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By H. W. Judges

A 16.5-kt/day underground molybdenum mine is being developed at Questa in Northern New Mexico by Molycorp, Inc., a wholly-owned subsidiary of Union Oil Company of California. Construction of the underground mine began in 1979, and first production is scheduled for early 1983. A gravity block caving method has been selected for mining the ore. Access to the mine will be through a service shaft, development shaft, and a conveyor decline. The shafts are being sunk under contract and the conveyor decline is being driven by Molycorp. The driving of the decline began in February, 1979 with a 10-man mining class. By the first of May, enough men had been trained to begin a continuous operation and by March 1, 1980 the face had reached the 1500 m mark. The heading is being driven with trackless rubber-tired equipment using a three-boom drill jumbo, 2.7 m3 LHD units and 7.3 m3 trucks. Ground support has been by rock bolts and wire mesh, followed by Fibercrete. A 16.5-kt/d underground molybdenum mine is being developed at Questa in northern New Mexico by Molycorp, Inc., a wholly-owned subsidiary of Union Oil Company of California. The new $200-million underground project will revitalize mining and milling activity at Questa, where small scale underground mining first began in 1920. Large scale open-pit mining was initiated in 1965 but now, because of the high stripping ratio, surface mining is being phased out. Construction of the underground mine began in 1979, and first production is scheduled for early 1983. The company expects full capacity - 9 Gg of molybdenum per year - to be reached in 1984.

Jan 1, 1980

By Arthur W. Ruff

The iron-ore beneficiation and shiploading facilities of the Marcona Mining Company are at San Nicolas Bay which is on the Peruvian coastal desert about two hundred and seventy miles south of Lima. The mines are at elevation of 2,500 ft. Crude ore is transported from the Mine primary crushers to the beneficiation plants by ten miles of overland belt conveyors. After the predominantly magnetic ore is reduced to minus 3/4 in. in the secondary crushing plant, the ore is ground by rod and ball mills and concentrated with magnetic separators. The concentrate slurry is pumped to a thickening and filtering installation for desliming and dewatering. Pelletizing is accomplished with a Lurgi and also a Dravo-Lurgi machine. Deep-water shiploading facilities are available close to the beneficiation plants. Figure 1 shows a flowsheet of the general operation. Pelletizing operations are scheduled 24 hours a day and 365 days per year. A maximum tonnage rate with a high percentage of operating time is necessary to produce the three and one half million tons per year required from the two pellet lines. Process control is a major responsibility and of primary concern to all Operating personnel. The particle size, moisture, and chemical composition of the filter cake must be closely controlled to get uniform high-grade pellets. Key points are sampled routinely and analyzed on a two-hour basis to provide the necessary structure and chemical data to maintain a superior final product. The iron content of the pellets is held between 65.3 and 65.8 percent with 4.0 percent Si02. Sulfur is below 0.04 percent and copper is below 0.02 percent in the finished pellet.

