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By Thais Cristina da Costa Caldas, Alline Sardinha Cordeiro Morais, Carlos Maurício Fontes Vieira, Sergio Neves Monteiro

"This work has as its objective to evaluate the firing behavior of a kaolinitic clayey body from Campos dos Goytacazes-RJ incorporated with flat glass waste (FGW) from civil construction. Incorporations of the waste, with a particle size less than 74 µm (200 mesh), were performed in the red ceramic in the following amounts: 0, 2.5, 5 and 10 wt%. Specimens were prepared by uniaxial press-molding and then fired at 850 and 1050°C. The characterization of FGW was done by X-ray Fluorescence. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural rupture strength. The microstructure of the fired ceramics was evaluated by optical microscopy (OM). The obtained results showed that the flat glass waste can be used as a component of ceramic bodies once it was noticed tolerable modifications of technological behavior.IntroductionBrazil is one of the world’s largest producers and consumers of clayey ceramic. Campos dos Goytacazes is located in the north of the State of Rio de Janeiro, southeast of Brazil, it’s known as a large producer of red ceramics. It is estimated that the production of bricks can reach 1 billion pieces per year [1].Nowadays, recycling processes became more and more important, due the generation of wastes in large scale and the preoccupation with environmental. The amount of glass waste has been exponentially growing with the growth of the population. It is estimated that the amount of discarded glass as bottles, construction windows, packing and other glass waste represented in 2006 an amount of 7.5% of the total weight of the world´s domestic garbage [2]."

Jan 1, 2012

By J. Evans

Including: Tailings thickeners, CCD?s, paste thickeners, HI-rate thickeners, lamella thickeners, high compression thickeners, clarifiers etc. Flocculant dosing control for mining thickeners and clarifiers is influenced by a number of process factors. 1. Flow rate into the thickener or clarifier a) As the flow rate increases into the thickener or clarifier ?retention time? decreases which causes a greater affect hydraulically on the settling solids. So as the flow rate increases it will generally mean an increase in flocculant dosing rate. b) As the flow rate decreases into the thickener or clarifier the retention time increases which reduces the hydraulic affect on settling, improving settling rates. This will generally mean that as the flow rate decreases, we will decrease the flocculant dose rate.

Jan 1, 2011

By Ergin Arioglu, Werner Burger

"SUMMARY The Istanbul Strait Road Crossing Project includes a 3.34 kilometer subsea tunnel excavated by TBM with an excavation diameter of 13.71 m. The tunnel will incorporate two road decks, each employing two traffic lines and shoulder with the daily capacity of 100,000 light vehicles. The tunnel alignment crosses full face rock sections with heavily fractured zones due to tectonic events as well as a long central stretch of difficult mixed face and very variable soft ground conditions. The demanding ground conditions and the large diameter in combination with realized face pressures well above 10 bar required a highly specialized and well adapted TBM. The paper describes the project challenges and the related technical solutions incorporated within the TBM design as well as the real site experience. INTRODUCTION In 2013, a 13.71 m diameter Mixshield was manufactured in Germany for the Istanbul Strait Road Crossing Project. The delivery of the TBM in late 2013 was a major milestone for the Istanbul Strait Road Crossing Project, also known as the Eurasia Tunnel Project. The Eurasia Project (www.avrasyatuneli.com.tr/en) consists of a 14.6 km route including a 5.4 km tunnel segment in its central part crossing the Bosphorus. The 3.34 km subsea section of the tunnel was excavated in closed mode using a Mixshield TBM. The remaining tunnel length is constructed by sprayed concrete lining (SCL) method followed by a cast in place (CIP) lining or by cut and cover (CC) structures for the TBM transition boxes (Figure 1, right). Other project sections on the European and Asian side consist of upgrading and widening surface access roads towards the tunnel. Conceptual ideas of connecting Asia with Europe via a tunnel crossing the Bosphorus have been around for an extended time and only became realistic towards the end of the 20th century based on significant technical developments in mechanized tunneling. Feasibility studies for a new Bosphorus crossing in 2003 and 2005 confirmed and suggested a road tunnel in its present alignment as the preferred solution. Following an international tender process the Ministry of Transport, Maritime Affairs and Communications of Turkey assigned ATAS, a special purpose company formed by Yapi Merkezi (Turkey) and SK E&C (South Korea), to design, build and operate the Eurasia Tunnel Project. The Implementation Contract was signed in February 2011. In 2012, Herrenknecht AG was selected as the supplier for the 13.71 m Mixshield TBM."

