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By Dave Stefanuto

Voisey?s Bay Project Components ? Mine/Mill Port In Labrador ? Mini Plant in Mississauga ? Demonstration Plant in Argentia ? Supply Vessel (Umiak1) ? Transshipment Facility (Quebec) ? Concentrate Handling & Transport to Sudbury/Thompson ? Cobalt Refinery Upgrade (Thompson) Project Setting ? The Project is on the traditional lands of the Labrador Inuit and the Labrador Innu ? Canadian courts have held that Aboriginal peoples in Canada possess special rights to traditional Aboriginal lands Those rights can include requiring resource developers to enter into Impacts and Benefits Agreements (IBAs) on traditional lands to set forth how lands can be used and benefits to be received by Aboriginal people

May 1, 2006

By P. Wells

"In the past decade, there have been many developments in processing of nickel/copper sulfide ores. Improved pentlandite/pyrrhotite flotation selectivity with the use of new reagents, fine regrinding and Redox measurement (control) has led to increased pyrrhotite rejection and thus higher concentrate grades. Flash flotation has increased overall nickel and associated precious group metal recoveries. Recovery of both fine and coarse particles has been improved through an understanding of flotation cell hydrodynamics. The separation of copper from nickel in such ores has seen a similar level of development. From the late 80s to very recently, the use of flotation columns, the use of pyrrhotite depressing reagents and the improved understanding of the complex mineralogy of chalcopyrite, pentlandite and pyrrhotite have considerably increased copper / nickel separation efficiency. Copper concentrate with more than 30% copper and less than 0.5% nickel grade is now obtainable at 80-85% copper recovery from mill feed compared to 70-75% copper recovery with 30% copper and 1% nickel grade only a few years ago. Improved copper / nickel separation in milling operations has the potential to substantially improve the processing of the resulting concentrates and thus the overall return from the extraction of nickel and copper from sulfide ores.INTRODUCTIONNickel metal by itself or in alloys with other metals and materials makes a significant contribution to modern society. The relatively high price that nickel commands compared to other base metals is a reflection of the fact that, although abundant in the universe, nickel is sparingly distributed in the earth’s crust. There are two types of nickel deposits that are currently being exploited: complex sulfide ores and lateritic oxide ores. Lateritic contain no copper but in sulfide deposits, nickel– bearing minerals, principally pentlandite (Pn, [Ni,Fe]8S9), some millerite (NiS) and violarite ([Ni,Fe]S) are often found in association with copper-bearing minerals, mainly chalcopyrite (Cp, CuFeS2) and cubanite (CuFe2S3). The copper content of such ores can vary considerably from as high as 5-8% (in some Sudbury basin ores) to as low as 0.1% (in ores mined by Western Mining at Mount Keith, Western Australia and by Inco in Thompson, Manitoba). The valuable minerals Pn and Cp are almost invariably found associated with pyrrhotite (Po, Fe7S8) which along with nonsulphide rock has to be rejected to tails in the primary milling stage. The bulk concentrate from the primary stage is then treated to depress Pn and float Cp. A complete Cu/Ni separation at the mill would be highly desirable but this is not possible because of locking between a small fraction of the valuable minerals. As a result, Cu/Ni separation has to be carried out both during milling and during refining of the matte following smelting. At Inco, Jinchuan and in Norilsk, a chalcocite / heazlewoodite separation is made by flotation following slow cooling of the matte. In the present Sudbury Inco operations, Cu/Ni separation has not been conducted at the mill since 1991 and all Cu/Ni separation takes place at the matte processing plant. Because of the rising ratio of Cu to Ni in the ore, this strategy is under review and this paper describes some recent studies of circuits in preparation for possible installation of a copper / nickel separation circuit at Inco’s Clarabelle Mill in the Sudbury area."

Jan 1, 2004

By Brett Campbell

The San Vicente to 2nd Aqueduct Pipeline?Tunnel project is a raw water conveyance tunnel linking the San Vicente Reservoir (SVR) to the 2nd Aqueduct Pipeline via Rancho Penasquitos Pressure Control Facility (RPPCF). This 58,230 lf long tunnel will be 8.5? final ID, and has four points of construction access. The job is classified into 6 Reaches of tunnel, identified by the dominant geology within the reach. This paper will focus on Reach 3, specifically the measures necessary to drill and blast a 550 lineal foot section of granitic rock tunnel immediately in front of an open face digger shield.

