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By Pascal Turcotte

_ Introduction _ LaRonde _ Controlling Instability in Haulage Drifts _ Failure mechanism in drifts walls _ Failure mechanism in drifts back _ Field Behaviour of Support Elements _ The ?Hybrid Bolt? _ Conclusions

Feb 1, 2008

By K. J. K. Weglo, M. U. Savich

"At the Falconbridge Limited, Canadian Nickel Division, Sudbury Operations, we investigated the ""NO NOISE"" ear muffs model NN3-F which is a Swedish product with foam-filled sealing rings (the Hellberg Standard Volume Hearing Protector). It is used extensively at Falconbridge mines in Sudbury.The research which was carried out in the four Falconbridge mines was conducted under three different headings: manufacturer's attenuation data (psychophysical method), clamping force and head size (bizygomatic diameter), and attenuation tests (physical methods) under working conditions.Manufacturers of hearing protectors claim their products offer noise reductions of 23 decibels (NRR) or more, but they fail to point out that this reduction is obtainable only under ideal conditions. The reality of attenuation under working conditions, as several studies have found, is quite different.Methods for using short measurements to determine the noise exposure index, and for controlling muff-wearing habits, were developed at the Elliot Lake Laboratory. Measurements taken at Falconbridge on ""NO NOISE"" ear muffs revealed that they have a practical attenuation of some IO to 13 decibels. It is important to note here that measurements also revealed that clamping force (thus attenuation) was in an inverse relationship with ear muff comfort. Measuring attenuation using noise dosimeters was a difficult job. Not a single surveyor would accept these measurements (physical method) for absolute accuracy. Apart from that, it was impossible to measure, in one shift, more than two work stations. Because of this, we sought a solution: measuring head size and clamping force in relation to actual attenuations.A detailed analysis of the relationship between attenuation and head size/clamping force was done at four mines. Standard deviation ellipses (standard error ellipses) for head size versus clamping force are in close agreement with measurements that were carried out. In order to measure clamping force an apparatus was constructed and a method for measuring suspension system durability is described in Appendices Band C of this report. At the same time we sought to reduce deterioration of ear muffs in mines as well as to put in place a system whereby attenuation can be controlled and improved. The clamping force apparatus can be operated automatically. The proposed control system is quick, simple and efficient . This system is equally applicable in small and large mining operations, and it can be totally automated and the data computerized for audit of the results. This control system is a new step in controlling ear muff attenuation in working environments.From these measurements of NN3-F ""NO NOISE"" muffs it can be concluded that ear muffs are not the total solution to protect the worker from noise.As the results were evaluated folio wing measurement, Falconbridge switched from the NN3-F ""NO NOISE"" muffs to approximately 90% Mark V ""NO NOISE"" muffs and 10% Mark V MSA muffs. These new muffs showed much better head size versus clamping force relationship and can be expected to produce 14 dBA or better attenuation of noise. RESUMEUne étude des casques antibruit ""NO NOISE"" modèle NN3-F, de fabrication suédoise, avec anneaux d'étanchéité en mousse (dispositif de protection contre le bruit ""Hellberg "" pour volume ordinaire)a été effectuée Ii la Falconbridge Ltd. , Division canadienne du nickel aux installations de Sudbury . Ces casques sont largement utilisés dans les mines de la Falconbridge Ii Sudbury.Cette étude aeu lieuen milieu de travail dans les quatre mines de la Falconbridge sous trois rubriques différentes soit: les données d'atténuation du bruit du fabricant (méthode psychophysique), la force de serrage et la taille de la tète (diamètre bizygomatique), et les essais d’atténuation de bruit (méthodes physiques). Les fabricants de dispositifs de protection contre le bruit prétendent que leurs produits offrent une réduction du bruit s'élevant Ii"

Jan 1, 1986

By G. F. Vander Voort

Over the past twenty years, steelmakers have introduced improved practices for reducing the inclusion content of steels. The success of these practice changes can be monitored in a variety of ways. Chemical analysis of the bulk sulphur and oxygen contents provides a relatively simple means to assess the impact of these changes. However, microscopical test methods are still needed to assess the nature of the inclusions present. Traditional chartbased measurement methods have wide acceptability, and their data are well understood by both purchaser and producer for heat acceptance purposes. However, these methods do have inherent weaknesses which limit their usefulness for quality control, SPC, and database applications. Image analysis-based chart measurements are an improvement over manually generated chart ratings, but the data still do not lend themselves to databases and statistical comparisons. ASTM Committee E-4 on Metallography has developed a stereologicallybased image analysis standard test method, E 1245, which provides the necessary data in a form which is easily databased and analyzed statistically. This paper describes E 1245 and shows how data from different heats and melting practices can be compared statistically to ascertain valid test differences.

