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By W. G. Stevenson

With the author's background of extensive experience, this paper delineates the role of the prospector in modern-day exploration programs. The stages in the development of a prospect to a producing mineral district are outlined, and examples are given from the Ross River area of the Yukon Territory and the Peachland and Highland Valley areas of British Columbia.

Jan 1, 1970

By I. Dymov, W. Phillips

A process has been evaluated, on a continuous pilot plant scale, to treat refractory gold arsenopyrite/pyrite concentrates. The process consisted of biological leaching to partially oxidise sulphides, followed by pressure leaching for complete sulphide oxidation and arsenic precipitation, followed by liquor neutralisation and cyanidation of the autoclave residue for gold recovery. This paper provides a brief description of the treatment flowsheet and discusses some of the main parameters and results of the process. During integrated pilot plant campaigns, it was confirmed that acceptable sulphide oxidation and gold extraction of 96-98% could be achieved by a two-stage oxidation with BIOX® (4 days total retention time) followed by PDX (40 minutes retention time at 220°C). Only partial arsenic precipitation was achieved in the autoclave, followed by complete precipitation by neutralization under atmospheric conditions. The overall process could be significantly simplified, and capital and operating costs reduced, with a flowsheet modification allowing all of the BIOX® liquor to bypass the autoclave directly to the neutralization circuit.

Jan 1, 2004

By M. A. Vasina, I. A. Matveeva, E. A. Naumova, V. V. Doroshenko, N. A. Belov

"Using the calculated (Thermo-Calc software) and experimental methods (SEM, TEM, EMPA, DSC, XRD, etc.) the phase composition, structure and hardening of aluminium alloys of the Al-Ca-Zn-Mg system were studied in the following range: 2. 5%Mg, up to 10% Ca, and up to 14% Zn (wt%). Fragments of this quaternary phase diagram in the aluminium corner were constructed, including the liquidus surface, as well as some vertical sections. It was shown that the relatively large amount of zinc enters in the Ca-containing phase, which formula can be described as (Al,Zn)4Ca. An increase of Zn content leads to formation of Al4Ca primary crystals at lower concentrations of calcium. The eutectic (Al)+(Al,Zn)4Ca has a fine structure and aluminide particles are capable to spheroidization during the heat treatment at temperature 500 C. The maximal level of hardness observed on calcium containing alloys was higher than 200 HV, what gives the reason to expect good strength properties. With an example of an Al-9% Zn-2,5%Mg-3,5% Ca model experimental alloy based on the (Al)+(Al,Zn)4Ca eutectic, a principal possibility of manufacturing thin rolled sheets was demonstrated.INTRODUCTION Aluminum alloyed with calcium was first studied in 1970-80s by such authors as Piatti (1976), Moore (1978, 1980), Il'enko (1985), Swaminathan (1990), and Perez-Prado (1997) as superplastic materials. In particular, the alloy systems Al-Ca-Zn were studied (Il'enko, 1985, Swaminathan, 1990, Perez-Prado, 1997). For some time there was no new published works concerning the aluminum-calcium alloys. During the last years many works were published dedicated to the calcium alloying of magnesium alloys (Kim, 2011; Xu, 2011; Aljarrah, 2008; Bakhsheshi, 2014). This urged the authors (Belov, Naumova & Akopyan, 2016) to start studying cast and wrought aluminum-calcium alloys for construction (2008–2014). There is almost no information in the literature concerning triple and more complex diagrams of the aluminum-based system states with calcium and other elements. In recent work, parts of the state diagrams are plotted for the aluminum angle zone: Al-Ca-Mg-Sc (Belov, Naumova & Bazlova, 2016), Al-Ca-Ni-Sc (Belov, Naumova & Bazlova, 2017), Al-Ca-Si-Sc (Belov, Naumova & Akopyan, 2017) and others. Special attention was paid to the study of the system Al-Ca-Zn-Mg (Naumova, 2017). Based on this system creation of advanced extra-high tensile alloys is planned. Wrought extra-high tensile alloys series 7??? based on the system Al-Zn-Mg-Cu are well studied."

