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By J. W. Hendry

"This paper will discuss the application of tools and the evolution of computer-assisted procedures in the production planning process at Quintett e Coal Limited (QCL). In 1986, QCL produced 5.3 Mt of clean coal from their surface mining operation located in north eastern British Columbia. The structural complexity of the sedimentary deposit and high rate of mining necessitate the consideration of large amounts of geological information which continually updates the interpretation. There are multiple unit operations required during the process of mining through a given multi-seam sequence, which results in many interdependent faces, and multiple iterations of scheduling sequences in order to satisfy a given set of objectives. In order to facilitate these activities in a timely fashion, it was recognized that a computer systems' capability needed to be developed which could increase the efficiency of information input, manipulation and output. IntroductionQuintette Coal Limited (QCL) has been operating a large metallurgical open pit coal mine in northeastern British Columbia, since 1982. The mine produced 5.3 Mt of clean coal in 1986 for export to Japan. Throughout the start-up period and the subsequent build -up of production levels, it became evident that the primary producing area was comprised of extremely complex faulted structures. This has resulted in development and modification of specialized mining methods employed to effectively recover the resource. Similarly, the planning and engineering techniques employed have been evolved over the same period of time. The implementation of computerized methods has been one of the major developments in this process, including geology interpretation, modelling, reserve definition, quantification, production planning and scheduling, and graphical plan presentation. These capabilities have been employed, in various forms, for project scale feasibility work and long range planning for some time, however, the use of computer tools for short-term, detailed production planning of a complex mining environment presents a different set of problems. It is hoped that a presentation of the current state of evolution and future plan s for development will be of interest to organizations considering implementation of a similar system."

Jan 1, 1988

"The gravimetric dust sampler is one of the tools now available to the industrial hygienists for determining the worker 's exposure to the numerous types of particulate matter that may be present in the workplace. The paper ' reviews the different sampling trains that can be used for the two major criteria for respirable dust and some of the sources of error in this dust assessment technique.IntroductionIt may be stated simply that the measurement of airborne dust in the working environment is done for one or two reasons: namely, for engineering control purposes and! or to evaluate the potential for toxicological insult arising from the inhalation of dust particles.This paper reviews the progress made in the development of dust-assessing instruments, particularly the gravimetric types designed to meet British and U.S. dust criteria , and discusses the limitations in their use for this purpose."

Jan 1, 1981

By J. W. Smith, J. Van Dusen, A. Papachristodoulou

"As part of a study to evaluate factors affecting tankroom air quality, the mechanism of aerosol generation from bursting bubbles in electrowinning operations has been investigated. Typically 2 to 3 mg/m2.s are produced in zinc tankrooms. Analysis shows that the rate of production of film drops (geometric mean diameter - 2 urn] increases with decreasing bubble size, and that jet droplets (geometric mean diameter - 20 um) are not produced with gas bubble larger than - 4 mm. Both mechanisms of drop formation and current efficiency are affected by surface active agents, with an over-all reduction in emission of up to 60% to 70% being achievable. A source control system which does not adversely affect electrolyte properties is always preferred, and coalescence of all gas bubbles in to a continuous stream of gas at a single point on the electrolyte surface would eliminate aerosol emissions. This objective was the basis for design of a coalescence device which, in laboratory tests, reduced the emission rate by over 95%.The control device fit s over the electrodes in the electrowinning cell and is partially immersed in the electrolyte. A number of changes in the design which resulted in significant improvement in the performance of the device are reported.Field tests have shown that only about 75% of the aerosol below 10 um can be eliminated by coalescence. The remainder (up to 95% of the total) is controlled by coalescence of droplets, by impaction on the exposed collector surface and gravitational settling.The device does not interfere with operation of the tankroom, handles the effect of surges in power during harvesting, and is simple and inexpensive to maintain. IntroductionDuring the electrowinning of metals (such as zinc and copper) gases are evolved along the electrode surface forming small bubbles. The bubbles travel upwards and burst on the electrolyte free surface generating, in this way, small droplets. Because the electrolyte is often highly acidic or contains toxic materials, the whole process can result in the formation of an aerosol in the atmosphere above the electrowinning cells which poses a serious health hazard to workers in the area, and corrodes equipment."

