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By Paul M. Tyler

The term "milling" as applied to nonmetallic minerals often refers merely to pulverizing without preliminary beneficiation. As applied to dimension stone, it embraces all the gteps involved in shaping and giving the desired finish to blocks. Processes such as sawing, planing, rubbing and polishing seem far removed from milling as the term is used in ore dressing, nevertheless they involve the element of concentration, for only 25 to 50 per cent of the gross quarry output may leave the mill as finished products after imperfect stone has been culled and the rough blocks trimmed. On the other hand, numerous nonmetallic minerals have to be concentrated in much the same manner as low-grade ores. Engineers and machinery manufacturers have begun to recognize more clearly the opportunities awaiting them in the nonmetallic field and have brought with them the methods and equipment developed in metal-mining camps, occasionally with little modification. General Economic Considerations Approximately one-half of the total value of the mineral production of the United States represents mineral fuels, and the other half is about equally divided between metals and nonmetals, the nonmetals recently having become relatively more important. In terms of volume the domestic output of nonmetallic minerals other than fuels is more than 10 times the annual output of metals. Considered on the basis of industrial utility and general commercial and military significance, moreover, the flow of nonmetallic mineral products is quite as needful to our national integrity and well-being as is that of metals, fuels, or other basic materials. Despite their importance individually and as a group, the nonmetallic mineral industries differ so widely in essential characters and economic environment that producers thereof have been slow to develop a community of interest among themselves or with the metal-mining fraternity. A spirit of change is in the air, rule-of-thumb methods soon may be relegated to limbo, and new methods—especially time-tested ideas borrowed from ore-dressing practice—are being introduced. A faithful record of plant practice in certain of these fields, however, must register

Jan 1, 1935

The Century zinc-lead-silver deposit has a geological resource of 118 million tonnes averaging 10.2% zinc, 1.5% lead and 36 g/t silver. It lies approximately 250 km NNW of Mt Isa in NW Queensland, Australia, and is hosted by middle Proterozoic age siltstones and shales of the Lawn Hill Formation. Within the orebody, most mineralisation occurs selectively within black shale units as fine grained sphalerite and galena lamellae with minor pyrite and siderite. The black shale units are separated by weakly mineralised sideritic siltstone horizons. The deposit is unmetamorphosed and only weakly deformed, displaying excellent lateral stratigraphic and grade continuity.

Jan 1, 1995

By Y. Tang

"Rare earth elements (REEs) have many key applications in traditional and advanced technologies. A shortage of several critical REEs is expected due to the discrepancy between the availability of REEs from REE deposits and the REE demand from the market. REE recovery and separation from secondary resources such as uranium wastes and recycled materials might help balance the shortfall in a cost-effective way. This paper presents data concerning the recovery of heavy REEs (HREEs) from uranium raffinate. It also discusses the design, commissioning, and operation of a solvent extraction pilot plant for the separation of REEs.RÉSUMÉ Les éléments des terres rares (ÉTR) trouvent de nombreuses applications importantes dans les technologies classiques et de pointe. On prévoit une pénurie de plusieurs ÉTR critiques en raison des divergences constatées entre la disponibilité des ÉTR provenant de gisement d’éléments des terres rares, et la demande d’ÉTR sur le marché. La récupération et la séparation des ÉTR à partir de ressources secondaires telles que les déchets générés par le traitement du minerai d’uranium et les matériaux recyclés pourraient contribuer à équilibrer cette pénurie de manière rentable. Cet article présente des données relatives à la récupération des ÉTR lourds (HREE, de l’anglais heavy REEs) à partir de raffinat d’uranium. Il aborde également la question de la conception, de la mise en service et de l’exploitation d’une usine pilote d’extraction par solvants pour la séparation des ÉTR INTRODUCTIONSignificant amounts of strategic specialty heavy rare earth elements (HREEs) are present in waste streams in Saskatchewan uranium operations. Selective precipitation including neutralization, oxalate, and double-salt precipitation, as well as sulfide precipitation, ion exchange (IX), and solvent extraction (SX) are commonly used technologies for the recovery and purification of rare earth element (REE) solutions. REE oxalate precipitation can effectively remove Fe, Al, Ca, Si, and other impurities by taking advantage of the solubility difference between REE oxalates and impurities in the acidic solution (Xu, 2005)."

