Search Documents

By H. W. Fleming

In 1955, the results of a regional, geological interpretation of the northern portion of New Brunswick were used as a basis for selecting, for intensive exploration, three areas in which structural and stratigraphic conditions were believed to be favourable. Airborne electromagnetic work, in one of these areas, provided the justification for acquiring the Murray group. Even though the initial results were discouraging, this geological interpretation, combined with the fortuitous discovery of cop• per-bearing float, was sufficient reason for carrying out further work using geochemical methods. This work finally resulted in the discovery of the Murray massive-sulphide deposit, after about eighteen months of coordinated exploration on the property. While this deposit is a typical New Brunswick-type base-metal occurrence, extensive leaching has produced a fossil gossan that rendered it an elusive target for exploration techniques of limited penetration Full credit for localizing the target area is given to the geochemical techniques, but geophysical surveys were needed to provide the necessary

Jan 1, 1961

By B. L. Dorey

"Performance management is a systematic, practical approach to managing people. It is founded on some basic assumptions about people and is designed to focus on people in the work place. Organizing meaningful information and using it to involve people is a cornerstone of this system.Some common sense practices are developed to involve people in an organization's effort to improve performance. The successful implementation of this program requires solid commitment and total involvement from all levels of supervision and employees for maximum results and lasting impact. All levels of supervision participate in training sessions to tailor the systems for implementation in their areas. This style of management is data-oriented and the bottom line of success is to measurably improve performance. Basic Assumptions about PeopleMost people in an organization, regardless of level, take pride in their work and generally want to do a good job. When performance falls off, there is usually some explanation other than the employee not really caring. People like to know their exact responsibilities and clearly what is expected of them. People like to know where they stand with the boss and would like to be evaluated on what they do and accomplish, rather than on what others think or feel about them. Further, people like to be rewarded for their good results, indeed, to understand what motivates people, we must look at what happens as a result of their actions. Another belief is that supervisors often have a greater influence on the performance of their people than they fully realize. Simply letting people know how important their performance is can have an impact. The Key ElementsGiven these basic assumptions and beliefs about people, some common sense practices have been systematically developed to manage more effectively."

Jan 1, 1989

By J. F. Wang, Y. Jin, Z. L. Wang

Smelting reduction as an ironmaking technology for the 21st century has been challenging the traditional blast furnace. The process has many attractive advantages over the blast furnace, however, the massive by-produced coal gas mainly containing CO, H2 and CO2 requires further treatment. From a chemical engineering view, coal gas is a valuable chemical stock and can be transformed into hydrogen-rich synthesis gas. Hydrogen can be directly used as clean fuel and synthesis gas can be used for the production of some important chemicals such as methanol, ammonia and dimethyl ether. Among those chemicals, dimethyl ether as an alternative clean fuel for diesel engine and liquefied petroleum gas has been drawing more attention. It has excellent environmentally-benign behaviours not only in compression ignition combustion, but also in the much lower emission of SOx and NOx. In this work, a combined technology of smelt reduction ironmaking and direct synthesis of dimethyl ether, which will strongly promote the energy efficiency, environmental protection and resource recovery, is proposed and described in detail.

Jan 1, 2004

By Engin Burak Anil

Objective, accurate, and fast assessment of damage to buildings after an earthquake is crucial for timely remediation of material losses and safety of occupants of buildings. Laser scanners are promising sensors for collecting geometrical data regarding the damaged states of buildings, as they are able to provide high coverage and accuracy at long ranges. Yet, we have limited knowledge on the performance of laser scanners for detecting earthquake damage, and requirements of such data collection. This paper focuses on characterizing the performance of laser scanners for detecting thin cracks for damage assessment of reinforced concrete frames. We identified a series of crack parameters based on the state-of-the-art damage assessment codes and standards. Similarly, we identified parameters, which affect the performance of laser scanners for detecting cracks, based on prior research in this area. We studied the width, depth, and orientation of cracks; sampling interval of the scanner, and the range of the laser beam from the surface. Effects of these parameters on the detection of the minimum crack size were determined in an experimental setting. An automated algorithm was used to analyze the data. The results show that it is possible to detect as small as ~1mm cracks.

