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By Vladimir N. Rudashevsky, Louis J. Cabri, Nikolay S. Rudashevsky, Thomas Oberthür

"EPD (Electric Pulse disaggregation) and HS (hydroseparation) are exceptional technologies for research, concentration, evaluation, and mineral extraction of specific minerals such as precious metals (Au, Ag, PGM), kimberlites (extraction and concentration of indicator minerals), zircons and baddeleyite (recovery of objects for geochronology), and even gemstones (method of evaluation and production of the 100% gemstone concentrate of ideal crystals) etc. EPD is used for recovery of pristine undamaged crystals of diamond, emerald, ruby, sapphire etc, including large crystals. It was tested on various hard ores and was especially successful for recovery of “soft” minerals from “hard” matrix. EPD products are very convenient for HS processing, resulting in representative concentrates of all heavy minerals including the finest particles (5-10 µm). The combined EPD and HS method enables high sensitivity (20 ppb) for evaluation of precious metal ores providing objective information about original grain size, associations, and recovery using a very small amount of sample (1-3 kg). Latest developments of EPD and HS techniques at CNT Mineral Consulting Inc. include the HS-21 hydroseparator (50 kg/hr) and the Spark-21 EPD (5 t/hr), which enables use of both techniques for prospecting and mineral processing of industrial size samples of certain ores.INTRODUCTIONThe main task for mineral processors is to find a reliable technology for testing of mining feasibility and the efficiency of mineral extraction procedures. Among various mineral processing approaches of extraction and concentration there are two alternative cost-effective methods that can be described as the most environmentally benign and complementary: electric-pulse disaggregation and hydroseparation. These techniques were tested on many different ore types and process products with great success providing a precise and comprehensive mineralogical determination of different accessory precious metal and other useful minerals constituent in rocks, ores, and tailings.This article describes several examples of EPD and HS use: native gold from the Kostomuksha deposit (Karelia, Russia), a Ag-Au deposit in South America, zircons from ancient ultramafic igneous rocks of SW Greenland, bauxites of West Australia, PGM from the Driekop dunite pipe and gemstones (ruby, sapphire, emerald and demantoid) from different deposits."

Jan 1, 2008

By Agbo Chima

Low-lying sections of open-pit mines accumulate water, especially during the rainy seasons, preventing access to resource-bearing areas. To sustain mining operations, the water must be lifted out of the flooded pits at a high flow rate using pumps. These pumps need to be mobile so that they can be removed during drill-and-blast operations. Most mobile pumps rely on diesel engines with high maintenance requirements. A special pump design was developed to address the unique needs of open-pit mining while making the dewatering process more sustainable. Using the target flow rate and head data, an efficient pump was designed, encased, and deployed in the open pit. A variable speed drive (VSD) was installed in a protective skid so that the pump could be tuned to match the preferred flow rate at any point during its operation. This system was tied to the national electrical grid instead of being powered by diesel pumps, which reduced the carbon intensity per kilowatt-hour. The high availability, low maintenance requirement, and greater reliability reduced the use of spare parts, the fuel consumption, and the logistics associated with operating the pump. This further reduced the carbon footprint of the dewatering process. This paper provides some of the two-year performance metrics for a deployment in West Africa. With a focus on availability, maintenance costs, average cost per volume lifted, and carbon footprint, this encased pump system is compared to the diesel-driven pumps that it aims to replace.

Jan 1, 2023

By Laura Kelsey

Contaminant Robust In Situ Water Extractor CRIWE Nafion-based water clean-up Extract purified water from natural extraterrestrial sources In situ water processing for downstream electrolysis Chemically resistant to process contaminants such as acid

