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By D. H. Wilson

"This paper examines the increasing need for mechanical-electrical people within the industry and some of the reasons why such a shortfall exists. It is suggested that, in part, it is image related. The present industry-education relationship in addressing the situation is examined and some thoughts are expressed on how these may be built on, in order to help solve the problem of attracting people to this critical area.IntroductionAs a long-time proponent of plant engineering and maintenance as a management function, I would like to review the progress made by the industry/ educational approaches in satisfying the needs in that area. In doing so, I would like to make the following points:1) that there has been an accelerating shortfall of mechanical-electrical people relative to the needs of the industry;2) that the condition will probably get worse before it gets better; ,3) that the past industry I educational approaches to alleviate the problem have met with limited success; and finally4) I would like to review some of the things being done and consider how these efforts might be extended."

Jan 1, 1981

By Kosei Ishida

To achieve renovation work without noise, the authors developed techniques of manufacturing pre-cut interior finishing components for renovation work. In this paper, to achieve the system of pre-cut interior finishing components, the authors describe a measuring method of reinforced-concrete structure by 3D laser scanner and then describe a method of making a design of pre-cut interior finishing components with the polygon model. Using these two methods, the steps of manufacturing pre-cut interior finishing components consist of the following four steps: First, measure the building shape using a 3D laser scanner. Secondly, integrate a point cloud data and retrieve the markings on the floor. Then, create a polygon model of the building based on the point cloud data. Lastly, make a drywall design using a polygon model. To evaluate the technique feasibility of manufacturing pre-cut interior finishing components, the authors have conducted an experiment of the finishing interior work of the drywall. Using pre-cut interior finishing components, the authors have been able to achieve interior finishing work without noise.

Aug 1, 2013

By R. M. Graves, C. B. McKenzie, D. Barbour, D. W. Desnoyers

"The prospective Tulks volcanic belt hosts five significant massive sulfide deposits, Tulks Prospect, Tulks East, Jack's Pond, Daniel's Pond and Victoria Mine, as well as numerous showings and indications throughout its 70 km outcrop length. Regionally, the 498 Ma sequence consists dominantly of felsic pyroclastic rocks and flows with interbedded mafic volcanic units and finegrained sediments, commonly graphitic. Contemporaneous granitoid rocks occur in the south half of the belt. Rocks usually display a strong NE-SW, steeply dipping, penetrative foliation and other shear-related high-strain fabrics. Facing directions are normally northwest, although there is local evidence of folding. Sulfide bodies and their alteration systems are deformed and shape-modified in the style of ambient strain.The Tulks, Tulks East and Jack's Pond prospects appear to occupy a similar stratigraphic level, on or near the contact between a thick felsic pile and an overlying broad, conductive package of graphitic sedimentary rocks. All are pyritic deposits with well-developed footwall alteration systems. The Tulks prospect comprises four polymetallic lenses totalling 750 000 t. Three lenses constituting more than 6 000 000 t of sulfide mineralization are indicated at Tulks East but only the 210 000 t ""B"" lens contains significant base metals. Jack's Pond consists of a very extensive, zoned alteration complex in which four lenses of massive to semi-massive pyrite + chalcopyrite are known. The central part of the system, characterized by Mg chlorite and carbonate, is enveloped by pervasive sericitization and capped by intensely silicified and pyritized volcanics. The sulfide lenses are interpreted as part of the footwall zone and are beneath that part of the system most likely to hostpolymetallic massive sulfides.Daniel's Pond differs from the other prospects in such fundamental ways as metal content, associated alteration and structural setting. The deposit comprises strongly tectonized, Ag-rich, Zn-Pb mineralization distinguished by a pronounced Ba-As-Sb signature. Mineralization is confined to a narrow, north-south high-strain zone which separates unstrained mafic volcanic rocks to the east from well-foliated felsic rocks. The deposit lacks an extensive alteration halo and at its north end is associated with a lens of barren, undeformed massive pyrite.The Victoria Mine deposit, the most cupriferous of the five, is related to a moderately dipping structure that separates well-foliated Tulks volcanic rocks from an overlying, less deformed volcanic sedimentary sequence that may be as young as 462 Ma. The structure is also the locus of black chlorite, dolomite and quartz alteration. Structurally remobilized precursor sulfide mineralization is one possible source for the deposit."

