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By I. O. Ojala

Detailed knowledge of velocity-depth trends is essential for constructing well-to seismic ties, determining background velocity and generating synthetic seismic traces for interpreting seismic amplitudes in terms of porosity, lithology and pore fluid type. The acoustic properties of shales are of particular importance in the exploration setting as shales constitute more than 80% of sediments and rocks in siliclastic environments. Seismic and sonic log data may be used for estimating overpressure in shales in order to maintain borehole stability during drilling. In addition, velocities in shales can be used for predicting its mechanical properties and hence, borehole collapse. Despite of the apparent importance of understanding shale acoustics, sonic logs in shales are frequently unavailable or unreliable especially for older wells. Hence, it is essential to compute pseudo-velocity logs from other available information. This can be accomplished by using empirical relationships or rock physics transforms. In this study we have compared the predictive power of resistivity (Faust 1951, Hubert 2008) and porosity based models (Wyllie 1956, Holt & Fjær 2003) for computing synthetic P-wave velocity logs using wireline log data from mudstone intervals at three North Sea wells. The wells 6507/2-1, 6507/2-2 and 6507/2-1 are located at the Haltenbanken area at the Norwegian Sea. The wells targeted hydrocarbon potential at the upper Cretaceous and lower Tertiary sandstone sequences. The sandstone beds are overlain by thick Tertiary and Cretaceous sequences of mudstones. Since our primary goal is to model acoustic velocities in shale, we used wireline data from the Nordland (NL), Rogaland (RL) and Hordaland (HL) groups that are mainly composed of mudstone. The mudstone beds were identified from the well log data by using natural gamma log, sonic and resistivity data as well as information from the Norwegian Petroleum Directorate website. The volume of shale was estimated from the natural gamma log and the data points with values higher than 0.65 were discarded. Similarly, the data points with shale volume less than 40 % were discarded. Furthermore, exceptionally high resistivity values amounting to more than 6 Ohm m were not included in the analysis. Porosities were determined from the density log assuming 2.7 and 1.05 g/cm3 for matrix and fluid densities, respectively. The depth that was used for calculating Vp from Faust (1953) was the depth below mudline in order to the compare of well data from wells that have been drilled at different depths (Hubert 2008).

May 1, 2009

By Sir Stopford Brunton

Gold was first found in Nova Scotia about 1830-40, but its significance at that time was not appreciated. Probably the first discovery that resulted in any work was made by Lieut. C. !'Estrange, at Mooseland, on the Tangier river, in 1858.1 Since that time gold has been mined with varying success until now, and from 1868 onwards work has never altogether ceased. Gold mining in Nova Scotia is at the moment under a cloud, and the idea generally accepted by most people is that it has failed in the past, and that there is no prospect for it in the future. The actual reasons for the present situation have never been carefully analysed, and it seems a good thing to see what really is the state of the case and whether or not this general idea is worthy of credence. It is the purpose of the present paper to analyse the situation in the light of present knowledge, and to set forth some data which may assist in the future development of the Province.

Jan 1, 1926

By Nicolae Dobritoiu

The literature in this field and the practical activity record that a method, respectively the technology used for an underground mining work have many components which, in order to be applied, demand that for each of the parameters that describe the environment of the mining work and that influence the chosing of that method and that technology of execution, must have values in an interval well determined. There are situations when one or many parameters of the set of parameters that describe the environment of the mining work, can modify its values, and, as a result, one or more components of the methods or technology cannot be applied anymore, making necessary a replacement of their values. The information offered by this graphical-analytical model allow the determination of optimum solutions for the process of digging of the underground mining work and thus it will result the incresing of the technical-economical efficiency of the digging process and, also the increasing of the quality of the underground mining work.

