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By Nehad Elsafty

It is always necessary to expand existing buildings, so that they could meet the growing societal needs. Compared with demolishing them and then constructing new ones, the expansion of existing buildings could not only reduce project cost, but also save the use of energy and raw materials in projects. Therefore, it is widely adopted in most under-developed countries. However, the expansion of existing buildings is not an easy task. It has been involved with a lot of issues in defining the scope of work, planning landscape, managing construction activities, etc. This paper investigates the potential challenges in expanding existing buildings. The project of expanding the Al-Agoza Hospital, one of the biggest and oldest hospitals in Cairo, Egypt, is selected as a case study. In the case study, the project documents have been carefully reviewed. The project engineers and the health-care professionals working in the hospital have been interviewed. This way, the point of views from the owner, the architect/engineer, and the contractor have been taken into account. Several lessons are learned through the discussion with these people. The results from this paper are expected to provide pieces of useful advice and suggestion for the expansion of existing buildings in the future.

Aug 1, 2013

By A. Thielen

In experiments for the production of steel the principal problem has always been the introduction into, or removal from, the iron of a definite quantity of carbon. Although the solution of this problem had engaged a more or less blindly and empirically directed effort for a long time, it was only with the development of analytical chemistry that the rôle which carbon plays in the constitution of steel was disclosed in its full significance, and that many of the problems confronting the steel-maker were thereby more clearly defined than before. For a long time, and to a certain extent even to this day, the percentage of carbon in steel has been the controlling means of deter mining its quality and hardness. In many cases the percentage of carbon alone has been relied on for judging large consignments, such as the large deliveries of wire-billets and blooms to America during the past twenty years; and though to-day the influences of the other constituents are recognized and many other considerations are taken into account, and though, moreover, some special steels, such as the Hadfield manganese steel, apparently dispense to a certain extent with the assistance of the carbon, yet fix our Bessemer, Thomas, Siemens and crucible steel the carbon still remains one of the most important constituents, and I venture to say it is indispensable. In order to produce in the Bessemer converter a steel of a certain required percentage of carbon, two methods, as is well known, present themselves. By the one the decarburization process is stopped when the desired carbon limit in the bath has been reached ; by the other the bath is completely decarburizecl, and then a calculated amount of carbon added in the form of spiegel, ferro manganese, etc. In Germany the latter method only was adopted, and it was retained when the Thomas-Gilchrist process for the production of low-Phosphorus steel from high-phosphorus iron eame into use, since from the nature of the new process complete decarburization is neces-

Jan 1, 1891

By John P. Hager

A special inlet system has been developed for a TOF mass spectrometer that allows the equilibrated high-temperature vapors from an atmospheric-pressure flow reactor to be leaked into the ion source of the mass spectrometer without undergoing any compositional changes. Using this flow reactor - mass spectrometer system and a modified transpiration system (one that allows for the carrier stream to be equilibrated with two different condensed samples) a series of fundamental vapor transport studies were undertaken. The results of these studies are summarized as follows: 1. The vapor species in equilibrium with condensed copper (I) chloride were determined to be Cu3C13, Cu4C14, and Cu5C15. The gas mixture is fifty percent tetramer near the melting point (703°K), with the percentage of tetramer decreasing with increasing temperature. The following thermodynamic results were obtained.

Jan 1, 1977

The Role of Mineral Processing in the Development of Cement with Low Carbon Emissions

Sep 13, 2010

By Hamid Maleki

Roof falls are one of the leading ground control problems that adversely influence productivity and worker safety in underground mines, construction sites, and nuclear waste repositories. To control roof stability problems, the operator needs to have practical methods for measuring changes in strata conditions and criteria for defining the timing of secondary support installation. The objective of this study was to develop measurement techniques and criteria for assessing roof conditions at the mining face. An integrated rock deformation and tomographic imaging method was developed and applied at two sites in a western U.S. trona mine. It was shown that rock damage occurred at a deformation of 30 to 60 mm (1.2 to 2.4 in) (2 to 4 pct strain) and was associated with a significant (16 pct) reduction in wave velocity. Thus, supplementary support may be installed when there is a measured change in wave velocity of at least 16 pct. Tomographic measurements can be obtained in rocks rapidly, thus providing a powerful tool for analyzing growth of failure and for installing supplementary support systems in a timely manner.

