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By Witold J. S. Ostrowski

The shaft structure being part of an underground mine, depends on programned functional duties, and on geological and hydrological conditions. The majority of Canadian metal mine shafts are in hard competent igneous rocks, which are in an elastic state of equilibrium around the excavation. Others penetrate soft sedimentary or very weak water-bearing rock formations in which the equilibrium varies from plastic to hydrostatic. Knowledge of how to interpret the underground conditions, determine acting forces and design proper structures is essential for the production and safety of the future mine.

Jan 1, 1973

By O. Worku, J. H. Masliyah, Z. A. Zhou

ABSTRACT The viscosity of concentrated kaolinite or illite clay in aqueous suspensions was measured in the presence and absence of a small amount of montmorillonite (<1 wt%). To avoid solids settling and to increase the sensitivity of the suspension viscosity measurements, solids concentrations higher than 38 wt% were used. The pH of the suspensions and the concentration of calcium and bicarbonate ions were found to significantly impact the viscosity of the clay suspensions. The results showed a significant increase in the viscosity of kaolinite suspensions with the addition of as low as 0.25 wt% of montmorillonite on a solids weight basis. In addition to illustrating the role of water chemistry in modifying slurry rheological properties, our study demonstrated that viscosity measurement could be a simple, yet sensitive technique for determining the content of smectite clays, such as montmorillonite, in a complex mix of various types of clay.

Jan 1, 2012

By Rayleen Riske

Why do we look for better reconciliation when times get tough? Why wait? Mine reconciliation should be a priority throughout the good times too. In fact, with good reconciliation, those good times are going to be even better and will help pave the way to success through those preventable bad times. Reconciliation throughout the entire mining value chain requires the capture, validation, and analysis of copious amounts of data. This task can be daunting for a team in a small mine, let alone reconciling across a suite of large mines. This paper will outline the different ways we can reconcile across the value chain, why we should reconcile over differing periods of time and how Snowden?s solution to proving reconciliation can be a simpler, reliable and transparent process. Snowden?s Reconcilor is proving to be a valuable tool on any mining scale, by capturing, validating, sorting and reporting data for timely decision making by the site geologist through to corporate management. By instigating vigorous reconciliation, you are setting your mine up for the future. Not only will you have the means to analyse your current processes and measures, but you will have the opportunity to identify and improve your mine?s performance from the resource model through to the final product.

May 1, 2010

By Patrik Ericsson

During the 90?s Atlas Copco and LKAB developed a pioneering fully automatic long hole production drilling system based on the Atlas Copco Simba W469 drill rigs. These drill rigs have since then drilled about 8.000.000 drill meters at the LKAB Kiruna and Malmberget mines. In 2005 LKAB ordered three new Atlas Copco Simba W6 C, to complement Simba W469s still in operation. These new Simbas are based on the latest generation computerized drilling technology have proven to meet the expectations of LKAB and now form a base for future automation in Kiruna and Malmberget mines. This paper will present experiences from the introduction of Simba W6 C in LKAB Kiruna and Malmberget mines. The paper will also elaborate on the latest developments in remote access and remote control technology making it a common automation option available for all computerized Atlas Copco drill rigs.

May 1, 2007

By Donald Carlisle

"IntroductionTHE OPINION is held by many persons outside the mining industry, and by some within it, that mine •operators customarily find it advantageous to mine •only the richer parts of orebodies and to leave behind, perhaps permanently, leaner material which could be mined only at a lesser profit. This opinion and the inference which might be drawn from it that 'gutting' of mineral resources is a common feruture• of the mining industry are prejudicial to the intertsts of the industry and deserve careful scrutiny. Oddly enough, a theory of mine economics which gives much support for the opinion was advanced first by members of the mining profession itself, has been repeated •several times in mining literature, and to my knowledge has never been adequately refoted.According to the theory, selective mining of the rich ore first on a large scale will yield substantial gains and these gains do not merely reflect the desire of 'money minded investors' for a quick return but derive from the logical application of compound interest rates and the concept of ;present value. W. O. Hotchkiss and R. D. Parks (1) illustrate the reasoning with a hypothetical example in which an orebody of 4,000,000 tons may be mined either in its entirety in forty years at $1.00 per ton profit or selectively with the recovery of only the richest half in twenty years at $1.50 per ton profit. They show that, with Hoskold rates of 4 and 8 per cent, the present value of profits from mining only the richer 2,000,000 tons exceeds the present value of profits :from mining the whole orebody by about 20 per cent."