Jan 1, 2018

By Antonio Lourenço Batista de Souza

A simulação da evolução microestrutural, durante a etapa de acabamento, na laminação de tiras a quente de aços carbono, através do software DEFORMTM3D, foi estudada para prever a carga de laminação, distribuição de temperatura, de deformação e de tamanho de grão. A boa concordância dos valores da carga e temperatura na simulação com os valores da literatura, mostra que o presente modelo é viável para representar o processo de laminação. A deformação acumulada próximo à superfície foi maior quando comparada a da região central da tira laminada, indicando uma distribuição heterogênea da deformação, que diminui com a evolução do processo. O aumento da fração de recristalização dinâmica (DRX) e a diminuição do tamanho de grão foram mais significativos nos primeiros passes. Além disso, houve uma fração de DRX maior e um tamanho de grão menor próximo a superfície da tira, esta diferença no tamanho de grão, no sentido da espessura, também diminuiu com a evolução do processo. Estes resultados sugerem que múltiplos passes podem diminuir a não homogeneidade microestrutural da tira. Assim, este estudo mostra a eficácia do modelo microestrutural em predizer o comportamento do material em um processo de laminação a quente.

Jul 30, 2018

By E. P. Polushkin, Henry L. Shuldener

THIS paper describes the results of microscopic examination of a series of brass pipes removed from apartment and office buildings in New York City, adjacent localities on Long Island, and Philadelphia. They were selected as typical of approximately four hundred pipe specimens obtained over a period of five years during an investigation of corrosion in hot-water installations. A part of the investigation is reported in this paper and includes a brief history of the pipes, a description of their inside surface and microstructure, and a study of the effects of corrosion, with particular reference to the structural aspects of local and selective dezincification. Although the bibliography on the corrosion of brass pipes is quite extensive, it refers almost entirely to corrosion in sea water. The authors believe that their examination of this series of pipes, which had been subjected to the corrosive action of fresh water for various lengths of time, may throw some additional light on the problem of corrosion. PIPES EXAMINED The pipes were made by different manufacturers and their sizes range from ¾ in. to 4 in. nominal inside diameter, the majority being within I to 2 in. They can be divided into two groups according to chemical composition: (I) with a copper content of 60 to 62 per cent and (2) with a copper content of 65 to 68 per cent. The first group (pipes made of Muntz metal) comprises 22 pipes and the second (pipes made of high brass) comprises 18 pipes. The pipes had been in service in various locations in the hot-water systems of the buildings involved. Some were taken from horizontal lines in the basement, some from overhead distributors and some from vertical risers. The distance, in terms of feet of pipe, of the specimens from the hot-water generator was no less than 75 ft. and often 100 to 300 ft. In the majority of cases the water-heating equipment was provided with a regulator to limit the temperature of the hot water supply. The normal range of temperature in pipe systems of this kind is 100° to 160°F. WATER SUPPLIES The average chemical composition of the water supplies carried by the pipes is shown in Table I. In evaluating the corrosiveness of a natural water, four factors are considered of prime importance: namely, hardness, alkalinity, pH and silica content. The waters listed in Table I are characterized by relatively low hardness, low alkalinity, low pH and low silica content. The waters of lower pH and higher CO2 content are more corrosive. A characteristic of all of these waters is that they do not deposit a protective mineral coating as do waters with high bicarbonate of lime content, which would be reflected

