an opportunity to explore and improve the integration of mobile PDSs in underground coal mines. The current research study applied the task-technology fit framework to investigate the fit between mobile PDS technology and mining relative to health and safety, from the perspective of leaders at two coal mines. Quantitative results from the study show that mine leaders evaluated mobile PDS favorably for training and ease of use, system feedback, user authorization and experience, and less favorably for safety, compatibility, task completion, and reliability. Qualitative results reveal specific task, mine, and system characteristics that may have influenced leaders’ evaluations. The study includes considerations and suggestions for safe technology integration

By Richard L. Ash

In many instances, blasting exerts the dominant control over the economics and safety of excavation, where the materials involved are too hard and tough to be fragmented efficiently by other means. However, associated with the fragmentation process other effects very often result that are not desirable and may even be hazardous, such as fly rock, air blast, excessive overbreak, and damaging ground virbrations. It has always been the desire of those concerned with blasting to better control the forces involved so as to improve the breakage of materials, but at the same time reduce, or eliminate if possible, the unwanted side effects. Until the last decade or two, little was known of the phenomena concerned with blasting. However, since that time many investigators have studied blast mechanisms produced from both chemical and nuclear explosions, with the result that general concepts of the principles have been developed. But, in general, it is assumed that the energy from the explosion would be propagated spherically throughout the material, the latter of which for convenience of analyses is considered homogeneous and isotropic, i.e., the properties are the same in all directions, However, rocks are not isotropic as a rule, and evidence clearly indicates blasting forces rarely function uniformly or in spherical form as theorized.

Jan 1, 1965

By James R. Jones

It has been 2-1/2 years since the Congress passed the Surface Mining Control and Reclamation Act of 1977 (PL95-87) the Office of Surface Mining every deadline specified in the Act. Hopefully the Congress will begin to realize that specifying unrealistic deadlines does not accomplish the end desire of legislation any sooner -- it only adds to the confusion, and actually hinders orderly, efficient progress. OSM has been sued by all categories of involved parties -- environmental activitist organizations, the states, and the coal operators. This situation has resulted for two reasons: (1) insufficient time was allotted by the Congress to properly develop the regulations and program, and (2) OSM?s philosophy that it must dictate every detail of reclamation operations from Washington, even though many of its people are inexperienced with coal mining. These law- suits are now demonstrating their value. OSM is showing signs of "pulling-in-its horns" and, hopefully, will approach the revised regulations in a more realistic fasion.

Jan 1, 1980