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By Richard Howie

Avian Diversity ?? Pre-mining ?? 110 - 125 species would have occurred ?? Dominated by forest species ?? Wetland productivity unknown ?? Post mining ?? 192 documented ?? Forested species in reduced numbers ?? Increase in wetland species ?? Increase in open country/grassland species

May 1, 2008

By Douglas A. Grieg

THE EXCUSE for producing still another paper dealing with the oilfields of the Middle East is the overwhelming importance of this area to everyone, both inside and out of the oil industry. Figure 1 shows the area defined as the Middle East for the purpose of this paper. No description of what constitutes the Middle East is generally acceptable to everyone and, in fact, in many parts of the world it is referred to as "Western Asia". At the time ?the writer went to work as a geologist in the Middle East -this was in 1926 -there were just three known oilfields, namely, Hurghada in Egypt, Naft Khaneh in the Transferred Territories of Iraq, and Masjid-i-Sulai-man in Persia. Their combined producing rate at that time was around 100,000 barrels per day. Toda y, just thirty years later, some forty-two fields have been proven to exist, and a recent discovery in Syria -if commercial -may add one more to the list. Producing rates at the end of last year ( 1956) were approaching four million barrels per day. This sizable figure re presents nearly 23 per cent of the total Free World's production. What is more important still, something over 70 per cent of the Free World's proven oil reserves are known to exist in the subsoil of the Middle East.

Jan 1, 1957

By J. M. Hemstock, H. L. Ames

THESE forums have been held annually since they were introduced by Mr. L. E. Djingheuzian in 1957. The response of millmen to questionnaires such as the one this year is ample evidence of the interest these create. This year's topic is unlike those of past years since it is an attempt to understand a new concept of grinding rather than to improve the old. Before, we were thinking in terms of 2-5 cents improvement in grinding costs, now we will be discussing savings of 15-2 5 cents. As a background for this forum we will begin by summarizing the major controversial issues relating to grinding with steel, many of which will undoubtedly apply to pebble milling. Our •task to-day is to learn what has already been done in pebble milling and obtain a fair overall view of this method of grinding.

Jan 1, 1961

By H. Wotruba, L. von Ketelhodt, M. Kowalzcyk, M. Robben

ABSTRACT Decreasing reserves, water shortages, increasing energy costs, and environmental and social constraints are challenges to the gold mining industry that must be met with innovative machines and methods. This paper introduces the principles of sensor-based sorting and installations that demonstrate the technical and financial viability of the method. The scenarios discussed highlight the potential and advantages of this dry processing technology that requires little infrastructure. Case studies are presented for different ore types using optical- and X-ray transmission–based sorting. Current research is discussed in terms of the potential of near-infrared spectroscopy and X-ray fluorescence sorting for gold applications.

Jan 1, 2013

By Chantale Doucet

L?utilisation du remblai en pâte dans les exploitations en vrac est de plus en plus importante. Puisque la technologie existe pour fabriquer du remblai en pâte sans construire une usine coûteuse, il est maintenant possible d?élargir le domaine d?utilisation du remblai en pâte pour y inclure des gisements filoniens où le besoin annuel de remblai est moindre. Dans certains cas, l?utilisation du remblai en pâte pourrait permettre de réaliser d?importantes économies telles que la réduction de la dilution, la stabilité des ouvertures, la récupération d?une plus grande partie du minerai par la réduction de la taille des piliers et l?entreposage de moins de résidus à la surface. L?ampleur des économies est parfois difficile à chiffrer mais il est tout de même important d?en tenir compte lors de la décision d?utiliser du remblai en pâte puisque ce sont souvent ces économies qui seront déterminantes. Différentes méthodes d?extraction avec remblai en pâte appliquées aux mines filoniennes seront présentées. Des défis et les solutions reliés à l?utilisation du remblai en pâte à la Mine Doyon seront discutés.

