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By B. Petri, N. Rouse

"Air overpressure monitoring procedures and instrumentation guidelines which apply to production blasting in underground limestone mining are not readily available. The industry also lacks an applicable source for air overpressure levels that are produced by blasting operations in underground limestone mines. As such, there was no available background data from which the expected overpressure levels from production blasting in a new underground limestone mine could be predicted. During the development phase of the mine, it was imperative that newly constructed underground structures be capable of withstanding the overpressure produced by blasting in nearby production headings. To ensure the structures could withstand the blast-induced overpressure, a study was conducted to record empirical overpressure data and develop a model which could be used to control air overpressure levels by the production crews. This document describes the procedures used to develop the model, the development of the model, and the applicability of the model for predicting underground blast overpressures. INTRODUCTION A developing underground limestone mining operation required that a ventilation wall be built to house the permanent mine fans. At the time of the study, the mine was a single-level room and pillar operation with a 7.9 meter (26 ft) high roof, 13.7 meter (45 ft) wide entries, and 13.7 meter by 13.7 meter (45 ft by 45 ft) pillar dimensions. The mine is accessed via a 396 meter (1300 ft) long decline and 100 meter (330 ft) deep ventilation shaft. The ventilation wall was to be partially constructed of autoclaved aerated concrete blocks, for which dynamic strength data from explosives loading were unavailable. The company ownership feared that airblast may affect the wall due to the close proximity of the working faces. Therefore, the company management asked that the overpressure levels be estimated and compared with the designed wall strength. Few studies that apply to explosively-driven air overpressure levels in underground production blasting were found through a literature review. Therefore, the logical approach to assess the overpressure levels was to monitor the blast pressures at the site and conduct a thorough evaluation of the data. As a result of this study, the equipment setup and monitoring procedure used to record the airblast data is described. Finally, the experimental data gathered during the monitoring program is presented, trends and findings from the data are discussed, and recommendations for further study are presented."

Jan 1, 2015

By M. Javier

Mining is an industry of experimentation throughout human history. Recently, societies are giving a clear message about mining because many projects are being rejected around the world. These refusals are a generational reaction to the activity of mining. In practice, it generates the perception that mining is using the same methodology without attending to the gradual initiation of conflicts. This is in spite of the best engineering and technology of the time that are put in place at the presentation of those mining projects. Some of these rejected projects are geographically distant from each other, but the communities? rejection occurred during many cases under similar characteristics. This concern shows that the current model of mining projects needs to be replaced with a new one: A new Design, one within which the socio-environmental values of this millennium are inherent. This paper describes Mining Project 101 to help the industry to set the highest and cleanest standards for mining. It also presents its aspects to sustainability and nature, which provides the principles and procedures for designing, planning, and operating mining projects with sensitivity to nature. It offers methods of diagnostic, remediation, and extraction while at the same time preventing and preserving a physical, chemical, and biological equilibrium of nature. This emerging process will be a step up from having a mining industry unaccountable to the socio-environmental conflicts it perpetrates and will abandon the ?cosmetic? repair on the caducity of traditional models in today?s practice. In conclusion, we have the opportunity to change this model. KEYWORDS: Equilibrium in Nature, Geomímic, Deproduction, mine design.

Feb 27, 2013

By E. R. Bauer

The trend in underground room-and-pillar coal mining is to employ remote-control continuous mining machines and extended cuts, 12 m (40 ft) deep or more. This system of coal extraction, adopted by over 435 mines, can create additional worker-safety hazards. To address the ground control and worker-positioning hazards, a combination of statistical analyses and numerical modeling was conducted. Initially, the reported roof-fall incidents and fatalities were reviewed to delineate the ground-control hazards. Then, the application of the Coal Mine Roof Rating (CMRR) for estimating safe extended-cut depths was evaluated. Finally, computer modeling to predict roof displacements during extended-cut mining was completed. The paper describes the results of these studies and their impact on the safety of extended-cut mining.

