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By J. Burgess Winter

It is an honor to present the lecture in honor of Daniel C. Jackling, the developer of the technology of copper mining that we continue to use 100 years later. He made a dramatic breakthrough in the early part of this century in the development of bulk-mining methods for large, low-grade porphyry copper-sulfide ore bodies. At Magma Copper, we are particularly proud that the Jackling Award states we have "made significant contributions to technical progress." Before Jackling's time, copper mining had exploited with primitive equipment very high-grade underground ore bodies and high-grade open pits. During the 20th century, the situation changed. Three significant innovations occurred within about 10 years around the turn of the century. In 1903, Jackling's concept of large-scale mining with steam shovels and rail haulage was implemented at the Bingham Canyon mine in Utah. Eighty years after the introduction of rail haulage, the mine converted to truck haulage with large-capacity high-efficiency haul trucks and reduced the stripping ratio from 3.5:1 to less than 1:1.

Jan 1, 1995

By J. F. Lupo

Leaching operations combine both metallurgical and hydraulic processes to extract metals from the ore heap. In the design of leaching operations, metallurgical tests and simple hydraulic tests are often conducted to define operational parameters such as leach cycle time, application rate, lift height, and effective leach area. While metallurgical constraints are often the primary focus on leach facility design, the hydraulic factors are also critical to the overall success of the operation. Some of the hydraulic factors that are known to impact solution flow through heaps include: • Ore physical and hydraulic properties, • Variation in ore properties under heap loading, • Ore mineralogy and its susceptibility to chemical and/or mechanical degradation, and • Heterogeneities within the heap. This paper presents a discussion on hydraulic factors that may impact the effectiveness of leaching operations. In addition, methods are presented which may be used to assess flow conditions within active and inactive heaps.

Jan 1, 2000

By G. Arpa

Ventilation survey using tracer gas measurement is one of the techniques for mine ventilation design, monitoring and investigation of movement of fresh air and contaminants. However, there has been little research into using both tracer gas monitoring and numerical simulation. In this research, tracer gas technique was used for quantitative assessment of airflows through narrow vein shrinkage stopes with various opening shapes and friction factors. SF6 was used as a tracer gas to monitor airflow through three narrow vein shrinkage stopes in order to obtain diffusion concentration curves against elapsed time. The mine ventilation simulator, MIVENA Ver.6, was used to construct the entire ventilation network of the mine to monitor airflows through the stopes. The diffusion concentration curves against elapsed time were simulated with a numerical model. The result shows that the concentration-time curve is unsymmetrical and is skewed to the front of the flow direction. From the results of history-matching between the measured and the simulated curves, volume flow rates of airways and stopes were evaluated. Importantly, the tailing effect of the concentration-time curve between the measured and simulated is greatly improved by reconstructing an equivalent airflow route to represent unused mine openings, dead end drives and other open spaces. Finally, it can be concluded that openings, dead end drives and other open spaces have no relation on flow rates, but affect the airflow quality provided from the inlet portal as shown by tracer gas diffusion characteristics.

Jan 1, 2009

By H. J. Haselhuhn

Selective flocculation and dispersion processes for the concentration of hematite ore are strongly dependent on the ionic content of the process water. It has been noticed that magnesium ions are more detrimental to iron recoveries during desliming and flotation processes than calcium. This phenomenon was studied by measuring the zeta potential of hematite ore at various concentrations of magnesium, calcium, strontium and barium at a pH of 11. Results show that zeta potential inverts from negative to positive at very low concentrations of magnesium ions in the solution. It takes a significantly higher concentration of calcium, ions to achieve the same effect. This difference may be attributed to the ability of magnesium ions to adsorb to all surface hydroxyl groups, whereas calcium, due to their larger size, can only adsorb to every other hydroxyl group. This hypothesis was confirmed by results similar to those seen with calcium when this test was repeated with strontium and barium ions. The tendency for calcium ions to adsorb to every other surface hydroxyl group causes higher concentrations of calcium to be less detrimental to hematite concentration processes than magnesium.

Feb 27, 2013

By E. Galán

The largest Spanish kaolin deposits formed on granites occur in Galicia (NW Spain) due to a widespread kaolinization of Variscan granitoids. This paper provides insight of the origin of this kaolinization process on the basis of a mineralogical and geochemical study carried out in two kaolin deposits, presently mined to be used in the paper industry. Mineral composition of the deeply kaolinized rocks is dominated by well-ordered kaolinite with minor quartz, K-feldspar, mica (illite/muscovite), locally gibbsite, and traces of resistant accessory phases (rutile, ilmenite, zircon and monazite). The content and structural order of the kaolinite decrease with depth. Kaolinite formed by extensive replacement of feldspars (plagioclase). Differential mobilization of major and trace elements during kaolinization has been inferred by using a mass-balance approach. Significant amounts of Na, Ca and minor Mn, Sr, P and U were removed from incipiently leachable minerals (plagioclase and apatite), and K, Rb, Cs and Ba were released from K-feldspar and mica. On the contrary, Ti, Zr, Th, Hf and the REE are retained in the resistant trace minerals that are concentrated in the fine fractions of the kaolins.

