Search Documents

By I. A. Tinto

"Labrador City is located in the southwestern portion of Newfoundland-Labrador, approximately 965 kilometers north-east of Montreal. The mine and beneficiation complex of the Iron Ore Company of Canada, known as the Carol Project, is situated 535 metres above sea level in a climatic region characterized by cold winters and short, cool summers.HistoryThe Iron Ore Company of Canada commenced work in the area in 19 4 9' however, it was not until 1958 that the decision was made to proceed with mining operations. The ore body consists of Specular Hematite (Fe203) and Magnetite (Fe304) with small quantities of Limonite and Geothite. The average grade of the ore bodies is 39% iron.The mining facilities, crushing plant, and concentrator were in operation by the early part of 1962. In the summer of 1961, a decision was made to build a pelletizing plant adjacent to the concentrator. This plant was designed, erected and placed in operation during 1962 and the first half of 1963. Since the completion of the pelletizing plant, additional expansions to both the pellet plant and concentrator have taken place in 1967 and 1973. Today, the Carol Project has the capacity to produce 20 million tonnes of concentrate from which 10.5 million tonnes of pellets can be produced.The period 1980-85 spans a period of energy crisis, world-wide recession, and a consequent re-structuring of the North American steel industry as it struggles to survive in an arena of excess world steel making capacity, government subsidized industries, and the increasing competition from overseas and from developing countries.The media headlines over the past few years echo the woes of the industry and the strategy plans for survival of the fittest. Today's buzz words are foreign competition, steel import quotas, joint ventures, employee participation, work rules, quality, productivity, and state of the art technology."

Jan 1, 1986

By M. H. Col

Within the last few years, there have been numerous techno-logical advancements within material handling due, in part, to the introduction of conveying systems and mobile material handling systems to the industry. Although the traditional material handling methods are still commonly used, the introduction of conveyors to the industry has provided companies with some very efficient and economical options. These "new" systems change with the industry to accommodate rigorous demands, ease of operation, and low operating cost requirements. The number of mobile material handling systems utilized in mining operations is increasing, especially in heap leaching applications. Ten years ago, mobile material handling systems like Mobile Stacking Conveyors (MSC) were considered a novelty. There were two (2) MSC's in actual operation and only one of those in a heap leaching application. Today there are numerous proven systems operating at mine sites around the world-La Coipa, Zaldivar, Florida Canyon, Cananea, El Abra, Chuquicamata, and Radomiro Tomic. The popularity of mobile systems is due to the benefits realized by individual projects. As technology advances, so do the concepts behind mobile material handling systems. Implementing self leveling mechanisms, Programmable Logic Controllers, and Global Positioning Systems to control the equipment are just a few of the recent advances that will be discussed in this paper. We will also discuss current proven systems, and touch on what we see as some of the future advances.

Jan 1, 1998

By AIME AIME

HEREWITH is presented a preliminary report of a special committee, consisting of Erle V. Daveler, Paul D. Merica, and C. H. Mathewson (chairman), dealing with sundry matters of which many are of vital interest to all members of the American Institute of Mining and Metallurgical Engineers. As the report states, the initial purpose of the investigation was to determine ways and means to stimulate "the welfare and growth" of the Institute of Metals and Iron and Steel Divisions. However, it soon became apparent to the committee that most of the problems and possible correctives were of no less vital concern 1o members of the other Divisions and to the "unattached" group of members. Consequently, the Committee has authorized publication of the report and invites written comment from any member on the specific recommendations or on any other phase of the broad subject.

