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By Golaleh Riahi

An original method is used to obtain stable nanoparticles of gold-based mono- and bimetallic systems supported on an acidic zeolite. This approach has been applied to PtHY (1wt% Pt) and to bimetallic Pt-AuHY containing 1% of platinum to which is added the amount of gold required to give Au/Pt molar ratios of 20,40,60 and 80%. Metal clusters of Au or Pt-AuHY are formed inside the supercages of the zeolite framework by the thermal reduction of cations by the ligands (en = H2N-CH2-CH2-NH2) under inert gas flow at a temperature depending on the metal. The use of acidic zeolites favours the dispersion of the metal and the thermal stability of the particles. This stability is explained by chemical anchoring of metal clusters by the Brønsted sites of the support. Several techniques have proved that for a molar ratio of 20% metal particles of Pt-AuHY are bimetallic. The segregation of Pt and Au starts for molar ratio =?40%. The catalysts tested on the methylcyclopentane hydroconversion reaction reveal that the addition of gold to platinum leads to an increase in the activity and an improvement in the selectivity for isomerization of the skeleton (cyclohexane and benzene) to the detriment of hydrogenolysis. Similar results were obtained for the dodecane isomerisation to isododecane. These catalysts were also tested in CO, propene and propane oxidation. The activity of fresh catalysts is rather low. It increases after their pretreatment in oxygen or hydrogen atmosphere. In propene oxidation in the reaction mixture O2 ? H2, beside total oxidation of propene to CO2, also propene hydrogenation was observed, particularly at low temperatures. The presence of Au enhances the hydrogenation properties: high selectivities (> 90%) to propane and high propane yields on PtAu HY are observed up to ~150oC, whereas for Pt HY catalyst the selectivity and yield to C3H8 decreases rapidly with the temperature beginning from ~100oC.

Oct 1, 2003

By N. Ginouse, S. Reny

"In the mining industry time is critical as production depends on the speed of the mining cycle. During the mining process, the time required to re-open access for the next phase of an underground heading is a key point that strongly depends on the ability of the selected ground support technique to promptly ensure the safety of workers. Fiber reinforced dry-mix shotcrete has been proven to be an efficient and well adapted technique, able to produce a ground support material with the required energy absorption or flexural toughness in a single application phase. In this context, this paper demonstrates the possibility of significantly speeding up the mining process by using a new fiber reinforced dry-mix shotcrete. The new fiber reinforced dry-mix shotcrete is capable of developing flexural toughness in only 24 hours that is equivalent to what is typically achieved after 28 days using current fiber reinforced drymix shotcrete technology.INTRODUCTIONShotcrete is often used for ground support when using the drill and blast method or other tunnelling methods. But before re-opening access for the next phase of the underground heading, the applied shotcrete is required to reach a minimum compressive strength and in case of fiber reinforced shotcrete, a minimum flexural toughness (energy absorption) in order to ensure the safety of the workers going into the heading. Combined with bolts, the use of conventional fiber reinforced shotcrete becomes an interesting method for ground support as it is applied very soon after excavation and works to stabilize ground movements (Bernard E. S., 2009). In this case, the toughness development of fiber reinforced shotcrete becomes an important feature of the material when looking to speedup the mining cycle. However, early re-entry criteria in underground openings are difficult to ascertain as the load carrying capacity of fiber reinforced shotcrete is usually assessed after 7 or 28 days. For this reason, re-entry criteria varies from one mining area to another and are usually based on compressive strength requirements. For example, in northern Ontario, Canada, one of the current practices in the mining industry consists of allowing safe re-entry once fiber reinforced shotcrete has developed a compressive strength of higher than 4 MPa (Dufour, O’Donnell, & Ballou, 2003). Flexural toughness requirements on fiber reinforced shotcrete are also typically based on evaluation after 28 days."

