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By Everett M. (Original by) White

Numerous articles have been written about the coal mine ; he has been compared with brave men who have gone out to conquer some unknown hazard throughout the ages. Now, however, modern mining is no longer something to be avoided, but a vocation that anyone can be proud of, with remuneration equal to or above that of almost any industry. A concerted effort is being made each day by both the operators of most mines as well as the state and federal inspectors to see that coal mines are as safe or safer than work places in any other industry. How- ever, it is true that mine fires and explosions have occurred in the mining industry since its inception. One of the earliest accurate references to such an occurrence is found in the transactions of the Royal Society of London. In the Colliery Managers' Handbook, 1898, Caleb Pamely writes of an explosion that occurred at Fatfield, England in August 1708, resulting in the deaths of 69 persons. He states: "Three of them, viz, two men and a woman, were blown quite up from the bottom of the shaft, fifty-seven fathoms deep, into the air, to a considerable distance from the mouth of the pit." It is interesting to note that women were employed as miners in England during that period. In the United States, the first record of coal mined was in 1702 by the Jamestown colonists. In 1786, about 20 years after Pittsburgh, PA was first settled, a charter was granted by William Penn to mine coal on the banks of the Monongahela River. Then in 1803, the first important coal company, the Lehigh Coal Co., was established. From this beginning, the mining industry continued to grow in importance and the first state mining law was formulated in 1870. The Pennsylvania state mining law was followed in 1873 by Ohio's, and in 1876 by Maryland's. A mine explosion at Avondale, PA in 1869 stimulated state legislatures to formulate these early laws. In 1907 near the town of Fairmont, WV, there were, within three days, two explosions resulting in a total of 597 deaths. Because of this, the federal government took action and by 1910, the US Bureau of Mines had been established. This was perhaps the most significant change in health and safety for miners during the first half of the 20th century as the USBM concentrated its entire efforts in the study, research, and testing of methods totally directed towards improvement of the health and safety of the miner. After a mine disaster in Illinois, a federal law was passed in 1940 calling for federal coal mine inspectors. Then in 1969, Congress enacted the Federal Coal Mine Health and Safety Act following a mine explosion near Farmington, WV. In 1977, the law was revised and included noncoal mining operations.

Jan 1, 1981

By E. L. Reed

This paper addresses the state and federal permit- ting requirements and regulatory constraints associated with the development of new "grass roots" surface coal mines in the Western United States. Since a major portion of new coal development in the West will be on federally leased coal in Wyoming, my comments are directed towards that geographical area. This will give the reader some insight into the current regulatory framework within which western mining companies must operate-i.e., the major applicable state and federal laws and regulations, the more important state and federal regulatory agencies, and the major construction and operating permits that are required. Before discussing the impact of the regulations on our business, I would like to tell you something of my company and then briefly discuss Exxon's forecast of the long range outlook for coal. Carter Mining is an Won affiliated surface coal mining company. Exxon became interested in the coal business in the mid 1960's with the recognition of the future need for alternative fuel sources. Since that time, it has acquired coal reserves located in Wyoming, Montana, North Dakota, Arkansas, Texas, Illinois and West Virginia. Carter's first surface mine, the Rawhide Mine, located north of Gillette, Wyoming began production in August, 1977. Our second surface mine, Caballo, located just south of Gillette, began operating last October. We have a third block of federally leased coal just east of Gillette. By 1985 we anticipate Carter's western surface mines will be producing at an annual rate of 30 million tons, subject, of course, to successful market development efforts and regulatory considerations. Rawhide will ultimately have a permitted capacity of 24 MM tons per year. The coal at Rawhide is in two seams; one 80 feet in thickness and the other 20 feet (including a 6 to 10 foot parting). A large shovel is used to remove the overburden, and a similar shovel and dragline are used to mine the coal. Caballo has a 75 foot seam; otherwise it is similar in design and operation to the Rawhide Mine.

