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When it comes to safety in the mining and extractive industries, success is literally a matter of life and death. Anything short of perfection is not acceptable. In recent years, the mining industry in the United States has made tremendous strides in terms of health and safety for its workers. Part of that success has come with an increased focus on the issues of safety, an intense examination of procedures, liberal sharing of best practices and a focus on the synergy between safety, reliability and environment. During his closing keynote address of the Safety Management & System Reliability Conference in Minneapolis, MN on Nov. 15, Joe Driscoll, vice president of Great Basin Gold, showed a calendar from the coal fields in Pennsylvania from the early 1900s. The calendar marked the number of mine-related deaths each month. Some months, the number was as high as 50. It was an illustration of how far things have come, but there is still much more work to be done.

Jan 1, 2013

By Jerry C. Tien

In 2009 China mined 2.695 billion metric tones (Gt) of raw coal. It is estimated that only 3-5% or roughly 135 million metric tones (Mt) of these were mined from 300 some surface operations. Except for a dozen or so large modern operations, most of China's surface coal operations are small by western standards, with annual production ranging from a few thousand tones to 300,000 metric tones (mt). Depending on the size of operations, equipment used range from small trucks and shovels to large bucket wheel excavators and draglines in sizable pits. This article provides a brief overview of China's surface mineable coal reserves, mining methods commonly used and increasing environmental concerns; introductions of several large surface operations are also provided.

Jan 1, 2012

By Robert C. Dyni

The Bureau of Mines in cooperation with the Solution Mining Research Institute conducted surface and subsurface investigations over five solution-mined salt cavities in the Hutchinson, KS, area. The purpose of these investigations was to determine the mechanisms that lead to the formation of sinkholes above collapsed solution cavities. Of the five salt-solution cavities investigated, four had collapsed and produced sinkholes prior to the time of the investigations; the fifth cavity was considered stable. Exploratory drilling and coring operations were conducted at all five sites; surface stability monitoring was conducted at three of them. The results of these studies indicate that excessive dissolution at the salt-shale contact of each collapsed cavity produced large, unsupported roof spans that ultimately exceeded the structural integrity of the overburden. The stable cavity was not exposed to excessive dissolution at the salt-shale contact; this limited the roof span and ensured a stable cavity. The data also show that surface settlement in the vicinity of the two surface-monitored sinkholes continued for approximately 7 years after the sinkholes formed, indicating that the rubble piles of the collapsed cavities were undergoing gradual consolidation.

Jan 1, 1986

By B Hawkins, S Durkin, V Lawrence

The requirement for secondary egress from underground workings has long been regulated in Australia. Escape way systems have evolved from simple airleg rising ladders and timber ladders to steel galvanised ladders and more recently fully enclosed polyethylene ladders.The polyethylene ladder, Safescape Laddertube, was introduced to the underground mining industry in 2010. It is an enclosed cylindrical modular plastic ladder designed for use in underground escape ways and access ways. Since its first installation in May 2010, the Laddertube has been installed in 43 mines across four countries, totalling 8800 m of ladders installed to December 2013.The Cracow Gold mine is one operation using Laddertube, located 500 km north-west of Brisbane, Queensland, Australia. Upon discovering and developing both the Empire and Roses Pride orebodies, a safe and economically viable secondary egress system and surface primary ventilation exhaust shafts were necessary to support development and production activities to these workings. The need arose to merge these two critical requirements together between surface and underground mine workings some 200 m and 400 m respectively for each orebody. Neither egress has intermediate access points within their full service length from top to bottom. Several options were considered, the preferable and most feasible method adopted was Laddertube.The longest egress length requiring Laddertube within the two vertical surface exhaust shafts was 400 m long, within a 3.5 m diameter shaft. Due to the length of the vertical Laddertube system in both egresses, personnel are to be assisted by mechanical means using the Extended Ladder Climb Assist system.The Gossan Hill mine also uses Laddertube for their escape ways. Part of the Golden Grove operation, Gossan Hill is an underground sublevel open stoping mine located in the mid-west of Western Australia.With a considerable mine life remaining and a history of acidic water and stress related deterioration in vertical openings, the mine operators sought an escape way solution that would provide for the long-term needs of Gossan Hill. Laddertube was selected due to its non-corrosive properties and the ability to fill in around the ladder way to provide stability to the raise opening.Laddertube is a recent development in escape way systems, and is effectively being applied in a variety of operations, meeting the specific needs of underground mines.CITATION:Durkin, S, Hawkins, B and Lawrence, V, 2014. The application of Safescape Ladders at the Cracow and Golden Grove operations, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 311–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By P. P. Kim, M. Tangstad, T. A. Larssen

