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By L. Zhou, D. Bahrami, Y. Xue

Underground mine fires are a threat to the safety and health of mine workers. The timely determination of the location and size of an underground fire is of great importance in developing firefighting strategies and reducing the risk of any injuries. Machine learning was used in this paper to develop a predictive model for fire location and fire size in an underground mine. The ventilation data were obtained by simulating different mine fire scenarios with MFire. The ventilation data of all airways were used as features to predict the fire location. Based on the feature importance, five airways were selected to monitor, and the airflow data of the selected airways were used to predict the fire location and fire size. An accuracy score of 0.920 was obtained for the prediction of fire location. In addition, in-depth analyses were conducted to characterize the wrong predictions with the purpose of improving the performance of the random forest model. The results show that the occurrence of fire at closely connected airways at some locations can generate misleading ventilation data for each other and the model performance can be further improved by grouping them. Fire size is another factor affecting the model performance and the model accuracy increases with increasing fire size. The result from this study can help mine safety personnel make informed decisions during a mine fire emergency.

Mar 2, 2022

By Eleanor Kentish, Edward Batty, Alan Skarda

"The design of the tunnels at Bond Street Station includes a final sprayed concrete fireproofing layer. The performance of this layer was verified by a program of testing to Crossrail’s KT24 specification, which proved that a dosage of 1kg/m³ polypropylene fibers and a layer thickness of 50mm would be sufficient to limit spalling in the event of a fire. Application of this thin layer was achieved using a state of the art spraying robot, with the ability to scan the profile and automatically apply a uniform layer of concrete. To provide assurance and calibrate this spraying robot, BFK developed a bespoke survey system for checking SCL thicknesses in the field. This provided an instant independent check of the spraying robot and allowed areas of inadequate thickness to be rectified without risk of cold joints. This paper describes the practical application of the fireproofing layer and how design compliance was ensured. INTRODUCTION Fire is one of the most serious risks to a tunnel. The nature of tunnels — being long enclosed spaces — can increase the intensity of a fire, and make fire-fighting and rescue operations difficult. The damage that can be caused has been demonstrated by a number of historic tunnel fires, such as the Channel Tunnel fires of 1996 and 2008, and the Mont Blanc Tunnel fire in 1999. Without any intervention, the high temperatures in a fire create thermal stresses and a build-up of vapor pressure within the pores of concrete, which eventually exceed the tensile strength and trigger explosive spalling. Spalling exposes the core of the section to severe temperatures, leading to a loss of concrete and steel reinforcement strength or further spalling of successive layers. The concrete used in tunnel linings is particularly susceptible to explosive spalling, due to its low permeability achieved by the addition of microsilica (Bailey 2011). The sprayed concrete lined (SCL) tunnels on Crossrail have been designed to resist the worst anticipated fire in operation, in order to prevent collapse and minimize damage to the structure. The design called for a system of passive fire protection, the efficacy of which was validated by the contractor through a testing regime. It was critical that the application on site reflected the test conditions, which demanded special control of the profile and thickness of the lining. In order to meet these constraints on tolerances and quality, BAM Ferrovial Kier joint venture (BFK) developed a reliable method of working with the Meyco Logica spraying robot, and a bespoke survey system for accurately checking thicknesses in the field. These innovations are the focus of this paper."

Jan 1, 2016

By J. Paraszczak

With regards to the cost and profitability of a mining operation, the performance of the equipment employed is one of the key issues. Cost and profitability depend on, among other factors, the reliability and availability of the equipment. In an attempt to reduce equipment downtime, it is indispensable to collect and analyze reliable data and information on failures and maintenance actions. This paper reviews common problems encountered in this respect, with particular emphasis on the lack of uniform terminology and methodology. Recommendations concerning the standardiztion of reliability and maintainability concepts and measures are given. Regarding the benefits that the latter may bring, the paper concludes with a proposal for an industry-wide initiative in this respect.

