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By J. A. Madonna

Independent prospectors and small to large-scale exploration company personnel have requested, and are in need of, guidance in geochemical field sample collection methods which will provide the most reliable results during chemical analysis. In cooperation with analytical laboratories, experienced geochemical exploration scientists and mining companies a systematic collection procedure has been developed. The procedure consists of collecting uncontaminated, water, sediment and rock chip samples of the appropriate quantity and/or dimensions to meet the needs of analysis.

Jan 1, 1999

By W. A. Crosby

All mine operators using explosives want to maximize explosive performance while minimizing blasting costs. Use of bulk explosive products such as AN/FO, heavy AN/FO, slurries and emulsions has greatly improved blasting efficiency over the years. Many operators have improved energy output from these products by adding aluminum. A major problem facing them is the fluctuation in aluminum price. The question therefore becomes, when is it economically advantageous to use aluminum in bulk products? This paper answers this question by first reviewing the energy output from the main types of aluminized and non aluminized bulk mixed explosives and then by showing the relationship between the different products on a cost and energy basis. The paper finally presents examples of charts and tables which will aid mine operators to conveniently select the most economically correct bulk explosive, including the level of aluminum addition.

Jan 1, 1991

By Jr. Babcock

The Pyke asbestos deposits were discovered by Kennecott Explorations (Australia) Pty. Ltd., in 1969 during the course of base metal exploration on the South Island of New Zealand. Extensive occurrences of chrysotile asbestos were found associated with the Red Mountain Ultramafics in the headwaters of the Pyke River, and to the north and south along the ultramafic belt for a distance of 70 kilometers. Surface evaluation and drilling by Kennecott in 1970 and 1971 identified numerous small deposits of good grade fibre in the Little Red Hills between the Pyke and Barrier Rivers. Additional drilling and three adits have been completed by other companies since that time. The property is presently held by Lime and Marble, Ltd. Of Nelson, New Zealand, and Kennecott Explorations (Australia) Pty. Ltd. This paper will present the regional and local setting of the asbestos deposits, including the geology and nature of mineralization. In addition, the exploration methods used by Kennecott in the discovery and evaluation of these deposits will be outlined. Subsequent work by other companies will be mentioned, but not described in any detail. This subsequent work did not alter Kennecott's conclusions or produce any serious changes in the interpretation of geology and mineralization. The author acknowledges the contribution of the many employees of Kennecott Explorations (Australia) Pty. Ltd., who have been involved in the project, particularly Ramon Farmer, N. G. Comer, and A. W. McConie, who were responsible for completion of field work and reporting on the project. The responsibility for the conclusions and interpretations of this report are solely that of the author and result from his involvement in discovery of the deposits and management of the exploration program.

Jan 1, 1978

By Peter Johnson, David Barber, Lachlan Henderson

"The traditional approach to rail tunnel fire safety design is to follow NFPA 130, which assumes a major tunnel fire could occur and requires bi-directional emergency ventilation. There is no regard to the impact of ventilation on fire growth and smoke production. In Europe and other parts of the world, the need for tunnel ventilation systems to provide smoke management in the event of fire is being questioned. The European Commission’s Safety in Railway Tunnels TSI is based on a philosophy that improved running capability (preventing fires and other events stopping the train in the tunnel) and elevated fire performance of materials means the chances of a major fire in a tunnel is highly unlikely, with only small fires expected, and no tunnel ventilation required. This approach is reinforced by the International Tunneling Association which has recently published an Engineering Methodology for Performance Based Fire Safety Design on Underground Rail Systems, which includes a methodology that does not require assessment of tenability in tunnels, but requires a scenario based risk assessment to be undertaken to determine overall fire safety measures. Recent research by the University of Edinburgh has shown that forced airflow from a mechanical ventilation system may promote fire growth and increase smoke volumes much more than with natural ventilation. Whilst the concept of no mechanical ventilation (i.e. natural ventilation) is a new concept for some, for many rail tunnels it is worthy of serious further consideration. RAIL TUNNEL SMOKE MANAGEMENT AND STANDARDS Smoke management using mechanical bi-directional ventilation systems has been a central part of the fire safety design solution under NFPA 130 for rail tunnels since 1982. The current version of the standard, NFPA 130: 2014, states that mechanical ventilation should be fitted to rail tunnels of length greater than 305 meters and an engineering analysis should be undertaken for tunnels of length 61 to 305 meters to determine whether mechanical ventilation should be fitted. However, this approach is not necessarily reflected elsewhere in the world. In Europe in particular, mechanical ventilation systems for smoke control within rail tunnels have taken a much less central role within the standards framework."