Oct 1, 2009

By Gerald Whittle

What is Enterprise Optimization? Releasing value through better planning decisions: Philosophy, Methodology, Software The key to 5% -35% increase in enterprise value (NPV) The culmination of 25 years development in optimization for the mining industry ?Jeff Whittle Simultaneously optimizing: ?all steps in the value chain ?all assets in the enterprise portfolio ?all periods together

May 1, 2010

By H. F. Zurbrigg

Introdduction The main line of ascent in the development of the nickel industry may be traced back through the International Nickel Company of Canada, Limited, to its earliest antecedents, the Canadian Copper Company and the Orford Copper Company. Mining geology is but one aspect of the overall development of this organization, and the stress it has placed on geology grew according to the need. In the early days, intensive geology was not required because ore supply was not one of the main problems of this or any of the pioneer companies. The difficulty then was to find economic methods for reducing the ores to nickel and copper, and markets for absorbing nickel in the face of a limited demand from consumers heavily prejudiced in favour of the New Caledonia product. "Very early in the history of the region it was patent to everyone that to share in the full benefits of the industry the same individuals or company must control the whole of the operation necessary to manufacture the finished product' (1, p. 45). These conditions were fulfilled for the International Nickel Company in 1902 when the Canadian Copper Company (incorporated 1886), with its ample ore supply, took the initiative to merge its interests with those of the Orford Copper (Refining) Company (incorporated 1887) to form the new company which, with reorganizational changes, emerged as the producer of the overwhelming bulk of the world's nickel. The Mond Nickel Company, Limited, entered the field in 1899 with a refining process, and over a period of years acquired ore through purchase of mining properties. This Company operated successfully and independently until 1929 when its assets were joined with those of the International Nickel Company in order to permit the most economic exploitation of the Frood-Stobie orebody in which both Companies were interested.

Jan 1, 1948

By \/eena Sahajwalla, Jonathan Dicker, Paul O'Kane, Cath Skidmore, James Dankwah, Magdalena Zaharia, Rita Khanna, David Knights, N Saha-Chaudhury, Somyote Kongkarat

Due to the inherent limitations of current methods of disposal of end of life polymeric materials, avenues are researched towards developing alternative, environmentally friendly and economic recycling processes. Different polymeric materials (i.e. rubber, high density polyethylene (HDPE) and polyethylene therephtalate (PET)), quite distinct in terms of chemical structure and composition, were considered in the present study as carbon resources in EAF steelmaking. Investigations were conducted in both laboratory and industrial scale steelmaking to assess the effectiveness of using these materials as carbon sources for slag foaming in EAF steelmaking. Slag foaming is important because it enhances furnace efficiency.

Jan 1, 2011

By W. J. Witte, M. K. Witte

"The purpose of this report is to present a generalized preliminary design and cost estimates for a typical heap leach operation such as might be undertaken in Northern Ontario. This report should be of value to anyone in the mining industry planning, or contemplating, a heap leaching operation in Ontario, either on a large or small scale. While more detailed costing and design work will obviously be required for each specific project being contemplated, the data provided in this report should enable parties to make preliminary estimates of the costs of proposed projects and should identify most of the planning and design parameters that will need to be considered.Although heap leaching has been used extensively as a low cost gold recovery method in other parts of the world for many years, it has only recently become of interest to the Canadian mining industry.In order to investigate and demonstrate the feasibility of using heap leaching in Ontario, the Ontario Ministry of Natural Resources in 1982, undertook to locate a private sector proponent willing to undertake a 10,000 ton demonstration project. This project was to have been carried out at a production scale under normal northern Ontario field conditions. The Ministry was to have provided technical management and design for the designated project."

Jan 1, 1985

By Dave Stefanuto

Voisey?s Bay Project Components ? Mine/Mill Port In Labrador ? Mini Plant in Mississauga ? Demonstration Plant in Argentia ? Supply Vessel (Umiak1) ? Transshipment Facility (Quebec) ? Concentrate Handling & Transport to Sudbury/Thompson ? Cobalt Refinery Upgrade (Thompson) Project Setting ? The Project is on the traditional lands of the Labrador Inuit and the Labrador Innu ? Canadian courts have held that Aboriginal peoples in Canada possess special rights to traditional Aboriginal lands Those rights can include requiring resource developers to enter into Impacts and Benefits Agreements (IBAs) on traditional lands to set forth how lands can be used and benefits to be received by Aboriginal people

