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By Sara Hornby

After almost half a century of experience in using DRI/HBI in electric arc furnaces (EAFs), and taking into account the decrease of natural gas cost in the USA, it is interesting to revisit some trends and controversial issues around this alternative iron source. This paper reviews aspects like the evolution of iron ore quality and its influence on EAF operation; DRI stockpiling and transport, regarding the risk for selfcombustion; optimum charge design; cold DRI/HBI charging (fifth hole, bucket, transporter); hot charging (ways and results); carbon content, metallization and silica in DRI/HBI, and its influence on EAF operation and performance; oxygen / carbon balance; chemical energy and DRI/HBI charge.

Aug 16, 2017

By T. R. Kostecki, A. J. S. Spearing, A. Hyett, M. Gadde

Ground control research for underground coal mining has progressed significantly over the past several decades. With this progression, and the ability to analyze and model underground conditions, underground working conditions have significantly improved. In order to progress further, the behavior of roof support must be known and be adequately modeled, such that models can be used for support design under different geological and mining conditions. This paper discusses the results from a research project funded by the U.S. National Institute for Occupational Safety and Health (NIOSH) and undertaken by Southern Illinois University Carbondale and Peabody Energy. The research involved installation of active and passive instrumented bolts in mines, recording relevant in situ data and then attempting to model the behavior of the bolts as mining progressed. Such calibrated models could aid in design of roof supports under different geological and mining layouts and thus, hopefully, further improve rock related safety.

Jan 1, 2012

By Shawna Munn, Nadir Ansari, Allison Bennett

"This paper outlines how specification driven design has made Toronto Area transit infrastructure projects more expensive than similar private projects, and provides a case study of the results of an excavation at Launch Shaft 1 (LS1) for the Eglinton Crosstown Light Rail Transit project in Toronto, Ontario. The paper will describe the impact specification driven design parameters can have on design economy, constructability, and schedule and will suggest an alternative approach utilizing the Observational Method. As a result of the initial specification based design, Isherwood was retained by both the General Contractor and the Specialty Excavation Shoring Contractor to provide value engineering leveraging the Observational Method to improve constructability and construction schedule. By using well known, accepted design methods coupled with local experience in lieu of the specified design pressures and parameters, the redesigned bracing scheme reduced construction cost and schedule. This excavation case history can be a lesson learned for future transit projects.The City of Toronto has been developing its transportation network since the mid 1800’s. “Canada’s First Subway” along Yonge Street opened in March 1954 (TTC 1954), with a few additions to the subway network through to the 1980’s. The following two decades marked a long period of slow development due to recessions, budget cuts, and politics along with several cancelled projects. To fill the gap left by years of underfunding, several new transit projects are now under construction in the city as a part of Metrolinx’s $50B, 25 year, “The Big Move” initiative (Metrolinx 2013). The work on these types of infrastructure projects is highlighting a different and developing challenge within the tendering and design specification structure we will call Prescriptive Specification Design (PSD).PSD is a method used within contract specifications to control design risk on a project by applying conservative design methods, factors of safety, or other parameters to make a “fool proof” design. It is akin to requesting a colouring by numbers approach from a painter. There are inherent risks of using this method of tendering a project including increased project costs, longer construction schedules, and decrease of overall project economy. In PSD, the Owner “owns” all of the design risk on a project, including any additional costs due to changed site conditions. However, the Contractor commonly “owns” the risk of any deviations from the design specification they pursue, therefore making any improvements to the design, cost, or schedule less desirable from the Contractor’s point of view. The impact of this type of strict specified approach to design has been seen in transit infrastructure projects in the Toronto area. Figure 1 outlines the range of specified AEPD design pressures as a function of excavation height (H) specified for use in Toronto underground transit projects since the 1970’s to present day. A clear trend can be seen with respect to increased design pressures specified. The ranges shown for each project are intended to account for the potential differences in soil conditions for the highly overconsolidated glaciated soils in the Toronto area. The graph also highlights the typical range, in blue, for the industry practice in Toronto for comparison."

