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By F. Kitzinger

Electromagnetic testing of wire rope has become more and more reliable over the past two decades. This improvement is partly a result of an unprecedented progress of electronic technology, which permitted the development of a new breed of testing instruments. There are two basic methods for the electromagnetic testing of wire ropes, the AC method and the DC method. Both methods rely on magnetic field disturbance caused by mechanical anomalies in the rope structure. The wire rope under test is passed through a magnetic excitation field, which can be a weak alternating field or a strong static field. Because the alternating field is produced by an alternating current, these instruments are of the AC type(l). In the early days of ND-testing, strong permanent magnets were not yet available; therefore, the static magnetic field was produced electromagnetically with direct current. Instruments based on static excitation are still called DC instruments(2), even though the field is now produced by a permanent magnet. Both these methods have certain characteristic features. The AC method can detect loss of metallic area caused by corrosion or other effects, whereas localized faults such as broken wires are better detected by the DC instruments . The basic principles of the wire rope testers have remained unchanged over the years and the improvements present in the new instruments usually reside in the signal processing and recording sections. The Instrumentation Department of the Noranda Research Centre* has been involved in a four-year development program which resulted in a new type of wire rope tester, the Magnographv** . This new instrument in many ways represents a considerable departure from the traditional wire rope testers. The Magnograph has already been patented in Canada and the U.S.A.(3), and patent applications are pending in other countries.

Jan 1, 1979

By A. Atef

Vulnerability is a measure of the extent to which a community, structure, services or geographic area is likely to be damaged or disrupted by the impact of particular hazard. Current asset management practices focuses on studying factors that affect performance of isolated infrastructure networks and model a set of actions to control the expected performance of these networks. This approach ignores the underlying spatial and functional interdependencies among these infrastructure networks and their vulnerability. The purpose of this paper is to introduce a new method that recognizes the effect of spatial and functional interdependencies on vulnerability rating of water, sewer and road networks. The proposed method consists of: 1) risk assessment model, 2) interdependency assessment model and 3) vulnerability assessment model. The risk model is composed of two modules: 1) water and sewer risk module and 2) road infrastructure module. The water and sewer risk module will cluster these assets into three risk categories based on environmental, social, operational and economical factors. The road infrastructure module will cluster road assets into three risk categories by using rational factorial technique based on road type, serviceability index, traffic load, and freeze and thaw index. The interdependency model will deploy the risk ranking to perform geospatial analysis in ArcGIS which results in determining the interdependent layers of waters, sewers and roads. The vulnerability model will deploy fuzzy neural networks technique to determine the vulnerability rating based on spatial and functional interdependencies. The fuzzy neural networks are utilized to overcome the lack of historical data and incorporate experts? preferences for establishing the knowledge base for vulnerability assessment. The expected contribution of this framework is to aid decision makers in understanding the interdependencies between civil infrastructure assets and to which extent such interdependencies can compromise assets performance.

Aug 1, 2013

By D. E. Ayres, J. Farstad

"The Midwest uranium deposit is located within the Athabasca Basin near its eastern margin and displays many of the features seen in a number of other similar deposits in this area. The mineralization occurs in the vicinity of a tectonically disrupted portion of the unconformity separating the clastic sedimentary rocks of the Helikian Athabasca Group from Aphebian pelitic meta-sediments which are equivalent to the basal pelitic meta-sediments of the Wollaston Group. The orebody consists of pods of massive pitchblende and sulphur-arsenides within an elongate and tablular envelope of disseminated and fracture controlled mineralization. The massive pods are intimately associated with overbank mudstones of the lowermost Athabasca Group. Both structure and lithology have played major roles in localizing the deposit as follows:1. The basement lithology influenced the mineralogy of the regolith produced on the pre-Athabasca unconformity.2. The style of clastic deposition and the character of the regolith on this unconformity favoured local preservation of mudstones.3. The basement lithology influenced the location of zones of post-Athabasca faulting.4. The proximity of these fault zones to mudstones provided for the coincidence of circulatory channels for fluids bearing uranium, with a good precipitant for the metal.IntroductionA brief summary of the geology of the Midwest uranium deposit was presented by J. Farstad (1979) to the attendees of the Saskatchewan Potash and Athabasca Basin uranium deposits field trip organized by the Canadian Institute of Mining and Metallurgy (May 28 to June 1, 1979). Since that time a substantial amount of data has been collected and studied. This paper is a precis of a report by J. Farstad (1981) which summarizes the geology of the deposit as inferred by visual examination of diamond drill core, augmented by information obtained from detailed examination of selected cores by D.E. Ayres."

