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By Gema Ribeiro Olivo

The hydrothermal Au-Pd deposits are hosted by the jacutinga in the Lake Superior-type iron-formation of the Itabira Group, Minas Supergroup. Jacutinga is a highly sheared, metamorphosed, hydrothermally altered iron-formation composed of hematite, magnetite, quartz, talc and phlogopite (Cauê) or muscovite (Conceição) and minor tourmaline, palladian gold, arsenopalladinite, mertierite II and palladeisite (hydrothermal) and native gold, native palladium Pd-Cu-oxides, and kaolinite (weathering products). The highest concentrations of Pd-Au occur in quartz and hematite veins parallel to the S1 foliation (Corpo Y, CorpoX, Aba Leste and Central orebodies, at Cauê and a single orebody at Conceição) or parallel to the S2 foliation (Aba Norte). The average ore grade is 30-40 g/t Au+Pd. The characteristics of the Au-Pd ore favor an epigenetic model for gold and palladium concentration in the iron-formation. During the D1 deformation and peak metamorphism, the oxiziding, acid and hot hydrothermal fluids transported Au and Pd preferentially as chloride complexes. The reaction of the fluid with the dolomitic carbonate (the probably protolith of the jacutinga) would have dissolved carbonate and K-feldspar to form muscovite or phlogopite and tourmaline, resulting in an increase in solution pH and a decrease of Cl concentration and subsequent deposition of gold and palladium minerals.

May 1, 2003

By Edouard Masengo

A long dyke will be constructed in a lake with rockfill placed by end dumping method. Its crest will be at elevation 521.5 m compared to the nominal lake level at 520 m. In the first portion, its height will vary from 1.5 m on a 35.1 m thick tailings layer to 18.3 m on about 0.5 m of tailings. In the second portion, the dyke will be built on native silty clay and will vary from 18.3 to 15.2 m in height. The tailings consist in stratified layers of fine-grained soils showing lateral and vertical segregation. The tailings are compressible and may develop excess pore water pressure on loading. The tailings overlie a thin layer of relatively soft native silty clay. The till beneath the silty clay is considered incompressible compared to the material above. After construction, as the tailings and silty clay consolidate, pore water pressures will dissipate and dyke stability will improve. Since dyke stability will increase with time, the primary concern is its stability during construction. As a result of construction activities, three potential modes of failure were identified and recommendations were provided regarding the measures that should be undertaken to increase dyke stability during construction.

May 1, 2003

By Kernaghan Webb

Organization of Presentation ?Genesis, Premise, Hypothesis ?Background ?Methodology ?Key research questions ?Research Team to Study Kinross Maricunga ?Research Milestones ?Chilean context ?Chilean Legal Framework ?Kinross Gold the basics, CR approach, Maricunga ?Issues, Perspectives ?Concluding remarks

May 1, 2010

Presentation Agenda ?Background ?OEM Recommendations before RCM ?Operating Context ?OEM Recommendations after RCM ?Reality of Failure ?RCM Deliverables ?Maintenance program optimization ?Spare part optimization ?Implementation ?Further Considerations -Three scenarios ?Summary and Conclusion Background ?P&H Mining?s LCM division performed a RCM study on a ?generic 4100 XPB shovel?in Milwaukee. ?P&H soon realized that the analysis required context -The recommendations were manufacturer knowledge based. -The outcome based on manufacturer requirements. -The strategy was not applicable to all machines, etc. Operator experience and ?local knowledge? are key to the success of an RCM analysis. P&H approached Teck Coal?s Fording River Operation to assist with ?Operating Context?. Teck provided operator and maintainer experience.