May 1, 2006

By J. H. McKibbon

THE metallurgical industry has purchased more than sixty per cent of the industrial gas cleaning equipment installed in Canada. This includes cyclonic collectors, scrubbers, cloth filters and Cottrell Precipitators. These are the principal types of equipment which are used commercially for the cleaning of gases which result from the processing of iron, nickel, copper, lead, zinc, gold, gypsum and aluminum ores. The recovered dust, which usually contains metal values, is returned to the process. The cost of the equipment is thus economically justified. This is in contrast to other industries, such as those involving steam power generation, asbestos, cement and lime production, where, though dust collection equipment is extensively used, it is installed primarily for nuisance abatement. Communities are becoming more and more conscious of air pollution, new and more stringent legislation is being enacted, and, for other than economic reasons the smelting industry will eventually be required to install more efficient gas cleaning equipment. This paper

Jan 1, 1962

By J. A. López-Molina, S. García, V. Castellanos-Pedroza

"Grouting aims to reduce the permeability of rock mass below a predetermined value and has been widely used in rock engineering field for a long time. However, the injection procedure needs several empirical decision makings and it is rather difficult to reliably confirm the achievement of improvement, because the grout penetration process is not sufficiently clarified. This investigation proposes a neuronal method of defining spatial distribution of rock hydraulic properties and a fuzzy scheme for estimating their relation with the grout penetration (consumption, localization and filling material). The intelligent method stands as a tool for helping in harmonizing the sealing activities and the medium conditions. The virtual simulation of grouting strategies embraces geology, hydraulic and rock characteristics and the filling process. Important aspects as different pressure injection levels and fracturing systems can be holistically studied using the intelligent environment, resulting in an advantageous, economic, flexible and interactive tool for planning better this critical activity.INTRODUCTION Grouting is a very common method of sealing rock and repairing concrete structures (Butron et al., 2010) and its use in engineering of dam-foundation and tunneling has been documented as very successful (Yang, 2004). Generally speaking, to achieve the closing purpose, boreholes are drilled into the rock mass and grout is injected (under pre-selected pressure) until the fractures around the borehole are filled. The complete filling of these fractures is possible if they are connected to each other in such a way that the remaining water and air can be displaced outside the designed grouting zone (Houlsby, 1990; Kutzner, 1996). Water testing is necessary for evaluating seepage potential and for determining whether grouting is necessary or practical. Regardless of the main reason for the investigations, design of a program for water testing for grouting should consider the type of structure to be built, the geologic conditions at the site and the level of seepage control desired. As information gathered the report must content the fracture openness, number and connectivity, exploratory drill holes orientations, materials situation and a panorama of rock-mass state (quality)."

Jan 1, 2015

By R. E. Barbosa

Seepage forces generated during tunnel excavation affect the ground response and may cause severe instability problems, including total ground collapse and flooding into the tunnel. This paper presents a new closed-form analytical solution, for stresses and displacements around a cylindrical tunnel excavated in a porous water-bearing elasto-plastic material, which includes the effects of seepage forces. The analysis is carried out in terms of effective stresses and pore water pressures. The solution shows that seepage forces may have a major effect on the effective stresses around the tunnel, on the extent of the plastic zone, on the radial displacements, and on the tunnel support requirements. The conditions for development of a ?flowing ground? condition at the tunnel face have been identified. The paper presents a procedure for the hydromechanical ground-support interaction analysis, to determine the excavation induced inflow and the pressures acting on the lining, throughout the progressive driving of the tunnel, including the effective pressures exerted by the ground and the pressures generated by the water.

