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By K. Awuah-Offei, A. U. Rehman

"Information diffusion potential of a social media user affects how quickly information about a mineral project can diffuse through that user. If management can use social media and network analysis, in community engagement program, to understand how fast and how far information will diffuse to communities and followers of particular social media users, it can selectively focus on the most influential users. This paper proposes a method to examine the information diffusion potential of social media accounts. The work uses Gephi, an open source software, to extract and analyze data from different Twitter handles to predict their information diffusion potential. The work uses case studies of real Twitter users (e.g. mining news organizations and bloggers) associated with mining to illustrate the approach. The case study results show that there are significant disparities in information diffusion potential that will demand selective attention. This research will help mines develop effective social media engagement strategies. INTRODUCTION The mineral industry provides raw material for industrial activity to support our society (Martens and Rattmann, 2001). Mines have changed conventional mining practices to sustainable ones because of the negative impacts of mining and increased public awareness (Wang et al 2016). The concept of sustainable mining is getting mature as stakeholders (e.g., governments, investors and host communities) are getting involved in mining projects (World Economic Forum, 2014). The failure of mining companies to address the demands of these stakeholders might result in failure to acquire social license to operate (Thomson and Boutilier, 2011). The social license to operate (SLO), if granted, is mutually beneficial to all stakeholders. Mines prefer being granted SLO and keeping it to avoid any kind of social unrest due to their operation (Prno, 2013; Moffat and Zhang, 2014). Mining communities can grant different levels of SLO; ranging from withholding SLO to psychologically identifying with the project (Joyce and Thomson, 2000; Thomsan and Boutilier, 2011). Most of the previous work to understand community perceptions and SLO in mining is generally qualitative (ICMM, 2012a; Thomson and Boutilier, 2011; Prno, 2013; Moffat and Zhang, 2014; IFC, 2014). In particular, there is limited work on how community perceptions change over time due to information diffusion (Boateng and Awuah-Offei, 2017). However, SLO changes with respect to time (Yates and Horvath, 2013), which can result in risks that are not easy to predict. Mine managers and engineers have a desire to understand these changes so as to mitigate these risks (Que and Awuah-Offei, 2014; Que et al., 2015)."

Jan 1, 2018

By R. D. Wunder

The Chino Mines Company, a Kennecott-Mitsubishi partnership, located in Hurley, New Mexico, recently completed a $405 million modernization of its mine, concentrator, and smelter facilities. The mine/ concentrator modernization commenced in 1980 and the smelter modernization began during 1982. Modernization of the mine and concentrator facilities involved increasing the mining rate from 98 kt/d (108,000 stpd) to 152.2 kt/d (167,800 stpd). Ore mining was designed to increase production from 20.2 kt/d (22,300 stpd) to 34.0 kt/d (37,500 stpd). A new concentrator was constructed near the mine using semi-autogenous grinding. The new smelter uses the INCO flash smelting process, increasing capacity by 40.8 kt/a (45,000 stpy) to 99.8 kt/a (110,000 stpy) of salable copper.

Jan 1, 1985

By Shawn McWilliams, Aini Sun, Mike Lichte, Greg Colzani

The Allegheny County Sanitary Authority (ALCOSAN) adopted its Clean Water Plan (CWP) in May 2020, as part of a federal consent decree to comply with the USEPA’s Combined Sewer Overflow (CSO) Control Policy. Planned improvements include constructing a new regional storage/conveyance tunnel system, promoting green infrastructure/ source control, and expanding the treatment plant. Preliminary planning for the tunnel system was completed in October 2020. The Ohio River Tunnel (ORT) project is the first of three tunnel projects that make up the regional tunnel system. The ORT project began final design in 2021. This paper discusses the advancements made to the ORT preliminary planning concepts considering property availability, alignment optimization, tunnel boring machine evaluation, contract packaging and delivery schedules.

