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By Deborah A. McCombe

"One of the cornerstones of NI43-101 Standards of Disclosure for Mineral Projects is the technical report. The purpose of the report is to provide a summary of the scientific and technical information concerning mineral exploration, development, and production activities on a mineral property that is material to an issuer. The reports must be prepared in accordance with NI43101 and Form 43-101F1 Technical Report and the information must be current as of the date of the filing of the technical report. As these reports provide important information to the investing public, qualified persons preparing these reports should, as much as possible, write in plain, simple language that can be easily read and understood by people who are not geoscientists or engineers. So let’s review some of the common deficiencies with technical reports. Non-current technical report Some of the factors you should consider when determining if your previously filed technical report is still current are as follows: •,Is there new technical information on the property, such as drilling, assays, metallurgical testwork? •,Have you made changes to key assumptions, parameters relating to mineral resources or mineral reserves, or economic analysis? If you have completed the previously recommended work, are your recommendations still current? Similarly, are your report recommendations consistent with what you are telling your shareholders or disclosing in the use of proceeds in your offering documents? For example, if the recommendations in the report consist of further exploration and metallurgical test-work prior to completing a preliminary feasibility study and you have completed the proposed work and are now raising money for a final feasibility study, the report is probably not current."

Jan 1, 2003

By J. E. Gill

"The name 'Canadian Shield' is used for a vast area; largely in northeastern; Canada; underlain by Precambrian rocks. The part in Canada has an area; of about 1; 790; 000 square miles. Extensions in Greenland; Labrador; Newfoundland; and the United States bring the total area to around 2; 800; 000; square miles. The boundaries of the Canadian part are shown in Fig. 1.; At its margins; the Precambrian rocks can be seen at many places to; extend beneath a cover of flat-lying Palxozoic or later sediments. Information; from borings in the Plains and natural exposures in mountain-built belts; show that similar rocks form a large part of the continental platform. The; Shield; therefore; is a large exposure of what may be regarded as the foundation; of the continent."

Jan 1, 1954

By P. Scinto, P. Hudson

"Modern day ore bodies are becoming increasingly harder, more abrasive and lower grade. The Mako deposit is located in Senegal and consists predominantly of primary mafic and felsic lithology that are both very competent and very abrasive ores (Axb < 30, BWi >20 and Ai >1.0). The deposit was initially discovery in 2010 and the Toro Gold management team fast tracked the Mako Project through development and into production to achieve its first gold pour in January 2018. The comminution circuit comprises primary crushing single stage SAG milling with recycle crusher (1oCR SS-SAC). The mill reached design throughput and grind size seven weeks after first ore. The Mako project marks another successful international application of single stage milling, which represents a simple and easy to operate comminution circuit for small-to-mid size projects with a low capital cost. This paper describes the ore interpretation, comminution modelling, grinding circuit selection and design, as well as an overview of the commissioning and ramp-up of the mill.INTRODUCTION The Mako Gold Project is operated by Toro Gold Ltd., which holds a 90% interest in the project. The project is located in south-eastern Senegal in the Kedougou region, close to the Gambia river and township of Mako. The Mako deposit lies in the “Kenieba Window” of eastern Senegal and western Mali, which hosts a number of gold mining operations and development projects. The Mako Gold Project has an estimated life of 8 years with overall recoverable gold estimated at 924 koz. The process plant is designed to treat 1.8Mt/a of ore and produce 128 – 143 koz of gold per annum. Lycopodium Minerals Pty Ltd (Lycopodium) was appointed to provide feasibility studies and EPCM services for the greenfield project. Forming part of consultancy services provided by Lycopodium, Orway Mineral Consultants (OMC), a subsidiary of Lycopodium, was involved in the design, commissioning, ramp up and ongoing post commissioning support of the comminution circuit."

