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By Nordau R. Goodman

"IntroductionTHE HISTORY of Nova Scotia's gypsum industry goes back about two hundred years. The extensive deposits found in the Windsor formation, which is Lower Carboniferous, were the first discovered in North America and were known to the earliest .settlers. There has been a steady increase in production from these beds, except for minor setbacks in years of wars and depressions, but at the same time there has been a decrease in the number of operating quarries. This decrease reflects the change from the days of horse-and-cart recovery to the modern, large-scale, highly mechanized operations. In the beginning, almost any outcrop could •supply the tonnage requirements and the most •convenient were selected, but the millions of tons needed to meet present-day needs are not easily found.Despite the size and importance of the Nova Scotian deposits there has been little detailed geological work. Sir Charles Lyell, in 1843 ( 10), established that the beds are Lower Carboniferous and this was confirmed by Sir William Dawson (3) a .few years later. Both Lyell and Dawson agreed the calcium sulphate beds were an original part of a bedded series .but did not consider they resulted from a concentration of sea water. Lyell reached the conclusion that the gypsum was related to volcanic action in the form of heated vapours or hot springs. Dawson believed it was formed by the action •of sulphuric acid on calcium carbonate. The acid, derived from the oxidation •of iron pyrites which was abundant in the older formations, was carried by rivers into basins which were rich in shells."

Jan 1, 1954

By W. B. Morrey

This paper deals with the development of the new cap-sensitive slurry explosives. The history and special features of these explosives are outlined, and recent field trials are described.

Jan 1, 1973

By M. Sengupta, A. A. de Gast

"With rapid deterioration in the urban environment caused by air pollution, the possibility of chemical reaction between dimension stone and the industrial waste gases present in the ambient atmosphere remains. The chemical reaction can cause expensive damage to building stone; it is essential that a stone evaluation for use in construction should assess the possibility of this type of decay. This paper endeavours to develop testing procedures for evaluating stone decay in polluted environments. Such tests can accompany other standard tests used in dimension- stone evaluation."

Jan 1, 1972

By E. H. Chown

Scattered outliers of the Chibougamau Formation and the more continuous Mistassini and Otish Groups lie unconformably on an Archean basement abutting the Grenville Front. All the Aphebian rocks are deformed and offset by faulting related to the Front. The older Chibougamau Formation is exclusively elastic in origin, whereas the two later, time-equivalent groups include carbonatedominated (Mistassini) and elastic (Otish) sequences. Known syngenetic mineralization within these formations is limited to various radioactive showings in the Mistassini and Otish elastics, and the iron formations of the upper Mistassini Group. Three distinct types of epigenetic mineralization occur within the sedimentary rocks; pitchblende fracture fillings in all types of rocks in the Otish Group, widespread Mississippi-Valley type galenasphalerite showings at certain levels in the Mistassini Group, and chalcopyrite-pyrite bearing veins in or near argillaceous horizons of the Mistassini Group and Chibougamau Formation. The Otish elastic basin is part of a large area of the central Ungava peninsula which contains a variety of radioactive showings, the most promising being of the unconformity type, The final control for many individual showings appears to be local physico-chemical changes within faults and fracture zones. The overall structural control is in part supplied by the faulting episode related to the Grenville Front, which in turn limits the mineralization to the depth zone appropriate for open fracturing. The lead-zinc showings exhibit a strong stratigraphic control as well as close ties to secondary porosity developed by f aulting. The ore solutions were probably derived during the low grade metamorphism of the formations. Chalcopyrite- pyrite veins have provi ded the only mine production (Icon Mine) to date. They appear later than the low-grade metamorphic fluid circulation, and deposition is related to favourable structures and stratigraphy. The veins are clearly related to major faults. Thus, whereas stratigraphic settings appropriate to individual types of deposits are important, an overall structural setting may be demonstrated for a wide range of mineralizations. Detailed structural interpretations of individual showings may be the most fruitful pursuit in developing a concrete prospecting model.