Jan 1, 2018

By F. Baczek, S. S. Rocks, D. Chaiko, T. Walters

The atmospheric leaching of chalcopyrite concentrates using acidic ferric sulfate lixiviants is well known to suffer from slow leach kinetics and poor copper recoveries. A number of approaches have been proposed for improving both leach kinetics and recoveries in this system. Many of these, while effective, suffer from high CAPEX and/or OPEX. As many mine sites begin transitioning from heap leaching of copper oxides to processing of primary copper sulfides, cost-efficient leach processes that are compatible with existing SX/EW processes will be needed to maintain existing cathode production. To this end, FLSmidth is exploring process options and reactor technology for the hydrometallurgical processing of primary sulfides. One approach that appears to be highly effective at increasing copper recoveries takes advantage of the enhanced reactivity of transitory, surface-defect structures generated during particle fracture. Significant process efficiencies are gained by matching the rate of grinding to the rate of electrochemical leaching in Mechano-Chemical leach processes. The patent-pending FLSmidth® ROL process uses a Stirred Media Reactor (SMRt reactor) to achieve copper recoveries of 97+% in 6 hours or less. This approach overcomes many of the surface passivation problems that have hindered other atmospheric leach processes. New insights to leach mechanisms are presented.

Jan 1, 2015

During the past 10 years, research work to improve the survey of stope limits after mining supplied useful information, particularly for large open and sub-level stopes, regarding waste dilution caused by differences between final production limits and planned stope limits. However, the efficiency of this information to improve the overall efficiency of the mining process is limited, given that the impacts of inaccurate ore limits leading to dilution (sensu stricto) and ore losses haw not been considered adequately. Geological/sampling information should be optimized in terms of quantity and/or quality for the deposit characteristics and the constraints of the mining method used. As industry practice regarding the definition and recording of dilution is flexible and as ore losses frequently am poorly doc-umented, the use of these terms is reviewed. Simulations were carried out on two typical narrow gold deposits, based on an earlier study at Inco's Thompson mine regarding the impacts of wide to narrow delineation grids using recorded variations of vein geometry. Vertical to sub-vertical deposits of 3 m and 6 m widths mined by long-hole open stopes were considered. Deposits delineated by 7.5 m (25 ft) grids were taken as a base case and the impacts of less accurate limits in conjunction with long hole mining based only on a 15 m (50 ft) delin¬eation grid. The impacts of overestimation (dilution) and underestimation (metal losses) were considered separately, using the average error of +/-0.62 m recorded in the Inco study. The impact of less accurate information was much stronger on the narrower deposit: both dilution and ore losses diminished the net present value of the 3 m wide deposit by 39.27% and 45.41%, respectively, and that of the 6 m wide deposit by 12.84% and 11.55%. As the impacts of ore loss and those of dilution on the net present value am almost identical in these simulations, we could, in practice, assume a 50/50 split between dilution and ore losses in such a case. These results do no take into account the effects of local optimization measures taken at the mine production level (blasthole sampling near stope limits, etc.) The potential impacts of geological and sampling uncertainties in terms of lower NPV justify and require more systematic efforts to ensure that deposit appraisal work and feasibility studies are adequate to optimize company revenue and competitive returns to investors from mine production activities.

Jan 1, 2005

By A. A. McDonald

Anode casting has been in operation for two years in Hudson Bay Mining and Smelting's Flin Flon smelter. The new plant allows all casting to be done on one shift and so achieves considerable labour savings. The equipment and operations are described. Some important features are as follows: very consistent anode weights by the use of the load-cell controlled casting ladle; excellent mould life ; very low reject rate; and trouble-free take -off tower. Some of the start-up problems are described and an outline is given of the main operator functions. Data on labour, propane and maintenance costs are presented.

