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By J. R. Levin, E. J. Schelter

"We present some of our recent efforts in the development of predictive, directed oxidation chemistry of cerium(III) complexes under non-aqueous conditions. The electrochemistry of cerium(III)- alkali metal heterobimetallic aryloxide complexes is reported and compared with cerium aryloxide complexes that are kinetically stabilized by hydrogen bonding cations that span between the complexed aryloxide ligands. Comparative electrochemical measurements reveal differences between the heterobimetallic complexes and the hydrogen-bonded complexes.INTRODUCTIONThe rare earth elements comprise the lanthanides, La–Lu, and the element yttrium (Aspinall, 2001). Rare earth ores such as monazite, LnPO4, and bastnäsite, LnFCO3, typically bear mixtures of light rare earths: La–Sm while monazite, LnPO4, contains mixtures of heavy rare earths (Eu–Lu) (Cotton, 2006). Pure rare earth elements typically are isolated using a liquid-liquid separations process.(Bautista, 1995) The hydrometallurgy of these elements is a difficult problem because the separation factors between neighboring rare earths, which are predicated on the small differences in the sizes of the trivalent ions, are quite small (Cox, 1992). The element cerium, with its 4f1 electronic configuration in the trivalent state, is unique among the rare earth elements due to a relatively accessible 4f0 electronic configuration. The accessibility of the 4f0 configuration underlies the chemistry of cerium(IV), the only rare earth ion with molecular chemistry in the tetravalent oxidation state (Cotton, 2006). Cerium is trivially separated from mixtures of light rare earths by making use of its unique oxidation chemistry. In an effort to extend separations chemistry by oxidation reactions to other rare earth elements such as terbium and praseodymium, the solution electrochemistry of well-defined cerium complexes is of interest."

Jan 1, 2012

By R. A. McGuire

THE recorded production of the Sheep Creek camp from 1900, when the Yellowstone Mining Company first put its mill into operation, to the present day is in excess of $17,500,000. Of this total, $2,500,000 can be attributed to the early period from 1900 to 1916, at which time increased costs of labour and material due to the Great War forced abandonment of any operations on a large scale for a number of years. Since the camp was revived in 1929, at which time the Reno mine started large-scale operations, and the early 'thirties', when the increased price of gold induced the commencement of operations on other properties in the district, total gross production has been in excess of $15,000,000. In addition to the above totals, intermittent shipments were made by lessees and small operators, principally during the period of inactivity from 1916 to 1929, but no records of this production are available. The Sheep Creek camp would rank fifth in the Province-behind Rossland, Portland Canal, Bridge River, and Hedley-in gross gold production, but, because of relatively inexpensive mining and milling costs, would occupy a more prominent position in regard to total dividends paid. Operating mines at the present time include Reno Gold Mines, Gold Belt Mining Company, Kootenay Belle Gold Mines, and Sheep Creek Gold Mines. Each one of these companies, with the exception of Kootenay Belle, represents a consolidation of several smaller properties, all of which were in existence for a number of years prior to 1929. These four companies, at the present time, own, or hold options on, practically all the important claims in the district with the exception of a very few claims and fractions still held by private owners.

Jan 1, 1942

By G. Lucas

"Material substitution occurs continuously in response to competitive and economic pressures. Technical development can accelerate or slow substitution by improving the performance of the invading or defending material. The choices are seldom simple and have to be made in the context of continuous commercial change.The development and commercialization of a new aluminum material is examined. The material has been introduced into· several different markets, so it is possible to compare and contrast the degree of success obtained in each.IntroductionAluminum-based materials have been in use for over one hundred years and , therefore, the development of a new family of alloys is rare. In the early 1970s, Dr. L.R. Morris and his coworkers at Alcan' s Kingston Research Centre started work on what was, at the time, something of a scientific curiosity-a family of alloys strengthened by an unusual mechanism.This paper deals with the development and commercialization of what became known as the Alcan 255 alloys"". These alloys have found uses in several markets, usually as improved substitutes for existing materials. Forecasting the usefulness of a substitute material in an existing marketplace is difficult, in part, because even material users are seldom able to specify precisely their requirements. This uncertainty can cause the failure of some substitutions but can also lead to opportunities which were not initially obvious.Technical BackgroundPure aluminum is a soft, weak material. It can be strengthened by the addition of various alloying elements and by work hardening. Alloying elements usually act by forming solid solutions which are stronger than the pure metal or by precipitating during heat treating or aging and so preventing the easy movement of dislocations during deformation. Elements which can perform either role had been investigated for decades and were thought to offer little chance of technical breakthrough in 1970. An outgrowth of the then new and exciting research on directional solidification seemed, however, to offer such promise.Some aluminum-iran-manganese alloys will solidify under certain conditions as 'coupled growth' eutectics (Figs. I and 2). The microstructure shows one phase growing as long rods through the other. This is an uncommon structure and it was investigated to see if it had equally unusual properties. On deformation by rolling the rods were broken up into small equiaxed , evenly-spaced particles (Fig. 3). Materials with this structure were found to be stronger than other alloys with similar amounts of alloying addition, and to resist thermal softening remarkably well. This combination of properties was thought initially to be due directly to the particles by a dispersion strengthening mechanism, but later this was found not to be strictly true."

