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By E. Thomson

This type of microscopic investigation, although still in its infancy, has already found practical applications in several different phases of mining activity. The study of the transparent minerals in rocks, by means of the ordinary petrographic microscope, has for long been a very useful supplement to observations in the field, but the opaque minerals, until recently, have had to rest content with a more or less superficial determination with the hand-lens or the blow-pipe. In a great many cases, particularly where the association of metallics has been somewhat complex, this has been entirely inadequate, and the determination of these opaque minerals under the micro- scope, has opened up a new field of scientific investigation that bids fair to surpass, in practical value at least, the micro-scopic determination of the rock-forming minerals. As the details of this kind of microscopy are possibly not entirely familiar to all mining men, it might be well to outline them very briefly before dealing with the practical directions in which this method may be applied. The ordinary petro-graphic microscope, with but one extra attachment, will serve for this work. A small reflecting device, called a vertical illuminator, is inserted immediately above the objective lens. This reflects the light down to the surface of the specimen and from here the light is directed up the middle of the microscope tube to the eye. As it is desirable that the maximum amount of reflection should be secured from the surface of the section, it is first polished and set in a position perpendicular to the vertical axis of the microscope.

Jan 1, 1924

"Ore deposits containing rare earth elements normally contain small amounts of the radioactive elements thorium (Th) and/or uranium (U). These are the naturally-occurring isotopes U238, U235, and Th232 (and associated decay-series daughter products) that are ubiquitous in nature, and that contribute a small percentage of the natural background radiation exposure encountered by humans. The presence of these radioactive materials in the ore deposit creates potential hazards to human health and the environment that must be dealt with properly in the mining, processing, and refining of the ores, as well as management of waste streams and residues. This paper presents an overview of the environmental and safety issues associated with U and Th, with particular emphasis on rare earth mining, processing, and refining projects; the regulatory approaches followed to ensure that rare earth deposits are developed, operated, closed, and decommissioned safely; and the development of information during the project predevelopment work and permitting processes that feed into the design, operation, and closure of tailings impoundments and milling/separation/refining facilities. Case studies will be presented subject to the availability of relevant public information. INTRODUCTIONNearly all ore deposits containing economically-recoverable rare earth minerals also contain small amounts of the radioactive isotopes for the elements thorium (Th) and/or uranium (U) and their associated radioactive decay products. Therefore, the handling and management of these materials in mining and mineral processing operations must be performed so that workers and the environment are protected from harm from Th and/or U (and their radioactive decay products), just as they must be protected from any other potentially harmful constituents present in the ore or introduced in processing. Examples of these might include ores with high sulfide content, which may pose a risk of acid rock drainage, or chemicals used in ore processing and metals production.The purpose of this paper is to present information on how rare earth mining and processing projects with ores containing Th and/or U can be developed, operated, and decommissioned safely according to applicable regulations intended to protect worker health & safety and the environment.It should be noted that some countries are considering developing Th as a feedstock for producing nuclear energy, which could have some effect on future development of rare earth ore deposits. To avoid confusion, that issue is not discussed in this paper."

Jan 1, 2012

By N. Dobrin, R. Sheinman, Y. V. Kokotov, L. N. Braginsky

Increasing the production of a Mixer-Settler unit requires either increasing flow rates or increasing extractant concentration. The mixers still have to ensure complete emulsification and to maintain high values of specific interface surface area in order to provide a high rate of mass transfer. Theoretically, an increase in mixing intensity can support increased flow rates without reducing extraction efficiency. Unfortunately, conventional pump mixers and mixing systems create small droplets that do not separate easily. As pumping action and mixing intensities are increased, the quantity of small droplets increases. We describe the development and industrial application of a novel mixing system for efficient mass transfer without forming significant quantities of small droplets, targeting both high mass transfer rate and low entrainment values.

