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By G. S. Cole

By 2025, the U.S. automotive industry will have to average 54.5 mpg (4.3l/100km) Corporate Average Fuel Economy (CAFÉ). While new/improved powertrain technology (turbocharging, electrification, diesels, transmissions and stop/start) will be critical, it is estimated that 25-40% of the new CAFÉ standards will require significant mass reduction, and lightweight structural materials will be required. This presentation examines vehicle mass reduction based on new developments in manufacturing automotive structures and components using light metals (aluminum and magnesium), conventional heavy metals (iron and steel), polymers, and carbon-fiber reinforced polymer composites. Components that used to be sand cast or pressure die cast provided minimal fatigue strength and ductility. But greater mass reduction uses more light metals in structural applications. They require eliminating porosity and inclusions to improve ductility and fatigue strength. Improved casting processing, with vacuum die casting, counter pressure and squeeze casting, and new forging and extrusion applications are being developed for this purpose. New grades of ultra-high strength steels can be made thinner, and save over 1/3 the mass vs conventional mild steels. But more complex and expensive processing, such as hot stamping and in-mold quenching, is required. Most engine block structures have migrated from grey cast iron to aluminum over the past 40 years. But compacted graphite cast iron has higher strength at high combustion temperatures and pressures so that high powered engines can be smaller and even lighter than aluminum. Assembling a range of lightweight materials into vehicle structures requires specialized assembly techniques, including sophisticated structural adhesives that can mitigate vehicles’ unique corrosion environment. The presentation will conclude with discussing lightweighting strategies of Asian, American and, European marques and the materials, component designs and assembly techniques used to achieve 2025 CAFÉ.

Jan 1, 2016

By Robert B. Parsons

"The Canadian Exploration Incentive Program (CEIP), which was announced by the federal government on May 3, 1988, promises to maintain the viability of flow-through shares as a financing mechanism which has proven to be so crucial to the health of the junior exploration sector. This month, Tax Notes examines, the main features of CEIP, which will come into play on January J, 1989. IntroductionOn May 3,1988, the Honourable Marcel Masse, Minister of Energy Mines & Resources, and the Honourable Gerald Merrithew, Minister of State (Forestry and Mines) announced the Canadian Exploration Incentive Program (CEIP). Under CEIP, the federal government will make cash payments to eligible applicants equal to 30% of eligible exploration expenses. CEIP payments will be available with respect to both mineral, and oil and gas, exploration. In essence, the program will replace the ""mining exploration depletion allowance"" (MEDA) presently applicable to mineral exploration, and the Canadian Exploration and Development Incentive Program (CEDIP) which is presently available to the oil and gas exploration sector.This paper discusses briefly the main features of CEIP insofar as the program will affect mineral exploration. The comments herein are based on the Canadian Exploration Incentive Program Act which received Royal Assent on July 21, 1988, and on a discussion paper which was released by EM&R in May 1988. The bulk of the rules relating to the program will be in the form of regulations which have yet to be finalized. It is understood that EM&R would like to have the regulations in force by October I, 1988, when the oil and gas portion of CEIP becomes effective. (The rules relating to mineral exploration will become effective January I, 1989)."

Jan 1, 1988

By Xu Feng, Han Shufeng, Zhu Bin, Wang Mingming

Due to urban subway tunnels mostly built in the cities with highly density buildings, the geological and construction conditions is complex, especially certain sections of the subway tunnel will pass through from the foundation of the overpass, therefore the stability and surface deformation control of that section’s tunnel excavation is particularly important. Taking Xi'an Metro Line Three interval tunnel as a research object, we have used FLAC3D simulation to analyze the tunnel’s surrounding soil deformation and tunnel lining stress distribution under bridge foundation with shallow buried covered excavation method. Analysis results show: (1) After the excavation of the tunnel right line, due to the bias of the upper bridge foundation the right of the tunnel showed relatively large deformation. In order to ensure the construction safety, we recommended using the grouting anchor reinforcement on the right side wall to further control the deformation zone. (2) The maximum vertical displacement of the ground occurred in the right wall of the tunnel portion which was due to the intensity of soil outside the grouting range of the arch is low, as a result the deformation is larger; this position requires special attention, strengthening the monitoring measurements of this part is necessary to avoid the large deformation and other adverse effects of the upper portion of bridge foundation. (3) The maximum vertical force area of the initial lining of the tunnel is in the middle of the side wall, while the second lining in this part of forces is smaller, thus at the beginning of the construction of the liner, attention should be paid to this area. On-site grouting or steel bracing reinforce support may be used if necessary.

