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By R. Heikkilä

As a part of a large research and development program in Finland, a system calibration for an UAV measurement method having practical experiments in a Jorvas Railway Yard design and construction project. The Railway yard construction are was measured using an UAV measurement device by Smartplanes (Smartone) and using some reference points measured by a GNSS device. The measured data was cleaned, combined and adjusted through Least Squares Optimization using the software developed by a Finnish company Pieneering Oy. As references, two different laser scans as well as total station surveys were used. For applicability evaluation, the accuracy of measurement, the reliability of measurement, and the economy of measurement were used. Based on the comparisons, the achieved precision of the UAV measurement was high, instead the accuracy of measurement was not sufficient in this case. The principle of this photogrammetric measurement includes a lot of redundant observations making it possible to achieve a high level of reliability. The economy in this Railway Yard Design project was not able to achieve.

Aug 1, 2013

By J. H. Nantel, J. F. Archibald

"The presence of radon from uranium-bearing ores, waste and from backfill material introduced underground to provide ground support, work platform and waste disposal functions, requires that ventilation controls be established to maintain safe working level concentrations. One approach has been developed at Queen's University to quantify radon and radon daughter source level s and to estimate ventilation requirements necessary to maintain these safe levels.Knowledge concerning the sources of radioactive contaminants and their production quantities is of value for planning and design stages of ventilation control systems. For any given mine layout, radiation level estimates may be forecast and modified by ventilation network design where excessive production quantities may exist.Behaviour of Radon Gas in MinesRadon gas, produced from the decay of Ra-226 in a host medium, will diffuse through porous media. In areas adjacent to mine workings, radon will be liberated into the mine atmosphere. The rate of radon emanation is proportional to the rate at which radon is produced within the host material (a function of the ore grade of U308) , to the radon concentration gradient in the host pores and to the diffusion properties of the material.The radon source concentration is determined by the rate at which Rn-222 is produced by the decay of Ra-226, and by the emanating coefficient (E), or fraction of the radon which escapes from the source matrix and is free to diffuse through the pore spaces."

Jan 1, 1984

By Yve Aymong

"The objective of this paper is to help readers benefit from the practical experience of persons who have been engaged for several year s in the testing and repair of power transformers. Power transformers are known to be reliable pieces of equipment with expected usage of 25 to 30 years, but simple problems such as leaking radiators, or a bad contact on a tap changer, could shorten the life of a transformer. To ensure a longer life span, transformers should be checked on a regular basis.What is a Power Transformer?It can be a 90 MVA transformer for Hydro-Québec or a power transformer can be a 500 KVA unit in a small hospital. Generally a power transformer is an oil -filled type of 3 to 5 MVA. It can also be a dry type transformer, that should be treated in the same manner as oil-filled transformers, and some of the tests explained in this paper also apply."

Jan 1, 1984

By J. E. Dutrizac, J. B. Sunstrum

"Lead was among the first metals known to man, and there are indications that lead was produced by the reductive smelting of galena in the mountains surrounding the Black Sea as early as 3000 B. C .(1). The early metallurgists soon discovered that silver could be recovered from lead bullion by cupellation techniques, and that the litharge product of the cupellation process could be reduced to give silver-free lead metal. By the Graeco-Roman era, lead-silver ores were being extensively exploited for both their silver and lead contents. Although silver was always of prime concern, a number of industrial uses existed for lead that included piping and sheeting. Subsequently, lead metallurgical practice developed steadily in different parts of the world, and was a relatively mature technology by the time of the European colonization of North America. In the United States, lead was produced on a small scale as early as 1720, and by 1800, the extensive Pb-Zn deposits of Missouri-Kansas and the upper Mississippi Valley were being developed(2). Many of the early American lead ores were low in silver, and seemed to have been worked primarily for their lead contents. Major uses of lead at the time included bullets, pipe and sheeting. During the period 1860-1890, the silver-rich galena ores of the western United States were exploited, and a number of lead smelters were operated. Although all the smelters produced lead metal, the recuperation of the associated silver and gold values was generally of prime concern. In Canada, lead deposits are abundant, and galenarich outcrops frequently attracted the attention of the early explorers and prospectors. In fact, the first record of a Canadian ore deposit seems to have been the observation of an argentiferous galena vein near Lake Temiscamingue in 17 41(3). The presence of silver-bearing lead deposits naturally attracted the attention of the mining community, and many outcrops were worked throughout the country. Because of the problems associated with transporting lead concentrates to existing American or overseas smelters, attention soon shifted to the establishment of local lead smelting facilities. The purpose of this article is to examine those early smelting efforts and to try to identify the first ""successful"" Canadian lead smelter."

