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By S Durucan, A Korre

The application of simple methods of statistical analysis, coupled with geostatistical analysis and geographic information systems, can only summarise and give an outline of the spatial distribution of the parameters measured. Spatial analysis of the components or factors calculated, through principal component analysis or factor analysis, allows assessment of the geographical distribution of the dominant processes contributing to soil composition and/or contamination. Neither of these tools, however, distinguishes between the different sources of pollution. The application of canonical correlation to the data, driven by expert appraisal of the potential pollution sources, allows their quantitative and spatial assessment while GIS provides the environment in which to organise and present the results. The methodology is illustrated by its application to soil-contamination data from the Lavrio area in Greece, where silver-bearing orebodies have been mined for more than 25 centuries

Jun 21, 1905

By A. Yehia, M. I. Al-Wakeel

Flotation behavior, of magnesite and dolomite pure minerals was studied separately. Rice bran oil (a source of fatty acid ) was used as a collector for both minerals . The aim of this study is to find a separating zone in the flotation of these pure minerals to be used in the separation of their mixture. Factors affecting the flotation process, such as pH and collector, were studied. It was found that magnesite can be separated, from its mixture with dolomite, in the pH range of 5-7. At this pH range flotation recovery of dolomite reaches~98% where magnesite reaches ~20% only. Besides, the effect of collector concentration on the flotation shows that the separation of magnesite from dolomite is feasible at a collector concentration of 3x10-4 M. At such concentration, dolomite recovery reaches ~98%, where magnesite reaches 25%. The differences in the flotation behavior of dolomite and magnesite were investigated by studying the adsorption isotherms of rice bran oil on magnesite and dolomite surfaces. The adsorption study indicates that while there is an excessive adsorption on dolomite surface, the adsorption density on magnesite was restricted to be lower than monolayer capacity. The adsorption behavior of dolomite and magnesite was discussed in the light of their solubility and crystal structure. It was found that due to the higher solubility of dolomite than magnesite, Ca2+ and Mg2+ ions are available and more reactive on dolomite surface increasing collector adsorption. In addition, it was indicated that dolomite mineral has a crystal lattice structure more compatible to the geometry of the fatty acid carboxylic group than magnesite. However, the adsorption of collector on dolomite surface is more compact and more regular than on magnesite surface.

Jan 1, 2000

By Thomas G. Goonan

Copper production through smelting generates large volumes of material flows. As copper contained in ore becomes copper contained in concentrate to be fed into the smelting process, it leaves behind an altered landscape, sometimes mine waste, and always mill tailings. Copper concentrate, fluxing materials, fuels, oxygen, recyclables, scrap and water are in-puts to the process. Dust (recycled),gases — containing carbon dioxide(CO2) (dissipated) and sulfur dioxide (SO2) (mostly collected, transformed and sold) and slag (discarded or sold) — are among the significant process outputs. This article reports estimates of the flows of these input/output materials for a particular set of smelters studied in some countries. They include Chile (Altonorte, Caletones, Chagres, Chuquicamata, LasVentanas and Potrerillos), Japan(Naoshima, Onahama, Saganoseki,Tamano and Toyo), the United States(Garfield — Fig. 1 — Miami and Hayden) and Europe (Glogow I, Glogow II, Huelva, Norddeutscheand Ronnskar).