Jan 1, 2019

By 000-900-009-492

The flotation has been and is still the most widely used mineral concentration method. Because of its complexity, the flotation process required the development of robust control strategies which was facilitated by the introduction of on-line sensing instruments such as x-ray fluorescence (XRF) on stream analyzer (OSA), gamma density gauges and electromagnetic flowmeters. The interest in developing control strategies has persisted because the benefits to be gained in terms of improved metallurgical performance are substantial. As the flotation control becomes more and more difficult due to the emergence of low grade and complex ore cases, other control strategies have to be introduced. Froth based control is one of the emerging useful control strategy This paper will focus on the state of the art in the on-line froth characterization as obtained by numerical image analysis. The technology of machine vision provides a novel solution to several of the problems encountered in conventional flotation systems for monitoring and control, and constitutes a powerful tool for the investigation and interpretation of the effect of various flotation parameters as driven for the froth phases. Copyright @2001CIM

May 1, 2001

By Kaiwen Xia, Bibhu Mohanty, Per Svedensten, Sheng Huang

"The mechanics of crushing and grinding operations in mining and excavation processes has been investigated in a laboratory simulation study. It employs a multi-particle bedded rock target, which is subjected to multiple impacts. The impact set-up consists of a Hopkinson pressure bar and a Piston-holder system. The apparatus, employing a 38 mm diameter pressure bar, was used to apply varying but calibrated dynamic loading force on the rock particles. The energy consumed by the sample during fragmentation was determined by considering the energy carried by the incident wave and the reflected wave. The Pistonholder system is used to hold rock samples and to recycle fragments after each test for particle size analysis, for single as well as multiple impacts. The feed size selected was in the range of 9.5 to 12.7 mm for all rock samples, and the impact velocity was set at 14 m/s. Two strong granitic rocks and a relatively weak limestone were the target rocks. The resulting particle size distribution after each set of impacts, ranging from single to 10 consecutive impacts, were analyzed, and various size distribution functions (i.e. Rosin- Rammler, Swebrec, Grady and Gilvarry functions) were fitted to compare their suitability in predicting the fragment size distribution for each rock type. INTRODUCTIONCrushers are widely used in the mining industry all over the world. Understanding fragmentation behaviour of rock under crushing process is fundamental to improved productivity and efficiency in mining operations. This is particularly so as all subsequent size reduction processes such as crushing and grinding are far more energy intensive than the initial blasting process employed in breaking of in situ rock. A considerable body of experimental studies exists on the behaviour of rock crushers for specific rock types in order to aid in the design of various types of crushers. However, these studies are mainly site specific, that is, the results are largely empirical, and the fundamentals of fracture process that lead to size reduction have not been dealt with adequately. Most such studies have attempted to link the input parameters, such as feed size and crusher parameters, with output particle size, and global energy expended in the process. However the physical mechanism of crushing process is still not well understood. First of all, the energy consumed by the rock sample is hard to calculate during standard crushing or grinding tests; secondly, multi-particle test is hard to perform in the laboratory due to irregular shape of the subject rock sample. In This paper, describes a laboratory crushing apparatus for multi-particle rock samples, with sufficient control of the energy expended in the process, with a view to relate creation of new fracture surfaces in the size reduction process."

Jan 1, 2015

By F Kelly

"A central composite experimental design was used to determine empirical relationships between the operating variables of a ball mill and the characteristics of the ground products. The independent variables selected for the study were the work index and size distribution of the feed material, the feed rate and the pulp density. The measured responses included product size distribution, product surface area, viscosity of pulp discharge, weight of dry solids in mill, mill time constant and emitted sonic vibrations. The ball mill was operated continuously in open circuit during each experimental run.Multivariable regression techniques were used to derive linear empirical models from the experimental results. Of the four factors studied, the grindability of the feed material significantly affected every measured response. The size distribution of the ground product was affected significantly by the feed rate and the size distribution of the feed, but not by the pulp• density. Feed throughput capacity and pulp density were significant to the viscosity of the pulp discharge, the weight of solids in the mill and the mill time constant. Significant first-and second-order models are given for the above relationships. The relation-ships between the characteristics of the sonic vibrations of the operating mill and the various dependent variables have not as yet been established."

