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By R. R. Klimpel

The process of froth flotation as a means of upgrading the quality of coal by removing ash/pyrite and of separating selected mineral(s) from undesired gangue materials is certainly one of the most common unit engineering operations in use today. Flotation has been successfully practiced at the industrial scale for well over 50 years, and if anything, its use is increasing due to the ever decreasing feed grades of the coals and minerals being processed. Flotation, as a process, has also shown itself to be an extremely flexible process that lends itself well to a wide variety of solid/solid separations. Thus separations can involve very different particle sizes, particle densities, relative weight ratios of materials to be separated, etc., with surprisingly little modification in equipment and operating philosophy required.

Jan 1, 1988

Since gold was first discovered in Colorado in the late 1850s' mining has been a major part of the state's economic history, according to Stanley Dempsey, chairman and chief executive officer of Denver- based Royal Gold Inc. While the mining industry has seen some lean times throughout the past century, it has always bounced back. Today, dozens of major gold companies are headquartered in the Denver area. The state's coal mines produced record amounts during 1996. And even some of Colorado's uranium mines are resuming production. Dempsey joined other speakers in addressing the state of Colorado's mining industry during the Colorado Mining Association's (CMA) National Western Mining Conference. Some 800 people attended the CMA meeting, held Feb. 2-5 in Denver. The meeting was the association's 100th since it was incorporated in 1897.

Jan 1, 1997

By M. Heger, V. Lund, P. Mongeon, D. Bogunovic, V. Kecojevic

The U.S. coal mining industry consumes a significant amount of energy, primarily diesel fuel and electricity. The continuous global increase in energy demand, high energy prices and environmental issues related to carbon dioxide emission represent a substantial challenge for the mining industry. This paper presents the result of research on development of an integrated data environment system for analysis of energy consumption in a surface coal mine. A case study on an operating surface coal mine is carried out to demonstrate the practical application of the developed system. The research work presented here may be used by mining professionals to help provide the answers to the crucial questions of when, where and how much energy is being used. This developed system represents a framework for efficient management of energy consumption.

Jan 1, 2009

By R. H. T. Garnett

Offshore mining of placer diamond deposits along the coast of South Africa and Namibia has become a multi-scale activity. It is a successful offshoot of a land-based mining industry that has operated along the coastline for more than 80 years. Onshore diamond deposits have been worked by several methods from the foreshore to some kilometers inland (Hodgen). These deposits are the foundation of an ongoing industry along the coastline. The offshore diamond industry began in the late 1950s and has now come of age. Diamonds are produced along 800 km (500 miles) of coastline in water 200 m (660 ft) deep. About half of the coastline is in Namibia, north of the Orange River that defines the border with South Africa. The other half is in South Africa.

Jan 1, 1995

By Barbara C. Williams

U.S. Bureau of Mines researchers conducted field studies at an abandoned copper-gold mine tailings impoundment. Pore water quality was analyzed in the vadose and saturated zones. Three statistical procedures were employed to summarize the variability within and between the two zones. The results indicated that linear combinations of those variables reflecting sulfide oxidation and aluminum-silicate weathering best summarized the variability in each zone, and that the zones were most different on the basis of sulfide oxidation variables. The geochemical computer code WATEQ4F was used to assess the solubility status (saturation index) of minerals. Saturation indices of sulfide oxidation and aluminum-silicate weathering minerals were different in the two zones. It was demonstrated that the statistical analyses produced similar and complementary results to the geochemical code.

Jan 1, 1992

By Mollie Hunt, William Riley, Russ Downer, Kate Willa Brown Requist, Víctor O. Tenorio, Geoffrey Gill

One of the first activities after returning to the Moon will be finding sources of water and materials for the construction of human settlements and other infrastructure. There is evidence of the existence of deposits in the bottom of craters at the South Polar region and in flat areas around. Based on geological data from the Moon, a block model representing a deposit or icy regolith has been defined in the vicinities of Shackleton Crater, with unique characteristics of shape, thickness, and water contents. A mine plan utilizing surface mine modeling software for ore extraction from an open pit- type of excavation to a delivery point near a water processing facility is proposed, with monthly, quarterly, and yearly schedules. Production results, dashboard charts and progress of the topographic changes are also presented.

Feb 1, 2024

By S. P. Brown, J. E. Worthington

Increasingly, exploration geology seems to be growing into a practice overly separated from production geology, yet the eventual purpose of exploration is a producing mine. To help in the search for new deposits, exploration "lessons" will be drawn from the papers given at the Fall AIME Applied Geology Symposium. In addition, examples will be re-emphasized to show how early observation of matters now routine to mine work (for example, hydrology, rock mechanics, oxidation state) can help increase the effectiveness of exploration.

