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By John Frostiak

"Kahama Mining Corporation Limited, a wholly owned subsidiary of Barrick Gold Corporation, poured the first dore bar and filtered the first concentrate produced at the Bulyanhulu mine on February 28, 2001. This event marked the completion of the initial development of the Bulyanhulu Mine – Barrick’s first mine located outside of the Americas.Bulyanhulu is a 2,500 tpd underground mine located in the Lake Victoria gold belt of northern Tanzania. Gold is recovered as a gravity concentrate and smelted on site to produce dore bars or collected in copper concentrate that is shipped to offshore smelters. The facilities were constructed to meet Canadian standards. Unit operations include single stage crushing, SAG milling, gravity recovery, flotation, thickening and dewatering. Tailings are converted to paste and returned underground as paste backfill or pumped to the surface tailing site. The surface paste tailing disposal system is believed to be first of its kind in the gold industry. Paste disposal has several advantages over slurry, including lower dam construction costs, reduced water losses, and lower reclamation costs. This paper describes the facilities and discusses the challenges faced during development and construction including logistics, lack of infrastructure, recruiting and training, security, and social issues as well as initial operating results.INTRODUCTIONBarrick Gold Corporation completed the Bulyanhulu mine development in 2001. Capital cost of the project was US$280 million. The mine produced 241,575 ounces from start of milling to year end at a total cash cost of $197 per ounce. Numerous challenges were overcome in the mine’s development due to the general lack of infrastructure in Tanzania and the mine’s location some 1200 km inland by road from the port of Dar es Salaam."

Jan 1, 2003

By B. Caro Vargas

The Toulon South Tunnel in France is the second part of a project started 20 years ago. After the problems and delays suffered during the construction of the North Tunnel, due to a complex geologic context of highly fractured and soft rocks under a highly urbanized environment, a very dense automatic monitoring system was implemented to control the settlements of surface (more than 1000 points), the structures adjacent to the tunnel alignment and the underground galleries being constructed. The latest automatic instrumentation systems were installed, using for example AMTS capabilities in terms of ?automatic prismless settlement monitoring?. All the data (geotechnical, structural and geological) was gathered in a global automatic data acquisition system and continuously available on a web based interface. Three different threshold levels (notification, anomaly, alert) were set up, each one with a differential and an absolute value for settlements. Depending on the actual geological site conditions and the actual monitored settlements, different supporting systems and excavation techniques were used. Furthermore, the monitoring data was also used to predict and anticipate the future settlement, by comparing it continuously with the theoretical Peck settlement curves. This method allowed a better risk management by limiting the settlement on existing structures and helped to secure the Works progress schedule, for a project that lasts from July 2007 to March 2011. The implementation of this observational method application is presented in this paper.

Jan 1, 2012

By G. F. Kuncir

The analysis summarized herein evaluates the Bureau of Mines Program for Advancing Mining Technology Oil Shale in terms of the economic benefits which may be derived for the Nation as a result of its successful research and development efforts. On the basis of postulated oil shale production scenarios, benefit-cost ratio indicators are computed for the program elements as they apply to surface, underground, and modified in situ oil shale mining systems. Eight value indicators are used to measure the Program's beneficial impact on the future oil shale industry in relation to planned research and development costs. These are: capital cost savings, operating cost savings, labor savings, environmental quality maintenance cost reduction, reduction in production costs, byproduct production benefits, total production benefits, and additions to recoverable reserves. Program costs are aggregated from 1974 through 1987 and major benefits are accrued from 1982 through 2040. Both cost and benefit streams are discounted to mid-1975 present value.

Jan 1, 1977

By Greg S. Williams, Richard W. Givens

This paper examines the effect of prill size consistency, internal panicle density, and oil absorbency on Ammonium Nitrate Fuel Oil (ANFO)-emulsion blends. By analyzing these physical properties of prill and the nature of the blending process, a mathematical model has been developed to theoretically predict blend densities. Calculated densities can now be compared to actual field densities to give an operator a basis for comparing various manufacturers’ emssions and Ammonium Nitrate (AN) during bid solicitation. The lowest priced emulsion and/or AN may not be the most economical, due to the impact of specific physical characteristics. These factors dictate the blending mechanics and resulting density yields for various mixes. The research was driven from observed ‘field’ mixing relationships and data. Ultimately, such a model can be an effective tool in evaluating blends from a cost and performance basis.

