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By R. R. Swanson

Liquid ion exchange is becoming more and more important in hydro-metallurgical processing and recovery of metals. The key to success for this process are reagents which have suitable operating characteristics. One of these important characteristics is a relatively fast phase separation rate in the extraction and stripping circuits, as this greatly affects the size of plant required. A test for measuring phase separation rate is needed to help evaluate liquid ion exchange reagents. Such "a test also would be useful for evaluating carrier solvents that are used for diluting the re-agents. In fact, one standard test method would be very desirable as it would provide a common basis for comparing reagents and sol-vents. The phase separation test described in this paper has been used successfully for several years with the copper reagent, LIX®64N. The test is set up for feed liquors containing low copper concentrations. For other types of systems, modifications in procedure probably would be necessary. However, this test and the associated apparatus could be the basis for a standard phase separation test.

Jan 1, 1972

By Lawrence Adler

The design of an underground opening involves the coincidence of two highly complex and poorly specified components. First, the structural or mechanical characteristics of a geologic rock mass are not only extremely variable but are also very difficult to evaluate. Second, the general lay¬out of mine workings contains a large degree of indeterminancy as to the structure itself as a result of the indefiniteness of the mining process, and also because of the inherent redundancies associated with bulky and weighty structures. Even for the relatively simple problem of tunneling this complexity is well recognized to be "without question that to which the study of geo¬logy (for the Engineer) can most fitly and usefully be applied".1 It can, therefore, be appreciated that the comprehensive opening design problem involves a complicated assemblage of component structures made up of a sketchily defined, or sometimes even an undefined material and acted upon by largely unknown tectonic forces.

Jan 1, 1968

By A. K. Sinha

Inspite of the growing demands worldwide, thermal coal must compete in the market both in price and quality. The design and performance efficiency of coal preparation plants is thus crucial to the survival and profitability of a coal industry. While the coal recovery influences the cost of production, the quality produced by a preparation plant determines the selling price. Several coal preparation plant simulation models have been developed in recent years to help Improve the performance of coal preparation plants. A research project was recently conducted at Southern Illinois University to evaluate the practical applicability of such a model. The results of this study are presented and discussed.

Jan 1, 1986

By J. E. Murphy, L. A. Walters, F. H. Nehl, G. B. Atkinson

The US Bureau of Mines investigated the selective electrowinning of Ag and Au from cyanide solutions contaminated with Cu with the goal of decreasing the amount of Cu codeposited. Decreasing Cu codeposited will reduce refinery costs. Direct current was applied to the cell in pulsed and square wave voltages at 0.7 A h/150 mL of solution. Times tested for each cycle ranged from 1 to 10,000 msecs. Graphite, lead and stainless steel were evaluated as electrode materials. Square wave electrowinning at 70°C (158° F) gave the best separation of Ag and Au from Cu. Applying 2.5 V during the duty cycle, 0.0 V the rest of the period, a duty cycle of 10% to 30%, and a period of 100 msecs to 1000 msecs gave the following results: Ag concentrations decreased from 34 µg/mL to 0.1 µg/mL. Au concentrations decreased from 54 µg/mL to 0.2 µg/mL and Cu concentrations remained almost constant at 560 µg/mL.