Jan 1, 1986

By Kai Zhang, Aijun Huang, Jeremy H. Rao, Xinhua Wu, Paul Rometsch

"As one of the most typical additive manufacturing (AM) technologies, selective laser melting (SLM) removes many of the shape restrictions that limit materials design, thereby allowing computationally optimised and high performance structures to be directly produced and tested. Due to the high reflectivity and lower absorptivity of Al alloy A357 powder during high temperature laser melting, one of the issues SLM might bring is the surface roughness and defects present on the parts. In this regard, this study investigates the surface roughness – fatigue property relationship for a heat-treated aluminium alloy A357 after SLM. Via the adjustment of SLM parameters, an ultrafine microstructure can be obtained due to the fast solidification rate. Therefore, comparable or even better mechanical properties can be achieved with respect to traditional A357 casting counterparts. Meanwhile, the surface roughness conditions of the SLMed Al alloy are also influenced by various processing parameters, raw powder properties, and sample building methods. For selective laser melted Al alloy A357 specimens, a dense part with a smoother surface would be expected to correspond with a good fatigue performance.INTRODUCTION Additive Manufacturing (AM), also known as 3D printing, is a process in which a complex part is fabricated layer by layer from a digital design package (Martin et al., 2017). AM has the potential to conserve raw materials, reduce the energy consumption, part cost, and fabrication time. Furthermore, as a typical additive manufacturing (AM) process, selective laser melting (SLM) was originally developed from selective laser sintering (SLS) based on higher quality lasers (Rao, Zhang, Fang, Chen, Wu, & Davies, 2017b). Different from conventional casting consuming valuable time and energy, SLM is now used as a cost effective method for the manufacturing of metals, such as Al-Si alloys, to produce almost full density parts using fine metallic powder and high power laser beam (Tang & Pistorius, 2017)."

Jan 1, 2018

By Lionel C. Kilburn

"This geological engineering method is based on jour main characteristics of mineral properties, viz; location: inclusion of valuable mineralization; inclusion of geophysical and/or geochemical targets; and inclusion of geological targets. These are subdivided into a total of 19 subcategories, which are used to determine the value of the property.The nineteen subcategories are prioritized and assigned relative value factors from 1.3 to 10. Value of each mineral claim unit is determined by applying the appropriate subcategory factors to a base value of $400per 16.2 hectare unit. Property value is calculated by totalling the values of such individual claim-units.The boundary between ore grade and sub-ore grade must be estimated for each property under valuation, thereby making the method sensitive to mineral commodity prices.A clear and disciplined sequence of decisions based on personal experience forms the basis of this method. The method utilizes all factors normally used to value a mineral property.IntroductionIt is generally accepted in the exploration industry that valuation of exploration properties is a subjective rather than objective process (Roscoe, 1986; Lawrence, 1988; Lawrence, 1989; Woodcock, 1985), and that it is greatly influenced by the experience and qualifications of the person who is doing the valuation. However, the significantly low degree of objectivity in mineral property valuation at this point in time invites effort to achieve a more quantitative engineering basis.Value of a mineral property depends basically upon metal prices, recoverable grades, mining and metallurgical practices, commodity supply and demand , and political-economic conditions, all of which vary with time. Therefore, any valuation is valid for only that point in time when it is made. Mineral deposits can decrease as well as increase in technical value with time."

