Search Documents

By Tom Shumka

Introduction ?This technique detects 100% of all gear tooth surface indications, providing comprehensive data, and has the ability to size indications accurately. ?The remarkable advantages of ECA technology, is improved inspection capabilities and significant time-savings. ?The advantage of using EMCD is its ability to size indications accurately. ?This technique does not require the gear teeth to be wiped down by hand after cleaning as in MT, LT or UT inspections. (Figure 1) ?This technique will inspect one gear tooth in 30 seconds. ?All of the data can be archived for future comparisons in an electronic report. Methodology ?This technique utilizes Eddy Current Array (ECA) as the principle inspection technique. ?What has been added are specialty scanner probes with multiple coils, a multiplexer and a software package. ?With 2 and 3D dimensional isometric displays, the defect can be seen electronically as it is on the gear tooth surface, thus, reducing the reliance on human interpretation.

May 1, 2011

By Jeffrey S. Loen

"The size, morphology, surface texture, per cent mineral inclusions, and bulk chemistry (Ag and trace elements) of placer gold particles vary systematically according to transport distance from source rocks, as indicated by a case study from the Pioneer district in Montana, and data from the literature.Placer gold samples show a rapid decrease in mean and maximum particle length, and a gradual increase in flatness index (F.I. = length + breadth/2 x thickness) from about F.I. = 2 in bedrock deposits, to as much as F.I. = 45 over transport distances of several tens of kilometers. Primary mineral inclusions (mainly quartz, sulfide minerals, and iron oxides) are mostly lost within 10 km to 20 km of fluvial transport; this loss of quartz and trace metals causes a major change in bulk chemistry of placer gold samples. Following the loss of inclusions and the development of flakes, edges of flakes are folded and the mean number of folded edges in a sample increases with distance. When viewed under the electron microscope, surface textures of placer gold particles also become progressively more pitted with distance.Analysis of placer gold particles can be used to help evaluate placer source-area problems (placers with no known hard-rock gold deposits). For example, coarse placer gold containing abundant inclusions indicates a proximal source. On the other hand, an abundance of thin flakes is evidence of a long transport distance and possible reworking from older gravels. Placer gold characteristics can therefore provide information on distance to mineralized source rocks."

Jan 1, 1995

By Gary Pattrick

A new class of spongy Au catalysts is studied for the selective catalytic reduction of NOx by propene under leanburn conditions. The spongy catalyst is an unsupported powdered Au that consists of micrometer particles (~5 microns) that have nanometer scale (~10 nm) internal skeletal structures. The effects of alloying 1 ? 50 atom % platinum group metals (M= Pt, Pd, Rh) and 5 wt% first row transition metals (M = Ti, Mn, Fe, Co) were studied. Even low additions of PGMs (1 at.%) cause significant shifts to lower temperature regions of activity and the largest shift is obtained for Rh. For Rh this is interpreted as a strong synergistic interaction between Rh and Au. Possibly related to the Rh effect, Co is the only other metal studied that lowers the temperature of NOx reduction. The other first row transition metals inhibit the reduction reaction.

Oct 1, 2003

By T. G. Joseph

The chicken and egg scenario where adverse truck motions cause ground deterioration and poor ground profiles that in turn cause adverse truck motions is a downward deterioration spiral that dominates in our industry. If we can remove one action, the reaction must stop and vice-versa. A simple 'truck to excavator' load data analysis and wireless communication system is outlined in this paper; that will provide visual assistance to the excavator operator in achieving improved load placement and balance in a truck body. In turn this will reduce the subsequent hauler duty cycle adverse motions and g levels that contribute to structural fatigue, higher tkph, reduced tire life and ongoing maintenance of haul roads