May 1, 2013

By T. Vovan, A. Galibois, M. Fiset

"In order to establish some links between the 22 specimens found on the site of Les Forges du St. Maurice, their slag inclusions have been analyzed by electron microprobe. Comparison between their contents of various specific oxides allowed us to segregate them into two major groups and even to isolate two sub-groups possibly characterized by some equilibrium between their oxides and/or the type of ores used.In all probability, limes/one coupled systematically with a soil rich in hydrated aluminum silicates was used as a flux.Based upon the existence of a pseudo equilibrium between the slag and the metal, the elaboration of the bulk of the specimens can be ascribed to the indirect rather than the direct method whereas the process temperature can be estimated at at least /400°C.RESUMEDans le but d'etablir des liens entre les 22 objects provenant des Forges du St-Maurice, leurs inclusions de scories ont été analysées par microsonde. La comparison des teneurs en divers oxydes a permis de les séparer en deux groupes majeurs et même d'y distinguer deux sous-groupes pouvant être reliés à la forme d'équilibre entre certains oxydes et/ou au type de minerai utilisé. Selon toute vraisemblance, le fondant utilisé était de la pierre à chaux à laquelle on ajoutait systématiquement une terre riche en silicates hydratés d 'aluminium.Des considérations sur l'existence d'un certain équilibre entre les scories ei le métallaisset croire que la plupart des objets ont été élaborés plutôt par la méthode indirecte que directe et que la température d'élaboration se situait à au maint 1400°C."

Jan 1, 1984

The process of gold recovery by gravity concentration is incorporated in the metal recovery flowsheet at seven Newmont Mining Corporation owned mining operations in Australia, North America and Africa. In 2009 gold recovered by gravity processing was equivalent to nine percent of Newmont's total gold sales of 5.3 million ounces. This paper will discuss these applications in detail including a review of plant flowsheets and presentation of recent operating results. Operating performance will be discussed with reference to ore characterisation procedures, interpretation of results, design considerations and optimisation practices as they relate to the recovery of gold by gravity concentration.

Jan 1, 2011

By Harold L. Gibson, David H. Watkinson

"Volcanogenic massive sulphide deposits of the Noranda Camp cur throughout the Noranda Shield Volcano but are concentrated and along the margins of the Noranda Cauldron. The deposits are realized along synvolcanic faults that also accommodated subsince and controlled the location of eruptive centres. Deposits within e 3 000 m thick Mine Sequence formed during a period of active volcanism and subsidence coinciding with the onset of two cauldron subsidence cycles. The Noranda Cauldron was a restricted site of 10malously high heat flow and structural permeability that favoured e development of a high-temperature hydrothermal system. Metals may have been derived from leaching of aquifer rocks by convecting a water or directly from a shallow underlying magma chamber, now presented by the Plavrian Pluton, that was at its highest position !thin the crust during cauldron subsidence. The deposits formed rough a combination of sulphide precipitation from exhaled fluid td replacement at and below the seafloor in a manner analogous to ose on the modern seafloor.RESUMESi les dépôts de sulfures massifs volcano gènes du camp minier de ~uyn-Noranda sont présents dans les différentes parties du volcanluclier de Noranda, ils se trouvent concentres toutefois, en plus ·and nombre, sur le pourtour de la caldeira (cauldron) de Noranda. ~s dépôts sont localises le long des failles synvolcaniques qui ont cilite la subsidence et contrôle la position des centres d’éruption.~dépôts situes dans la séquence des mines (3 000 m d’épaisseur) sont formes durant un épisode d' activité volcanique et de subsiden qui coïncide avec l' amorce de deux cycles d' affaissement de la rldera (cauldron) de Noranda. Celle-ci Jut le site exclusif d’unflux : chaleur anormalement élevé et d’une perméabilité d’origine cucturale qui ont favorise le développement d’un système hydrothermal a haute température. Les métaux proviennent soit directement d’une chambre magmatique situee afaible profondeur, so it d’un lessivage des roches de l’aquifère par l’eau de mer circulant par convection. Cette chambre magmatique, représentée maintenant par le pluton de Flavrian, se trouvait à son niveau le plus élevé dans la croute au moment de l’affaissement de la caldeira (cauldron). Les dépôts se sont constitués par un mecanisme combinant remplacement et précipitation de sulfures à partir des fluides exhalatifs, au niveau ou au-dessous du plancher océanique, de la même manière que se forment de nos jours, les dépôts de sulfures massifs au fond des océans."

