Search Documents

By George J. Simandl, Suzanne Paradis, Kirk D. Hancock, Jana Simandl

Traditional prospecting and boulder tracing are the two most important field techniques used in exploration for magnesite deposits hosted by sedimentary rocks. Consequently, success depends largely on the prospector's ability to identify magnesite. A density agent called sodium polytungstate (3Na2W04·9WOj'HPJ was successfully used to determine the presence of magnesite in sedimentary carbonate rocks of southeastern British Columbia. A rapid field method was developed and tested. This method permits discrimination between limy dolomites, dolomites, magnesite-bearing dolomites and magnesite-rich rocks.

Jan 1, 1993

By C. Karpuz, Y. S. Istanbulluoglu

This paper describes the results of convergence measurements conducted about five years for the re-use gate roadways at OAL lignite mine in Turkey. Double lignite seams separated with a marn layer, are mined with long-wall retreating mining system at the mine. Rib pillar has been abandoned and gate roadways were planned to be packed for the re-use of full extraction. Various packing systems have been attempted, namely three rows of woodenchock, one row of wooden chock plus concrete wall and concrete wall only. The re-use of maingate roadways packed with wooden chock yielded 62% of closure. Lastly developed concrete packing of 3 meters wide and specially developed support set composed of three friction props and a cap, which is a modification of yieldable set, have successfully maintained the main and tail gate roadways stability with a total vertical convergence of 32%. Good correlation has been established between pack stiffness and floor heave as well as maingate and tailgate convergences. The elimination of rib pillars by re-use of gate roadways increased the coal recovery by 20% and decreased the development/production ratio from 0.065 m3/ton to0.022 m3/ton.

Jan 1, 1997

By John Wightman

LOCATION OF PROPERTY THE property of Caribou Gold Mines, Limited, is situated in the north-eastern part of Halifax county, seven miles south of the Canadian National railway line at Upper Musquodoboit. Approach to the village is by a secondary road, improved recently by waste rock from the mine dump. A two-wire telephone line, seven miles long, built and owned by the present operators, provides communication to the nearest telephone exchange, Parker's Corner. HISTORY In 1870, the Caribou area was recognized as a proclaimed gold district. From then on, operations were intermittent, with periods of considerable activity by small companies until there were no fewer than seven mines in a district two miles long by three-quarters of a mile wide. These were the Holman, Truro, Caffrey, MacDonald or Elk, Lake, Dixon, and Hilchey properties, all of which have had separate stamp-mills, and have produced gold for varying periods. Depths of the workings range from 100 feet to 1,000 feet. Power was generated at each property by means of steam boilers. At the present time, the Consolidated Mining and Smelting Company of Canada, Limited, controls all the leased areas, approximately 800 acres, and is operating by means of one central vertical shaft. GEOLOGY The district in and about Caribou Mines has an elevation of approximately five hundred feet above sea level. The area is fairly well wooded, with rock outcrops here and there. These outcrops, along with information from test-pits and shafts, have been the basis for the very excellent geological map of the district prepared by E. R. Faribault some years ago. The rock structure, which is one of the best examples in Nova Scotia of an elliptical dome, has its anticlinal axis in a northeast-southwest direction, and flat plunges in the same directions.

Jan 1, 1938

By B. Dyck, C. Rodgers

ABSTRACT Cameco Corporation is revitalizing its Key Lake Operation uranium mill in northern Saskatchewan. The mill currently uses ammonia stripping in solvent extraction (SX) and ammonia yellowcake precipitation. As part of the revitalization, the company considered installing strong acid stripping in solvent extraction (used at its Rabbit Lake Operation), which would lead to using hydrogen peroxide for uranium precipitation. As part of the process evaluation, tests were carried out to study how the drying temperature in indirect fired dryers would affect the uranium peroxide yellowcake precipitate properties. This paper discusses the test work results, including the relationships between drying temperature and product reactivity with water, product colour, product grade, and energy input requirements.