Jan 1, 1999

By A. Khan, C. Ciriello, W. Oliveira

"The purpose of this paper is to demonstrate the value of Operational Readiness (OR) in the successful delivery of capital projects. OR can be captured using several technical and practical definitions:• To ensure that the capital project being delivered is capable of an effective start up, ramp-up as planned and a sustainable productive operation.• To function as intended when started, with the appropriate people able to run it.• To increase the value in delivering the product/service through established systems, processes and procedures, while simultaneously minimize risk to both the project and the business.Historically, mining and metallurgical capital projects concentrate efforts on cost and scheduling during the implementation and design phases. The completion and subsequent handover of the operational unit is the main objective.When reviewing the mining and metallurgical industry’s capital projects, it seems many poor results and errors in terms of project design and ramp-up are self-inflicted, with the project neglecting to account for key aspects of the future operational plant. Interestingly, if the problems for the future plant occur during project implementation, they can be prevented during the project phase. It is required to connect the operational knowledge with the project in order to ensure an effective start up and operation.The benefits of OR will be shown to be applicable not only to mining capital projects but also to sustaining and business transformation projects. The paper also includes industrial examples showing both proper and improper use of OR techniques.The paper will cover 3 main areas of Operational Readiness: the OR model, OR related risk elements (i.e., risks associated specifically with the improper execution of OR) and conclude with OR specific case studies."

Jan 1, 2016

By M. Rafati

In this investigation, the effects of T4 and T6 heat treatments of AZ91 magnesium cast alloy have been studied. The effects of different microstructural details such as morphology, size and distribution of precipitates and their influence on fracture mechanisms were investigated by optical and scanning electron microscopy. The mechanical strength of the alloy after T6 treatment was found to increase in comparison to the T4 treatment, due to the formation of discontinuous precipitates in the grain boundaries. Precipitation in this alloy occurs in two ways: continuous precipitation, which nucleates and grows inside the grains, and discontinuous precipitation, which forms at the grain boundaries. During ageing, the length of the continuous precipitates increases, and, hence, interprecipitate distance decreases. The formation of discontinuous precipitates causes initiation and propagation of cracks at and the weakening of the grain boundaries. This is the principal reason for the reduction of the ultimate tensile strength in T6 heat treatment in comparison to the T4 condition.

Jan 1, 2006

By J. G. Whellock, R. J. Phillips, J. W. Matousek, P. J. Marcantonio

"Stillwater Mining Company (SMC), a partnership of Chevron Resources and Manville Corporation, produces a copper-nickel, platinum-palladium flotation concentrate at its Nye, Montana mine. The concentrate is then toll processed in Europe. Recognizing the economic advantage of treating the concentrates at the mine site and of retaining this strategic resource in the United States, the Company commissioned Tolltreck International Limited and International Process Research Corporation to conduct pilot scale smelting tests with a flowsheet that would maximize metal recoveries while satisfying the environmental requirements of operations at Stillwater.Primary smelting was conducted in a single phase, 50 k W, submerged-arc, electric furnace. Refining the product mattes to copper-nickel ""white-metal""; containing approximately 2% iron, was accomplished in a Tolltreck, IV-litre, top blown rotary converter. Over-all platinum and palladium recoveries were approximately 99%; copper and nickel recoveries averaged 94%. INTRODUCTION(l-4)Stillwater Mining Company (SMC) a partnership of Chevron Resources and Manville, operates a copper-nickel, platinum palladium mine and concentrator at Nye, Montana, located in the valley of the Stillwater River, approximately, 100 km southwest of Billings. It is North America's only primary producer of these precious metals. The Stillwater area was mined for chrome ore during World War U and the Korean War, but it was not until 1961 that attention was drawn to the similarities between the Stillwater Complex and the Bushveld Complex of South Africa with its deposits of platinum group metals.A concentrated search for platinum was begun by Manville Corporation in 1967. Its presence, together with palladium, in mineable quantities was confirmed in the period 1976-1978, and the first partnership to develop the deposits was formed by Manville and Chevron in 1979. Anaconda joined the group in 1983, and in 1985 its share was purchased by Lac Minerals. In 1988 the interests of Lac Minerals were purchased by Chevron and Manville.The decision to develop the mine and build a concentrator was made in 1986. Construction began in the fall of that year, and the first concentrate was produced six months later, in March 1987. Underground mining is done in a two-shift, five day- week operation. Since startup, the concentrator has operated on a 24 hour/day, 7 day/week schedule, treating an average of 635 tonnes of ore per day and producing approximately 10 tonnes of concentrate."

