Search Documents

By T. S. Grewal, S. C. Gupta, H. Natarajan, T. W. McQuade, N. Nejibulloev-Mamedov

Cigar Lake is one of the world’s largest high-grade uranium mines. The ore mined at Cigar Lake is milled at Orano Canada Inc’s (Orano) McClean Lake mill. The average Cigar Lake ore uranium grade since the start of mining activities in 2014 is 17.8% U (range 8– 28%). To achieve budgeted production of 18 M lbs U3O8/yr the required average feed tonnage to the mill is about 45 kt/yr. Arsenic, occurring as arsenides and sulpharsenides, is one of the major elements of concern associated with Cigar Lake ore. The leaching process is a sulphuric acid leach under oxidizing conditions at near atmospheric pressure. The presence of arsenic in the ore consumes oxidant in leaching as well as ferric sulphate in tailings preparation for arsenic sequestration. The average arsenic grade since the start of mining at Cigar Lake is 0.57% As. Further, the ore is hosted in a matrix of sandstone and clay, which results in poor settling in CCD. The average uranium grade for the balance of Cigar Lake Phase 1 ore is expected to drop to 12.5% U and the average arsenic grade is expected to increase to 1.6 % As, with an annual average peak of 2.5%. Therefore the tonnage throughput required to sustainably meet the production target will increase to 55 kt per year. Orano partnered with Hatch Ltd. (Hatch) to perform a gap analysis study to identify key circuits and equipment in the mill that would require debottlenecking. A METSIM mass balance model of the McClean Lake mill was generated and validated with actual mill operating data. Various feed scenarios were then studied, and the outcome was a traffic light table, which highlighted feed scenarios that exceeded installed capacity of major equipment and circuits. The results provided the basis for the PDC for the pre-feasibility study. This paper will outline the results of the gap analysis, the mass balance model, the feed scenarios and the study undertaken to prepare the McClean Lake mill for the change in ore quality from Cigar Lake.

Jan 1, 2020

By T. Nagasaka, T. Miki

Suppression of CO2 and waste such as slags discharged from iron- and steelmaking processes are some of the typical major issues for the protection of global environment and sustainable growth of steelmaking industry. Utilization of active phytoplankton growth will be one of the best options to stabilize and suppress carbon dioxide at high-efficiency. Inorganic minerals such as C, 0, N, Si, P and Fe are necessary for phytoplankton multiplication. It is crucial for supply of nutrition into seawater effectively for phytoplankton multiplication to understand the dissolution behavior of some elements from steelmaking slags into seawater. The morphology of the precipitated phases in steelmaking slags during cooling period was investigated in the present work. The dissolution behavior of some elements from steelmaking slags into artificial seawater has also been studied. The effect of nutrient dissolved into seawater on phytoplankton multiplication, some examples of marine structure made from steelmaking slag, and estimation of CO2 fixation amount by marine phytoplankton are also discussed.

Jan 1, 2004

Conventional waste management practices produce two waste streams for the construction of separate disposal facilities. The design of tailings impoundments is usually controlled by physical stability. Waste rock materials offer high shear strength characteristics for waste dump construction, however the hydraulic properties promote oxidation. The problem of oxidation is significantly reduced for tailings due to a fine texture that augments water saturation. Co-mixing of tailings and waste rock involves the intimate blending of tailings and waste rock to create a new material with superior physical and hydraulic properties. The new material has a low hydraulic conductivity, low compressibility, high water retention capacity and high shear strength. Co-mixed tailings and waste rock restrict oxygen entry and water seepage to minimize acid generation and metal leaching. Co-mixed tailings and waste rock may be used to construct cover systems, internal barriers and seals, confinement structures and full depth waste repository. The results of a laboratory program to characterize the physical and hydraulic properties of Comix tailings and waste rock are presented here. Various ratios of tailings were blended with three distinct waste rock materials. The saturated hydraulic conductivity for the Co-mixed materials was found to vary between 2 x 10-7 m/s and 5 x 10-8 m/s depending on blend ratio, waste rock type and compaction. This paper introduces concepts for the co-disposal of tailings with waste rock and evaluates the hydraulic behaviour of a Co-Mix waste system. The potential benefits of Co-Mix are shown for a typical mine.