Jan 1, 2015

By Leslie Gertsch

Outline First progress report ? ?Introduction ?Non-terrestrial mining ?Near-term targets ?Stages of mining ?Study procedure Capabilities needed for non-terrestrial mining ?Mining methods ?Mining unit operations ?Typical surface mine operations sequence ?Results to date General effects of gravity ?On fragmentation ?On excavation ?On transport ?Conclusions / Recommendations

May 1, 2013

By C. Gerow

THIS paper is entitled "Some" problems, rather than "The" problems, met in selling coal, since the problems to be met in selling any commodity have to deal with an infinite number of circumstances and conditions. These are believed to be more varied in the case of coal than probably any other commodity. This is due, perhaps, to the fact that coal has been one of the basic materials in the guiding of industrial and national achievement for the past two hundred years. During this time its use has developed from a most haphazard one to uses involving all modern scientific methods, which, rather than simplifying matters as regards the marketing of coal, have added many fresh problems, and these vary according to the particular market served. Since the concern of this paper is primarily the selling of Nova Scotia coal, it is proposed to deal chiefly with some of the specific conditions met in the markets presently served by this coal. For the purpose of discussion, these markets may be considered as divided into three main groups, namely, the Maritime market, the Quebec market, and the Ontario market. THE MARITIME MARKET First of all, let us consider the Maritime market. This is a market which has been regularly served by Nova Scotia coal since coal mining became the first industry in Cape Breton, slightly over one hundred years ago. Conditions as applying to the use of coal have naturally tended to adjust themselves to the characteristics of the coal most readily available, and, therefore, marketing problems are fewer in the Maritimes than in districts where many coals of varied characteristics are offered. Up to recent years, the problems involved were chiefly those of providing satisfactory service insofar as de-liveries were concerned. However, with the speeding-up of manufacturing processes and the necessity of reducing costs to a minimum, users of coal have become interested in obtaining coal that will give the most economical service. It is, therefore, now of importance that the salesman should have full knowledge of the particular conditions applicable to each customer's use in order to deal to the best advantage.

Jan 1, 1936

By Rosie Moore, Harvey Keats, Kerry Sparkes, A. J. Naldrett

"Abstract-The Voisey’s Bay Ni-Cu-Co deposit was discovered in late 1994 as the result of prospecting initiated in the summer of 1993. By July 1995, proven mineable reserves were 31.7 x 106 tonnes grading 2.83% Ni, 1.68% Cu and 0.12% Co, and current total resources in all categories are quoted to be in the order of 150 X 106 tonnes. The deposit is associated with a body of troctolite belonging to the Nain Anorthosite (1.35 Ga - 1.29 Ga) suite, which was emplaced across the boundary between the Proterozoic "Rae" Province to the west and Archean "Nain" Province to the east.The deposit can be described in terms of three geological settings. The "Ovoid" is a 600 m long by 350 m wide by 100 m deep lens of massive sulfide, covered by 10 m to 20 m of glacial overburden, and separated from the underlying country rock quartz-plagioclase-biotite gneiss by a breccia of gneissic fragments in troctolite known as the Basal Breccia Sequence. To the west of the Ovoid lies the "Western Extension", comprising disseminated and massive sulfides in a north-dipping sheet of troctolite which ranges from upper unmineralized troctolite down through troctolite with increasing amounts of sulfide (up to 50%), to massive sulfide (in some places only), and then to Basal Breccia Sequence. East of the Ovoid, the troctolite sheet broadens out into a troctolite intrusion, within which occurs the "Eastern Deeps", a zone of massive and disseminated sulfide up to 100 m thick that is currently being explored. The mineralization of the Eastern Deeps lies along the line of intersection of a feeder sheet with the base of the intrusion. The current interpretation is that the three geological environments represent different erosional levels through a single mineralized intrusion. In this model, the deepest erosional level lies to the west and exposes the feeder to surface, whereas the Ovoid represents the base of the intrusion at surface, and the Eastern Deeps the base of the intrusion overlain by 600 m to 900 m of troctolite. Sulfides and gneissic fragments were brought up by magma flowing quickly through the feeder, and settled out where the flow rate decreased as the sulfide-bearing magma mixed with magma already emplaced in the intrusive body."