Jan 1, 1944

By Vitor Manoel de Araújo Silva

Os aços inoxidáveis austeníticos são materiais utilizadas nos ramos petroquímico, nuclear e aeroespacial cujas demandas se resumem essencialmente à: boa resistência mecânica, excelente soldabilidade e elevada resistência à corrosão. Apesar destes metais atenderem a estes requisitos, não raro são submetidos a etapas de conformação para elaboração de peças, o que pode modificar as suas propriedades originais. Basicamente, a causa desta mudança são alterações metalúrgicas induzidas por deformação, como a transformação da austenita (paramagnética) em martensita-a’ (ferromagnética). Tendo em vista que tais mudanças são acompanhadas de variações nas propriedades elétricas/ magnéticas destes aços, uma maneira de monitorá-los de maneira não destrutiva é através da técnica de correntes parasitas. Para este estudo, diversas amostras de aço inoxidável AISI 321 foram solubilizadas e deformadas por laminação a fim de produzirem diferentes frações volumétricas de martensita. Em seguida, submetidas à microscopia ótica, magnetômetro de amostra vibrante e correntes parasitas. De acordo com os resultados, percebe-se que toda a transformação martensítica se passa no intervalo entre 0,10 e 0,55 de deformação verdadeira. Além disso, com os dados de magnetização de saturação, foi possível estabelecer uma curva de calibração de comportamento exponencial, permitindo a quantificação da martensita de maneira não destrutiva.

Oct 30, 2017

By Claudio Cesar da Costar

O Alto Forno 1 da ArcelorMittal Tubarão, operou entre 30 de novembro de 1983 e 18 de abril de 2012, produzindo 93.915 Mt. Durante esta campanha, inúmeras melhorias foram implementadas para aumentar sua longevidade mantendo o volume e custo de produção. O Alto Forno 1 da AMT é reconhecido como recordista tanto em volume de produção quanto em tempo de operação para uma única campanha. Durante sua reforma, foram empregadas as técnicas de reforma em grandes blocos, as quais foram trocados todo o cadinho, corpo e topo do Alto Forno, trazendo recursos tecnológicos possibilitando obter melhores resultados durante a segunda campanha. Após a reforma, o Alto Forno 1 continua apresentando bons resultados em termos de produtividade, consumo de combustíveis e índices de trabalho, colocando-o entre um dos Altos Fornos com melhores resultados do grupo ArcelorMittal.

Aug 16, 2017

By Shun Myung Shin, Dong Hyo Yang

Cobalt is recovered from square type of spent lithium ion batteries (LIBs) containing 5~20 % Co, 5~7 % Li, 5~10 % Ni, 15% organic chemicals, and 7% plastics together with Cu, Al, Fe, and Mn. The waste LIB was prepared by physical treatment. After screening, the crushed LIBs were separated to +8 mesh, -8/+16 mesh, and -16 mesh powder. Among these, -16 mesh powder was selected for leaching. The leaching test was investigated at 2 M H2SO4, 6 vol.% H2O2, reaction temperature 60 ?, agitation speed 300 rpm, solid/liquid ratio 50 g/ 500 ml, reaction time 1 h. The leaching efficiency of cobalt was more than 99 % and its concentration was 24.9 g/L. For removing of impurities such as copper, iron, and aluminum in the leaching solution before cobalt solvent extraction, the impurities were eliminated by pH control with alkali solution. For selective extraction of cobalt, the aqueous phase removed impurities was equilibrated with different volumes of 0.4 M Cyanex 272 saponified of 50 %. Extraction efficiency of cobalt was about 80 % at first step. Separation coefficient (ßCo/Li) of cobalt and lithium extractions was 206.5. Over 9.0 % of pure cobalt sulfate solution was obtained after stripping with H2SO4 solution.