May 1, 2010

By D. F. Sangster

"Eight volcanogenic massive sulphide districts in Canada and Japan, ranging in age from Archean to Miocene, were selected for analysis. The study revealed that: {I) each district has an average diameter of 32 km; (2) the districts contain 4 to 20 deposits each, with an average of /2 deposits; (3) the average total base metal content per district is 4.6 million tonnes, with a coefficient of variation of32%; (4) ranked in order of size, the largest deposit in each district contains, on average, 67% of the total metal and the second largest about 13 %. The remaining deposits range downward in decreasing proportions. Empirical observations such as these may be used f or evaluating the undiscovered potential of new districts as well as contributing to a better understanding of the distribution and genesis of this important class of base metal deposits. Previous WorkThe characteristic geological features o f volcanogenic massive sulphide deposits have been described by numerous authors over the past fifteen years and it is now widely accepted that these deposits comprise a major ""deposit-type."" In addition to these geological parameters, however, it is now becoming apparent that volcanogenic massive sulphide deposits show several distinctive grade-tonnage relationships. For example, Singer et al. (1975) demonstrated a slight negative correlation between copper grade and ore tonnage in their sampling of 146 volcanogenic deposits. In a study of 110 Canadian Precambrian deposits of this type, Boldy (1977) showed that the size of the modal deposit is 0.39 million tons, that of the median deposit is 1.40 million tons and the arithmetic average is 6.85 million tons. Moreover, Boldy's data show that the average grade of combined base metals (Cu + Zn + Pb) for each of the se three deposit-sizes is, respectively, 6.25%, 5.35% and 6.47%. Because the lead content of Canadian Precambrian volcanogeni c deposits is most frequently less than 1%, the total metal grade is effectively Cu + Zn . From Figure 2 in Bold y (1977), it can be seen that 83% of the deposits fall in the range of 0.l to 10 million tons ."

Jan 1, 1980

By J. Drozdiak

In this paper we present the results of preliminary investigations into the applicability of new laboratory scale tests for the prediction of operating gap and specific throughput in high pressure grinding rolls (HPGR). The work is a part of the CAMIRO HPGR research program being conducted at the University of British Columbia, which aims to develop a suite of small-scale tests and procedures for the selection and sizing of HPGRs. A focus of the presented study is to test sample types in terms of their terra-mechanics based characteristics and relate them to specific throughput and gap results from pilot HPGR testing on the same samples.

Jan 1, 2012

By J. Shahabpour

"Breccias with angular and rounded clasts of a late-mineralization, ""barren"" hornblende porphyry dike set within a comminuted matrix consisting of rock fragments and quartz, cemented by quartz and K-feldspar of hydrothermal origin is observed in diamond drill cores from the Sar Cheshmeh porphyry copper deposit. Studies of age relationship between vein types, phyllic-altered clasts and the breccia groundmass suggest that the brecciation is a late event. The breccia clasts record evidence of hydrothermal reaction between the clasts and fluids responsible for the brecciation.Formation of bornite, in the breccia clasts of the originally barren hornblende porphyry dike, and in the breccia matrix, along with the scarcity of bornite in the Sar Cheshmeh deposit itself suggest involvement of fluids which are later and of different composition from the fluids responsible for the known mineralization at Sar Cheshmeh. These later fluids may be related to a later plutonic event and suggest the possibility of a later, and concealed deposit."

Jan 1, 1994

By Louise Corriveau

Exploration strategies have traditionally considered felsic gneiss complexes of the Canadian Shield sterile. This paradigm is challenged with the discovery of extensive granulite-facies Cu-Au, Fe oxides-bearing hydrothermal systems in the 1.4 Ga Bondy and 1.5 Ga La Romaine volcano-plutonic complexes of the Grenville Province. Early identification of magnetite-rich units in association with meta-exhalite and pelite-like units was key to targeting the search for mineralization, protolith information and indicators of pre-metamorphic hydrothermal activity during regional surveys of these frontier terrains. Textural evidences for a volcano-plutonic setting were found. There remained, however, numerous impediments to the recognition that the ubiquitous magnetite-laden units and associated aluminous gneiss were hydrothermal in origin. Many metamorphic reactions form magnetite at the amphibolite to granulite facies transition, and hydrothermally-leached rocks resemble metapelite or migmatitic restite, while carbonate alteration zones may look like marble or calc-silicate rock. Non-typical metamorphic mineral assemblages, modes and colours arise when hydrothermally-derived rock types are metamorphosed. These effective markers served as tools for reliable field identification of hydrothermally-altered rocks. In our case-studies, we traced pre-metamorphic hydrothermally-driven Fe-oxide precipitation in association with sericitization, albitization, pyrophyllite alteration, chloritization, and B enrichment by mapping unusually high contents of (1) magnetite or hematite, (2) biotite, (3) albite, (4) sillimanite, (5) orthopyroxene or phlogopite with cordierite, and (6) tourmaline or kornerupine. The unveiled garnetite, tourmalinite, and aluminous gneiss had assemblages that vary according to metamorphic grade and composition. To assess if high mode of Fe-Mg-Al phases resulted from partial melting (restitic residue) or metamorphism of hydrothermal rocks, we compared leucosome mineral assemblages, shape and amount with that expected of in situ partial melting reactions. In both areas there is no compelling evidence for these units to be restites. In contrast, the presence of lapilli in garnet-cordierite-sillimanite gneiss, though extremely rare, constitutes conclusive evidence for extreme pre-metamorphic high-sulphidation alteration of a volcanic protolith, while Fe-oxides or sillimanite-bearing nodules and veins record a less pervasive alteration. Geochemical research on element mobility and mass balance calculations further testified of an hydrothermal origin for these gneisses. The magnetite-rich units, together with calc-silicate rocks, garnetite, hornblendite, albitite among amphibolite, provided effective guides to sites of fluid discharge and led to the discovery of Cu and Cu-Au showings. With the presence of highsulphidation alteration, these features suggest early Cu-Au VHMS-type alteration halos within a predominantly felsic composite volcano-plutonic arc setting for both case-studies. Evidences for subsequent F-driven orthomagmatic fluid activity are also present.