"The kinetics of MnO and SiO2 reduction in SiMn slags based on Assmang/Comilog ore and HCFeMn (highcarbon ferromanganese) slag were investigated between 1500 and 1650°C under a CO atmosphere. The results showed that charges containing HCFeMn slag had relatively faster reduction rates than those without. The difference in the driving force for MnO reduction was insignificant among the SiMn slags at 1500°C, which implies a low contribution of the driving force for reduction rate. The slag viscosities were also rather similar, around 1 poise at 1500°C, which could not explain the different reduction rates. Instead, the different charges containing various sulphur contents are believed to give rise to the varying reduction rates. The estimated activation energies for MnO reduction were around 500–920 kJ/mol for charges containing HCFeMn slag, and between 250–300 kJ/mol for those without. Based on the estimated kinetic parameters, the considered rate models were able to describe the reduction of MnO and SiO2 in SiMn slags between 1500 and 1650°C. IntroductionManganese ferroalloys such as ferromanganese (FeMn) and silicomanganese (SiMn) are important ingredients in steel production due to the beneficial effects of manganese on the physical properties of steel. Mn enhances the strength, toughness, and hardness of steel products, and both Mn and Si are used as deoxidizers to prevent the development of porous structures (International Manganese Institute, 2014; Olsen, Tangstad, and Lindstad, 2007; Subramanyam, Swansiger, and Avery, 1990; Tomota et al., 1987).The thermodynamic background of manganese ferroalloys is well established (Olsen, Tangstad and Lindstad, 2007), but kinetic information is rather scarce, especially for the SiMn process (Tranell et al., 2007; Tore-Andre Skjervheim, 1994). The absence of kinetic information makes it more difficult to understand the reduction mechanisms of MnO and SiO2. It is not clear how different raw materials affect the SiMn process. The main metal-producing reactions in the SiMn process are described by Equations [1] and [2]:"

May 1, 2019

By Andrew J. Petruska, Austin F. Oltmanns

The paper proposes a capacitive load cell for detecting changes in material and tool wear conditions for conical picks used in underground mining. The current process is dangerous and subjective, relying on human operators near the cutting interface. The new sensor aims to improve worker safety by allowing operators to perform their functions from a greater distance.

Aug 1, 2023

By S. P. Singh

"The geological features of a rock mass have a direct influence on its blasting characteristics. It has been observed that perimeter control techniques provide excellent results in massive crystalline formations but may give poor results in weak and or highly jointed formations.A field study was conducted with the objective of understanding the role played by the geological features of a rock mass in producing and controlling blast damage. The field work involved the assessment of blast damage at several operating mines and the blasting of drift rounds in a geologically dominant rock mass.The effect of rock strength, rock quality designation (RQD), joint parameters and hydrogeological conditions on blast damage is described below. The influence of number and thickness of weak layers on blast damage is also discussed below on the basis of quantitative data. In addition, critical particle velocity ranges for damage to different rock types have also been outlined in this paper."