Jan 1, 1996

By W. J. Pearson

"""POTASH"" is a term applied to the compounds of the element potassium (K) and when used in agriculture and industry is ex-pressed in terms of potassium oxide (K2O), regardless of the actual com-position of the compound. When a chemical analysis is made of a fertilizer, the amount of K is deter-mined and then calculated to the equivalent amount of K2O. However, the compound K2O does not exist in nature. Most of the world's potash supply is derived from mineral deposits similar to those in Saskatchewan and New Mexico. However, there is some production from concentrated surface brines such as occur in Searles Lake, California; Salduro Marsh, Utah; the Dead Sea; and from well brines in Micl1igan."

Jan 1, 1960

By D. B. Dreisinger, M. Rasouli

"Developing technology to address the environmental hazards associated with selenium in mine-impacted waters has been a serious challenge. Ion exchange (IX) has been identified as a potential treatment technology. This paper begins with a review on selenium adsorption with commercially-available basic anionic exchangers (BAS). It then looks at the use of resins for selenium removal via modification with the addition of -O, -N, or -S-containing chelating ligands and chelating polymeric ion exchangers pre-loaded with immobilized metal cations. The synthesis of chelating exchangers requires a final product with a highly stable metal in the ligand-metal complex. The nature, oxidation state, size, and affinity of the metal for the target oxyanions and the size, degree of protonation and space configuration of the oxyanion are among critical factors affecting the oxyanion uptake. There is a limited number of studies on the critical parameters affecting the selenium affinity for chelating exchangers. Such a study could fill in the gaps of our understanding of selenium-metal-chelating ligand interactions and assist in developing a new ion exchanger. In addition to commercial IX resins, layered double hydroxide materials (LDH) have received attention for oxyanion removal from waste water. The adsorption capacity of the LDHs are affected by the crystallinity of LDH, the nature of metal components, the ratio of metals, charge and type of anion, and the space between the layers. In particular, the Friedel phase (FP), a member of the LDH family, showed high adsorption capacity for selenate removal from synthetic solution. A study is currently underway at the University of British Columbia to investigate the effect of different synthesis methods and aging on the suitability of FP for selenium removal from mine waste water."

Jan 1, 2017

By N. Ogbonna, D. G. Dixon

Although heap bioleaching has been recognized as an economic alternative for treating low grade mineral ores, the underlying physical, chemical and biological processes involved are complex. A detailed investigation into the dynamics of heap bioleaching processes has provided much insight into the underlying complexities, and has led to the development of a sophisticated modelling tool - HeapSim. This tool can be of great help in the design and operation of heap bioleaching processes. In this paper, the mathematical model implemented in HeapSim is examined. The model takes into account mineral kinetics, particle level effects, bacterial growth, oxidation and adsorption, gas absorption, pore diffusion, bulk advection, gas balance and heat conservation. Three case studies where the model has been applied are briefly discussed. Computational Analysis in Hydrometallurgy 35th Annual Hydrometallurgy Meeting held in conjunction with the 44th Annual Conference of Metallurgists of CIM Calgary, Alberta, Canada Edited by

Jan 1, 2005

By C. E. Rodgers

WHEN the writer was engaged early last year by Canadian Comstock and its subsidiary, the Metropolitan Electric Company, to act as Consulting Mining Engineer in connection with the layout and equipment of the new ore-dressing laboratories at Laval University, Quebec, the metallurgical laboratory section of the School of Mines building was completely erected, including plastered walls, partitions, etc., and finished concrete floors. At that time, however, no equipment had been ordered, except three Dominion ball-mills and two Bell screening machines. ADVANCED OR CONTINUOUS LABORATORIES The continuous laboratory section of the Department occupies the basement and three floors of the building, with an approximate floor area of 9,000 square feet. Because of limitations imposed by the design of the building (height and arrangement of rooms, strength and design of floors, etc.), modifications of layout from what otherwise seemed most desirable were, of necessity, made. These included: (a) Omission of automatic sampling of the dry ore. (b) Complete elimination of inclined belt-conveyors through floors. (c) Exclusion of bucket elevators for either dry or wet ore transfer. (d) As a substitute for grill-covered drains and floor sumps, drainage from sections or from individual pieces of equipment was piped to a disposal system in the basement. (e) Substitution in several instances of fabricated steel in place of the usual concrete foundations for machinery. (f) Reducing floor cutting and area of such opening to a minimum. Ore storage and chute capacity above the basement level was also minimized to reduce total weight.