Jan 1, 1988

By Rod Maclean, George Stewart

"This paper covers the planning, development, and mining of an underground pillar complex using a bulk mining method. To achieve the long-term goal of continually improving our operating processes, all cut-and-fill and undercut-and-fill workplaces at Thompson Mine have been evaluated for their conversion potential to the bulk method referred to as VerticalBlock Mining (V.B.M.).Since December 1979, conversion has occurred to the extent where 80% of the ore hoisted is mined using Vertical Block Mining (V.B.M.).Productivity and profitability have been substantially improved by converting to this bulk method, especially in pillar areas.IntroductionThompson Mine is a 6000 ton per day underground nickel mine located 3 miles outside the City of Thompson, 400 air miles north of Winnipeg . The mine has two shafts, T-l and T-3 (Fig. 1). The T-l shaft is 4427 feet deep with the deepest mining taking place on 4000 level. The T-3 shaft, which is the area of this presentation, extends to a depth of 2607 ft with the deepest operating level at 2400 ft. The two shafts, some 10 000 ft apart, are connected underground on numerous levels. The ore mined at T-3 is trammed on 2400 level to the T-I main ore pass and hoisted through the T-l shaft. Eight hundred and fifty thousand cubic feet of fresh air per minute ventilates the mine.The 1400 level 310 pillar complex is located in the T-3 mine area. There are six rib pillars, two crown pillars and one main pillar (boundary pillar between cut-and-fill stopes) within the complex (Fig. 2). The majority of the ore in this area has been mined using mechanized cut-and-fill techniques .Undercut-and-fill mining was the method originally planned to recover these pillars. It is slow, labour-intensive, and requires extensive use of timber during the mining cycle. The extraction drifts in the area are heavily timbered due to their proximity to the ore and the age of the facilities. Increasing drift maintenance costs and the successful mining of two main pillars with V.8.M. techniques provided the stimulus to review the mining plans for this area."

Jan 1, 1988

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 N. A. McPherson, P. C. Stevens, A. J. Rigby

"There has been a consistent move in recent years to continuously cast small billets while utilizing ceramic stream protection between tundish and mould. The need to have ceramic stream protection has developed from a need to improve billet surface quality by submerged pouring. The need to protect the ladle to tundish stream in conjunction with tundish to mould protection is explained.The continuous casting of thin slabs is at the development state and will require a great deal of ceramic development to ensure the economic viability of the project. An insight is given to the main problems.IntroductionDuring the early development period o f the continuous casting of steel in the late 1940s and 1950s, much of the work was carried out on small cross section products. For example, the continuous casting of 50 mm square billets was carried out on a production scale in the United Kingdom at Barrow. Slab casting was initiated on a production basis on 100 mm thick stainless steel slabs at Atlas Steel, Weiland, Ontario. In the case of slab casting the thickness increased gradually until it was similar to Slabbing Mill feedstock , i.e. in the range 200 mm to 250 mm , although stainless steel continued to be lower at around 185 mm thick.For billets , a significant proportion of steel is now cast at around 100 mm square which creates specific difficulties when casting with a submerged pour - mould powder practice. The move back to smaller cross sections is further emphasized by the current interest in "" Near Net Shape Casting"" . If this move continues, then significant development will be required to create the refractories used between tundish and mould in the continuous casting process.Two specific areas which will receive attention are; (I) the casting of small cross section billet s; and (2) the casting of thin slab."

Jan 1, 1990

By Fiona Campbell

"Modern history is full of breakthroughs in technology, all striving to increase productivity and efficiency. What are the elements that should be taken into consideration in the design and implementation of modern automation systems in a control room? Both industry and international standards are now demanding that Human Factors be considered as part of the design of control rooms to maximize efficiency and minimize the potential of human error which can lead to downtime and a loss of profit as a result of interruptions in production. As the current workforce ages and the younger generation matures, this is also becoming a key element when planning a control room. New standards are helping to address some of these challenges that are facing the mining industry today. With an increased focus on the operator, an intelligent and ergonomic workspace can both mitigate risk and optimize production. Optimization is money. We will examine how to analyze and implement innovative control room planning to maximize mineral processing production and minimize risks that can impact overall production and profit.INTRODUCTIONIn this day and age, optimization of production in an industrial environment is becoming more and more of a challenge. With ever changing technology as well as other external factors, this can be especially daunting. There are several key elements that may not be immediately obvious when planning a control room design or renovation, most notably the role of the human in this environment. Fatigue, stress, distraction, reaction times and situational awareness are all critical in a 24/7 environment. With the growing need to include human factors when considering and designing an optimal work and production environment, it is becoming even more important to design a control room that can address as many of today’s challenges as possible.The standard definition of the word “optimization” is “an act, process or methodology of making something (as a design, system, or decision) as fully perfect, functional or effective as possible.” (www.merriam-webster.com). If we apply this to business, what it really means is finding the most cost effective way to achieve the highest level of performance while considering constraints, both external and internal, by maximizing the desired factors and minimizing undesired ones. Sometimes, however, we can get caught up in the day to day processes, without taking a moment to step back and objectively review what it is we need to achieve, and more importantly, the steps that can facilitate our success."