Jan 1, 1953

By G. Cordingley, A. Mwanza

Lumwana is an open pit Copper mine located in the Northwestern Province of Zambia approximately 80 km west from the provincial capital of Solwezi, approximately 300 km northwest from the Copperbelt and 700 km northwest from the national capital of Lusaka. The mine has two major Copper deposits: Malundwe and Chimiwungo. Copper mineralization includes Chalcopyrite, Bornite and Chalcocite. In addition to Copper, these deposits also contain the undesirable element Uranium contained in vein hosted and disseminated Uranite. The processing plant was designed using conventional technologies: semi-autogenous grinding (SAG) and ball mill for grinding, and mechanical cells for rougher and cleaner flotation. Soon after commissioning in early 2009, it was recognised that two stages of conventional cleaning were unable to produce plant final Copper concentrates with the desired Uranium grades. Studies have shown that a significant quantity of liberated and fine Uranium particles (up to 80-90%) is recovered with the concentrate by entrainment. Lumwana Operations sought the use of the Jameson Cell technology after observing successful implementation at other sites in rectifying similar issues. In late 2009, Jameson Cell pilot-plant test work was conducted at the site and this quickly led to the installation of a full-scale B5400/18 model into the existing cleaner circuit. Inclusion of the Jameson Cell resulted in the plant being able to effectively produce clean and saleable concentrate with Uranium contents consistently below acceptable levels. Initially designed to be used as a cleaner scalper cell at the head of the existing conventional cell circuit, subsequent operational issues with the existing recleaner cells forced reconfiguration of the cleaner circuit and reintroduced the Jameson Cell for the recleaning duty. This paper reports the Lumwana Operation from the first two years of operation where it struggled to produce a saleable concentrate with Uranium grades below 150 ppm, which is the maximum allowable limit set out in the smelting contracts, to steps taken in the subsequent years to implement a satisfactory solution. The plant can now consistently produce a clean Copper concentrate with Uranium grades well below 130 ppm and the overall improvements implemented at site have seen the overall plant recovery improve by 1.3%.

Jan 1, 2014

By Scott A. Stebbins

Cost evaluation models constructed specifically to evaluate the economic potential of an individually motorized railcar system of ore and waste transport demonstrate that the approach may be considerably more cost effective than traditional rubber-tired haulage methods. The system design places a motorized drive unit on each railcar, as opposed to the more common configuration in which a series of un-motorized cars trail behind a single locomotive. These motorized railcars are directed to various load and dump points by a computerized dispatch system, and as such have the advantage of operating unmanned. In addition, the tractive effort of the rail-type drive system is noticeably more efficient than that of the rubber-tired mode of transport. The savings are realized primarily through comparative reductions in the requirements for labor and, to a lesser degree, energy.

Nov 1, 2011

By Gyan S. Rajhans

"The strategy of fibrous dust sampling is discussed, various sampiing methods are critically reviewed .and their application to coal dust is demonstrated. Fibre counting is described in detail. An attempt is made to explain the basis of determining the threshold limit value of asbestos and other dusts. The paper also discusses such dust control methods as enclosure of the process, effective local exhaust ventilation, segregation, substitution, wet processing and continuous monitoring of the return air for recirculation."

Jan 1, 1970

By Joe Zhou

"Mineralogical characterization and metallurgical extraction of silver is challenging due to its complex mineralogy and chemistry. Over 200 Ag-bearing minerals have been identified and a silver-rich ore body would typically contain 5 to 10 different silver minerals. Silver can occur not only as discrete microscopic (visible) silver minerals but also as submicroscopic (invisible) silver in other minerals. During processing, silver may form passivation compounds such as silver hydroxide, silver sulphide, jarosite-like silver sulphate, silver halide or silver cyanide precipitate, all of which may negatively impact on silver extraction. Knowing the deportment of silver in the ore and its metallurgical products is important in flowsheet design and plant optimization. This paper begins with the classification of silver ores and minerals and a review of processing techniques, and focuses on the major mineralogical factors to explain why and how these factors affect silver extraction. Case studies are provided to demonstrate the application of silver process mineralogy in flowsheet design and plant optimization.INTRODUCTIONSilver was known to and utilized by mankind since ancient time. Actually, it was one of the earliest metals discovered and utilized by mankind after gold and copper.Silver is the whitest metallic element. It is rare, strong, corrosion resistant, and unaffected by moisture, vegetable acids, or alkalis. Silver is also resonant, moldable, malleable, and possesses the highest thermal and electric conductivity of any substance. The chemical symbol for silver is Ag, from the Latin argentum, which means white and shining. Although silver does not react with many chemicals, it does react with sulfur, which is always present in air at trace amounts. The reaction causes silver to tarnish, and consequently it must be polished periodically to retain its luster.Silver possesses many special physical characteristics and qualities that make it useful to a variety of industries. The photography industry is the biggest user of silver compounds. Silver forms the most light-sensitive halide salts, which are essential to developing highquality photographic prints. Silver also has the highest electrical conductivity per unit volume of any metal, including copper, so it is used extensively in electronics."