May 1, 2003

By Lesley Hymers

First Nations Natural Resources Youth Employment Program PDAC Mining Matters ? Charitable organization ? Provide education to students, teachers, and the public about rocks, minerals, metals, and mining ? Provide current information and offer exceptional educational resources that meet provincial Earth science and geography curriculum expectations First Nations Natural Resources Youth Employment Program ? Provide instructional development workshops for educators who are teaching Earth science and geography ? Since 1994, reached more than 400,000 students, teachers, industry representatives, and members of the public

May 1, 2009

By W. A. Crosby, W. K. Smith, K. L. McDonald

"IntroductionThis paper describes how the introduction of two blasting techniques and the resuItant development of new dragline digging methods have increased the productivity of single- and double-seam dragline operations at the Rietspruit opencast mine.LocationRietspruit , one of South Africa's largest opencast strip mines, is situated some 11 5 kilometres east of Johannesburg in the Witbank coal field.BusinessRietspruit is a joint venture between Transvaal Consolidate d Land and Exploration Company (T.C.L.) and Shell, South Africa. Rietspruit is administered and managed by Rand Mines, the Mining division of Barlow Rand, transportation and marketing being the responsibility of Shell. The total saleable coal product, approximately 5,5 million tons per annum, is exported via Richards Bay.Presplitting and Throw BlastingPresplitting was initially introduced in September 1980, as a means of dewatering t he overburden and mid burden to facilitate the use of dry-mix explosives a s opposed to slurry explosives.The utilization of the throw blasting technique arose as a direct result of observed ground movement after the successful introduction of presplitting. The first trials commenced in March 1981 on the double-seam operation. The methods, economics and resulting advantages are fully described elsewhere. A brief description follows.Method of PresplittingAfter determining the desired presplit line, 250-mm holes are drilled to top of coal at 4-m to 6-m intervals, dependent on the competency of the rock overlying the coal. A single 60-kg charge of slurry explosives is located at the bottom of each hole, no tamping is used and all the holes are detonated simultaneously. The results are a competent, straight, vertical highwall. This enables accurate control of the first row of blast holes closest to the highwall, which is a prime requisite for successful throw blasting."

Jan 1, 1983

By Simon Pelletier, Jose Delgadillo, Dave Page, Pramod Kumar, Raj Rajamani, Dilek Alkac, Martin Fillion

"In general, many past works examine mill load, mill power, shell lifter design etc with a view to improving the mill capacity. On the contrary, only a handful of papers have addressed the transport of fine slurry through the pulp lifters. We present the flow dynamics of pulp lifters via laboratory scale experiments, high speed photography and modeling with computational fluid dynamics. Next, the flow behaviour in ArcelorMittal’s Mont-Wright autogenous mill discharge flow is examined. In an effort to improve mill throughput, a comprehensive simulation and plant scale study of the mill was taken up with a focus on the shell and pulp lifter design. The shell lifter was found to be at its optimum limit for breakage of ore particles given the constraints of wear life and occupied volume. Next, the pulp lifter study was taken up with computational fluid flow code and discrete element code. The simulations directly showed that there was considerable carry-over of slurry. This effect was traced to the area restriction in the pulp lifter channels. Further, crash-stop studies confirmed slurry pooling within the mill. Thus it was readily apparent that mill throughput can be increased if the pulp-lifter could be redesigned. Consequently, the discharger section of the pulp-lifter was redesigned.First, this paper outlines the modeling in laboratory scale studies and plant scale studies leading up to the discharger design. Next, the discharge flow in seven different published mill surveys is predicted with computational fluid dynamics (CFD) methodology shown here. Finally, Mont-Wright mill circuit performance before and after the discharger redesign is described. The usefulness of fluid flow simulations in the design of pulp-lifters is emphasized."

