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By Thomas D. Henderson

Este capítulo presenta- un "caso histórico" de los pasos a dar para estimar IDS castes de capital y operativos para un concentrador típico de cobre porfirico de ± 9;070 toneladas métricas de producción diaria. El concentrador que se describe es hipotético, pero está basado en la experiencia propia y es, en efecto, una composición de varios proyectos reales. Las cifras utilizadas son ilustrativas solamente y no representan los castes reales de ningún lavadero en particular. Estas cifras son, sin embargo, representativas de los castes tipicos de molienda en un punto en el tiempo y son to suficientemente precisas coma para iIustrar los procedimientos de estimación de castes descriIos en este capítulo, No es posible publicar cifras reales y corrientes de los castes del lavadero y, en cualquier caso, las cifras de Ios castes reales pierden rápidamente su significación en Ia actual situación económica con los rápidos incrementos de las diversas partidas que configuran los castes. El trabajo está dividido en tres partes: (1) orden de la magnitud estimada, (2) estimación def estudio de viabilidad, y (3) comparación entre los castes estimados y los castes rea¬les. Con vistas a este trabajo supondremas que una mina tiene una propiedad minera explorada mediante perforación con testigos que refleja un yacimiento, ampliamente definido, como de unas 45,3 millones de toneladas métricas con una ley del d,6°/ de sulfuro de cobre, Esta compañia desea obtener primero una estimación del orden de magnitud de los costes (canto de los costes operativos como del capital) para determinar si la pertenencia garantiza más perforación y desmuestre de testigos. Suponiendo que esta evaluación económica obtenida utiIizando Ia orden de Ia magnitud de Ios costes sea favorable, sera a continuación requerido un estudio de viabilidad más preciso de los castes de capital y operativos. Seguidamente of recemas una descripción de los diferentes pasos dadospara desarrollar ]as costes del orden de primera magnitud y a continuación para los castes del estudio de viabilidad.

Jan 1, 1982

By Yashar Pourrahimian, Roberto Noriega

Truck fleet dispatching plays a crucial role in reducing operational costs and fulfilling operational targets in open-pit mining operations and is subject to large uncertainty arising from the operating cycles of trucks and loading equipment. This paper proposes a reinforcement learning-based truck dispatching system. Reinforcement learning is a machine learning area that deals with learning an optimal sequential decision-making strategy in an uncertain environment. An open-pit load-and-haul simulation is developed that also captures the truck movements and interactions in the shared road network, and a Neural Network is successfully trained to suggest truck dispatching decisions in a real-time manner.

Jun 25, 2023

By D. Hodouin

The optimisation of mineral processing plants requires the evaluation of performance indices such as production rate, product quality, valuable mineral recovery and process efficiency. Decision to change operating conditions or equipment to improve plant performances rely on the significancy of the estimated performance indices. The better is the quality of the estimation, the better is the discrimination capability of the index and as a consequence the larger is the operation improvement. The reliability of performance calculation depends on the sensors nature, accuracy and location, on the data redundancy, on the correction method applied to raw data and finally on the propagation of measurement errors along the calculation of performance indices. To maximize the quality of the data collected for performance evaluation, the following techniques are presented, discussed and illustrated: redundancy and observability analysis, data filtering for mass conservation, variance analysis of performance calculation, and data acquisition strategy design.

Jan 1, 1991

By J. D. Miller, J. Hupka

Important aspects of kerosene penetration into tar sand have been investigated. The natural tar sand porosity was measured and used to analyze the performance of the hot water process. Subsequently, pretreatment experiments, using 20-kg tar sand samples (Asphalt Ridge and Whiterocks, Utah) and kerosene as a diluent were carried out at the expected summer temperature (26°C) and the expected winter temperature (-14°C). The natural tar sand porosity accessible by diluent has a crucial impact on the reduction of bitumen viscosity and influences the penetration time required for successful bitumen separation from tar sand by hot water processing. Thus, the tar sand porosity is a critical variable that determines appropriate operating conditions. Experimental results indicate that diluent penetration into the Asphalt Ridge tar sand (high porosity) is almost complete after 30 min, whereas for the Whiterocks tar sand (low porosity) the penetration process is much slower, being still incomplete after 15 hours regardless of the ambient temperature.

