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By Michael Quadagno

Hudson River Pier 86, home of the historic USS Intrepid Aircraft Carrier and the Intrepid Sea-Air-Space Museum, is currently undergoing a $30M reconstruction. This project involves the demolition of the old timber pile supported pier and construction of a new 150 ft wide by 782 ft long concrete pier, built over the footprint of the old piles. The new pier consists of steel pipe piles, precast concrete pile caps, and a composite deck, made up of precast, prestressed concrete planks and cast-in-place concrete topping. This paper focuses on both the structural design and construction of the new pier, with emphasis on the pile foundation. Pier 86 is unique in that it is required to resist the extremely high lateral loads imposed on it by the permanently moored 898 ft long aircraft carrier during severe storms. A total of 360 steel pipe piles support the new pier. These piles, which are 24 in. in diameter and range in length from 58 ft to 175 ft, were driven down to bedrock. The piles, each having 200 ton allowable capacities, work together to resist the significantly large lateral loads exerted on the pier by the ship. The installation of the piles was unique in that all the piles, including the ?super-longs?, were fabricated to-length offsite, delivered to the site via truck and barge, and installed in one piece, eliminating the need for field splicing. The Pier 86 reconstruction will be completed within an extremely aggressive 18 month schedule, from January 2007 through June 2008. The refurbished aircraft carrier Intrepid will return home in September 2008, and the grand re-opening of the pier will be on Veteran?s Day 2008. This paper provides a case history for owners, government agencies, engineers, and construction professionals that will be faced with the challenges of designing and building new piers.

Jan 1, 2008

By E. E. Harton

Bureau of Mines Information Circular 16, Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants, was published in October 1949 as an aid in making estimates of investment and operating costs of processes for manufacturing synthetic liquid fuels. Development of such processes by the Bureau of Mines was authorized by Public Law 290, 78th Congress. This bibliography included refer¬ences to and abstracts of publications appearing from 1930 to September 1948 on all processes in general use in the petroleum refining and chemical industries. Publications in this field have been numerous since compilation of the above bibliography, and the present report was prepared to cover the field from September 1948 through June 1952.3/

Jan 1, 1955

By Fábio de Oliveira Braga

A proteção balística contra projéteis de alta energia, como o 7,62 mm, é mais eficientemente realizada por meio de sistemas de blindagem multicamada (SBM). Estes são formados, em geral, por uma camada frontal de cerâmica, uma camada intermediária de tecido sintético ou de compósito, e uma camada posterior de um metal dúctil. Em trabalho recente, Monteiro et al. (2016) estudaram um SBM com camada intermediária formada por compósito reforçado com tecido de rami em substituição a um laminado tecido de aramida. Eles obtiveram resultados satisfatórios com boa redução de custo. No presente trabalho, foram investigadas fibras de rami in-natura como substituição ao tecido de rami na camada intermediária compósita. Os resultados foram comparados ao desempenho de um compósito reforçado com 30% de tecido de aramida, bem como aos resultados anteriores. Observou-se que a utilização dos compósitos reforçados com fibras de rami manteve o bom desempenho do SBM, com um custo cerca de 5 vezes menor que o SBM com aramida, e 60% menor que com tecido de rami.

Oct 30, 2017

By Bisweswar Das, Barada Mishra, Hrushikesh Sahoo, Swagat Rath

Banded hematite jasper (BHJ) containing 45.2% Fe, 32.64% SiO2, 0.63 % Al2O3 and 1.25 % LOI is found difficult to beneficiate either by magnetic or flotation techniques due to fine intergrowth of jasper with hematite. Phase transformation by reduction roasting with activated charcoal followed by low intensity magnetic separation to achieve a suitable iron concentrate has been attempted in this study. The mineralogy of the ore and different roasted products has been studied by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) to understand the reduction mechanism. The magnetite formation is observed at 850ºC while metallic iron appeared at a higher temperature. The effects of reduction variables such as reduction time (30-270 min), temperature (750-1050ºC), and reductant (1-12 %) using activated charcoal are studied. An iron concentrate with 64.65% Fe and 55.8% recovery could be obtained under optimum conditions of temperature: 850ºC, time: 1.5 h, and reductant: 6% by weight.

