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By Brooke T. Mossman

Asbestos fibers are highly fibrous silicate fibers that are distinguished by having a large aspect (length to diameter) ratio and are crystallized in an asbestiform habit that causes them to separate into very thin fibers or fibrils. These fibers are distinct from nonasbestiform cleavage fragments and may appear as thick, short fibers which break along cleavage planes without the high strength and flexibility of asbestiform fibers. Since cleavage fragments of respirable dimensions have generally proven nonpathogenic in animal studies, little data exists on assessing well-characterized preparations of cleavage fragments in in vitro models. The available studies show that cleavage fragments are less bioreactive and cytotoxic than asbestiform fibers. © 2007 Elsevier Inc. All rights reserved. Keywords: Asbestiform; Cleavage; Fibers; Fibrous

Jan 1, 2007

By E. F. Schnitzer, D. R. Haight, G. T. Krogman

The 1997 New Year’s Day Rogue River flood near Medford, Oregon, USA, entered historic channels, eroded a 150-foot-wide buffer, and captured an inactive gravel pond located within the channel migration zone. Channel redirection caused by pit captures threatened adjacent inactive gravel ponds. In response to this capture, a stakeholders group of concerned individuals and organizations was formed. This group ultimately developed a rehabilitation plan, which conformed to the Rogue River’s geomorphic trends. A two-dimensional model, FLO-2D, was used to evaluate channel splits, flood storage, backwater, and future conditions. Modeling results coupled with trend analysis were used to create a stable design where stream barbs, gravel redistribution, a channel outfall spillway, bendway weirs, bank reshaping, and revegetation were integrated into a single plan for a three-mile reach. The quick action by the stakeholders group averted further damage to the Rogue River system and surrounding environment. The project has preserved three miles of mainstem habitat, one mile of side channel habitat, and protected ten gravel ponds from pit capture.

Jan 1, 2006

By Wendy M. Brunner

A 70% excess of mesothelioma, an asbestos-related cancer, has been reported among men in northeastern Minnesota, where iron mining has been the major industry. The Minnesota Department of Health has studied iron miners who developed mesothelioma to identify possible sources of asbestos exposure. A database of all Minnesota residents diagnosed with mesothelioma between 1988 and 1996 was linked to a database of approximately 72,000 current and former Minnesota iron-mining employees to identify cases who had ever worked in the mining industry. The job histories of the cases were examined to determine if any of their jobs could have involved exposure to commercial asbestos. Seventeen individuals diagnosed with mesothelioma in Minnesota between 1988 and 1996 were found to have worked in the iron mining industry. Of the 15 for whom adequate work histories were available, 14 had identifiable sources of exposure to commercial asbestos in jobs held both inside and outside of the mining industry. The time between employment in these asbestosexposed occupations and the diagnosis of mesothelioma is consistent with the 20 or more year latency period that has been observed in other studies of this cancer. © 2007 Elsevier Inc. All rights reserved. Keywords: Mesothelioma; Asbestos; Iron miners; Taconite; Epidemiology; Case series