Jan 1, 1993

By T. Sugawara, H. Sekimoto

Electrorefining of low-grade copper alloys containing various amounts of nickel, lead, antimony, bismuth, arsenic, selenium, silver, and gold in sulfamic acid media was demonstrated. The copper concentration of the alloys used as an anode was 70–90 wt%. The electrolyte contained 100 g L-1 of free sulfamic acid and 40 g L-1 of cupric ion. Galvanostatic electrolysis was conducted at 200–300 A m-2 in the electrolyte using a low-grade copper alloy anode and a stainless steel cathode at 25C. The terminal voltage was approximately 0.8 V at the start of the electrolysis, although it increased periodically to approximately 2.0 V and then shortly returned to its initial value. Nickel, lead, and arsenic from the anode dissolved in the electrolyte and were removed. Antimony, bismuth, selenium, and silver were removed as solids. Consequently, a dense copper cathode was obtained, and the concentration of copper was evaluated by inductively coupled plasma – optical emission spectrometry to be 99.82–99.99 wt%. INTRODUCTION Electrorefining of copper is conventionally carried out in a sulfuric acid electrolyte using crude copper assaying at 99.5 wt% Cu as the anode (Biswas & Davenport, 1994). Elements more noble than copper do not react anodically, and consequently, they are distributed in anode slimes. Elements less noble than copper dissolve from the anode. Nickel and arsenic are stabilized as aqueous species. Lead, antimony, and bismuth react with water, sulfuric acid, or arsenic acid to form barely soluble compounds; thus, they are distributed in anode slimes. An emerging issue in the electrolytic refining of copper is an increase of impurities in crude copper used as the anode (Moats et al., 2013). This is due to an increase in the content of impurities in copper concentrates as well as an increase in the types of secondary copper feedstocks (e.g., E-Scraps, automotive shredder residues, and smelting residues) treated in the copper pyrometallurgical process. An extreme case is a copper smelter that does not use copper concentrates as feedstocks. In such a process, copper-bearing feedstocks are smelted in a top submerged lance furnace to prepare low-grade copper alloys assaying at 80– 90 wt% Cu (Sekimoto et al., 2013). Such low-grade copper is not acceptable as an anode in the conventional copper electrolytic refining process because it is easily passivated during electrolysis. Consequently, electrolytic copper is produced by leaching the atomized low-grade copper in a sulfuric acid solution with oxygen, followed by electrowinning. However, electrowinning should be avoided whenever possible because the electrical energy consumed in electrowinning is 5–10 times higher than that consumed in electrorefining. Therefore, the development of technologies for electrorefining of low-grade copper alloys is desirabl.

Jan 1, 2019

By S. Eckert, M. Reuter, D. Obiso, S. Kriebitzsch, M. Akashi

The present paper focuses the application of CFD techniques to investigate the Top-Submerged- Lance (TSL) gas injection in liquid metal. Previous works of the authors have shown that up- and down- scaling procedures based on the modified Froude number have some shortcomings, as this approach does not take into account the interfacial and viscous forces. Indeed, surface tension and dynamic viscosity of the smelting slags (σ = 0.4-0.5 N/m, μ = 0.2 Pa·s) are higher than the operating fluids that have been used in literature (water, paraffin oil) to study TSL injection in down-scaled furnaces. In order to get closer to real systems, the authors study the TSL injection of Argon in a liquid metal. An experimental campaign was carried out in the X-ray lab at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), where the eutectic alloy GaInSn was used as liquid phase. The alloy is liquid at room temperature, and X-Ray imaging is used to picture the multiphase flow in a quasi-2D vessel. The aim of the present work is to demonstrate the applicability of CFD techniques to model multiphase flows involving liquid metals, and validate the model using the data produced at HZDR. The commercial software ANSYS Fluent® was used together with the Volume of Fluid model to directly resolve the gas-liquid interphase. Some features of the flow, such as the void fraction distribution and bubble detachment frequency are tracked with CFD and compared to the experimental data. INTRODUCTION In the last thirty years the TSL smelting technology has increasingly been used for industrial non- ferrous smelting processes and is now one of the significant pyrometallurgical processes. Developed in the early 1970’s at CSIRO, the furnace is nowadays commercialized in different market sectors, including copper and lead smelting, zinc fuming, waste treatment and slag recovery (Floyd, 2005). Despite the wide application of these reactors in the pyrometallurgical market, some aspects of the process are still not fully clarified, since in-situ measurements and optical accesses are prohibitive because of the high temperatures and aggressive conditions. Phenomena such as the bubbling regime, the slag solidification and the submerged combustion still need a deeper scientific investigation to obtain a better understanding of the process.

