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By M. A. Nadar

Harsh and dynamic construction sites are generally equipped with cranes in order to rapidly and conveniently move heavy loads from one location to the other. If not properly inspected and managed, this operation can be very hazardous and lead to accidents. As such, a reliable and self-contained monitoring system that can update construction and safety personnel about the status of the crane, the weight of the load lifted, the location of the boom with respect to nearby buildings and other tower cranes, and the weather conditions under which the crane is operating, is deemed necessary. This can lead to significant time and cost savings as well as safety and productivity improvement due to the accuracy and immediacy of relevant on-site crane information delivery. This paper takes the initial steps and presents research targeted at evaluating the capability of wireless sensor networks (WSN) for monitoring tower crane operations in construction environments. A reliable long range WSN system is implemented and information is obtained from various special-purpose sensors (temperature, wind, proximity, etc.) mounted on special motes that relay data to and from each other and a central hub. The latter continuously monitors and manages network performance and relays incoming data to the host application. This application, in turn, displays the received data, and maps it onto a user-friendly visualization scheme, triggering alarms when a set of pre-programmed rules and safety conditions are crossed. The components of the proposed system have been tested through proof of concept experiments and preliminary results highlighted the potential of WSN systems for improving monitoring of tower cranes and reducing related accidents on construction sites, especially in Lebanon and the Middle East region where safety precautions are usually not properly implemented.

Aug 1, 2013

By K. Thuro, H. Käsling, C. Wieser, G. Nuijten

"The time-dependent behavior of brittle rocks during stress relaxation is of great interest for mining industry, nuclear waste disposal as well as tunneling and underground construction. Several studies have shown that both elastic as well as inelastic deformation occur during stress relaxation (Emery, 1964; Zang & Berckhemer, 1989). While elastic strain occurs already during the drilling process, inelastic deformation is time-dependent and can endure for hours, days or weeks. To investigate the evolution of microcracks during core relaxation, two crystalline core samples were recovered from high in situ stress conditions in Europe’s deepest mine in Pyhäsalmi (Finland). Samples were prepared for testing within one hour after coring such that a large portion of the time-dependent component of relaxation could be recorded over several days using ultrasonic velocity as well as acoustic emission (AE) measurements.Results from AE analysis show an exponential decrease in the number of events over a period of several hours. Repeated sudden increases of acoustic events can be related to the propagation or the interaction of cracks. In the first hours of recording also the signal energies reached the highest values and the increases in signal energy correlate well with increased event rates. On additional drill cores, P-wave velocities were measured parallel and in 45° distances perpendicular to the core axis. After core recovery, stress-induced microcracking caused an exponential decrease in wave velocities similar to AE rates. Lowest compressional wave velocities were measured parallel to the core axis and thus normal to the foliation and in the direction of the maximum in situ stress component. The highest measured velocities occurred parallel to the foliation plane. Within the samples, the anisotropy ratios were up to 1.37 at the beginning of the measurements and increased to values of up to 1.8 after 45 days. The wave velocity anisotropy is in agreement with the in situ stress orientations."

Jan 1, 2015

By W. L. Stuewe

The Dominion Steel and Coal Corporation requires enormous quantities of bricks each year for its Sydney steel plant operations. Clay brick of all types are purchased, while silica brick is made in the Company's plant at Sydney. A description of this plant was given in a paper presented by H. B. Gillis and F. C. Morrison at the 1938 Annual General Meeting of the Institute. The rock used to make silica brick was for years obtained from a quarry at Leitches Creek, about eighteen miles from Sydney. Due to the gradual deterioration of this deposit, the Corporation was forced to look for other sources of supply. In 1945, the problem was presented to the Nova Scotia Department of Mines and, through the efforts of Dr. A. E. Cameron and Mr. J. P. Messervey, an examination was made of a silica-rock deposit some six miles northwest of Yarmouth, N.S. Preliminary samples proved satisfactory, and arrangements were made with the Department of Mines to ship to the steel plant at Sydney a fifty-ton car load for the purpose of further testing. Brick made from this sample shipment stood up very well in the furnaces. At the same time, two hundred and fifty tons of silica rock from a deposit at Lac Bouchette, Que., were purchased from the Industrial Silica Corporation, and brick made from this rock also was found suitable for our requirements. Comparative transportation costs, however, led to a decision to open the Yarmouth deposit. The silica rock, or quartzite, of this deposit outcrops at Chegoggin point along what is known as the 'Pembroke shore', a northerly trending section of the coast-line at the extreme southwest of the Province, in Yarmouth county. The country here is fairly flat, with elevation averaging about twenty feet above high tide, and is for the most part mantled by a growth of brush and some scrub trees, chiefly small fir. Bed-rock is generally concealed beneath three to four feet of clayey soil, but scattered outcrops of the quartzite indicated that a band of this rock, some 260 feet wide, extended inland in a northeasterly direction from Chegoggin point at least to Utleys lake, a distance of about three miles.

