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By CIM Standing Committee

The CIM Definition Standards on Mineral Resources and Reserves (CIM Definition Standards) establish definitions and guidance on the definitions for Mineral Resources, Mineral Reserves, and mining studies used in Canada. The Mineral Resource, Mineral Reserve, and mining study definitions are incorporated, by reference, into National Instrument 43-101 – Standards of Disclosure for Mineral Projects (NI 43-101). The CIM Definition Standards can be viewed at mrmr.cim.org. Readers should be aware that reports written by persons issuing technical reports that disclose information about exploration or other mining properties to the public in Canada are governed by a number of securities regulations.

May 10, 2014

By G. F. Round

In order to obtain values of angle of shearing resistance and initial resistance for McMurray oil sand for use in general design calculations, the shear strength of this oil sand was measured in a controlled strain type tester, modified so that the rate of deformation could be varied between 0.01725 and 0.1869 inches per minute. Effect of temperature was investigated by adapting the equipment to operate at both 71 ° and 185 °F. The data are reported in terms of angle of shearing resistance and initial resistance for varying rates of deformation, composition and temperature. While the main sets of results reported here were obtained at a bulk density range of 108.7- 109.5 lb. / cu. ft., some results were obtained at a bulk density range of 101-102 lb. / cu. ft. Analysis of varance tables have been drawn up from the results obtained from least squares correlations and significance tests applied. It was concluded that oil content and temperature were significant variables for the degree of shear strength developed by the oil sand; increase of oil content and decrease of temperature each cause an increase in shear strength. The bulk density range 108.7 to 109.5 lb./cu. ft. gave angles of shearing resistance from 30° to 40° and initial resistance values of 0.37 p.s.i. to 0.85 p.s.i. For the bulk density range 101 to 102 lb. / cu. ft., lower values of shear strength were obtained, indicating that compaction density was also of importance

Jan 1, 1960

By E. J. Sides

In this paper, the argument is put forth that the codes used for public reporting of mineral resources and mineral reserves have some significant limitations with regard to the information provided to investors on the short- to medium-term value of mining properties. Such limitations include a) failure to explicitly incorporate a time element and b) failure to state explicitly the quantity and quality of mineral product that will be produced for sale. A time-value framework for reporting mineral assets is proposed in order to overcome these limitations. The proposed system is based on two classification axes: a) an X-axis representing time in years during which the value of the asset is likely to be realized and b) a Y-axis representing the value identified by a mining or exploration company\u2019s activities. The potential benefits of this system are discussed, including the ability to incorporate factors, such as permitting and construction times, directly into the magnitude of the reported mineral assets. The proposed framework would assist in the standardization of mineral assets reporting in such a manner that they could eventually be more readily included in financial statements. Year of Publication: Not explicitly mentioned in the document.

Jan 1, 2010

By G. Deschênes

Located in North West Tanzania, Buzwagi is an underground narrow-vein gold mine owned by Barrick Gold. The plant was commissioned in 2000. The reserves are estimated to be more than 25 years. The ore, containing gold, silver and copper mineralization in sulphides, is processed at 3,300 tpd. This paper presents the results of an investigation to determine the performance of an ammonia-cyanide leaching approach to recover gold from two samples. Coarse gold was recovered by gravity prior to leaching. The gravity tailings had the following composition; 1.97 g/t Au and 0.31% copper for the medium cyanide soluble copper (MCSC) sample and 2.80 g/t Au and 0.53% Cu for the high cyanide soluble copper (HCSC) sample. Experiments were conducted for 72 hours in stirred tank reactors with monitoring and control of parameters. The straight cyanidation produced gold extractions of 76.1% for the MCSC sample and 84.6% for the HCSC sample. Associated cyanide additions were 6.1 kg/t and 11.5 kg/t respectively. The gold extraction of the MCSC sample was improved to 88.8% using 350 ppm NaCN and 700 ppm ammonia. The associated cyanide and ammonia additions were 2.5 kg/t and 1.7 kg/t respectively. For the HCSC sample, 82.5% gold extraction was obtained using 500 ppm NaCN and 600 ppm ammonia. The cyanide addition and ammonia additions were reduced to 3.8 kg/t and 1.0 kg/t respectively. No significant decrease in gold extraction was noticed when the cyanide and ammonia were reduced to 150 ppm and 500 ppm respectively. In the presence of ammonia, a significant amount of cyanide was oxidized to cyanate by the cupric ion. In the absence of ammonia, the formation of copper cyanide was the predominant reaction responsible for consumption of cyanide.