Nov 1, 2011

By D. Neely, D. Milne, L. R. Feldman

"Resin-anchored rebar is commonly used for rock support in mining. The rock properties and environment determine the average bond strength, allowing mine engineers to select the appropriate length and installation pattern for the support. In weak material such as potash, the average bond strength tends to be lower than for a typical hard-rock installation. Determining the failure mechanism by which the support fails in soft-rock applications could lead to improved bond strength and better calculated installed support capacity. This paper reports on research conducted at a potash mine in Saskatchewan and analyzes the failure mechanism of the support.RÉSUMÉ Dans les mines, les barres d’armature enduites de résine sont fréquemment utilisées pour soutenir le roc. L’environnement et les propriétés du roc déterminent la résistance moyenne d’adhésion, permettant ainsi aux ingénieurs miniers de choisir la longueur de barre appropriée et le diagramme d’installation du soutien. Dans des matériaux faibles, tels que la potasse, la résistance moyenne d’adhésion tend à être plus faible que pour une installation typique dans de la roche dure. La détermination du mécanisme de rupture selon lequel le soutien fait défaillance dans des roches tendres pourrait conduire à une meilleure force d’adhésion et à un meilleur calcul du soutien installé. Le présent article fait état de la recherche effectuée dans une mine de potasse en Saskatchewan et analyse le mécanisme de défaillance du soutien. ,"

Jan 1, 2016

By S. Banisi, J. Marois, A. R. Laplante

"This paper compares the behaviour of gold and ore in the grinding circuit of Hemlo Mines Ltd. Particular attention is given to grinding kinetics, classification behaviour, and liberation. For grinding kinetics, laboratory grinding of gold flakes and silica, 840 µm to 1200 µm in size (14/20 mesh), was also performed to provide a standard for comparison and to study in a controlled environment the mechanisms of breakage, folding , smearing and impacting.Grinding kinetics were characterized at laboratory scale with breakage and selection functions. The breakage function showed that 75% of gold disappearing from the 840 µm to 1200 µm class reported to the 600 µm to 840 µm; this figure is much higher than for silica (46%) or most other minerals, and implies that comparatively fewer fine fragments are produced from the breakage of gold flakes, on account of gold's malleability. The selection function of silica was four times that of gold. At plant scale, the ratio of the selection function of ore and gold increased from 6 for at 50 urn to JOO pm to 20 at 500 um to 1000µm.Observation of original flakes and their fragments with the scanning electron microscope showed that the main mechanism of ""grinding"" from the 840 µm to 1200 µm to the 600 µm to 840 µm class was folding rather than actual breakage. This was confirmed by a measure of individual flake weight. The postulated breakage cycle is that relatively globular flakes become increasingly serrated through grinding; they can then regain their original shape through folding and reflattening into cylindrical and spherical shapes, as the majority does; however, some fragments will at this point undergo actual breakage. Photograhic evidence is presented to support the proposed mechanisms.Smearing of gold unto silica was observed when silica was ground after a gold, and embedding of silica into gold flakes when gold was ground after a silica. Both mechanisms occur whenever gold and harder minerals are jointly ground, and result in ""unliberation"" of gold. It is postulated that smearing of gold onto other minerals plays an important role in explaining how gravity recovery can increase over-all gold metallurgy, especially when used ahead of flotation.Classification of gold in the primary hydro cyclones takes place at a much finer cut-size than ore, 20 µm vs 57 µm. This and the slower grinding kinetics result in high gold circulating loads in the primary loop, 6700%, and a gold content in the primary cyclone underflow (PCUF) is twenty-four times that of the ore. The gold size distribution for primary cyclone overflow is much finer than that of the ore, although they are essentially similar in the PCUF.Liberation, or more accurately ""gravity recoverability"", was assessed with a 7.5 cm (3 in.) Knelson concentrator. It varied between the thirties for the primary mill discharge and two cyclone overflows, to highs of 89% and 92% for the PCUF and secondary mill discharge."

Jan 1, 1991

By S. Koppalkar

ABSTRACT: The development and evolution of the gravity recoverable gold (GRG) test procedure at McGill University is reviewed in this paper. Since the late 1980s, the research group led by the late Professor André Robert Laplante at McGill University has undertaken fundamental studies and applied research of the Knelson concentrator to develop a sustainable method of estimating GRG. Historically, a concept of “free gold” was used, and it was de?ned as the gold that could be separated and recovered from gold ore by amalgamation. Due to health and safety hazards, the practical use of amalgamation has declined. Around 1994, a methodology using a 3-in Knelson concentrator to measure gravity recoverable gold was established at McGill University. As a result of more than 10 years of improvement and optimization, this technique has become a standard method of evaluating GRG for gold ores, gold plant streams and platinum group metals. By 2006, about 200 GRG tests were carried out at McGill University on ores from all over the world. Recently, a modi?ed version of the GRG test (a simpli?ed test) was developed to provide a quick and rough estimate of the GRG in a sample; this simpli?ed test has the advantage of reduced mass, processing time and cost. To recognize and honour the contributions made by the late Professor Laplante towards the establishment of a standard test procedure for assessing gravity recovery potential, the authors propose that the GRG test be named after Laplante.