Jan 1, 2008

By Donald P. Blasko

The first well that produced commercial quantities of oil in the Cook Inlet Basin of Alaska was completed in 1957. Since that time oil production in the basin has increased rapidly and by the end of 1969 had reached an annual rate of 74 million barrels. Five major oilfields had been developed, and two additional discoveries awaited development. Estimated amounts of recoverable oil by primary and secondary recovery methods total 2.7 billion barrels, or 36 percent of the estimated oil originally in place. Repressurization by injecting gas or water in formations containing undersaturated oil has significantly increased the volume of recoverable oil. All production has been from formations of the Tertiary age; that much of it is from depths of 10,000 feet or more is unusual for Tertiary formations. The oils are low in sulfur and contain low to moderate amounts of asphalt.

Jan 1, 1972

By C. W. Owings, L. D. Tracy

"IntroductionMany bituminous coal-mining companies have inaugurated extensive safety Programs, but the failure to have approved or permissible equipment or safe practice in only one part of a mine has resulted in disaster. The necessity of using only equipment bearing the U. S. Bureau of Mines approval plate is emphasized by the fact that many accidents are the direct result of carelessness on the part of trusted employees using non-permissible equipment. A concrete example is found in the case of an explosion on October 26, 1926, in a mine in the Pittsburgh district, Pennsylvania.Story of the ExplosionAt about 10 o'clock on the night of the explosion an examination was made in No 2 butt left and parallel off 7o. 14 north, and was found to be clear of dangerous accumulations of gas. (See figure). Several hours later a crew of two men brought a self-propelling rock-dusting machine within 50 feet of the face of Po. 2 butt parallel before they examined for gas. The machine operator found an accumulation of explosive gas about 18 inches from the roof. He began to wave his arms thoroughly mixing the gas and air. Undoubtedly a highly explosive mixture was created, and as the men attempted to run the machine back to fresh air an explosion occurred.The helper dropped to the floor and was burned about the face and wrists. The machine operator ran down the entry and was more severely burned about the face, neck, and arms. He later developed pneumonia and died. Both men reached the door in the chute between No. 14 and No. 15 north. A pumper, who had felt the rush of air, found the men and helped them to walk outside."

May 1, 1927

By K. Moxham, A. Smit, R. Pickering

Since the early 1970s research has been ongoing to develop a cost-effective way of continuously mining the narrow reef, hard rock, typical of South African gold and platinum mines. In the late1980s it was shown that impact ripping was a practical solution for the deep gold mines. In March2001 Lonmin and Sandvik agreed to co-operate in an endeavour to design and manufacture a prototype narrow reef mining machine with the ultimate aim of producing such a machine on a commercial basis that would enable Lonmin to create a safer and more productive environment within its mines and for Sandvik to enhance its leading position as a supplier of a new generation hard rock cutting machine. This paper describes the developed technology, the current progress of the delivery of the required objectives and the optimum mining layout for the roll-out of the mining method.

Jan 1, 2006

By A. Bhagwat, S. Tadolini

"Steel members of the ground support systems in underground mines are routinely exposed to corrosive environment that may range from acidic to alkaline. Corrosion of steel bolts leads to metal loss and thereby, reduction in strength and useful life. Protective coatings are commonly applied to the steel bolts to combat corrosion. However, coatings are expensive and often cumbersome in practical applications. Instead, Minova has developed an innovative technology based on sacrificial anodes. The anodes were designed from non-ferritic alloys that are inferior to steel on the Galvanic Series. This paper will present data from field testing to show significant benefit of the technology. Potential applications in current products will be discussed. INTRODUCTION Corrosion is a physical alteration of a steel material from electrochemical reaction with its environment that often results in reduction of the mechanical and physical properties of that material. Mine roof bolts, the subject of this investigation, are particularly susceptible to corrosion as they can be exposed in their working environment to ground water and air with high humidity. As other researchers have determined, corrosion increases markedly in sulfide ore bodies due to acid runoff. There are several types of corrosion that a rock bolt is likely to undergo when used for ground reinforcement in underground mines (Aziz et al., 2013). Of all the types of corrosion, pitting is particularly dangerous as it can remove capacity for the bolt to deform with subsequent strata movements. Sudden failure of a bolt is likely to occur when severe pitting corrosion is experienced. The type and nature of corrosion depend on the nature of the ground condition and bolt encapsulation. Generally, the type of corrosion and severity of the corrosion varies along the axis of bolt. Almost all of the mine roof bolts used in mines, with the exception of fiber reinforced polymers, are made from steel. The corrosion of iron is an electrochemical phenomenon with the overall equation:"

