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By D. Haraguchi, S. Izawa, C. Tokoro, S. Owada

"Arsenic is widely known as a toxic element for humans, animals and plants. Because of more stringent wastewater standards not only in Japan but also around the world, research for appropriate and efficient treatment method for arsenic is becoming increasingly important. Coprecipitation or adsorption process using ferrihydrite is widely implemented for dilute As(V) removal from wastewater. In this study, the sorption mechanism of dilute As(V) with ferrihydrite in coprecipitation or adsorption process was investigated. To accomplish this, we conducted batch experiments of coprecipitation or adsorption and compared these results for sorption isotherm and zeta potential. These experimental results showed that sorption mechanism in coprecipitation process depends on the initial As/Fe molar ratio; simple twodimensional adsorption onto the surface of ferrihydrite when the initial As/Fe molar ratio was < 0.4, and some three-dimensional uptake with ferrihydrite when it was = 0.4. We also evaluated the sorption mechanim by analysis of X-ray diffraction (XRD) and X-ray Absorption Fine Structure (XAFS). XRD or XAFS spectra showed that surface precipitation of amorphous ferric arsenate was formed when the initial as/Fe molar ratio was = 0.4, beyond the thermodynamic bulk precipitation range for ferric arsenate.INTRODUCTIONArsenic is toxic to animals, including humans, and long-term exposure to arsenic via drinkingwater causes cancer of the skin, lungs, urinary bladder, and kidneys, as well as other effects on the skin such as changes in pigmentation and thickening (Ghosha et al., 2008). Elevated levels of arsenic are often present in the environment as a result of the weathering and dissolution of minerals as well as in response to numerous anthropogenic sources including the discharge of mine wastes, coal fly ash and the use of pesticides that contain arsenic (Nriagu, 1994; Singh et al., 2007). Indeed, the potential for arsenic exposure affects many people, as evidenced by several million people in Bangladesh and India being at risk of exposure via drinking water obtained from contaminated groundwater sources (Ahmed, 2001).Acid mine drainage (AMD) containing arsenic is a global environmental problem (Dold, 2008; Liang and Thomson, 2008) that also affects Japan, which has many abandoned or closed mines that have been generating AMD for the last few decades (Masuda et al., 2008). Several such facilities in Japan produce AMD containing dilute concentrations of arsenic that exceed Japanese effluent standards (0.1 mg/dm3) (METI, 2006). For example, AMD from the abandoned Horobetsu sulfur mine, the largest AMD source in Japan, contains approximately 10 mg/dm3 arsenic."

Jan 1, 2012

By A. C. A. Howe, J. C. Rowntree

"The Bernie Lake pegmatite near Lac Du Bonnet in southern Manitoba is a complexly zoned pegmatite containing several lithium-bearing units in addition to the western world's largest known reserve of cesium. The pegmatite forms a flat-lying ellipsoidal body within an east-west-trending Precambrian amphibolite. The pegmatite enclosed by this vertically schistose amphibolite lies near the eastern tip of a granitic intrusive. The relationship of this intrusive to the pegmatite is obscured by Bernie lake. To date, the pegmatite body has been delineated aver an area of approximately 80 acres; it attains a maximum thickness of 280 feet. Several distinct zones, including three assemblages of economic importance, comprise the pegmatite itself. The combined spodumene and lepidolite assemblages provide a recoverable defined lithium ore reserve of almost 5 million tons averaging more than 2 per cent lithium oxide. The recoverable cesium ore of the pollucite assemblage provides 300,000 tons averaging more than 20 per cent cesium oxide; this represents more than half of the western world's pollucite reserve. The Bernie Lake pegmatite deposit, owned by Chemalloy Minerals Limited, is well located with respect to the growing United States markets, and its reserves of cesium are large enough to enable it, under favourable economic circumstances, to become the major producer of this metal in North America."

