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By Rodolfo V. de la Cruz

The stresses in the materials surrounding an underground opening are dependent upon the virgin stress field, the geometry of the opening and changes in boundary conditions as mining progresses. For most underground openings especially in coal mines, roof bolts are installed to help stabilize the opening. While most parameters in roof bolt design and installation have been thoroughly investigated, the effects of the initial stress field on the effectiveness of roof bolts have not been recognized. This paper summarizes the results of investigation of the effect of the initial stress field on the performance of mine roof bolts. Roof bolt installations are duplicated in the laboratory utilizing conventional roof bolt frame, commercial roof bolts and shells, mine torque wrench and encapsulated rock specimens for anchorage. A special and primary feature of the laboratory set-up is the addition of a loading system for generating stresses at the anchorage specimens. For this preliminary study, different levels of hydrostatic stress fields were induced at the anchorage specimen, instrumented roof bolts were installed in the usual manner, and the bolt load loss-with-time observed. Statistical analysis of data showed that the stress field at the anchorage horizon has a considerable influence on the performance of mine roof bolts, i.e. the higher the stress field, the higher the anchorage efficiency. From this observation, methods of improving the performance of mine roof bolts utilizing new shell designs and methods of installing them are suggested.

Jan 1, 1978

By S. Gering, R. Ruiz, C. H. Calderon-Arteaga, J. Barrios

"INTRODUCTION Located in the northeast corner of Zacatecas State, Mexico, the Peñasquito Operation is comprised of the Peñasco and Chile Colorado (Brecha Azul) deposits. Open pit mining (pre-stripping) began in 2010 and full production commenced during 2011. The open pit mines feed both a sulphide concentrator (mill) and a heap leach pad. The project is owned by Goldcorp, Inc. Penasquito is a poly metallic deposit with Au, Ag, Zn and Pb being recovered as payable metals. As a consequence of lower grade ores expected with advancing mine-life Peñasquito is facing a declining metal production profile. To maximize returns and asset value plant modifications including the addition of a carbon pre-float circuit and a pyrite leach circuit to improve recovery are currently being undertaken. This carbon pre-float circuit will enable the recovery of precious and base metals from carbonaceous sediments. This material is currently being stockpiled. With the associated increase in complexity in the process circuit, the requirement of the ore control system to accurately predict ore feed characteristics is critical to maximizing metal recovery at the Penasquito operation. The addition of the carbon pre-float circuit was also a key driver in allowing the Chile Colorado open pit to be developed. These conditions alongside Goldcorp’s drive to increase profitability, and maximize net asset value has created challenges. These challenges are numerous and are multifaceted, however the ability to accurately route materials from the ore control system is critical to site success, and some of these challenges have been overcome by the adoption and implementation of a new ore control (OC) technology. Examples of these technological innovations in the ore control program are discussed in this paper and include improvements in geo-modeling, material routing and reconciliation. Successful implementation of these elements has led to significant improvements in selectivity, performance, and data management, while reducing the variance between planning and execution, thus helping to drive overall improvement across the operation."

Jan 1, 2018

By M. Poulton, J. A. Botín, C. Gatica

"The Chilean minerals industry faces a shortage of 27.000 new skilled professional by 2023. Enhancing the integration of women into the workforce is a possible solution. This study analyzes the state of women in the mining workforce over the past decade. Several key indicators are presented: percent in the workforce, salaries, career profiles, presence at management level, and participation in academia are studied. The study also analyzes the strategies used by government, industry, and universities to recruit and retain women for the minerals industry. The main results show that women represent 7.4% of the mining workforce in Chile and less than 1% of senior positions with a salary gap of approximately 30%. Systematically, women prefer professional programs in geology, chemistry, and environmental areas. The Chilean statistics are compared to data from the United States mining industry. INTRODUCTION The Chilean mining industry faces a significant shortage of professionals for the next decade which compromises competitiveness and productivity. The demand for human capital in mining depends on several factors. First, the age structure of workforce, which determines future retirement needs. Second, minerals market considerations, determining the amount and size of mining projects entering production in the coming years. Third, the evolution, positive or negative, of productivity, mainly driven by technology and innovation, and negatively affected by the declining ore grades. Finally, negative trends in lead times to production of mining projects, due to social opposition, changing regulations and other project contingencies, negatively affecting the demand for human capital. Regarding the supply of human capital, the fast increase in the technology level of the minerals industry and hence, the increase of technical qualification requirements of the human capital generates a rise in the time required for trade and university education of mining professionals, which may cause imbalances in the labor market. According to (Consejo Minero, 2014) human capital gap in Chile by 2023 will be around 27.000 workers for extractive, processing and maintenance jobs, which represents 14% of the current workforce (Figure 1)."