Jan 1, 1968

By Christine E. Turner-Peterson

Pore-filling organic material concentrated uranium to form sandstone-hosted primary uranium deposits in the Jurassic Morrison Formation of the Grants uranium region, New Mexico. Petrographic observations and radiometric ages for primary ore in the Westwater Canyon Member require that the organic material was emplaced early in the diagenetic history of the host sandstone; in fact, organic material was emplaced before major compaction. This inferred early emplacement constrains models concerning the nature and origin of the organic material and thus also constrains models of ore genesis. Reconstruction of the burial history of the basin indicates that Late Jurassic-Early Cretaceous time, the interval of inferred emplacement of the organic material, was probably not a time of hydrocarbon generation and migration. Nuclear magnetic resonance analyses, elemental abundances, and isotopic studies provide further constraints on the nature of the organic material, and data from these studies are consistent with a humic acid rather than an oil origin. In addition, the overall tabular shape of primary uranium orebodies and the way these orebodies are suspended in the host sandstone mimics Recent deposits of humate, the precipitated form of humic acids. The critical clue that favors a humic acid origin for ore-related organic material is provided by the nature and patterns of postdepositional alterations that are spatially and temporally related to primary ore, specifically destruction of detrital magnetite and ilmenite (iron-titanium oxide) grains. Humic acids are implicated in the destruction of iron-titanium oxide grains because these organic acids are one of the most effective natural agents in leaching of Iron from these grains. Thus, timing constraints, chemical evidence, orebody geometry, and the nature and patterns of ore-related alterations favor a humic acid origin and suggest that an oil origin is highly unlikely. Because alteration of iron-titanium oxide grains tracks the pathways of humic-bearing solutions through the host sandstones, it is possible to trace these solutions back to their source. Alteration patterns in the Westwater Canyon Member suggest that the humic-bearing solutions originated as pore fluids in the mudflat facies of the overlying Brushy Basin Member and moved into adjacent sandstones during early dewatering of the mudstones. The humic acids precipitated, by the process of cation loading, in tabular layers. Uranium was concentrated within these tabular layers by complexation with the humic acids to form primary uranium orebodies.

Jan 1, 2013

By Ashish Ranjan Kumar, Barbara Arnold, Luis Sanchez Gonzalez

The health and safety of miners is critical in the industry. Prolonged exposure to dust-laden air results in irreversible ailments like pneumoconiosis that have a severe impact on their lives. Operations use various personal protective devices (PPEs) to alleviate their exposure to respirable dust. Powered Air Purifying Respirator (PAPR) is one such device that uses high- efficiency filters and positive pressure masks to shield miners from airborne contaminants. Used in the medical and other industries, these respirators efficiently protected healthcare workers during the COVID-19 pandemic. Recently, the mining industry has shown a growing interest in adopting this PPE to ensure safe working conditions for the miners. We present an introduction to the PAPRs and discuss their dust capture efficacy in this manuscript.

Feb 1, 2025

By Ashis Bhattacherjee, Bijay Mihir Kunar

A literature review on quantitative analysis of mine safety studies revealed that investigators use a wide range of statistical techniques for the analysis of mine injury data. Researchers have addressed the various issues of accident causation and prevention through analysis of mine injury data collected from mines. These studies are generally based on historical accident/injury data without considering the injured person/population at risk. In this paper, a public health approach, based on scientific methods of epidemiology, is presented to address mine safety issues. Epidemiology is the scientific study of disease and injury patterns among populations in time and space. Originally, epidemiology was concerned with epidemics of communicable diseases. Then it was extended to non-communicable diseases. Safety researchers found that epidemiologic methods are the best tools for injury research, because the occurrences of injury and the occurrences of disease are quite similar. As a result, some researchers started applying this concept to injury research. This paper presents some of the techniques used in epidemiologic studies and illustrates the application of a case-control study design to evaluate the role of some risk factors associated with injuries in underground coal mines. In this study, the injured persons were identified and, simultaneously, interviews were conducted to find the significant risk factors responsible for occupational injuries in coal mines.