Jan 1, 2017

The extremely cold weather and heavy snowstorms of January and February in northeastern Pennsylvania--with frozen mining equipment, diminished preparation and lack of railroad cars--severely hampered the production and distribution of anthracite. As a result, the previous estimates for the 2 months have been revised. On March 1, 1977, at the Porter Tunnel of the Kocher Coal Company at Tower City, Pa., an underground flash flood, which apparently broke through the wall of an adjoining abandoned shaft, swept through the mine. As of March 9, 1977, four miners were reported killed, three injured, and five trapped in the wreckage. The Kocher Coal Company began operations at the Porter Tunnel in 1968 and has had no fatalities until this current tragedy. The mine employs 20 persons on the surface and 115 miners underground, producing 750 tons of coal per day. Of the 109 underground mining operations in the anthracite region, this is the one remaining large mine that employs over 100 men.

Jan 1, 1977

By Robert Torbin

The objectives of the Continuous Shaft Lining (CSL) System are to reduce the costs, safety hazards, and time currently required in lining mine shafts with concrete. The CSL will line machine bored shafts downward from the shaft collar on a continuous basis using an inverted, pressurized slipforming technique. The technique for slip-forming downwards has been demonstrated and refined under this program. The approach taken involved laboratory scale testing of key features of the CSL concept. These feature tests included concrete distribution, concrete sealing, concrete slipforming and development of a reliable concrete mix. Based on these results, a full scale above-ground test facility and CSL were designed and fabricated. The objectives of these tests were to demonstrate the viability of the basic concept; to establish operating limits; and to provide input data and information for the design of a second generation shaft lining system. The results of the program have led to a CSL design and operational philosophy which will need to be tested in an underground environment before industry will accept the technology. However, the next generation CSL promises to meet all the original program technical objectives.

Jan 1, 1983

By Ry Stone

"There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical use of empirical databases, and focuses on the main drivers for ground support as demonstrated in conceptual models.Golder Associates’ empirical databases used for ground support include a Primary Roof Support Database and a Primary Rib Support Database. Both are based on successful ground support designs installed in mines in Australia, the US, the UK, South Africa, New Zealand, and Europe. The term “successful” refers to those designs that were used on a repeated basis for the purpose of roadway development.The Primary Roof Support Database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the Coal Mine Roof Rating (CMRR), and in situ stress. As roof displacement is essentially a function of horizontal stress and roof competency, in order to provide some form of measure as to the likely magnitude of roof deformation during roadway development, the depth of cover is divided by the CMRR to arrive at a “Stress Strength Ratio” (SSR). The database indicates that the higher the SSR, the greater the likelihood that the roof will require higher densities of support.In regard to the Primary Rib Support Database, it is evident from the current database that the primary factors affecting the capacity of rib support required for a successful design are roadway height and depth of cover. In order to provide some form of measure as to the likely magnitude of rib deformation during roadway development, the depth of cover is multiplied by the height of the roadway to determine a “Rib Deformation Rating” (RDR). Similar to the roof, the database indicates that the higher the RDR, the greater the likelihood that the rib will require higher densities of support.These databases have been used to help determine the minimum primary ground support designs required at many mine sites in Australasia, Europe, and the US. This paper will demonstrate the effectiveness and practicality of these databases at two selected mines in Australia and the US.In order to improve the Primary Rib Support Database, this paper will also propose a new rib deformation rating based on the addition of site specific coal strength data for the Australian mines. The proposed rating attempts to capture the main variables that define the behaviour of a buckling column."

Jan 1, 2015

By A C. Robertson

Over the past decade there has been continual change in the way that mines have been managed and the component roles of those people who make up the total mine management system. Major issues have included the change in the business structure of mining companies, the change in on-site infrastructure, increased personal liability of managers for the safety and health of employees and increasing social and environmental pressures on managers and their staff. This paper looks at the changing roles of two of the many groups of professionals associated with the mining industry - the equipment supplier and the mining consultant. The profiles of the ACME Group Pty Ltd, suppliers of ventilation equipment and ancillary canvas and plastic products to the mining and construction industry, and Tennent, Isokangas Pty Ltd, Consulting Mining Engineers, are presented.