Jan 1, 1979

By David P. Kimball, Dalva L. Moellenberg

On May 21, 1990, EPA released its Strawman II draft program for mining wastes. It proposes to expand RCRA regulation of mining operations to include materials other than wastes. Strawman I1 would establish strict standards for the states to follow, rather than technical guidance. It proposes to establish performance standards; design criteria; monitoring requirements; and corrective action, closure, post-closure, and financial assurance requirements. It suggests "pollution prevention" concepts for mining operations. This paper explores the Strawman II proposals, particularly the technical criteria, and addresses several of the important concerns raised by industry.

Jan 1, 1991

"The National Mining Hall of Fame and Museum (NMHFM) announced the class of 2019 National Mining Hall of Fame inductees. This year’s inductees, selected by the National Mining Hall of Fame’s Board of Governors, represent exceptional financial acumen in assembling several operations that formed the basis of a successful American mining company; conception and development of equipment which contributed to improved efficiency and mine safety; and unrelenting advocacy for the U.S. mining industry and its workers. These individuals, selected for being determined, forward-thinking innovators, doers and leaders have propelled the industry toward vastly improved safety and social responsibility.The Prazen Living Legend of Mining Award, named for renowned mining artist Gary Prazen, will also be presented at the ceremony. This award recognizes an individual or organization for significant and sustained commitment to educating the public about the relationship of mining to our everyday lives through educational materials, programming, and outreach.2019 National Mining Hall of Fame inducteesFrank Calandra, Jr. has devoted more than 50 years to the mining industry and he is an icon in ground control technology for the mining, tunneling and civil construction industries.From the ground up, his passion, sweat equity and shrewd business acumen have grown Frank Calandra, Inc. (FCI) and Jennmar from a single plant in Pennsylvania to a world-class enterprise with 25 plants employing thousands globally. As evidenced by Calandra’s more than 20 patents on ground control devices (not to mention the additional 80 patents his companies hold), his innovation and commitment to safety have made underground mining safer and more efficient. In the late 1970s and early 1980s, Calandra was instrumental in upgrading American Society for Testing and Materials (ASTM) standards in roof control for both state and federal regulations. Through his work with industry associations such as the National Mining Association, National Coal Council and Center for Energy and Economic Development, among others, Calandra has contributed his time, expertise and financial support to ensure a balanced political and regulatory climate for mining. Calandra is an inductee of the West Virginia Coal Hall of Fame."

Aug 1, 2019

By Carl (Original by) Hrovatic

Land is a precious resource and should be treated as such by all members of our society. The soil covering this earth is only a very thin outer layer, varying in thickness from a few inches to a few feet and covering the rocks and minerals lying beneath the surface. The wise use of this valuable commodity is the responsibility of everyone. Many everyday activities disturb e earth's surface. Examples are highway construction, housing and commercial developments, agriculture, and various types of mining. This chapter discusses the relationships of the environment to land as it applies to surface operations in the coal industry. Mining by surface methods disturbs, for a brief period of time, thousands of acres of land annually. In addition, refuse piles, slurry ponds, abandoned mine structures, unprotected mine openings, and unsightly cleaning plants can also adversely affect land unless properly handled.