Jan 1, 2015

By Norman M. P. Low

"IntroductionIndustrial applications of mica utilize two commercially important varieties of mica: muscovite and phlogopite. Muscovite mica is a potassium mica with a general chemical formula, H2KA1(Si04)3 h, and is sometimes referred to as a potas hsilicate. Phlogopite is a magnesium mica having a general chemical formula, H2KMgSi(Si04)3, and is distinguished from the muscovite mica by its decomposition in sulphuric acid.Canada is one of the major natural mica producers in the world. A large tonnage of the mica powders is at present mined and processed in the Eastern Townships of Quebec. This Canadian mica is of the phlogopite type. A closely related mineral of the mica family which is widely used in the construction industry is vermiculite. It is a dehydrated magnesium-aluminum-iron silicate characterized by a foliated structure. Expanded vermiculite, which is often referred to as exfoliated mica, is used as many types of thermal and acoustic insulation, as loose fill in buildings, as an aggregate in concrete, as an ingredient in plaster and insulating concrete , and in fire-proofing compositions. Natural phlogopite and muscovite mica powders are used extensively as reinforcing agents in organic polymers. They also have a wide range of applications in commerical products. For example, dry-ground mica powders are used in large tonnage as a surface finish in roofing materials and as a bonding agent in wallboard joint cement. Common products such as paint, rubber, plastics and welding rods contain mica. Recent studies have also shown that mica powders can be added to portland cement in the preparation of concrete products, as they could improve the tensile strength of the concrete products. The potential and possible"

Jan 1, 1982

By Jean-Francois Magnan

"The old conventional process to produce lithium raw material dates from 1954 (CA patent #504477A). This process produces low purity lithium carbonate (Li2CO3) only. To obtain battery-grade carbonate, another polishing process is needed. To further obtain lithium hydroxide, another chemical conversion process is needed. That is why historically, the value of lithium hydroxide has always been higher than that of the lithium carbonate precursor. With the old conventional process, the low quality lithium carbonate is precipitated from a lithium sulfate solution (Li2SO4) by adding soda ash (sodium carbonate and its impurities). The resulting reaction produces significant quantities of sodium sulfate (salt cake) as a by-product with amounts larger than the impure Li2CO3 recovered with part of the soda impurities. When this conventional process was invented, the salt cake by-product was not an issue: it was discarded in a river near the plant. This practice cannot be done today in North America. While looking to find a solution for salt cake, electrolytic salt splitting of Na2SO4 into NaOH and dilute sulfuric acid appears as a technically feasible solution to get a rid of the salt cake. However, the sodium sulfate salt splitting process has difficulties to economically compete with the chlor-alkali process, which produces millions of tons of NaOH from sodium chloride (NaCl) every year.In contrast, the process developed by Nemaska to directly produce LiOH by Li2SO4 salt splitting not only solves the environmental problems related to the conventional process to produce lithium carbonate raw material, it also produces very high purity lithium hydroxide monohydrate directly at very competitive OPEX cost in comparison with industry peers (Figure 1). It also drastically reduces the amount of reagent and the direct greenhouse gas emissions."

Jan 1, 2016

By A. Gillis

"In order to obtain the equipment necessary to automate the equipment it was decided that the Department of Mines and Milltronics would jointly survey the circuit. This survey involved a metallurgical study by the Department of Mines and Milltronics took sound recordings during manual operation, checking in circuit bottle necks and determining the number of sensors that could be applied.The conveyer is driven by 2 PIV drives, each has a variable speed of 3/ 1. The cross conveyer that feeds directly into the rod mill feed chute will contain an automatic sampler and will eliminate the necessity of stopping the belt feeders to take samples. At present, hourly samples are taken from this point and the circuit is upset and cycling results.The Adequate scale is very close to the rod mill to totalize and thereby give a continuous indication and the second purpose is to take a signal from it and control the solution addition to the rod mill.A pneumatic positioner was obtained and put on the scale which produces a 3 tp 15 psi signal which is proportional to the actual tonnage going across the scale. This signal was fed to a bias loader which was mounted on the control panel. From there the operator can set the amount of solution that is wanted by the rod mill. No matter what the feed rate is, the signal coming from the bias loader will follow it automatically. This in turn goes to the pneumatic solution valve (1 ½” ) and the solution goes in with the feed to the rod mill. This is only part of the solution required for dilution since the rest of it is used as a force jet for the feed to the rod mill."