Jan 1, 2014

By A. A. Brant

ONE of the reasons advanced for the decline in prospecting and discovery is that, as regards surficial examination, the law of diminishing returns is becoming applicable. Fewer surficially unprospected fields remain; therefore, fewer discoveries by such means result. Much in the nature of mineral resources remains to be unearthed, but even now, and more so in the future, will discovery depend on painstaking petrographic and structural mapping, aided, where necessary, by judicious applications of all the complementary scientific knowledge and devices (e.g., thin section microscopy, geophysics, and drilling) that experience proves effective in localizing a mineral deposit even beneath drift, lake, or muskeg. It is to be expected, then, that the rate of discovery will decrease, that the cost per discovery will greatly increase, and that the work of discovery will become more and more the careful, methodical assembling of field data, conscientiously interpreted on the basis of scientific knowledge by trained, experienced operatives. In view of these trends, the status of applied geophysics to Canadian mining exploration and development work might well be reviewed. The niche which geophysics may occupy relative to geological surveying and drilling has been clarified by the last twenty years' experience. The cloud of somewhat justifiable scepticism that followed the 'geophysical promotion' period of the late 1920's has lifted. Mining, exploration, and finance companies, in open-minded fashion, are seeking sound advice as to what are the scope and limitations of the geophysical methods at present practised. The purpose of this paper and the following one is, therefore, as far as lies within the author's power, to review briefly the geophysical methods at present in practice in Canada, and, at greater length, to joint out impartially and critically their scope, merits, shortcomings, an possible future development. The treatment will be non-technical, the hope being that an accurate statement of the present status of geophysics in Canada may do much to result in a sounder, saner growth of what, in the future, shall undoubted} y prove an increasingly useful tool in exploration and development work. ?

Jan 1, 1942

By J. B. Mawdsley

From the view point of the mining engineer, the square-set method of stoping as practised at Butte, Montana, is one ?of the outstanding features of well conducted mining operations in that camp. The following information was obtained in the course of two months underground work in the Granite Mountain mine, during the summer of 1920, which is one of the properties of the North Butte Mining Company, situated on the well known Speculator vein. Most of the information was derived from personal observation and from discussions with various miners and with members of the staff. Geology The copper mining area of the Butte district is some two miles long by one and a half miles wide, a mineralized area in a great batholith of monzonite granite, locally known as the Boulder batholith. This extensive body of granite is traversed by several series of mineralized fault-fissures which differ in strike but generally dip steeply. Geologists agree that following the formation of the fissures, alkaline solutions ascended and decomposed the felspathic portions of the granite in the immediate vicinity of the fissure walls, and that these alkaline solutions were followed by cupiferous solutions which filled the fissures and replaced the granite next to the walls. A zone of oxidized ore, varying in thickness from 10 to 400 feet, overlies a sulphide zone containing chalcocite, enargite, bornite and chalcopyrite, with a small amount of quartz gangue. The veins are from 3 to 100 feet in width and contain, on the average, 3 per cent of copper, 2 ounces of silver, and 15 cents in gold per ton.

Jan 1, 1925

By R. H. Wallis

Weighted moving-average contour maps have been constructed for molybdenum, copper and zinc using 7850 stream-sediment samples from 5430 square miles (14,063 sq. kms) of south-central British Columbia. Regional trends for molybdenum and zinc are northeast, north and northwest and those for copper are north and northwest. These trends are interrupted by zones markedly low in metals . The metal-rich trends cross rocks of different lithology and age and thus appear to be structurally controlled. The northeast trend may have exerted control on metal distribution at two different times.

