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By J. J. Zaluski

The Surface Mining control and Reclamation Act (public Law 95-87) (here-inafter the "Act" or "SMCRA") passed by congress in August of 1977 represents a comprehensive federal scheme for controlling surface coal mining and the surface effects of underground mining through permitting requirements, performance guidelines, and reclamation planning. While the provisions of the Act have been the subject of numerous legal challenges and court battles over the years, it is difficult to identify a more controversial program within the Act than the provisions for designating lands as unsuitable for surface coal mining operations. The lands unsuitable designation process provides for the acceptance and review of petitions submitted by citizens or organizations seeking to have specified land areas designated unsuitable for all or certain types of surface coal mining activities. In filing these petitions, the interested parties or petitioners are required to make allegations about potential adverse impacts on people or the environment and submit evidence supporting their allegations.

Jan 1, 1992

By K. Lang

A test section of the upper most lift and underlying lifts of a large scale copper heap leach operation was instrumented and monitored with advanced wireline geophysics, fiber optics and resistivity electrode arrays. Elemental Capture Spectroscopy (ESC) copper measurements, resistivity measurements from an Array Induction Tool (AIT), electrical resistivity tomography (ERT) and distributed temperature sensing (DTS) with fiber optics provided integrated near real time data about the performance of the heap. During the leaching cycle, ECS provided continuous vertical measurements of copper in the upper most and underlying lifts in the test section of the heap and was used to generate a copper recovery curve. ERT inversion modeling provided high resolution 3D resistivity measurements, which were used to evaluate moisture distribution. DTS measurements of temperature were used to track the PLS front and calculate velocity. AIT induction provided highly precise bulk resistivity measurements. In-situ samplers provided PLS chemistry at multiple points. Properly integrated monitoring data can provide the heap leach operator with information that can be used to evaluate the hydrodynamics and metallurgy of the leaching process in near real time. Problems in the heap, such as pooling, channeling, longer lag and breakthrough times, excess acid consumption, increased solution in inventory, toe saturation and slope stability can be detected in near real time with the in-situ measurements evaluated.

Feb 23, 2014

By E. Ilgar

Biodegradation of spodumene by Asnergillus niger has been investigated. This organism oxidizes sucrose to citric and oxalic acids (in approximately 50-sot proportions) which degrade the spodumene mineral. The kinetic effects of leach variables on the dissolution of lithium were determined. The maximum theoretically attainable rate of lithium extraction was calculated for the effect of pulp density, to be V : 3.01 x 10 kg m sand the corresponding constant value, K = 12.47% pulp density. The apparent activation energy of lithium extraction vas found to be ^E = 20.3 kJ and frequency factor A = 5.66 x 10 s for S-spodumene leaching by synthetic -3 citric and oxalic acids (each in 0.05 kmol m-3 concentrations).

Jan 1, 1989

By C. Rodriguez, T. BoBo

Comminution, being the energy intensive part of a mining operation receives much scrutiny by cost controllers, CEO’s, investors and others as the mining industry goes “back to basics” to reverse the decline in productivity which occurred during the mining super cycle. Blasting is the first and lowest cost per ton stage in the comminution value chain. The basic principle that effective blast design can optimize fragmentation from the Run of Mine (ROM) ore muck pile to improve productivity through digging, loading and crushing to grinding and increase mine site profits has been well documented. Benefits of controlling fragmentation in the blast include reduced wear on equipment, faster loading, increased truck loads while detecting oversize rocks at the muck pile can reduce the frequency of a blocked primary crusher. A second basic principle is a measure of particle size distribution (PSD) at each unit operation in the comminution cycle allows engineers to manage blast design to produce fragmentation in the ROM ore most suitable to optimize downstream unit processes to improve mine site productivity and profits. Split-Online® systems have measured PSD of rocks on conveyors from the primary crusher to the SAG mill for over 20 years. Split-Engineering partnered with various mining companies to develop Split-ShovelCam® to automatically measure fragmentation from shovels and excavators working the ROM muck pile. This paper takes the reader “Back to Basics” by discussing the use of real time fragmentation analysis at the muck pile as an important parameter to optimize energy factors required for each blast. Case studies are given. INTRODUCTION The basics of mining are: • Explore for and find economic resources of valuable minerals • Mine rocks containing valuable minerals using blasting • Crush and grind rocks to liberate valuable minerals (comminution) • Recover valuable minerals for sale Comminution is an energy intensive process which accounts for a major proportion of mine site costs. Effective blasting can improve comminution and deliver significant reductions to mine site unit costs, (CEEC, 2016). Engineers, scientists, builders and even philosophers have long promoted the phrase “measure to manage”; the premise being “you can’t improve what you don’t measure”. Blast Engineers measure fragmentation in ROM ore for feedback to manage energy input in the design of blast patterns to optimize the ROM product size for downstream operations, whether they be for ROM Leach or feed into the primary crusher.