Jan 1, 2001

By Cynthia Belt

"Before energy can be saved in the materials industry, the process must be understood. At the same time, baby boomers are starting to retire. New people are entering the field without experience and training especially in methods to save energy. Various classroom courses, seminars, books, software, and websites are available for the professional to better understand the industry with the ultimate goal to reduce energy use. This paper is a review of what is currently available with some comments on potential needs.IntroductionEnergy use is high within the materials industry. For the United States, the primary metal industry uses 8% of all energy used in manufacturing (Figure 1 )1 or 1, 736 trillion BTUs per year. Sadly, while energy use is high, energy management is not universal within the industry. Counting both internal programs and external such as the utility supplier, equipment manufacturers, federal and state programs, only 66% of primary metals companies participate in an energy management activity1.For the materials field, process heating is the majority of the energy use in a plant2. Understanding and optimizing process heating is a critical need for materials energy professionals. Surprisingly, process heating is not necessarily the work addressed within an energy program. The U.S. 2006 Manufacturing Energy Consumption Survey (see Table 1) found more primary metal companies addressing lighting with 31 % participation versus 15% with process heating work even though energy used in lighting tends to be a minor (in the range ofl-3% ofa typical plant's energy use)."

Jan 1, 2013

By V. Ross

"Bench-scale flotation tests play a major role in the geometallurgical process value chain. Despite their apparent simplicity, these tests pose pitfalls in terms of operation, as well as the interpretation and modelling of results. In this paper we highlight key aspects to consider in generating accurate and reproducible experimental results, and critically review some assumptions relating to the estimation of entrainment and froth recovery. We subsequently focus on first-order equations to model kinetics and propose a method that accounts more realistically for the decay in kinetics over the duration of a float, and the contributions of froth stability and hence mass pull. The method was applied to three case studies on platinum group metal (PGM) ores and matched or outperformed first-order, two-component models. Also, it allows for a deeper analysis of the integrity of the bench-scale flotation results. IntroductionGeometallurgy is a structured, multidisciplinary approach that integrates key data from the geological, mining, mineralogical, and metallurgical aspects of the value chain to construct spatial models of an ore deposit such that the overall economic benefit and sustainability of an operation can be optimized. Process geometallurgy is aimed primarily at enhancing metallurgical efficiency and plant throughput by the application of appropriate mining and processing strategies, as well as supporting production planning and operational strategies to reduce the impact of highly variable ores. With flotation being the dominant concentrating process in the mineral value chain, the bench-scale flotation test is an important characterization tool – a relatively cheap, simple, and rapid way to obtain key information about the ore and its amenability to economic extraction of valuable minerals. This includes the evaluation of different ore types and the implications of mineralogical composition and texture for comminution and floatability, the effect of the grinding environment on the liberation of minerals, the electrochemical environment in the pulp (Bradshaw et al., 2006), the screening of reagents to improve floatability (Ekmekci et al., 2003), and the role of hydrodynamics in the recovery of valuables and the entrainment of gangue (Amini et al., 2016; Wang et al., 2016). It is also a critical tool in auditing the performance of a flotation plant by hot floats, paving the way for concept and feasibility studies and providing essential data on kinetics for the purposes of scale-up, optimization, and simulation of flotation circuits."

Mar 1, 2019

By E. L. Garton

[AnalY3e s of Qany crude t) i 1 s prod.uced in Loui sia.na are incl udeo" in re!Jor~ ~ th'l t have b en u~li shed by the BurOllU 0: i?{ine s. The first rc-port,j} givin..; analyseG of 6 Louisiana crude oils, '-vas pUblluhed in 1921'l.s,nd this was 1'0110\ cd a year later by P.ep rt of InvBstign.tions 21a6t~ givi~ 7 addi tional analyses. The G7even :,ost il'!lportant of these analyses were incol"]lorated in Bulle~in 91,.2, is~ued in 1928. In 1934, analyses of 26 cl ... ude oils j)roduced in southern Louisiana ",ere published ? .§! The present report I)renonts analysos of 72 ad(~itional samples of crude oil frorl 4-, fields in 23 "l)ari shefl in Loui f",io.r]

