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By K. Johanson, M. Hubert, C. Eckert, D. Ghose

The mining industry routinely processes material with different particle sizes. Coal, nickel ore, copper ore, lignite, shale, and phosphate ore are all examples of materials with wide particle size distributions. It is often assumed that these materials are homogenous and that any particle size distribution has the same chemical activity and composition. It is entirely possible, and quite likely, that chemical composition is a function of particle size distribution. In addition, particle size distributions in ore materials are often responsible for the difference in flow behavior in process equipment. This is evident in coal electrical production facilities. Fine coal may have the same ash content, sulfur content, and BTU value as coarse coal. However, all electrical production facilities know the extreme flow problems that result when attempting to handle wet fine coal. Segregation of these bulk materials is an important issue that must be understood to prevent these cohesive flow problems. Additionally, fertilizers are mixtures of particles with different shape and sizes. These mixtures must remain homogenous to optimize fertilizer performance. Segregation leads to poor product quality. This paper presents a method of measuring the magnitude of sifting segregation occurring in bulk material and the relationship between the strength of the bulk material and the separation tendency. It shows an inverse relationship between the yield strength of the material and the bulk segregation.

Jan 1, 2004

By J. W. Smith, J. G. Eacott, D. H. Napier

"Three hydrometallurgicat processes (Noranda chloride leach, B. C. Research biological leach and Sherritt-Cominco activated oxygen leach) and the Noranda pyrometallurgical process have served as the basis for design projects in the final year of the chemical engineering program at the University of Toronto. Each member of a team of five or six students devotes about 200 hours to the project and the final report is expected to include an economic analysis.None of the processes has been developed to full- scale plant, nor, in the case of the B.C. Research and Noranda processes, were pilot plant data available. Nevertheless, the designs developed provide a useful basis for a preliminary estimate of capital and operating costs and for a preliminary assessment of project feasibility.This paper discusses the approach used in the design projects with respect to engineering and economic aspects, and outlines the educational features and benefits of such a program as well as some of the problem areas that arise.IntroductionAs part of the undergraduate degree course in chemical engineering at the University of Toronto, students devote some 200 hours to a design project in their final year. Hydrometallurgical processes, not yet proven at the commercial scale, have been selected for study. The students are required to develop laboratory and / or pilot scale results into a conceptual plant design, using sound engineering principles. Capital and operating costs are then determined and a preliminary feasibility study and economic analysis are carried out."

Jan 1, 1986

By D. F. Machuca-Mory

The new algorithm for high-order simulation of ore deposit grades termed HOSIM is based on the concept of spatial cumulants. The algorithm is tested using data from Apensu, a structurally controlled gold deposit in Ghana. The required high-order spatial structures are obtained from a training image or analogue of the deposit. Using the available drillhole data and training image, HOSIM realizations are able to model well the grades and geometry of the large and well sampled mineralized structures. However, under-sampled small structures remain difficult to model. HOSIM offers a promising alternative for the spatial simulation of complex non-Gaussian orebody attributes of interest.

Jan 1, 2011

By M. Soleimanifar

With more and more industrial construction projects implementing RFID and other sensor-based technologies on fabrication and project sites, new innovative processes are needed to help automatically read and re-position RFID tags while reducing the cost to deploy RFID infrastructure over large areas. RFID tags are being used on construction sites to help identify the location of materials, equipment and personnel to aid in finding project critical materials and equipment required to construct the industrial facility on time and on budget. This research provides a cost-effective process for reading tens of thousands of RFID tags over large project sites from outdoor laydown yards, to warehouses to the workface where the materials and tagged equipment are installed. Based on the collected RFID and sensor data, localization mechanisms determine the most recent coordinates of the tagged components. The paper will cover analysis of RFID collected data and key lessons learned from a commercial deployment of the SiteSense® system with one Alberta-based industrial contractor, JV Driver Fabricators, at an 80-Acre module, pipe spool and structural steel fabrication site.