Jan 1, 2007

By Paul Nicholas, Raju Gottumukkala

"India’s economy is expanding with rapid urbanization. Improvement in infrastructure is a keystone to the Indian government’s economic plans, including expansion of transit systems. Most of these systems are designed with elevated and underground sections. New Delhi, a city of 23 million people, suffers from heavy traffic congestion and pollution. The transit (metro) system is seen to be of critical importance. Phase 3 of the Delhi transit system project is 140 kilometers (km), with 40 km of twin-bore tunnels requiring 35 tunnel boring machines (TBMs) for construction. Transit systems are also under design or construction in Chennai, Bangalore, Kolkata, Hyderabad, Jaipur and Mumbai. Most have twin-bore tunnels. At present, 55 TBMs are operating on underground metro construction, and future projects will increase this number. This paper highlights the unique challenges of construction of underground metro systems in highly congested urban environments, using Kolkata and Delhi systems as examples. INTRODUCTION The first transit system in India was constructed in Kolkata (India’s third-largest city by population.) This line is 28 kilometers (km) in length, has underground and at-grade sections, was built in phases, runs north/south, and has 24 stations. This project was sanctioned in 1972, started construction in 1984, and was completed in 1995. The tunnels were constructed primarily by cut and cover methods with some open-face, compressed air shield tunneling. In 2006, the urban transport policy recommended construction of transit rail systems in all urban cities with a population exceeding 2 million. Further, in 2014 the central government stated that it would assist in financing transit systems in all cities with a population of over 1 million. In 2015, the central government approved the development of transit systems in 50 additional cities across India with a budget of $75 billion (see Figure 1). Transit development is just part of a huge expansion in planned rapid transport systems, which include metro, bus, high-speed rail, and monorail systems. Metro systems will include elevated and underground sections with twin-bore tunnels and underground stations. In the Delhi/National Capital Region (NCR), now the largest city in India by population, Delhi Metro Rail Corp (DMRC) was formed in 1995 as a joint venture company between the central government and Delhi state. DMRC operates the Delhi metro system. (see the case studies described later in this paper). DMRC has developed an external function to carry out studies and to offer consultancy to other cities planning transits. Since its inception, DMRC has produced Detailed Project Reports (DPRs) for every metro and monorail project in India. In 2012, DMRC became a partner in the management consultancy for Jakarta Mass Rapid Transit System, its first project overseas. DMRC became a model organization for other cities to follow. These cities have included Chennai, Hyderabad, Kolkata, Bangalore, Jaipur, Mumbai, Ahmedabad, and Nagpur. Other cities (e.g., Lucknow and Patna) are in the metro planning phase. Metro systems are under construction or partially operating in Hyderabad, Bangalore, and Jaipur."

Jan 1, 2016

Paper and paperboard manufacturers need to quantify the carbon footprint and environmental impact of their products to satisfy market, social and government demands. Coated paper products contain minerals, such as kaolin and calcium carbonate, at significant levels; some coated paper grades have mineral contents as high as 45% by weight. Some uncoated paper has no mineral content, but most uncoated paper contains some mineral to improve appearance, process efficiency and cost. Super-calendared paper grades can contain levels of mineral up to 35% by weight. This paper describes how to calculate the carbon footprint of kaolin and calcium carbonate minerals used for white pigments. The carbon footprint of these minerals strongly correlates to the primary energy sources, final product form and energy used to calcine kaolin and lime. Kaolin and calcium carbonate pigments have a favorable impact on the carbon footprint of paper and paperboard products by directly substituting for fiber and by reducing the energy needed for paper making. Key words: Kaolin, Calcium carbonate, Paper production, Carbon footprint, Lifecycle analysis

Jan 1, 2010

By M. L. Matt

The Pittsburgh Safety and Health Technology Center of the Mine Safety and Health Administration has developed the Mine Emergency Responsiveness Development (MERD) program to improve the reaction and response of mine personnel in mine emergency situations. The MERD program simulates problems that may be encountered in underground mine fires, underground mine explosions or surface mine accidents. Since its inception in 1982, the MERD program has been presented to MSHA, Industry, Labor and State Government Personnel. The program is extremely versatile and is easily adapted to suit various training requirements. It gives the participants the opportunity to experience some of the emotions, frustrations and successes of a mine emergency in a controlled environment without having to be involved in one. Past participants have indicated that this training has better prepared them in actual emergency situations through increased awareness and advanced preparation of plans and resources. In 1992, a Mine Simulation Laboratory, which simulates a coal mine and metal/nonmetal mine, was built to improve training for mine emergencies and prevention and fighting of mine fires. This facility has been included in the MERD Program to provide realistic and practical training for mine rescue teams and MERD participants in advanced mine emergency operations. This paper presents an overview of the MERD program.