Jan 1, 1992

By Q. Wu

Neural network methodology is used to predict mean particle size resulting from rock blast fragmentation. A blast data base developed in a previous study is used in the current study. A part of this blast data was used to train a single-hidden layer back propagation neural network model for each of the similarity groups obtained in the same previous study. Levenberg-Marquardt algorithm provided the most stable and efficient training out of the four algorithms evaluated. An extensive analysis was performed using a part of the blast data to estimate the optimum number of units for the hidden layer for each similarity group. The remaining blast data are used to validate the trained neural network models. Capability of the developed neural network models is determined by comparing predictions with measured values and predictions based on one of the most applied fragmentation prediction models appearing in the blasting literature. Prediction capability of the neural network models was found to be strong and better than the existing most applied model. Diversity of the blasts data used is one of the most important aspects of the developed models. The developed neural network models are suitable for practical use at mines.

Jan 1, 2011

By William N. Patterson

Drive systems for mining machines are usually sized to accommodate anticipated peak loads. Usually, the average power requirements are considerably less. Energy storage and power averaging are attractive concepts for mining machinery and could have far-reaching implications. The purpose of this program was to: ? Identify truly feasible concepts, ? Identify advantages/disadvantages, limitations, and constraints, ? Evaluate feasibility based on today?s technology, ? Identify anticipated safety problems, and ? Provide the designer with a comprehensive literature base. Concepts evaluated include flywheels, high energy batteries, gas charged accumulators, inductive storage, capacitive storage, springs and counterweights, thermal, closed cycles, internal combustion engines, trolley systems, and hybrid systems. A comprehensive reference index is provided. Included is an appendix containing abstracts of the pertinent literature.

Jan 1, 1980

By D. K. Caddel

Several problems exist with the present design of coveralls used by miners in low coal (seam height 48 inches or less). The back portion of the coveralls often tears when roof bolts or rough areas in the roof are hit. Movement in the shoulder area is restricted. Female low coal miners find it difficult to purchase coveralls that fit properly, and must remove both their hard hat and safety belt in order to urinate and defecate. The objective of this research was to design coveralls which would alleviate these problems. The following features were incorporated into the coveralls; padding in the upper back area to avoid tearing, an action pleat in the shoulders to increase mobility, an inseam zipper to more easily allow miners to perform their bodily functions, and reflective tape to increase visibi¬lity of the miner. A heavyweight denim fabric was used to increase warmth and durability of the coveralls. The coveralls were assessed K long four parameters (comfort, safety, worker productivity, and fabric suitability) using both an in-field assessment by low coal miners and simulation studies. The experimental coveralls proved superior to conventional coveralls along all four parameters. Work clothing sizes for female miners were developed.

Jan 1, 1982

Jan 1, 2004

By J. Evans

Including: Tailings thickeners, CCD?s, paste thickeners, HI-rate thickeners, lamella thickeners, high compression thickeners, clarifiers etc. Flocculant dosing control for mining thickeners and clarifiers is influenced by a number of process factors. 1. Flow rate into the thickener or clarifier a) As the flow rate increases into the thickener or clarifier ?retention time? decreases which causes a greater affect hydraulically on the settling solids. So as the flow rate increases it will generally mean an increase in flocculant dosing rate. b) As the flow rate decreases into the thickener or clarifier the retention time increases which reduces the hydraulic affect on settling, improving settling rates. This will generally mean that as the flow rate decreases, we will decrease the flocculant dose rate.

Jan 1, 2011

By C. Froger

Since its creation in 1950, the Centre d'Etudes et Recherches des Charbonnages de France at Verneuil-en-Halatte (Oise) has been conducting many investigations concerned with airborne dust measurements, particularly in underground mines. The work has resulted in the development, a few years ago, of a new process of dust sampling, whereby the airborne dust particles are collected by a rotary filter of polyurethane foam rotating at high speed within 8 housing.