Jan 1, 1943

By E. Heaton Hemingway

DURING the past year, the Watertown Arsenal has been interested in the occluded gas and oxide content of certain ordnance steels in order to determine, if possible, whether some of the peculiar failures in their physical properties might not be traced to these causes. For the purpose of best accomplishing a study of this nature, it was decided to heat the various samples of steel in a vacuum for definite periods of time at high temperatures and carefully examine the quantity and composition of the gases evolved. By the use of a fused quartz tube fitted with a water-cooled, ground-glass stopper, it was possible to maintain a vacuum at a temperature of 1000° C. for 10 hr. without perceptible leakage being evidenced as measured by a McLeod gage. The silica tube was connected with an evacuating system so constructed that the volatilized gases could be removed from time to time and a low vacuum of 0.002 to 0.0010 mm. of mercury continuously maintained. At no time during the period of heating or in the removal of the gases did the evacuated system come in contact with rubber stoppers or any rubber connections, making contamination from such a source impossible. In other words, the only volatile products that could be obtained must necessarily have come from the steel itself or from the glass and fused quartz system or from the mercury used as a sealing agent. In the earlier experiments, the steel treated was in the form of turnings, but this practice was discarded because the weights of the turnings before and after being heated were widely inconsistent, even when taken from the same piece of steel. This discrepancy developed largely through variation in the amount of metal volatilized with the gases; this metal could always be seen in the form of a ring where it condensed in the cooler portion of the tube either in the amorphous or crystalline condition. Because of the frequency in occurrence and the variation in the manner of deposition, this material was roughly analyzed and found to consist for the most part of iron. At the same time two samples of steel that had been

Jan 8, 1920

By Reinhard Gertl, Maximilian Weithaler, Harald Kammerer, Juan Pablo Muñoz, Juan-Carlos Rueda

The Guillermo Gaviria Echeverri tunnel and its access roads project in Antioquia, Colombia is a mega infrastructure project that includes a road network with the longest tunnel in Latin America and several short tunnels, the latter being the focus of this study. The design of the project required careful consideration of several special factors, such as the tunnels’ steep slopes of up to 5%, high fire load of 100 MW, bidirectional operation, and short lengths that make it difficult to place ventilation equipment. The combination of all these parameters cause a challenging design problem for the ventilation systems and smoke control of the short tunnels. To address this challenge, a risk assessment study was conducted to support the design of a new and innovative ventilation strategy that deviates from relevant guidelines and standards, like the Austrian RVS [1][5][6] or the German EABT [8] in order to provide a customized solution for this particular project. This strategy resulted a cost-effective solution, that allowed a reduction in the number of required jet fans and at the same time reaches or reduces the risk level compared to traditional ventilation strategies.

Jun 13, 2023

By Curtis G. Kremer

"New explosives initiation systems continue to be developed as new technologies make advancements possible. Due to recent initiator developments, explosives users now have the most reliable, accurate, safest and easy to use systems ever offered. Three initiation systems recentlyintroduced which offer significant improvement over standard electric and nonelectric initiation systems include Magnadet, EXEL high-strength shock tube, and Redundant two-Dath surface delay systems. These three systems will be discussed zn cecail with rmpiasis on their functioning, safety characteristics, ani specific application areas."

Jan 1, 1991

By Rachel E. Gooding, George C. Emmett, David R. Bradley

The United States (U.S.) Department of Homeland Security (DHS) Directorate of Science and Technology (S&T) is using a probabilistic risk assessment (PRA) approach to evaluate the risks from terrorist use of explosive materials against the Homeland. A similar approach is currently being used to evaluate the risk from terrorist use of chemical, biological, radiological and nuclear materials.

Jan 1, 2017

By Gerard McAlinden, Daniel Frost, Patrick McAlinden, James McAlinden

In an effort to recover Polychlorinated biphenyls (PCB’s) that had leached into bedrock below the Hudson River in Upstate New York, a shaft and tunnel complex was designed that would allow installation of inclined and vertical wells into the zones of contamination to recover PCB’s by gravity. A joint venture of Merco Inc., of Lebanon, NJ, and Obayashi Corporation, of San Francisco, CA, was awarded the contract for constructing the first Tunnel Drain Collection System in the world. Conventional drill and blast techniques were the most economical method to construct the project but due to the presence of PCB’s and community concerns, innovative drill and blast practices were needed.