Jan 1, 2011

By Rainer Antretter

"THE CHALLENGE The 14km long, Arlbergtunnel, closed for public traffic during summer 2015, receiving a comprehensive and substantial renovation from 2015 to 2017. The main works discussed here, carried out during 2015, comprise 37 drill and blast SEM/NATM emergency escape tunnels from road level to the ventilation duct plenum have to be constructed as well as eight additional lay-by niches and three transformer tunnels. This presentation comprises the construction ventilation design, designed according to national regulations, suitable for 150 employees working 24/7 simultaneously at more than 40 single working sites lined up along the tunnel. The ventilation-system chosen was utilising two existing shafts for intake/discharge and a cross passage to surface, to handle a total fan power of 1.600kW. DESCRIPTION OF RENOVATION WORKS Linking Tyrol and Vorarlberg, two Federal States of Austria, the Arlbergtunnel is a single tube two-way road tunnel with vent duct plenum, constructed in the mid-1970s. According to latest EU legislation, additional escape exits have become obligatory. The existing seven cross passage links to the adjacent Arlberg Railway Tunnel, with average spacing of about 1.500m constructed in 2007, an additional upgrade to shorter escape spaces of approx. 400m was now required to comply with the updated legislation. Additional transformer tunnels, lay-by niches and small niches for emergency maintenance use, cleaning and other purposes, as well as a the installation of a new fire main in the invert, coupled with the simultaneous replacement of virtually the entire power and signaling cables, generated several dozen small and large single sites distributed along the 14km of tunnel.Purpose of the 37 walkable emergency escape tunnels is to reach the “upper deck” of the Arlbergtunnel, the vent duct plenum. These have an 180deg curve in plan, inclined at 10% and approx. 60m (65yd) long tunnels, excavated using drill and blast method starting from road level and working upwards to the level of an “intermediate soffit”, the vent duct plenum in the crown of the tunnel. The vent duct plenum is separated into a fresh air part and an exhaust air part, shown in Figure 1. The escape tunnels end with a pressure door in the fresh air section of the ventilation duct plenum. From there illuminated signs show the shortest escape route to the safe area between the road tunnel and the railway tunnel, as shown in Figure 2."

Jan 1, 2016

By R. V. Ramani, K. V. Raj

"The air flow problems in open pit mines are complex. Computational fluid dynamics (CFD) models provide a detailed knowledge of the airflow pattern and velocity distribution, temperature, and pollutant concentration within an enclosed domain of the open pit. A range of turbulent model can be selected for varying complexity and accuracy. Pollutant transport models, however, differ in their assumptions and structure as well as in the algorithm they use; as a result, prediction varies from model to model. This paper presents a study of pollutant transport in an actual open pit mine under stable boundary layer. The objective is mainly to test two turbulence models using the same input conditions, model constants, and similar geometry. Measured data are used to compare results of the two CFD models, namely, the kappa-epsilon (?-e) model and the Large Eddy Simulation (LES) model. Despite the complex synoptic situations, different meteorological input data and the fast changing conditions, the simulation results from both the models are in good agreement regarding the dispersion of pollutants.INTRODUCTION Modeling of contaminant transport under Arctic air inversion is an important step for an assessment of the amount of pollutants within the open pit. The Airflow in open pit mines is of larger scale and does not follow the principles of pipe flow. The air flow problems in actual open pit mines are thus far more complex. CFD models provide a detailed knowledge of the airflow pattern and air velocity distribution, temperature, and pollutant concentration within an enclosed domain of an open pit. There is no known application of CFD in three-dimensional modeling of air flow in large open pit mines. Two equation RANS kappa-epsilon (?-e) and Large Eddy Simulation (CFD) models, however, have been developed to solve the stable boundary layer (SBL) problems in Atmospheric Sciences (Baklanov 2000, Basu and Porté-Agel 2006, Dop and Axelsen 2007, Bandopadhyay et al. 2014). Because an exact flow situation in open pit mines is not known a-priori, it is therefore, necessary to investigate various turbulent models to identify the appropriate model that would simulate the flow phenomena with reasonable accuracy, and predict the contaminant distributions within the pit. Dispersion models differ in their assumptions and structures as well as in the algorithm they use and, as a result, predictions vary from model to model. Furthermore, it is also important to investigate the behavior of a CFD model in simulating a complex phenomenon such as the transport and distribution of contaminants in open pit mine under Arctic air inversion. The simulation of an enhanced period of turbulence in SBL is of particular interest because traditional air pollution dispersion models cannot explicitly treat such intermittent events, and yet the SBL is often the worst-case scenario in an open pit pollution transport"

Jan 1, 2015

By A. Rajoria

A dynamic process model for predicting the fluidized bed roasting of copper concentrates with high arsenic content is presented in this work. Mass and energy balances were performed based on roasting mechanism derived from thermodynamic data of species. The reaction rate data, obtained from pilot plant studies on major reactions, were used in tuning the kinetic parameters of the model. DEAS, a dynamic simulation package, is used in setting up the fluidized bed roaster plant model. The effect of process parameters such as concentrate feed rate, concentrate composition, airflow and cooling water rate on the temperature and conversion of roasting reactions are analyzed. The plant model captures the highly transient conditions occurring during the plant start-up, shutdown and other process perturbations. The application of this model in constructing a virtual plant environment for validating the operating procedures and operator training is presented.