Jan 1, 2012

By M. Nzotta, L. Teng, S. Seetharaman, A. Chychko

The objective of the present work is to optimize the EAF practice towards Mo alloying with maximum retention of the alloying element in molten steel. During Mo additions, there were significant losses to the dust (ca 7 %) and to the slag phase (ca 2 %), which had serious economic and environmental impacts. The present work was aimed at designing a suitable Mo precursor, an alternative to ferromolybdenum, as the Mo source and a process sequence for optimal retention of Mo in the steel. The design of the Mo source should be in such a way that low cost raw materials such as MoO3 concentrate have to be used, stable during the addition so that the vapour phase losses as MoO3 are kept minimum and the dissolution of the precursor in molten steel is easy without loss to the slag phase. After thermodynamic considerations, three precursor materials were chosen, viz. CaMoO4, MgMoO4 and Fe2MoO4. Synthetic mixtures of the component oxides in each case as well as pure MoO3 were investigated by TGA and high temperature XRD in order to find out the temperature range in which the compounds were formed. Experiments were also conducted separately where the evolved gases were analyzed. All the three precursors were formed easily and the loss of MoO3 to the vapour phase was found to be extremely low. Addition of the oxide mixtures to steel melts were conducted in three different scales, viz. 16 g, 500 g and 3 tons (induction furnacle). Initial experiments showed that MgMoO4 was not suitable since the Mo yield in the steel melt was not very high. Fe2MoO4 was found to perform best, the Mo yield reaching 98 %. Further trials were conducted in the 65 ton Electric Arc Furnace (EAF) at Uddeholms AB in Hagfors. Mixtures of mill scale, MoO3 and carbon in suitable proportions were added in a pre-determined addition sequence. It was found that, in the actual practice, the Mo yield reached 99 %, equaling in performance the addition of ferromolybdenum. The process offers an effective use of cheaper raw materials and very high Mo yield avoiding a pre-treatment step like the production of ferromolybdenum. This is both cost effective and environmentally advantageous. The process has been patented and is being currently implemented at Uddeholms AB, Hagfors, Sweden.

Jan 1, 2011

By Mousa Mohammadi

Due to operational advantage of dragline in simultaneous excavation and back-filling, the equipment has gained vast importance in open-pit mining. Besides, absence of auxiliary haulage units and a myriad of other benefits are also credited in favor of excavation of muck piles by the draglines. However, the aspects of production, productivity and economics are of utmost significance in dragline operation and planning. In this light, the present paper is an endeavor to analyze availability and utilization of dragline operations. The paper presents a good amount of data for 4-draglines operating in one of the major opencast projects in India. The study reveals the trends of availability and utilization of these draglines during last 11-years. Furthermore, the study also highlights the salient reasons for loss of available hours and for idling of the draglines. Some startling information and facts have been illustrated in form of graphs and pie charts.

Aug 1, 2013

By Ben Sheneider

AT THE Flin Flon plant of the Hudson Bay Mining and Smelting Co., Limited there are two types of multiple hearth furnaces used in the roasting of sulphides. This pa-per will deal primarily with the wedge-type furnace in the roasting of zinc concentrates. The other furnace, the Nichols-Herroshoff type, is used in the copper smelter and is described in the papers given by (1) J. H. Ambrose in 1935 and (2) R. E. Mast and G. H. Kent in 1954. The design and operation of these roasting furnaces at the present time is essentially the same as given in the write-up in 1954. No at-tempt will be made here to describe these furnaces, except to mention that there are five Nichols-Herreshoff multiple-hearth furnaces, four of which are used to roast a dried mixture of copper concentrate, zinc plant residue, and flux, before this material is fed to the reverberatory furnace.