Jan 1, 2010

"This model specification includes sample text shown in normal font with commentary in italics. The commentary is intended to highlight project-specific items the specification writer should consider during development of the specification. In some sections, typical values are presented to indicate common practice, and these values may be changed to reflect project-specific requirements. The commentary should be removed before using the specification for a project. 1. SCOPE The work consists of designing, furnishing, installing, and testing helical piles used to support foundation loads (compression, tension and lateral), and any ancillary materials (e.g., load transfer devices, etc.) according to the project plans provided and these specifications. Unless otherwise noted, the installing contractor shall provide all labor, tools, equipment and materials necessary to install the required piles. The parties referred to in this specification are as follows: • The Owner is the property owner. • The Owner’s representative is the individual or firm hired by the Owner to design and oversee the overall project. • The pile designer is the individual or firm generally hired by the installing contractor to design the helical piles. • Installing contractor installs and tests (if necessary) the helical piles, and possibly tasks associated with the project. It is important to clearly define the roles and responsibilities of every party on each project to promote good communication and reduce potential for contractual misunderstandings. Different types of contractual vehicles (design-build, value engineering, etc.) require different roles and responsibilities for the various parties, which should be considered in specification development. The Owner will provide suitable access to the construction site for the installing contractor’s personnel and equipment. Unless specifically noted otherwise in the contract documents, the Owner will remove and replace any structures, utilities, pavements, landscaping or other surficial improvements in the work area as necessary to facilitate the work. The Owner will be responsible for overall construction oversight to minimize potential for developing unsafe conditions. The work may include post-construction monitoring of pile performance if required by the Owner or the pile designer to confirm performance of the piles subsequent to their installation. The work may also include installation of additional piles if the initial installation does not meet specified capacity or performance requirements. Responsibility for providing subsurface investigation shall be addressed in the bid documents. The Owner is responsible for providing to the installing contractor all available subsurface soils, rock and groundwater information and geotechnical testing data."

Jan 1, 2015

By J. W. Mausteller

Chemical oxygen supplies have been used for nearly 60 years, with their greatest application during the last 25 years. They are of two types, the superoxides and chlorate "candles", The superoxides are demand chemicals, responding to the needs of the user and to supply oxygen and remove carbon dioxide. Chlorate candles are formed solid element which furnish oxygen only and do not remove carbon dioxide. Properties of these materials will be described, with comments on the respiratory requirements of a man under various workloads, types of equipment which use chemical oxygen, comparison with other systems and potential application to an underground mine survival system.

Jan 1, 1971

By Craig Bournes, David Chapman, Michael DiPonio

Historically, boulders are a frequent source of problems in soft ground tunneling. During tunnel construction, the need to manually break and remove boulders as obstructions causes delays to the project. Repairs to a tunnel boring machine (TBM) can also be a source of delays. Managing these problems is difficult since normal soil investigation techniques do not accurately predict the presence or frequency of boulders. This has lead to considerable number of claims for extra costs and delays during the construction of soft ground tunneling projects. These issues are exacerbated in pressurized face tunneling systems where there is limited access to the TBM cutterhead for obstruction removal and/or cutterhead maintenance. The project team that built the Big Walnut Augmentation/Rickenbacker Interceptor (BWARI) Project for the City of Columbus successfully managed the design and construction of a 4,267 mm (14 ft) diameter soft ground tunnel with high boulder concentrations in a complex geologic setting. The management of the boulder issue tookplace during several phases of the project.

Jan 1, 2007

By L. B. Berger

In this investigation, the ampoule type of carbon-monoxide (CO) detector which is manufactured under license of U. S. Patent 1,644,014 (October 4, 1927) was tested for sensitivity and reliability. This detector was devised primarily for examining the air of manholes and sewers for possible dangerous contamination with CO before workman enter those places, but dine to the simplicity of the device it may have a more general usage for examination of atmospheres which are known or suspected to be contaminated with CO. Some of the suggested uses are the examination of the air in garages, tunnels, mines, around blast furnaces, gas plants, and in the home.