Jan 1, 2010

By C. J. Newman, D. J. Kemp, R. M. Sweetin

"The smelter is described by area; feed preparation, continuous furnace line, gas handling and auxiliary systems, blister refining, Hazelett casting of thin anodes, and scrap remelting. Early smelter campaign data is presented and compared to design. Some modifications to the basic design of the furnaces and gas trains are indicated, with their respective impacts on improving smelter performance.Plant compactness, the use of jumbo tanks, and a highly automated electrode handling system are featured in the refinery description, with brief coverage of the liberator and slimes leaching sections. Early experience in refining thin regular Hazelett anodes, and submersible pump recovery of raw slimes are relayed, together with automatic stripping from titanium blanks.Refinery tonnages and operating parameters are given showing the relatively trouble-free attainment of refinery design performance.IntroductionPrevious papers and articles ( 1), (2) ,(3 ) have described the metallurgical facilities serving the copper-zinc-silver Kidd Creek orebody located near Timmins, Ontario. For convenience a brief review of their mid-1983 operating status is presented.The concentrator, originally designed for 9,000 short tons, was commissioned in late 1966. It can now comfortably process over 13,000 metric tonnes per day largely as a result of the addition of a fourth circuit in 1978."

Jan 1, 1984

By J. B. Watts

"THE Mine Engineering Department at Gaspe Copper is staffed by a chief engineer, assist-ant engineer, research engineer, chief surveyor, four instrument men, chief bonus clerk, draftsman, and a helper pool of four permanent men plus one or two students in the summer. The men are grouped according to function for organization purposes. Routine services provided by the Mine Engineering Department in-elude ail surface and underground surveying and mapping, preparation of working drawings, compilation of engineering reports, recommendations on ventilation, testing the mine air for carbon monoxide, research on mine equipment and its use, and the calculation of incentive bonus. Demand jobs from departments other than the Mine Department .are done on request. Such jobs may be in the plantsite, the Town of Murdochville, or at the shipping points at Gaspe harbour or the St. Lawrence river."

Jan 1, 1959

By Eugene F. Mehr, Dennis C. Martin

"Development of the final slope for the 340 m (1200 ft) high hanging wall at Cassiar Mine precipitated an area of deep seated instability involving an estimated 17.6 million tonnes. The deformation mechanisms involved squeezing of soft deformable serpentinite rocks in the toe which caused planar sliding and graben toppling of the stronger sedimentary rocks in the middle and upper sections of the slope. Although movement rates up to 150mm/day were recorded, by understanding the controls on failure, the mine was able to install a suitable monitoring system and complete the open pit with only minor loss of the mineable ore. Accelerated mining was required in the last full year of operation. This paper describes the deformation behaviour, failure mechanisms and back analysis results for the failure. The monitoring systems and operational aspects related to the failure are also presented.IntroductionCassiar Mine is located in steep mountainous terrain in northern British Columbia approximately 1200 km north of Vancouver (Fig. I). During the final mining phase of the open pit, instability developed in the approximately 340 m high hanging wall (east wall) slope. A unique graben toppling mechanism was identified based on detailed assessment of slope monitoring data and visual observations. Comprehensive slope monitoring enabled mining to continue even though movement rates as high as 150 mm/day were being recorded. Three-dimensional limit equilibrium back analyses and numerical modelling have been used to assess the various controls on the slope movements and to understand the failure mechanism."

Jan 1, 1993

By J. Contreras

In the period 2003-2004, the situation of the copper concentrate market was unfavourable for smelters and refineries, with low TC/RC values and euro-dollar parity affecting European companies negatively. Within this scenario, Atlantic Copper decided to develop a plan to increase its competitiveness and to improve its results in these market circumstances. The plan affected all departments in the Company and was based mainly on cost reduction in energy and manpower. A general analysis of the Complex's overall efficiency was carried out and, based on this analysis, two major Projects emerged, "Primavera" and "KF". Each Project consisted of smaller sub-projects which aimed at improving the areas which could perform better according to our general analysis. The paper describes how this entire project developed and the final results obtained by the Company.

