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By Rebecca Mae Summer

Large scale surface mining has a major impact on land use. Without reclamation, abandoned mining sites are usually less productive than before mining. With increasing and completetive land use demands in the United States, it becomes increasingly evident that multiple land use should be considered for all areas that will be mined, with special emphasis on coal, sand, gravel, and stone. The mining of these commodities affects the largest land areas and the latter two are commonly mined near population centers where high land-use pressures justify serious consideration of multiple use. Typically, sequential use will mean restoration of the mined land or at least transformation of the land into a useable state. Determination of land reclamation capability is a viable approach to planning reclamation of surface mined land. The natural resource base--geology, soil, and water--controls the type and intensity of land-use practices which can be sustained following mining. Evaluating physical limitations can eliminate consideration of uses which would severely impair the environment or which are impractical. This approach provides for an environmentally and economically sound land use at very little cost. In addition, it can save or make money for the mining company and landowner. Sand and gravel is an especially significant resource because it is mined throughout the entire country and commonly extracted near cities. Increasing urban growth and industrial activity require increased supplies of sand and gravel. This translates into expanded surface mining and an increase of disrupted land. Oftentimes this land is within an urban area and has potential for real estate or water-based activities. Therefore, if reclamation is planned and carried out concurrently with mining, it is definitely feasible and

Jan 1, 1977

By C. B. Kettering

In the early operations of the Inspiration Consolidated Copper Company, which extended from 1914 to 1926, the ore as mined contained principally sulphide copper minerals, manly chalcocite (Cu2S), This ore was milled in a 20,000-ton concentrator and the copper was recovered as a flotation concentrate which, was smelted at the nearby plant of the I ternational Smelting and Refining Company. In those days no attempt was made torecovercopper from any oxide minerals present. As mining operations progressed it soon became evident that the proportion of oxide minerals present would steadily increase, and. it was realized that some method of treatment would have to be developed whereby copper could' be recovered from both oxide and. sulphide minerals contained in the ore. A research program was instituted and after some years of experimental and, pilot plant work a new hydro-metallurgical process was developed whereby it became possible to extract copper from both the oxide and. sulphide minerals in a single leaching operation. The solvent adopted consisted of a mixture of sulphuric acid and ferric sulphate,' Following dissolution, the dissolved copper would be recovered by electrolysis. Also in the process of electrolyzing, spent solutions of sulphuric acid, H2SO4, and. ferric sulphate, Fe2(SOk)3, would be regeneratede and. somade available for continuous reuse. The process appeared to be a success and the decision was made to build a full-sized leaching plant for the future treatment of I spiration mixed ore. Construction was started and the leaching plant was completed in 1926, With the start of ferric-sulphate leaching the Inspiration Concentrator was shut down and, with the exception of a few short time runs has not operated since that time. The ferric sulphate leaching process served. Inspiration well for some 30 years and during that time won a name for itself as a classic example of hydro-metallurgical treatment of mixed sulphide oxide ores. Originally the plant was designed. to process some 7,500 tons per day of a mixed ore containing about 1,2% copper, of which 60% was present as oxide and. 40% as sulphide, Down through the years various improvements were made for the purpose of increasing plant capacity and as well to change the limiting 'factor of sulphide-oxide ratio, The final result was a leaching capacity of 9,600 tons per day when treating a 1% copper ore with a reversal of the sulphide-oxide ratio to 60% sulphide and 40% oxide.

Jan 1, 1958

By MAHESH SHRIWAS, CHRISTOPHER PRITCHARD

Ventilation monitoring and control in mines are becoming an integral part of day-to-day activity for maintaining the health and safety of miners. This paper evaluates potential real-time monitoring solutions for detecting and reducing diesel particulate matter (DPM), mine fires and dust in situ and examines the state-of-the-art use of ventilation monitoring and control in underground mines for detecting and reducing air contaminants to acceptable regulatory limits. In this study, relevant documents, including research papers, trade publications and manufacturer website information, are reviewed to identify research gaps. This paper also includes evaluations of contemporary sensors (airflow, gas, dust and silica), control system and software technologies, data transport systems, the Industrial Internet of Things (IIoT), ventilation network simulators and control devices to identify potential health and safety research gaps. Examples of some mines in Canada, Australia and the United States that have been using ventilation monitoring and controls are included as well. Overall, this review identifies multiple challenges and research gaps in applying mine monitoring and control systems that could be the focus of future research, offering potential improvements to miner safety and health and financial benefits.