Jan 1, 1998

The Cooperative Research Centre for Mining Technology and Equipment (CMTE) is funded by the Commonwealth Government, by its mining research members Ñ the Universities of Queensland and Sydney and the CSIRO1, and by its industry members Ñ BHP Coal, RioTinto R&TD, Hamersley Iron, Mining Technologies Australia, Pasminco, Shell Coal, WMC Resources, Advanced Mining Technologies, and Aberfoyle. The Centre conducts work aimed at improving the competitiveness of the Australian mining industry. The current work is focused in four areas: new mining and drilling systems, geological sensing, automation, and equipment maintenance and reliability. This paper describes much of the work in these program areas that relates to metalliferous mining.

Jan 1, 2001

By E. Yan, M. Mankosa, E. Wasmund

"Rougher flotation in sulfide ore applications is typically performed using conventional flotation machines. The trend over the last 100 years has been for these cells to become larger in volume with cells reaching sizes of 600 m3 and in some cases even larger. The associated foundation loadings, transport and installation requirements along with building size have also increased. In an economic environment where projects must be executed with dwindling capital supply, bigger is not always better. More recently, industry is being challenged to identify new technology that allows for improved flowsheets and financial returns through efficiency gains. To meet this challenge, a novel high-intensity two-stage flotation system known as the StackCell™ was tested to potentially achieve installation volume and required retention time gains when compared to conventional flotation circuits. The results from on-site pilot scale work conducted on typical copper concentrator rougher flotation feed showed retention time gains on the order of 6 to 9 times when compared with conventional flotation equipment. This finding has the potential of reducing capital demands for rougher flotation circuit designs when incorporating the StackCell. The results from test work will be discussed in this paper showing comparative test data generated with a Denver bench batch test, pilot StackCell and large conventional cells, all receiving the same feed.INTRODUCTION Over the last few years, a number of flotation devices have been described as two-stage or multi-stage flotation units. The idea behind multi-stage flotation devices is that flotation performance can be improved by utilizing cells with multiple specialized units in series, but not all units of the same type, as is practiced in trains of multiple tank cells or columns. Instead, each unit is specially designed to provide the optimized fluid environment for each stage of the sequential flotation process. This idea has been proposed based on a study of the fundamentals of the flotation process, and the realization that the process consists of discrete sequential processes, that are each optimized with dissimilar process conditions (Finch et al, 1995), (Zhou, 1996). Instead of executing each step simultaneously in a homogeneous fluid environment, where the conditions would be a compromise between particle collection and froth recovery, the multi-stage flotation unit operates in a set of segregated process environments, each with a set of conditions optimized for that step."

Jan 1, 2018

By J. E. Dutrizac, J. B. Sunstrum

Until relatively recent times, virtually all gold was recovered by gravity and/ or amalgamation methods. Although such techniques are very effective on coarse gold, they become increasingly less useful for finer grains especially when the gold is partly enclosed in rock matrix. Throughout the nineteenth century a number of bonanza gold fields were found in the United States, South Africa, Australia and Canada. In every case the abundant supply of gold nuggets and coarse alluvial gold soon gave way to hard rock mining with its inevitable losses of fine gold in the stamp mill tailings. Continuing efforts to develop new technologies capable of dissolving gold from finely ground ore were eventually successful first with chlorination (the Plattner process) and subsequently with cyanidation. Even before the nineteenth century, however, European chemists such as Scheele and Berthollet were aware that gold could be readily dissolved in an excess of free cyanide(1). As early as 1840, a patent was issued to the Elkington brothers for the dissolution of pure gold in cyanide solution and its subsequent plating onto various metals, with or without an applied electrical current. In 1846, Elsner showed that oxygen was also required to solubilize gold or silver in cyanide media(1). Despite the fact that much work was done on the reaction of cyanide solutions with gold, a viable leaching process for gold ores did not quickly emerge although cyanide solutions were used to enhance amalgamation from the 1860s onward. Major problems were associated with the use of concentrated cyanide solutions; the costs of cyanide were excessive and it was difficult to recover gold from the concentrated media.

