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In presenting this address I am conscious of the honour that has been paid me in my election to this important office, and I am very aware that I follow, in the position of President, many distinguished men who have led the Institute over the 70 years since its inauguration in Broken Hill in 1893.It is perhaps appropriate tonight that I intend to talk about a metal which recalls the birth-place of the Institute, and is also one with which I have had a direct association throughout the whole of my working career. This metal is Silver.Silver is associated traditionally in everyone's mind with money and silverware, and has always been prized for its natural beauty and elegance. It is today one of the few metals in which world consumption has outstripped production, and the events which have occurred to bring about this situation make an interesting story.In telling this story, I propose firstly to indicate our development as a silver producing country, give an historical review of the metal, trace its use as currency and the factors influencing its price, and then say something of the old and new uses of silver. Finally I shall give some comments on silver production in Australia today.Australia, with 6-5 per cent of the world's output of silver, ranks sixth among the producer countries and over the years has contributed 892.5 million ounces to the world's supply which, based upon production since the discovery ofAmerica, is estimated to have been 22,150 million ounces or nearly 680,000 tons.Although our production appears relatively small by...

Jan 1, 1963

By R Hardie, J Crerar, J Merritt, B Kirsch

Longwall mining and related subsidence, and watercourse diversion for surface mining operations have the potential to impact on fluvial geomorphic processes and the health of river systems. This is evident in the Isaac River in central Queensland. The scale and likelihood of these impacts are a function of the extent of existing and proposed mining developments and of the ongoing geomorphic, hydrologic and ecological processes within the Isaac River. Understanding the objectives for the river, the past and ongoing processes at work, the cumulative impacts of longwall mining development and the options for managing those impacts is essential for the development of an effective strategy to manage the health of the river system. An assessment has been undertaken to identify and understand the cumulative impacts of mining subsidence and other mining influences on geomorphic processes and waterway health in the Isaac River over a river length of approximately 100 km near Moranbah in central Queensland. The assessment included the development of a vision and objectives for waterway health. The assessment has identified mining and landuse changes that have impacted on the hydrology, geomorphology, ecology and hence the health of the Isaac River. The assessment has then sought to identify the cumulative impact of longwall mining and related subsidence on current stream condition and the proposed vision for the system. The primary impact of longwall mining on the river was found to be associated with sediment transport. The investigation included assess- ment of total sand available for transport, the volume of sand transported annually and the fluvial process response to subsidence. Recommendations have been developed for the management of the system and for longwall mining to increase system robustness and achieve the river health objectives.

Jan 1, 2009

Esso-BHP have installed a production supervisory control system that is presently controlling the offshore oil and gas facilities on the Barracouta and Marlin platforms from an onshore master station. This control is achieved with a computerized master station onshore which uses a UHF radio system for telemetry and control.The system is designed to control, monitor, and gather data from a large number of oil and gas production platforms and has flexibility to handle future variations in operating conditions.The system will be extended to the Halibut platform late in 1970 and to the Kirlgfish platforms during 1971.

Jan 1, 1971

Despite the recovery of approximately six million ounces of alluvial gold from the West Coast of the South Island, New Zealand during the last 140 years, a great deal of this having been obtained via sluice boxes and riffle tables, there has been little advance in riffle table technology during this period. In this paper contemporary riffle table design and current operational practices are examined. Studies of gold loss to undersize tailings are described. In addition recommendations derived from recent research carried out in North America are contrasted with gold saving strategies adopted by West Coast miners.

Jan 1, 1992

By Roy C. Fedotoff, Jon Hurt, Gregg Sherry, Gilbert Tang

The 1,380 m (4,200 ft) long New Crystal Springs Bypass (Polhemus)Tunnel (NCSBT) will replace the existing Crystal Springs Bypass Pipeline. This tunnel project is part of the SFPUC’s $4.3 billion capital improvement program to repair and seismically upgrade their aging pipelines, tunnels, reservoirs and dams that provide drinking water to more than 2.4 million customers in the San Francisco Bay Area. This paper describes the development of the tunnel alignment and design, and the complex ground conditions of the Franciscan Mélange. Of particular interest is the challenge of tunneling with a possible downhill grade of 3%, a rigorous environmental process and incorporating the lessons learned from 1960s construction of the adjoining Crystal Springs Bypass Tunnel.

