Search Documents

By David R. Cole

Before discussing some of the specific public relations issues in Colorado mining, I would like to define public relations, identify the "publics," review Colorado's population profile, and outline Colorado's mining history. Public Relations In describing public relations, a definition which is frequently quoted appeared in the PUBLIC RELATIONS NEWS, and is as follows: "The Management function which evaluates public attitudes, identifies the policies and procedures of an individual or organization with the public interest, and executes a program of action to earn public understanding and acceptance..' As you can see, this covers a "multitude of sins."

Jan 1, 1975

By Eugene A. Lang

Mr. Chairman, ladies and gentlemen. As a member of the uranium and coal producing community, I am pleased to participate in a session dedicated to a look at these and other mineral markets.(title slide) before sharing some of my thoughts with you, let me tell you a little bit about rocky mountain energy company. It was established as a subsidiary of union pacific corporation in 1971 with responsibility for coal, uranium, and industrial minerals. We participate in four coal mining operations and a uranium mine and mill all in Wyoming, and an aggregate and an abrasive operation in Utah.

Jan 1, 1984

By L. C. Atkinson

A three-dimensional finite element Ground-water flow code has been developed that incorporates saturated/unsaturated, two-regime flow (i.e., both Darcian and non-Darcian) and solves for the seepage face at a surface of outflow. This code is capable of more realistically predicting ground-water inflows to an open-pit mine under the throttling effects of non-Darcian flow. The height of the seepage face on highwalls and the shape of the phreatic surface in the vicinity of the pit that it calculates can also produce more probable estimates of pore pressures for analysis of slope stability.

Jan 1, 1992

By The SME Sustainable Development Committee

The evolution of sustainable development in mining is recognized as a key contributor to sustainable development (SD), which is defined as the ability of current generations to meet their needs without compromising the ability of future generations to meet their own needs (Brundtland, 1987). This includes, in equal parts, social, economic and environmental impacts ? triple bottom line (Munashinge and Shearer, 1995). Alternately, sustainability has been defined in relation to social, natural, human, physical and financial capital. Our way of life relies significantly on the materials provided by mining, while mining activity affects the triple bottom-line or the five capitals. The mining community and its professionals have come to realize the importance of engaging all stakeholders in the discussion on sustainability. SME, as the leading professional mining organization, has been involved in these discussions. The society has various initiatives in sustainable development for members and stakeholders. The objective of this article is to: provide historical context for current trends in mining and SD and share SME sustainability initiatives ? their goals and rationales ? with the broader mining community. This article is timely because the past year saw two landmark forums on sustainable development: Rio+20 ? the 20th meeting of the United Nations Conference on Sustainable Development, and MMSD +10, the Mining, Minerals and Sustainable Development project 10 years on. Furthermore, this year marks the 10th anniversary of the Milos Declaration on the minerals professional?s responsibilities in achieving sustainable development, forums in which SME was involved.

May 1, 2013

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 D. Kruse, M. Sanaei

"3D finite element models of the Segmentally Lined Shaft (SLS) structure are simulated as means of numerical analyses of the system’s structural behavior. Top-down constructed rings, comprised of precast concrete segments, create a large diameter, relatively shallow underground space that can be utilized for various applications. To further investigate the effects of soil conditions and different loadings on the shaft structure, the FE model was run under various boundary conditions. Simulations include a) effects of various soil layers on the SLS, including a circumferential boundary of modified ground, b) effects of various soil layers on the SLS without any ground modification, c) Seismic analysis of the SLS with ground modification and d) Seismic analysis of the SLS without any ground modification. Comparing the analyses outcomes emphasizes the significance of the inclusion of the ground modification boundary in the structural performance of the SLS. INTRODUCTION TO SLS Underground structures are classically built rectangular in shape, which normally requires a two-step construction process beginning with installation of temporary shoring to support earth loads during the excavation, followed by the construction of the permanent structure. Attractive and practical alternatives are circular shafts referred to as segmentally lined shafts (SLS). The structure consists of a stacked series of rings formed from an assemblage of precast concrete segments. Top-down constructed systems of large diameter, relatively shallow SLS structures provide both temporary earth support during excavation and permanent structural support for many civil and building applications. The circular shafts sustain the lateral earth pressure mainly through hoop-stress mechanism, resulting in improved stability and structural efficiency. Cylindrical shell structures with large diameter to wall thickness ratios are prone to buckling under external pressure. In typical designs of small diameter shafts and tunnel linings with small diameter to wall thickness ratios, nonlinear buckling analysis (i.e., nonlinear geometric analysis) is usually not considered, since the buckling capacities for those structures are much higher than typical pressures encountered at their design depths. With an economically viable wall thickness, buckling becomes a critical issue, which should be addressed, for circular shafts with very large diameters. In the design and construction of the SLS, the stability of the structure can be improved by modifying the soil surrounding the circumference of the shaft to a limited thickness and to about 10 ft below the finished shaft structure. This thick wall of soil mixed with cement creates a composite integrated structure while serving additional purposes such as ground control and ground water seepage cutoff."