Jan 1, 1992

By J. V. Belke

There are many aspects of a grinding mill supply and installation that can result in the mill not operating as intended, resulting in unplanned shutdowns, poor reliability and headaches for all concerned. One of the largest aspects, both in criticality and physical mass, is the mill foundation; if not properly specified, designed and constructed the mill operation will be compromised. The mill foundation starts with the design specification and loading diagram supplied by the mill builder. The importance of understanding these documents and how to apply them is critical for the start of any mill project. When designing mills with a GMD the foundation must be properly modeled to ensure that all interactions of the mill and motor structures, foundation and subsurface strata behave in the intended fashion. All of the previous efforts can be laid to waste if the construction of the mill foundation is poorly handled. Mill foundations are typically the most massive concrete structure at a processing plant and can easily cause nightmares for inexperienced contactors. This paper explores some of the more important facets along the lifecycle of the grinding mill foundation.

Feb 23, 2014

By J. Franko, M. S. Klima

Wet-drum magnetic separators are used extensively for upgrading iron ore and for magnetite recovery in dense-medium separation circuits. In this study, the performance of a continuous, laboratory wet-drum magnetic separator was evaluated both with and without the application of ultrasonic energy when processing dense medium slurries. Test variables included magnetic-to-nonmagnetic ratio, solids concentration and nonmagnetic material. The results indicate that, under certain conditions, the purity of the magnetic material increased after ultrasonic treatment. Key words: Ultrasonics, Wet-drum magnetic separation, Iron ore

Jan 1, 2003

By K. A. Natarajan, M. K. Yelloji Rao

Significance of grinding media wear and its effect on chalcopyrite flotation are discussed. Laboratory marked ball wear tests were conducted grinding chalcopyrite ore and quartzite dry, wet, and with collector added during grinding. The effects of oxygen and nitrogen on ball wear were evaluated by the addition of chalcopyrite mineral while grinding quartzite. The effect of dry and wet grinding on chalcopyrite flotation was also studied. Results show abrasive wear is greater in quartzite grinding than in grinding chalcopyrite. Oxygen increases the corrosive wear of high carbon low alloy steel balls in the presence of chalcopyrite ore. Chalcopyrite flotation was retarded due to wet grinding in the presence of oxygen. Though collector reagent increased the media wear, it improved the flotation of chalcopyrite. Probable electrochemical reactions encountered in a grinding mill are outlined.

Jan 1, 1991

By T. M. Gurr

It is estimated that in excess of one-half million chemicals are used throughout the American workplace. Hundreds of new chemicals are also being introduced into the workplace annually. Exposure to some of these chemicals can be harmful to workers and to the environment. The Occupational Safety and Health Administration (OSHA) estimates that approximately 25% of the U. S. labor force or approximately 25 million workers are exposed to one or more chemical hazards each year. OSHA has determined that this poses a serious problem for workers exposed to such chemicals. Chemical exposure may cause safety and health problems. Health problems can include a cause or contribution to heart ailments, kidney and lung damage, sterility, cancer, burns, and rashes. Safety hazards can include the potential to cause fires and explosions and other serious accidents.

Jan 1, 1989

By Carrie Smith

The 2025 Women in Mining USA National Conference, held April 15-18 at the Grand Hyatt Riverwalk in San Antonio, TX, brought together hundreds of professionals for a fourday event focused on empowering women and creating space for all individuals in the industry. Under the theme “Empowering the Future of Mining,” the conference served as a dynamic platform for professional development, knowledge-sharing and cross-sector collaboration. Organized by Women in Mining USA (WIM USA), whose mission is to foster equity, sustainability and leadership in mining, the event featured an extensive agenda including workshops, keynote speeches, panel discussions and networking opportunities. Attendees ranged from industry veterans to emerging professionals and students, united by a shared commitment to progress within one of the world’s most essential and traditionally maledominated sectors.

Jun 1, 2025

By M. I. M. Darwish

In this paper, an effort was made to get more in-sight about the parameters that can affect air sparging technique optimization. Numerical simulations were used in predicting the effects of different parameters utilizing Shell?s in house MoRes simulator. The case of using air sparging to remediate source zone is considered in this work. Different air injection scenarios using continuous and pulsed air injection techniques, with different frequencies and durations, were compared. The amount of MTBE mass removed from the saturated zone and arrived to the ground surface, through the vadose zone, was the main criterion while comparing different air injection scenarios. The simulations results showed that pulsed air injection is better than continuous air injection in removing the MTBE and that the longer the OFF time is the better the MTBE removal.

Jan 1, 2008

By James P. Rider, Robert P. Vinson, Fred N. Kissell, Jon C. Volkwein, Gregory J. Chekan, Jay F. Colinet

The Thermo-MIE personal DataRAM dust monitor (pDR) is a light-scattering instrument approved for use in gassy underground mines by the U.S. Mine Safety and Health Administration (MSHA). However, the use of lightscattering monitors has been inhibited by concerns about inaccurate readings resulting from changes in dust size distribution and composition, as well as concerns about the impact of moisture in the mine air. Because of this concern, the National Institute for Occupational Safety and Health (NIOSH) has evaluated the pDR using available data from laboratory tests and mine surveys. The data show that accuracy can vary widely from test to test and mine to mine. In most cases, the results can be improved by using a companion gravimetric measurement to adjust the pDR data.