Jan 1, 2016

By W. B. Evans, D. P. Taylor

"ANFO has two major disadvantages as an explosive low density and no water resistance. ANFO can be blended with more dense, water-resistant explosives to form ""Heavy ANFO"". The use of emulsion or slurry explosives as a matrix is an attempt to correct deficiencies on the basic ANFO while maintaining cost effectiveness.This paper will deal with four main topics.1. Product description, general properties, strengths and weaknesses.2. Technology of ""Heavy ANFO"" , the emulsion matrix concept and the range of products.3. Relative performance and economics in various rock types.4: Current status in Canada and worldwide, and the expectations for future use.IntroductionANFO has been in use for roughly three decades and remains the explosive of choice where conditions are suitable. ANFO has not become the universal explosive - despite its undoubted superiority in cost effectiveness - because it has serious flaws as an explosive. The most serious of these flaws are the low density and absence of water resistance in ANFO. Low density implies a low concentration of explosive energy in a borehole. The amount of energy available can be increased by. adding an energetic material, generally aluminum, or by drilling more holes. Both solutions add considerably to the over-all costs. The absence of water resistance in ANFO is inherent and can only be overcome by changing the fundamental nature of the product. The history of research in the explosives industry since the advent of ANFO is mainly the story of the various attempts to overcome one or both of ANFO's shortcomings.Many technologies and products have been developed to compete against ANFO, among them slurries, emulsion s and the so-called Dense ANFOs (ANFO with an extra nitroalkane liquid sensitizer). None of them was cost-competitive with ANFO so their market penetration has been limited to wet holes or specialized applications. The exception to this result is Heavy ANFO. The aim here was to have the best of both worlds, the high density and water resistance of emulsions or slurries plus the low cost of ANFO. The concept is very simple. ANFO is about 50 % air, roughly 30% in the prills and 700,10 between the prills . The air in the prills provides the necessary sensitivity but the air between them is waste volume. If one fills this volume with a high density, waterproof product, the resultant mix will be denser and more water resistant than ANFO and with very little added cost. This basic concept was invented by B. Clay in the 1970s and is covered by Canadian Patent No. 1 115 959. The water resistance and/or density of the mix can be tailored by changing the emulsion level. Because Heavy ANFO is relatively inexpensive while providing good in-hole densities and water resistance, it can compete successfully against all other bulk products. It competes against ANFO and Al / ANFO by allowing pattern expansion and reducing over-all costs while it competes against emulsions and slurries on price."

Jan 1, 1987

By Eric R. Skonberg

"Technology exists today to blind drill a mine shaft 20 feet in diameter, unlined, over 3,000 feet deep. These shafts must be lined in the most economical, safe and expedient manner possible. A new technique of stacking precast concrete cylindrical sections in the unlined shaft has been developed to yield a dry and hydrostatically lined shaft .These sections must withstand an external radial pressure of 3,000 feet of water yet take up as little room as possible in the shaft . Using high-strength concrete, wall thicknesses may be kept at 2 feet. The outside diameter of the sections has been chosen to be 18 feet to allow for some annular space between the liner and shaft wall. The concrete sections are produced in segments 10 feet long weighing 75 tons each. During drilling operations, the concrete sections are cast and cured. After drilling operations are complete, a headframe is situated over the shaft. The unlined shaft remains full of fluid. A special liner running tool is mated with the section in three steel ports at the bottom of the section. The section and running tool are lowered into the hole, and the tool is disconnected and returned to the surface. Subsequent sections are lowered and stacked using the same operation. Grout is placed behind the liner to result in a dry shaft."

