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By B. E. Jones

"The area of uranium deposition is situated within the Churchill Province on the western edge of the Wollaston Iithostructural domain where it underlies the eastern edge of the Helikian Athabasca Formation. The Collins Bay deposit is 6 miles north-northeast of the Rabbit Lake mine. Two principal zones of uranium mineralization are described.The ""A"" zone is a partly eroded, high-grade pod of metal oxide and arsenides sheathed by clay-like minerals. It trends north-northeast and lies under 25 to 40feet of water. Uranium mineralization is localized at or adjacent to the unconformity between the Athabasca Formation and the basement rocks. The basement comprises a granitoid Archean terrain overlain by paragneisses of the Aphebian Wollaston Group. ""A "" zone ore contains phyllosilicates, quartz, pitchblende, rammelsbergite, pararammelsbergite, carbonaceous material, galena, gersdorffite, niccolite, carbonate and a trace of sphalerite.The ""B "" zone lies 6,000 ft south of the ""A "", and subcrops under till cover. It is a partly eroded zone composed of metal oxide and arsenides which occur within variably altered Athabasca Formation. Minerals recognized are phyllosilicates, pitchblende, niccotite, gersdorffite, millerite, carbonaceous material, pyrrhotite, skutterudite and a trace of galena. The Athabasca Formation varies from 90 to 160ft thick. Granitoid gneisses of probable Archean age and paragneisses of the Wollaston Group underlie the deposit. An easterly dipping thrust fault transects its length.The deposit is typical of the ""unconformity-type"" uraniumnickel deposits of the Athabasca Basin. Observed features fit well with the ""diagenetic-hydrothermal"" model for such deposits, as envisioned by Hoeve and Sibbald (/978)."

Jan 1, 1980

By James D. Bliss, David M. Sutphin

"On the basis of differences derived from genetic, descriptive, and grade-tonnage data, graphite deposits are classified here into three deposit types: disseminated flake, amorphous (microcrystalline), or graphite veins. Descriptive models have been constructed for each of these deposit types, and grade-tonnage models are constructed for disseminated flake and amorphous deposit types. Grade and tonnage data are used also to construct grade-tonnage models that assist in predicting the size and grade of undiscovered graphite deposits. The median tonnage and carbon grade of disseminated flake deposits are 240 000 tonnes and 9% carbon and for amorphous deposits, 130 000 tonnes and 40% carbon. The differences in grade between disseminated flake and amorphous deposit types are statistically significant, whereas the differences in amount of contained carbon are not .IntroductionIndustrial minerals, including mineral construction materials such as sand, gravel, and crushed stone, have historically exceeded metals in global production value. Today, industrial minerals are being used in new and sophisticated ways in response to the late 1980s emerging information- and service-based economies' requirements for less metal and more industrial minerals . Natural graphite is an example of one such mine ral that has been known since ancient times, and is now finding new applications. Graphite was first used as an industrial mineral in Bavaria in 1400 A.D. where it was an important component of crucibles. Traditionally, natural graphite has been used in heavy industries. New applications, such as development of carbon-magnesite bricks a decade ago and the current advancement of alumina/graphite refractories, are increasing its graphite use. Other new uses for natural graphite, such as the use of graphite powder as a thermal blanket for the continuous casting o f steel (Northern Miner, 1987) and the addition of expanded graphite to polyurethane foam where it acts as a flame retardant (Industrial Minerals, 1987), are increasing the demand for this mineral. To meet future demand for graphite and other industrial minerals, knowledge of the characteristics of the deposit types in which they are found is important. A further look at the deposit types for graphite and at construction of descriptive and grade-tonnage models is warranted .The graphite industry recognizes three basic types of graphite , distinguished primarily on the basis of grain size: crystalline flake, lump and chip, and amorphous. These naturally occurring forms of graphite are products of metamorphism and are found in schists of various types, gneisses, and marbles. Temperatures of at [east 400°C are thought to be required for graphite formation (Landis, 1971). Synthetic graphite, also known as artificial or manufactured graphite, is a man-made carbon product and offers higher purity and lower crystallinity than natural graphite. Several authors have written about graphite's unique physical and chemical properties and the uses for individual types of graphite (Krauss et 01., 1988; Graffin, 1983; and Harben and Bate s, 1984)."