Jan 1, 2007

By R. F. Tylecote

"The closure of the iron and steel making plant at Consett in Durham in 1980 marked the end of an era-a long era in the world's iron and steel making history. Iron had been smelted in the Tyne-Wear area of the United Kingdom since before the Roman period, but apart from evidence of smithing in the Roman period, the historical evidence for iron production on a large scale dates from the 14th century.The paper describes sites in the area that first worked the bloomery process and then, in the 16th century, as did most of Europe, graduated to the blast furnace process. The main emphasis is on the early introduction of coal to iron making at the end of the 18th century and the use of the steam engine to render integrated sites possible.IntroductionIron has been smelted in the Tyne-Wear area of the United Kingdom since before the Roman period, but apart from clear evidence of smithing in the Roman period, the historical evidence for iron production on a large scale dates from the 14th century. Like many other countries, the United Kingdom benefitted from the visits of foreign observers, such as Jars, Svedenstierna, de la Houliere and Dufrenoy, who left detailed records. In modern times, information gained from excavations of iron and steel making sites has supplemented the historical record.Natural ResourcesUp to the end of the 19th century, the industry was wholly dependent on its own resources. Iron ore, limestone, wood, coal and water power were all found a short distance away from the main valleys of the Tyne and Wear. The main sources of iron ore were the coal measures, with rider ores from the lead vein s in Alston and Weardale, and carbonate ores from shale horizons in the Carboniferous limestone. Good coking coal was available from West Durham and reasonable coal from the Tyne valley and Northumberland limestone. Limestone was plentiful."

Jan 1, 1983

By J. Elderton

"The combination of A C induction motor and flu id coupling, of either the fixed or variable filling type, constitutes a simple, low cost, highly reliable drive unit, with many applications in the mining field.The paper will, however, concentrate on the variable filling fluid coupling in three principal applications-conveyor starting, infinitely variable speed control for slurry and slimes pumping and dewatering pumps for deep mines. Fluid couplings can be used with standard or custom-built control gear equipment, ranging from the most simple, time-based open loop types, to those having the latest microprocessor techniques.IntroductionThe first industrial applications of fluid couplings included their use in the mining field as hydraulic slip regulators for flywheel generating sets. These installations, usually rated at around 1700 to 2500 hp, were located at mine shafts where the electrical grid transmission lines were not strong enough to cater for the peak power demands of the cage winding cycle. In Canada, the first two significant examples of variable filling fluid couplings for mining were on conveyor drives, at Steep Rock Mines Limited, closely followed by the major iron ore handling term inal on the St. Lawrence River at Sept-Iles. Successful and reliable operat ion of the fluid couplings at these two sites set the pattern for use on many subsequent mining projects throughout the Canadian Continent."

Jan 1, 1986

By M. B. Kime

"A set of experimental batch leaching tests studied the effect of pH, time, temperature, and stirring speed on the relative Cu, Co, Ni, and Fe leaching yields of an oxidized copper-cobalt ore sample in an aqueous hydrochloric acid solution. The results were statistically analyzed and modelled using the structural equation modelling method. Models showed that Cu, Co, and Ni leaching yields were strong functions of the leaching time and leaching temperature, whereas the Fe leaching yield depended on the leaching temperature, stirring speed, and pH. Under optimum leaching conditions yields were 99.8% Cu, 82.4% Co, 91.3% Ni, and 30.6% Fe.RÉSUMÉ Une série d’essais expérimentaux de lixiviation en bâchée ont été menés pour étudier l’effet du pH, de la durée d’attaque, de la température et de la vitesse de brassage sur les rendements relatifs de lixiviation du cuivre (Cu), du cobalt (Co), du nickel (Ni) et du fer (Fe) d’un échantillon de minerai de cuivre-cobalt oxydé dans une solution aqueuse d’acide chlorhydrique. Les résultats ont été analysés et modélisés statistiquement à l’aide de la méthode de modélisation par équation structurelle (SEM, de l’anglais structural equation modelling). Les modèles ont montré que les rendements de lixiviation du Cu, du Co et du Ni dépendaient énormément de la durée d’attaque et de la température de la lixiviation ; le rendement de lixiviation du Fe, quant à lui, dépendait de la température de la lixiviation, de la vitesse de brassage et du pH. Dans des conditions optimales de lixiviation, les rendements étaient de 99,8 % pour le Cu, de 82,4 % pour le Co, de 91,3 % pour le Ni et de 30,6 % pour le Fe."