Jan 1, 2019

By Hoke M. Garrett

The domestic cement industry demands about 550 trillion Btu annually, at a time when reduced fuel use has become a necessity due to the energy shortage. In terms of the overall power picture, that 550 trillion Btu, which includes both fossil and electrical energy, means about 0. 870 of all energy consumed in the U. S. The various factors influencing reduction of this energy consumption are the subject of this paper. Nationally, the energy shortage is being tackled on two fronts--increasing supply and reducing demand. Making cement consumes energy; therefore, the industry cannot join the effort to increase the energy supply except indirectly as noted later. Demand can also be attacked on two fronts--by reducing cement consumption or by reducing the amount of energy required to make cement. The following discussions on reducing cement industry energy consumption center briefly on the prospect of reducing cement consumption followed by a broad evaluation of the potentials for improving cement-making thermal efficiency.

Jan 1, 1974

By Jerome F. Sheldon

The earliest recorded history in the use of belt conveyors in the United States is in O. Evans' "Miller's Guide" published in Philadelphia in 1795. Evans defines a conveyor as a "broad endless strap of thin pliant leather or canvas revolving over two pulleys in a case or trough." (Ref. 1) In this definition, pulleys are being used in a bulk material belt conveyor application. Pulleys used in belt drives can trace their origin back to 1200 A.D. In fact, Engineers had considerable experience designing them into drives transmitting greater horsepower than those used in the early belt conveyors. In belt conveyor application, a pulley's purpose is primarily three-fold, 1) support the belt in directional changes, as designed in the conveyor, 2) transmit driving power to the belt, and 3) guide or train the belt. There are various types of pulleys used in belt conveyor systems and these are thoroughly covered in "Belt Conveyors For Bulk Materials" prepared by CEMA, 1966. For our discussion, however, the most common used in belt conveyors are drive pulleys, snub pulleys, head pulleys, tail pulleys, takeup pulleys and bend pulleys. The drive pulley imparts the driving force to the belt and may be located at the head or discharge end of the conveyor, in return strand, or at the tailor loading end of the conveyor. A snub pulley is located near the drive pulley to provide more arc of contact between the belt and pulley for maximum

Jan 1, 1971

By Charles Dumaresq

The management of mine tailings poses a complex range of potential risks, including physical risks, such as the risk of catastrophic failure of a tailings facility and chemical risks such as the risk of long-term leaching of contaminants into the downstream environment. If these risks materialize, they can lead to a wide range of impacts on people and the environment, including human fatalities and severe impacts on downstream ecosystems, and the costs of recovery borne by industry, communities, governments, and society as a whole can be immense. Tailings facility failures in Canada (2014), Brazil (2015 and 2019), South Africa (2022), and in other locations around the world underscore how high the stakes are when mines produce and manage tailings (WISE Uranium Project 2019). Understandably, many people do not trust the mining industry to manage tailings responsibly. As an industry, it is our responsibility to manage tailings in a manner that is responsible and strives to minimize harm associated with tailings management, including effectively managing both the physical and chemical risks associated with tailings. Standards have an important role to play in responsible tailings management by setting expectations for standards of care and providing a means to measure and report on performance. In jurisdictions with strong legal requirements for tailings management, standards play a complementary role, pushing performance improvements in areas that may be difficult or impossible to address in legal requirements. In jurisdictions where legal requirements are lagging, standards may represent the de facto leading practice and may be the primary tool to help ensure responsible tailings management. Implementation of standards can help companies demonstrate that tailings are being responsibly managed and help build trust and credibility. Most importantly though, standards are important tools to help ensure that the risks associated with tailings are reduced, and that remaining risks are effectively managed. However, we must recognize that conformance with standards can have a down-side – the proverbial two-edged sword. Having standards is vital but there is a risk that implementing standards becomes a “box checking” exercise, with ongoing conformance leading to complacency. We must not allow ourselves to fall into the trap of believing that, just because we are complying with applicable standards and laws, we are therefore doing our best, and that “it can’t happen to us.” In addition, if conformance becomes the goal and the standard does not have mechanisms to drive continual improvement, then once the standard is met, there may be no incentive to improve. The point of complying with standards is not to pass the test. The point is to manage tailings responsibly, prevent catastrophic failures, and minimize harm. The point is to do better, because we must do better. To do that, we need to strive not for conformance, but for excellence in tailings management, driven by continual improvement and a quest to do better.