Jan 1, 1967

By R. W. Wein, L C. Bliss

Northern ecosystems are dominated by a harsh physical environment which dictates a need for biological adaptation. As yet, it is unknown just how these adapted plants and animals will tolerate industrial development. Our work, sponsored by university, government and industry, is part of an effort to evaluate this developmental impact. Our present studies and the results to date will be discussed. Other problems to which the environmental student may address himself in the future to ensure against environ-mental degradation will be suggested.

Jan 1, 1971

By Stephen G. Mlot

The evaluation of mineral projects involves the identification, mitigation and management of significant uncertainty. Benchmarking is an essential and effective way of increasing confidence and reducing uncertainty associated with input parameters and assumptions. Comprehensive and detailed benchmarking will ensure ?best practice? technologies, methods and systems have been considered and that the appropriate practices can be identified and incorporated into the project. In conjunction with the involvement of experienced industry practitioners, benchmarking is best employed throughout project evaluation to enable early identification of ?errors?, producing more accurate and predictable outcomes. Considerable time and effort is required to gather data and information, which should be benchmarked by the project evaluation team. There is a history of mining projects underperforming, on production, on costs and on return to the investors. The quality of mine plans and feasibility studies, and the quality of the input data is being questioned in many ways. Benchmarking assists sound project evaluation practices, by providing a database of actual results, to validate project inputs and outcomes, ensuring they are realistic and achievable. Benchmarking also provides unbiased, statistical support as the basis for sound investment decision making and ensures well considered decisions are made resulting in a more efficient study process. The evaluation of the quality of projects which are the subject of transactions also benefits from the use of real data obtained from a benchmarking database. Vendors are quick to highlight the benefits of their projects, and conceal the flaws, inflating the value. Buyers will want to quantify the potential of a project through the due diligence process relying on actual results from benchmarking. For the reasons broadly outlined above, benchmarking should be considered as an essential component of effective Project Evaluation.

Aug 1, 2013

By U. Storck

"Shaft sinking for exploitation of the deep potash beds in Saskatchewan involved great difficulties from the very first because of the need to exclude from the shaft the high-pressure water encountered in the overburden. Control of the troublesome Blairmore quicksands was achieved relatively quickly by use of the freezing method and by lining with cast iron tubbing. The unsolved problem remained, however, of sealing the water-bearing Devonian where the formations had extremely low permeability and were thus hard to grout. Long experience in German potash mines had shown that the permanency of the whole mine would be seriously endangered if large amounts of unsaturated salt water were allowed to flow in from the shaft wall and merely removed by pumping. The prevention of water movement and the resulting dissolution of salt in the overburden were known to be most important. In the Alwinsal shaft, water flow from the Devonian has been prevented by the use of a steel and concrete sandwich lining similar in principle to a kind of lining introduced a few years earlier, and for another reason, in German coal shafts. As its installation is neither more expensive nor more time consuming than that of cast iron tubbing lining, this same lining was also chosen as protection against the Blairmore quicksands. The great advantage of the steel lining, in addition to its relatively high strength, is the fact that it is possible to make the joints of the individual segments absolutely and permanently water-tight by means of tested welds. The virtual dryness of the Alwinsal shaft will also result in lower costs because significant corrosion of all its steel installations, including skips, cage and ropes, will be prevented."

Jan 1, 1968

By D. Weston

"IntroductionIn preserving this paper, the author would like to acknowledge the basic development work carried out by the Consolidated Mining & Smelting Company of Canada, without whose initiative the development of the Aerofoll mill would not have been possible. In particular, he would like to pay tribute to the late Mr. C. T. Oughtred, Superintendent of Concentration for Cominco, whose vision and research-mindedness was the chief contributing factor in the carrying alo.ng of the original development.He would like also to acknowledge the help and co-operation of the staff of the Mines Branch, Department of Mines and Technical Surveys, Ottawa, without which the finalization of the un.it and its application would have been many additional years in coming to industry; and the assistance and encouragement given so freely by Mr. C. W. Dowsett, Consulting Metallurgical Engineer, Ventures Limited, and Professor A. M. Gaudin, Massachusetts Institute of Technology."