Jan 1, 1947

By Lyall J. Lichty

THE property of New Calumet Mines, Limited, is on Calumet island, in the Ottawa river, about sixty-six miles northwest of Ottawa. Lead and zinc orebodies were discovered here in 1893. A gravity concentration plant was built in 1912 but was not a success metallurgically, and the plant was later destroyed by fire. A programme of diamond drilling on the property, started in 1937 and continuing to 1942, indicated ore reserves amounting to 1,300,000 tons averaging 2.75 per cent lead, 8.82 per cent zinc, and 0.041 oz. gold and 6.24 oz. silver per ton( l ). These orebodies have been developed underground by cross-cutting and drifting from a three-compartment vertical shaft, sunk to a depth of 745 feet. 'The ore is a contact metamorphic deposit occurring in rocks of the Grenville series, on or near the contact between biotite gneiss and an overlying calcareous amphibolite(2,3). It consists chiefly of iron-bearing sphalerite, galena, pyrrhotite, pyrite, and minor amounts of chalcopyriteand argentite. The gangue minerals closely associated with the ore are calcite, quartz, and various lime-silicate minerals.

Jan 1, 1945

By J. L. Gartshore

PRACTICALLY all of Quebec's chrysotile asbestos production derives from twelve mining and milling operations located in the "Eastern Townships" area of the province. The annual output of these twelve operations exceeds one million tons of chrysotile asbestos, valued at over one hundred million dollars, and is shipped to manufacturers spread over all six continental areas of the world. A total of approximately twenty million ton of asbestos ore yearly, or about seventy-five thousand tons a day, is mined. Individually, the operations vary in size from about two thousand tons to thirty thousand tons per day. Removal of waste rock and overburden to develop these ore tonnages varies greatly from one mine to another, but would probably average out at about a one to one ratio.

Jan 1, 1962

By André Chagnon, Héroux. Yvon

"Résumé - Cette étude porte sur l'altération de la matière organique et des argiles dans les boues carbonatés dévoniennes du facies ""F' de la Formation de Pine Point et ses équivalents stratigraphiques la Formation d'Evie et l'unité bitumineuse de la base de la Fonnation de Hom River. La matière organique se compose principalement de bituré solide et de quelques fragments de fossiles (organaclastes). La majorité des échantillons ne renfement que de l'illite et des inter-stratifiées illite/smectite.Si on compare les températures d'homogénéisation (Th = 100°C) des inclusions fluides de la sphalérite et des dolomites associées a la minéralisation aux températures estimées à partir de la réflectance de la collinite (84°C à 117°C), l'on ne peut pas conclure à la présence d'une anomalie thermique dans le district minier de Pine Point. De plus, la réflectance des organoclastes n'est pas plus élevée dans le district minier de Pine Point que dans les localités plus éloignées des gites. L'analyse des minéraux argileux conduit à la même conclusion: aucune anomalie thermique n'est décelable dans les unités échantillonnées à l'intérieur du district minier de Pine Point quelque soit l'indicateur utilisé.La kaolinite et la matière organique altérée, affichant des valeurs anomales de sa réflectance, se trouve essentiellement en présence de soufre et de sulfures. Cela suggère une origine authigène de la kaolinite et une altération de la matière organique reliées au phénomènes de minéralisation.Abstract - The alteration of organic matter and clays is studied in the Devonian Pine Point Formation carbonate muds, ""F"" facies, and its lateral equivalents the Evie Formation and the bituminous unit at the base of the Hom River Formation. The organic matter is mainly composed of solid bitumen with few fossil fragments (organoclasts). Most samples contain only illite and mixed layer illite/smectite.If we compare the Th (100°C) from fluid inclusions of sphalerite and dolomites associated with mineralization to the temperatures calculated from the reflectance (Ro) of the collinite (84°C to 117°C), we cannot detect a thermal anomaly in the Pine Point mining district. This result is based on the reflectance values of organoclasts from the mining district that are not higher than those reflectance values measured on organic matter (OM) away from the ore deposit. A similar conclusion is reached from the clay study: none of the parameters used allow us to identify a thermal anomaly in the samples from the mining district.The kaolinite and the altered OM showing anomalous Ro values mainly occur with sulfides and sulfur. This association suggests an authigenic origin for the kaolinite and an alteration of the OM due to the mineralization events."