Jan 1, 2010

By M. Javier

Defining the concept of sustainability is an important step for industry and society. It is necessary in order to clarify what it means when debunking the many misinterpretations pervasive in different levels of anthropogenic activities. Essentially, the extractive industry has a harvest of differences. Mining involves the extraction of natural resources which are finite, exhaustible, non-renewable, unsustainable, and pay only once. It is remarkable that the definition of sustainability that we will shortly arrive at has totally different characteristics from the definition accepted throughout society. We categorize nature as having its own destiny which is controlled by its own rules and principles and its own society, and is part of nature; therefore, society depends on nature and not vice versa as the initial focus. To society there are no conditions to humanize nature but only respect nature?s rules. It was a challenge to find simplicity for this task not only for the definition but also for the explanation of this concept specifically, to answer the question, ?what is the true meaning of sustainability?? Finally, we are also able through this definition to provide fuel for wide discussions and stimulate critical thinking to improve such a concept. As a result, we present this definition as the tool for society today and for future generations.

Jan 1, 2012

North American Coal is a subsidiary of NACCO Industries. Originally founded as Cleveland and Western Coal in 1913, North American Coal took its present name in1925. Today, North American Coal is one of the 10largest coal producers in America, mining about 32Mt/a (35 million stpy). The company mines primarily lignite for electric utilities. Its current operations are in North Dakota, Texas, Louisiana, and Mississippi. In addition, North American Coal’s Florida operation provides dragline mining services for quarries that produce more than 18Mt/a (20 million stpy) of limerock. With more than 1.8 Gt (2 billion st)of bituminous and lignite coal re-serves in the United States, North American Coal constantly seeks new technologies to keep its operations modern, productive and cost competitive.

Jan 1, 2004

By F. Bruey

The Factorial Model Experimenters are often interested in systems that are multi-factorial. A multi-factorial system is one whose output is believed or known to be dependent on the particular settings of several inputs, or factors. We can think of these factors as defining a space, with each point in this space corresponding to a particular set of factor settings. Experimenting can be thought of as exploring this space - finding out how the response of the system changes as factor settings are changed. There are several challenges in this exploration, among which are deciding what region to explore, designing an experiment that explores it most effectively, and describing the results of the exploration. This paper deals principally with the last of these; it shows how the factorial model can be used to describe how the response of the system changes as factor settings are changed. A strength of the factorial model is that it treats the factors as causes of change in the system's response and focuses on relations among these causes. In particular, the factorial model focuses on whether causes act independently on the system (in a sense to be explained below), or whether they interact. This is important because the experimenter generally seeks to control the system, and because control based on causes that act independently of other causes is relatively simple, whereas control based on causes that interact is more challenging. Also, mapping the space - finding out how the response of the system changes as factor settings are changed - will require less work if, during the exploration, it can be determined which of the causes act independently. For the sake of example, let us assume that the space we are exploring is three-dimensional, and that we have already defined, for each of the three factors, the range of interest. Let us consider all the ways in which the response of the system might depend on the settings of these three factors. In the simplest case, the response in this region does not depend on any of the factors. The response is constant throughout the space, at say, 80 units.

Jan 1, 2007

By Thom Seal, S. J. Jung

This paper will combine three SME annual meeting presentations on reducing gold inventory in cyanide heap leaching. Information on Part I – Side slope leaching (SME 2003), Part II – Determining the dry zones using geophysical resistivity (SME 2004), and Part III - Presents a new technology “Hydro-Jex”, to introduce the required lixiviants to the un-leach or under-leach zones in heaps (SME 2005). This paper will describe how Newmont Mining Corporation continues to improve the economics of the heap leaching process for precious metals recovery.

