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By Jim Hazzard

A numerical investigation is presented to examine fluid flow in fractured rock slopes. In mining geomechanics, different numerical modelling approaches are used to estimate fluid pressures in open pit mines. The most common technique is the Equivalent Porous Medium (EPM) approach in which the fractured rock is assumed to behave as a porous continuum. Depending on the geometry and properties of the problem, this may not always be the best approach. The paper presents a parametric study to examine the effect of fracture spacing, fracture and matrix diffusivity and excavation rate on the fluid behaviour in rock slopes. Based on the model results, guidelines are provided as to when EPM models can be used and when different modelling approaches (e.g., discrete fracture flow) may be necessary.

Jun 1, 2012

By C. Yoo

"Geosynthetics engineering has made phenomenal advances during the last decade in areas of manufacturing as well as practical applications. As a result, geosynthetics are now being recognized as essential construction materials that can be used to facilitate construction, ensure better performance of the structures and reduce the long-term maintenance in routine civil engineering works. The creative use of geosynthetics in geo-engineering practice is expected to continuously expand as innovative materials and products are becoming available. In this paper, a wide variety of geosynthetic products available to geoengineers to solve a wide range of problems are briefly presented along with their functions and possible applications. Fundamentals of geotextile filter design principles are then introduced for use in the tunnel drainage system. Practical applications of geosynthetics relevant for tunnel engineering are also highlighted with emphasis on the issues associated with the geotextile filter application for use in the tunnel drainage system.INTRODUCTIONGeosynthetics have emerged as essential engineering materials in a wide range of civil engineering applications, e.g., transportation, geotechnical, geoenvironmental, hydraulics, and private development since the first geosynthetic conference in Paris, 1977 (Koerner 2012). Due to their costeffectiveness, ease of installation, and well established mechanical and hydraulic properties, geosynthetics are now playing important roles in the field of geo-engineering.As indicated in the 9th Bucahanan Lecture paper by Holtz (2001), major developments in civil engineering have only been possible with the parallel developments in the technology of construction materials. For example, larger scale structures became possible with the help of developments in concrete, reinforced concrete, and prestressed reinforced concrete technology which replaced wood and building stone as construction materials. The best example of a parallel development in geo-engineering between the material and the geotechnical application may perhaps be the soil reinforcement technology which has a direct analogy with reinforced concrete as a polymeric reinforcement material provides added level of tensile resistance and stability to soils that have little to no tensile strength, thus giving additional margin of safety."

Jan 1, 2015

By Si Qin

Unknown goafs and roadways of abandoned coalmines can be a great water inrush hazard for coalmine workers. Consequently, advance detection of such hazards is of great importance. By detonating seismic charges in underground coal seams, we can collect seismic data using a surface survey line, which is located across the ground projection of the underground shot point. This experiment was conducted in a coalmine in Shaanxi Province, China. After surface elevation compensation and travel time adjustments, we accurately determined the position of the goaf boundary along the survey line based on the wave velocity anomaly on the seismic record. Then we used a scattered wave imaging technique to enhance the energy of the scattered waves that are generated when the coal seam roof slide wave (refracted wave when the incident angle bigger than the critical angle) hits the roadway, thus confirming location of a geological discontinuity (roadway). This experiment shows that the coalmine ground seismic method, employing an underground explosive charge and a surface seismic array, has the ability to detect an abandoned roadway and goaf in advance of coal mining, thus can improve worker safety.

Aug 1, 2013

By Z. Zhang, D. Bouchard, H. Blanchette, A. Lemieux

This paper describes quality control methodologies for the production of semisolid A356 aluminum slugs with the SEED process. A methodology based on destructive tests carried out with an apparatus measuring the force to slice the slugs is presented. The force measurements were correlated with the solid phase morphologies of the slugs and were validated against a non destructive methodology that consisted in monitoring the temperature evolution of crucibles to produce the slugs and the drained metal. Results from the destructive and non destructive methodologies are compared and discussed.