Jan 1, 1994

By Changyoon Kim

Technological advances in mobile systems, such as smartphones and tablet computers, provide engineers with new opportunities to enhance the current facility management processes. Equipped with powerful system processors, touch screens, and wireless communication capabilities, mobile systems enable the experience of omnipresence of facility information. Building information modeling (BIM) also enables improvements in facility management. With an advanced data structure and visualization capacity, BIM can be used in numerous applications for facility management. This study aims to incorporate the strength of mobile systems and BIM in facility management. The proposed system, which utilizes smartphone technology, allows engineers to conduct facility management functions, such as maintenance planning, inspection, and assessment, irrespective of a user?s location. The integration of building information modeling in a system provides detailed visual information of the building components. A case study was conducted to verify the applicability of the mobile system in terms of the hardware functions, system design, and user interface. This proposed system, with its study results, provides a guideline as to how mobile systems can be effectively integrated with BIM for improved management of facility information.

Aug 1, 2013

By J. Drozdiak

In this paper we present the results of preliminary investigations into the applicability of new laboratory scale tests for the prediction of operating gap and specific throughput in high pressure grinding rolls (HPGR). The work is a part of the CAMIRO HPGR research program being conducted at the University of British Columbia, which aims to develop a suite of small-scale tests and procedures for the selection and sizing of HPGRs. A focus of the presented study is to test sample types in terms of their terra-mechanics based characteristics and relate them to specific throughput and gap results from pilot HPGR testing on the same samples.

Jan 1, 2012

By J. Kang

Large-scale land reclamation has been undertaken in Singapore since the 1960s. In the early years, the fill materials excavated from the hills. In recent years, sea sand is the main source of the fill materials. The contractors used to import the sea sand from the neighbouring countries such as Indonesia. However, in early 2000, the sea sand import from Indonesia and Malaysia was banned. Cambodia, Myanmar, and Philippine therefore became the alternative sources for sea sand. Distance between the jobsite and these countries is over 1,200 km, and transporting sea sand from these areas became a critical issue that could affect the contractor?s performance. Figuring out the right combination of transportation means for a longdistance sand transportation would be challenging because of uncertain situations. We developed a stochastic simulation model, using ARENA, to figure out the right quantity of small-size barges, bulk carriers, and loading/unloading equipment, which could help project managers yield the most production for sand transportation. This paper presents how we developed the simulation model, how it was applied to figure out the optimum combination among various size barges, different bulk carriers, and various types of loading/unloading equipment, for the sand transportation project in Singapore.

Aug 1, 2013

By A. Vasenev

The quality and durability of asphalted roads strongly depends on the final step in the road construction process; the profiling and compaction of the fresh spread asphalt. During compaction machine operators continuously make decisions on how to proceed with the compaction accounting for project specific aspects as: ambient conditions, road geometry, roller type, asphalt mixture characteristics and behavior of other machines. In discussions over quality improvement in road construction it is often suggested to robotize rollers. To operate such robots would of course require operational strategies and routines. The reality of this moment is that these operational strategies and routines are not documented. To identify the existing best working practices and, ultimately, to proceed with developing automated robotized compactors, the knowledge of machine operators should at first be explored and described in a formalized way. Unfortunately operators have difficulty verbalizing their expertise. Observation of behavior, as machine movement patterns, could be helpful to extract the operational strategies, but such observations are time and labor consuming. To overcome this burden we developed a Virtual Reality (VR) environment. In this VR environment operators perform compaction virtually, and their operational choices are traced and analysed. This paper describes this VR development and explains how it helps in following machine operators and extracting their (tacit) professional knowledge. The road geometry and the working conditions are visually represented; the operators show - rather than explain - how they would proceed with the compaction process in the given conditions. Movements of virtual machines are documented, analysed, visualised and discussed. This VR approach is expected to contribute to learning, to more formal description of operational strategies; stepping stones towards compaction algorithms for roller robotisation.