Aug 1, 2013

By G. J. Hamilton

"THE Royalite-Canada Southern Coleville No. 1 gas strike of August 15th, 1951, and the closely following low gravity black-oil strike of August 23rd, were the first of a series of recent oil and gas discoveries in western Saskatchewan. They are in what is now known as the Coleville field, 25 miles north and west of Kindersley and 30 miles east of the Alberta-Saskatchewan border (Figure 1).Gas flows have been recorded in the Viking sand at daily rates of between 5 and 10 million cubic feet, and black oil of 15° A.P.I. gravity is produced from Mississippian sediments of Banff age at a daily rate .of 50 to 100 barrels on pump.Development drilling was carried on during the winter months, with very little attempt at step-out exploratory ventures. This year, however, a step-out programme to the northeast (Figure 2) is •being carried on in order to determine the position of a possible truncation of Mississippian sediments in that direction. Section 30 of the Coleville area has been fully developed on a 20-acre wellsite basis, and structural information is restricted to local rather than regional interpretation. No attempt will be made in this paper to interpret the Coleville area with respect to the regional geology in any but a general manner."

Jan 1, 1952

By N. Romani, R. Provost

"Commissioning of a circulating dry scrubber plant was recently completed at an existing facility, in order to treat the sulphur dioxide off-gas emitted from rotary kilns. Proper planning of the different commissioning stages and staffing an integrated team are the most important factors required for a successful plant start-up. A strong operational readiness plan must be in place as early as the start of construction in order to ensure a smooth transition from commissioning to operations. Plant performance can meet or exceed performance criteria within the required timeframe if the proper group dynamic and good communication is established between construction, commissioning and operations teams.INTRODUCTIONCommissioning of a circulating dry scrubber (CDS) plant was recently completed at an existing facility in Quebec, Canada. The CDS plant treats the sulphur dioxide off-gas emitted from rotary kilns in order to meet increasingly stringent environmental requirements. This installation enables the existing facility to reduce their sulphur emissions by over 90%.The CDS ProcessA general overview of the CDS process is presented in Figure 1 below. The combined, de-dusted off-gas from multiple kilns is sent to the CDS, which acts as an entrained fluid bed, where the gas is contacted with a water mist, re-circulated solids and hydrated lime. The SO2 from the gas stream and the available calcium hydroxide (Ca(OH)2) from the hydrated lime dissolve in the water and react to ultimately form calcium sulphites and gypsum. The solid residue (referred to as CDS residue), is the primary byproductof the process.Fresh hydrated lime and CDS residue is captured by the dust collection system and is re-circulated to the CDS via a fluidised transport system. Clean off-gas passes through the dust-collection system and is then sent to the atmosphere by a single exhaust fan.The CDS residue purged from the system is combined with the dust collected from the kiln offgas system and this mixture is wetted in the already exiting agglomeration system, to minimize dust generation during handling, and then sent to disposal."

Jan 1, 2016

"With the plethora of cable bolts on the market, geotechnical engineers can be baffled by the differences in performance claims from the manufacturers but perhaps more importantly they are sometimes at a loss in making an optimal selection matching behaviour with a particular site condition. To this end a new testing methodology has been developed that can cater for the varying types of cable bolt behaviours. The methodology is based on the laboratory short encapsulation pull test (LSEPT) as recommended in the British Standard and overcomes several deficiencies such as cable rotation. Of most significance however, is its inability to measure the post-peak residual performance of high load transfer capacity cables and consequently, there is an inference that these cables may be susceptible to sudden anchorage failure with relatively little yield. This paper details the results of anchorage performance tests of a range of cable bolts and the differences in performance with rock strength and drill hole diameter.INTRODUCTIONA research project was undertaken to develop a new laboratory-scale test apparatus to study the axial performance of fully grouted cable bolts that are used in the Australian underground coal mining industry. Work by Thomas (2012) and others in recent years found there were a number of deficiencies in the testing methodologies making it difficult to determine and compare the performance of the dozen or more different types of cable bolts on the market. This has meant that geotechnical practioners have been hamstrung in optimizing the design of ground support systems in underground environments that are increasingly more arduous.A cable bolt is a flexible tendon consisting of a quantity of wound wires that are grouted in boreholes at defined distances between holes in order to provide ground reinforcement of excavations (Hutchinson & Diederichs, 1996). They were initially introduced into the underground hard rock mining industry in the 1960s (Thorne & Muller, 1964) and since the early 1970s have been brought to coal mining operations."