Jan 1, 2016

By Z. Zhang, R. G. Reddy

The viscosities of industrial lead slags with various compositions were measured as a function of temperature. It was found that viscosities of lead slags decreased with increasing temperature, and the plots of ln(11) vs. 104tr followed a linear relation over the reported ranges of temperature. Using the data of this study and available other related data from the literature, a viscosity expression was developed as a function of composition and temperature. The calculated results using this viscosity expression are in good agreement with the measured data. The composition dependency of viscosity of lead slags is discussed.

Jan 1, 2000

By John D. Bardill

This report covers the magnetic surveying done in the Plattsburg area , which was part of a general survey, of magnetite deposits in New York State . Other areas being surveyed are the Star Lake district , St. Lawrence County ; Brewster district , Putnam County; and the Sterling district , Orange County. Reconnaissance indicated an area about 3 miles long and 1,200 feet wide , but detailed surveys have been completed on only a portion of that area . In several districts , surveys of this type have served as a basis in the selection of areas for exploration by diamond drilling by the Bureau of Mines .

Jan 1, 1947

By L. F. Christianson

The presence of salt in crude petroleum has been known for many years, but recently the percentage of chloride salts of calcium, magnesium, and sodium produced with some crude oils has increased to such an extent that the removal of the salty compounds is imperative for some refiners and their presence causes considerable apprehension for others. The exact reason for this increase of salts is not known definitely, but in all probability a combination of factors contributes to the condition. The most important are acidizing of wells, development of new fields producing crude oils of greater salt content, and the depletion of old fields with an attending increase in the production of emulsified brine. Due to handling

Jan 1, 1938

By L. F. Christianson

The presence of salt in crude petroleum has been known for many years, but recently the percentage of chloride salts of calcium, magnesium, and sodium produced with some crude oils has increased to such an extent that the removal of the salty compounds is imperative for some refiners and their presence causes considerable apprehension for others. The exact reason for this increase of salts is not known definitely, but in all probability a combination of factors contributes to the condition. The most important are acidizing of wells, development of new fields producing crude oils of greater salt content, and the depletion of old fields with an attending increase in the production of emulsified brine. Due to handling

Jan 1, 1938

By G. Thodos, D. E. Matschke

Cansiderable time and effort frequently are expended to establish, with a degree of confidence, the PVT behavior of pure substances. In particular, a great deal of experimental information contributed by a number of investigators is available in the literature. The data of each investigator, although significant in themselves, cannot be used with a high degree of confidence until they are compared with the continuum of information presented by others. Current interest in thermodynamic and transport properties, for not only the gaseous state but the con-densed state as well, requires that PVT infarmation be presented for both regions. The density dependence on temperature and pressure, when presented as a continuum, is of considerable value in itself, especially since the available equations of state fail to properly account for the PVT behavior in the condensed state. For this reason and to incorporate PVT data recently presented in the literature, this investigation was carried out. In their studies concerned with the thermodynamic properties of methane, Matthews and Hurd in 1946 utilized the data of Kvalnes and Gaddy and Olds, Reamer, Sage and Lacey to establish the PVT behavim of methane in the superheated region and the saturated liquid densities of Keyes, Taylor and Smithl in conjunction with the Clapeyron equation to develop the densities for the saturated envelope. Current activity sponsored by API Project No. 44 under the direction of F. D. Rossini has led to a tabular presentation of compressibility factors for gaseous methane in the superheated region.la These values were obtained by using smoothed residuals, developed from experimental data and the Ben edict-Webb-Rubin equation,' to establish internally consistent compressibility factors for the real gas. This approach offers probably the most precise presentation of PVT information for gaseous methane to date. The PVT behavior of methane also can be represented accurately by equations of state such as the Benedict-Webb-Rubin equation or the Martin-Hoa equation.' These equations, although valuable for analytically representing the PVT behavior, lack precision in the compressed-liquid region. The PVT data available in the literature for methane were utilized to obtain reduced densities that are presented in Figs. 1 and 2 as functions of reduced temperature with parameters of reduced pressure. The critical constants utilized for methane are those reported by Kobe and Lynn." These critical values, T, = 191.1°K, PC = 45.8 atm and p, = 0.162 gm/cc, produce a critical compressibility factor, z, = 0.289. The PVT information, as obtained from the literature, in many instances was not presented in an immediately

