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By D. K. Fountain

"High metal prices and advanced technology in open-pit mining methods have resulted in considerable interest in the development of large, low-grade mineral deposits. Brenda Mines Limited is presently testing such a deposit of copper-molybdenum mineralization near Penticton, British Columbia.The mineralization of economic interest at Brenda has a total metallic sulphide content of between 1 and 1.5 per cent. This sulphide content approaches the limits of detectability of standard geophysical methods. How-ever, due to a favourable geological environment, it has been possible to utilize the Induced Polarization Method to outline the mineralization at the Brenda property."

Jan 1, 1968

By L. V. Kin, V. V. Lodeischikov, A. V. Byvaltsev, IRGIREDMET JSC, O. D. Khmelnitskaya, S. V. Petrov

"Irgiredmet Institute carried out the study on the development of gold recovery technology from refractory ore from a Russian deposit. The ore contained 1.1 g/t Au, 1.5% of pyrite and 2.4% of pyrrhotite. The recovery of gold achieved was 84.7% using gravity with generation of high grade recoverable gold concentrate and gravity middling. In the course of lime treatment, cyanidation of the middling followed by tailings detoxification the consumption of reagents was 13.0 kg/t CaO, 95 kg/t NaCN and 72 kg/t Ca(OCl)2 of the concentrate. This was capital intensive.In order to decrease the consumption of reagents, magnetic separation of the middling of the concentrates from gravity separation was added to this flow sheet. Pyrrotite recovered to magnetic fraction, which did not contain gold in accordance to this advanced flow sheet. The mass yield of pyrite goldbearing non-magnetic fraction decreased down to 1.5 times in relative to gravity middling. The slurry filtration prior to and after cyanidation allowed the organization of cyanide solution recycling.The results of pilot plant tests using the developed flow sheet showed that the content of pyrrhotite in the non-magnetic fraction decreased from 59.1% to 11.3%. The reagents consumption was 12 kg/t CaO, 3 kg/t NaCN and 16 kg/t Ca(OCl)2 of the pyrite concentrate. The total gold recovery using this flow sheet was 83.4%. Due to a decreased consumption of reagents, cost efficiency of the process was achieved. Based on the results of this research, a project design criteria was developed. A processing plant with the annual throughput of 2.6 million tonnes of ore is being designed."

Jan 1, 2016

By David K. Fountain

"The growth of the mining industry in British Columbia in the last ten years has been largely the result of the development of large low-grade copper and molybdenum deposits. There are two problems which must be solved in the search for mineral deposits of this type. It is necessary to detect large volumes of rock containing a low percentage of total sulphide mineralization1 and, secondly, to get some idea of the economic significance of this mineralization. The standard geophysical exploration techniques available have a varying degree of application in the search for disseminated sulphide de-posits. The electrical methods, and the induced polarization method in particular, are the most successful direct methods, and magnetic methods have indirect application in most situations. This is illustrated by geo-physical survey results from several properties in British Columbia."

Jan 1, 1968

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 Ralph W. Edie

"IntroductionTHIS PAPER deals with chemical and mineralogical changes in wall-rocks associated with pitchblende mineralization in the Gold-fields area of Saskatchewan. The localities at which the rock specimens studied were collected, and descriptions of the various rock-types referred to, are given in a previous paper by the author (5).The geological field work upon which this paper is based was carried out while the writer was employed by the Eldorado Mining and Refining Company during the summers of 1948, 1949 and 1950. The laboratory work§ consisted largely of quantitative spectrographic analyses for both major and minor elements, supplemented by an examination of 250 thin sections of both altered and unaltered rocks.Character of the AlterationHydrothermal alteration, with associated pitchbende mineralization, is widespread in the Goldfields area of Saskatchewan. The most intense alteration is restricted to the immediate vicinity of fault or breccia zones, but large areas are affected to a minor extent.In detail, the relationship between alteration and pitchblende mineralization is complex, as individual veins do not in general have separate alteration halos. Pitchblende generally occurs in gash-like calcite veins or stringers in wide, fractured zones associated with faulting. Large, lenticular and tabular masses of slightly to intensely altered rock occur in the same wide fracture zones as the mineralized veins. However, vein deposition appears to be-long to a later fracturing period, after hydrothermal alteration was more or: less completed. Generally, the veins transect and are confined to highly altered rock, but on the other hand many highly altered zones intersected in diamond drill-core are barren of mineralized veins."