Jan 1, 2016

By D. R. Hembree

This paper discusses the mineralogy and metallurgy of the Kuroko-style volcanogenic massive sulfide ores mined at Formosa Exploration Inc. I s Silver Butte Mine located in southwest Oregon. The principle ore type is pyrite + chalcopyrite + sphalerite, while subsidiary pyrite + bornite + sphalerite ore is also mined. The two styles of mineralization have distinctly different metallurgical behaviors and must be treated separately. Selective flotation methods are used to produce copper and zinc concentrates from the first ore type, while bulk concentrates are produced from the bornite ore. Careful mine planning and coordination between the mine and mill are utilized to achieve optimal recoveries.

Jan 1, 1993

By Philip M. Rice, Paul Schmall, Peter W. Deming, Hugh S. Lacy

A groundwater cut-off is needed to provide a stable face of tunnels to be constructed by jacking precast rectangular tunnel segments beneath commuter rail tracks for the new I-90 extension in Boston, MA. Extensive obstructions are present within the path of the tunnels. This paper describes how the use of artificially frozen ground is being planned to provide a reliable groundwater cutoff and assure a stable tunnel face. Monitoring during freezing assures continuity of the cutoff. Laboratory testing of frozen soil samples aided the design of this frozen soil boundary. Logistics of installing vertical freeze pipes are described.

Jan 1, 1999

By Justine Ealy, Daniel Yang, Christina Foster

Maintaining stable high walls can be a challenging task. Complex geological and structural features, alteration zones, rock mass properties, and hydrogeological conditions must be well understood to design a safe mining environment. Economic considerations must also be taken into account as the mine operator must provide ore deliveries and protect reserves. However, even when good engineering practices are followed, and proper blasting and mining techniques are implemented, slope movements may still occur. When these slope instabilities are minor, the mine is often able to continue operations with minimal impacts on safety or production. When these occurrences are excessive and coupled with high rates of movement, a robust monitoring system is crucial to continuing mining activities while protecting personnel. This paper summarizes the approach an open pit mine in Nevada took as excessive and rapid high-wall movement was experienced in an integral area. Creative mining approaches, combined with slope monitoring radar technology, were utilized to maintain safe and successful mining activities despite active movement that exceeded an average velocity of 30 inches per day.

Feb 1, 2024

By Keith Kern, Joseph P. Matoney, Kenneth E. Harrison

INTRODUCTION "When there is an economic need for cleaning fine coal to low ash, the technical difficulties will be solved. The utilization of fines below 28 mesh will determine the degree to which beneficiation will be carried. Whenever these "fines" will be processed into smokeless fuels or used as new materials for the chemical industry or for hydrogenation, a higher degree of cleaning will be economically justified”.(l) This quote from the 1943 edition of Coal Preparation correctly anticipates the use of fines as "smokeless" fuel or as a future component of boiler fuel and a1 so as a raw material for the chemical industry or possible new uses such as for internal combustion engines. Fines utilization depends upon an economic need and possibly neglects to say an environmental need or a government funded development program as the prime mover for development. In any event, this conference is faced with the "need" to beneficiate fine coal and undoubtedly among the processes that will be discussed are the unit processes of future coal preparation facilities. HISTORY OF DEVELOPMENT It is interesting to look at where we have been, where we are now and where we possibly will be in the future. In order to put some limitations on this presentation, we will for the most part confine our remarks to this century and particularly developments since World War II. We also will limit our remarks to the preparation of bituminous coals in the United States, and for the most part, to wet processes. In the 1943 edition of Coal Preparation, clues to the processes being used to beneficiate coal are contained in the Chapter Titles. An extensive treatment of "Hand Picking" was contained in Chapter 8. Chapter 7 contained a description of methods for "Preparation at the Face". Chapter 18 dealt with "Slurries, Sludges, Slimes and Water Treatment" and defined this size of coal as being the size at which "Jigs and Chance Cones are usually dispensed with and other methods such as the hydrator, tables, and froth flotation are employed. Generally the limit is 1.7mm to 3.4mm. In the days before World War I1 the then modern bituminous coal preparation plant contained jigs or Chance Cones for the coarse material +6.35mm, concentrating tables, launders or some classifier type of coal washer for the fines (6.35 x 0.15mm), and froth flotation as the only method of cleaning minus 0.15mm coal which was used very sparingly.