Jun 13, 2023

By J. Swanepoel, J. H. van Laar, J. C. Vosloo, W. A. Pelser

Deep-level underground mining costs in South Africa are continuously rising due to the increased depth at which gold is being mined, resulting in a rise in virgin rock temperature and an increase in cooling requirements. Therefore, mines must evaluate various ventilation and cooling optimisation projects required to be implemented throughout their life of mine (LOM). This study develops a method to identify and prioritise large capital expenditure (CAPEX) underground environmental improvement projects, to improve thermal comfort underground. The solution presents a ‘multi-criteria decision-making’ (MCDM) process, incorporating the ‘analytic hierarchy process’ (AHP) and the ‘technique for order performance by similarity to ideal solution’ (TOPSIS) into the method to provide for scientific decision-making. These projects are evaluated based on four criteria, namely project risk, the impact on the underground thermal comfort, cost, and implementation time. This study’s solution uses ventilation simulations to determine the impact of the projects on the underground environment. The identification and evaluation of an environmental improvement project to best suit the current economic climate, while improving underground conditions and decreasing the safety risk is an essential aspect of the solution developed in this study. The method was implemented on a mechanised deep-level underground mine and showed that surface refrigeration is the most suitable alternative, which was implemented at the case study mine as validation of the developed solution. The study proves that the MCDM method is an adequate solution to incorporate subjective criteria into the decision-making process, resulting in a scientific and structured approach to making significant and complex decisions.

Feb 17, 2023

By K. Wangerud, B. S. Caruso

A water balance model with deterministic and stochastic components was developed and used for the Gilt Edge Mine Superfund Site, South Dakota, to evaluate risks of contaminated runoff discharging to surface waters based on assumed water treatment plant (WTP) rates for different remedial alternatives. The objectives of the modeling were to use a stochastic approach for analysis of precipitation based on historic records, and for probabilistic estimation of annual and monthly runoff from primary disturbed/mining activity areas that currently requires, or will need, treatment at the WTP, water storage and changes in a major pit, and risk of contaminated water bypass of the WTP to a downstream drainage. Subareas/source areas generating contaminated runoff requiring treatment were delineated. A simple water balance model was used based on precipitation inputs and evapotranspiration and groundwater losses. Annual and monthly precipitation records for Lead, South Dakota were used to estimate precipitation at the mine site. A lognormal distribution was estimated for monthly precipitation. The stochastic software package/Excel add-in “@Risk” was used to generate random monthly precipitation values using a Monte Carlo method based on the distributions. The average annual and monthly distribution of pan and lake evaporation, and groundwater losses were also estimated for the site. Stochastic outputs from the model for the end of each month and year included contaminated runoff requiring treatment, water storage in mine pits and the risk of WTP bypass given different assumed WTP rates. The probability of the time required to dewater the pits was also modeled.

Jan 1, 2002

By Y. Paul Chugh

NIOSH and the Illinois Clean Coal Institute are funding studies on characterization of coal and quartz dust in Interior Basin mines since 2009. Coal dust characteristics vary significantly and, are vital for the development of the engineering controls. This paper presents wettability characteristics of coal dust with respect to its chemical and physical properties, since wettability is considered to be a primary dust control technique. Particle size distribution, inter-particle interactions during wetting and quartz associations with organic and inorganic matter in coal seams is critical for understanding wetting phenomena. Silica content in the un-wetted fractions was found to be very high during wetting tests. Wetting of quartz may be limited by its association to hydrophobic materials as well as buoyancy forces resulting from particle size characteristics and particle-particle interaction in the wetting agent. Temperature of the wetting solution and effective contact time between dust particles and water droplets are found to be two important variables affecting the wettability. The characterization data obtained from this study can be utilized to develop engineering controls.

Jan 1, 2011

By A. M. Whiting

Competition for coal producers and their primary customers has constantly increased during recent years. The effects of the Clean Air Act Amendments of 1990 on the electric utility industry, coupled with the normal complexities of coal production, quality control, transportation and contracting techniques have spurred both buyers and sellers to increase their level of sophistication. This paper will review the basic aspects of the U.S. coal business and explore the commercial approaches which have proven to be most successful.

Jan 1, 1994

By Gary Jackson

Preliminary engineering for the Waller Creek Tunnel was completed in 2001, but the project was held in abeyance until the summer of 2007. This paper describes several features of the revised design, which required significant changes from the original concept. Most notable is the expected replacement of a tunnel boring machine (TBM) by conventional tunneling. The considerable influence of geological conditions on the tunnel vertical alignment is discussed, in particular the impact of the zones of Eagle Ford Shale with swelling potential. Other features which are described include the wide span tunnels and large diameter shaft requirements.