Jan 1, 2005

By Tony S. Calayag

Throughout the mining industry today, new bearing materials - ZA* high-performance zinc-aluminum alloys - are reducing costs of maintaining and rebuilding a wide range of equipment. As replacements for bronze bearings, installed in original equipment at the plant or during maintenance and repair operations in the field, the zinc alloys frequently provide better or equal performance at lower cost. The ZA Alloys The ZA alloys are a family of three high-performance zinc-aluminum alloys that compete in cost and performance with cast iron aluminum and bronze. The growing number and uses testifies to the versatility of these alloys and is encouraging their consideration in a wider range of applications. The ZA alloys are referred to as ZA-8, ZA-12, and ZA-27, the numbers corresponding approximately to the percentage of aluminum each alloy contains. ZA-8 is a permanent-mold casting alloy and is usually selected for decorative purposes; ZA-12 provides both performance and cosmetic benefits; ZA-27 offers the greatest functional strength. The term high performance ZA alloys distinguishes them and their improved engineering properties from traditional zinc die casting alloys. Maintenance Savings At its mine in Timmins, Ontario, Kidd Creek Mines Ltd. operates over 40 Joy VCR- 150 crawler-mounted air-powered rock drills. Most of the drill components undergo severe stress as the drill batters through the under-ground rock. As the components wear, the drill bits wobble; when the wobble becomes excessive, the drills are rebuilt. In the gear train, which rotates the drill steel, there are three planetary gears with - historically - bronze bushings. Since the planetary gear bushings are wear items, they are routinely replaced during overhaul. The bronze planetary gear bushings (three bushings per assembly) were replaced up to five times annually. With 43 drills in use, bushing consumption approached 600 per year. At the manufacturer's replacement part cost, the 600 bushings and gears would cost more than $20,000 a year. Even though a major saving was achieved by having the bronze bushings manufactured locally, the 600-unit annual usage provided ample incentive to investigate other ways of lengthening drill life and reducing the part costs. One approach was to consider using a bushing material that offered good bearing properties, but was lower in cost. About three years ago, ZA-12 zinc-aluminum casting alloy, costing less than half as much as bronze, was evaluated and selected for testing. One hundred ZA bushings were manufactured and placed in service as the drills came in for rebuilding. At the next rebuild the "drill doctor" (drill maintenance mechanic) noticed that, although the bronze bushings were completely destroyed, on occasion the zinc alloy bushings were not. In addition, he noted that some of the ZA bushings showed less wear than the bronze bushings. Because the bushings were changed routinely during each overhaul, the actual operating life of each bushing was not determinable. Therefore, it was not possible to statistically compare the life of the ZA bushing against the bronze. However, the desired life of the part was from overhaul to overhaul. So the ZA alloy obviously met the objective, giving equal or better life than bronze at a significantly lower price. Based on the favorable results of the testing under actual operating conditions, Kidd Creek maintenance personnel decided to switch permanently to the ZA bushings for rebuilding the VCR-150 rock drills. Original Equipment Application As one of the leading companies marketing the ZA alloys, as well as a zinc -copper-silver mining company, Kidd Creek is interested in developing applications for the alloys by original equipment manufacturers such as joy Manufacturing. Kidd Creek marketing representatives provided joy with information on the Timmins mine tests, along with ZA-12 bushings for evaluation and testing. Based on this information, joy installed ZA bushings in 12 new VCR-150 units and delivered them to customers for use in such areas as granite quarries and copper, lead, zinc, and limestone mines. During the following year, joy engineers closely monitored repair reports to verify the performance of the ZA part. The engineers' findings convinced them of the advantages of ZA-12. As a result, joy now uses ZA-12 bushings in the manufacture of its VCR-150 air tools. Advantages for Casters and Users In the foundry, the new alloys have proved their castability and profit potential in sand and metal permanent-mold processes, as well as the new graphite permanent-mold gravity casting process. The energysaving, pollution-free and ease-of-machining benefits they offer are important to all of these processes. Most recently, the high-performance alloys entered the arena of cold-chamber die casting, where they provide properties beyond those of

Jan 7, 1983

By J. David Lowell

The first part of this article is a review of industry techniques and styles during the past 50 years. It is followed by my career history during the same period. The second part covers my ideas about what works in mineral exploration. These include estimates about discovery costs, thoughts about education of explorationists, organization of exploration groups and my opinions about the relative value of exploration techniques. Evolution of exploration techniques [Table 1] shows the evolution of mineral exploration techniques and styles from 1950 to 2000. During the first half of that period, there was a progressive increase in exploration drilling. During the second half, there was a decrease in prospecting and an increase in high technology, indirect exploration and a rapid increase in discovery cost.