Jan 1, 1973

By H. Yavuz

Closed form solutions assume opening shape to be circular to simplify the calculation of the ground response curve for the design of underground openings. However, in mining and civil engineering works, non-circular openings are commonly excavated. Therefore, there is a need to estimate the ground response curve for such openings. In this respect, a simple model for circular, arch and rectangular shape underground openings subject to a hydrostatic stress field is the aim of this study. A comprehensive numerical modelling, using the finite difference method, based on numerical modelling code FLAC version 4.0, was carried out. In addition to shape of an opening, the effect of rock mass strength, opening size, in situ stress on strain (tunnel deformation to tunnel radius) of the opening in response to applied support pressures was investigated parametrically by developing models for each specific condition. The strain results for each excavation shape obtained from this large number of models against the normalized strength of rock mass and internal support pressure with in situ stress magnitude were evaluated by multiple regression analysis. As a result, a model that was well correlated to data was developed for an overall estimate of the ground response curve depending on relevant effecting parameters. The regression coefficients of the model were given for estimating both roof and sidewall response curve of each excavation shape. The model was verified by statistical tests and by an analytical solution. Diagrams were also established to highlight the influence of relevant parameters and to estimate the support pressure for a stable opening staying within the acceptable limits of strain. Strains occurring in a rectangular opening are found to be larger than those in the arch and circular openings for the other fixed parameters. In the mean time, larger strains occur around an arch shape opening than a circular opening.

Jan 1, 2006

By Mark Jolly

"Instead of using the traditional batch casting process, the CRIMSON [1] (Constrained Rapid Induction Melting Single Shot Up-Casting) method employs a high-powered furnace to melt just enough metal to fill a single mould in a closed crucible. The crucible is transferred to a station for computer-controlled counter gravity filling of the mould for optimum filling and solidification. The CRIMSON method therefore holds the liquid aluminium for a minimum of time drastically reducing the energy losses attributed to holding the metal at temperature. With the rapid melting times achieved, of the order of minutes, there isn’t a long time at temperature for hydrogen to be absorbed or for thick layers of oxide to form. The metal is never allowed to fall under gravity and therefore any oxide formed is not entrained within the liquid. Thus higher quality castings are produced leading to a reduction in scrap rate and reduced overall energy losses.IntroductionEngineers at the University of Birmingham, England, with local company, NTec, have invented a new casting process that will reduce the energy costs of light-metal foundries. The technology, entitled CRIMSON, means that foundries need only heat the quantity of metal required to fill a single mould rather than large batches that use unnecessary energy and create waste. The complete concept of CRIMSON requires a change of philosophy in the approach to casting and requires the user to think holistically in order to reap the full benefits from the process. This paper will discuss the various aspects of energy wastage within the foundry sector and discusses the processes whereby the energy can be reduced. Primarily the author focuses on the aluminium sector but CRIMSON can be applied to many of the non-ferrous “light” alloys. Ferrous materials and non-ferrous “heavy” alloys can also benefit from some of the ideas but not necessarily directly from the application of CRIMSON."

Jan 1, 2010

The 108th Annual General Meeting of The South African Institute of Mining and Metallurgy was held at The Country Club, Johannesburg, Napier Road, Auckland Park on Thursday, 11 August, 2005. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations, also to recipients of awards, senior members of industry, Honorary Life Fellows, past-presidents, our members and other guests, among them the following: Dr Con Fauconnier, President, Chamber of Mines of South Africa Prof. Jay Barton, President, The Geological Society of South Africa V. Townshend, President, Institute of Certificated Mechanical and Electric Engineering, South Africa M. Livingstone-Blevins, President, Institute of Certificated Mechanical and Electrical Engineers, South Africa Prof. B. Lacquet, President, South African Institute of Electrical Engineers Dr F. Malan, President, South African National Institute of Rock Engineering

Jan 1, 2005

By Lukasz Maciag, Ryszard Andrzej Kotlinski, Ryszard Krzysztof Borówka, Dominik Zawadzki