Jan 1, 1995

By Carlos A. Jaramillo, Seng Hing Ngu

"The Murum Hydroelectric Project is a 944-MW development consisting of a 145 meter high RCC dam, two 2660 meter long, 9 meter excavated diameter upper pressure tunnels, surge shafts, two 950 meter long 7 even meter OD penstock tunnels and a surface powerhouse. The project is located in the eastern section of the State of Sarawak, Malaysia, about 200 kilometer from Bintulu, in the Rajang Fold-Thrust Belt, an Upper Cretaceous to Upper Eocene fold and thrust belt that extends under most of Sarawak. The Belaga Formation consists of a thick sequence of deep marine sediments currently appearing as steeply dipping strata of thin to thick bedded, fine to medium grained sandstone interbedded with argillaceous rocks, resulting on a “Flysch” type geologic environment. The project pressure tunnels were excavated perpendicularly to these strata resulting on frequent change on rock conditions and behavior, and required rock support. This paper describes the characterization of the rock mass, design of rock support, and incidents during construction. Particularly interesting were convergence issues in Tunnel 1 resulting from Tunnel 2 excavation. INTRODUCTION The Murum Hydroelectric Project is located in the eastern section of the State of Sarawak, Malaysia, about 200 kilometers from Bintulu, and upstream of the Bakun Hydroelectric Project. The project consists of a 145 meter high RCC dam, a 50 meter high intake tower, two nine meter OD and 2660 meter long upper pressure tunnels, two nine meter OD and 175 meter long vertical shafts, two 25 meter diameter and 80 meter deep surge tanks, two seven meter OD and 950 meter long penstock tunnels and four seven meter OD and 50 meter long branch tunnels, two 8 meter diameter to 3.4 meter diameter and 1400 meter long penstocks installed within the shafts, penstock tunnels and branch tunnels ending in a powerhouse with 944 MW installed capacity. LAYOUT OF THE WATERWAY TUNNELS The two waterways tunnels are basically parallel as shown in Figure 1, with each tunnel supplying water to two units in the powerhouse. The tunnels start separated 25 meters center to center, but 250 meter from the intake the separation increases to 35 meters. The tunnels are lined with reinforced concrete until they reach the surge shafts and steel lined from there to the powerhouse. The tunnel profile is shown in Figure 2."

Jan 1, 2016

By Philip L. Hageman, Paul H. Briggs

An important tool for use in the geochemical assessment of abandoned mine-waste piles is a leach procedure that can easily be done in the field and used for on-site screening of historic mine-waste material. We have developed a simple field leach test that is an effective indicator of waste pile geochemistry and can be used in order to establish the relative geochemical fingerprint for a given pile. This simple procedure also provides indication of the potential chemical composition of run-off from the weathered surface of these piles. As part of developing the technique, a comparative study was carried out on eight mine-waste composite samples from different deposit types. Splits of all eight composites were leached using the field leach test procedure and a modified version of EPA Method 1312 (SPLP). We found that the field leach test consistently provides relative indication of leachate geochemical trends comparable to leachate data derived from the more regulated, time consuming and laborious EPA Method 13 12 (SPLP).

Jan 1, 2000

By Kal V. S. Sastry

Mineral processing simulation has come a long way since its beginning about thirty years ago. With our increased understanding of mineral process systems and the advent of new software and hardware technologies, we can visualize an ideal mineral processing simulator. This paper attempts to identify a number of desirable features of an ideal mineral process simulator and to describe the exciting trends in making such an ideal simulator a reality.

Jan 1, 1992

By John J. Dwyer

As one begins to contemplate the organization of a talk with the title "Iron Ore - The Permanent State of Evolution," the main divisions appear to be the past, the present, and the future. But distaste for repetition of the present production achievements, which scarcely need additional description on this occasion, soon leads one to the conclusion that a more appropriate division of the subject is simply the past and the future . . . with emphasis on the future. We are working in the present, but it can only be understood by what has taken place in the years and decades gone by, and/or under what terms we will have to face the future. Evolution is more often thought of as a steady change - but steady change is really the product of revolutions, sometimes making headlines but often unnoticed at the time. With hindsight, we recognize the great importance of the emergence of the Bessemer converter and the open hearth and the vast influence that both have had on steel making and the changing ore demand. In this country we also see schooners opening the era for lake transportation of iron ore from Michigan to Take Erie. Later, steamships haul the ore from the Mesabi Range to the steel centers of the country. In order to take full advantage of the inland seaway, there had to be revolutions in ship design, loading and unloading facilities and channel and lock development. Full scale utilization of the resources of the Mesabi Range, itself, required parallel upheavals such as the development of new production equipment, and substitution of modern forms of energy for horsepower, and, yes, manpower, as well.

