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By W. R. Reed, S. Klima, J. Driscoll, T. W. Beck

"Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration’s lower coal mine respirable dust standard of 1.5 mg/m3. Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control. IntroductionAbout one-half of U.S. underground coal is produced by longwall mining, which allows for mining high volumes of coal but generates significant amounts of coal mine dust. This can lead to overexposures for longwall miners and possibly occupational respiratory diseases, including black lung and silicosis, which have no cure and can be disabling or fatal. The only method to avoid these occupational illnesses is through elimination of exposure to respirable coal mine dust and crystalline silica (quartz). The current occupational exposure limit for respirable coal mine dust is 1.5 mg/m3 during each shift that a miner is exposed in the active workings of the mine or in mine facilities (Mine Safety and Health Administration (MSHA), 2015a). When respirable quartz is present, the mine must maintain average concentrations at or below 0.1 mg/m3. If the mine exceeds the 0.1 mg/m3 respirable quartz dust concentration, then the applicable respirable dust standard is reduced, calculated as 10 divided by the percent quartz present (MSHA, 2015b)."

Jan 1, 2018

By R. Thorpe, M. Dosbaba, A. Kopriva, A. Niiranen, J. Ruokanen

"Automated Mineralogy (AM) is an important diagnostic tool in flotation plants as it adds ore and particle mineralogical properties to traditional mass and chemical data. AM is used in project development, for future ore studies and for diagnosing concentrator operations. With the exception of operations who own central laboratory or on-site systems, the use of AM is often limited to the analysis of a comparatively small set of samples. Metrix Plant Technologies has partnered with TESCAN to integrate TIMA AM technology into the implementation of Performance Assessment Campaigns (PAC). Routine daily composite samples from the mill are analysed mineralogically on a size-by-size basis over several weeks. All the relevant metallurgical, process control and mineralogical data is combined into a single large database for mass balancing and interactive examination. This paper describes the implementation and results of a PAC at the Agnico Eagle Kittilä gold mine in Finland. Although challenging, the addition of mineralogical data as dependent variables in multivariate analysis leads to a much deeper understanding of the root cause effect of events driving the flotation performance. INTRODUCTION TO STUDY The Kittilä mine, owned by Agnico Eagle, is Europe’s largest primary gold mine, with annual production of approximately 180,000 Oz. The operation is located in Lapland in northern Finland, and is currently expected to operate until 2035. The location of the operation is shown in Figure 1. Historically, the mine was an open pit, although in recent years ore is sourced solely from underground operations. The processing plant features crushing and grinding, followed by carbon flotation and sulphide flotation. Carbon concentrate is a waste stream, and sulphide concentrate reports to pressure oxidation (autoclave) and CIL circuits for gold extraction. The final flowsheet is shown in Figure 2. Following commissioning in late 2008, the operation achieved commercial production on May 1st 2009. Gold recovery in flotation gradually increased to a 92-96% range at a throughput of ~3500-4000 tonnes per day. In late 2014, the operation commissioned a plant expansion to ~5000 tonnes per day. Following a commissioning period, the operation stabilised with recoveries in a 90-94% range, which over any given period was determined to be ~2% lower with statistical significance. The trends from start-up of gold recovery in flotation and throughput are shown as follows in Figure 3. In early 2016, Agnico Eagle Kittilä mine, along with Agnico Eagle Technical Services (AETS) partnered with Metrix Plant Technologies and TESCAN, to perform a Performance Assessment Campaign (PAC) at Kittilä, involving automated mineralogy on five key streams at Kittilä on 40 days selected from a 50 day period between February 15th and April 4th 2016, when plant operations were stable. In addition to the mineralogical data, metallurgical and operational data were pooled into a single, powerful database to explore opportunities for the operation to improve recovery in a sustained manner, ideally to the levels pre-expansion."

