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By C. H. Bucknam

Net carbonate value (NCV) characterization methods for acid generation potential measurement originated from studies on the Carlin Trend during the 1990's and have been subsequently standardized through cooperation of the Acid Drainage Technology Initiative Metal Mining Sector and the American Society of Testing and Materials International. The paper describes the evolution and standardization of the NCV methods, the importance of mineralogy in interpreting the results and application of the methods to implementation of the Global Acid Rock Drainage (GARD) Guide.

Jan 1, 2011

By M. D. Vance, G. R. Corbett, S. D. Butt

Surface wave imaging is a relatively new seismic technique that generates subsurface depth images without having to drill boreholes into the ground, and is rapidly becoming a standard tool in non-destructive geotechnical characterization. This paper presents a case study of the application of these surface wave techniques to image shallow abandoned mine workings at the Montague Gold Mines district near Dartmouth, Nova Scotia. This district has numerous steeply dipping narrow vein workings from historical mining activity, and has actively subsiding and collapsing crown pillars. Due to the rugged conditions at the site and the relative narrowness of the openings (often less than 1 m), a surface seismic system was developed that had improved portability and lateral resolution over other available seismic imaging systems. Seismic surveys were conducted over two sites where independent evidence indicated the presence of shallow mine workings. At one site, a comparative gravity survey was also conducted. The seismic data was processed to generate velocity vs depth images. Overall, the velocity images show vertical zones of zero velocity in the same lateral positions where historical mapping, current subsidence and gravity surveys indicate the presence of steeply dipping workings. Further, the velocity sections are consistent with the thickness of the till cover at each site and the possible weakening of crown pillars at one of the sites.

Jan 1, 2005

By L. M. Scovell

The Internet and its related technologies will radically change the way that mines manage and control their maintenance, repair, and operating supply chains. The Internet is creating new distribution channels and offers new technology platforms with significant advantages over more traditional methods. Mines will have to re-evaluate both the strategies and the tactics employed in these areas. Mines will use e-commerce to integrate their maintenance, repair, and operating supply chains. The integration will extend beyond traditional trading partners to a worldwide network of communities with similar interests and goals. The changes will transform the way mines operate, lower mining costs, and thereby increase their chances of success in an increasingly competitive environment.

Jan 1, 2000

By L. Bryson, J. H. W. M. Brits, K. Voogt

"The Anglo American Platinum’s Rustenburg Base Metals Refinery (RBMR) has the world’s first full deposit nickel plating tankhouse. Impurities in the nickel electrolyte can induce stresses in the electrowon nickel deposits that could lead to delamination of the deposit. Identifying the impurities that contribute to increasing internal stresses in the nickel deposit is key to successful operation and automation of the tankhouse. Impurities were introduced in the plant electrolyte and the effects on the full-scale nickel deposits evaluated. The impurity-adjusted electrolyte solutions were also analyzed using commercially available bench-scale methods to determine the induced stress. A correlation between impurity-induced deposit stress and full-scale delamination was developed. A direct correlation can now be made between feed quality, i.e. impurity concentrations, and degree of delamination in the plant. This methodology has the potential to rapidly predict the effect of new reagents, upstream process upset conditions and synergistic interactions between impurities on deposit stress and delamination of nickel deposits.INTRODUCTION Nickel electrowinning in sulphate media was first pioneered by Outokumpu in its Harjavalta refinery in 1960 (Saarinen and Seilo, 1985). The original process was very manual with starter sheets plated onto “acid resistant” steel for 36 hours and then manually stripped and cut into sheets which could be inserted into the main production cells for a further 4–5 days. The starter sheet stripping and manufacture process was later automated. The same technology was subsequently implemented on a number of plants around the world. Anglo American Platinum’s Base Metal Refinery (BMR) began nickel electrowinning in the early 1980’s. The recent expansion of Anglo American Platinum’s Base Metals Refinery necessitated the construction of a new nickel tankhouse to achieve two primary objectives. The first to increase the capacity to 32 400 tpa nickel and the second to reduce employee occupational exposure to nickel aerosols. The new tankhouse has been commissioned and is in the process of ramp-up; more details are given by Hagemann et al. (2016). Fundamental to lowering employee exposure to aerosols was automating both harvesting and final handling of cathode. In order to accomplish this a bold move was taken to plate up to 10 days on permanent titanium blanks which are harvested by automatic crane and automatically stripped. The original development work for the plating nickel on titanium blanks over a ten day cycle is given by Bryson et al. (2006)."