Aug 1, 2013

By H. Rafiei Renani, C. D. Martin

"The Cohesion Weakening Friction Strengthening (CWFS) is adopted in numerical analysis to capture the observed progressive failure of hard rock pillars. As a case study, pillars at the Elliot Lake mines with width to height ratios of 0.5 to 3 were analyzed in FLAC3D. Pillars with width to height ratios of 0.5 and 1 show a very similar strain softening behavior while with width to height ratios of 2 and especially 3 indicated prolonged strain hardening. The CWFS model successfully captured the mechanism of progressive failure observed in hard rock pillars including initiation of spalling at the corners, progress of spalling towards the centre and formation of hour-glass shaped pillar, and eventually shearing through the width of pillar. Both the CWFS model and site specific empirical formula successfully separated the stable and failed cases in the Elliot Lake mines. While both models are in reasonable agreement for width to height ratios of less than 2, the empirical formula gives increasingly lower strength values for wider pillars which may result in excessively conservative and uneconomical design.INTRODUCTIONPillars are the portion of in situ rock left between the adjacent openings to maintain the stability of excavations. Conditions of equilibrium require that the loads previously carried by the excavated rocks be transferred to the pillars resulting in elevated stresses within the pillar. Hence, prediction of the behavior of pillars under these loads is important for underground design. Determination of the strength of pillars is a classic subject in underground mining. In conventional mining methods such as room and pillar operations, economic incentives point towards higher excavation ratios i.e., leaving smaller pillars between the mined excavations, while safety and stability requirements favor wider stronger pillars. In some mining methods such as caving operations, the problem is even more challenging. On one hand, the whole operation is directly dependent on the proper continuous flow of caved ore between the drawpoints which requires optimizing the spacing between drawpoints and thereby often leaving narrower pillars. On the other hand, the pillars should be wide enough to ensure the safety of mining operation. Both the blockage of drawpoints as a result of wide pillars and uncontrolled failure of narrow pillars can jeopardize the investments and mining operation.Therefore, design of pillar poses a somewhat unique challenge to rock engineers where simple conservative approaches frequently used in other design methods are no longer acceptable. The behavior of pillar under elevated loads should be predicted accurately."

Jan 1, 2015

"In flotation research, relatively little attention has been paid to understanding particle-bubble detachment phenomena compared with attachment processes. With CFD models now incorporating attachment/detachment kinetics, it is important to obtain more accurate formulations for detachment probability. The formula most often used is due to Bloom and Heindel (2002) who proposed that the rate of detachment would equal the product of detachment frequency, as previously estimated by other authors, and probability of destabilization, as estimated previously by Schulze. These two factors both account for the balance between stabilization and destabilization forces, so the product accounts for this effect twice. An integrated procedure has been followed to estimate the overall detachment rate by re-analysing the process. In this analysis, detachment rate is calculated as the frequency of eddy-aggregate interactions (or “collisions”) sufficiently energetic to cause detachment. The Bond number analysis of Schulze has been incorporated into the turbulence frequency analysis of previous authors in an integrated way. The new formulation has essentially the same type of dependencies as the previous model, but gives a lower detachment frequency. Detachment frequency has been calculated using the new formula for conditions relevant to an industrial flotation cell. INTRODUCTIONIt is well known that the effectiveness of froth flotation for separating different minerals is limited to the particle size range of approximately 10–100 mm (Trahar & Warren, 1976; Trahar, 1981). Fine particles tend to follow fluid streamlines around bubbles limiting the likelihood of bubble–particle collision, while coarse particles can be more easily detached from bubbles before collection can be achieved.Phenomenological models have been developed to quantify the physico-chemical aspects of flotation in order to better understand factors affecting these limitations, and to suggest ways of broadening the window of feasible flotation. Koh and Schwarz (2008) have incorporated these models into computational fluid dynamics (CFD) models of flotation cells, which have then been used for design and scale-up purposes (Schwarz et al., 2015). The models are based on dividing the process of bubble–particle interaction into three subprocesses: collision, adhesion and detachment. Of these, the hydrodynamics of bubble–particle collision and the probability of adhesion have been studied most extensively, while the dynamics of detachment have received relatively little attention from investigators."