Jan 1, 2005

By Y. Nien Wang, Moe Amini, Heiner Sander, Max John

INTRODUCTION As the population increased along the coast route (California Route 1), and the people’s need to have guaranteed access increased, the landslides and related road closures began to have serious adverse economic impacts. Landslides were causing major long-term road closures about every 10 years on average. In 1983, ground movement at Devil’s Slide caused Highway 1 to be closed for an extended period of time which caused significant economic loss to the surrounding coastal communities. A number of options for bypassing the slide area were considered, and the Martini Creek inland bypass was selected for design. Subsequent litigation led to the creation of the Devil’s Slide Tunnel Study in 1996. The results of this study indicated that a tunnel alternative would be competitive with the inland bypass. The final decision was left to the citizens of San Mateo County, who approved the tunnel alternative in the November, 1996 election After completion of environmental studies and the processing of legal challenges, the final environmental document was finished in 2001. The preferred tunnel alternative was designated to proceed for final design and construction. PROJECT DESCRIPTION The Devil’s Slide Tunnels consists of a separated two-lane road, one lane in each direction, which passes through twin tunnels and over twin bridges and then connects with the existing non-separated, two-lane road at each end. The total length of the project is approximately 1900 meters consisting of four main project divisions, which are described below, going from south to north. 1.Operations and Maintenance Center (OMC) area, 2.Southern approach roadways to the South Portals (250 meters), including the South Rock Cut,

Jan 1, 2005

By A. Bobet

Design of a new underground laboratory is underway through the auspices of the United States National Science Foundation. The Deep Underground Science and Engineering Laboratory (DUSEL) is scoped to provide a diverse group of researchers with a dedicated underground facility capable of supporting a broad spectrum of fundamental and applied research at depth in the Earth?s crust. Key research partners in the endeavor are physicists, biologists, geoscientists and engineers. Engineers are not only designing the underground facilities, but are also actively involved in developing research initiatives. This paper will introduce the DUSEL engineering research program to the mining community, provide an overview of the site, geology, and laboratory facilities, and describe some key program initiatives. The particular technical challenges and opportunities afforded by the construction of DUSEL and the performance of the integrated science-engineering program will be discussed by reference to a subset of research initiatives that are currently under development: Cavern Design, CO2 Sequestration and Transparent Earth. These research initiatives target the development of new techniques that can support improved subsurface investigation, design and construction procedures. An increased use of the subsurface can actively contribute to the development of new, more sustainable solutions for use in mining and civil engineering practice.

Jan 1, 2011

By S. Ragab

The objective of flotation models is to predict the recovery rate of minerals from a flotation cell. In this paper a CFD?based flotation models is presented. The model uses first order rate equation, and the collision frequency is estimated using Abrahamson [1] model with input from CFD two-phase simulations. Spatial distributions of dissipation rate and air volume fraction (also called void fraction) are determined by the two-phase hydrodynamic simulations. Knowing these parameters throughout the machine is essential in understanding the effectiveness of different components (rotor, stator or disperser, jets) on the flotation efficiency. Not only the average pulp recovery rate can be estimated but also the regions of high/low recovery rate can be identified. The CFD-based flotation model presented here can be used to determine the dependence of recovery rate constant at any locality within the pulp on particle diameter, particle specific gravity, contact angle, and surface tension.

Jan 1, 2012

The mining industry continues to experience a skills shortage and this is having an impact on the ability of mining companies to operate sustainably. Apart from a few exceptions, there is a dearth of geologists, mining engineers, metallurgists as well as environmental scientists and other professionals in the global mining industry. This relates to both quantity and quality. It makes good business sense for mining companies to employ local professionals rather than expensive expatriate staff. In some cases a mining company could employ more than 10 local mining engineers for the cost of one expatriate. However, in many countries local professionals are not always equipped professionally to work on mine sites. The result is that many companies are not operated optimally due to human resources gaps. In some cases, particularly in key areas such as mine planning, this threatens the sustainability of the operation or at the very least results in sub-optimal resource utilisation. This paper briefly presents some of the issues and strategies being implemented and that might be implemented to maintain a sustainable supply of quality minerals graduates to the industry in 2011 and beyond.

Jan 1, 2011

By Bruce W. Woolpert

During the SME Board of Directors’ midyear meeting in Monterey, CA Aug. 25, I discussed trends in the construction aggregates industry. Many construction-material suppliers may not have yet fully internalized the changes that are taking place. But the changes are significant. And they have shifted the focus in the aggregates industry from “assets” to “people and innovation.” Construction-material suppliers serve many customers. A typical quarrying operation at Graniterock would have more than 1,000 customers, mostly civil engineering contractors. Along with the push toward people and innovation, there is increased emphasis on vertical integration from aggregates to ready-mix concrete and hot mix asphalt, to final construction. If a company is not vertically integrated, it will at least have strong partnerships with other firms, to deliver a high-quality finished project on time.