Jan 1, 1990

By Maurice Hall Haycock

ONE result of the higher price of gold has been the exploitation of many low-grade deposits, the successful treatment of which depends upon obtaining high recovery of the contained gold. Modern methods have made it possible to recover gold from many ores formerly regarded as impossible to treat economically, but in order to apply these methods efficiently it has become desirable, and indeed in many cases indispensable, to gain precise information concerning their mineralogical and physical character. The most successful means of doing this is the use of the reflecting microscope. Reflecting microscopes had long been employed by metallurgists for studying polished surfaces of iron and steel when, thirty years ago, Dr. W. Campbell, of Columbia University, advanced the idea of using similar methods for studying opaque minerals (1). The immediate result was the completion of two microscopic studies, the first on Cobalt silver ores (2) and the second on Sudbury nickel ores (3). The idea was surprisingly slow in being adopted, and not until 1911 did it begin to spread through the universities of this continent. From then on, ore microscopy, or 'mineragraphy', made rapid progress, and, during the next fifteen years, research in universities of North America and Europe led to the development of somewhat specialized apparatus and technique. This phase of development, which resulted largely in contributions of a descriptive nature, furnished a mass of data from which the possibility of economic applications was soon recognized. Ore microscopy became an aid to the mining geologist in solving many problems of ore deposition. This soon led to its application in the study of ores and mill products in connection with their treatment. Its usefulness in this latter field has been very marked and has led to its widespread adoption by the mining industry.

Jan 1, 1937

By Roger M. Nendick

"IntroductionThe stages of development for bringing a mill into production demand that a flowsheet for the process be developed at an early stage. Detailed engineering of the mill may then proceed without duplication of engineering effort on alternative processes. In the case of gold and silver mills, several process alternatives exist which must be evaluated before the flowsheet is finally fixed. The recently developed Carbon-in-Pulp process has added to this choice.Clearly, the major factor in determining the most suitable process is the amenability of the particular ore to a given treatment. Other factors that will also influence the choice are location, climate, power and water supplies, and available capital.Gold and silver milling processes can be divided into three main types:Gravity Concentration;Flotation;Cyanidation.Combinations of the three are frequently used; i.e. flotation followed by cyanidation of the concentrate, or gravity concentration in the grinding circuit with cyanidation of the classifier overflow. The following are the salient advantages and disadvantages of the three main alternatives.Gravity ConcentrationGravity concentration is suitable for free-milling gold ores, i.e. ores in which the gold is relatively coarse and free from sulphides. It should be noted that just because an ore is high grade, it is not necessarily free milling.Gravity concentration methods include jigs, shaking tables, spirals and more recently Reichert cone concentrators. All methods exploit the density difference between gold, which has a specific gravity greater than 15, depending on how it is alloyed, and the gangue, which usually has a specific gravity range of 2.7 to 3.5.A concentrate grade of several hundred ounces per ton might be produced, but recoveries by gravity alone are generally low in comparison to other methods. For this reason, gravity circuits are usually used in combination with flotation or cyanidation circuits."