Jan 1, 1988

By F. F. Aplan, D. D. Xu

A novel system for the depression of pyrite and the ash-forming minerals has been developed. A metal ion, including but not restricted to Fe+2, is added to form a hydroxide coating on the pyrite or ash-forming minerals. A polymeric depressant is then added to attach to these re- surfaced minerals. Nearly 200flotation tests with I1 different coals indicate the effectiveness of this system. Many of the important process variables such as the coal source, frother- collector system. grind size and procedure, pH, metal ion, and depressant type and concentration have been studied.

Jan 1, 1995

By Burton E. Gilpin, Dr. George W. Annadale

A two level risk analysis procedure which is specially designed for use in river environments, is presented. The first level risk assessment (Level I) is often adequate for purposes of most projects, and entails hazard assessment, exposure identification, consequence estimation, and risk characterization. Two unique features of the method are the Composite Hazard Rating system, which is used in hazard assessment, and a formalized decision model for risk characterization. The risk characterization procedure provides information on the acceptability of risks, can be used to distinguish between the relative severity of risks, and to evaluate whether more advanced risk assessment would be required.

Jan 1, 1992

By S. Zaman, John Bulter, M. E. Defoe, Franklin T. Davis

This section deals with the carbon minerals and materials: graphite, tar sands, gilsonite, and diamond. as well as sulfur and the sulfides of mercury, arsenic, antimony, and bismuth. Table I contains the production figures for each of these commodities in the United States and in the world. Specifications for concentrates are also summarized as are prices for concentrates at the time the section was written. In each chapter an attempt has teen made to describe the more common commercial mineral involved with the commodity, the processes used to recover and concentrate the minerals, as well as geographical areas where these processes are utilized.

Jan 1, 1985

By Liu Cheng-si

Variable airway is controllable, which is an important discovery in ventilation research in recent years. For this reason, conventional calculating methods are no longer suitable to solve this problem. I used Mayeda-Seshu and Newton methods to solve the above problem before, they have been proved feasible. However, it is troublesome and difficult to apply to operation with a large amount of calculations. In this paper combination theory and simplified formula are used in determine all control plans and its parameters. This new method with less calculation is easy to understand and master, so it is more important in research and application.

Jan 1, 1997

By J. R. Muhm

Environmental due diligence investigations, also known as Phase I Environmental Audits, are increasingly important to major investors, venture partners, or prospective purchasers or sellers of mineral properties. Knowledge of environmental risks associated with a property will allow better appraisal of a property's overall desirability prior to completing the transaction. It is possible that the cost of environmental cleanup could exceed the value of the property. Topics appropriately investigated include permit status, water quality, past use of the property, hazardous materials management, storage tanks, public records pertaining to the environmental character of the property, and environmental costs.

Jan 1, 1991

By O. E. Etheridge Jr., R. A. Lowe, C. I. Basilio, J. M. Randolph, S. W. Sheppard

The low-shear viscosity of kaolin slurries is one of the principal characteristics that determine whether a clay can be utilized for paper and ceramic applications. In this work, the causes of high low-shear viscosity and methods for improving the rheological behavior of the slurries were investigated. The presence of fine-grained smectite impurities within the kaolin was shown to detrimentally affect the low-shear rheology of the slurries produced from these clays. It was also shown that mechanically working (i.e., pugging) a crude kaolin followed by desliming to remove these impurities can reduce the low-shear viscosity.