Jan 1, 1994

By Andrzej Wala, Henry P. Cole, Perry David Passaro

Cognitive representations and misconceptions of flow through circuits is an area which has received little attention from science educators, cognitive psychologists, or accident investigators. Misconceptions are also called Aristotelian thinking. They involve a person using primitive unscientific ways of reasoning to make decisions about events (Piaget, 1929; Nussbaum & Novick, 1982; McCloskey, 1983). The use of such primitive concepts leads to errors in reasoning about scientific and technical problems. The existence of misconceptions is well documented among children, adolescents, and adults involved in learning science concepts (Piaget, 1929; Cole & Raven, 1969; Clement, 1982; Mistrell, 1982; McDermott, 1984; Richardson, 1987). Concepts of flow through circuits are important because miners' conceptual errors about these aspects may be, in part, responsible for two fatal mine disasters. On at least two separate occasions, methane gas explosions occurred in underground mines when separate ventilation systems were connected (Elam, Fuller, Carter, Cavanaugh, Fesak & Painter, 1983; Fesak & Cavanaugh, 1984). A review of these disasters indicates that conceptual errors made by miners may have resulted in the accidents (Cole, Wala, Haley, & Vaught, 1987). In this study, co-author Andrzej Wala, stated that his research had "identified conceptual errors that may have caused the miners in these disasters to make fatal mistakes" (Cole et al. 1987), p. 167. Further exploration of these conceptual errors by Wala has led to the hypothesis that misconceptions of basic aspects of flow distribution changes in mine ventilation circuits, are at least, in part, responsible for some mine disasters caused by errors in ventilation systems (Wala & Cole, 1987). Why should these conceptual errors occur? Ausubel (1963) suggested that students come to a new area of study with their own conceptions or preconceptions about how a process operates. Furthermore, these preconceptions may be in conflict with the empirical data from the discipline. In such cases, learning becomes a process in which new concepts must displace or be re-molded from stable concepts that the student has constructed over many years (Clement, 1982). Given the existing research with misconceptions and the work of Wala and Cole (1987), it was hypothesized that experienced miners; either working miners, students of mining engineering, or professional mining engineers, harbored misconceptions about the formal or conceptual aspects of mine ventilation circuits. The misconceptions hypothesized to exist involved flow distribution changes in complex mine ventilation circuits; specifically, how does flow distribution change when a ventilation circuit pathway is altered? Given this information, the following research questions were proposed. Research Questions 1. Do experienced miners and mining engineers harbor misconceptions about mine ventilation systems? This question was addressed by: A. The administration of the Cutthrough Ventilation Arrangements (CVA) exercise that measures subjects' performance level when making decisions about major ventilation changes when connecting two mine sections;

Jan 1, 1989

By James A. Morrison, Stephane Carayol, Paul H. Madsen

The Rio Piedras Alignment Section 7 of the Tren Urbano is currently being constructed beneath a historic commercial section of San Juan. Different portions of the section are being constructed using open cut, cut-and-cover, New Austrian Tunneling Method (NATM), Earth Pressure Balance Machine (EPBM), and as tacked drift mined support system. The combination of complex geology, low ground cover, and several innovative construction methods present many challenges to the ground control program. Mining and construction sequences were first developed to minimize ground movements and risk of damage to structures. A unique compensation-grouting program was developed to improve the ground, limit settlement, and recover settlements incurred due to mining.

Jan 1, 1999

By J. R. Palmes

Three coal samples, selected out of eight with well characterized surface properties, were used in flocculation tests and synthetic mixture of coal and silica was used in the selective flocculation experiments. Coal wettability and flocculant type were found to have a strong effect on the flocculation results.

Jan 1, 1993

By Brent A. Elliott, J. Richard Kyle

This article reviews the production trends of industrial minerals since 2000 for Texas, the leading U.S. producing state of industrial minerals with a total value of $5.2 billion in 2017, equivalent to 6.9 percent of all U.S. minerals value. Most current Texas industrial-mineral value comes from the production of cement, crushed stone, industrial sand, and construction sand and gravel. Construction material consumption is concentrated in the 25 metropolitan areas of the state, with production of industrial minerals in nearby counties. With Texas’ population projected to reach 50 million by 2050, continuing in-state development and production of industrial minerals will be required to meet in-state and regional demand. Texas’ most rapidly growing production of industrial minerals is industrial sand to supply proppants for multiple unconventional petroleum plays. Texas’ favorable geology and economic factors provide opportunities for the identification and development of new industrial-mineral production sites. Repurposing of former industrial-mineral production sites for post-production development likely will increase as efficient land use evolves. Understanding the geologic, economic and societal framework of industrial-mineral resources will facilitate more informed decisions about the complex issues that the region will face, including effects of sea-level rise on coastal infrastructure.