May 1, 2009

By H. J. McQueen

Friction stir welding (FSW) generates complex microstructures in the nugget and thermomechamically affected zones (TMAZ) that have led to diverse explanations. However, consideration as an extension of microstructure development in piercing/extrusion can lead to a better understanding of flow patterns and microstructures during FSW. Furthermore, the intense strains in the nugget/TMAZ can be interpreted by comparison with ultra-high strains in torsion that exhibit dynamic recovery as extending into regions with high angle boundaries strongly serrated with spacing near the subgrain size defined by the high temperature. The subgrain diameter and extrusion pressure have been shown to be dependent on the Zener-Hollomon parameter Z (=t exp(Q/RT), Q activation energy, R gas constant) combining temperature T and strain rate E in the same mariner as for torsion and compression. Moreover, such tests exhibited steady state stress os above a certain strain Es (rising as Z increases) in which T, , subgrain diameter and dislocation spacing remain constant. Due to the subgrain boundaries (SGB, low angle <5°, i.e.,LAB), continually rearranging by migration, decomposition and reformation, the subgrains remain equiaxed in elongating grains, whose boundaries (GB) become serrated as they migrate to absorb SGB. As confirmed by straining in torsion at constant T and Z. , more subgrains bordering the greater GB area have several high-angle facets (HAB) ; these small cellular regions with a mixture of HAB and LAB facets are designated HAB-subgrains. As serrations in neighboring grain boundaries impinge, the grains pinch off becoming shorter; this occurs at higher strains as subgrain size decreases with rising Z. The pinching-off makes the neighbors thicker so the grains never become thinner than about two subgrain diameters. In conjunction with such geometric dynamic recrystallization (gDRX), GB&apos;s undergo a net migration into grains with denser substructure, enlarging those with larger subgrains. Consequently a better name has been proposed: grain dimensioning dynamic recovery (gDRV).

Jan 1, 2007

By Mohamed Ourriban, Stéphanie Somot, Éric Proulx, Jean-Sébastien Marois, Marjolaine Drouin, Paul Blatter, Ahmed Bouajila, Claude Gagnon

"The mining industry has to face increasing restrictions concerning the use of fresh water in Québec and throughout the world. Increasing recirculated water usage could lead to a better control of the quality and the quantity of water supplied to the mineral processing units. Furthermore, it could reduce the volume of waste water to be managed and treated before its release to the environment. However, process water may have a negative impact on mineral processing operations, thereby limiting the incentive for sustainable development initiatives. As a first step into selecting and testing remediation strategies, one of which being blending local waters, a mapping of process water quality (inorganic and organic fractions) allowed to locate zones in an industrial case study where fresh water is introduced into the circuit and to detect dissolution and precipitation zones. A complementary hydro-geochemical modeling study on water blends was also performed showing encouraging results towards the objectives of the project.INTRODUCTION The industry has to face increasing restrictions on the use of fresh water in Québec (Quebec Government, 2009) and throughout the world (Brown, 2003; UNESCO, 2006). The cost for the use of fresh water and for water management is highly variable and case-dependent (from 0.2 to up to 7 million dollars/year according to available private estimations, excluding the capital expenditure). It may be, or may become, significant for any plant; thus, risk assessment is of concern here. Using recirculated water could lead to a better control of the quality and the quantity of water supplied to the mineral processing units. Furthermore, it could reduce the volume of waste water to be managed and treated before its release to the environment. However, process water may have some positive and negative impacts on mineral processing operations (Janssen, 2003; Johnson, 2003; Rao and Finch, 1989). Negative impacts could limit the incentive for sustainable development initiatives. Water management strategies at mineral processing sites are supported both by a strategic plan and a water management plan. The strategic plan includes legal aspects, investment costs, potential benefits and various risk levels (Corder and Moran, 2006; Côte et al, 2006; Evans et al., 2006; MacIntosh and Merritt, 2003; McLellan et al., 2008; Merritt and MacIntosh, 2006; Robinson and Keddie, 2006; van Beers et al., 2007a; van Beers et al., 2007b; van Berkel, 2007). In practice, the strategic plan evaluates technical possibilities and costs of various scenarios, such as for example: bringing fresh water to the plant or recirculating waters, or using blends of both. Two important factors to consider in order to enhance the future production efficiency and to minimise risks are: the durability and the stability of the resource, both from quality and quantity points of view."