Jan 1, 1990

By G. B. Hobbs, S. Saimoto, L. Collins

"Plastic yielding and flow in metals is dependent on the microscopic process of simple shear along crystallographic planes and directions known as slip. Thus, by altering the crystallographic direction of the stress axis or placing constraints in the direction of plastic flow, anisotropy of yield strength for the same material is observed. This phenomenon is called texture strengthening. The application of this concept to highly anisotropic crystal structures such as the hexagonal group of titanium and zirconium alloys, the former in missile casing and the latter in nuclear reactor fuel tubing, seems obvious. The outstanding example in cubic structures is the case of deep-drawing steel. The R value, the width strain over the thickness strain during a tensile test, is taken as a measure of texture strengthening. In face-centred cubic structures, texture strengthening has been completely ignored on the basis that materials with R less than one are not amenable to this beneficiation. This study will review two aspects of texture which will lead to strengthening, first the thermal stability of the deformed microstructure, which is dependent on the stress axis, and second, the texture strengthening aspect of fcc metals.A review of recovery and recrystallization in textured aluminum wires, copper and cupro-nickel sheet will be presented with the view of extending these concepts to the manufacture of heat-exchanger tubing. The superior creep properties of specially processed commercial products such as TD-Ni, TD-NiCr and MAR-M200 will be shown to be a manifestation of the same physical phenomena."

Jan 1, 1981

By M. H. Moys, J. A. Engelbrecht

"Large-diameter flotation columns are subject to severe axial mixing which has reduced column recovery and has generally limited it to cleaner applications. It has been assumed that columns with diameter greater than 1 m should be baffled to reduce axial mixing, but little work has been reported quantifying the effectiveness of baffling. Tests were done on a 0.2 m by 2 m column fitted with baffles of different geometry. It was generally found that the inclusion of baffles in the column worsened rather than improved mixing conditions in the column. This is explained in terms of a model for the effect of poor gas distribution on the behaviour of the column; this showed that under typical conditions a 16% excess of gas flux in the one compartment of a two-compartment column could result in one of the compartments being ""dead"" (i.e. with no net flow of slurry through it), resulting in a substantial loss of performance. The quality of mixing in the laboratory column was only reliably improved when the baffle was raised so that its top was positioned above the froth-slurry interface level. It should be possible to increase column recovery substantially with this configuration. The improved residence time distribution also means that columns can be used more effectively in roughing and scavenging applications. IntroductionFlotation columns have generally been used in cleaner applications, starting with their dramatic success at Mines Gaspe(1). Their lack of applications as roughers and scavengers is probably due to their poor residence time distribution (RID) when compared to the conventional cells they would replace. Espinosa-Gomez et al,(2) recently used them in rougher applications but installed three columns in series, presumably to cope with this disadvantage.Dobby and Finch in their seminal papersl(3,4) on the scale-up of flotation columns were the first to quantify the impact of axial mixing on the performance of industrial flotation columns. Laplante et al.(5) collected further data from the literature for column diameter D, ranging between 5 cm and 183 cm, gas superficial velocity Jg ranging between 0.7 cm/s and 2.8 cm/s and per cent solids in the feed S ranging between 3% and 52%. These data were analyzed with reference to the axial mixing model using the boundary conditions for closed vessels (the latter are more appropriate for flotation columns but the model is more difficult to use because analytical solutions for the RID are not available). The data were correlated by:"

Jan 1, 1993

By Robert White

?Introduction of BMS?Paste fill generalities?Development through paste?Development through rock fill?Conclusion ?Brunswick mine is operated by Xstrata. The mine has been in operation since 1964 and produces around 10 000 tons per day of ore containing (in order) zinc, lead and silver? The ore body consists of close to ten sub-parallel massive sulfide lenses. The length of the ore body is 1200 m with a width of up to 200 m. From the surface, the ore body extends to a depth to 1200m ?There is 100 km of active drifts for a total 400 km ?The mine is divided by 7 levels and 23 actives sub levels