Jan 1, 2008

The following observations on the mineral composition of the lead-zinc ores at Captain's Flat, New South Wales, are based upon the examination of a collection of specimens made during a brief visit to the mine in January, 1942, in conjunction with earlier studies of specimens and mill products, which have 'been the subject of various Mineragraphic Reports, Captain's Flat is about 35 miles south of Canberra, and is connected with the main line from Goulburn to Bombala by a branch line to Bungendore, 23 miles away from the mine.The geology of the mine has been described by Kenny and Mulholland2 and by Harper.3 The country consists of Silurian sediments, which have been invaded by a composite sill of quartz-felspar-porphyry. Both sediments and sill have been folded gently, the axial lines of the folds trending north and south. In the vicinity of the orebodies the folds are steeper, and thru,st faults are associated with the anticlines. The intense compression and shearing that accompanied the faulting has converted the adjacent porphyry to schist. The Captain's Flat orebodies occur along such a zone of shearing and faulting, on the eastern limb of a steep, north-pitching anticline. At their southern end the orebodies are enclosed in the slates underlying the porphyry, but the northerly pitch of the fold carries the slate to greater depth in the northern part of the mine, where the orebody lies beween schistose porphyry on the hanging wall and massive porphyry in the footwall.THE OREBODIESThe orebodies occur along a N.-S. strike length of 4,200 ft., and from the point of view of mining, fall into three sections: the Elliot's Section to the north, the Central Section, and the Keating's Section to the south. The Keating's Section is separated from the Central Section by 500-600 ft. of mineralised ground of so low a grade as' to be called barren, and is offset about 125 ft. to the 'east of the Central body by an oblique fault striking N.300E. Elliot's Section and the Central Section are connected by persistent veins and stringers of lead-zinc ore, but although these are...

Jan 1, 1943

By C T. Hollick

Conventional processing of heavy mineral deposits containing radioactive rare earth minerals such as monazite and xenotime may cause industrial hygiene problems through atmospheric dust and contamination of product concentrates. An alternative procedure has been developed in which such minerals are removed from bulk heavy mineral concentrates by flotation with little loss of other economic minerals. With fine ores, recoveries of over 95 per cent have been achieved and with coarse ores over 80 per cent, in both cases at high grade. Several flotation regimes have proven effective. The potential for generation of radioactive dust or product contamination is subsequent processing is correspondingly reduced.

Jan 1, 1990

By W. D. Northrop

This paper gives an account of the development of a technique whereby the vertical limits of geological horizons may be identified by the use of vertical variograms on the mineral of economic interest. This information may supplement or guide the correct subdivision of the individual horizons into meaning full data sets by diligent geological observation. This process then improves the quality of the variance modelling of the gold distribution in the plane of the individual layers and therefore enables better estimates to be made into the grids or blocks of the mine model. The technique is explained by an account of the development work, which was performed, on duplicate superimposed reef horizons in the Kimberley formations. The paper then shows how the correct approach was developed to evaluate the mineralized layers in a multiple stacked conglomerate layer sequence in the Elsburg reefs of the Witwatersrand Rand System at the Target deposit. The method of categorization of resources according to confidence in the estimate is also explained. The feasibility processes carried out on the three-dimensional model, in accordance with the SAMREC code are also described. An example of the development of a reconciliation process utilizing chip sampling is also explained.

Jan 1, 2003

By R. P. King

The MODSIM mineral processing plant simultor is used to find optimal combinations of target separation specific gravities in a typical modem coal washing plant. A plant that is set up with these optimal targets can deliver up to 10% more yield at the same ash content as the same plant set up with separation targets chosen by conventional methods. MODSIM is the only simulator currently available that can simulate the liberation of pyrite and other mineral matter during open- and closed-circuit grinding operations. The simulator can therefore be used to assess the benefits of grinding operations in the flowsheet.

