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By David Mast, Amanda Foote, Mina Shinouda

The Michigan DOT’s I‑75 Modernization Project, Segment 3, is a 30-year, $1.2 Billion design-build-finance-maintain project in Southeast Michigan. The scope includes building a nearly 4-mile long, 14.5-foot ID stormwater storage tunnel. The tunnel and pump station are being built concurrent with new roads and bridges, requiring multiple levels of design and construction coordination. Underground risks include the poten‑ tial for encountering granular soils, groundwater, and explosive gases. The new tunnel will be mined by a new open-face TBM and lined with a one-pass steel-fiber-reinforced precast concrete segmental lining. Shaft construction began in early 2020 and tunnel mining in July 2020.

Jun 13, 2021

By d&apos, L. F. G. Assumpcao

Kaolin samples from Rio Capim resources were treated in conventional and superconducting magnetic separators to study the main variables that influence the color removal process. Coating clays and delaminated clay were tested. Retention time (or pulp injection velocity), magnetic field intensity and matrix type were the' variables studied. The feed brightness ranged from 84.7 to 87.6 % ISO for the coating clays and from 80.7 to 85.4 % ISO for the delaminated clay. The results showed unleached brightness values higher than 88 % ISO for coating products and higher than 87 % ISO for the delaminated product, using a conventional magnetic separator with an applied field of 1.5 to 2.0 Tesla. With a maximum field intensity in the superconducting machine of 5.0 Tesla, unleached brightness values higher than 88.5 % ISO for both coating and delaminated clays were attained.

Jan 1, 1995

By R. E. Snow

The analysis of ground water inflow and discharge from underground mines has received increased attention in recent years due to environmental issues which must be addressed under current state regulations for coal mining and processing operations. In particular, coal operators must assess the probable hydrologic consequences associated with mining activities, and must plan for mine water handling during operation and following completion of mining. The prediction of ground water inflow rates with future mine development allows preparation for potential operational problem and identification of inflow reduction methods. Similarly, evaluation of mine discharge rates is necessary to address potential long-term acid mine drainage (AND) concerns. As part of mine discharge analyses, methods. to control seepage and AMD can be considered. The objective of this paper is to discuss the practical applications of mine inflow and discharge analysis, describe the typical flow components, outline the procedures necessary to perform the analysis, and illustrate the modeling procedures and potential results of mine inflow and discharge predictions.

Jan 1, 1990

By A. Fuerst

This paper delivers insights into how high availability combines with high efficiency at the Yanacocha Plant, Newmont Mining Corporation, Peru. Advances in motor design and maintenance with integration of smart control support the approach plant maintenance staff is applying to deliver such excellent results for availability and efficiency in Yanacocha and elsewhere. Detailed efficiency and availability data for 2011 and 2012 in Yanacocha are provided. ABB and Yanacocha teams collaborate closely by combining their experience and continuous development of gearless mill drive procedures and maintenance knowledge to deliver the impressive performance being achieved. The secrets for high performance shared by the Yanacocha maintenance operations point to their systematic, practical adherence to modern asset management and maintenance concepts.

Feb 27, 2013

By William V. Robinson

The Iron Ore Company of Canada mines, processes and ships crude iron ore, concentrate and pellets from the rich ore bodies of the Labrador Trough area in the extreme north-eastern part of Canada, some five hundred miles from Montreal (see figure 1). There are three main sites of activity. At Schefferville, approximately 12 million tons a year of crude ore (chiefly limonite) are mined, crushed, screened and shipped to Sept-Iles. At Labrador City, 40 million tons of specular hematite are mined annually for processing into 17 million tons of concentrate. Of this, 9 million tons are converted into pellets. All product 1s shipped to Sept-Iles. At Sept-Iles, on the north coast of the St. Lawrence, a six million ton per year concentrator and pellet plant process much of the Scheffervllle ore into high-grade pellets. Also at Sept-Iles are the company's administration offices stockpiles and shipping facilities. The Terminal facilities can berth and load a 250,000 ton bulk carrier at 19,000 tons per hour.