Jan 1, 1998

By R. W. Courtney

The objective of this study is to make a critical evaluation of the magnitude and extent of electrostatic hazards in typical U.S. mining operations and to assess the adequacy of techniques, materials, and equipment for detecting and minimizing these hazards. This was accomplished with an incident/accident survey, mine visits, literature search, and engineering analysis. It was concluded that it would be desirable to (1) utilize ground fault interrupters to minimize stray current from electrical utilities, (2) decrease the current and electrostatic sensitivity of electric detonators used in areas with a high incidence of lightning strikes or troublesome stray currents, (3) institute quality control and test standards for blasting material and protective devices, (4) establish an electrostatic monitoring program for loading ANFO in plastic lined holes, and (5) establish a risk criteria for operator exposure in mines.

Jan 1, 1982

By J. Ritchey

This report describes the engineering feasibility and economic advantages of using a mobile bridge-type cross-pit belt conveyor system in conjunction with a large dragline to excavate and transport spoils in a typical Western surface coal mine. The studies show that such a system could be built to survive operational and climatic mining conditions, and that its implementation would offer a reduction in both acquisition and operating costs versus conventional mining units of comparable rapacity. Reclamation costs can also be significantly reduced, and the total reclamation process accelerated, making the cross-pit conveyor system attractive to mine Owners and environmentalists alike.

Jan 1, 1976

By Ergin Arioglu, Werner Burger

"SUMMARY The Istanbul Strait Road Crossing Project includes a 3.34 kilometer subsea tunnel excavated by TBM with an excavation diameter of 13.71 m. The tunnel will incorporate two road decks, each employing two traffic lines and shoulder with the daily capacity of 100,000 light vehicles. The tunnel alignment crosses full face rock sections with heavily fractured zones due to tectonic events as well as a long central stretch of difficult mixed face and very variable soft ground conditions. The demanding ground conditions and the large diameter in combination with realized face pressures well above 10 bar required a highly specialized and well adapted TBM. The paper describes the project challenges and the related technical solutions incorporated within the TBM design as well as the real site experience. INTRODUCTION In 2013, a 13.71 m diameter Mixshield was manufactured in Germany for the Istanbul Strait Road Crossing Project. The delivery of the TBM in late 2013 was a major milestone for the Istanbul Strait Road Crossing Project, also known as the Eurasia Tunnel Project. The Eurasia Project (www.avrasyatuneli.com.tr/en) consists of a 14.6 km route including a 5.4 km tunnel segment in its central part crossing the Bosphorus. The 3.34 km subsea section of the tunnel was excavated in closed mode using a Mixshield TBM. The remaining tunnel length is constructed by sprayed concrete lining (SCL) method followed by a cast in place (CIP) lining or by cut and cover (CC) structures for the TBM transition boxes (Figure 1, right). Other project sections on the European and Asian side consist of upgrading and widening surface access roads towards the tunnel. Conceptual ideas of connecting Asia with Europe via a tunnel crossing the Bosphorus have been around for an extended time and only became realistic towards the end of the 20th century based on significant technical developments in mechanized tunneling. Feasibility studies for a new Bosphorus crossing in 2003 and 2005 confirmed and suggested a road tunnel in its present alignment as the preferred solution. Following an international tender process the Ministry of Transport, Maritime Affairs and Communications of Turkey assigned ATAS, a special purpose company formed by Yapi Merkezi (Turkey) and SK E&C (South Korea), to design, build and operate the Eurasia Tunnel Project. The Implementation Contract was signed in February 2011. In 2012, Herrenknecht AG was selected as the supplier for the 13.71 m Mixshield TBM."