Jan 1, 1981

By Thomas P. Meloy

Theoretical development of comminution models has come about in the last 10 years. These models assume that the material being broken is homogeneous and that the compression or energy wave is uniform throughout the specimen. Obviously, this is not the case because most comminuted materials are rocks with either many phases and/or definite grain size. The mathematical models deriving the size distribution of daughter fragments resulting from the comminution of brittle, single particles are of two schools. The first model, proposed by Gilvarry in 1961, was based on the concept of volume, surface, and edge flaw activation. The second, proposed by Meloy in 1960, was based on the concept that the crack density is a function of the energy in the comminution wave. The flaw theory has run into increasing theoretical problems and is now being abandoned. On the other hand, the crack density theory has been expanded and has successfully considered the case where there are inhomogeneities in the comminutive wave. However, the main constraint of a homogeneity in the solid being comminuted has hitherto never been overcome. In this paper, a very general derivation of the crack density model is made for inhomogeneous solids by replacing the assumption of homogeneity with an arbitrary function, P(y), which describes the susceptibility of the material to comminution as a function of position. The restraints on this function, P(y), are very broad and, hence, the derivation is extremely general. General use of the equation derived necessitates a detailed a priori knowledge of both the fracture process and of the physical properties of the material being fractured; this knowledge is expressed in open form as, P(y), the linear probability density that a plane of fracture intersects at point y on an arbitrarily oriented line segment of total length xo through the original particle. From these assumptions, a general expression for the cumulative mass distribution of particles resulting from fracture is then postulated. It is: [ ] where, B(x), is a cumulative mass of material finer than size x, r is the average number of crack,, (y), is defined above and xo is the initial particle size. It is shown that suitable assumptions reduce the expression to the theoretical results of Gaudin and Meloy and to special forms of the empirical equations of Rosin-Rammler, Gaudin and Schuhmann. Semi quantitative agreement is demonstrated by Grimshaw with experimental results of a very complex fracture of heterogeneous sandstone blocks. A need is expressed for more theoretical development of P(y), and a more extensive experimental study of both homogeneous and heterogeneous fracture. The full mathematical derivation is presented for the first time in this paper. The general implications of the equation and its application are also discussed.

Jan 1, 1968

By R. Y. K. Yang, O. Olajide, E. H. Cho

"This study focuses on partial leaching of coal pyrite with sodium sulfite in order to increase its degree of liberation from the coal matrix, which might help to increase the removal of coal pyrite, together with trace elements of arsenic (As), selenium (Se) and mercury (Hg) by froth flotation. The U.S. Bureau of Mines’ two-stage reverse flotation process was applied to further reject coal pyrite in the second stage, where pyrite was floated while coal was depressed. The results show that the leached coal flotation with sodium sulfite produced lower pyritic sulfur content in the clean coal by approximately 25% compared to the flotation of unleached coal. The synergism mechanism between the leaching and the two-stage flotation is delineated. The rejection of trace elements (As, Hg and Se) after the two-stage flotation process with unleached coal followed approximately that of pyritic sulfur (64.6%). However, after the two-stage flotation with leached coal, the rejection of Se was as high as that of pyritic sulfur (77.9%), while the rejections of As and Hg were 20% lower than that of pyritic sulfur, or followed approximately the same rejections obtained through the two-stage flotation with unleached coal.IntroductionSO2 is a reducing reagent, but when it is combined with oxygen in an acidic solution, it will become a strong oxidizing reagent for leaching coal pyrite. Sundaram et al. (2001) found that the reagent could leach coal pyrite to produce ferric iron, which, in turn, catalyzed the oxidation of SO2. Similarly, Cho et al. (2009) found that the reagent could leach pyrite as well as mercury from coal. In the present study, coal was preconditioned by partially leaching coal pyrite in water-coal slurry with sodium sulfite at 48° C. The partial leaching of coal pyrite may enhance its degree of liberation from the coal matrix and give a chance to be rejected more effectively during the flotation.The two-stage U.S. Bureau of Mines’ reverse flotation process (Miller, 1975) was used in this study. The first stage is conventional flotation, in which coal is floated while material with higher ash and pyrite content remains in the cell. Kerosene is used as a promoter to float the coal and MIBC (methyl isobutyl carbinol) is used as a frother. In the second stage, the floated coal from the first stage is depressed using a starch-based reagent, while coal pyrite is floated using potassium amyl xanthate. In this second stage, the liberation of coal pyrite from the coal matrix seems to be an important factor for successful rejection of coal pyrite."