Jan 1, 2016

By M. C. Fuerstenau, J. J. Fitzgerald

Aluminum silicate hydrosol synthesis and characterization are discussed. Plausible polymeric aluminosilicate species are presented together with their effect on electrokinetics of selected minerals and flotation response of various ores. The addition of aluminosilicate hydrosol to porphyry and oxide copper ores and to a tungsten ore resulted in enhanced flotation recoveries ranging from about 1.5 to 5 percent. A significant portion of the nation's mineral resources are presently lost in the form of particles with very fine grain size. In the case of copper, for example, approximately 225 million tons of ore are concentrated by flotation per year in the United States. Total losses from porphyry ores are generally 15 to 20 percent with half of these losses being finely-divided copper sulfide minerals which do not respond to flotation. The additional 5 to 10 percent loss is the result of copper oxide minerals which are not floated. The losses of copper sulfide minerals are thought to be due in part to the lack of appropriate dispersion of the finely-divided solids less than 20 microns in size. To effect dispersion in flotation systems, sodium silicate is commonly added. Enhanced dispersion effectiveness is achieved when polyvalent metal salts are combined with sodium silicate. Since originally described by Patek (1), numerous workers have explored the utility of metal silicates. Makrousov (2), Belash et al. (3), and Eigeles (1950) (4) showed the applicability of these reagents to calcite/apatite and fluorite/calcite ores. Mercade (5, 6) reported depression of calcite in the presence of 3.33/1 mole ratio Al/Si hydrosols prepared from Type N sodium silicate (Si02/Na20 ratio 3.22/1) and 1% A12(SO4) 3•18H20 solutions. He importantly observed that the colloidal precipitates did not play a significant role in dispersion and depression but that the soluble species were responsible for this action. Patented work by this author described metal silicates used to depress calcite in scheelite flotation using 1% metal salt (FeSO4•7H2O, CoSO4•7H2O, etc.) and 5% Type N sodium silicate solutions to produce hydrosols with Si/Fe or Si/Co ratios of 8.79/1. Aluminum (III) ion systems were less effective as depressants than the iron and cobalt systems. Yang (8, 9) has studied metal silicate sols for use in the flotation of lithium and ultra-fine hematite ores. Using 10/1 Si/Fe mole ratio hydrosols prepared from 2% ferric nitrate, Fe(NO3)3.9H20, and 5% Type N sodium silicate solutions, solutions, he showed that the hydrosols either modify the slime particle surfaces or are adsorbed on the slime particles preventing anionic collector adsorption. In a subsequent patent, Yang also reported the use of these hydrosols as dispersants for beneficiation of lithium ores. Recent studies of aluminum silicate hydrosols in the flotation of chalcocite, chalcopyrite and scheelite have been reported using Si/Al dispersants prepared from 5% Type N sodium silicate and 0.1 M aluminum chloride (A1C13.6H20) solutions. Dispersant properties were shown to be dependent upon the method of synthesis, supernatant pH, and the hydrosol Si/Al mole ratio. Polymeric soluble species in these hydrosolsupernatants have been proposed as the active dispersant species. Aluminosilicate hydrosols are synthesized by the general reaction scheme presented in Figure 1. Commercial sodium silicates are available with ratios of SiO2 to Na20 of 1.60-3.25. The sample which is most frequently employed is Type N whose ratio of Si02/Na20 is 3.22/1.00. Gel filtration chromatography and NMR studies have shown that these sodium silicates contain numerous species of molecular weight from 325-2,000 gm/mole. Monomeric, oligomeric and higher molecular weight linear polymeric arrangements of these structures are found in these solutions.