Jan 1, 1970

By John S. Stevenson

THE Twin "J" Mine, operated by Twin "J" Mines, Limited, represents an amalgamation of the old Lenora, Tyee, and Richard III mines (see Figure 1) on mount Sicker, eight miles by road, northwesterly, from the city of Duncan, on Vancouver island. These mines produced 253,000 tons of copper-gold ore between 1898 and 1909 (see Table I). During the more recent period of production from these properties, July, 1943, to May, 1944, Twin ?J? Mines, Limited, mined and milled ore with values mainly in copper and zinc, and minor values in gold, silver, and lead. Figures are not available for this later production. Field work at the property was started by the writer in 1941 and continued in 1943 and 1944.

Jan 1, 1945

By K. Adham

Both the dry and the wet fluorination systems require hydrogen fluoride (HF) for the process of uranium conversion to uranium hexafluoride (UF6). The dry methods depend on the electrolysis of HF to generate the fluorine (F2) required for the high temperature pyro-fluorination. The wet methods require aqueous HF in water solutions for the low temperature hydro-fluorination (Argonne, 2019). This paper uses the available HF safety guidelines and industry information to discuss the issues of transportation, storage and utilization. Health effects and environmental considerations are reviewed. Safe practices for handling the HF (both as anhydrous and as aqueous) are considered. Proper selection of different materials of construction are discussed, for both the anhydrous and the aqueous HF.

Jan 1, 2020

By B. Konda, R. Lauer, D. Camilucci, D. Gladwin

"Income based taxes are significant cost elements to be considered in evaluating investment in new mine development. This paper presents the results of comparative analysis of effective income-based tax rates for mining in the Northwest Territories (NWT), selected Canadian provinces and international jurisdictions. The study was done as background to a review of royalty regulations for the NWT. ObjectiveThis paper presents results of comparative analysis of effective mining royalty1 rates, and combined effective mining royalty and income tax rates on selected mine models for the Northwest Territories (NWT), with those for several other jurisdictions in Canada and abroad which compete with the NWT for mining investment.BackgroundThe February 27, 1995 federal budget directed the Department of Indian Affairs and Northern Development (DIAND) to proceed with a comprehensive review and amendments to northern natural resource management legislation in order “to increase revenues and ensure a fair return to the Crown.” DIAND is responsible for the administration of the Territorial Lands Act, and its regulations.The Territorial Lands Act gives the Governor-in-Council the authority to “… make regulations for the leasing of mining rights in, under or on territorial lands and the payment of royalties therefor,…”. In the NWT, the Canada Mining Regulations (CMR) provide for the disposition of mineral rights for most minerals, other than coal, petroleum and related hydrocarbons, in return for the payment of a royalty to the Crown.As part of this review of the NWT mining royalty regime, several computer mine models were developed and tax regimes in a number of jurisdictions were analyzed. Effective mining royalty rates, and the combined effective mining royalty and income tax rates were compared across the jurisdictions. The results presented in this paper are a part of the background work done in preparing a discussion paper on proposed changes to the NWT mining royalty that is expected to be released for public consultation in the very near future."