Jan 1, 2018

By Mark Van Dyke, Ted Klemetti, Jake Beale, Zoheir Khademian, Joe Wickline

In 2016, a 3.7-ML magnitude event caused by mining activity occurred at a longwall mine in southwestern Virginia which was recorded by the United States Geological Survey (USGS) and felt by local residents. The event was the largest of its kind since a global mine design change by the operator was instituted in 2008 following three large events in 2005, 2006, and 2007 (3.4, 4.3, and 3.4 Moment Magnitude (Mw), respectively). Two of the three pre-2008 events (2005 and 2007) damaged ventilation controls in the mine which fueled a mine fire. In 2016, the mine’s management requested researchers from the National Institute for Occupational Safety and Health (NIOSH) to access geological data and determine what parameters could possibly lead to events of a magnitude of 1.0 ML or greater. Evaluation of 2152 geological data points and modeling revealed three major geological factors in common with the majority of the 181 recorded +1.0 ML events from 2009 through 2016. Three levels of seismic potential were identified as follows:

Aug 4, 2023

By Harry Perry

U. S. consumption of sulfur and sulfur products is expected to increase at a rate of 8 percent per year between now and 1980, largely as a result of their use in fertilizer markets. World consumption is also increasing rapidly, but at a-lower rate, about 6-percent per year. In 1965, sulfur recovered in the United States from purification of natural gas; nearly doubled from the 1956-1960 average; production from pyrites declined; and production of elemental sulfur increased 15 percent. Concern about air pollution resulting from sulfur oxides produced from the combustion of fossil fuel has lead to intensive research on methods of removal before combustion, during combustion (in-process methods), and from the resulting flue gases. If all the sulfur in fossill fuels were recovered, more sulfur products would be produced than were consumed in the United States in 1965. Removal of sulfur from coal before combustion could result in a product sufficiently-high in sulfur to be a suitable raw material for sulfuric acid manufacture. In-process methods produce solid sulfates, some of which may have commercial value. Flue gas removal' methods for sulfur oxidest generally result in the production of a byproduct either of sulfuric acid or sulfur. The projected sale of these materials significantly lowers the anticipated cost of sulfur dioxides pollution abatement. Alternate methods for sulfur dioxide reduction are discussed. The various proposed processes are described and costs are given for the various methods for which estimates have been made.

Jan 1, 1967

By Ronald D. Hill, Elmore C. Grim

Surface mining drastically alters the ecological characteristics of the area disturbed and in some cases has a decided effect on surrounding areas. Vegetation is removed, topographic features and characteristics are changed, and the original geologic overburden profiles are destroyed. Spoil banks generally are a heterogeneous mixture of rock fragments, rock particles, and soil-sized material derived from the overburden strata. With proper mining techniques, the various strata can be partially or completely segregated. Segregation of over- burden material offers the opportunity to bury the toxic, acid, or salt-pro producing strata under growth supporting material. In some situations, lower strata may have more desirable characteristics than surface material and can be placed near or on the surface. For example, limestone strata appear in some lower overburden profiles that have shale and/or sandstone near the surface. Also, some lower strata have higher nutrient levels that have been leached from the surface. Experience has shown that natural revegetation is a very slow process on strip mined areas. Native vegetation may not be compatible with the environment on the mined areas, for example : 1. Low nutrients in the spoil. 2. Toxic spoils (very acid or highly alkaline ). 3. Surrounding vegetation may be of the climax type and may not have pioneer- or primary-invader-type species present. 4. The seed source may be to far away from the adjacent mined areas. Early attempts to revegetate strip-mined lands with trees also proved to be unsatisfactory as they did not provide the initial ground cover required to stabilize the spoil. Erosion control with trees only may take up to 10 years before the canopies close and an effective cover is established. They are slow to form soil profiles and do not provide effective chemical pollution control until long after planting. A quick growing cover of herbaceous species is necessary to obtain quick stabilization and initial protection against erosion by reducing runoff and rain-drop splash. Vegetative cover will also build up a concentration of organic matter in the soil, which in turn will