Jan 1, 2016

By L. Dekker

"In 1979 Chevron Standard Limited and Irving Oil Limited intersected a thick, high-grade sylvinite zone in the Windsor Group in the Chevron Irving Malagawatch No. I well in central Cape Breton. This well was the third and final hole of a program designed to evaluate a non-commercial oil discovery made by Chevron Standard's Mineral Staff in 1978 while carrying out base metal exploration. Nine holes were subsequently drilled to evaluate the significance of the potash discovery. The delineation drilling proved the Malagawatch structure to be complex with the potash zone showing erratic grade and thickness distribution. Based on the drill information the potash accumulation at Malagawatch is uneconomic, however, other salt ""structures"" in the Bras d'Or Basin may in time prove to have better potential.History of DiscoveryIn 1972 Cuvier Mines discovered the Gays River lead-zinc deposit (MacEachern and Hannon, 1974) which prompted Chevron Standard's Minerals Staff to carry out a study of the Windsor basins in Nova Scotia (Figs. I and 2). As a result of this program several carbonate-hosted lead-zinc prospects were identified in the basal Windsor carbonate; one of these was at Malagawatch on Cape Breton Island . In 1978, after preliminary exploration surveys, a diamond drill program commenced consisting of 5 BQ holes (Fig. 3), three of which tested the basal carbonate. Instead of the reefoid bank facies of the Gays River Formation (Giles et al., 1979), the favoured host for economic base metal mineralization, this carbonate was developed as a laminated, pelletoidal, lime packstone more characteristic of the facies equivalent Macumber Formation (Schenk, 1967). While drilling one of these holes, No. 3-78, oil scum was intermittently detected on the drilling mud. The hole was abandoned at 191 m in anhydrite, without having reached the basal limestone."

Jan 1, 1985

By Jorge Blanco, Joaquin Gotor, Enrique Delgado, Carlos Frias

Since 2009 Cobre las Cruces (CLC) has successfully operated a sustainable mining business near Seville, Spain, applying the most advanced hydrometallurgical technologies to process secondary copper sulphide ores through atmospheric leaching in ferric sulphate media and using oxygen sparging in a cascade of ten reactors. In comparison to conventional copper smelters, the CLC hydrometallurgical process does not generate SO2 gas, airborne emissions or slags. The copper ore is ground and sent directly to atmospheric leaching reactors; flotation is not required, and consequently, copper extraction is maximized at 93-95%, while producing 72,000 t/y copper cathodes of the highest purity (99.999 wt.% Cu, Grade A). Reserves for the CLC deposit were estimated at 16 million tonnes of ore averaging over 6 wt.% Cu and containing principally a chalcocite mineralization. Other copper bearing species include digenite, covellite, chalcopyrite, bornite and enargite. Pyrite represents over 70 wt.% of the ore. In the CLC leaching process, chalcocite reacts with ferric sulphate at approximately 90 ºC and copper is released into solution while ferric ions are reduced to ferrous ions. The ferric sulphate leachant is regenerated continuously by oxygen injection and consumes sulphuric acid. It is remarked that pyrite plays a crucial role to yield high copper leaching rates. When pyrite is oxidized, a small proportion of iron is co-leached and some sulphuric acid is generated. The CLC leaching technology has been designed to allow a certain level of pyrite oxidation, which is positive in many ways: (i) to maintain a Fe/Cu ratio in solution; (ii) to facilitate Fe(II) oxidation; (iii) to produce a high redox potential; and (iv) to counterbalance a bleed solution that removes some iron. Moreover, galvanic interaction between pyrite (cathode) and chalcocite (anode) can substantially increase atmospheric leaching kinetics and efficiency (copper recovery).