Jan 1, 2000

The Small Pebble Process for Reducing Ball and Power Consumption in Secondary Grinding Ball mills are used widely for secondary grinding. A mixture of ball sizes can be used to optimise grinding efficiency, but the use of balls smaller than about 30 mm in diameter is not normally viable, particularly when alloy steel is required. Preliminary testing of the grinding efficiency of various combinations of 40 mm steel balls and crushed stone in the size range 7 to 25 mm was carried out in a 300 mm diameter mill, which has accurate power measurement.The primary interest was to assess the potential benefit of adding small pebbles (from a primary circuit crusher or mill) to a secondary ball mill, to reduce ball consumption and to improve grinding efficiency. The optimum proportion of pebbles was found to be about 25 per cent by volume. This mixture produced about the same amount of fines as balls alone, but with lower power consumption, due to the lower density of the pebbles. The net result was a 12 per cent saving in power and a 25 per cent saving in ball consumption. The production of fines was partly due to pebble wear. The use of portions of 15 mm balls, (ceramic and steel), was also tested for comparison. A few batch pilot-scale tests were conducted in a 1.2 m diameter, 0.31 m long mill to test the viability of the pebbles at a larger scale. The pilot-scale tests confirmed the reduction in power and that the rate of production of fines was the same as that obtained with balls. The same residence time was used and this implies that pebbles can be added to an existing full-scale ball mill, with no loss in capacity. Samples of secondary mill feed and pebbles were obtained from a copper mine and the steady-state consumption of pebbles was determined by locked-cycle laboratory-scale tests. These tests demonstrated that mill power could be reduced by up 13 per cent and that the consumption of 40 mm balls could be reduced by up to 38 per cent, while maintaining the same throughput and product size. The rate of pebble addition was about 4 per cent of the primary circuit feed rate. Application has been made for patent protection.

Sep 13, 2010

The Kalgoorlie Golden Mile is proposed as an Archaean volcanogenic-type deposit, modified and redistributed along later-developed structures. Rich pyritctelluride and Green Leader gold mineralization is associated with the end phase of basic volcanism and, in a general sense, is confined to a broad interface zone between the products of marine basic volcanism and later acid volcanism. There is virtualIy no ore associated with the main body of acid volcanics.Green Leader is the local name of a type of ore that occurs at some igneous rock contacts in association with graphitic sediments and layered acidic tuffs. It is characteristicalIy green, of various shades, and commonly yields very high gold assays, the reasons for which are not apparent in hand specimen.Carbonates, carbonaceous shales, tuffites, rich gold ores, and acid and intermediate dykes, alI indicating a common heritage, are features common to the main ore hosts, viz. the Paringa Basalt (Calc Schist) and theGolden Mile Dolerite ("Quartz Dolerite Greenstone").Several probably related fracture systems have reconstituted most, but not all, of the original deposits into a large number of steep tabular lodes.Includes two sets of discussions and comments from later Proceedings volumes.

Jan 1, 1974

By A. Kapito

The formation of bainite in steel is dependent on the size of the casting, the heat treatment, and the alloying elements. It is difficult to obtain a fully bainitic microstructure in steels during heat treatment because of its close proximity to the martensite (a?) reaction. The ferrite (a) and pearlite reactions in steels are also rapid and shield the bainite reaction. Alloying elements therefore need to be added to separate the bainite reaction. Boron (B) and molybdenum (Mo) are key elements added to bainitic steels because of their ability to retard the a reaction. Other elements used in the production of bainitic steels are silicon (Si), chromium (Cr), manganese (Mn), and titanium (Ti). In this paper we investigate the effect of alloying elements on the bainite reaction through the use of dilatometry. Dilatometry is a technique that determines phase transformations in the steel and through which continuous cooling transformation (CCT) curves can then be developed. Some initial results are presented of an ongoing study on the development of bainitic steels for railway wheel applications.