Jan 1, 1993

By K. P. Wang, Ta M. Li

The Chinese energy and mineral industries are readying themselves for a period of dynamic transition, unprecedented in the country's long and sometimes turbulent history. The transition comes as a result of the government's new program of "Four Modernizations" in its agricultural, defense, industry, and science and technology sectors. The announced program is generally considered by Western observers to be a moderate, pragmatic approach to get China on the road to industrial parity with Western nations by the year 2000. The game plan calls for integration with the West to beef up Chinese know-how and the purchase of foreign technology to supplement areas where China lacks the ability to do so itself. While the role of energy and minerals is not specifically mentioned in the program, it was made clear to ME that China realizes the basis of any sustained modernization program is tied closely to the health of its minerals sector. Various published reports have indicated the existence of an already vibrant energy and minerals sector with world rank production in coal, iron ore, tin, antimony, cement, pyrite, asbestos and tungsten to name just a few. For the most part, except for the export metals, the primary focus of China's production has been on fulfilling domestic needs. Now the new initiatives are aimed not only at self-sufficiency, but also on propelling the country's natural resource clout into international prominence. With a mineral resource base that is considered by many westerners a potential bonanza, China's new long march toward modernization will be an exciting adventure, well worth watching. Big Projects Spark Excitement China's renewed commitment to a more liberal program is as much a desire to "walk on its own two legs" as it is a backlash from the frustrating years that followed the Cultural Revolution of the 1960s and early 1970s. Much of the early excitement was initiated by China's Premier and Party Chairman Hua Guo-feng in speaking to the fifth National People's Congress (NPC) in 1978. Here, Chairman Hua presented the Communist Party's 10-year blueprint for economic development. Specifically, the Party's plans called for completion of 120 large-scale industrial projects by 1985. Mentioned were 10 new iron and steel works, 30 power plants, six new railways, 10 oil and gas fields, nine nonferrous metal

Jan 3, 1980

By Paul O. Knorr

The Bureau of Ocean Energy Management (BOEM), a bureau within the U.S. Department of the Interior, has responsibility over both energy and non-energy mineral development on the United States Outer Continental Shelf (OCS) under the OCS Lands Act (“OCSLA”). BOEM’s Marine Minerals Program (MMP) manages federal offshore mineral deposits through non-competitive, negotiated agreements for sand and gravel (“sand”) used in coastal restoration efforts and the competitive leasing of critical and hard economic minerals (“critical minerals”). As the steward of OCS critical minerals, BOEM MMP is responsible for understanding where critical minerals are located, identifying and understanding their environments, managing activities that affect these resources, and implementing pertinent federal policies. Fulfilling these responsibilities involves the collection and analysis of environmental, geological, and geophysical data; supporting the science needed to understand the impacts of resourcerelated authorized activities on the biological, physical, and sociocultural environments; encouraging emerging technologies that can reduce the environmental impact of activities; and communicating with stakeholders to foster an understanding of existing federal regulations and potential needs to revise the legal framework. Four U.S. federal rules in the Code of Federal Regulations (CFR) currently inform MMP’s procedures: 30 CFR 580 (prospecting for minerals), 30 CFR 581 (leasing of minerals), 30 CFR 582 (operations in the OCS related to minerals), and 30 CFR 583 (negotiated noncompetitive agreements for sand). Other federal laws and regulations are also pertinent, particularly those supporting the National Environmental Policy Act, Endangered Species Act, National Historic Preservation Act, Marine Mammal Protection Act, Coastal Zone Management Act, Clean Air Act, Federal Water Pollution Control Act, and Magnuson Stevens Fishery Conservation and Management Act.

Feb 22, 2026

By M. Canty

Results are presented that were gathered during pilot-and field-scale testing of an innovative technology, sulfate-reducing bacteria (SRB), designed to treat and control acid mine drainage (AMD). The project was performed under the Mine Waste Technology Program (MWTP), which is funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by the EPA and the U.S. Department of Energy through an Interagency Agreement. The MWTP is implemented by MSE, Technology Applications, Inc., located in Butte, Montana. Sulfate-reducing bacteria, a common group of anaerobic bacteria, produce hydrogen sulfide and bicarbonate when supplied with sources of carbon and sulfate. Hydrogen sulfide reacts with metal ions in AMD, precipitating them as metal sulfides; the bicarbonate serves to help neutralized the drainage. Pilot-scale testing was performed within eight packed-bed reactors at a temperature representative of a field application of this technology in a northern climate, nominally 8°C. The reactors, packed with an organic substrate, were operated continuously in upflow configurations receiving AMD at a flow rate corresponding to a 5-day retention time over a test duration of 60 days. During this time, numerous physical and chemical parameters were monitored. Pilot-scale metal removal efficiencies reached 99% for zinc, 99% for aluminum, 96% for manganese, 98% for cadmium, and 96% for copper. Iron and arsenic removal was not as effective as the aforementioned metals, which was largely attributed to the high levels of iron and arsenic contaminating the organic substrate. Evidence existed that both adsorption and sulfate reduction were occurring within the reactors.