Nov 1, 2002

By Buse Florian

This paper presents the specific features of the large-scale production and transportation systems (LSPTS), describing the main notions and characteristics of the LSPTS elements. A methodologically unitary approach of the formulation, formalization and solution of the problems regarding the planning of the LSPTS structure development is offered, based on the system description by the aggregation-decomposition method, as weil as on the complex of interreloted models for the planning optimization. The paper describes the characteristics of the complex of dynamic models for investments, utilized in solving the planning problems of the LSPTS structure development.

Oct 1, 2009

By Turgut Yalcin

"High-grade concentrates are achieved in flotation columns primarily due to the use of thick froth layers and wash water, both of which facilitate the drainage of hydrophilic minerals from the froth. However, conventional columns employ tall, non-agitated recovery sections for bubble-particle attachment that require high headroom and special gas spargers as well as imposing particle size limitations. These disadvantages can be all alleviated by carrying out the recovery part of the process in a mechanical or pneumatic cell which generate froth more conveniently and efficiently.This paper describes the combining of mechanical and column flotation in a single unit and discusses the influence of various parameters on the performance of the system.INTRODUCTIONIn a flotation process, some of the minerals lifted up to the froth phase may drain back to the pulp due to various reasons such as weak attachment of particles to air bubbles, bursting of air bubbles, agitation of froth, etc. Weakly floating and entrained hydrophilic minerals drain at a faster rate than the strongly floating minerals, and effective exploitation of such differential drainage can lead to cleaner concentrates.For a given mineral, if the rate of flotation from pulp to froth is k1 (min·1) and the rate of drainage from froth to pulp is k2 (min""1), then the net (overall) flotation rate of the mineral, k (min-1 ), will be [Lynch et al., 1981 ]:"

Jan 1, 1997

By Michel Massé

Eleonore Project- Agenda ? Purpose and Technical Overview ? SmartEXEC Control Capabilities ? SmartEXEC System Archetecture ? SmartEXEC System Advantage Eleonore Project- Purpose and Technical Overview ? Control air quality while maintaining target production levels at minimum energy operating cost ? Improve safety, work place conditions and operation flexibility ? Reduce energy consumption and green house gases footprint

Aug 1, 2013

By Cecilia Arrue, Dominic Fragomeni, N. O. Lotter

"A statistically designed benchmark mill survey was carried out in July 2005 at the Kidd Creek Concentrator, D Division circuit, which processes Ni/Cu ore from the Montcalm deposit. A structured statistical survey approach was followed, together with defined quality controls, which would assign a 95 percent level of confidence in the result.A set of six surveys were completed over a limited time; the corresponding stream samples of the surveys found acceptable were combined to obtain high confidence composite samples. The head grade of each survey is compared to two distributions to test its acceptability; surveys that fail to conform to these trials are rejected. The accepted set of surveys, which is a robust representation of the process, is prepared into a composite for QEM-SEM analysis and mass balance purposes.Where the above practice is a standard procedure in Falconbridge for QEM*SEM purposes, in this case each individual two-hour survey unit was measured and analysed for a mass and value balance. It is shown that none of the individual mass and value balances close as well as the composite set of accepted two-hour survey units. This founding is in keeping with the averaging properties of the Central Limit Theorem.INTRODUCTIONMontcalm OperationsNi/Cu bearing ore from the Montcalm deposit is being processed at the Falconbridge, Kidd Creek Concentrator in a modified D Division circuit. The circuit was commissioned in the fall of 2004. Ore is crushed at the minesite to –19 mm and trucked to Kidd for delivey into the 4 parallel fine ore bins.Ore is milled in a rod mill followed by cyclones and 2 parallel ball mills. The grinding circuit treats Montcalm ore at an average feed rate of 100 wet tonnes/hour (750,000 tonnes/annum) and produces a flotation feed particle size of 83% -53 um. A simple flowsheet including bulk Cu/Ni roughing and 2 bulk cleaning stages followed by Cu/Ni separation in 2 stages is practiced. Soda ash is used as a pH modifier in bulk flotation. SIBX is the collector. Lime and Dextrin are added into Cu/Ni separation for the depression of pentlandite."