Jan 1, 1975

By J. Fisher, M. Barish

Over the past several years, Somerset International has successfully installed over 20 patented Sub325® Fine Coal Recovery Systems in the United States, Australia, Canada and Russia. These installations recover between 5 TPH and 40 TPH for the host sites. In addition to the increased revenue from the direct recovery of a recirculating load (Screen Bowl “Insurance”, Direct Recovery vs. Indirect Recovery via Recycle, CPSA 2020), host sites have seen benefits ranging from improved operation of refuse equipment to a reduction in the solids content of the refuse streams. As Somerset has improved ultra-fine coal recovery through the introduction of Sub325® Effluent Flotation and, most recently, the Sub325® Effluent Settler™, the amount of coal that has been recovered from these systems has increased by up to as much as 25%. Many host sites have taken a sense of ownership in the Somerset system and consider it to be a critical circuit in the overall optimal performance of the plant. In the past year, Somerset has taken the initiative to expand upon the capabilities of the Sub325® Fine Coal Recovery System, primarily the Sub325® Solid Bowl Centrifuge, to include Refuse Tailings Dewatering to allow for co-mingled refuse disposal. As slurry ponds and boreholes are becoming difficult to impossible to permit and operate, there is a need for a reliable, low-maintenance, continuous operation that can produce a handleable refuse cake. Refuse tailings disposal applications are by no means limited to coal plants and impoundments. Somerset has successfully tested at iron ore and phosphate locations throughout the world and have begun commercial installations. The ability to dewater -325 mesh material, whether it be coal, coal refuse, iron ore tailings, or something else, is a vital piece of processing capability for the continued production of mining operations across the globe. This paper highlights the success that Somerset has had in the coal industry worldwide as well as the initial successes with phosphate, iron ore, and copper tailings (patent pending).

Mar 2, 2022

By Brendan Demich, Linda L. Chasko, Brendan Macdonald, Timothy J. Orr, Jessie J. Mechling, Cassandra Hoebbel, Jason Navoyski, William Helfrich, Jessica Cohen, Paul E. Schmidt, Jennica L. Bellanca

The National Institute for Occupational Safety and Health (NIOSH) in partnership with the Mine Safety and Health Administration (MSHA) developed VR Mine Rescue Training (VR-MRT). It is a training platform that allows mine rescue team members to explore virtual emergency scenarios collaboratively. Team members use a head-mounted display to visualize and interact together with equipment, hazards, and dynamic ventilation. All player actions are recorded and displayed for debriefing. Researchers at NIOSH demonstrated the training platform at various mine rescue competitions, including the International Mine Rescue Competition, and collected feedback. Participants’ responses were overwhelmingly positive. This paper describes the development of the software platform and the results of the usability surveys and interviews.

Jun 25, 2023

By E. W. Sawyer

Attapulgite is a magnesium aluminosilicate clay mineral which exhibits unique, processing-enhanceable physical and chemical properties that are related to its current commercial uses. Properties of commercial interest are gelling, absorption, adsorption, binding, acid neutralization and many others. Major industrial applications are: (1) absorption by heat treated grades utilized in industrial oil and grease absorbents and in agricultural pesticide carriers; (2) gelling of aqueous liquid products by colloidal grades for stabilization and viscosity control in salt water drilling fluids, suspension fertilizers, liquid animal feed supplements, paints and tape joint compounds; (3) adsorption by heat treated varieties for the removal of catalysts, color bodies and other polar compounds from hydrocarbon streams; (4) gelling of organic liquids by colloidal attapulgite/surfactant blends in oil-type paints, fibrated and nonfibrated asphaltic coatings and mastic compositions, and (5) the binding of feeds and molecular sieve sorpents with colloidal type attapulgite products. These applications and other less common uses and potential uses will be discussed along with, the necessary selective mining and plant processing features related to each property and application.