Jan 1, 1939

By R. Horn

The financial performance of the mining industry, measured by return on equity and capital employed, has been inadequate for many years. Consequently, mining companies are not valued highly by stock markets. Among the more important causes for the decline in the sector are the conservative working practices and reluctance to adapt to change or to develop new technology, although some relatively recent developments such as SX-EW copper and heap leach gold have made a significant impact on the cost base of these metals. The subsidiary business of metals exploration suffers from the same problems as the rest of the industry. The rate of discovery of ore deposits has been falling over many years and since the late 1990s, there has been a sharp reduction in global exploration activity that, if it continues, will further reduce the global supply of new ore reserves. New technological developments, particularly in geophysics and different operational practices may help reverse this trend. Statistical methods for evaluating the risk of ore reserve estimates will also improve the economic return on new mining ventures. The science of ore geology has potential to reduce exploration risk, but modern ore genetic theory has not contributed greatly to recent discoveries. The junior exploration market has almost ceased, but a new style of technically specialized efficient small exploration company has emerged which, in alliances with major companies, may be the vehicle for future global exploration. Exploration in virgin terrains has a higher risk discounted potential for the discovery of very large orebodies than that in known mining districts but mining companies have little financial incentive for this high risk exploration because of the very long lead time to production. Alliances of two or more companies reduce the risk in both the exploration for and development of major new mining projects. If new orebodies are not found, then metal prices will inevitably rise in the long term. Governments of industrial countries, particularly those with a significant mining industry such as Canada, should therefore provide assistance to exploration in order to maintain their existing industry and prevent a metals shortage from developing in the future with its consequent impact on the world economy and increased environmental damage as large lowgrade orebodies are developed to supply an expanding market.

Jan 1, 2002

By James R. Wait

An attempt is made here to collect together various reports and publications that are based on research supported all or in part by Contract No. H0155008 for the past two years. The subject matter deals primarily with the excitation, transmission, and reception of electromagnetic waves in mine environments. This contract from the U.S. Bureau of Mines with the Office of Telecommunications supports the efforts of James R. Wait (Principal Investigator and Consultant to OT), David A. Hill (Co-Investigator), and various associates within the Boulder scientific community. The contributions of Samir F. Mahmoud were supported, in part, by the contract while he was a Visiting Fellow with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado. Administrative assistance in CIRES has been provided by Mrs. Lana R. Hope.

Jan 1, 1976

By JOHN HOMER, KATHLEEN STABRYLA, JACOB L. CARR, JONATHAN K. HRICA, JENNICA L. BELLANCA

Given the recent focus on powered haulage incidents within the U.S. mining sector, an appraisal of collision avoidance/warning systems (CXSs) through the lens of the research literature is timely. This paper aims to evaluate the maturity of CXS technology through the application of a technology readiness assessment (TRA) to research literature identified by systematic search methods. Results indicate that much of the evidence for CXS performance is at lower levels of maturity: that is, components and prototypes tested in a laboratory and in relevant environments. Less evidence exists for CXS performance at higher levels of maturity — that is, systems evaluated within operational environments — despite the existence of commercial products in the marketplace. This lack of evidence at higher maturity levels within the scientific literature highlights the need for more peer-reviewed research to evaluate CXS technologies. Additionally, results of the review reveal that most of the literature relevant to CXS technologies is focused on vehicle-to-vehicle interactions, which contrasts with haul truck fatal accident statistics that indicate most are due to vehicle-to-environment interactions, such as traveling through a berm. Lastly, the relatively small number and segmented nature of relevant studies suggest there is a need for more incremental research that would better facilitate the improvement of CXS technologies. This progression could be achieved through continued long-term interest and support for CXS technology research.