Jan 1, 2015

By E. J. Mayhew

Bentonite and newly discovered deposits of sepiolite, saponite, and hectorite are now being processed and marketed from the Amargosa Valley of Nevada. All of these deposits are large. The bentonite has been known for decades and is the whitest known. The only other sepiolite deposit is in Spain. The only other commercial hectorite deposit is at Hector, California. No other saponite deposit is known. All the components except bentonite are hydrous magnesium silicates. The bentonite is mixed layer Na-Ca. All the materials have characteristics unique to their locale and type, such as high yield point for drilling muds and liquid suspending agents. The sepiolite has geothermal stability. Figure 1.

Jan 1, 1979

By Sam Lo Grasso, Carlos Herranz Calvo, Stuart Warren, Ted Giesing, Charles Marchesano

Mott MacDonald and Project Management Advisors are providing Technical and Project Management services for San Diego County for the Courthouse Commons Project. The Courthouse Commons Project involves the redevelopment of three downtown blocks owned by San Diego County and construction of an Inmate Transfer Tunnel between the County Central Jail and the San Diego Central Court. The tunnel will be 327 feet long, crosses the San Diego Fault and is being constructed using the Sequential Excavation Method (SEM). This paper discusses the history and procure‑ ment strategy for the project, the technical aspects of the transfer tunnel and the con‑ struction progress of the tunnel to date.

Jun 13, 2021

By Diler Katircioglu-Bayel, Oner Yusuf Toraman, Safak Gokhan Ozkan

Calcite has found many applications in the industrialized countries recently, such as filler for paper, paint, plastics, rubber and food. Furthermore, calcite separates many toxic elements, and thus it is used in water treatment, and it is also used to raise the pH of drinking water. Due to its special features, calcite has been characterized as a useful coating and reinforcement filler for applications. Finer particle size of calcite has been determined to provide improved features for all of these applications. For submicron particle production, wet milling is selected over dry milling to produce finer particle sizes. Wet stirred media mills are also used in many industries. For that reason, this study investigated the effects of operating parameters on particle size reduction in the wet grinding process. The knowledge acquired by this study will allow the finding of optimal operating parameters for a stirred media mill to optimize specific energy consumption and reduce particle size.

By James W. Estep

The sulphur shortage that has occurred in the past two years has directed attention more and more toward sour natural gas reserves, Wellhead values of sour gas vary widely depending upon the acid gas composition, location, market conditions, and necessary processing charges. Preparation of a saleable residue gas is considerably more involved and expensive than that normally encountered in treating a sweet gas. Recent revisions in sales gas specifications have increased capital costs and processing charges. The presence of hydrogen sulphide and carbon dioxide in a natural gas contributes to shrinkage factors that may approach 50%. Fuel required by the gas sweetening process and sulphur slant tail gas incineration also contributes to a further reduction in the volume of residue gas available for sale. The additional processing facilities involving gas sweetening, mercaptan removal, expanded utilities, sulphur recovery and sulphur handling, all demand additional operating and maintenance staff. A favorable sulphur market under certain conditions may justify the processing of sour gas whereby sulphur is either a by-product or a co-product, Five typical cases involving different compositions of sour gas are presented for evaluation. Capital costs, operating problems, and operating costs are presented in detail for full economic evaluation

Jan 1, 1967

By G. Bylapudi, A. Bhagwat, K. Mondal, A. J. S. (Sam) Spearing

Minimizing the effects of corrosion improves the long-term performance of the rock anchors and ground control systems in underground mines, which is fundamental for safe operation over the design period. The primary objective of this study is to explain the problems due to stress corrosion cracking (SCC), strain-induced corrosion cracking (SICC) and other forms of corrosion, and why the mining industry’s ground control professionals should take this into serious consideration. It is important to clearly determine the kind of SCC mechanisms that causes roof bolt failures in order to suggest the necessary action plan to mitigate or eliminate the possibility of the cause. Pertinent literature and studies around the globe on this complicated subject are reviewed. The secondary objective is to encourage the use of corrosion-resistant ground control products in the underground mining industry in areas of high corrosion potential. Characteristics of SCC on high strength steel are also reviewed. The literature and preliminary studies to date indicate that research work is necessary in United States.

