Search Documents

By Ann Lamontagne

Le parc à résidus de l?ancienne mine Dunraine contient des résidus générateurs de drainage minier acide. Le concept proposé pour la restauration du site est d?utiliser le fort potentiel alcalin des boues rouges, résidus d?aluminerie, afin de neutraliser les résidus miniers. En appliquant une certaine quantité de boues rouges à la surface du parc, on provoquera une neutralisation de l?acidité. De plus, les alcalis contenus dans les boues rouges vont provoquer la précipitation de minéraux stables (sulfates tel la jarosite). La précipitation de ces minéraux provoquera la formation d?une couche indurée qui rendra difficile la circulation de l?oxygène et de l?eau. Bien que ce concept ait été vérifié en laboratoire, ce sont là des hypothèses qui restent à vérifier dans des conditions réelles d?exposition. Les principales questions soulevées par l?utilisation des boues rouges, mis à part le contexte géochimique, est le contexte technico-économique. En effet, le transport de quantité importante d?un matériel argileux humide présente un défi économique important. Outre le défi économique, la manipulation et l?épandage de ce produit sur des parcs à résidus constituent également un défi important. Cet article présente les conclusions d?une étude technique sur le transport, la manutention et l?épandage de boues rouges sur un parc à résidus situés en Abitibi : le site de Dunraine.

Nov 1, 2002

By Karina Forster

Open stope design depends on the ore body geometry, loading conditions and rock mass properties to estimate stope dilution and ground support requirements. Rock mass conditions for design primarily rely upon estimates of well established rock classification systems. Many sources of data exist for obtaining estimates for these rock mass classification values which include core logging, geotechnical mapping, geological mapping as well as linking one classification system to another through the use of empirically derived equations. The extent of mapping coverage can also vary significantly based on the data collection technique. This paper proposes an approach where individual components of rock mass classification systems are collected by the different available data collection techniques. Data from different rock types are also considered separately based on their alteration characteristics and general observation products. Data from the Cameco Corporation Eagle Point Mine is presented and an approach is outlined for obtaining average representative classification values for stope hanging wall characterization. The effectiveness of this approach is demonstrated through the analysis of a data base of hanging wall dilution information.

Jun 1, 2012

By S. Joshi, E. Asselin

An electrochemical quartz crystal microbalance (EQCM) was used to study the leaching of pure gold in deaerated 1 M Na2S solution. Multiple cyclic voltammograms were measured between -0.76 and 1.242 V (SHE) at 20 mV/sec and 2 mV/sec and the frequency shift of the quartz crystal was simultaneously measured. Both the forward and reverse scans showed oxidation occurred between -0.40 to 0.20V. The frequency shift increased during both the forward and reverse scans in the potential range of -0.40 to -0.06 V indicating electrode mass decreased. Since at -0.40 to 0.20 V oxidation peaks were also observed, part of the oxidation was due to oxidation of gold. Eh-pH diagrams were constructed and showed soluble Au(I)-S(IV) species formed between -0.30 and 0.10 V (SHE). Atomic absorption spectroscopy of the test solutions and the mass change recorded by EQCM both showed about 0.015 mg of gold leached. Since the majority of the frequency shift increase corresponding to gold oxidation occurred at -0.40 to -0.06 V during multiple cyclic voltammogram measurement, the total leaching of gold could be approximated to occur at this potential interval to give a leaching rate of ca. 6.4x10-5 mg/s-cm2.

Jan 1, 2011

By C. G. Anderson

As the global demand for copper and gold steadily increases and the need for environmentally sound processing also grows, successful hydrometallurgical treatment of enargite (Cu3AsS4) concentrates has come to the forefront. This type of concentrate contains considerable arsenic so that successful arsenic fixation, for example as scorodite, is of the essence. This paper outlines the successful application of low temperature and low pressure nitrogen species catalyzed (NSC) hydrometallurgical pressure oxidation of enargite concentrates. The successful stabilization of the arsenic as an iron arsenate compound is discussed. Also, the use of experimental design software is highlighted as a process application and optimization tool.