Jan 1, 1983

By P. R. Brito-Parada, G. Bhutani

"The physical processes occurring in flotation columns are very complex as they take place at different scales over a range of sizes and multiple phases. Column design and optimum operating parameters are usually obtained from empirical studies and although progress has been made on its numerical modelling, most column models rely on simplifications that do not fully capture the hydrodynamics. In particular, Computational Fluid Dynamics (CFD) models of the pulp phase in flotation usually assume the bubble population to be monodispersed. While this assumption may be reasonable in some situations, the polydispersed nature of the gas phase can have a significant impact on the predicted flotation rates.Techniques to model size distribution do exist in the literature and have been rigorously analysed in the past two decades for bubble columns, which are very similar to flotation columns from a hydrodynamics point of view. In fact, available CFD models of flotation columns are an extension of bubble column models, sometimes including additional equations for solids treated as passive scalars. This work focuses on the development of an efficient CFD model for flotation columns. The bubble size distribution in the column has been modelled using the Population Balance Equation (PBE), which is solved using the Direct Quadrature Method of Moments (DQMOM). Coupled with the PBE, the multiphase flow equations in the column have been modelled using the standard Eulerian–Eulerian approach. The solution of this coupled system has been made tractable in this work with the implementation of a highly parallelised adaptive-mesh finite element method. This powerful framework has been implemented in the open source CFD code Fluidity and it allows the carrying out of detailed simulations of flotation columns in 2D and 3D, with important implications for industrial column evaluation and design."

Jan 1, 2016

By Scott L. Ewart, William M. Bryden, Donald E. Wakefield

"Osler, Hoskin & Harcourt develops commentaries from time to time on topics of legal interest. These may deal with new legislation, changes or developments in government policy or recent judicial decisions of importance to its clients. The commentaries are, of necessity, general in nature. Because the law which they deal with is often new and untested, it is hard to arrive at precise statements of the way in which the principle s discussed in a commentary might be applied in specific circumstances. When further guidance is needed , consult a solicitor.The purpose of the Bill is to simplify, modernize and standardize the regulation of mineral exploration and development in Ontario. Many of the changes proposed by the Bill are of an administrative nature and move much of the detail with respect to staking, assessment work, prospecting work, surveys, quarry permits and leases contained in the existing Mining Act to the Regulations contemplated under the Bill.The Bill will undergo revision and be re-introduced and therefore it is not the intention of this present article to detail the specific changes contemplated by the Bill; however , its more significant changes are as follows:1. Provision is made for a lifetime prospector's licence with the elimination of annual renewals;2. Perimeter staking of a block o f claims is permitted to reduce the cost of staking;3. Assessment work requirements are expressed in term s of dollars spent rather than days worked;4. Persons doing exploratory work are required to furnish notice to owners of surface rights of intention to perform assessment work;5. Annual work summaries will be available to the industry to lessen duplication in exploration work;6. The option of continuing assessment work rather than applying for a lease is provided;"

Jan 1, 1984

By M. P. Brameld, R. H. McCorkell

"Overburden covering bedrock uranium deposits was sampled to depths of 29 m and Rn concentrations measured at the same depths. Total-alpha activities, V concentrations and Rn emanation (J) of the samples were measured. The U-flux into the overburden was greater in the past: oxidation and dissolution has since removed most U, leaving decay products which indicate the presence of U deposits when U itself does not. Distributions of U and decay products and their ratios to each other reflect U-migration and degrees of U-removal. Rn distribution in overburden is related to the J of overburden samples and the presence and movement of groundwater. Simple, rapid methods of total-alpha and J measurement are described.IntroductionThe overburden drilling apparatus developed by Bondar-Clegg and Company makes possible sampling and radon measurement in overburden from the surface down to about 50 metres. This apparatus was used here to study the diffusion of uranium and its decay products from ore deposits into over lying overburden at the N deposit of the Amok Ltd. property (Cluff Lake, Saskatchewan) and on the Imperial Minerals Ltd. property at Gooderham, Ontario. These ores are enclosed in bedrock; the overburdens were deposited by glaciers or streams. The migration of uranium and its decay products in such situations and the factors which affect it have been little studied in the past, as readily usable techniques for mapping it in three dimensions have not been available. The results reported here are somewhat sketchy and preliminary, but they indicate the value of the methods used and some of the patterns to be expected. Surface and subsurface sampling and measurements were carried out on 3-line grids crossing known zones of mineralization. The lines were 60 metres apart at Gooderham and 40 metres apart at Cluff Lake."