Jan 1, 1978

By M. C. Harris

"Excess Gibbs energy is a thermodynamic parameter which quantifies the difference between the value of the Gibbs energy for a real mixture and that for an ideal mixture. More specifically the partial molar excess Gibbs energy of a species (i) in a mixture is indicated by the change in the overall excess Gibbs energy of the solution as the number of moles of species (i) changes while keeping temperature, pressure and the number of moles of all other species in the solution constant. Generally it is obtained from the activity coefficient which in turn can be obtained for a species in a mixture using a variety of models. The most widely used method is to use UNIFAC. Flotation is probably the most important process in the concentration of minerals and requires the use of reagents such as collectors and frothers. There is abundant experimental data which illustrates that collectors of different alkyl chain lengths will change the contact angle and that frothers of different structures and molecular weights will result in changes in key flotation properties such as froth behavior, surface tension and critical coalescence concentration. In this paper it is shown that there is a strong linear relationship between measured parameters such as froth volume/height, surface tension, critical coalescence concentration and contact angle and the partial molar excess Gibbs energy of the molecules used. Proposals are made to explain these correlations.INTRODUCTIONAs is well known froth flotation is arguably the most widely used process in the separation of minerals. In broad terms the process relies on the use of reagents known as collectors to adsorb onto a mineral surface and thus render the mineral particle hydrophobic. Alkyl thiolates are very commonly used for this purpose. The hydrophobicity is induced as a result of the alkyl group’s molecular structural properties which results in it forming a non-ideal mixture with the process water. Surfactants (or frothers) are typically alcohols and are known to lower the surface tension of the system and also inhibit bubble coalescence and reduce bubble size. Since alcohols are polar they will also form a non-ideal mixture with water. The hydrophobic mineral attaches to the bubble and rises to the froth phase where the valuable mineral is recovered as a concentrate. Frothers have often been characterized using the so-called HLB (hydrophobic-lipophilic balance) number but recently it was shown that the use of activity coefficients (?) or excess Gibbs energy (G ex ), which is calculated using equation (1) is a much more appropriate way to describe the behavior of these reagents in non-ideal mixtures with water (Corin and O’Connor, 2014)."

Jan 1, 2016

Who is ArcelorMittal Mines Canada ?One of Canada's leading suppliers of iron ore to steel markets around the world ?Past company name = ??Quebec Cartier Mining?? ?Operator of one of North America's largest open-pit mines ?Mont Wright Mines ?Fire Lake Mine ?Largest ArcelorMittal iron ore mining subsidiary ?Annual production of 15 million tonnes of concentrate ?Major expansion program to 24 MT/Y ?Internationally competitive pellet plant ?9.0 million tonnes annually

May 1, 2011

By G. Russo

During the construction of the S.Martin La Porte access adit, 9m in diameter, extreme squeezing conditions occurred while crossing Carboniferous schistose formations, with diametric convergence up to 2m. Back-analysis of monitoring results shows that an acceptable simulation of the observed excavation behaviour can be derived using a combined analytical and numerical approach, with simple elasto-plastic laws but a progressive reduction of residual parameters and a relevant increase of dilatancy.