Jan 1, 1989

"The Schist Lake mine, owned and operated by the Hudson Bay Mining and Smelting Co., Limited, is situated on the northwest arm of Schist Lake, 4 miles southeast of Flin Flon, Manitoba.The deposit was discovered early in 1947, during a diamond drilling program exploring small copper showings along the west shore of the lake. The orebodies came to surface between the mainland and the north end of Stitt Island.Production began in August, 1954, at an initial rate of 300 tons per day. Underground workings have been carried to the 1,700-foot level, where exploration work is now being done.General GeologyRocks of the area are Precambrian lava flows, with associated pyroclastic breccias and tuffs, and related minor intrusions. Their general strike is northwest and their dip is nearly vertical. Shearing is common and is related to the activity which caused intense folding and much faulting in the area. The larger faults and the fold axes trend a few degrees west of north. The lavas are mainly andesitic but a layer of sericite-carbonate schist, which is probably derived from a fine-grained, grey quartz porphyry, occupies most of Stitt Island and extends into the mine area. It is within this layer of schist that the ore deposit occurs (Figure 1).The OrebodiesThe ore occurs as tabular to lens-shaped bodies which strike northwest, dip nearly vertically, and plunge at 60 degrees to the southeast. The ore zone is 800 feet long and has been traced for a distance of 2,000 feet along the plunge (Figure 2). The maximum length of continuous ore within this zone is 200 feet. Widths of individual ore lenses vary from a maximum of 35 feet to a minimum of 2 feet.The ore consists of three distinct types: massive sphalerite-pyrite, massive chalcopyrite-sphalerite, and disseminated chalcopyrite-pyrite. The No. 1, or eastern, orebody is predominantly massive sphalerite-pyrite. The western part of the No. 2 orebody is massive chalcopyrite-sphalerite. The disseminated ore forms the eastern part and the lower end of the No. 2 orebody. All three types of ore, with patchy distribution, are found in the smaller lenses below the 1, 100-foot level.Metallic minerals, in order of deposition, are pyrite, arsenopyrite, chalcopyrite and sphalerite, galena, enargite, and gold. Both massive types of ore exhibit banding in many places, probably as a result of the selective replacement of schist. The disseminated ore was formed as a filling of the interstices in a brittle chert rock which appears to have been crushed by the same forces which produced the schist."