Jan 1, 1950

By L. M. Pidgeon

"Part I. - PrinciplesIntroductionIf the oxides of the metals are listed in decreasing order of the magnitude of their heats of formation, the list appearing in Table 1 will be formed. It will be apparent at once that this is essentially the well-known electrochemical series (Table li). The metals at the bottom of the list exhibit great stability and are attacked only by the most violent of chemical reagents. Higher on the list, the metals become more reactive until, at the head of the list, the metals lithium and calcium are unstable in moist air.The reactive metals to be considered lie above manganese. In this group will be found familiar and abundant metals such as aluminium and magnesium, the unfamiliar yet abundant metal titanium, the rare and mysterious metal beryllium, and others of greater or less interest.While these metals exhibit properties as unlike as those of uranium and magnesium, they have in common a specialized and difficult extractive metallurgy. They form compounds of great stability, and their reduction is to varying degrees difficult. The position of a metal in Table 1 (and more particu1arly its position in the free energy column) gives a numerical value to this property.Oxides with low free energies of formation may be reduced with great ease; thus silver and mercury may be produced from their oxides by simple heating in air.Lead, iron, and zinc may be separated from their oxides by heating with carbon to moderate temperatures. Magnesium oxide, on the other hand, .requires a high temperature and very special conditions before it will yield magnesium metal."

Jan 1, 1950

By G. R. Phare

Explosives formulation is dictated by desired field performance, which in turn is dependent on such physical properties as strength, velocity of detonation, sensitivity, and water resistance. The design of explosives to obtain these properties is discussed with some reference to detonation and rock mechanics theory.

Jan 1, 1958

By C. Nikolic

A process utilizing ozone for the precipitation of cobalt from nickel sulphate liquors containing ammonium sulphate has been developed. Best results were obtained using nickel carbonate to maintain solution pH at 5.0 to 5.5. Work was performed both in column and stirred-tank reactors. Variables studied included neutralizer type and concentration, NH4+ concentration, temperature, Ni++ and Co++ concentration, per cent O3 in the O2 carrier gas, O3 input rate and agitation. The over-all rate of cobalt rejection increased sharply with increasing agitation and ozone concentration in the gas phase, reflecting relatively slow transfer of ozone from the gas to the liquid phase.

Jan 1, 1978

By A. D. Huffman

This paper covers the major salt deposits of Canada, with a brief summary of the early history of the industry and a more extended outline of progress since the second world war. Both dry mining and solution mining are covered, and the future of salt mining in Canada is discussed.

Jan 1, 1968

By Š. Šachlová, T. Lokajícek, M. Petružálek, T. Svitek, A. Štastná

During the past 20 years, alkali silicate reaction (ASR) as a cause of concrete deterioration has been studied by a wide range of experimental methods such as microstructural and macrostructural analysis, bulk chemical analysis, X-ray and neutron diffraction analysis, etc. All of these data are compared with expansion values of mortar bars (following ASTM standard C 1260). Recent studies indicate the useful application of non-destructive methods with the aim of better reflecting mechanical properties and the degree of deterioration of real concrete. Ultrasonic testing methods (including ultrasonic pulse velocity UPV) are widely used to determine material mechanical properties and the changes induced by a variety of mechanical or chemical processes. However, only a few laboratory studies of ASR focused on ultrasonic testing of mortar bars. Due to this fact, a heating chamber was designed and constructed to enable ultrasonic sounding of mortar bar specimens while stored in accelerating solution. Regular ultrasonic sounding of mortar bars reveals significant dependence of ultrasonic data such as longitudinal P-wave velocity, signal energy, signal amplitude and signal frequency on mortar bar storage time. Ultrasonic data were subjected to time domain as well as frequency domain analysis. Different storage conditions were used to determine the effect of ASR on ultrasonic parameters. Mortar bars, prepared in the same manner with one type of aggregate, were stored in cold or warm water or in an accelerating warm medium. Ultrasonic data accurately reflects the differences in hardening and deterioration of tested mortar bars due to different storage conditions. Ultrasonic results showed very good correlation with the results of ASTM standard expansion tests and much higher sensitivity to ASR-induced concrete deterioration. Expansion tests showed 1% measured length differences in comparison with up to 80% resolution of ultrasonic data. The ultrasonic testing proved to be a suitable laboratory method for investigating ASR-related processes and could lead to an improvement of standard testing procedures.