Jan 1, 1999

By S. Jain

Construction industry is considered as labour intensive, having shortage of skilled labour, unsafe with large number of industrial accidents. Construction industry requires high technology automation products (Robots) for improving productivity, safety, quality etc. Robots are developed by various countries in different areas like demolition, earthwork, bridge, tunnels, road work, underwater works, trenches and piping, maintenance etc. however they are still not used to their full potential by construction industry. Hence in this paper, the authors propose a ?model for adoption? of robots in construction industry. This model considers how a construction firm will adopt full scale robots like manually controlled machine, tele-controlled machines, computer controlled machines and cognitive robots and assimilate them through various stages.

Aug 1, 2013

By Lloyd W. Trevoy

Titanium and zirconium heavy minerals occur in the tailings streams from processing plants which use the hot-water extraction process for recovery of bitumen from tar sand. In a research program conducted by Syncrude Canada Limited, the crude tailings stream was upgraded to produce quality zircon and titanium mineral products. To process the tailings through conventional upgrading equipment, bitumen residues must first be removed from the mineral grains. Then, by gravity separation, fines and coarse sand grains were removed and a 71% heavy minerals concentrate was prepared which was further separated by high-tension equipment into zircon and titanium minerals concentrates. The zircon concentrate was upgraded by gravity, magnetic and high-tension cleaning to produce a high-quality 98% zircon product. The titanium minerals concentrate was separated into rutile, leucoxene and ilmenite fractions. Heavy minerals distribution in tar sand drilling core samples has been evaluated for various locations on Syncrude Lease 17, and expected annual production levels of heavy minerals have been estimated. A preliminary evaluation has been made of the potential for zircon, leucoxene and rutile production and for further upgrading of ilmenite and leucoxene to synthetic rutile for titanium dioxide pigment production.

Jan 1, 1978

By M. Rafiee

Indoor physical security, as a perpetual and multi-layered phenomenon, is a timeintensive and labor-consuming task. Various technologies have been leveraged to develop automatic access control, intrusion detection, or video monitoring systems. Video surveillance has been significantly enhanced by the advent of Pan-Tilt-Zoom (PTZ) cameras and advanced video processing, which together enable effective monitoring and recording. The development of ubiquitous object identification and tracking technologies provide the opportunity to accomplish automatic access control and tracking. Intrusion detection has also become possible through deploying networks of motion sensors for alerting about abnormal behaviors. However, each of the above-mentioned technologies has its own limitations. This paper presents a fully automated indoor security solution that leverages an Ultra-wideband (UWB) Real-Time Locating System (RTLS), PTZ surveillance cameras and a Building Information Model (BIM) as three sources of environmental data. Providing authorized persons with UWB tags, unauthorized intruders are distinguished as the mismatch observed between the detected tag owners and the persons detected in the video, and intrusion alert is generated. PTZ cameras allow for wide-area monitoring and motion-based recording. Furthermore, the BIM is used for space modeling and mapping the locations of intruders in the building. Fusing UWB tracking, video and spatial data can automate the entire security procedure from access control to intrusion alerting and behavior monitoring. Other benefits of the proposed method include higher accuracy and robustness, more complex query processing, and interoperability with other BIM-based solutions. A prototype system is implemented that demonstrates the feasibility of the proposed method.