Feb 1, 2025

By A. T. Yu

Two major events highlight recent developments in US ore and coal ports: completion of the last series of modern taconite pellet transshipment facilities on the Great Lakes; and modernization and construction of coal ports, particularly on the East and Gulf Coasts. The New Taconite Transportation System To reduce raw material transportation costs, a fleet of new generation high-capacity 304-m (1,000-ft) self-unloading vessels were built to carry iron ore pellets from the Minnesota-Michigan iron ranges to the steel plants on the lower Great Lakes. Existing port facilities had to be modernized, revised, or completely rebuilt to accommodate these large vessels. Some of these were Burlington Northern's Allouez, WI, loading dock; Duluth, Missabe & Iron Range Railway Co.'s Two Harbors, MN, facility; Republic Steel's Lorain, OH, facility; and Chessie's Toledo, OH, dock. Allouez and Two Harbors receive taconite pellets from unit trains and load them onto large vessels either after dumping or via a large stockpile and reclaim system. The Lorain facility receives iron ore pellets from self-unloading vessels' discharge boom conveyor and reloads the pellets into rail cars or small vessels destined to inland steel mills. The Toledo facility receives Armco pellets from vessels, stockpiles them through the winter, and reloads into unit trains destined for Armco's mills along Chessie's rail tracks. Burlington Northern's $75-million Allouez pellet dock, completed in June 1977, was built to receive pellets produced by Hibbing Taconite Co. and National Pellet Plant in Minnesota, stockpile them through the winter when the lakes are frozen, and load them into 304-m (1,000-ft) vessels in the shipping season. As much as 10 Mt (11 million st) of pellets may be stockpiled within the loop track. A 6-km (4-mile) long conveyor system connects the stockpile area and the dock. Thirty-six new concrete silos were built on the dock to house 2 kt (2,000 st) each of pellets before shiploading. The $35.5-million expansion of the Two Harbors transshipment facilities began shiploading in July 1978 after ground breaking in Aug. 1974. Particularly noteworthy is the first application of the Orboom system-a breakthrough in technology for the modernization of the century-old pocket docks on the Great Lakes to accommodate the new generation of super vessels. The pocket-type loading dock has been a standard on the lakes for nearly a hundred years. Bottom-dump rail cars fill the ore pockets on top of a finger pier. Gravity chutes matching standardized ore ship hatch spacings are lowered to fill the holds of a 20.3-kt (20,000-dwt) ship. The construction is simple and the loading swift. In spite of advances in technology elsewhere, most of these docks continue to serve the iron ore and coal trade in the same manner they did in the 19th century. Although performance of the pocket docks on small vessels remains outstanding, the new 304-m (1,000-ft) vessels are beyond the reach of the old docks. After extensive development, the Orboom system (Patent No. 4,065,002) for pocket docks was successfully developed. The heart of the Orboom system is the retractable shuttle loading arm which loads the wide beam vessels. The Orboom shuttles are fed by existing pockets of the dock that, in turn, are charged by a tripper conveyor along the length of the dock. The Two Harbors shiploading system is supported by a 0.9 Mt (1 million st) storage-reclaim network. Unit trains are bottom dumped. Taconite pellets are stacked and reclaimed by bucket wheel reclaiming systems. Lower Lakes New Ore Ports At the lower Great Lakes receiv-

Jan 10, 1982

By Dominick Mandalari, David Mast, Heather Ullinger, Juan Granja, Amanda Foote

The City of Akron will construct the Northside Interceptor Tunnel (NSIT) project to control and reduce combined sewer overflows. One component of the project a large diameter tunnel diversion / flow control structure that will facilitate tunnel storage, divert dry weather flow to the treatment plant, and divert large wet weather events that are greater than the tunnel capacity to the Cuyahoga River. The structure is designed to pass up to 1.2 billion gallons per day of flow and includes floatables screening. This paper will discuss project background, factors that influenced shaft location, and options evaluated to manage the large design flows.