Jan 1, 2017

By Tony Amis, Marco Barla, Alice Di Donna

"Energy geostructures are becoming an increasingly popular solution around the world for Developers looking to reduce CO2 and system running costs. Energy geostructures are geotechnical structures that provide both the important role of structural stability while also acting as a heat exchanger with the ground, enabling the supported buildings and or infrastructure to be heated and cooled using the principle of low enthalpy geothermal systems. The main advantage of this innovative technology with respect to standard geothermal plant is the reduction of the initial installation costs and construction schedule benefits, compared to installing conventional geothermal solutions, largely due to the additional use of structures which would be constructed in any case. However, it is important with respect to energy geostructures that additional aspects need careful consideration. For this very reason, several research studies have been carried out over the last decade on this subject and a number of real case studies have been monitored and analysed. The key difference with respect to conventional shallow geothermal systems are mainly related to the geometry, which is imposed by the geotechnical project, and the need to ensure that the primary structural role is always guaranteed. Special boundary conditions, the reduced depth, the influence of atmospheric external temperature can also play an important role for energy geostructures. They can affect, both energy efficiency and, the geotechnical behaviour because of the possible thermal induced mechanical effects. This paper presents a picture of the current situation regarding energy geostructures and their peculiar features, and collects available data to provide a reference framework. Data has been collected from literature and personal communications and then processed to provide easy-to-read charts useful for practical consultation at a glance. This paper provides, an indication of the distribution of such systems worldwide, their spread in time, and a global view of their actual efficiency from the structural, energy, economic and environmental point of view.1. IntroductionEnergy geostructures are becoming an increasingly popular consideration around the world. Energy geostructures are geotechnical structures with a dual role of providing structural stability and the ability to exchange heat with the ground, to provide low carbon heat and coolth to supporting and or adjacent buildings and infrastructure, using the principle of low enthalpy geothermal systems (Barla and Di Donna, 2016; Laloui and Di Donna, 2013). A closed circuit of high density polyethylene (HDPE) pipes is embedded in the concrete, and a heat carrier fluid circulates through them exchanging heat with the ground. The HDPE pipework circuit inside the geostructure is linked to one of the above buildings or infrastructure through a heat pump, which adapts the temperature of the circulating fluid to the heating (winter mode) and cooling (summer mode) needs. In this way, heat can be injected into the ground during summer and extracted from it during winter. In principle, all structures in contact with the ground can be used as energy geostructures. The first examples of energy geostructures date back to the eighties in Austria and were mainly piles and shallow foundations. A decade later, Henderson et al. (1999) reported on what would appear to be the first successful use of geothermal energy piles in the US, with loops incorporated into the foundation for a hotel in Geneva, New York. As was their use in this New York case history, the typical geothermal energy pile application is used in conjunction with additional closed loop boreholes to provide the required energy capacity for a structure. Interestingly the report concludes that the geothermal energy piles had a better heat transfer performance than the borehole field. The first energy walls appeared slightly later, while still today only a few experimental cas"

Jan 1, 2017

By Hitch M.

Many mining wastes, especially those from the metal mining industry, have traditionally been treated as a matter of little or no value and in practice a cost burden. Some wastes, due to their reactivity characteristics, have emergent values that go beyond purely economic and into the environmentally beneficial realm. This paper discusses the changing paradigm of mine waste management. Such fundamental parameters such as cut off grade, and strip ratio, are positively impacted by the revaluation of waste rock material. Mine rock waste can now be seen as a commodity of value, similar to the underlying ore being mined and influences the economic performance of suitable projects. This valuable material can be used for industrial purposes including acid neutralization as well as the capture and long-term disposal of anthropogenic carbon dioxide. The Turnagain Nickel project, located in northern British Columbia serves as an example of how waste rock material can become an important matrix for carbon capture and sequestration and can benefit economically from it. By producing material that has emergent economic value as well as carbon capture and sequestration capabilities, the sequestration matrix producer is a beneficiary of new carbon credits that have a market value and is looked upon favourably by regulatory authorities and affected stakeholders.

Jan 1, 2010

By J. Howard Bird

The purpose of this publication is to discuss grounding mediums and the phases of grounding related to corrosion and cathodic protection. The material presented is believed to contribute to a better understanding of this subject. It also indicates more effective methods of reducing corrosion damage to metal structures and equipment in the mining industry by cathodic protection. The authors do not intend to discuss technical aspects but rather to explain the general principles of this method of inhibiting corrosion. The relationship between soil resistivity, protective grounding, and corrosion is presented. Corrosion causes the annual loss of billions of dollars; which can be greatly reduced. Losses in the mineral industry can be excessive owing to the extensive use of direct-current power, the presence of considerable dampness, and the frequent, indiscriminate use of dissimilar metals.