Jan 1, 1961

By Karl Dufresne

Blasting in geothermally high temperature ground and/or extremely reactive ground is an increasing common challenge for surface and underground mines. Many current PETN based non-electric and electronic detonators have manufacturer published in-hole temperature limits ranging from 55°C to 65°C (131°F to 150°F). When confronting blasthole temperatures above the manufacturer published limits, operations may request site-specific guidance and qualification for use. The advised safe loading window for in-hole PETN based detonators is often too short to be practicable for production blasting. To overcome limitations of PETN based initiation systems, surface mines with high temperature ground and/or reactive ground are known to load blastholes with a qualified high temperature bulk emulsion that are top primed with a cartridge of temperature qualified detonator sensitive emulsion plus an RDX detonating cord downline. As there is no in-hole delay detonator in this system, blasthole timing is accomplished with surface delays. Although this system is safe, top priming and surface delaying does influence floor quality and top size fragmentation, and safe loading windows times reduce blast block size and increase blasting frequency. A mining company with a site characterized by geothermally high temperature ground plus highly reactive ground employed a blasting system like the one described above. The site desires to improve blasting performance by moving to an in-hole delay initiation system that can withstand the site ground conditions. At the request of the mining house, DynaEnergetics developed an electronic initiation system for application in geothermally high temperature ground and/or extremely reactive ground conditions. The DynaEnergetics IGNEO high temperature electronic initiation system is rated for in-hole use in ground up to 150C (302°F) for 48 hours. The detonator consists of a high strength detonator with an HMX base charge and thermally resistant downline. To make up a primer, the detonator is inserted into a booster charge assembly that is fitted with a small HMX shape charge. This high energy primer is designed to be compatible and reliable for firing bulk emulsions, including those with high percentages of urea inhibition to combat reactive ground. Up to 1000 detonators may be programmed in 1ms increments up to 1500ms. The system is controlled by a digital firing panel that can be used with either a wired or wireless trigger.  The system enables high temperature and/or reactive ground sites to utilize in-hole delay initiation and realize the associated performance benefits. Conclusions and Future Work 1] The HMX based electronic initiation system permits bottom in-hole delaying in ground temperatures above 80°C (175°F). As compared to top priming and surface delaying, in-hole bottom delaying is known to improve floor quality, muckpile fragmentation uniformity and reduce oversize. 2] Field evaluation of the HMX initiation system at the Lihir Mine is continuing. 3] Work on the next generation of the HMX initiation system is underway and will bring with it expanded application range and flexibility. 

Oct 1, 2024

By Olivia Gamache

When working in remote and extreme environments, projects are faced with new challenges for engineering and project execution. This is heightened when also working in countries with a developing environmental regulatory framework, small skilled workforce available for recruitment, and minimal infrastructure such as power, roads, and water. There is an increasing realization that social and environmental aspects need to be built into project execution. Giving proper attention to these issues during project development and execution, and maximizing opportunities is an ongoing challenge.

May 1, 2013

By Denis Blackburn

La Direction générale du développement de l?Industrie minérale (DGDIM) du ministère des Ressources naturelles et de la Faune (MRNF) du Québec tient un inventaire de toute l?activité minière sur le territoire. Cet inventaire s?est enrichi, au cours des dernières années, d?un grand nombre de projets dédiés au fer ou à des substances qui y sont associées (titane, vanadium, phosphate). Actuellement, cinq régions du Québec sont principalement touchées par la recrudescence de projets dédiés au fer : Fermont, Schefferville, Baie d?Ungava, Baie-James et Chibougamau. Fermont et Schefferville sont les régions les plus actives. Les infrastructures en place, telles que les routes, les chemins de fer, les ports, les lignes électriques et les municipalités, ont atteint, dans certains cas, leur capacité et de nouvelles infrastructures devront être construites pour satisfaire les besoins. À la Baie-James et sur le flanc ouest de la Baie d?Ungava, des projets d?exploration sont aussi en cours. Le manque d?infrastructure pourrait peser lourd sur le développement de projets miniers dans ces régions. Enfin, dans le secteur Chibougamau/Matagami et à quelques sites ailleurs au Québec, des projets d?exploration qui visent le vanadium, le titane ou le phosphate pourraient aussi fournir comme produit secondaire des concentrés de fer. Tous les projets, décrits dans cet article, sont situés sur le territoire du Plan Nord du gouvernement du Québec.