Jan 1, 2012

By Stephen G. Mlot

The evaluation of mineral projects involves the identification, mitigation and management of significant uncertainty. Benchmarking is an essential and effective way of increasing confidence and reducing uncertainty associated with input parameters and assumptions. Comprehensive and detailed benchmarking will ensure ?best practice? technologies, methods and systems have been considered and that the appropriate practices can be identified and incorporated into the project. In conjunction with the involvement of experienced industry practitioners, benchmarking is best employed throughout project evaluation to enable early identification of ?errors?, producing more accurate and predictable outcomes. Considerable time and effort is required to gather data and information, which should be benchmarked by the project evaluation team. There is a history of mining projects underperforming, on production, on costs and on return to the investors. The quality of mine plans and feasibility studies, and the quality of the input data is being questioned in many ways. Benchmarking assists sound project evaluation practices, by providing a database of actual results, to validate project inputs and outcomes, ensuring they are realistic and achievable. Benchmarking also provides unbiased, statistical support as the basis for sound investment decision making and ensures well considered decisions are made resulting in a more efficient study process. The evaluation of the quality of projects which are the subject of transactions also benefits from the use of real data obtained from a benchmarking database. Vendors are quick to highlight the benefits of their projects, and conceal the flaws, inflating the value. Buyers will want to quantify the potential of a project through the due diligence process relying on actual results from benchmarking. For the reasons broadly outlined above, benchmarking should be considered as an essential component of effective Project Evaluation.

Aug 1, 2013

By W. L. Murphy

The Star Lake property, located 115 km northeast of La Ronge, Saskatchewan is underlain by metamorphosed andesitic tuffs and flows which have been intruded by the dioritic to granitic Star Lake Pluton. Gold mineralization on the Star Lake property was first discovered at Ru h Lake by E. Beveridge in 1959 and by M. and E. Hird in 1961. In 1960 E. Partridge discovered Kahn 18 and Kahn 28. In 1982 the SMDC-Starrex joint venture completed geophysical and geochemical urveys including magnetics, VLF, IP/Resistivity, vegetation, bulk till and oil sampling, followed by drill testing of pecific targets. To date the most ignificant depo it is the 21 Zone which contain drill indicated reserves of 230,000 tons grading 0.5 oz/ton Au . The 21 Zone con ists of quartz with 5-10% (locally > 30%) drusy pyrite, minor chalcopyrite and trace amounts of scheelite, chalcocite and arsenopyrite. The 21 Zone is enclosed by a 25-50 m wide band of mylonitized monzonite. The mylonite occurs in the central portion of a 300 m wide northeasterly trending zone of brittle deformation .

Jan 1, 1986

By J. J. Denny

IN November, 1932, an investigation of silicosis was undertaken at the Mcintyre Porcupine mine, Schumacher, Ont., after a discussion of the p"roblem with Sir Frederick Banting and his staff. As a result, it was decided to carry on dusting experiments with animals at the mine in a manner that would duplicate as far as possible actual industrial conditions. At that time 50 guinea pigs were placed in the crusher house tunnel of the mill where a considerable quantity of fine dust, containing approximately 35 per cent of free silica, was being constantly produced. These animals lived in this atmosphere for periods up to one year, and, while on autopsy large amounts of dust were found in the lungs, not a single case of silicosis had developed. These negative results suggested, among other things, that the mine gases might be a predisposing factor in the production of silicosis, and the results of this investigation (1) led us to undertake the study of the hydrogen-ion concentration of the condensate of the atmosphere, both in the mine and in various sections of the mill. The CO, combining power of blood serum on a series of 400 miners was also studied at this time. While these results were inconclusive, the variation in the hydrogen-ion concentration of the condensate between the surface and underground atmospheres encouraged us to investigate the effect of neutral, weak acid, and alkaline solutions on the solubility of siliceous materials. Gye and Purdy (2) were the first to point out that the chemical reaction, and not the physical presence of siliceous material, was responsible for the production of the fibrosis in silicosis. This work was investigated by Gardner and Cummings (3), who showed that the tissue reaction to quartz was definitely proportional to the size of the particle. They found that 1-3 micron particles of quartz produced an acute proliferative fibrotic response, while the 10-12 micron particles produced only a foreign-body reaction up to a period of three years. It is accepted that the dangerous silica particles retained by the lung are under 5 microns in diameter.