Feb 24, 1997

By Özgür Bezgin

This paper presents observations on the installation of drilled shafts from two construction projects and an academic study with experimental and analytical parts. The construction projects involved the use of pressurized drilling methods. The experimental part of the academic study involved the use of the auger drilling method. The analytical part of the academic study investigated the effect of drilling methods on the soil-structure interaction and the behavior of drilled shafts under lateral loads. The concept of ?free-length? is introduced for the lateral load design of pressure-drilled shafts that are thought to be fully embedded within a soil media. The academic part of the study presented herein was conducted in Rutgers, the State University of New Jersey.

Jan 1, 2009

By Brian Flintoff

"When I was first asked to prepare this paper and presentation in late June, I thought it might be fun to ""step back and paint the bigger picture."" Having attempted to do this, fun is not the first descriptor that now comes to mind, and speaking dyslexically, I've had 'nuf.'Unlike Nostradamus, or even Orwell, I've discovered that I'm ""clairvoyantly challenged"" and not even the psychic hot-line was of much help, at least with respect to process control! I am somewhat comfortable speculating on evolutionary change, but the radical developments that will arise from revolutionary changes are well beyond my mortal capabilities. Even with evolutionary change, I'm reminded of the lessons of time series analysis which show the prediction error to grow exponentially as the horizon moves into the future. As Macluhan is reported to have said: ""Predicting the future based on the past is a little like driving your car while looking in the rearview mirror!""Having honestly presented my qualifications, allow me to try to look at process control and to offer some conjecture on where we're probably headed. In the end, it is said that: ""The plant of the future will have only two employees, a man and a dog. The dog will be there to keep the man from touching the equipment.1""IntroductionA little less than a decade ago Andy Mular and I co-edited a monograph entitled ""A Practical Guide to Process Control in the Minerals Industry."" The work was commissioned by the senior management of a consortium of Canadian mining companies, since it was widely perceived that control was an area of great economic potential, but one that had not been effectively tapped. The concern was that if the industry could not soon deliver on the ""potential"", the term may well have appeared in the epitaph of what was, to these men, a very attractive investment opportunity. I think it is fair to say that over the past few years process control has clearly established itself as an essential technology in plant operation and optimization. That isn't to say that we get it all-right, all-the-time, but, the circumstances are much different than they were. In the eyes of many, process control has attained the distinction of being considered a mature technology, even though there are still countless avenues for exploration."

Jan 1, 1998

By T. Tholana, P. N. Neingo

"Mining companies globally are currently facing severe economic and financial challenges. In addition to global challenges, the South African mining industry has to face other operational challenges that are unique to the country and which threaten the survival and competitiveness of the industry. Profit margins are being squeezed by rising costs and decreasing commodity prices, while labour productivity is greatly affected by intermittent labour unrest. This paper analyses how the South African gold mining industry has performed pre-, during, and post the global financial crisis of 2008. The competitiveness of the industry in terms of labour productivity and industry cost curve position is analysed for the period 2006–2013 to assess the impacts of both the global financial crisis and labour unrest. An analysis of the South African gold mining industry is presented at company as well as mine level. Productivity measure in this paper is limited to labour productivity, in line with limited reporting on productivity. All the data analysed was obtained from the public domain. IntroductionSouth Africa dominated the world as the number one gold producer until 2009 when China took that position, and today South Africa ranks fifth after China, Australia, Russia, and the USA. According to Statistics South Africa (2009), South Africa still had about 30 years of production in the gold sector, a forecast that fluctuates based on the day’s modifying factors. Although South Africa has a comparative advantage in terms of minerals endowment, there are challenges faced by the mining industry that hinder translation of the comparative advantage into a competitive advantage. The industry continually seeks to address these challenges to remain competitive in global markets while addressing national and community needs.Neingo and Cawood (2014) argued that stakeholders in mining are continually concerned with mine management’s ability to translate use inputs effectively into quality outputs. They further suggested close monitoring of effective utilization of people, materials, and money to obtain maximum production of commodities under given conditions. Productivity is measured in various ways, including unit cost, output per employee, and output per unit capital equipment"

Jan 1, 2016

The National Economic Viewpoint? Any substantial project undertaken by private enterprise would normally be subjected to a Discounted Cash Flow analysis of its commercial viability, and would proceed only if the rate of return was judged satisfactory. A 'national viewpoint' analysis attempts to do the same but from the viewpoint of the community as a whole. The objective is to ensure that those projects are undertaken which yield the best return, economic and social, to the nation as a whole.