Feb 1, 2008

By S. I. Vobnout, J. Wm. White, J. P. Olson

"Mine management now recognizes the value of computer-based truck-shovel dispatching in open pit mines. The key tangible benefits are substantial productivity increases with a given fleet of equipment or, alternately, significant reductions in equipment required to meet production quotas. In this paper, the authors review the literature, report on efficient, optimal algorithms for haul truck dispatching in real-time, and briefly discuss methods used by various mines to evaluate productivity improvements over manual methods. Actual results obtained at thirteen mining operations around the world are also presented.IntroductionModular Mining Systems manufactures, installs, and supports its computer-based DISPATCH system at mines worldwide. DISPATCH is a large scale, computer-based mine management system which controls the dispatching of all haul trucks in any open pit mine (Fig. 1). When increased production is important, DISPATCH gets the needed production increase with fewer new or recommissioned trucks. DISPATCH also helps operations meet its blending objectives while minimizing rehandle and maintaining production. Furthermore, DISPATCH includes a powerful, eventdriven simulation subsystem. With the simulator mine management can pose ""what if' situations and see the predicted effect on production"

Jan 1, 1993

By G. E. Norman, R. E. Michelutti

"One of the major objectives of Falconbridge has been and continues to be, to minimize the impact of its operations on the environment around its Sudbury operations.The approach to achieving this objective and the results, are discussed under the following topics .I . Sulphur Dioxide Emission Improvements.2. Effluent Treatment Improvements .3. Effect of the Envrionmental Improvements.Sulphur Dioxide Emission ImprovementsHistoryThe rejection of pyrrhotite in the concentrators is one method of reducing the amount of sulphur to the smelter and therefore the sulphur dioxide emissions. In the 1950s and 1960s, Falconbridge developed the capability to remove 54% of this pyrrhotite. Numerous attempts were made to increase this amount by treating the pyrrhotite for recovery of nickel and in some cases elemental sulphur. Processes tested and operated were: hydrometallurgical pilot plant, roast-leach commercial operation and nickel-iron refinery. None of these processes proved to be commerically successful for both technical and economic reasons. Falconbridge therefore redirected its efforts to reducing sulphur emissions by improving its smelting process under The Smelter Environmental Improvement Project. A major component of this project was the installation of a sulphuric acid plant to recover the S02 in the roaster off-gases."

Jan 1, 1984

By J. A. Finch, G. Labonté

"A long-standing objective has been to obtain interpretable measurements of the oxidation-reduction potential in mineral slurries. For this purpose several sensing electrodes (black platinum wire, platinum foil and spiral, gold foil and spiral, and sulphide minerals such as chalcopyrite and galena) were investigated to determine their response to the presence of sulphide minerals in the pulp, and to the addition of reagents commonly used in flotation. The observed discrepancies between the electrodes may be explained using a combination of the classical mixed potential model for complex solutions and the probability of contact between the mineral particles and the sensing electrode. It is shown from laboratory testwork that gold spirals are preferred over platinum electrodes. Finally, some of the practical aspects of using the electrochemical measurements in a plant environment are discussed.IntroductonThe interpretation of flotation of sulphide minerals in terms of electrochemical (electron transfer) processes has brought new possibilities for process control of selective flotation. Investigations on massive and compacted particulate bed electrodes have shown that the flotation of a given mineral in the presence of a collector can be controlled by the potential induced on the mineral surface. Also, phenomena such as collector less (self-induced) flotation, activation by heavy metal ions, and natural selectivity sustained by galvanic coupling during flotation might also be controlled by electrochemical means.The technique for measuring electrochemical potential in slurries is an adaptation of that used for solutions. The measurement of the oxidation-reduction potential of a solution (ORP , Redox, Eh) is usually carried out by immersing a noble metal electrode (platinum, gold or silver) and a non-polarizable reference electrode: Standard Hydrogen Electrode (SHE), Standard Calomel Electrode (SCE), or silver/silver chloride (Ag/AgCl) in the solution. (The abbreviation Eh implies the SHE is the reference electrode.) The potential difference between the two electrodes is measured using a high impedance electrometer. ASTM standard D 1498-76 (revised 1981)(1) covers the practical details of such measurements; however, it does not deal with their meaning either in complex solutions or in mineral slurries ."