Jan 1, 1965

By Z. Abbasloo, A. Masoomi, L. Ebrahimi, A. Mortazavi, A. Keshavarz

"Investigation and 3D analysis of Heap no. 2 of Meydook copper complex was the subject of this study. In this project all geological and geotechnical investigations conducted in the mine were evaluated aiming at determination of Heap no. 2 design parameters. The main objective of the project was to evaluate the potential for construction of Heap. No. 2 on a waste dump built in a valley in the north side of the pit.Considering the space limitation for dump location this was a viable alternative to reduce the costs associated with heap no. 2 construction. Moreover, it allowed for a significant reduction in overall mining costs. Considering the project condition, a 3D analysis of heap major structures including; valley rock foundation, waste dump, and low grade ore was carried out. Five sets of analyses were conducted and the displacement and stress fields were calculated within the heap no. 2 components. In all analyses conducted the subsident profile was determined for the valley base rock and heap foundation (waste dump). Moreover, the shear interaction between heap and waste dump was evaluated at the heap interface. The analyses results showed that the maximum settlement at the heap base is about 4-5 cm and the waste dump provides a safe and reliable base for heap construction. Moreover, the analysis results showed that the selected %5 grade for the heap interface is good and does not pose any risk in terms of heap Interface shear displacements. A sensitivity analysis of heap mechanical parameters was also conducted. The obtained results show that if the friction angle of heap material is reduced below 25 degree due to acid spraying process, the heap walls become unstable and the heap geometry must be redesigned."

Jan 1, 2015

By SeyedBijan Mahbaz

Development of Geomechanical Earth Models (GEM) is a prerequisite to reservoir management, involving issues such as stress path analysis, prediction of induced seismicity and sanding initiation, and coupled flow-stress modeling that leads to more realistic predictions of oil rates and rock response. Part of GEM development is the stipulation of the 3-D lithostratigraphic disposition (geometry) which is used to choose the geomechanical units. The digital geological model is then populated with quantitative and semi-quantitative data on rock properties, fluid properties, saturations, initial conditions (p, T, [_]) and other information. Both fluid and solid properties are needed this requires integration of geomechanics skills with geophysical and rock physics skills, and this article deals with a subset of this integration process, with an example from two wells in southwest Iran.Rock physics approaches are used to predict reservoir rock and fluid properties with wellbore and 3-D seismic data, which are also used to interpolate rock mechanics properties to the inter-well regions. The first step in a generic rock physics approach is diagnostic and involves the introduction of a suitable Rock Physics model.Acoustic impedance (AI), shear impedance (SI), and density (_) are the fundamental rock properties usually derived using AVO equations, and these parameters, along with attenuation coefficients, can then be correlated to static rock mechanics properties that define deformability and perhaps even strength. In this study, Poisson Impedance is introduced as a new seismic attribute used for lithology and fluid differentiation in the FahliyanFormation (reservoir rock) in two oil wells in the southwest of Iran. To do this, a novel rock physics model was developed for this naturally fractured carbonate reservoir.Currently, these data are also being used to correlate to a limited rock mechanics data base to develop a more extensive GEM to serve as input to more general geomechanical and reservoir modeling tasks.

Jun 1, 2012

By S. Banisi, A. R. Hasankhoei, Gh. Parsapour, A. R. Ghasemi

At the Gol-E-Gohar mining and industrial Company, a pelletizing plant, which includes two parallel dry closed grinding circuits and a pellet production circuit, produces 600 t/h. Each grinding circuit consists of a burner, a dry ball mill (6 m×13 m) and an air separator. Each ball mill consists of a 2 m-long dryer chamber and an 11 m-long grinding chamber. Iron ore concentrate is fed to the drying chamber to decrease its moisture from 2.5% to below 0.2%. The drying chamber consists of 56 flights in two rows. It was found when the feed moisture content decreased from 1.3 to 3.5%, the throughput decreased by 14% (40 t/h) indicating a low performance of the dryer. In order to improve the efficiency of the drying section, a scale down version of the dryer was constructed in a 1m diameter mill with a transparent end to make image analysis possible. It was found that because of the inappropriate veiling profile in the drying section, most of materials are not subjected to the hot gas tunnel. To overcome this problem, various flights with different geometries were physically tested and also simulated by the KMPCDEM © software. With the aim of arriving at a proper veiling profile which maximizes the particles contact with hot air, a new flight design was obtained and tested. The installation of the rectangular tooth type flights in one of the mills in the plant made the comparison of the old and new designs possible. The evaluation of the designs in a period of three months indicated 15 t/h increase in the throughput in the case of the new flight design.