Jan 1, 1999

The accurate estimation of ore reserves along with capital and operating costs are two key components to the successful outcome of any feasibility study. In recent years, there have been many project failures caused by improper estimation of ore reserves. The accurate estimation of ore reserves for any deposit relies heavily on understanding its geology and underlying assumptions unique to the estimation techniques being used. The assumptions unique to commonly used traditional and geostatistical reserve estimation technique will be reviewed. The shortcomings of the estimation techniques and their possible impact on a given project's economic outcome will be discussed. The latest developments in geostatistics in overcoming existing reserve estimation problems will be presented.

Jan 1, 1994

By Christian Heinz, Doug Harding

TBMs can last for decades and be rebuilt project after project with proper maintenance. How successful can rebuilt TBMs be? At the DigIndy Tunnel System in Indianapolis, Indiana, USA, a rebuilt TBM was used to great effect. The 6.2 m diameter Main Beam, originally manufactured in 1980, bored 40+ km of tunnels and set three world records in its size class of 6 to 7 m, including a best month of 1,754 m. In this paper, the authors analyze the TBM rebuild, performance and lessons learned to make recommendations for future projects seeking to use rebuilt TBMs over long distances.

Jun 23, 2024

By R. M. Cox

Pneumatic coal loading and conveying systems provide alternative methods for the safe and efficient mining of the thin high-grade coal seams found in the Southern Appalachians. Pneumatic systems eliminate most of the health and safety hazards associated with the operation of conventional mining and haulage equipment in small low-coal mines by removing powered mobile equipment from the mine. Ventilation is also improved by the coincidental removal of gas and respirable dust from the mine by the operation of the pneumatic loading and conveying system. Other significant advantages of pneumatic coal recovery systems are relative simplicity, operating flexibility, low capital cost, quiet operations, environmental benefits, and ease of automation. The design considerations and field evaluations of experimental prototype pneumatic coal loading and conveying systems, installed and operated in small thin-seam mines, are presented in this report. In addition, fundamental design criteria and recommendations for the installation and operation of a variety of pneumatic coal loading and conveying systems are proposed, which offer alternative coal recovery systems that alleviate the serious health and safety concerns of current small mine operations.

Jan 1, 1999

By R. M. Schuster

This study attempts to compare the costs of transporting coarse coal by pipeline, versus the more conventional use of belt conveyors. Hydraulic conveying of crushed (not pulverized) coal has not had widespread commercial acceptance. However, there is little doubt that the technology is available, so that, should this method be proven economical for a given application, implementation of this technology will become more acceptable. Hydraulic transport by pipeline between the mine stockpile and the coal preparation plant, for distances normally considered practical for an overland belt conveyor, should be an ideal application. In this application there is no need for dewatering facilities at the receiving end of the pipeline, because, the receiving screens at the plant serve this purpose. Further, clarified water from the preparation plant can be recirculated back to the mine, a plus for water resource and environmental considerations.

Jan 1, 1982

By J. C. Irvine

Meramec Mining Company, a joint venture by Bethlehem Steel Corporation and St. Joe Minerals Corporation, is engaged in the mining, concentrating, and pelletizing of iron ore from the Pea Ridge Mine located near Sullivan, Missouri, about 70 miles southwest of St. Louis. The orebody was delineated in the mid-1950's by St. Joe during an exploration program to discover new lead orebodies. An airborne magnetometer survey which was run by the U. S. Geological Survey, the Missouri Geological Survey, and several min¬ing companies was published in 1950 and showed an anomaly in the Pea Ridge area. Test holes drilled in 1953 and 1954 revealed the presence of a large orebody of probable commercial significance; additional drilling in 1956 and 1957 provided confirmation of this. Meramec Mining Company was incorporated in 1957 and shaft sinking began in the latter part of that year. The Pea Ridge orebody lies under about 1300 feet of sediments. It is tabular, about 2600 feet long and up to 600 feet thick, and lies in an approximate east-west delineation. The orebody dips about 800S and is of unknown depth. The ore is primarily high grade magnetite with smaller zones of specular hematite, The Pre-cambrian wall rock is rhyolite porphyry. The mine is serviced through two concrete-lined shafts, 19 feet 1 inch in diameter and 2500 feet deep. No. 1 shaft, equipped with an "A" type head-