Jan 1, 1941

By Jasmin Raymond

Ground source heat pumps are used to heat or cool building and heat water supply. Such heat pumps use the earth as a heat source or sink to efficiently provide or store thermal energy. For example, a ground source heat pump typically requires less then a third of the electric or fossil fuel energy of a conventional heater. Ground source heat pumps could therefore help reduce the energy consumption of active mines where low-grade geothermal resources are abundant. In most heat pumps, water or a water-antifreeze mixture having a temperature ranging from -6.5 to 43.5 °C is circulated through a heat exchanger at a rate of 0.000033 to 0.000067 m3/s (2 to 4 L/min) for each kilowatt of heating/cooling capacity. The groundwater that is continuously pumped to drain mines could be used to operate heat pumps. Water feeding a heat pump can alternatively circulate in a close loop network of pipes buried underground or installed in a surface water body. Retention water ponds, tailings and waste dumps commonly found at active mine sites could provide excellent environments to install the close loop system. Further research will help take advantage of the unexploited geothermal resources associated with actives mines.

May 1, 2007

By H. Kudelka

Copper electrowinning at Duisburger Kupferhuette was introduced in March 1975. The electrowinning plant has a capacity of 10,000 mT of copper cathodes a year. The cuprous oxide feed material is an intermediate product of the treatment of the leach solutions, originating from chloridizing roasting of pyrite cinders. This material is characterized not only by a wide spectrum of accompanying impurities, but also by an unusually high level of precious metals. As the priority set was the production of high-purity cathodes. there was a need for developing a process which would be suited to treat complex leach liquors . The process adopted consist s of an oxidizing leach in spent electrolyte, followed by two- stage purification, By this means. a low- acid pregnant copper electrolyte is obtained free of elements detrimental to copper quality. Electrowinning is carried out at a current density of 200 A / m2 in the presence of 10 g/l zinc. The electrowon copper has a conductivity of at least 101.4% lACS and a softening temperature not exceeding 200°C, which makes it a suitable product for continuous casting and dip ?forming.

Jan 1, 1977

By H. R. Butler, R. N. Browne

"The International Nickel Company of Canada Limited consumes some 33 ½ millions of gallons of fresh water and reuses more than 100 millions of gallons of water daily. The continuing search for suitable recycle methodology has enabled the Company to put one 25,000 TPD mill on line utilizing recycled water entirely and a second 35,000 TPD mill is under construction which will likewise employ the concept of recycled water. Future milling plans are aimed at the replacement of all fresh water with recycled water, including sewage effluent and mine waste water.WATER REUSE AT INCO’s SUDBURY MILLSAs man searches unexplored horizons for new and economic industry, he must be constantly and acutely aware of the presence or absence of that precious commodity without which Industry, indeed Man himself, could not survive -- W A T E R. The water requirements of the world today are magnanimous, considering that in 1960 the estimated consumption in the United States was over 300 billion GPD (l) or more than 1,700 GPD per person(5) The magnitude of the problem can be visualized as one considers that three times this quantity of water will be required in the United States by the year 2000, when the dependable supplies of water are estimated to be only two-thirds of that required(2). How, then can we continue to wreak such havoc on that life-sustaining substance - WATER?"