Jan 1, 1982

By James F. Allan

"The Kipawa yttrium-zirconium prospect is located about 150 km south of Noranda, Quebec. Yttrium-zirconium mineralization occurs in an elongate, regionally metamorphosed and deformed peralkaline complex in the Grenville terrain. The mineralized zone, as defined by =.0.10% Y2O3, is 1300 m long and 10 m to 30 m wide. Zirconium content typically ranges from 0.50 to 1.20% ZrO2, The mineralized zone strikes northwest and dips 20 degrees to 35 degrees to the southwest. It occurs at the structural base of the peralkaline complex in syenite gneiss and calc-silicate rocks and is conformable with both the footwall contact of the complex, and the layering and gneissosity in the enclosing rocks. Minerals of economic interest are eudialyte (sodium-zirconium silicate), mosandrite (sodium-titanium silicate), britholite (calcium-silica phosphate), and a few other uncommon zirconium and titanium silicate minerals.The highest and most continuous yttrium grades occur in the upper part of the syenite gneiss unit in areas containing eudialyte, mosandrite and minor britholite. Yttrium also occurs in britholite in calc-silicate rocks and in mosandrite in syenitic rocks in the lower part of the syenite gneiss unit. Both the yttrium-bearing minerals and yttrium grades are erratic in the lower part of the unit. Zirconium is generally more uniformly distributed than yttrium. A peralkaline granite gneiss phase of the complex intrudes the syenite gneiss and possibly truncates it, and the mineralization, near the southern boundary of the mineralized zone.The mineralized zone is coincident with a radiometric anomaly and discontinuous yttrium and zirconium soil anomalies.More drilling and metallurgical studies will be required to determine the economic viability of the yttrium and zirconium mineralization at Kipawa."

Jan 1, 1992

By James F. Allan

"The Kipawa yttrium-zirconium prospect is located about 150 km south of Noranda, Quebec. Yttrium-zirconium mineralization occurs in an elongate, regionally metamorphosed and deformed peralkaline complex in the Grenville terrain. The mineralized zone, as defined by =.0.10% Y2O3, is 1300 m long and 10 m to 30 m wide. Zirconium content typically ranges from 0.50 to 1.20% ZrO2, The mineralized zone strikes northwest and dips 20 degrees to 35 degrees to the southwest. It occurs at the structural base of the peralkaline complex in syenite gneiss and calc-silicate rocks and is conformable with both the footwall contact of the complex, and the layering and gneissosity in the enclosing rocks. Minerals of economic interest are eudialyte (sodium-zirconium silicate), mosandrite (sodium-titanium silicate), britholite (calcium-silica phosphate), and a few other uncommon zirconium and titanium silicate minerals.The highest and most continuous yttrium grades occur in the upper part of the syenite gneiss unit in areas containing eudialyte, mosandrite and minor britholite. Yttrium also occurs in britholite in calc-silicate rocks and in mosandrite in syenitic rocks in the lower part of the syenite gneiss unit. Both the yttrium-bearing minerals and yttrium grades are erratic in the lower part of the unit. Zirconium is generally more uniformly distributed than yttrium. A peralkaline granite gneiss phase of the complex intrudes the syenite gneiss and possibly truncates it, and the mineralization, near the southern boundary of the mineralized zone.The mineralized zone is coincident with a radiometric anomaly and discontinuous yttrium and zirconium soil anomalies.More drilling and metallurgical studies will be required to determine the economic viability of the yttrium and zirconium mineralization at Kipawa."