Jan 1, 1953

By A. P. Sasmito

It is well known that underground miners are exposed to one of the most dangerous working environments on earth. As mine delve deeper, the geological factor, mine position and climate condition as well as heat generation from mining machine give rise to the mine operating temperature. This, in turn, has an adverse effect on the environment and thus leads to higher operating costs. Careful estimation and design of air flow rate, spray system, cooling load and additional ventilation auxiliary equipment are of importance to ensure safety, comfort and productivity whilst maintaining low operating cost. A computational fluid dynamics simulation approach is employed to examine underground mine ventilation in a 36 m cul-de-sac of tunnel of coal mine. The model predictions in the turbulent range were validated by comparison with published data. Different turbulence models were tested to select one that yields adequate accuracy and is computationally efficient. Effects of the following parameters are evaluated: tunnel geometry, air flow rate and inlet air temperature. The objective of the simulation is to arrive at an optimal strategy for ventilation and thermal comfort at low cost.

Aug 1, 2013

By A. A. Millar

THE output of coal from the Province of Alberta reached its peak; in the year 1928, when 7,334,179 tons were produced. Following this, a steady decline was recorded, and in 1930 a low mark of 4,564, 290 tons was made. Since that time, however, the tendency has been upward, and this year (1937) 5,551,682 tons were produced, compared with 5,696, 375 tons in 1936 and 5,462,973 tons in 1935. The value of the output in 1937 was $14,434,969, against $14, 720,004 in 1936. The coals of Alberta have been classed under three heads, viz., domestic, sub-bituminous, and bituminous The domestic (or lignite) and the sub-bituminous coals are used chiefly for domestic purposes, with the possible exception of the smaller sizes and the output of the two stripping pits at Stereo and Coal Valley The bituminous output is used mainly by the railways, for locomotive purposes, which, in 1937, accounted for 80.6 per? cenr of the total sales of bituminous coal. A fair proportion is sold for stationary engine and steam purposes and, in 1937, 25,000 tons were used in making briquettes at plants operated by the Canmore Coal Company, Limited, and Brazeau Collieries, Limited. The International Coal & Coke Company, Limited, used 99,500 tons in their plant at Coleman, for making coke. The bulk of the 66,000 tons of coke produced was sold for use at the smelter at Trail, B.C.

Jan 1, 1938

In most instances, the preferred mining methods in steeply dipping narrow vein deposits are selective methods such as cut and fill or shrinkage. The main advantage of these methods lies in the higher degree of control over dilution that can be achieved. However, where ore body geometry lends itself to it, high yield bulk methods can also be attractive. Higher productivity (and the associated lower costs) and lower worker exposure are some of the significant advantages that have made such methods so popular. The Lapa gold mine located in North-Western Quebec uses the long hole mining method (with cemented rock fill) very successfully despite challenging ground conditions. This paper focuses on the experience of the mine with regards to drilling and blasting practices. Firstly, the reasons that prompted the selection of this mining method at Lapa are examined. Secondly, the challenges that the difficult ground conditions found at Lapa pose to drilling and blasting are discussed. Finally, the results of trials of different drilling and blasting strategies that were performed at the mine are presented with particular emphasis on the lessons learned.

Aug 1, 2013

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. Holder

"A key barrier to vertical mineshaft construction is the construction access required for workers. A suspended work stage is used to provide this access for the mechanical, electrical and structural applications and other tasks. Work stage design is complicated considering the numerous types of construction activities that are executed simultaneously, the confined environment in which the work stage operates, the significant corrosion attack that is present, the weight limitations imposed by the mechanical hoist systems, and the risks associated with worker safety. Also complicating the design, these structures and their construction environment can vary with time. Hence, they can be described as 4D structures. The author has discovered significant synergies and advantages with integrating engineering design with detailed three-dimensional (3D) fabrication design. The significant reduction of minor design errors needing field correction will be underscored. The tender process is also accelerated since the design output is fabrication shop drawings including a detailed quantity takeoff output which lists each component required and its specific quantity. The paper presented will document the numerous advantages to the project using this approach. INTRODUCTION A key barrier to vertical mineshaft construction lies in the access for the workers to execute the construction. Suspended work stages are used to provide this access for the mechanical, electrical and structural applications as well as other tasks. The design of such work stages is complicated considering the numerous types of construction functions that need to be executed simultaneously, the confined environment in which it operates , the significant corrosion attack that is present, the weight limitation imposed by the mechanical systems for suspension, and the risks associated with worker safety. Also complicating the design, these structures and their construction environments can vary with time. They can be described as 4D structures with the fourth dimension being time. This design is a time consuming process. The post tender award is meticulous and requires strong teamwork between the steel fabricator and the consulting engineer. This teamwork may or may not be present and is dependant on the experience and relationship the team members have working together as well as other factors."