Jan 1, 2015

By D. J. Reddish

The paper describes a case study where numerical modelling has been applied to predict potential risks associated with inflows of water in active mine workings from an overlying sandstone aquifer. The objective of the modelling was to predict the development of strata fractures and strains as the longwall panels were extracted and investigate their relationship to an sandstone aquifer. The numerical modelling study also included the investigation of the effect of mining on a fault that existed close to the start position of one of the panels. The potential effects of mining on the fault were undertaken by parametric studies adjusting properties for the fault and the relative position of extractions, which allowed the mine planner to position the panel layout accordingly.

May 1, 2003

By M. Y. Williams

Introduction During the economic investigation of Pacific Great Eastern Railway subsidy lands, the P.G.E. Survey of Resources made a geological and mineral survey of a large part of the valley of the Peace river as included in the Province of British Columbia. The immediate valley of the Peace river was surveyed from the mountains to the Alberta boundary; the valley of the Pine river was surveyed throughout; and the Dominion block, 70 miles square and lying astride the Peace river, westward from the Alberta boundary, was very carefully surveyed. The writer was in general charge of the field work, and spent half the field season of 1929 and the field season of 1930 in the region . J. B. Bocock, however, did the major part of the work, spending two seasons, 1929 and 1930, in the area. General Conclusions The rock formations within the area discussed are all sedimentary and range in age from pre-Cambrian to recent. As might be expected, the minerals are in the main non-metallic, coal being by far the most important. Favourable conditions exist for natural gas occurrence, and suitable structures for petroleum concentration occur, although the high carbon ratio of the coals sheds considerable doubt upon the actual occurrence of oil in the area. Materials of minor interest are ochre, calcareous tufa, marl, limonite, gravel, and building stone.

Jan 1, 1934

By D. S. Cronan, S. P. Varnavas

Abstract - Metalliferous precipitates from submarine hydrothermal discharges have been investigated at four inshore locations off Milos in the Hellenic Volcanic Arc. The fine fraction of the sediments shows considerable variability in the concentrations of elements frequently associated with hydrothermal activity. Manganese varies from 30 ppm to 2500 ppm, encompassing the entire range of values found off Santorini also in the Hellenic Arc. Iron occurs in lower concentrations than off Santorini and Yali, while other elements often associated with hydrothermal activity such as Pb, Zn, As, and Cu also show enrichments in sediments from the hydrothermal vent areas. Selective leaching studies have shown that most elements are variably distributed between the different phases of the sediments but with enriched Pb, Zn, and Mn mainly in easily soluble secondary phases. Hydrothermal inputs are strongest at Palaeochori Bay, less at Voudia Bay and lowest at the Airport Springs and Rivari. The weathering of sulfide and possibly other orebodies is also thought to contribute to some of the elements enriched, while background concentrations are largely supplied from detrital sources.