Jan 1, 2016

By Charles H. Greene

This paper will describe briefly the steps taken in the development of a Central Florida phosphate ore deposit from acquisition to mining. Further, the design and early operation of the mining and beneficiation facilities will be depicted. During the 1950's, with confidence in the continually increasing requirement for phosphate fertilizer materials essential for producing food, I'. R. Grace & Cc acquired the Hookers Prairie tract containing approximately 45 million metric tons o. (50 million short ton~ of potential phosphate rock product. In 1973, at a point when the Grace captive need for rock was being greatly enlarged by a planned doubling of its Bartow phosphate chemicals plant capacity, the decision was made to expand existing phosphate rock production by building a new mine and plant. The initial annual capacity was to be 2.3 million tons (2.5 million st); however, subsequent investigation pointed to a higher than estimated dragline operating factor 'and the forecast of annual capacity was set at 2.5 million tons (2.8 million st).

Jan 1, 1977

By Patrick J. Maessen, Bart H. M. Hendrix

"In the Netherlands, the Dutch Tunnel Standard has been developed for the execution of road tunnel projects. The Dutch Tunnel Standard is based on the Dutch Tunnel Law (WARVW) which sets the minimum safety standard for road tunnels in the Netherlands. Uniformity of tunnels and the uniform perception of a tunnel by its users leads to a higher safety level. Therefore, several items in the Dutch Tunnel Standard are specifically developed to ensure safety in emergency situations through the plane of human factors. Taking human factors into account is important in regular traffic situations, but in an emergency situation, this can be vital. In this paper, the development and contents of the Dutch Tunnel Standard are explained in the first part and in the second part, the systems related to human factors are described. DUTCH TUNNEL LAW AND THE NEED FOR THE DUTCH TUNNEL STANDARD In the 90’s of last century and the early 2000’s, several serious accidents occurred in tunnels in Europe. These accidents involved fire and led to many casualties. After these accidents, the European Union decided to change the regulations for tunnel safety, leading to the EU directive 2004/54/EG. The primary goal of this directive is, that casualties are minimized in case of a calamity in a tunnel (e.g. fire). In the Netherlands, the EU directive led to the development of the tunnel law and a tunnel regulation (in 2006) to prescribe the safety features required for a safe tunnel. The new Dutch tunnel law – cited in the Building Act – was meant to make tunnel design easier – but resulted at first in the opposite effect. Tunnel design in the Netherlands and design standards of Rijkswaterstaat Rijkswaterstaat – the executing organisation of the Dutch Ministry of Infrastructure and the Environment – is the owner of the tunnels in the Dutch national motorway network, thus owner of the majority of the road tunnels in the Netherlands. In the early years of tunnel building in the Dutch national highway network (approximately 1950 – 1970), Rijkswaterstaat was not only owner, but also designer of its own assets. Most Dutch tunnels are submersed tunnels, because these type of tunnels provide a cost-effective way to make river crossings. Another type of tunnel that is used, is a TBM tunnel. Because of the geological conditions in the Netherlands (merely clay/peat and sand), there are no NATM or drill-and-blast tunnels in the Netherlands. Since the last decades, land tunnels (covered roads) are becoming more common to provide for multiple use of surface space and to meet more modern environmental regulations as traffic increases near densely populated areas. Tunnel lengths in the Netherlands vary from 500 m to 1.5 km for river crossings up to 6 km for the Western Scheldt (bored) tunnel. The lengths of land tunnels vary from 500 m up to 3 km. With these increasing lengths, some safety topics and design topics arise, topics that were non-issues in the past, when tunnels were only used as river crossings."