Jan 1, 1988

By E. Henderson

"This paper outlines the upgrading of a double-drum 2000 hp cage hoist to provide fully-automatic operation from shaft station control panels. The application utilizes programmable controller technology to provide all necessary functions for movement of personnel and material to 22 locations in a 4000 ft shaft.Various functions involving special design considerations such as ""chairing"", ""jogging"", and three modes of ""multi-level calling service"", are outlined. The use of higher level PLC functions to optimize memory utilization and simulate ""elevator service"" required the addition of a comprehensive fault finding software section to aid in troubleshooting.This paper will deal primarily with the automation portion of the project with references made to other pertinent aspects which were prerequisite to automatic operation. It is not intended to deal with every design detail, but rather to provide an overview of what can be done in the area of automation for those considering such an application. INTRODUCTIONEarly hoisting control systems provided only the essential elements of control, leaving many responsibilities with the operator. With advancements in various areas of technology, electromechanical devices were incorporated to enforce slow-down in end zones, control acceleration rates, monitor safety devices, etc. Brake control systems were supplied to allow for ""single-stick"" operator control, regulated deceleration during emergency brake applications, etc.These additions enhanced the over-all performance but were generally confined to speed and current regulation. Some mechanical devices, such as travelling nut limits, etc.; were used to provide ""position"" control to multiple locations within the shaft. These devices, in conjunction with rather extensive relay control panels, did allow for the establislunent of some automatic cage hoists . The hoists were often limited to service from point ""A"" to point ""B""', involving a limited number of levels due to the complexities of the mechanical interfaces employed. Only limited systematic work sequences were possible . .Programmable Logic Controllers (PLCs) were introduced into industry in the mid-70s and have since gained acceptance in mining applications such as pumping, ventilation, ore handling, etc. This technology, being ""software"" based, allows complexities to reside in the program rather than increasing the number of physical control elements. This has opened the door into hoisting systems for automatic loading and hoisting of ore as well as a means to achieve a comprehensive package of automated cage hoisting functions."

Jan 1, 1989

By A. L. Mular

"IntroductionSince the mid -1960s, automatic control of grinding circuits has become the rule, to avoid losses attributable to frequent circuit upsets associated with uncontrolled disturbances such as ore hardness variations. Higher capital costs of grinding equipment and corresponding operating costs-especially with respect to energy consumption-are major factors that continue to stimulate interest in grinding control.Grinding circuit control strategies depend upon the control objectives defined by the processing plant and are subject to constraints such as: maintain final per cent solids within some range, do not transport steel ball s out of the discharge trunnion, or do not overflow or empty the pump box and so on. Constraints depend on the nature of equipment employed within the grinding circuit and may actually determine the characteristics of the control scheme. Typical control objectives are:1. Maintain final particle size at set point by ,a. manipulation of fresh feed rate with circulating load maintained by manipulation of pump box water addition rate, orb. manipulation of pump box water addition rate with circulating load maintained by manipulation of fresh feed rate, where the methodology utilized to accomplish either (a) or (b) is dependent upon equipment/circuit constraints such as the availability of a variable speed pump.2. Maintain circuit throughput at a maximum by,a. manipulation of fresh feed rate subject to constraints on final particle size and variables such as power draw, circulating load and mill overload.3. Maintain mill load at set point by a. manipulation of fresh feed rate subject to constraints such as on power draw.4. Maintain mill power draw at set point bya . manipulation of fresh feed rate subject to mill load constraints. Often, a grinding control objective is dictated by the recovery vs fineness-of-grind characteristic that exists for downstream separation circuits. When recovery is relatively insensitive to size, maximum throughput in the grinding circuit is advantageous.The purpose of this paper is to review control strategies for primary ball mill grinding circuits, rod mill/ball mill grinding circuits and semi-autogenous grinding mill circuits. Primary sensors employed are highlighted and modern trends are documented briefly."