Jan 1, 1968

By George R. Mitchell

It is a common observation that objects having, different; temperatures exchange energy by radiative transfer. The quantity of radiant energy emitted by an object is a definite function of its temperature. Therefore, a measurement of emitted radiation, by means of a calibrated radiometric instrument, provides a temperature measurement without contacting the emitting object. The physical laws describing radiant energy transfer and their application to remote temperature measurement form the substance of this paper. The energy radiated by bodies having temperatures up to 4000°C is largely in the infrared spectral region. The infrared spectral region is that part of the electro-magnetic spectrum having wavelengths longer than visible light and extending to the microwave region. The wave-lengths range from 0.7 micron (1 micron = 10-4 cm) to 1000 microns. In general, infrared radiometry deals, with the methods of measuring energy flux in the 1 to 15 micron region of the infrared spectrum.

Jan 1, 1960

By Philip Lindstrom

Retreat mining, using yielding steel friction props, over a seven-year period has been successful at a uranium mine operated by Hecla Mining Company in southeast Utah. The support system allow good roof control, maximum profit, complete extraction, and good ventilation. Unusual subsidence observations were made in that some of the surface was raised rather than lowered, Longwall mining, commonly practiced in European coal mines, has a potential of broader application because of mechanization possibilities and better roof control and ventilation at greater depths.

Jan 1, 1964

By T. Grounds, K. Singh, W. R. Reed, R. Cross, G. Ross, S. Klima, M. Shahan

"A 2nd generation roof bolter canopy air curtain (CAC) design was tested by National Institute for Occupational Safety and Health (NIOSH) at a Midwestern underground coal mine. During the study, the roof bolter never operated downwind of the continuous miner. Using a combination of personal Data Rams (pDR) and gravimetric samplers, the dust control efficiency of the roof bolter CAC was ascertained. Performance evaluation was determined using three methods: (1) comparing roof bolter operator concentrations underneath the CAC to roof bolter concentrations outside the CAC, (2) comparing roof bolter operator concentrations underneath the CAC to the concentrations at the rear of the bolter, and finally, (3) using the gravimetric data directly underneath the CAC to correct roof bolter operator concentrations underneath the CAC and comparing them to the concentrations at the rear of the bolter. Method 1 dust control efficiencies ranged from -53.9% to 60.4%. Method 2 efficiencies ranged from -150.5% to 52.2%, and Method 3 efficiencies ranged from 40.7% to 91%. Reasons for negative and low dust control efficiencies are provided in this paper and include: incorrect sampling locations, large distance between CAC and operator, and contamination of intake air from line curtain. Low dust concentrations encountered during the testing made it difficult to discern whether differences in concentrations were due to the CAC or due to variances inherent in experimental dust measurement. However, the analyses, especially the Method 3 analysis, show that the CAC can be an effective dust control device. INTRODUCTION Canopy air curtains (CAC) have been shown to be an effective respirable coal mine dust control for roof bolters in a laboratory setting with dust control efficiencies ranging from 14% up to 75% [Goodman and Organiscak 2001, Listak and Beck 2012, Reed et al. 2017]. Unfortunately, there is limited information on their effectiveness for controlling respirable coal mine dust in the field. On continuous miners, CAC dust control efficiencies ranged from 23% to 69% [Krisko 1975]. Two underground tests of the CAC on roof bolters demonstrated dust control efficiencies of 35% and 53% [Listak and Beck 2012] before problems occurred with operation of the CAC. Since the implementation of the new respirable coal mine dust limit from 2.0 mg/m3 to 1.5 mg/m3 (Code of Federal Regulations, 30 CFR 70.100, 2015), roof bolter CACs are becoming more commonplace in underground coal mines as a dust control tool to prevent roof bolter operator overexposure to respirable coal mine dust. J.H. Fletcher & Co. has been instrumental in delivering an effective design which incorporates the filter, blower, and canopy plenum seamlessly into the design of the roof bolter, resulting in a successful operational roof bolter CAC."