Jan 1, 2007

The use of solid state detector and radioisotope x-ray source for x-ray fluorescence analysis is illustrated by analysis for iron, copper, zinc, tin, and lead in about 700 samples taken from Australian mineral process streams. Limits of detection based on counting statistics (3 standard deviations) range from 0·001 to 0·004 per cent by weight element. The analysis accuracy was usualIy between 2 to 10 per cent (rms) of the mean element concentration and was determined by comparison with assays supplied by mineral companies. In most cases the main cause of error appears to be due to this assay and not the x-ray fluorescence technique.Some potential fields of application of solid state detector and radioisotope x-ray source for analyses in the mineral industry are indicated.

Jan 1, 1974

By N. E. Mkadmi

Backfilling increases the stability of underground stopes and may help reduce the environmental footprint from the mining operation. The barricades holding the backfill in place must be designed to prevent failure based on the total and effective stress states, which depend on fill properties, stope geometry, and filling rate. This paper presents results from a numerical study aimed at analyzing the stress states associated with the response of paste backfill following stope filling, with an emphasis on the short term behavior. The simulations illustrate how stresses evolve with backfill drainage and filling rate in a vertical stope.

May 1, 2011

By Michael A. Knott

Large lateral forces on bridge foundations due to extreme events such as vessel collisions, earthquakes, and wave forces on storm surges during hurricane events are often the controlling design condition for bridge foundations. A review of the American Association of State Highway and Transportation Officials (AASHTO) vessel collision analysis and design codes used in the United States for highway bridges will be presented. The paper includes the background and development of the AASHTO Guide Specification and Commentary for Vessel Collision Design of Highway Bridges (1991) and vessel collision provisions of the AASHTO LRFD Bridge Design Specifications (3rd Edition 2004 and the approved 2005 Interims). Experience in using the AASHTO codes will be discussed and observations on the adequacy and gaps, comparison with the European Standard Code, and recommendations for immediate and long term needs will be presented.

Jan 1, 2013

By T. Holmes, D. C. Russell, G. Jolly

"The AMEC Oakville office is involved in the design and construction of an iron ore concentrator located in Liberia. Currently, the site ships Direct Shipped Ore (DSO) to overseas customers. The DSO mine-site and port can experience heavy annual rainfalls. The IMSBC Code requires that cargoes are only accepted for loading when the moisture content of the cargo is less than its Transportable Moisture Limit (TML). The moisture content of the DSO has, on occasions, risen to near or above its TML. AMEC was asked to advise whether the concentrate produced from the new concentrator would or would not have the same problems with moisture content and ship loading as the DSO.INTRODUCTION Liberia was, at one time, the world’s sixth largest exporter of iron ore and used some of the most modern mining operations of their time. However, the country has not produced iron ore over the past seventeen years because of civil unrest. The return of stability to the country has allowed the redevelopment of the iron ore industry. ArcelorMittal Liberia (AML) obtained a concession for mining in the Nimba County area of Liberia (Figure 1) in December, 2004 and has studied the known iron ore deposits and former mining operations in this area. It began phase 1 operations in June 2011 with the direct shipping of high grade ore at a rate of up to 4Mtpa. The processing of the lower grade ore in phase 2 of the project requires additional processing capability to produce at the design rate of 15Mtpa. DSO and Concentrate The DSO in the first phase is selectively mined at an average grade of 60% Fe, and then crushed and screened to -10 mm with no washing or concentration. Testing of samples has indicated a size distribution that is finer than typical sinter feed material, although critical material below 0.10 mm is low in most cases, and overall the ore is coarser than typical concentrates or ultrafine products (Feasibility study report, 2011). The phase 1 DSO facility will cease operation after the phase 2 concentrator comes into operation."