Mar 1, 2023

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

The steepness of an openpit mine’s slopes has a substantial influence on the mine’s financial return. This 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 cross section within each rock layer: that is, the profile inclination across each layer tends to be constant. Here, instead, a new geotechnical software, OptimalSlope, is used 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).

By Liming Yuan, Isaac Zlochower, RICHARD THOMAS, Thomas H. Dubaniewicz, Teresa Barone

Mining vehicle manufacturers are developing lithium-ion (Li-ion) battery electric vehicles as an alternative to diesel-powered vehicles. In gassy underground mines, explosion-proof enclosures are commonly used to enclose electrical ignition sources to prevent propagation of an internal methane (CH4)-air explosion to a surrounding explosive atmosphere. Li-ion batteries can create pressurized explosions within sealed enclosures due to thermal runaway. Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) measured thermal-runaway pressures of lithium iron phosphate (LFP) cells as a function of free space within sealed enclosures and observed an inverse power relationship. A well-confined cell produced 4260 psia (294 bar) of pressure during a thermal runaway, far exceeding minimum pressure containment specifications for conventional explosion-proof enclosures. Results indicate that adding enough free space surrounding LFP cells can reduce thermal-runaway pressures to levels below that expected for CH4-air ignitions. Measured thermal-runaway temperatures were below the minimum autoignition temperature of CH4-air.

By W. A. Wright

The use and abuse of social media restate common employee relations issues. Business solutions to these issues require advanced preparation. Employers should establish and enforce social media policies to guide their reactions to employees? social media posts that reflect on the employer and its business.

Jan 1, 2011

By B. van Beek, T. Goff, P. Gebski, P. Szyplinski, W. L. Ying

"Monitoring the refractory lining integrity is essential to assure the safety of the operators and to determine the remaining campaign life of a furnace. Early detection of refractory lining degradation is essential to avoid sudden furnace failures and prevent unscheduled shutdowns. In the mid-1990s a stress wave propagation technique was developed and since then it has been utilized by Hatch Non-Destructive Testing (NDT) Group to evaluate furnace linings. For the last 17 years the AU-E technique evolved in terms of hardware, software and signal acquisition and interpretation. Most importantly, based on more than a decade of commercial applications, an extensive database of various failure modes, refractory deterioration trends and material properties has been created. This knowledge base is an integral part of AU-E which progressed from a NDT technique towards a comprehensive approach for furnace condition monitoring. All of the improvements introduced over the last several years have greatly improved the accuracy of the measurements. The data analysis process has also become more time efficient making the critical results available to the furnace operators in a more timely manner. Today the AU-E technology is used on a variety of process vessels in non-ferrous, glass, chemical and iron and steel industries.In this paper we are reviewing the available techniques for furnace refractory lining measurement and discussing the pros and cons of each method. The need for continuous improvement and development of new techniques for refractory monitoring is also emphasized. Finally, we are presenting a number of case studies and comparisons between the physical verifications and the AU-E measurements."

Jan 1, 2015

By Paul Lynch

"Since being reported to the 2012 UMI in Shanghai, the Cook Islands has been steadily developing for the commencement of it Seabed Minerals sector in its large Exclusive Economic Zone which contain a vast and unique Manganese Nodule resource, estimated at 10 billion tonnes1. At the 2013 UMI in Brazil, it was reported that the Seabed Minerals Act had commenced and all the necessary complex Technical aspects of this developmental work was being undertaken. At the 2014 UMI in Portugal, full details of the final developments leading to the opening of the Tender of Exploration Blocks in the Cook Islands EEZ will be presented in a brief but comprehensive method, using Poster displays, Powerpoint and active Website interaction. This will show the drafted Regulations, prepared on best international standards, to address both Licencing and Environmental requirements, to give clarity and security to the Resources Owner, industry and stakeholders. This work in being coordinated by the Cook Islands Seabed Minerals Authority, with the valuable collaboration of many international, regional and national stakeholders, including the Cook Islands NGOs, Marine Resources, Marine Park and National Environment Service."