Aug 1, 2013

By William Skinner, Jim Pae Lem, Massimiano Zanin

It is well known that the specific density of minerals has adverse influence on the classification performance of a hydrocyclone, particularly when liberated high density minerals such as gold or uranium are present in sulphide ores. These liberated heavy minerals often misreport to the underflow and recirculate to the system. Such phenomena does result in serious issues in a closed-grinding circuit, such as overgrinding, leading to production of flaky particles (as in gold) or ultrafines, in addition to increased energy inefficiency. In plants which present gold liberated at coarser size, loss of gold due to cyclone inefficiency is sometimes prevented by incorporating gravity concentrators into the grinding circuit to recover the gold. The work reported in this paper looks at whether the effect of density will prevent successful rejection of liberated U-bearing minerals in the –10µm size range of a plant re-cleaner feed, which is necessary to minimize penalty U accumulation in a copper concentrator. The study was carried out using a cyclone rig with spigot diameter of 0.25 inches in combination with batch flotation. It was found that the density effect is almost negligible at particle sizes below 10µm. Consequently, the liberated U-bearing particles finer than 10 µm were successfully removed in the overflow stream as rejects and hence U grade in the copper concentrate remarkably reduced, by 16 ppm. Based on the results, de-sliming of the re-cleaner feed was recommended for plant trial and implementation.

Jan 1, 2016

By Leonardo F. Trivino

Despite the significant economical and safety implications of poor blasting practice in mining and quarrying operations, the default practice in many large operations, including both design and control, is considerably below standard when compared to other engineering disciplines. Blast dynamics includes a number of complex phenomena, such as the generation, propagation and interaction of stress waves, the expansion of high pressure, high temperature gases from the explosive components, and their combined effects upon the rock mass, including fracturing, fragmentation and displacement. In order to tackle this non-trivial problem, a combined finite and discrete element software (Y-code) capable of accounting for the dynamic behaviour of stress waves, simulating fracturing processes and modeling the expansion of gases is under development. The constitutive models used in this particular software are fundamentally simple, however, non-linearity and chaotic behaviour result as natural consequences of the interaction of relatively simple processes and mechanisms, such as propagation of stress waves in the immediate vicinity of the exploding borehole, and the creation and propagation of fractures. Advances on its development and comparisons with experimental data show realistic propagation of stress waves and fracture networks.

May 1, 2013

By J. D. Galloways

The northern part of the P. G. E. railway traverses and opens up that part of the province known as the Cariboo district, comprising the Cariboo and Quesnel Mining Divisions, which are a part of the Northeastern Mineral Survey District. Williams lake, a divisional point on the P. G. E. is near the southern boundary of the Quesnel Division and from this point the railway runs northerly to Quesnel, its present terminus. From Quesnel the railway is projected and partially constructed to Prince George on the Canadian National railway; therefore its general trend is northerly through the heart of the Cariboo district. Early History There is no need to outline at any length the early history of mining in the Cariboo. It is sufficient to say that the great gold rush to the Cariboo, in the early sixties, was practically the commencement of mining in British Columbia. These early placer mining operations centred around the old towns of Quesnel Forks, Keithley Creek, Barkerville and Van Winkle, the latter now called Stanley. Many millions of dollars of placer gold have been taken out and the end of production is not in sight yet. The maximum yearly production was reached about 1863, after which there was a gradual decline in output. During the war years production was at a very low figure but a steady, even if small, increase has occurred in the last three years and prospects are encouraging for a much greater output.

Jan 1, 1925

By Jan W. Merks

The objective of metrology in mineral exploration is to derive unbiased confidence limits for masses of metals contained in reserves and resources. Sets of test results for gold and silver determined in pairs of interleaved bulk samples give unbiased confidence limits for the central value of each metal. The same sets of test results show how to verify spatial dependence by applying Fisher?s F-test to the variance of a set and the first variance term of the ordered set. A significant degree of spatial dependence gives a higher degree of precision for the central values of gold and silver. Plotting variance terms of an ordered set against the variance of the set and its lower limits of asymmetric 99% and 95% confidence ranges gives a sampling variogram. Sampling variograms put in plain view where spatial dependence in sampling units or sample spaces dissipates into randomness. The application of statistical methods to test results for sets of ordered core samples within boreholes, and for sets of ordered ore volumes within profiles, plays an important role in defining reserves and resources.