Jan 1, 2017

By L. Callele, C. DiGiovanni, L. Li, R. Driver

"Hot-dip galvanizing is a common procedure used to protect structural steels from corrosive environments. However, in a construction project involving welded structural steel platforms by a Canadian steel structures company, numerous connections were found with large cracks in the welded corner joints and T-joints after galvanizing. Historically, in other similar projects by the same industry partner, cracking did not occur making this an unforeseen and new phenomenon. The project explored the mechanical properties of the base material, the thermal stresses induced by the hot-dip galvanizing, and the fracture surface of the cracks. A key feature to note, the fracture surface showed intergranular cracking with no plastic deformation. Lab testing showed the base material exhibited intergranular brittle behavior when heated and fractured at the galvanizing temperature. The transition to a brittle fracture mode is due to temper embrittlement and the segregation of elements in the grain boundaries.INTRODUCTION Galvanization is a common practice for protecting steel structures from the corrosive environment. Hot-dip galvanizing is the most common approach to bonding the zinc layer to the steel, and it is highly cost effective. In the case of welded structures, it is common to do the hot-dip galvanizing process after welding. This is so the protective layer can be applied to the structure as a whole and over the welds. In a recent construction project carried out in industry, a steel frame platform structure measuring approximately 3 m x 7 m was galvanized after welding fabrication. The structure was built of CSA G40.21 350W and CSA G40.20/G40.21 300W plain carbon steels and welded using a metal core arc welding process for the flanges and a flux core arc welding process for the webs of the beams. Due to their size, the platforms underwent a double-dip galvanizing process meaning half of the structures were submerged in the molten zinc path while the other half was exposed to the ambient air. This was repeated for the remaining side. Shortly after the galvanizing process was completed, numerous large cracks were found in the welded joints. Given there was no history of weld cracks after galvanizing in previous similar frames that were double dipped, this failure posed a new and curious problem."

Jan 1, 2017

By J. E. Carrasco, J. D. Stinnette, R. A. Alvarez

"Chuquicamata Underground Mine is one of the main projects for the Chilean government copper company (CODELCO). Underground mine project has been under construction since 2013 and presents a solution for the lower production levels of the open pit and prolongs the life of the mine for the next 40 years. Currently, around 2000 workers operate in the mine daily. Dozens of trucks and heavy machines drives through all main routes and access in the mine. As a mine under construction not all the infrastructure necessary to operate safely in the mine has been completed. Risk of a truck or fixed facility fire is always a challenge to keep under control. One important part of fire simulation relays on what we can do prevent a fire and what can be done with the existing infrastructure to control a declared fire and start evacuation plans. This study has been made as a feasible emergency plan to implement, in this case, of a mine under construction, were limited resources are available. Several fire scenarios have been made to support all the emergency plan strategy and a detailed step by step procedure indicates what the elements of a fire emergency plan and risk analysis are.INTRODUCTIONThe main objective of this study is to describe the importance of fire risk analyses (FRAs) and different methods to be used before commencing fire simulation and methodology steps utilized for a fire emergency plan strategy (EPS) at the Chuquicamata underground mine. It also describes how to classify zones which are going to be affected by fumes and gases propagation derived from the exact location of a fire event. Fire simulation study is helpful to determine the impact on a ventilation system with the main purpose of providing relevant information to complement emergency plans and stablished control techniques in ventilation design and its operation. Most fire simulation studies only concentrates in simulation techniques on itself. But what is the next following step in developing an emergency plan? How can we evaluate, classify and treat risky areas? This study is focused mainly in the phases before and after a fire simulation process. Phases corresponds to a good FRA and how output data can be used for an EPS."