Jan 1, 2002

By M. Baumann

Introduction Gold Quarry is one of the largest gold deposits in Nevada, located along the Carlin Trend, approximately seven miles north of Carlin, NV. Owned and operated by Newmont Mining Corporation, as of December 31, 2005, Gold Quarry had produced over 13 million ounces of gold. Multiple simulations were constructed for gold and metallurgical variables using the Stepwise Conditional Transformation method. Analyses of these simulations have been used for a variety of purposes, including an assessment of uncertainty with various ore types. This assessment provides insight for improved modeling and reconciliation. Geological Framework Gold Quarry is a large, low-grade disseminated gold deposit hosted in Silurian-Devonian aged sediments at the Chukar/Alunite-Good Hope fault intersection. Gold bearing hydrothermal fluids appear to have migrated upwards along the Chukar/Alunite and Deep Sulfide Feeder faults and then moved outward along favorable stratigraphic horizons and structural intersections.

Jan 1, 2007

By M. Li, J. D. Miller

Many technology problems must be solved if we are to continue to produce phosphate at our current rate of consumption. The U.S. produces at least 25% of the world's phosphate, 40 million tons of phosphate rock per annum with most of the production coming from Florida. Of particular concern are improved separation efficiency and the ability to treat new dolomitic resources. Phosphate flotation technology needs include: 1. Simplification of the standard flowsheet 2. Improved recovery of coarse phosphate 3. Selective flotation for phosphate recovery from dolomitic resources Preliminary results, including tests on plant feed from Florida show that these objectives may be achieved with a new collector chemistry depending on the specific circumstances. The effectiveness of the new collector chemistry has been demonstrated by the preliminary results from single stage flotation experiments both at the University of Utah laboratories and at Florida Institute of Phosphate Research (FIPR) laboratories. In the best case, from these experiments with low grade (5% P2O5) coarse feed (16x35 mesh), a single stage phosphate recovery of 95 % was achieved with a concentrate grade of 31 % P2O5. Such a separation efficiency could not be achieved using the traditional fatty acid/fuel oil collector. Based on these results it seems that a one step process may be possible for phosphate flotation and a research program is justified for the development of this new flotation strategy.

Jan 1, 2001

By U. Heuer, B. Rathmann

Many mining operations have gained an impressive expertise in trouble shooting and maintenance with their existing fleet over the years. Whether it is an in-house maintenance group or an external service group - most of the systems weak points are well known and can be corrected by maintenance personnel. As some of these issues get more and more serious each year, too much time is lost in unscheduled downtime, often taking hours to be repaired and to find the failure with obsolete diagnostic tools (Fig. 1.). Many of the breakdowns result from failures that cannot be detected in advance. The maintenance system is much more reactive than preventative. The state of the art of mining equipment today uses advanced, efficient, and reliable systems for electrical drives, control and diagnostics of the machines. The demand for highly sophisticated solutions on such mining equipment is well known. Mining operators need to ensure the highest level of productivity, lowest operating costs, least maintenance and highest reliability in a drive system. The paper will introduce you to the state of the art of drives technology for dragline (Fig. 2) and shovel mining equipment (Fig. 3).

Jan 1, 2007

By Thomas J. DeMull

Development of the Batu Hijau copper project was completed in the fourth quarter of 1999 with the formal handover and start-up of ore processing facilities. The project began in August 1996 when the owner, PT Newmont Nusa Tenggara (PTNNT), awarded an engineering, procurement and construction (EPC)contract to Fluor Daniel (FD) for the development of the project. This included a copper concentrator, port, power plant, town site and infrastructure. PTNNT managed the development of the mine and the procurement of the mine equipment. In 1996, Batu Hijau was the largest mining project ever undertaken. Developing the Batu Hijau Mine was complex. It involved the work of thousands of people in all parts of the world to plan, engineer, procure, fabricate and manufacture equipment, supply and deliver materials and equipment, and build the plant.

Jan 1, 2002

By M. Buxton

Sensor derived data can add value across the mining operating chain ranging from resource definition, extraction, pre ? concentration, mineral process monitoring and assessment of product quality. Most documented studies on the use of sensors in mining focus on specific technologies for specific applications. These studies do not take into account different aims, objectives and operating conditions at different steps in the value chain. The first part of this contribution assesses key physical performance and discriminatory requirements of sensors applied in each portion of the mining value chain. The second part proposes a framework of methods for quantifying the value added by additional sensor information. Integrating the sensor based technology and the economic value quantification allows for both, designing an economically optimal sensor monitoring network along the whole mining value chain and optimizing efficiencies. Illustrative studies demonstrate the significant economic benefits, in particular in reduction of exploration expenditures, increase in extraction efficiencies, increase in ore product quality and improvement of processing efficiencies.

Feb 27, 2013

By W. H. Langer

Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

Jan 1, 2009