Jan 1, 2018

By Stuart Lister

"When MacLean Engineering chairman and founder Don MacLean got the first question from a minesite about the possibility of addressing ventilation limits through incremental fleet electrification, he was intrigued. It was back in 2015, and the MacLean scissor bolter was already diesel-electric (jumbo trailing cable), so it made sense to him that if they could engineer a battery drive system for the unit’s tramming cycle, they would have the inaugural electric vehicle (EV) MacLean unit.At that time, there were not any entirely diesel-free hard rock mines in existence on the planet, and that remains the case to this day — although the Borden project in northern Ontario is progressing toward that goal (see page 33). This meant there was essentially zero market demand for battery electric vehicles as well as a complete lack of battery technology to address the battery electrification of heavy haulage. Heavy haulage is the part of a typical mine’s mobile fleet with the largest footprint when it comes to diesel particulate emissions, greenhouse gases and wasted energy in the form of heat.Three years later — the wave of battery electrification that is currently picking up speed across the mining industry promises to hit full swing by the early 2020s when a slew of new build, diesel-free mines will start construction. But this movement toward emissions-free mobile fleets is not a completely new phenomenon. Instead, it is an updating of mining technology from a previous generation. What is going on now is the re-electrification of mining. Up until the 1960s, early generations of battery technology (lead acid) and electric locomotive systems were the norm for material and ore haulage in Canada and elsewhere.The thought of a coming paradigm change in mining was particularly pertinent to Don MacLean back in 2015, as he had been part of the era that ushered in the first generation of rubber-tire diesel equipment, when he was a divisional foreman with Inco in Sudbury in the 1970s. He was part of the operating team that was tasked to build a rail loop on one extraction level of the mine. At that time, events on the ground overtook the project, as diesel-powered mobile equipment became a viable option. Once the first diesel scoop was introduced at Creighton #3 shaft, it was clear what the power, haulage capacity and mobility could do for operations and that era of electric rail haulage underground was effectively over."

Jan 10, 2018

By Antonio Tafra, Rene Dominguez, James Spenceley, Brady Hays

"Extracting one of the world’s most valuable natural resources — copper — hinges on the availability of the world’s most essential resource: fresh water. But try sourcing fresh water in one of the driest places on Earth, Chile’s Atacama Desert.BHP, majority owner of the Escondida copper mine in Chile’s Antofagasta region and Minera Escondida Limitada (MEL), operator of the mine, were looking for sustainable solutions to deliver desalinated water to the mine, while protecting the environment and complying with the local water authorityregulations.The mining giant chose Black & Veatch to solve this challenge.Solving a global miningchallengeMines use large quantities of water for mineral processing and metal recovery. Water supply, and not mineral ore, is often the major constraint to mining production and development of projects, especially in Chile. Mining operations must have a reliable water source that complies with local regulations, without adversely impacting the environment or affecting the water supply of nearby communities.Worldwide, mining companies and their owners, shareholders and regulators are placing new levels of focus on minimizing the impact of mines on the surrounding landscape and communities. Balancing the economic benefits and needs of mining operations with the potential freshwater impacts requires mines to pay serious heed to the environmental and social issues related to water. Today, mining companies are being proactive and are taking action to protect precious freshwater resources while seeking opportunities to reduce and mitigate their water impact.Delivering a desalination solutionBHP and MEL needed an efficient, technologically advanced seawater desalination plant, along with a conveyance system and infrastructure that would carry desalinated water more than 180 km (112 miles) from the ocean to the mine. Four pumping stations convey the water to a reservoir at the mine site, which is 3,200 m (10,500 ft) above sea level."