Jan 1, 2019

By T. Gerritsen, R. MacRosty, R. Pula, P. Gebski, W. L. Ying

Furnace run-outs can cause extended furnace downtime for repair, while leaks or more severe failures in the cooling system can lead to brick hydration or in severe cases, steam explosions. These incidents can result in lost production, damage to equipment, injuries and casualties. To prevent such incidents, reliable and accurate techniques to monitor the critical components of the furnace such as refractory lining, furnace structure, taphole integrity and main water circuits are required. This paper describes several advanced methods that have been developed to assess the condition of furnace integrity, refractory lining, tapholes and cooling water circuits.

Jan 1, 2015

By J. A. Vonhof, R. O. van Everdingen

Since 1949, a total of 59 disposal wells have been installed in Canada to inject liquid wastes from refineries, mining operations and chemical plants into subsurface formations at an ever-increasing rate. Well depths range from around 600 feet to almost 5,500 feet; injection rates range from 0.5 (U.S.) gpm to more than 1,000 gpm for individual wells; wellhead injection pressures range from a slight vacuum to over 500 psi. Apart from strictly technical considerations of well design, the geological, hydrodynamic and hydrochemical conditions at the disposal site have a strong bearing on the safety and success of such operations. Prevailing hydrogeological conditions in large portions of the country do not allow safe subsurface disposal.

Jan 1, 1973

By W. N. Roman

This paper will examine the challenges involved in ventilating and cooling South African mines, with particular emphasis on solutions to the issues of heat (generally associated with depth), mechanization and energy efficiency. Comparisons will be made with other international mining areas. Some of the deepest mines in the world are to be found in the South African goldfields. The Mponeng mine is approaching 4,000 m below surface, with virgin rock temperatures (VRT) of between 60°C and 70°C. Mining at these depths has only been possible with the use of large refrigeration plants supplying cold air, water and ice to the workings. In the Bushveld Igneous Complex, where most of South Africa?s platinum mines are located, similar VRTs are being experienced at significantly shallower depths. This is due to the different geothermal properties of the host rock between the two areas. Existing mines are being forced to go deeper and new underground mines are being planned and constructed in other areas with widely differing thermal conditions. South African metal mining has traditionally been labour intensive for historical reasons as well as for the narrow tabular nature of many ore bodies. Due to cost pressures and labour problems, some mines have been investigating the possibility of using mechanized equipment, both diesel and electric, to increase production and to improve efficiency. Studies have been carried out to determine the effect of the additional equipment on the overall ventilation system and some of the conclusions are discussed. The use of diesel equipment adds heat and pollutants to the ventilation air but, although electrical equipment has a lesser effect on the ventilation systems, it is generally less favoured due to claims of lower flexibility/manoeuvrability. Mechanization holds the promise of more concentrated mining activities but, with higher localized ventilation and cooling needs. Systems which will control the provision of air and cooling more effectively are required and are being implemented. In the 1990s and early 2000s, the South African economy experienced significant growth which was not matched by the growth in infrastructure. Consequently, at present there is a shortage of electricity generation capacity which affects large industrial consumers, including mines. Increasing levels of heat and mechanization will require more electrical energy for ventilation and cooling. There are many initiatives underway to save power or to shift consumption to periods of national low demand and these will be described.

Aug 1, 2013

By John D. Galloway

Mining is one of the important primary industries of Canada, with a gross production in 1927 estimated at $241,773,000- the highest in the history of the country-and an impressive dividend record. It is quite apparent, therefore, that mining is a business worthy of the careful attention of the people of Canada. Furthermore, with a vast undeveloped territory more or less mineralized, it is highly probable that our mining industry will continue to expand indefinitely, with a consequent increase in production and in the amounts of the yearly profits distributed. In recent years, the public has taken a larger interest than formerly in mining-an interest, moreover, that is not academic, but primarily from the viewpoint of profits. It is quite evident that mining is a profitable business, at least to some, and the average man on the street, hearing of these profits, is attracted thereto. I have no doubt that many of you have .read in promotion prospectuses, with figures to prove it, that mining is the most conservative, the safest, and the highest-yielding business in the world. Now, a lot of this information is best judged by the old saying that "While figures don't lie, liars figure". At the same time, mining, properly conducted, is a profitable business, even though speculative, and undoubtedly much profit will come from Canadian mines in the future. In this paper my conclusions regarding mining investments are based largely on British Columbia experience, together with some slight knowledge of mining conditions in the other Provinces. It is considered, however, that the inferences drawn are applicable to mining throughout Canada.