Jan 1, 2010

By E. Wraith, W. W. Culver, B. Wesstrom, P. J. Mackey

Electrodeposited copper of the 1860s was of unprecedented purity, although the profound significance of this achievement was not fully realised until the dawn of the electrical age a decade or so later. By the 1870s there were three somewhat large (4 to 4.5 tonnes Cu/day) electrolytic copper refineries in Germany based on J. B. Elkington’s process, first patented in the United Kingdom in 1865. More such refineries were planned throughout Europe. At the same time, copper output in the U.S.A. was starting to expand and with the spread of European electrolytic copper refining technology across the Atlantic, the door opened to major increases in North American output. The technology was first taken up in 1879 by James Douglas at the Chemical Copper Company in Phoenixville, Pennsylvania, where he was Superintendent. Douglas was assisted in this pioneering work by Edward Weston. The copper refinery at the Chemical Copper Company was small, not unlike the first plants in Europe. The present authors contend that the electrolytic copper refinery at the Chemical Copper should be regarded as the first copper refinery in the United States. The Balbach Copper Refinery in New Jersey, which commenced operations in 1883 with an initial production of about 2 tonnes Cu/day, has been erroneously considered as the “first commercial refinery”; it rightly belongs in second place. The early developments at these plants are discussed in this paper. INTRODUCTION In the mid-1800s, the main uses for copper were as sheathing on the wooden sailing ships of the day to protect from marine growth, boiler components in locomotives and steam engines, along with some construction uses. Copper ores were generally smelted, and further fire-refined for market. The recovery of gold and silver, if present in payable amounts, was a slow and relatively expensive step. This situation regarding copper would change by the 1870s with advances in the generation and use of electricity. The introduction of the dynamo led to major developments in electrorefining. First demonstrated in principle by Faraday in 1831 (Faraday, 1832), the dynamo was subsequently adapted and further developed by J.S. Woolrich for electro-metallurgical applications in 1842 (Woolrich, 1842; Napier, 1845). It provided a new source of power with the unprecedented potential to significantly change the scale of metal production by electrometallurgy. Interestingly enough, copper would be needed for the electrical age just beginning. By 1869, advances in dynamo design offered relatively reliable large machines, which enabled J. B. Elkington in the United Kingdom to use the dynamo in the radically new Pembrey copper electrorefinery — the first copper electrorefinery in the world (Wraith, 2013). Initial production at Pembrey was small — in the range of 1 to 2 tonnes/day — while gold and silver were recovered more readily by the treatment of the slimes than with methods used hitherto.

Jan 1, 2019

PERSPECTIVE ?Natural resources exploration, extraction and beneficiation is complex and challenging: ?Input costs rising, complexity increasing, rising stakeholder management needs, regulatory compliance issue, etc. ?With increasing costs and complexity of managing operations are we simply getting less bang for our buck?

May 1, 2013

Certain information contained herein regarding Champion Minerals Inc., including management?s assessment of future plans and operations, may constitute forward-looking statements under applicable securities law and necessarily involve risks, including but not limited to risks associated with mining exploration, operating costs, production costs, volatility of share prices, currency fluctuations, imprecision of resource and reserve estimates, environmental risks and ability to access sufficient capital from internal and external sources. As a consequence, actual results may differ materially from those anticipated in any forward looking statements. Plans, intentions or expectations disclosed in any forward-looking statements or information should not be read as guarantees of future results or events, and will not necessarily be accurate indications of whether or when or by which such results or events will be achieved. Except as required by law, Champion Minerals Inc., expressly disclaims any intention and undertakes no obligation to update any forward looking statements or information as conditions change. The historical mineral resources mentioned are strictly historical in nature and are non-compliant to National Instrument 43-101 mineral resources and mineral reserves standards, and should therefore not be relied upon. A qualified person has not done sufficient work to upgrade or classify the historical mineral resources as current National Instrument NI-43-101 compliant.