Jan 1, 1974

By Walter Campos, Yuri Gallegos, Sául Vigil

El proyecto Educación Digital Rural ha sido analizado con instrumentos de corte cuantitativo, a través de la aplicación de encuestas a docentes y personal directivo de escuelas del área de influencia directa de Minera las Bambas; además, del uso de la técnica de análisis documental sobre el estado de las matrículas y situación final de estudiantes en el año 2020 y 2021 (Hernández et al., 2020). Los resultados muestran que la intervención ha evidenciado la importancia de tener el personal capacitado sobre el aprovechamiento de las tecnologías digitales en el proceso educativo y sobre la intervención clave del liderazgo del directivo para orientar el trabajo docente y asegurar condiciones que permitieron dar continuidad al servicio educativo en las II.EE. rurales de Fuerabamba, Huancuire y Pamputa.

Sep 30, 2022

IN 1949 the Government Printing Office issued Bureau of Mines Bulletin 468 3 and previously (in 1948) Bulletin 467 4 as part of the program under the Synthetic Liquid Fuels Act of April 5, 1944 (30 U. S. C., 321-325, and amendments). The two bulletins, relating to oil shale and its products, were published to present abstracts of all patents in this field from 1845 to 1945 5 or before the Synthetic Liquid Fuels Act was passed. Also, as part of this program, bulletins were published on patents relating to the pressure hydrogenation of coal e and the Fischer-Tropsch synthesis.7 The Synthetic Liquid Fuels Act was not extended beyond April 1955, but it inspired much increased activity in the field of oil-shale research, and many patent applications were filed. It is the purpose of this bulletin to abstract the patents issued in the United States, the United Kingdom, and Europe from 1946 to 1956, inclusive. A few older patents omitted in the previous bulletins have been included.