By R. G. Benson, P. R. Wotruba, K. W. Schmidt

Introduction The Fortitude deposit is located in Nevada's Battle Mountain mining district in the central Great Basin region of the Basin and Range province of the western US. The deposit is at Copper Canyon in the southernmost portion of the district, about 19 km (12 miles) southwest of Battle Mountain (Fig. 1). Mining activity in the district began in 1866 (Roberts and Arnold, 1965). Base and precious metals were mined by underground methods intermittently until 1955. Placer gold was first discovered at Copper Canyon in 1912. Moderate scale dredging of alluvial gravel at the mouth of Copper Canyon was conducted by the Natomas Co. from 1944 to 1955 (Johnson, 1973). In 1967, Duval Corp. began large scale open-pit copper mining. (Sayers, Tippett, and Fields, 1968). Copper prices decreased and precious metals prices increased in the mid-1970s so Duval's exploration efforts at Copper Canyon shifted to precious metals. These exploration efforts resulted in the discovery of the Tomboy-Minnie deposits and shortly afterward, the Northeast Extension deposit at Copper Canyon (Blake, Wotruba, and Theodore, 1984; Fig. 2). The Fortitude deposit was discovered in late 1980, after Duval had proceeded with precious metals production at Copper Canyon. Converting the existing plant facilities at Copper Canyon to a precious metals recovery system was completed in 1978 (Jackson, 1982). Production from the Tomboy-Minnie deposits began in early 1979. Precious metals production moved to the Northeast Extension deposit in 1982. In late 1984, after three years of preproduction stripping and mining of the Upper Fortitude ore zone, production from the higher grade Lower Fortitude ore zone began. Currently, Battle Mountain Gold Co. operates the Fortitude deposit. Production from the Battle Mountain mining district before 1967 included 4.6 t (150,000 oz) of gold, 65.3 t (2.1 million oz) of silver, 13.6 kt (15,000 st) of copper, 4.5 kt (5,000 st) of lead, and 13.6 kt (15,000 st) of zinc (Roberts and Arnold, 1965). At the time of Duval's 1967 start-up, ore reserves at Copper Canyon included 12.6 Mt (14 million st) in the East ore body and another 3.6 Mt (4 million st) in the West ore body. Both had average grades of 0.79% copper, 16.1 g/t (0.47 oz per st) silver and 0.86 g/t (0.025 oz per st) gold (Blake et al., 1984). The Tomboy-Minnie deposits collectively contained 3.5 Mt (3.9 million st) of ore grading 3.09 g/t (0.09 oz per st) gold and 9.6 g/t (0.28 oz per st) silver. The Northeast Extension reserves were identified as 1.4 Mt (1.5 million st) of ore with an average grade of 2.9 g/t (0.085 oz per st) gold and 5.1 g/t (0.15 oz per st) silver. Initial total reserve estimates for the Fortitude deposit were 14.5 Mt (16 million st) grading 5.14 g/t (0.15 oz per st) gold and 29.8 g/t (0.87 oz per st) silver (Jackson, 1982). Therefore, before large scale mining, the Copper Canyon area contained a minimum of 102.6 t (3.3 million oz) of gold and 541 t (17.4 million oz) of silver as mineable reserves. The Fortitude deposit reserves as of Jan. 1, 1985 were 10.6 Mt (11 million st) grading at 5.28 g/t (0.154 oz per st) gold and 28.5 g/t (0.83 oz per st) silver. Currently, the company is producing 6.8 t (220,000 oz) of gold and significant amounts of

Jan 7, 1986

Ventilation network modeling in mine planning dates back at least three decades, but it is not widely accepted and/or practiced until the last decade, thanks to the advent of modern computers with their increase d speed and storage space. There are at least half a dozen such modeling software packages available on the market each with different features and acceptance. This paper compares five popular software packages,?? VnetPC Pro, MineVent, VentSIM Visual, VentGraph and MFIRE 3.0. A case study using Missouri S&T?s Experimental Mine is conducted to compare the five software packages in features, interface, output display and user-friendliness.

Jan 1, 2012

By J. Drelich, M. Pawlik

An improved experimental procedure to measure contact angle has been consolidated with coal surface preparation involving polishing with abrasive paper, alumina powder, and a cloth, followed by ultrasonic and mechanical cleaning. Specifically, the captive-bubble measuring technique has been compared with the sessile-drop technique and the former has been recommended for the examination of the hydrophobic properties of coal surfaces. Results of the research program, which is currently under way, on the examination of the effect of the nature, amount, size, and distribution of mineral inclusions in coal, on its wettability are briefly reviewed.