Jan 1, 1984

By Meghan McGrath

Third generation advance high strength steels with microstructures of acicular ferrite and retained austenite were investigated and meet mechanical property goals. A good combination of strength and ductility were achieved with duplex ferrite and austenite microstructures where cementite formation was suppressed. Transformation induced plasticity (TRIP) behavior produced rapid work hardening. The mechanical properties of two hot-rolled steels with duplex microstructures were compared and had the following compositions: (1) Fe-0.14C-13.87Mn-1.42Si-3.51Al; and (2) Fe-0.06C-14.2Mn-1.85Si-2.38Al. These steels were cast, homogenized, and hot rolled at 900ºC to obtain a refined microstructure with ultimate tensile strengths and elongations to failure of 865 MPa and 39% and 1,217 MPa and 28%, respectively. The amount of metastable austenite in both compositions decreased after tensile testing from 58% and 28% to 6% and 0%, respectively. Microstructures were characterized using optical microscopy, scanning electron microscopy (SEM), and x-ray diffraction.

Jan 1, 2010

By B. Tripp

Utah produces a wide variety of industrial rock and mineral commodities, valued in 2005 at a record $758 million (21 percent of the total non-fuel mineral production of Utah). Major commodities produced in 2005 include salts (halite, potash, and magnesium salts), Portland cement, sand and gravel, carbonates (lime, limestone, and dolomite), phosphate, crushed stone, clays, lightweight aggregate (expanded shale and perlite), gypsum, silica, sulfur and sulfuric acid, and building stone. Commodities produced in smaller amounts include diatomite, pumice, gemstones, ornamental stone, fluorspar, and mineral and fossil specimens. Utah is in a period of rapid growth in industrial rock and mineral production; however, some commodities have grown faster than others. The robust western economy has stimulated production of construction-related commodities like sand and gravel, Portland cement raw materials, lime, and building stone, resulting in exploration for raw materials, development of new quarries, and expansion of existing plants

Jan 1, 2007

Development of Process for Beneficiation of Low-Grade Iron Ore Samples from Orissa, India The paper deals with the results of characterisation and beneficiations studies undertaken on two low-grade Indian iron ore samples (IO-1 and IO-2) with a view to develop process for beneficiation of composite of the two samples to a high-grade concentrate, suitable for iron making through pelletisation. Indian iron ores contain relatively high iron but cost effective reduction of alumina within the specified limits has been a challenging task. Characterisation of the samples revealed the ore to be laminated and fine grained with hematite as the major mineral. Clay is the dominating gangue in most of the ore pieces followed by silica. Occasionally goethite and quartz/jasper were recorded. Clay occurs either as patches within the hematite mass or as cavity/fracture fillings. Liberation studies on the representative samples crushed to 2 mm indicated that around 95 per cent of the grains are liberated below 105 micron. Beneficiation of the two individual samples and their composite based on gravity and magnetic separation techniques resulted in products with varying yield and grade of the products. The effects of various process parameters were studied. Granulometry of the feed was observed to be important for improving quality of concentrate. The results of bench-scale studies were validated through pilot-scale continuous trials. Based on the studies undertaken a suitable process was developed for beneficiation of the composite sample, comprising 60 per cent IO-1 and 40 per cent IO-2, to a high-grade product assaying over 65 per cent Fe and material balance was computed. A commercial plant for beneficiation of low-grade iron ore to produce DRI pellet grade concentrate is proposed to be installed.