Jan 1, 1989

By M. A. Bérubé

Le but principal de cette étude était de vérifier certaines hypothèses de nature minéralogique susceptibles d'expliquer en tout ou en partie les variations importantes observées au concentrateur no 1 de Mines Gaspé quant aux performances du circuit B de broyage et de flottation. A cette fin, nous avons examiné six séries d'échantillons prélevés lors d'une campagne de mesures effectuée au cours de l'été 1980. Ainsi, la capacité du circuit de broyage semble dépendre principalement devariation s dans les caractéristiques minéralogiqu es et texturales du minerai, par exemple du rapport grenat/quartz, le grenat ayant une influence néfaste sur le rendement de cette étape, contrairement au quartz . Quant au processus de concentration, la fraction du cuivre sous f orme de minéraux difficilement récupérés par flottation, en particulier des carbonates de cuivre, varie de façon significative dans le minerai, et cela peut certes expliquer en partie des récupérations parfois plus basses. Malgré ces variations important es de la composition minéralogique globale du minerai et de sa broyabilité, le degréde libération des sulfures de cuivre dans le produit de broyage dépend presque seulement de la granulométrie de ce produit. Afin de garantir des performances égales à l'étape de concentration, il est fortement suggéré de contrôler cette granulométrie à un niveau constant.

Jan 1, 1984

By K. Tsuchihashi, A. Kishimoto, T. Uda, Y. Kado, S. Maruyama

We recently proposed a continuous production process for titanium metal with some experimental results. In the process, titanium tetrachloride is reduced by Mg in the presences of Bi to form a Bi-Ti alloy at 900ºC. At this temperature, the obtained alloy is liquid and allows for the continuous removal of product and heat from the reaction vessel. The obtained Bi-Ti alloy was vacuum-distilled at 1000ºC for 24 hr, and 98 at % (92 wt %) titanium, which was easily crashed to powder, was obtained. Bi solvent was selected because of the highest titanium solubility at 900ºC and the moderate vapor pressure among the candidate metals (Bi, Sn, Pb, Zn, and Sb).

Jan 1, 2014

By Philippe Monier, Frank C. Basham

"This paper outlines the scope and applications of 'COALMOD', the British Columbia Ministry of Energy, Mines and Petroleum Resources' computerized financial simulation model for coal mining developments. After a description of the computer system and language of implementation, the logic and scope of current model sub-routines are presented. This is followed by a presentation of examples on the current applications of the model to public policy evaluation, including benefit-cost analysis, fiscal analysis and evaluation of the effects of public infrastructure investments made in support of mining projects.IntroductionThis presentation has been developed in response to a number of requests from coal mining companies and various public agencies who have indicated interest in understanding our application of contemporary analytical techniques to public policy in the coal sector. In particular, the subject of this paper is an explanation of COALMOD. a mnemonic given to a computerized, mine-specific, financial simulation model which is assisting the Government of British Columbia in evaluations of new coal projects, assessment of public sector investments made in support of these projects and. more generally, measurement of the financial effects of current or proposed government policies, and factors outside immediate government control such as coal prices and transportation costs."