Jan 1, 2016

By Dae Young Kim, Sim Bo Kyung, Ebrahim Farrokh, Ki Chang Hyun

"TBM cutter life evaluation in abrasive granitic rocks is a very important issue, especially in pressurized face tunneling with mixshield TBM for which the planning of costly interventions becomes crucial. This paper presents an overview of methodologies for cutter life evaluation in rock. A comparative study is performed to indicate the predictability of cutter life evaluation methods based on detail data from the NS3 tunnel project in Singapore. A new model is developed based upon the cutter wear information of eight TBM tunnels from around the world. New methods are proposed to evaluate the optimum intervention interval length and the number of worn-out disc cutters for a tunnel project. Finally, two new laboratory tests in the evaluation of disc cutter abrasion, including a full-scale and a small-scale test, are introduced, and their test results are discussed. INTRODUCTION The issue of wear evaluation for hard rocks has been extensively studied in drilling and pavement industry. In this regard, several tests and evaluation methods have been proposed to estimate or evaluate the state of tool life (e.g. bit life for drilling). In the case of TBM tunneling, tool wear may depend on several factors such as mineral composition, strength, or type of cutting, but as the abrasion is usually the major mechanism for the tool wear in hard rock, the developed methods for cutter wear or cutter life evaluation are mostly based on the abrasion indices such as Cerchar Abrasivity Index (CAI). This paper attempts to review the major methodologies for disc cutter wear and life evaluation and to propose new methods to evaluate cutter life and intervention interval evaluation based on detail information of a mixshield tunnel project in Singapore as well as general information of some other projects from Iran, Italy, South Africa, and France. As the laboratory tests are crucial in the process of evaluation, two new lab tests are developed and used to inspect suitability of the new proposed model for disc cutter wear evaluation."

Jan 1, 2016

By E. D. Gálvez, L. A. Cisternas, A. López-Valdivieso, F. Lucay

"The floatability of molybdenite fines in saline solutions was investigated through microflotation studies using a modified Hallimond tube. In addition, the effect of pH and gypsum precipitation from calcium ions (Ca2+) and sulfate ions (SO4 2-) ions in saline water on the recovery of the molybdenite was analyzed. It was found that the floatability of molybdenite fines significantly increased with the ionic strength of the saline solutions and is independent of pH above 0.5 mol/L ionic strength. The high floatability of molybdenite in saline solutions is explained as being due to the low electrostatic repulsion between bubbles and the edges of molybdenite particles, which is exceeded by interactions due to van der Waals and hydrophobic forces. The precipitation of Ca2+ and SO4 2- ions as gypsum had a detrimental effect on the natural floatability of molybdenite because of gypsum crystal attachment on the faces of the molybdenite particles. This precipitation phenomenon may be initiated in copper–molybdenite flotation circuits that use recycled saline water, like seawater containing Ca2+ and SO4 2- ions.IntroductionWater availability is a significant factor in mining projects. Water, particularly fresh water from rivers and underground water, is becoming a scarce resource for mining operations and new projects. Under these circumstances, the use of water with high concentration of salts in flotation plants is becoming increasingly important (Cisternas and Moreno, 2014). The use of seawater has been studied as a sustainable solution for many mining companies in dry areas located near the sea. Notably, using seawater in mining operations is how mining companies in Chile have coped with the problem of water resources (Cisternas and Gálvez, 2014). In 1930, small plants in Chile used seawater to float chalcopyrite from high-copper-grade ores. In 1975, the results of tests in pilot plants for the flotation of copper minerals with seawater were reported. It was found that froth formation in seawater at pH 9.5 was suitable to make the rougher circuit work properly, even without frothers. The Cenizas mining group successfully floated chalcocite, bornite and chalcopyrite in the Las Luces plant in Taltal in Chile using seawater (Moreno et al., 2011). Minera Centinela (Antofagasta Minerals S.A. Chile) is currently processing porphyry copper ores using a seawater mixture consisting of 20 percent fresh seawater and 80 percent recycled water. Lower consumption of flotation reagents was reported in both seawater and salt water. In addition, studies performed with synthetic seawater showed that certain frothers increase the froth volume, whereas others decrease it. Additionally, the froth produced with seawater carries a high amount of gangue, and low-quality concentrates are obtained, requiring more cleaning stages."