Jan 1, 1998

By J. P. Stone

The Mining Regulatory Affairs review arrived in time for the May issue. The Managing Editor inadvertently buried it in one of his paper piles. Regulatory developments at the federal level involving the minerals industry solid waste disposal under the Resources Conservation and Recovery Act (RCRA) remained at the forefront of concern. The Environmental Protection Agency (EPA) received public comments on two major documents. One was a strawman draft rule covering wastes from mining and beneficiation. The other was a report to congress covering selected mineral processing wastes. The regulation of minerals industry waste management is moving forward on parallel paths. Mining and beneficiation waste is somewhat further advanced.

Jan 1, 1991

By K. B. C. Brady, B. E. Scheetz, J. E. Cuddeback, T. W. Bergstresser, W. A. Telliard, S. C. Parsons, R. J. Hornberger

Two weathering procedures are being developed by the Acid Drainage Technology Initiative in cooperation with federal agencies(OSM and EPA). Objects are to: (1) standardize existing humidity cell and leaching column procedures; (2) improve test methods by maintaining a carbon dioxide enriched environment needed to optimize carbonate mineral dissolution, and quantifying particle size variables to evaluate reaction kinetics, and (3) provide flexibility in test method implementation consistent with EPA guidelines for Performance-Based Measurement Systems. Preliminary results indicate the CO2enriched leaching environments produce alkalinities that are similar to field observations and greater than the tests run under atmospheric PCO2. Leaching columns produce higher alkalinity than humidity cells.

Jan 1, 2003

By Fredrick Fränding

In mining and quarrying operations, electric motors can fail for a variety of reasons. Some failures are directly linked to demanding production requirements and contaminant-laden environments and, consequently, are difficult to prevent. A sizeable number, however, are caused by ?offline? factors that have nothing to do with production. These include inadequate or substandard motor repair practices and improper motor shipping, storage and installation. The fact that failures are at times attributable to repair- or rebuild-related errors and problems raises the stakes when selecting an electric motor repair provider. Teaming with high-quality electric motor shops can help a company reduce failures due to offline factors, improving motor reliability and cutting downtime costs. Regardless of location or annual revenues, the best motor shops have similar business cultures and share many of the same characteristics.

Jan 1, 2009

By R. Hedin, M. Dunn

The Pennsylvania Department of Environmental Protection (US EPA 319 program) provided funding to aid a public-private effort in the installation of an environmentally-friendly system to treat abandoned mine drainage at Jennings Environmental Education Center (Pennsylvania Department of Conservation and Natural Resources). Through this cooperative effort among state and federal agencies, mining, excavation, and environmental companies, college and home school students, Girl Scouts, and volunteers, a successful multi-component passive system, readily accessible for upgrades and public education/research activities, was built. 90 people were directly involved in construction of this award-winning system and about 1000 people annually benefit from the educational opportunities.

Jan 1, 2002

By W. Collingwood

As openpit mines continue to grow deeper and productivity continues to increase, the management of respirable dust and noxious gases can become a challenge. The natural wind flow in openpit mines is often recirculatory. This recirculation traps dust and gases in deep openpit mines. This problem is particularly acute in high-latitude openpit mines, due to a phenomenon known as atmospheric inversion. In the winter, arctic and subarctic regions experience short days and long nights. This deficit of solar radiation creates a situation in which cold, still air accumulates near the bottom of the pit. In openpit mines, this can result in unhealthy accumulations of gases and other contaminants. In this study, the natural wind flow patterns in and around openpit mines were investigated using a computational fluid dynamics (CfD) program. Two-dimensional models were created for a variety of pit geometries. The effect of depth, slope angle and wind speed on the recirculation pattern in the pit was examined.