Jan 1, 1997

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 R. B. Harkness

Many of us are familiar with the history of oil in the Province of Ontario, but for the benefit of those who have never heard the story I will repeat it. In 185 7 J. H. Williams, of Hamilton, an old-country Scotchman, who had the advantage of experience gained from the primitive methods used for refining the oil collected at seepages in Roumania, heard of the "gum beds" along Black creek in Enniskillen township, Lambton county. He erected a small plant in the bush and refined illuminating oil, where the village of Old Springs now stands. The labor of collecting this thick ?gummy substance from the sluggish water of the creek, prompted him to dig a well, the next year ( 1858), in the hope of obtaining a greater quantity. When his excavation reached a gravel bed on top of the rock, oil, resembling "lubricating oil of commerce", rose several feet. Several of these wells were dug and his refining business flourished. The following year the Drake well, in Pennsylvania, was drilled into rock, resulting in an oil find which encouraged one James Shaw to make a similar attempt on Black creek. With a spring-pole drill he completed his well in the spring of 1861 to a depth of 160 feet, and at that depth struck a gusher that flowed uncontrolled for several days. Great excitement followed and the village of Oil Springs had a mushroom growth. The Petrolia field was discovered in 1865. Lick followed up the Thames with a spring-pole rig testing the formations along that river and discovered the original Bothwell field in 1865. During the sixties wells were drilled in many counties in southwestern Ontario.

Jan 1, 1924

By W. A. Gow, J. A. Vezina

"A new process for treating scheelite for the production of tungstic tri-oxide is described. The novelty of the process resides in that an ion-ex-changer is used to convert sodium tungstate to either ammonium tung-state or tungstic acid.The process consists of a conventional hydrochloric acid leach of the scheelite concentrate, and the dissolution of the impure tungstic acid thus produced with sodium hydroxide at pH 8. The sodium tungstate solution is clarified and passed through a column of Dowex 50Wx8 ion-ex-change resin to exchange the sodium ions for either hydrogen or ammonium ions, both being suitable. The tungsten-bearing column effluent is evaporated to crystallize the tungsten as ammonium tungstate; the crystals are washed with nitric acid and water and decomposed by heat to pro-duce tungstic trioxide of high purity.Ninety-six per cent of the tungsten in the concentrate may be re-covered as tungs tic trioxide (W03), and the reagents consumed are 0.7 g HCl, 0.41 g NaOH and either 1.73 g NH.Cl or 225 g HCl per gram of tungsten."

Jan 1, 1966

By K. E. Prince, S. Burling, R. J. Ring, M. K. Maley, W. R. Taylor

Vanadium occurs as a component of carnotite, which commonly occurs in calcrete type ores, and in association with uranium in some sandstone-hosted deposits. Increasing demand for vanadium, which is used in high-strength steel and Vanadium Redox Flow Batteries (VRFBs), is offering some uranium producers a potential option for by-product vanadium recovery to improve project economics at a time when uranium prices are low. This paper presents the results of recent optimisation studies on the Bigrlyi deposit for the recovery of both uranium and vanadium. The impact of carbonate leaching conditions on uranium and vanadium extraction from a range of carnotite-in-calcrete ores is also examined, with vanadium extraction limited by the proportion of non-carnotite vanadium present in the ores. The findings are particularly relevant to developing projects as results show that elevated vanadium content in ore does not necessarily equate to a high vanadium extraction in leach.

Jan 1, 2020

By B. D. Pandey, M. S. Kim, B. S. Kim

The recovery of Sn from used Pb-free solder (Sn, 3~4 % Ag, < 0.9 % Cu, < 1.2 % Pb) has been investigated by electrorefining in sulfuric acid solutions containing small amount of hydrochloric acid. This involved preparation of the anode material by melting and casting the used solder followed by refining. During electrorefining, dendritic tin was deposited on stainless steel cathode. Increasing the amount of hydrochloric acid up to 0.3 mol /L in the electrolyte enhanced the current efficiency to 92.2 % and the enrichment ratio of silver to 94.3 % in the anode slime which was otherwise 84.7% and 81.6 % in absence of HCl, respectively. The electrolyte containing hydrochloric acid has also prevented the precipitation of tin oxide in the bath. In the scale-up experiment using 1.6 kg anodes, 84.3 % current efficiency and close to 100 % Ag enrichment ratio were obtained, while the purity of electro-refined tin was over 99.9 %. The energy consumption of the winning process was found to be 0.151 kWh /kg-Sn which is competitive as compared to commercial tin electrorefining processes.