Jan 1, 1989

By J. Noll

There is a need for direct tailpipe sampling of diesel vehicles in mines in order to determine the effects of an emissions-based maintenance program, evaluate control technologies such as diesel particulate filters and identify the worst diesel particulate matter (DPM) emitters in a fleet of vehicles. therefore, this study examined the performance of three portable instruments: a personal dust monitor (PDM) manufactured by thermo Scientific, a prototype elemental carbon monitor (Airtec) manufactured by FLIr and a prototype Ae91 instrument from Magee Scientific. These instruments were evaluated on the basis of their ability to provide direct reading tailpipe analysis for DPM. It was determined that the average bias of the tailpipe results from the PDM and the Airtec were 3±12% and 4±20%, respectively, when compared to the standard method of determining tailpipe particulate concentrations from a diluted exhaust. It was also determined that the Ae91 instrument correlated with the standard method.

Oct 1, 2013

By P. Kawahata

Newmont?s Twin Creeks Mine, located in northern Nevada, is producing gold ore from surface mining operations. The ore is currently processed at three different on-site facilities depending on ore type and grade. Processing facilities operate under stringent geochemical blending constraints that must be met from mine ore deliveries and off-site sourced ore. To analyze various strategic options, the technical team utilizes the mathematical optimization approach. However, due to the size and complexity of the operation, there are unique challenges in optimizing life-of-mine production scheduling. This paper describes those challenges and methods developed to take advantage of different scheduling software to effectively compensate each other and result in reasonable guidance. This paper also describes how those scheduling results are reflected in detailed mine plan and cost estimate work.

Jun 1, 2013

By Crystal Poon, Paul Matlashewski, John Morkeh, Kathryn Dorfschmidt, Jose Carvalho, Chad Williams

Rockfall hazards are ubiquitous in mining environments making their control critical for safe mining operations. The complex processes involved in rockfall events necessitate a probabilistic modeling approach with well-calibrated material properties. The controls designed to mitigate rockfall hazards need to be reliable, efficient, and safe to deploy to meet the constraints present at an active mine. This paper presents an innovative solution to rockfall at Rio Tinto’s Bingham Canyon Mine. The solution incorporates the site-specific calibration and creation of a predictive rockfall model with the design, field testing, implementation, and monitoring of the rockfall controls.

By J. M. Christian

Silver has been a much maligned metal in recent years. In the last three and a half years the price has fallen from around US$7.00 -$7.80 to as low as $3.50 this spring. It has consistently under-performed most other precious metals in the past few years, and has fallen to its lowest levels since the late 1940s in inflation-adjusted terms. Perhaps this is beginning to change. Since April, silver prices have outperformed gold and platinum. While this may continue in the years ahead, key questions remain regarding the pace and timing of any future silver price advances. I want to talk about the supply and demand factors that have led silver to its recent position. Also, I will outline a possible path for silver supply, demand, and prices for the next several years. Before I dive into my discussion of the silver market, allow me to explain who I am. One of the points we always make to clients early in a relationship is that, when you are listening to someone's opinions, you always must remember who it is you are listening to, and why he might be saying whatever it is he wants you to hear. So often, people take opinions from brokers, traders, or investment advisors as gospel truth, never stopping to ask themselves two key questions: Is there any reason to believe that this person knows what he is talking about, and, second, is he trying to sell me something, in telling me this.

Jan 1, 1992

By Crystal Poon, Paul Matlashewski, John Morkeh, Kathryn Dorfschmidt, Jose Carvalho, Chad Williams

Rockfall hazards are ubiquitous in mining environments making their control critical for safe mining operations. The complex processes involved in rockfall events necessitate a probabilistic modeling approach with well-calibrated material properties. The controls designed to mitigate rockfall hazards need to be reliable, efficient, and safe to deploy to meet the constraints present at an active mine. This paper presents an innovative solution to rockfall at Rio Tinto’s Bingham Canyon Mine. The solution incorporates the site-specific calibration and creation of a predictive rockfall model with the design, field testing, implementation, and monitoring of the rockfall controls.