Jan 1, 1981

By W. S. (Steve) Vaughan

The Origins of Joint Ventures in Canada?s Mining Industry ? Among the most important financing structures used in our mineral industry today ? Virtually unheard of in the Canadian industry prior to the 1970s ? Borrowed from the U.S. oil and gas sector where it came into prominence in the late 1930s ? The Securities Acts of 1933 and 1934 in effect killed the sale of (equity) shares for financing oil and gas wells and start up mining companies

May 1, 2013

By G. Begin

"The expansion undertaken at Selbaie in 1985 necessitated an adaptation and expansion of the equipment maintenance system. This paper relates briefly the stages of transformation of the maintenance administrative structures, work methods and tools. The maintenance in a mechanized mine requires an expenditure level in the order of 20% of the total operating cost of the enterprise. Thus, the maintenance organization was modified to apply more computerized planning and follow-up, and the role of preventative maintenance was further advanced.IntroductionAs far as maintenance is concerned at Selbaie, the scenario described herein is a resume of the current situation. Although positive results have been obtained, this outline is in no way a detailed account of a fail-proof maintenance system.Once zone A-I was put into production, the expansion the mine experienced in 1985 had a direct impact on the equipment maintenance system. As centralized as it was in the beginning, the system is now partially decentralized.The over-all changes to the maintenance department demonstrate the flexibility required by organizations in new situations. In spite of the exceptional results obtained before the expansion, it became evident that both the maintenance and production sectors would have to be combined. In doing so, a more appropriate coordination of maintenance work could be obtained and the maintenance staff would obtain a more detailed knowledge of the equipment in each sector. In addition, by keeping the general and specialized departments centralized, it was possible to offset the negative effect s of a decentralized system, namely too much manpower."

Jan 1, 1990

By Robert B. Parsons

"No Canadian or his family is likely to escape the effects of proposals for pension reform tabled on October 9, 1986 by Finance Minster Michael Wilson. New tax rules are proposed for Registered Retirement Savings Plans (RRSPs), company pensions, and other forms of retirement plans. Draft legislation is expected to be released in the first half of 1987.IntroductionOver two years ago on February, 15, 1984, Mark Lalonde, then Finance Minister, tabled two White Papers. The first, Action Plan for Pension Reform, proposed improvements to the public pension system and increases in the minimum pension benefits standards to be mandated by the federal government. Since then changes have been made to the Old Age Security, Guaranteed Income Supplement and Canada Pension Plan programs. Also, benefits provided under pension plans subject to the federal Pension Benefits Standards Act have been improved significantly.The companion paper, Building Better Pensions f or Canadians, proposed to standardize and, in many cases, improve retirement savings through private plans by revising the tax rule s. The tax proposals in the Notice of Ways and Means released by Finance Minister Wilson on October 9. 1986 implement, with modifications, the tax treatment of retirement savings originally proposed in the May 1985 budget in response to that second paper."

Jan 1, 1987

By Thomas J. Ferree

"There has been a major evolution of mineral processing technology in the past decade. The evolution has been driven by recognition of broad environmental changes which have impacted various areas of the world. Numerous government regulations have required many mining and mineral processing organizations to introduce changes to reduce the undesirable effects on the environment; many mining companies have voluntarily introduced new technologies and practices which surpass the limits imposed by the regulations. Surprisingly, some of the 'new' technologies are modifications of concepts developed decades earlier. Gravity separation technology is in this category.Mineral Deposits Limited, an Australian company, has been a world leader in the development of mining concepts, reclamation practices and equipment technology that is environmentally suited to today's requirements. This paper relates to equipment used for gravity concentration and electrostatic separation systems, including Reichert cones, spirals, and electrostatic separators. The basic devices and technologies were developed more than forty-five years ago, but use of the systems was quite limited until environmental and conservation practices were recognized and introduced. Spiral concentrators, for example, were patented in the mid-l940s by I.B. Humphreys in Denver , Colorado. The two types of spirals marketed (the Model 24A for minerals and the Model 24C for coal) remained essentially unchanged until expiration of the patents. During this early period most spirals were used in iron-ore wash plants on the Mesabi Range to recover fine iron which previously had been discarded. About the same time sand mining plants in Florida incorporated spirals to recover titanium minerals and zircon from lowgrade beach sands. The Labrador Trough opened new opportunities for spirals when hard-rock iron-ore deposits were developed; approximately 10 000 Model 24A Humphreys spirals were installed between 1958 and 1966. About 5000 spirals of this model are still operating in the same capacity, in spite of the fact that extensive improvements have since been made in gravity separation technology."