Jan 1, 1928

By L. H. Thorleifson

Demand for both gem and industrial diamonds is very strong. Synthetic production supplies industrial uses, but synthetic gems remain inferior and expensive, so the large gem market is supplied by mining. Several major mines have been depleted, and the market is receptive to new sources of high quality gems. Canada's Precambrian terrane, extending across the Canadian Shield and under the Phanerozoic cover of the Plains and Hudson Bay, has excellent potential for diamonds, but exploration conditions are difficult due to recent glaciation. Early world exploration relying on recognition of diamond in alluvial sediments was adequate to launch pre-1900 production from India, Brazil, and Africa. Exploration success in Canada, as was the case in Russia and other more recently discovered sources, however, had to await large investments in effort supported by advanced science and technology. Canadian exploration in many ways is similar to that in other regions, relying on analysis of tectonics, indicator minerals, geophysical surveys, and multiple stages of drilling and sampling. Very different from other regions, however, is Canada's surficial environment, in which recent glaciation has caused fresh indicator minerals to be transported hundreds of km. Exploration accelerated in Canada after 1960, first in Ontario and the Arctic Islands, then in Saskatchewan in 1988, and most importantly after the Chuck Fipke - Stew Blusson discovery at Lac de Gras, Northwest Territories, in 1991 that led to the billion-dollar BHP - Dia Met Ekati Mine that opened in 1998. In 2003, production from Ekati is expected to be supplemented by that from the similar and nearby Diavik Mine of Rio Tinto and Aber, currently under construction. These mines will bring Canadian output to over 10% of world supply, and will position Canada with Botswana and Russia as world leaders in production of high quality gem diamonds. There could be other mines as well, as sites across the Arctic and in the south from Alberta to Québec are being explored by an array of companies, including De Beers, other majors, and several juniors.

May 1, 2001

By Zihe Ren, Edouard Asselin, Marcus Tomlinson, Tianbi Zhang, Jing Liu

"Raman spectroscopy is used to quantify the extent of disorder in the carbonaceous matter associated with preg-robbing ores. Previous studies of Goldstrike ores showed that the height and width of the peaks for the “D” (disordered) and “G” (graphite) bands, the so-called “Raman ratio” had a strong correlation to the preg-robbing value (PRV) measured for various ore samples. A brief literature review on Raman spectroscopy as it applies to preg-robbing ores is presented. Further, recent studies, presented here, have shown no correlation between the Raman ratio and the PRV for a wide variety of ores. This suggests that the extent of organic carbon crystal disorder is not the main factor in determining preg-robbing characteristics.INTRODUCTION Preg-robbing may arise from natural carbonaceous materials in the ore. Several mechanisms have been proposed in the past decades including a physical sorption process by the carbonaceous matter, or via the reduction of aurocyanide at the mineral surface (Abotsi & Osseoasare, 1986; Afenya, Osseoasare, & Abotsi, 1983; Tan, Feng, Lukey, & Van Deventer, 2005). Nevertheless, the mechanisms of preg-robbing remain poorly understood. Understanding the nature of the preg-robber is of practical importance for the selection of a suitable treatment process. Fine carbon particles in the ore have been recognized as preg-robbers due to their similarity to the activated carbon used in the carbon in leach (CIL) or carbon in pulp (CIP) processes. Previous research has illustrated that the activated carbon (also referred to as amorphous carbon in some literature) has a much higher absorption ability than pure graphite with high crystallinity (Adams & Burger, 1998). Adams et al (Adams, Swaney, Friedl & Wagner 1996) concluded that carbonaceous matter is largely responsible for the overall preg-robbing capacity of a given ore. However, the mechanism of carbon preg-robbing was still not clear mostly due to the complexity of amorphous carbon and its behavior in different solution matrices, and at different pH and temperature (Adams, 1990, 1993)."