Jan 1, 1984

By Jochen Petersen, Jean-Paul Franzidis, Allan Nesbitt

This study presents a method for the determination of intra-particle diffusivities in ion-exchange resins for the purposes of evaluating the state of resin degradation during service. The method uses a zero length column (ZLC) in a closed circuit with variable speed pump and reservoir. The intra-particle diffusion is determined from absorption data by using the Nernst-Plank approximation along with the ‘mass transfer factor’ - which is a product of the mass transfer coefficient (kf )and the concentration of the adsorbing ion in the liquid at the surface of the resin - in a computer algorithm fitting simulated curves to experimental data.. Through this approach the changed intra-particle diffusivity, of a gel-type acid resin, over a 1000 loading and elution cycles, is shown.

Jan 1, 2014

By T. Bhambhani, Mukund Vasudevan, Partha Patra, D. R. Nagaraj, P. Somasundaram

Selective Ni separation from ultramafic ores rich in serpentines has been a huge challenge in the mineral processing industry, and therefore highly inefficient. Analysis of the root causes of the challenges and consequent development of robust processing solutions were the main goals of the Cytec-Columbia. University-Vale Joint Development Program. In this context, the subject of this paper is limited to one of the key findings of this research program which is the influence of fibrous serpentines on grade-recovery characteristics. Specifically, the poor flotation behavior is characterized by an atypical reverse C-shaped grade-recovery curve.

Jan 1, 2011

By P. Burke, V. Vuaroqueaux, A. Doyle, C. Petit, Kipouros. G. J.

Magnesium and its alloys are attractive for use in automotive and aerospace applications because of their low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. The present work reviews the efforts to improve the attractiveness of magnesium through non-traditional processing, and presents results of current work on producing magnesium alloys via powder metallurgy (P/M). P/M can be used to alleviate the formability problem through near-net-shape processing, and also allows unique chemical compositions that can lead to new alloys with novel properties. The surface layer formed on the Mg powders during processing acts as a barrier to diffusion and sintering is problematic. The layer contains oxides, hydroxides and carbonates of magnesium, formed by reactions with the atmosphere. There are several means to possibly overcome this barrier. Alloying additions have been identified that may promote surface layer disruption during sintering. Processing variables such as sintering atmosphere may reduce the layer or allow the formation of less detrimental compounds. Post-sintering processes such as hot working may disrupt the layer and improve density. The experimental effect of all these processing parameters is presented in this paper.

Jan 1, 2010

By P. E. Cavanagh

THIS REPORT is not intended to be a ?comprehensive survey of the steel industry in Europe. For the past ten years the Ontario Research Foundation has been interested in several developments in the steel industry in Europe which it was felt would be of particular interest in Canada and might possibly find application in this country. This is an account of the present status of some of these developments. The economies of steel making in Canada are somewhat different than in the United States because of the nature of the market and the relative costs and availability of such raw materials as metallurgical coke and electric power. There are cases in Europe where a great deal of effort and money has been spent in trying to make steel profitably by methods which take advantage of locally available and cheap raw materials by modifying standard practices. ln cases wl1ere the investigations have been successful and the data are available to allow translation of the results into Canadian conditions, it is felt that such information may be of great benefit in the future in Canada and at !east should be known to all those in the steel industry in this country. The field to be covered in this report only comprises the steps from concentration and treatment of iron ores to production of iron and is only concerned with those commercially operating processes well known to us and judged to be of present interest in Canada.