Jan 1, 1993

By L. Lamothe, C. H. The

"Pilot precipitator tests were conducted at Noranda's Horne Smelter in late 1978 to evaluate methods of improving converter dust collection efficiency. A bout 35 Nms/min. of converter off-gas were isokineticatly diverted from the converter flue to the pilot precipitator leased from Flakt (Canada) Ltd., consisting of three fields, one transformer-rectifier set per field and 77-m2 total collecting plate area. The effects of gas volume flow rate and conditioning the gas with sulphur trioxide and/or additional moisture were tested. II was found that gas flow rate and moisture level had the most pronounced effect on collection efficiency. Based on a techno-economic assessment of different options for improving converter Courell efficiency, waffle hoods and water sprays were installed on the converters to reduce air infiltration and increase the moisture level in the gas.BackgroundThe Horne Smelter of Noranda Inc. is situated in northwestern Quebec and, since the closure o f the min e in 1976, has been operating as a custom smelter. The concentrates treated at the smelter come from various mines with mixed sulphide ores , many o f them containing significant amounts of lead and zinc which makes dust collection in electrostatic precipitators mo re difficult than normal.As part of a continuing program on reducing smelter dust emissions, the No . 6 Cottrell was installed in 1972 up stream of Nos. 2 and 4 Cottrells (in parallel) in a n attempt to improve dust collection by increasing the over- all precipitator capacity ( Fig. I). However, it has never per formed a t its designed efficiency o f 94%. The average efficiency established in various test s was in the range of 60 – 65%."

Jan 1, 1985

Induced microseismicity monitoring is: ?Essential tool in improving the geotechnical understanding about a mine and its inaccessible surrounding rock masses. It helps to determine: -Event timing, location, and magnitude - identification of highly stressed areas -Event source mechanism - the physics of fracturing in its seismic source region -Seismic strain-rate distribution in 5D - identification of stress concentration or migration patterns -Geomechanical interpretation - identification of hidden geological structures or weaknesses in the ground -Strategy for mining e.g. by a block caving method - maximization of mine production and to optimize ground support design -Potential of future seismic hazards -Large event re-entry protocol, to improve mine safety ?The norm as part of mine safety maintenance and long-term mine design practices

Aug 1, 2013

By Todd S. Harris

"IntroductionThe western region of North America has long been considered a dynamic market supporting such diversified industries as lumber, agriculture, cement, and electronics. In recent years however, the region has also been the focus of a great deal of activity in the extender and filler mineral s business from companies seeking to position themselves to take advantage of the large demand for these materials both here and abroad.Extender and Filler MineralsExtender and filler mineral s include 15different products used in numerous end uses. The nine most important extenders and fillers are listed in Table I. These products range in price from under $50 a ton to over $4,000 a ton and basically represent the following three different types of minerals:Particulate products-Calcium carbonate; Kaolin; Silica.Platy minerals-Talc (Montana, Canada); Mica.Fibrous minerals-Talc (California, Eastern U.S .A.);Wollastonite.What distinguishes these products from other industrial minerals? For one thing, an important feature of extender and filler minerals is that they are used primarily in such consumer non-durable good s as paper, paint, plastics, sealants, and rubber which traditionally do not react as violently to swings in the economic cycle. In addition, these minerals are sold principally on key physical properties, usually brightness, particle size and shape, oil absorption, and hardness. As part of the physical minerals segment of industrial minerals, extenders and fillers are traditionally the most stable group and typically the most profitable. Studies by C.H. Kline over the past decade on extender and filler minerals has revealed historic average profitability (expressed as a percentage on sales) nearly double that of most other industrial mineral s.The demand for these minerals in the western region (Fig. 1), closely follow s the areas of greatest population concentration. These markets include pulp and paper, mainly in the Pacific Northwest, and paint, around Los Angeles and San Fran cisco. Other significant markets for extender and filler minerals in western North America include joint cements, carpet backing, and plastics, mainly PVC pipe."

Jan 1, 1986