Jan 1, 1972

By C. Roos

"Nearly every input to a mine plan is based on an estimate. The estimates may be from sample data, historical information, models, or personal opinion, but in all cases, these values are simply expected values (means). In real life, we do not get to iterate the exact conditions at our mining operation many times to ensure that that average value is attained. The expected value also tells us nothing about the spread of values that that input might take on. The result is a significant amount of unquantified uncertainty in our mine plans. Unfortunately, it is often too expensive or time consuming to update planning processes and software. This paper presents a proof of concept spreadsheet scheduling tool that can be utilized to incorporate many geologic realizations (simulated models) into the mine scheduling process. While this POC is not intended to be a detailed model of uncertainty, it is to show that there are stepping stones available for mine planners to begin to embrace uncertainty and produce more achievable plans without requiring a significant change in their planning process. INTRODUCTION Mining companies have included quantifying uncertainty, or at least risk, as a requirement of project justification for many years, however many times this process lags behind the traditional mine planning process and the results are rarely used to improve the plan. Nearly every parameter used in a mine plan is an estimate and the mine planning engineer should recognize and even embrace the inherent uncertainty in those parameters and its effect on their forecast results. While many of the uncertainties are beyond the scope of the traditional mine plan (e.g. global market uncertainty, socio-political uncertainty, environmental uncertainty), some uncertainties can, and should, be included in the mine planning process. Many mining engineers have incorporated techniques such as Monte Carlo Simulation or Discrete Element Simulation to understand the range of productivity that can be expected for an operation but most still rely upon one estimated model for what is likely the critical component of technical uncertainty, the geologic resource. Modern geostatistical methods can provide multiple ore body realizations to provide a thorough unbiased “picture” of the geologic uncertainty but most traditional mine planning techniques are not formulated to allow for multiple (100-200) realizations of each material quality/grade parameter. Commercial software companies and research groups are progressing with development of tools that can incorporate geologic uncertainty, and even optimize extraction plans in the uncertain environment. Unfortunately, this author believes that a significant number of mining operations will not be able to adopt these techniques due to the computational requirements of the advanced techniques and the costs associated with implementing proprietary software. In an attempt to encourage mining engineers to embrace the inherent uncertainty in their mine plans, this paper presents a cost-effective alternative that can be developed in-house, at any mine, to schedule mid to long-term mine plans while continuously monitoring the uncertainty in the results. The author hopes that by demonstrating the usefulness of such a system that mining companies will encourage engineers, geologists, and geostatisticians to find ways to incorporate this powerful data into their processes and procedures."

Jan 1, 2017

By T. P. McNulty

During the last decade, many exhaustive studies have been made of process energy requirements for the production of various metals and materials. Some excellent technical papers and text books have resulted, and some of these are included in the bibliography of this paper. These studies were, of course, prompted by the economic pressures which resulted from the beginning of the "Energy Crisis" in 1973. Our intensified consciousness of the cost of energy led, then, to a greatly improved understanding of the energy consumption attributable to individual mining, processing, and refining steps. It is worth noting, however, that an awareness of the cost of energy is not new and that efforts to minimize this cost were an important part of sound mine and plant management practice throughout the earlier days of our industry. One only has to read a few accounts of mining operations around the beginning of this century to develop an appreciation for the cost of supplying wood, coal, fuel oil, or electric power to remote locations.