Jan 1, 2007

By Mika Muinonen

"Dewatering of nickel concentrate at the INCO Thompson integrated mine-metallurgical site takes place within the smelter plant. The eight original 60 foot diameter cable torque thickeners of which four were operational and eight Dorrco internal drum filters have been replaced with a single Outokumpu high rate thickener and a single Lasta pressure filter. The modernization has resulted in a filter cake which has a more stable and lower moisture content. Control of the entire dewatering process has been improved and costs have been reduced.Typical filter cake produced from the Dorrco filters during processing of high tonnages of Birchtree mine ore was ~20% moisture vs. ~13% moisture for concentrate produced from the Thompson mine ore. The high moistures were correlated with the amount of fine magnesium silicate gangue in the concentrate. As Birchtree ore processing rates have increased, this filter cake moisture became unacceptable because of material handling problems and the impact on furnace metallurgy. The Dorrco filters were replaced with the Lasta filter in 2003 that has consistently produced filter cake at ~11% moisture.This paper summarizes the piloting, design, installation and commissioning of the modernized dewatering circuit.INTRODUCTIONThe Thompson integrated nickel processing facility was built in 1958 and originally consisted of a mine-mill-smelter and, soon after, a refinery.Nickel concentrate is pumped from the mill as a dilute slurry directly to the smelter facility ~200 meters along an unheated pipe trestle. Originally, nickel concentrate was de-watered using up to 8 conventional 60-foot diameter thickeners and 8 internal vacuum drum filters."

Jan 1, 2006

By Christoph Mueller

Broad band mine communication today is characterized mainly by individual solutions, which have in common their long development phases and their high cost for development, operation and service. The use of Ethernet and TCP/IP on the other side provides an uniquely price efficient combination of high bandwidth open networking, universal use and accessibility of cheap development tools, especially because it forms the technical infrastructure for the worldwide Internet. TCP/IP and Ethernet assures reliable networking however it is not able to guarantee the latency timing of forwarding network information. Therefor, the network design requires strict load limitation and application level traffic control especially if moving equipment has to be manually remotely controlled via the network. To optimize the use of bandwidth on mining networks using load limited, ?bandwidth wasting? local Ethernet segments, long distance broadband traffic should be carried out using more efficient, deterministic communication backbones providing a guaranteed quality of service for each of the physically separated networks. Open networking and broadband systems however may lead to the anticipation that any demands on bulk data or multimedia traffic can be fulfilled in the future. This definitely will not be the case as the bandwidth demands of applications will be growing as least as fast as the bandwidth provided by communication systems. Looking on those problems from an overall system integration perspective, machines and equipment in the future have to be equipped with intelligent computing devices capable of an intelligent local data preprocessing. Such ?Embedded Machine Information Servers? running commercial computing power in the future will be the intelligent bridge between open networking and a secured, high safety local automation system. These ?Embedded Machine Information Servers? then also can make advantage of intelligent video and audio data preprocessing to store and transmit multimedia information ?on demand? or when the application requires it. Summarizing the potential for the future Ethernet based networking together with powerful communication backbones and intelligent local data preprocessing on the machines in the future will lead the way to integrative, reliable and cost efficient mine automation solutions.

May 1, 2002

By G. M. Ritcey

The recovery of copper from low-grade solutions res ulting from dump leaching is well known, whereas the recovery from highly concentrated copper solutions has not been practiced. This paper discusses the use of Ashland Chemical's Kelex 100, a substituted quinoline, for the recovery of copper from solutions resulting from leaching copper-nickel concentrates. A flow sheet is described, and an economic comparison shows Kelex 100 to be superior to either the LIX 64N or LIX 70 reagents of General Mills for the recovery of copper.