Jan 1, 2016

By D. Lessard, S. Nantel

"Surface crown pillars are important Canadian,mining structures. Mines operating in the Canadian Shield usually have several, forming a first line of protection from surface elements.Detailed technical information from twenty-four Canadian hard rock mines show that the deposits dip steeply and are generally either single or multiple veins. Considerable overburden usually cap the deposits. The rock mass is often altered and intersected by important discontinuities.The designs for these types of pillars lack basic data and are based on experience rather than a scientific approach. Regardless of the competence of the rock mass, the surface crown-pillar thickness to width ratios (an unscientific design tool used by the industry) are usually less than five. Rock bolting is, in almost every case, used as a support measure. However, there are many openings neither backfilled nor monitored.The characteristics of openings with surface crown pillars are also examined."

Jan 1, 1988

By F. Rosenblum, P. Spira

"A correlation has been established between the oxygen demand of Brunswick Mining and Smelting ore and flotation results at the bench, pilot plant and operating plant scale. A method of dete""1llining the aeration requirement of sulphide ores on the basis of this correlation is presented. It is shown that abraded iron from grinding media plays an important role in aeration and flotation. Laboratory grinding must therefore be conducted under controlled conditions with suitable grinding media in order to obtain the true aeration requirement of the ore.A method of evaluating aerator efficiency, also based on oxygen demand measurements, has been used successfully at Brunswick Mining to design pilot plant and full-scale aeration systems.1. IntroductionPre-flotation aeration of sulphide pulps has been practiced in the Noranda Group for many years to help in the depression of pyrite and pyrrhotite and to promote chalcopyrite and/or galena. Recently, two out of three parallel circuits at the Brunswick Mining and Smelting Corp. Ltd. concentrator have been converted on a test basis to a new flowsheet incorporating aeration as a basic step. Among other benefits, a substantial decrease in the middlings load has been achieved as a result of improved pyrite rejection. There has been increasing interest in other organizations in the potential advantages to be derived from' aeration in terms of improved metallurgy and/or decreased reagent consumption."

Jan 1, 1978

By Peter N. Calder

Long range mine planning involves developing a mining sequence that schedules the extraction of the ore and waste materials within a final pit limit. The objective is to define a sequence that best meets the defined strategic objectives. The main steps in the creation of an open pit mine plan are the final pit limit design, the design and sequencing of the mining phases, equipment selection and operating cost estimation. Flexibility is the key strategic element in developing a mine plan. Planning the extraction sequences and rates for the various mining areas is a challenging and demanding activity. It is often necessary to consider numerous alternative strategies and what if scenarios. The number of alternatives that can be studied with limited manpower and time resources is restricted. In order to investigate strategic aspects of mine planning, a system to generate workable mine plans rapidly is required. The concept of Visual Mine Planning is that the engineer can visualize the current plan, easily change a component of the plan, such as the annual cut-off grade schedule or the production rate within a particular Phase, and immediately see the effect on the mineralogical and cash flows. If the desired result is not achieved, a change is made and the effect is again immediately seen. This paper presents results of research in this area conducted at the Pontificia Universidad Católica de Chile. The work includes the examination of cut-off grade strategy, sequencing, blending, stockpiling and shovel-truck fleet requirements using simulation.