Jan 1, 1937

By A. Rodriguez-Prado

"Magnetic fields affect the growth of cultured cells and plants; however, limited information exists about their effects on vegetation performing environmental remediation. Constructed wetland mesocosms treating hexavalent chromium (Cr(VI)) wastewater exposed to low-intensity magnetic fields (60 Hz, 56.5 × 10-6 Tesla) produced 100% more biomass than the unexposed control. Nonetheless, they removed only 43 ± 27% of Cr(VI), compared to 60 ± 21% for the control. A Cr(VI) reduction expression was developed as a function of the magnetic field. The design and operation of constructed wetlands to treat mining wastewater can be corrected for magnetic field effects.RÉSUMÉ Les champs magnétiques affectent la croissance des cellules et des plantes cultivées; toutefois, il existe peu d’information quant à leurs effets sur la végétation utilisée à des fins d’assainissement environnementale. Les mésocosmes des marais artificiels traitant des eaux usées, contenant du chrome hexavalent (Cr(VI)), exposés à des champs magnétiques de faible intensité (60 Hz, 56,5 × 10-6 Tesla) ont produit 100 % plus de biomasse que le contrôle non exposé. Néanmoins, ils n’ont enlevé que 43 ± 27 % du Cr(VI), comparativement à 60 ± 21 % pour le contrôle. Une expression de réduction du Cr(VI) a été développée en tant que fonction du champ magnétique. La conception et l’exploitation de marais artificiels pour traiter les eaux usées des mines peuvent être adaptées pour tenir compte des effets des champs magnétiques."

Jan 1, 2015

By H. J. Handewith

"After having performed qualitative and quantitative tests on nearly 550 rock specimens from tunnel projects throughout the world and comparing the results with actual boring in eight distinctly different rock types which varied in compressive strength from 12,000 to over 34,000 psi, it has been concluded that any rock -andesite, granite and even taconite -can be machine-bored. The question is -can it be bored economically? The intent of this paper is to delineate the investigative needs to accurately and reliably answer this question. A piece of NX core in the hand represents less than 50 per cent of the worthwhile geologic information that could have been obtained from a given core hole. A thorough site investigation by competent personnel can gene-rally foretell to what extent, if any, varying geologic conditions will hinder machine progress.A laboratory testing technique has been developed that has been correlated well (80 to 120 per cent) with actual boring results. This technique will be discussed in detail. Rock cutter life is a function of the penetration rate and the forces required to sustain that rate. Cutters are now, and will be for .some time to come, the single, most expensive consumable item involved in continuous tunneling in hard rock. It is by strict attention to predicting these rates and forces that tunneling costs can be optimized."