Oct 1, 2001

By J-F. Turgeon, Y. Pépin, G. Hudon

The high temperature hydrochloric acid leaching of titanium slag in the QIT upgraded slag process (UGS) creates a harsh environment for materials of construction. Because of their excellent chemical and heat resistance, furan mortars are a key component in the lining system of the UGS pressure leach reactors. Similar products coming from different manufacturers have however shown unequal performances in service. In some cases, cracking of the brick lining has occurred during curing of the mortar. This study was initiated to investigate the impact of the curing conditions on the properties of carbon filled furan mortars. Laboratory tests were conducted to assess the effects of temperature and exposure to water and HCl solutions on mortar shrinkage and mechanical properties (tensile, compressive and bond strength). Three commercial furan mortars that have been used in the UGS leach reactors were thus characterized. Mortar properties were found to vary significantly among the products tested. Moreover, the curing conditions were shown to have a significant impact on mortar shrinkage and mechanical strength. The experimental findings provide explanations for the unequal performances of the mortars in service and for the problems of brick lining cracking that occurred in the UGS leach reactors. This study demonstrates that excessive mortar shrinkage compromises the integrity of a brick lining system.

Jan 1, 2004

By Karl J. C. Harries

13.1. RIGHT TO RECEIVE ROYALTY CONTRACTUAL ONLY1

Jan 1, 2003

By V. Aprahamian, T. Cheng, M. Tangen, R. Beauprie

The Royal Canadian Mint has implemented significant process additions since 2005. Installation of a whole new highly automated silver refining circuit has allowed recovery of physical silver from gold and silver dorés . To complement this change, a small Top Blown Rotary Converter has been in operation. On the gold refining side, a new hydrometallurgical process to recover precious metals from Miller Chlorination slag has been developed. Finally, new systems have been put in place to improve treatment of waste water, wet and dry fume and dust.

Jan 1, 2011

By Clifford S. Gibson

THESE troubled times suggest three reasons for maximum effort to control silicosis: (1) To keep to a minimum the ever-increasing burden occasioned by past deficiencies in this respect. (2) To effect the greatest production with maximum efficiency, which means at the least cost. (3) To preserve man-power in every way. Good control of the silicosis problem aids these aims. Inadequate control hampers all three. Insofar as our knowledge goes, silicosis in Ontario mines is caused by the inhalation of finely particulate quartz. It follows, therefore, that removal of dust containing this mineral automatically erases the cause. The achievement of this ideal is the aim of the mine operator. His best tool to this end is ventilation. This paper discusses mine ventilation from the viewpoint of dust control and it is hoped that in so doing there may result a better understanding of the part played by air in silicosis prevention. No attempt will be made to treat the subject fully. Instead, there will be presented certain salient aspects culled from field observations, the data in all cases referring to gold mines, unless mention to the contrary is made.

Jan 1, 1942

By Dianne M. Lapierre

Mining firms in Canada are increasingly incorporating the social and environmental interests of their stakeholders into their projects in an effort to become more sustainable. Such initiatives have included negotiating Impact and Benefit Agreements (IBAs) directly with would-be impacted, often aboriginal, communities near resource developments in the Canadian north. Why does a mining firm take on this extra time-and cost-intensive initiative when governments and regulatory measures are in place to address social and environmental issues? Past research has paid little attention to the corporate rationales for IBAs. Based on document review and interviews with mining executives, this study investigates the rationales of mining firms that ?over-comply? with legislative requirements by negotiating IBAs or similar types of agreements with communities. The results indicate that mining firms increasingly recognize IBAs as an intrinsic part of the permitting process. When queried, executives regularly identified the negotiation of agreements as ?the right thing to do?. While this response could be read in ethical terms, a commercial rationale is also clearly present. By building strong relationships with nearby communities, addressing community concerns, and directing benefits to local people, all of which are explicitly achieved with an IBA, mining firms are maintaining their long-term financial viability, thus their sustainability, within an evolving industry.

May 1, 2008

By M. H. Pettibone

Sohio Petroleum Company's new L-Bar uranium mill near Grants, New Mexico. refines 2722 kilograms of yellowcake daily from 1360 metric tons of ore produced at Sohio 's J.J. No. 1 mine and other nearby mines. This paper follows the ore from the mine through the various processing steps - semi-autogenous grinding, acid leaching , countercurrent decantation, solvent extraction , ammonium diuranate precipitation, washing and drying, and tailings disposal.

Jan 1, 1978

By A. S. Gendron

A brief description of Inco's ORC copper refinery tankhouse and the electrowinning tankhouse is followed by a comparison of the requirements for the production of the high-quality copper in both systems. The description will focus on both tankhouses, with emphasis on experience to date in the electrowinning tankhouse. Particular attention will be paid to sensitivities of each tankhouse to process upsets which can. significantly afject the quality of the product cathodes.