May 1, 2011

Project Located in northwestern British Columbia 70km West of Cassiar Highway Galore Creek Project and Road Access Corridors Designated For Mineral Development in Stikine-Cassiar Land Resource Management Plan (LRMP)Approved in 2000Strong BC Government, local community and Tahltan First Nation Support for Project

May 1, 2006

By F. Baerhold, S. Mitterecker

"Acid recovery is an important process step in pickling and leaching processes. Pyrohydrolysis in spray roasters and fluidized beds is a well-established technology to recover hydrochloric acid, but the hydrolysis in the liquid phase is more and more considered as an alternative new process route. The characteristic features of these three processes will be discussed along with select industry trends. For example, hydrochloric acid based leaching processes for ilmenite and nickel laterite ores produce far larger volumes of waste acid streams than the steel industry. Scaling-up of the spray roasting technology to the highest possible capacity is necessary in order to become more cost effective. In addition, process routes based on ferric chloride pyrohydrolysis allow the production of super-azeotropic HCl (up to 30 wt.%). Finally, the new ECOmode concept optimizes the operation of both pickling lines and the spray roast acid recovery plant. Long term results from industrial applications show that fuel savings in the spray roaster of 25% are easily achieved without additional process steps. An attractive feature is also to upgrade existing installations to higher plant capacities.INTRODUCTION Pyrohydrolysis is the conversion of metal halides into metal oxides at elevated temperatures in the presence of water vapor. Reaction products are a hydrogen halide gas and a metal oxide. The process was originally developed and introduced into the market by ANDRITZ Ruthner in the 1960’s. It has found wide technical application in the field of acid recovery and oxide production. The introduction of this process has revolutionized pickling technology. The use of hydrochloric acid has strongly increased over the last decades, since pyrohydrolysis is available for the total recovery of waste pickle liquors from mild steel pickling, as illustrated in Figure 1.Chloride media are also used increasingly in the metallurgical industry. Oxide production processes for Mg, Co, Ni, and Al have been installed. Processes using hydrochloric acid are known for the leaching of ores as well as for the re-extraction of metals from organic solvents. In both cases the recycling of HCl is of substantial importance to achieve highly economic processes and to reduce waste."

Jan 1, 2016

By K. K. Murray, D. G. Gelderland

"The pressure oxidation autoclave at the Goldcorp’s Red Lake Gold Mines (RLGM) was commissioned in 1991. Since commissioning, the circuit has been well maintained and its capacity increased to mechanical and gaseous oxygen limitations. With advances in available technology, opportunities to produce more sulphide concentrate and a changing business environment, an optimization project has been initiated at RLGM. A multi-phase approach has been developed to optimize both the operations and economics of the circuit. This paper describes the history and future of the autoclave circuit at RLGM.AcknowledmentsWe would like to thank the operations and maintenance staff at Red Lake Gold Mines for their support and openness of mind to enact changes to enhance the operation. We would also like to acknowledge the members of the integrated team from Red Lake maintence, metallurgy, operations and corporate technical services that did the hard work to push past the status quo in order to advance productivity.OpportunityThe Red Lake Gold Mines (RLGM) pressure oxidation (POx) circuit has been in operation for over 25 years processing the high sulphide content gold bearing minerals. Increased sulphide concentrate production from improved flotation recovery and increasing gold sulphide association at depth has led to the POx circuit becoming a throughput bottleneck. The opportunity exists to process increased tonnages of sulphide concentrates and increase gold production. In order to realize this value, it will be necessary to increase the throughput capacity of the POx circuit.BackgroundThe POx autoclave at the RLGM, commissioned in 1991, was Canada’s first gold autoclave. It was installed to replace the two-stage fluid bed roaster that was built when the Campbell mine and mill were constructed in the late Forties. The circuit was originally designed to process 12.5 t/d sulphide sulphur in about 50 t/d of Campbell flotation concentrate. Following the merger of the Campbell and Red Lake Mines in 2006, the POx circuit started processing flotation concentrate from both Campbell and Red Lake Mills. In recent years, the circuit has been processing about 18 t/d sulphide sulphur in 75-85 t/d flotation concentrate."

Jan 1, 2017

By Corinne Boone

CO2e.com, LLC - launched in November 2000 - aims to be ?the global hub for carbon commerce.? CO2e.com is a subsidiary of the Cantor Fitzgerald Group, one of the world?s leading brokerage firms Recent Investor in CO2e ? Mitsui & Co. Alliance with Cantor Fitzgerald Environmental Brokerage Services Group (CFEBS) Offices in London, Toronto, Tokyo, New York, San Francisco, Los Angeles, Connecticut, Houston Primary Goals/Benefits of ET § Goals of Emissions Trading: ? Permit Industrial Growth/Expansion ? Promote Economic Efficiency and Flexibility in Meeting Air Pollution Standards § Benefits of Emissions Trading: ? Enhance Air Quality w/o Economic Stagnation ? Encourage Development of New Technology ? Foster Most Efficient Use of a Limited Resource -- Clean Air § Contributes to Sustainable Development and objectives of UNFCCC, Kyoto Protocol?.