Jan 1, 2012

By L. Telfer

Summary During Palaeozoic time, there were deposited in the Canadian Rockies four beds of phosphate rock, ranging in age from Mississippian to Jurassic. Two of these beds are of probable economic importance if some means of separating the phosphate from the gangue can be devised. All the more important beds of phosphate rock so far discovered are just behind the front ranges of the Rocky mountains, within fifty miles of the prairie lands of Alberta. Mining conditions are favourable, with an abundance of timber and ample power available. The phosphate beds are all of the sedimentary type, and they all occur, apparently, at the same stratigraphic horizons over a wide area. The conditions necessary for deposition evidently occurred at several different periods in geological time, and were widespread. The most important factor appears to have been the condition of the land surface surrounding the basin of de-position. Both oolitic and nodular phosphate were laid down under nearly similar conditions. Introduction Following the discovery of phosphate rock in Idaho and Montana, search was commenced in Canada to determine whether formations of similar age in the Canadian Rockies carried similar beds of phosphate. The most widespread search has been that undertaken by the mines department of the Consolidated Mining and Smelting Company of Canada. The following paper will discuss some of the results of this exploration.

Jan 1, 1933

By Manuel Sanchez, Marcial Medina, Matt Hurley, Hugo Granados, Pramod Kumar, Raj Rajamani, Jose A. Delgadillo

"Large-diameter ball mills have traditionally used steel liners—steel being a highly durable material that can be shaped into any desired geometry, among which the double-wave has been the preferred design. Such a design produces a purely cascading charge motion, which is ideal for the shearing action needed to produce a finer product. Today, however, rubber liners, which have been in existence for over forty years, are now preferred over traditional steel, largely because they weigh less and are easier to maintain. In this paper, we show the operating data from the Hudbay Minerals’ Constancia Mine, wherein the liners on a 26-by-40-foot mill were changed from conventional steel liners to PolyStl™ liners. It is then shown that this change reduced the amount of energy consumed whilst being able to maintain previous grind and throughput levels. The design is verified via discrete element simulations.IntroductionThe Constancia Mine (“Our Business: Peru,” 2016) is located in the southeastern Andes of Peru, at an elevation of approximately 4,200 m. It can be accessed via the CU-126 road, about 95 km from the town of Espinar in Espinar Province. The mine also contains both the Constancia and Pampacancha deposits in the Province of Chumbivilcas. Hudbay Minerals, Inc. acquired the mine in 2011, through the purchase of Norsemont Mining, Inc. and currently retains sole ownership of the property. Production of the Constancia Mine began in 2014, with commercial production levels being achieved in April 2015.The Constancia and Pampacancha deposits primarily include hypogene, supergene, and skarn ores. The Mine’s main products, however, are copper concentrate, with silver contents, and molybdenum concentrate. These mineral reserves are expected to last approximately 22 years. Constancia’s open-pit mine supplies a processing plant that is designed for 81,900 metric tons per day of throughput. Average annual copper production is estimated to be 82,000 mT (contained metal in concentrate). Actual plant production can be found in Table 1."

Jan 1, 2017

By Fathi Habashi

"Crushing and grinding of ores and their beneficiation by washing away gangue minerals has been practiced since ancient times. Primitive crushing was done by hand pounding the ore with a hard stone then by using metallic hammers. The mortar and pestle was mechanized using a lever and when the size of operations increased in the middle ages, the stamp mill was introduced. The grindstone played an important role in grinding of ores. Panning for gold and hand sorting of minerals were two old methods of separation, now gave way to modern techniques. Flotation started in the middle of the nineteenth century by using oils to collect the mineral particles and float them on the surface of the aqueous slurry. It was only in the 1920s when it was discovered that organic compounds were affective floating agents. Textbooks written by distinguished engineers such as Rittinger, Rickard, Pryor, Taggart, Richards, Gaudin, and others contributed to the recognition of this field as a new discipline to be taught in Universities. INTRODUCTIONThe ancient Egyptians knew already that it would be easier to melt an earth rich in gold particles than another which is poor. As a result all efforts were made to enrich the gold by washing away the light gangue minerals (Figure 1). Another ancient method for enriching gold particles from a river stream was by means of fleece, hence the Greek myth of the “golden fleece”. The present day Georgia was known in ancient times as Colchis and was a center for gold working. It was known to the ancient Greek as the land of Golden Fleece. The use of special cloth to catch gold particles was also described by Agricola in his 1555 book De Re Metallica (Figure 2)."