Jan 1, 2016

By Sean Gallagher

This report was written in an effort to provide better control measures for low back pain (LBP) and low back disability in the mining industry. There are numerous factors associated with development of LBP, many of which can be effectively controlled while some cannot. Better job design is promoted as the best method of reducing cases of LBP and can also reduce the disability (i.e., lost time from work) associated with LBP when it happens. The report draws attention to what is currently known about LBP, what the causes are thought to be, and discusses recent back injury trends in the mining industry. Research describing unique physical demands in mining, such as the capabilities and limitations of working in awkward postures, is also presented. Methods that can be used to prevent initial LBP episodes are provided, including facilities design and layout for materials and supplies, use of mechanical-assist devices, improved design of lifting tasks, and better seat design. Methods of reducing the disability associated with LBP (including workplace design, proactive return-to-work efforts, communication, and management commitment) are also discussed. The report concludes that control of LBP and disability in mining requires a comprehensive approach to limit the repetitive loading that can occur on the low back due to manual materials-handling tasks and exposure to whole-body vibration (WBV). Specific recommendations include the following: ? Successful LBP prevention efforts require a proactive program that has strong management commitment and incorporates employee involvement. ? More efficient supply handling systems and use of mechanical-assist devices can greatly reduce exposure to hazardous lifting tasks. ? Lifting tasks should be designed to minimize low back stress. Tools to evaluate and redesign lifting tasks are presented. ? Improved seat design can reduce exposure to WBV and improve posture, leading to reduced LBP risk. ? The disability associated with LBP can be reduced. Getting the worker back on the job as quickly as possible is in the interest of everyone involved.

Sep 1, 2008

By James A. Finch, Stéphanie Gélinas

"A colorimetric technique, originally developed for methyl iso butyl carbinol (MIBC) based on the Komarowsky reaction, has been extended to a wide range of common mineral flotation frothers. The procedure, which is briefly described, is shown suited to on-site determination in a series of industrial campaigns. Some frother observations are described, including: concentration evolution down a bank, distribution between pulp and froth phases, and a mass balance around a circuit. Minute amounts of frother in recycle water were also measured.The contribution of frother and alcohol by-products in the analysis was generally additive for plants using aliphatic alcohol type frothers and decoupled for systems using glycols. Typically, U250C (polyglycol) was used at higher concentration (>10 ppm) than MIBC (aliphatic alcohol) (<10 ppm) or F-150 (polyglycol) (<3ppm).The ability to monitor frother easily will help interpret gas dispersion behaviour and should permit further optimization of flotation cell hydrodynamics and chemistry. The capability to directly measure should help optimize the type, amount and location of frother addition, and to assess frother recycled with reclaim process water.INTRODUCTIONOwing to the lack of analytical methods, the task of determining frother concentration in plant flotation circuits is not routinely performed. Industrial sites seldom outsource analyses that are both costly and inconvenient, due to the necessity of shipping freeze-dried samples to remote testing facilities. A more direct colorimetric method has recently been demonstrated for the laboratory characterization of common industrial frothers (Gélinas and Finch, 2004). The approach, based on the Komarowsky reaction (Penniman et al., 1936; Coles et al., 1942; Duke, 1947), was previously described by Parkhomovski et al. (1976) for methyl iso butyl carbinol (MIBC). The reaction involves the interaction of the OH group of a higher alcohol, concentrated sulphuric acid, and salicylaldehyde, to yield coloured solutions with intensities that can be analyzed by UV-visible spectrophotometry."

Jan 1, 2007

The 1963 Lignite Symposium was held on the University of North Dakota campus, Grand Forks, N. Dak., April 30-May 1, 1963, under the cosponsorship of the University of North Dakota and the Bureau of Mines. This symposium, the third in a series, had as a general objective the dissemination of information concerning advances in technology and utilization of solid fuels, with emphasis on lignitic coals. Approximately 150 representatives of industry, government, and educational institutions from 21 states and 3 Canadian provinces were present at the symposium. Those attending were welcomed by Marling J. Ankeny, Director of the Bureau of Mines, representing the Bureau, and Dean T. H. Clifford, Vice President of the University, representing the University.

Jan 1, 1964

By Sidney Katell

This report covers the period January 1964 through December 1964; it is a continuation of the series that began with the publication of Information Circular 7516 in October 1949. Also, it is the sixth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load involved in the preparation shared equally. The abstracted articles, concerned with all facers of cost engineering in the field of chemical and petroleum. plants and related subjects, are from the following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress,

Jan 1, 1965

By Sidney Katell

This report covers the period January 1964 through December 1964; it is a continuation of the series that began with the publication of Information Circular 7516 in October 1949. Also, it is the sixth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load involved in the preparation shared equally. The abstracted articles, concerned with all facers of cost engineering in the field of chemical and petroleum. plants and related subjects, are from the following sources:

Jan 1, 1965

The 1963 Lignite Symposium was held on the University of North Dakota campus, Grand Forks, N. Dak., April 30-May 1, 1963, under the cosponsorship of the University of North Dakota and the Bureau of Mines. This symposium, the third in a series, had as a general objective the dissemination of information concerning advances in technology and utilization of solid fuels, with emphasis on lignitic coals. Approximately 150 representatives of industry, government, and educational institutions from 21 states and 3 Canadian provinces were present at the symposium. Those attending were welcomed by Marling J. Ankeny, Director of the Bureau of Mines, representing the Bureau, and Dean T. H. Clifford, Vice President of the University, representing the University.