Sep 13, 2010

By Oliver Bowles

"INTRODUCTION Slate has earned a high reputation as a roofing material, carefully selected and properly placed it is rainproof, attractive, and extraordinarily durable. Despite there qualities in its favor, the slate industry during the past 30 years has suffered marked reduction in volume of sales. An increase in building construction and general improvement in business will doubtless bring renewed activity, but considerable ground has to be recovered before the industry can become prosperous. Influences tending to dwarf this long-established industry producing materials of world-wide reputation are analyzed briefly in the following pages in the hope that they may be rectified.HISTORY OF SLATE PRODUCTIONFigure 1 shows graphically the rise and fall from year to year of sales of roofing slate since 1885. In quantity, the peak was reached in 1902, and the most serious decline was from 1912 to 1918, sales at the end of this 6-year period being only one third those at the beginning. Unlike most building materials, slate experienced only a slight recovery in volume of sales during the post-war period, 1920-29. The value closely parallels the volume up to the World War period. Subsequently, however, as unit values increased the aggregate value rose sharololy above the volume curve, attaining in 1928 the point reached in 1903, although the Lumber of squares sold was scarcely one third as great. The increased unit value was due partly to larger sales of heavy architectural grades."

Nov 1, 1933

By S. Kevin McNeil, William Joa, Catherine Johnson, S. Omar Garcia

The geometry of an explosive is known to have a fundamental effect on the resulting shock wave propagation. Typically researchers use a spherical or hemispherical geometry in order to simplify the shock wave so that resultant overpressure and impulse are uniform in all directions. The goal of this research is to understand the overpressure characteristics from a sheet explosive, a geometry often utilized for breeching in the military. In training alone, soldiers can be exposed to several tests per day, which may be contributing to the prevalence of blast induced mild traumatic brain injuries. Using PCB pressure transducers and high speed video, it was found that as the angle departed from normal (perpendicular) to the face of the sheet explosive, the over pressure decreased significantly. When in line with the plane, a decrease of over pressure by as much as 20% was observed. Time of arrival was roughly 20% faster directly in front of the charge with a pressure amplification of 46% relative to a spherical baseline charge of the same mass. This testing may reveal a more complete relationship between the pressure and angle from the explosive that could have applications for military and law enforcement with respect to best practices on blaster location for reduced over pressure exposure.

Jan 1, 2019

The outlook for suppliers of energy to the expanding economies of the Pacific Basin region is essentially positive, but particularly for exporters of high quality steam coal. This paper argues that economic growth in the Pacific Basin region has exceeded world economic growth for some years and that this will continue to be the case for the next decade at least. It looks briefly at the link between economic growth and energy demand and at the relationship between energy demand and the demand for electricity. Changing preferences in fuel mix for electrical generation in the region are noted and tentative forecasts made about variations in this mix. The pros and cons of various forms of fuel used to generate electricity are considered from the point of view of the consumer. Having concluded that steaming coal in particular is likely to become even more important as a generator of base load electricity, the paper looks at the opportunities this presents for exporters such as Australia, and touches on some factors that could prevent development of those opportunities. This paper will concentrate on electrical energy. For the purposes of this paper, the Pacific Basin refers essentially to Australia, New Zealand and the Asian countries bordering the Western Pacific. As a supplier, Siberia is not included because, although it has great potential, it is thought that problems of climate, infrastructure and political restructuring will delay the realisation of that potential until the next century. Although it deals with the Pacific Basin region, where many countries are industrialising rapidly from a predominantly agricultural base, it looks at the experience of mature industrial DECD economies where their experiences seem relevant.

Jan 1, 1990

By Thomas O. Glover

Cameroon continued to enjoy sustained economic growth that began with its independence in 1960. Growth in the gross domestic product (GDP) averaged 2.8% per year during the 1960's and the first half of the 1970's. Starting in 1976 and for the succeeding 10 years, the GDP accelerated rapidly owing to the coming on-stream of Cameroon's small but domestically significant offshore oil industry. In 1985, the GDP grew by 7.8%, but in 1986, it was only up 5.5%. The country's sustained economic growth in dollar terms of gross national product (GNP) per capita reached $1,075 in 1986. The ranking in GNP per capita by the International Monetary Fund put Cameroon in the middle-income category for developing countries. The sustained economic growth rate up to 1986 was due to the injection of income from oil into the economy, but crude oil price reductions in 1986 brought a slowdown. In 1986, crude oil production grew to 200,000 barrels per day, an increase of 8.2% from that of 1985. Most of the oil came from the Société Nationale Elf Aquitaine (SNEA) wells in the multifield Rio del Rey complex. Additional output came from the Moudi Field operated by Compagnie Française des Pétroles S.A. Proven oil reserves in Cameroon were 540 million barrels. At 1986 production rates, and in the absence of further discoveries, Cameroon will have exhausted its recoverable oil reserves by the year 1995. Owing to worldwide crude price reductions, the country's oil income fell 60% between 1985 and 1986, from $1.82 billion2 to $0.72 billion. Cameroon's refinery operator commenced operating the Sonara refinery in 1981 at Point Limboh. Sonara's capacity of 43,000 barrels per day was small by most standards. In 1986, natural gas reserves, estimated at 100 billion cubic meters, were not produced commercially because there were no domestic users. Proposals for a multibillion-dollar liquefied natural gas plant at Kribi had been submitted; however, work on the plant had not commenced.