May 1, 2009

By A. M. Nordale

Let us first trace a line, mentally, across Alaska and Yukon, starting at a point in the west slightly south of the delta of the Yukon river and from there continuing eastward, loosely following the 63rd parallel of latitude until we have passed beyond the eastern border of Yukon. We will make two pronounced digressions southward to include the greater parts of the Iditarod and Tanana River valleys. That visualized line roughly defines the southern boundary of permafrost. North of it lies a vast region, fully three-fourths of the area of the two territories, which includes Seward peninsula, the great Yukon River basin, and the tractless wastes of the Arctic. During some frigorific cycle in the distant geological past, the ground there was frozen to a depth of many hundreds of feet. How deep the frost actually penetrated is not known, but it has been found to exceed three hundred feet in many places. Nature afterwards provided a perfect insulating cover in the form of heavy moss and dense grass, which has protected the ground from the heat of the sun's rays during the intervening ages. This frozen condition has always been accepted as something indigenous to the North and little thought was given to -it until recently, when the United States Government and, I believe, the Canadian Government, began extensive studies of it, particularly in respect to its effect and bearing on the development of the great oilfields of the Arctic. Within this large region and but a short distance south of the Arctic circle are the three principal producing placer gold fields in the sub-arctic, whose hubs centre at Nome and Fairbanks in Alaska and at Dawson in Yukon Territory. The geological structure and history of the gold-bearing deposits of Dawson and Fairbanks are very similar and probably closely related. They are typical placer deposits produced by stream action during periods of erosion and inundation and subsequently covered with a thick layer of fine, powdery silt mixed with decayed vegetation which, locally, is termed 'muck'. The depth of muck varies from less than 10 to more than 250 feet, with the greater depth near the lateral edges of the valleys. The gravel underlying it is medium in size, well rounded, and composed mostly of quartz and schist. The proportion of sand or fines is approximately 40 per cent. No large boulders and little clay are found, for those districts, as well as that of Nome, have not been subjected to glaciation. The most common bed-rock found is either decomposed or hard schist, but infrequently it is slate, quartz, diorite, or a porphyry. The vertical concentration of the gold is invariably on bed-rock and in the lower few feet of gravel which overlie it. The horizontal concentration or paystreak is roughly parallel to the trend of the valley but does not ordinarily coincide with the course of the present stream. The width of the paystreak usually expands from a few feet at the head of a creek to several hundred feet near its mouth.

Jan 1, 1947

By A. A. Brant

Self-potential methods are based ?on measurements on the surface of voltage distributions caused by natural sub-surface oxidation phenomena. The attempt is made to. correlate voltage minima or maxima with the location of mineral materials or geological conditions which may give rise to such naturally produced spontaneous potentials. Any orebody undergoing oxidation is a source of electric current. Ground waters carrying free oxygen attack the upper surface of the body, rendering this the positive pole of a galvanic cell, with the lower portion of the body the negative pole and the surrounding weak acidic waters the electrolyte. Current flow is from positive to negative through the orebody and negative to positive through the electrolyte, i.e., through the surrounding rock. The upper end of a steeply dipping, tabular orebody is hence indicated as lying below the point on the surface where the largest negative potential is observed(l). From its basis, it is apparent that the self-potential method was developed primarily for ore exploration.

Jan 1, 1942

"5.1. IntroductionThe sample preparation requirements for bulk analyses of platinum-group elements (PGE) are different from the requirements for ore microscopy and in-situ analyses. It is necessary that the initial sample collection results in as representative a sample as possible for both types of analyses. Ingamells (1980) believes, however, that sampling is always imperfect and that there is no such thing as a truly representative sample. Once collected, the usual low content and irregularly dispersed nature of the PGE require that samples for bulk analyses be made as uniform as possible, whereas in samples for ore microscopy and in-situ analyses the PGE must be concentrated. Because of the generally high specific gravity of platinum-group minerals (PGM), certain precautions must be taken, such as mixing the sample material in the bags prior to opening.5.2. Preparation forBulk Analytical MethodsThe principal factors that determine the size of the sample required for a bulk analysis are grade, heterogeneity and grainsize. Initially, the grade and sample heterogeneity can only be estimated and a sampling methodology is developed with experience. It is essential at all times, however, that the assayers have information about the source of the sample and the purpose for the analysis. Information on the grain-size, which can only be obtained through mineralogical analysis, is also very important for PGE analyses, but, unfortunately, is often ignored.5.2.1. Samples fromUnconsolidated DepositsConcentrations of PGE may occur in eluvial deposits as well as in a large variety of alluvial deposits, including those of fluvial and glaciofluvial origin. These deposits are often difficult to map and sampling is further complicated by the wide range, from sand-size to boulders, of the non-POE-bearing constituents, and by the irregular distribution and shape of the ""pay streaks"". PGE concentrations in unconsolidated deposits are largely composed of resistant Pt-Fe and Os-Ir-Ru alloys (cf. Cabri and Harris, 1975 and Raicevic and Cabri, 1976), thus making comminution to the usual-150 to -200 mesh somewhat unreliable, due to the malleability of these alloys."