Jan 1, 2019

By E. N. Durussel

"The Fox Mine has been producing copper/ zinc ore since 1970 at a rate of approximately one million tons per year, and until 1978all production was derived from longhole open stopes. In June 1978, a trial stope using bighole mining methods was started to eliminate the development of two sublevels between 400 level and surface. The trial proved to be successful, and bighole mining is now an accepted mining method for both stopes and pillars at Fox Mine.When production blasting was started in the first stope, the biggest problem encountered was the production of large amounts of sulphur dioxide gas as a result of secondary sulphide dust explosions. This gas generation resulted in lost production time and caused minor damage to underground installations to the blast level, and to the headframe. Sulphur dioxide generation has been noted in secondary drawpoint blasts and, on rare occasions, in drift rounds.This paper discusses the occurrence of the sulphur blasts and the practices and precautions used to prevent their reoccurrence at Fox Mine.IntroductionThe Fox minesite is located 30 miles southwest of Lynn Lake, Manitoba. With production startup in 1970, Fox Mine is owned and operated by Sherritt Gordon Mines Limited.The Fox orebody occurs as a large lenticular zone of semi-massive sulphides approximately 1,500 feet long and 15 to 100 feet wide running east and west. Dipping 70 degrees to the north, the orebody tends to bottom out at the 3200-foot level and reaches to within 15 feet of surface."

Jan 1, 1981

By Jiahao Xu, Namsoo P. Kim, Guikuan Yue

Iron (ferrous ions and ferric ions) plays an important role in the heap leaching of copper sulfide minerals and copper electrowinning. In our previous study, a novel oxidation-reduction potential (ORP) equation only based on the variables of temperature and nominal ferric/ferrous ratio was developed to predict the redox potential of the quaternary H2SO4-Fe2(SO4)3-FeSO4-H2O system, and its applicability was also extended to more complex acidic iron sulfate solutions, especially those generated during the acidic leaching and bioleaching of Printed Circuit Boards (PCBs) to recover copper. In this work, the broader range of applicability of this equation to other complicated acidic iron solutions containing copper ions has been extended and determined. Specifically, synthetic iron-containing solutions with copper ions according to the conditions of industrial electrolyte during copper electrowinning and heap leaching have been used to measure the ORP and test the developed equation. It seems that this equation can still be employed to predict the redox potential of the Fe3+/Fe2+ couple for the simulated solutions under conditions related to copper electrowinning and pregnant leaching solution generated during heap leaching over a wide range of solution concentration, nominal Fe3+/Fe2+ ratio and temperature. It has shown that the prediction and measurement of redox potential is highly useful to estimate and understand the iron chemistry of industrial leaching and electrowinning processes. INTRODUCTION It is well-known that iron (ferric or ferrous) ions are widely involved in the hydrometallurgical production of non-ferrous metals such as Cu, Au and Zn, mainly in the form of acidic iron sulfate solutions. As far as Cu is concerned, in a typical leaching-solvent extraction-electrowinning process, ferric ion plays a central role in the heap leaching process and is reduced to ferrous ions in the pregnant leaching solution. Ferric ion is the most important surrogate oxidant and the dissolved ferric/ferrous couple plays an important catalytic role in accelerating the leaching rate with oxygen as an oxidant (Peters et al., 1986; Schlesinger, King, Sole, & Davenport, 2011). In addition, during the traditional electro-winning process, oxygen is evolved at the anode, and copper is reduced at the cathode. A common idea is that iron in the electrolyte in copper electrowinning cell (with total iron of 1–4.4 g/L) plays an important role in reducing the current efficiency. According to the published results (Winand et al., 1975; Dew et al., 1985; Moats et al., 2009; Khouraibchia et al., 2010), thecurrent efficiency decreases linearly with increasing ferric ion concentration and the energy consumption increase was mainly caused by the decrease in current efficiency.

Jan 1, 2019

By William Petruk

Mineralogical investigations in connection with gold metallurgy are usually performed to find the reason for poor recoveries by cyanidation or by other leaching techniques. Poor recoveries most commonly are obtained when (I) native gold is encapsulated in an insoluble mineral as "invisible gold"; (2) native gold is coated with a precipitate; (3) gold-bearing products are insoluble in cyanide solutions; (4) carbonaceous material in the ore adsorbs gold; and (5) associated minerals decompose and consume cyanide. Samples of refractory material quite often have low gold tenors. It is difficult to find the gold-bearing minerals in such samples with an optical microscope because the probability of finding trace minerals in samples is small. The probability decreases with decreasing grain size of the gold-bearing mineral and with decreas¬ing gold tenor of the sample. Techniques have been developed to increase the success rate of finding gold grains; some are (1) concentrating heavy minerals; (2) preparing special polished sections; (3) searching with an image analyzer; and (4) dissolving associate silicate and sulphide minerals.