Jan 1, 1977

By D G. Boxall

As an alternative to heavy water cooling, reactors cooled by organic liquids are being actively developed in Canada under the sponsorship of Atomic Energy of Canada Limited. One of the areas in which development has been required is that of core materials. The factors affecting the selection of fuel canning and coolant tube materials are discussed. It is shown that S.A.P. is a potentially attractive material for these applications. The fabrication of fuel sheathing is discussed. Difficulties met due to large inclusions and blistering due to high hydrogen contents have been overcome by magnetic separation and vacuum sintering of the powders. High-quality tubes can now be produced by extrusion to finished size. A study has been made of the mechanical properties of fuel-sheathing tubes and bar stock. The stress rupture properties of the tubes subjected to uniaxial and biaxial stress have been determined. The biaxial stress tests were performed by internal pressurization. For times in excess of about 200 hours, the curve of stress against time to rupture is extremely flat. The secondary creep rates of

Jan 1, 1965

By A. H. Burns

"Regenerative and recuperative burner systems require advanced combustion techniques to minimize NOx emissions. Various methods of pollutant minimization and furnace design considerations are described. Cited examples are a large high temperature furnace and a small Zinc vaporizing furnace. The concept of total carbon footprint is introduced. The application of Biomass combustion as an effective method of cost and green-house gas (GHG) reduction is discussed. Practical considerations of scale, location and process limitations are discussed. Two examples of biomass fired equipment are cited. Ideal sites have large biomass resources available locally. Processed biomass fuels will be an important substitute for fossil fuel. INTRODUCTIONIn 1992, I presented a paper entitled Combustion Strategies In The Modern Industrial Environment (1992). At that time an abundant supply of cheap fossil fuel made many of the measures I talked about difficult to justify for anything but new equipment.Since 1992 we, as a society, have demonstrated an ability to accelerate the pace of industrial and societal change. The term industrial revolution applied to this age of incessant change is completely meaningless, implying a discrete moment in historical time. What our society has built is a system capable of unfettered, continuous and accelerating technological change. With this change comes an increasing demand for energy and materials.This year is the anniversary of the Titanic disaster, a moment in time when technological certainty met the caprice of nature and gave us a brutal reminder of what can happen to us if we underestimate that power (Mowbray, 1912). In the intervening interval we have regained the technological arrogance that was lost in 1912 bringing us back to the problems of climate change and the need for sustainable industrial activities.We use advanced mathematics to describe many complex systems, sometimes with disastrous results. For example there has been a recent attempt to model the global economy as a completely deterministic system. This premise is flawed at its foundation as human nature and emotion are indeterminate constants in the equations, yielding probabilistic solutions at best. As engineers we are all familiar with stiff problems. The solution to such a problem is meaningless and we have all had the misfortune to live through and rue the effects of that miscalculation over the last few years."

Jan 1, 2012

By Balmer Neilly

We are regularly told that before making a new investment one should seek the advice of his banker. If we were to place the subject matter of this paper before bankers. other than those who have experience in our mining camps, their reply would probably be evasive. However, if for example: a mining company asks them for a loan and offers as security certain mining investments, they are, in most cases, explosively candid. The idea is preposterous, unless, under Section 88 of the Bank Act, the mining company is able to deposit with the bank, gold or silver bullion, to an amount sufficiently in excess of the loan, to provide for what the banker describes as a reasonable margin of safety in case of contingencies. In addition the directors of the mine personally must jointly and severally guarantee payment of the loan. With any of these conditions missing the banking atmosphere becomes chilly. The local manager explains that the general situation, and particularly European conditions, are so unsettled that head office has warned him that his discretionary powers must not be exceeded under any circumstances.

Jan 1, 1924

By M. E. Charles

The use of water flowing as a lower layer to reduce pressure gradients in petroleum pipelines was investigated using 17.5 deg. A.P.I. Lloydminster crude oil in a 1-inch laboratory pipe-line and a 21h-inch field pipeline. The method was found to be very effective in reducing the pressure gradient below that for the oil flowing alone. The factor by which the pres-sure gradient was reduced varied with the percentage of water added, and in general exceeded 10 for water contents ranging from 40 to 60 per cent. Within this range of water content the pressure gradient reduction factor was independent of the oil flow rate.