Jan 1, 1988

By R. J. Visintainer, W. L. Whitlock

"Difficulties with the sizing and operation of centrifugal froth pumps are common and the underlying fluid dynamics are complex. Design and selection often relies on previous experience, offering unreliable guidance for novel applications or unexpected problems. The current paper describes a program of extensive laboratory testing on froth handling centrifugal pumps, covering a range of flows, heads, speeds, viscosity, air content and froth stability. Variations in impeller vane design and the effectiveness of an airlock venting apparatus were also examined. The program resulted in a better understanding of centrifugal froth pump dynamics and insight for the troubleshooting of field applications.INTRODUCTION The Challenge of Pumping Froth In pumping mineral processing froth, the handling of large quantities of air within the fluid is often unavoidable. Efforts to reduce the amount of air present at the pump suction, while always recommended for improving pump performance, may have limitations. Some strategies may also carry an economic penalty, such as unwanted process dilution (e.g. due to water spray or injection), or increased capital cost of equipment due to oversized pumps, sumps and/or piping. Froth pumping losses fall into several categories, as described below and represented graphically in Figure 1. • Density effects: Entrained air reduces the pressure created by the centrifugal pump in direct proportion to the reduction in bulk density. This is not a true “loss”, since the head produced by the pump (in meters of froth), may remain unaffected. However, the reduction in pressure often leads to a corresponding increase in pump speed required to drive the system, which itself leads to increased NPSH required by the pump (NPSHR). Furthermore, by adding a gas phase, the overall volumetric flowrate is increased, assuming a fixed quantity of de-aerated liquid being handled. This leads to increased suction velocity which further reduces the NPSH margin by simultaneously increasing pump NPSHR and decreasing system NPSH available at the pump suction (NPSHA). • Viscosity effects: Increased viscosity introduces an additional factor in some froth pumping applications, such as oil sands bitumen froth. Losses result from increased shear stress within the fluid flow, which increase with flowrate. Viscosity also facilitates the formation of airlock by reducing turbulence and allowing individual bubbles to coalesce more easily within the flow stream. Finally, it increases pump NPSHR by increasing local pressure drop in the vicinity of the vane inlet edges. • Airlock effects: Also known as air binding, it occurs when air or gas coalesces within the pump suction or impeller passages and begins to collect there, held by buoyancy forces within the rotating flow field. In essence, the liquid “floats upwards” towards the pump suction against the outward directed centrifugal forces. The airlock acts as a blockage, with corresponding reductions in flow, head and efficiency. NPSHR also increases, due to increased velocity and distorted streamlines in the flow circumventing the blockage."

Jan 1, 2012

Twenty field-scale tests were conducted in a 28 MW pulverized coal power plant in Healy, Alaska, to examine mill power consumption in relation to coal grind size. The intent in this field-scale study was to verify if grind size truly impacted power consumption by a detectable amount. The regression model developed from the data indicates that grind size does impact mill power consumption, with finer grinds consuming significantly more power than coarser grinds. However, other factors such as coal hardness (i.e., the lower the Hardgrove Grindability Index, or the harder the coal, the higher the power consumption) and mill throughput (i.e., the higher the throughput, the higher the power consumption) had to be included before the impact of grind size could be isolated. It was also observed that combining amperage and flow rate into a single parameter, i.e., specific amperage, hurt modeling. Cost analysis based on the regression model indicate a power savings of $19,972 per year if the coal were ground to 50% passing 76 mm rather than the industry standard of 70% passing 76 mm. The study also demonstrated that size reduction constituted a significant portion of the power consumption.

Jan 1, 2008