Jan 1, 2017

By Himmelman. Nicholas P.

In this paper, the hardware foundations and data collection methods of a real time collision avoidance system for electric surface mining rope shovels are described. The primary goal of the system is to help a shovel operator avoid accidentally colliding the shovel?s dipper with either a nearby haul truck or the shovel?s tracks. To achieve this goal, the system requires complete and precise knowledge of the shovel?s geometry and movement, as well as the location of any nearby haul trucks. This paper describes the subsystems created to acquire this necessary information. This system is unique in that all of its components are mounted solely on the shovel and that it is designed to be easily retrofitted to a shovel without significant modifications.

Oct 1, 2009

By Teresa Sikora

For over 40 years the Institute of Innovative Technology EMAG has specialized in the development of systems and equipment for laboratory and on-line monitoring of coal quality parameters, as well as the implementation of these systems and devices in mines and power stations. Some of these systems, based on advanced radiation detection techniques such as ?-ray backscattering (ALFA-06 and ALFA -06/T systems) or dual energy ?-ray transmission measurement (ALFA-06/2E ash meter), and also the ALFA-06/3E system applying microwave technology for the measurement of moisture, have had numerous applications in Poland. At present, over 100 systems and devices are used in Polish hard and brown coal mines. For over 10 years, EMAG has been specializing in the development of systems and devices, based on natural gamma measurement technology. An on-line ash meter, RODOS and RODOS Ex, based on measurement of natural gamma radioactivity of coal, has been developed and put into operation. This technique has been also used in developing the portable ash meter WALKER and laboratory analyzer GAMMA NATURA. The paper briefly presents features of the above-mentioned devices, their limits and their obtained accuracy, but in particular refers to the laboratory analyzer, GAMMA NATURA, as the first such device in the world, and presents the results of ash and moisture content measurement in hard, brown coals and potassium salts. The possible applications and advantages of the device in coal mines are discussed. The paper also presents the implementation results of the portable ash meter, WALKER, and the on-line ash meter, RODOS, that is used underground in coal mines.

Aug 1, 2013

By Michel Ruel

Most plants do not track how their systems perform. Optimization is the easiest way to benefit from your control systems. We suggest an approach in four phases. The first phase is to assess all equipment to determine the performances for instruments, valves, variable speed drives, and other equipment. The second phase is to remediate instrumentation problems, including the ones pertaining to valves, variable speed drives, analyzers, transmitters. When equipment is in order, loops are put back in automatic mode. If a loop oscillates, use standard default values for this type of loop. The third phase consists in validating the control strategies, properly configuring the systems (control system, programs and parameters, HMI, alarms), and then tuning the loops and control strategies. The fourth phase consists in analyzing the process and expected performances in order to optimize the control loops and control strategies. If performance is not sufficient, a decision tree will be presented to determine the right approach: advanced regulatory control, model predictive control, or fuzzy logic control. Once all steps have been completed, control performance monitoring software is used to sustain the results and pinpoint equipment or loops not performing as stated. Alarm management and rationalization could also be performed after auditing the alarm system, if needed. Examples from plants will be used to demonstrate how this step-by-step method is applied and produces results. INTRODUCTION Maximizing what you already have is the best investment to remain competitive. This article aims to show the benefits of a systematic approach using modern tools to improve plant performance. We at BBA suggest dividing the work in four phases, and a subsequent phase can begin when the previous one has progressed: Assess, Remediate, Stabilize, Optimize, or add advanced control. This approach has been successfully applied to several sites. Examples and illustrations from these plants demonstrate how this step-by-step method is applied and produces results. Under the BBA method, there are four questions to answer before proceeding to the next step. For each control strategy, you should ask the following questions: Assessment: Does it work? Remediation: Do you use it? Stabilization: Is it stable? Optimization: Does it perform? Do you need advanced control?