By E. Steel

The asbestifom habit is most commonly developed in certain amphiboles and chrysotile, but other minerals may also crystallize with this unususual habit, The habit may be characterized by 1) a fibril structure, single or twinned crystals of very small widths (generally less than 0.5 inn) which have gram with a common fiber axis direction but which are disoriented in the other crystallographic directions, 2) anomalous optical properties, primarily parallel extinction, 3) unusual tensile strength, 4) high aspect ratio, and 5) flexibility. In addition, there is evidence to indicate that some amphibole asbestos may have unusual surface properties.

Jan 1, 1979

By M. Govinda Raj, S. Sridhar, M. Aruna

Hand-transmitted vibration (HTV) exposure is associated with various health risks for operators of mobile mining equipment (MME). The case–control research was conducted to determine the musculoskeletal disorder (MSD) risks associated with exposure to HTVs in the exposed (case) and non-exposed (control) groups. HTV readings were measured at the interface between the hand and the steering device using the SV 105B triaxial hand accelerometer connected to the SV106 human vibration analyzer involving 40 MME operators in accordance with ISO 5349:2001 guidelines. A questionnaire survey was also carried out among both the study groups using Cornell Musculoskeletal Discomfort Questionnaire. The European Union's 2002/44/E.C. was used to assess the health risks posed to the MME operators. Twenty-eight out of the 40 MMEs were generating HTVs exceeding the stipulated daily limits of vibration, putting 70% of the operators at increased risk for developing MSDs. The case group was found to have an elevated risk of exposure with odds ratio (OR) 7.56 (95% confidence interval (CI), 1.159, 49.39) and OR 12.80 (95% CI, 2.436, 67.285) times more likely than the control group to suffer discomfort in the left shoulder and left wrist, respectively, indicating increased risk of exposure to HTV. Additionally, cases had elevated risk associated with exposure to tobacco, OR 9.35(95% CI, 1.856, 47.129) compared to those who did not use tobacco. MSDs were more prevalent in the case group compared to the control group. This observation was validated by the field investigations and the responses of MME operators to the questionnaires.

Aug 2, 2022

By L. F. Zeiler

In the past, health concerns in coal mines have primarily centered on those elements which have been essentially inherent to the mining environment. These would include respirable coal mine dust, respirable crystalline silica, excessive noise levels, and diesel exhaust particulates. Commercially-available chemical products are prevalent on mine property. These potentially toxic materials are chemical formulations that can degrease, clean, and lubricate metal parts, separate coal from rock in float/sink operations, and aid in roof consolidation, among other uses. As the general public has become more aware of the hazards of chemical exposures, miners have likewise become more concerned about working with an ever-expanding variety of chemical products on the job. Often, product or chemical specific hazard communication training is inadequate or ineffective, and miners do not know exactly what the ingredients are in the products they handle, or the health hazards involved with their use or misuse. Currently, the Mine Safety and Health Administration (MSHA), by law, enforces 1972 Threshold Limit Values (TLV). MSHA is making preparations to adopt new personal exposure limits for enforcement. The values given throughout the article are 1994 TLV's and are not enforcement standards, but are used for discussion purposes. They reflect the current scientific thinking regarding personal exposure to these chemical agents. An overview of these products is presented, and the potential health hazards associated with their use are discussed. Controls needed to prevent overexposures, such as proper handling procedures and personal protective equipment, are covered. Methods used to collect and identify contaminants are presented.

Jan 1, 1995

By Andrew R. Thomas

As the demand for most industrial minerals on the world market continues to climb, educational institutions maintain traditional policy in emphasizing chiefly metallic ore deposits and energy resources in addition to the general disciplines. In spite of their increasing importance, few universities exhibit great depth with respect to industrial minerals courses due to the shortage of specialized faculty in a category this broad. As new ideas are formulated and technological advances are developed in the field of industrial minerals, the classroom still exists as a student's primary source of information. This opportunity to give today's students the benefit of modern developements has not been utilized to its utmost potential.