Jan 1, 2006

By H. M. Giegerich

"INTRODUCTIONThe Red Dog Project in Alaska is being developed by Cominco Alaska, a subsidiary of Corninco Ltd. of Canada, and the Nana Regional Corporation, one of the 12 native corporations created by the Alaska Native Claims Settlement Act of1971.The State of Alaska is also a very key part of the project through its financing of the transportation system for Red Dog. Red Dog will be the third, and largest, of Cominco's Arctic mining developments in the past thirteen years, after the Black Angel Mine in Greenland, which started up in 1973, and the Polaris Mine in the Canadian Arctic, which began production six years ago in 1982.Red Dog is one of the world's great mineral deposits, with a unique combination of large size, high-grade, and a waste-to- ore ratio less than I: I, which will make it the world's largest, and one of the lowest cost zinc producers, when at full production. The present mineral reserve is estimated to be 85 million tons , at a grade of 17.1010 zinc, 5% lead, and 2.4 ounces per ton of silver. Based on the current production forecast, this will give a mine life of almost 50 years, and the deposit is still open in two directions, although the structure is becoming thinner at depth. As well, there is a satellite zone about one mile south of the main deposit which could contain up to another 8 million tons of mineral at Red Dog grades or better. This is not presently included in the reserve due to potential processing difficulties.In relation to other zinc deposits, Red Dog is the second largest ever discovered, smaller than the original Broken Hill deposit in Australia, but larger than Cominco's own Sullivan Mine in British Columbia, which is number three. It is quite possible that, when the area is adequately explored, Red Dog will be number one."

Jan 1, 1989

By Man-Chao He

One of the critical problems involved in deep coalmines is unusual gas emissions. Many researchers agree that there is a relationship between coal gas emissions and geological features such as tectonics or geological disturbances, gas content, properties of the coal and rock and the mininginduced stress state in the coal seam and rock. Thus, the present paper intends to investigate complex mechanical phenomena during the process of gas emission in underground coal-mines. A program of laboratory testing was undertaken to study the effects of temperature and pressure on mechanisms of gas emission. It must be noted that this paper describes new techniques developed to simultaneously measure deformation and gas pressure, as well as flux during the test, taking the characteristics of gas transport into consideration under certain temperature and pressure conditions. The results indicate that under certain temperature and pressure conditions, gases adsorbed to coal start to desorb, and increase the pore pressure. High pressure gases entering coal fractures can generate high tensile stresses near the crack tips, leading to crack propagation and coalescence, which in turn can cause the specimen to dilate. From the experimental viewpoint, these test results may help us discern why mining seismic events can trigger gas emissions.

Aug 1, 2013

The tensile test results of as-cast A356.2 grain-refined alloy castings show that the tensile strength can be improved by strontium modification (`SrM'), superheating at 900°C OM, and melt thermal treatment of the Sr-modified alloy melt (`SrMTT'). Both SrM and SrMTT processes can greatly improve the ductility (percent elongation) of the as-cast alloy. During solution heat treatment at 540°C, eutectic Si particles undergo fragmentation, spheroidization, and coarsening, thereby affecting their morphology. The effects of solution heat treatment on the tensile properties of the variously treated A356.2 alloy castings can be summed up as follows: the yield strength of the castings is significantly improved after 8 h solution heat treatment due to the precipitation of Mg2Si, after which it remains more or less the same with the further increase in solution treatment time up to 80 h; the ultimate tensile strength is also greatly improved within the first 8 h of solution heat treatment and then remains at the same level thereafter, up to 80h of solution treatment. The improvement in UTS is attributed to Mg2Si precipitation, dissolution of Si within the aluminum matrix, and changes in the Si particle morphology (spheroidization). The ductility of the as-received grain refined non-modified (`NM'), grain refined and superheated at 900°C (`SH'), and melt thermal-treated grain refined (`MTT') A356.2 alloy castings can be improved considerably with solution heat treatment e.g. from ~6% in the as-cast non-modified casting to ~10% after 80 h solution treatment.