May 1, 2003

By Laxman M. Amaratunga, Glen G. Hein

"Most mining operations utilize the tailings coarse fraction for backfilling while the fines have been traditionally disposed on surface in tailings ponds. Recently, paste fill has been developed which uses a fraction of the fine tailings (10-30% w/w of <45 µm) in the fill (Brummer and Moss, 1991). This development allows a mining company to use a portion of the fines for backfill, but still requires surface impoundment of the unused tailings. Reactive tailings have the added problem of generating acid after being oxidized in the presence of air and water. Treating acid mine drainage (AMO) from these ponds has proven to be a costly environmental problem and a long term liability.One practical method to reduce the environmental impacts associated with the tailings pond is to modify the physical and chemical prope1ties of the fine tailings so that they can be utilized in an environmentally safe manner. This was accomplished by agglomerating the tailings into pellets and using theses pellets as a coarse aggregate in a total tailings paste fill. This technology does not require any supplemental sand or gravel to be added to the fill.This paper presents the ongoing research into utilizing these tailings agglomerates as a coarse aggregate fraction, in order to create a total tailings paste fill which has supe1ior strength characteristics.IntroductionThe Canadian mining industry produces more than 500 million tonnes of tailings and waste rock annually. The waste rock is usually returned underground for use as rock fill in underground support with the tailings remaining to be disposed of in tailings ponds. Tailings consist of a coarse and fine fraction, and can be either reactive (acid generating) or non-reactive. In an effort to minimize tailings disposal, the coarse fraction has been used underground in backfill along with alluvial sands. This diversion of the coarse fraction, however still requires that the fine fraction be disposed of in tailings ponds. This disposal creates the potential for acid mine drainage (AMO), since in the presence of air and water, reactive sulphide tailings can generate acid. It is therefore an important goal in the mining industry to minimize the disposal of fine tailings into tailings ponds since the treatment of AMO is a costly and long-te1m environmental liability."

Jan 1, 1997

By J. Shibata, N. Murayama, H. Yamamoto

As one of effective usages of wastes discharged in the non-ferrous metal industry, the syntheses of AlPO4-5 and hydrotalcite were carried out using aluminium dross as a raw material. AlPO4-5 is an aluminium phosphate condensate with properties of zeolitic materials and large pore size. Hydrotalcite is an inorganic anion exchanger and has a layered structure of complex hydroxide. They were synthesized in an autoclave at high temperature and pressure. Various physical properties such as crystal structure, surface texture, and specific surface area were measured. AlPO4-5 can be synthesized from aluminium dross under hydrothermal conditions at 180°C-200°C, and 3h. At the same time, AlPO4-34 and non-porous AlPO4 were also formed as by-products. The crystals of AlPO4-5 have a hexagonal structure. Lt is desirable to heat the reaction product at around 550 °C to remove tri-ethyl amine. The specific surface areas of the reaction product before and after heat treatment at 550°C were 17.9m2/g and 358m2/g, respectively. Hydrotalcite can be obtained by a co-precipitation method from the aluminium dross and waste MgCl2 solution discharged in the aluminium regeneration process. Small amounts of SiO2, Al2O3, and Fe2O3 remain in the reaction product as an impurity component. The interlayer distance of the obtained reaction product is about 0.3 nm. Hydrotalcite changes to Mg-Al oxide during calcination at 500 °C for 3h, and then hydrotalcite is formed again by a rehydration operation. The physical properties of the reaction products obtained from the wastes were very similar to those from fresh reagents.

Jan 1, 2004

By Robert B. Parsons

"Although the April 19, 1983 federal budget appears to put greater emphasis on new or expanded government spending programs in an effort to get Canadians working again, the budget proposals contain a light sprinkling of tax changes which could be of some direct benefit to the mining industry.This month, Tax Notes examines some of the more important of these changes.IntroductionSome sectors of Canada&apos;s mining industry could benefit from the proposed income tax changes announced by Finance Minister Lalonde in delivering his budget address to the House of Commons on April 19, 1983. Improved depletion allowance rules, expanded investment tax credits, better use of business losses, and inflation proofing of personal capital gains on Canadian common shares are all part of the measures included in Mr. Lalonde&apos;s first budget to try to reinvigorate the battered Canadian economy.Improved DepletionUnder the Income Tax Regulations, a taxpayer who incurs Canadian exploration expense (and certain other eligible expenses) is permitted to deduct not only the full amount of the Canadian exploration expense (""CEE""), but also an additional allowance (the so-called earned depletion allowance) equal to one-third of the CEE. Thus, a taxpayer in certain circumstances can claim a deduction of $1.33 for each $1.00 of eligible expenditure, including CEE.Although CEE can be deducted from any source of the taxpayer&apos;s income (for example, from investment income, salary income, and so on), prior to budget date the earned depletion allowance was deductible only from the taxpayer&apos;s resource profits. This restriction on the deductibility of the earned depletion allowance substantially reduced the attraction of the allowance: few individual investors or investment companies, for example, have the required stream of resource profits, at least when the CEE or other eligible expenditure is made."