Jan 1, 1957

"Load-haul-dump machines (LHDs) are typically used in underground metal mining operations. Delays or inappropriate use of LHDs can result in production loss. Optimized LHD use is especially crucial in larger mines because longer travel distances increase heat, dust, and gas emissions, which in turn increase ventilation costs. This study, conducted at an existing Swedish sublevel cave underground mine, used discrete event simulation and the AutoMod™ DES tool to determine the ventilation costs related to using too many diesel LHDs in a production area with reduced ore pass availability. When fewer ore passes are available, ventilation costs related to operating LHDs in the production area were found to increase by as much as 200, 224, and 306% for one, three, and six LHDs in operation, respectively. ¦ KEYWORDS Discrete event simulation (DES), Loading operations, Production rate, Ventilation costs RÉSUMÉ Dans les exploitations souterraines d’extraction des métaux, on utilise généralement des chargeurs-transporteurs (LHD, de l’anglais Load-haul-dump machines). Les retards ou l’utilisation abusive des LHD peuvent entraîner une perte de production. L’utilisation optimisée des LHD est particulièrement importante dans les grandes mines en raison des longues distances parcourues, lesquelles augmentent la chaleur, la poussière et les émissions de gaz qui, à leur tour, décuplent les coûts de l’aérage. Cette étude, menée en Suède dans une mine souterraine utilisant la méthode d’exploitation en sous étages avec foudroyage, s’est basée sur la simulation à événements discrets (SED) et l’outil de SED AutoMod™ pour déterminer les coûts de l’aérage liés à l’utilisation d’un nombre trop élevé de LHD alimentés au diesel dans la zone de production, avec une disponibilité réduite de la cheminée à minerai. Lorsque les mines disposent de moins de cheminées à minerai, l’étude montre que les coûts de l’aérage liés à l’exploitation des LHD dans la zone de production augmentent respectivement de 200, 224 et 306 % pour un, trois et six LHD en fonctionnement. ¦ MOTS CLÉS coûts de l’aérage, opérations de chargement, simulation à événements discrets (SED), taux de productionINTRODUCTION Transporting material from the mine face to the dumping location requires flexible loading and hauling equipment that is able to cope with sharp curves and a complex mining environment. Load-haul-dump machines (LHDs) are designed for such an environment. Models are available to suit specific features of the working environment such as small, large, or narrow open stopes (Atlas Copco Rock Drills AB, 2007). When carrying a full load, haulage speed is higher for LHDs than for front-end loaders with the same engine size. Also, payloads are approximately 50% higher for LHDs than for front-end loaders (Atlas Copco Rock Drills AB, 2007). LHDs are capable of climbing steep (Bloss, Harvey, Grant, & Routley, 2011). The haulage distance between stope and ore pass is usually between 50 m and 400 m. LHDs are efficient for tramming distances up to 200 m (Bloss et al., 2011), whereas when loading trucks, the LHDs work efficiently when the distance is less than 100 m (Atlas Copco Rock Drills AB, 2007). The largest diesel-powered LHDs, with drive motors of up to 350 kW, can handle a payload of 21 t (Wennmohs, 2014). Most mining equipment runs on diesel fuel, which provides flexibility, high durability, and high efficiency (Pronk, Coble, & Stewart, 2009); however, other alternatives such as electric, hybrid diesel/electric, or hydrogen fuel cell machines are increasingly being developed and used. This change is due to diesel-powered machines accounting for a significant portion of the ventilation costs in the mine (Chadwick, 2008; Paraszczak, Laflamme, & Fytas, 2013). Currently, as part of the European sustainable intelligent mining systems (SIMS) project, Epiroc AB is planning to demonstrate technology for a diesel-free underground mine at Agnico Eagle’s Kittlä mine in Finland using"

Jan 1, 2019

By R. E. Whitehead

"Abstract - Alkali-alumina and MgO-alumina plots are an effective instrument for displaying chemical and mineralogical compositions of altered and unaltered rhyolites and rhyodacites. They reveal that most supposedly unaltered rhyolites, apart from those of Cenozoic age, have undergone losses in Na2O and gains in K2O. The extreme loss of Na2O from highly altered rhyolites immediately adjacent to VMS deposits is strikingly illustrated by alkali-alumina plots. MgO/Al2O3 vs. K2O/Al2O3 diagrams display a strong negative correlation between MgO and K2O that results from the conversion of sericite to chlorite. A similar negative correlation between MgO and whole-rock d18O is apparent on plots of these two parameters. Alkali-alumina plots underscore problems in selecting appropriate precursor compositions required for mass-balance calculations. Molar ratio plots are a viable alternative to such calculations. Sommaire -Les diagrammes alcali-alumine et MgO-alumine constituent un instrument efficace pour la représentation des compositions chimiques et minéralogiques des rhyolites et rhyodacites altérées et fraîches.Ces diagrammes révèlent qu’à l'exception de celles d’âge Cénozoïque, la plupart des rhyolites qualifiées de fraîches ont subi une perte de Na2O et un gain de K2O. L’intense perte en Na2O que l’on note dans les rhyolites fortement altérées associées aux gîtes de type SMV est particulièrement bien mise en évidence par le diagramme alcali-alumine. Le diagramme MgO/Al2O3 vs. K2O/Al2O3 montre une forte corrélation inverse entre le MgO et le K2O due à la conversion de la séricite en chlorite. Une corrélation inverse analogue entre le MgO et le d18O de la roche totale s’observe sur un graphe comparant ces deux paramètres. L’usage du diagramme alcali-alumine fait ressortir combien il peut être difficile de choisir un précurseur de composition appropriée pour des calculs de balance de masse. Les diagrammes de rapport molaire constituent une alternative à de tels calculs."