By J. Kretschmann

According to the model of product life cycles, the global coal mining industry is in the stagnation phase. The coal demand of the main consumer, China, has peaked in 2013 and is slowly declining. The Norwegian sovereign wealth fund, the world´s largest, has excluded coal-related companies for ethical reasons. Important players like the UN or the EU have already begun to describe pathways towards de-carbonization. Increasing competition between coal mining companies and the mining regions can be expected worldwide if companies want to keep their positions on the global and national coal markets. Companies will focus on the best deposits. European countries like France, Spain or Germany are only forerunners of this development - their centuries of coal production have been finished. The concept of Sustainable Development (SD) is fundamentally based on a model of progress where ecological, economic and social dimensions should be developed equally and positively. But without the idea of competition, the concept of SD is incomplete. Questions arise, such as: How can SD be realized on stagnating or declining markets without guarantees for companies “to live forever”? How can SD be a corporate goal in a phase of decline? How can declining mining regions sustainably progress into a better future? The German hard coal mining industry´s lifecycle has ended in 2018 after 60 years of stagnation and decline. As of 2019, all hard coal consumed in Germany will be imported, especially from Colombia, Russia and South Africa. What has been done in Germany to handle the coal decline in a sustainable way and the lessons learned from this process is described in this paper. It may be useful for mining regions who will face a similar future sooner or later. INTRODUCTION Principally, mining natural resources is a finite business that reaches its limits once the deposits mined are depleted, the resources can no longer be mined in an economically profitable way, or substitutes are pushing the mined products out of the market. An example for the latter is the increasing replacement of coal with natural gas and renewables in power generation in the USA. (Kok 2017) According to the model of the product lifecycle, the global mining hard coal mining industry has reached the stagnation phase. (Kretschmann 2000) Although the coal mining business is more a multi-regional than a global business the trend is obvious. The peak of coal use is behind us, especially because the coal demand of China is slowly decreasing since 2013. (Shell 2018) China´s government has announced investing $360 billion in renewable energy by 2020 and scrap plans to build 85 coal-fired power plants. In March 2018, Chinese authorities reported that the country was already exceeding official targets for energy efficiency, carbon intensity, and the share of clean energy sources. China’s energy regulator, the National Energy Administration, rolled out new measures to reduce the country’s dependence on coal. (Kejun and Woetzel 2017) Coal consumption in the US is facing a 16 % decline in five years from 800 to 670 million short tons between 2015 and 2019 and - according to the EIA – will not rise again. (EIA 2018) The decline is attributed to complex market dynamics from low gas prices because of the “shale gas revolution” (Kok 2017, p. 3) to federal environmental regulation like the Clean Power Plan. The United Nations´ UNEP Finance Initiative is cooperating with the Portfolio Decarbonization Coalition of institutional investors to implement decarbonization strategies across their portfolio. Amongst these investors is the New York State Common Retirement Fund, the third largest public pension plan in the USA. (UNEP 2017) The European Union has already begun to de-scribe pathways to decarbonization. (European Union 2018) The Norwegian sovereign wealth fund, the world´s largest, excluded coal-related companies for ethical reasons. The oil giants Total S.A. and Royal Dutch Shell, tradi