Jan 1, 2006

By K. Szczesny

This paper considers the integration of uncertain real-time logistics data for reactive construction scheduling. In order to manage a construction project efficiently, an accurate schedule representing the current project progress is inevitable. The quality and up-to-dateness of such a schedule depends on the availability of real-time data. Typically, real-time logistics data contain information about the availability of material, equipment and personnel as well as delivery dates and site conditions. The accuracy and inherent uncertainty depends on the location where the real-time data was acquired. Currently, the integration of such data into a construction schedule is a very time-consuming, manual and, thus, errorprone process. Therefore, this paper proposes a methodology that enables an automatic integration of such uncertain data into construction schedules. By integrating uncertainties into the existing schedule their impacts on the construction work can be evaluated. For this, discrete event simulation is applied. In order to model uncertain input parameters for simulation models this methodology applies the fuzzy sets theory. In combination with alpha-cut sampling technique, discrete model input parameters are obtained. By applying reactive scheduling with several discrete event simulation experiments, the results can be used to modify construction schedules according to agreed timeframes and costs. In order to demonstrate and validate the presented approach an example is conducted.

Aug 1, 2013

By M. Kamyab

The Deep Exploration Technology project, as part of the Australian Cooperative Research Centre, is developing technologies to drill deep boreholes for mineral exploration purposes. The aim of the initiative is to transfer drilling technologies from oil and gas into mining applications. Several modifications have to be pondered due to this technology exchange: smaller cuttings sizes because of using impregnated diamond bits; narrower annulus space; higher drilling fluid velocity and likelihood of turbulent flow regime in the annulus; and higher pressure loss. In particular the results of our lab experiments have shown that the increase in concentration of small size cuttings can significantly change the rheology of the mud when drilling in hard rocks. This, in return, could have a noticeable increase in the pressure loss encountered along the annulus space. As a continuation of the above study, numerical simulations were conducted to investigate the cuttings transport behaviour in small size annulus space. Fluid velocity, annulus size, cuttings concentration, cuttings density, and cuttings size were some of the parameters that were varied to see their effects on cuttings transportation and the pressure loss along the annulus space. The results indicate that, due to the differences between oil and gas and mining drilling, conventional oil well planning is not applicable for mineral exploration drilling and numerical simulation would help in this matter.

Aug 1, 2013

By Peter Moon

THE mineral industry of Canada relies heavily upon the talent of its technical men. It is vital to the well-being of the industry that its supply of young, trained men be adequate. At the present time, the industry is acquiring only 200 new graduates a year. The shrinking supply is far below present and future requirements. Other industries and research organizations are competing for engineers and scientists. Dr. J. B. Mawdsley (1), Past-President of the Canadian Institute of Mining and Metallurgy, has recently outlined a program designed to attack the problem. Dr. J'. C. Sproule (2), another former President of the Institute, has stated that: "The need for selection of trainee material is commonly recognized, but little is done about it." The following paper contains a short discussion of occupational interests, and outlines research, using psychological knowledge and measuring techniques, aimed at the identification of desirable recruits for the mineral industry.

Jan 1, 1963

By R. W. Lawrence, O. Lopez

Many gold deposits in the world have not been developed clue to the presence of copper and other base metals which can cause metallurgical and environmental challenges clue to the formation of base metal cyanide complexes. SART technology (sulphidization-acidification-recycle-thickening) can resolve these issues by recovering copper as a high grade sulphide concentrate, recycling the associated cyanide back to the gold leach, and eliminating the downstream environmental liabilities. Project economics can be improved substantially, leading to a positive re-evaluation of new and existing gold-copper projects. Some aspects of the design and operation of two recently commissioned SART plants will be discussed.