Jan 1, 2013

From time to time lead, which is normally considered to be a soft ductile metal, fails by cracking. The cracks which form appear to be of two distinct types-(a) those which follow a zig-zag course around the boundaries of crystals and (b) those which follow a more direct path, frequently two systems of cracks appearing at right angles.The former appear definitely to be associated primarily with the properties of the crystal boundaries, whilst the latter appear rather to be determined by the system of stresses applied. In both cases the lead appears to be a brittle rather than a ductile metal, for the failure occurs without the large amount of deformation usually associated with the tensile breaking of lead. The latter is, however, a function of time and when lead is deformed by long applications of stress, the metal appears to- be less ductile than when the stress is applied suddenly. Thus, if a given test piece of commercial lead is broken by a stress of 1100 lb. per sq. in. in several hours, it may extend 40 to 50%before failing, whereas when broken by a stress of 500 lb. per sq. in. acting for 12 months or more it willshow an extension of only 15 to 25 %. With lower stresses still, failure would take much longer and undoubtedly lower extensions would be obtained.As the stress is lowered it is found that the marked local contraction characteristic of ductile metals becomes less noticeable, and failure, instead of being by extension of *Lecture delivered to the First 'Ordinary Meeting of the Australasian Institute of Mining and Metallurgy, 21st August, 1935.

Jan 1, 1935

By P. J. Knottenbelt

Outcomes from a workshop organized through the SAIMM revealed that the minerals and metals industry must develop its ?Engineering Team? if it is to continue to meet the challenges of globalization. The very economy of the country is largely dependent on a competitive and stable engineering team within the minerals and metals sector. With the Chamber of Mines (COM) passing on its education and training initiatives to the industry, the professional bodies like SAIMM must (despite meagre resources) continue the good work done through the COM in the past. The workshop highlighted recruitment and selection, further/higher education, socialization and initial training, deployment and retention and continuing education as priority areas. These are further detailed in this report. Office Bearers have considered the outcomes and the areas where the Institute should or should not be involved have been stated.

Jan 1, 2002

By M. Drozd, M. Somppi, Z. Yamak

"Granular activated carbon is widely used in the gold mining industry for gold extraction from aurocyanide-containing slurry. The extraction process can employ carbon as part of the gold recovery operation for various circuit designs including carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) circuits. However, various qualities of activated carbon exist and the durability of the material can change significantly from source to source. Handling this expensive reagent can pose challenges when fine carbon losses occur in the CIP, CIC, and CIL circuits. Additionally, any gold that is adsorbed to these carbon fines can also be lost by various mechanisms including carbon attrition and fracturing, inefficient coarse-fine separation, and poor carbon fines capture. With the above in mind, a series of tests were conducted to investigate standardizing simple laboratory methods for testing carbon quality. A standard procedure beyond or enhancing ASTM methods can serve as additional starting points for evaluating carbon specific to the gold industry. The investigation focused on size distribution, flatness, wet attrition resistance, surface area, gold kinetics, and gold loading. The final results provided information to generate an equation for ranking carbon samples to plant performance.IntroductionActivated carbon for use in gold extraction is amongst the most commonly found processes in modern gold-milling plants. Although gold losses are inevitable in the milling process, operators often focus on the importance of maximizing gold recovery. One focus area that is important in gold recovery is optimizing the use of activated carbon and examining potential changes to realize improved economics for carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) processes."