Jan 1, 1989

By A. W. Johnston, R. E. Barrett

"The Central Patricia mine is in the greenstone belt north of lake Sc. Joseph in northwestern Ontario. It is 90 miles north of Allanwater on the Canadian National railway and 220 miles east of the Manitoba boundary. The unusual feature of the ore of this mine is that the gold does not occur in quartz but in sulphide minerals filling fractures in iron formation.AREAL GEOLOGYThe rocks of the area in which the mine occurs belong to the Early Precambrian. They consist · of andesite lavas and tuff interbedded with greywacke-like sediments and iron formation . A siliceous phase of the sediments lying north and south of the greywacke enclosing the ore-bearing iron formation in places resembles a sheared and sericitized quartz porphyry. This is shown in the legend of Fig. 1 as quartz porphyry and quartzite, but it is possible that the quartz porphyry-like phase is sediment. A northwest- striking dyke of diabase crosses the property 3,000 feet east of the shaft ( Fig. 1).IRON FORMATIONAlthough there are numerous bands of iron formation in the v1cm1ty of the mine, ore has been found to date in only one main and two lesser zones. The iron formation bands range in width from a few inches to 60 feet, and are interrupted along their strike by gaps that are parallel and rake to the east at about 65°. The iron formation is definitely banded and laminated."

Jan 1, 1954

By Tom Setterfield

Monster Copper Resources ?Junior focused solely on IOCG deposits ?Founded by ex-WMC geoscientists ?Properties in Brazil, Wernecke Breccias (Yukon), Central Mineral Belt and Nova Scotia Nova Scotia ?JV with Wallbridge Mining Company ?Ongoing Story ?Presented as a case study in generation and implementation of IOCG exploration program

Apr 1, 2005

CFD (Computational Fluid Dynamic) models have been developed and validated for a pulsed column with disk-doughnut internals, as used for solvent extraction. First a single phase model was developed to simulate the turbulent oscillating flow around the internals of the column. This model was successfully validated using detailed PIV measurements of velocity taken at eight different phases through the pulse cycle. Second, the CFD model was extended to allow for a continuous aqueous phase and a dispersed organic phase (kerosene) flowing counter-currently. The model was a two-fluid model that accounts for droplet breakup and coalescence, and solves for droplet size distribution using a population balance model incorporated into the CFX4 package. PDIA (Particle Droplet Image Analysis) measurements were taken on a pilot scale solvent extraction pulsed column to determine droplet size distribution for calibration and validation of the CFD model. The measurements were made under pulsing intensities ranging from 10 mm/s to 32.5 mm/s.

Jan 1, 2007

By Brian Putland, Fred Kock, Leigh Siddall

Single stage semi-autogenous / autogenous (S/AG) milling has become a common design for a variety of ore types with the advantages of being comparatively low capital cost and flexible for future expansion. The single stage SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to ensure a robust circuit and the operating techniques adopted at successful installations.

Jan 1, 2012

By J. Paraszczak

Application of teleoperated and automated (or ?autonomous?) mobile equipment in underground metal mines represents a promising avenue for overcoming some of the challenges facing the industry. This paper addresses the overall effectiveness of autonomous loading and haulage equipment compared with conventional human-operated machines. Factors affecting availability, utilization, and production rate are explored, and an emphasis is placed on some problems and risks not present in conventional human-operated systems, as well as on the character and criticality of autonomous equipment. The need for a more in-depth analysis of factors affecting overall autonomous equipment effectiveness is stressed; these factors should be taken into consideration at the stage of feasibility studies. The paper concludes with recommendations and directions for future research.

Aug 1, 2010

By J. W. Matousek

"Computer modeling of smelting processes requires internally consistent equations for calculating the compositions of mattes and slags. That is, the sum of the calculated assays must total 100%. One set of equations that satisfies this requirement for copper produced under oxidizing conditions (pSO2>one atmosphere pressure) is given by the following:%[Fe] = 62.0 – 0.775%[Cu]%[S] = 28.0 – 0.00125%[Cu]2%[O] = 10.0 – 0.225%[Cu] + 0.00125 %[Cu]2Mattes containing nickel in appreciable quantities do not have the defined “white metal” end point of approximately 80 percent copper and 20 percent sulphur that is found in the copper system during the converting process. The above equations, however, are readily extended to nickel and nickel/copper mattes for any desired end product composition."