Jan 1, 2011

By William Hawker, James Vaughan, Jeff Chen, Antony van der Ent

"Nickel agromining utilizes hyperaccumulator plants (“metal crops”) to extract nickel from low-grade soils, a process that yields high-grade nickel bio-ore. This feedstock is further processed into a range of nickel products. The bio-ore is relatively free of impurities that complicate the traditional processing of laterite nickel ores. In this paper, current primary nickel processing routes and proposed nickel bio-ore processing options are summarised. A novel pyro-hydrometallurgical route demonstrated at the laboratory scale is described. This process produces a precipitated nickel hydroxide product and takes advantage of the water-soluble basic compounds in the ash to minimise reagent requirements, thereby making it suitable for small-scale implementation in close proximity to the nickel farm. In this process, nickel is precipitated from the leach solution using the basic ash wash liquor. Leaching nickel from ash generated from open air burning requires strong acid and long residence times to obtain high recoveries due to its complex nature and distribution of nickel in multiple phases. This process can be improved by optimising the ashing process with respect to nickel leachability.INTRODUCTIONHyperaccumulator plants have the unique capacity to ‘biopurify’ and concentrate certain trace elements (e.g. nickel) from the soil into their biomass (Reeves 2003; van der Ent et al., 2015). Cultivating these plants as ‘metal crops’ by periodically harvesting and incinerating their biomass generates a high-grade bio-ore (Chaney et al. 1998; Li et al. 2003). This process is called phytomining or ‘agromining’ which is an emerging technology for extracting nickel from sub-economic resources (van der Ent et al., 2015). Potential near-term applications of the technology include implementation on land ahead of processing of the underlying ore-body (Willis 2015), as a mine-site rehabilitation strategy or as an alternative crop for farmers on land that is not suitable for normal food crops. In the longer term, nickel agromining could provide a significant supplement to the nickel supply chain. Critical to the success of agromining is effective bio-ore processing. Due to the unique chemical composition of this feedstock material, existing processes are not very efficient. Our current research efforts aim to develop new process options that overcome limitations of previously trialled routes. In this paper we summarise conventional nickel process routes and proposed new options for producing agromined nickel."

Jan 1, 2016

By L. Voisin, K. Yamaguchi, D. G. Mendoza, K. Ltagaki

The behavior of arsenic and antimony in the Cu-0 system was thermodynamically investigated to understand their elimination during a blister-making stage in copper smelting. Firstly, the phase relations in a miscibility gap composed of the liquid slag and copper phases in the Cu-0-As and Cu-0-Sb systems at 1523 K were established by a quenching technique. It was found that arsenic and antimony distributed preferentially into the slag phase in the miscibility gap. Secondly, the activities of arsenic and antimony in the miscibility gap of these systems were determined at 1523 K by using a double Knudsen cell - mass spectrometer method. It was clarified that the activity of arsenic in the copper and slag phases showed the negative deviation from ideality while that of antimony in the copper phase a slightly positive deviation. These data obtained in this study suggest a possibility to eliminate arsenic and antimony by means of over-blowing in a converter after discharging the slag.

Jan 1, 2007

By C. Carrasco

Caletones Smelter, Division El Teniente of Codelco Chile, has used Teniente Converter (TC) as the only smelting unit since November 2000. The modernization project considered the shutdown of the last reverberatory furnace, the installation of the fourth Teniente Slag Cleaning Furnace, the installation of a new fluidized bed dryer and the modification of the concentrate injection system into TC. The modernization project and related investments allowed for the increase of the smelting capacity up to 1.25 million t of concentrate annually.Next stage of the smelter expansion in the year 2004 considered the increase of the smelting capacity up to 1.44 million t/year. The expansion required technology modernization and the installation of the new equipment, such as concentrate injection system, oxygen plant, fluidized bed dryer and storage bin. Currently the annual smelting capacity is about 1.35 million t of copper concentrate, being limited by sulphuric acid plant treatment capacity. This paper presents the technology and production evolution in the Caletones Smelter in the years 2000 - 2006, demonstrating the potential of development and competitiveness of Teniente Converter as world-wide recognized smelting/converting reactor.

Jan 1, 2007

By Kazutoshi Haga, Ariunbolor Narankhuu, Ariuntuya Battsengel, Yasushi Watanabe, Altansukh Batnasan, Akita University