Jan 1, 1996

By M. Dworzanowski

Beneficiation, in the context of this paper, has two distinct definitions. From an economic perspective, beneficiation relates to adding value to a mined raw material. From a metallurgy perspective, beneficiation relates to processes used to upgrade the mined raw material. Clearly then, ?economic beneficiation? is dependent on ?metallurgical beneficiation?. South Africa possesses the world?s largest mineral resources by value and is a significant global producer of many mined commodities. Significant metallurgical beneficiation of ores does occur in South Africa. The role of metallurgy in economic beneficiation will be examined in terms of current practice and the potential for expansion. South Africa?s main mining commodities will be covered ? namely gold, platinum, coal, iron ore, manganese, chromium, vanadium, copper, nickel, titanium, zirconium, uranium, and diamonds.

Sep 1, 2013

By Robert Hopler

In accordance with the 57th section of the Explosives Act, 1875, the following report on the working of the Act during the year ending December 31, 1903, is submitted. There have been no modifications of the law during the year. No complaint is made of any falling off in the general condition of factories and magazines, and in one instance only during the year have legal proceedings been taken for any irregularity. The occupiers of factories and magazines have invariably shown perfect readiness to remedy any defects, and the managers have themselves in many instances introduced improvements tending towards greater safety. The number of deaths (5) from accidents by fire or explosion in the manufacture of explosives is below the average for the decade (6•4). Looking to the large number of persons employed in this trade, the number of deaths is not excessive and will compare favorably with the death-rate in other dangerous trades. Notwithstanding the large increase in the manufacture of explosives, the average number of deaths has greatly decreased since the passing of the Explosives Act, whereas the number of fatal accidents with explosives under conditions to which the Act does not apply appears to increase with the extension of trade.

Jan 1, 2006

By R. J. Colony

DEPOSITS of iron are widely scattered in the folded Cretaceous rocks and the associated igneous intrusives of Puerto Rico. Most of them are too small for commercial development, but a few have aroused some scientific and economic interest, among them the large body of residua] limonite at the west end of the island near Mayaguez1-6 (Fig. 1) and the mixed hematite and magnetite deposit on the southern slopes of the Sierra de Cayey, about four miles north of Arroyo.7-9 Neither of these orebodies has been developed, nor have investigations of the widely distributed deposits of magnetite, which include all the remaining occurrences of iron deserving of economic consideration, proceeded beyond the exploratory stage. With the possible exception of the mixed deposit near Arroyo, the magnetite is directly associated with andesitic and dioritic intrusives, which invade the Cretaceous rock section, and the bulk of it, occurring in calcareous sediments, is clearly of contact-replacement origin. The small deposit on Rio Portugues, north of Ponce, is found in a limestone band near its contact with an andesite dike.10,11 Two deposits of unde-

Jan 1, 1935

By S. L. Gay

The conventional mass-balance equations used as constraints can lead to flow estimate values of zero even though the flow estimates should be some positive number. This is because many of the constraint equations are satisfied if the flow rates are zero. The way to overcome the problem is to use a slightly different form of the equations. For example, rather than use the conservation of flow of solids as a constraint it is better to use the constraint that the percentage of solids going into a unit equals the percentage of solids coming out of the unit. Examples are given using mineral processing data sets from Mount Isa, Queensland, and Red Dog, Alaska

Jun 21, 1905

By Z. Y. Ding

This paper emphasize two points in piled wharf design which are important than structure calculation. First, during design of piled wharf on soft stratum, the bank slope stability is the first important item. Second, the live load, the backfill and the original ground's settlement will influence the wharf structure causes cracks. Two practical examples were illustrated.