Jan 1, 1930

By A. Yazadni-Chamzini

Risk ranking of projects is one of the importance parts of the complicated risk management procedure. Recognizing the riskiest criteria enable the managers to plan for risk reduction. The first stage for meeting this aim is defining the risky parameters and then working to establish order between them. There are variety methods for risk ranking. The ELECTRE method is one of the best among the multi criteria decision making methods. In this paper with implementing the fuzzy ELECTRE, The risky criteria in the Tehran Subway project are being ranked. The result of this research presents damage and accident of machineries as well as the lack of labor and equipment safety is located in the first order. Collapse factors and local prices are in second rank. Also wrong design, pollution, urban facilities damageable are in third to fifth respectively. Delay and ? are located in the last positions.

Jan 1, 2012

By A. L. Engel

As a part of the program of the Rare and. Precious Metals Experiment Station, Reno, Nev., in connection with investigations of treatment methods for precious and precious-base metal ores, to further conservation and recovery of precious and base metals, tests Were made on samples from the Buzzard Mine, located in the vicinity of Placerville, Calif. These samples represented ore exposed during previous development work, in tunnels and a shaft on the property, including highly oxidized material from the surface zone and sulfide ores from depths of 150 to 300 feet. The surface samples contained little base metal and only enough gold 80 that economic exploitation of them would depend on development of a large tonnage of ore, low-cost mining methods, and satisfactory treatment methods. The sulfide samples were valuable enough to warrant further exploration and development and, if present in suitable tonnage, the installation of a treatment plant for recovery of both precious and base metals. The oxidized surface-zone samples carried 0.11 to 0.14 ounce gold per ton. Standard amalgamation and flotation tests of these samples gave low recoveries. Standard cyanidation tests indicated high consumption of lime and cyanide and gold extraction of 79.4 and 82.7 percent. Water-leaching the ore after crushing to minus 10-mesh improved cyanidation considerably. Ex-tractions of 82.7 to 85.8 percent were obtainec1 with lime consumption of 6 to 7 pounds per ton of ore and cyanide consumptions of 1 to 4 pounds. Grinding the samples to minus 200-mesh followed by water-leaching and cyanidation gave improved extractions of 91-92 percent of the gold, but with slightly increased consumptions of lime and cyanide.

Jan 1, 1949

By Federico Pagliacci, Claudio Asioli, Marco Chiarabelli

"""Rigid inclusions"" are a consolidation method that provides improvement of soft soils thanks to the installation of cylindrical columns made up of a material with significant and permanent cohesive properties, whose stiffness is 500÷5000 times greater than the surrounding natural soil’s. ""Rigid inclusions"" find their application in marginal areas (reclamations, polluted sites) to ensure stability of adjacent structures during construction of new buildings and to reduce the impact of natural disasters (liquefaction in the event of earthquakes, embankment collapse in the event of floods). This paper analyses the “rigid inclusion” construction method, related materials and equipment. Moreover, two performed projects will be illustrated. The first is the restoration of Lungarno Torrigiani Embankment in Florence, Italy. In May 2016, the Torrigiani embankment underwent a structural collapse causing a 3 m. displacement of the riverbank towards the Arno River. “Rigid inclusions” (with 300 mm diameter) have been used to re-compact the loose soil and create a stable working platform for the equipment. The second project illustrates the use of “rigid inclusions” (800 mm diameter and maximum depth of 36.6 m) to control the settlement of a new automatic cold store (30 m high with a 65 x 120 m foot print) for fresh frozen vegetables.RIGID INCLUSIONSIn general, the word ""inclusions"" means a type of consolidation that improves the strength of a soil mass through the inclusion of elements constituted by a material having better characteristics than those of the surrounding natural ground, to improve the overall mechanical characteristics of the treated soil. Inclusions are ""rigid"" when the material introduced into the ground has significant and permanent cohesive properties (concrete or cement mortar) and a significantly higher stiffness (500 ÷ 5000 times) than that of the surrounding natural ground.Typically, medium-small diameters (from 300 to 800mm) with low percentages of treatment (from 2% to 10% of the volume of soil) are employed, ensuring a high quality and consistency of the obtained product, both in terms of diameters and elastic modulus.According to the scope of the project and in urban areas, ""rigid inclusion"" columns can also be performed by means of small diameter drilling rigs (micropiles), weighing less than 20-25 tonnes."