Jan 1, 2019

By C. D. Mann

INTRODUCTION The sublevel stoping mining method is usually applied to a relatively steeply dipping, competent ore body, surrounded by competent wall rock. Ore is produced by drilling and blasting longholes, which can range from 50 mm (2 in.) to 200 mm (7% in.) diam, with lengths up to 90 m (300 ft). Longholes can be inclined in any direction, but the ring or pattern usually forms a plane, and the holes are blasted as a unit. Recently developed mobile drilling and loading machinery, as well as new explosives products, blasting techniques, and cemented sand and rock fill have made sublevel stoping a highly efficient and versatile mining method. When designing a sublevel stoping production sys- tem, it should be kept in mind that production rates from conventional sublevel stopes vary widely through- out the life of the stope. Early production is at a low rate, coming only from the drawpoints near the slot, but increases as new drawpoints are reached by the stope face. As the stope nears completion, again, fewer drawpoints are productive. Enough drawpoints must be available at any time to provide required production. Drawpoint availability should be compared to equipment availability; plan for more drawpoints than are needed at any one time. Accurate, realistic scheduling is essential to smooth production rates. Also, initial recovery of ore in a stope/pillar block is normally from 35% to 50% in sublevel stoping. Planning of pillar recovery, representing the majority of ore tonnage in a production block, must be done during early mine planning. Since much of the development already done for primary stoping (access for drilling, drawpoints, and haulageways), can be used for pillar recovery, early production from pillars is highly desirable. The following description of components of the system is an attempt to highlight some of the most important features and requirements of mechanized sublevel stoping methods. Similar comments would apply to the use of older equipment (column-and-arm drill setups, slushers, etc.) in similar methods. As in any good mining system, maximum economic recovery of the resource in the ground is the primary consideration. STOPE DESIGN CHARACTERISTICS Length and Width The following are some of the factors which affect sublevel open stope length and width dimensions: ore body geometry, principal stress directions, competence of stope back, optimum drill pattern, and drilling drift layout. In new mines initial stope layout design may occur before the ore body is actually intersected by mine workings. Stope dimensioning is a critical decision, and assistance from as many knowledgeable people as possible at this stage is essential. Operators with past experience in similar ore bodies, rock mechanics experts, and others with mine design experience should participate at this stage of stope planning. Height The following are some of the factors which must be considered in determining stope height: competence of stope pillar and stope/fill walls; slenderness ratio of adjacent pillars; ore body dip; ore body thickness; hole depth capability of the drilling machine; fragmentation characteristics of the ore; and level intervals in existing mines. In competent ground, drill-hole length and accuracy are the most important determinants of stoping height. Frequently entire drilling sublevels can be eliminated because of the depth capability of sophisticated drilling equipment, resulting in significant development cost savings. Drawpoint Location and Design Some of the most important considerations of a good drawpoint system are optimum spacing of draw- points, within the constraints of stope dimensions, for uniform drawdown and maximum recovery; excavations designed for stability for the life of the ore block to be drawn-primary stope ore as well as subsequent pillar ore; floor or roadway design including type of surface, reinforcing, grade for water runoff; orientation with respect to the main haulageway, for optimum loader maneuverability and ground stability at the inter- section; and length, to allow articulated front-end loaders to work in a straight configuration. Careful drawpoint design and construction are keys to successful production. Extra care in development, such as smooth wall blasting, rockbolts or grouted rebar, wire mesh, and shotcrete usually will ensure long draw- point life. Human exposure during production loading is of longer duration than during development or production drilling, and consequently preparation of draw- points is easily justified, particularly when pillar ore can be drawn through the same drawpoints. Secondary blasting of boulders can weaken drawpoints, also justifying good ground control techniques. A smooth draw- point floor of poured, reinforced concrete, on a grade of +3% or +4% toward the ore pile facilitates water flow out of the drawpoint, and ease of loader bucket penetration into the muck pile. Slot Raising, Slotting A slot or other space for rock expansion is necessary in conventional sublevel stoping where vertical rings or rows of holes are blasted. The slot can be started at a slot raise driven by conventional raising methods, raise boring, drop raising (predrilling and blasting a raise from the top, using small diameter-less than 200-mm (7%-in.)-holes for relief), or crater blasting (similar to drop raising, but without relief holes). The slot usually extends from the extraction level to the back of the stope. It is normally expanded to full stope width by

Jan 1, 1982

By J. D. Miller

The fossil resins of certain western coals are of significance and of sufficient value as a chemical commodity to justify a fossil resin industry. At the present time these valuable fossil resin resources, worth more than $0.50/lb as a chemical commodity, are being burned as fuel for electric power generation. This waste of our fossil resin resources corresponds to a loss in revenue of $200 million per year -equivalent to the value of the coal itself! Improved process technology for the recovery of fossil resin is under development and includes selective flotation of fossil resin from fine coal streams and solvent refining of the fossil resin flotation concentrate to produce a premium resin product. The most recent developments in process technologies are discussed with respect to separation efficiency and product quality. It is clear that the development of a fossil resin industry should not be limited by process technology.