Jan 1, 2015

The Carboniferous sedimentary rocks of southwestern Newfoundland merit investigation because of petroleum, salt and gypsum possibilities and indications of base metallization along the equivalent of the Horton-Windsor con-tact. In this paper, Lower Mississippian (Anguille) strata are divided into three formations: (1) the Cape John below, (2) the Snakes Bight and (3) the Seacliffs. A correlation between these formations and the Craignish, Strathlorne and Ainslie formations of the Horton group? in western Cape Breton Island is suggested. The criteria for the Anguille subdivision are essentially lithological, but preliminary study of included spore assemblages suggests more precise interformational correlations between Anguille and Horton sequences. The re-measured lower portion of the type section of the Codroy group is presented to define more clearly the stratigraphic position of numerous gypsum and limestone beds. Because of rapid facies changes within the Codroy group a simplified two-fold division into upper and lower units is proposed on the grounds of

Jan 1, 1964

By C. Blais, G. L’Espérance

Characterization of second phase particles is important with regard to their influence on mechanical properties of materials. Analytical electron microscopy offers the possibility to achieve complete characterization of inclusions. Complete characterization of inclusions means quantitative evaluation of their chemistry and the stereological parameters. A characterization technique based on integrated microscopy and involving scanning electron microscopy, image analysis and energy dispersive X-ray spectrometry is presented. A discussion of the use of transmission electron microscopy and electron energy loss spectroscopy is also presented for the characterization of very small particles and compounds (>100 nm).

Jan 1, 1998

By D. L. Morgan, J. A. Butterfield

"Geological data, production trends and current projects underway suggest that enough molybdenum will be available from more diversified sources to meet the world's growing demands. The growth in molybdenum consumption has been primarily related to its beneficial effects as an alloying agent in steel. This rapid growth has been deliberately fostered by stable prices, adequate supply and application research. The molybdenum industry is now in a process of change which has been seen in several other metals, such as aluminum and nickel. As supply sources have become more diversified, the market has become more competitive. The recent drop in consumption has led to excess production capacity, accumulation of substantial producer inventories and increased market uncertainties. While consumption is expected to increase in the next two to three years, it will take some time to absorb the excess capacity and inventory. The increased proportion of by-product capacity indicates that prices may become more variable. Producer discipline will be required to prevent serious price erosion in times of surplus. Future prices may not continue to increase with inflation. For the longer term, several factors favour the increased consumption of molybdenum. Engineering requirements are becoming more severe and molybdenum alloys can help to meet these changing needs. In addition, consumers can rely on a large and increasing supply of molybdenum. A 7 per cent growth rate in consumption can probably be sustained through the next decade, but new applications and reasonably stable prices will be needed to make this possible."