Aug 1, 2013

By W. W. Heywood

"IntroductionCIRCULAR structures on the Arctic islands were first noticed early after World War II. During the indexing of the 1950 Royal Canadian Air Force photographs their occurrence was brought to the attention of the Geological Survey of Canada by Mr. W. B. Waugh, Surveyor General. As a result, I. C. Brown ( 195l) of the Geological Survey of Canada studied the air photographs of these structures and discussed theories that might explain their origin. The author, as a member of the Geological Survey of Canada, spent several months in 1952 and 1953 in reconnaissance study of the geology of Ellef Ringnes island, using the Isachsen meteorological station as a base. Twelve days in the summer of 1953 were spent mapping the Isachsen dome and adjacent areas. The Isachsen dome, one of several similar structures occurring on Ellef Ringnes island, is situated 35 miles southeast of the meteorological station.PhysiographyEllef Ringnes island is a mature, stream dissected plain having an average elevation of about 400 feet. The surface of the plain is undulating with a relief of about 150 feet; only a few of the numerous streams that form a dendritic drainage pattern have eroded valleys this deep. Long, low, cuesta escarpments cross' the plain, which is underlain by sedimentary rocks of Lower Cretaceous and possibly younger age. The sedimentary strata have a low regional dip to the southeast; exceptions are found in the vicinity of the domes, where the strata are up-turned, and in the plateau region, northeast of Deer bay, where they are flat lying. The plateau, which is underlain in large part by basalt, is deeply dissected and has an average elevation of 1,000 feet."

Jan 1, 1955

By J. G. Phillips

Introduction Throughout the Great Plains region (the provinces of Manitoba, Saskatchewan, and Alberta), numerous clay deposits of widely varying composition and character are to be found. These may be classified into two general types: (1) surface clays, and (2) shales. The surface clays consist of a heterogeneous mantle of silts and clays interspersed with grave! and sand deposits, and may belong to any of the following groups: (1) lake clays: (2) river-terrace or flood-plain deposits; (3) delta deposits . In most cases, the water from which these deposits were ' laid down was derived from the melting ice of the continental glaciers. These surface clays, in general, possess certain characteristics in common, being all more or less calcareous, often silty, and showing a tendency to 'check' in air-drying. The shales found in this region are of Cretaceous and Tertiary age. These deposits have a wide extent, but there is frequently such a heavy covering of drift material that the clays are accessible chiefly along the walls of stream valleys, or along the escarpments of uplands.

Jan 1, 1929

By Terry Gerritsen, Sylvain Picard, Bruce MacKay

Virtually all new technologies require a control system. Any intense process has many process variables that react quickly making manual control difficult. Control system design has a significant impact on the success of a plant especially during ramp-up. New technology projects are particularly sensitive to control system design as the process response is unknown. This paper discusses the important factors encountered in the design of a control system for a new technology. Examples are given of successful new technology plant start-ups where tight coordination of the process control system implementation, process design and selection major equipment led to rapid ramp-ups.

Jan 1, 2011

By W. C. Whittaker

Introduction When one thinks of a coal stripping deposit, the picture that usually comes to mind is that of a more or less flat seam from two to twenty feet in thickness overlain by ten to fifty feet of overburden, in suitable ratio for economic operation. This is the usual type of stripping deposit and is quite a common occurrence in various parts of the prairie provinces. Rather unusual types of coal stripping deposits are being presently worked as open-cut mines by Sterling Collieries, Limited, and the Co al Valley Mining Company, Limited, at Miles 47 and 48 on the Alberta Coal Branch, some 150 miles south west of Edmonton. These deposits are of interest chiefly because they represent turned-up and greatly thickened sections of the Mynheer seam, and as such they present their own problems, peculiar to the commercial exploitation of a seam of this type. The area in which these deposits occur was originally owned by the Pacific Pass Collieries, whose operations, however, were confined to under-ground mining at Lovett, some eight miles to the southeast. It was not until l918 that the value of these deposits was realized, when the Company now known as Sterling Collieries, Limited, opened their pit at Mile 47. At the inception of the work, coal was loaded directly into the railway cars by men using wheelbarrows. In 1920, a tipple was built, after which the coal was loaded by steam shovel into mine cars, hauled by steam dinkeys, and loaded over the tipple into railway cars. In 1922, the Coal Valley Mining Company entered the field at Mile 48, with an entirely mechanical equipment, and at the present rime these two are the only stripping properties in Alberta using mechanical equipment both for the removal of overburden and the loading of the coal. These Companies have operated continuously since that time, and have to date mined and shipped 4,000,000 tons of coal, and moved some 5,255,000 cubic yards of stripping. The present annual coal output for the two mines is about 240,000 tons.