Jun 23, 2024

By SIMON DIAZ-QUEZADA, HUMBERTO ESTAY

The heap-leaching process is widely used for recovering different metals. In Chile, copper production by heap leaching has been accounting for between 30 and 40 percent of annual copper production over the last 10 years. This level of production has been achieved through and supported by the use of a mathematical relation known as the leaching ratio (LR), which correlates operational parameters with metal extraction in a heap-leaching operation. In spite of the widespread industrial use of this relation, few scientific studies mention it. This disparity between industrial practice and scientific research could lead to operational decisions that lack substantial theoretical support and to scientific studies with limited industrial impact. This study describes the LR and its current uses and limitations.

By C. Hanson

Two modes of potential loss of oxime extractants in liquid extraction processes for the extraction of copper have been studied. In loss "by chemical degradation, two mechanisms of acid hydrolysis are possible, some reagents degrade primarily in the organic bulk phase, Others at the interface between the organic phase-- phase protects the oxime but salts added to the aqueous acid phase can promote the rate of degradation. The reagents reported on are the LIX series (Henkel Cpn), SME529 (Shell Chem.Co.) and P5100 (Acorga) Loss by organic entrainment in the aqueous phase leaving mixer-settlers has also been studied, parameters investigated including impeller/tank geometry and the phase inlet arrangements. The consequences of extractant loss by the above mechanisms...are commented upon. They include the direct economic cost, the possible environmental problems and the implications for downstream operations such, as electrowinning.

Jan 1, 1980

By R. K. Singhal

A variety of mining equipment is used in the mining of oil sands by surface mining. This includes bucket wheel excavators, draglines, hydraulic shovels and off-highway trucks. This paper examines the existing mining schemes and equipment used Peculiarities of oil sands surface mining and their influence on equipment selection, utilization and mining schemes are described. Recent developments undertaken to improve mine productivity are also dealt with together with some notes on proposed measures to obtain further gains in productivity.

Jan 1, 1985

By R. F. Hadley

Alluvial valley floors constitute a valuable land resource and have been important to ranching operations in semiarid western United States. This resource may be in jeopardy locally if the alluvial deposits are disturbed by surface mining of coal deposits. Erosion problems caused by poor land-use practices can cause trenching of the unconsolidated alluvium with a consequent lowering of the water table and depletion of soil moisture needed to support vegetation. Historical evidence of this sequence of events is abundant in geologic literature and serves as the basis for assessing potential impacts of surface mining. The potential geomorphic impacts of surface mining on alluvial valley floors with regard to fluvial processes are: (1) disruption of the longitudinal profile followed by valley trenching and high sediment yields downstream and (2) replacement of the excavated alluvium with unconsolidated material that does not have similar physical characteristics and may be susceptible to erosion. Mining may disrupt the existing hydrologic framework affecting streamflow, ground-water levels and water quality of both surface water and ground water. Although functional hydrologic and geomorphic processes are similar, each valley represents a complex environment that does not submit to broad generalizations.

Jan 1, 1978

By John J. Sammarco

"The mining industry has made great strides in making mining safer and reducing the occurrence of mine disasters. Nevertheless, sometimes miners encounter smoke while trying to escape from a mine. Underground miners use different visual cues to help them escape from a smoke-filled environment. Foremost, miners look for primary and secondary escapeways that are typically indicated with reflective markers of various colors, with at least 11 colors available from manufacturers. Federal regulations require that escapeways be marked, but they do not specify the colors to be used. Thus, no standard color code exists and some colors can be more difficult to see in a smoke-filled mine.Researchers at the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) tackled this problem by taking a human-centered approach to provide miners with better visual information that would improve their ability to see escapeway markers in smoke, thus enhancing their ability to self-escape. What marker colors does your mine use?Does your mine use blue retro-reflective markers to indicate primary or secondary escapeways? Is your mine ready to purchase new or replacement retro-reflective markers? Color is important and blue had the poorest visibility as determined by OMSHR’s recent research investigating the visibility of markers in smoke. OMSHR researchers are not alone in their interest to improve a miner’s ability to escape - specifically when their efforts are hampered by smoke. For instance, there is a LinkedIn Mining Safety subgroup called "Standardized Color Code for Escape Ways and Returns in Underground Mines," and a recent National Academy of Sciences report recommended the development of humancentered technologies to enhance self-escape from underground mines. The mining industry has a common goal of helping improve miner safety, especially when it can be done by way of a simple and relatively low-cost solution of using escapeway colors that are more visible."