Jan 1, 2006

By C. M. Díaz, P. J. Mackey, P. Coursol

In a recent paper [1], the present authors discussed calculated energy consumption numbers in copper sulphide concentrate smelting for four different smelting technologies. For the present study, from among these technologies, they selected the Noranda/Teniente continuous bath smelting followed by Peirce Smith (PS) converting route to investigate the impact on total energy requirement of some key process variations, such as tuyere injection of dry concentrate vs. slingering of wet concentrate over the molten bath, continuous converting vs. conventional batch PS converting and commercially proven slag cleaning alternatives. In their calculations, the authors used the same thermochemical model and methodology used in their earlier paper. This approach to explore plant design options provides an interesting basis for evaluating flowsheet modifications that could lead to significant copper smelting energy savings. The METSIM software was used in the present paper to carry out heat and mass balance computations for 8 different flowsheet configurations. The results are presented and discussed in the paper with respect to copper recoveries, energy requirements and CO2 emissions.

Jan 1, 2011

By Jie Deng, Wenliang Xiong, Binyan Chen

"With falling rare earth metal prices, low cost beneficiation of rare earth minerals is essential. The “Flotation-Agglomeration-Magnetic” (FAM) separation process is a newly developed technology by IMUMR to economically recover rare earth elements from different types of deposits. The theory of FAM process is to selectively agglomerate rare earth particles and separate from gangue minerals by bubble flotation process. The flotation product is further upgraded by magnetic separation. The FAM process has been successfully applied in industrial production on the Dalucao rare earth ore, Sichuan, China. The average REO grade of rare earth concentrate is 65% in the latest 12 month production run, with an average recovery of 55%.INTRODUCTIONRare earth elements (REEs) include fifteen lanthanide elements coupled with two chemically similar elements (yttrium and scandium). These elements are split into two sub-groups, La to Sm are classified as light rare earth elements (LREEs) and the remaining elements including yttrium are heavy rare earth elements (HREEs) (Kumari & Panda, 2015). The demand of rare earth elements surged in recent years due to their increasing usage in diverse industrial aspects including high strength magnets, phosphors, clean energy, polishing compounds and catalysts (Goley &Scott, 2014).More than 250 REE-bearing minerals have been discovered, but many minerals are with very low concentrations of REEs, varying from 10-300 ppm (Adam &Ping, 2013). The most common rare earth minerals mined are bastnaesite, monazite, xenotime and ion-adoption REE (Chelgani & Rudolph, 2015; Kanazawa & Kamitani, 2006). Before the 1960s, most rare earth resources were extracted from monazite in the beach placer, with the exploiting of Mountain Pass in the United States and Bayan Obo mine in China, bastnaesite became the chief mineral source of rare earth resources (Klinger, 2015). These minerals are commonly separated with gangue minerals by froth flotation, gravity concentration, magnetic separation, or any combination thereof based on their specific physical characteristics (Zhou & Wang, 2014; Adam & Richard, 2014; Yang & Satur, 2015; Xia & Brian, 2015a,b)."