Jan 1, 1981

By L. Hales

Process control systems have evolved from single loop control to distributed control with computer based expert control strategies. The next step is to add adaptive control to the expert control strategies. An object-oriented adaptive optimization approach is defined and simulated results are presented for a plant.

Jan 1, 1996

By Kenneth A. Pietila

The thickening and dewatering characteristics of refuse slurries are as variable as the coal mining operations and preparation plants that create them. This paper discusses these characteristics based on field studies at a number of mine sites. The connection between bench and full scale performance is confirmed with the design, construction and operation of an integrated 18m (60 ft) diameter thickener and 2.5 meter belt filter press system in Western Kentucky. The data from this system are presented.

Jan 1, 1984

By Hooman Askari-Nasab, AHLAM MAREMI, EUGENE BEN-AWUAH

In oil sands mining, tailings are voluminous unwanted by-products generated from extracting the desired mineral from the mined ore. Dyke construction and backfilling activities require well-managed techniques to facilitate progressive reclamation at the earliest opportunity. This directly affects the sustainability and profitability of the mining operation. This research introduces a goal programming framework that simultaneously optimizes the (1) production schedule with limited duration stockpiling and directional mining; (2) dyke construction schedule; (3) size, shape, and location of tailings-cells; and (4) mining and processing production targets. The results show that in creating in-pit tailings-cells designs, decreasing the mining-cells volume and increasing the number of mining-cells improve the net present value of the operation due to increased operational flexibility. The model generated a uniform schedule for ore and practical tailings-cells designs for backfilling activities. Integrating tailingscells optimization into oil sands mine planning and waste management ensures the efficient use of in-pit mined-out areas required for sustainable operations.

Apr 14, 2021

By Arnold Dix, Oliver Heger, Bernhard Kohl

In the USA, risk-based decision making has not been a common approach to tunnel safety in the past, but this is changing, as concepts such as “equivalency” in the NFPA 502 framework gain acceptance in the USA and elsewhere. In other regions, in particular in Europe, risk assessment techniques have been used for nearly two decades in many jurisdictions as an additional tool to complement the application of prescriptive guidelines and support decisions related to tunnel safety. After some initial difculties these methods are meanwhile a well-established element of tunnel safety management. There are several tools available which have been practically applied and further developed over years, such as the Austrian tunnel risk model TuRisMo, or the PIARC owned DG-QRAM model. Whereas TuRisMo is a holistic, system-based model, which is best suited to quantify and assess re risk and associated mitigation measures, DG-QRAM focusses on the risks related to the transport of hazardous materials. Depending on the objectives and the scope of the investigation and the regulatory environment tunnel risk assessment tools are in use for different purposes, mainly to demonstrate a sufcient level of safety and to decide on and select additional risk mitigation measures. The international eperience substantiates that the general approach is eible and that the methods and tools are mature and can be applied for different problems in different environments. First case studies like the risk study on conditions and permissibility of the transport of hazardous materials through the Eisenhower-Johnson-Memorial Tunnel in Colorado demonstrate the applicability of a risk-based concept for decision making in the US-American environment.

Jun 23, 2024

By John B. Goddard

Crystallization of ammonium paratungstate (APT) is frequently the last effective purification step in producing high-purity tungsten. However, crystallizer mother liquors are often several times higher in tungsten than predicted by the solubility of APT. The formation of heteropoly anions, particularly those containing phosphorus and silicon, is largely responsible. Solubility of tungsten in APT mother liquor can be linearly correlated with the concentration of these and other impurities. The problem can be overcome by direct treatment of the crystallizer feed solution with alum. By appropriate treatment, the aluminum hydroxide flocculates and is easily filtered, resulting in a purified low-aluminum crystallizer feed from which high APT yields can be attained.