Jan 1, 1999

By M. L. Harris, J. Organiscak, S. Klima, I. E. Perera

"The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH’s Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners’ exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device IntroductionTwo recent regulations have modified operators’ rock dusting schedules in order to meet compliance standards. First, the 80 percent incombustible requirement in intake entries has increased both on-section and out by the- section rock dusting. Secondly, the recent change to the respirable dust regulation has increased the number of respirable dust samples taken per sampling cycle. Previously, when only five samples were needed bimonthly, rock dusting could be scheduled to not interfere with the respirable dust sampling schedule.The significant number of samples now required under new regulations, combined with the need to maintain 80 percent total incombustible content in active mining areas, require the schedules for respirable dust sampling and rock dusting to overlap. Although rock dust is considered a nuisance dust in relation to U.S. Mine Safety and Health Administration (MSHA) sampling, these overlapping schedules raise concerns about the amount of rock dust that potentially is included in the sample. Additionally, the respirable dust maximum was lowered from 2.0 mg/m3 to 1.5 mg/m3 effective Aug. 1, 2016, increasing concern that rock dust contamination may be an issue (MSHA, 2016). Currently, the acceptable practice is to apply administrative controls such as keeping the miners upwind during rock dust application, or to schedule rock dusting during a maintenance shift when the number of miners present is lower."

Jan 5, 2017

By Hernan Fernandez, Khalid Saif F S Al- Khayareen, Volkan Salepciler, Jacek B. Stypulkowski

Wakrah and Wukair Drainage Tunnel, WWDT is 13 km long with a 4.5 m ID sewer water tunnel about 50 to 60 m below ground surface. Integral to the project are several adits with provisions for future connections as well as four work shafts, four intermediate access shafts, ancillary hydraulic structures, and an Odor Control Facility. The shaft depths range from 50 to 60 m. The project is constructed in aggressive ground with aggressive ground water. The construction activities require years of pumping and disposal of the ground water during tunneling operations as well as construction of permanent structures in shafts. Grouting of the corrosive rock mass in corrosive groundwater for the WWDT has been described in detail.

Jun 23, 2024

By Amy McBrayer, Andrea Brickey

Area mining is a surface mining method that allows for efficient mining and contemporaneous reclamation of tabular or bedded deposits, e.g., coal. Mine planning methods for area mines differ from those of open pit metal mines. Area mines in the Powder River Basin (PRB) use various processes for mine planning at both the strategic and tactical stages. With the ever changing commodity markets, it is becoming increasingly important for mine operators to be able to react quickly to the changing business environment. Tools that allow for the development and rapid comparison of production schedule scenarios are key to ensuring agile mine operations. A survey of mine engineers responsible for mine design and production scheduling at coal operations provides clarity on the current mine design and production scheduling processes in the PRB, as well as a discussion on potential solutions to upcoming challenges. In this article, we describe various mine planning processes used by the coal producers in the Powder River Basin. The survey identifies a clear gap in the ability to create comprehensive schedules associated with limited tools and lack of engineering labor needed to frequently conduct the mine design and scheduling process.

Jul 8, 2023

By M. A. Meyer

Underground mining accidents in the USA in recent times have prompted the Mine Safety and Health Administration (MSHA) to review emergency and tracking systems for underground mines. Several communication and tracking systems are available on the market and various systems have been installed in mines around the world. In addition, MSHA?s standard on Diesel Particulate Matter (DPM) requires mines to comply with the final PEL of 160µg/m3 by May 20, 2008. Barrick Goldstrike Mines Inc., Underground Division, has been in operation since 1995 and an extensive control and monitoring network, and a leaky feeder voice network is in place. Enhancements to the communication and control system are currently being implemented to include a PED emergency notification system, wireless LAN with tracking of personnel and equipment in the mine, and a ventilation control system that will use the tracking information and ventilation data to automate much of the mine ventilation system. Expected benefits from such a system would be enhanced communication with miners, emergency notification, location of miners and equipment, energy savings, improved ventilation control, and improved atmospheric conditions in the mine including reduction of diesel particulate matter (DPM).

Jan 1, 2009

By M. L. Harris, J. Organiscak, S. Klima, I. E. Perera

"The National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using an untreated rock dust and a rock dust treated with an anti-caking additive. Using PDM 3600s and 3700s, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH’s Bruceton Experimental Mine (BEM) using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners’ exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device. INTRODUCTION Two factors have combined to renew concern regarding respirable dust measurements and compliance. This renewed recognition is due to two regulations that have modified operators’ rock dust schedules. First, the 80% incombustible requirement in intake entries has increased both on-section and outby-the-section rock dusting. Secondly, the recent respirable dust regulation change that has increased the number of respirable dust samples taken per sampling cycle. Previously, when only 5 samples were needed bi-monthly, rock dusting could be scheduled to not interfere with the respirable dust sampling schedule. The significant number of samples now required under new regulations combined with the need to maintain 80% total incombustible content in active mining areas require the schedules for respirable dust sampling and rock dusting to intermix. This raises concerns about the amount of rock dust that potentially is included in the sampler weight gain. Additionally, the respirable dust maximum was lowered from 2.0 mg/m3 to 1.5 mg/m3 (effective August 1, 2016) increasing concern that rock dust contamination may be an issue. Currently, the acceptable practice is to apply administrative controls such as keeping the miners upwind during rock dust application or to schedule rock dusting during a maintenance shift when the number of miners present is lower. NIOSH’s research examining the quality of rock dust has led to the development of hydrophobic rock dusts."