Jan 1, 1983

By H. Houali

Corrosion is an electrochemical process that causes degradation and deterioration of various steel works (pipelines, drains, cisterns) whether they are buried, immersed, or not. Worldwide, we estimate that corrosion destroys a quarter of the annual production of steel at a rate of 5 tons per second. Several techniques are used to protect against corrosion. Among these processes, Cathodic protection, which is regarded as the best technique to assure the protection of steel, works against this phenomenon. This is achieved either by a system of reactive anodes, or by the technique of impressed current protection or other techniques. Before any installation of cathodic protection, a preliminary study and pre-evaluation of certain parameters must be made. In the present work, we will present an example of dimensioning of an installation of cathodic protection by imposed current of a pipeline using solar energy, where we discuss the following items: ? Evolutions of the potential as well as current along the pipeline and their respective expressions deduced from the laws known as telegraphists; ? Range of protection (potential of protection along the pipeline); ? Influence of the isolation resistance of the coating on the range of protection; Effect of the aging of the coating and its influence on the current of protection

Jan 1, 2005

By M. K. Gangal, A. E. Hall, S. B. V. Stewart

"An investigation into the problem of atmospheric fog in Canadian mines is described. Fog occurs in several mines and the reduced visibility can result in the closure of workings for safety reasons. Information on the mechanisms of fog formation are discussed and the methods for improving conditions are reviewed with their relative costs.INTRODUCTIONAtmospheric fog occurs in several Canadian mines during spring and summer. The fog which reduces visibility, contributes to loss of production and increased accident risk . Closure of ramps in mechanized mines causes mining to be stopped or rescheduled, and stoping and grade control may be affected . Increased corrosion of equipment may result from acidic fog .Fog is commonly caused by saturated air being compressed and heated by an inlet fan and then being circulated in an ascensional system with heat transfer to the walls of wet airways. This causes supersaturation and water droplets condense to create fog, with liquid water contents of 0.5 g/kg to 3 g/kg of air. These concentrations reduce visibility to less than 10m and prevent mining. Less severe fog is usually tolerated as a nuisance, about which little can be done."

Jan 1, 1989

By J. C. Kurnia

Presence of fine dust in air causes serious health hazard for mine operators resulting in such serious problems as coal workers? pneumoconiosis and silicosis. Major sources of dust appear of course along the mining face where the minerals are extracted. Proper control and management are required to ensure safe working environment in the mine. Presented here is the use of a computational fluid dynamic (CFD) approach to investigate the flow and dust behaviour in mining tunnels. The objective of this study is to propose and examine various strategies to mitigate dust dispersion from the mining face and reduce dust concentration to a safe level for the operator. In a companion study, the authors investigated various methods for mitigating dust dispersion from the mining face to ensure safe dust concentration levels in the mine tunnel. Among the examined methods, implementation of brattice to direct the flow from the main airway to the mining face is the most effective method to disperse dust particles away from the mining face. The installation of brattice, however, will limit the movement of mine operators and vehicles in the tunnel. Hence, application of a hybrid brattice which is a combination of a physical brattice along with suitable directed and located air curtains is proposed and examined. Based on the CFD simulation results, over a range of parameters of interest, it was found that the physical brattice blocks the ventilation air and directs it to the mine face while an air curtain located along the brattice outlet offers flexibility in keeping the dust away from the operator allowing more freedom for the operator and the equipment. Results of the modelling over a range of parameters of interest are presented and discussed with the goal of managing dust concentrations within safe limits for the operator.