Jan 1, 1983

By Hans Janzon, Ernst Buechi

INTRODUCTION The headrace tunnel in Amlach is part of a hydro electric power scheme near the city of Lienz in south west Austria. The project is owned and developed by Tiroler Wasserkraftwerke AG, the regional electrical supply utility. The construction work was divided into seven contracts for the entire scheme. The power output will be 60 MW, this being developed from a head of 370 m and water flows of 20 m3/s. The water will be tapped from the river Drau and lead through a 22 km long headrace on the south side of the Puster valley through the Lienzer Dolomiten mountain range. Contract No. 4, which is a joint venture between Mayreder, Züblin, Strabag, Rella and Innerebner, involves the construction of 13.5 km of the headrace. It was decided to bore this from one single adit, which probably makes it the longest pressure tunnel driven from one side by a TBM. (See Fig. 1.) For the tunnelling an Atlas Copco Jarva MK 12 TBM was chosen. The excavation diameter is 3.90 m, with the final lined diameter being in the range of 3.20 to 3.40 m. The back-up is a 145 m long single track rail system supplied by Mühlhäuser (Germany). Side-tipping cars with a capacity each of 8.2 m were used for removing the muck. One California switch was attached to the back-up after 3,000 m, and a second fixed switch was installed after 8,000 m of boring. 3 m long

Jan 1, 1987

By F. Dehghani, B. Rezaie, T. Ghosh, A. Sachan

Comminution is an integral part of the mineral extraction process. However, the influence of the comminution method (ball and rod mills) on silica and magnetite particle shapes has not been substantially investigated. Shape parameters for fractions of -250+212, -150+125, and -106+75 μm sizes were examined utilizing a scanning electron microscope and a Clemex vision PE image analysis system. The silica particles displayed higher elongation and flatness parameter values for rod mill products, but roundness and relative width parameter values of rod mill products are less than that of the ball mill products. Magnetite particle elongation and flatness parameter values of ball mill products in fraction sizes of -250+212 and -106+75 μm are larger than rod mill products, but roundness and relative width parameter values of ball mill products are smaller than rod-mill products, but for the -150+125 μm size range the result is converse. Furthermore, particle elongation and flatness increased with decreasing particle sizes of silica, whereas, roundness and relative width decreased for both Ball and Rod Mills. In case of magnetite, ball mill products displayed an increase of flatness and particle elongations with decreasing particle sizes but flatness increased and roundness and relative width decreased. Similarly for rod mills, magnetite fractions of -150+125 μm were found to have the largest values of elongation and flatness. INTRODUCTION Comminution alters the size and shape, causes lattice distortion, changes chemical composition, surface area, surface-free energy, and polymorphic transformation of all materials. The quantity and quality of such changes depend on specifications of the material feedstock, the type of mill being utilized, the specific energy input, ambient temperature, and environmental pressure [1]. The shape difference between the milled products depends on different grinding mechanisms and the respective breakage principles that these mechanisms depend on [2, 3]. With decreasing particle sizes, the nature of the particle surface become crucial [1]. The influence of the breakage technique has been found to be non-trivial and heavily dependent on the type of grinding mill used for particle size reduction [4]. Shape is an important industrial parameter for predicting particle behavior in downstream processes. The shape parameter affects the way particles burn, compact, are recovered, flow in fluids, sinter, float, agglomerate, fluidize, interact with pulmonary tissue, cut, abrade, react with chemicals, form structural materials, and retain and permit fluids to flow [5, 6]. The distribution of particle sizes and shapes are important for mining, civil and chemical, pharmaceutical, and various other industries with interest in the population modeling of atmospheric dusts, smoke, and grit [1, 3, 6]. The shape parameter not only affects the chemical, physical, surface properties of particles but is also important for downstream processes [5, 6]. Image analysis has been found to provide detailed information about size and shape of the particles and can be used for the control of product quality [4].