By William F. White

It is a pleasure to have the opportunity of being here today to discuss the application of horizontal filters in the metallurgical industries. The use of horizontal type filters has been limited in metallurgical plants. However, in the recent past there have been new designs of this type equipment which greatly broaden their field of application. Through their use in many applications, important economies can be achieved over more conventional methods. The first of the modern continuous horizontal filters was initially developed by Oliver United Filters as their scroll type horizontal filter. This was an outgrowth of the old Oliver Sand Table that was limited to very coarse, free filtering pulps containing no appreciable amount of fine particles. The sand table was rather limited in application. The later continuous scroll type horizontal filter provided for a reverse air blow after discharge which reslurried the heel remaining and permitted the filtration of pulps containing finer particles. In the manufacture of phosphoric acid by the ?wet? process, the filtration of gypsum from the strong acid presented an extremely difficult filtration problem due to blinding of the filter media caused by crystallization of the soluble salts contained in the acid. A filter which allowed for continuous cloth washing was required, and this led to the development of the continuous pan type, and travelling belt type horizontal filters which provided for this need. Among the filters developed were the Prayon by Engineering and Industrial Corporation of Luxembomg for use in their phosphoric acid plants. They are one of the largest manufacturers of phosphoric acid in Europe. The Dorr-Oliver Traveling Pan Filter was also developed by Mario Giorgini, Manager of Dorr-Oliver?s Italian subsidiary, for use with the Dorr Company?s phosphoric acid process. Basically, there are four existing types of horizontal filters in commercial use at this time: The scroll discharge non-pan type, the continuous belt type (Lurgi), rotary pan type, and the traveling belt type. The construction and principle of operation of these various filters will be discussed.

Jan 1, 1958

By M. Takayasu, J. Y. Hwang, F. J. Friedlaender, G. Kullerud

Al unite has been used as raw material for producing alumina and potassium sulfate fertilizer in Russia for many years. In the United States, this mineral has not been commercially processed though reserves of 5 to 10 billion tons of alunite ore have been estimated. Major constituents of these ores are quartz and alunite. The minerals are finely intergrown and liberation occurs below 10 µm. Adequate separation techniques for such ultrafine particles have not been developed. A new method for the beneficiation of al unite ore is proposed in this study. This method utilizes a small amount of fine magnetite upon which the liberated quartz is selectively flocculated. The co-flocculated magnetite and quartz are then separated from the alunite in a high gradient magnetic separator. Clean products, e.g., an al unite concentrate of 90% grade with 80% recovery, has been obtained from Utah ore. Techniques for selective co-flocculation of magnetite and quartz, separation of the carried quartz, and recovery of magnetite after separation are discussed.

Jan 1, 1987

By R. D. Miller, D. W. Steeples

Seismic reflection is a powerful geophysical exploration method that has been in widespread use in the petroleum industry for more than 60 years. This paper addresses some basic principles of the method and its application at depths shallower than 30 m (100 ft). Since 1980, the shallow reflection technique has been increasingly used for engineering and environmental problems, such as mapping bedrock beneath alluvium and delineating intra-alluvial features near hazardous waste sites, detecting voids in coal and karst, defining the top of the saturated zone and mapping shallow faults. New applications will be added with improved resolution and increased cost-effectiveness.