Jan 1, 1999

By Q. J. Xu

In blasting sensitive areas, the use of traditional blasting for rock fracture is restricted. Soundless cracking technology has been presented to achieve rock fracture instead of blasting. However, when the diameter of a borehole is larger than 50 mm, it is very dangerous that the soundless cracking agent (SCA) will have a tendency to gush from the borehole, which also leads to cracking failure. In this paper, a new large scale borehole soundless cracking technology is presented, using a new enlarged drill bit and mechanical plugging, which could solve the hole gush problem. Experiments were made to measure the expansive pressure of the SCA working in boreholes of F40 mm and F100 mm. The difference between two sizes of cracking phenomenon was compared and analyzed to show that large scale borehole soundless cracking has larger expansion pressure and faster reaction speed than traditional soundless cracking. Based on the experimental data, finite element analysis was utilized to study the stress concentration and stress distribution between two neighboring large boreholes in several media during the cracking process. Using the data from experiments with finite element numerical simulation, the brittle material fracture condition was analyzed to design the parameters of the borehole mesh. With the theoretical analysis, the technological process and reference parameters of large scale borehole soundless cracking were proposed, including the borehole spacing, burden distance, depth of the borehole and so on. Then a single rock was cracked with the new enlarged drill bit and new plugging, and the results proved the feasibility of the new large scale borehole soundless cracking technology, which achieved the expected goal of improving the cracking ability and reducing the cracking time. This paper presents a new efficient rock cracking method for blasting sensitive areas, and which could apply to mining engineering, demolition engineering, excavation engineering and other engineering applications where there is a demand soundless and non-vibration fracturing of rock.

Aug 1, 2013

By P. Hr?enjak

Two groups of methods are usually used in design procedures of underground excavation of dimension stone: the analytical and numerical methods of analysis. In all of these methods the in situ rock mass strength represents the main problem. This is due to massive rocks in dimension stone deposits, consisting of large blocks of rock separated with particular discontinuities, for which the Hoek-Brown empirical criterion, developed for jointed rock masses, cannot be realistically used to estimate rock mass strength, especially for a particular block of rock mass or a particular pillar. On the basis of the regular underground excavation process of dimension stone by separating blocks with the flat jack application, we developed the in situ flexural strength testing method. We carried out numerical analyses and evaluation of uncertainty of measurement in order to validate the in situ flexural strength testing method. On the basis of very good validation results, as well as results of the in situ flexural strength testing of exploitable layers on the ?Kanfanar? quarry, we introduced a new coefficient of reduction, which can be used for correction of other strength parameters determined by laboratory testing for obtaining a realistic value of rock mass strength.

Aug 1, 2013

By Robert B. Parsons

"The Province of Manitoba tabled a Budget on March 11, 1992, which contains some important new initiatives designed to improve the fiscal environment for mining in the province. In addition, the Minister of Energy and Mines has released details of the Mineral Exploration Incentive Program which was originally announced in the 1991 Budget.Introduction""We recognize the important contribution o f mining to the economic activity of our province, including direct and service jobs and export earnings. We are determined to secure its future."" - The Honourable Clayton Manness, Minister of Finance, Province of Manitoba, March 11, 1992.With these words of introduction, Manitoba Finance Minister Clayton Manness announced a number of significant measures aimed at improving the fiscal regime for exploration and mining in Manitoba. At the same time, details of the Manitoba Mineral Exploration Incentive Program (MEIP) were released."

Jan 1, 1992

By Robert B. Parsons

"New Brunswick Finance Minister John Baxter pulled something out of a hat for the mining industry in April, but there is a general concensus in the industry that he should put II back where it came from.The industry has never been in the mood f or progressive rate structures, but that is exactly what New Brunswick 's 1984 budget offers to this depressed sector of the economy.IntroductionThe Province of New Brunswick stunned the Canadian mining community in April with the announcement that the province' s 16% mining tax rate would be replaced with a progressive rate structure effective January 1, 1984 (Table I). The proposed change, contained in the bud get papers tabled by Finance Minister John Baxter on April 17, caught the industry totally by surprise. The move to a progressive rate structure was completely unexpected for a variety of reasons:• Generally speaking, relations between the province and the industry have been relatively good, yet the industry was apparently not consulted with respect to the proposed measure and had no indication that a change of th is nature was coming. This is in stark contrast to the mood which prevailed during the major revamping of the province' s mining tax regime in 1977: at that time, the industry was invited to contribute in advance to the province's plan for a new tax structure.• The new structure would appear to make th e province less competitive in terms of mining tax rates with Ontario , Quebec, and other provinces, despite indications in the past that New Brunswick is very cognizant of this competitive factor in formulating mineral policy.• A joint report in November 1978 by federal and provincial officials to federal and provincial finance and resource ministers, which was careful not to directly criticize Ontario and Quebec's progressive mining tax rate structures, recommended that provincial "" tax regimes be examined to ensure the inclusion of appropriate mechanisms to avoid the excessive taxation of cyclical type profit "" , and that ""the federal and provincial governments consider the concern over progressive tax regimes expressed by the industry and examine mining and royalty tax regimes and the income tax regime with a view to alleviating the effect of such regime on the aggregate marginal tax rate"". In this context, any move to a progressive rate structure would be viewed by many observers as retrograde."