Jan 1, 2017

By George R. Pratt

Although the title of this paper focuses attention to the Winnipeg coal market the following remarks should be considered applicable not only to conditions in Winnipeg but to the whole western coal industry. Technical descriptions of coal and coal-burning have been omitted. These details are already covered in other numerous publications. In discussing a market the first consideration must be the product which is required to be sold. The class, quality and price at the point of origin must be taken into account and therefore this feature will be discussed before proceeding to outline conditions in the Winnipeg local market. The writer thinks of coal as a manufactured article, not, as it is generally considered, a fuel to be dug from the ground and dumped into the consumer's bin. The work of manufacturing must be considered in detail:- 1. Consider first the coal as it is in the ground: (a) What is its fuel value? (b) Where is its market? © With what will it be in competition? 2. Consider secondly: (a) What it will cost to mine the coal. (b) What has to be done to prepare the coal for market after it is mined. This must be considered in conjunction with the answer to question 1 ©. 3. Thirdly, consider the method of business to be adopted by the producer:- (a) Is it proposed to build a market on price? Or (b) On quality?

Jan 1, 1925

By D. N. Madge

The use and development of industrial process control computers in the mineral industry during the 1970's has been sluggish. This cautious approach is due to lack of commitment by senior management. The lack of commitment is due to several reasons: variable mineral processes and technologies, market fluctuations, and excessive costs and inadequacies of applicable products supplied by computer vendors.

Jan 1, 1979

By Amir Karami, Derek Kinakin, Catherine Schmid

The Mathews Stability Graph Method (Mathews et al., 1981) has been used by geotechnical engineers and mining engineers for over 40 years to estimate the performance of longhole open stopes in underground mines. The method is widely used and accepted by practitioners because it is relatively simple to use and can be modified to account for observed performance at a given mining operation. While the simplicity of the method increases its accessibility and utilization, it does not intrinsically account for variability in the various inputs, including rockmass quality, structure, stress, or stope orientation. This paper presents a modified approach for the Stability Graph Method, whereby Python scripts are used to process available geotechnical datasets and combine them with actual or potential distributions of Q parameters, induced stress, structure, or stope orientation. The resulting Stability Numbers are then plotted as a contoured distribution on the Stability Graph.  This allows the practitioner to quickly incorporate large datasets into the analyses, while also developing an understanding of how variability in rockmass quality, induced stress, structure, or stope orientation could affect stope stability.  This paper presents the fundamental principles of the Stability Graph method, the Python script and workflow, and two case studies to demonstrate the utility of the tool.

Oct 1, 2024

By R. A. Ford

The paper outlines: methods used for the determination of wear metals in motor and transmission oils; contaminents in motor, transmission and crusher lubricating oils; and viscosity determinations. Case histories and costs are presented to illustrate the value of an oil analysis program. Introduction NORANDA MINES LIMITED (BELL COPPER DIVISION) is located on the shores of Babine Lake, approximately 450 miles north of Vancouver, British Columbia. Access to the mine is by road from Topley, B.C., about 40 miles away. When a preventive maintenance analysis program was first considered, it was obvious that if samples were to be sent out for analysis, results would not be available for at least a week, due to the distance from any commercial laboratory. The assay laboratory was asked to investigate the possibility of determining wear metals on site. A limited program was started soon after production commenced, and this has now grown to include all large mobile equipment as well as crushers and grinding mills. The laboratory also now determines viscosity, fuel dilution, dirt and abrasives, glycol and water. All these results are ready within two days. This paper will outline the methods used, data interpretation, several case histories and the benefits from such a program.

Jan 1, 1977

By D. S. Evans

Major Project Blues Over the last two decades, almost every major project has suffered significant cost overruns, significant schedule delays, and/or poor quality work. Exceptions are rare and most projects that tout being ?On Time and Under Budget? have re-cast schedules, significantly modified scope or revised base estimates. The problem isn?t new. In the late 1980?s the Rand Corporation published a study showing that 80% of all major projects had significant cost and schedule overruns. The problem is not restricted to the Canadian environment, or to a specific industry. It is a global problem.