Jan 1, 2014

ABSTRACT Understanding process histories and worker exposures in nickel production operations is critical in determining the role nickel compounds play in respiratory cancer incidence. As part of a series on Vale Canada’s (previously known as Inco) nickel processing operations, this paper includes descriptions of Ni electrolytic operations at refineries in Port Colborne, Ontario (1922–1984), and Thompson, Manitoba (1961–present). Industrial hygiene measurements, by area and personal sampling, of workplace aerosols at these operations are reported.

Jan 1, 2014

By John E. Udd

"For decades, writers have expressed concern about impending shortages of professionals for Canada&apos;s minerals industry. Even under the present difficult economic circumstances, it is anticipated that the supply which will be available will not be adequate to meet the requirements in certain key areas including mining and petroleum engineering. It is evident that, unless further initiatives are taken, shortages will exist for some time.In this paper, the writer reviews information which relates to both the demand for, and the supply of, persons with advanced-level education in minerals-related disciplines. In particular, a summary is made of the information regarding supply which has been collected by the CIM General Committee on Education for many years.In concluding, the writer expresses some personal opinions regarding imbalances between demand and supply and offers some recommendations for future actions.IntroductionLast year, in a paper which was presented at the Annual General Meeting of the CIM in Calgary, the writer presented a review of the situation regarding professionally educated manpower for the minerals industry, and concluded that indications were that the gap between demand and supply was widening and that the situation could be expected to continue. Since that time, the deterioration of the nation&apos;s economy has caused an appreciable reduction in demand. Simultaneously, a further annual survey by the CIM has shown that the numbers graduating in certain specializations, notably geology and some of the technologies, are rising very rapidly. One of the great concerns of educators at present is that adequate opportunities may not exist for all of those who are now graduating.The danger of the present situation, then, is that a momentary lack of opportunities may cause potential students to choose alternative careers . Because of the lead-time which is involved, it is very possible that this could result in greater shortages during a period of economic recovery or expansion. Action must be taken to ensure that adequate numbers will be attracted to the industry, and this applies particularly to those who have already made the career decision and who are enrolled in minerals-related programs."

Jan 1, 1982

By M. Bender, H. D. Goodfellow

"Belt conveyors, because of their low capital and operating costs and inherent flexibility in handling a wide variety of products, have numerous applications in the mining industry. With the increased emphasis on improving the workplace environment, dust emissions from belt conveyors at transfer and other points have become a significant problem for many applications.The paper reviews belt conveyor dust control technology and compares dust emissions from belt conveyor systems with other possible materials handling systems. Technical information on existing belt conveyor installations which have been designed to minimize or eliminate dust emissions is summarized. The important features of good design as well as the necessary input from operating and maintenance personnel are highlighted. The status of research and development work on dust control on belt conveyor systems on a world-wide basis is discussed. A proposed methodology for field measurements of emission factors from belt conveyor systems is presented. Data collected from such a test program can be used to establish a design basis for new dust-free belt conveyors.IntroductionBelt conveyors have proven themselves over the year s in the mining industry as a reliable and low-co st method of moving bulk material at high tonnage rates. Because of the above, as well as their inherent flexibility in handling a wide variety of products, belt conveyors are often called the ""workhorses"" of bulk material handling systems. For many processing plants, belt conveyors serve as the ""vital link"" in providing feed to the plant and the removal of the finished product. As would be expected, there has been considerable engineering effort in designing rugged and reliable belt conveyor systems.It is also well known that belt conveyor systems are a primary source of respirable dust emissions. The major sources are from the tail pulley where material is received and the head pulley where material is discharged, from the return idlers, due to the fine material attached to the return belt, and from the take-up pulley. It is usually considered that for dust particles less than 10 microns, these particles will remain airborne and thus can have a profound effect on the workplace environment."