Jan 1, 1970

By C. S. Gibson

INTRODUCTION I WELCOME the opportunity to speak on Programmes in Safety. The invitation to do so shows that those guiding affairs of the Institute in this District realize the practical importance of this subject. My remarks are intended primarily for mines having 100 to 400 employees, approximately. With minor modifications, however, they apply also to larger or smaller operations. Others, I hope, will derive benefit from this paper, for they, too, have a part to play in accident prevention; for example, contractors such as shaft-sinkers; manufacturers of equipment; and consultants and designers of mining, milling, and metallurgical methods. These troubled times stress, as never before, the importance of efficient operations in mining. The days are gone when neglect can be afforded. Safe working conditions and satisfied employees are essential for efficient production at reasonable cost. The mining industry of Ontario long has been keenly aware of the human aspects of this subject, and as a whole it has done much to decrease the frequency and severity of disabling accidents. The number of fatalities per 1,000 employees has been reduced from a high of 5 some two decades ago to an all-time low of 0.89 in 1948; the incidence was slightly higher in 1949, being 1.17 per 1,000. The reduction in non-fatal compensable accidents also has been outstanding, frequency having ?been reduced from over 200 per 1,000 employees some two decades ago to 54 per 1,000 at the producing mines in 1949. These statistics demonstrate progress. Nevertheless, the general picture still leaves much to be desired when viewed from two other angles.

Jan 1, 1951

Automation Defined ?Using self-operating equipment to reduce human exposure to the mining environment and routine or repetitive work.?-Atlas Copco Terminology: ?Manual Operation ?A vehicle being operated by a person ?in the cab?. ?Radio Remote Control (RRC) ?A vehicle being physically operated by a person through a Line Of Sight (LOS) or Video-Remote equipment. ?Tele-Remote Control ?A vehicle being physically operated by a person at an operator station which is not necessarily located near the vehicle?s working area. ?Autonomous Operation ?A vehicle under self control with the possibility of human supervision and override.

Oct 1, 2010

By K. G. Chipman

IN 1936, the Department of Mines and Resources was formed by the amalgamation of the former Departments of Mines, Interior, Indian Affairs, and Immigration. In the amalgamation, the Geological Survey and the Topographical Survey became the major divisions of the Bureau of Geology and Topography, which is a part of the Mines and Geology Branch which, in turn, is a part of the Department of Mines and Resources. The Topographical Survey was formed by combining the former Topographical Division of the Geological Survey and the air and ground mapping sections of the former Topographical and Air Survey Bureau of the Department of the Interior. The latter organization, previous to 1933, had been known as the Topographical Surveys Branch of the Department of the Interior. The amalgamation of 1936 definitely placed on the Topographical Survey the responsibility for the original mapping required for the development of our natural resources. The war has brought upon us the situation where all work has had to be in the furtherance of the war effort. With decreased staff and limited appropriations, the mapping on those scales which are directly concerned with the natural resources has been confined to the search for oil and strategic minerals. The reconstruction period will produce a different situation, with different problems. The past is behind us and it is necessary to prepare for the future. First, we should consider briefly a few general principles in the making and using of maps, then take stock of what we have, see what the needs are, and consider how we are to meet these needs.