Jan 1, 1981

By Fritz F. Prugger

In August, 1970, during routine shaft grouting, a major water source was intersected. Water and quicksand under very high pressure entered the shaft at a rate of 65 m3 per minute. The mine and both shafts were flooded. The breach was sealed simultaneously from within the shaft and through a relief hole drilled from surface. The mine was dewatered, rehabilitated and the equipment was restored. Production resumed two years after the accident.

Jan 1, 1979

By Yu. V. Ponomarenko, A. I. Meka, P. A. Witherspoon, Yu. I. Volkov, J. E. Gale

"The mining of iron ore in the Kursk Magnetic Anomaly (KMA) region of the U.S.S.R. is done mostly by the open-cut method. An assembly of open pits capable of producing about 100 million tons of ore per year makes KMA the largest iron ore field in the world. Three gigantic open pits are currently in operation: Lebedinsky, Mikhailovsky and Stoilensky. These pits are as large as 13 km2 on the surface and as deep as 230 m. The mining operations are constantly faced with the problem of flooding from aquifers that overlie the orebodies; the magnitude of the problem is evident from the fact that the present groundwater inflow to these three pits is about 110 million mt /yr.Under such conditions, safe operations and pit wall stability are of great importance, and this has been accomplished very effectively by the appropriate use of seepage barriers and drainage systems. At KMA, the most important items used in the system of groundwater control are standard pumping wells, raise wells that drain into a 20 km to 30 km long underground drift located just outside the perimeter of the pit, horizontal wells driven through the pit walls, and horizontal drains. This paper describes the mining and engineering technology that have been developed at KMA to control the groundwater systems and protect the mines from flooding."

Jan 1, 1992

By Roger J. Goodman

"Major industrial restructuring, which started to manifest itself in the mature economies of the Western World and Japan in the 1970s, will accelerate in the 1980s and 1990s. Conventional heavy manufacturing industries will continue to lose ground to lighter processing/assembly operations and the new wave of high technology, information and service sectors. The decline in heavy manufacturing has severely impacted on the steel industries of Western Europe, the U.S.A . and Japan.World trade in metallurgical coal has shifted correspondingly, with declining demand in the mature developed countries being only partially offset by large increases in the steel intensity of the newly-industrialized countries (NICs) of the Far East, Latin America and, to a more limited extent, the Middle East and Africa. These trends will be accentuated in future years with direct implications for the distribution of metallurgical coal trade. This paper discusses, in quantitative terms, such changes in the 1980s and 1990s, and examines the implications for, and impacts on, Canadian metallurgical coal exporters.IntroductionThe twenty-year period from the early 1950 s to the early 1970s was characterized by inexorable growth in consumer demand and industrial expansion in most of the advanced countries of the western world. Long- term forecasting during this period typically used linear extrapolation techniques which , despite their simplicity, invariably ended up predicting future demand and production level s with uncanny accuracy. Times have changed!The last decade has been characterized by a n abysmal failure of our economies to respond to simple long-term, linear growth patterns. We appear to have entered a new world in transition, where we can observe a wave of dying or sunset industries reluctantly being submerged by a wave of emerging or sunrise industries.This paper is aimed a t examining the evidence for long-term industrial restructuring trend s. For want of a better word, these so -called, megatrends are then used to predict future demand level s and spatial distribution of steel development and , hence, metallurgical coal trade. It is tempting to correlate the decline in economic activity in the western world with the first Organization of Petroleum Exporting Countries' (OPEC) crisis of 1973. This crisis was probably no more than the straw that broke the camel's back, as the megatrends and embryo s of major industrial restructuring were already evident. Today these megatrends are merely more apparent and transparent than they were ten years ago.While the concept of industrial restructuring is the new economic buzz word, the process was at work, to a lesser degree even throughout the period of strong economic growth of the post-Second World War boom. Many people still remain convinced that our present-day sluggish economy is just part o f the typical , though rather more prolonged, recessionary cycle. Yet, we have always been part of a dynamic economic system and industry throughout history has been the subject of a continuous process of evolution, restructuring and reconstitution . Now the time is ripe to examine the evidence for such restructuring in order to develop coherent policies of adjustment in this transition from one industrial regime to another."