Jan 1, 2002

By B. A. Kennedy

The instrumentation, monitoring, and prediction of a major slope failure at the Chuquicamata mine are described. In December 1967, pre-existing tension cracks on the south end of the east wall of the Chquicamata mine began to open. Various forms of instrumentation were installed for continuous monitoring. These systems included tension crack stakes, crack extensometers, linear extensometers, tape and transit lines, sliding wire contacts, and a seismograph. From the information obtained, the failure date was accurately predicted some five weeks before failure, enabling the mine to reroute truck and rail access; hence, causing a minimal mine shutdown of two and one-half days and preventing any injuries to persons or damage to equipment. The shape and form of the sliding mass are analyzed, as are the possible modes of failure.

Jan 1, 1970

By T. D. MacQueen

Thank you Mr. Stevens. It's a pleasure for me to be speaking to this meeting of the Society of Mining Engineers of AIME this afternoon, and the Gypsum, Association is grateful for the invitation. A brief word about who we are: the Gypsum Association is the trade association for the gypsum industry - the manufacturers of gypsum board and lath a-d plaster. We have a membership of eight companies. These eight companies produce about 90% of the gypsum products manufactured in the United States ... closer to 94% actually. Our headquarters is in Evanston, Illinois. We have an east coast office in Washington, D.C. where the eastern manager handles technical and building code matters and maintains liaison between all of the government agencies and departments and our industry. We also have a west coast office in Los Angeles where our west coast representatives is heavily involved with the Uniform Building Code and ICBO. And then in the Evanston office our manager of technical and building code services, Herb Carlsen, bites his nails and loses his hair over these problems and various other projects that come in, such as conversion to metric and various other things. We also have a research associate at the National Bureau of Standards in Washington who is currently concentrating his efforts on the combustibility of building materials. His studies involve current testing methods, definitions, data analysis, and proposed new testing methods,.' It is anticipated that this program will lead to a better understanding of non-combustibility of building materials and systems. I mentioned that our members represent over 90% of gypsum products,' manufactured in the United States; it might be well to point out a couple of statistics about what that really means. According to the Bureau of Mines,

Jan 1, 1977

By B. Li

"The spontaneous combustion of coal storage pile(Gangue Hill) is one of the seriously threat encountered in coal mining and storage. The dynamic accumulation of internal heat in coal storage pile(Gangue Hill) provides continuous heat-source for coal spontaneous combustion. Combined with the features and characteristics of coal pile storage, a technology of heat pipe(HP) is applied to enhance heat transfer. In order to prevent spontaneous combustion of coal storage piles (hillock) due to regeneration, a method using heat pipes to destroy the heat preservation conditions of coal storage pile(Gangue Hill) is proposed, which reduces the risk of coal spontaneous combustion and prevents coal fire. A theoretical model of Coal-Thermosyphon has set up to analysis the radius of cooling effect area quantitatively. An experimental equipment of the heat transferring in a set of heat pipe, which used to study the influence on coal pile temperature distribution, has been designed. Results show, the heat pipe has a significant effect on inhibiting the coal spontaneous combustion process by destroy the heat preservation conditions of the coal. Under the experimental conditions, the most obvious coal temperature decline appears at radius 20.0mm around the pipe, dropped from 45.8? to 32.5?, a decline of 29%; the coal pile temperature at radius 420mm from 12.9? to 12.4?, a decline of 3.87%. And the research offers an effective and new approach in its application and promotion for preventing and controlling in coal spontaneous combustion.INTRODUCTION China is one of a few countries which utilize coal as the major source of energy in the world, and is the one whose characteristic of energy structure is rich coal, deficient oil and lean gas. Relatively speaking, China is abundance in mineral resources. The coal, which is the fundamental resource in the process of industrialization, is the main energy in china. Thus China cannot alter the situation of coal consumption dominated a leading role in its energy structure in near term.A massive of coal gangue would be produced every year in China with the mining activities. And it’s estimated that almost 360 million tons gangue were dumped in 2003, accounting for 10 percent of the whole coal production. Huge numbers of coal waste piles have more than 2,600 seats, which cover an area of over 12,000 hectares. Worse more, the coal gangue still has an annual growth rate of 100 million tons. Toxic smokes and greenhouse gases are discharged directly and prolongly into the atmosphere due to coal gangue spontaneous combustion. Even worse, waste dump explosion cause massive losses and are able to endanger the safety of workers. For example, one waste dump of the NO.4 Mine of Pingdingshan Coal Group Co., Ltd. occurred twice of explosions in 2005, and about 3.13 million tons of waste rocks were thrown within the range from 100 to 300 meters, eight people were killed and 122 rescuers and miners were burned, and economic losses were estimated more than 3,000 million."