Jan 1, 1987

By P. Strand

Talk Outline ? Location and Regional Geology ? Two Unique Kimberlite Sources ? Mineral Chemistry ? Petrography, Age Dates ? Geophysics ? Exploration and Challenges ? Dyke versus Pipe dispersions ? Geophysics ? Prospecting ? Diamond Results ? Summary & Conclusions

May 1, 2008

By Troy Boisjoli, Sean Hillacre, Matt Batty

Discovered in 2014, the Arrow Uranium Deposit has undergone rapid development through successive drilling programs informed by geostatistical drill hole spacing studies. An independent third-party geostatistical drill hole spacing study was completed by Clayton V. Deutsch Consultants Inc. in 2017, evaluating the uncertainty of thickness, grade, density, and areal limit of the Arrow Deposit to determine a drill hole spacing suitable for Indicated Mineral Resources. Indicated spacing was defined to be 24 to 32 metres (“m”) to be within 15% of predicted for a nominal quarterly production volume with a probabilistic tolerance between 75 and 90%. The study not only defined the Indicated Mineral Resource resultant from the 2016 drill program, but also provided drill hole targeting criteria for subsequent drill programs aiming to convert Inferred to Indicated Mineral Resources. A subsequent geostatistical drill hole spacing study on the Arrow Deposit was completed by Clayton V. Deutsch with Resource Modeling Solutions in December 2018 to define Measured Mineral Resource spacing in support of the 2019 drill campaign. The study resulted in a drill hole spacing of 9 to 17 m to be within 15% of predicted for monthly and quarterly production volumes using an accepted industry probabilistic tolerance of 90%.

Jan 1, 2020

By F. J. Reichhardt

Abstract -The Molopo Farms Complex is a major, layered ultramafic/mafic, early Proterozoic intrusion which is totally covered by sediments of the Karoo and Kalahari Formations and situated in southern Botswana and northeastern South Africa. The approximately 3000 m thick, generally fine- to medium-grained ultramafic and mafic cumulates are intrusive into equivalents of Transvaal Supergroup sediments and lavas. Multiphase deformation resulted in tilting and segmentation of the Complex into individual tectonic blocks. Sr isotopes document at least two chemically distinct parental liquids which interacted in a complex manner to form an approximately 1000 m thick rhythmically layered succession which straddles the ultramafic/mafic boundary. Repeated mixing resulted in a complex cryptic layering pattern and numerous sulfide-enriched layers which contain significant PGE +Au concentrations.

Jan 1, 1994

By P. Cleyle, K. McDermott, M. Hall, C. A. Harris

"This paper describes the implementation of an expert system for monitoring and control of the NO. 4 autogeneous mill and spiral circuits at Wabush Mines.This process control system incorporated the mill operating expertize of Wabush Mines operating personnel and was implemented to improve spiral iron recovery and mill productivity by:1. Continuously monitoring the mill power draw and ensuring that the mill feedrate is regulated to prevent damage to the mill motor, while simultaneously maintaining the feedrate at or as close as possible to the maximum feedrate determined by the process supervisor.2. Improving control over the spiral density and feed rate.3. Improving control over both tbe rougher and cleaner wash water.4. Reducing the frequency with which pumps are plugged.5. Allowing modifications to be made easily and quickly to test various operating strategies.This system was installed using COMDALE/C, a real-time Expert System for Process Control. It was readily accepted by the process operators and produces higher production performance in comparison to the other 5 parallel mill lines at a lower power draw."