Feb 23, 2014

By R. Benito

This paper describes the development of a life of mine schedule (LOM) for one of the world?s largest known sedimentary Copper-Cobalt districts located in the Katanga Province, Democratic Republic of Congo (DRC). A particular feature of the Tenke Fungurume LOM schedule is the considerable number of pits/phases for scheduling, each competing to provide the best ore available to a capacity constrained process facility. This paper discusses the main scheduling objectives and constraints, data pre-processing as a scheduling aid, the mine scheduling approach, and results and conclusions.

Jan 1, 2011

By A. Taghavi, I. Hassan, A. Solecki

"The Eglinton Crosstown Light Rail (LRT) Project is part of an $8.4 billion investment to expand transit in the Toronto, Canada area and is the largest transit project initiated in Province’s history. Settlement control and impact to over 1400 adjacent structures due to tunnelling was identified early as a critical project risk. The ground conditions along the 10km tunnel alignment consist of water bearing soft ground deposits (clays, sands, silts) which required careful analysis and control during design and construction. This paper will describe the process used to analyze settlements along the numerous of adjacent structures and evaluate achieved settlement results to those used during design. The paper will demonstrate that with the appropriate design specifications, selection of modernized EPB machines, and contractor performance, settlement can be maintained well below typical industry (volume loss) standards, expanding the application and suitability of soft ground tunnelling in sensitive settlement areas. INTRODUCTION The Eglinton Crosstown Light Rail Transit (LRT) Project is part of an $8.4 billion (2010$ CND) investment from the Ontario provincial government to expand transit in the Toronto, Canada area. The project is being developed by Metrolinx, an agency of the Government of Ontario to provide 19 kilometers of dedicated LRT service connecting the City of Toronto from the west to east along Eglinton Avenue. Upon completion in the year 2020, the Crosstown will be the first LRT constructed in Toronto. It will link regional and local transit, cut travel time along the route by half and provide over a thousand jobs during construction."

Jan 1, 2016

By J. Perlacia

Introduction The Bulk Handling Technology has already started its transformation to the Industry 4.0. Having some of the harshest working and environmental conditions of the industry, the possibility of remote analysis and maintenance of the components seems a perfect target to focus on. The most important and expensive tools have been adapted to the digital era during last years, from remotely controlled haul trucks to monitored conveyor belts. However, these big parts of the installations rely in smaller parts that have been left aside for a while, mainly due to the difficulty to adapt them to IoT (Internet of Things). The paradigmatic example is the lack of monitored rollers whereas all the other components of the conveyor belt installations (the belt itself, motors, drums etc.) were monitored some time ago. The main problem is that a failure of a single roller can cause the stop of the whole conveyor, due to the possible damages to the belt, thus the implementation of an integral monitoring system of all the components of the conveyor is a must. The R&D Department of ULMA Conveyor Components, has been working since early 2012 on the development of Monitored Rollers, facing all the problems until its final installation in very different demanding conveyors, from the Australian extreme heat to the freezing cold Norway. All the tests done under actual working conditions, in real installations, have given a valuable knowledge in the identification of problems, their solution and the final advantages of a roller monitoring system. Background and Current State The malfunction of a single roller in certain conveyor belts can suppose the standstill of the whole installation until its replacement, due to the risk of greater and more expensive failures like the rip of the belt. In the case of a bulk handling installation where a continuous supply of material is necessary, an unexpected stop of one hour could entail huge economical losses. What’s more, many conveyor belts are several kilometers long or the access to some parts of them is very complicated. Due to these difficulties the inspection and maintenance operations can become expensive and hard going, with staff going over the whole area checking the correct condition of the conveyor and rollers, which means a dangerous activity. As in many other industry products, the condition of rollers can be recognized measuring key parameters like the temperature of the bearings, the vibration level etc. The traditional way is to use the characteristic noise of a failing bearing, but this method usually implies to change several rollers because the maintenance team is not able to identify a single source of the noise. In recent years different attempts to measure the temperature of the bearings have been made, but the result is not accurate enough due to the proximity of the rollers in the idlers