Jan 1, 1935

By V. Falmagne

The mining sequence at Noranda?s Bell-Allard mine calls for two mining fronts retreating toward a central pillar known as the Retreat Zone between pyramids A and C. It is clear from numerical modelling and rock mass characterization that the induced stress level in the pillar will exceed the rock mass capacity. A mining plan was developed including the re-dimensioning of stopes in the Retreat Zone, additional ground support and instrumentation in order to ensure the safety of the workforce and to maximize ore recovery while minimizing production delays. The mining strategy consists in allowing the rock mass to fracture and fail progressively while maintaining control of the existing openings with the appropriate support. A systematic analysis of rockbursting and caving hazards was conducted for all accesses and stopes in order to plan ground support and instrumentation needs.

Apr 1, 2004

By N. F. Faria, F. Monteiro, B. O. Taiwo, A. Palangio, D. Fonseca, J. Manuel

This paper explores the interpretation and application of Particle Size Distribution (PSD) curves in optimizing blast design and enhancing downstream operations. The study looks at important factors like D50, D80, fines content, and the uniformity index to show how PSD curves affect the efficiency of different mining processes. The first section of this paper discusses the impact of blast design parameters such as burden, spacing, and explosive energy on the resulting PSD, highlighting their significance for downstream operations like crushing, and material handling. The section concluded that proper alignment of PSD with downstream size classes, like primary crusher inlet sizes, among others, can result in substantial cost reductions and productivity gains. The second part presents a case study from dstgroup aggregate quarry in northern Portugal, utilizing fragmentation analysis to evaluate blast performance and promote continuous improvement. The section specifically examines the effect of stemming material size on blast fragmentation, comparing the impact of using aggregate with a D80 of 12.32 mm versus a D80 of 21.94 mm. The D80 value represents the particle size at which 80% of the stemming material is smaller, making it a critical parameter in evaluating the stemming's effectiveness in confining explosive energy. The drilling and blasting designs were meticulously planned using O-PitDev and O-PitSurface software to ensure accuracy in blast parameters and layout. To assess the fragmentation resulting from these different stemming material sizes, the study utilized WipFrag 4 software. The software allowed for precise measurement of particle size distribution after the blast, as well as a detailed comparison between the two stemming sizes. Results from the analysis indicate that using bigger-sized stemming material led to improved blast confinement, which in turn resulted in better fragmentation compared to the smaller-sized material. The reviewed blast videos demonstrate that the larger aggregate effectively contained the explosive energy within the borehole, thereby reducing premature venting and directing more energy towards breaking the surrounding rock mass. This led to finer fragmentation with D80 = 1240.1 mm, D50 = 685.9, and Dmax = 2580 mm, which is advantageous in downstream operations like crushing and milling. On the other hand, the smaller stemming material (D80 = 21.94 mm) did not confine the explosive energy as efficiently, resulting in coarser fragmentation (D80 = 1327.37 mm, D50 = 750.76, and Dmax = 2370 mm) and reduced overall blast efficiency. These findings highlight the significant influence of stemming material size on blast performance and fragmentation outcomes. 

May 4, 2025

By A. M. Simons

Cyanide destruction by Caro’s acid is one process commonly employed by gold operations to meet regulatory requirements and/or the International Cyanide Management Code compliance for weak acid dissociable (WAD) cyanide in cyanidation tails or waste water from such operations. Typically smallscale bench tests to evaluate and assess the suitability of the Caro’s acid destruction process are conducted. Additionally, the experimental procedure used during these preliminary investigations may also differ from that implemented at the full-scale. This paper presents the results from a fundamental investigation of the Caro’s acid process to establish a more detailed understanding of the impact that the experimental procedure has on the destruction of cyanide. In particular, it was found that the control of pH was important to avoid copper(I) cyanide precipitation at low pH and maximise WAD cyanide destruction. Residual peroxide in the preparation of Caro’s acid has the potential for subsequent cyanide destruction and could be exploited.