Jan 1, 2016

By G. M. Hughes

"400 cubic foot Agitair Flotation Cells are in use at Sherritt Gordon's Fox and Ruttan Mine Cu-Zn concentrators. The 4 impeller model No. 120, used at the Fox Mine Operation, appears to offer superior agitation and aeration qualities compared to the single impeller model 120A, in use at Ruttan. The advantages of the model 120 are most significant with ores of high specific gravity and coarse grind.IntroductionSherritt is using 400 cubic foot Agitair flotation machines at both the Fox and Ruttan Mine Concentrators.At the 3000 tpd, Cu-Zn Fox concentrator, 18 model 120 machines have been in operation since May, 1969.The 10000 tpd, Cu-Zn operation at Ruttan utilizes 49 model 120A machines. The plant started operation in May, 1973.The 4-impeller model 120 flotation cell has been marketed by Galigher since the early 1960's but the single impeller model 120A is relatively new.Model 120 Agitair -Cell DataThe Model 120 (Dwg. 1) has floor dimensions of 101 x 10' and a lip height of 2~ to 4 feet to provide up to 400 cubic feet of volume. This machine is shown with a froth crowder and stabilizer plates which are optional.Each motor drives two agitators. 20 HP is recommended by Galigher but 25 HP is more realistic with massive sulphides. The SG of ?ox ore is about 3. 6.The Model 120 can handle up to 600 cubic feet of air per cell at 2 psig which requires 5-6 HP at the blowers. Air volume to each impeller is controlled by a valve from a main header.During the first 3 years of operation at Fox there were few mechanical problems with the 120's."

Jan 1, 1974

By Chao Yang, Liguo Tian, Yan Yang

"The Jinfeng gold mine is one of the three gold mines that Eldorado Gold has in China and it is the second largest gold mine in China. The mine is located in a relatively remote and mountainous area in the southwestern Guizhou province. The orebody is similar to the Carlin type deposit in Nevada. The mill throughput was designed to treat 3,600 tones per day. The ore comes from open pit mining and underground mining, and is fed to one-stage jaw crushing. The crushed ore is stockpiled, reclaimed and then fed to the SABC grinding circuit. After classification with hydrocylones, the ore is floated, and the resultant concentrate is oxidized biologically in a process known as BIOX®. The oxidized concentrate is then washed in a CCD circuit and finally leached with cyanide in a CIL circuit for gold extraction. Jinfeng produces about 180,000 oz of gold per year.This paper introduces operations and modifications of SABC circuit over the past three years, and then describes some technical characteristic of the SAG mill and other circuits in the processing plant.Major modifications and improvements on the SABC circuit are described in the paper, including:1. Impacts of grinding ball and mill liner with respect to material selection, quality, hardness, manufacturing methods, and interactions between mill liner and grinding ball.2. Effect of milling operation parameters on milling efficiency.3. Impacts of SAG mill scats and modifications of grate size to improve mill throughput.4. Design and construction of a pebble crushing system, and recycle the crushed scats to the SAG mill to improve mill throughput.With the above-mentioned modifications, 20% increase over the design in mill throughput has been realized over the past three years, and operating cost has been significantly reduced. However, some issues still remain, and thus process modifications and technical innovations are still needed."

Jan 1, 2012

By Patrick Rennkamp, Wolf-Dieter Trodel, Andy Fearn

"The Jansen shafts are completed using purely mechanical excavation. This paper summarises the geology, a description of the shafts, the method used for excavation and the results achieved along with the challenges encountered and the solutions developed during the project. This experience is now being applied in the next generation machines and shaft sinking processes. This pioneering approach is changing shaft sinking in soft and medium to hard rock. INTRODUCTION The Jansen Mining project located approximately 150 km east of the city Saskatoon is the location of the BHP owned potash mine with an expected mining output of eight million tonnes annually upon completion. Mining contractors DMC Mining Services have used two Herrenknecht Shaft Boring Roadheaders (SBRs) to excavate the two blind shafts with an approximate excavation diameter of ten metres (inner diameter approximately 8.3 m) to depths of -975 and -1005 metres, respectively. The SBRs excavate the rock by a partial-face cutting method, using a transverse cutting drum mounted on a telescopic boom. The excavated rock is then conveyed away from the bench by an innovative pneumatic system and transferred into muck buckets to be hoisted to the surface. No drilling and blasting was done to keep to the BHP philosophy of using only mechanical excavation for this reference project. BHP VISION – MECHANICAL EXCAVATION BHP focused on mechanical excavation at Jansen due to the following perceived benefits: 1.No workers in the excavation chamber (shaft bottom), minimizing the exposure to traditional shaftsinking hazards associated with working in the shaft bottom. 2. Minimal damage to the rock fabric reducing the need for ground support and avoiding potential impact damage to freeze tubes located around the shaft. 3. Accurate excavation diameters with no overbreak, reducing volumes of rock to be removed and replaced with concrete lining."