Jan 1, 1979

By W E. vanSteenburgh

The Polar Continental Shelf Project was initiated in 1959 to provide an administrative and logistic vehicle for research in the physical sciences of the land, sea and channel area of the Arctic Archipelago. Most of the scientists are supplied on secondment from the professional branches of the Department. The yearly expeditions number some eighty scientists and sub-professional staff, and they are supported by a fleet of fixed-winged aircraft and helicopters. Accurate positioning is obtained by the use of a Decca Lambda navigational system which is moved as the area of interest is shifted. The Project is designed to accommodate not only physical scientists, but to provide facilities for other scientist who may have an interest in the area under study. The main research scope of the Project includes topographical surveys, hydrography, oceanography, geology, including marine sedimentary studies, gravity, magnetics, seismology, glaciology and geography. The Polar Continental Shelf Project was initiated and recommended by the Committee on Northern Development in 1958.

Jan 1, 1963

By N. K. Jaber

The "Pidgeon Process" for the extraction of magnesium from dolomite ore utilizing ferrosilicon as the reducing agent has been studied extensively by active metallurgists such Mr L,M, Pidgeon the father of this process, Most of the work sited so far has focused on heating the (FeSi/MgO,CaO) briquette mix under vacuum in stainless steel retorts by external fuel hydrocarbon heating, In this work Electrical Induction Heating was employed as the heating method whereby the briquette mix was placed in a steel crucible around which an Induction Heating copper coil was wound and placed inside in a stainless steel vacuum tank, It was observed that by virtue of the fast Induction Heating method utilized in the silicothermic extraction process higher reduction temperatures were reached in shorter periods of time due to fast heat transport into the ore charge mix, This facilitated shorter metal reduction times as compared to the conventional fuel heating methods.

Jan 1, 2006

By Joseph W. Mills

"The Mic Mac property comprises 994 acres held under mining concession and approximately 2,000 acres held under development licenses in Bousquet township, Abitibi county, western Quebec.Gold was first discovered in this locality by Tom Duval in June, 1936. In February, 1937, Cassels Duval Mines, Limited, was incorporated under Quebec charter to take over the property. In September, 1937, the property was examined by Agaura Explorations, Limited, and an option agreement was signed on October 6th, 1937. In June, 1938, an option for complete ownership was taken on adjoining claims belonging to Norgold Mines, Limited, and in September, 1938, a mining plant was installed and the sinking of a 3-compartment shaft begun. In June, 1939, an option was taken by Mic Mac Explorations, Limited, on seven claims of Mooshla Gold Mines Company, Limited, that adjoined the Norgold block to the east. In December, 1939, a new company, Mic Mac Mines, Limited, was formed, amalgamating the Cassels Duval, Norgold, and Mooshla claims, as well as two claim groups to the west of the mine known as the Vaughan and West Cassels groups."

Jan 1, 1954

By J. Beland

The Rimouski-Matapedia region is along the southwestern extension of the central Siluro-Devonian synclinorium of Gaspe Peninsula. As in Gaspe about 30,000 feet of Siluro-Devonian strata rest on a "basement" of tightly folded Ordovician rocks. The central synclinorium is divided up into two northeasterly trending belts each of which is characterized by distinctive lithologies and patterns of folding. The northwestern belt is gently to moderately folded and includes lithologies which point to a stable environment. The southeastern belt on the other hand is tightly folded and the lithologies indicate a less stable environment. A marked angular unconformity separates the basement from the Siluro-Devonian cover near the north-western margin of the northwestern belt. At the southeastern margin of the southeastern belt the relationship of cover to basement has not been as-certained because of a fault. The northwestern belt has several features significant in the search for petroleum; the Silurian strata are exposed in broad open anticlines