"Rare earth minerals are usually concentrated by flotation, magnetic or gravity separation methods to produce concentrates that are subsequently leached with hydrochloric (HCl), sulfuric acid (H2SO4) or nitric acid (HNO3). About 75 % REEs are lost in gypsum by-product when apatite is dissolved in H2SO4, whereas more than 80% of REE can be extracted from the apatite using HCl and HNO3 leaching processes, respectively. Therefore, the main aim of this study was to find an efficient process of dissolution of rare earth elements (REEs) from apatite ore by sulfuric acid solution due to its lower cost. In order to optimize the dissolution process, effects of different parameters, namely, concentration of H2SO4 (0.05 – 6 M), solid/liquid phase ratio (1:50 – 1:100), temperature (20 – 80 ºC), agitation speed (300 – 900 rpm), and leaching time (0.5 - 6 h) on the dissolution of REEs from apatite ore were examined in various intervals. The contents of main REEs in the apatite ore used in this study were (as % wt): 3 % La, 6 % Ce, 0.6 % Pr, 2.1 % Nd, 0.2 % Sm and 0.3 % Y. X-ray diffraction (XRD) analysis identified fluorapatite and phlogopite as main minerals in the ore. The results obtained from leaching experiments showed that more than 85% of REEs were dissolved from the apatite ore under the optimized conditions, which were: 1 M H2SO4, particle size of -150 + 100 µm, S:L phase ratio of 1:50, agitation speed of 500 rpm at 20 ºC for 1h. The XRD analysis revealed that main mineral compositions of the residues from 1M and 6 M H2SO4 leaching are gypsum (CaSO42H2O) and hemigypsum (CaSO40.5H2O), respectively.INTRODUCTIONThe term rare earth elements (REEs) denote the group of 17 chemically similar metallic elements consisting of the 15 lanthanides, plus yttrium (Y) and scandium (Sc) in the periodic table. These metallic elements are generally divided into two sub-groups; (1) the cerium sub-group, which is called “light rare earth elements” (LREEs), includes the elements from lanthanum (La) to europium (Eu), and (2) the yttrium (Y) sub-group elements, which are known as “heavy rare earth elements” (HREEs), are the remaining lanthanides from gadolinium (Gd) to lutetium (Lu) plus yttrium (Gupta and Krishnamurthy, 2005). The REEs occur together in the minerals due to their chemical and physical similarities, which cause problems of separating them from one another (Abreu and Morais, 2014). Although REEs are relatively abundant in the earth’s crust, they are typically dispersed and rarely occur in concentrated forms, making them economically challenging to obtain. There are a wide variety of rare earth minerals, however economic deposits of REEs in mining are bastnasite (La, Ce) FCO3, monazite (Ce, La, Y, Th) PO4, and xenotime YPO4 (Binnemans, 2013; Xie, et al, 2014). Due to the unique physical, chemical, catalytic, electrical, magnetic and optical properties of REEs, demand of these elements has increased dramatically with the advent of new technologies in electronics, communication, construction, energy and medicine (Jordens, et al, 2013). Since 1990, China has provided about 90 % of REEs worldwide. Japan and United States are the largest consumers of China’s REEs. In 2010, China announced to reduce REEs exports to Japan, as it tended to increase prices of REEs and to reduce a stable supply of REEs in the world market (Humphries, 2013). Therefore, there has been an increase in recent exploration activities intended to reveal new commercial sources of REEs and to bring them into production (Antico, et al, 1996). Apatite is an important host mineral for REEs in igneous and metamorphic rocks and can be used as an ore for those metals (Kanazawa and Kamitani, 2006). Apatite is also the main source of phosphate fertilizers and phosphoric acid (Habashi, 2013; Emsbo, 2015)."

Jan 1, 2016

By E. R. Mitchell

When we grow up in an urban environment and choose to become a part of a way of life, it is sometimes difficult to appreciate the cost of this decision in terms of pollution. Explained in this article is our dependence on technology and the amount of pollution that technology produces. Inventories of air pollution on both a personal and a national basis are given so that the reader may judge the magnitude of the problem. In doing so, it is hoped that the reader will understand the need for a responsible attitude toward pollution by everyone and how he can make a personal contribution.

Jan 1, 1971

By Shuan-cheng Gu

Roof bed separation often occurred due to the deformation incoordination of surrounding rock following the excavation of mine roadway. Bed separation has effect on the bolts, and the estimation of the influence will directly affect the safety of support systems. In this paper, the hyperbolic function model to analyze the load transfer mechanism on the bolts was simplified as the exponential function form for easy calculation. An elastic-plastic analysis model of the bolt loading occurred by the bed separation was established. And the development low that the bed separation affected to the bolt loading was discussed. According to the parameters analysis of different separation values and locations, the influence law of the bolt loading caused by roof bed separation was summarized. Finally, the effects of bed separation were considered for the bolting design, it was able to provide a reference to the anchorage design of stratified rock.

Aug 1, 2013

By Dong-kil Lee

A ventilation improvement index (VII) was developed in an effort to propose an optimal ventilation improvement measure for a designated mine. The index was designed to incorporate both ventilation effectiveness and cost efficiency. To verify the effect of the index, a mine experiencing a ventilation problem was selected, the ventilation assessed and ventilation network analyses were conducted. In the selected mine, four areas with ventilation difficulties were detected and an improvement schemes for each area were proposed. These were simulated through network simulation and evaluated using the ventilation improvement index. As a result, an optimum ventilation improvement scheme was proposed. The improvement scheme with the highest VII value was incorporated in the design.