Jan 1, 2014

By Alfred Weiss

Selecting a minicomputer is not unlike selecting a costly piece of mining equipment such as a truck, shovel, crusher, or conveyor belt system. A marked difference might lie in the frequency at which such selection takes place; another difference might be mine management's familiarity with mining equipment vis a vis a minicomputer. These basic differences might prompt a mining company to seek the aid of a consultant when selecting a minicomputer system. Advantages and Disadvantages The fundamental advantage of employing an independent consultant is that it provides management with a source of knowledge and breadth of experience not readily available within the organization. If the consultant has a minerals background, such knowledge and experience are further enhanced by actual experience in exploration, mining, and mineral processing. If the consultant has worked within a mining company, such hands-on experience is supplemented with a meaningful understanding of the client's business; this facilitates communication between the consultant and members of the client organization. The consultant has been, so to speak, "in the client's shoes." There are several other advantages. Since computer systems cut across organizational boundaries, the independent consultant may be able to move within the organization more easily than an inside staff person to collect necessary information. Also, detachment from any manufacturer should provide the client with an objectivity and a set of recommendations as near optimal as feasible. The principal disadvantages lie in the area of continuity and accountability. Once the consultant's report has been submitted and his recommendations implemented, a discontinuity might occur. Also, if implementation does not provide the desired results, the consultant might not be available to correct the situation or account for actions taken. Proper selection of consultant services, relative to kind and duration, and the consultant's method of operation, will often prevent many of these aftereffects. Services Offered The professional consultant can help a client: •Define and summarize information systems technology* needs; • Evaluate alternatives such as in-house capability and capacity, time-sharing, or service bureaus; • Prepare a formal request for proposal (RFP) to be submitted to vendors; •Evaluate vendor proposals; •Evaluate the economics of lease vs. purchase; and •Assist in the conversion and installation. Thus, consulting services may range from evaluating an existing system and upgrading to a larger piece of equipment, to selecting a new first-for-the-organization computer. First, Define and Summarize Needs Regardless of circumstances, the most valuable document required before equipment selection is the information system plan (I/S plan). It helps insure that the company's information needs are met in a cost-effective manner. An I/S plan is usually a comporient of the mining company's overall business goals. Since an I/S plan is a formal vehicle for establishing and communicating the direction the organization intends to take to satisfy information requirements needed to achieve goals and objectives, most initial systems services are likely to center around creating such a document or updating an existing document. The trend toward company-wide I/S planning is increasing in the mining industry; however, smaller scale efforts focused at the information systems needs to support an individual

Jan 11, 1981

By A. L. Garassino

Dans cet article on parle sortout de l'approche de calcule pour les pieux charges horizontalement avec particuliere reference aux curbes p-y et è une solution semi-empirique qui prende en consideration les variations typiques du module du sol avec la deformation obtenue par les données expérimentales. 1. INTRODUCTION The analysis of the piles under lateral loads depends very strictly from the pile stiffness and geometry, from the soil type and from the strain field. Different approaches were adopted in solving the problem. Some Authors developed methods for estimating the ultimate lateral resistance of piles and pile groups by conventional static approaches, as the Brom's widely known (1964) or by the plane strain solution developed by Davis (1961) or by empirical engineering con­siderations l