Jan 1, 1990

By D. Chadwick, J. W. Matousek

Between 1860 and 1890 -- from the time of the American Civil War to the last decade of the 19th Century -- nickel production in North America was dominated (even monopolized) by the output of the industrial complex of the Gap Nickel Mine near Lancaster, Pennsylvania and the American Nickel Works in Camden, New Jersey. In some years, from one sixth to one third of the world's metallic nickel supply came from this enterprise. Mining and smelting were conducted at Lancaster; a matte of high iron content was shipped to Camden for pyrometallurgical and hydrometallurgical refining to produce nickel metal, copper sulfate, and cobalt oxide. The high purity nickel product was rolled into sheet for marketing, primarily for coinage, as nickel had few other uses at that time. The undertaking experienced all of the problems that face the mining and metallurgical industries of today: declining reserves, high labor and fuel costs, high transportation costs, fluctuating demand and prices, pollution concerns, and foreign competition. The technical features of the geology; the mining, smelting, and refining operations; and some of the economic aspects are assessed. The view is taken from that of the present time -- seeking those lessons from history that we are supposed to learn or face the prospect of repeating the mistakes of the past.

Jan 1, 2005

By T. Skinner, M. Sahebkar

"In recent years, the mining industry has been inundated with new technologies and software systems to aid in productivity improvement. Accompanying this increased level of technology and computer systems has been the exponential growth in data sources and sinks for all aspects of a mining operation. This rapid growth in data and technology has evolved through vendor “push” approaches and user “pull” scenarios, the result of which has been that currently, no standards exist defining how data from new technology should be accessed and transferred from surface mining equipment and systems. Consequently, many incremental benefits of the systems have not been realized. This paper will present a discussion of this important issue and introduce a new committee formed to address standards to assist the industry in making effective use of current and future technology. Potential benefits accruing from the development of these standards will be illustrated through the use of a case study at Fording Coal Limited. IntroductionThe mining industry is currently faced with a rapid evolution in the computing-based systems capabilities of mobile production equipment. At the same time, there is a trend toward the introduction of even larger machines, with novel designs or incorporation of new technologies within existing designs. Computing and control technology will be required to operate and acquire knowledge about equipment operation, utilization, and performance. Such knowledge has the potential to lead to enhanced equipment design, more appropriate equipment selection, and optimized equipment performance. The equipment systems will be required to be integrated with mine production monitoring systems, maintenance management software, and a wealth of other information systems to provide a complete understanding of the effects of various factors such as maintenance, equipment design and production on economics (Roman and Daneshmend, 2001). This will lead to a better understanding and implementation of the opportunities to enhance the performance of the mine through interaction of the mine operations."

Jan 1, 2003

By E. S. Moore

Introduction The geology of the Sudbury nickel field has been studied extensively, but there are few reports dealing with the structure of the interior of the basin. It was not until the Treadwell-Yukon zinc-lead deposits were discovered that attention was strongly directed toward the large-scale faulting that has split the basin parallel to its long axis. This faulting has been responsible for the , ore deposits in the basin and it may be regarded in many ways as the most important geological event, next to the intrusion and differentiation of the nickel eruptive sheet, that has occurred in the Sudbury region. The early reports on the nickel region by Bell, and Barlow, were chiefly concerned with the nickel-copper ores and with the formations of the region. Coleman was the first geologist to map the nickel eruptive as a continuous sheet around the belt and to emphasize its basin character. On the map accompanying his later report, he shows an important offset in the nickel eruptive at its southwest end, where the large fault cuts this portion of the basin, but the fault was not traced into its interior, as little detailed work was clone in the basin at that time. No ore-bodies had been developed outside of the nickel-copper deposits associated with the norite when the map was prepared, and attention was mostly concentrated on the nickel eruptive. Coleman did, however, map and name the various formations found within the basin and, in general, his delineation of these has remained the standard for prospectors and other workers in the field until the present day.