Based on experimental and computer simulation results from our group, we report a systematic, atomic level analysis of carbon dissolution from carbonaceous materials in molten iron. Experimental results on graphite/Fe-C-S system were obtained using carbon dissolution studies, XRD and FESEM investigations and were supplemented with Monte Carlo simulations. Three basic mechanisms, namely carbon atom dissociation rate, interfacial phenomena and mass transfer in the melt were found to be responsible for the overall dissolution process. While mass transfer in the melt is governed by the concentration gradients, melt composition and temperature; impurities present in ash play a significant role in the interfacial phenomena. For less ordered forms of carbonaceous materials, carbon atom dissociation rate depends strongly on the degree of long-range order and is an important rate controlling mechanism in the overall dissolution process. A systematic comparison of dissolution rates for a variety of coal-chars, natural and synthetic graphites has been carried out in an attempt to identify rate-controlling mechanisms. The structure of the carbonaceous material appears to be an important underlying factor in the carbon dissolution process.

Jan 1, 2003

By M. P. Sinha, Rashmi, Tata Steel Ltd., S. Jaiswal, A. Bhatnagar, P. Garg

Reagents form a crucial part of flotation process as they have the power to control the surface properties of minerals. In case of coal flotation, collectors and frothers are two the important and commonly used reagents. But other types of reagents such as promoters, modifiers and depressants are also finding wide applications because of their availability to improve selectivity and increase recovery. Because of these chemicals the scenario has changed from flotation being used mostly for high rank hydrophobic coals to low rank, oxidised or inferior coals. In the present work a case is presented in which two non-ionic surfactants (abbreviated as A & B) known to act as emulsifier have been studied to get a better flotation performance for a preparation plant with varying feed characteristics. Laboratory flotation tests were conducted with both the surfactants using three feed samples of the plant by varying the dosage at three different levels. The highest combustible matter recovery (more than 80%) was obtained for surfactant B at a dosage of 75 ppm (parts per million) for feed 1. But at the same dosage the recovery decreased by 21% and 10.2 % respectively for feed 2 and 3. On the other hand surfactant A showed a consistent result for all the three feed samples giving the highest value at a dosage of 50 ppm followed by a decrease beyond this point. The tests were complemented by contact angle measurements that demonstrated the same trend. In addition to this the reproducibility of data for Surfactant A was checked and found that the standard deviations for both separation efficiency and combustible matter recovery were within the permissible range (less than 5%). Finally an in-plant process optimization study to evaluate the performance and applicability of surfactant A at industrial level was done and has been discussed.

Jan 1, 2016

By Dennis Travagini Cremonese

In the early stage of front end studies of an Iron Ore Project, the sizing of surge capacities and stockpiles are normally assumed based on the experience of the study team. Understanding and sizing of these capacities at the early stages of the project are important for future stages of the project as drastic changes in sizes will impact the economics of the project at that stage. An innovative user configurable high level dynamic modeling tool has been developed to assist in speedy evaluation of assumptions made by the study team. This model incorporates systems or facilities that are commonly used iron ore project from mine to port. This model includes subsystems that will simulate all the logistical components, major process plant systems required for an Iron ore project. The output data provided by this high level dynamic simulation tool will enhance the confidence level of engineering carried out during the early stage of the project. This paper discusses the innovative tool capabilities and a test case comparing various techniques used in iron ore project front end studies.