Jan 1, 2019

By Biswajit Samanta, Pranjal Pathak

This article presents a customized genetic algorithms (GA) with new crossover and mutation operators to solve the short-term production scheduling problem of multi-mine mineral value chains (MVC). The preceding problem consists of determining the extraction sequence and destination allocation of blocks from all the mines collaboratively while closely meeting the quality and quantity requirements of the processing units subject to relevant technical and operational constraints. The short-term production scheduling is carried out at shorter scales wherein the operations are modeled in a great detail with large number of constraints. This makes the industry-scale instances of the problem computationally intractable for standard mixed-integer programming (MIP) solvers. Thus, a GA-based heuristic approach is developed to obtain nearoptimal solutions to the large-scale instances of the problem in a reasonable amount of computational time. Computational experiments show that the developed GA-based method is a promising way to handle industry-scale instances of the problem. Moreover, the sensitivity analysis on various parameter combinations of crossover and mutation operators indicates that the customized global mutation operator, when used in combination with the customized crossover operators, took on average 12.5% less time than the customized local mutation operator to converge to a solution.

May 21, 2022

By M. J. Virnig, G. A. Kordosky

Throughout time, the mining industry has been very successful in meeting the world's requirements for metals and materials while meeting the challenges of decreasing ore grades and increased emphasis on protection of the environment. This success has been due to the development and implementation of new technologies. A clear example of such a development over the past 25 years is the increasing use of leaching/solvent extraction/electrowinning for the recovery of copper from oxide and sulfide ores. The key to the successful introduction of this technology was the discovery and development of the hydroxyoxime liquid ion exchange reagents by General Mills Chemicals (now Henkel Corporation). An important role was also played by the close working relationships between General Mills Chemicals and Ranchers Exploration which resulted in startup of the first plant in 1968 and between General Mills Chemicals and Bagdad Copper which resulted in the startup of the second copper SX-EW plant in August of 1970. Following on the heels of the hydroxyoxime development came the commercialization of other new chelating reagents based on different chemical functionalities, i.e., beta-diketones, alkylated 8- hydroxyquinolines and sulfonamidoquinolines. This initial spurt of activity was then followed by a slowing of development in terms of new reagent functionalities. Activity has continued in terms of further optimization/improvement of existing reagent functionalities but the commercialization of new reagent functionalities has slackened. This observation reflects the fact that the development of new reagent functionalities for metal recovery has become increasingly more expensive such that the right combination of price and sales volume must exist in order to justify the investment required to bring a new reagent to the market place. Given the dependence of the mining industry on innovation to meet the needs of the future, one can ask how these new developments, particularly in new reagents, will occur. To arrive at an estimate of the costs involved in commercializing a new metal extractant functionality, particularly a chelating type functionality, a case study of the development of LIX ®* 34

Jan 1, 1994

By Deborah McCombe

-Canadian Regulators -Qualified Person -Professional Association -Resources & Reserves -Foreign Codes -Disclosure of Historical Resources -Issues in Application of Resources & Reserves -Industry Best Practices developed by CIM -Technical Report and Reserves and Resources -Summary

Jan 1, 2003

As opposed to a prescriptive-based design, a performance-based fire-protection system design allows the system planner the flexibility in choosing specific method, materials and design tools to achieve a preset goal. A different approach in fire protection and a powerful addition to existing method, the system has been around for many years, and has gone through numerous improvements. Despite its popularity in the building industry, it has not been introduced to the mining industry yet. As mines get deeper, increases in size and complication, mine fire safety system will also become increasingly challenging, a new and proven system should be able to great potential to eradicate many of the problems that are either unsolvable or cost-prohibitive with the traditional method. With increasing globalization and international exchange with other major mining countries a common language/practice also make the performance-based design method a desirable feature in mine fire safety system. This paper will first define a performance-based system, step-by-step design methods, likely impacts on fire-protection practices and possible challenges in implementing the system in US underground mines.