Jan 1, 1949

By M. Jackman

"Froth stability is critically important for an effective separation of fine and ultrafine particles using column flotation. While a desirable froth stability is required to facilitate the drainage of entrained gangue particles for secondary cleaning, excessively stable froths could create problems in separation efficiency and down-stream processing. In this work, we demonstrate that a stable foam was produced using a poly (N-isopropylacrylamide) (PNIPAM) solution at the temperatures below the critical solution temperature. In contrast, very little foam was produced at the temperature above the critical solution temperature (~32 oC) of PNIPAM. We can also tune the foam stability by changing the temperature of wash water. When warm water of temperature of 50 oC was applied, the foam collapsed and diminished. This is probably attributed to the switching of PNIPAM molecules from coiled to a globule conformation as the temperature is increased. Our results indicate that the foamability and foam stability can be tuned by tempartureresponsive PNIPAM. This is the first time that thermo-responsive PNIPAM has been shown to have potential as a modifier of froth stability in column flotation.INTRODUCTIONIn mineral processing, column flotation has become a more prevalent process in the separation of fine mineral particles (typically < 100µm). Traditional flotation cells are sometimes less efficient in selective separation of ultra-fine particles (Kohmuench et al., 2009). The efficiency of flotation columns is dependent on the froth stability at the top of the cell to drain the unwanted gangue particles entrained in the froth. The greater froth height in flotation columns, compared to mechanical flotation cells, gives a longer froth residence time, allowing more of the drainage process to take place before the froth reports to the launderer. Secondary cleaning, by applying a wash water shower to the froth, enhances drainage of gangue particles entrained in the froth, and improves the recovery of the targeted minerals (Finch et al., 2007).While a stable froth is desirable to facilitate drainage of entrained gangue particles, greater amounts of fine particles have been found to contribute to excessively stable froths which could create problems for down-stream processes (Bethell et al., 2012). Operators have tried spraying additional wash water on the froth, and reducing frother dosage to destabilize the froth and to prevent backup at the launderer. The former is sometimes inefficient, and the latter results in unacceptable recovery loss. Currently, the best practice is often the installation of larger froth launderers, adding expensive defoaming agents, and/or using deaeration tanks (Bethell & Luttrell, 2005)."

Jan 1, 2016

By Michel Masse

1. A battery-powered wireless mesh network for dynamic diesel machinery tracking and operating status monitoring. 2. A real-time ventilation model and fan speed optimizer. 3. An OPC server for information interchange. 4. OPC linkage to existing control infrastructure. 5. A Human Machine Interface (HMI) providing data archiving, trending and reporting. 6. Live MS-Excel to interrogate the simulation, controls and optimizer. 7. The battery-powered network mesh also provides SCADA functionality to route optimized setpointsto the fans and automated regulators not linked to PLCs.

Feb 1, 2008

By C. Matthews, A. Vo

Australia is one of the world’s leading exporters of bulk commodities and the extensive use of sampling equipment is key to the successful management of each mining operation. At the process plant, without a full understanding of the feed, product and tails, it is impossible to fully optimise the performance of the plant, such that the metallurgical balance is often open to error. At the port, a statistically correct, bias free and compliant sampling system is crucial to ensuring exported minerals are reflective of their true value and to avoid penalties. Over the last decade, as a result of the iron ore boom, there has been high demand for reliable, representative and standard compliant solids sample systems in Australia. This paper reviews several solids sampling applications at Australian mine sites, the challenges and experience gained and how the implementation of reliable representative sampling systems has provided better understanding of plant process performance, improved plant control and overall benefits to the operations. INTRODUCTION Mining is the primary contributor to the Australian economy with Australia ranking in the top 4 in economic resources for 21 primary industrial minerals in 2016 (Britt, et al., 2017). Australia is one of the world leaders in the export of the majority of its commodities including gold, copper and iron ore (Britt, et al., 2017). Therefore, a suitable and standard compliant sampling system is essential for evaluating plant performance and content verification. At the mine and at the port, the larger iron ore miners in Australia have developed stockpile models to predict the grade of their ore down to individual blocks of the stockpile. This allows the miner to create the right blend of material for sale to their customers and ensures they are not underselling their product or at risk of penalties for impurities or low grade. As an example, the average difference between the benchmark 62% Fe and low grade 58% Fe fines at the time of this report averaged US $20/tonne according to the Metal Bulletin Iron Ore Index (Fastmarkets MB, 2019). At a shipload of 180kt this would be a variation of US $3.6M. Whilst this is an extreme example, it highlights the economic importance of producing the correct grade product and a recognised representative sample of said product.

Jan 1, 2019

The PEMAC Commitment to World Class Industry in Canada The Plant Engineering and Maintenance Association of Canada PEMAC is a national, not-for-profit industry and technical association for plant and facility maintenance, engineering and physical asset management practitioners and professionals. Founded mid 80?s in the last century PEMAC is a knowledge based organization that focuses on sharing knowledge with our members and the profession. We provide education and professional development programs and certification for maintenance practitioners and professionals. We develop, produce and participate in conferences, seminars and trade shows.