Jan 1, 2019

By P. Rosario

"Industry practice for high-pressure grinding roll (HPGR) assessment and sizing relies on tests using pilot-scale machines with 0.7–1.0 m roll diameters. Typically 1–10 t of sample are required, depending on the level of study and resource complexity. This is challenging during early-stage development, which hinders incorporating HPGR into designs. With support from the Canadian Mining Industry Research Organization, researchers at the Norman B. Keevil Institute of Mining Engineering at The University of British Columbia developed bench-scale piston–die press tests (PPTs) that correlate to pilot- and full-scale HPGRs. This paper describes a new regression model to estimate the HPGR-specific throughput rate using both PPT results and an HPGR database. A case study is presented to show how the current PPT method is used for engineering studies. ¦ KEYWORDS Empirical modelling, High-pressure grinding roll (HPGR), Piston–die press test (PPT), Sizing and scale upRÉSUMÉ La pratique en vigueur dans l’industrie concernant l’évaluation et le calibrage d’un cylindre de broyage à haute pression (HPGR, de l’anglais high-pressure grinding roll) dépend d’essais menés à l’aide de machines à l’échelle pilote dont les diamètres de bobine sont de 0,7 à 0,10 mètre. On a généralement besoin de 1 à 10 tonnes d’échantillons en fonction du niveau de complexité de l’étude et des ressources. C’est une pratique difficile durant les premières phases de développement, qui empêche l’intégration du HPGR dans les plans. Bénéficiant du soutien de la Canadian Mining Industry Research Organization (CAMIRO, l’organisation de recherche de l’industrie minière canadienne), des chercheurs du Norman B. Keevil Institute of Mining Engineering (l’institut Norman B. Keevil de génie minier) de l’université de la Colombie-Britannique (UBC) ont mis au point des essais en laboratoire sur des presses à matricer à pis¬ton (PPT, de l’anglais piston–die press tests), qui mettent en corrélation les HPGR aux échelles pilote et réelle. Cet article décrit un nouveau modèle de régression qui évalue le taux de production spécifique aux HPGR à l’aide des résultats tirés des PPT et d’une base de données dédiée aux HPGR. Une étude de cas est présentée afin de décrire l’utilisation de la méthode actuelle des PPT dans les études techniques. ¦ MOTS CLÉS calibrage et mise à l’échelle, cylindre de broyage à haute pression (HPGR), essai sur presses à matricer à piston (PPT), modélisation empiriqueINTRODUCTION It is widely accepted that high-pressure grinding rolls (HPGRs) are a viable, energy-efficient solution for modern comminution flowsheet design. Table 1 summarizes select examples of HPGR applications in the mining industry. The main benefits of HPGRs are energy savings, which leads to lower operating costs, and stable operating characteristics that can better cope with variations in ore hardness compared to the conventional autogenous (AG) or semi-autogenous (SAG) mill-based comminution circuits."

Jan 1, 2019

By P. J. Adams

Environmental regulations require means for controlling emissions of SO2 NOx and particulate when burning coal. The combustion of coal in limestone fluidized beds is one of the most promising techniques for the necessary reduction in emissions. Fluidized-bed firing, furthermore, offers potential economies in capital equipment. The world's largest steam generator applying fluidized-bed techniques was built under the sponsorship of ERDA and installed in Rivesville, West Virginia. This paper describes the design and discusses the start-up and development difficulties which were experienced during the period from initial operation to current readiness for commercial operation. Other developments leading to utility and industrial fluidized-bed steam generating equipment are reviewed. The future potential of this promising technique is discussed.

Jan 1, 1979

By A. G. B. Hayes, C. L. Renzoni

"AbstractThis paper provides a rough outline of economic expectations for the near future and then goes on to discuss their effect on the expected demand for metals, using zinc, copper, nickel and aluminum as detailed examples.IntroductionMINING, as you are all painfully aware, is a cyclical business. We believe that it will remain so as long as there are economic cycles.The fortunes of the industry are tied to those sectors of the economy where decisions can be postponed until more favourable times: automobiles, housing, appliances, inventory building and capital spending. Over the past two years, while U.S. GNP fell by 3.8%, automobile production declined by 31 %, from 9.7 million units in 1973 to 6.7 million in 1975. Housing starts plummeted some 43% from 2.1 million units in 1973 to 1.2 million in 1975. Little wonder that U.S. copper consumption fell by 37% and zinc consumption by 38% over the same period.With the rest of the world's economies moving in unison with that of the United States, it is also not surprising that times have been tough for mining.Arthur Burns, chairman of the U.S. Federal Reserve, contends that each recession sows the seeds of its own recovery. The worse the recession, the better the subsequent recovery. If this is true, then the lot of the mining industry should improve significantly over the next two to three years."