Jan 1, 1991

By J. L. Lytton

The flow-stress recovery of high-purity aluminurn following a 10 pct tensile prestrain was studied in terms of a fractional flow-stress recovery parameter fr. The flow-stress recovery behavior was related to the dislocation arrangements using transmissiort electron rnicvoscopy. During recovery at 120° and 160°C, nearly stable strength levels were attained, the strength level for 120°C recovery being greater than that for 160°C. This stabilization of flow stress was related to the formation of meta-stable dislocation networks bounding nearly perfect cells. Both network formation and the annealing of dislocation loops were found to be recovery mechanisms, and the stronger metastable strength level joy 120°C recovery was related to a smaller average cell size. Analysis of the networks was consistent with the reaction of sets of dislocations with a/2 (110) Burgers vector to give product Burgers DURING isothermal annealing of cold-worked metals, a degree of softening occurs without re-crystallization, and the processes responsible for this change are termed recovery processes. During recovery annealing, the dislocations generated during cold work become rearranged into low-energy configurations, and as much as 50 pct of the stored energy is released."' The relationship between this rearrangement of dislocations and mechanical behavior is of considerable importance, since the dislocation substructures formed during recovery provide a significant degree of low-temperature strength3j4 and can favorably alter the course of primary creep at high temperatures.4 The purpose of the present study was to relate the flow-stress recovery behavior of high-purity aluminum to the substructural modifications that occur. Electron transmission microscopy was therefore employed for direct observation of dislocation substructures at various stages of recovery following 10 pct prestrain. Several investigators5-' have proposed that dislocations can become rearranged or lost during the preparation of thin foils. It was found early in the present study that the dislocation structures in the thicker regions of the foils changed in a systematic way during the course of recovery. Therefore, it is unlikely that substantial losses or rearrangements occurred during thinning. This point will be discussed in more detail later. The results of various investigators indicate that recovery processes in fcc metals can result in release of 50 pct or more of the total energy stored in the as-prestrained metal, this percentage decreasing with increasing prestrain.' Alloying elements or impurities tend to increase this percentage. The release of stored energy of fcc metals during recovery appears to occur by 1) annealing of point defects if the deformation occurred at sufficiently low temperaturesg and 2) rearrangement of dislocations into low-energy Configurations.1,2In bcc metals, the annealing of dislocation loops has also been observed during recovery after prestrain,10-12 and it has been proposed that this is a recovery mechanism for unidirectionally strained fcc metals.' The density of dislocations in bcc metals has not been observed to decrease appreciably during recovery,10 although the formation of regular dislocation networks has been observed. has shown that the formation of such networks can result in elimination of long-range stresses and can lead to significant release of stored energy without dislocation annihilation. It might thus be expected that network formation is a significant recovery mechanism in fcc metals, although extensive network formation has apparently not been reported in controlled recovery experiments. The formation of sub-boundaries in aluminum has been observed by various investigators13'17 during recovery studies of aluminum, but the structure of these boundaries was not resolved. In this regard, it is significant to note that Bailey and Hirsch,' using transmission electron microscopy, detected no network or sub-boundary formation during recovery of 99.99 pct Ag. Furthermore, Clarebrough et al.2 found no such rearrangements during recovery of copper. EXPERIMENTAL PROCEDURE The high-purity aluminum used in this investigation was obtained in the form of 0.125-in.-thick sheet. Spectrographic analysis revealed that the sheet was 99.995 pct A1 with the following weight-percent impurities: 0.001 Cu, 0.002 Fe, 0.001 Si, and 0.0004 Mg. The as-received sheet was in the heavily cold-rolled condition. The as-received sheet was cold-rolled at room temperature to 0.040-in.-thick sheet in the longitudinal direction, which was the original rolling

Jan 1, 1965

By H. J. Schroeder

Legislation and Government Programs.-The Occupational Safety and Health Administration (OSHA) accepted written comments until July 23, 1976, and held an informal hearing on August 24, 1976, to receive oral testimony regarding an economic and inflation impact statement prepared by OSHA on the proposed standard for occupational exposure to inorganic arsenic. These written and oral submissions were to be used in conjunction with information supplied at 1975 hearings to promulgate emission standards. An in-depth study for the Environmental Protection Agency (EPA) assembled and interpreted comprehensive information on arsenic and its compounds and the effects of these substances on people, animals, and plants.2 Another study for EPA assessed the role of arsenic and its compounds in the environment and in the economy of the United States and evaluated the need for and the projected effect of controlling its production, use, dissipation, and emission.3