Jan 1, 2015

By K. G. Black

When one's attention moves from the control of a process unit or from the control of a department of similar units, to the control of an entire plant, two things must change. One is the techniques of control, and the other, the goal or purpose of control. The goal is no longer maintaining a certain quality of product or maintaining a particular flow rate through a process unit. The goal becomes economic - how to make the most money out of the plant. The principal control techniques become those of optimizing, rather than regulating. It is quite common to discuss the control of an entire plant in terms of three levels of control l; regulation, supervision, and optimization. Regulation is the control of inputs to a process unit at desired values. This is accomplished by two or three mode analog controllers or DDC loops. The second level of control is the selection of these desired values, e.g., set-points of the regulation controllers. The third level is to make such adjustments or corrections to the supervisory calculations so as to optimize the plant profit. It is immediately evident that supervisory control and optimizing control are intimately related, and a distinct dividing line cannot always be drawn between the two. Some authors prefer to add even more levels such as adaptive control and management information systems, but we believe our point is well made without further division of the functions which are necessary for complete plant control. To accomplish the economic goal, that is, the optimizing (maximizing) of the profit of a mineral processing plant, the plant should ideally be operated as if it were a separate company, buying its raw materials on the open market and selling its products on the open market. While petrochemical plants endeavor to operate in that manner, unfortunately this is not true of a mineral processing plant. The plant manager has to accept the amount and quality of ore the mining department delivers to him, and the products (concentrates) are delivered to another department of the company for further refining. In some cases he may sell

Jan 1, 1972

By Jan K. Wolski

The PC computer program PCVENT, version 3.3, for the ventilation network analysis now incorporates a real-time fire simulator. Position of the fire or a source of contamination and the character of the event are input from the keyboard. There are several options of type of fire: heat only, contaminant only, or both with a constant burning rate or with oxygen as the only limiting factor. Airway resistances or fan characteristics can be modified during a fire simulation. This allows testing of various fire suppression strategies. Program application in the analysis of a real mine fire is presented.

Jan 1, 1991

By R. A. Winters

At the operations level, productivity is a principle key to profitability. If you are competing with other mines that are paying roughly the same wage rate and the same prices for capital, materials, and energy, the only way your profit can be greater is by producing more output per unit of input. Mines with higher productivity have higher profit margins. Higher profit margins lead to greater operating cash flow, and cash flow is what distinguishes a dog from a cash cow. The turnaround in U.S. metals during the 1980s was in large part due to incredible improvements in productivity. According to statistics compiled by Kaufmann, 1991, labor productivity, measured as tonnes of primary production/manhour, increased 64% in steel, 94% in copper, 75% in lead, 143% in zinc, 132% in molybdenum, and 75% in gold. These improvements were hard won. However, with most modernization programs now complete, measuring and monitoring productivity becomes even more important as producers strive to maintain the gains they have achieved.

Jan 1, 1993

Electronic detonators have been in commercial use for a decade, with an excellent safety record. This paper lists known incidents involving electronic detonators. Typical standards required by regulatory bodies for static electricity and electromagnetic fields are reviewed. The performance of some detonators is compared to these standards; in general the minimum standards are easily exceeded. The general resistance of electronic detonators to extraneous electrical energy that can be derived from the body of test results is compared to danger levels for exposure of humans to these energies; it is shown that electronic detonators can safely tolerate higher electrical energies than people can. This comparison includes comparable data for electric detonators, which are shown to be more vulnerable to extraneous electrical energy than people are. Electronic detonators also bring significant safety benefits in blasting due to their testability, two-way communications, reliability, programmability and precision. The links between these attributes and enhanced safety are discussed with examples from actual blasting. Although electronic detonators are usually more vulnerable to extraneous electricity than non-electric initiation systems, the paper shows that the net safety benefit in handling and blasting is in favor of electronic detonators, which are the safest initiation system that has ever been offered to the mining industry.