Jan 1, 1994

By John J. Mulligan

Coal is found in every major geographic region throughout Alaska and in two offshore areas. Since about 1852 over 100 small mines have opened and closed. Last years production was almost entirely from one mine in central Alaska. Clearly the utilization of Alaska's abundant coal resources presents political, economic and technical problems that are far from solution. Location and Physical Features Figure one illustrates the geographical and geological similarity between Alaska and western United States. The Arctic region of Alaska generally resembles Wyoming and the Dakotas. The Brooks Range is an extension of the Rocky Mountains. The Central region of Alaska between the Brooks Range and the Alaska Range bears a general resemblance to the basin and range country of western United States. The Southcentral and Southeastern regions has a similar resemblance to the Sierra Nevadas and the west coast of the United States.

Jan 1, 1982

By Zohreh Kazemi Motlagh, Evan J. Owen, Virginia T. McLemore, Jakob Newcomer

Five-element style deposits are unusual hydrothermal systems that are typically characterized by a nickel-cobalt-arsenic- silver-bismuth metal assemblage. This mineralization is often represented by abundant native silver, arsenic, or bismuth, and followed by nickel, cobalt, and iron arsenides (skutterudite, safflorite, nickeline, rammelsbergite, and lollingite). The Black Hawk district in Grant County, New Mexico is one of the few examples of this mineralization style in the United States. Despite the differences in formation temperature, depth of emplacement, and host rocks between five-element style deposits worldwide, there are commonalities in mineralogy, ore texture, and composition. A detailed exploration of the native metal and arsenide phases will be performed to compare ore forming fluids between systems and the effects on styles of mineralization and paragenesis, as well as to aid in broader classification of the deposit style. Mineralogy and mineral relationships of the Black Hawk District and other five-element deposits worldwide will be characterized by reflected light petrography, scanning electron microscopy, X-ray diffraction, and electron microprobe analysis. Mineralogical phase diagrams will be generated to better understand the driving processes and evolution of the systems through native metal and arsenide precipitation.

Feb 1, 2024

By BERND SCHÖNHERR, JÖRG DEHNERT, PETER WINDISCH, JENS STOPP

The Quick-Erect Stopping System (QESS) offers a new way of reducing the radon exposure of miners in Germany, especially during remediation work in old mines. The QESS is a lightweight, modular and reusable construction kit of interlocking telescopic aluminum tubes, radon-proof foil and expanding foam. It is designed to seal off radon-rich parts of galleries within minutes. Originally, the QESS was developed to protect miners against radon exposure. Then, the QESS found the attention of several mine rescue teams at a German mining conference. Some mine rescue drills by The Student Mine Rescue of the Technical University Bergakademie Freiberg, Wismut Mine Rescue and Front Range Mine Rescue helped to improve the system and highlighted its potential for mine rescue operations. Now, the QESS is well-suited for small-scale mining. The QESS can be used to both protect miners from radon exposure and to support mine rescue operations. Moreover, the QESS was also successfully used in ventilation experiments.