Jan 1, 1977

This paper presents the results of research aimed at proposing new solutions in the area of belt conveyor elements. Many factors, such as energy consumption costs, and operating costs of belt conveyor elements, including belts, idlers and drives have an impact on the operational costs of conveyors. The paper presents special tests of new materials for the bottom cover of an energy-saving belt conveyor, which decrease rolling resistance. It also presents large-scale in-situ tests of a high-output belt conveyor for the purpose of simultaneous measurements of various types of conveyor belts (standard vs several energysaving types) under typical operating conditions of a lignite surface mine. Improvements in materials used for the bottom belt covers, supported by specially developed comprehensive tests of the new types of belts have provided valuable results of various proposed solutions. Since the tests of belts were done at exactly the same time and in the same operating conditions, direct comparison of the results is valid and should lead to a substantial decrease in the conveyors? drives? energy consumption, which will improve the effectiveness of belt transport and minimize its negative influence on the environment.

Aug 1, 2013

By Tsuyoshi Adachi

Photovoltaic (PV) system is especially taken notice as one of important renewable energy resources, because PV has potential to provide a certain amount of energy supply as well as without greenhouse gases emission. Considering recent rapid increasing demand for PV system, more expansion of PV system is expected in the future. However, some precious metals and minor metals such as silver, indium and others are used as component materials of solar cell in PV system. Even if energy supply would become renewable, strict limitation of these metals still remain because amount of natural resources and recycling of metals has restrictions intrinsically. The aim of this study is to reveal the possibility of materials supply restrictions for Photovoltaic system quantitatively and to propose several measurements to assess supply risks for materials. Especially, silver supply potential which is used as wire line in PV system as well as PV demand forecast to estimate material use in the future are focused on. We divide underlying supply risk into 5 measurements and analyze them by time series, i.e. price volatility, resource potential, recycling ratio, production type and supply concentration are investigated. Comparing these factors of silver with other metals, the potential of silver supply for PV is presented. In addition to it, we propose another method to quantify country risk applied an insurance pricing model in finance pricing theory and combine it with the supply concentration measurement. As a result, supply risk of silver will increase gradually in the near future because of its resource constraints and supply-demand balances although silver market is sufficiency competitive one. From the country risk analysis, Peru is not only a significant supply country but also has the highest country risk. Some higher risk countries will increase the level of supply risk even if the concentration ratio of supply indicates moderate level.

Aug 1, 2013

By K. Purazrang, P. Musavi Garavi, P. Sh. Naseri, P. Abachi

The fracture behavior of high strength Al7050 alloy was investigated at room and elevated temperatures using small size, V-notched tear (called Kahn specimen) and compact tension, CT, specimens, respectively.To study the elastic-plastic behavior of the alloy, the tensile test was also performed on the sub-sized cylindrical tension test specimen. The microstructure of the alloy was examined using optical- and scanning electron- microscopy. The rupture mechanisms and crack path were also studied by examination of specimens' fracture surfaces using SEM. The microstructure examination revealed equiaxed grains and some elongated grains in rolling direction, with the areas of partial re-crystallized grains where coarse intermetallic particles are mostly found.In general, fracture surfaces were indicative of dimpled ductile type. Considering the fractographs of tensile specimens, the void growth mechanism is also dominant in fracture of these specimens. Nevertheless, in some regions, smooth areas can be observed due to the friction during rupture process. The results of mechanical tests at RT made the evaluation of tear strength to 0.2 % tensile yield strength ratio, as a measure of notch toughness, available. According to elevated temperature, 150°C, test results and plots of log da/dt vs. log KI , the crack propagation behavior over discrete ranges of crack growth rates could be assumed linear and then be obeyed as a power law equation in the form of da/dt = A (KI)n .

Jan 1, 2015

By P. Cheung, J. Gulyas, R. Clary

Over the past 50 years, the use of autoclaves in the metallurgical industry has evolved from final metal recovery (hydrogen reduction) and purification (sulphide precipitate oxidation) to treating whole ores and concentrates. Recent process developments, such as the use of autoclaves for laterite leaching, have necessitated higher temperature and pressure operations, which in turn have seen marked advancements in technology and manufacturing capabilities to keep in step with process demands. This paper will discuss the advances in technology in terms of design, materials and construction of autoclaves and liners, typical dip tube design and geometric layout. This paper will also address specific auxiliary equipment, such as acid and steam injection systems, and components, such as agitator seal systems.