Jan 1, 2010

By A. Heriba

Cyanide is highly toxic to humans and other organisms. Concentrations of RCN as low as 0.05 ppm can be lethal to fish (Scott and Ingle', 1981). In wet climates and in colder climates where natural degradation is slow, it is becoming mandatory to destroy cyanides in effluents before they can be discharged. The disposal of spent gold ore as tailings from cyanide heap leach processing facilities is a matter of concern to the public, the mining industry, and regulatory agencies. South Dakota mining laws and regulations require that spent ore be neutralized to a suitable level with respect to cyanide before disposal (Durkin, 1990). To safeguard the environment and protect ground-water and surface-water supplies adequately, a reliable test is needed to determine the amount of cyanide in the solid spent ore.

Jan 1, 1993

By Danny Chan, Shahram Tafazoli, Nicholas Himmelman, Edmond Chow

"While wearable technology has been garnering attention in the consumer market, enterprise and industry have just begun exploring its potential applications. Since February 2014, Motion Metrics International has been working in collaboration with Vandrico Solutions Inc. to apply wearable technology to improve productivity and safety in the mining industry.This article discusses the value proposition of using wearable technology to deliver critical notifications in mining. The advantages and disadvantages of various form factors are explored. The challenges, both specific to mining and in general to wearable technology, are defined. Finally, the concept of MetricsGear, the first wearable technology platform developed for mining by Motion Metrics International in collaboration with Vandrico Solutions Inc., is described. MetricsGear is designed to notify the user with minimal distraction to keep the user focused on his or her primary task and aware of mission-critical events. This focus and awareness allows the user to work more efficiently and safely. The mining process consists of a series of intricate stages, where certain events or conditions in one stage can have a huge impact on other stages. The notification of these critical events or conditions is vital for ensuring the overall efficiency of the mining process. Critical notifications can be classified as two types: timecritical events and contextual information. Time-critical events are situations where a timely response from a responder can have a significant impact on seizing an opportunity or mitigating cost. Some human-computer interaction (HCI) experts classify notification types based on the interruption, reaction and comprehension (IRC) framework. Time-critical events are classified to have high interruption, high reaction and low comprehension due to their urgency. The responder should have just enough information to identify the crisis and react as soon as possible (Chow, 2014). For example, when a tooth is lost during shovel operation, it is necessary to recover the missing tooth before it jams the primary crusher. The consequence of missing this critical time period is a jammed crusher that can cause the mine to be out of production until the jammed tooth is extracted (Baumann, 2013). In this case, the responder only needs to see an image to confirm if the tooth is missing and information to identify which equipment and when the tooth went missing (Fig. 1)."

Jan 1, 2014

By T. D. Barkand

A recent coal mine elevator accident resulted in serious injuries to four passengers. The miners struck the ceiling of the elevator car as it collided into the overhead structure at an estimated speed four times faster than normal. In response to mine hoisting accidents, safety authorities have required additional protective devices on new and existing mine hoists and elevators. This paper examines supplemental safety circuits and new devices designed to provide ascending car overspeed protection on mine hoists and elevators. These devices provide needed protection that eliminates the hazard or significantly reduces the potential of a mine hoisting accident.

Jan 1, 1995

By Jan M. Mutmansky

Since 1973 when the first edition of the SME Mining Engineering Handbook was published, many significant changes have occurred in the US mining industry. The industry went through a fairly prosperous period immediately after 1973, but then many economic pressures came to bear on mining companies, particularly in the metal and coal branches of the industry. These pressures changed both the mining methods used and the general economics of the mining methods. As a result, the industry today is different in many ways titan it was in 1973. A general summary of some of the more important changes that have come about will be provided here as well as some assessment of the effects of these changes on the choices of mining methods. In the metal mining industry, the most significant trends were increased surface mining, the use of larger and more efficient equipment, and increased technology and automation. The primary impetus for these changes was unprecedented competition from foreign producers. In many cases, this competition came about because of the nationalization of foreign mines and the tendency for these mines to become a source of foreign exchange. Under these circumstances, the mines could be operated even though they were not profitable. As a result, domestic