Jan 1, 1973

By B. S. W. Buffam

Introduction The development of uranium deposits is a relatively recent phase of mining in Canada. To date, the only producer of uranium ores on a commercial scale has been the Port Radium mine on Great Bear lake, N.W.T. However, with.-in the past few years intensive prospecting has been carried on throughout Canada and many occurrences of uranium-bearing minerals have been discovered. Eldorado has been active in the search for and the exploration of uranium deposits in Canada for a longer period than any other company and has, therefore, accumulated a considerable fund of information, especially about occurrences in Saskatchewan and in the Northwest Territories along the western fringe of the Precambrian Shield. The Company has also had experience in the underground operation, and in the mining, of uranium ores at Port Radium. During the past year or so many requests have been received from the prospecting and mining fraternity for information and guidance regarding the development of the many new uranium discoveries that have been made in Canada. Assistance by Eldorado is freely given whenever possible and this paper is presented to supplement the private discussions and to provide as wide a distribution as possible of the data acquired by Eldorado.

Jan 1, 1951

By W. Duyvesteyn, B. Sabacky, T. Spitler, D. Verhulst

"The Altair TiO2 pigment process is based on hydrochloric acid leaching of ilmenite at high-acid concentration. Titanium is transferred by solvent extraction into a high-purity aqueous stream with a high titanium concentration. HCl gas is recovered by pressure-swing distillation and is used to regenerate the leaching solution.A new method of TiO2 recovery in dense film with simultaneous dehydration and hydrolysis provides great flexibility in adjusting the characteristics of the TiO2 pigment product.Modifications of this method lead to a flexible, low-cost, high-tonnage process first for the production of nano-sized TiO2, and later for stabilized zirconia-based nanomaterials and nano-sized titanates.IntroductionProcesses for the production of TiO2 from ore by a hydrochloric acid route have been proposed in the past. Most of these processes dissolve impurities and recover TiO2 as a residue or as a hydrolyzed phase in the original solution (Turner, 1948; Berkovich, 1975; Morris, 1982; Judd, 1986; Chao, 1993). Solvent extraction of titanium after leaching in aqueous HCl has also been studied (Tsuchida et al., 1982; Narita et al., 1983) or at least mentioned as an alternative (Ellis, 1963). A number of small-scale studies on leaching and solvent extraction in both sulphuric and hydrochloric systems have appeared recently (John et al., 1999; Lanyon et al., 1999; Sole et al., 1999. As far as we know, only Kerr-McGee (Morris, 1982) and a plant in India and one in Malaysia use a hydrochloric acid route (20 wt% HCl) to commercially produce synthetic rutile.The Altair process originated in a search for an economical method to treat high-magnesium ilmenite deposits, while avoiding the production of a waste metal salt by-product. The first attempts aimed at producing pure TiO2 by leaching out the impurities. Further work centred on completely dissolving the ilmenite in concentrated hydrochloric acid and reprecipitating TiO2. To decrease the impurity level in the product, solvent extraction of titanium into a purified stream was introduced. It also became clear that to take full advantage of the increase in leaching efficiency provided by concentrated acid, it was necessary to regenerate HCl gas."

Jan 1, 2002

By J. N. Van der Merwe, M. Mathey

"We present an analysis of the mechanical properties of coal specimens from various coalfields and seams in South Africa. Our database comprises of 1800 test results from uniaxial and triaxial compression tests, as well as indirect tensile strength tests, which we collected from the various mining houses and research agencies in the country. We inspected the database for possible errors and present a brief description of the verification procedure in the paper.In the analysis, we reveal that the collected samples of strength and elastic properties of South African coals can be represented by single lognormal or normal distributions with only few outliers. This finding indicates that the samples realistically approximate the population of mechanical coal properties in the country and may suggest that the properties are randomly distributed. Significant coalfield- or seamspecific trends for the mechanical properties of coal are not clearly discernible from our data.Typical coefficients of variation for the individual mechanical properties range between 25-50 % on a country-wide and seam-specific level of analysis. Average uniaxial compressive strength values, however, are closely clustered for all seams. A comparison with data available from international coal strength studies show the distinct difference between South African coals and seams in countries of the Northern Hemisphere, where differences in the average coal seam strength are more pronounced.We observe that the number of specimens whose failure mode is influenced by the presence of natural discontinuities reduces drastically with the application of very small confining pressures to the specimens. Further, the strength-reducing influence of discontinuities diminishes with increasing confining pressures."