Jan 1, 1930

By J. P. Sairrlon, K. G. Wheeland, K. J. Mintz, B. J. Kiener

Iwenty-one ore dusts of varying mineralogy, sulphur content and reputed in-mine explosibility were selected from eight mines. After chemical and mineralogical analysis and sieving into two size fractions (+45/ -63 microns and -45 microns), these sarrples and seven pure minerals were tested for explosibility in oxygen in a Harbnann chamber. '!he maximum explosion pressures and maximum rates of pressure do not correlate with sulphur content alone; the types of minerals are also .important. Residues were analyzed to check the combustion reactions. Further comparisons between laboratory and mine results are planned to improve predictability.

May 11, 1988

By M. S. Badollet

"IntroductionAsbestos as received by the manufacturer of asbestos products is •in the •form of either crudes or milled fibres processed to different degrees of texture. Frequently, the manufacturer finds that l:ihe fibres as he buys them are not adaptable to his plant processes, and, therefore, it is necessary for him either to contact the mine supplying the material and request a specific texture for the :fibre or to reprocess the fibre in his own plant.When the mine or mill manager is requested to change his milling equipment to produce a special grade of fibre with a specific texture, he would like to comply. However, if he began to make special fibre grades for each customer, he would be in the position of constantly rearranging his milling technique, adding more equipment, or building a new mill. In the end, his mill would he producing hundreds of different fibre grades of varying degrees of texture, which is a difficult accomplishment if he desires to maintain any quantity of production."

Jan 1, 1950

By C. Pichler, S. Luidold, C. Wagner, C. Sagadin, D. Kreuzer

Engineers and scientists have been combating the attack upon refractory materials of molten metals/matte and slags for hundreds of years. The details in many cases are still questionable or at least debatable. The corrosion is a major concern for furnace operators as refractory wear or failures inevitably results in reduced production efficiency and furnace reliability. Also the cost to industry is considerable and only a thorough understanding of all the complexities of the process will help to minimize that cost. One of the critical questions to overcome is the correct selection of refractories for the individual process steps to provide long and predictable refractory life together with high furnace availability. To understand the nature of the reactions involved in refractory corrosion, it is crucial to determine the complex thermo- chemical equilibria of the reactions occurring between the refractory materials and the process phases. A simulation model coupled with commercial software like FactSageTM is demonstrated aiming to understand the corrosion mechanisms between refractories and the molten process phases and draw implications for improving the performance of refractories and refractory lifetime. INTRODUCTION The extraction or recycling of valuable materials, e.g. metals, can be done by two main routes, pyro- and/or hydrometallurgical processing, depending on the chemical behavior of the used ore, scrap or pre-treated concentrate. Sometimes it is also necessary to use both process routes for the extraction or the recycling of valuable materials. In the case of a pyrometallurgical treatment, the usage of refractory materials is inevitable. This is mainly caused by high temperatures, prevailing during processing. The interaction between refractory material and slag, metal or matte leads to different reactions and interactions. As a main result corrosion of the furnace lining (refractory material) takes place. Hence, recurring furnace shutdowns occur for renewing the refractories. This leads to reduced production efficiency. Such refractory lifetimes are between some hours and decades, depending on the processes.

Jan 1, 2019

By D. H. C. Wilton, W. A. Sears

"Abstract-The 682.8 ± 1.6 Ma Tickle Point Group consists mainly of rhyolite flows and tuffs with- in the Avalon Zone of the Appalachian Orogen in Newfoundland. Stratabound massive sulfide mineralization, consisting of pyrite, sphalerite, chalcopyrite and galena, occurs at the Winter Hill prospect, where a lower pyritic, Cu-rich zone and an upper Zn-Pb-rich zone are hosted by a carbonate-calc-silicate lens. At the Frenchman Head prospect, stringers of pyrite, minor sphalerite, chalcopyrite and rare galena are hosted by felsic volcanic rocks of the Tickle Point Group .Base metal ratios, metal zonations and the overall stratigraphic framework suggest that these sulfide occurrences represent volcanogenic massive to semi-massive sulfide mineralization (stringer type at Frenchman Head). As such these prospects represent the only known VMS occurrences within the Avalon Zone of Newfoundland. Pb isotope data indicate that galena from the Winter Hill prospect is less radiogenic and older than galena from Dunnage Zone occurrences, and suggest that the Winter Hill mineralization formed in an environment tectonically distinct (exotic) from the Dunnage Zone."