By D. Bahrami, G. Danko, W. Asante

"It is prudent to interpret atmospheric monitoring signals in real-time for checking the safe limits of the air conditions in underground mines. In gassy mines, such real-time evaluation increases the safety of operation. In all mines, the continuous monitoring and evaluation contribute to maintaining air conditions to be within healthy and safe limits. Signal interpretation for safety conditions in mines is difficult for many reasons. An increase of hazardous contaminant concentrations can be predicted by signal pattern recognition, root-cause analysis of rapid changes toward deterioration and forward prediction in time using algorithms and numerical models. This paper focuses on analyzing signal patterns to recognize dangerous trends as well as forward predicting the various environmental and working conditions that may affect safety in underground mines. Efficient numerical ventilation model with heat and gas contaminant simulation components is needed for the analysis of real-time atmospheric monitoring data. Computational speed enhancement methods are discussed and tested in numerical examples, using the Jacobian sensitivity matrices for signal propagation prediction. INTRODUCTION The focus area of this paper is mine safety, related to hazardous atmospheric conditions in a mine ventilation system. Improvements by recognizing safety hazards caused by heat of combustible gases or the accumulation of poisonous gases in a mine are addressed. The recognition of safety hazard by manual evaluation is difficult because of the complex nature of information and the large amount of monitored data from measurement by atmospheric sensors such as air velocity, pressure, hazardous gas contaminants and temperature. In order to recognize problem-causing trends, it is necessary to evaluate continuously individual measurement data from the Atmospheric Monitoring System (AMS) of the mine during their time-dependent variations. In addition, the combined effects of various signal trends need to be simultaneously interpreted in their cross-effects. It is very difficult to foresee the possible outcomes of intertwined signatures of various problems by continuous human observation. For example, a steady, continuous methane concentration measurement together with a sharp drop in barometric pressure from the AMS sensors may be a case for worry in future time due to pressure-induced methane increase from the coal seam or the gob (Danko et al., 2013). This future increase can be predicted by a time-dependent Ventilation Air Model (VAM) and its surrogate Air Parameter Predictor Solver (APPS) model. A calibrated VAM or APPS model can indeed predict a likely methane concentration variation in future time as a function of previous and new air pressure as well as air velocity (Danko, et. al., 2013). Such a future trend, however, cannot be seen from the raw measurement data."

Jan 1, 2017

By BARBOSA AMILTON, Denise C. R. Espinosa, David B. Dreisinger

Chelating resins can be used to recover important metals from different sources, and it is important to understand which resin is most suitable for each metal [1]. This review  benefits the mining industry because chelating resins can be used to recover metals from low-grade ores and mining tailings, increasing the industrial process efficiency [2–4]. Furthermore, the use of chelating resins in mining processes and mining tailings has the common problem of metals contamination, with iron being the main contaminant in low-grade ores and tailings. Understanding how contaminants decrease ion exchange efficiency is significant for industries [5

By Dru Brown

More than 150 Mt (165 million st) of material crashed down at the Bingham Canyon Mine (Rio Tinto/Kennecott Utah Copper) near Salt Lake City, UT on April 10, 2013. The mine, one of the largest openpit mines in the world, ceased operations and evacuated personnel prior to the slide when it was discovered that material was moving at a rate of 5 cm/d (2 in./day). The slide destroyed the mine?s visitor?s center, buried several pieces of large mining equipment and severely hampered production. The Kennecott Utah Copper Corp. immediately began to assess the damage and look for options to reestablish operations. The highly unstable ground ? emphasized by another minor slide in September 2013 ? makes any cleanup efforts extremely dangerous. With terrain too dangerous for human operators, Kennecott was forced to look for alternatives that would help the company work on the treacherous slopes of the landslide while also keeping personnel safe.

Jan 1, 2014

By James A. Berberick

Research methods to develop an economic model for the determination of regional mineral advantage are discussed. An industrial complex conceptual framework is used to study potential mineral resource outputs of Kansas. A procedure for making a comparative cost analysis of potential outputs for a Kansas-based industrial complex is outlined and illustrated. Methods for estimating aggregate demand and for developing an input-output matrix for a hypothetical limestone complex are explained. The input-output matrix is expressed in physical units. A computer algorithm for converting physical production data and input cost data into total cost per unit of output information is briefly explained and flowcharted. Limitations and usefulness of this procedure in determining regional advantages are surveyed.

Jan 1, 1969

By Claudia Castillo, Katja Freitag, Jan Cilliers, Diana Drinkwater, Robert Seitz

The talent gap in mining is not a new challenge. Mining companies continue to seek innovative ways to attract, develop and retain talent, and younger workers are looking for opportunities to develop their professional careers. Training provides a key value proposition for both employees and employers as it helps build a talent pipeline while offering opportunities for learning and growth and value creation. In 2020, Metcelerate launched its 20-month program for early career mineral processing engineers. The program helps develop critical technical skills in the workplace and is a tool to identify motivated engineers and change culture within teams. Learners cap their skills development by executing a technical investigation. This generates immediate value—a win-win outcome for learner and company.

Feb 1, 2025