Aug 1, 2018

By R Varden

Friction rock stabilisers, commonly termed ‘Split Sets’, friction rock bolts, or continuous friction coupled bolts are the most widely used rock bolt in the Australian underground metalliferous industry. Historically, they were used for temporary reinforcement, mainly within ore development. However, their use as primary reinforcement has grown with the demand for higher development rates at lower costs. The introduction of galvanisation has increased their longevity and pattern bolting in conjunction with weld mesh, specifically made for use in development headings, has allowed the use of friction rock stabilisers to increase rapidly with development jumbo’s undertaking the installation. The installation of friction rock stabilisers appears to be deceptively simple, particularly when compared to resin encapsulated bolts. The friction rock stabilisers capacity is a function of the borehole parameters, rock mass quality/strength, the bolt dimensions and steel quality, and lastly and perhaps the most important the operator skill levels. However, as in industry we are still seeing common occurrences of friction rock stabilisers not reaching their design pull test capacity. Pull testing the friction rock stabilisers is used to verify the installation of the design capacity. It involves loading the collar of the bolt with a hydraulic ram until the design load is reached or the bolt slips. Pull tests often show failure rates of 20 per cent or higher. This is despite over 40 years of use and with millions of units installed annually. Such high failure rates would suggest there remain issues with the quality of installation. Ground support quality assurance and quality control (QAQC) programs are needed in combination with operator training to ensure that pull test failure rates are kept as low as practical. However, there are times when despite the QAQC being completed the pull test failure rates increase quite suddenly. When this occurs, it is important to conduct a thorough investigation. These investigations often show there are several factors that are not obvious to personnel installing the bolts. To complete a useful investigation, it must also be done methodically, working through the entire process that includes less obvious factors such as steel quality and the calibration of the hydraulic pull test kit. The aim of the paper is to give mine practitioners an understanding of the complexities of friction rock stabilisers, what QAQC requirements they should be doing on-site, what can go wrong during installation and, if necessary, a process of how to conduct investigations into high friction rock stabiliser pull test failure rates.

Mar 29, 2023

By Raymond B. Ladoo

"The talc and soapstone deposits of Vermont have been worked more or less continuously for nearly 100 years, but all of the early efforts seem to have been directed toward the production of slabs for foot warmer, and other similar uses. Altho soapstone of good quality occurs at several places, much of the material first utilized was really talc and was not massive enough to be cut successfully. The grinding of talc in Vermont seems to have commenced in about 1902 and has shown continuous growth since that time. Statistics compiled by the Geological Survey in Mineral Resources of the ,United States show that the production of talc in Vermont has increased, from 8,978 short tons valued at $65,525 in 1905 to 93,960 short tons valued at $625,150 in 1917. Until 1917, New York was the leading producer in both tonnage and value with Vermont second, but in 1917, Vermont took the lead in tonnage produced, although not in value, with a production of over 47% of the total tonnage produced in the United States and over 35% of the world's pro-duction. This increase in production will probably be continued, though possibly at decreased rate, for the reserves of talc In Vermont are large.Active talc mines and mills in Vermont are found in four districts: Chester, Windsor County; Rochester, Windsor County; Waterbury, Washington County; and Johnson, Lamoille County, These mines and mills are distributed as shown in the following table:While there are a great many other known deposits of talc and soapstone in Vermont, some of which have been worked, those listed above are the only ones which have survived and are producing on a commercial basis. The closing down of many mines and quarries, for example, those at Perkinsville, Stockbridge, Reading, Cavendish, and Athens, has been attributed to several causes. Of these causes the most important seem to be exhaustion of the deposit, poor grade, long haul to the railroad, poor management due to lack of knowledge of mining methods and failure to consider talc mining strictly as a business proposition. The companies which are now operating with greatest apparent success are those which have realized the present and future possibilities of their industry, and have invested sufficient capital in both equipment and personnel to establish their companies on a firm business basis."