Jan 1, 1972

By H. Rozovsky

"AbstractThis paper discusses the methods of handling air in a large asbestos mill presently being completed at the Jeffrey mine of the Canadian Johns-Manville Company in Asbestos, Quebec.The mill, being the largest single asbestos producer in the world and capable of handling over 14,000 tons of ore per day, requires vast quantities of air. A minimum of 2,500.000 c.f.m. is required or about 10 tons of air for each ton of ore milled.Short descriptions of the process and systems requiring this air are given, followed by details of the fans and filters which make up the heart of the mill.This 'draw through' system, located on the top or 12th floor, is an automatically .controlled volume-pressure system creating the required suction to draw .air throughout the mill building and its numerous air systems.The dry mechanical method of milling develops enormous quantities of airborne dust and fibre. A section of this paper is devoted to a description of the multiplicity of dust systems within a system to control, filter, and remove this dust.Finally, the paper describes the method of returning the filtered air to the• working floors or to the outside, with some notes on heat, humidity and dust counts.IntroductionGeneralTHE discussions in this paper deal only with operations where air movement is involved. No attempt is made to delve into production methods.The Jeffrey mine of the Canadian Johns-Manville Company, located about 100 miles east of Montreal, is the largest single asbestos producer in the world, being responsible for over half of Canadian asbestos fibre production."

Jan 1, 1955

By Andrew J. Freyman, George S. Barry

"Mineral endowment in northern British Columbia and the Yukon Territory was assessed on the basis of geological opinion which was gathered in a quantitative framework of subjective probabilities. The survey area encompassed 364,000 square miles and was divided into 310 cells having dimensions of one degree of longitude by one-half degree of latitude. The response solicited related to tonnage, grade and number of deposits of a particular mineral in each cell. The questionnaire sought an expression of mineral endowment down to mine-able depth as distinct from economic expectations. Details on the questionnaire and responses are presented in a series of contour maps on individual commooities, which illustrate the collective occurrence picture of the respondents. The approach is largely dependent on the cooperation of an adequate number of geologists familiar with the region being examined. This approach to an assessment of the mineral endowment of a region has a wide range of applicability, from the focusing of exploration effort to aiding government and development bodies in the formulation of regional strategies and the planning, for example, of road, rail and power facilities."

Jan 1, 1970

By A. R. Miller, R. A. Stanton, M. J. Male, G. R. Cluff

"The Dubawnt Group consists of continental sedimentary and volcanic rocks which fill structural depressions - Baker Lake Basin, Yathkyed Lake and Angikuni Lake subbasins- whose evolution was controlled by late Aphebian extension, between 1.9-1.8 Ga. Structurally controlled uranium mineralization having the signature U + Mo + Ag + Pb + Cu ± Zn is spatially related to (i) intersecting fault systems that record multiple movements, (ii) chemically reactive lithologies containing sulphide, chlorite or graphite/ carbonaceous matter in the Archean and Aphebian basement complex and as alkaline volcanics of the overlying Dubawnt Group and (iii) areas containing thick successions of basal Dubawnt Group red clastic sediments.The most significant uranium occurrence found to date is the Lac Cinquante deposit, which contains 14 million pounds U3O8 of drill-indicated reserves. Mineralization is hosted in Archean meta-volcanic and metasedimentary rocks of the Henik Group adjacent to the basal Dubawnt unconformity in the northeastern A ngikuni Lake subbasin and occurs as plunging pods in and peripheral to a fractured and brecciated tuffaceous meta-sediment- sulphide+ carbonaceous exhalite. This deposit exhibits many features typified by the classical vein deposit at Beaverlodge, northern Saskatchewan.Epigenetic stratabound U + Cu + Ag ± Mo mineralization, typified by the 74-1E prospect in the eastern Baker Lake Basin, is hosted in thermally altered Kazan redbeds adjacent to alkaline dykes.At the eastern end of the Baker Lake Basin, small prospects having an elemental signature U + Se + Cu + Ag +Au are interpreted as unconformity-related mineralization associated with the Helikian The/on Basin.The Dubawnt Group rocks of the Baker Lake Basin, subbasins and adjacent basement complex contain uranium mineralization of two eras- Late Aphebian and Helikian."