Jan 6, 2018

By M. K. McCarter

INTRODUCTION Mining activity and basic geometry of open pit mines represent major obstacles in geotechnical mapping. Mining creates a constantly changing topographic base which may require corresponding updates of field sheets before mapping can proceed. The rapid pace of mining operations may also threaten removal of important geologic and engineering features before adequate base maps and surveyed control can be established. Maintaining such control during the mapping process is yet another complication. In addition, basic geometry yields nearly vertical outcrops. Access required for direct observation and measurement, essential to conventional plane table or Brunton techniques, may be impossible on such surfaces. Also, nearly vertical surfaces appear fore- shortened in plan view. This reduction in area provides little room for recording geotechnical detail. The difficulties encountered in open pit mapping can be substantially reduced by utilizing a modified form of plane table photogrammetry. This technique employs photographs taken from the ground as the base upon which details are recorded. The information is later transferred to plan maps using the plane table principal of location by intersection (Davis and Foote, 1953). Any change in topography can be accommodated by simply taking additional photographs. Proper spatial representation in plan view can be determined later when updated maps and surveyed control are available. In addition, horizontal photographs from the ground portray vertical surfaces as they are normally viewed thus providing maximum area for recording details. Any detail which can be identified on the photograph can be located correctly even though the actual feature is physically inaccessible. The technique presented in this paper was developed by the author for special applications at Kennecott's Bingham operation in 1970. The procedure was rapidly adopted for general use and has proven to be a practical tool for detailed investigation of potentially unstable areas (Zavodni and McCarter, 1976) and routine geological mapping (Richardson, 1975). Major advantages, other than those mentioned above, include: The speed and accuracy are greater than for conventional plane table or Brunton methods. The photo- graph represents a view from a station at some distance from the area being mapped. This vantage point allows evaluation of possible continuity of structures from one level to another which may not be evident at close range. The photographic base provides a permanent record of the topography at the time

Jan 1, 1977

By Edgar O. McAlister

Associated with cordilleran intrusives of intemediate to acidic composition, gold/silver ores are generally found in the intruded host rocks which are adjacent to these intrusives. Generally precious metal deposits lie further from the intrusives than allied base metal deposits. For vented intrusives, the associated volcanics may constitute the intruded rock and form the host for precious metal accumulation. Potential field methods, particularly magnetics, can help to define unseen boundaries of intrusive systems and thus can point to generalized prospecting targets. Other clues arise from the intrusive system type, its emplacement fracturing, the host rock type and local magnetic changes caused by mineralization processes.

Jan 1, 1984

"What is your assessment of the minerals business?My experience with mining has been primarily in the coal sector until about 10 years ago, when I also became heavily involved in the aggregates and industrial minerals sectors. I have also had peripheral involvement through family and partners in the gold sector, with just enough exposure to gold to become fascinated. In 1994, I visited Ghana and considered the possibility of taking an expat assignment at a surface gold mine that had just been started.It is not news that the coal sector in this country has suffered tremendously in recent years. Especially hard hit is the central Appalachian region, where a number of factors combined have had a devastating effect on production, jobs and the economy. These factors include federal regulations affecting coal production and use, higher production costs and decreasing market share of Appalachian coal by the switch from lower sulfur coal in favor of lowercost, higher sulfur coal from the Illinois Basin, as utilities have installed scrubbers to comply with Phase II of the 1990 Clean Air Act Amendments. Nationally, the lower cost of natural gas has been a huge factor affecting coal use. In Kentucky, for example, which exports to other states around 70 percent of its coal, those markets are disappearing, as utilities close coal units in favor of natural gas. This is a structural change in the electricity market, and one that will become more pronounced as federal greenhouse gas regulations are implemented.We often hear the phrase, "the war on coal." While there are certainly a number of market factors affecting coal production and use, this phrase captures a different element that is all too real. The attacks have come from environmental activist groups for many years; from some in the media and, in the last few years, from a White House administration that believes strongly in alternatives to coal. Then, there really is an alternative to coal in the form of the previously untapped unconventional gas reserves that allowed utilities to move away from coal.Coal mining will continue in this country. In fact, it appears that our production is holding fairly steady at about a billion tons a year. And predictions that I have seen indicate this will continue for the next few years. What impact the Environmental Protection Agency’s Clean Power Plan will have beyond 2020 is another question.What do you feel is the future of the minerals industry - near term and longer term?Our society depends on the future of minerals in this country being strong. Near term, we are going through some of the typical cycles. Having also been involved in aggregates during the last few years, the business follows government infrastructure projects, such as highway construction and public and private sector development. Those sectors are heavily dependent upon government spending and a strong economy. Increased spending in those sectors, which appears to be on the horizon, should provide additional market shares for aggregates."