Jan 1, 1984

By G. S. Austin

New Mexico produced 83% of domestic potash and 27% of domestic consumption in 1992. The potash industry of New Mexico produces sylvite (KCI), langbeinite (K2SO4-2Mg(SO4)2), and artificial K2SO4. Average sylvite grade in New Mexico today is about 14%. The average grade of langbeinite is 8-10% Kp. Commercial potash occurs in the middle or McNutt Member of the Salado Formation (Upper Permian Ochoan Series). The 120-m-thick McNutt Member dips about 1° east and contains 11 of 12 potential ore zones in the Salado. The mineralogy and proportion of clay minerals, up to 7% of the ore, influence optimum milling procedures and ore grade cutoff.

Jan 1, 1994

By E. G. Kelly

This paper describes the performance of a modern compound trough profile spiral that is optimized for fine coal cleaning. Reduced performance (Tromp) curves are presented to compare these new spirals with older designs, as well as with other commonly used coal cleaning equipment. As an aid to equipment selection and circuit design, data are also presented to show how variables, such as flow rate, pulp density, and particle size affect efficiency and the separation specific gravity.

Jan 1, 1984

By V. T. McLemore

New Mexico Bureau of Geology and Mineral Resources (NMBGMR) has been collecting data on uranium mining districts, mines and mills since it was created in 1927 and has converted years of historical data into a relational database that can be imported in ArcMap. The database includes information on mining districts, mines, mills and geochemistry, as well as photographs and bibliographic resources. The available data includes location, production, reserves, geologic, geochemical, resource potential and other data. The National Uranium Resource Evaluation (NURE) stream-sediment data provides geochemical analyses for >27,000 samples collected in New Mexico during the 1970s. The NURE hydrogeochemical data provides analyses of water samples. ArcMap includes the location of individual ore bodies as polygons and incorporates the mines and NURE data as individual site locations. The purposes of these databases are to provide computerized data that will aid in identifying and evaluating resource potential, resource development and management, production and possible environmental concerns, such as physical hazards (i.e., hazardous mine openings), indoor radon, regional exposure to radiation from the mines, background geochemical data and point sources of possible pollution in areas of known mineral deposits.

Jan 1, 2010

By Y. Luo

In designing and operating underground room-and-pillar coal mines, it is always difficult to achieve a good balance between preventing surface subsidence and achieving high recovery ratio. In this paper, a design methodology applying the pressure arch theory is proposed, and the principles and mathematical models involved are detailed. A computer program was developed to carry out the design optimization process and was applied to the examination of a documented case in which a massive cascading pillar failure had occurred over a large area in a shallow coal mine. The results indicate that the proposed design method can be applied to prevent subsidence while achieving reasonably high recovery ratio for roomand- pillar mining operations.

Jan 1, 2014

By J. L. Boyd

The mining and processing of basic metals relies on water as a medium for transport. Metallurgical ores are ground, concentrated, leached and refined in an aqueous medium. Water is used for temperature control during processing and in air pollution abatement during smelting. All of these process steps result in liquid wastes. Many of the aqueous wastes from ore processing areas become the raw product for a second stage and water recycling may begin. The point at which water recycling or reuse has been initiated in the past, rather than water discharge, was where water conservation was manditory due to a shortage, where process conditions would allow or benefit from reuse, and where economic considerations demanded reuse. The Fontana, California plant of Kaiser Steel Corporation is an example of an integrated steel plant that was forced to practice water conservation and reuse due to its location in an arid environment.1 Only a small amount of water required to maintain the water reuse system in balance with respect to dissolved solids and product quality is discharged. The Butte, Montana copper ore processing plant of The Anaconda Company obtains 66% of the water required for production by recycling, after clarification and chemical treatment, 30 MGD of wastewater from its tailings ponds. This operation is estimated to save the company about $1200/day over a once through water system.2 Here plant location and economics favored water reuse.