May 1, 2013

By D. F. Zhang, X. Q. Jiang, N. Tahreen, D. L. Chen, F. S. Pan, D. Y. Li

Alloying with rare-earth elements has been proven to be an important tool for magnesium to achieve superior properties via texture randomization. The role of yttrium in texture weakening and the link between texture and formability are fairly well known. Since annealing is a vital part of metal processing which could significantly contribute to ductility, it is important to ascertain the impact of annealing in terms of texture change. Also, an understanding about texture development during pre- and post-deformation annealing is essential to improve the industrial deformation processing as texture is closely related to formability. While there is independent information in the literature regarding the effect of rare-earth addition and heat treatment on the texture formation, no systematic studies have been reported on the collective impact of yttrium addition, annealing and deformation on texture evolution. The present study was, therefore, aimed to identify the inter-relationship among texture evolution, yttrium content, heat treatment and deformation behavior in an extruded Mg-Zn-Mn-Y alloy. Annealing at 450°C for 1 hour and uniaxial compression tests at a certain amount of deformation were performed. The deformed and annealed samples were then subjected to annealing and compression test, respectively, followed by texture measurements. It was observed that yttrium addition effectively weakened the crystallographic texture in all conditions, which was evident from the changes in the microstructures and textures.

Jan 1, 2015

By S. E. Malouf, W. Thorpe

"The Chibougamau Explorers property comprises 35 claims or 1,726 acres in La Dauversiere and Rohault Townships along the west shore of Norhart Lake. The property is serviced by a twelve-mile all-weather high-way leaving the main St. Felicien-Chibougamau highway at mileage 121. This road junction will be a railway siding on the C.N.R. St. Felicien-Chibougamau branch line in early 1957. The property lies 30 miles due south from the town of Chibougamau. The mine-sponsored Chibougamau Explorers town has a population of 250 with 28 residences and a well equipped recreation centre.The original showing was found by Rider Storn, a prospector financed by Val d'Or interests during the 1950 field season. This showing did not stand up to detailed prospecting but it did lead to the discovery of the main zone by A. Oakley during the following winter.The company was incorporated in I 950 under the presidency of E. Ayrhart. Financing following the initial drilling involved an increase of capitalization from 3 to 5 million shares and the advent of financing and management control by Anacon Lead Mines Limited.Exploration and development to Jan. I, 1956, has included 42,331 feet of surface diamond drilling; 31,363 feet of underground drilling; a 3-compartment shaft to 1,245 feet, with 8 levels at 150-foot intervals; and I 1,054 feet of drifts, crosscuts, and raises. Ore reserves to the 900-foot level, proven and partly developed, total 546,725 tons averaging 0·30 ounces gold and 0·93 per cent copper. A mill with capacity of 500 to 750 tons will be installed by January 1956.GeologyThe Chibougamau Explorers property lies along the belt of Keewatin volcanics striking through Bachelor Lake, Opawica Lake, Doda Lake, Coapatina, Norhart Lake, and Rohault Lake, where it is in close proximity to the paragneisses of the Grenville series. The boundary of the paragneisses, a gradational contact, lies within a mile of the Chibougamau Explorers shaft collar."

Jan 1, 1949

By Rakesh Kumar, Rajabrahma K., A. K. Verma, V. Mukesh

"In this study, laboratory investigation as well as numerical investigation is carried out to ascertain the transition from one mode to another for Semi-circular bend setup. Laboratory investigation is carried by varying the span length (s/2R); crack length (a/R); notch angle (a); and notch thickness (t). The specimen consists of cement, sand and water mixture in a ratio of 1:1:0.5 by weight and are prepared as per the ISRM standards (2014). Tests are conducted by a servo controlled universal testing machine at a strain rate of 0.2 mm/ min. The results are collected in terms of failure load, crack mouth opening displacement (CMOD) and images of crack initiation and propagation.Image analysis of laboratory tested samples shows that crack initiates at the notch tip when the notch inclination angle is 0°. As the notch angle increases (i.e. 30° and 60°) the fracture begins to initiate behind the notch tip. The direction of crack propagation in front and back side of the sample is same for notch inclination angle is 0° whereas it differs more and more as crack inclination increases. The transition represents the change in mode of failure from mode I (0°), mode II (30°) and mixed mode I/II fracture (60°).Finite element method used to find the transition based on MTS failure criterion. The inclination of notch is varied like 40, 42, 44, 45, and 50 deg and FEM analysis shows that the transition from mode-I to Mode-II take place at 49 deg. The same procedure can be extended to find the transition from mode-II to mode-III."

Jan 1, 2015