Jan 1, 2019

By Charles Dumaresq

The management of mine tailings poses a complex range of potential risks, including physical risks, such as the risk of catastrophic failure of a tailings facility and chemical risks such as the risk of long-term leaching of contaminants into the downstream environment. If these risks materialize, they can lead to a wide range of impacts on people and the environment, including human fatalities and severe impacts on downstream ecosystems, and the costs of recovery borne by industry, communities, governments, and society as a whole can be immense. Tailings facility failures in Canada (2014), Brazil (2015 and 2019), South Africa (2022), and in other locations around the world underscore how high the stakes are when mines produce and manage tailings (WISE Uranium Project 2019). Understandably, many people do not trust the mining industry to manage tailings responsibly. As an industry, it is our responsibility to manage tailings in a manner that is responsible and strives to minimize harm associated with tailings management, including effectively managing both the physical and chemical risks associated with tailings. Standards have an important role to play in responsible tailings management by setting expectations for standards of care and providing a means to measure and report on performance. In jurisdictions with strong legal requirements for tailings management, standards play a complementary role, pushing performance improvements in areas that may be difficult or impossible to address in legal requirements. In jurisdictions where legal requirements are lagging, standards may represent the de facto leading practice and may be the primary tool to help ensure responsible tailings management. Implementation of standards can help companies demonstrate that tailings are being responsibly managed and help build trust and credibility. Most importantly though, standards are important tools to help ensure that the risks associated with tailings are reduced, and that remaining risks are effectively managed. However, we must recognize that conformance with standards can have a down-side – the proverbial two-edged sword. Having standards is vital but there is a risk that implementing standards becomes a “box checking” exercise, with ongoing conformance leading to complacency. We must not allow ourselves to fall into the trap of believing that, just because we are complying with applicable standards and laws, we are therefore doing our best, and that “it can’t happen to us.” In addition, if conformance becomes the goal and the standard does not have mechanisms to drive continual improvement, then once the standard is met, there may be no incentive to improve. The point of complying with standards is not to pass the test. The point is to manage tailings responsibly, prevent catastrophic failures, and minimize harm. The point is to do better, because we must do better. To do that, we need to strive not for conformance, but for excellence in tailings management, driven by continual improvement and a quest to do better.

Feb 1, 2025

By K. L. Lownie

For research and test data to serve a useful purpose, it is essential that it be derived from some known standard test procedure that allows for comparative analysis as well as independent replication and verification. Fan performance data provided by manufacturers is not absolute, and is influenced by the geometry of the test installation. For these reasons, fan test standards have been prepared in order to establish a clearly defined test procedure that allows for comparison of different fan designs, and also allows for the independent verification of test data. Internationally recognized Standards such as BS848, ISO5801, and AMCA 210 etc. are highly prescriptive, and precisely specify test duct configurations, measurement procedures, measurement planes and instrumentation to be used. Provided the laboratory tests are conducted strictly in accordance with the relevant Standard, the performance data will accurately reflect fan performance within the appropriate tolerances for efficiency, pressure and flow when tested in the defined configuration. Major differences in performance exist between a fan tested in accordance with a Fan Test Standard, and an identical fan installed in a mine ventilation system. The aerodynamic performance of any fan will be influenced by the quality of the fan manufacture, the flow system within which it is operating, the location of measurement planes, and the system stability. The flow distributions present in a standardized Laboratory test are unlikely to be repeated in mine ventilation systems, and this will also disadvantage fan performance. Unless the fan supplier takes all of these influences into account, there will an inevitable reduction in fan aerodynamic performance, and the end user will experience a shortfall in expected flow through the mine. The effect on fan performance can range from minor inconvenience to catastrophic fan failure resulting in major rectification costs and significant loss of mine production.

