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By Vivas

Goldcorp is one of the largest gold producers in the world with projects in South, Central and North America. Goldcorp?s flagship operation is Peñasquito, a world class, polymetallic deposit that started production in 2010 and is one of the largest mines in Mexico. Since the early stages of the project, Goldcorp has used the most advanced technologies available to maximize its value. However, the implementation of optimum mine plans has been challenging to put into practice. This is due to the fact that the mine operation involves more complexity than the plans usually reflect. This challenge is an industry-wide issue that presents opportunities for improvement. This article discusses the mine planning methodologies and procedures used to connect long-, medium- and short-term planning strategies in order to bridge the gap and produce optimum mine plans that can be practically implemented in the field.

By F. F. Peng, S. S. Peng, V. Z. Sun

A detailed study of ponding phenomenon relative to surface subsidence due to longwall mining was conducted for various surface stream conditions. Based on field monitoring, the stream-ponding process and three forms of stream water are described. Also discussed are the criteria of stream ponding and the influences on the ponding process by two key factors: the angle of stream flow and the change in the stream-bed gradient. A numerical (mathematical) model, which combines trend surface technique that describe the topographical features in the vicinity of a stream and the modified influence function, which represents the profile of the surface subsidence trough (or basin), is constructed to predict the formation characteristics of stream ponding in terms of location, boundary and accumulated water volume of migratory and stationary ponds produced by the stream-ponding process. Three cases are analyzed using the model to predict the interaction of the underground operations and the environmental impact due to stream ponding. The feasibility of various mitigative measures are assessed.

Jan 1, 1997

By C. E. Stack

For the purposes of this presentation, "refractory clay" is intended to include any clay suitable for refractory products and thus represents a description based on industrial application. Other common examples based on use would be white-ware clay, bleaching clay, paper clay, or cement clay. Most users and producers of refractories have specific quality requirements which determine the quality or type of clay that can be utilized. Many clays can however be interchanged or substituted in use by changing manufacturing processes or upgrading less desirable clays. U.S. Bureau of Mines publications (Ampian, 1985) categorize days into six groups. These are kaolin, fire clay, ball clay, bentonite, fuller's earth, and common clay. These are practical groupings based on clay production and usage in the United States. Among these groups bentonite, fuller's earth, and common clay are primarily composed of the minerals, smectite, illite, or chlorite, and are non-refractory. Kaolin, ball clay, and fire clay are commonly used in refractories and thus qualify as refractory clays.

Jan 1, 1986

By Brett Schug, Caelen Anderson, Sohail Nazari, Carlos Cristoffanini

"The Haile gold mine in South Carolina is increasing the automation level of its processing plant in order to improve operational stability. One step toward this goal is the application of a digital twin concept to provide virtual instruments. Haile has engaged Andritz to implement virtual instruments at its grinding area hydrocyclones and at its tailing thickener underflow pump. These virtual instruments provide density values in a traditionally difficult location for reliable slurry density measurement. The digital twin is a first-principles integrated design engineering with advanced simulation (IDEAS) simulation model, connected in real time to the control system. Results have been promising, with the virtual instrument values matching the physical instrument under normal operating conditions and showing better prediction under upset conditions. Haile plans to use the virtual instruments as optional process control parameters.OceanaGold’s Haile gold mine is located near Kershaw, SC, about 80 km (50 miles) southeast of Charlotte, NC. This location was first mined in 1827 and has produced gold through several operating periods since then, including a heap leaching operation from 1985 through 1992. In October 2015, OceanaGold acquired Romarco Minerals, the previous owner of the Haile operation.The current operation began in 2017 as an openpit mine with additional underground resources. The nameplate throughput is 5,760 t/d (6,350 stpd) ore, and 2017 production was 3,345 kg (118,000 oz) gold, with 3,968 to 4,384 kg (140,000 to 155,000 oz) gold expected in 2018. Proven and probable reserves exceed 85 t (3 million oz) gold at a grade of 2 g/t (0.06 oz/st) gold. The process, as shown in Fig. 1, includes a primary jaw crusher, comminution with a semiautogonous grinding (SAG) mill and ball mill circuit, flash flotation, rougher flotation, regrinding, pre-aeration, carbon-inleach leaching, carbon elution and regeneration, cyanide recovery, electrowinning and refining. The Haile operation’s inaugural gold pour took place Jan. 20, 2017. Mine life is expected through the year 2030."