Concentration and composition of rare earth elements (REE) and major elements in the sediment samples from the IOM H11 Fe-Mn nodule deposit, eastern part of the Clarion-Clipperton nodule field (located between the Clarion-Clipperton Fracture Zone - CCFZ; tropical Pacific), have been studied. We show the controls on REE concentrations and described vertical/horizontal variability of selected metals in pelagic sediments from the CCFZ. According to Kato et al. (2011), who analyzed 2000 seafloor sediment samples at 78 sites of the Pacific Ocean, deep-sea mud shows high concentrations (2230 ppm maximum) of ?REY and could be potential resource of these elements in the future. However, our work does not fully confirm that sediments in the IOM H11 are significantly enriched in REE.

Sep 1, 2014

By Bradford C. Wesstrom, Ricardo Parra

The Freeport McMoRan El Paso Refinery uses co-generation to produce some of its electricity and all of its steam. This paper will cover the operation of the co-generation plant natural gas turbine at a fixed RPM for blade longevity and energy output. The by-product heat from the turbine passes through boilers with additional heat from a duct burner to produce steam for the Tank House and auxiliary operations. The steam demand varies dramatically throughout the day based on unloading activities in the Tank House. The use of an automated steam control system within the El Paso Refinery will help stabilize line pressure by incrementally controlling steam consumption based on electrolyte temperature. This will minimize steam line pressure fluctuations. INTRODUCTION In the mid 1920’s the Nichols Copper Company of Laurel Hill, New York recognized the need for a modern copper refining facility in the southwest. Due to the many railroad heads, affordable power and abundant labor supply, and the close proximity to regional copper smelters in Mexico, Arizona, and New Mexico, El Paso became the logical location. In December 1928, ground was broken for the joint venture refinery between the Nichols Copper Company, Phelps Dodge, and the Calumet and Arizona Mining Company. In September 1930, Nichols Copper Company became a part of Phelps Dodge Corporation after a stock exchange. In July 1938, Nichols Division officially became Phelps Dodge Refining Corporation. In March 2007, Freeport McMoRan Copper & Gold acquired Phelps Dodge. Energy costs (electrical and thermal) are critically important in the viability of modern copper electrorefineries. The El Paso Refinery produces electricity and steam through its cogeneration system. The El Paso cogeneration facility is a natural gas, 15-megawatt facility containing five turbine generators and associated waste heat recovery boilers. The facility is divided into two phases. Phase I consists of two Allison 2.2-megawatt turbine generators. Phase II consists of three Solar Taurus 3.5-megawatt turbine generators. Presently three units in Phase II are operated. The Phase I units were purchased and installed in 1986 and the Phase II units in 1992 (Solar 1991). The facility operated at full capacity until 2003 when steam demand was significantly reduced due to decrease in cathode production and closure of the copper sulfate and precious metal operations. Phase I units were taken out of service and put on care and maintenance status.

Jan 1, 2019

By H. Reginald Hardy

This report describes the results of a research project carried out to investigate the feasibility of using transducer arrays, located on surface or in shallow boreholes, above an active coal mine to detect and locate the source of underground microseismic activity which normally occurs during mining. The initial stage of the project involves the design and development of a self-contained mobile microseismic monitoring facility capable of use in remote field locations. Following this a variety of transducers, and transducer field installation techniques were investigated to obtain optimum sensitivity and high signal-to-noise characteristics. Preliminary efforts were also undertaken to develop semi-automated techniques for analysis of microseismic field data. Using the facilities and techniques developed field studies were carried out at a number of surface locations over a central Pennsylvania coal mine operating at depths of the order of 500 feet. In particular studies were con-ducted over a previously mined development area, troubled by extensive problems of roof instability, and over two longwall panels during mining. Although many of the field studies were carried out during the development stage of the project, results in general have been most encouraging. Limited results were obtained over the development area, however excellent microseismic signals, correlating with underground strata instability, were detected over both long-wall areas, proving the general feasibility of surface monitoring techniques. More recent studies, carried out as part of a subsequent project, and utilizing modified geophone installation techniques at a third longwall site, have verified explicitly the feasibility of measuring underground microseismic activity from surface locations. Sections of typical field data are included in this report along with a brief review of the studies carried out at each of the field sites. Detailed analysis of data obtained at the second and third longwall test sites will be presented in a later report.