Jan 1, 2016

By William M. (Bill) Shaver

"The author will review the early history of shaft sinking as well as focus on the improvements made in shaft design and construction over the last fifty years (1970 to 2019) to predict how shaft sinking will change over the next fifty years and describe what the shaft sinking world might look like in 2070. INTRODUCTION It is a great honour to be one of your keynote speakers for the Fourth International Conference on Shaft Design and Construction being held in Toronto in November 2019. This is one of the opportunities we have to thank the Mining Companies of the world as well as the industries and companies we serve for their support of the mining contracting and shaft sinking business of Canada and the world at large. Many of these companies are represented here today. Without your support many of the innovations we will talk about today would not be possible. We would also like to thank all the companies that work with us in our business including all the contractors and suppliers who provide the various services we require. These include equipment manufacturers, engineering companies, project management companies and suppliers large and small who cater to our every need as quickly as possible. Without all these partners we would not be as good as we are. Many of these companies are our sponsors this week. Thank you from all of us! This is also an appropriate time to pause and think about those Shaft Sinkers we have lost and those who have been injured on our projects around the world. Please bow your head and remember the Shaft Sinkers you have worked with, who did not return home or those who returned home injured. Think about how we can continue the work of making shafts safer every day as we go forward with our projects so everyone goes home to their families safe and sound. Pause for a minute and thank you. The subject matter we have chosen to discuss today is “Shaft Sinking in the Next Five Decades”. How will the work be done, how fast will it be done, what will it cost, and why we think this may occur? It is appropriate to consider this over the next few days with this auspicious group we have assembled. Today, we will look back at all the advances that have been made over the last many years and look ahead to the future to attempt to predict what shaft sinking will look like in 2070. When I look around the room I recognize that many of us will not be around then so we need not worry about being wrong. Suffice it to say that the next 50 years will be very interesting and exciting for the shaft sinking business."

Jan 1, 2019

By Matt Manson

Renard?1-10 kimberlite pipes and ?Lynx-Hibou?kimberlite dyke system within ?Foxtrot?property 50/50 JV with SOQUEM, Stornoway operator 2001: Discovery of the Renard kimberlite pipes 2003: Discovery of the Lynx-Hibou kimberlite dykes 2006-2007: Bulk sample program 2008: First 43-101 Resource and Preliminary Assessment 2009/2010: Updated 43-101 Resource

May 1, 2010

By S Sokhanvaran

Electrodeposition of silicon from a cryolite based electrolyte at a relatively low temperature (1000°C) is a promising approach to generate high purity silicon. In order to obtain fundamental data pertaining to electrowinning of silicon from Cryolite?SiO2 melts, density and electrical conductivity measurements were made. A range of temperatures and SiO2 contents was studied for each property. It was found that while density has an inverse relationship with temperature, the dependence for electrical conductivity is direct. Increasing silica content up to the saturation limit (~ 5 wt%) increases the density whereas further increase in SiO2, lowers the melt density. On the other hand, the conductivity is lower for the melts with greater SiO2 content, at any temperature.

Jan 1, 2011

By J. E. Hawley

Abstract Spectrographic methods for the analysis of minor constituents such as platinum-group metals, gold, silver, and silica in palladium and platinum refinery sponge are described. These involve the conversion of the sponge metals to the black form by reduction with high purity aluminum filings in either acid or alkaline media. Standards of known composition are prepared in the same manner from either refinery or spectrographically standardized sponge metals. Samples of the black metals are mounted in pellet form and a multisource spark discharge used for excitation. The range of concentrations of impurities studied are those common to refinery samples. Excellent reproducibility of intensity ratios using major constituents as internal standards, is demonstrated and two methods have noted by which the accuracy of the procedures are shown to be of the order of 3 per cent, on the basis of synthetic preparations. Introduction During the past two years an investigation has been carried out in the Spectrographic Laboratory, Queen's University, to determine the suitability of modern spectrographic techniques for the precise analysis of the platinum-group metals palladium, platinum, rhodium, iridium, and ruthenium in the form of refinery sponge analyzing about 99 per cent of the major constituent.

Jan 1, 1951

By D. W. Boydell

The response of reclaimed gold tailings to acid leaching was investigated in the laboratory, followed by a pilot-plant program in which the operations of CCD, CIX and SX were tested with plant feed material. These results formed the basis for the design of the extension to the existing uranium plant at Blyvooruitzicht Gold Mine, commissioned in July 1977. This circuit consists of slimes-dam reclamation by bucket-wheel excavator at a rate of 100,000 t solids per month, acid leaching in pachucas, a five-stage CCD washing section, two parallel C1X absorption columns and two elution columns, SX and an ADU precipitation section. Barren solution is recycled to the CCD section as wash and to the repulper at the slimes dam. The performance of the plant during the first year of operation is compared with the predictions on which the plant design was based. Rated capacity was achieved within three weeks of start-up at a nominal dissolved uranium recovery in the ion-exchange section of around 98%. Owing to recycle, the over-all recovery in the ion-exchange and solvent extraction sections is somewhat higher than this figure.