Jan 1, 1984

By L. I. Kiss, S. Perron, S. Poncsák, A. Perron

Aluminium industry has an increasing interest in the diminution of the energy consumption of the Hall-Heroult process by the reduction of the anode bottom covering with gas. Electrically isolating carbon-dioxide bubbles, produced at the anode, increase the ohmic resistance of the cell. As the gas production rate is determined by the applied current density, anode covering can be decreased only by a faster evacuation of the gas from the inter-electrode space. Among others, the inclination and curvature of the anode bottom promotes the release of the bubbles and thus decreases the mean value of the covering. Indeed, anode, insert in the molten cryolite bath has a square shape with horizontal bottom. However, inhomogeneous anode consumption, electro-erosion, bath circulation and the inclination of the bath-metal interface modify this shape gradually during electrolysis. Anode bottoms become inclined with rounded comers. This concentrates the gas generation to the center zone of the anode. As the bubble layer cannot be observed directly because of the hostile environment and the opacity of the bath, real scale air-water systems are used to study the impact of the anode geometry on the anode covering and the bubble induced flow. However, the physical properties of such a system are different than that we can found in the real cells. A simulator using the Lagrangian description of the bubble layer has been built and presented in earlier papers. This tool was used to investigate the effect of the anode inclination on gas covering and bath velocity, for both C02-cryolite and air-water system. Results obtained for the second system were compared to experimental data .

Jan 1, 2006

By H. Hejny

Given the current status of political discussion in Europe about raw materials issues, the sustainable development of the extractive industry and the reduction of its environmental and societal footprint are among the key topics in this discussion. In this context, the European Commission approved the EO-MINERS project (Earth Observation for Monitoring and Observing Environmental and Societal Impacts of Mineral Resources Exploration and Exploitation). The overall aim of EO-MINERS is to bring into play EO-based methods and tools to facilitate and improve interaction between the mineral extractive industry, authorities, and the society in view of its sustainable development while improving its societal acceptability. Developing generic, standardised and reliable EO-based products to monitor the environmental and societal footprint of mining projects is the way chosen by EO-MINERS to improve this interaction, along with the organisation of tripartite meetings gathering all relevant stakeholders. The project uses existing EO knowledge and carries out new developments on three demonstration sites (Sokolov lignite mining area, Czech Republic, Witbank coal field, South Africa, Makmal gold mine, Kyrgyzstan) to further evaluate and demonstrate the capabilities of integrated EObased methods and tools in monitoring the environmental and societal footprints of the extractive industry during all phases of a mining project, from the exploration to the exploitation and closure stages. It contributes providing reliable and objective information about affected ecosystems, populations and societies, to serve as a basis for a sound ?trialogue? between corporate stakeholders, governmental organisations and societal stakeholders. The project already developed a set of consolidated indicators based upon previous knowledge about mining-related issues along with interviews of national, regional, and local stakeholders. These indicators reflect known environmental and societal issues at mining sites as well as the interest of various relevant stakeholder groups. The process described in the EO-MINERS project ? policy assessment > indicator identification > choice of suitable EO tools able to serve monitoring task > monitoring by EO tools > making available objective information for fair dialogue among stakeholders ? is generally applicable to all stages of a mining project. The key to success will be the right choice of indicators addressing the problem and subsequently the right choice of suitable EO tools and finally the willingness of all stakeholders to find a common solution. To this end, the EO-MINERS project organises site-specific ?trialogue? workshops at each demonstrations site, which aim to provide relevant information in adequate quality to the stakeholders as common ground for discussions. Local stakeholders, including mining companies, regulatory bodies, and community representatives are invited to participate in these workshops where the relevance of the developed EO-based products to environmental and societal impact assessment will be discussed. The presentation will discuss results obtained during these trialogue workshops, as well as the success and difficulties and reluctances encountered. The project will further indicate ways and means how the EO products and other project results may be used for monitoring purposes in all phases of a mine.