Jan 1, 1974

By J. Bleeck, G. Mahrt

INTRODUCTION Many excellent papers have been written and presented regarding agricultural lime and the subject has been covered extensively in books concerning soil science, fertilizing, limestone, etc. We felt challenged to construct a paper that wouldn’t merely be a repetition of past presentations. Therefore, we chose to begin with factors having the most impact on plant growth realizing that the audience is likely to be relatively unfamiliar with this subject. So, we decided to dig deep into the roots of soil and plant growth science in order to better understand the significant role of limestone in this important area. The soil with the higher plants growing upon it forms an open and dynamic ecosystem in which there is flux of energy and material (heat, light, water, nutrients, mineral and organic matter, organisms). Plants root in the soil and then take up oxygen for root respiration, yielding energy for nutrient uptake, water for turgescence and transpiration and use in photosynthesis and the mineral nutrients needed for the synthesis of organic matter. Above the ground the plant takes in light energy and heat using them in photosynthesis to assimilate atmospheric CO2. Photosynthesis is the basic life process of creation. However, we will look at the root room where soil, water, air, and heat economy and the supply of nutrients determine soil fertility and the important role lime plays here. Location is the primary point to be considered when discussing agriculture (climate and soil); secondly, the dynamic and mobility of the minerals (plant nutrients) in the soil; and thirdly the conversion of organic substances into humus. And then there is a great deal of water involved in the growing process. In order to produce 1 kg of dry plant substance, 300 to 800 kg of water must be pumped through the plant and is then lost by transpiration. Cereals, vegetables, and sugar beets consume between 400 to 500 kg of water during the growing process and long-growing crops, such as alfalfa and clover, can consume 600 to 800 kg of water per kg of finished product. Without water, a plant cannot grow. (Reference 1)

Jan 1, 2006

By Wm. Ross Wayment, Innes P. Grantmyre

INTRODUCTION It has been recognized for some time that major changes in mining methods will be required in the near future. Two types of factors contribute to this need for change. Intrinsic factors include ground control problems associated with mining at increasing depths, noise, dust, toxic fumes, and logistics problems which arise from operation in a cyclical fashion. Extrinsic factors include competition for labor from industries offering safer and less difficult work, pressure for less impact on the environment, and changing economic and political conditions. The search for new mining methods has resulted in extensive research being carried out on such novel approaches as thermal fragmentation, high-pressure water jets, sonic drilling, microwave fragmentation, and laser cutting, among others. Joy Manufacturing Co. has elected to concentrate on impact breaking in stopes as a first generation continuous hard rock miner. IMPACT BREAKING Fragmentation techniques show a drop in specific energy as efficiency improves. Specific energy is the energy consumed per unit volume of rock removed and is affected by such variables as rock material properties, fragmentation method used, operator skill, tool design, etc. Mechanical fragmentation methods generally have specific energies much lower than that of the more novel methods. Table 1 shows impact breaking to have an efficiency exceeded only by that of drill and blast methods and it is this high efficiency which led Joy to impactors as the subject for research on potential mechanisms for continuous mining in hard rock.

Jan 1, 1976

By W. W. Weller

Heat capacity measurements of anhydrous cobalt sulfate (CoSO4), copper sulfate (CuSO4), nickel sulfate (NiSO4), and zinc sulfate (ZnSO4) were conducted over the temperature range 51° to 298° K. The results were used to evaluate the following entropies at 298.15° K (cal/deg mole): CoSO4, 28.1; CuSO4, 26.8; NiSO4, 24.8; and ZnSO4, 26.4. Entropies were combined with heats of formation to give free energies of formation.

Jan 1, 1965

Mineral Processing Engineering Education in China - Bringing up the Engineering Diathesis and Design Competence of the College Students

Sep 13, 2010