May 1, 2011

By I. C. Brown, J. F. Henderson

"IntroductionThe Yellowknife greenstone belt lies along the west side of Yellowknife bay on the north shore of Great Slave lake, some 600 miles north of Edmonton, Alberta. The producing gold mines along the belt include the Con-Rycon and Negus which came into production in 1938 and 1939, and the Giant Yellowknife, which followed in 1948. In addition to these, the Akaitcho and Crestaurum mines are potential producers and there are several promising prospects.Early geological work along the belt was done by A. W. Jolliffe who first recognized a number of great faults, the largest of which is the West Bay fault with a horizontal movement of more than 3 miles. In 1943, A. S. Dadson, following an examination of the Giant-Yellowknife property, advanced the hypothesis that Baker Creek valley was underlain by a series of major gold-bearing shear zones. Subsequent diamond drilling in 1944 bore out the correctness of this view and outlined the great ore-bearing shear zones that are now being developed and mined by Giant Yellowknife Gold Mines. Near the south boundary of the Giant property, the shear zones are cut off by the West Bay fault. This prompted Neil Campbell, District Geologist for the Consolidated Mining and Smelting Company, to make a detailed study of the geology along the West Bay fault in the hope of finding the faulted extension of the Giant shear-zone system on the west side of this fault. In this he was entirely successful. By careful geological mapping he matched several faulted diabase dykes on both sides of the fault and, knowing their dip, determined the horizontal and vertical components of movement along the fault. Subsequent •diamond drilling based on Campbell's work located the presumed correlative of the Giant shear-zone system on the Con-Rycon and Negus properties, where it has been named the Campbell zone or system. At the present time, all production at the Negus Mines property is coming from orebodies along the Campbell zone."

Jan 1, 1950

By Rolf A. Knopp

This paper discusses how design differences in FLP diesel equipment in underground coal mines came about. "Design standards" tend to create differences between countries while fostering uniformity among products of competing manufacturers. "Performance requirements," on the other hand, tend to eliminate differences between countries while encouraging competitive development of better products. Examples of regulations from the U.S., Canada. Great Britain. Australia. South Africa, etc., are used to illustrate differences in the design and certification of diesel equipment for underground coal mines.

Jan 1, 1978

By Z. Bibak, S. Banisi, A. Ghasemi, E. Nematollahi

"The major importance of liners in grinding is their role in providing an appropriate trajectory for the charge. Since it is not possible to study the charge movement by direct observation in operating industrial mills, this task is accomplished by physical (laboratory), and/or, mathematical (software) methods. Because of the high cost and a longer time required for a physical analysis, mathematical simulations have become more common. Simulation of the effect of liner shape on the charge movement has provided a means to select a proper design based on the operational objectives and conditions. Furthermore, the liner shape changes due to wear and impact during operation, which will influence the charge trajectory. This adds more of an incentive to use simulation. These changes in liner could be predicted through liner profile measurements during operation and/or simulation. In this research, an inhouse developed DEM software called KMPCDEM © was used to simulate the charge movement in industrial plant SAG mills. A geometrical method of implementing the shell liners on SAG mills at the Sarcheshmeh (9.75×4.87 m) and the Gole-E-Ghohar (9×2.05 m) operations facilitated the software simulation. Point by point implementation of the measurements of liner profiles of these mills enabled the study to trend the change in the charge movement as the liners wear. Comparison of the simulation to a laboratory mill (1 m diameter) showed that the difference between the measured and predicted charge impact point, shoulder angle and toe angle were 6, 4 and 3°, respectively.INTRODUCTIONComminution is the most energy intensive operation constituting the major portion of operating and capital costs of a mineral processing plant. In the last decade, a vast number of research was aimed at studying various aspects of grinding with the aim of performance improvements (Davis, 1919; Mishra & Rajamani, 1990; kalala, Breetzke, & Moys, 2008). Mill liners transfer the input power to the charge and play a significant role in affecting the motion of the charge (Mclvor, 1983; Mishra & Rajamani, 1990; Radziszewski, 1997; Van Nierop, Glover, Hinde, & Moys, 2001; kalala et al., 2008). Lifters are usually used with mill liners to extend their life and to enhance the grinding and impact breakage efficiency. Mill lifters are used to raise the grinding media and ore to transfer the energy from the mill to the load (Rezaeizadeh, Fooladi, Powell, & Weerasekara, 2010)."