Jan 1, 2009

Choosing the right valve for corrosive, abrasive slurry applications requires exacting analysis and a comprehensive understanding of the complete slurry process. Within the realm of flow control in abrasive and corrosive slurry applications, there is no room for a one-size-fits-all approach. To ensure minimal maintenance, maximum uptime and the lowest overall cost of ownership, the slurry processing toolbox must contain countless alloy and elastomeric pairings ? each carefully targeted to the particular process medium and conditions. This materials selection process is best tackled by turning to expert slurry application engineers and valve product managers who work closely with customers to specify the optimal valve for the given parameters. ?When plant operators and design engineers apply conventional valves in abrasive applications or use metal seated valves or simply apply the wrong valve for a particular flow control situation, it typically leads to rapid valve failure, the potential for hazardous leakage, unexpected shutdowns and costly downtime,? said Cal Cobb, valve products manager for Weir Minerals North America, manufacturer of Isogate slurry valves for service in mining, minerals processing and metallurgical environments.

Jan 1, 2011

By Toby Mayo, Tassos Grammatikopoulos, Massoud Aghamirian, MARK FEDIKOW

The Zoro pegmatite project in east-central Manitoba occurs 20 km east of the historic mining town of Snow Lake. A composite sample (Master Comp) was prepared fromthree pegmatite zones within Zoro Dyke “D1” including the North, Central, and South Zones for mineralogical analysis and heavy liquid separation (HLS). The mineralogical examination was conducted on a subsample crushed to ca. P80 of 600 μm to determine the overall mineral assemblage, liberation of spodumene, and assess the potential recovery of spodumene by flotation. XRD and QEMSCAN results show that the sample consists of spodumene (10.5%), quartz (29.3%), plagioclase (29.0%), K-feldspars (21.3%), micas (5.1%), tourmaline (2.9%), and Fe-Mn-phosphates (0.1%). Spodumene is well liberated (88%), but also forms complex particles (7%), and middlings with quartz (4%). Liberation of spodumene increases from 81 in the + 600 μm to 95%in the − 106 μm size fraction. Liberation of quartz, feldspars, and micas account for 89%, 94%, and 83%, respectively. Electron probe micro-analyses and LA-ICP-MS showed that the average Li concentration is 3.7% in spodumene, 2196 ppm in micas, 1001 ppm in tourmaline, and 115 ppm in K-feldspars. Thus, spodumene accounts for 96%, micas 2%, Fe-Mn phosphates 1%, and both K-feldspars and tourmaline for < 1% of the total Li in the sample. The mineralogical data indicate the potential to recover spodumene by flotation with minimal Li losses due to other than spodumene carriers. Heavy liquid separation was conducted on the Master Comp which was crushed to − 6.4 mm, while the − 600 μmfractionwas removed fromthis test. The coarse fraction − 6.4mm/+ 600 μmwas subjected to HLS tests with eight heavy liquid-specific gravity cut-points (2.65 to 3.10 g/cm3). HLS indicates that it is possible to produce a high-grade lithium concentrate (close to 6% Li2O) after the rejection of iron silicates with magnetic separation.

Sep 16, 2020

By E. R. Hoskins

The Gulf Coast States ranging from South Texas to Alabama contain vast resources of lignite ranging in energy content from about 4000 to 7000 Btu/lb (as-received) with sulfur content ranging from about 0.5 to 2 percent. Currently, the strip mining rate is about 35 million tons per year in Texas and essentially zero in the other Gulf Coast states. Estimates of future mining rates are as high as 310 million tons per year by the year 2000 with 240 being in Texas. In this paper, we examine the life cycle of the surface mineable lignice based on the most recent estimates of surface mine recoverable resources with two scenarios. The first indicates that a 310 million tpy rate could be sustained for only 15 years while the second scenario suggests that the 310 million tpy could be sustained for 25 to 30 years. If lignite resources are required beyond those that are surface mineable, the deep basin lignite will be developed. Five strategies for developing deep basin lignite are discussed.