Jan 1, 2011

By S. J. Root

The mineral processing industry supplies raw materials to a wide variety of manufacturing sectors. Large companies such as Ford, Microsoft, and Johnson&Johnson have pledged carbon neutral supply chains in the coming decades, leaving suppliers to reevaluate their energy sources [1–3]. National Renewable Energy Lab [4] has partnered with over 700 organizations with similar goals in mind. The energy needs are broad in scope in the mineral processing industry. Generation IV of nuclear reactors, which is currently under development in both the private and public sector includes a class called microreactors like the small modular reactor XEnergy plans to install at Dow Chemical’s Gulf Coast facility by 2023 [5]. As the name implies, these are smaller than the utility scale nuclear power plants in operation today, and are intended to be more versatile. A specific reactor core design, along with modules could be selected to fit a certain application without needing to design a greenfield power plant. Basic water cooled designs could easily supply shaft work, electricity, and low grade process heat to a facility. More advanced designs, such as molten-salt-reactors and high-temperaturegas-reactors can achieve higher temperatures needed for ore roasting. Similarly, these reactors could produce hydrogen by high temperature electrolysis to use as combustion fuel and reducing atmosphere in blast furnaces.

Feb 1, 2023

By I. Loomis, D. Rachmad, I. Duckworth

During the past two years the Underground Mine Ventilation Group at PT Freeport Indonesia has undertaken to upgrade their Hygiene Laboratory. This process has included upgrading equipment for dust sampling and gas monitoring, as well as procurement of an OCEC analyzer for Diesel Particulate Matter analysis. While the laboratory equipment represents one factor, these changes have also required re-evaluation of the sampling protocols and the burden of ventilation monitoring personnel. This paper provides a review of these experiences.

Jan 1, 2006

By R. A. Hodge

Over the past decade, there has been a significant increase in effort put to tracking progress toward sustainability. Many aspects of society are participating in this “movement” including mining. The drivers are diverse and include evolving ideas in business and public administration as well as concerns for human well-being, community robustness, environmental integrity, and overall social and ethical responsibility. The scale in question varies greatly from local to global. For the most part, there has been a pre-occupation with developing discrete measurable signals. This paper argues that the overwhelming focus on the quantitative is ill-advised and that a more effective approach is to bring together the best of both quantitative and qualitative. The mining industry in particular is well-placed to affect this shift and reap the associated benefits.

Jan 1, 2004

By A. G. Mayton, D. H. Ambrose, C. C. Jobes, N. K. Kittusamy

In a systematic study, the National Institute for Occupational Safety and Health (NIOSH) evaluated seat designs in low- and mid-seam shuttle cars during production operations at two underground coal mines in southern West Virginia. The purpose was to support, with additional data, earlier findings that NIOSH ergonomic seat designs (featuring viscoelastic foam padding and lower-back support) may help reduce health risks to operators of coal mine shuttle cars. Eight shuttle car operators evaluated seven seat designs (one already in use in each vehicle and five NIOSH designs) relative to perceived and measured whole-body vibration (WBV) exposure (including vehicle jarring/jolting) and discomfort. Operators’ perceptions using a visual analog scale (VAS) and questionnaire ratings were compared with International Standards Organization (ISO) 2631-1:1985 fatigue-decreased proficiency (FDP) limits and measured WBV levels on low- and mid-seam shuttle cars. Objective and subjective data results indicated that NIOSH seat designs (with added adjustability, lower-back support and improved seat padding) performed better to reduce vehicle jarring/jolting levels and that shuttle car operators favored them over existing seat designs. The NIOSH low- and mid-seam shuttle car seats showed 45 to 77 percent better performance in FDP and 9 to 60 percent better performance overall in operators’ ratings. Considering the VAS results for low- and mid-seam shuttle cars under no-load conditions, operators rated the level of jarring/jolting 18 to 89 percent lower with the NIOSH seats. Reductions in measured vehicle jarring/jolting were 19 to 46 percent for the three-directional vector sum accelerations relative to the existing seats on the low- and mid-seam shuttle cars. Questionnaire responses indicated that operators for both shuttle car models rated NIOSH seat designs as more comfortable overall. Vehicle operators most frequently suggested adding armrests to improve the seats on the mid-seam shuttle car. A suggested improvement for the low-seam shuttle car was to make the seat a better fit for the operator compartment, which would enhance clearance between the operator and vehicle controls and allow for better seat adjustment and operator visibility.

Jan 1, 2009