Jan 1, 2008

By S. S. Sephton

The La Perla Mine, owned by Altos Hornos de Mexico, S.A., is located approximately 100 miles east of the City of Chihuahua in the State of Chihuahua, Mexico. The mine began operations in 1958. Existing ore beneficiating facilities, consisting of heavy media and jig plants, upgrade the ore prior to shipment by rail to the Altos Hornos steelmaking complex in Monclova. Sizable reserves of two distinct ore types, which were not amenable to treatment in the existing beneficiating plant, or usable in the blast furnaces, have been mined and stockpiled in order to uncover the treatable ores. One of these ore types has been labeled "Diseminado" ore, and is low grade containing approximately 42% Fe with sulphurs ranging from 1 to 2%. The other ore type has been labeled "Pulverulento" ore, and is high grade containing approximately 65% Fe and 0.1% S, but at 80% minus 325 mesh, is too fine grained for efficient sintering. Late in 1968, Arthur G. McKee & Company became involved with the problem of improving the above ores for their efficient and economical use in Altos Hornos' blast furnaces. Early in 1969 representative samples of Diseminado ore were obtained for laboratory bench-scale testing at the University of Minnesota, Mineral Resources Research Center. Concentration tests incorporating magnetic roasting, wet magnetic separation, high intensity separation, high tension magnetic separation, anionic flotation of apatite, cationic flotation of silica and oleic acid flotation of iron were performed. Laboratory testing was concurrently carried on at La Perla Laboratory, which resulted in plans to construct a 10 TPD pilot plant. The pilot plant was operational in September, 1969. Analyzing laboratory results as well as pilot plant results, Altos Hornos and Arthur G. McKee & Company metallurgists agreed that the most promising flowsheet for the low grade Diseminado ores entailed wet magnetic cobbing, desliming, and oleic acid flotation of the non-magnetic fraction. A combined concentrate of

Jan 1, 1972

By W. Collingwood, K. V. Raj, S. Bandopadhyay

In the mining industry, computational fluid dynamics (CFD) modeling is used extensively to simulate air flow in underground mines. CFD modeling of pollutant transport in openpit mines is relatively new. Modeling the actual pit geometry of an openpit mine and the open domain is complex. The complexity is primarily due to the faceted geometry of an openpit mine with its numerous associated sharp features. Important issues that are not considered carefully at the geometry level are generally propagated to the subsequent processes. Several challenges and pitfalls are encountered in modeling pollutant transport in openpit mines. These challenges and pitfalls are related to the geometry, meshing, boundary conditions and turbulence modeling parameterization. An appropriate mesh selection is critical. A detailed discussion of the meshing of the domain of an openpit mine is presented in this paper. The selection of an appropriate turbulence model, such as kappa-epsilon (κ-ε), large eddy simulation (LES), Reynolds stress model (RSM), etc., to obtain the best possible solution is equally significant. This paper discusses the various challenges in modeling the pollutant transport process in an openpit and some of the approaches adopted to address these challenges.

Jan 1, 2013

By K. M. Kim

An analysis was conducted to determine the effects of blasting on slope stability and downstream comminution processes. To investigate these effects, the extent of blast-induced rock damage and the magnitude of induced stress were examined. This analysis showed that damage may extend up to 500 m (1 MPa, tensile strength) into the rock mass, a distance that is sufficient to have an impact on the pitscale slope over the long term. In addition, the damage zone was calculated using the assumption that compressive waves are the primary agent in microfracturing during blast fragmentation. The calculated damage zone — up to 2.2 m (43 MPa, rock mass compressive strength) — indicates that microfracturing can occur throughout 20-50% of the entire rock mass in the blasting area, depending on the blast geometry, burden and spacing. Finally, an economic analysis was conducted by comparing two assumed blasts in a copper mine. The change in energy required for crushing and grinding was demonstrated using Bond’s law after increasing the blast energy from 180 kcal/t to 350 kcal/t. A total cost saving of 13.3% ($9.4M) was achieved with the increase. However, the benefits of blast-induced microfracturing must be balanced against the potential impacts to slope stability to ensure safe conditions, a top priority in mining operations.

Jan 1, 2014

By L. M. Cenegy

The formation of scale is common in gold ore processing plants. A working definition of scale, applicable to the various scaling conditions found in gold ore processing plants, would be: "a hard, tightly adhering deposit formed in place by the precipitation of calcium-bearing mineral compounds from water". The most common scale found in gold processing plants is calcium carbonate (CaCO3) although calcium sulfate (CaSO4) is occasionally a problem.