Jan 1, 2017

By J. Kretschmann, A. Müterthies, T. Rudolph, C. Yang, P. Goerke-Mallet

Catastrophic failures of dams and tailing storage facilities (TSF) have triggered the development of integrated ground monitoring concepts for hazard assessment, risk management and public safety. These concepts are based on knowledge and expertise of persons technically responsible for TSF. The aim is to combine this implicit and explicit knowledge with the data of in-situ- and remote sensors. Risk management for TSF must include a comprehensive monitoring program that integrates data from ground based-, air-borneand satellite-based sensors. Researchers at Technical University Georg Agricola (THGA) in Bochum, and EFTAS, Muenster, Germany, are fusing a variety of sensor data to enhance the capability and performance of TSF monitoring to ensure public safety downstream of TSFs. This paper describes the variety of sensors implemented in numerous research projects. It gives an outlook in terms of planned satellite missions with innovative equipment like hyperspectral sensors. The implementation of the data of these sensors in the analysis will increase the understanding of spatio-temporal impacts of mining activities. Future opportunities are explained by a datacube approach.

Mar 2, 2022

By B. Comley, M. C. Harris

There is as yet no accepted method of predicting flotation frother performance in plant processes based on laboratory scale characterisation techniques. This paper investigates the use of dynamic surface tension, using the maximum bubble pressure method, as a means of evaluating frothers and frother mixtures. An adsorption model is presented, which has been used to quantify the role of frother type and concentration during frother bubble interaction, based on the correlation of model parameters to physical frother characteristics. This approach was found to provide useful insight with respect to blending and selection of flotation frothers to meet specified flotation performance criteria.

Jan 1, 2001

By G. ALBORNOZ, S. Utili, A. AGOSTI, C. VALDERRAMA, R. PELL, N. Morales

The steepness of the slopes of an open pit mine has a substantial influence on the financial return of the mine. The paper proposes a novel design methodology where overall steeper pitwalls are employed without compromising the safety of the mine. In current design practice pitwall profiles are often planar in crosssection and the profile in between ramps especially tend to be planar and defined by a constant inter-ramp angle. Sometimes rock layers exhibiting different strengths require the inclination of the profile to vary with depth, but the inclination across each layer is usually constant. Here instead, a new geotechnical software, OptimalSlope, is employed to determine optimal pitwall profiles of depth varying inclination. OptimalSlope seeks the solution of a mathematical optimization problem where the overall steepness of the pitwall, from crest to toe, is maximized for an assigned lithology, geotechnical properties and Factor of Safety (FoS). Bench geometries (bench height, face inclination, minimum berm width) are imposed in the optimization as constraints which bind the maximum local inclination of the sought optimal profile together with any other constraints such as geological discontinuities that may influence slope failure. The obtained optimal profiles are always steeper than their planar counterparts (i.e. the planar profiles exhibiting the same FoS) up to 8 degrees depending on rock type and severity of constraints on local inclinations. The design of a copper mine is first carried out employing planar pitwalls, secondly adopting the optimal pitwall profiles determined by OptimalSlope. The adoption of optimal slope profiles leads to a 34% higher net present value and reductions of carbon footprint and energy consumption of 0.17 Mt CO2 eq and 82.5 million MJ respectively due to a 15% reduction of rockwaste volume.

Mar 2, 2022

By Todd S. Webster, Matthew J. Pierce, Brad D. Krumel

With the Working Shafts and Starter Tunnel under way, it became apparent this 4.7-mile, 19-foot diameter wet weather tunnel was going to live up to its name. The shaft’s pre-excavation grouting was completed, and ground water inflows were slowing project progress. As the tunnel drive was approaching 50% complete a cooperative effort was underway between the owner, engineer, and contractor to raise the base of the Retrieval Shaft by 65 feet to avoid ground water infiltration construction challenges. The tunnel alignment needed to be raised in kind. The project was behind schedule and rethinking the cast-in-place adit work was next on the agenda due to the very wet environment in the tunnel. The race was on to finish the project within the owner’s time constraints while completing multiple redesign aspects of the tunnel alignment and associated adit construction. This paper will evaluate original design criteria and actual in-route design modifications and change management to meet the owner’s just-in-time schedule needs.

Dec 1, 2022