Jan 1, 1978

During the lifetime of an open pit mining project, each stage from exploration activities to exploitation and mine closure produces disturbances on the mining region. Mined land reclamation plans establish constructive solutions to rehabilitate the disturbed areas. Open pit mining as an effective method for exploitation of a wide range of orebodies especially for massive reserves of shallow metallic substances has exhaustive and harmful environmental effects on the mining project region. Nowadays, closure and reclamation stage in a mining project is emphatically enforced by the relevant environmental protection regulations in many countries. It is therefore obvious that closure and reclamation costs of an open pit mining project, as costs of other stages of project, must be estimated to enter the planning and design processes in open pit mining. Post-mining land use is the most important factor to recognise closure and reclamation costs. Thus, using a model to define optimal land use in planning phase of an open pit mining project is necessary in this regard. In this project a model was developed to define optimal land use regarding different sections of open pit mines such as pit(s), waste dump(s), tailing pond(s), roads, areas for onsite facilities and free land zones which are not mined. TOPSIS and PROMETHE techniques were applied to create the developed model. Lumber production was recognised as the optimal post-mining land use for the pit area of the case study in this project.

Dec 6, 2010

The principle activities of the Explosives Research Laboratory from July 1, 1961 to June 30, 1962, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1962; in general, the research reported in these publications antedates the report period. Part 3 gives the results of an investigation which, although too limited to warrant separate publication, merits presentation in some detail because of current interest in ammonium nitrate-fuel oil compositions.

Jan 1, 1964

By P K. Banerjee, S Kumar

Indian iron ores with less than 62 per cent Fe are currently unexploited, except for a few sectors which export them to foreign countries. It is anticipated that by 2012 the countryÆs domestic steel production is likely to rise to the tune of 60 million tonnes per annum. To meet this requirement, it is necessary to utilise not only the existing high-grade deposits but it is also necessary to look into exploiting the leftover iron ores of lower grades. Hence, reserves with Fe content 62 per cent and below (particularly the ores with In the present paper, an attempt has been made to beneficiate three different types of low-grade iron ores selected from three different parts (states) of the country. In the paper, alternative routes for beneficiation and effective utilisation have been tested using different techniques in the laboratory in an attempt to match their (Al2O3/SiO2) ratio after thorough characterisation and liberation studies. The paper also encompasses the geological formations, occurrences and distribution of Indian iron ores as well as highlighting the problems associated with the fines, possible metallurgical routes, and their market segregation from the perspective of end users.

Jan 1, 2007

By J Fut=

The rotary drilling of rocks is widespread technology in mining and in tunnelling. The paper describes the results of research by aim to find relationships between optimal drilling and sound signal of drilling machine. The optimisation criterion has been formulated as the minimisation of specific energy with maximal effective speed of drilling in process of the rock disintegration. The research in this field has been made on experimental drilling stand. Our monitoring system has measured following variables: the pressing force of core drill, the revolutions of drilling head, the length of drilling, the time, the power, and the acoustic signals. For measurement of acoustic signals have been used very sensitively sound meter MEDIATOR 2238. From this measurements have been processed acoustic spectrums. Then we are found relationships between optimal control of drilling and composition of acoustic spectrum. On base of experimental results, we can formulate the optimal control following: æTo achieve the minimum difference between the equivalent sound level at the load and idle modes only at the representative frequency (f = 1000 Hz)Æ. The representative frequency dependences on type of the rock New method based on these relationships enables the optimal control of drilling machine by using measured acoustic signals only.

Jan 1, 2003

By Brown H. R, Wright E. A

The authors identify the workable coal seams, their distribution in relation to quality and economic occurrence and relate their analytical characteristics to industrial use. The development of established collieries is also discussed with regard to increased production demand.The authors also indicate the potential of the coal resources of the Southern District and postulate their ultimate development.INTRODUCTIONThe Southern Coalfield yields 30 per cent of the total production of bituminous coal in New South Wales. The economic potential of the coalfield was examined last by Harper (1915). Since that time additional knowledge has been gained by prospectors, mining companies and public authorities. Expansion in the steel industry and the building of power stations on the coalfields together with improvements in fuel technology, mining methops and road transport have resulted in production of coal from seams mice thoughtto have no economic value.DESCRIPTION OF THE COALFIELDFor the purpose of this paper the term Southern Coalfield includes also the South-Western Coalfield which together comprise the following Coal Districts:IllawarraDouglas ParkWollondilly-NattaiMoss Vale-Berrima (Hanlon, 1953).Geographically the coalfield is contained by the Illawarra Range in the east, the Shoalhaven River to the south, the Wollondilly River to the west, and in the north by a line...