Jan 1, 1996

By M. Bustin, A. Hosseinian, G. Preisig

Hydraulic fracturing and hydraulic shearing techniques are essential for the development of unconventional oil & gas and geothermal resources. Such techniques will also play a key role in the development of CO2 sequestration, and management of high stresses encountered with deep mining. However, the optimal design of hydraulic injections is often limited by continuum treatments of the rock mass without consideration of the influence of the natural fractures present. These may interact with the hydraulic fracture to promote offsets or arrest, or may cause the natural fractures to undergo shear and dilation. Given the limited access to the rock afforded by deep boreholes common to oil & gas and geothermal projects, advanced numerical modeling is critical for understanding key mechanisms and interactions. In this work, we first present a coupled hydromechanical distinct-element model focusing on the propagation of a hydraulic fracture. Normal and shear displacements arising from the generated hydraulic fractures are subsequently integrated into a fracture flow model for detailed analysis of specific flow behaviour and fracture permeability. For this, a scanned 3-D profile of a natural fracture is used to correlate surface roughness to dilation as a function of shearing. Fracture flow is computed at different time steps corresponding to different fracture propagation states and geometries. Modeling results indicate that the opening of a tensile hydraulic fracture is accompanied by millimetre-scale shear displacements associated with slip and wedging between adjacent blocks. This may leads to a mismatch between the upper and lower walls of the fracture if asperities are irregular and strong enough. However, fluid-induced tensile fractures have low Joint Roughness Coefficients (JRC), and associated millimetre-scale shear displacements are too small to ensure a significant offset of asperities that prevent a fully-elastic closure when the hydraulic fracture is depressurized. Injection of proppant is thus critical to keeping hydraulic fracture apertures open. Future work is planned that will see the models calibrated against field data including microseismic event locations, magnitudes and source mechanisms, tiltmeter deformations, stress change, and pore pressures.

Jan 1, 2015

By Q. F. Wang, M. H. Lai, T. Q. Liu, G. G. Dong

Compared with the traditional pre-treatment process, biological oxidation process has many advantages including higher gold recovery, less cost, easier operation. The bio-oxidation reactor is the most important equipment for biological oxidation process. In this paper, the characteristics of biological oxidation are investigated, and the design principles are proposed based on laboratory tests. Both increasing the tank height and taking new inflation system can enhance higher dissolved oxygen. The new type of large-scale industrial bio-oxidation reactor is designed, which is 9.5 m in diameter and 10 m in height. The bio-oxidation reactor metallurgical performance has been tested by industrial-scale experiment. The slurry of flotation concentrate is divided into two parts to feed two bio-oxidation reactors. The feeding rates of two reactors are adjusted on the basis of getting the same content of S, Fe, As in overflow. The result shows that the feeding rate of the new type of 700 m3 bio-oxidation reactor is 3.72 m3 per hour, and the feed rate of the conventional 700 m3 bio-oxidation reactor was 3.23 m3 per hour. The processing capacity of the former is 15.2% higher than that of the later, which demonstrates the new type of bio-oxidation reactor has higher oxidation rate.

Jan 1, 2015

By M. Hosseinzadeh

By changing the quality of consumed refractory bricks in burner zone of sarcheshmeh copper complex anod kiln removing of carbon precipitation phenomenon was studied. For blister deoxygenation LPG is blowing in anod kiln and cause destoring microsturcture and bonding of refractory bricks. Studies are shown that in a part of the bricks which have a temperature of 800 - 1000 °C , iron content phases in magesia - chromite bricks are like catalist and cause increasing the rate of carbon precipitation reactions . In a way that in comparsion of two bricks with best and medium quality with different analysis, this problem is more critical in best quality bricks containing high iron oxide. Therefore special magesia spinel bricks suggested and installed in burning zone.