Jan 1, 2012

By Scott L. Ewart, William M. Bryden, Donald E. Wakefield

"Osler, Hoskin & Harcourt develops commentaries from time to time on topics of legal interest. These may deal with new legislation, changes or developments in government policy or recent judicial decisions of importance to its clients. The commentaries are, of necessity, general in nature. Because the law which they deal with is often new and untested, it is hard to arrive at precise statements of the way in which the principle s discussed in a commentary might be applied in specific circumstances. When further guidance is needed , consult a solicitor.The purpose of the Bill is to simplify, modernize and standardize the regulation of mineral exploration and development in Ontario. Many of the changes proposed by the Bill are of an administrative nature and move much of the detail with respect to staking, assessment work, prospecting work, surveys, quarry permits and leases contained in the existing Mining Act to the Regulations contemplated under the Bill.The Bill will undergo revision and be re-introduced and therefore it is not the intention of this present article to detail the specific changes contemplated by the Bill; however , its more significant changes are as follows:1. Provision is made for a lifetime prospector's licence with the elimination of annual renewals;2. Perimeter staking of a block o f claims is permitted to reduce the cost of staking;3. Assessment work requirements are expressed in term s of dollars spent rather than days worked;4. Persons doing exploratory work are required to furnish notice to owners of surface rights of intention to perform assessment work;5. Annual work summaries will be available to the industry to lessen duplication in exploration work;6. The option of continuing assessment work rather than applying for a lease is provided;"

Jan 1, 1984

By K. E. Waters, N. Brodusch, R. Gauvin, C. Teng, H. Demers

Rare earth elements play an increasingly important role in renewable energy devices and high-end electronics. In this project, the composition and morphology of REEs-bearing minerals are characterized with a field-emission scanning electron microscope at high spatial resolution and high counts rate using an X-ray silicon drift detector system. High spatial resolution imaging and energy dispersive X-ray microanalysis were applied at low and high magnification to obtain the composition of each phase in the minerals. From the standardless quantitative analysis results, the amount of REEs in each phase was measured and the relationships between those phases were identified.

Jan 1, 2014

By F. O. Verret, A. McKen, G. Chiasson

Several grindability tests were developed over the years to design grinding circuits or optimize existing operations. Each test has its own strengths and weaknesses and it is imperative to select the proper test procedure(s) to meet project deliverables and minimize the risk of a project. Pilot plant testing of large bulk samples historically constituted the traditional approach for AG or SAG design, but was gradually replaced by small-scale tests. Nowadays, conducting grindability tests requiring only a few kilos of material on several samples is a more typical approach to grinding mill design. This paper summarises the requirements and deliverables of various bench-scale test procedures, their strengths and weaknesses, and cases where AG/SAG pilot testing should still be performed.

Jan 1, 2012

By Larry Urbanoski

"This paper describes the application of a radioisotopic energy dispersive X-ray aY1alyser to complete on-stream analysis in a base metal concentrator.The major components of the system are outlined and some description of the application, operating experiences and benefits are provided.IntroductionThe ma1n intent of this paper is to describe the on-stream analysis system in operation at the Geco concentrator. X-ray analysis systems installed in Canadian concentrators to-date may be broadly classified as wavelength dispersive analysers whereas the installation described herein is an energy dispersive x-ray analysis system. Energy dispersive x-ray analysis techniques may utilize radioactive sources to provide primary x-rays for excitation of elements and separate the secondary x-rays on the basis of energy levels. In contrast wavelength dispersive analysers apply high voltage x-ray tubes to provide primary x-rays and utilize crystals to disperse and thereby separate x-rays generated by bombardment of the sample."