Jan 1, 2014

By J. F. MacGregor, M. Hou, D. Hodouin

"RésuméDe nouvelles méthodes efficaces sont maintenant devenues nécessaires pour traiter les quantités massives de données en temps-réel que collectent les ordinateurs industriels modemes. Les méthodes statistiques multi variables comme l'analyse en composantes principales et la projection sur des structures latentes sont des méthodes analytiques bien adaptées aux données industrielles bruitées et mal conditionnées. L'efficacité de ces méthodes est illustrée sur des données historiques collectées dans une usine de broyage et de flottation. Trois cent cinquante observations de quarante quatre variables de procède ont été utilisées pour démontrer les aptitudes de ces méthodes pour l'analyse préliminaire de données, la classification des régimes opératoires, le contrôle de qualité et la modélisation empirique des precedes.AbstractBecause of the availability of powerful industrial computers which collect huge amounts of real-time data in mineral processing plants, there is a need for efficient methods to extract relevant information from them. Multivariate statistical techniques, such as principal components analysis (PCA) and projection to latent structures (PLS), are well suited to analyze these large sets of noisy and ill-conditioned data. The power of PCA and PLS is illustrated on historical data from a grinding and flotation plant. Three hundred and fifty observations of forty-four process variables are used to show the capacity of these techniques for preliminary data analysis, classification of operating regimes, process monitoring, and process empirical modelling."

Jan 1, 1993

By Jehan Rondot

Les trois intrusions alcalines de Suzorite en haute Mauricie, bien que non datees, son! sans doute d ,attacher aU)( nombreuses autres intrusions alcalines dispersees sur les blocks Grenvillia et Laurentia et datees de I 050 Ma =t= 10%, done reliees d l'orogene grenvilien. L 'utilisations de la Suzorite est liee d sa forte proportion de phlogopite (>50%). Le rapport Mg/Fey varie de 3 d 7. Sa mineralogie et sa composition particulieres (forte proportion de Mg, Ket H20) en font son attrait.

Jan 1, 1984

By R. G. K. Morrison

As mines grow deeper, the problem of ground control becomes one of increasing importance. The literature on the subject has grown extensively in the past few years, but is still far from conclusive. Detailed and precise observations are on record covering most phases of the problem, and control measures have progressed to the point where, in a large measure, they are effective. The success of methods to date must be attributed to the efforts which have been exerted to reduce convergence of stope walls and to the realization that a regular progression of stope faces approaching longwall has a beneficial effect. This paper attempts to explain the relationship between these two factors and the general problem of ground control. The problem at present lacks the co-ordination of the practical with the scientific outlook, but fortunately as time goes on there are indications that our scientific friends are becoming more interested and more familiar with the practical issues involved. Opinions vary widely regarding the mechanism of the problem and there are several schools of thought, two only of which will be discussed. One associates the incidence of rock-bursts with the stresses built up by a sagging hanging-wall, while the other takes the view that stresses primarily responsible for the sagging hanging-wall are also the cause of rock-bursts. The first group starts its reasoning from the convergence of the walls, probably the most conspicuous feature of deep mining, and works back to the conclusion that rock-bursts are in sorne way due to the breaking up of the sagging layers. The second group begins with the stress zone apparent around excavations at depth and follows mathematical conceptions based on certain assumptions which, in the absolute sense, are known to be inaccurate, but which are justified by the similarity between the conclusions reached and the results obtained in practice. This reasoning is followed to the point where rock-bursts result from the failure, under stress, of rock in situ, quite independent of wall convergence.

Jan 1, 1939

By Stewart W. Daniel

"Increasing labour costs, the trend to larger mills, the processing of lower grade ores and a diminishing sup-ply of well-trained and experienced mill operators contribute to the necessity of automating a grinding circuit. With sophisticated process control techniques, supervision of the mill line is reduced to an occasional inspection by the shift supervisor. Process operating decisions and/or adjustments are quickly and accurately performed by the electronic devices to be described. When the variables in the grinding circuit are stabilized using the sensors and controllers as discussed, the over-all grinding circuit is maintained at its optimum grinding load level, with ample protection against under-and overloading."

Jan 1, 1967