Sep 1, 1919

By L. K. Marshall

Last month's engineering fundamentals article discussed some general considerations of underground mine ventilation. This month's article takes a look at auxiliary ventilation-brattice, fans, and ducting-in underground mines. The need for good, efficient auxiliary ventilation increases as mines get deeper and move farther from ventilation shafts. New mining methods and equipment resulted in faster work area advances, liberating more dust, gas, and heat. As a result, worker health and safety requirements in the face area have become more stringent. For all these reasons the safety and efficiency of any underground mine depends heavily on its auxiliary ventilation. The purpose of such ventilation is to supply sufficient quantities of clean air to the face of the drift and to maintain air quality within desired limits until expelled from the mine.

Jan 2, 1982

By J. Szekely, S. Rhee

"A mathematical formulation has been presented to describe heat and fluid flow phenomena in CVD operations. In the statement of the problem, which included consideration of plasma enhanced CVD systems, emphasis was placed on identifying the parameters which play a key role in determining the rate and the spatial uniformity of the deposition process. This was done both through the appropriate dimensionless groups and by presenting an extensive set of computed results. The main conclusions that may be drawn from this work are that the deposition rate will be inherently non-uniform for atmospheric CVD systems; this may be somewhat ameliorated by inclining the susceptor or changing the vessel contours. Operation at greatly redeced pressures and for PECVD systems will give a much more spatially uniform deposition rate.1. INTRODUCTIONIn recent years, there has been a growing interest in chemical vapor deposition techniques for the preparation of thin films for semiconductor, photovoltaic applications and for coatings in general, as evidenced by numerous journal articles and symposium proceedings devoted to this topic (1-6). An interesting variant of this technique is to perform the deposition in a plasma or glow discharge at low pressures because this technology obviates the need for the thermal decomposition of the precursor at the substrate surface and permits operation at greatly reduced temperatures (7-10).By far, the largest portion of the reported work dealing with both these aspects of the technology has been concerned with the characterization of the deposit, quite properly so. However, in more recent times it has been realized that the transport aspects of these processes are also deserving of attention because the understanding of heat flow, fluid flow and diffusional phenomena may provide the key to the solution of problems associated with obtaining uniform deposits and the proper scaling of laboratory measurements in order to design industrial CVD systems."

Jan 1, 1986

By Baha Abulnaga

Slurry pipelines are used in a number of countries to convey processed ore mixed with water over long distances from remote mine sites to ports or plants for further processing. In Egypt and Sudan, numerous mineral resources are scattered in remote areas. Through the years, Egyptian geologists have identified 268 sites for metallic ores and 386 sites for industrial nonmetallic minerals. A large portion of these sites are in the Eastern Desert in an area called the Nubian Shield. Similar sites are found in the Sudan where mining contributes to less than 1 percent of the gross domestic product (GDP). There are three important components of infrastructure needed to develop these resources ? power, water and transportation. While Egypt is able to satisfy 70 percent of its needs in iron ore from the Gadideh Mine in the Western Desert, it needs to expand its other resources to reduce imports heavily sedimented. Dredging of these sediments and transporting them by slurry pipelines would enhance an industry of bricks or agricultural development based on tailings technology often used in mining. This article explores the potential for slurry technology for opening new mines in the desert or recuperating the sediments of the Nile. The technology by itself would be new to both countries and would benefit from collaboration, particularly to de-silt the Nasser-Nubia Lake.