Aug 1, 2013

By G. Chung, W. Petruk, D. Doyle

"A series of tests was conducted on Carol Lake iron ore, which contains about 38 wt % hematite and 19 wt % magnetite, to establish a flowsheet for high weight yield by spirals. A pilot plant was run in parallel with the IOC concentrator to simultaneously test two flowsheets on the same feed material. The IOC concentrator processes the ore by treating it directly in a spiral circuit, whereas the pilot plant used a laconite flowsheet which had a low intensity magnetic separator (LIMS) at the front of the circuit. The LIMS produced a non-magnetic (hematite-rich) product and a magnetic (magnetite-rich) product prior to treating the ore in two separate spiral circuits. The results from about 150 tests were evaluated by chemical assays and materials balancing techniques, and a selected test was evaluated by the image analysis and materials balancing technique.The image analysis and materials balancing evaluation showed that a higher hematite recovery was obtained by the hematite spiral circuit than by the IOC concentrator spiral circuit, and a slightly lower magnetite recovery by the magnetite spiral circuit than by the IOC concentrator spiral circuit. Furthermore the hematite recovery by hematite spirals was higher than the magnetite recovery by magnetite spirals. The better hematite recovery was achieved because a higher liberation is obtained for hematite than for magnetite, and the hematite in the Carol Lake ore has a narrower grain size range than magnetite. Consequently, better spiral control can be maintained when processing a hematite-rich spiral feed, than when processing a magnetite-rich spiral feed. Since the feed to the IOC concentrator spiral is a mixture of hematite and magnetite, an intermediate hematite recovery is obtained by the IOC concentrator. INTRODUCTIONA study of characteristics that affect recoveries of hematite and magnetite from the Carol Lake ores of the Iron Ore Company of Canada (IOC), was carried out in connection with a project on designing a flowsheet for maximum weight yields. A pilot plant using a taconite flowsheet was run in parallel with the existing IOC concentrator which uses a classical iron ore flowsheet. About 150 tests were run to compare iron recoveries and weight yields by the spirals in the two flowsheets. Better iron recoveries were indicated for the taconite flowsheet, but the results were not consistent and the reasons for the observed differences were not apparent. The material from one test (Test 61), which gave better iron recoveries for the taconite flowsheet, was evaluated by the image analysis and materials balancing technique. A suite of samples was taken from 5 points in the IOC concentrator and from 8 points in a pilot plant (taconite flowsheet). The samples were analyzed to compare the behaviours of the Carol Lake hematite and magnetite in the spirals of the two flowsheets. The results provided a sound basis for further tests in designing a high weight yield flow sheet."

Jan 1, 1993

By Roger Lacroix

Presentation outline Project definition Characterization of mine ventilation systems Strategies in place and results Detailed study (2 mines) Other potential energy savings Conclusions Next steps

Feb 1, 2008

By Kernaghan Webb

Organization of Presentation ?Genesis, Premise, Hypothesis ?Background ?Methodology ?Key research questions ?Research Team to Study Kinross Maricunga ?Research Milestones ?Chilean context ?Chilean Legal Framework ?Kinross Gold the basics, CR approach, Maricunga ?Issues, Perspectives ?Concluding remarks

May 1, 2010

By Charles Graham

For hundreds of years the standard vertical mine shaft was rectangular shaped and timber lined. There are many advantages to rectangular shafts but as mines became deeper the circular shaft became more popular. The chief advantages of circular, concrete lined shafts are their ability to resist lateral pressure and they offer less resistance to ventilation air. A number of elliptical shafts have been sunk in an attempt to realize the advantages of both the rectangular and the circular shaft. A concrete lined elliptical shaft provides better space utilization than a circular shaft, would allow for shaft sinking with two double drum hoists, as well as concurrent level development. The design also makes one sided stations possible and provides for a simple headframe design.

Feb 1, 2008