Jan 1, 2017

By C. J. Pretorius

More than 30 percent of the global demand for zircon (ZrSi04) is supplied by South Africa. A significant amount of the zircon is exported, and beneficiated products are then imported for industrial applications locally. Beneficiating the zircon locally could have a positive impact on the local market, since zircon is only one of many such cases. Ammonium acid fluoride serves as an alternative anhydrous fluorinating agent for zircon in the synthesis of several metal fluorides1,2. It provides an effective dry fluorinating method and is easier to handle than hydrogen fluoride or fluorine gas. Zircon exposed to extreme plasma temperatures dissociates and becomes more reactive. The reaction of the plasma-dissociated zircon (Zr02.SiO2) with the ammonium acid fluoride (NH4F.XHF, where x= 1 to 5) forms two main intermediate compounds (NH4)3ZrFr(s) and (NH4) 2SiF6(s), the latter decomposing to form volatile products at relatively low temperatures, providing easy separation of the silicon and zirconium compounds. The ammonium zirconate compound decomposes to form zirconium tetrafluoride (ZrF4), which can be further manufactured into zirconium metal, to name but one product. Data on the kinetics of the reaction of ammonium acid fluoride with zircon and plasma-dissociated zircon, combined with the thermo¬dynamic parameters of the reaction, is essential for the development of an industrial process for the production of a precursor for the manufacturing of zirconium metal, namely anhydrous ZrF4. Both the reaction kinetics and reaction parameters will be included in this study, as well as some proof that the reaction proceeds to ZrF4 on a small batch scale. If the exact reaction parameters can be pinned down, a wide spectrum of anhydrous metal fluorides can be synthesized through this fluorination route.

Jan 1, 2012

By Isaac Girón

Dado que se descubrieron grandes depósitos de fosfatos de Bayovar en Piura, se anunció la creación de la reserva subterránea de salmueras, donde sobresale el potasio, la sal común y el magnesio. Posteriormente, se relacionó la explotación de los fosfatos a la recuperación de sal y KCL. y la presencia de salmueras se convirtió en la única reserva de potasio del pais. En ese sentido, el presente texto describe la importancia del magnesio en dichas salmueras en tanto permite recuperar el magnesio a partir del proceso de evaporación y concentración. De forma que es posible la obtención de magnesio por el tratamiento térmico de los amargos y así fabricar el fosfato dicálcico mediante el proceso convencional, sin necesidad de usar el agua de mar.

Sep 13, 2001

By Michael Hood

An overview is given of some of the major mining research activities in Australia. Automation of mining equipment is not an objective in its own right. The objective is to improve the safety and the economic performance of mining operations. Automation can be a useful method for achieving this objective. There is a strong focus on mining equipment automation and related issues and specific examples of ongoing and recently completed automation projects are described.

May 1, 2002

By J Ward, B Rohrlach, B Rosero, J Silva, O Poma

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Alpala copper-gold deposit is a recent, high-grade porphyry Cu-Au discovery located in the Imbabura Province of north-western Ecuador. The deposit lies along the crustal-scale Chimbo-Toachi Fault Zone within the Dagua-Piñon terrane, which is an oceanic plateau accreted to the South American convergent margin in the Late Cretaceous. The deposit is hosted by quartz diorite stocks that intrude andesitic volcanic breccias of the Oligocene to mid-Miocene San Juan de Lachas Formation. Miocene-age calc-alkaline plutonism is associated with porphyry Cu, Cu-Mo and Cu-Au deposits in southern and northern Ecuador. The Alpala deposit lies along a sector of the Miocene arc that has recently been underplated by the Carnegie Ridge seamount chain that induced shoaling of the subducted Nazca plate beneath northern Ecuador.Surface expressions of the deposit were recognised in May 2012 during follow-up of stream sediment anomalies, when outcropping sheeted and stockwork porphyry-related veins were discovered in Quebrada Alpala. The roots of a NW-trending, structurally-controlled lithocap were recognised over an area of 4.5 × 0.9 km. The remnant lithocap exhibits well-defined mineral zonation mapped by TerraSpecTM analyses on grid soil samples. Soil sampling, heliborne magnetic surveying and channel sampling defined initial drill targets.Seven diamond drill holes were completed in the year from September 2013. Drill hole CSD-13-005 intersected 672 m grading 0.93 per cent Cu and 0.91 g/t Au in high-temperature, inner propylitic and locally potassic-altered quartz diorite intrusions. Overlying hydrothermal clay alteration assemblages define the base of the lithocap. A NW–SE trending footwall structure defines the south-west margin of the deposit. Drill hole 5 intersected high-grade sheeted ‘B-type’ and ‘C-type’ veins (Gustafson and Hunt, 1975) that lie along the south-west margin of an 1100 × 500 m magnetic anomaly that is the focus of ongoing exploration.CITATION:Rohrlach, B, Poma, O, Rosero, B, Silva, J and Ward, J, 2015. High-grade porphyry copper-gold mineralisation in north-west Ecuador – The Alpala Cu-Au porphyry discovery , in Proceedings PACRIM 2015 Congress, pp 369–376 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By C. P. Kempter, H. L. Brown