Jan 1, 2016

By X. -G. Chen, A. M. Nabawy

A novel manufacturing technique for Al-TiB2 nanocomposites has been developed, in which TiB2 nanoparticles were incorporated into liquid aluminum under mechanical stirring and in the presence of a K2ZrF6 flux-wetting agent. The microstructure of the Al-TiB2 nanocomposites was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microhardness test was conducted to investigate the strengthening effect of TiB2 on the aluminum matrix. The TiB2 nanoparticles were successfully incorporated and dispersed into the aluminum melt in the presence of the K2ZrF6 flux during mechanical stirring. In the as-cast microstructure, most nanoparticles segregated in the interdendritic regions as a result of particle redistribution during solidification. The addition of 2, 5 and 10 wt% TiB2 nanoparticles increased the composite hardness by 60, 90 and 150% respectively when compared to commercial purity aluminum, indicating that the TiB2 nanoparticles imposed a significant strengthening effect on the aluminum matrix. The role of K2ZrF6 flux agent on the incorporation of nanoparticles into aluminum melt was discussed.

Jan 1, 2014

By Paul Ransom

Sullivan Production and Present Value ? Mined 150 million tonnes ? 6.0% Pb, 5.5% Zn, 2 opt Ag, + Sn, Cd, In ? May 2006 Value + US$43 Billion ? 50% of metal from first 37% (55MT) of tons ? True original size ~ 110-120 Mt @ 17%Pb+Zn ? 30MT unconsolidated fill + HW cave

May 1, 2006

By F. Logsch, H. Pempel, J. Markowski, P. Ay

"Due to the European Directive 2000/53/EC on end-of-life-vehicles, from 2015 on more than 95% of car materials have to be recycled. In order to recycle the materials back into the economic cycle, it is necessary to produce products with high quality and purity.Plastic components in cars, which are coated with metals by vapour deposition or electroplating, have a wide circulation (e.g., as cladding panel or trim strip for interiors and exteriors). In the end-of-lifevehicle recycling process, these plastic-metal composites are not considered in usual technologies (car shredder) and are not separated from Automotive Shredder Residue. These parts can be separated by optical or HF-detection sorting and then introduced to a specific treatment.Experiments with a specially developed bioleaching configuration showed that the thin coatings, which consist mainly of copper, nickel and chromium, can be removed efficiently from the polymer base materials by a bioleaching solution with Acidothiobacillus ferrooxidans as a leaching agent. The solution used was produced in special fermenters with a 9K-nutrient salt media. During the bioleaching process at 35°C maximum temperature, most of the copper is dissolved and the other metals accumulate as metal sludge. The bacterial cultures based on A. ferrooxidans are robust and resilient.After a 48-hour bioleaching period while the composites were stirred regularly with ventilation, the plastic particles were completely free from metallic coatings. The metal components are separated for further use: undissolved components (mainly Ni and Cr) are separated by decantation of the solution; dissolved copper recovey is carried out by cementation of copper. The cementated solid contains ~98% Cu, along with small amounts of other metals.With the bioleaching process, good separation and re-utilization of the metallic coatings is possible. The cleaned plastic parts were prepared by compounding for new applications with injectionmoulding."

Jan 1, 2016

By Paul Clayton

Case Study ? Site: BMA Saragi Coal Mine Queensland Australia ? Model: Marion 8050 ? YOM: Mid 1970s ? Boom: 97M ? Bucket: Original capacity of 100 Tonnes upgraded to 125 tonnes at time of filtration upgrade. ? Apps: Swing, Hoist & Drag Gearboxes ? Oil: Oil Castrol Alpha TT1200 Viscosity of 1208 cSt @ 40° C (104° F) 720ltr Oil Volume Trial and Installation Justifications ? To reduce gearbox overhauls. Typical schedule being 5 years. ? Bucket upgrade from 100 tonnes to 125 tonnes. Increased gearbox demand and stress. ? Increase of overhauls out to 10 years + ? Saving per Dragline estimated to be US$8-10M in downtime and maintenance if successful. ? In compliance with BHPBilliton Global Maintenance FLAC program ? Fuels, Lubricants, Air and Coolants ? Cost Justification ? Downtime: 4 days ? Lost production: $420,000 ? Cost of parts: $162,000 ? Labour and misc: $41,000 Gearbox failure cost $623,000