Jan 1, 2014

"What is your history and how did you get involved in mining?Like many SME members, I came from a mining community with a family history in mining, in my case Walkerville, MT. Both of my grandfathers were underground miners. My father was a miner for a short time. He later sold drinks to the miners. Unfathomable by today’s standards, my dad would pick up the miners’ checks at the pay office and have them cashed and waiting with a shot and beer for the miners when their shift ended. My mother was a nurse, who from time to time, would patch up an unfortunate miner. I remember walking past multiple picket lines on the way to and from grade school, watching homes being boarded-up. I grew up with a deep respect for the critical relationship between labor and management.I had no intention of going into mining and initially set out to pursue a career in chemical engineering. But I attended my first two years of engineering at Montana Tech, due to the proximity and affordability. This is where I met Dr. Tom Finch, a mining professor who taught statics to the engineering students. After a coaching session in a hallway, half way through my sophomore year, I switched to mineral processing engineering. In his colorful way, Professor Finch advised me that, “You do not want to make #@*!! erasers and #@*!! Jell-O the rest of your life go talk to the guys in mineral processing.” He was very persuasive and here I am today.How about your involvement with SME?I encountered SME out of school and a little later in my career. Terry Maio and Jim Arnold invited me to local section meetings in the Missouri Lead Belt. That was my first exposure to the technical programming and relationship building that was possible at the local level. After Ozark Lead shut down and I relocated to Nevada, Rich Johnson, Scott Barr and Dave Collins encouraged me to attend my first annual meeting in Salt Lake City, UT. I joined SME at that time and was fortunate to be engaged by members like Art Schweizer and Jim Arnold, and I soon began the leadership progression for the Mineral & Metallurgical Processing Division. Since then, I have supported SME at the national and the local level serving in multiple roles and capacities."

Mar 1, 2017

By Eung Ha Cho, Olufemi Olajide

A laboratory study of dense-medium cycloning with Redstone seam coal has been conducted. The investigation was performed using a 203 mm (8 inch) Heyl-Patterson dense-medium cyclone. Two underflow orifices of 31.8 mm (1.25 inch) and 44.5 mm (1.75 inch) in diam were used. The effects of feed pressure and particle size were determined on the cycloning performance. In addition, the cyclone performances with coal-rich and refuse-rich samples were also investigated. The results of the experiments were analyzed using basic hydrodynamic principles. The increase in the feed pressure increases the specific gravity of separation (defined as the specific gravity of a particle which has an equal chance of reporting to either the overflow or underfow) for both underfow orifices. The specific gravity of separation increases as the particle size decreases with the smaller underflow orifice. However, an opposite relationship has been observed with the larger under flow orifice. The separation becomes sharper with the smaller under flow orifice than with the larger underflow orifice especially for fine material. Also, the separation becomes sharper with an increased feed pressure for a coal-rich sample. However, this effect is less significant for a refuse-rich sample. This means that a high feed pressure is required for a coal-rich sample to maintain a good separation. It also means that applying a high feed pressure provides a good separation regardless of the type of feed coal in terms of ash content in the solid.

Jan 1, 1990

By Ernest L. Bradley

A positive pressure ventilation system, augmented by a dewatering well curtain and underground longhole drilling, provides effective ventilation and radon control at EXXON Minerals Company's Highland Underground Mine in the Southern Powder River Basin of Wyoming. Testing different types of bulkheads, sealants, and bleeder systems has led to improvements in the basic ventilation system. Continued testing of new or different materials and equipment is expected to lead to further improvement in the ventilation program. Effective training of both miners and supervisors is essential to maintaining and improving ventilation techniques. This paper addresses the ongoing ventilation program and experience to date at the Highland Uranium Mine.

Jan 1, 1979

By James L. Patton

Automation of mining increases the productivity of labor, thereby reducing the unit cost of labor. Such cost constitutes the largest portion of the direct or variable costs of producing coal. Therefore, any increase in productivity directly reduces variable cost. The large investment in mechanical equipment carries with it the burden of increased fixed charges. As the proportion of fixed cost to the total cost increases, the effects on the cost of production changes are amplified. Therefore, equipment must be fully utilized at all times. Averaged fixed costs rise with any decline in production. Such a situation forces coal companies to seek every means of main¬taining full production. Figure I will reflect the story on the relationship of production to cost.

Jan 1, 1962