Jan 1, 1960

By N. M. Steven, J. M. Moore, J. L. Kuyper

Abstract - Mineral exploration and research has led to the identification of four types of tungsten mineralization in the NE-trending, largely ensialic, inland branch of the late Proterozoic/early Paleozoic Pan-African Damara Orogen. The mineralization (mainly scheelite) occurs in a terrane (the Central Zone) that is characterized by multiple deformation, greenschist/amphibolite-facies metamorphism and numerous peraluminous S-type granitic and pegmatitic intrusions. The four major types of scheelite mineralization are (in ascending stratigraphie order of host rock): (1) thin (5 cm to 2 meter) quartz+ plagioclase+ diopside ± scapolite cale-silicate granofels with finely disseminated scheelite (scheelite-bearing granofels; SBG) developed as discontinuous intercalations within the cale-silicate rocks of the Khan, Spes Bona, Oberwasser and Kuiseb Formations (Nosib and Swakop Groups); garnet+ pyroxene ± vesuvianite + scheelite ± fluorite replacement skarns hosted by Okawayo, Karibib and lower Kuiseb Formation marbles in the aureoles of late tectonic, unmineralized leucogranites; metaturbidite-hosted scheelite- (and possibly wolfrarnite-) bearing tourmalinites, both stratiform and crosscutting, in the Kuiseb Formation located in the 'cleavage fronts' of late tectonic granitoids; scheelite-bearing vesuvianite +quartz+ garnet skarnoid rocks (several hundred meters in length) in the calcareous metaturbidites of the upper Kuiseb Formation. These scheelite occurrences were discovered by the follow-up of a large number of tungsten anomalies located during a regional stream sediment sampling program. Detailed mapping, ultra-violet surveys and rock sampling proved to be the most effective surface exploration techniques for locating mineralization; soil sampling and geophysics were of almost no use. The largest, continuous scheelite-bearing skarn of economic interest, Otjua, has a drill-indicated reserve of 250 000 tonnes at 0.53 wt% W03 and 8 wt% CaF2.

Jan 1, 1994

By Jochen Petersen, Jean-Paul Franzidis, Allan Nesbitt

This study presents a method for the determination of intra-particle diffusivities in ion-exchange resins for the purposes of evaluating the state of resin degradation during service. The method uses a zero length column (ZLC) in a closed circuit with variable speed pump and reservoir. The intra-particle diffusion is determined from absorption data by using the Nernst-Plank approximation along with the ‘mass transfer factor’ - which is a product of the mass transfer coefficient (kf )and the concentration of the adsorbing ion in the liquid at the surface of the resin - in a computer algorithm fitting simulated curves to experimental data.. Through this approach the changed intra-particle diffusivity, of a gel-type acid resin, over a 1000 loading and elution cycles, is shown.

Jan 1, 2014

By R. L. Stanton

"The present contribution examines, in some detail, what appear to be the three outstanding features of the field occurrence of the conformable ""pyritic"" deposits. These are their association with fragmental volcanic rocks (and derivatives), their occurrence in sediments of near-shore formation, and their highly variable structural associations.In a recent paper it has been suggested that two such ""pyritic"" de-posits in New Brunswick may have originated as marine concentrations of volcanic base metal and sulphur compounds, and that many of their present features are the result of diagenesis, folding, and regional metamorphism. This is now put for-ward as a general explanation for the particular class of deposit considered.Such deposits should, on this hypo-thesis, be regarded quite simply as an integral part of the particular geological environment in which they occur -as a normal, though minor, sedimentarry type developed, char-acteristically, in near-shore and shelf facies of intravolcanic units formed along the margins of eugeosynclines. They should not be considered -as, for example, is required by the re-placement theory -as later features simply superimposed on a geological situation to which they are genetically unrelated. Where they are associated with folds and other structures, this may be attributed, from one in-stance to another, to mechanical migration during folding, weaknesses induced by pre-existing sulphides, and, occasionally, to fortuitousness.In the light of this postulated origin, it is suggested that the first stages in regional prospecting for deposits of this particular class should be broadly palaeogeographical. Later phases of the search should then be directed to the delineation of sedimentary facies and, finally, to the investigation of geological structure."