Jan 1, 1958

By Louis J. Sousa

This Bureau of Mines report examines aggregate trends in foreign direct investment in the U.S. mining and mineral processing industries between 1977 and 1984, and provides an analysis of foreign investment in several major mineral commodity industries. In 1984, 11.1 pct of total employment in the U.S. minerals industry was at firms that were U.S. affiliates of foreign firms. In 1985, the proportion of U.S. capacity held by foreign investors in nine major mineral commodity industries was as follows: steel, 5 pct; silver, 16 pct; lead, 18 pct; aluminum, 25 pct; zinc, 26 pct ; copper, 30 pet; cement, 32: pct; gold, 44 pct; and ferroalloys, 56 pct. Almost 90 pct of the total foreign investment in the U.S. minerals industry was accounted for by eight countries-Canada, the United Kingdom, France, Federal Republic of Germany, Switzerland, Japan, Australia, and the Republic of South Africa. The most fundamental reason behind the growth in foreign investment in the U.S. minerals industry has been that an increasing proportion of U.S. mineral firms and assets have been for safe, while foreign mineral companies have been the ones most willing and able to purchase these firms and/or their assets. mile the growth in foreign ownership in the minerals industry has not been without controversy, it has helped save jobs, reduce the minerals trade deficit, and- from the national defense perspective-maintain the Nation's overall mineral and metal self-sufficiency at reasonably high levels. In the absence of domestic buyers, foreign investors have helped to maintain a viable domestic minerals industry.

Jan 1, 1987

By Melvin S. Taylor

The environmental control program at Cassiar Mine is an active one involving government, unions and company personnel all working together to achieve a goal- "A clean and safe working environment". This can only be achieved by utilizing three of Cassiar's most important resources; i.e., people, time and money. Past environmental programs have more than proved that the goal can be reached and. with the future programs now in progress. Cassiar Asbestos will achieve its environmental goals.

Jan 1, 1978

By Edward Holloway

The basis for the selection of the ultimate pit for an open pit mining operation is generally opaque. Some form of value-based analysis will generally guide the final decision; however, the value will often gradually plateau whilst the ultimate pit size continues to increase. There is no established framework to guide specialists in the selection of the ultimate pit, with such decisions regularly made on a somewhat arbitrary basis. The key component that is missing from the analyses typically used to select the size of the ultimate pit is risk. Once risk is quantified within the analysis framework, the decision-making range is significantly reduced, and the process for selecting the ultimate pit becomes more consistent, replicable, and defensible. This paper provides an approach to including risk in the process used to select the ultimate pit.

Feb 21, 2024

By David S. Smith

Almost nine years after the assertion of enormous and pervasive federal control over coal mines by means of the Federal Coal Mine Safety and Health Act of 1969, 30 USC Section 801 et seq, as amended by the Federal Mine Safety and Health Act of 1977 (which basically increases the punitive powers of government) a brief assessment of some of the underlying causes, present status, and possible alternatives to governmental control is appropriate. In a governmental system based upon the principles of democracy and the protection of individual freedoms and constitutional rights the ultimate mechanism for abrogation of these rights is the creation and exploitation of fear. Machiavelli in rendering advice concerning the power over men provided by fear stated, "... it is much safer to be feared than loved .. fear preserves (the government) by a dread of punishment which never fails." The Prince. Within the context of the assumption of control by the government over industries or segments of our population - popular fear provides a convenient and almost necessary mechanism for the avoidance by law or regulation of democratic principles. The popular fear of coal mines has been successfully exploited by various goal oriented groups in the past and most recently by a Congressional constituency with a vested interest in controlling the mines through regulation.

Jan 1, 1979

By A. Romero, M. Carvalho, D. L. Millar

"The number of underground mines replacing diesel by battery powered mobile equipment is growing worldwide. The latter produces locally zero emissions and less heat, improving air quality in the working areas, and can potentially reduce energy costs due to lower ventilation requirements and in the face of higher fuel prices. However, there is a lack of systematic approaches to evaluate the potential economic benefit of switching from diesel mobile technologies to electric ones. This paper presents a method to answer the question of whether a mine with known operating conditions should invest in battery-powered electric equipment to reduce its total costs. Furthermore, this method provides the optimal number of electric and diesel equipment in relationship with their impact on the ventilation system and the total costs of running the mine from the energy perspective. A case study of an underground mine in Northern Ontario (Canada) is presented to validate the method proposed. The scenarios studied include the specific climatic conditions of the region, and the possibility to use heat recovery for the ventilation system. Overall, results show that the use of electric mobile plants is cost competitive, especially so when electricity cost can be lowered through load-shedding strategies.INTRODUCTIONOf the multiple advantages of using electrical vehicles (EV) underground in mining, the potential increase in air quality and comfort is the most significant (Paraszczak, Svedlund, Fytas, and Laflamme, 2014). Until recently, fully battery-powered electrical underground heavy duty machinery (i.e., loaders or trucks) were not available, so that tethered and trolley assisted vehicles were the only electric alternatives to diesel powered vehicles (Bétournay et al., 2011). Today, several commercial battery-based alternatives are available (General Electric Fairchild, 2015; RDH Mining Equipment, 2015; Paraszczak et al., 2014). Operational details can be found in Ewing (2015). The main battery technology used (Lithium Iron Phosphate, LiFePO4, or LFP) was already anticipated in Bétournay et al. (2011) as a good candidate for these types of vehicles. More details on these batteries, along with state of the art and future perspectives can be found in Zubi, Dufo-López, Carvalho, and Pasaoglu, (2018)."