Recently Chang determined heat content values of tantalum monocarbide and tungsten monocarbide from 325" to985°Kand 326" to 912"K, respectively, and, using other published data, made certain solid-state calculations for these two compounds. Chang expressed his Cp values in units of cal per "g-atom alloy" OK. We consider this poor usage since l) tantalum monocarbide and tungsten monocarbide are not alloys, and 2) an atom of an alloy does not exist. However, one may convert his values to units of cal per mole OK by merely doubling them. For TaC he calculated a Nernst-Lindemann parameter of 9.07 x lo-' "g-atom per cal". We have refined the calculation of this parameter and have arrived at a much lower value. Rather than approximating the true coefficient of volume expansion, a,, as three times the true coefficient of linear expansion, a, we calculated u, from the TaCo.99, lattice expansion data of Fries and Wahman.38 At 25°C a, = 14.3 x 10s per OC. The molar volume was calculated to be 13.32 cu cm per mole at 25°C. From the lattice compression data of Champion and Drickamer~' for "TaC,.,," we determined the room-temperature compressibility to be 3.5 x 10-l3 sq cm per dyne by plotting l/Vo (aV/ap) vs applied pressure. (Since the lowest pressure at which Champion and Drickamer reported a relative volume was 20 kbars, one may calculate an approximate compressibility only. Chang calculated a compressibility of 3.175 x 10-l3 sq cm per dyne from the same data.) We also used twice Chang's value of Cp = 4.38 cal per "g-atom alloy" OK for the molar heat capacity at 25°C. From these four values we calculated a Nernst-Lindemann parameter of 5.8 x 10-l4 mole per erg or 2.4 x lo- ' mole per cal, and a Cdil value of 2.3 x 10' ergs per mole OK. In the case of tungsten monocarbide no isothermal compressibility has been reported; however, one may calculate an approximate Nernst-Lindemann parameter by using the adiabatic compressibility reported by Brown, Armstrong, and Kempter." Using the WC lattice expansion data of Mauer and Bolz~l we calculated a, to be 12., x l0-' per OC. The molar volume was calculated to be 12.5 cu cm per mole. We used twice Chang's value of Cp = 4.18 cal per "g-atom alloy" OK for the molar heat capacity at 25°C. From these four values we calculated an approximate Nernst-Lindemann parameter of 2 x lo-' mole per cal, which is much

Jan 1, 1969

By Yuexin Han

The wet preconcentration of haematite, comminuted by high-pressure grinding roller was studied, using the cylindrical ferromagnetic medium. The effects of various factors including rod diameter, rod gap and background magnetic field intensity (BMFI) on the performances of preconcentration for different size fractions and the force analysis of single mineral particles with different diameter in the separation zone were emphatically investigated. The results showed that as the rod diameter increased, the rod gap decreased, and the BMFI increased the tailings grade and the tailings yield reduced while the concentrates recovery raised that was regardless of variations in feed size distribution. For the -3.2+0.18mm size fraction preconcentration, the magnetic medium with a rod diameter of 4 mm and a rod gap of 7 mm at BMFI of 454kA/m is used to get a higher performance. For -0.18mm size fraction preconcentration, the magnetic medium with a rod diameter of 4 mm and a rod gap of 4 mm at BMFI of 263kA/m is used to get a higher performance. After the classifying preconcentration, at the optimum condition, the overall concentrate grade increases by 9.56 percentage points and the concentrate recovery is up to the 82.67% with a tailing grade of 10.68% and a tailing yield of 40.31%. The magnetic force, exerted on weekly magnetic minerals was proportional, to the specific susceptibility and square of BMFI. For the same BMFI, the magnetic capturing force on coarse particles increased, and that on fine particles decreased with the increasing of rod diameter. For the lean locked-particles, considering the gravity and viscous resistance of particles, rods with a big diameter were beneficial to the capture of coarse particles and had no influence on the capture of fine particles, while rods with a small diameter were good for the capture of fine particles and not suitable for the capture of coarse particles of lean locked-particles. Keywords: low grade haematite, high-pressure grinding roller, high intensity magnetic separation, pre-concentration