Jan 1, 1994

By O. Rabeau, M. Legault, A. Cheilletz, L. Z. Cheng, J. J. Royer, M. Jébrak

"By compiling geological, structural, geophysical, and geochemical information into a 3D geological model, we evaluated the orogenic gold potential in the vicinity of a hidden segment of an important Archean fault zone, the Cadillac-Larder Lake fault (CLLF) in the region of Rouyn-Noranda. The segment of CLLF in the present study is partly covered by Proterozoic sedimentary rocks. Because more than 2000 t Au have been extracted along the CLLF to date, our objective is to evaluate the gold potential at depth along a poorly known segment of this fault. A 3D geological model (50 km × 9 km × 1.5 km) including the covered segment was built through the compilation and homogenization of available geological data and the construction of 23 cross sections. The geology under the Proterozoic cover was evaluated using geophysical inversions, drill holes (42 in total), and surrounding geology. All available assays were filtered and upscaled to a 250 m × 250 m × 250 m regular cell grid to determine and quantify spatial relationships between geological features and mineralized occurrences using the weights of evidence method. Structural features, such as E-W-trending faults and fault intersections, and certain lithologies with a high primary porosity such as volcanoclastic rocks of the Blake River Group and Timiskaming sedimentary rocks, proved to be very prospective, yielding favourable factors with a weight of evidence index W+ > 0.24. These salient features were then assigned a combination index for ultimately evaluating the orogenic gold potential under the sedimentary cover. The zones resulting in an optimization of exploration targeting were attributed the highest probability, representing ~1% of the initial volume. La compilation des données géologiques, géophysiques, structurales, et géochimiques et leur intégration au sein d’un modèle géologique 3D a permis d’évaluer le potentiel aurifère dans les environs d’une importante zone de faille archéenne sous couverture protérozoïque. Cette méthodologie a été développée en utilisant le cas de la Faille Cadillac-Larder Lake (FCLL) dans la région de Rouyn-Noranda. Puisque plus de 2000 t d’Or ont été extrait à proximité de la FCLL, l’objectifs des travaux est l’évaluation du potentiel aurifère en profondeur de ce segment. Un modèle géologique 3D (50 km × 9 km × 1.5 km) incluant le segment sous couverture de la FCLL a été construit en utilisant l’ensemble des données géologiques disponibles et 23 coupes géologiques. La géologie du socle archéen sous la couverture protérozoïque a été interprétée avec des inversions géophysiques, des forages (42 au total) et les contacts géologiques exposés. Les teneurs aurifères dans le secteur ont été filtrées et ajusté à une grille régulière de 250 m × 250 m × 250 m afin d’évaluer et de quantifier les relations spatiales existantes entre certaines entités géologiques et les emplacements minéralisés en utilisant la méthode du poids de la preuve. Les failles de direction Est-Ouest, les intersections de failles ainsi que certaines lithologies possédant une porosité primaire importantes comme les certains tuf du Groupe de Blake River et les sédiments du Timiskaming se sont montrés très prospectifs avec des valeurs de W+ > 0.24. Ces entités géologiques ont ensuite été utilisées par le biais d’un indice de combinaison pour évaluer le potentiel en or de type orogénique sous le couvert sédimentaire. Cette méthodologie permet une optimisation des campagnes d’exploration puisque les zones pour lesquelles la probabilité de minéralisations a été évaluée à la plus haute valeur représentent 1% du volume initial."

Jan 1, 2009

By Xiaowen Liu

The DSC/TG, IR and XRD analysis were used to characterize the heating phase transformation of illite, which came from Ouhai deposit, China. It was discovered that the dehydration and de-hydroxylation of illite carried out stage by stage during heating. The adsorptive water and layer-inter water were dehydrated from room temperature to 500°C; and dehydroxylated in the range 500°C~800°C. In these stages of process, illite?s layer structure kept almost unchanged. After 800°Cillite began to change into disorder structure. At about 1100°C, the layer structure of illite had been destroyed, and amorphous SiO2 and mullite crystallite appeared. At about 1200°C the structure of illite completely destroyed and mullite crystal phase had become perfect..

Jan 1, 2006

THE following really forms the second part of, or a sequel to, a paper, " Ventilating Metalliferous Mines: a Method of Attack," read before the Broken Hill Branch of the Australasian Institute of Mining and Metallurgy in May, 1920. In that paper the writer advocated a consideration of the question of ventilation in metal mines from a different aspect to that 'which had hitherto prevailed locally. Various factors regarded as having an important bearing on the subject were set forth, together with the results of observations made during ventilation tests carried out at the mining department of the Zinc Corporation.During the subsequent discussion the question was raised of the possibility of any practical application of the method of attack described, and also whether the theoretical considerations mentioned were likely to be of any real utility to the mining engineer engaged in ventilation work in a metalliferous mine.

Jan 1, 1923

By A. Fuerst

The recent seismic events have shown that earthquakes have an immense destructive power. Chile was hit in February 2010 with a seismic intensity of 8.8 on the Richter scale, and had loss of about 700 killed persons, while Haiti was hit in January 2010 with 7.0 killing about 220?000 people. The event in Haiti showed that the seismic events can lead to a disaster if no preventive measures are taken. On the other side, the seismic event in Chile has hit a well-prepared country with moderate consequences. The earthquake with 6.6 Richter in Japan in March 2011, have further shown how severe the consequences can be if critical equipment is involved. Fortunately, the equipment in a mine has not the potential hazard as a nuclear power plant. Anyway, we are diligent and it is obvious that the seismic risk may lead to a real disaster even if the probability is small. The GMD is an important component in the grinding circuit of a mine. This paper maps out earthquake-prone areas including expected earthquake magnitude calculated according to relevant standards, focusing mainly on the building code IBC 2009. An overview is provided on how this standard is applied to mining equipment to minimize damage and aid large mills in operation to successfully withstand seismic effects. The differences in stresses and forces on the GMD and foundation are shown based on a turning and stopped mill simulation during an earthquake. The results demonstrate the need to maintain active and operating earthquake detection systems. Aside from detecting an earthquake?s magnitude, the sensor information can also be used to reduce the harmful effects that an earthquake has on mining equipment. As follows the earthquake requirements are defined. The last part of this paper explains how to fullfill these requirements.