Jan 1, 1990

By H. Ehnes

"“Industry 4.0” – “Mining 4.0” - perhaps you have already heard of these terms? These keywords signify the next stage of industrial production. The internet and production technologies are growing closer together. Machines can communicate with one another, wherever they may happen to be located. The “Internet of Things” is the appropriate term. But what does SAFETY 7.0 mean? It is both brand new and traditional at the same time. It also has to do with the success of companies, with efficient production. And yet there is a great deal more at stake. It has to do with our lives and our safety – the supreme commodity in this world. What exactly SAFETY 7.0 means, what the number 0 stands for and the meaning of the number 7, and what this all has to do with mining will be explained in the following article. Mining is a fascinating undertaking. Mining is indispensable for a country’s economic development, whatever that may concern: infrastructure, energy supplies or raw materials for industrial production. Mining has brought forth many technological developments and innovations that can currently be found in our daily lives. Mining is impressive, grandiose and repeatedly fascinates mankind with its immense dimensions. Miners throughout the world still work hard and, for this reason, are bound to one another in a special way. In mining, every man looks out for the other; you have to be able to rely on each other. That creates a strong bond. The other side of the coin is that mining and disasters belong to normality in the media and thus also in our perception. Accidents at work and even catastrophes occur in mining, quarries, or raw material operations almost on a daily basis somewhere in the world. They are often associated with extremely serious injuries, or even a fatal outcome, for the miners affected and, in turn, dramatic consequences for the families of those involved. It could be in China, India, Russia, or somewhere in Africa, Asia or America – it mostly does not happen in front of our door or in our neighbour- hood. Perhaps because of this in the daily concert of negative headlines, we do not register these catastrophes any more in our minds. We write them off under the heading “Nothing special”, since there are, day in day out, more terrible news items about wars, civil wars, famines, or ecological disasters. Things only really change if there is a dramatic number of deaths or when we are personally affected, close by in the vicinity, or can witness the rescue action live. In Europe, these three mining disasters in particular have recently generated media resonance:"

Jan 1, 2016

By Rex T. Ellington

The fluidized bed is an effective method for investigating retorting phenomena and possibly a commercial means of retorting oil shale. Both were examined by Sinclair Oil Corp. (now part of Atlantic Richfield Co.) in the period 1.965 to 1968. The results of the work show that presence of an oxidizing environment during retorting results in loss of oil yield which indicates that vapor phase oil burns in preference to combustion of coke on spent shale. This has implications for several types of retorts. Correlation of the results of this work with that of other investigators shows that the partial pressure of retorting products in contact with oil shale during retorting has an effect on yield. Consideration of hardware indicates that there are several possibilities for commercial embodiment. As a companion to shaft-type retorts the fluidized bed could have good potential. Realistic assessment of costs suggests that further development may have to await commercialization of another process. The existence of a plant in which to test prototype size would markedly reduce such development costs. Results Preliminary development work with the apparatus was carried out using a fluidized bed of sand, as explained later, with the entire system brought up to temperature and flows stabilized. The shale was injected rapidly in a slug (batch) which had small mass compared to that of the high temperature system to make the reaction approach isothermality with reasonable approximation of instantaneous preheating. Typically, the temperature in the center of the bed dropped from 900°F to 600°F one minute after batch addition. It returned to 750' within three minutes and 900° within seven minutes. Obviously, the bed was quenched but it recovered rapidly. Average bed temperatures of 700' to 1020°F were examined to compare the effect of temperature with published results. Yields In the 700°F range were only 10 to 15%, of Fischer Assay (FA). Above about 950'F, oil yields decreased and gas yields increased. Nitrogen was used first as the fluidizing gas to provide a chemically inert medium. Incept for an insignificant dip at 895"F, Figure 1, oil yield was not affected by retorting temperature in the 800° to 900' range as long as residence time was adequate (16 minutes). At 925°F, the oil yield was some 103% FA. With further increase in temperature, the yield decreased to 86% FA at 1015°F. There is no increase in carbon on spent shale, the lost oil goes to Increased gas make.

Jan 1, 1972