Jan 1, 1986

By Patrick J. Doig

The NS9 Drop Shaft contract formed part of the Waste Pollution Abatement Program (WPAP) conducted by the Milwaukee Metropolitan Sewerage District (MMSD). The contract involved the construction of two shafts, a deaeration chamber and connecting tunnel, and ancillary facilities. Portions of the construction were located in saturated overburden where dewatering was prohibited. Ground freezing was utilized for temporary support of the excavation. This paper concentrates on the freezing system and the excavation of frozen ground, with particular emphasis on the use of mechanical cutting equipment, including a raiseborer and a roadheader.

Jan 1, 1991

By D. R. Wilburn

This summary of international mineral exploration activities for the year 2010 draws upon available information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities performed by the mineral industry. Three sources of information are reported and analyzed in this annual review of international exploration for the year 2010: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia; 2) regional and site-specific exploration activities that took place in 2010, as compiled by the USGS, and 3) regional events including economic, social and political conditions that affected exploration activities. These were derived from published sources and unpublished discussions with USGS and industry specialists.

Jan 1, 2011

By Robin J. Hickson

The Grasberg copper-gold deposit was discovered in the spring of 1988, one year before the planned closure of Freeport Indonesia's original Ertsberg openpit copper mine. In spite of Grasberg's remote location, 600 m (1968 ft) above the Ertsberg, atop a hitherto inaccessible mountain, Freeport-McMoRan brought its latest open-pit mine into production in the last week of 1989, less than two years after discovery. Freeport Indonesia's (FI) copper-gold mining operations are located in Irian Jaya, the easternmost province of Indonesia on the western side of the island of New Guinea. Fl's six ore deposits are all located within a 10- x 10-km' (3.9- x 3.9-sq mile) Contract of Work area. They are all between the elevations of 2900 and 4300 m (9515 and 14,100 ft) above sea level, some 96 km (60 miles) from the island's southern coast. A 118-km (74-mile) access route connects FT's port site of Amamapare on the Arafura Sea to the project area. The first section is an 18-km (11-mile) barge waterway. The final 100-km (63mile) is a two-lane gravel highway. The highway terminates 9 km (5.5 miles) beyond the FI townsite at the project's central mill, some 2850 m (9250 ft) above sea level. The mining areas are separated from the mill by a 780-m (2560-ft) sheer cliff face. The world's longest free span tramway system, with a total length of more than 1.6 km (1 mile), is the only means of access for men and materials between the mill and the surface mines. Weight restrictions for the tramway for equipment considered for the project are 15.4 t (17 st). The minimum clear width dimension of two tunnels along the portsite access road is 5.6 m (18.4 ft).

Jan 1, 1991

By Toshio Fujiwara, Sumikichi Ito, Masao Kitamura

The Tennohji-Benten Giant Trunk Sewer Project has been under construction since 1974 in the eastern part of Osaka, the second largest city in Japan. The entire project is divided into 7 blocks, some of which have already been completed. This 8.8-km sewer tunnel, being driven through a densely populated area, was planned to be constructed by the shield tunneling method. This paper described shield tunneling performances and ground behaviors during the construction of Blocks 2 and 3. An earth pressure shield (dia., 6,750 mm) was employed in Block 3 tunneling. The ground was generally soft and the cover over the tunnel varied from 13 m to only 4.5 m, so that a considerable amount of chemicals was injected to stabilize the ground. A hand-digging type shield (dia., 7,250 mm) was used in Block 2 tunneling under compressed air. For 85 m of the total length of 1.6 km, the soil at the face was extremely soft, and therefore, the ground freezing method was additionally employed.