Jan 1, 2005

By D. Baker

Alternative material handling methods are allowing material handling operations to be performed with increased cost savings. This allows for higher production levels with better returns. RAHCO International Inc.'s Continuous Mining Excavator (CME) has recently received a lot of attention due in part to its operating efficiency, flexibility, and associated low operating costs. The CME is designed to perform three primary functions. These include material excavation, sizing and loading operations. In many applications, a drilling and blasting process can be eliminated. The CME was developed originally in 1985 for open pit coal mining. See figure I. Since this time, it has been proven an effective system for excavating many other types of materials including friable and sticky materials. It has also been shown to suitably handle hard rock in certain site conditions.

Jan 1, 1998

By P. R. Bridenbaugh

The products of the coming decade will possess such stringent design criteria that it is unlikely today's monolithic materials will be able to meet them. The discovery, characterization and cost- effective manufacture of a whole new generation of highly engineered materials therefore have become essential requirements for participation in the materials marketplace of the 1990s and beyond. Meeting these challenges will require advances on a broad variety of scientific and engineering fronts, including: strengthened fundamental understanding of materials behavior; composite and laminate programs offering the compatible and synergistic combination of metals, ceramics and polymers; advanced engineering and structural design techniques; processing technologies capable of producing advanced materials efficiently; and, the development of new products taking advantage of the availability and cost-effectiveness of these highly engineered, advanced materials.

Jan 1, 1986

By Steven Schurman

Acid Rock Drainage (ARD) is one of the most serious and persistent pollution problems facing today's mining industry. ARD is formed when pyrite (FeS) is exposed to natural weathering conditions. Pyrite weathering, formally the oxidation and hydrolysis of pyrite, leads to the generation of soluble, hydrous iron sulfa-salts and the production of acid in the form of H+. The resulting effluent is water that is characterized by high levels of iron (and any other metal contained in the rock undergoing weathering) as well as high concentrations of sulfate and a low pH (acid). Rocky Mountain Remediation Services, L.L.C., has developed a patents pending Envirobond'™ product, Envirobond™ ARD, to treat acid rock drainage. Treating pyrite with Envirobond™ ARD inhibits the oxidation and hydrolysis of pyrite thus curtailing the pyrite oxidation cycle.

Jan 1, 1999

By J. Girard-Dwyer, T. Camm

Direct costs such as medical, legal, administrative, and worker’s compensation costs, property damage, lost earnings, and lost benefits are typically used to compute the economic impacts of occupational injuries. However, there are also a number of less obvious, indirect costs that substantially contribute to the overall loss costs. In fact, for every $1 of direct costs an estimated $3 to $5 of indirect costs are also incurred. This paper presents a systems approach that incorporates engineering, economics, psychology, and sociology in order to evaluate the total value of investments in safety. By studying the interrelated system comprised of the injured worker, their family and coworkers, as well as the organizational structure that was the setting for the incident, a methodology can be developed that will more accurately capture the true costs of mine injuries.

Jan 1, 2004

By C. L. Karr, E. J. Gentry

Researchers at the U. S. Bureau of Mines have developed a control algorithm to efficiently manipulate chaotic systems. The control, based on both fuzzy logic and genetic algorithms, prescribes actions that drive the chaotic system to acceptable regions of state space. The use of fuzzy logic enables a person who has limited experience with a chaotic system to establish a set of rules for manipulating the problem environment, and a set of membership functions that define terms used in the rule-set. Genetic algorithms are search algorithms based on natural genetics, and are used in the control algorithm to select membership functions that provide for a suitable level of control. The Bureau-developed algorithm controls the computer simulation of a ball bouncing on an oscillating table, a system that exhibits chaotic behavior.

Jan 1, 1993

By M. Ericsson

The extractive industries consist of five major sectors: - Mining equipment and services - Dimensional stone - Industrial minerals - Aggregates - Metal mining These industries produce some finished goods but mostly semi-finished products as they feed into other industrial sectors: Basic metals, fabricated metals, construction, chemicals, dyes and pigments, inorganic chemicals, fertilizers, rubber and plastics and non-metallic mineral products. These are the major down-stream industries in this study. Taken together with the extractive industries they form the mineral resource based cluster. The mineral resource based cluster is a substantial part of the Finnish economy: It employs 211 000 persons, 39% of the number of employees in industry. The cluster?s exports account for 20% of industry exports. Value added is 34% of total value added in industry. Investments reach 35% of total industry investments.

Jan 1, 2003