Jan 1, 1992

By M. Thérien, M. Rémillard

"Data from two industrial plants are treated by mass balance package BILMAT. The first application concerned a base metals/precious metals (PM) producer and the second, implementation of a hydrocyclone for the recovery of iron chips in the granite industry. Also LOTUS 123 software can easily be adapted for laboratory test mass balances using an IBM-PC computer. INTRODUCTIONThe present paper deals with two different BILMAT program applications. The first application concerns a copper-zinc-gol d-sil Yer producer based in North-western Quebec and the second, concerns the iriplementation of a hydrocyclone for the recovery of iron chips in Quebec granite company.Afterwards, we deal with some LOTUS 123 software applications for laboratory test mass balances using an IBM-PC.1. Base metal and P.M. producerNoranda Inc, Mattagami division, which operates mines in North Western Quebec, produces copper and zinc concentrates from a sulphide ore. Small amounts of gold (0,34 g/t) and silver (20 g/tl are present. At the time of the study, only 30% of the silver content was recovered in the copper concentrate. The main objective of this study is, to evaluate the metallurgical behaviour of silver in the flotation circuits, to increase its recovery in the copper concentrate and therefore to improve its final economic value. It is then worthwhile to identify the silver bearing minerals and to determine the critical flotation stages where they are lost. The methodology proposed is based on the coupling of a mineralogical study and a detailed mass balance ca1cu1ation in the flotation circuit performed using the BILMAT mass balance package (1, 2, 3).The results are discussed with respect to the distribution of silver in the circuit. The recoveries obtained at the various separation stages for the minerals present in the ore are also discussed."

Jan 1, 1987

"Line Creek Resources Ltd. produces three million clean tonnes per year of metallurgical and thermal coals for the international market. The mining operation, which is located in the mountains of southeastern British Columbia, produces coal from four pits by conventional truck and shovel methods.The South Pit, which has been in operation since J982, has a benched highwall 490 m in height. Shallow dipping coal seams at the base of the syncline formation will be exposed in the highwall over the next four years of pit life. The first of these seams, which will measure 500 m in final highwall length, was exposed in J994. An auger, powered by a 1250 hp engine capable of cutting 2.2 m diameter holes, was brought on site in J994 and has proven to be a successful means of recovering coal from the J3 m thick seam.This paper covers the background to the selection of an auger mining method to recover highwall reserves together with the geotechnical and methane considerations for this approach.IntroductionLine Creek Resources Ltd., a wholly owned subsidiary of Manalta Coal Ltd., owns and operates the Line Creek mine. The operation which consists of four active pits, a processing plant, and rail loadout is located in the southeastern coal fields of British Columbia. Figure 1 shows the general area.The coal bearing sequence at the mine is preserved on the east and west limbs of a major syncline. Up to twelve mineable coal seams, ranging in thickness from 2 m to 15 m are contained in the formation. Within the pits the seams are stratigraphically consistent and structurally undisturbed, except for small-scale thrust faults that create multiple repeats of the seams."

Jan 1, 1995

By Miguel A. Cuba

Resource models are generally constructed using data of different types and/or from different sources. A common issue is the consistency of scale in the information that often leads to a requirement to composite the data prior to model construction. For the purposes of mine planning, development and/or resource assessment, this model may then be upscaled to a relevant selective mining unit. It is well established that the geostatistical parameters for resource model construction is scale dependent. In particular, the volume variance of integrating these various scales has a direct impact on the variogram that should be used in model construction and/or the assessment of volume variance relations as it affects resource estimation. The scaling laws are a set of guidelines that detail how the variogram should change as a result of a change in the volume; these laws are empirically derived and involve some simplifying assumptions, not the least of which is an assumption of shape invariance in the variogram structure. An alternative approach was proposed to directly upscale the variogram via numerical integration, which demonstrates that the assumption of shape invariance is not required and we can directly access the new variogram shape given any volume of interest. This paper compares these two different approaches to variogram upscaling by considering two applications: the first corresponds to a 2D synthetic case and the second looks at a 3D case with data from a porphyry copper deposit. The simulation studies in these cases show that the direct upscaling approach performs better than the scaling laws in fitting the average experimental variogram values at any block size. This is based on a mean absolute error criterion. Moreover, it is also shown that with an increase in the block size, direct variogram upscaling significantly outperforms the scaling laws approach.