Jan 1, 2015

By I. G. Townsend, S. A. Buckley, C. I. House

"SummaryBritish Petroleum plc is developing a new gold recovery process known as coal gold agglomeration (CGA) for the recovery of gold from its ores. Liberated gold grains are recovered with high efficiency by adhering to agglomerates of coal and oil. The process is simple, can recover gold grains down to very fine sizes, avoids the large scale use of cyanide and provides the industry with an important new process option.A technical appraisal of the process has been performed on an extensive range of gold bearing materials. Ore types have been identified from which high gold recoveries can be achieved. A spreadsheet based computer program has been used to estimate the preliminary capital and operating costs of the process. Comparison with established gold production costs shows that the process costs of CGA, on the appropriate ore types, are potentially very attractive, which will enable economic treatment of lower grade ores than is currently possible using conventional cyanidation. Treatment of known placer deposits or gravity concentration plant tailings may be the most rapid means of demonstrating the process at a commercial scale prior to more widespread applications.1. INTRODUCTIONWestern world gold production for the 1980s has shown rapid growth sustained by a demand for gold at a favourable price (Fig. 1). Heap leaching and CIP/CIL operations have been responsible for the major part of new production during the 1970s and 1980s with present overall production costs averaging US$200/oz in Canada, USA and Australia and US$265/oz in South Africa [l]. A great deal of research and process development effort in the 1980s has been towards the treatment of refractory ores. Operating costs for the economic processing of these ore types by currently available routes are around US$300/oz [2]."

Jan 1, 1989

By Chuck Edwards

"The development of two large, high-grade uranium projects has been proposed for northern Saskatchewan. The projects are now under review by a joint federal/provincial panel. The McArthur River project is owned by the McArthur River joint venture (Cameco Corporation 53.991 %, Uranerz Exploration and Mining Limited 29.775%, Cogema Resources Inc. 16.234%) and operated by Cameco. Cameco proposes to mill the McArthur River ore at the existing Key Lake mill. The Cigar Lake project is owned by the Cigar Lake joint venture (Cameco Corporation 48.75%, Cogema Resources Inc. 36.375%, Idemitsu Uranium Exploration Canada Ltd. 12.875%, Korea Electric Power Corporation 2.000%). The Cigar Lake joint venture proposes that Cameco operate the Cigar Lake mine for the owners, and that Cogema mill the ore at their McClean Lake mill, now under construction. Proposed systems provide safe mining and ore handling, and allow the milling of McArthur River ore at Key Lake and Cigar Lake ore at McClean Lake. This avoids the disturbance of new sites for milling and tailings disposal.The McArthur River and Cigar Lake deposits are the largest known high-grade uranium deposits in the world. The ore grades at McArthur River and Cigar Lake are at least 100 times those that are mined elsewhere. It is proposed to mine these deposits using remote underground mining methods, to crush and grind the ore underground, to pump a thickened ore slurry to surface, and to transport it in special containers by truck to the mills.During all mining and processing stages the ore is fully contained. Radon emission is controlled by positive ventilation of all process vessels, with the process ventilation backed up by the primary mine ventilation system. Radiation is controlled by heavy steel pipe and vessel walls, concrete walls and sometimes lead sheeting."

Jan 1, 1997

By John G. Henning

The Porcupine Joint Venture operates the Dome Mine in South Porcupine, Ontario. Dome underground began production in 1910. It is the longest continuous operating gold mine in Canada, producing in excess of 15 M ounces. More than 900 underground stopes have been mined and hundreds of miles of drifts, sublevels and raises developed. Underground mining methods included shrinkage, cut and fill and longhole. Not all stopes were backfilled upon completion, particularly the longhole stopes. The Dome open pit was designed above the underground mine workings such that, as the pit is excavated, it intersects underground drifts and stopes. Potential operational problems associated with the interactions between the stopes and the pit walls may occur, necessitating pit wall redesign, ground support installation and operational rescheduling. Each intersection of the pit with the underground mine workings is closely evaluated to maintain a safe working environment and wall stability. This paper discussed how risks to pit wall stability are assessed, mitigated and monitored.

