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By A. F. Robertson

FOR several years, the rock-burst question has been given serious consideration by the operating staff at Wright-Hargreaves mine and, as a result of observations and experiences, several different methods of mining have been developed which are now in use in various parts of the mine. These are described in the following pages. It should be emphasized, how-ever, that these methods, and the views expressed in this paper, are based solely on conditions at Wright-Hargreaves mine. Such conditions may or may not be similar to those obtaining in other mines in the Kirkland Lake area, where ore occurrences, veins, wall-rock, faulting, intrusives, etc., may be entirely different. Size and shape of ore-bodies, composition of the ore-bodies and their surrounding rocks, locations of intrusives and sedimentary rocks, and direction, dip, and strength of faults, all introduce problems that are peculiar to each individual mine. Ground failure' in coal and metal mines is not at all unusual. A variety of systems of mining have been developed to delay movement of large or small blocks of ground, or, in some instances, to take advantage of the fact that ground movement, due to mining operations, is unavoidable. Ground failure may be either slow collapse or it may take place with explosive violence. It is principally with the latter condition that we are concerned in the mines of the Kirkland Lake district.

Jan 1, 1939

By Kent Zehr

Suncor Energy Inc. is an integrated producer and refiner of oil and gas headquartered in Calgary, Alberta. The bulk of revenue comes from the Oil Sands Group (OSG) operating in the McMurray formation of the Athabasca Oil Sands. Located some 25 kilometers north of Fort McMurray, Suncor OSG began life in 1967 as Great Canadian Oil Sands, the first operator to successfully enter commercial production of synthetic crude oils from the area. For most of the last decade, dramatic growth has been the standard mode of operation for Suncor OSG. Production of synthetic crude first reached 100,000 barrels per day in 1997 and less than five years later is averaging in excess of 200,000 barrels per day. Within this dynamic organization, Suncor Extraction is the business unit that processes run-of-mine ore into clean diluted bitumen for Upgrader feedstock. Extraction also delivers and places the barren sand and process affected water into tailings storage in one of several ponds from which water is recycled to support the various processes. For reference purposes, Extraction on a typical day currently receives more than 400,000 metric tons of oilsand ore, which is all processed to water based slurry for separation in one of two extraction plants. Separated tailings are disposed of as a slurry and the cleaned bitumen froth is diluted with naphtha and sent to tankage for storage until required by the Upgrading Unit. As a consequence, on a typical day Suncor Extraction pumps more than 1,000,000 tonnes of aggressive slurry into and out of the two extraction plants.

May 1, 2003

By R. G. Eggert

"A critical element, as the term has come to be used, provides essential properties to a modern engineered material and is subject to supply risk. The rare-earth elements became perhaps the most prominent of the critical elements in recent years because of their important uses in permanent magnets, advanced lighting, and military materials; the geographic concentration of production in China; and the dramatic run-up in prices in 2010-2011 followed by price collapse between 2011 and 2016. Yet criticality extends beyond the rare earths. What is critical depends on your perspective – who and where you are, and when you ask. This paper reviews the many perspectives on, or faces of, critical elements. It compares and contrasts perspectives of industry (General Electric), national or regional manufacturing sectors (Japan, European Union), emerging energy technologies (as seen by U.S. Department of Energy and, separately, Joint Research Centre of the European Commission) and the world as a whole (as evaluated by academics). This comparison reveals a diversity of not only perspectives but also methodologies and time frames of concern.INTRODUCTIONRare-earth elements appeared prominently in the news in 2010 and 2011 because of the dramatic increase in their prices; their important uses in permanent magnets, advanced lighting, and military materials combined with the geographic concentration of production in China, which reduced export quotas significantly. Rare earths became the most prominent of what have become known as critical elements or materials – that is, those that provide essential properties to modern engineered materials and yet are subject to supply risks.Yet criticality, the state of being both essential and subject to supply risks, extends beyond rare earths. What is critical depends on your perspective. This paper begins by reviewing a little history and presenting a general conceptual framework from which to think about critical materials. It then reviews the many perspectives on, or faces of, critical elements – corporate, national, and global, as well several that focus on emerging energy technologies. The paper concludes with thoughts on what to do to mitigate the potentially negative effects of the supply risks associated with criticality."

Jan 1, 2016

By Xue Yang

Even though many approaches have been proposed for automated fault detection and diagnosis of Heating Ventilation and Air Conditioning (HVAC) systems, and advanced maintenance programs, such as preventive and predictive maintenance have been applied for the systems, issuing work orders for corrective maintenance is still a reality. Currently corrective maintenance still accounts for more than 55% of all maintenance programs in average facilities in the US (DoE, 2010). Indoor air related problems are especially important among corrective maintenance work orders. This paper provides details of a case study conducted to capture the workflow that HVAC mechanics follow, their rationale in diagnosis process and the information they typically refer to while responding to indoor air related corrective maintenance work orders. The general workflow for HVAC mechanics to complete such types of work orders was summarized into 5 stages, and generic information requirements recorded from the case study were synthesized. Initial findings show two main challenges in the industry for HVAC mechanics to get access to required information, which highlights the need for a systematic approach that would enable identification of such information applicable to a given context under which a work order has been generated and provide values of required information for HVAC mechanics to do sound diagnosis through integrated data repositories.