Dec 1, 2018

By Stephen D. Schwochow

Aggregate producers nationwide well recognize the numerous problems often faced in securing local approval to open and operate new gravel pits and rock quarries. Similar problems are faced in Colorado, but this region also presents certain political, social, and geological complexities that have become particularly troublesome in the last 10 years. The gravity of the local permitting dilemma can be related directly to the worsening supply-demand imbalance for aggregates in the state's most populated area, the Front Range urban corridor, particularly the Denver metropolitan area. The drive to develop crushed-rock reserves to supplement dwindling alluvial supplies and to meet increasing regional growth demands was somewhat predictable but perhaps more a "last resort" alternative forced onto producers by a hesitant and often apathetic government.

Jan 1, 1982

By Carol A. Hill

Native sulfur occurs with barite, celestite, and bioepigenetic calcite in the Culberson, Pokorny , and Leonard Minerals deposits, Delaware basin. The sulfur in these deposits, in "castile" masses, and in deposits of the Fort S tockton district have 6 34s values between +9 and -15. Native sulfur in the caves of the Guadalupe Mountains is somewhat lighter [(634s = -15 to -25)]. Barite in the Culberson, Leonard Minerals, and Comanche Creek sulfur deposits have 63% values of +35 to +73; celestite in the Culberson and Leonard Minerals occurrences have values of +38 and +36, respectively, and 87Sr/86Sr values of 0.707808 and 0.708138, respectively. Barite associated with sulfide, deposits, Guadalupe Mountains, have [634s] values of +41 to +62. Barite at Seven aeart Gap, Apache Mountains, is somewhat less enriched in heavy sulfur [(634s = +14 to +37)].

Jan 1, 1992

By R. H. T. Garnett

Recovery performance may be measured in absolute terms or in relative ones that relate the actual mining outcome to what was expected. Consideration is possible in terms of the control exercised by the operator. The eventual mineral output is the only figure known with complete certainty. The paradox is that, while performance is judged against the sampling, the reverse also applies. The R/Efactor and its four component factors are the best overall measures of performance. The choice of equipment for sampling and mining is very important. The sampling process may introduce errors and the sample density may lead to poor mining block selection. The resulting recovery performance is most visible on a regression curve. Changes in the cutoff grade must also be taken into account to avoid unrealistic production targets. Estimation methods incorporating different mathematical assumptions and techniques may cause over-or underestimation of the grade and volume. If the selective ability of the mining equipment does not match the size of the reserve blocks, the performance will be compromised. The treatment plant efficiency, the throughput rate and the degree of bedrock clean-up also affect performance. The maximization of throughput does not yield the optimum results. Marine conditions, which are outside the operator's control, affect not only operational availability but also performance. Examples are provided from actual operations for various commodities, showing the relative magnitude of the different effects upon performance.

Jan 1, 1999

By L. Alan Weakly

The Powder River Basin of northeastern Wyoming and southcentral Montana contains the largest strip minable reserve of compliance coal (0.27 kg or 0.6 or less Ibs of sulfur per million Btu) in the United States. In mining parlance, it is the mother lode. Wyoming's portion of the Basin is called the Southern Powder River Basin (SPRB). It has been the nation's top coal producer for the past nine years. And based on 1997 production statistics and estimated strippable compliance coal reserves, Wyoming should remain the nation's top producer for the next 51 plus years. In August 1994, ME featured 10 articles that covered all aspects of coal production in the SPRB. In this issue, five authors update the 1994 articles and provide a pre- diction of what the Basin will look like at the turn of the century. In addition to this article, the titles and authors of the other five articles include: ? "Geology of Wyoming's Powder River Basin coal field," by Gary B. Glass and Robert M. Lyman. ? "Coal quality challenges in the Powder River Basin," by Sharon Roness, Richard A. Turpin and Robert A. Young. ? "Markets for Southern Powder River Basin coal," by , Patti J. Best and Patrick W. Wright. ? "Evolution of mining equipment in the Powder River Basin," by Kenneth R. Miller and James L. Long. ? "Hauling coal into the 21st century," by Dave Willis and Will Cunningham.