Oct 1, 2009

By M. K. Senicie

IN July, 1937, Asbestos Corporation, Limited, installed an automatic conveyor-belt scale at their King mine, Thetford Mines. The equipment was purchased 'on trial' and its performance has proved entirely satisfactory to the staff. The scale was manufactured by the Toledo Scale Company, of Toledo (Ohio) and Windsor (Ont.) and was installed by one of the Scale Company's engineers. The electrical recording equipment was installed by Keith Mercer, Reg'd, of Montreal, Canadian agents for the manufacturers, the Builders Iron Foundry, of Providence, Rhode Island. The recording equipment consists of a duplex weight-transmitter attached to the scale-head, a duplex totalizer with differential relays, a belt-speed compensator, a rate-of-delivery recorder, and a rate-of-delivery indicator. As it was desired to run the mill at maximum capacity, it was necessary to know the rate of feed at all times, so that any lessening of rate of feed or delays would be recorded and could be corrected. After having determined the rate of feed to the mill (100 per cent capacity), it was required to have weighing and recording instruments which would show: (1) The rate of feed per hour. (2) Any variations .in the load. (3) Any delays and the duration and time of the delays. Rate of tonnage recorders in the mill superintendent's office and at the point of feedi.ng were necessary, as was automatic control between the mill superintendent and the feed man. It was desired to have a permanent record of total tonnage fed per shift or day; weighing and recording mechanism had to have sensitivity to record all previously mentioned conditions. Mechanism had to be of rugged construction, and be so built that it would stay in good operating condition, with the minimum amount of adjustment and supervision.

Jan 1, 1938

By Graham Swan

The case is presented for the development of a spray-on liner for ground support, but only in the context of a new mining system, consistent with the technical and business case advantages of liners compared to alternatives. Over the past 10 years much effort has been expended in specifying and testing the mechanical/environmental properties of various liners, without actually fulfilling any mining system requirements. The results have been generally disappointing, with no consistent and sustained application in a dayto- day production environment being achieved, anywhere. Central to this shortcoming has been the failure of mining/liner ma nufacturing companies to realise that screen/mesh or shotcrete cannot simply be replaced with thin, deformable liners: success will depend upon closely defining and evolving a new, liner- functional mining system. The paper begins with a discussion of some fundamental technical capabilities and constraints associated with 3M Canada?s liner material that has been developed in partnership with Falconbridge Limited. Intended applications for this liner include the support of bursting ground associated with deep mining conditions. With safe application and consistent performance in mind, the paper argues for a new mining system that derives in the first place from best quality drilling and blasting practices. Taking this as a given, a system for waterscaling and liner application prior to mucking out is proposed, followed by bolting through the liner while arranging for the bolts to be explicitly connected to the liner. Some logistical and equipment related challenges of such a mining system are then reviewed and discussed in the context of the business case for liners. It is concluded that this approach, if successful, will provide the greatest benefits in the areas of safer mining, due to reduction in worker exposure, and in reduced mining cycle times.

May 1, 2003

By Ayako Iwakoshi

Highly concentrated pastes of gold nanoparticles were successfully produced by use of a special kind of protective polymer and a mild reductant. Solid part of the pastes consists of up to 85wt% of gold nanoparticles, 10~30 nm in diameter, and residual protective polymer. This component can be diluted by any kinds of solvent at arbitrary rates. Electronics, optics, catalysts, colorants and surface metal coatings are possible application fields. 1. Introduction Noble metal nanoparticles are of interest in a variety of fields ? such as colorants, metal coatings, electronics(1), optics(2), and chemical catalysis(3). Especially, in the color field, the gold nanoparticle has been known as an aesthetic red colorant for stained glass and fine glassware, such as Venetian glass. The mechanism of coloring is attributed to surface plasmon absorption of gold nanoparticles(4,5). The gold nanoparticle in stained glass shows very clear red color, which is very durable for hundreds years. On the other hand, the red color of organic pigment in paint films often fades away within several years. We intended to reproduce the elegant and stable coloring of stained glass in paint films. In order to color a very thin, 20~50?m, paint film like stained glass, production of highly concentrated dispersion of gold nanoparticle is necessary. To achieve this, there were two issues to be overcome. One is how to prevent the coagulation of gold nanoparticles in highly concentrated solution. So far, several methods to prepare gold nanoparticles(6,7) were reported. But only a few methods succeeded to stabilize the gold nanoparticle dispersion at higher concentration than ppm order. The other is controlling of the particle size, this is because the color of gold nanoparticles is very sensitive to the particle size. Only when the particle size lies around 10 nm, the suspension exhibits red color like stained glass.