Jan 1, 1986

By L. J. Cunningham

I THINK it can be safely said that no mining operation, whetl1er open-pit or underground, is ever entirely free of water. It follows that every ton of ore bears a charge which represents, either directly or indirectly, the cost of keeping the mine workings as dry as possible. Water problems occur in all phases of mining operations. They cause difficult and costly drilling conditions during the exploration stage, they often seriously delay mine development, they can slow mine production and reduce efficiency, and they are a continued burden over the life of the mine. It is therefore in the interest of all mining men to be familiar with the methods and materials used for grouting. The most common grouting material is cement. Cement grouting is old and well established, and many engineers are familiar with its uses and limitations. The technique of cement grouting is relatively simple and fairly well understood, and the materials utilized are relatively in-

Jan 1, 1962

By J. Cayouette, . Blatter, P. Cousin

The Laronde mill was commissioned in 1988 and has been treating the Laronde Perim ore since 2000. The Laronde plant, situated in the Abitibi region of Quebec, has experienced mill expansions to accommodate 7500 mtpd and to recover gold and silver as well as important amounts of base metals (Cu, Zn, Pb). Ten sequential metallurgical and environmental processes are responsible for metals recovery and process viability. Over 200,000 ounces of gold, 4,5 million ounces of silver, 7000 tonnes of copper, and 78,000 tonnes of zinc are produced annually. In 2008, the Goldex plant began trucking high wade (35-45 Wt Au) pyrite sulphide concentrate (TCGO) for gold extraction at a newly constructed treatment plant, increasing gold output at Laronde by 40,000 ounces. In 2009, the high gold wade Lapa ore processing facilities were annexed to the Laronde plant increasing output by 120,000 ounces of gold. TCGO and Lapa productions are forecasted until 2018 and 2015 respectively, with known reserves of each mine. Today, up to 140 permanent employees run and optimise the Laronde plant operation. As a result, Laronde has intricacies intrinsic to a large and varied operation. The paper will outline the metallurgical highlights, challenges, and future outlook related to the treatment of each ore type (Laronde, TCGO, and Lapa)

Jan 1, 2011

By H. -L. Heikkilä, E. Peuraniemi

"Boliden Harjavalta Oy has a long tradition in the Finnish metal industry starting from the 1930's. The Smelter consists of copper and nickel flash smelting lines. Off-gases are captured in the acid plant to produce sulfur products. During the early years of production, the surrounding environment suffered from high SO2 and dust emissions. The first acid plant started in 1947, a few years after commissioning of the smelter. The flash smelting method was developed and commissioned in 1949. This created the basis for today’s environmentally sound metal production. Recent air emission reductions are related to treating lean ventilation and granulation gases. Emissions from the stacks are monitored with continuous measurement devices. SO2 and PM10 concentrations are also measured from the residential area and reported online in cooperation with Harjavalta community and other local industry.INTRODUCTIONProductionBoliden Harjavalta Oy smelts copper and nickel concentrates and refines copper in the western part of Finland. The copper concentrates come from external copper mines mainly in South America and Europe. Concentrates are unloaded at the Pori harbor and transported to Harjavalta by train from a distance of about 60 km. Boliden Harjavalta Oy has operations in Harjavalta and Pori. The smelter in Harjavalta produces copper anodes that are transported via railway to the copper refinery in Pori. The anodes are electro-refined into copper cathodes and by-products like Se, Ag, Au and Pt/Pd concentrate. In the Harjavalta smelter SO2 containing gases are delivered to a sulphuric acid plant where sulphuric acid and liquid sulphur dioxide are produced.Our nickel smelter smelts nickel concentrates on a tolling basis to produce nickel matte for customer needs. SO2 containing off-gases are delivered to the sulphuric acid plant for sulphur capture and modification into products.All our operations are certified according to the Quality, Environmental and Occupational Health and Safety Standards ISO 9001, ISO 14001 and OHSAS 18001. Boliden Harjavalta Oy was the first company in Finland operating in the metal and technology industry to be certified according to the Energy Management Standard EN 16001, currently this certification is done according to ISO 50001."

Jan 1, 2012