Jan 1, 1979

By Victor F. Hollister, Robert W. Hodder

"The petrology and mineralogy of porphyry copper deposits are thoroughly described in recent literature and cited as the definitive characteristics for this type of deposit. The magmatic-hydrothermal aspect of genesis is also dealt with in detail. However, descriptions of their internal structure and regional setting are not as rigorous, and the genesis of this structure is simply stated as the release of high fluid pressures in a cooling magma emplaced along large fault zones. Genetic relationships between internal structure, regional setting and the tectonic evolution of continents has been alluded to infrequently in the past, but can now be considered together within the developing concept of orogeny at the margins of drifting crustal plates.Tensional structures, on both local and regional scale, and a Triassic to Tertiary age are described for porphyry copper deposits. We contend that such structure and age are distinct and unifying characteristics for this type of deposit and are genetically related to major crustal movements. British Columbia has porphyry copper deposits contemporaneous with plutons 180 to 200 million years old and 40 to 60 million years old. The former age group correlates with early stages of the continent's westward drift, and the latter group with a change in tectonic style during late development of the Canadian Cordillera. Hence, one can in British Columbia reflect on the genesis of a deposit's structure in the broader context of tectonic evolution. Such consideration should lead to more definitive criteria for area selection in exploration."

Jan 1, 1972

By A. F. Matheson

"Bankfield Consolidated Mines, Limited, and Tombill Gold Mines, Limited, in the Little Long Lac area, Ontario, mined an orebody that was common to both. The discovery' of this orebody was made by surface prospecting in May, 1932, on Bankfield ground, following an original discovery made in the same manner on the same property on a small reef in Magnet lake in October, 1931. The production from the two mines between 1937 and 1942 was approximately 135,000 oz. gold from about 420,000 tons of ore, an average grade of 0.32 oz. a ton. Production was nearly equally divided between the two properties. Both mines are now closed, the ore exhausted.""The ore is mainly sheared and fractured greywacke and porphyry impregnated by silica and small amounts of metallic minerals. To a lesser extent there are definite quartz veins in the ore zone""(l). The metallic minerals present were principally pyrite, arsenopyrite, pyrrhotite, and native gold .As at other mines in the Little Long Lac area, an elongated, broad, deep trough of folded, steeply dipping volcanic and sedimentary rocks, striking roughly east-west and surrounded by younger granite, is host to the orebodies of the Bankfield and Tombill. In the immediate area of the two mines iron formation and conglomerate bands occur nearby both north and south of an intrusion of porphyry-Cliorite, suggesting repetition of beds and folding. Although considerable drag folding is in evidence, folding on the above scale has neither been proved nor disproved."

Jan 1, 1954

By W. R. Lindsay

Considerable attention has of late been given to the blasting of large amounts of ore in one operation, on account of the saving in labour and explosives and consequent low cost per ton, and also on account of the additional safety to employees. The blast here described, at the Hidden Creek mine. at Anyox, B.C., is not necessarily unique either in size or methods employed, but some interesting p10blems were encountered and the solutions of these may be of interest to others engaged in similar work. The ore consisted mainly of old scope-bottoms and sill pillars, although there also were some braces and parts of vertical pillars included. Some of the stope-bottoms were overlain by caved waste, and one of the problems was to break them in such a manner that the maximum amount of ore could be recovered without serious dilution with waste. The ore blocks, designated as the 385 silt and the 7 A-103 blocks, were under preparation for blasting for over a year, as conditions permitted. This work consisted in drilling long machine drill holes, varying in length from 14 to 20 feet. These holes were drilled with the Numa detachable bit, made locally, starting at 2~-inch diameter and bottoming at 2 inches for the longest length. The long hole drilling was used in the thinner sections of the area. For the stronger, thicker portions, powder drifts (3 ft. by 4 ft. in section) were driven for the powder charges. Reference to the plan and sections (Figures 2 co 8 inclusive) show the relative location of these, as well as the long drilling. The amount of explosives used in the powder drift charges averaged 0.25 pounds per ton of estimated burden, varying from 0.2 to 0.3 pounds per ton.

Jan 1, 1934