Jan 1, 1944

By Beaumier. M., J. -P. Lalonde

"Les réultats obtenus dans les sols sur quatorze aires d'essai et six cheminements régionaux dans I'A bitibi-Témiscamingue indiquent clairement qu'il existe des variations régionales importantes dans les teneurs en éléments traces de l'horizon A1 formé sur l’épais recouvrement glacio-lacustre de cette région. Les anomalies obtenues correspondent à celles qui ont été décelées lors de précédents levés des eaux souterraines et du till de base.Selon les critères d'évaluation utilisés, treize des quatorze aires d'essai ressortent comme anomales dans Ie contexte abitibien; dix de celles-ci sont tres anomales. Ceci suggère fortement qu'un levé régional de sols, fondé sur une approche multi-éléments, identifierait entre 70 et 90 % des cibles géochimiques reconnues par des échantillonnages en profondeur. Les résultats d'un échantillonnage systématique effectué sur une région de 1000km2 viennent aussi appuyer cette hypothèse. Conséquemment, les sols formes sur les sédiments glacio-lacustres sont un médium très utile pour inventorier de grandes regions recouvertes par ce typ e de sédiments.L 'horizon A1 est Ie plus utile pour ce type de levé parce qu'i1 est facil e d échantillonner, qu 'it assure une plus grande constance du typ e de matériel échantillonne et qu'il contient des teneurs accrues.De multiples mécanismes de dispersion géochimique ont joué des rôles d 'importance variable pendant et après la mise en place des sédiments glacio-Iacustres. Les plus importants sont la pression hydrostatique, la diffusion chimique et électrochimique ainsi que la bio-accumulation. Si on veut progresser dans la connaissance de ce milieu complexe, on devra adopter une approche plus systemique tenant compte de I'interaction des mécanismes agissant dans l'environnement global avant, durant et apres Ie depôt du mort-terrain."

Jan 1, 1984

By K. Gardner

"Many deposits have a geological model developed early in the project stages, which is not always reviewed or modified as the project matures and production commences. Conversely, ongoing pressures, due to a combination of declining head grades, a push for increased revenue and a multitude of other reasons, leads to processing plant modifications, with the primary aim being to increase production. Often, the ore deposit knowledge is not sustained or developed during the operational stages to the level carried out during the prefeasibility and feasibility study phases. This results in the variability within the deposit being poorly understood and a lack of data and knowledge being available to support (and ideally optimise) operations particularly in an environment where the flow sheet has changed and ore feed requirements are complex.INTRODUCTION This paper presents a case study of ore deposit knowledge development and corresponding process plant operating strategy at the Ladolam Gold Deposit, commonly referred to as the Lihir gold deposit in Papua New Guinea. The gold deposit is located in a tropical equatorial climate on the east side of Lihir Island in the New Ireland Province of Papua New Guinea. Gold mineralisation was discovered in 1982, and was followed by a major exploration campaign by a joint venture between Kennecott (Rio Tinto) and Nuigini Mining Limited. The first drillhole was drilled in 1983, and after an extensive period of drilling consisting of 343 holes for 83,500 m, the final Feasibility Study was completed in 1992. The feasibility study was based on a Reserve base of 37.9 Moz in refractory sulphide ore, with gold extraction proposed to occur via whole ore pressure oxidation due to the refractory nature of the mineralisation. The Lihir Special Mining Lease (SML) was granted in 1995 to a new PNG company – Lihir Gold Limited, and Rio Tinto established Lihir Management Company to develop and operate the mine on behalf of LGL. Mining and processing of the deposit commenced in 1997. Newcrest Mining Limited purchased Lihir Gold Limited in August 2010, and subsequently completed a major plant upgrade including the installation of additional grinding, autoclave and carbon-in-leach capacity. Post commissioning of the upgrade, Newcrest has continued to increase throughput and production. A reinvigorated ore body knowledge development program has significantly assisted this process in identifying operating strategies for the process plant and delivering recovery improvement projects to address declining head grade and recovery due to increased stockpile feed and flotation circuit use."

Jan 1, 2017

By J. R. Porter, C. Panaou

"A significant effort is expended on preparation of the capital estimate for feasibility studies. The development of the operating cost estimate is usually allocated a significantly smaller budget and less emphasis is placed on ensuring the accuracy of the operating cost. This paper presents a comparison of capital and operating costs of hydrometallurgy processing plants in order to demonstrate the importance that variations in operating costs have on the overall life-of-mine costs. The analysis is supported by a case study on the operating costs of a water treatment plant at an existing Australian hydrometallurgy facility at the feasibility design level. INTRODUCTIONDetermination of the economic validity of a minerals processing project is a critical outcome of a feasibility study. In many cases, the financial results of the feasibility study will determine if the project should proceed to execution. Ensuring that these results are reliable and built upon sound engineering practices allows companies to make informed decisions on resource opportunities and the selected technology.The methodology for developing a capital cost estimate at the feasibility level is well established. Specialist engineering estimators use budget quotations, first principle estimation and rules-of-thumb to develop an estimate with an accuracy of typically -10% to +15%. Cost reporting software packages are used to methodically build up the estimate from design information supplied by the engineering disciplines. Risk analysis and capital expense workshops are carried out to identify potential deficiencies in the estimate. It is widely recognized that in order to successfully produce a feasibility level capital estimate with an appropriate level of accuracy, a rigorous development process is necessary.The development of the operating cost estimate is typically less rigorous than the capital cost estimate. The operating cost is normally derived by the process engineering discipline and rarely are specialist estimators used to support the development. The allocated budget for producing an operating cost is usually smaller and less emphasis is placed on ensuring the accuracy and contingency reflect the most likely operating cost scenario."