Jan 1, 1970

By C. Doyle, J. Brennan, C. Díaz, J. Hrepic, K. Cushnie

"In 1991/1992, INCO undertook a successful R&D program aimed at extending the lining lives of the top blown rotary converters (TBRCs)at its Copper Cliff Nickel Refinery (CCNR) and the electric furnace at INMETCO. At the laboratory scale, this effort was divided into three phases. In the first part, mineralogical work was performed on six refractories that were either currently being used to line these vessels or were considered suitable alternatives. In the second part, this mineralogical knowledge was used to help determine the compositions of slags that would not corrode the bricks at the operating temperature (1600°C) of the above furnaces. Finally, several important properties of the six refractories were measured to complete their evaluation as candidate linings. This paper reports the results of all three phases of the laboratory scale R&D work.The mineralogical work showed that rebonded fused grain magnesite-chrome (RFG-MC) bricks consist principally of periclase with minor amounts of free chromite and trace quantities of silicates monticellite and sometimes olivine. The bricks are principally held together by periclase-periclase direct bonding. Of note, the bulk of the chromite exists as exsolved precipitated blebs within the periclase grains. These likely redissolve at high temperature.Slags on the periclase liquidus coexist stably with these refractories. Examples are presented using CaO-MgO-Al2O3-SiO2 slags at~1600°C.Finally, the two refractories manufactured using close to 100% fused grain material generally outperformed the others in terms of physical properties and certainly were superior in their resistance to slag penetration damage."

Jan 1, 1997

Access to accurate real-time information is critical to maintaining efficiency and competitiveness in any modern minerals processing facility. At MMG LXML Sepon Copper Operation in Lao P.D.R., controlling the copper grade of the feed to the leaching circuit is paramount for maximising productivity and copper recovery. Since 2008, real-time analysis data has been available to process engineers from the Geoscan on-belt analyser installed on the Copper Mill feed conveyor. Access to accurate real-time results from the Geoscan has allowed the process engineers to strictly control blending based on copper grade to overcome variability in the plant feed, where conventional sampling and laboratory analysis is difficult, error prone and time consuming. In addition to enjoying these benefits since the Geoscan’s installation, in recent times the process engineers have expanded the use of the Geoscan by observing elemental results other than copper grade to control different aspects of the operation, focussing on the reduction of Gangue Acid Consumption. This paper discusses the process of expanding the Geoscan use at the operation, including an explanation of the calibration process. Additionally, a brief description of the Geoscan and its use at MMG LXML Sepon Copper Operation is provided, as well as a summary of recent calibration and analysis results. A discussion of future works concludes the paper.

Jan 1, 2016

By Pamela Paradis-Sokoloski, Deni Thibodeau, J. Denis, Samantha J. Espley, P. O’Donnell

"During the previous decade, the role of spray-on liners within the mining industry was limited to providing a corrosion resistant coating to screen and bolts; however, increasingly, liners are being used as ground support products. Expanding use and testing of liners have demonstrated their ground support function, yet the definitive support mechanism is still under debate. The most promising theory is the retain/hold/reinforcement concept (Kaiser et al.,1992). This conceptual theory has been the basis for the recent underground trials at INCO where, specifically, shotcrete and MIROC Mineguard were tested in two trials to further define limitations and applications of each liner.In a cursory overview, shotcrete is becoming accepted as a support product, while Mineguard is only slowly gaining acceptance.This discrepancy is the result of the corresponding life-spans within the industry, whereby shotcrete has had wide-spread use for decades, yet Mineguard has only recently been introduced. Currently at INCO, shotcrete is primarily used: to provide support in poor ground conditions, to add stability when developing through backfill, and to provide damage control in seismically active mines. It is also used to protect production headings and secondary-blasting chambers from fly-rock damage during blasting. Despite an obvious support function of the liner, shotcrete has always been used in addition to bolts and screen. Comparatively, Mineguard is still in the testing stage, where the greatest potential is increased productivity for applications in multi-tasking development headings. In this scenario, Mineguard provides instant support to replace screen, and bolts temporarily. When the heading has advanced, the drill and support crews work in tandem, drilling off the next round and installing bolts for long-term radial support, respectively. Other potential applications of Mineguard are within production headings to replace screen in the back, and screen and bolts in walls. The potential for both liners to replace conventional support is clearly war-ranted, such that defining the support role was the primary goal of the two underground trials."

Jan 1, 1996

By K. Lascelles

ABSTRACT Nickel compounds vary significantly in their toxicological properties, so it is critical that continuing studies to accurately quantify worker exposures consider the processing that accompanies refining nickel-containing materials. The Clydach nickel refinery, which has operated for more than 100 years, was the first nickel-producing facility to show a high risk for lung and nasal-sinus cancers among workers employed since it opened in 1902. Process chemistry and equipment have changed dramatically over Clydach’s history. This paper describes the processing evolution at Clydach with a focus on the propensity for aerosol formation and the forms of nickel in airborne dusts.