Jan 1, 2004

By J. S. Redpath

There appears to a definite trend toward the hoisting of greater tonnages from greater depths. There is every indication that this trend will continue and we feel that improvements in the design, fabrication and installation of mine guides will be of significant importance in the future. The present state of the art in mine-shaft guide systems is reviewed and the parameters required for improvement are derived in this paper. Finally, a proposal is made for a new steel guide system which meets the parameters and is economical to fabricate and install.

Jan 1, 1977

By George F. Crocker

Introduction The Helen mine and the Victoria mine of Algoma Ore Properties, Limited, in the Michipicoten district, Ontario, are 120 miles north of Sault Ste. Marie, on the north shore of lake Superior. They are on the Algoma Central railway between Hawk Junction and Michipicoten Harbour. Between them, these mines have produced 10,757,113 tons of iron ore. From 1900 to 1918, 2,823,369 gross tons of brown ore was shipped, and from 1939 to the end of 1949, 7,933,744 tons of siderite was produced from the open-pit operations and underground development. The finished product, known as 'Algoma sinter', is shipped to blast furnaces both in Canada and the United States. The iron-ore bodies are a part of a tabular shaped area of iron formation that extends over a length of more than 10,000 feet and has maximum width of 1,000 feet. The two siderite orebodies, known as the Helen and Victoria, are separated by two diabase dykes. The Helen orebody is 1,600 feet long with a maximum width of 250 feet and the Victoria is 1,200 feet long with a width comparable to the Helen. These orebodies are considered to be a replacement of the original rock by iron carbonate. The introduction of the iron-1bearing material probably occurred after the development of the major folded structures. The open-pit mining of siderite started in the Helen ore body in 1939 and continued until 1945. During this period, 3,853,395 tons of ore was mined. Open-pit mining started in the Victoria body in 1946 and is still being carried on. Underground development commenced in September, 1947. Diamond drilling and surface sampling had shown the Helen deposit to average 35.61 per cent Fe and 7.28 per cent SiO2, and the Vi.otoria deposit 33.73 per cent Fe and 10347 per cent SiO2?

Jan 1, 1950

By A. Abdollahi

Modification of the silicon in Al-Si alloys can be performed by adding a very small amount of some elements like Na, Sr and Ca to alter the form of silicon from an acicular shape to a fine fibrous one. This modification results in a considerable improvement in mechanical properties especially elongation, Metallographic observations in A356 alloy indicated the degree of the modification with Na, Sr and Ca, They showed that the effect of Ca as a modifier is not as strong as is Na or Sr while Na is the most effective modifier, Although modifiers improve mechanical properties, they also increase porosity in castings, The reduced pressure test (RPT) and Tatur test showed that the increasing porosity with Na is the most and with Sr is the least.

Jan 1, 2004

By M. J. Sapko, R. W. Watson, E. S. Weiss

The relative incerdivity of several blasting agents was evaluated in the Bureau's Bruceton Experimental Mine (BEM) . The minimum charge weights resulting in the ignition of predispersed oil shale dust clouds were measured for each of the explosives. A 400 g unstennned charge of ANFO (ammonium nitrate-fuel oil) was sufficient to initiate an oil shale dust explosion, whereas a 1000 g unstenuned charge of an emulsion blend did not ignite the dust even with the addition of 4% methane gas. Several stenuning materials were evaluated in the BEM for their effectiveness in preventing the ignition of near stoichiometric methane-air mixtures. Water stenuning was superior to all other inhibitors tested against methane. Explosibility testing of fine sulfide ore dust in a 20 L chamber and in the BEM show that the dust is capable of propagating an explosion given nominal concentrations of 700 to 800 g/m3. Results are encouraging and irrlicate that there is merit in pursuing explosive composition as a means of reducing ignition probability of oil shale and sulfide dust clouds generated during nonnal blasting operations. The proper selection of explosives and stenuning materials should significantly reduce the probability of secondacy dust explosions in oil shale and sulfide ore mining.

May 11, 1988