Jan 1, 1985

By E. Gervais

"In today's marketplace, heavy competition between materials is the norm. This is particularly true f or the base metals, which are being increasingly challenged by new or improved materials in all traditional applications. Current usage of base metals results from a combination of a metal's intrinsic properties, and technology. The future of the base metal industry rests with innovative, high-quality product development, its ability to take advantage of the results of worldwide, massive material R&D investments, and with the dynamism and effectiveness of its market development programs.The ZA casting alloys program is an illustration of the zinc industry’s efforts to protect and expand its market position in the casting field through state-of -the-art technological developments. The market potential f or these advanced engineering alloys is substantial, and their impact on traditional zinc die casting alloy consumption is particuarly important. The ZA alloys, in offering increased performance through zinc castings produced at low cost and by a wide range of moulding processes, have unlocked a multitude of new end-use applications.Following a review of the development of ZA alloys, of their key properties and of their performance characteristics, the numerous challenges that the alloys present to the zinc industry and to the R&D community are discussed.IntroductionZinc is anodic to steel and has a low, uniform rat e of corrosion; it has a low melting point, can be cast with precision , and is readily finished. In addition to its use in protecting steel and in the production of a wide range of castings, zinc is employed : (1) to produce brass, high-strength aluminum alloys and magnesium die casting alloys, (2) in the wrought state for coinage and in building products, particularly as roofing materials , and (3) as an oxide, in the rubber industry, in ceramics, glass, cosmetics, pharmaceutical products and as the starting materials for many chemicals.Zinc die castings are produced with accuracy at high speed, at low cost, are easily finished and have excel1ent mechnical properties . Car fuel economy, changes in automobile styling, competition from other materials, increased sophistication of design and miniaturization have all led to a dramatic change in the volume of zinc consumed for die-casting applications. This has been particularly notable in the United States. Throughout the 19505 and the I960s, casting was the fastest growing major use of zinc; it was firmly established, accounting for 35% of the total zinc consumption(1), By 1983, the volume of zinc being purchased for casting applications had dropped to less than 20% of all zinc consumed in the United States. In the western world(2), consumption for zinc casting application s is currently at about 15%; being nearly equal to the zinc consumed by the brass industry. Coating applications dominate with a consumption of more than 40% of the total market."

Jan 1, 1987

By L. A. Homeniuk, R. Bonnar

"The Athabasca Basin has been the scene of an intense exploration effort since the late 1960s, resulting in the establishment of this area as one of the major uranium districts in the world.The A thabasca Group is of Helikian age and unconformably overlies metamorphic rocks of Aphebian and Archean age. Most of the known uranium deposits have a close spatial relationship with the unconformity, graphitic meta-sediments, major northeast-trending structures and the basin edge. It should be noted that, in regard to the latter, some of the Cluff Lake deposits are exceptions.The pre-Helikian rocks underlying the Athabasca Group have been divided into six Iithostructural domains. The known uranium deposits are concentrated in the Wollaston and Mudjatik domains in the southeastern portion of the basin.The orebodies typically have a narrow high-grade portion below the unconformity and a broader, lower-grade disseminated zone in the overlying sandstone. Over-all grades average over 1% U3O8 and our estimate of known reserves totals more than 400 million pounds of contained U3O8. Some of the deposits have high concentrations of other metals, including nickel, arsenic, cobalt and gold. Ubiquitous chlorite and clay alteration is characteristic of the orebodies.Other Proterozoic basins in Canada of similar ages and having analogous geological settings to the Athabasca have received far less attention. Although little of the known uranium mineralization in these basins is related to the Helikian unconformity, there may be an exploration potential for deposits similar to those of the Athabasca basin.IntroductionThe Athabasca sedimentary basin is located within the Churchill Structural Province of the Canadian Shield in Northern Saskatchewan. The basin is elliptically shaped and is approximately 800,000 square kilometres in area.The objective of this paper is to summarize the various elements in the genesis of the unconformity-type uranium deposits of the Athabasca Basin and to evaluate the comparative potential of other Proterozoic basins to host similar unconformity-type deposits."