Oct 1, 2009

By X. -G. Chen, K. Liu, N. Parson

"Precipitation-strengthening 6xxx alloys are widely used for building and construction and automobile industries due to their high strength, good weldability and corrosion resistance. However, their elevated-temperature properties (250–300°C) decrease rapidly due to the fast-coarsening of precipitates. On the other hand, dispersoid-hardening is one of the most efficient approaches to improve the elevated-temperature properties. Therefore, the evolution of dispersoids during heat treatment in Al-Mg-Si-Mn alloys was investigated in the present work. Various heat treatments with temperatures ranging from 300–500°Cfor up to 24 hours were performed. Electrical conductivity and microhardness were measured while optical and scanning electron microscopy combined with image analysis, were used to characterize the dispersoids. Special emphasis was placed on the evolution of the size and number density of the dispersoids under different heat treatment parameters. It was found that dispersoids started to precipitate at 350°Cfor 1 hour. Nucleation and growth were the main mechanisms at temperatures up to 400°Cwhile coarsening occurred at temperatures above 450°C. The quantitative results indicated that dispersoids precipitation reached the optimum condition after treatment at 400°Cfor 2–4 hours with a fine size and high number density, resulting in the highest hardness.INTRODUCTIONThe precipitation-hardening 6xxx aluminum alloys with major alloying elements of Mg and Si are one of the most widely used aluminum alloys for building and construction and automobile industries (Dinaharan & Murugan, 2012). In recent years, there have been increasing demands for aluminum structural components to be used at elevated temperatures (250–300°C) for different applications. However, the mechanical properties of 6xxx alloys at elevated temperature are typically reduced due to the rapid coarsening of precipitates at 250–300°C. It has been reported that the yield strength (YS) of AA6061 in the peak-aged condition drops from 276 MPa at room temperature to only 30 MPa at 315°C(Kaufman, 1999). Therefore, it is a key concern to improve the elevated-temperature properties of 6xxx alloys to expand their range of applications."

Jan 1, 2018

By W. H. Hastings

Introductory In the amount of her coal reserves, Saskatchewan ranks third among the provinces of the Dominion, with a total, as estimated by D. B. Dowling, of 59,812,000,000 tons. All the coal so far discovered in the Province is lignite, and it would appear unlikely that bituminous or higher grade coals exist. General Occurrence of the Coal The location of the coal-bearing formations in Saskatchewan is shown on the accompanying map. It will be seen that the areas lie principally in the southern part of the Province. The more darkly shaded areas indicate locations where development is taking place, or where coal-seams are known to occur, either through outcrops in valley-sides or through having been encountered during boring operations. The coal-seams are not necessarily continuous throughout the shaded areas, but in all pans of these there are coal possibilities. It is quite possible that small outliers of the coal-bearing formations may occur further north in the Province, but, generally speaking, coal is not likely to be found outside the shaded areas.

Jan 1, 1929

By J. A. Hillier

The staff of the Hudson Bay Mining and Smelting concentrator have developed a new type of reagent feeder. Several factors encouraged the development of such a system: varying heads caused by the mixing of ores from several mines, the increasing number of flotation circuits operated and reagent feeding stations remote from the flotation operator's work area. The reagent feeders also had to be compatible with future plans for reagent control from an on-stream X-ray analyzer and computer system. The new feeder is a positive-displacement pump set to deliver a constant volume per stroke. At a remote panel, the feed rate is altered by changing the time between strokes. The feeders have been found to be reasonably trouble-free and accurate to less than 2 per cent error.