Jan 1, 2014

By D. A. Bird

Geochemical models using published thermo-dynamic data and laboratory derived kinetic rate laws allow prediction of post-closure pit lake geochemistry at open pit mining sites. A combination of "forward" and "inverse" modeling techniques can predict the pit lake geochemical evolution from initial infilling to eventual steady state attained decades or centuries after closure. Computer codes have been developed to model chemical reactions such as pyrite dissolution, describe the ground-water flow regime, and provide rock-water ratios. The incorporation of site specific information, such as ultimate pit dimensions, geologic and hydrologic data, acid generating potential (AGP) vs. acid neutralizing potential (ANP), and laboratory derived kinetic rates, allows application of the model to open pit mines at any stage of development.

Jan 1, 1994

By W. C. Bagby

The Dee disseminated gold deposit is the northernmost mine in the Carlin gold belt. We analyzed soil samples £ran undisturbed areas overlying the deposit to determine the usefulness of soil geochemistry in identifying ore zones. The depth of sampling ranged from 12 to 14 inches, depending on soil development. The -80 mesh fraction was analyzed by atomic absorption for Au, As, Sb, Hg, and T1 and by semiquantitative spectrographic analysis for Ag. Highly anomalous Au, Kg, As, Ag, and Sb are most closely associated with ore zones whereas T1 is more broadly dispersed. Hg is the only element that identifies deep ore.

Jan 1, 1984

By M. Yavuz

Due to workability difficulties, people have begun to use iron ore much later than gold, copper and bronze. In addition, iron and steel products are the most commonly used metals which are necessary for human life today. It is a fact that iron ore is raw material of the steel production process as known. Iron&Steel sector is plays an important role in the economic development of countries all over the world. Therefore, the amount of production and consumption of steel is one of the basic indicators of industrialization all over the world. The amount of steel consumed per capita of the country is considered as a measure of development. The world average per capita consumption of steel is around 210 kg in 2007 (Yildiz, 2009).

Jan 1, 2010

By J. C. Gathje

The Robinson copper ores were mined for many years from pits containing varying ore grades, sulfide and oxide ore types, and differing mineralogy. The ores also contain gold and molybdenum values, and their recoveries are an integral part of the flowsheet development. Metallurgical responses were characterized using a standard flotation procedure. Further studies investigated primary and regrind particle sizes, reagents, and other variables. The metallurgical testing was supported by mineralogical studies. Results demonstrated a high degree of metallurgical success for flotation. Final copper concentrates ranged in grade from approximately 28 to 30% copper and copper recoveries were 89 to 95% based on laboratory and pilot plant data.