Jan 1, 1994

By L. O. Bond

High costs--and high risks--are normal in coal exploration and mine development. But risks and ultimate costs are minimized by foreknowledge of prospective coal seams and adjacent formations. Extensive drill hole programs are often used to obtain needed information. Cores and cuttings from these holes are used to determine coal location, thickness, and quality; they are also used to study physical and geological characteristics of surrounding beds. Valuable as these core and cuttings studies are, their effectiveness is often diminished by loss of recovery or by incomplete analysis. Needed is an effective and economical method for augmenting these studies. Well logs provide information of the type needed for efficient cool prospecting. Furthermore, obtaining these logs in drill holes, and evaluating the data they provide, is both fast and economical. To investigate the usefulness of well logging methods in coal explorations, the authors worked with Mr. Jon Jenkins of Truax Truer Coal Company. Logs were run in a number of drill holes in various areas of the Illinois Basin; these areas provided variety both in coal quality and geologic conditions. The data were studied extensively using computer methods similar to those now used in the evaluation of oil and gas wells. (2, 3) This study was used to produce a computer-generated analysis designed especially for mining problems.

Jan 1, 1969

By C. H. Lee, F. Concha, L. G. Austin, P. T. Luckie

The Concha-Almendra batch-settling treatment for concentrated suspensions of single-diameter spheres has been modified. This modified version is used in the differential equations of simple batch settling of a particle size range of different density materials. The equations have been programmed for a finite difference solution, and a number of test cases have been analyzed. By cutting the settling column at a fixed fractional height, the material below this height can be treated as underflow and the material above as overflow. The predicted partition curves obtained from treating the settling in this way have Sharpness Indices in the range of 0.5 to 0.6, in the absence of dispersion effects. The Sharpness Indices decrease as dispersion increases. When the feed size distributions are of the Rosin-Rammler form, the partition curves (corrected for the bypass fraction) fit the Rosin-Rammler equation with reasonable accuracy. The predicted Sharpness Index of a component of a mixture of two materials of different densities was unchanged from that of the same materials settled alone. However, for the same, feed size distribution and volume fraction of solids in the feed, the heavier material settled faster, and the lighter settled slower, than when settled alone.

Jan 1, 1993

As noted by D.W. Fuerstenau in his Plenary Lecture at the Conference on Extractive Metallurgy of Gold and Base Metals, Kalgoorlie, Australia, "Com¬minution of solids is surely one of the oldest technologies that, even in this day and age of DNAs, chips and space exploration, continues to challenge our scientific acumen and engineering ingenuity." Thus, the fundamentals of comminution continue to receive a great deal of attention in the literature. This was particularly true in 1992 with the publication of the proceedings from the SME-sponsored symposium, Comminution Theory and Practice. Papers covering topics ranging from liberation to comminution fundamentals to novel size reduction techniques are included in this review. Liberation Liberation continued to be a prime area of research interest, not only in terms of liberation modeling, but also in understanding the basic mechanisms involved in mineral liberation. King (Comminution - Theory and Practice, pp. 3-15) described a method for determining the interphase area between mineral grains. He showed how the mea¬surement of interphase area before and after comminution could be used to determine the presence or absence of intergranular fracture. Lin, Miller and Cortes (Kona, Vol. 7) discussed the use of computed tomography (CT) as a nondestructive means of investigating three-dimensional particle composition. The use of this technique in constructing coal washability curves from CT data was presented.

Jan 1, 1993

By James Wm. White

Mine management now recognizes the value of computer-based truck-shovel dispatching in open pit mines. The key tangible benefits are substantial productivity increases with a given fleet of equipment or, alternately, significant reductions in equipment required to meet production quotas. In this work, we review the literature, report on efficient, optimal algorithms for haul truck dispatching in real-time, and briefly discuss methods used by various mines to evaluate productivity improvements over manual methods. We also present actual results obtained at thirteen mining operations around the world.

Jan 1, 1992

By Matthew Burdick, Andrew Rule, Erica Bailey

The Second Narrows Water Supply Tunnel, Burrard Inlet Crossing project for the Greater Vancouver Water District entails deep shaft construction, subway sized pressurized face tunneling through highly variable ground conditions, installation of three permanent steel water mains and construction of elaborate valve chambers adjacent to either shaft. The paper discusses key elements of the planning and implementation of 6.69 m Ø slurry mixshield tunnel boring machine (TBM) assembly in a small diameter deep shaft including incorporation of a fully pressurized launch lock, preparations for saturation diving, surface support infrastructure and initial mining sequence.