Jan 1, 2015

By W. A. Hockings

This report describes a computer program for the solution of material balances in complex mineral processing flowsheets. The program, which is entitled MBS Metallurgical Balance System), evolved as the culmination of a series of material balance programs whose development began in 1967 at the Institute of Mineral Research, Michigan Technological University. The need for such a program became evident when the Institute became heavily involved in a large number of short-term pilot plant projects. Calculating material flows from analytical data by means of the standard two-product formulas grew increasingly difficult and time-consuming as the complexity of the flowsheets increased and as choices between conflicting analytical values had to be made. It was recognized that what was needed was a program that would assimilate all of the available data and calculate mass flow rates so that steady-state inputs and outputs would balance at each point in the flowsheet. Such a program should be capable of handling underdetermined, overdetermined and mixed systems, and when the given data are inconsistent, the program should adjust the data in such a manner that the adjustments are minimized. Missing analyses should also be calculated whenever possible. In addition to solving material balances, the program should be convenient to use and print out the results in a useful form. Thus, the inputting of data should be simple enough to be handled by relatively untrained personnel with diagnostic messages being printed out to identify errors and anamolous data when they occur. Most importantly, the program should produce well-formatted output which can be directly included into a report without the necessity of retyping. The proper spacing of table titles, column headings and the ability to control the columns being printed are important features in this respect.

Jan 1, 1977

By Donald M. Duncan

An acceptable source of concrete aggregate is available in Kansas City in a continuous, medium bedded, slightly dipping limestone unit. Removal is accomplished in shallow depth, 12 feet to 17 feet high, room and pillar mines. The accepted empirical design spaces 20 foot pillars 60 feet on center. A portion of the 20 foot unit is left in place for roof support. Rock and soil cover is variable to 100± feet maximum. Long-term stability of these mines is affected by numerous factors, including the above mine-rock profile, ground water conditions and mining practice. Crusher-run aggregate sells at the mine for $2.20 per ton, yielding a gross income of $2.00 to $2.80 per square foot of mine. Use of mine space for real estate development requires a new perspective in mine development. Mining practices to obtain long term stabile structures can become an over-riding factor as compared with minimum production costs and maximum extraction ratios. Poorly mined areas are unusuable for secondary purposes. Development cost for lease space in less desirable mines is substantially greater than those planned for a secondary use. Real estate development in mine space involves unique engineering problems. Properly engineered developments offer singular advantages. Warehouse lease space sells for $.50 to $1.00 per square foot per year; fully developed office areas may double these values.

Jan 1, 1968

By H. A. Kortmann

For the commercial production of iron ore pellets from hematite ores, as it is practiced in various pellet plants, the addition of lime has shown to be an efficient means with a view to improving cold compression and abrasive strength of the indurated pellets considerably. Unfortunately, it has also been shown at the same time, that the metallurgical properties as, for instance, swelling behavior, softening during reduction under load and disintegration of the grain, can be adversely affected to a high degree. In the course of smelting tests carried out by renowned steelworks, blast furnace operation was heavily disturbed by the swelling and early softening of the pellets, also by their disintegration in the low-temperature range, which altogether led to a considerable lowering of the smelting rate (1, 2, 3).

Jan 1, 1972

By C. W. Baxter

Eveleth taconite company was formed in 1963 to mine and beneficiate taconite on the Mesabi range of Minnesota. Its thunderbird mine is located midway between the cities of Eveleth and Virginia, Minnesota, and the crude ore is transported by rail to its Fairlane plant approximately ten miles to the south of the mine, "figure 1". As is implied by the names of the mine and plant, the ford motor company is the principal owner of Eveleth taconite company, with an 85% interest, Oglebay Norton company holds the remaining 15% interest and also is the managing agent.

Jan 1, 1972

By Clement K. Chase

Since the dam of cyanidation leaching techniques for precious metals, certain manganese-bearing silver ores have been a problem due to low silver extractions. Since simultaneous occurrence of silver and manganese is common in nature, this situation has made many otherwise attractive silver deposits uneconomic in the past. Several older techniques have been useful but at $1.29 per ounce of silver, the economics were unfavorable. With the new look in silver prices and some improvements in processing technology, neglected silver districts offer new promise.