Aug 1, 2013

By Karl J. C. Harries

This paper looks briefly at some of the agreements and types of royalties that may be met during exploration activities, but does not go into details relating to them. Agreements can either make or break a deal or relationship. A well drafted, comprehensive and fair agreement can create good relations and trust among the parties and will go a long way towards making a deal work. In the best of all worlds the agreement will be put away and not need to be referred to after it has been signed (but it will be there if needed to sort out potential problems). On the other hand, a poorly drafted agreement or one that is inappropriate to the circumstances or unfair to one of the parties can break a deal and end up with the parties facing each other in that expensive, unproductive and time-consuming occupation ? a lawsuit. Accordingly, it is advisable to involve professional advisers with any agreement. The straightforward one may involve no more that a read through whereas the more complex agreement will require considerable involvement. There is, however, one rule for every explorationist to remember: a professional adviser is only an adviser. His responsibility is to make sure that you have the necessary information to make a reasoned decision but the decision is yours, not the adviser?s. It is your deal, you are going to have to live with it, and it is inappropriate for an adviser to introduce new concepts or amend negotiated ones without your specific instructions. Mineral exploration agreements, although basically option, acquisition and joint participation agreements, come in all the shapes and forms, appropriate to give effect to the endless variety of deals negotiated by the ever-active minds of explorationists. You will note the reference to "joint participation agreements" rather than "joint venture agreements". The latter term was purposely avoided because, with the current activity of explorationists from common law jurisdictions in civil law jurisdictions, it has become necessary for the explorationist to become familiar with corporations and shareholders agreements. As most of you are no doubt aware, under the civil law system a joint venture is normally not recognized as a legal entity and, therefore, joint participation in projects is usually by way of corporations.

May 1, 2003

By A. J. Paul Laprairie

"ADVANCE planning of mining methods, from the first development openings to stope layout and pillar recovery, has long been accepted as a normal method of operating a mine. Recently, mine managers have become increasingly aware that advance planning of cost and accounting controls can also be considered a normal method of operation. The use of such controls is wide-spread in manufacturing industries. In mining, the gold mines of South Africa have pioneered, with marked success, in this field and have been closely associated with most of the research and field work in accounting control. Canadian mine managers are also beginning to realize the advantages of using planned costs. The control procedures which subsequently have been introduced at various mines have come to be known by such names as ""Responsibility Costing"" or Budgetary Control"".Budgetary control, the term used in this paper, is based on the concept of decentralized authority with centralized control. ;The control is achieved by measuring results against yardsticks which are in the form of budgets or standards. Bud-gets are made for the future activities of each possible operation as planned by the department head, and attention is directed to variations from this plan. Furthermore, the control process charges to each operation only those costs which are incurred directly for that operation, and which can be controlled by the person in charge. Thus, budgetary control relates results to the officials responsible for those results. Expenditures are analyzed according to the organizational structure of the mine and the people who run it, and not according to production processes."

Jan 1, 1960

By Eldridge Haynes

IF you ask the average American to define 'total war' he is apt to fumble for an answer. But in Britain everyone knows the answer, because Britain has mobilized its total labour force, including women. If we were to match, proportionately to our population, Britain's mobilization of labour, we should have 60,000,000 people working full time in the armed services, civilian defence, and war industries. Actually we have fewer than 35,000,000 so employed. In Britain two out of every three persons between the ages of fourteen and sixty-five are so engaged. For the first time in the history of any democracy Britain conscripts women for service in the army, navy, and air force. Two hundred thousand British women have been conscripted for the army, known as ATS, meaning Auxiliary Territorial Service. There are more women in the air force than the total personnel of the RAF at the outbreak of the war and almost all of the land base jobs of the British navy are now handled by women. In addition to cooking and office work, Britain's women soldiers and sailors are driving trucks and motorcycles, repairing motor vehicles, packing and repacking parachutes, installing, inspecting, and maintaining gun equipment and ammunition of combat planes after each raid, raising and lowering barrage balloons, forecasting weather, manning harbour craft, sending and receiving radio messages. A normal ack-ack unit is composed of 229 women and 189 men. The women man the gun height finders and predictors, give bearings, and signal to fire.

Jan 1, 1942

By Mark Freberg

"IntroductionThis chapter is intended to provide information on the operation and maintenance of several pieces of equipment used in heavy media separation. Most heavy media separation circuits, particularly those involving bath separators can be considered as high maintenance areas. Because of this the efficient operation and maintenance of these circuits is very important if the cost per ton of material treated is to be kept to an acceptable level.Heavy media separation (HMS), is a process used to separate particles of different specific gravities. Under laboratory conditions the ideal way to separate two types of particles which have different specific gravities is to suspend them in a heavy liquid which has a specific gravity between those of the two types of particles. Those particles with the lower specific gravities will float on top of the liquid while the higher specific gravity material will sink to the bottom. Given enough time and a sufficient volume of heavy liquid this process will be essentially insensitive to the sizes of the particles involved.Heavy media separation circuits make use of the same principles described above. The material to be treated is introduced into a mixture of finely ground solids, called media, and water which takes the place of the heavy liquid; the mixture of solids and water is known as medium. The separating force can be either gravity or centrifugal force. The type of solids used as media varies but it is usually a high specific gravity material such as magnetite, galena or ferrosilicon.Heavy media separation is used extensively in the cleaning of coal and to a lesser extent as a preconcentration step in base metal and iron ore operations."

Jan 1, 1989

By Melanie Grob

Two commonly estimated fractal dimensions, called b and D values, represent statistical characteristics in the distribution of magnitude sizes (b) and spatial hypocenter locations (D) of microseismic events, respectively. We postulate that the values of b and D are related to specific stress regimes. Through different case studies of fluid injection into an oil/gas reservoir or geothermal field, we infer that the measured temporal variation in fractal dimension b is most likely due to significant changes in the local stress regime. The fracture dimension D indicates the spatial clustering of events. The distribution of these events can vary with time because of stress perturbations that (re)activate fractures whose direction favours their movement under a specific stress regime. Thus a combined statistical study of these two dimensions can help infer the variations of local stresses in a reservoir.

Jun 1, 2012