Jan 1, 1962

By R. F. Baxter, C. M. Read, R. I. McCulloch

"Globalization of the aluminium industry continues to increase the pace of change and the intensity of competition, while simultaneously, society demands better products, cleaner technologies and sustainable industries. Bechtel, a global engineering, construction and project management company, is not immune to either the opportunities or the challenges created by globalization. However, and not withstanding the challenges, for aluminium industry ""players"" with a true global perspective, globalization presents very real opportunities that may be leveraged to deliver value creating goods and services. The following paper will focus on the exploitation of one of the opportunities created by globalization in the Knowledge Management domain - the application of high level tools and methodologies to improve global delivery of greenfield and brownfield aluminium smelter construction projects. Specific examples will be presented of value driven solutions that were delivered at the early stages of project engineering."

Jan 1, 2006

By A. W. JR. Whitaker

Introduction Within the last quarter of a century the Lake St. John-Saguenay valley has been converted from a quiet agricultural district to one of the important industrial centres in the Dominion. First there was the expansion -of the pulp and paper industry, and then, starting a little over ten years, ago, the development, in large .blocks, of the enormous hydro-electric power resources of the Saguenay river. Coincident with this power development, the world aluminum industry was rapidly expanding and looking for a new source of cheap power. This was found in the Saguenay valley-and so, in 1925, Arvida was established by the Aluminum Company of Canada as a location for one of the largest aluminum plants in the world. Arvida, an incorporated city comprising an area of some ten square miles, is ideally located on a more or less level plateau about 350 feet above the Saguenay river. Seldom has industry stepped boldly forth and carved out of Nature a community with full city status. The process usually goes through the steps of camp, village, town, and city, involving improper planning or lack of planning; all of which has been avoided at Arvida by starting out in the right way. While this community has only a population of approximately 2,000 at the present time, it is carefully planned for a population many times this figure. Streets, city parks, business and residential sections, have been definitely planned, and, with a City government, proper ordinances were passed at the beginning to ensure the building and maintenance of a model industrial community. As the crow flies, Arvida is about 35 miles due east of lake St. John, and 0 miles west of the St. Lawrence river at Tadoussac. From a shipping standpoint, it is well served by the Canadian National railways, with direct lines to Quebec and Montreal, and by ocean shipping facilities at Port Alfred, which is about 15 miles to the east on the Saguenay river and is served by the Roberval & Saguenay railway. The latter has interchange connections with the Canadian National at Arivda, and also operates a branch line into the city of Chicoutimi.

Jan 1, 1933

By M. Jahazi, J. Gholipour

Design and manufacturing of parts using hydroforming process require knowledge about material behaviour and tribological effects during hydroforming. Lubrication is one of the key issues in successfully hydroform the tubes. A Ni-based super alloy tube with 50.8 mm (2 inches) outer diameter and 0.9 mm (0.035 inches) thickness is considered for this research to study the effect of lubricants on the formability of the tubes. Hydroforming of a hollow compressor blade is considered for this project. A combination of press forming and hydroforming is employed to produce the part. LS-DYNA, an explicit dynamic finite element code, is used to model the experiments. Different lubricants are modeled using different coefficient of friction in the model. Predicted results for strain distribution at a critical section of the tube are extracted for each case to evaluate the effect of different lubricants on the process.

Jan 1, 2006

By C. Barlow

The White Mesa Mill (WMM) began operating in 1980 as a regional processing mill owned by Energy Fuels Nuclear, Inc. Original mill design was for 656,000 Mtpa of U ore producing 1,250 tpa of U3O8 concentrate. Sustained market downturns delayed facility upgrades during most of the 1980s and 1990s. The new owners of WMM, Denison Mines, elected to advance the regional mill concept in 2007 with the modernization of these facilities. This paper details decisions taken and lessons learned in plant redesign, choice of leading-edge instrumentation, motor controls and process automation, training and some example benefits from process control stabilization.

Aug 1, 2010