Jan 1, 1960

By W. R. Lindsay

Considerable attention has of late been given to the blasting of large amounts of ore in one operation, on account of the saving in labour and explosives and consequent low cost per ton, and also on account of the additional safety to employees. The blast here described, at the Hidden Creek mine. at Anyox, B.C., is not necessarily unique either in size or methods employed, but some interesting p10blems were encountered and the solutions of these may be of interest to others engaged in similar work. The ore consisted mainly of old scope-bottoms and sill pillars, although there also were some braces and parts of vertical pillars included. Some of the stope-bottoms were overlain by caved waste, and one of the problems was to break them in such a manner that the maximum amount of ore could be recovered without serious dilution with waste. The ore blocks, designated as the 385 silt and the 7 A-103 blocks, were under preparation for blasting for over a year, as conditions permitted. This work consisted in drilling long machine drill holes, varying in length from 14 to 20 feet. These holes were drilled with the Numa detachable bit, made locally, starting at 2~-inch diameter and bottoming at 2 inches for the longest length. The long hole drilling was used in the thinner sections of the area. For the stronger, thicker portions, powder drifts (3 ft. by 4 ft. in section) were driven for the powder charges. Reference to the plan and sections (Figures 2 co 8 inclusive) show the relative location of these, as well as the long drilling. The amount of explosives used in the powder drift charges averaged 0.25 pounds per ton of estimated burden, varying from 0.2 to 0.3 pounds per ton.

Jan 1, 1934

By E. C. W. Perryman

Materials research and development has played an important role in the commercial success of the CANDU- PHW nuclear reactor and in the production of heavy water. Both capital investment and energy conservation demand very high component reliability in such systems. The interactions among reliability, plant performance and economics will be discussed in relation to materials research and development. Likely materials requirements for the nuclear industry over the next twenty five years will also be discussed.

Jan 1, 1977

By S. Kelebek, U. Demir, T. C. H. Richards, E. Koss

"Laboratory-scale tests were carried out to investigate the response of a high-grade (~143 g/tonne) well-liberated gold ore to flotation using two collector types. Octyl and amyl xanthates, representing conventional types of collectors, were tested against an n-octanoic and hexanoic acids under moderate and high redox potential conditions. The latter was based upon a suggestion in literature that monocarboxylic acids are able to adsorb onto the surface of gold at redox potentials near 600 mV (SCE). This investigation did not demonstrate that these carboxylic acids could function as collectors for gold in real ores. In fact, they appear to have slightly depressed gold. However, the results demonstrated that octyl and amyl xanthates acted as highly effective gold collectors for this ore and that an increase in the collector dosage led to an increase in recovery for all mean particle sizes. In some tests, gold recoveries of around 95% were attainable in concentrates with grades around 6 kg/tonne, indicating that xanthate flotation remains a viable means of concentrating gold even at coarse grain sizes. Various aspects of the process such as grade-recovery performance and recovery by size are discussed.INTRODUCTION Three methods are used for the recovery of gold in mineral processing, either alone or in combination: gravity concentration, cyanidation and flotation. Gold occurs as a by-product in some ores together with platinum group metals and as the primary metal in other ores in the form of native gold and electrum, which are alloys of gold, silver and minor amounts of copper. Flotation is a viable method for recovering liberated gold where the gold is visible under an optical microscope (greater than 1 µm in size) and where the attachment of gold grains is not prevented due to bubble loading by competing minerals. It is generally known that grains finer than 150 µm in size will float with most collectors."