May 1, 2008

By J. A. Hillier

"IntroductionThe purpose of sampling is to remove a portion of material from a stream which is representative of it in size, moisture and mineral content.To prevent the effects of segregation, generally caused by the way in which a conveyor, pipe or launder is loaded or directed, the sampler should cut proportionally the entire cross section of the stream.If one conveyor transfers to another at a right angle, fines may be dropped on the near side, and the coarse material thrown to the opposite side. Segregation can also occur as a result of the motion of a conveyor belt passing over the idlers causing the coarse material to roll to the sides of the belt.When slurry changes direction of flow in a launder or pipe, the heavier and coarser fraction will centrifuge to the outside of the curve and tend to remain on one side of the stream. Similarly, if two streams joining in a common launder are not mixed at the point of confluence, they will continue down the launder unmixed . This effect is particularly noticeable in a plastic lined launder.Therefore, a proportional sample is usually accomplished by a constant rate of cutter travel across the entire stream, making certain that the cutter is not full or splashing over before reaching the end of travel.The cutter should operate on a constant interval based on time, tonnage and uniformity of flow. The opening should be at least three times the width of the largest piece to be sampled. The cutter width is more critical with ore samples where particle sizes are large. With slurry samples, the opening is usually much larger than the minimum in order to obtain sufficient samples"

Jan 1, 1989

By W. J. Mcgaughey, R. G. McCreary, S. C. Maxwell, R. P. Young

"Seismic tomography is a process for obtaining images or maps of seismic velocity or other seismic properties of a rock mass. Seismic velocity images reveal variation in elastic moduli which, in tum, are related to several properties required in the geological or geomechanical assessment of a rock mass. Seismic velocity is sensitive to lithology, discontinuities, and in situ stress. Spatial or temporal variation of these properties may be indirectly assessed. Tomographic measurements are sensitive to volumes of ground, rather than determinations at points, or along lines or surfaces, as in conventional geological or geomechanical measurements or mappings.Tomography surveys are complementary to conventional measurements as they have the capability to interrogate a substantially larger volume of ground. They are thus useful in discerning trends or patterns in regions between or surrounding conventional ""point"" measurements of lithology, rock quality, stress, or other parameters of interest. Seismic velocity images give broad indications of trends in velocity; their spatial resolution of ground properties is typically on the order of five to ten per cent of the nominal survey dimension.Research in seismic tomography has been carried out for several years, and the capabilities and limitations of the technique in mining environments are beginning to be understood. This report reviews the present capabilities of seismic tomography surveys in mining, emphasizing rock mechanics applications. Six case studies are used as examples to demonstrate the capabilities of the method in assessing lithological variation, density and orientation of discontinuities, and the effects of stress."

Jan 1, 1994

By Liangtian Liu, Tie Ou, Guangqiang Li, Chenghuan Yu

For stabilizing the production of containing nitrogen steels, a study on nitrogen absorption behavior of killed molten steel has been carried out by means of the RH vacuum device in which nitrogen was used as a driving gas. The results showed that there was an increase of nitrogen content in molten steel under vacuum processing but the rate of nitrogen absorption was slowed down by the surface active elements. Therefore, a kinetic equation for nitrogen absorption of molten steel with apparent first order reaction was derived by constructing a modified model in which the adsorption of closed surface site was taken into account. The experimental results confiimed that the calculated values agreed with the observed ones. This model is suitable for the prediction of nitrogen adsorption operation for containing nitrogen steels.

Jan 1, 2004

By M. S. Hedley

"The Lucky Jim mine is at Zincton in Slocan mmmg division; on the Kaslo-Nakusp branch of the Canadian Pacific railway. It is owned and operated by Zincton Mines; Limited; a subsidiary of Sheep Creek Gold Mines; Limited. The mine is far in the lead in the production of zinc in the Slocan. Its recorded production from concentrates and shipping ore was 102; 260; 191 pounds of zinc to the end of 1945.GENERAL GEOLOGY With the exception of acidic dykes the rocks near the Lucky Jim mine belong to the Slocan series, which is Triassic in age and consists principally of argillaceous rocks. It disconformably overlies greenstones of the Triassic Kaslo series about 3 miles to the northeast, and is cut by granitic rocks of the Nelson batholith 5 miles to the southeast.The sedimentary rocks in this area are best referred to on the whole as slates. They lie within the more fissile basal part of the Slocan series. The term 'slate belt' conveniently distinguishes this area of rocks characterized by slaty cleavage from the more massive argillites that are more characteristic of the Slocan as a whole. The contact between the slaty and massive argillites lies ½ mile southwest of the mine."