Jan 1, 2017

By W. L. Saunders, Richard T. Dana

The dynamites are graded according to the percentage of nitroglycerin that they contain. Thus a “40% powder” would be one in which the sticks, weighing one-half pound each, would include one-fifth of a pound of pure nitroglycerin. Dynamite is usually packed in paper cartridges weighing about one-half pound each which will vary in diameter. When ordering, it is customary to specify a size of cartridge that will as nearly as possible fill the drill hole, the commonest size being 1 ¼” in diameter by 8” in length. It is nearly always shipped in 50-lb. boxes, which have a volumetric capacity of 3/4 cu.ft.

Jan 1, 2013

By Guy Bridges, Elton Ko, Cheng Ting Ning, Owen Ng, Giovanni Chang, Robert Anderson

"PROJECT OVERVIEWThe Liantang/Heung Yuen Wai Boundary Control Point (BCP) and Associated Works will be the seventhland crossing between Shenzhen and the Hong Kong Special Administrative Region (HKSAR) of China.The project includes site formation of about 23 hectares of land for the development of the BCP and anapproximately 11-kilometre (km) long dual two-lane trunk road (the “Connecting Road”), connecting theBCP with the existing Fanling Highway. The route alignment is within a relatively rural area of HongKong, with very limited similar infrastructure works carried out nearby. It passes beneath bothmountainous terrain, and alluvial plains, and falls within an area of several major regional faults andassociated metamorphism, resulting in a complex variety of ground conditions.ALIGNMENTThe Civil Engineering and Development Department of the Government of the Hong Kong SpecialAdministrative Region carried out extensive public engagement in selecting the alignment of theConnecting Road. Over 70 consultation forums with public bodies, including the District Councils, RuralCommittees, local representatives, etc. were held during the alignment design process. In order toalleviate the concerns of various nearby villages, and to minimize land clearance and environmentalproblems, the original alignment of 10 km long (3.5 km of tunnels and 6.5 km of viaducts) was revised toits final alignment of 11 km long which comprises 5.7 km of tunnels, 4.3 km of viaducts and 1.0 km of atgrade roads.The finally adopted alignment commences at the southern end with an interchange with the existingFanling Highway, part of Route 9, which is a dual three lane expressway currently being widened to dual4 lane. Alongside the expressway is the main rail connection to the mainland of China, and theinterchange viaducts connecting to the southern portal of the Lung Shan tunnel must cross over thisrailway. The southern portal is located in the foothills of Lung Shan, and the 4.8km long tunnel is alignedin a north-northeasterly direction. The southern half passes under mountainous terrain of Lung Shan,and then crosses a valley containing the Kwan Tei river. The northern section comprises low hillsseparated by an alluvial plain and Tan Chuk Hang village area. At the northern end, the tunnel turns tothe north-west to connect with Sha Tau Kok road, an existing single carriageway road, with a newroundabout interchange. Mid-way along this tunnel there will be a ventilation building, connected to the main tunnel by a 330m long ventilation adit. To the north-western side of this interchange is the900m long Cheung Shan tunnel, and after this the remaining 4.3km of the highway connecting with theBoundary Control Point is to be constructed as an elevated viaduct. The alignment is shown in Figure 1."