Jan 1, 1982

By K. E. Haque

"This paper is a brief overview of the role of oxygen in cyanide leaching of gold feeds (e.g. ore, concentrate). As the majority of gold occurs in the elemental state (Au °), its oxidation is of vital importance for dissolution in the cyanide lixiviant. The cyanidetion at high pH is favourable for the oxidation of Au° with a mild oxidant such as air or oxygen. Beside oxidation of gold, deleterious effects of soluble sulphides, arsenates, antimonates on cyanidation of gold can be alleviated by preaerating the leach slurry with air or oxygen (i.e. preaeration process).If gold is refractory due to its occlusion in sulphides, silicates, tellurides, etc. then gold liberation is possible by roasting in the presence of oxygen or by leaching under oxygen pressure. The data in the recent literature indicate that reactive oxygen supplied by H202, Na202, Ca02 or 03 during cyanidation can accelerate considerably gold oxidation-cyanidation and yield high gold recovery in much shorter leach time. The information compiled in this review leads to the conclusion that oxygen plays a vital role in the dissolution of gold in cyanide lixiviant."

Jan 1, 1992

By W. K. Muwais, R. G. Cuddy

"The Lower Cretaceous McMurray Formation contains the bitumen reserves of the Syncrude Mine in northeastern Alberta. This formation comprises sediments deposited sequentially in fluvial, estuarine and marine depositional environments. The Syncrude Base Mine area consists mostly of estuarine sediments, as much of the original marine sediments have been eroded away. These estuarine deposits consist of channel-fill sediments and interchannel tidal flat sediments with the channel-fills comprising most of the orebody.Channel-fills contain, among other lithologies, interbedded sand, silt and clay rich layers that often occur as sequences of inclined beds with dips up to 25 degrees or more. A detailed knowledge of the distribution of these inclined beds, their lithological characteristics and their continuity is very important in assessing the risk of mine highwall instability . Techniques used to identify and characterize adverse structures are reviewed. INTRODUCTIONGeneralThe Syncrude Canada Ltd. oil sand mine is located within the surface mineable portion of the Athabasca Oil Sands area about 40 kilometres north of Fort McMurray in northeastern Alberta, Canada (Fig. I). The company commenced large-scale strip mining of oil sands in June 1977in the area, referred to as the Base Mine, situated in the southeast corner of the company's two lease areas (Fig. 2).The mining method (Fig. 3) utilizes large electric drag lines operating on a single bench with highwall depths up to 60 metres. Feed grade oil sand (= 6 wt.% bitumen) is mined by draglines and windrowed parallel to the highwall crest. Lower grade oil sand « 6 wt. 0J0 bitumen) occurring as waste bands is selectively mined by the draglines and cast back into the mined out pit or placed on the bench and hauled by truck. The windrowed feed is delivered to the extraction plant by a bucket wheel reclaimer and conveyor system. Stripping of Recent, Pleistocene and Cretaceous overburden units is done outside the conveyor systems by mobile equipment. The 4.5 kilometre long mine is split into four quadrants for planning and scheduling purposes, with each quadrant having an individual dragline-bucketwheel-conveyor system.Surface mining of oil sand at Syncrude requires the removal of vast quantites of material. The design of the open pit mine relies heavily on knowledge of the distribution of ore and waste materials, and on the physical characteristics of these materials.The geology of the oil sand below the dragline bench at the Syncrude Mine is complex. Geological, geotechnical and hydrogeological factors play an important role in the design and operation of the mine. This paper describes aspects of the geology that impact on the design and operation of the mine. Some of the methods and procedures adopted by Syncrude to successfully overcome difficulties that the complex geology creates are discussed."