Jan 1, 2015

By Feridon Ghadimi, Saeed Mojeddifar, Massume Khavari

Separation of geochemical anomalies from background is an important and essential issue in the exploration of mineral deposits. Statistical methods are used to separation of anomaly from background. Fractal/multifractal and singularity methods are very suitable for the separation of weak anomalies. For interpolation, various methods could be used such as most distance-weighting methods, kriging, spline interpolation, interpolating polynomials, and finite difference methods. This paper addressed application of multifractal techniques together with finite difference procedure to detect the anomalous regions. Fractal models such as concentration–area, spectrum–area, and singularity index model were selected to identify Pb–Zn anomalies. In this research, 170 samples from 33 boreholes were taken in the Haft-Savaran area and analyzed for determination of Pb–Zn anomaly. Singularity method was a suitable method for separating Pb and Zn anomalies. Also, the results showed that the geochemical anomaly has occurred along NE–SW trend and is consistent with the sulfide mineralization process and the faults of the region.

May 18, 2020

By H. R. Manouchehri

In flotation practices, as particles become finer, such as smaller than 20 μm, process efficiency declines markedly. Selective agglomeration of fine particles is a technique to enhance the recovery of fine valuable minerals in flotation circuits. Different agglomerating methods have been introduced and tested. One method that has recently received much attention is to make use of magnetic force to aggregate fine particles. A selective aggregation of fine paramagnetic particles, such as sulfide minerals, can be achieved in the high-intensity magnetic field prior to or during flotation. The method is simple, selective and effective for fine particles and has low operational cost, though a minimum magnetic susceptibility for fine grains is required to promote the process. In this paper, the implementation of the ProFlote magnetic conditioning device in Boliden’s Garpenberg old concentrator in Sweden, where a complex massive sulfide ore is treated, is presented and discussed based on Boliden’s Garpenberg plant. The results showed an increase in the flotation recovery of fine valuable minerals. Zinc (Zn) production was increased by between 1,100 and 1,500 t/a, while salable yearly silver (Ag) production was increased by 1,500 kg. The copper (Cu) grade in the final concentrate was increased by 1 percent, while reductions in its Zn and lead (Pb) grades were obtained. Moreover, considerable reduction in Zn deportment to the final tail was observed

By Zohreh Kazemi Motlagh, Virginia T. McLemore

There are more than 15,000 abandoned mine features in New Mexico. A considerable number of these mines have not been cataloged or assessed for prioritized reclamation efforts. These mine wastes can be examined as a resource of critical minerals. Many of legacy mine waste deposits have undiscovered commodities and critical minerals, due to low recovery processes during past production. In this project, Black Hawk mine wastes in Grant County, New Mexico are examined by thorough mineralogical and geochemical characterization. This project seeks to characterize and estimate the critical minerals in mine wastes of Black Hawk mine, and determine the acid generating potential of mine waste. Identifying and producing critical minerals in New Mexico may directly benefit the U.S economy and national security.

Feb 1, 2024

By H. M. Thorne

Industrial shale-oil operations in North America and Europe predated the Drake discovery, but, since then, most have succumbed to competition from petroleum. However, the existence of enormous oil-shale resources in the Green River formation of Colorado, Utah and Wyoming [estimated at over a trillion bbl of shale oil in place] and the advancement of United States oil- shale technology by research and development programs of government and industry during the past 15 years point to a natural partnership of petroleum and oil shale to meet the accelerating energy demands of the future. The utilization of oil shale is not a question of limited petroleum supplies, but one of economics. Two factors are expected to improve the economic outlook for industrial shale oil production -- a rise in petroleum replacement cost and further advances in oil-shale technology.