Jan 1, 2019

By R. A. Parra, Fuentes, C. Godoy, L. E. Arias, C. A. Toro, M. Marin, E. Balladares, V. Parra, G. Reyes, S. N. Torres, D. Sbarbaro

In this paper, we report on the detection of spectral molecular emission of iron oxide (FeO) and copper oxide (CuxO) emitted by reactions occurring in a laboratory scale flash smelting process of pyrite (FeS2) as well as copper concentrate. The novelty of the technique is that, the molecular spectral emission sensing is achieved by using a low spectral resolution and low sensitive radiometer, enhanced with signal processing and matrix factorization techniques. The method was validated using a highly sensitive spectrometer, with a high spectral resolution; achieving a similar FeO spectral pattern as the one obtained after signal processing techniques over low resolution spectral signals. INTRODUCTION Visible-near infrared (VIS-NIR) spectroscopy is an optical contactless sensing technique commonly used to capture information about the emitted, absorbed, transmitted or scattered radiation in a physical or chemical process, with the presence or absence of an excitation light source such as a laser or a broad spectral band source. These techniques coupled with signal processing and machine learning algorithms, sometimes referred as chemometrics (Pisapia et al., 2018), can be found in processes such as: pharmaceutical (Kandpal et al., 2016); food (Coelho et al., 2016); combustion (Ballester & García-Armingol, 2010); siderurgy (Strakowski et al., 2014) industry, among others. In the extractive copper industry there are several technological developments using optical sensing techniques aimed to retrieve information about copper ore and concentrate mineralogical composition such as X-Ray Fluorescence, Qemscan® (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) and X Ray Diffraction (XRD) analysis, however, because of the manual procedures to analyze the samples with these laboratory instrumentation, only discrete information during a daily based operation can be retrieved, making impossible for the operators to take decisions over the involved processes in real time. The aim of our research work presented here is to contribute with sensing and data analysis procedures based on VIS-NIR spectroscopy for the flash smelting process characterization, particularly in this paper, with the detection of FeO and CuxO molecular emissions in a laboratory scale setup.

Jan 1, 2019

By Eric L. Hoffman

Sample preparation technology changes Rock Soil Vegetation Analytical Innovation Assay or Geochem Choice of Digestions Choice of analytical method Whats new in analytical technology? Innovations in surface Geochemical Methods Hydrogeochemistry Biogeochemistry Soil Gas Hydrocarbons (SGH) Selective Extractions Glacial Environment Arid Environment

May 1, 2008

By L. A. Mells

"A laboratory test program was initiated by the Department of Energy, Mines and Resources as part of the National Uranium Tailings Program to investigate the applicability of a radium selective ion exchange complexer for removing radium from Canadian uranium mining effluents. The test program was carried out by Melis Consulting Engineers Ltd. under contract to the Department of Supply and Services using the Saskatchewan Research Council facilities located in Saskatoon, Saskatchewan.The results of this work showed the ion exchange complexer, Dowex XFS 43230.00, to be efficient in removing radium from contaminated water of uranium mining operations with the ultimate loading capacity of the resin on one type of water treated being determined as approximately 1,600 Bq/cm3 of new resin. Although this resin has potential application for treatment of effluent streams in uranium operations it has been identified that the resin efficiency and capacity is directly related to the chemistry of the water being treated and site-specific testwork is required in order to establish reliable design data for full-scale operations.IntroductionThe possible applicability of a radium-selective ion exchange complexer for removing radium from Canadian uranium mining effluents had been identified and discussed as a possible alternative to present radium removal methods during a review of disposal technology options for the National Uranium Tailings Program of the Department of Energy, Mines and Resources(1). Work by other workers(2.3) had shown the complexer to be very efficient in removing radium from contaminated water. Also, plant trials on contaminated minewater at the Mt. Taylor uranium mine in New Mexico is reported to have shown the resin complexer to be efficient under plant operating conditions.As a result, a laboratory test program was initiated by the Department of Energy, Mines and Resources as part of the National Uranium Tailings Program to investigate the suitability of this resin for Canadian uranium mining effluents. The test program was carried out by Melis Consulting Engineers Ltd. (MCEL) under contract to the Department of Supply and Services using the Saskatchewan Research Council (SRC) facilities located in Saskatoon, Saskatchewan."

Jan 1, 1985