Jan 1, 1998

By Jaroslav Briancin, Katarína Gáborová, María Florencia Márquez-Zavalía, Marcela Achimovičová, Ol’ga Šestinová, Pavel Škácha

Naumannite (Ag,Se), a silver selenide mineral, was first discovered in 1828. This study investigates the structure, morphology, chemical composition, and leaching kinetics of naumannite. Mechanical activation in a planetary ball mill increased its specific surface area, enhancing the leaching rate of silver in nitric acid (HNO3). The study found that mechanical activation significantly improves silver recovery.

Jul 1, 2023

By Thomas E. Browne

The Electric Power Research Institute Energy Supply Program is developing coal supply forecasts. By coal supply forecasts I mean the future relationships between coal price and production levels. A representative supply curve is shown in Figure l. It will make the rest of my presentation clearer if at this point I give you some background about EPRI and the Energy Supply Program. EPRI is funded by the nation's electric utility industry to develop new technologies for the production and conservation of electricity. Most of the research is conducted by outside contractors. We participate in joint projects with the Department of Energy and other organizations. The Energy Supply Program is one of three "economic" programs. The other two are Energy Demand and Conservation, and Systems. The Systems Program's main function is to provide the means to integrate the output of the other two Programs. The primary function of the "economic" programs is to provide information pertaining to future energy prices, availability, requirements, etc. to the EPRI personnel planning R&D programs. A secondary role that is becoming more and more important is providing information of direct use to the electric utility industry. I should note that the results of all EPRI's contract work are available to the general public. A "Coal Supply Analysis System" is being developed for EPRI by Charles River Associates. To the extent possible it will draw upon existing work, but much additional work needs to be done in the area of coal supply economics.

Jan 1, 1977

By M. K. Gangal, E. D. Dainty

The CANMET diesel-related work, carried out in cooperation with the Canadian mining industry, resulted in the identification of several useful R/D studies. One such study was the development of a dash-mounted alarm signal system to indicate overexposure of production LHD diesel vehicle operators to toxic contaminants in a mine environment. The resulting instrument has been called the [CO2 Exposure Meter]. This meter is particularly applicable to LHD machines because previous investigations have indicated that operators of LHDs and some haulage truck drivers are exposed to up to 200% of the contaminant concentrations measured in the general mine return air. This paper describes the development of the system which continuously monitors and displays the operator's exposure to diesel pollutants, and indicates an overexposure by an alarm light. The overexposure limits are preset by mine personnel based on carbon dioxide (CO2) measurements, which in turn are related to simultaneous spot respirable combustible dust (RCD) measurements (or to Air Quality Indices - AQI, if available). The CO2 settings are, in general, related to the engine/exhaust treatment selections, vehicle duty cycle and local ventilation rates and efficiency. The system continuously displays one of three lights: green for underexposure, yellow for caution, and red for overexposure. Overexposure can occur for several reasons, such as: reduced ventilation, malfunction of the diesel vehicle, and excessive airborne contaminants. The paper confirms satisfactory operation of the system in a laboratory-simulated mine environment, as well as in field trials.

Jan 1, 1993

By F. Soumis

This paper describes an integrated procedure for the very short term production planning of an open pit and the execution of this plan: the truck dispatching. Integration of plan and dispatch means that the plan is realistic so that its objectives can be realized by the dispatch. This realism is obtained by supplying the plan optimization, which involves mixed integer programming, linear programming and non-linear programming, with experimental O.R. models of waiting and blending. The arrangement of these models in the computer programm has made it possible to obtain very short computing time for the planning in spite of the width of the optimisation. The dispatching of a truck is made by solving a classical assignment problem for each dispatch over a horizon of the expected*next 10-15 trucks to request dispatches. This deep-reaching dispatch procedure uses the continuously arriving information about trucks' positions and shovels situations and models by probability functions the expected waiting time of shovels and trucks. In this manner trucks and shovels are synchronized and last moments' opportunities for productivity gains can be obtained. The dispatch procedure takes .5 second on PDP11. This integrated planning and dispatch procedure gives high productivity while ensuring good blending. Results from the Mount Wright mine of the Quebec-Cartier Mining Co., where the integrated procedure has been installed on the existing computer equipment PDP11, are included.