Nov 1, 2002

By A. J. MacRae

Metallurgical furnaces are made up of complex multi-component systems that must function either together or in parallel for safe, and reliable operation. Thermal expansion of single material components experience induced stresses during heating and cooling, which can lead to cracking or failure. Multi component elements and systems can experience significant thermally induced stresses during both steady state and transient temperature conditions. Examples pertaining to temperature effects on refractory, copper cooling blocks, furnace shells, and complete systems will be discussed. The purpose of the paper is to highlight how stresses and strains are developed due to differential thermal expansion.

Jan 1, 2015

By H. R. Banks

"AbstractThe rod mill introduced into the Sullivan Concentrator flow in September, 1948, replaced two sets of 74 in. by 20 in. rolls and their accompanying screens. In addition to the work formerly done by the rolls, the rod mill is producing a finer product and one which provides more suitable feed for the primary ball mills. The object of the finer discharge from the •primary mills is to make possible a feed directly from the mills to a series of flotation machines where a large portion of the galena can be withdrawn from the circuit while the galena is still coarsely granular. The interposing of classifiers between grinding and flotation means the selective grinding of the galena.The author summarizes the work of •the rod mill through the first 5,000,000 tons and shows that the wear of lifters, liners, and rods is definitely below normal for the type and size of rock being handled. The rod mill, driven through a fluid coupling, has been subject to a range of speeds from 13.5 to 19. A pinion in the speed reducer was changed to allow the extending of the normal speed range of the fluid drive of approximately 4 r.p.m.Since the critical speed inside the liners •is 23.4, the range •in per cent of criticial is 57.7 to 81.2 per cent.The capacity of the mill increases with increasing speed but the character of the product remains approximately the same except when the feed rate is too high.Consumption of steel, power, and other operating data are presented.The author introduces certain fundamental observations on the principles involved •in comminution in order to support the special design and operation of the rod mill."

Jan 1, 1952

By R. E. de Barrio, M. E. Lanfranchini, R. O. Etcheverry

"The El Abuelo Ca-Fe-magnetite skarn and related hydrothermal quartz veins are located at Cerro Pepita Hill, in southwestern Chubut province of southern Argentina, 1700 km southwest of Buenos Aires. These deposits are developed in a continental magmatic arc environment linked to the Andean orogeny. Iron skarn mineralization is mainly hosted by an Upper Jurassic to Early Cretaceous sedimentary sequence interbedded with Upper Jurassic basaltic andesite, and is spatially associated with Early Cretaceous calc-alkaline dikes. Ore grades vary between 40 and 63 wt.% Fe. In addition, anomalous metal contents (>10 000 ppm Cu and up to 81 g/t Ag) are present in the hydrothermal quartz veins.At least three paragenetic mineral assemblages have been identified in the El Abuelo exoskarn: (1) amphibole > epidote ± chlorite ± quartz, formed by isochemical contact metamorphism; (2) Fe-clinopyroxene ± Ca-garnet, formed during prograde metasomatic anhydrous exoskarn formation; and (3) actinolite ± epidote ± chlorite ± quartz ± magnetite > titanite, resulting from hydrous retrograde alteration of exoskarn. Endoskarn alteration involved an early Mg-Fe-clinopyroxene ± Fe-garnet assemblage followed by retrograde actinolite replacement of pyroxene. Lower temperature hydrothermal alteration related to quartz veins was superimposed on the skarn assemblages, showing an innermost sericite ± adularia ± pyrite ± chalcopyrite assemblage and an external propylitic halo.Some metallogenic characteristics of the mineralization and the geological setting resemble those in several iron oxide copper-gold deposits elsewhere in the world."

Jan 1, 2007

By Piotr Litwa

The paper focuses on actions aiming at improvement of work safety in mines, particularly in those extracting hard coal, taking into account the characteristics of natural hazards in Polish underground mining and the reasons of mining disasters connected with those hazards. It refers to conclusions addressed to scientific and research centres, drawn during last decade by Commissions appointed by the President of the State Mining Authority in order to investigate reasons and circumstances of incidents, which till now, could not have been accomplished because of financial reasons. Furthermore, the paper presents basic assumptions of the Strategic Research Project Improvement of work safety in mines, announced by the National Centre for Research and Development at State Mining Authority?s President request.

Aug 1, 2013