Jan 1, 2012

By M. B. Boyer, C. H. Herty, F. A. Hartgen, G. L. Frear

"DEFINITION OF VISCOSITYViscosity has been defined as the resistance experienced by one portion of a liquid moving over another portion, such as one molecular plane moving over an adjacent plane. A measure of viscosity is the force required to keep one plane in motion at Unit velocity, the other plane being considered stationary. Figure 1 illustrates the general idea that the surface friction between two adjacent areas will be greater the larger the molecules. Therefore it may be assumed that viscosity will be increased by molecular association or agglomeration, and likewise dissociation rill decrease viscosity. According to Maxwell (1)6 the unit of viscosity, the poise, is the tangential force per square centimeter of area of either of two horizontal planes 1 centimeter apart, one of which is fixed while the other moves with unit velocity, the space between being filled with viscous liquid of unit viscosity.The need for a satisfactory apparatus and experimental procedure for the determination of viscosity of high-melting materials at temperatures corresponding to those in pig-iron and steel making has been recognized during the past few decades. The condition of the slag during the smelting and refining periods in the iron- and steel-making processes exerts an important influence on the metal product obtained, this slag condition really meaning the state of viscosity or, vice versa, fluidity, which the slag attains under certain conditions."

Jun 1, 1934

By Mike Turner

The Otter-Juan mine was closed by WMC Resources? Kambalda Nickel Operations (WMC-KNO) in 1999 due to the combined effects of low Nickel prices and high mining costs. GBF Mining Pty Ltd purchased Otter-Juan Mine from WMC in early 2001 as part of WMC?s disinvestment from the nickel mines in the Kambalda area. Goldfields Mine Management (GMM), (a wholly owned subsidiary of GBF Pty Ltd) re-opened Otter-Juan in May 2001. The Otter-Juan mine is one of the oldest mines in the Kambalda region and is now mining at depths below 1160mbs. Stresses are very high, rock mass deformation considerable, and the mine has a history of serious seismic activity. Orebody widths in the current mining area range from 2 to 2.5m, with dips from 25° to 40°. On taking over the operation, GMM converted the mining method from the previous mechanised drift and fill method to a slot-rise and strip method using hand held airlegs. During the latter years of production under the control of WMC, production averaged around 12000 tonnes per month, with grades of 2.7% and orebody extraction of only 55 to 60%. In the last three years of operation under the control of GMM the mine has produced an average of 12000 tonnes per month of ore at an average grade of 4.2% and with an orebody extraction of 70 to 75%. The mine is now highly profitable with at least another 3 years of reserves remaining at depth. The main benefits of the current method include reduced dilution and increased extraction. In the relatively poor ground conditions experienced this has only been possible using airleg mining, with excavations designed to suit conditions, support to suit rockmass deformations, and with improved extraction sequencing. Other benefits have included improved operating conditions, reduced falls of ground incidents and a dramatic reduction in seismic activity. These achievements have only been possible by stepping back in time and using traditional airleg stoping methods to extract the maximum amount of the orebody with minimum dilution. This paper includes details of the mine history, geology, mining method, seismicity, and support.