Jan 1, 1992

By M. E. Wilson

"The property of McWatters Gold Mines, Limited, is in the east-central part of Rouyn township and about 6 miles east-southeast of the town of Rouyn. It includes 35 claims, the group of 5, staked originally, and 30 claims acquired in later years. The Rouyn-Val d'Or road and the Noranda Senneterre branch of the Canadian National railway both pass within a few hundred feet of the mine.The group of claims in which the mine occurs was first staked in 1922, but gold was not discovered until August 1932 when a schistose zone including veins of quartz carrying considerable free gold was laid bare in a stripped area in the northeastern part of claim R.11604. Diamond drilling undertaken in 1932, and continued into 1933, shouwd that the gold extended for at least 1,000 feet along the strike. A 3-compartment shaft was sunk to 418 feet in 1933. A mill having a capacity of 50 tons a day was constructed in 1934, and enlarged to 150 tons in 1935. Production began in 1934 and continued without interruption to June 1944. Except for a few diamond drill holes, there have been no operations on the property since that time. The maximum depth of the mine workings is 1,50) feet. A total of 368,013 tons of ore having a value of $3,946,752 and an average grade of $11.04 was mined during the years of operation.GEOLOGYThe ore mined from the property occurred within the south limb of an eastward plunging syncline of volcanics and sediments cut off on the north by the Cadillac-Bouzan Lake fault. Because the rock formations within the syncline have been severed from those outside with which they were originally continuous, their correlation is based almost wholly on lithological similarity. They include an irregular middle zone of conglomerate and greywacke underlain by north and south bands of andesite agglomerate and andesite tuff, in which lenticular bands of pillowed andesite are included."

Jan 1, 1954

By T. Kerr, C. Mattich, J. Wilson

"In refractory gold concentrates, gold is occluded in sulphide minerals preventing efficient cyanide leaching. Hence, roasting is used to oxidize sulphur and organic carbon, the latter being necessary to minimize recovery loss through the preg-robbing effect. In 2009, Outotec commissioned the circulating fluidized bed roaster at Syama gold mine in Mali. Since 2013 Resolute and Outotec have been implementing improvements to the roaster performance with the capacity increasing from 8000 t/month in 2013 to above 13,000 t/month in 2016, while achieving a residual sulphide sulphur and organic carbon contents of below 0.1 wt.% and 0.4 wt.%, respectively. Thus a gold recovery in the CIL of above 90% is attained. In 2016, Outotec audited the Syama roaster. The analysis resulted in the Low Carbon Roaster (LCR) upgrade concept which (i) allows re-processing of calcine dust from the spray cooler and ESP after pelletization and (ii) allows the roasting of a further fine-organic carbon rich feed, i.e. de-slime circuit tailings. The LCR upgrade aims to reduce organic carbon to <0.2 wt.% and increase roaster-leaching gold recovery by >3%. Project development included extensive testwork. The LCR process is expected to become operational during FY 2019.INTRODUCTION Double refractory sulphide ores exhibit the characteristics of gold locked within pyrite grains, in the presence of preg-robbing natural (organic) carbon. Hence, to achieve high recovery during subsequent processing steps, i.e. cyanide leaching, oxidation of sulphide sulphur is required, producing a porous calcine by way of a roasting step. This allows for the gold contained within the pyrite grains to be accessible during cyanide leaching. Furthermore, it is necessary to oxidize the organic carbon. Oxidizing the organic carbon is essential as gold recovery loss occurs as a result of gold-cyanide complexes being adsorbed on organic carbon, this phenomenon is termed as preg-robbing (Miller et al., 2016). The gold absorbed on the organic carbon is lost, reporting to the tailings stream. Hence, the aforementioned oxidation of sulphide sulphur and organic carbon is the process goal. Nonetheless, the latter must occur at a controlled temperature which is concentrate/ ore specific, since the pores of the produced calcine should not sinter, as this makes the gold contained in the calcine less accessible during leaching, leading to gold recovery loss. The tight temperature control requirement is a decisive factor in the choice of a Circulating Fluidized Bed (CFB) as the roasting reactor, due to the excellent mixing characteristics of the CFB which results in temperature homogeneity of (+/-10°C). Roasting of double refractory ores, as described above, can be included in the flowsheet after comminution and grinding, a process termed as whole ore roasting, or by including a flotation circuit termed as concentrate roasting. Roasting the flotation concentrate results in less solid flow, increased sulphide sulphur grade and organic carbon content resulting in a higher heating value and higher gold content. A typical composition of the Syama ore and concentrate is given in Table 1. Ore average values presented correspond to the period 2015, while concentrate values are typical for the flotation performance throughout the period 2012–2015."