Jan 1, 2000

By Richard A. Thomas, Liming Yuan, Wei Tang, JOHN SOLES

Lithium-ion (Li-ion) battery applications are increasing for battery-powered vehicles because of their high energy density and expected long cycle life. With the development of battery-powered vehicles, fire and explosion hazards associated with lithium-ion batteries are a safety issue that needs to be addressed. Li-ion batteries can go through a thermal runaway under different abuse conditions, including thermal, mechanical and electrical abuse, leading to a fire or explosion. The National Institute for Occupational Safety and Health (NIOSH) mining program is conducting research to prevent and respond to lithium-ion battery fires in battery-electric vehicles in the mining industry. In this study, experiments were conducted to investigate the effectiveness of different suppression systems including dry chemical, Class D extinguishing powder and water mist for lithium-iron-phosphate (LFP) battery pack fires. The effects of activation time and release time of the water-mist system on the suppression of the LFP battery (a type of Li-ion battery) fires were studied. The results of this study may be helpful for developing strategic firefighting and response plans for battery-powered vehicles used in mining.

Aug 1, 2024

By William W. Edgerton, Moussa Wone, David H. Corkum, Carlton M. Ray

"The DC Clean Rivers (DCCR) Project is a 25 year, $2.6 Billion court ordered project to reduce combined sewer overflows (CSOs) discharging into the Potomac and Anacostia Rivers and Rock Creek, and also reduce flooding in the northern areas of the District of Columbia. Like all massive infrastructure programs, DCCR faced technical challenges, management challenges, risks of cost and schedule overruns, procurement challenges, and financing challenges. While DC Water is no stranger to large capital improvement projects (CIP), this CSO Program represents a once in a lifetime event for the Owner requiring the assembly of a single purpose team to implement. Some of the DCCR Project team’s most successful accomplishments to date are attributable to its introduction of early contractor involvement (ECI) to thoroughly vet the work from the perspective of the future constructors, development of functional baselines to share risks that are difficult to price and reduce reliance on geotechnical baseline interpretation during tunnel excavation, and attainment of financing through Municipal Century Green Bonds based on using design criteria of a minimum of 100 year life for the structures to establish intergenerational equity and fairness. This paper will discuss these innovations in detail and provide some sets of recommendations for the underground industry on when and how to use different approaches to better manage projects of this magnitude. INTRODUCTION The District of Columbia Water and Sewer Authority (DC Water) is an independent multi-jurisdictional authority that was established in 1996. Its primary mission is to provide water distribution services to more than 640,000 residents in the District of Columbia (District), and sewer treatment and disposal to 1.6 million residents of the District, Montgomery and Prince George’s counties in Maryland and Fairfax and Loudoun counties in Virginia."

Jan 1, 2016

By Richard A. Thomas, Liming Yuan, Wei Tang, JOHN SOLES

Lithium-ion battery applications are increasing for battery-powered vehicles because of their high energy density and expected long cycle life. With the development of battery-powered vehicles, fire and explosion hazards associated with lithium-ion batteries are a safety issue that needs to be addressed. Lithium-ion batteries can go through a thermal runaway under different abuse conditions including thermal abuse, mechanical abuse, and electrical abuse, leading to a fire or explosion. The NIOSH Mining program is conducting research to prevent and respond to lithium-ion battery fires for battery electric vehicles in the mining industry. In this study, experiments were conducted to investigate the effectiveness of different suppression systems including dry chemical, class D powder, and water mist for lithium iron phosphate battery pack fires. The effects of activation time and release time of the water mist system on the suppression of lithium-ion battery fires were studied. The results of this study may be helpful for developing strategic firefighting and response plans for battery-powered vehicles used in mining.

Feb 17, 2024

By J. D. McKendrick

Alaska's Arctic Slope lies between the Brooks Range and Beaufort Sea and is a region about the size of Nebraska. It has some of Alaska's richest hydrocarbon deposits. In addition to containing petroleum and natural gas. Much of the area west from the Colville River has low-sulfur coal deposits which are shallow enough for surface mining. Developing those resources will require a firm and realistic' commitment to protecting and rehabilitating the natural habitats. Balancing such a commitment with economic constraints in a practical sense requires knowledge of the environment and its associated biological components, i.e. the soil/water-plant-animal relationships.

Jan 1, 1988