Jan 1, 1959

By Y. M. Zhao, C. L. Duan, Z. F. Luo, X. L. Yang

"Fine coal beneficiation in a dry way is considerably imperative for the efficient utilization and conservation of coal resource in drought regions, especially for China. In this study, a continuous vibrated gas-fluidized bed separator was established and developed based on the results of laboratory batch separation results. The fluidization behavior and the effects of several main parameters including superficial air velocity, vibrational parameters, bed height and separating time were systematically investigated. The results showed that the bed expansion increased linearly with the superficial air velocity and theoretically, higher bed expansion benefited the hindered settling process of fine coal particles. However, larger superficial air velocity would induce intense fluctuation in bed surface and a poor performance of density segregation. The conveying velocity of particles was mainly determined by the vibration angle and a predicted model was established by the nonlinear regression analysis. A theoretical model of bed height distribution was established and this model fitted the measured value well. The beneficiation performance of this separator was evaluated by separating -3+1 mm Wuhai fine coal. The results showed that the probable error, E, is 0.225, indicating a continuous vibrated gas-fluidized bed separator could achieve a satisfactory performance.INTRODUCTIONFine coal beneficiation in a dry way is considerably imperative for the efficient utilization and conservation of coal resource in drought regions, especially for China. Meanwhile, it is also conducive to environment protect and low-carbon, green development of coal sector. In recent years, the increasing academic interest in the field of fine coal dry beneficiation has been aroused in most of big coal countries. In summary, recent processes of fine coal dry beneficiation are, according to their processing principles, mainly classified into two categories: dense medium beneficiation (Dong et al., 2015; Fan, Chen, Zhao, & Luo, 2001; Luo et al., 2008; Macpherson, Iveson, & Galvin, 2011) and improved pneumatic beneficiation (Patil & Parekh, 2011; Yang, Zhao, Luo, Song, & Chen, 2013; Yang, Zhao, Luo, Song, Duan, et al., 2013; Zhao, Zhao, Chen, & Luo, 2015). The former deploys artificial dense medium, such as magnetite powder and fine sand, to form a stable gas-solid suspension with certain density under the function of the upward fluidizing air flow and in some case, the external force field like vibration and magnetic field. Generally, it is believed that the process of air dense medium fluidized bed (ADMFB) is suitable for separation of coarse coal (-50+6 mm) and can't obtain a satisfactory result for fine coal separation (Luo, Chen, & Zhao, 2002; Luo et al., 2008). However, some recent laboratory efforts (Patil & Parekh, 2011; Zhang et al., 2014) attempt to find an improved performance for fine coal beneficiation in ADMFB with some modifications. The point of these works is to use a comparatively shallow bed and finer magnetite powder with appropriate size distribution. It is known that fluidization of finer magnetite powder is prone to arouse adverse fluidization properties such as channeling and slugging. Thus, the external force is introduced to an ADMFB in order to improve the fluidization quality of a magnetite powder bed. Some recent literature on air dense medium magnetically stabilized fluidized beds (Fan et al., 2001; Luo, Zhao, Chen, Fan, & Tao, 2002; Song, Zhao, Luo, & Tang, 2012), air dense medium vibrated fluidized beds (Luo et al., 2008) and Reflux Classifier (Macpherson, Iveson, & Galvin, 2010) reports that the separation efficiency, namely the probably error E value, of dense medium separation of fine coal ranges from 0.066 to 0.07, indicating a good separation performance. But, the main unresolved problems of dense medium beneficiation are located in the processes of product purification and medium recovery and are urgent to be solved befor"

Jan 1, 2016

By Francis X. Cannaday

The Bureau of Mines developed equipment to measure the sonic velocity of pulses transmitted through rock samples varying in size from laboratory specimens to mine pillars in place. Pulses are produced by electronically excited piezoelectric ceramic transducers. Special equipment components were developed by Bureau facilities; other components are commercially available. The technique permits a nondestructive, repetitive, stable, shaped pulse to be used in place of explosive caps or hammer blows. Longitudinal wave travel time measurements were taken on an oscilloscope screen; transverse wave measurements were taken under special field conditions. Results were consistently repeatable within the accuracy of the oscilloscopes utilized.

Jan 1, 1966

By F. Bosché

Previous research has shown that ?Scan-vs-BIM? systems are powerful to provide valuable information for tracking structural works (progress, quality, safety). However, the transferability of this capability to other construction areas such as MEP works has not been assessed so far. Comparatively, the construction of MEP systems, in particular pipes and ducts, tends to be more flexible with respect to the positioning of individual components, so that Scan-vs-BIM systems could be defeated when tracking MEP installation works. This paper presents recent results on the feasibility and performance of using a Scan-vs- BIM system to track MEP works. The approach followed is presented and then tested with two real-life challenging case studies were conducted simultaneously but totally independently in Canada and Italy. The results show that, as expected, pipes and ducts tend to be more loosely positioned than structural elements leading to a poorer performance of the Scan-vs-BIM system. Nonetheless, it appears that the system works well to assess the level of conformance of site installation works, providing valuable information for estimating emerging performance metrics like ?percent built as-designed?. In addition, the proposed system could also be useful to accelerate and thus reduce the cost of delivering as-built BIM models for in the case of new builds.

Aug 1, 2013