Jan 1, 1989

By John W. Ahlrichs, E. Daniel Baker, Erich U. Petersen, William J. Tafuri, Douglas N. Halbe

The combined Bootstrap and Capstone deposits, located in the Bootstrap subdistrict (Section 10, T36N, R49E, M.D.B.M., Elko County, Nevada), are approximately 27 miles northwest of Ca-1I: Nevada. The contiguous Bootstrap Capstone deposits are located along the northeastern and northern flanks of Round Mountain, a horst block separated by grabens from the sheep Creek Mountains to the north-northwest and the Tuscarora Mountains to the east. Open-pit-minable gold reserves as of December, 1989, were 13.27 million short tons with an average grade of .057 troy ounces gold per ton and an overall waste-to-ore strip ratio of 2.5:1. Ore zones in Bootstrap are concentrated along north striking high-angle dikes localized along faults, while ore zones at Capstone are strata form and structural, occurring at the Devonian limestone/siliceous sediment interface and in high-angle fault-filling dikes. Pre-ore faulting produced a complex structural setting for Capstone, dominated by strong northwest fault sets cross-cut by northeasterly structures. Alteration associated with both deposits is silicification with a-strong argillic overprint. Dike emplacement, which post-dates silicification, marked the onset of mainstage gold deposition and argillic overprinting of silicified lithologies. Gold displays an affinity for moderately argillized sedimentary and igneous lithologies. Mineralogic and geochemical analyses of rotary percussion drill samples show good correlation between gold, silica, antimony, and arsenic.

Jan 1, 1990

By John A. Lombardi

The HW Process Technologies Engineered Membrane Separation (EMS"') technology is a patented system for the removal of multivalent base metal cyanide complexes from cyanide process streams, and EMSni permeate, concentrate and recovery terminology is explained. Specifically, use of the EMS™ system for the removal of Cu(CN)i- and Cu(CN)43- cop­per from cyanide process streams is discussed. The historical "Copper-Gold" processing paradigm of copper related cyanide consumption and complexation and methods to recover copper and copper complexed cyanide from Cu-Au process solutions are summarized. An advanced stage R&D sequential Cu-Au leaching circuit is proposed wherein two PLS streams are generated, i.e., a high copper tenor "first flush" Cu-PLS and low Cu tenor "second flush" Au-PLS. Copper and cyanide recovery from the EMS"' concentrate generated by Cu-PLS EMSTI,f processing by well known acidification processes and lesser developed, but techni­cally feasible, electrowinning processes are projected to be lower cost than similar dilute solution treatments. Gold is described as Merrill-Crowe plant recoverable from the EMS™ permeate stream coming from the Cu-PLS EMS"' process. Gold is also recovered from the EMSTI,f permeate generated by the processing of an Au-PLS bleedstream. The economics of the proposed Cu-Au-EMS"' circuits are estimated as $2/ gpd capital cost for large systems and $1- $3/ l 000 gallons treated operating cost plus royalty.

Jan 1, 1998

By L. Adler

Determining whether a railroad locomotive will skid under varying conditions is a fairly routine, pervasive problem. However, some of the equations provided are wrong, others are at best murky. All require correction or clarification. Skidding during heavy braking is a crucial safety problem, possibly resulting in loss of control and collision. It can also be an economic detriment, ruining wheels and tracks and, by inhibiting acceleration, causing reduced full-speed times. While skidding is less likely for rubber-tired equipment, a comparable problem exists for tractor-trailers operating on poor surfaces. The primary reference is to the SME Mining Engineering Handbook (pp. 14-11, Eqs. 7 and 8), which is taken as authoritative and normative (Brantner, 1973). Fundamentally, the physical weight of the locomotive can never be negative (-). However, based on this reference it can be negative on adverse grades, during braking (Eq. 7), and on favorable grades, whether accelerating or braking (Eq. 8). Additionally, it should be noted that the term rW should be Rw. To avoid having the locomotive weight turn out negative, "absolute value" brackets must enclose the right-hand expression of both equations. Also, the weight of locomotive can be greater than the right-hand side value introducing the common "greater than or equal to" symbol (>_). While these alterations are easy to make, the use of the algebraic sign associated with each term is still confusing, as

Jan 1, 1991

By S. K. MONDAL, K. K. K. SINGH, S. Singh, R. K. TIWARY, S. K. Chaulya, G. C. MONDAL, R. S. Singh, T. B. SINGH