Jan 1, 1954

By Anthony P. Makuch

Dynatec Corporation is an integrated mining services company, providing mine development, operations management, engineering, drilling and metallurgical services to the North American mining industry. Dynatec was the contract operator of the Ken Snyder Mine in Midas, Nevada from start of production in January 1999 to September 2001. This paper summarizes Dynatec?s experience and approach to the use of longhole stoping methods for mining to widths of 1.3 to 2 metres in a steeply dipping narrow vein orebody.

Oct 1, 2001

By Ö Yilmaz

In this study, the behaviour of rock mass subjected to blasting load is investigated using three dimensional finite difference numerical modelling. In the analyses, Mohr-Coulomb failure criterion has been used for the characterisation of the rock mass strength. Stresses acting on the borehole boundary have been simulated by an exponential function which reaches its maximum within a short time and then falls to zero value in a considerable time period. The strain rate effect on the mechanical properties of rock material has also been taken into account in the analyses. Four different explosive-rock mass combinations have been studied to investigate blast induced damage zone. It has been observed that proposed equation for the dynamic compressive strength of rock material fits very well to general suggestions. Results have shown that blast damage analysis model recommended with this study is successful.

Aug 1, 2013

By Robert B. Parsons

"A study recently completed by the Prospectors and Developers Association, assisted by the author and computerized mine models he developed, presents a strong case that present tax rules severely handicap the junior exploration company relative to the established producer. This month, Tax Notes briefly summarizes the highlights of the study and some of the Association&apos;s ideas which came out of the study.IntroductionIn the case of any industry, a particular project or investment will generally generate a more attractive after-tax rate of return to a tax paying entity than to a non-tax paying entity: the ability to shelter current taxable income with tax deductions related to the project or investment can present a definite advantage as compared to shielding taxable income in the future with the same deductions. But, this advantage is probably seen nowhere more clearly than in the mining industry where the tax rules allow for substantial up-front write-off&apos;s. Studies show that the junior mining company which is earning no taxable income currently can be seriously disadvantaged, compared to the mining company which is currently generating taxable profit and paying taxes. This is particularly disturbing when one considers the importance of the junior segment of the mining industry. One might well ask where the equity is, in a tax system which causes the junior company to look at a deposit and see rock in the ground, when at the same time the deposit represents a viable mine to an operating company. This inequity and the importance of the junior mining company have been recognized to some extent in the income tax legislation. In recent years, the expansion of the rules for deducting certain earned depletion allowances against any source of income, and changes to improve the flow-through share rules, have gone part way in helping to put the junior on a more equal footing with the operating company. But it is questionable whether or not these helpful changes to the tax rules have done enough to alleviate the apparent inequities in the income tax legislation."

Jan 1, 1985

By M. C. Villeneuve, P. A. Siratovich

We present an integrated analysis of laboratory-based thermally induced fracturing and results of numerical models to give insight to the role of thermal shock fracture on geothermal reservoir rocks. Thermal stimulation is a reservoir permeability enhancement technique applied to commercial geothermal reservoir rocks to enhance fluid injection capabilities for spent power plant working fluids. The process is well known to enhance permeability but the thermodynamic and physical constraints of the process are less certain. In an attempt to constrain the interaction and the ideal conditions that lead to permeability enhancement, experimental procedures were carried out to mimic the conditions that a reservoir rock would experience during a thermal stimulation using temperature differentials ranging from 50-300°C. Samples underwent such thermal gradients under controlled laboratory conditions and were characterized for the changes to permeability, porosity, ultrasonic velocities, dynamic elastic moduli and petrological changes. The thermal stimulation was simulated in a FLAC2D thermal numerical model to investigate the nature of the thermally induced changes in the sample. The development of this model also allows us to investigate the relationship between geological characteristics and the ability to thermally stimulate any type of rock. The results indicate that numerical thermal shocking experiments are corroborated by laboratory-based results. The implication of this study is that the refined numerical models present an insight to the conditions and constraints under which thermal stimulation can prove to enhance permeability that could not be gained through purely laboratory-based studies.

Jan 1, 2015