Jan 1, 2012

By A. Toulet

Mining in Mexico has an immensely long tradition. In his first letter reporting to his sovereigns from Mexico in July 1519, Hernan Cortes wrote, "To our mind it is probable that this land contains as many riches as that from which Solomon is said to have obtained the gold for the temple ... " 1 But not only precious metals drew his attention; in 1524, short of tin needed for casting guns, he found it in Taxco. As an added bonus, those who went to find it "came upon a vein of iron which according to experts is of exceeding richness." 2 Since then, the mines of Mexico have yielded up enormous amounts of mineral and continue to do so. Mexico is one of the ten principal producers of minerals world-wide both in production volume and diversity. 3 Tens of thousands of tons of iron, sulphur, and coal come from its earth annually; it is the world's second largest producer of barite; third of antimony, fluorite, and graphite. 4 Copper, zinc, silver, molybdenum, arsenic and cadmium and others are wrested from its mines. The wealth is there; but maximizing its potential requires investment, technology, and markets that the government cannot itself provide. Thus mining, since the Mexican Revolution severely restricted by both law and policy, today looks to private investment to develop its potential. Beginning in 1989, Mexico's government cautiously moved to liberalize private sector involvement in mining; 5 using the experience gained from these initial regulatory changes, the current new Mining Law was adopted in 1992 6 and new Regulations were promulgated in 1993. 7

Jan 1, 1994

By Kenneth A. Grace

Each and every mining operation from a simple sand-and-gravel pit to the largest integrated mine-mill-concentrator-smelter-refining complex has, as its foundation, a quantity of extractable natural resource the reserves. Without reserves, there is no mine, and any concentrating or extracting plant, no matter how sophisticated, is simply so much scrap metal. And, of course, without resources there are no reserves. It is remarkable, therefore, especially in this age of careful planning, high quality engineering, and state-of-the-art financial analysis, that such a fundamental and vital item is so little understood and the subject- of so much confusion. Time and time again it has been the experience of the author, when called in to a mining operation that has run into trouble in reaching projected production targets, to find that the designed-for tons were not reaching the concentrator/extraction plant, and/or the grade of such tonnage was substantially below the forecast and design grade of the plant. The mill blames the mine for delivering below standard tons and/or grade and the mining engineer blames the geologist for overly-optimistic assessment or incorrect interpretation of the deposit. The geologist blames the mining and metallurgy division for wrongly interpreting his data and conclusions, or simply fouling-up a fine orebody.

Jan 1, 1983

By J. L. Sloughfy

The size distribution and mechanical strength of the iron ore pellet burden are important parameters in determining the efficiency of the blast furnace. From the very outset, the guiding principle of our pellet quality improvement program was that these parameters are also the key to improving productivity and cost control at the pellet plant. Recognizing the need for improved blast furnace burdens and for higher productivity and lower costs at the pellet plant, Carol Lake operators, in conjunction with the IOC Pellet Quality Committee, established the following goals for the improvement of Carol pellets: [ ]

Jan 1, 1981

By John S. Lagarias

While systems to remove sulfur oxides from flue gases have been used at coal fired power plants since 1931, critical need for flue gas desulfurization has only occurred since the late 1960s following the passage of the Clean Air Act Amendments. Commercial and advanced flue gas desulfurization processes (FGD) are reviewed. Advantages and disadvantages of the processes are discussed. Regulatory requirements leading to the development of FGD systems are identified. The location and operation of coal fired plants may be determined more and more by the regulatory requirements for sludge disposal, waste, water discharge and air emissions.

Jan 1, 1978

By Steven I. Olson

Since the introduction of froth flotation, the Florida Phosphate Industry has faced the challenge of coarse particle -850 +425µm (-20 +35 Tyler mesh) beneficiation. Several techniques have been used to upgrade this difficult size range. This paper discusses one approach that has met with success; namely, improved fractional recoveries through enhanced areation and improved material transport characteristics via larger than standard flotation cell mechanisms.

Jan 1, 1981

By Paul I. Eimon

Mineral exploration involves the selective collection, organization, evaluation, and interpretation of geologic and economic data. The sources for such data are original field observations and existing documented information of various types (publications, reports, maps, company files, etc.). As exploration data are accumulated, their storage, organization, indexing, and J retrieval is key to exploration progress. Initial use of computers by mineral exploration groups indicates that data can be meaningfully handled by machines. A computer system makes possible: 1) the storage, manipulation, collation, and selective retrieval of data; 2) the utilization of data banks developed by geologic service groups and available at relatively low cost; and 3) the retrieval of stored data more rapidly, completely, and effectively than by manual systems. Profitable utilization of these capabilities is conditioned by several factors, particularly by the information selected for the system data base and by the design of the computer system itself.

Jan 1, 1968