Jan 1, 1982

By Michel Jébrak, Claude Bellehumeur

Abstract - Regional and orientation geochemical stream sediment surveys were carried out by the Quebec Department of Energy and Resources in southwestern Quebec, over a part of the Mont­ Laurier Terrane of the Grenville Province. The area contains some small stratiform zinc deposits. The response of Zn mineralization to geochemical surveys is weak; the known mineralization is not defined by anomalous samples and consistent patterns. This study uses a technique that increases the geochemical signature of Zn mineralization in filtering out geochemical background components related to lithologies and surficial conditions. The background variations were modelled using principal component analysis, and the filtering technique consists of the partial reconstruction of the data matrix from results of principal component analysis . The filtering procedure considerably enhances the Zn anomalies located in the catchment basins of Zn deposits, and defines some new anomalies in proximity to the marbles of the Mont-Laurier Terrane, the principal metallotect of Zn mineralization.

Jan 1, 1993

By M. Sahoo, P. Burke, Y. Fasoyinu, J. P. Thomson

The effects of grain refinement, mold temperature and chemical composition on the hot tearing resistance of aluminum alloys 535.0 and 206.0 has been studied by pouring constrained rod castings in metal molds. In addition, two prototype components that could be used in automotive applications were also poured from both alloys by gravity tilt-pour and low pressure permanent mold casting processes. This paper summarizes the results and issues encountered during the casting trials. It was shown that grain refinement and mold temperature ::::: 400°C reduced, and sometimes eliminated hot tear cracks in both alloys. The two prototype engineering components could be cast successfully from both alloys in metal molds. The metallurgical issues related to molten metal treatment and processing temperatures were well controlled. However, issues related to the control of hot tearing, casting and mold design must be addressed in future studies to guarantee the production of defect free castings.

Jan 1, 2006

By J-P. Rossetti, A. Guerin, M. Jaboyedoff, L. Baillet, A. Mariscal, J. D'Amato, D. Hantz

"The processes leading to the fall of rock compartments from rock walls are poorly known as well as their velocity. It ensues that quantitative prediction of the failure time for a rock compartment which is presently stable, is not possible by a purely geomechanical approach. However a quantitative probabilistic prediction of rockfalls at the scale of a rock wall is possible if the spatial-temporal rockfall frequency can be determined or estimated (Hantz, 2011). For a better knowledge of failure processes and frequency, rockfalls have been detected in several rock walls, using annual terrestrial laser scanning, allowing comparison of the frequencies in different geological conditions. For one of these rock walls, the spatial detection have been completed by a precise dating of the events, using a quasi-continuous photographic survey (one photo every 10 mn), allowing the study of the influence of meteorological factors.The precise dating of rockfalls has been carried out for the Saint-Eynard cliff which towers above a residential area of the town of Grenoble (French Alps). The South-East facing cliff consists in bedded limestone gently dipping North-West and located at an elevation between 850 m and 1100 m. The surveyed zone is about 750 m large and 250 m high. Between 01/02/2013 and 26/11/2013, 65 rockfalls ranging between 0.01 m3 and 20 m3, have been detected by diachronic comparison of laser scanner data and dated by comparison of photographic images. The temperature at the elevation of the cliff has been calculated from the temperature measured (every 5 mn) at a meteorological station located at an elevation of 245 m and 2.5 km away from the cliff, using a temperature gradient of 0.003°C/m (D’Amato et al., 2014). The precipitation were measured 900 m away from the cliff at an elevation of 469 m. Different meteorological conditions have been defined: (a) “freeze” qualifies days with negative mean temperature (but with a thaw period, except for two days); (b) “thaw” qualifies days with positive mean temperature, but following a freeze day; (c) “rain” qualifies days with precipitation.Table 1 shows the rockfall temporal frequency for the different meteorological conditions. It appears that the frequency is about 6 times higher the freeze days, 2.5 higher the thaw days and 3 times higher the rain days than days without freeze, thaw or rain."

Jan 1, 2015