Jan 1, 2011

By A. Montini, M. H. Moys

"A conductivity probe mounted in the shell of the mill has been used to measure the behaviour of the load in the mill as a function of operating variables. It was found that certain properties of the conductivity signal correlate strongly with the per cent solids of the slurry passing through the mill; in particular the angular location ?D of the shoulder of the load is an increasing function of the per cent solids. A method for measuring the viscosity of the pulp discharging from the mill has also been developed. The use of the measurements in mill control is illustrated by simulating various control strategies for open circuit milling. It is shown that the use of ?D allows very tight but imprecise control of the slurry rheology in the mill, while the use of viscosity is subject to severe limitations in speed of response. A cascade control system involving both measurements provides adequate control of slurry rheology within the mill. Applications to closed circuit milling are discussed.IntroductionMultivariable control of milling circuits continues to receive a lot of attention in the literature. Hulbert and co-workers and Niemi, et al. have described the use of Inverse Nyquist Array (INA) techniques while Herbst has recently described the use of Optimal Control. It is significant that in neither of these three projects was any variable associated with the grinding mill itself (e.g. power or properties of the mill discharge) used in the control strategy. Pauw, et al.do, however, use mill power in their multivariable peak-seeking controller for pebble-mill control. Little work has been published on the use of measurements of the properties of the slurry being discharged from grinding mills, in spite of the fact that milling efficiency is known to be strongly affected by slurry rheology».Moys has recently developed a technique for measuring the dynamic behaviour of the load in the grinding mill. This method involves the monitoring of the response of a conductivity probe mounted in the shell of the mill which gives a measurement of the orientation of the load inside the mill. It was found that the load behaviour was strongly influenced by slurry rheology. In this project a technique was also developed for the measurement of the viscosity of the slurry in the mill discharge. It was, thus, decided that it would be worth investigating the use of these measurements in mill control schemes since direct control of the slurry rheology in the mill must inevitably increase the efficiency and productivity of the grinding circuit as a whole.This will be done by using the dynamic responses measured by Moys and Montini to simulate the behaviour of an open circuit ball mill. While the control of open circuit mills is of little interest, this simulation provides a simple but powerful demonstration of the advantage provided by these measurements, advantages which should apply to closed circuit operation of any mill type (including autogenous milling). Investigations into multivariable control of a closed circuit ball mill are currently nearing completion and will be published soon."

Jan 1, 1987

By Chaluvadi K. Sridhar, Prashanta K. Chatterjee

"IntroductionThe planning of an underground coal mine requires a complex blend of technical expertise, experience and subjective design criteria implemented by the mining engineer. Currently the procedure is largely manual and requires considerable resources to generate a single mine plan. Often three or four people are assigned to work in the development of a single draft layout. Evaluation of the layouts is also tedious as it requires many repetitive calculations. The evaluation of layouts developed manually generally attempts to derive a single economically feasible solution. Operational constraints in underground coal mining such as manpower, time, equipment, etc., do not allow the generations of more than one alternative layout. As a result, the first plan is generally the only one considered.Computer-aided mine planning can automate many of the manual procedures and calculations involved in mine planning thus allowing to evaluate man y layouts and mining strategies and to select the optimum plan with confidence. An optimized planning procedure will also provide the capability to evaluate mine performance continuously and critically, thereby helping to maximize return on investment. Although recent advances in computer graphics have provided the hardware necessary for developing and evaluating min e plans rapidly, software that will allow the mining engineer to make use of the new technology is slow in developing. The need for such software packages has been recognized and ackowledged.At several sessions in recent conferences on the applications of computers in the mining industry, the use and benefit s of computer-aided mine planning were discussed. However, there were few papers presented that referred to actual applications of interactive graphics to underground mine planning. The emphasis of this study is toward the development of a completely integrated computer-aided underground mine planning package that integrates geological modeling, engineering design and planning"

Jan 1, 1986

By I. Govender

Positron-Emission-Particle-Tracking (PEPT) has enabled the non-invasive observation of charge and slurry transport in model mills under operational conditions. We use high quality PEPT data to infer that the charge motion can be effectively described by a non-Newtonian granular fluid. An improved theory for slurry transport, including inertial effects, is presented.

Jan 1, 2012

By I. Pérez-Rey, J. Arzúa, L. R. Alejano

"The decrease in strength with increasing rock specimen size is usually associated to the increase in the number of defects inside the specimens at small scale (centimeters) but also to the role of the rock mass structure at the rock mass scale (meters to decimeters).This matter of concern was particularly focused when determining the size of pillars in underground mines. Some formulae regarding strength of pillars have been proposed but they usually consider only the size and shape of the pillars and the strength of the intact rock. The structure tends to be overlooked or hidden behind the scale, but it is probably very relevant. For standard tunnel design, the approach by Hoek and Brown (1997), taking the structure into account in terms of the GSI, is commonly used. However, this approach does not specifically consider the size of the tunnel. Thus, a size larger than the so-called representative elementary volume is implicitly contemplated.The authors have recently performed a lab study on the effect of the structure in the strength, deformability and post-failure characteristics of granite at lab scale (NX size) extended here. This experimental program included intact and artificially jointed rock specimens. Obtained results permit to observe the changes in strength, deformability and post-failure behavior of this “small scale rock masses”, associating the role of the structure to the observed complete stress-strain response of the specimen, which can improve our understanding of the actual complete mechanical response of rock masses."