Jan 3, 2010

By Xiaozhen Song, Ashish Ranjan Kumar, Shimin Liu

To investigate the influence of boreholes, fans, and curtains for large opening underground mines (LOUM), we conducted a field survey for LOUM with the survey data serving as the numerical modeling inputs using computational fluid dynamics (CFD) models. Five different CFD modeling results were obtained with different borehole, box fan, and curtain setting conditions. The results indicate that most air quantity directly escapes through outlet 1 after coming into the inlet, causing a huge loss of airflow; volumetric air exchange index (VAEI) and minimum hours of fully exchanging the air (MHFEA) measure air exchange efficiency, with zone 2 of case 5 having the highest VAEI; The borehole minimally affects zones 2, 3, and 4, but drastically alters airflow direction in zone 1; The box fan enhances airflow to zone 2, improving ventilation efficiency and increasing VAEI; Curtains have little effect on distant working faces but influence airflow near inlets and outlets. This study provides a foundation for future research on the influence of boreholes, fans, and curtains, as well as optimizing their placement and effectiveness in face ventilation.

Feb 22, 2026

By Chu E. Ho, Paul Napoli

A new waterfront park was developed on Long Island in close proximity to the East River and Newtown Creek. The existing ground consisted of fill over soft organic clay, medium dense silty sand, glacial till and schist bedrock. The ground was initially raised to preload the underlying soft soils to stabilize the ground in preparation for site development. The ground was subsequently cut down to temporary grades for installation of foundation piles for the overlook structures and construction of reinforced concrete cantilever retaining walls forming pathways located adjacent to the water bodies. The retaining walls were located in two rows at different elevations along the sides of a steep embankment. Where the pathways converge, some of the walls were too close to each other, and were redesigned as a combined U-wall with a common base slab. The individual retaining walls were designed for adequate bearing, sliding and overturning resistance. Ground anchors were installed to enhance global stability of the retaining walls. This paper presents the design considerations for the retaining walls for various loading conditions, and evaluation of the trial and proof tests for the anchors. INTRODUCTION The New York City Master Plan included the transformation of an approximately 30-acre parcel of land in Long Island City, Queens, New York from a former manufacturing zone into a residential, commercial and recreational zone for middle-income community. The site was located at Hunters Point South along the eastern shoreline of the East River and Newtown Creek (Figure 1). The development included low to high- rise residential buildings, a public school, and retail structures. Open spaces were provided along the East River and Newtown Creek waterfronts in the form of a continuous park providing for recreational and community-related activities. Waterfront structures included small park buildings, walkways and viewing platforms. The shoreline was surrounded by revetments as part of the flood mitigation strategy. The project involved extensive site re-grading and several retaining walls were constructed. The earthwork volume amounted to approximately 47,000 cubic yard of imported fill and 93,000 cubic yard of cut. The exposed height of the retaining walls ranged from 3 to 15 feet. This paper focuses on the design and construction of the retaining walls for the project.

Jan 1, 2019

By William A. Riggs

Salt, a non-metallic mineral whose use dates back to earliest history of mankind, and whose uses cover the widest range for any mineral raw material, is generally of widespread occurrence in commercially recoverable quantities in the oceans, in certain sedimentary rocks, in certain lakes, and in certain underground waters. Passing over geological detail, it may be said that, generally, all of the salt in the world has, at least once in geological history, been in solution in the oceans. The total salt content of today's oceans, said to equal 4.5 million cubic miles of rock salt, dwarfs the tremendous volume of salt in the sedimentary rocks. In 1958, United States production of salt was about 22 million net tons and world production about 82 million. About 3 percent of United States production is table salt, with chemical, municipal, industrial and agricultural uses taking the remainder. Mississippi River. Figure 1 has been expanded sufficiently to show also those salt occurrences and producing points which might economically ship salt into these states. Although widespread in occurrence, salt deposits and possible production areas generally show very sharp local boundaries. Salt-for non-table use is susceptible to ?place value?, a common problem in low valued raw materials, where transportation costs often exceed the value of the material f.o.b. the production point. Generally only large capacity mechanized salt producing operations can compete in United States markets, as contrasted to the many small local salt evaporators in less industrialized Mexico.

Jan 1, 1962

Cyclone Process for Heavy Metals Decontamination of Sediments

Sep 13, 2010