Jan 1, 1981

By W. G. Pariseau

Face and pillar bursts, bumps and bounces are violent failures that occur in underground coal mines in response to a complicated interplay of face and pillar geometry, seam depth, coal strength and moduli and interactions between roof, seam and floor strata. Additional complications arise from the presence of gas, mainly methane, and associated pressure and flow that vary with time and are further influenced by the rate of face advance. Numerical models provide a means of quantitatively accounting for the various complications of mining geometry, the stratigraphic column, mechanical properties, gas flow properties and associated interactions. A fully coupled hydromechanical finiteelement code, utAH4, serves the purpose well and allows study of the important interaction between stress concentration and gas pressure in determining safety and stability of the face during the advance of a longwall panel in a deep underground coal mine in central Utah. Face advance is relatively fast compared with gas flow and depressurization in coal seams of low gas permeability. Consequently, gas pressure is high at the face. When a longwall is stationary, depressurization occurs at the face, so effective stress and strength increase. thus, when gas flow at the face is high and requires a pause in face advance to bring gas concentration to an acceptable level, a second benefit occurs because of timely depressurization. However, quantitative analysis of a deep coal mine shows that regardless of gas pressure, high stress concentration is more likely to pose a threat to face and pillar wall stability.

Aug 1, 2013

This chapter contains the edited transcript of the "Gold Heap Leach Information Exchange" session that was held at the 1990 SME/AIME Annual Meeting in Salt Lake City, Utah. The exchange occurred on the afternoon of February 27, 1990. The session was intended to act as a forum for discussing some of the more prominent operating problems associated with heap leaching precious metals. The information exchange was very successful. The exchange consisted of several panelists introducing and discussing different topics, follow by a comment and question period. This transcript contains the panelists' presentations as well as comments and questions from the floor and the panel. Extraneous comments and remarks have been edited out. Some wording has been changed for clarity, but the transcript is basically an accurate account of what was said. At the end of the transcript are two papers submitted as part of the panel discussion

Jan 1, 1990

By J. Marsden

Lift height, overall heap height and climate all play an important role in determining precious metals leaching rates, recoveries, operating costs and capital cost requirements for heap leaching operations. The effects of these factors are not easy to predict from testwork, and this can result in unexpected delays in metal production, lower recoveries than expected and higher capital and operating costs than necessary. This paper investigates the economic impact of lift height, overall heap height and climate on heap leaching and provides criteria to assist in the design and operation of leaching facilities. Descriptions of three heap leach operations in the western USA are provided to support the discussions and conclusions.

Jan 1, 1995

By George R. Huebner

The White Pine Copper Company, subsidiary of Copper Range Company, is located in the Upper Peninsula of Michigan. The offices, plant, and mine are six miles south of Lake Superior in Ontonagon County. Employing 1700 people, White Pine is the largest single industry in the Upper Peninsula. 970 underground employees produce 16, 700, tons of ore daily. From this tonnage 363,400 pounds of refined Lake Copper are produced in various shapes as specified by the customer. The following paper explains the geology of the ore body and briefly outlines present mining methods. It enumerates the reasons for considering longwall mining of a hardrock* ore body and the preliminary investigations leading to the decision to undertake the initial test panel. Selection of the initial test panel location is covered in detail. Equipment choice and reasons for that choice are described as well as selection and training of personnel.

Jan 1, 1964

By Anthony S. Spearing

The vast majority of the estimated 100 million rock anchors installed in mines in the USA per year use resin cartridges (Tadolini and Mazzoni, 2006). About 4.5 million per annum of these are bolts with a mechanical shell that if properly installed become effective active supports on installation. In addition, cable anchors (mostly passive) are installed with typically 4 ft of effective resin anchorage length sometimes with mechanical shells, which further makes the installation more difficult. This is because the cable (even with a stiffener tube) is not very rigid. When installing bolts with mechanical shells and cable bolts in the holes, the back-pressure can be so high that the installation is unsuccessful often creating a ?spinner? (an un-tensioned bolt) at best or buckling the bolt thus requiring another bolt/cable to be installed, or leaving a poorly functioning unit. The installation problems can create a significant potential safety hazard and waste time and money. Using a purpose designed test rig that physically inserts different rock anchors into pipes with resin and measure the back-pressure developed with time during the insertion/ installation. The test installation procedure is designed to mirror that used underground by rockbolt operators in coal mines. In addition a computer model has been calibrated that can predict the approximate back pressure of new anchor and resin combinations acting as a screen before physical testing. This research has lead to an understanding and quantification of the insertion back-pressures and this already resulted in improved prototype designs that could lead to more reliable mechanical shell and resin bolt installations.