Jan 1, 2019

By WM. G. Heeley

This paper will describe the experience gained and explain the deductions made from the phenomenon of the great squeeze which occurred at Brule Mines. The first indication of the commencement of the squeeze was the breaking of posts on the high-side rib of the slope. At first we thought this was due to a lateral pressure only, and we renewed the broken posts with new ones, the result being that the new posts also were soon broken. A noticeable bending and breaking of the collars occurred, with a corresponding reduction in the height of the haulage slope. These symptoms were also evident on the counter above the slope, indicating that the trouble was of an exceptional nature. In the meantime, we had concentrated a large force of repair men, renewing broken timbers and brushing the roof and floor, but in spite of all our efforts we could not overtake the damage being done. Our next problem was to find the cause of this trouble. We were in a new basin of coal (No. 2) which had only been opened a few months, as we had worked the previous four years in another basin (No. 3) where no such trouble as this had ever been encountered. Naturally our first thought concerned the adequacy of the size of the pillars. We had worked in the No. 3 south basin for the previous four years. without any such experience, with 60-feet pillars between slope and counters; whereas we had established 100-foot pillars in the No. 2 south basin between the slopes and counters with an 80-foot pillar between counter and first line of cross-cuts, and 100-foot pillars between the breasts.

Jan 1, 1924

By K. Iturralde

The topic of this article is the automation and robotization in refurbishment processes of industrial buildings. The need to mold these production spaces is quite universal. Particularly in the regions with a high industrial development and with a lack of buildable land, there is a need to convert this kind of spaces into an improved production system. The latest developments can be a useful tool for achieving a more efficient way of reforming this type of construction. On the one hand we have the digital or computerized 3D Laser Scanning (Computer Aided Measurement) that allows an accurate 3D modeling of the entire building. On the other hand, the project management using BIM (Building Information Modeling) could provide an easy design of each of the elements of the refurbishment. Finally, through the production of construction elements using robotics as jig or for CNC (Computer Numerical Control) we achieve a neat production of each element. How can be all those technologies applied in the refurbishment or expansion of industrial buildings? The research takes a first approach and analyzes industrial buildings that can be called generic or not specialized. To narrow the field of refurbishment, three major factors are defined. The first is to minimize the bill of the energy consumption of the buildings. This could be done either insulating the envelope, reducing the waste-volume to be conditioned climatically or creating facilities for energy production. The second is that the refurbishment or expansion of industrial buildings should try not to interfere on the production process that takes place in the building. In other words, the assembly of the elements in the construction site should be quick and easy, causing the least of disturbance at the workplace. Finally, the research makes an approach towards a robot integrated industrial or productive building .

Aug 1, 2013

By Young C. Kim

A proper economic analysis of pit slope design must reflect the trade-off between the benefits and the increased risk of slope failure inherent in steeper slope angles. However, no formal framework for a proper analysis has existed to date. This paper summarizes the material contained in the Design Chapter Supplement (5-3) of the Pit Slope Manual. The supplement describes the results of the research effort in which a formal economic analysis framework was developed and tested through a case study. The case study results have demonstrated the practicality of the developed procedure and the availability of required data under "real-life" conditions.

Jan 1, 1979

Agenda 1.Energy consumption and energy costs ?focus and failings 2.Energy efficiency methodologies, people and supporting tools 3.Energy cost saving case studies from three minerals processing plants 4.The operations team and the supporting role of Operations IT 5.Conclusion: Reducing energy consumption and energy costs There are many good Energy Efficiency Methodologies ?Energy and GHG Emissions, Management Guidance Document, The Mining Association of Canada ?Energy Savings Toolbox ?An Energy Audit Manual and Tool, Canadian Industry Program for Energy Conservation (CIPEC) ?Lean and Energy Toolkit, Achieving Process Excellence Using Less Energy, www.epa.gov/lean ?Energy Efficiency Opportunities Assessment Handbook, www.energyefficiencyopportunities.gov.au

May 1, 2010

By Bernard Tougas, Franco Chiesa, David Levasseur, Bernard Duchesne

"In the present paper, the optimization of a tilt poured permanent mold will be carried out using filling and solidification modeling. This exercise resulted in 3 modifications of the initial mold design which was based on the foundry experience. The optimization provided a 20% improvement in the yield while increasing the output from 10 to 15 castings per hour.In a subsequent study, the value of the critical fraction solid of AlSi7Mg (A356) alloy was verified by radiographic analysis of the castings produced in the first 5 cycles of a run, which are necessary to bring the mold to a dynamic thermal equilibrium."