Jan 1, 2015

By A. A. Burgoyne

"The McDame chrysotile asbestos deposit located near Cassiar in northern British Columbia isfound at depth and on trend to the southeast of the currently mined open-pit Cassiar asbestos deposit. The ultramafic rock hosting the McDame is serpentinized peridotite of the Upper Paleozoic Sylvester Group contained in an ophiolitic sequence preserved within a lower thrust sheet of the Sylvester Allochthon. The Sylvester stratigraphic package is a series of thrust slices composed of argillite, tuff and volcanic flows, diorite and serpentinite. Contacts between units are often fault-controlled.The McDame asbestos-bearing ultramafite is considered to represent a separate interleaved fault-bounded slice of rock distinct from the Cassiar asbestos deposit.Asbestos mineralization of the McDame deposit was discovered in /978. Exploration during /980 and /98/ focused on extensive underground drilling of the deposit and in /983 on geological mapping, airborne and ground magnetic surveys. In /984 a 622.5 m borehole was drilled with a 242 m intersection of McDame ultramafite of which the lower 15/ metres contain potentially economic chrysotile asbestos. The McDame deposit averages 90 m thick, trends north-south, dips easterly and plunges southeasterly. The deposit is estimated to contain geological reserves in the order of 62 million tonnes containing asbestos fibre similar in value to the Cassiar deposit.The McDame is considered a major world-class asbestos deposit. A decision to develop and mine the deposit will require further substantial underground exploration and evaluation. A + 1200 m exploration adit driven to the hanging wall of the deposit was undertaken in 1985 in anticipation of bulk sampling and diamond drilling in 1986."

Jan 1, 1986

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 R. F. Favreau, R. A. Morin, G. W. Kuzyk, P. J. Babulic, N. J. Tienkamp

"Atomic Energy of Canada Limited is constructing an Underground Research Laboratory (URL) as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal deep in crystalline rock formations. Careful blasting methods have been used to minimize damage to the excavation surfaces. Good wall quality is desirable in any excavation. In excavations required for nuclear waste disposal, the objective will be to minimize blast-induced fractures which may complicate the sealing requirements necessary to control subsequent movement of groundwater around a sealed disposal vault. The construction of the URL has provided an opportunity for the development of controlled blasting methods, especially for drilling accuracy and optimization of explosive loads in the perimeter and cushion holes. The work has been assisted by the use of blast simulations with the mathematical model Blaspa.This paper reviews the results of a recent project to develop a controlled method of full-face blasting, and compares the observed field results with the results of a blast simulator called Blaspa. Good agreement is found between the two, and the Blaspa results indicate quantitatively how the blasting may induce damage in the final excavation surface. In particular, the rock in the final wall may be stressed more severely by the cushion holes than by the perimeter holes. Bootleg of the rock between the perimeter and cushion rows occurs when the burst out velocity imparted to it by the explosive loads in the perimeter holes is inadequate. In practice, these findings indicate that quantitative rock stress and rock burst-out velocity criteria can be established to minimize wall damage and bootleg. Thus, blast simulations become an efficient way to design controlled blasting and to optimize quality of the excavation surf ace."

Jan 1, 1989

By J. A. Finch, R. R. Cunningham

The amount of foam volume generated in relation to the gas flowrate has long been used to define the foaminess of a solution and to characterize surfactants. The vessel geometry and gas flowrate range can affect the foam volume results. A fixed area column was tested alongside a variable area conical vessel with two surfactants. It was found that the fixed area vessel will cause foam volume to expand or contract which masks the effect of the surfactant. The conical vessel showed two regimes of foam volume production dependant on gas flowrate. The low gas flowrate regime revealed the physiochemical nature of the surfactant while a high gas flowrate revealed kinematic properties. Foaming properties of a surfactant is best determined with a variable area vessel at low gas flowrate.