Jan 1, 1975

By Alexander N. Winchell

"THE MICHIGAN COPPER DISTRICT.Location. The copper mines of Michigan are all in the north¬ern part of that state on the Keweenaw Peninsula, which extends from the (Michigan) mainland for about seventy miles northeast¬erly toward the middle of Lake Superior. The mines occur in a belt or zone occupying the central portion of the peninsula from end to end.. The most productive mines for many years past have been those located not far from the city of Houghton in' the central part of the zone, in a section extending about ten miles southwest of Houghton and fifteen miles northeast. The most important mines in order of.location, from the northeast to south¬west, are the following: Mohawk, Ahmeek, Allouez, North Kearsarge, Wolverine, South Kearsarge, Centennial, Calumet. and Hecla, Osceola, Franklin, Quincy, Hancock, Isle Royale, Superior, Baltic, Trimountain, and Champion. The first three named are in Keweenaw county and all of the others are in Houghton county. Still farther to the southwest are the Lake, Mass, Adventure, Michigan, Victoria, and White Pine mines. These are in Ontonagon county.History. The exploitation of these copper mines extends back into prehistoric times. There is little evidence that the American Indians carried on mining operations in this region in the period shortly before the advent of white men, but there is abundant evidence that the ancestors of the Indians, •or some earlier inhabitants of the region, carried on primitive mining operations. For example, Mr. S. O. Knapp, Agent of the Minne¬sota Mining Company, in the winter of 1847-48, made the first discovery of prehistoric mining. This event is described as fol ,lows by Foster and Whitney : Location: As shown on the accompanying map, the Mar-quette district extends from the region of Marquette on Lake Superior westward for about forty miles. The main basin of the district is only about three to six miles wide, but outlying areas which are commonly regarded as belonging to the same mining unit, make the north and south dimension of the district about twenty miles. The most productive portion of the area is in the vicinity of Negaunee and Ishpeming, .about ten miles from Mar¬quette, but important mines are found also all along the range as far west as Michigamme and also to the south in the fold known as the Republic Trough. Comparatively recent developments indicate that important ore bodies have been developed in the outlying Swanzy district about eighteen Miles nearly due south of Marquette.The Marquette Iron District.History: The first discovery of iron ore in the Lake Supe¬rior region was probably that made in 1844 near the site of Ne-gaunee by the government surveying party in charge of William A. Burt, sent out under the direction of Douglass Houghton. This surveying party was using a solar compass, invented by Mr. Burt, and noticed variations in the direction of the magnetic needle at various times and places, but. on the 19th of September, while running the east line of Township 47 North, Range 27 West, the needle varied from its normal position until it stood nearly at right angles thereto."

Jan 1, 1920

By Ping Zhang, Xu Ma

Perturbations from mining operations significantly affect the stability of rock masses, especially with the increase in mining depths. This study uses the discrete element method (DEM) to investigate shear slip failure along discontinuities in an underground mine, aiming to quantify seismic moment and seismic energy to better understand seismic hazards.

May 1, 2023

By Larry A. Lien

Membrane technology has been available for about 30 years, but has been used very sparingly within the general mining industry. However, recent developments in polymer chemistry, spiral wound element construction, pretreatment equipment and element cleaning techniques have improved the reliability and robustness of membrane based systems. These improvements have expanded the potential to use this "new" technology to enhance critical recoveries of gold and silver in heap leaching operations or in the extraction circuit. Another opportunity for the mining industry will be to use membrane technology in new processes like controlling organic acids or ammonium thiosul­fate to enhance gold and silver extraction during leaching opera­tions. Finally, the most common use for membrane technology is for the control of mining water balance and acid mine drainage issues. Polymeric membranes, specifically thin-film composites, have been developed that will purify, fractionate or concentrate gold or silver. Recent applications have been developed for spi­ral wound modules that operate across the pH spectrum from 0 to 14. Systems using membranes have been constructed that operated on feed streams from 200° C to 3000 centipoise. Most recently, membrane based systems have been pilot tested suc­cessfully to purify solvents, like LIX. Opportunities exist to apply membrane technology to concen­trate gold and silver cyanide solutions with thin-film composite Reverse Osmosis (RO) membranes at elevated pH values above 10. Incorporating membrane technology could allow one to increase production without incurring additional expansion of the gold extraction side of the process. Furthermore, free cyanide is not rejected by the Reverse Osmosis membranes, but other inorganic salts are rejected 98+%, thereby, allowing an essentially ion free, except for the free cyanide, to be recirculat­ed back to the heap leach operation for enhanced extraction.

Jan 1, 1998