Jan 1, 1978

By Simon Hanner

November 2005 Memorial University Newfoundland and Labrador Mines and Energy Review of Activities Exploration and Mining New Brunswick ?Université du Québec a Montréal McGill University 2005 Manitoba Mining and Minerals Convention Université Laval Quebec Exploration 2005 Saskatchewan Open House December 2005 University of Calgary University of Alberta 'Laurentian University 'Queen's University 'University of Toronto 'Ontario Prospectors Association January 2006 Mineral Exploration Roundup, BC March 2006 Prospectors and Developers Association of Canada Convention April 2006 University of Ottawa Carleton University

May 1, 2006

By J. H. Bernard, K. Žák

The three traditional types of Variscan vein Pb-Zn-(Ag) mineralization recognized in the Bohemian massif from historic paragenetic studies are confinned by modem metallogenic studies. Stable C, S, and O isotope data, as well as Pb and Sr isotopic ratios of the deposits, indicate a predominantly crustal origin of the constituents in all three types. Although the data also suggest differences in temperature and pressure of formation, and the oxidation conditions and nature of the hydrothermal fluids, nonetheless they are consistent with prevailing metallogenic classifications of the vein mineralization

Jan 1, 1992

By M. B. McClenaghan

"The Ontario Geological Survey completed a regional till sampling project between 1984 and 1988 in the Black River Matheson (BRiM) area of northeastern Ontario. The project was designed to aid mineral exploration in the area by documenting the Quaternary stratigraphy and by providing a database of till geochemistry. This paper summarizes the results from the sonic overburden drilling component of the BRiM project carried out in areas of thick drift (> 5 m). Results from till sampling in areas of thinner drift (<5 m) have been presented in a separate paper. Approximately 1100 till samples were collected from 225 sonic drill holes. For each sample, the non-magnetic heavy mineral (>3.3 S.G.) and fine (-250 mesh) till fractions were analyzed geochemically and visible gold grains were recovered by panning.Gold and other multielement geochemical data were plotted using proportional symbols to highlight anomalous areas and to demonstrate how to evaluate and interpret a very large geochemical dataset. Thresholds for identifying anomalous concentrations of Au in till samples, defined using the 95th percentile, are 1500 ppb and 12 ppb for the heavy mineral and fine fractions, respectively. The heavy mineral fraction of older ti1ls and to a lesser extent, Matheson Till, display a number of significant gold anomalies in the study area, which in a few cases, are associated with base metal anomalies. The vertical position of gold anomalies in Matheson and older ti1ls varies from directly on bedrock to several meters above the bedrock surface and can provide information of relative ice transport distances."

Jan 1, 1994

By Emmanuel Henry

The Kiruna Mine, operated by Luossavaara-Kiirunavaara AB (LKAB), is a large-scale sublevel caving operation located in Arctic Sweden. Iron ore is extracted at a rate of 60 000 tpd from a four-kilometre long, 80-100 m thick and 60-degree dipping orebody. Actual production depth is 800 m under the top of the footwall and about 550 m under the average regional ground level. Because no support is left between the footwall and the hanging wall and despite the relatively low mining depth, extraction results in the formation of a huge stress shield modifying the original stress field and concentrating it just beneath the mining level. Effects of stress concentration on the rock mass are monitored through field observations and a seismic system. Severe stress-induced deterioration of openings is visible to a certain radial distance from the mining level: pillar crushing and fault slips are more and more common and extended. The seismic system, installed in collaboration with CANMET, confirms the field observations and completes them in the rock mass: fault slips and major seismic events are recorded. The system proves its effectiveness to outline the extension of the dynamic response of the rock mass, which actually seems much larger than field observations let think.

May 1, 2001

Objectives ? New deposits can be found in mature Mining CampsNew Camps ? Volcanogenic Massive Sulfide (VMS) deposits ? polymetallicpolymetallicexamples are desirable exploration targets examples ? Genetic and exploration models for VMS deposits are robustrobust ? subtle but important differences exist between deposits and districts ? sometimes ??neglectedneglected??in resource modeling and exploration efforts ? ReRe-evaluation of a prominent existing camp is rewarding ? update on the exploration strategies currently being applied on a practical level The Falconbridge-Alexis approach includes GoCAD modelling

May 1, 2006