Jan 1, 2009

By M. Sunkpal, K. C. Kocsis

"An underground environment with high air temperature and humidity conditions generated from various heat and moisture sources can significantly affect the thermoregulation processes of the human body. This can lead to a series of heat-related illnesses such as heat exhaustion, heat cramps and heat stroke. The majority of the metabolic energy of a mine worker results in the production of heat. If the human body is to maintain thermal equilibrium, then this metabolic heat must be transferred to the ambient surroundings at the same rate. The heat loss from the human body occurs through a combination of heat transfer processes, such as respiratory heat exchange, convection, radiation and evaporation. If the heat loss from the human body to the ambient surroundings is less than the metabolic heat produced, the excess will be accumulated within the human body, which will result in a rise in the core and skin temperatures. This can ultimately lead to a heat-related illness or a combination of heat-related illnesses. This paper aims to discuss major heat-related issues and provide an overview of various mine ventilation and cooling systems, which can be employed to overcome high levels of heat and humidity in underground mines. In this paper, the effects of heat exposure on the health, safety and productivity of the mine workers are also highlighted. IntroductionMining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injuries over the last century (Coleman and Kerkering, 2007; Saleh and Cummings 2011; Jacklitsch, Musolin and Kim, 2016). Occupational health hazards within the mining industry include hazards that are physical, such as traumatic injury or hearing loss; chemical, such as silica or diesel particulate matter; biological; ergonomic; and psychological (Donoghue, 2004; Saleh and Cummings, 2011). The effects of some of these hazards can be diagnosed immediately, while many, like black-lung and silicosis, will have long-term effects on the health, safety and life quality of mine workers (Donoghue, 2004; National Institute for Occupational Safety and Health, NIOSH, 2000). Among these hazards, exposure to heat and humidity can significantly affect the safety, health and productivity of mine workers, particularly in deep and hot underground mines (Roghanchi, Sunkpal and Kocsis, 2015). Short-term acute heat exposures can cause a rise in the core temperature of the human body, which can result in a heat-related illness or combination of heat-related illnesses. Adverse long-term chronic heat exposure can generate serious occupational heat-related illnesses, such as cardiovascular diseases, mental health problems and chronic kidney diseases. High core body temperatures coupled with dehydration can generate negative behavioral effects such as physical fatigue, irritability, lethargy, impaired judgment, loss of dexterity and loss of concentration (Xiang et al., 2014)"

Jan 9, 2017

By J. R. Hoskins

Method - A direct approach to instrument users, initially by letter and later by telephone or personal contact was made. The resultant data was compiled to give specific use information on the seven instruments. During the course of the study attempts to evaluate the Griswold Gage were abandoned when it became apparent that the gage was not being commercially produced. One company is developing the gage for its own use. The information presented is the result of over 1200 inquiries.

Jan 1, 1973

By Elwyn King, Donald J. Dodds

"...Unfortunately, the research activities in soil mechanics had one undesirable psychological effect. They diverted the attention of many investigators and teachers from the manifold limitations imposed by nature on the application of mathematics to problems in earthwork engineering. As a consequence, more and more emphasis has been placed on refinements in sampling and testing and on those very few problems that can be solved with accuracy. Yet accurate solutions can be obtained only if the soil strata are practically homogeneous and continuous...." This statement about soil mechanics was made by Karl Terzaghi, thirty years ago and applies to a greater degree today to the infant science of rock mechanics. More uncontrolled variables are added to the already many existing in soil mechanics. Variables, such as Macro-discontinuity and in situ stress levels. In no other field of engineering are the problems as site oriented. Presently this site dependance demands the investigator or rock mechanics engineer to get his hands dirty rooting in the muck of a tunnel floor trying to properly install or readout test apparatus in a comprehensive site investigation. This paper discusses such a site investigation designed to determine the problems and solutions inherent in the driving of the Trans Koolau Tunnel. The paper will describe the various types of tests to be performed, how the results are to be used and the interrelation of the various tests themselves.

Jan 1, 1997