Jan 1, 1964

By I. O. Ondicho, E. K. Mutinda, B. O. Alunda, E. Agyekum

Driven by the necessity to improve blast performance regarding fragment size distribution in limestone mines, this paper introduces the prediction and measurement of blast fragmentation distribution through the modified Kuz-Ram (MKR) and Kuznetsov-Cunningham-Ouchterlony (KCO) models. Precise prediction and measurement of rock fragmentation resulting from blasting play a critical role in hard rock ore extraction. This is due to the substantial influence of post-blast ore size distribution on the efficiency of all subsequent downstream rock handling and processing operations. Additionally, employing secondary breakage of boulders, when necessary, leads to an unjustified rise in production costs. In this paper, the MKR and KCO models were utilised to identify the most appropriate model for application in Bisil and Simba quarries situated in Kajiado County, Kenya. Split-Desktop was used for blast fragment measurement by processing digital images obtained after blasting and computing the fragment size distribution of the blasted rock. As per the investigation, the recorded percentages of boulders generated at the sites ranged from 7% to 12.3% for the Simba quarry and from 11.2% to 23.9% for the Bisil quarry, respectively. Regression, correlation, and root mean square error (RMSE) were employed as the primary performance indicators. The study concluded that KCO outperformed MKR in accurately predicting blast fragment sizes in the examined quarries.

Mar 5, 2025

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. A senior advisory staff, consisting of the Chief Staff Officer, Chief Scientist, and Chief Mining Engineer, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaisons with other government agencies, mineral industries, and professional societies. Bureau program activities are classified into two major functions: (1) Developing new and improved technology that will make the production and processing of minerals more efficient, safer and more healthful for mineral workers and the public, and more compatible with a quality environment.

Jan 1, 1980

By Sidney Katell

This report, covering the period January 1969 through December 1969, is a continuation of a series that began with the publication of Information Circular 7516 in October 1949. It is the 11th in a series of reports prepared in cooperation with the American Association of Cost Engineers. The abstracted articles are concerned with all phases of cost engineering in the field of chemical and petroleum plants and related subjects. They are from the following sources: 1. American Association of Cost. Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal Mining and Processing.

Jan 1, 1970

By IPMI Educational and Scientific Foundation

It is with great pleasure that we announce the availability of this fourth issue of the IPMI Journal, a publication of the International Precious Metals Educational and Scientific Foundation. This digital peer reviewed publication has been created as a vehicle for the sharing of technical information related to the science and technology of precious metals. Since 1976, the International Precious Metals Institute has championed the exchange of information of critical importance to the precious metals scientific and commercial communities through its various communications vehicles. This has included instructional videos, annual conference symposia, special topic committee meetings, regional seminars, and professional and student achievement awards. Due to the breadth of important topics related to all aspects of precious metals, it has been the vision of the IPMI to provide a publication available to the general public that would become a key source of pertinent topics containing high quality publications by experts in their fields of study. Historically, the IPMI has attracted world renowned experts in many fields (including Nobel Laureates Henry Taube, Ei-ishi Negishi, Robert Grubs, Professor Ben Feringa, and David MacMillan) in the dissemination of discoveries, inventions, and industry proven practices. Such information has a total value greater than the sum of its parts as seemingly unrelated innovations from distinct focus areas can be adapted to solve problems. Because of this important characteristic of information exchange, we have decided to create a digital journal, available to the general public, that will not only communicate state of the art discoveries and sound practices, but will also review historical communications from the IPMI’s archives that have value and use even in today’s environment. On behalf of the members and leaders of the IPMI, we hope you will find value in this new publication.

Dec 1, 2020