Jan 1, 1981

Mine managers need better information to locate new opportunities and then to assess the effect of their decisions. We are developing the Intelligent Decision Support System (IDSS) and its two major modules, the Pattern Recognition System (PRS) and the Knowledge Representation Subsystem (KRS) to automatically provide the information from monitoring system sensors. This paper focuses on the KRS Algorithms that extract key information from lists of time study type event sequences. Because a static system cannot operate effectively in a dynamic mining environment, we are prototyping an index based technique that allows the system to adapt itself to this dynamic environment.

Jan 1, 1990

By Thomas N. Walthier

Exploration is the systematically financed and technically oriented search for mineral wealth. Almost all established mining companies have an exploration department. The size of a company's search varies over the years as the company's profits, or the corporate philosophy change. While the established mining companies have exploration departments, they are also alert to acquiring discoveries made by others -- especially by prospectors and small companies without the resources to develop their find. The emphasis in some large companies stresses self-generated discoveries while others rely heavily on acquisitions; again, over the years the emphasis may alternate. In the last analysis, essentially all new mineral wealth was found through someone's exploration effort. Before we discuss how exploration is financed, it will be informative to analyze how discoveries have been made and by whom. Recently, the author conducted a survey of randomly selected major mining companies to answer these questions. Most companies responded and many went to considerable effort to give complete and detailed answers. I thank all for their help and cooperation. The questionnaire is attached as Appendix I. Appendix II is a list of the 400 companies that replied in a complete enough manner and format to be analyzed here. The results of the questionnaire are given in Table 1. Over 57% of the new orebodies acquired by 40 major mining companies during the past quarter of a century were generated

Jan 1, 1977

By A. Konya

"INTRODUCTION Underground Mining and Construction projects face several challenges unique to the underground environment compared to the surface environment. The goals of an effective blasting program are the development of a blast pattern that minimizes cost, maximizes face advance, and provides the desired fragmentation and face profile. In addition to these , mines must consider the very real operational problems that occur such as drill deviation, ground vibration, and deadpressing or sympathetic detonation of explosives. These operation problems lead to increased costs and decreased production in the mine, hurting the bottom line. Combined with these problems, underground blasts can be difficult to monitor and evaluate due to tight spaces, dust during the blast obscuring video, and the need to evacuate the immediate area with no clear line of sight to observe performance. This creates an environment which most mines know that blasting can be improved in their underground operations, yet most are hesitant to change due to fears of the shot freezing, misfires occurring, and questions about how to achieve a proper design. The explosive companies and shot service providers also offer limited assistance or knowledge in the underground blasting realm, unlike with surface blasting, leaving many underground operations in the dark. It is for these reasons that most underground operations are operating decades behind the current technologies and incurring significant costs, both real and hidden, from there blasting operations. This paper discusses philosophical changes to designs that need to be made for effective design and modifications of underground blast patterns to prevent deadpressing and precompression of modern explosive products (Konya, Konya, & Worsey, Modern Blasting Method Selection, 2017). While numerous different methods of underground heading development exist, there are two types that are used in a majority of mines around the world, these are the burn cut and the V-cut. The burn cut is a parallel cut that has holes that go straight into the face and are primarily used in smaller opening (due to ability to pull deep rounds with smaller room widths) and metal mines (helps in ore dilution and greater fragmentation). The V-Cut is a cut that uses angled drilling towards the center of the face (in the traditional method) and is primarily used in underground aggregate operations due to its cheap cost but larger fragmentation sizes and greater throw of the muckpile. This paper will discuss these two forms of cuts specifically with the understanding that modifications to these can be applied to other parallel and angled underground heading techniques. BURN CUT The burn cut is one of the older forms of underground blasting, where a part of the blast (burn) of a shot is heavily loaded with additional empty (relief) holes with the goal of smashing (aka burn) and pushing/blowing all the material in the burn out to provide relief for subsequent blastholes. The relief holes in the burn cut provide a parallel relief for the holes that are firing to break too creating a second plane of relief, however these are extremely small and can cause many problems if a design is improper."