Sep 1, 2012

By D. F. Malan

This paper presents an overview of work conducted over several years to investigate the continuous stope closure profiles recorded in tabular excavations and the use of this data as a hazard indicator. In spite of the brittle nature of the rock, measurements in gold mines and intermediate depth platinum mines revealed a significant time-dependent closure component. Various approaches to simulate the time-dependent closure have been investigated. Viscoelastic theory is able to simulate the time-dependent closure behaviour, but there are subtle problems with the use of this theory as it cannot simulate the failure processes in the rock. To overcome these problems, continuum and discontinuum elasto-viscoplastic models were developed by the authors. Discontinuum models have the advantage of being able to simulate the creep behaviour of prominent discontinuities. Development of these models has led to useful insights into rock mass deformation and has made the numerical simulation of parameters, such as rate of mining, possible for the first time. A number of practical applications for the mining industry have been developed from this study. Among these are the delineation of geotechnical areas using closure data, use of the data as a hazard indicator and to give warning of large collapses in the platinum mines, identification of areas to be preconditioned in the gold mines, measurement of the effectiveness of preconditioning and improved da

Jan 1, 2007

By C E. J de Ronde, I C. Wright

Oceanic subduction-related volcanic frontal arcs extend over 20 000 km within the western Pacific basin and over 21 500 km worldwide, yet they remain largely unexplored with respect to active seafloor mineralization. Systematic exploration of 26 major submarine volcanoes along ~840 km of the Kermadec arc northeast of New Zealand has documented ten (39 per cent) as being hydrothermally active. This frequency of venting is comparable to that on slow-to-moderate rate spreading mid-ocean ridges, which comprise ~80 per cent of the 60 000 km-long global system of spreading centers. The chemistry of fluids discharged from the Kermadec arc volcanoes is moderated by magmatic components in both the gaseous (CO2 + SO2-H2S) and liquid (Fe) phases at very high concentration.The high frequency of venting coupled with chemically rich discharge discovered during this first systematic survey of any arc system forecasts submarine arcs as being important sources of chemicals to the oceans and as potentially lucrative exploration sites for seafloor mineralization. The exploration protocols developed during these surveys include bathymetric mapping of mostly unknown volcanic edifices, followed by detailed water column profiling and sampling to detect and characterize volcanic fluid emission signatures. These procedures are being refined as the survey progresses, both for efficiency and as direct seafloor observations become available for predictive application of water column plume information to guide seafloor mineral exploration.

Jan 1, 2002

By C. Pelley, A. Piche

"The Canadian mining industry faces the prospects of a severe shortage of graduate mining engineers over the next decade. This arises from three factors: first, a growth in industrial activity; second, the average age of company engineering and management staff; and third, the reduced number of students in engineering faculties around the world. This paper aims to identify the critical factors underlying the trend of inadequate recruitment into higher education for mining and to examine means of alleviating the problem.This paper is based upon surveys of potential and current students and graduate mining engineers from four mining schools. An attempt is made to understand institutional and industrial images, career prospects and what is required to attract enough high-calibre young people into mining education over the next decade.IntroductionThe mining industry has started to experience a severe shortage of graduate mining engineers which is likely to persist and even worsen in the short- to medium-term.This arise s from three principal factors:1. a recent and strong growth in mining activity, which surpasses that experienced through the 70s, before the recent international industrial recession; .2. an increasingly older average age of mine engineering employees, at least in the industry's larger companies; and3. problems associated with maintaining adequate mining undergraduate recruitment levels ."

Jan 1, 1989