Jan 1, 1963

By F. W. Petersen

Slurry reactors are being used extensively throughout the chemical, biochemical and mineral processing industries. This paper describes the interaction between fine ore particles and granular porous adsorbents such as activated carbon and ion-exchange resins in a stirred tank reactor. Gold and silver cyanides were used as adsorbates to detect changes in the mass transfer characteristics of the adsorbents, which were ashed to determine the loading of ore particles. A simple kinetic model incorporating film diffusion, intrapanicle diffusion ~d the adsorption equilibrium, was used to interpret kinetic data and to estimate the effect of slurry conditions on the diffusion parameters. It was observed that the equilibrium loading of fines in the adsorbents was independent of their concentration in the slurry. Furthermore, the presence of these panicles inside an adsorbent decreases the effective diffusion of gold or silver cyanides into the adsorbent matrix. When fine suspended solids are present in the reactor, a decrease in the effective availability of the superficial surface of the pre-saturated adsorbent panicles for mass transfer from the liquid phase was observed. This newly defined surface availability factor was dependent on the concentration, panicle size, and the zeta potential of the fine particles in suspension.

Jan 1, 1993

By Dennis K. Mortensen

The warm southwestern desert of Arizona is an ideal location for ASARCO's new Sacaton Unit. The climate of this arid region played a major role in the design considerations of the Unit's crushing and concentrating facilities. Low yearly rainfall and relatively high yearly temperatures are a combination that was taken advantage of when designing the surface facilities. The plantsite, located due west of the mine pit, is in an area originally covered with sparse desert vegetation, underlain to an average depth of 125 feet by desert alluvium. The entire plantsite area slopes gently to the southwest at approximately 1%. Ground conditions at the plantsite area were not acceptable for construction due to the collapsability of the wetted soil when under loaded conditions, Overburden from the pit area was used to form the foundation for the entire plantsite. This waste material, entirely devoid of rock, was placed and compacted to an elevation approximately 20 feet above the desert floor. Elevating the plantsite by filling with waste material not only provided an adequate construction foundation but also eliminated the possibility of flooding from run-off in the surrounding desert areas.

Jan 1, 1974

By Liming Yuan, Isaac Zlochower, RICHARD THOMAS, Thomas H. Dubaniewicz, Teresa Barone

Mining vehicle manufacturers are developing lithium-ion (Li-ion) battery electric vehicles as an alternative to diesel-powered vehicles. In gassy underground mines, explosion-proof (XP) enclosures are commonly used to enclose electrical ignition sources to prevent propagation of an internal methane (CH4) air explosion to a surrounding explosive atmosphere. Li-ion batteries can create pressurized explosions within sealed enclosures due to thermal runaway (TR). Researchers at the National Institute for Occupational Safety and Health (NIOSH) measured TR pressures of lithiumiron phosphate (LFP) cells as a function of free space within sealed enclosures and observed an inverse power relationship. A well-confined cell produced 294 bar (4260 psia) of pressure during a TR, far exceeding minimum pressure containment specifications for conventional XP enclosures. Results indicate that adding enough free space surrounding LFP cells can reduce TR pressures to levels below that expected for CH4-air ignitions. Measured TR temperatures were below the minimum autoignition temperature of CH4-air.

Nov 6, 2020

By Klaydison Silva, Pedro Silva, Letícia Damet

The current situation of the global mining economy is increasingly focused on the utilization of materials previously discarded in the mining process. The waste from the past, through new processing routes, is gaining new contours for use as high-value-added products. The strategic mine planning process has consequently had to adapt to the new economic reality. In standard scenarios, the focus was primarily on mine sequencing aimed at the highest economic return, with all infrastructure allocated as a necessity of mining. This work aims, in strategic planning, to configure and select the best composition of mining structures. The entire Mine-Plant-Waste-Tailings-Products chain will be considered as a factor in the sequencing of a multimine complex, to achieve the most sustainable utilization of the current mines’ waste. The sequencing is based on concurrent flows of process configurations and capacities, structure sharing, and flexibility of feed types. These factors will guide the sequencing, which will be constrained by components such as waste and tailings disposal rates, lithology feed relationships, and especially product composition through market specifications, all while respecting product shipping capacities.

Feb 22, 2026