Aug 1, 2013

By K. M. Tait, M. M. McDonald

"An overview of the status of the development and application of Integrated Gasification Combined Cycle (IOCC) power generation is presented. Current projects in North America, Europe and Japan are described, together with the status of plans to apply the technology in Canada. A brief review of the technology is presented, including promising coproduction cycles and hybrid gasification fluid bed processes. The ability of the process to be modified for CO2 to be extracted for enhanced oil recovery or disposal is addressed. The environmental impact of IGCC technology is compared to those of other power generation technologies IntroductionDefinition and HistoryIntegrated Gasification Combined Cycle (IGCC) technology is a concept which has been around for about 50 years but has been generating increasing interest in the last 10 to 15 years. This paper focusses on coal as the feedstock for gasification. Other feedstocks used in gasification systems have included oil, biomass, tires and petroleum coke. IGCC technology integrates coal gasification with generation of electricity by means of a combined cycle system which fires the produced gas in the gas turbine. Figure 1 shows the basic components of an IGCC system which are the gasifier, the gas cleanup system and sulphur recovery plant, the gas turbine/generator set, the heat recovery steam generator (HRSG) and the steam turbine/generator set. The benefits of an IGCC system over a conventional Rankine Cycle pulverized coal (RCPC) fired system for the generation of electricity from coal are that the IGCC system has potential to have higher efficiency and lower emissions of NO., SO and CO2 per unit of power produced than the corresponding RCPC system."

Jan 1, 1994

By A. Saigal

The effect of temperature on the cutting forces during machining of alumina reinforced aluminum composites was investigated, Aluminum 6061, 10% Al2O3 reinforced composite and 20% Al2O3 reinforced composite were tested, A 5/8-inch diameter high-speed steel end mill, a Micro 100 TiN coated single edge endmill cutter and a two-fluted solid carbide insert cutter were used for tooling, The results, in general, showed an increase in the cutting forces as the temperature of the material increased, From the raw data, there are temperatures ranges in which the force data did decrease but they were insignificant with regards to predicting a downward trend. A regression analysis was used to understand which variables had the greatest affect on the forces being generated, The correlation and regression analysis showed that at 600 rpm (velocity: HSS- 98,2 sfpm, Micro 100 cutter - 78,5 sfpm, solid carbide cutter - 192,4 sfpm) the tooling, the workpiece material, built up edge, and temperature were statistically significant factors in the test, Tooling was a significant variable in all testing, The smallest forces recorded during machining were generated with the solid carbide two-fluted endmill cutter, Visually, the solid carbide tooling produced a better surface finish during the testing which made it the tool of choice, In addition, the force data proved that as the cutting speeds were increased, the cutting forces decreased.

Jan 1, 2005

By Pierre Montrueil, Marcel St-Amant

Within the next few years, underground mobile equipment will be partially automated. Mining methods will integrate more and more automation. Such an evolution will be possible only if adequate underground communication systems are developed. This is expected due to the available competence in Canadian telecommunication, to the economic pressure on the Canadian mining industries for international competitiveness and to the social changes where a better working environment (i.e. less accidents) becomes a major concern. CCARM propose the concept of a Production Area Network for Automated Mobile Units called PANAMU as an intermediate size communication system. It can be implemented using mature present-day technology and it can be integrated in some mine wide communication systems. It can evolve so as to incorporate new technologies because of its modular concepts. In this paper, the communication requirements are estimated, the amtmptions are defined, the concepts of the PANAMU are presented and an over- view of its implementation is described. CCARM presents this article to the mining industry as a document for discussion.

Jan 1, 1994