Jan 1, 1973

Diverse and considerable energies are associated with mobile equipment operated and maintained on mine sites. Loss of control of these energies is a common cause of injury on mine sites and this is well recognised by the mining industry. In 2006, 4 multi-national mining companies formed the Earth Moving Equipment Safety Round Table (EMERST), with the aim of engaging collectively with the manufacturers of equipment to accelerate improvements in mining equipment design. Originally focused on surface mining equipment, and particularly haul trucks, the focus of EMESRT widened to include underground and exploration equipment. Since 2006, EMESRT has maintained a program of regular visits and other engagements with a steadily increasing number of manufacturers. The membership of EMESRT has also increased, with 15 companies being members in 2012. An initial step undertaken by the EMESRT members was the development of ?Design Philosophies? which drew of the collective experience of mining companies to identify potential unwanted events which cause equipment related injuries and illness. A technique for analysing risks associated with operation and maintenance tasks, the Operability and Maintainability Analysis Technique (OMAT), was subsequently developed and trialled. In 2011, the EMERST members resolved to propose a common form of safe design information to be requested by all members companies during procurement, and the resulting EMERST Design Evaluation for Equipment Procurement (EDEEP) process was launched at MINExpo in Las Vegas in September 2012. The outcomes of OMAT risk assessment and control activities are integrated during this process into a common ?Safe Design Information? template for communication to prospective purchasers. The aims of requesting manufacturers to follow this process are to provide equipment purchasers with a common way of assessing how well the issues in the EMESRT Design Philosophies are addressed in the equipment design; and to provide manufacturers with additional information for use during equipment design. The process involves identifying priority tasks based on frequency and the severity of the consequences of potential unwanted events identified in the EMESRT Design Philosophies; undertaking a task-based risk assessment of priority tasks in conjunction with site-based personnel; evaluating the effectiveness of control measures; and providing information about safe design features in a standardised format.

Aug 1, 2013

By Shigeru Sarata

A wheel loader is one of the main loading machines in open pit mines. The authors have been conducting research and development on autonomous operation of loading by a wheel loader. The most common loading method by a wheel loader is the ?V shape? path method. The loading operation consists of cycles of scooping from the pile, traveling to the dump truck, loading on the dump truck and return traveling to the scooping point for the next cycle. The traveling path includes a switchback in the middle of the path. The moving direction of the loader is changed at the switchback point. From observation of V shape path loading operations by experienced human operators, it seems that they control the bucket position between the scooping point and loading point on a shorter path for higher productivity. A new path planning method is proposed this paper, whereby a point on the center of the tip of the bucket is controlled moving from the initial point and the final point. The motion of the controlled point is generated by the wheel steering the wheel loader. The controlled point is moved along the direction to the final point; however, the motion and mechanism of wheel loader have restrictions, such as the velocity of the loader, the steering angle, and the steering angular velocity. Because of these restrictions, the path of the controlled point is not a straight line between the initial and final points. When this control method is applied between the scooping and the dumping points directly, the planned path is not stable in the leaving wing of V shape path. Therefore, the initial position of the wheel loader is set at the switchback point, then two approach wings to the scooping and the dumping points are made. The whole planned path is obtained by connecting the two paths. The shape of the planned path is strongly affected by the position of the switchback point, as well as the scooping and the dumping points. By simulation of path planning at different switchback points with the combination of the scooping and the dumping points, the paths for more effective loading are determined. The results of the simulation are presented in the paper.

Aug 1, 2013

By Tony Lipiec, Greg Gosson

"When it comes to new mines being developed, there is a general industry consensus that most low-hanging fruit has been picked. Many projects currently in the mine development pipeline have been around for decades, but were held back because of technical challenges. Future development of these deposits will likely require access to the public capital markets, and in Canada that means providing scientific and technical disclosure on these deposits in compliance with NI 43-101. As many of these “challenged” projects have metallurgical issues, the companies that own the projects need to ensure their metallurgical Qualified Persons provide transparent disclosure regarding proposed solutions to those issues.This paper provides an overview of the disclosure requirements under NI 43-101 that are pertinent to metallurgists, and other Qualified Persons who prepare technical disclosure regarding the metallurgical characteristics of a mineral project. It lists the triggers for a technical report under NI 43-101 and Canadian stock exchange policies, and identifies the sections of the report that should involve input from a metallurgist or process engineer. It briefly outlines new civil liabilities under Canadian securities laws that increase the possible consequences for not complying with the technical disclosure standards.These materials are provided for general information purposes only and do not constitute legal advice. Readers are advised to seek specific legal advice from their own legal counsel in relation to any decision or course of action contemplated."

Jan 1, 2003