Oct 1, 2003

By Jessica Hurst, Mark Holdsworth, Jeff McKay

"In 2002, Kennecott Utah Copper Copperton Concentrator installed an Expert Control system for optimization of their SAG and Ball milling circuits. The advanced process control has been well received and is utilized well over 95% of the time. In the years since, many lessons have been learned and many advances have been made. Improvements have produced millions of dollars of benefits and have included directly controlling feedrate with complex logic as opposed to using a bearing pressure controller, modifications to how sound is used for control, modifying logic for maximizing asset utilization and using advanced control for automating equipment restart. INTRODUCTIONRio Tinto’s Kennecott Copperton Concentrator produces copper, molybdenum, gold and silver. The mill has 4 SAG mills (SAG 1-3, 34 foot diameter and SAG 4 36 foot diameter), 8 ball mills and copper and molybdenum flotation plants, as seen in Figure 1. The 2010 average data is shown in Table 1.In 2002, a Metso Cisa OCS Expert Control system was installed at Copperton for SAG and Ball mill advanced control. The expert control was first placed on SAG 2; data from the first few weeks compared with operator performance indicated approximately an 11 percent increase in throughput. After full commissioning, the system was gradually refined further by plant personnel to develop key performance indices based on SAG feed size, refinement of the sound setpoint for control of mill speed and throughput, specific rules to help the adjustment of speed based on loss of a feeder, etc. With the addition of the pebble crushing circuit, the expert control began utilizing a model estimation of crushed pebble bin level to help stabilize the impact of returned crushed and uncrushed pebbles on the SAG mills. As the ore and limitations change, it is necessary to evolve the SAG logic to better handle any constraints."

Jan 1, 2012

By A. J. Sinclair

"Abstract-Geology contributes essential information toward obtaining high-quality resource/reserve estimates. In this context, geology can be considered under the following overlapping topics: regional geology, detailed (deposit) geology, mineralogy, ore deposit models and continuity, with geological mapping being fundamental to all. Each of these topics is considered here in terms of potential contributions to "improved" mineral inventory estimation. Some of the principal conclusions are:1. Regional geological relations must be consistent with deposit geology. It is common that important geological relations are more clearly evident in various regional locales than in highly altered and/or highly deformed mineralized areas containing mineral deposit.2. Detailed geology provides information for a geometric model of a deposit, a model that serves as a basis for mine planning. It is important to distinguish fact from interpretation in such models. Substantial effort is required to characterize the geometric margins of a deposit and the relation of these margins to the simplistic geometric form that normally emerges as an interpretation.3. Mineralogical studies relate to many aspects of deposit evaluation including abundance of ore and deleterious minerals, spatial distribution of ore and deleterious minerals, grain size characteristics of important minerals, mill design, etc.4. Ore deposit models contribute substantially to confidence in developing a three-dimensional geometric model of a deposit for mine planning. Specifically, they are a basis on which to develop rules for interpolation and extrapolation of ore, and they contribute to recognition of domains, each with its own characteristic continuity and margin character.5. Continuity is dependent on mineralization style and may be controlled structurally and/or chemically. It is important to distinguish geological continuity and value continuity. A wide range of classical geological methods are useful in examining geological continuity; value continuity is best viewed as a statistical characteristic that is quantified by any of several measures of autocorrelation."

Jan 1, 1998