May 1, 2008

By Robert Boutilier

For more information on what the social licence means, see the following: Joyce, S. and Thomson, I. 2000. Earning a social licence to operate: Social acceptability and resource development in Latin America. The Canadian Mining and Metallurgical Bulletin, 93(1037) Nelson, J. and Scoble, M. 2006. Social License to Operate: Issues of Situational Analysis and Process. Vancouver, BC: Department of Mining Engineering, University of British Colombia. Thomson, I. and Boutilier, R.G. 2010. The Social License to Operate In P.Darling, (Ed.), SME Mining Engineering Handbook: Littleton, CO: Society for Mining, Metallurgy and Exploration. Much of what has been written and said about the social license to operate focuses on what the company has to do or not do. But the social license is a two-sided relationship. We also need to look at what the community has to do, or not do, in order to be capable of issuing a social license that is meaningful.

May 1, 2010

By N. Katsikaros, A. Lewis-Gray, P. Richards

"To optimize gold recovery in complex leach-to-electrowinning processes, Gekko Systems developed the Gekko resin exchange column (G-REX) as an intermediate step, using a highly gold-selective resin to isolate contaminant metals. The AuRIX®100 resin produced by Purolite is licensed exclusively to Gekko, with the G-REX column designed specifically for this resin. Operational experience has been gained at the Castlemaine Goldfields Ballarat gold mine. In near-continuous operation since 2008, the Ballarat plant treats unclarified concentrate leach solution. The extension of this technology to higher throughputs and more complex chemistry is discussed.RÉSUMÉ Afin d’optimiser la récupération de l’or dans des procédés complexes impliquant la lixiviation suivie de l’extraction électrolytique, Gekko Systems a développé la colonne Gekko de résines échangeuses d’ions (G-REX) comme étape intermédiaire, à l’aide d’une résine hautement sélective pour la récupération de l’or qui permet d’isoler les métaux contaminants. Gekko détient la licence exclusive pour la résine AuRIX®100 produite par Purolite, et la colonne G-REX a été spécifiquement conçue pour cette résine. C’est à la mine d’or Ballarat de Castlemaine Goldfields que l’expérience opérationnelle a été acquise. L’usine de Ballarat, en exploitation quasi-continue depuis 2008, traite une solution concentrée non clarifiée de lixiviation. L’extension de cette technologie à des capacités supérieures et à une chimie plus complexe est examinée."

Jan 1, 2017

By Mario E. Rossi

Geostatistical conditional simulations are becoming increasingly popular as tools that provide models of uncertainty at different stages of a mining project. They have been used as grade control tools in daily operations, to assess the uncertainty of minable reserves at the project?s feasibility stage, and to assess mineralization potential in certain settings. Other applications include assessment of recoverable reserves, resource and reserve classification, and drill hole spacing optimization studies. All large-scale applications of conditional simulations intend to benefit from the ?correct? (or ?accurate?) characterization of uncertainty, adequately describing the variability observed from the data and its impact on the final objective. The objective of this paper is to compare the ad-hoc ?uncertainty model? provided by a traditional classification scheme with the probability intervals resulting from a conditional simulation model. It is argued that the uncertainty model derived from the use of classification schemes is of little practical use to the mining company or operation. The paper emphasizes differences in uncertainty based on the size of the mining unit considered and the extraction method, and local geological differences. Most importantly, it discusses confidence intervals for these mining units, as compared to the relative precision envisioned by a typical classification scheme. The application described in this paper is taken from a medium-sized Cu open and underground mine in northern Chile, and it demonstrates the impact of several variables on the resulting conditional simulation models. It also compares a more ?traditional? resource classification scheme applied, and the wide difference in local confidence intervals for each mining unit.

May 1, 2001