Sep 1, 2014

By Rambabu Pothina, Rajive Ganguli

The economics of a mineral processing circuit is dependent on the numerous sensors that are critical to optimization and control systems. The sheer volume of sensors results in mines not being able to keep the sensors calibrated. When a sensor goes off calibration, it results in errors which can severely impact plant economics. Normally, these errors are not detected until the error grows and becomes a large (“gross”) error. Undetected errors are not remedied until the next calibration, which on average are a year apart Beamex (2019) [1] across all industries. Classical statistical methods that depend on linear relationships between input and response variables are typically used to find gross errors, but are not effective for highly non-linear and non-stationary operations in mining and mineral processing industries. Calibration of sensors is time-consuming and generally requires physical intervention that results in equipment downtimes causing production losses. Therefore, in situ detection methods are warranted that do not require physical removal of sensors to compare with standard measurements or well-calibrated sensors. Data-mining based techniques and algorithms have high success rate in tackling such problems. This paper presents results from a groundbreaking multi-year big data research project whose goal was to develop data-mining-based original techniques in a multi-sensor environment to identify when sensors start to stray, rather than wait for errors to grow. The carbon stripping (gold) circuit in the Pogo Mine of Alaska was selected for this project. Maintaining strip vessel temperatures at optimum levels is crucial for maximizing gold recoveries at Pogo, and hence the focus was on the temperature sensors of the two strip vessels. An automated algorithm to detect errors in strip vessel temperature sensors was developed that exploited data from multiple sensors in the strip circuit. This algorithm was able to detect with a high success rate when bias errors of magnitude as low as ± 2% were artificially induced into strip vessel temperature data streams. The detection times of about 1 month were much less than the industry average calibration frequency of 1 year. Thus, the algorithm helps detect errors early, without stopping the circuit. The algorithm alarms can serve as triggers when calibrations are done. Experimental methodology along with results, limitations of algorithms, and future research are also presented in this paper.

By K R. Vining, T E. Norgate

A study was carried out to compare the environmental impacts of the two major iron ore agglomeration processes, sintering and pelletising, using life cycle assessment (LCA) methodology. The following agglomeration processing routes, with the fuel options shown, were investigated:sintering with combined natural gas/coke breeze or charcoal as fuel, grate-kiln pelletising with combined natural gas/coke breeze as fuel, and straight-grate pelletising with combined natural gas/coke breeze as fuel. Inventory data for each process derived from the literature, and in some instances supplemented by additional simulations and calculations, were used in the study and the environmental impact categories considered were gross energy requirement (GER), global warming potential (GWP) and acidification potential (AP). The results of the study showed that the GER, GWP and AP for a sinter plant are higher than those for a pellet plant for the same amount of metallic iron in the agglomerated products. These results are partly due to higher consumption of solid fuel and flux in the sintering process. However, it should be pointed out that the study only compared substantially fluxed sinters with acid pellets that may require additional flux (and hence potentially more greenhouse gases emissions) to be a balanced blast furnace feedstock. Extending the LCA to the blast furnace process stage was beyond the scope of the current study. Within the sinter plant, the sintering stage itself is the largest contributor to the GER, GWP and AP. In the case of pellet plant, the pellet induration stage is the largest contributor to the various environmental impacts. The GER and GWP of a straight-grate pellet plant are marginally higher than those of a grate-kiln pellet plant due to the higher electrical power required by the straight grate system. The substitution of coke breeze with charcoal in the sintering process results in an increase in GER but a decrease in GWP. However, a substantial proportion of the GER is derived from renewable sources (wood), resulting in a decrease in the non-renewable components of this environmental impact. Given the source of the inventory data and the assumptions and approximations made in carrying out the LCAs, it is emphasised that the results presented in this paper should be considered as indicative rather than as definitive results for the two iron ore agglomeration processing routes considered.

Jan 1, 2006