Aug 1, 2013

By Glen Robertson, Jeff McLaughlin

"The Clarabelle Mill rock tailings have the potential to generate sulphuric acid through chemical and biological oxidation of sulphide minerals. Current rock tailings assay between 0.80 -1.40 %S, with sulphur occurring principally as coarse pyrrhotite. Acid generation within the tailings area can be substantially reduced by segregating pyrrhotite rich tailings in a submerged storage area and by depositing only low sulphur rock tailings in exposed areas. Laboratory tests confirmed that low sulphur tailings could be produced by flotation at reduced pH with a small xanthate addition. A plant test was conducted to evaluate the production of low sulphur tailings in conjunction with INCO's continuing commitment to environmental protection and progressive decommissioning of the metallurgical site.During the plant evaluation, approximately 5% of the mill rock tailings were reprocessed in a line of 100 tt3 Denver flotation cells. Tailing grades below 0.40% S were easily achieved through operation at pH 6 -7, with xanthate addition (dosages up to 0.02 lb/ton) and 10 -15 minutes of nominal retention time. Froth depths between 1 -3 inches combined with relatively liberal amounts of frother were required to pull the lightly mineralized froth into the concentrate which averaged 11% sulphur and less than 5% mass recovery. In addition, three field lysimeters were each filled with two hundred.ton bulk samples of low sulphur tails (0.35% S), standard rock tailings (0.98% S), and mill total tailings (2.30% S) for long term monitoring. The implications for full scale plant design, tailings area decommissioning, the possibility of increased nickel recovery and preliminary field lysimeter data are discussed."

Jan 1, 1994

By S. A. Bradford

The twenty years before World War I was the Golden Age of copper smelting in British Columbia. In this short time, the smelters developed from small, primitive units to large, efficient operations. The first copper claims had been staked on Howe Sound and Knight Inlet in 1864, and there was extensive copper mining in the interior by the mid-1880s, but before 1895, all ore was shipped out of the country for smelting, converting and refining. The first interest in smelter construction was undoubtedly inspired by a Provincial bonus and Dominion land grants offered to smelter builders. The early smelters made use of small blast furnaces which were designed to smelt any kind of ore, but usually far too little ore was available. The first smelter seems to have been the McRae furnace on the Spillimacheen River (1883), followed by Vancouver (1889), Revelstoke (1891), and Golden (1891) (1). They each smelted a few tons of galena and then quickly closed down permanently for lack of ore. Only smelters that actually produced some copper matte are described in the following sections.

Jan 1, 1999

By Akihiko Nishiyama

Unmanned construction technology used for remote control operation of construction machines has some problems to solve compared with manned operation of construction machines, such as fatigue due to long-term operation or decreases in operational efficiency. To solve these problems, we recorded the viewpoints of operators in both manned and remote control operation and analyzed the differences. This paper reports on our discussion of improving the operability of remote control operation based on the analysis results.

Aug 1, 2013

By G. Bonnivard

"A complete laboratory process for the treatment of lateritic ores containing a high proportion of iron, as well as chrome and alumina, has been established. The ores treated originate from the tropical zones and result from superficial climatic alteration. According to recent estimates, the known reserves of such ores reach many billions of tons, thus representing huge potential reserves for the elements they contain.The process used is based on the alkaline roasting of pelletized ore in the presence of sodium carbonate. This treatment results in the separate recovery of pellets of upgraded iron ore, pure chrome oxide and hydrated alumina. The research described in the paper aims at determining the best experimental conditions for obtaining the highest extraction of the required oxide from this type of ore."

Jan 1, 1967

By Roméo Roussin

"The yearly production from the Asbestos Hill pit is 1,550,000 tons of asbestos ore, with a yield varying between 18 and 20 % . The orebody was exposed at the top of a hill, and initial production started without having to remove any overburden. The projected ratio of barren rock to ore, based on the present orebody, was 2 to 1. However, as it was necessary to push back the upper benches, this ratio has changed to 3 to 1. The final pit will be 2,300 feet long by 1,000 feet at the longest and widest points. The final depth will be 680 ft. A pit slope stability study was carried out and an average wall angle of 60-70 degrees must be maintained. Preshearing of final pit limits will produce good wall stability. Permanent access ramps will be 60 ft wide, with an 8 % maximum grade. Geological conditions and the low rock temperature are the major causes of the operation's drilling and blasting problems."

Jan 1, 1976