Jan 1, 2019

By Edward E. Johnson

The Bureau of 'Mines publishes in its ?Minerals Yearbook? a series of indexes on the domestic minerals industry. Among these are the index of physical volume of mineral production, indexes of stocks, and indexes of average unit mine value and implicit unit value, This report describes the material coverage of these indexes and the methods used in their construction. Detailed descriptions are given for several other mineral-oriented indexes regularly published by other government agencies. These descriptions give the index user a better understanding of what each index purports to measure and aids him in selecting the most appropriate index for his purpose.

Jan 1, 1965

By Thomas Fraser

WHEN the Bureau of Mines initiated the program of large-scale research and development in the field of synthetic liquid fuels authorized in the Synthetic Liquid Fuels Act of April 5, 1044, the Coal Preparation Section was assigned the task of obtaining data on the preparation characteristics of the coal in large reserves that might be adaptable to use in this new industry. It is natural that, as the rapidly developing general research program brought about new concepts of raw-material quality, preferred geographical location, and the like, the orientation of coal-preparation investigations should have undergone some change. The first major assignment was the sampling and testing of a series of typical American coals deemed to he suitable for hydrogenation based on early research work conducted by the Bureau of Mines. This first series of tests has been completed and is reported in this paper.

Jan 1, 1950

By Robert B. Coleman

The recent surge in demand for uranium in the US, accompanied by a significant increase in price, has stimulated the search for and development of lower grade ore bodies. At the mill, this translates into much larger throughputs and-compounded by many recently enacted environmental considerations-has made the cost of milling a critical factor in today's uranium production economics. The three conventional milling methods employed in the extraction of uranium ores are reviewed in the following sections.

Jan 10, 1978

By David J. Hatem, K. Bhattarai

Effective risk management in major subsurface projects involves ways to mitigate adverse impacts to final design and construction approaches due to changed subsurface conditions. An Early Contractor Involvement (ECI) collaborated with Observational Method will be an effective contractual tool to address risk developed due to encountering differing site conditions. Observational Method (OM) can further be supported with artificial intelligence (AI) technologies with automated data-driven decision-making features in risk mitigation and implementation of proper design and construction approaches. This paper presents collaborative applications of ECI, OM, machine learning, and risk baselining in risk management and productivity enhancement in tunneling projects.

Jun 23, 2024

By R. S. Dean

The possibility of cheap electric power for a number of mining areas in this country has suggested to many the idea of electric smelting of nonferrous ores in small units at or near the mines. The electric smelting of nonferrous ores was tested fairly thoroughly 20 years ago by United States Bureau of Mines and by others, and the fact that it did not achieve continuing workable success in any instance is sufficient proof that it offered no advantages at that time.

Jan 1, 1937

By B. Calver, D. J. M. Farnsworth

"As open-pit operations expanded at Pine Point, hydraulic aquifer evaluation was undertaken to establish the criteria necessary for the design of a feasible dewatering system.The extreme climate of this northern location dictated that the ore zone under extraction be rendered as dry as possible to minimize freezing effects. The design and implementation of such a system necessitated detailed hydraulic evaluation, and the problems that occurred are typical of those inherent in open-pit mining operations in northern areas.The paper describes the problem solution as approached from a mine engineering point of view, with particular reference to the practical aspects of operation and installation. The hydrological analysis used is simple and readily applicable to most open-pit dewatering problems."