Jan 1, 2017

By Maurice Lauzon

"Aerial surveys of the open pits have been conducted regularly at Lake Asbestos of Quebec, Ltd. -a subsidiary of American Smelting and Re-fining Company -since 1958. Ground controls are supplied by Lake Asbestos, and a topographic map of the pits at a scale of 1 in. to 50 ft., with 2-foot contour intervals, is obtained by aerial photography. The information from the topographic map is then transferred by the Lake Asbestos engineering staff to sections from which the volumes removed are calculated. Considering the size and complexity of the operation, this system has proved to be the cheapest, fastest and most accurate way of determining the quantities of rock and overburden removed. More than 11,000,000 tons of ore and waste are mined each year in three different pits. Further-more, the nature, shape and extent of the orebodies make it necessary to mine on many (up to eight) benches of a pit during a single year. In addition, there are sections of the pits where it is impossible or un-safe to survey the crest of some benches by standard ground methods. For these reasons, the tonnages obtained by truck count are checked and adjusted by aerial survey. These surveys are now taking place every six months. With this system, it is possible for a two-man surveying crew to look after all field work in the mine area."

Jan 1, 1967

By B. Leonard

As of November 2012, the Alberta government listed 53 oil and gas, oil sands, and mining construction projects either proposed or currently under construction. These industrial plant construction projects have an estimated value greater than 105 million dollars. A common construction method employed for industrial plant projects is fast-track construction, which is used to reduce construction time. Contractors begin fast-track construction with highly generic scheduling information. This high level schedule turns into a lower level schedule as more detailed information becomes available. From a contractor?s perspective, a challenge faced using fast-track construction is the visualization of generic and constantly changing project schedules. This paper discusses the use of a Plant Information Modeling (PIM) system, designed to create a 4D animation to visualize project schedules for fast-track industrial plant construction projects. The proposed PIM system creates a modified project schedule by obtaining specific information from a generic construction schedule. Obtaining the information involves grouping schedule activities in accordance with the level of detail in a 3D model, and the level of detail in a project schedule. The modified project schedule is then used in conjunction with a 3D model to simulate the construction sequence in the form of a 4D animation. This allows for 4D visualization of project activities, installation dates, and crane movements. Furthermore, as engineering reaches completion, the PIM system creates a streamlined channel for schedule information updates to be easily uploaded into the model for a more accurate 4D visualization. Through analyzing a nonmodular construction case study, this paper discusses the successes and benefits of the PIM system for 4D visualization, such as increased productivity, shortened construction time, increased constructability, and decreased field costs.

Aug 1, 2013

By F. Bourgeois, J. -S. Kroll-Rabotin

ABSTRACT: Falcon concentrators are enhanced gravity separators designed for concentrating fine particles. The Falcon UF model is unique in that it is dedicated to beneficiation of ultrafines, one key feature being that it does not make use of any fluidization water. We investigated the physics of particle transport inside Falcon concentrators, and concluded that separation efficiency is governed by differential settling velocity. We derived and published a predictive model of the partition function under dilute conditions. We intend to extend the initial model to concentrated ultrafine suspensions for application to industrial scenarios by adding hindered settling to account for solid concentration effects.

Jan 1, 2011

By L. Ferland, D. LaRonde, J. C. Caron

"The free-world production of columbium ore concentrates has doubled in the last five years. St. Lawrence Columbium and Metals. Corporation has contributed largely to this expansion, its production rate increasing from 720 tons of concentrates per year in 1961 to 2 200 tons in 1965.To follow the normal market development, the Company initiated an engineering study aimed at establishing the most economical mining methods, thus permitting it to increase its milling rate from 1,000 tpd in 1964 to 2,000 tpd in 1967 and possibly to 3,000 tpd in 1968. The results of this study pointed out the advantages to be gained in converting from an open pit to an under-ground operation. This paper describes how the mining engineering department has successfully developed ""stopes"" from the walls of its No. 2 open pit, in order to assure continuity of its operation during the interval required to develop its underground mine."

Jan 1, 1967