Jan 1, 2013

By Keith Haddock

"The Sheerness Mine, a new surface coal mine located near Hanna, Alberta, went into full production in mid-1995. The mine, which is operated by Luscar’s subsidiary Forestburg Collieries (1984) Ltd., has the design capacity to supply up to 2.1 million tonnes of sub-bituminous coal per year to the adjacent Sheerness Generating station under a 30-year contract. This paper documents the construction phase of this project and highlights the major equipment purchases as well as the construction of the mine facilities. The paper also focuses on some of the areas where cost savings have been achieved that have allowed the mine to come on stream six months ahead of schedule, and under budget. Project ReviewMine DescriptionThe Sheerness Mine is located 25 km southeast of the town of Hanna in southeastern Alberta (Fig. 1). The mining property occupies the western portion of the Sheerness CoalField and borders the Montgomery Mine, operated by Manalta Coal Ltd. in the east, and Highway 36 in the west. The Montgomery Mine and the Sheerness Mine exclusively supply the total coal requirement of the adjacent Sheerness Generating Station. The station is owned jointly by Alberta Power Limited (APL) and TransAlta Utilities Corporation (TAU). APL is the operator. Manalta’s Montgomery Mine has supplied coal to the Sheerness Station since its opening in 1986. Coal is shipped by truck from the mines over a network of haul roads to the coal receiving hoppers located on the east side of Highway 36."

Jan 1, 1997

By J. J. Crowder, A. L. Coulson

Ground support is a significant component of underground mining costs. The rehabilitation of failed support, however, is often much more expensive than the initial installation. This paper investigates whether the right type and length of support can be designed correctly the first time, through forward modelling of the support and the mining process. Back analyses demonstrate how high-quality instrumentation and monitoring can help with the estimation of the post-peak (post-failure) rock mass parameters required for a comprehensive analysis. A hybrid modelling approach combines a three-dimensional mine-wide boundary element model with a non-linear finite element model to allow for the failure process in the rock mass. The back analyses demonstrate that, for the case study site, the post-peak Generalized Hoek-Brown value of mr must be reduced significantly in order to properly simulate displacements observed in instrumentation data. High-quality instrumentation data is the key to post-peak rock mass parameter calibration. The procedures outlined in the paper highlight the need for a new hybrid numerical modelling package that can use the influence of three-dimensional mining-induced stresses to predict displacements in, and potential failure of, rock masses surrounding mining infrastructure in order to radically alter strategic and tactical mine design.

Jan 1, 2007

By R. W. Wein, L C. Bliss

Northern ecosystems are dominated by a harsh physical environment which dictates a need for biological adaptation. As yet, it is unknown just how these adapted plants and animals will tolerate industrial development. Our work, sponsored by university, government and industry, is part of an effort to evaluate this developmental impact. Our present studies and the results to date will be discussed. Other problems to which the environmental student may address himself in the future to ensure against environ-mental degradation will be suggested.