Jan 1, 1969

By Scott Ellenbecker

Mining has evolved in recent years, taking steps forward in the way that the industry is considerate of the environment and the communities in which it operates. Technology plays a major role in that evolution. Osisko Mining?s Osisko Mine near Malartic, Quebec is developing a new way of doing business. One manager said, ?We are building the Osisko culture,? but the company is doing many things that could become industry changers. Much of the change is driven by mine ownership and management to offer a better workplace and better community relations. Mining equipment manufacturers are changing, too, by engineering products with more operator comfort, fuel economy, ease of maintenance and more cleanly designed machines. And for those drills working close to communities, smaller bore sizes and sound retention are just two changes for the better.

Jan 1, 2012

By A Keddie

Standard microeconomic theory suggests that the behaviour of mineral extraction and processing firms with respect to their demand for water can be modelled and a market demand for water subsequently derived. Such a model, although an abstraction of the real world, should be able to predict the responsiveness of quantity of water demanded to change in price, and, change in demand to a range of factors including: expectations about reliability of supply, changed commodity prices for mineral production, and change in water technology and storage at mine site. This paper demonstrates that the price of water is particularly responsive to changes in demand and that although price increases would result in some additional supplies, physical constraints on supply suggest that the industry will be paying considerably higher prices for water in the future. It is recommended that the mining industry undertakes quantification of possible price increases to position itself to minimise the impact on their operating costs as well as to make responsible capital investment decisions to facilitate future expansion or commissioning of new mines. Substantial investment is required to commission a new mining venture with expected rates of return subject to risk and uncertainty due to fluctuations in world commodity markets as well as reliability of secure supplies of inputs. If a reliable supply of water was subject to uncertainty and water was a critical input for production, then the initial mine design would typically consider a range of production decisions contingent on levels of uncertainty with respect to water supply. These states or sets of water supply, will affect production decisions and future water demand. Modelling production decisions contingent on different states of nature, termed the state-contingent approach, provides a number of insights about producer behaviour under uncertainty. This paper investigates the assumptions underlying the derivation of the market demand for water by the mineral resource industry and identifies the drivers of demand and the responsiveness of the industry to change in price and supply, particularly in relation to capital investment in water-use technologies. The usefulness of these models to the mining industry is considered by reference to the increasing demand for water by the industry in Queensland, in a climate of water shortages.

Jan 1, 2006

By A. L. W. Lips, B. P. J. Stevens, T. J. R. Bareley, E. Rothery, S. H. White

B.P.J. Stevens contributes a further response to the authors' earlier lengthy reply regarding their paper published in Trans.IMM B, vol.104, 1995, p.B1-B17, contending that despite the positive contribution clarifying their interpretations they perpetrate some misquotations, attempt to rewrite history and fail to understand the New South Wales Geological Survey's stratigraphic interpretation of the Broken Hill area. The paper's authors, in their further response, robustly defend their views, insisting that Stevens tends to misquote or take out of context what they have written and reiterating their findings that Zn is tectonically stacked above Pb at the north end of the orebody, that the written development of the stratigraphic interpretation is as they have stated, that shearing has attenuated or removed fold limbs in the Broken Hill block and that the 1:100 000 stratigraphic map reveals that magnetic anomalies are oblique to and truncated by the Geological Survey's interpreted stratigraphic boundaries

Jun 19, 1905

By D. C. Edwards

In an age where customer service and quality drive today's industry and business, no service or product is exempt from these demands. Industry and business are streamlining everything from people to equipment and today have a heavier reliance on the performance and quality of their assets and equipment, (one of the keys to staying competitive). In the mining process industry, the centrifugal slurry pump is a key piece of equipment that keeps product moving and aids in generating revenue for its owner. The continued improvement and customer success lies in a team effort between the mining industry and the pump manufacturers. We, the pump manufacturers, need to keep improving our designs to further extend the life of our pump with fewer failures and promote to our customers proper maintenance of the pumps to continually keep unexpected failures to a minimum. Strict equipment maintenance, as thoroughly demonstrated by the military, is key to the long life and success of any piece of equipment. In the often harsh duty of the centrifugal slurry pump, maintenance is something that requires "attention to detail". No area of the pump is exempt from attentive maintenance. Here, discussions will focus on the areas of the mechanical drive end, wet end, seals, and extended pump shut down and start up. There has not been a slurry pump designed to maintain or repair itself. So in effect, each pump warrants able bodied maintenance persons to maintain them who continually observe all the rules of safety. Prior to any maintenance discussion or action, the issue of safety should always be addressed. Here, as with everywhere, the same rules apply. Work at a safe pace, note all safety precautions, use associated safety equipment and personal protective attire, observe all tagout and lockout procedures, and most importantly, be aware.

Jan 1, 1996