Jan 1, 2014

By Javier Ramirez

"Recent R&D pilot plant testing was done to validate a full industrial scale system for recovering residual magnetite from the tails of an iron ore concentration plant. The recovery system is based on an autogenous heavy media separator treating a tailings slurry at 0.45% solids by weight. A 3,100 m3/h capacity concentrator was installed based on the testing findings. Excellent metallurgical results have been observed in two years of continuous operation. This experience is the basis for the proposal of a novel process consisting of the preconcentration of base metals ores; the idea being to obtain a heavy bulk concentrate of the polymetallic minerals and discarding in one step the light gangue mineral components. The bulk concentrate then proceeds to conventional froth flotation. The reduced volumetric flow of the bulk concentrate allows a reduction in the size of the subsequent flotation circuit. A prerequisite for the heavy media separation is a fine size grinding of the ore and a correspondingly high degree of liberation of the mineral species to be recovered. A process scheme is also presented in which the gravity concentrator works in conjunction with a companion tailings thickener for process water recovery. The underflow from this thickener, having paste consistency, can be sent to a tailings dam or mixed with Portland cement for mine backfill. The process water in the system is managed at an estimated recovery in excess of 98%. Additional R&D work using this novel approach is being considered by a large iron ore concentrator for removal of liberated silica from the final concentrate; and for upgrading 3.5 million tons of a marginal hematite reserve owned by the mining company.INTRODUCTIONGravity preconcentration (static and dynamic) of sulphides prior to froth flotation has been and is being practiced at various concentrator plants (Asarco´s Young Mill: heavy media cone; Mount Isa: DSM cyclone; Afton Mines: Denver jigs; Tsumeb Mine: Reichert cone) (Burt, 1984). The idea behind installing preconcentration equipment is to reduce the volume of feed processed on flotation, thus requiring smaller flotation plants although other advantages may be of importance, such as obtaining richer concentrates due to higher grade feed, better process water and energy management, and reduced flotation reagent consumption.The SedconTM solid/liquid separator is a versatile process unit patented in Mexico (MX/u/2007/000305). As a gravity device, it may be classified as an autogenous heavy media dynamic concentrator. Figure 1 depicts the Sedcon (Sedimentador de conos) separator. The four main components are as follows: the feedwell for efficient mixing of the pulp with dilution water and flocculant (and coagulant for water clarification); the inner cones (passive elements for solid/liquid separation); the discharge underflow cone; and the scraper mechanism. The standard discharge cone is a 60° inclined cone for general applications. For paste tailings thickening applications, a deep cone with a 69° inclined cone is used."

Jan 1, 2016

By J. Nsasi Bakambu

This paper describes an autonomous platform for exploration and navigation within networks of tunnels, as those typically found in underground mines and caves. In the exploration mode, a remotely located supervisor instructs the platform to move through successive sections of the network, gathering range data that is, then, concatenated into 2D/3D survey maps of the environment. In the navigation mode, the supervisor specifies high-level missions on the previously acquired survey maps. A motion planner, then, translates each mission into a set of consecutive navigation actions, separated by natural landmarks. Mission execution consists of detecting landmarks, self-localizing and performing the planned navigation actions.

May 1, 2003

By D. MacGREGOR, VERA TUREK

The St. Canul and Ste. Scholastique orthoquartzite sanrjstone deposits are located within the Potsdam Formation near Montreal. The sandstone lies on Precambrian basement and is Cam/3rian to Ordovician in age. The Potsdam Formation shows two distinct stages of development. One created a deepwater facies represented by impure, limey or shaley sandstone; the other produced a shallow facies composed of grey, highpurity sandstone. The shallow-water orthoquartzitic sandstone at St. Canul is being mined and beneficiated by lndusmin Limited. The operation manufactures a wide range of silica products and supplies industrial areas of Quebec and Ontario with material for the glass, foundry, silicon carbide and ceramic industries.

Jan 1, 1984