Jan 1, 1971

By M. du Plessis, D. F. Malan

"Crush pillars are designed to be in a crushed state whilst being formed at the mining face. The residual stress state of these failed pillars provides a local support function in mining stopes and is used in the majority of the intermediate depth South African platinum mines. On mines utilising crush pillars, the pillar dimensions are selected to achieve a width to height ratio of approximately two. This is not achieved in most cases as a result of practical mining problems and poor pillar-cutting discipline. Furthermore, pillar dimensions are seldom adjusted to compensate for the various factors governing crush pillar behaviour. The pillars should, however, be in a crushed state whilst being formed or whilst still in close proximity to the mining face to prevent potential damaging seismicity.An underground investigation was conducted into the behaviour of the crush pillars in a trial site on the Merensky Reef at Lonmin Plc. The aim of this investigation was to examine the mechanism of pillar crushing and the related rock mass behaviour. The underground test results and pillar behaviour are compared to a limit equilibrium model to investigate if the model provides a useful approximation of the behaviour of the crush pillars. This paper details some of the preliminary findings.INTRODUCTIONOn most mining operations, the design of crush pillars is based on trial and error. As the pillar strength is unknown, the pillar sizes are adjusted to obtain the correct behaviour. Crush pillar dimensions are generally selected to give a width to height ratio (w:h) of approximately 2:1, (Ryder and Jager, 2002). Several factors affect the behaviour of the crush pillars and in many cases satisfactory pillar crushing is not achieved. This results in a seismic hazard in many of the mines using crush pillars. If pillar crushing is not initiated whilst the pillar is being formed at the mining face, as the mining face advances and the pillars move to the back area of a stope, some pillars may burst while oversized pillars may punch into the footwall. If pillars are designed in such a way that they are fractured during cutting by the face abutment stresses so that the pillars will already have yielded and reached their residual strength, further compression of the pillars will be associated with an increase in load and stability will be ensured, (Ozbay and Roberts, 1988). The stiffness of the strata must therefore be greater than the post-peak stiffness of the pillar (Figure 1) or violent pillar failure and hanging wall instability will occur. The pillar design should be aimed at determining pillar dimensions for which the post-peak curve of the pillar is as flat as possible."

Jan 1, 2015

By Dale Verran, Jared Orynik, Chad Sorba, David Bronkhorst

Denison Mines Corp. (“Denison”) has a 90% interest in the Wheeler River Uranium Project (“Wheeler River”) located along the eastern edge of the Athabasca Basin in northern Saskatchewan between the Key Lake mill and the McArthur River uranium mine. The project is host to the high-grade Phoenix and Gryphon uranium deposits, discovered by Denison in 2008 and 2014 respectively, which include combined Indicated Mineral Resources of 132.1 million pounds U3O8 (1,809,000 tonnes at an average grade of 3.3% U3O8). The Pre-Feasibility Study (“PFS”), completed in accordance with NI 43-101 in September 2018, is highlighted by the selection of the In-Situ Recovery (“ISR”) mining method for the development of the Phoenix deposit, with an estimated average operating cost of $4.33 (US$3.33) per pound U3O8. Phoenix is the highest-grade undeveloped uranium deposit known globally, including Indicated Mineral Resources of 166,000 tonnes at 19.1% U3O8 for 70.2 million pounds U3O8. The paper aims to provide a summary of Wheeler River and an overview of the proposed development of the Phoenix and Gryphon deposits according to the PFS completed for the Project. Further details regarding the PFS, including additional scientific and technical information are described in greater detail in the NI 43-101 Technical Report titled "Pre-Feasibility Study for the Wheeler River Uranium Project, Saskatchewan, Canada" dated October 30, 2018 with an effective date of September 24, 2018. A copy of this report is available on Denison's website and under its profile on SEDAR at www.sedar.com and on EDGAR at www.sec.gov/edgar.shtml.

Jan 1, 2020

By G. G. W. Thom, A. A. F. Schuldt

At The Steel Company of Canada, Limited, iron oxide dust from the basic oxygen open hearths is being collected by means of electrostatic precipitators. The utilization of this dust, which has been hampered by the presence of zinc and lead oxides and sulphur compounds, is made possible by direct reduction in a rotary kiln. The description of the dust collection system and the results of kiln tests are presented.

Jan 1, 1966

By J. A. Cox, R. S. Mattson

"One of the main problems encountered in employing sublevel caving is the inherent high dilution factor. The operating results at Granduc illustrate that this dilution can be closely controlled and satisfactory recoveries achieved, in base metal ores grading less than 2.0% copper equivalent, by using an assay grade control system based on the fundamental draw characteristics. The history of draw control procedures employed since the start of operations provides an effective comparison between this system and one based mainly on tonnage. The transverse and longitudinal sublevel caving mining methods are described and it is shown how improvements in design layout, operating practice and draw control in narrow complex ore zones (12-foot minimum width) have raised the operating performance of the longitudinal system to a satisfactory level."

Jan 1, 1973