May 1, 2004

By Darrell L. Beddard

Pile driving started October 29, 1993 and was completed on January 27, 1994. Field work included driving piling from ground surface at one site and at or near proposed footing elevations for the remainder. Piles were driven to specified tip elevations or the elevations directed by the Project Manager. In an attempt to address what installation technique(s) performed the best, several methods were used, including varied predrilled depths, open ended piles, closed ended piles, and the use of both impact and vibratory hammers. Piles were driven closed ended where possible to study the feasibility of this option to reduce construction costs associated with pile cleanout. Piles were driven to different depths to measure capacity variations. The 24-inch (610 mm) diameter piling were driven in one piece while the 42-inch (1.07 m) diameter piling was driven in two segments. A total of 79 piles were driven for the four sites, 74 of the 24-inch (610 mm) diameter and 5 of the 42-inch (1.07 m) diameter. Various hammers were used to determine which hammers provided viable solutions to the potential problems anticipated in the design phase. Hammer selection was based on the driveability studies. Equipment included a 175 ton (1.56 MN) crane, support crane for pile stabilization, crane mounted auger drill, offshore leads, Delmag D30-32, D46-32, and D62-22 diesel hammers, an HPSI 2005 single acting hydraulic hammer, a Foster IHC S-90 double acting hydraulic hammer and a Kencho VM2-25000AII vibratory hammer with the weights set to produce 17,500 pound-inch (1.98 kN-m) of eccentric moment.

Jan 1, 1996

By Crazy Horse - The Journal of Explosives Engineering - Vol 20 No 1

The crew at Crazy Horse Memorial has produced a w o n d e rful new video called “The Fine Art of Mountain Carving.” The video closely examines for the first time, the extraordinary explosives engineering on the Crazy Horse mountain currently in pro g ress in the Black Hills of South Dakota. The 56-minute video takes the viewer up the mountain for a behind-the-scenes look at the drilling and blasting crew at work on the mountain. The video was written, edited and produced by Robb D e Wall and is available exclusively from the Crazy Horse Memorial in both DVD and VHS formats. For i n f o rmation, see www.crazyhorsememorial.org The following, is a brief summary of the 25 steps involved in carving the mountain. The video goes into extensive detail on each of the 25 steps. Both those in the explosives industry and those outside the industry will find the video intere s t i n g .

Jan 1, 2004

By Tassos Grammatikopoulos, Sarah Prout, William Mercer, C. Gunning

"The Nechalacho rare metal deposit is located in NWT, Canada. Avalon Rare Metals Inc. is now evaluating processing techniques for recovery of REE to be used in the industry. QEMSCANTM analysis coupled with whole rock, REE, Zr and Nb, and electron microprobe analyses were utilized to identify and quantify the mineralogy of the deposit, and define the REE distribution among minerals. QEMSCANTM mineralogy was performed on fifty intact drill samples using EXPLOMINTM that provided textural information for the mineralization; crushed samples were used to determine the variability of the ore and define REE domains, and composite samples to determine the liberation and association of the REE minerals. The sample matrix predominantly consists of biotite, feldspars, quartz, muscovite/clays, minor chlorite and amphibole, magnetite and hematite and carbonates. REE include in decreasing order of abundance allanite (3.6%), monazite (1.5%), synchysite (0.9%), columbite (0.9%), fergusonite (0.6%), bastnaesite (0.4%), and zircon 11.0%. The majority of the HREE are carried by fergusonite and zircon, and the LREE by monazite, allanite, synchysite and bastnaesite. QEMSCANTM mineralogical data is extremely valuable in assessing the mineralogy of the ore. The data have been implemented in defining the mineralogy of the ore body, support metallurgical test work, predict recoveries and grades, and finally calculate reserves of the deposit.INTRODUCTIONAvalon is in the unique position of owning and developing one of the world’s largest rare earth deposits in the Northwest Territories of Canada.The term Rare Earth Elements (REE) is used to describe the 15 lanthanide elements or metals and, more recently, the metals yttrium and scandium, which display similar physical and chemical properties. REE are not particularly rare and have a similar abundance in the earth’s crust to nickel, tin or tungsten. Unlike these better known metals however, the rare earths have little tendency to become concentrated into commercial ore deposits. When they do become concentrated, deposits of REEs usually display enrichment in one of two groups. The most commonly occurring deposits of REEs contain a sub-group of elements referred to as the “light rare earth elements” (LREEs), which include lanthanum, cerium, praseodymium, neodymium, and samarium. Less commonly, deposits of REEs contain the much more valuable sub-group of elements referred to as the “heavy rare earth elements” (HREEs), which include europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Yttrium and scandium most commonly occur in association with this second HREE sub-group. Generally, LREEs are produced from the mineral bastnaesite, and the HREEs have been produced from the minerals xenotime and monazite. LREEs continue to be produced from bastnaesite, however in the 1980s, China started production of HREEs from unique laterite clay deposits. China now produces approximately 95% of the world’s rare earths."

Jan 1, 2011