Jan 1, 1977

By J. K. Szymanski

"RÉSUMÉPour maintenir de bonnes performances technique et économique dans l’exploitation par chambres vides (open stope) il est primordial d’assurer un contrôle efficace des limites réelles des chantiers d’abattage. C’est pour cette raison que, de plus en plus souvent, les opérateurs miniers utilisent un dispositif de laser (Cavity Monitoring System: CMS) qui permet de mesurer les dimensions réelles de chantiers en vue de calculer principalement la dilution et les pertes du minerai ainsi que d’autres paramètres. Malheureusement, il n’existe présentement aucune méthodologie commune, qui permettrait d’interpréter ces résultats selon les mêmes critères pour faciliter d’évaluations juste et précise de la réalisation par rapport à la planification en vue d’en apporter de corrections, dans les différentes opérations minières, si nécessaire. Dans la première partie du présent article on discute les principales séquences d’exploitation utilisées dans l’extraction par chambres vides. Par la suite, à l’aide des sections transversales et longitudinales on illustre toutes les phases des travaux miniers. Ceci en vue de permettre au lecteur de comprendre mieux c’est qui peut se passer effectivement dans les chantiers d’abattage. Par après on donne les définitions générales de principaux facteurs de performance technique. Finalement, l’exemple numérique, élaboré à partir des résultats de l’arpentage au laser effectué par la mine Bousquet 2 dans un chantier d’abattage, donne les détails concernant les définitions ainsi que les valeurs de nombreux facteurs de performance technique, qui pourraient être utilisés, par après, par les opérateurs miniers dans le suivi de leurs exploitations souterraines."

Jan 1, 1997

By Xing-Liang Sun, Xian-Min Han, Zheng-Guo Zhu

The study on the material properties of frozen soils in China was being developed quickly in the past decades of years, because of the increase of the engineering constructed in frozen soil regions on the Qinghai–Tibet Plateau, and numerous research results were achieved mainly about strength and deformation behaviour and constitutive models of frozen soils. Studies have shown that the deformation procedure of frozen soils is irreversible; therefore, it is more appropriate to research mechanical properties of frozen soils by means of damage mechanics theory. In this paper, an elasto-viscoplastic anisotropic damage model is presented by introduction of Perzyna viscoplastic equation into analyzing the deformation of frozen soil. In addition, an anisotropic damage evolution equation is obtained by means of extending non-viscous damage to viscous damage. Triaxial tests at different strain rates are chosen to illustrate the application of this model, and good agreement between experimental data and numerically simulated results is obtained. The calculated results indicate that, under the same conditions, the damage at higher strain rate is less than that at low one. So the phenomena are explained from damage mechanics that the frozen soil has larger elastic modulus and shear strength at higher strain rates, and explained from mechanism that the emergence and development of micro-cracks in the body of frozen soil can be to some extent retarded at higher strain rates.

Jan 1, 2015

By C E. Gordon Brown

Aircraft utilization, weather and cost data are given for three separate projects north of the sixtieth parallel in the Northwest Territories and the Yukon Territory. These operations, carried out by helicopter-equipped geological and prospecting parties, have cost $24 to $30 per square mile, depending principally on the distance from the base. They provide adequate surface exploration of areas with 40 to 50 per cent rock outcrop. A good one-inch-to-one-mile geological map can be made. T HE exploration of the Canadian northland has been given increasing attention by the mining industry during recent years. In many cases, the initial problem is to make an adequate reconnaissance of a large area where existing geological information is meagre. The Geological Survey of Canada pioneered the use of helicopter-equipped geological parties for mapping at a scale of eight miles to the inch.