Jan 1, 1992

By J. Le Gac, P. Zettwoog, J. Brenot, J. W. Piechowski, J. C. Nenot

INTRODUCTION The components of the radiological hazard in uranium mines are: 1. exposure to radon and its short-lived daughters 2. exposure to long-lived ore dust 3. external irradiation With usual ventilation rates, the dosimetry relative to the first component only requires to know each miner&apos;s exposure to a potential energy of short-lived radon daughters, (EXP[a]). Presently in France, (EXP [a]) is determined monthly from radon concentration measurements. This is an indirect method based on ambient monitoring. After technical improvements achieved during the last years it is now possible to measure (EXP [a] directly with an individual portable monitor developed by the CEA. The purpose of this study is to analyze and compare monitoring results obtained by these methods. DETERMINATION OF INDIVIDUAL MONTHLY EXPOSURES TO[ a] POTENTIAL ENERGY OF SHORT-LIVED RADON DAUGHTERS [(EXP a) amb, by ambient monitoring] In this case, it is necessary to know individual monthly exposures to radon, (EXP Rn). As mentioned by Pradel, J.,et al., 1976, (EXP Rn) is estimated for each worker from informations both on radon concentrations (CRn) measured as described by Pradel, J., 1962 and times (t) elapsed in the various workplaces. (EXP Rn) is obtained by summing up the elementary radon exposures CRn x t relative to all the workplaces where the miner was successively engaged during the month. (EXP Rn) values are then corrected by an average equilibrium factor of 0.17 deduced from many measurements and taken as representative for all the French mines. Finally: [ ] (EXP [a])ind are obtained directly with an individual portable instrument described by Chapuis, A.M., et al., 1972. Samples of the air breathed by the miners are pumped continuously and radioactive aerosols containing the short-lived radon daughters are trapped on a filter. The principle of the measurement lies on track-etch detection of the a particles emitted by the deposited material. The technical aspects have been described by Duport, P., et al., 1980a, Mouden, A., et al., 1980 and Chapuis, A.M., 1980. As mentioned by Duport, P., et al., 1980, fiability is good. Indications on measurement reproducibility are given by Pradel, J., et al., 1977. PRESENTATION OF THE STUDY The underground miner population of a French mine was followed during a period of 8 months (October 1978 - May 1979). Monthly exposure values for each miner determined either by ambient or individual monitoring, (EXP [a])amb or (EXP[ a])ind, had been previously collected by Le Gac, J., 1980, who had also defined miner categories according to the characteristics of the work performed. Four groups are considered here, the "whole mine" and three categories as described in table 1. Data on the individual monthly exposures,(EXP [a])ind and (EXP [a])amb, were taken again to analyze the individual cumulative exposures instead of the "month by month" values. The influence of the mean habits of each individual on its surveillance results is thus taken into account. Each miner has a cumulative exposure as an individual of the "whole mine" and as an individual of each category in which he has worked. The results obtained by ambient or individual monitoring were analyzed (characteristics and adjustements of the distributions) and then compared (description of the discrepancies observed). Obviously, such a study is possible only if all the exposures are cumulated on a same duration. As miners have not worked during the same number of months in the course of the data collecting period, one must considerer the individual average monthly exposures, [(EXP a)]amb and[ (EXP a)]ind, instead of the individual cumulative exposures, which is typically the same thing. To be sure that the exposure values of a given group (A, B, C or D) are representative, only those miners really present for at least 3 months in this group were taken into account. Finally, each individual of the "whole mine" and of the various work categories has a pair of average monthly exposure values : [(EXP a)amb] determined by ambient monitoring and[ (EXP a)ind] deduced from the track-etch recording of the individual portable monitor. Let a miner be engaged during n months[ (3 < n < 8)] in a group, the following relations then apply : [ ]

Jan 1, 1981

Lingering effects of the 1990 oil shock that included overbuilding and corporate and individual financial distress caused the Gross Domestic Product to fall slightly to $5.67 billion (US billion = l09). With 254 million people - 697,000 in mining and petroleum - the US has more than 100 million dwelling units and 190 million licensed motor vehicles. New private housing starts fell 15% to one million units. New car production fell 11 % to 5.4 million units. Truck and bus production fell 8% to 3.4 million units. The inflation rate was 3%, while the prime rate of interest was 8.5%. The Producer Price Index (1982 = 100) changed as follows: -fuels and related products and power down 1% to 8l, • metals and metal products down 2% to 120, • chemicals and allied products up 2% to 126, and • non-metallic mineral products up to 2% to 117. Energy Imports of crude and refined petroleum, costing $50 billion, fell 5% to 2.8 billion bbl. Domestic petroleum production rose 1% to 3.6 billion bbl. Petroleum supplied about 39% of US energy, natural gas 24% and coal 22%. The National Energy Strategy was announced in February 1991. Its purpose is to encourage domestic production of fossil fuels and nuclear and renewable energy and to stimulate efficiencies in use. Congress continued to debate the strategy and took no action. Coal production fell 3% to 902 Mt (994 million st). About 60% of that came from surface operations. Seventy-eight percent of the total was used to generate electricity and 3% was coked.

Jan 1, 1992