Jan 1, 2017

By Unkown

To the Membership of the Institute Gentlemen: The Mineral Industry of Canada in 1948 The preliminary estimate issued by the Dominion Bureau of Statistics and tabulated in the Bulletin of January, 1949, indicated that the value of Canada&apos;s mineral production in 1948 reached an all-time high of $808,180,216, showing an increase of 25 per cent over the previous record of $644,696,007 established in the preceding year. The output value of metallics was increased by 22.4 per cent; of fuels, by 43.7 percent of other non-metallics, by 19 per &apos;cent; and of structural materials, by 16.8 per cent. The value of metals produced in 1948 at $483,770,759, was about $87,000,000 more than in the previous year. There were substantial increases in the tonnages of copper, lead zinc nickel, and other base metals produced, but the rises in market prices for such metals accounted for most of the gains in output values. Production of gold at 3,495,403 ounces valued at $122,339,105 indicated an increase in volume of approximately 500,000 ounces and an increase in value of 14 per cent. Despite the benefits provided under the Emergency Gold Mining Assistance Act 1948 the volume of gold produced in the year was still nearly 2,000,000 ounces less than the record of 5,300,000 ounces established in 1941. The value of mineral fuels produced in 1948, at $158,787,255, was 44 per cent above the 1947 total. Coal production at 18,431,250 tons valued at $107,298,757, while substantially higher than in the preceding year was still half a million tons below the record reached in 1942. Striking developments in the Leduc field in Alberta were responsible for bringing the output of crude petroleum in the year to a new high of 12,098,166 barrels, valued at $36,858,959.

Jan 1, 1949

By P. G. Smith, A. Axiuk

The objective of this paper is to present, from a practical perspective, a review of the most relevant maintenance procedures that are accepted or prescribed to be the most effective in optimising service life potential and to ensure continued safe use of steel wire ropes for shaft mining applications. The paper will address the most common operational issues encountered in the care and operation of shaft ropes for both conventional drum hoists and multi-rope friction winders. For each distinct maintenance procedure presented, a limited amount of theory is discussed to identify the underlying mechanisms at play that must be addressed and to emphasize the logical basis for the recommended course of action. It is recognised that each installation is unique and that the recommended maintenance procedures may not always be practical or cost effective from an operations standpoint under select circumstances, however the intent remains to promote industry best practices for the knowledge and benefit of the mine hoisting community, from experienced maintenance personnel to new entrants to the industry alike.

Jan 1, 2023

By B. S. Prosser, K. G. Wallace, A. Akansobe

"This paper describes a ventilation project at the Wassa gold mine in Ghana. Golden Star (Wassa) (GSWL), a subsidiary of Golden Star Resources, owns and operates the mine. Golden Star holds a 90% interest in GSWL, while the Ghanaian Government holds the remaining 10% ownership, earning a 5% royalty on the gross revenue of GSWL’s gold production. Construction of the underground mine began in mid-2015 and pre-commercial production started in June 2016. Commercial production from the underground mine was achieved in January 2017. This paper describes the ventilation studies performed to support the initial development and production at the mine. The initial ventilation design included four, parallel surface exhaust fans. Future designs will include booster fans, new primary fans, and additional connections to surface. The paper describes the long-term ventilation planning goals and expectations as the mine achieves a production of 4,000 tpd with truck haulage to surface.INTRODUCTIONThe Wassa Gold Mine is located in the southern portion of the Ashanti Greenstone Gold Belt in Ghana, northwest of Tarkwa as shown in Figure 1. The mine has been in production as an open pit since 1998, with some minor disruptions, but the surface minable reserves have become exhausted and the mine started a transition to an underground operation in 2015. The underground mine was initially developed with twin decline accesses extending from the base of the open pit to the mining areas. The mining method selected was sub-level open stoping with cemented rock backfill. The original production level for the mine was 2,500 tpd with ore and waste transported by trucks hauling in the ramps to surface. In 2017 the production goal was set to increase to approximately 4,000 tpd. This resulted in an increase in the truck haulage fleet in addition to a significant increase in ventilation requirements. This paper describes the ventilation upgrades at the mine as it transitioned from a surface to an underground operation and the adjustments the ventilation system needed to make in order to accommodate a significant increase in production"