Jun 13, 2021

By Scott Horton

In no Confederation of Independent States (CIS) country does the mining sector play quite so commanding a role as in the mountainous Central Asian republic of Kyrgyzstan. Its president, Askar Akayev, says he would like to develop his country into "a Central Asian Switzerland." However, in Switzerland, the gold is largely under the street along Zurich's renowned Bahnhofstrasse. In Kyrgyzstan, though, the gold is still in the mountains. Accordingly, Kyrgyzstan's recent adoption of a comprehensive new mining law has attracted widespread attention. Akayev recently completed a tour of the United States. His visit drew large crowds from the business community at events staged in New York and Washington, DC. The success can be attributed as much to the attractiveness of Kyrgyzstan's min¬ing sector as to the personal charms of the nation's president. Led by a half-billion-dollar investment by Canada's uranium giant Cameco, the mining sector is leading Kyrgyzstan's economic revival. And Bishkek is beginning to show some of the same signs of a "boom town" that already mark its Kazak neighbor, Almaty. Mercedes and BMWs already outnumber the Volgas on Bishkek's major traffic arteries. After nearly two years of debates involving government advisors and a final round of deliberation in Parliament, Kyrgyzstan finally adopted its second mining law. This followed quickly in the wake of measures enacted in neighboring Kazakstan and proposed in Russia. Kyrgyzstan's new law replaces the 1992 law "On Mineral Resources." It was one of the first enactments of an independent Kyrgyzstan. The 1992 law made a major contribution to the introduction of free-market economics in the country by ending the state monopoly over mineral exploration and development. It also laid the groundwork for an independent mining industry. According to Kyrgyz government reports, Kyrgyzstan has about 270 commercially viable deposits of almost 40 types of mineral resources. These include oil, gas, coal, precious-, nonferrous-, ferrous-, rare- and basemetals. However, the nation's key draw is gold. Since enactment of the first law, the government has issued more than 100 licenses for geological prospecting for and development of established deposits of gold.

Jan 1, 1998

By M. B. Haggerty, Joe Welna

The Minnesota Department of Transportation is constructing a stormwater storage facility (SSF) along Interstate 35W (I35W) south of downtown Minneapolis, MN. The project will provide storm surge capacity reducing the frequency with which major precipitation events result in flooding of I35W. The design consists of six, 42-foot diameter, 90-foot deep, adjacent underground shafts providing 14.7-acre feet of storage. Construction challenges include high groundwater with variable glacial outwash deposits. Constructability and ground variability were managed using construction manager general contractor (CMGC) project delivery. CMGC provides an environment for collaboration and innovation starting in the design phase and carrying through construction. This paper provides an overview of key efficiencies and collaboration examples implemented on the I35WSSF project which were aided by CMGC delivery.

Jun 13, 2023

By W. V. Harper

The travel path of a freed radioactive particle in an aquifer must be estimated from a limited number of available samples. This paper discusses geostatistical methods that minimize the 'uncertainty' associated with the predicted hydrologic surfaces and the predicted travel path. However, any estimation method will produce a single smooth predicted path. This 'sensitivity' will he evaluated using a geostatistical simulation method. The techniques will be illustrated using published data from the Wolfcamp and Pennsylvanian aquifers in the northern Texas Panhandle.

Jan 1, 1990

By J. P. Ulery

As a result of several recent methane/dust ignitions in surface auger and highwall mines, the U.S. Bureau of Mines investigated the occurrence of methane gas at these operations. Three mine sites were visited in western Kentucky and one in western Pennsylvania to collect run-of-mine coal samples for gas content determination using the modified-direct-method (MOM). Results indicate the samples emitted small quantities of methane, carbon dioxide, and nitrogen. Either methane or nitrogen was the predominant gas released. The same gases were released after crushing the samples for residual gas content; however, nitrogen was the primary component of this fraction. Total ~as contents ranged from less than 0.01 cm /g to 0.54 cm3/g. The hydrocarbon gases probably originated during coalification. Other gases may have originated partially as a byproduct of coalification and partially as a result of other, near-surface processes. The data suggest that although methane quantities are small, desorption could occur at near surface conditions prior to mining. The desorbed methane could accumulate as a free gas in fractures in the coal bed or roof rock. When these fractures are penetrated by the auger, methane could rapidly enter the whole atmosphere possibly creating explosive conditions.

Jan 1, 1994