Jan 1, 1996

By J. Paraszczak

ABSTRACT: Application of teleoperated and automated (or “autonomous”) mobile equipment in under-ground metal mines represents a promising avenue for overcoming some of the challenges facing the industry. This paper addresses the overall effectiveness of autonomous loading and haulage equipment compared with conventional human-operated machines. Factors affecting availability, utilization, and production rate are explored, and an emphasis is placed on some problems and risks not present in conventional human-operated systems, as well as on the character and criticality of autonomous equipment. The need for a more in-depth analysis of factors affecting overall autonomous equipment effectiveness is stressed; these factors should be taken into consideration at the stage of feasibility studies. The paper concludes with recommendations and directions for future research.

Jan 1, 2010

By Daniel B. Leznoff

The cyanoaurate anions [Au(CN)2]- and [Au(CN)4]- are shown to be useful building blocks for synthesizing supramolecular coordination polymers. For the gold(I) unit, aurophilic interactions often increase the structural dimensionality of the system and can impart increased thermal stability to the metal-polymers produced. A series of polymers of the form M[Au(CN)2]2(Ligand)x have also been prepared and show large colour changes upon changing the ligand, thus illustrating a sensor-type application. Both building blocks can mediate significant antiferromagnetic and ferromagnetic interactions between transition-metal centres in the polymers. For the gold(III) unit, no metal-metal interactions are observed, although weak Au-N(cyano) interactions control the intermolecular packing. Several structural examples of cyanoaurate-based coordination polymers are presented, including 2-D and 3-D arrays and a supramolecular square.

Oct 1, 2003

By Bob Butler

Brunswick Mine has been involved in a comprehensive research program investigating site specific aspects of thiosalt management to eliminate its adverse environmental effects. Minimum annual reagent cost estimates for thiosalt treatment using hydrogen peroxide and sodium hypochlorite are $400K and $1.5 million respectively. Also, minimum costs for the use of bicarbonate to buffer the pH depression associated with thiosalt oxidation in the receiving environment is in the order of $400K annually. A design of experiment (DOE) research program identified that natural UV radiation, temperature, DO and water chemistry are key factors influencing the natural oxidation rate of thiosalts within Brunswick?s water management system. A DOE surface response model was used to describe the thiosalt oxidation kinetics, which were then used to develop a predictive oxidation model for thiosalt and pH control of the mill?s reclaim water system.

Nov 1, 2002

By Cheryl L. Allen

The increasing energy costs associated with mining has become an issue that needs to be addressed for future sustainable production. Vale Inco is undertaking a Ventilation on Demand (VOD) Project in an effort to minimize costs, continue to mine at depth and reduce green house gas emissions. A dynamic VOD system is very complex with potential high risk. Therefore, a systematic approach is being taken for successful development and implementation of the concept. The physical components of the system are currently being tested at various Vale Inco mine sites. While the operability of the physical components are being tested, the strategy for optimizing the architectures of the system is being defined. This presentation discusses the method of developing a VOD system at Vale Inco.

Feb 1, 2008

By M. Honarmand, Z. Moezifar, H. Ranjbar

Abstract - The Sar Cheshmeh area covers an area of 640 km2, and is located in the southern part of the Iranian Volcanic-Sedimentary Belt. ETM+ images have been used for alteration mapping. The Crosta method was found useful for enhancing exposed areas containing hydroxyl and iron oxide minerals. However, field checking has shown that this method is not able to identify all the known areas of hydrothermal alteration. Many of these altered areas are also not clearly resolved in the geophysical data. In order to improve resolution of such areas, integration of remote sensing and geophysical data may be helpful. The Darrehzar Cu deposit was chosen as a control area. The data have been divided into two sets: explanatory and target variables. The explanatory data are Landsat hydroxyl and iron oxide images and airborne geophysical data (K, U, and Th total counts, and total magnetics). The target variables are rock geochemistry and ground geophysics. Data analysis and integration of geophysical and remote sensing data were performed using directed principal components. This technique is found to be useful for the delineation of hydrothermally altered areas with more confidence.

Jan 1, 2002

By Michel Ruel, Ali Soltanzadeh

This paper describes how to make advanced control choices when difficult processes need improvement. The decision-making process involves choosing between a rules-based approach and a model-based approach as well as weighing benefits and drawbacks, complexity and simplicity, investment and results. This paper will present briefly each solution: basic control, advanced regulatory control, model predictive control and expert systems such as fuzzy logic controllers and neural networks. Three examples are presented: ARC (Advanced Regulatory Control) on pH in a comminution circuit, MPC (Model Predictive Control) for combustible management and FLC (Fuzzy Logic Control) on a Semi Autogenous Mill. The article then proposes a decision tree for selecting the most appropriate approach. A table will compare usage, development, commissioning, maintenance and lifecycle costs for each approach. Finally, conclusions and suggestions will summarize the methodology.

Jan 1, 2014