Jan 1, 2016

The cost of production from truck and loader fleets is influenced by management development of the culture of the organisation, work practices, systems and procedures of the production and maintenance teams. Establishing if the cost of production is the best that can be achieved then requires the measurement of results against established standards of performance. This paper provides a series of discussion points of the factors that influence the cost of production from men and machines for large scale open pit mining operation and provides some suggested performance standards in the form of Benchmarks. Most of the references have been drawn from established large scale deep pit mines in USA, Canada and Australia which have had to implement and constantly fine tune cost efficiencies in order to survive. The discussion provides:ò a review of priorities or the relative importance of the various cost elements for a mining system;ò suggestions of systems and procedures for the operation and maintenance of machines which are considered to yield the best overall results;ò examples of operations that have developed and implemented management systems and controls that are achieving good results in specific functions; andò suggested benchmarks of performance.

Jan 1, 1992

By Arthur Gray

THE thermal analysis of a metal or alloy is ordinarily made with the aid of heating and cooling curves, in which transitions are indicated by the rapid changes in curvature that accompany .changes in the rate of heat absorption or evolution. Analysis by the method that depends on the change in thermal expansivity is not customary, partly, at least, because of the difficulties involved in making the necessary measurements. However, under certain circumstances, the dilatometric method of analysis may possess advantages over the thermometric method that will justify the additional trouble required. The addition of 1 per cent. of zinc to an alloy has been found to produce, upon the volume changes that take place during transition, effects that suggest the possibility of using the dilatometric method of thermal analysis as a rather sensitive means of obtaining chemical information. Although the illustrations presented in this paper are drawn from data obtained during an investigation of dental amalgams, similar phenomena can doubtless be observed with other alloys. Some of the results found during an investigation made in 19171 have been confirmed by data on the thermal expansivity of amalgams published by Souder and Peters of the Bureau of Standards in reporting tests of dental materials.2 Although the Bureau of. Standards made experiments for the purpose of discovering effects of including zinc as one of the constituents of a dental alloy-a matter much discussed in dental literature but without the presentation of reliable experimental evidence to support the views of ;either side-the reports of the test made by the Bureau give the impression that certain striking phenomena associated with the presence of zinc were not noticed. Among such phenomena are those connected with the conditions that determine whether or not a specimen of amalgam becomes covered with droplets from which crystals develop.

Jan 9, 1920

By I Sucholutsky, D M. First, D Mogilny, F Yusufali

Machine learning is creating value in all facets of the mining industry, from exploration to production. The authors provide an accessible, high-level introduction to artificial intelligence (AI), machine learning (ML), and deep learning (DL); the latter being widely recognised as one of the most powerful forms of ML. In particular, the authors will introduce deep learning models known as convolutional neural networks (CNNs), how they are applied, and the economic considerations necessary for determining when DL may be the right solution to de-risking complex block modelling problems. The authors present preliminary results from the mineral resource modelling study of the Jundee orogenic gold deposit, Yandal belt/gold province, Western Australia. The primary goal was to identify the direction and location of the narrow gold veins more accurately and demonstrate how non-linearly correlated elements are used as direct inputs to the resource model to assist with the target element’s grade prediction. This demonstrates that: (1) existing techniques for finding correlations between assayed elements do not adequately reflect the complex geology of the asset, (2) nonlinear correlations that are difficult to model as simple mathematical functions are representative of geological patterns in a deposit, and (3) non-linearly correlated assayed data, fed as inputs, increase the performance of the resource model as reconciled through blind tests. To conclude, the authors hypothesise that the patterns represented by the DL block models may be revealing the results of overprinting geological processes that generated mineral deposits. For example, the primary hydrothermal processes that deposited metals created depositional patterns that become particularly complex as a result of being overprinted, in part or in whole, by secondary physicochemical processes. This may explain why non-linear geochemical relationships have the capacity to generate more accurate block models of mineral deposits.

May 24, 2023