Jan 1, 2012

By K. Chotruangprasert

This paper explores Global Reporting Initiative (GRI) reporting practices within the mining industry. Specifically, this paper investigates how and why a mining company makes voluntary reporting decisions to include the GRI indicators that may be considered ?negative? to the company?s reputation. Due to the voluntary nature of the GRI Guidelines, a GRI adopter is not legally obligated to report every GRI indicator. Not surprisingly, empirical studies that evaluated the extent to which companies? sustainability reports meet the GRI requirements (Guenther, Hoppe, & Poser, 2006; Morhardt, Baird, & Freeman, 2002; Samy, Odemilin, & Bampton, 2010; Skouloudis, Evangelinos, & Kourmousis, 2009) have found that reporting practices of the companies under their studies are well below the standards reflected in the GRI Guidelines. An influential study by Clarkson et al (2008) uses economic-based and socio-political theories to explain variation in companies? environmental disclosure. They have found that, as predicted by economic-based theory, superior environmental performers disclosed more ?hard? (i.e. verifiable) environmental information. Inferior environmental performers are found to disclose more ?soft? (i.e., not easily verifiable) claims, which is consistent with socio-political theories (Clarkson, Li, Richardson, & Vasvari, 2008). However, this study and the existing literature do not adequately explain why a company may act in a way that cannot be explained by economic-based and socio-political theories, for example, why it would report some negative soft data that it is not required to report. This paper intends to address this literature gap. GRI reporting by a Canadian mining company, which I would like to call ?Company C?, is used as a case study for this paper. Company C was selected for this research because in addition to ?positive? information, its GRI-based sustainability report also includes both hard and soft ?negative? information such as grievances. Research methods include interviewing Company C?s employees who are involved in preparing GRI reports and reviewing documents prepared both by the company and by external parties. I find that integrative social contracts theory (ISCT) offers a valuable explanation to Company C?s reporting practices. From the ISCT perspective, Company C?s management appears to feel that the company is obligated under social contracts to be transparent. Therefore, Company C disclosed both positive and negative social and environmental information to the public because the management appeared to think that it is the right thing to do. At the same time, being transparent about the bad news gave the company an opportunity to conclude that it had done something to avoid future occurrence of the negative incidents. Therefore, I propose that, in addition to the economic and socio-political theories that are more often used in literature, insights from ISCT are instrumental in improving our understanding of the corporate non-financial reporting practices phenomenon.

Aug 1, 2013

By J. McCreedy

"The addition of Portland cement to hydraulic sand fill has resulted in the production of stable and self-supporting cemented sand fill. The use of cemented fill in the mines of The International Nickel Company has resulted in substantial economies in timber requirements, de-creased dilution of ore and greater flexibility in mining methods.Coupled with special mining techniques, it has permit-ted mining by both cut-and-fill and shrinkage stoping methods to much greater depths than heretofore. The use of cemented sand fill has permitted revisions to undercut-and-fill mining which have significantly improved the efficiency of this method.Automated mixing systems have been developed for preparing cemented sand fill in surface sand plants on a continuous throughput basis. Control of cement-sand mixtures is obtained by the use of a mass flow measuring system and weighing cement feeders."

Jan 1, 1966