Jan 1, 1989

By D. W. Smith, J. J. Koskinen, T. A. Enwald, M. E. Ball

"A full-scale demonstration unit of Tampella's LIFAC desulphurization process was tested at SaskPower's Poplar River Power Station Unit No. I. The test program included a series of parametric tests, followed by a 1500 hour operational evaluation. This paper summarizes the results of the test program, and SaskPower's economic evaluation which led to selection of the LlFAC process for SaskPower's 300 MW Shand power station. IntroductionOne of the major influences on the coal mining industry today is public and legislative response to acid rain. When sulphur-bearing fuels such as coal are burned, the sulphur oxidizes to sulphur dioxid e (S00 which, if uncontrolled, enters the atmosphere as one of the by-products of combustion. S02 then combines with water in the air to form an acid and acid rain results. Combustion also produces nitrogen oxides (N0J which can combine with water in the air forming nitrogen based acid , also contributing to acid rain.Acid rain has become a significant international concern. Newspapers have reported on dying forests, dead lakes and crumbling statues. Papers also include articles professing that the physical results of acid rain are vastly overstated. In the United States, a IO-year, Y2-billion dollar study called the National Acid Precipitation Assessment Program (NAPAP) was commissioned to evaluate the effects of acid rain. Even this extensive scientific study did not resolve the controversy. Despite disagreement over the quantitative effects of acid rain, there is no doubt that public concern over the issue is widespread and deeply felt.In response to this concern, legislators throughout the world have reacted with programs that restrict the emission s o f SO, and NO,. To industries involved in the supply and use of coal, the impact of these legislative programs has been extensive. United States power plants will be spending 10 billion dollars in the next decade for flue gas clean-up equipment. Even all this new equipment will not stem the tide of change to low sulphur coals and to “clean “natural gas. The following summarizes legislative actions taken for Canada and the United States."

Jan 1, 1993

By D. O. Tansey

This paper will describe the mechanisms involved in delay blasting and how they are applied with the use of D.S.B. It will examine the control of potential damage resulting from detonations, and show how good fragmentation and efficient recovery of this material blasted can be achieved

Jan 1, 1979

By N. Lecuyer

"During early 1980, pre-production work commenced at the ""Les Mines Gallen"" project, north of Noranda, Quebec. As a result of the acid mine water associated with this property, a major pre-production phase included the installation of a water treatment plant to render the water environmentally suitable.This paper emphasizes the planning, installation and operational factors of the treatment plant necessary to the success of the mining operations and the maintaining of a clean environment.Introduction,T he Gallen Project is a zinc, gold and silver open-pit mining operation approximately 10 kilometres north of Noranda, Quebec. This property has a long history, with initial diamond drilling done in the early 1930s and underground mining taking place between 1953 and 1962. This property was reactivated in 1980, with production scheduled a t a rate of 45,000 ton s per month.Included in the reactivation plans for the property was the installation of a water treatment plant to treat the acidic mine water.Plant DesignThe requirements for the Gallen water treatment plant were two-fold. Firstly, it was necessary to neutralize the acid water and secondly to produce a sludge containing metal hydroxides and sulphates which would be stable when stored, and a clarified overflow meeting governmental regulations to be discharged to the environment.The flow sheet (Fig. I) will explain the process in treatment of the acid water.Acid mine drainage is treated with lime to increase the pH to 9.50. Metals in solution are precipitated as metal hydroxides and the 504 as calcium sulphate. The precipitate slurry is then aerated to convert ferrous iron to ferric iron, which is more stable for storage and disposal.The precipitate is next flocculated with a polymer flocculant and settled in the thickener to produce a sulphate/Hydroxide sludge and a final effluent discharged to the environment."

Jan 1, 1983

By E. L. C. Martins, M. J. Nicol, D. Majuste, A. D. Souza

The effects of organic compounds on the current efficiency (CE), morphology, crystal structure and mechanical properties of the metal deposited during the electrowinning of zinc are described. A flotation collector and lubricating oil were selected based on observations made during the industrial production of zinc from silicate ores, in Brazil. The analysis by Fourier transform infrared spectroscopy of these compounds, which may be present in minor amounts in the electrolyte solution, indicated the presence of a polar amine group in the collector, while the lubricating oil is a non-polar compound. The average CE value obtained from organic-free industrial solution was 91.15 ± 0.26 %. The CE dropped to 54.35 ± 0.73 % in the presence of 100 mg·L-1 of collector in the solution, and a negative effect was also observed in the presence of similar amounts of oil (88.84 ± 0.61 %). The characterization of the deposits by scanning electron microscopy and X-ray diffraction revealed the formation of pores in deposits obtained from solutions containing the oil, while a different growth pattern (perpendicular zinc platelets) was identified when the flotation collector was added to the industrial solution. In the presence of these contaminants in the solution, guided-bend tests revealed that the deposits have a higher resistance to deformation, but lower ductility, properties that may affect the performance of the stripping stage. As a result of this work, simple control and optimization actions were applied in the industrial plant, which resulted in important improvements in the electrowinning process.

Jan 1, 2014