Jan 1, 2009

By Andreas Zielonka

To meet the increasing demands of the quality and long term stability of technical systems also the applied materials have to full fill higher standards. This is of special importance where the function of a whole system depends on the reliability of the used materials for example for connector systems in automotive, computer and other electronic equipment?s. In most cases for connector systems electro deposited top layers are applied. To improve the quality of the applied layers new electro deposited systems are developed. One important field of research are the development of composite materials as dispersion coatings and multilayer systems. Multilayers are systems with a high number of single inter-layers of different metals or alloys with the wide chance of the alloy composition. As gold is one of the most important contact material for high quality connector systems it is used as basis for the development of multilayer systems. For the electrodeposition of multilayers two different methods can be applied, the single and the dual plating process. As in the dual plating process two different electrolytes are used, the single plating process allows the formation of multilayers from one electrolyte. In the presented research results cobalt and nickel are used besides gold for the formation of the multilayers. The properties of the layers can be influenced in a wide range by the change of electrolyte composition and the process parameters as current density, current waveform, temperature, hydro-dynamic conditions at the electrode surface and by the number and thickness of the inter layers of the deposited materials. The paper describes the fundamentals of the electro deposition of multilayer systems. For the investigation of the properties of the multilayers different techniques are applied. One of the most important parameter are the thickness of the total layer and of the applied sublayers. The thickness of the sublayers can be varied between a few nanometers up to micrometers. The wear resistance, the contact resistance and the plug-in forces are measured as these parameters are important for the technical application of such layers. For the description of the structure composition and surface properties the sample where also investigated by scanning electron microscopy (SEM), energy dispersive x-ray-analyses (EDX) and glow discharge optical spectroscopy (GDOS). The paper shows that the deposition of gold based multilayers is possible and that the properties of such systems can be varied in a wide range what opens new fields of applications of such materials.

Oct 1, 2003

By Roland Froidevaux

"The main object of ore reserve classification is to assess the reliability of an ore reserve estimate. Because traditional classification schemes fail to provide a means of calculating this reliability, the terms 'proven "" 'probable' and 'possible ' ore were introduced as an attempt to qualify it.Geostatistics, on its part, allows the quantification of the precision of any ore estimate and thus appears as an appropriate tool for ore reserve classification.However, the problem of fixing quantitative boundaries for ore classes remains. In order to be meaningful, ore class limits based on the degree of reliability should be customized to the commodity, and the type and size of the deposit. In addition, the precision of an ore estimate will be affected by the cut-off grade and the size of selective mining units.IntroductionPrimarily, ore reserve classification should be seen as a communication tool between the geologist and the mining engineer on one hand and the management and policy maker on the other. By classifying ore reserves, the geologist tries to answer the very fundamental question: ""What quantity of metal is there in the ground and how sure am I that it really exists?""The difficult y of quantifying the degree of reliability of reserves has led to the creation of a large suite of terms and definitions, with almost every mining company having its own set of definition standards. As lower-grade deposits are brought into production, the margin of tolerable error in estimates of the grade and tonnage is becoming much narrower. Consequently, the need for unequivocal definition of the reliability of ore reserves is increasingly acute. Most of the generally accepted systems of classification, however, describe the reliability of reserves in qualitative, rather than quantitative, terms."