May 1, 2004

By J. B. Mitchell

Many of the pre-production and plant startup problems that we regard as inevitable are actually caused by poor organizational methods. Traditional methods of organization can be modified to provide clear definitions of responsibility, continuity and depth of involvement of key personnel in order to overcome these problems.

Jan 1, 1966

By Paul Krivokuca

Outline Quinsam Coal Mine ?? Location ?? Mine History ?? Safety ?? Production ?? Hiring 4S Mine ?? Depillaring design ?? Structural mapping, Risk assessment ?? Rock Bolt Design Selection ?? Training

May 1, 2008

By Dan Alexander, Ivan Crnkovic, Sarah Schwarz

"Several plant studies have been conducted at the Zinifex Century Mine over the past 5 years. For each of the plant studies, surveys of the zinc primary circuit were conducted, characterisation measurements for each operating cell taken, and the floatability components of the ore mapped to develop a model of the circuit. The floatability components and machine parameters were then used to simulate changes in circuit configuration and operating conditions, enabling further potential improvements in circuit performance to be identified.This paper reviews the current flotation practice at the mine, as well as various circuit changes and developments implemented by site. The application of the methodology and the evolution of the standard procedure are also discussed.INTRODUCTIONBase metals were first discovered in the Lawn Hill region of Queensland’s North West in 1869 and the first mining lease in this area was pegged in 1887 over what is now known as the Silver King vein deposit. The area encompassing these veins, which includes the Century deposit, was proclaimed the Burketown Mining Field in 1899. Exploration titles were granted to CRA in 1987, precisely 100 years after the initial discovery at Silver King, hence the name ‘Century’.Century was commissioned by Pasminco in late 1999, with the mine becoming fully operational on 1 March 2000 and the official opening taking place in April. Pasminco had bought the Century and Dugald River deposits from CRA in 1997 for A$345 million, and invested some A$710 million in bringing Century into production. Today, Century is the world’s second-largest zinc mine in terms of its output, having reached full capacity in 2003.The Zinifex Century Limited (“ZCL”) lead-zinc-silver deposit is located approximately 250 kms north-north west of Mt Isa in north-western Queensland. The deposit is a large flat-lying ore body covering an area of some 1.2 by 1.4 km, the 45 m-thick stratabound sulphide orebody is hosted within an 850 m-thick sequence of Proterozoic siltstone, shales and sandstone, amenable to open-cut mining methods. The mine has ramped up to full production delivering five and a half million tonnes of ore per annum, yielding approximately 900,000 tonnes of zinc concentrate and 90,000 tonnes of lead concentrate. Mine life is expected to be about 8 years"

Jan 1, 2008

By Daniel Hodouin, Claude Bazin

"A graphical method to assess the size reduction by grinding is presented and illustrated with data collected from laboratory grinding tests and industrial grinding circuits. The method lies between the graphical comparison of size distributions and the population balance model. The method is easy to apply and provides a quick way to compare grinding mill performances under various operating conditions and processed ores. The application of the method to industrial mills shows that a grinding mill operation could present an invariant behaviour that can be exploited for simulation purposes.INTRODUCTIONThe size reduction of particles by grinding has been studied for decades and several books were published on the subject. Most of the recent studies focus on the modelling of the ball, semiautogenous and autogenous grinding mills operation (Napier-Munn et al., 1996) because accurate simulators can be used for design, optimization and control. Although the development of realistic simulators is progressing, the trial and error method is still used by many operators to identify optimum operating conditions for a grinding machine.Laboratory tests allow the characterization of the material submitted to grinding and the analysis of various operating conditions, such as ball size or shape, mill speed and slurry concentration of solids, on particle size reduction. Similar tests can be conducted in a plant, but results are often difficult to analyze due to errors associated with sampling and sensor accuracy. This paper presents a graphical method to assess the degree of size reduction carried out by a grinding machine. The paper consists of three sections. The first section describes the method and the following sections illustrate the method with data taken from laboratory and industrial grinding machines."

Jan 1, 2004