Jan 1, 2019

By G. W. Evatt

This paper presents the scientific framework underpinning the Resource Valuation and Optimisation Model (RVOM). The RVOM is a Real Options software package, which helps mine owners optimally plan their operations, understand their project risks, and make defensible valuations. This is achieved in the presence of both financial and physical uncertainty. The three key outputs from the RVOM are: Valuation, Optimal Decision and Probability of Decision, where a decision can include any combination of: normal operation, expanded operation, care and maintenance, and abandonment (and variants thereof). This paper presents a clear example of the RVOMs usage to a case-study gold mine.

Jan 1, 2011

By Meimei Zhang

In the overall open pit mine planning process, mining phase design is a strategic driver in guiding and constructing the block extraction sequence and determining the annual net cash flow distribution. Mining phase design should obey some practical constraints, such as ?minimum mining width? and ?flat mining phase bottom?, to allow space for haul road development and truck and shovel access on each bench. However, these practical mining phase design requirements are not taken into account in all first-cut mining phase design methods and post-processing is always required to convert an impractical design to a practical one, resulting in a potentially significant loss of Net Present Value (NPV) relative to the first-cut impractical designs. In this paper, we present a method using a meta-heuristic algorithm ? Simulated Annealing ? to enforce those practical constraints in determining a mineable phase design whilst ensuring minimum NPV loss.

Oct 1, 2009

By G. Grassmück

The question of whether the air curtain principle could be used under conditions prevailing in Canadian metal mines was investigated. A vertical, portable BERRY air curtain was tested, at first in a wind tunnel built at Ecole Polytechnique at full scale (8-by 8-ft cross section) to simulate a drift and its lateral connections, and then in the haulage ways of a metal mine under actual conditions. The results permit us to predict under what conditions this type of air curtain is capable of acting as an air stopping or flow regulator and how it could be further developed.

Jan 1, 1969

By H. Kudelka

Copper electrowinning at Duisburger Kupferhuette was introduced in March 1975. The electrowinning plant has a capacity of 10,000 mT of copper cathodes a year. The cuprous oxide feed material is an intermediate product of the treatment of the leach solutions, originating from chloridizing roasting of pyrite cinders. This material is characterized not only by a wide spectrum of accompanying impurities, but also by an unusually high level of precious metals. As the priority set was the production of high-purity cathodes. there was a need for developing a process which would be suited to treat complex leach liquors . The process adopted consist s of an oxidizing leach in spent electrolyte, followed by two- stage purification, By this means. a low- acid pregnant copper electrolyte is obtained free of elements detrimental to copper quality. Electrowinning is carried out at a current density of 200 A / m2 in the presence of 10 g/l zinc. The electrowon copper has a conductivity of at least 101.4% lACS and a softening temperature not exceeding 200°C, which makes it a suitable product for continuous casting and dip ?forming.

Jan 1, 1977

By T. Grammatikopoulos, SGS Canada Inc.