In this work, a comprehensive field study was carried out to measure the background air quality status and identify the air pollution sources from opencast mines around a heritage site in India. Air quality modeling was conducted to envisage dust concentration due to existing and closed mines in the region. The air quality modeling exercise predicted that particulate-matter levels of PM10 and PM2.5 might increase in the ranges of 3.2 to 23.1 and 2.1 to 8.9 μg/m3, respectively, due to mining activities when some of the closed mines will be operated in the region without controlled emission. The predicted total PM10 and PM2.5 at the selected receptor locations were in the ranges of 86.39 to 194.89 and 34.82 to 99.55 μg/m3, respectively. Adequate measures were suggested to control air pollution from mining activities, and an intelligent dry fog system was designed to suppress dust emission efficiently from mineral processing plants and opencast mines. The developed system has special features for facilitating eco-friendly mining.

By Hans Svensson

INTRODUCTION The Alimak method of raising (Fig. 1) was intro¬duced in 1957. Because of its flexibility, economy, and speed, it soon became the most used system of raising in the world. With the same unit, raises of various areas, inclinations, and lengths can be driven. Air-motor¬-driven raise climbers normally are used in mines with short raises (Fig. 2). For longer raises electric or diesel-¬hydraulic drives are used. The Alimak raise climber is designed entirely in ac¬cordance with the instructions of the Swedish Board of Industrial Safety (Arbetarskyddsstyrelsen). There are good margins of safety concerning the breaking strength of the material and the raise climber comprises safety devices and features that practically eliminate the risks of accidents. The drive gear of air-driven climbers is equipped with an air-operated brake which is automatically activated when air for the motors is shut off. There is a safety device which activates automatically at overspeed and a speed-regulated brake for descent by gravity, by which the raise climber can be taken down to the bottom of the raise in case of cutoff of the air supply. The raise climber climbs along a pin rack welded to a guide rail which also comprises pipes for air and water. The guide. rail can be extended by using 1- or 2-m (3.2¬or 6.4-ft) sections as the driving progresses. Each guide rail section is bolted to the rock wall by special expan¬sion bolts of Alimak design. Men ride up to the face in the cage, traveling com¬fortably and easily while material is transported on the platform. There is no dangerous climbing up ladders. The men are well protected during ascent and arrive in good condition at the face. The greatest advantages of raise climber systems are flexibility and versatility. The equipment provides a comfortable working position in vertical as well as in¬clined raises of any area and length. The direction may

Jan 1, 1982

By Gregory P. White

A number of private companies and universities have developed computer programs which can be used to simulate surface coal mining by dragline. In this paper, we briefly discuss the concept of computer simulation, compare these computer programs with each other, describe the major changes required to convert these programs to an IBM computer system, and analyze their sensitivity to inaccurate input data. We also present a summary of the required data input for each program, core storage requirements, and output results. Sources for obtaining these programs and their documentation are listed at the end of the paper.

Jan 1, 1983

By T. BACHMANN, G. SHAPLAND, E. Amini, N. BEATON, M. BECERRA

In this study, several methodologies to manage low grade and often competent portion of the ore have been proposed and tested in lab, pilot and operational scales. Relevant to this subject, the Cooperative Research Centre for Optimising Resource Extraction (CRC ORE) has developed Grade Engineering® (GE) concept to modify feed streams by rejecting the low grade and possibly hard components in the stream at the early stages of a value chain. Application of GE requires to understand the impact of the process on the value chain as they are value modifiers on in situ opportunities. Traditional modelling approaches and tools do not have the ability to run the analysis in a block model scale with high fidelity in an integrated value chain. Integrated Extraction Simulator (IES) in conjunction with sophisticated analytical tools such as a neural network (NN) was used to develop and reconcile a fully integrated value chain. The value chain model makes it possible to run all available blocks in the Geomet block model, which could be several millions, under possible scenarios for Grade Engineering for economic evaluation analysis and mine planning.

Sep 16, 2020

By L. Xiao, P. Somasundaran

Using potassium oleate as a collector and alizarin red S as a modifying agent, selective depression of dolomite from francolite was achieved in an alkaline medium (pH > 9.0). Adsorption of alizarin reds alone on dolomite was found to be higher than that on francolite. Complimentary adsorption experiments of alizarin red S and oleate showed that oleate adsorprion was increased in the presence of alizaring red S. The results are explained in terms of comparative adsorption for the active sites on francolite and dolomite by oleate and alizarin red S and their interactions with dissolved mineral species in solution.

Jan 1, 1990