Jan 1, 2004

By Martin Grenon

This paper presents two case studies where fracture set orientation was quantified using three methods: a simple fracture pole grouping, a Fisher distribution and a Kent distribution. The three fracture orientation representations were then used as inputs for kinematic slope stability analysis. Differences showed up in the probability of sliding for all instability modes considered.

Aug 1, 2013

By T. Niedoba

Coal as an energetic raw material is characterized by many features that determine its quality. The data concerning coal are usually treated as independent values, despite the fact that this kind of approach is not always appropriate. In the paper the dependencies between sulfur contents and volatile components in coal and particle size and density were analyzed. The method of ordinary kriging is applied to experimental data to describe this relationship; this method can be used for particles of any size and density. An example of the application of this technique is presented for energetic coal Type 31, originating from one of the Polish hard coal mines in Upper Silesia. Results from ordinary kriging are in good agreement with experimental results. Similar analyses can be performed for other properties of coal material, such as ash content, Roga number, and moisture. On the basis of the data obtained by ordinary kriging, a more comprehensive multidimensional model is described, which can characterize certain deposits or strata from which the analyzed materials originate. This is superior to basing the model only on experimental data, which often is limited by size of the sample. The results obtained by ordinary kriging applied to various types of coal would allow more precise analysis of individual properties of the studied materials and increase the ability to determine significant differences between them. This method can be also applied to other types of mineral raw materials, such as copper ore.

Aug 1, 2013

"IntroductionThe Chairman, in his speech to this body last year in Montreal, stated that the Dominion Coal Board looked to and depended upon the Bureau of Statistics for statistical material, and the Bureau does collect and publish monthly and annual data on coal. It may therefore be asked why an officer of the Dominion Coal Board should prepare and give a talk on statistics.I would explain that it has been our experience in the Board that, since the supply and consumption of coal in Canada is subject to a seasonal ebb and flow, it can be more profitably studied on the basis of a twelve-month period ending on March 31st than of a calendar year, since the end of March does represent a fairly stable end point in this ebb and flow. The figures are not prepared or published by the Bureau on that basis and it has therefore been thought that a presentation on this fiscal-year period would be of interest. The Bureau of Statistics has agreed that this may be valuable and all the data here presented are based on the reports secured from various sources by the Mining, Metallurgical and Chemical Division, Dominion Bureau of Statistics. The only contribution by either myself or the staff of the Dominion Coal Board has been the tabulation in a different twelve month period, and the comments upon the picture presented.It should be noted that the data for the month of March, 1950, are not available in all cases and consequently the figures for that year contain an estimate for this month."

Jan 1, 1950

By S. Hume, J. Shepherd

Meso-2,3-dimercaptosuccinic acid(DMSA) was studied as an additive for thiosulfate leaching of gold. DMSA was added to solutionscomposed of either sodium thiosulfate or calcium thiosulfate and the solutions were tested for their ability to leach pure gold samples as well as a calcined gold ore from Barrick Gold Corp. Results showed prolonged leaching of pure gold samples when DMSA was added at a concentration of 5µM; however, higher concentrations were shown to inhibit leaching. Differential capacitance measurements of the interface indicated that DMSA adsorbed as a defective monolayer on the surface of gold at low concentrations and formed a more compact monolayer with increased concentration. It is proposed that a concentration of 5µM DMSA produces a defectivemonolayer on the surface that still allowsthe transport of oxidants to the underling metal while inhibiting the formation of polysulfide passive layers that arise fromdecomposed thiosulfate.The 5µM DMSA/CaS2O3 system was also studied using calcined ore. Results showed that the initial leaching rates in the presence of DMSA are lower than those obtained in thiosulfate alone. However, after 10h, prolonged leaching is again observed when DMSA is included.

Jan 1, 2015