Jan 1, 2018

By Teena Redhorse, David Tsztoo, Anthony Yu

"Since ancient times, storing and conveying water via underground water systems and tunnels has been touted for its strategic advantages. Underground cisterns and tunnels assured protection of essential fresh water supplies from man made contamination and especially from enemies who would gain an advantage by disrupting an adversary’s water supply in a siege. Modern day engineers do not usually specify tunnels for reasons of avoiding deliberate contamination or siege — however, they are just as enamored with the idea of building tunnels for water conveyances.Such was the case for the San Francisco Public Utilities Commission (SFPUC). The SFPUC provides drinking water to 2.6 million residential, commercial and industrial customers in the San Francisco Bay Area. The SFPUC’s water system includes 257 km (160 miles) of transmission pipelines and tunnels from the SFPUC’s largest reservoir, the Hetch Hetchy Reservoir inside Yosemite National Park, to San Francisco. About 129 km (80 miles) of the system consist of tunnels. A 30-km (19-mile) section of the tunnel network, called the Mountain Tunnel, was thought to be at risk of a catastrophic failure in its concrete-lined section of 18 km (11 miles). For much of the project planning process, a new replacement tunnel was presumed to be required according to the tunnel planners.Originally constructed between 1917 and 1925, the Mountain Tunnel has been in continuous service since 1925. The 30-km (19-mile) tunnel is located downstream of the Hetch Hetchy Reservoir water source in Yosemite National Park, between the Early Intake and Priest Reservoir (Fig. 1). Approximately 18 km (11 miles) of the tunnel is lined with unreinforced concrete. Though the condition of the tunnel was being monitored through water sampling and periodic inspections, there was growing concern that the tunnel lining was at risk of a partial collapse that could interrupt water delivery for up to nine months. The SFPUC was faced with a decision to construct a new bypass tunnel to replace the lined section of the Mountain Tunnel or to rehabilitate the existing tunnel."

Jan 6, 2018

By F. Calizaya

A booster fan is an underground fan installed in series with a main surface fan and used to boost the air pressure of the ventilation air passing through it. To accomplish this objective, the fan is installed in a permanent stopping and equipped with airlock doors, a monitoring system, and interlocking devices between main and booster fan controls. The stopping and doors are used to prevent flow recirculation, and the monitors to ensure safe operation of the fan. A booster fan, properly sized and sited, can be used to create safe work conditions and allow the extraction of minerals from areas that would otherwise be uneconomic to mine. In deep and large mines with heavy emissions of air contaminants, the required quantities of air can only be supplied by using high pressure fans. These fans will inevitably induce significant losses of fresh airflow through the stoppings and doors. For well defined ventilation circuits, booster fans can be used to decrease the main fan pressures and reduce the leakage flows. However, this will require a good understanding of the correct ventilation practice, from planning to operation and maintenance of booster fans. The objective of this study is to investigate the conditions under which booster fans can be used safely and efficiently in underground coal mines. Specifically, the study is directed at (1) collecting reliable information on airway resistances and flow requirements from two large U.S coal mines, (2) collecting fan performance data from one or more existing coal mine where booster fans are used regularly, (3) monitoring the performance of booster fans in a laboratory model and an experimental mine, (4) developing a booster fan selection method to assist the ventilation engineer at the planning stage, and (5) training six M.S. or Ph.D. graduate students in advanced mine ventilation.

Jan 1, 2010

By Neilson Rudd

Many deep well waste disposal. operations have adopted the technology of the petroleum industry but fail to make full use of the knowledge and experience upon which this technology is based. Inexperience in subsurface exploration commonly leads industrial personnel to an over simplified understanding of the complex subsurface rock/fluid environment and overly optimistic "degree of exploration /adequacy of knowledge" ratios. Several fundamental differences between disposal and petroleum production are discussed. In particular, the evolution of understanding of the subsurface in relation to degree of exploration is demonstrated by summarized case histories of such other forms of subsurface fluid exploitation as oil pro¬duction and underground gas storage, tracing subsurface interpretations from the initial exploratory concept to that of fullest development. Evolutionary changes in interpretation and their significance as applied to deep well disposal are stressed.

Jan 1, 1971

By Roberto Pimentel de Souza

Since 1976 CVRD is carrying out tests to develop a type of pellet made with organic binder. One binder that showed good possibility to be used in industrial plants is Peridur. An extensive framework of tests was run in CVRD's pilot plant. The results are presented in this paper. Finally, the decision was taken to carry out an industrial production of 50.000 t of pellets. It was scheduled for March '81. The results are shown in this pager. It was not observed any detrimental effect of the peridur neither in the process nor in the product quality.

Jan 1, 1981