Jan 1, 2009

By David Weiss

There is significant interest in magnesium alloy castings because of their low density and high strength-to-weight ratio. Lightweight, structural materials are in demand for aerospace components, hand tools, electronics enclosures and have found increased use in automobiles. Increased use of magnesium will depend on the resolution of a number of materials issues and development of more robust and economical casting processes. Most magnesium components are produced via high-pressure die-casting. High levels of porosity generally prevent die-castings from being used for structural applications. Structural castings are usually produced using sand casting, a relatively expensive casting process. Some work has been done on development of lower cost structural casting processes, such as lost foam casting, permanent mold casting or low-pressure casting. New programs are also emphasizing improvements to the die casting process. Research and cost reduction needs are discussed with respect to current programs and future components.

Jan 1, 2006

By Robert Gannicott

??A mining company without the burden of operating a mine ??Management focused on marketing a high-quality, run-of-mine range of Canadian diamonds ??Robust revenue stream ??Specialist diamond knowledge ??Canadian exploration and development expertise ??BUT ??Single asset revenue base from depleting ore reserve ??Limited influence on production plans

Apr 1, 2005

By Frank Cappuccitti, James A. Finch, Stéphanie Gélinas

"A colorimetric technique, originally developed for methyl iso butyl carbinol (MIBC) based on the Komarowsky reaction, has been extended to a wide range of common mineral flotation frothers. The procedure, which is briefly described, is shown suited to on-site determinations in a campaign at Kennecott Utah Copper Copperton Concentrator (Rio Tinto). Some observations are described, including: frother (MIBC) concentration evolution down a bank, frother distribution between pulp and froth phases, and loss of frother over time due to adsorption on certain minerals. A possible interference with a fuel oil addition was overcome. MIBC in recycle water was also measured.The ability to monitor frother easily will help interpret gas dispersion behaviour and should permit further optimization of flotation cell hydrodynamics and chemistry. The capability to directly measure should help optimize the type, amount and location of frother addition, and to assess frother recycled with reclaim process water.INTRODUCTIONOwing to the lack of analytical methods, the task of determining frother concentration in plant flotation circuits is not routinely performed. Industrial sites seldom outsource analyses that are both costly and inconvenient, due to the necessity of shipping freeze-dried samples to remote testing facilities. A more direct colorimetric method has recently been demonstrated for the laboratory characterization of common industrial frothers (Gélinas and Finch, 2004). The approach, based on the Komarowsky reaction (Penniman et al., 1936; Coles et al., 1942; Duke, 1947), was previously described by Parkhomovski et al. (1976) for methyl iso butyl carbinol (MIBC). The reaction involves the interaction of the OH group of a higher alcohol, concentrated sulphuric acid, and salicylaldehyde, to yield coloured solutions with intensities that can be analyzed by UV-visible spectrophotometry."

Jan 1, 2005

By James R. Kuipers

Center for Science in Public Participation CSP2 ? Organized in 1997 to provide technical assistance to public interest groups on mining and water quality issues ? 80%of effort devoted to direct support of grassroots groups and tribal governments ? 20% of effort devoted to public-oriented education for public, tribal, state and federal regulators, and for industry ? Board represented by public interest groups, at large citizens, and academia ? Professional staff with experience from mining industry, academia and government ? website: www.csp2.org CSP2 Mission Statement The CENTER for SCIENCE in PUBLIC PARTICIPATION provides training and technical advice to grassroots groups on water pollution and natural resource development issues, especially those related to mining. CSP2 seeks to focus the debate on factual issues, as brought to light by its technical analyses, and whenever possible to seek consensus and win-win solutions. CSP2 also performs policy related work with federal and state regulatory agencies on the implementation of water quality, waste disposal, and mining reclamation regulations.

May 1, 2002