Jan 1, 1964

By H. W. Kasaini, E. Bourricaudy, T. Larochelle

Rare Element Resources Inc., a U.S. based company, has developed a three-stage process for producing a +98% mixed REO powder from hard rock feedstock (-48 mesh, 2.9-4.8% REO) consisting of bastnaesite and ancylite minerals. Firstly, the whole ore is digested in chloride media at low temperature in counter-current flow mode. Secondly, the rare earths (REEs) are selectively precipitated as oxalates directly from an impure pregnant leach solution (PLS). Finally, significant amounts of free acid and water are recovered from the REE-depleted filtrate and subsequently recycled within the process. Excess heat from the oxalate calcination process is captured and reused in the plant. Due to the low leach temperature (45 ºC) and moderate acid dosage (240-297 kg/t, HCl), rare earth oxides (REOs) are preferentially leached out of fine solids leaving most of the base metals (Ba, Fe, and Al ) in the residue. Selective recovery of REEs from the PLS is achieved by mixing dilute oxalic acid (33% H2C2O4) and PLS at elevated temperature (85-95 ºC). The REEs plus thorium are precipitated as oxalates (REE2 (C2O4).xH2O) while the base metals are left behind in the barren filtrate. Multiple batch and pilot test results have confirmed that 50-80% of the oxalic acid can be recovered from the REE-depleted PLS through low-temperature crystallization (10-15 ºC). Typical leach efficiencies of critical rare earths at 45 ºC range from 85-99% (average 93%) while oxalate precipitation at high temperature increases the crystal size of RE oxalates (>450 microns, d80) thereby improving filtration. The economic benefits of this process include elimination of flotation and magnetic separation Capex and driving hydrometallurgical Opex down to $6- 7/kg, REO produced. As part of a comprehensive risk mitigation strategy, Rare Element Resources Inc has operated multiple pilot plants at SGS in Lakefield, Ontario, Canada to optimize counter-current leaching (CCL), REE oxalate precipitation (OXP), and thorium removal circuits. This paper presents pilot testing data from CCL and REE OXP circuits.

Jan 1, 2016

By Frank W. Cole, Sharanjit S. Dhillonn

A new method has been developed for calculating flowing bottom hole pressure in a gas well, using as a basis the general energy equation. Fundamentally, the method shows that a plot of flowing pressure versus depth for a gas well can be represented as a series of incremental .straight lines, with the accuracy in-creasing as the number of increments increase. It is shown mathematically that for most cases the slope of the flowing pressure versus depth curve is essentially constant, in which case a single calculation based on surface conditions will yield acceptable results. In all cases studied no more than two iterations were required for very good accuracy, and in most cases only one iteration was necessary. Several example calculations are shown and the results are compared to other commonly used methods of calculating bottom hole pressures These examples show that the method provides answers which are at least as accurate as other methods usually used, and results in a considerable reduction in computation time.

Jan 1, 1960

By F. E. Senftle

Introduction The usual laboratory methods of uranium analysis are either tedious, time-consuming chemical procedures or elaborate physical methods requiring sensitive equipment. There is thus an urgent need for a method of estimating the uranium content of ore samples by approximate analysis in the field. When a new property is being developed, it is desirable to know, with the least possible delay, the uranium content of channel samples in order to guide the diamond drilling and digging operations. Prospectors, too, require approximate analyses of their hand specimens to evaluate their discoveries. To satisfy the demand for these types of analyses, several field procedures have been tried. Two general plans can be followed. One is fast but will yield only a rough estimate. The other is slightly longer but, if done carefully, will give an assay probably within 10 per cent of the true value. For field operation it is necessary to strip the more accurate laboratory methods of analysis of all refinements because of the limited equipment and skilled techniques at hand. Most of the corrections normally applied, with the exception of that for equilibrium, will not alter the gross analysis to any appreciable extent. When uranium atoms in pitchblende disintegrate, they break down into other radioactive elements, and eventually the number of elements being formed is equal to the number breaking down. The ore is then said to be in equilibrium. Certain geological processes, however, such as leaching, may selectively remove some of these elements and hence reduce the radioactivity of the ore sample. The ore is then said to be out of equilibrium. The field analysis may then be in error by as much as 50 per cent since the apparatus is calibrated with standards that are in equilibrium. However, such a large error due to loss of equilibrium is the exception, and in most cases uncorrected field types of analyr.is are justified.

Jan 1, 1949

By M Safa

Addressing deficiencies and defects that occur during construction projects is costly and time consuming. The manual quality assurance programs currently used in the industry have certain limitations, including human error and lack of consistency. Hence, there is a need for integrated electronic models that employ new technologies and methods. This research introduces an integrated construction quality control system that has the potential to improve quality management processes in the construction field for piping construction, which is a complex process often requiring rework. The proposed integrated system relies on data collected from construction sites using photogrammetry and laser scanning, which is then used to compare actual work performed to that designed. The proposed system aims to improve the promptness and accuracy of quality assurance processes, in particular dimension measurements, by avoiding human error and integrating defect detection and quality management. The use of this system has highlighted some of the limitations during data fusion and acquisition process, which are highlighted in this paper. These aspects must be considered to increase the reliability of the acquired information.

Aug 1, 2013