"The Nechalacho rare metal deposit, located in the Northwest Territories, Canada, is currently being taken through Feasibility Study by Avalon Rare Metals Inc. QEMSCAN analysis and supplementary electron microprobe analysis were utilized to identify and quantify the mineralogy of the deposit, and determine REE distribution among the minerals. QEMSCAN mineralogy was performed to provide textural information on the mineralization, determine the variability of the ore and identify REE domains, and the liberation and association of the REE minerals. The sample matrix consists predominantly of silicate minerals. The REE minerals include allanite, monazite, synchysite, columbite, fergusonite, and bastnaesite. Zircon is present in considerable amounts and is a REE carrier. Fergusonite and zircon account for most of the HREE, and monazite, allanite, synchysite and bastnaesite the LREE. QEMSCAN mineralogical data is extremely valuable in assessing the mineralogy of the ore. The data are implemented to define the mineralogy of the ore body, support metallurgical test work, and predict recoveries and grades.INTRODUCTIONThe term rare earth elements (REE) is used to describe the 15 lanthanide elements or metals and, more recently, the metals yttrium and scandium, which display similar physical and chemical properties.Economic and potentially economic REE deposits form two main groups, a more commonly occurring “light rare earth element” (LREE) group containing lanthanum, cerium, praseodymium, neodymium, and samarium and a less commonly occurring “heavy rare earth element” (HREE) group which, in addition to the LREE, contains elevated concentrations of the more valuable REE, europium, gadolinium, terbium, dysprosium, holmium, yttrium, erbium, thulium, ytterbium, lutetium and scandium. The first group is hosted primarily by carbonatites and the second by highly alkaline (Na + K > Al) silicate igneous rocks. The LREE are produced mainly from bastnaesite, monazite, etc., while HREE are produced almost exclusively from low-grade secondary ion adsorption clay deposits in which the REE are adsorbed onto the surfaces of kaolinite and halloysite, clay minerals produced by the weathering of granite and sediments. HREE are also found in fegusonite, zircon, xenotime, etc but are not produced presently from these minerals. China is responsible for 97% of the World’s production of the REE, mainly from the giant Bayan Obo, carbonatite-related deposit and from the clay deposits mentioned above.Quantitative automated mineralogy is increasingly being applied to ore deposits. It helps users to understand and improve mineralogical parameters for geological and metallurgical purposes. Data include textural characterization, to quantification and distribution of ore and gangue minerals, liberation and association of the REE minerals. The data can be used to define mineralogical domains and predict the metallurgical response of the ore (Gunning, de Souza, & Grammatikopoulos, 2009)."

Jan 1, 2012

By L. Shasko

Deliberative mapping is a method of public engagement designed to bring citizens and specialists together to inform policy decisions in conflict-laden areas of science and technology (Stirling and Davies 2004a). Citizens and specialists participate in the process both separately and together. A deliberative mapping study was held in Regina, Saskatchewan in October and November of 2019. Participants in the study assessed options for reducing greenhouse gas emissions in small, remote or off-grid communities, including assessing the role of small modular nuclear reactors (SMRs) in climate change mitigation. Deliberative mapping is designed to facilitate direct, two-way conversations between citizens and specialists through both formal and informal discussions. The relationship building component of this process may increase trust. Public consultation processes that lack two-way dialogue or are seen as obligatory rather than meaningful can worsen public opposition or lead to negative public perceptions. Public education alone is not enough to change public opinion. Providing people with more information on topics they already hold opinions on can work to reaffirm previously held biases, but building relationships can provide new pathways to overcome divisions and turn close-mindedness into open-mindedness.

Jan 1, 2020

By J. R. Jutras, C. Brissette, J. Champagne

"Pure cadmium sulphide was leached by the action of the bacterium Thiobacillus thiooxidans in the presence of finely divided sulphur. The influence of time, temperature, pH and concentration of inoculum on the extent of the cadmium extraction was studied. Under optimum conditions, up to 72 per cent of the cadmium could be dissolved over a six-week period. A cursory study of the role played by elemental sulphur seems to indicate that its presence is essential but that the sul1>huric acid produced through its oxidation is a minor factor in the cadmium extraction."

Jan 1, 1971

By L H. Warren

The types of equipment available for generating a plasma have been reviewed. The efficiency and potential of the plasma generating equipment used in performing extractive metallurgical reactions have been determined. A general classification of the reactions that might be per-formed in a plasma has been proposed. Experimental work done on extractive metallurgical plasma reactions, heat transfer between the plasma and solids, and the quench of the products of plasma reaction has been summarized. From the preliminary results it appears that the high-intensity are or the transpiration-cooled anode plasma torch offer the most promising areas for further research. C ONSIDERABLE world-wide research effort is currently being devoted to the development of processing technologies which employ the new high-temperature generating devices that have appeared over the past few years. The plasma flames produced by these devices offer the potential for subjecting materials to any single gas or mixture of gases at temperatures up to 20,000°K. With these conditions available, many reactions in extractive metallurgy,

Jan 1, 1965