Jan 1, 1982

By Nural Kuyucak, Bohumil Volesky

"Extensive screening revealed a seaweed (alga) biomass type which in its non-living state possesses a very high cobalt sequestering capacity comparable to that of activated carbon and the ion-exchange resin currently used in the cobalt production process. Performance of the new bio-sorbent material was studied by examining its equilibrium metal uptake isotherms generated under different solution conditions such as initial cobalt concentration pH, temperature, and the presence of selected cations and anions. The rate of cobalt uptake was determined, which is a crucial parameter for recovery process design. Almost all cobalt sorbed can also be desorbed with a solution of CaCI2. The bio-sorbent material can be used repeatedly in the sorption-desorption cobalt concentration process. IntroductionIt has been well documented that certain types of microbial biomass, living or non-living, possess a high potential to sequester and accumulate inorganic ions present in aqueous solutions. Metal concentration by microbial biomass from a solution is termed bio-sorption. This phenomenon is quite complex and includes adsorption of metals onto the surface of a microorganism and/or into the cellular structure in combination with ion-exchange, complexation, and/or micro-precipitation. Bio-sorption is generally considered to be a rapid physical/chemical process. The cell wall structure is porous and allows metal ions, as well as large organic nutrient molecules, to pass freely through. Polysaccharides of the cell wall could provide binding amino, carboxyl, phosphate and sulphate groups. In addition to these functional binding groups, polysaccharides often have ion-exchange properties. Sometimes, bivalent cations, such as Ca2+ or Mg2+, help the formation of ionic bond bridges between the negatively charged cell surfaces and positively charged cations in the solution, Proteins in the cell wall could offer functional groups and also offer peptide bonds to bind ions. Interactions between metal and the cell wall components are responsible for the sequestering of metals by way of bio-sorption. Many metals feature a complex solution chemistry and it is not always possible to determine what ionic species are actually present in the solution. The equilibria involved are dependent on pH, concentration, the anions present and other factors. The transport system for the ions are sometimes dependent on both temperature and energy. Biosorbent material could also be regenerated for multiple reuse."

Jan 1, 1988

By A. P. Annan, C. Vaughan, J. L. Davis

"The increase in the price of gold in the last decade has led to a significant increase in placer gold exploration around the world. Placer deposits occur in depressions along ancient river and stream channels. In many instances these channels have been covered with materials from subsequent erosion or glacial activity. Use of high resolution geophysical techniques to map the bedrock and soil strata can improve the probability of finding the placer deposits. The buried bedrock surface is often the factor controlling deposition. Ground probing radar (GPR) and seismic sounding are complementary high resolution techniques which can be used to map bedrock topography and soil stratigraphy. Current radar instrumentation operates best in coarse grained soils. Penetration depths of up to 30 m have been attained, and stratigraphic horizons have been mapped with spatial resolutions of better than 0.5 m. Although its spatial resolution is considerably lower than radar, seismic refraction achieves superior penetration in electrically conductive environments such as clay and silt soils. The seismic refraction method thus proves to be complementary to the radar method. The seismic reflection technique is analogous to the radar method. Current seismic instrumentation and energy sources however, provide limited spatial resolution and do not permit the use of seismic reflection for reflecting horizons lying at depths of less than 20 m to 30 m.This paper discusses the use of both radar and seismic methods for placer exploration. The radar and seismic techniques, the field methods, equipment, and data displays are presented. Field examples illustrate the high resolution mapping capabilities of the techniques. The radar data agree very well with the borehole data, and in fact they sometimes detect subtle soil strata variations associated with changes of permeability that were not initially observed in the borehole logging. The radar method can give a continuous profile of water table and bedrock in sandy soils. Seismic soundings are necessary to differentiate between the bedrock and water table reflections observed by the radar."

Jan 1, 1987

By D. Pearcey, S. T. Vessey, V. Hegde, J. Staples

"Pellet quality has taken on a new dimension during the last ten years. Quality in the seventies was generally defined as adherence to certain physical and chemical specifications. Today, the talk is in terms of how the business is managed, how customer's expectations can be exceeded, not only in product quality, but in service responsiveness.Coke breeze and flux additions, lower silica levels, and improved furnace control practices have all contributed to the improvement of pellet physical and metallurgical properties. Statistical process control has provided additional insight into the parameters that affect pellet quality.Increased customer contact and product quality surveys have heightened our awareness of customer needs and also provide direction for quality improvement test work. Current work is focussed on improving reducibility and understanding the relationship between tumble, fired compression and metallurgical properties.This paper will review the Iron Ore Company of Canada's efforts during the past decade and describe some of its initiatives for the future.IntroductionThe Carol Pellet PlantThe Iron Ore Company of Canada's Carol Project is located in Labrador City in the southwestern portion of Newfoundland and Labrador , approximately 965 Ian northeast of Montreal. The project consists of mining facilities, beneficiation complex and a pellet plant, which began operations in 1962. The pellet plant consists of six Dravo-Lurgi straight grate machines, regrinding, filtering and balling facilities. The current capacity of the Carol pellet plant is approximately 10.5 million tonnes , while the concentrator has the capacity to produce about 18 million tonnes of concentrate.The orebody consists of specular hematite, magnetite and small quantities of limonite and goethite. The average grade of the orebody is approximately 39% iron."

Jan 1, 1991