Jan 1, 1983

By N. B. Pundari

Proper selection of large walking draglines, based on sound engineering principles and field experience, has not kept pace with the large capital expenditures needed to buy these stripping machines. The use of large walking draglines for stripping overburden in US surface coal mines grows steadily, but equipment selection continues to pose problems. An improper size, model, make, or spoil reach selected for a particular stripping application results in additional, unnecessary coal production costs. Large walking draglines are being used to dig deeper tar sands at the Syncrude operations near Fort McMurray in Northern Alberta, Canada. This application is compared with typical deep digging operations and dragline use prevalent at typical US strip mines.

Jan 4, 1981

By D. J. Rose

The San Miguel Mine is owned by San Miguel Electrical Cooperative, Inc. and operated by Atascosa Mining Company, a wholly-owned subsidiary of Morrison-Knudsen Company, Inc. This multiseam, single-zone lignite surface mine is located near Jourdanton, Texas, 110 kilometers (68 miles) south of San Antonio. Lignite extracted from four closely-spaced seams is used to fuel the 400-MW San Miguel Power Plant. Recovery depths range from 7 to 37 meters (25 to 120 feet). The mine began stripping operations in the spring of 1980 and now produces approximately 2.5 million tonnes (2.8 million tons) of lignite annually. Atascosa Mining Company is responsible for production, maintenance, engineering, and management services. Production responsibilities include topsoil removal, overburden removal, lignite mining, spoil pile regrading and topsoil replacement, as well as ash disposal and construction and maintenance of water retention and diversion facilities.

Jan 1, 1984

"From April 22 to 28, the eyes of the tunneling and underground construction world will be on San Francisco, CA, as the world’s most influential underground construction industry leaders gather at the Moscone Center for the 2016 World Tunnel Congress.Recognized as the most important international annual meeting for the industry, the 2016 version comes to the United States for the first time in 20 years and will be hosted by the Underground Construction Association of SME (UCA of SME). The conference will be held in lieu of the UCA’s biennial North American Tunneling Conference and will bring the strengths and resources of the UCA of SME and the International Tunnelling and Underground Space Association (ITA). The result will be a conference with unmatched technical programming and a showcase of more than 200 exhibiting companies.A program committee led by Randy Essex of Mott MacDonald, Lonnie Jacobs of Frontier Kemper Constructors, Michael Mooney, of the Colorado School of Mines, Priscilla Nelson, of the Colorado School of Mines and Amanda Elioff of Parsons Brinkerhoff formed the program committee and worked for more than two years to build the program. The result is four technical sessions with five tracks in each session and 185 oral presentations.“One challenge was the sheer size of the group that would be assembled, perhaps 2,500 attendees or more, and the large number of abstracts we were likely to receive,” said Essex. “ We investigated extending the conference a fourth day, but that was not workable with the Moscone Center. We settled on having five concurrent technical tracks – something that has not been attempted in past NAT or RETC conferences to my knowledge. The next step was to develop suggested session titles that would span the breadth of subjects that would interest conference attendees as well as serve the conference theme.”"

Apr 1, 2016

By D. A. Newman

The accurate prediction of mine profitability is essential for success in the present minerals market as is the ability to quantify the influence/of variations in revenues and costs on cash flow. A menu based spreadsheet template has been developed to determine annual cash flow, maintain depreciation schedules, and estimate labor and operating expenses. Sensitivity analyses may be conducted to determine the effect of productivity upon mining costs and the effect of selling price escalation upon rate of return. The advantage of this approach is that it can be used by a wide variety of professionals without extensive computer experience.

Jan 1, 1988