Jan 1, 1958

By SDN Wessels, WA Naismith

On 16 July 2004, at 07:10 a collapse of about 1.8 million m3 (about 4 ½ million tonnes) took place on the north wall on Nchanga Open Pit This collapse was the result of a developing instability that was first identified when the benches in this area were exposed during September 2002. The NOP Geotechnical and Survey Departments closely monitored the development of the failure. Control measures were implemented to reduce risk to men and equipment. These measures were continually improved and adjusted in reaction to observations and changing conditions. The purpose of this paper is to describe in detail the monitoring results that were obtained both by traditional methods and the novel Slope Stability Radar System (SSR). Difficulties encountered in establishing critical deformation levels and deformation rates that can be used to predict the onset of collapse are described. Details of the monitoring and control measures, which led to the successful completion of mining in the area, are also described in this paper.

Jan 1, 2005

By N. I. Basuki, E. T. C. Spooner

"Abstract - More than 2800 published fluid inclusion data (primary inclusions) from eighteen typical Mississippi Valley-type (MVT) Zn-Pb deposits and districts were examined to study possible relationships between MVT fluid properties and metal tonnages and ore grades. The mean Th and salinity values for fifteen MVT deposits and districts are 122°C ± 21°C and 20.7 ± 2.6 wt% CaCl2 equivalent, respectively. In general, temperatures increase from pre-ore to ore stages, and salinities decrease from ore to post-ore stages. From post-ore to late calcite stages, salinity and temperature decrease with various trends within specific districts.Several conclusions are drawn: first, results show that Hanor’s (1996) salinity threshold for metalrich basinal fluids applies to typical MVT ore fluids (~16 wt% CaCl2 equivalent). Second, the lower limit of mean Th values of measured MVT deposits and districts (n = 15) of ~75°C is similar to Hanor’s (1996) observed temperature threshold for metal-rich basinal brines of ~60°C (n = 224). Third, there is no statistically significant relationship between fluid inclusion homogenization temperatures (Th) and metal tonnages or ore grades. Fourth, there seems to be a tendency for large tonnage districts/deposits to be associated with mean fluid salinities that are relatively low (~16 to 21 wt% CaCl2 equivalent) within the overall range of salinity means (~16 to 26 wt% CaCl2 equivalent). There is also a correlation between higher ore grades and higher salinities. Finally, comparison with other sedimentary rock-hosted Zn-Pb deposit types shows a trend of salinity decrease and temperature increase from MVT, sandstone-hosted and diapir-related Pb-Zn deposits, to vein-type and Irishtype Pb-Zn deposits, and then to sedex deposits. However, more data are needed for sedex deposits. The salinity threshold for significant Zn-Pb transport decreases to =~10 wt% CaCl2 equivalent at ~250°C. This study suggests that fluid inclusion analysis during exploration may be useful in assessing ore-forming potential (threshold salinity) and possible ore grades (salinity)."

Jan 1, 2002

By R. L. Zick, J. D. Byars, T. P. Mucho

Recently, a large Pittsburgh seam longwall mine was nearing depletion of a major portion of its current reserves and had begun to develop in a different direction from its original portal area to access additional reserves. This meant that a large area of the mine would be abandoned and sealed. However, continued use of the original mine portal area required that the water accumulating in the abandoned mine would eventually need to be pumped to the surface. This would be in addition to the discharge water associated with the new portion of the mine. Several pumping and sump options were investigated to handle the quantity and quality of the anticipated discharge water. This paper describes some of these options, their advantages and disadvantages, and the final engineering decisions. Some problems and unanticipated outcomes, as well as the eventual solutions are discussed, including: (1) estimates of pump requirements, (2) water pool size, (3) eventual water quality, (4) anticipated inflows, and (5) integration into the overall mine water system.