Jan 1, 2014

This growing dependence of Canada upon foreign mineral commodities, just referred to, applies particularly in the direction of the United States. There is, in fact, no more significant feature of Canada's mineral trade than the manner in which it affects the Dominion's commercial standing with that country. Our heavy adverse balance of trade with the United States is perhaps not a matter of such wide concern or frequent comment as was the case two or three years ago. It is, of course, a well-known fact that the Dominion each year buys from the States a volume of goods to a value enormously in excess of our sales to that country. And it has come to be accepted as a ?normal, though not altogether satisfactory, feature of our international commerce that a huge portion of the bill incurred by our American purchases must be met, not by our American sales, but by the proceeds of our sales to other countries, not-ably Great Britain. It is a three-cornered situation in which our trading deficit with the United States is covered largely by our trading surplus with the United Kingdom. In this situation the mineral trade plays a remarkable part. If one delves into the details of our transactions with the United States it will be found that, in one sense, the mineral trade is entirely responsible for the huge annual balance against the Dominion. In fact, Canada gets decidedly better than an even break on Canadian American trade, if one leaves out of account the three mineral groups, "iron and steel", "non- metallic minerals", and "non-ferrous metals".

Jan 1, 1924

By C J. Moran

Given that the mining industry is committed to sustainable development principles and that Australia is experiencing changes to the regulatory environment that aim to modernise the water sector and encourage adoption of consistent approaches, there is a well defined need for the Australian minerals industry to develop a water accounting framework. This requires: key terms and definitions for water metrics for use in the Australian minerals industry that is consistent with the wider water sector, a suite of metrics representing key components of an operationÆs water balance, a calculation method for some of the metrics, and a reporting protocol. This paper presents the methodology that was used to derive these four components. Existing accounting frameworks were reviewed and key terms and definitions that were consistent with current requirements were proposed. A calculation methodology was developed to obtain some of the key indicators and variables that cannot be easily measured directly (water loss through evaporation is an example). The adopted terms and definitions dictated model development, with the conclusion that a systems approach was the most effective calculation process. To test the proposed definitions and calculation methodology, values for water metrics were derived for eight sites. The proposed framework and definitions could deal with the specific situations selected as case studies. The associated calculation methodology produced complete accounts at various levels. Some elements of the accounts could be directly checked against available data and simulations. The framework captured well variations in the reuse efficiencies; reuse efficiency could even vary for similar processes. It is concluded that this preliminary accounting framework provides a consistent language and metrics for quantifying and communicating water management, both at the intersection of the site with the surrounding landscape (through detailed reporting of site inputs and outputs) and within operational activities. Using this consistent framework for quantifying and documenting water use within an operation will provide a platform for compiling and comparing minerals industry water use with other sectors. This may support benchmarking activities within regions or companies and help demonstrate leadership amongst water users in water resource stewardship. The approach presented here is applicable to a wide variety of mining and processing activities, and biophysical environments, and can be adopted as the first step towards developing national water accounts for the Australian Minerals Industry.

Jan 1, 2009

By W. L. Dalmijn, J. M. Krowinkel

A recycling concept of end-of-life televisions starting with shredding will produce a complex material mixture, very heterogeneous in size, shape and degree of liberation. Basically all materials in television scrap are valuable, which means that recovery is important for either economic, environmental or sustainability reasons. However glass, plastics and metals are the materials with the highest potential for recovery. Non-magnetic materials from shredded television sets can be separated into three characteristic size fractions that need further separation for a high value-added recycling of the materials. This study investigated the potential of physical separation of these size fractions into valuable material streams using polyseparator, tlrldy current separator, dry and wet shaking tables and electrostatic separator. An overall mass balance of the mechanically processed televisions was calculated. Evaluation of the produced material fractions showed that heterogeneity in particle shape and size together with the presence of unliberated materials caused sever difficulties in separation when exclusively based on mechanical techniques. The results indicate that a certain degree of dismantling is necessary to achieve products of appropriate quality in physical separation. In order to improve recycling of electronic scrap through design for recycling cooperation between the electronics industry, the manufacturers and the recyclers of electronic goods is necessary.

Jan 1, 2000

By K. E. H. K. Ishak, S. R. M. Zan

Cement production requires significant energy, and entails high costs and CO2 emissions. This is because the clinker requires very fine grinding. Grinding aids can improve production and fineness and decrease energy consumption by reducing the agglomeration of particles and protecting the balls and liners in the mill. In this study we compare the effects of three different grinding aids on clinker grinding using a ball mill. A commercial grinding additive, triethanolamine (TEA), and two industrial grinding aids (GAA079 and GAA088) were compared by ball milling tests, with additions of 0.05, 0.25, 0.50 and 1.00 wt%. The industrial grinding aids were characterized using gas chromatography-mass spectrometry (GC-MS). Particle size and morphological analyses were performed using SEM and XRD. The best results were obtained with 0.25% GAA088, which has a higher active component of diethanolamine isopropanolamine (DEIPA) than TEA. The unique combination of TEA and DEIPA in GAA088 enhances grinding efficiency and significantly improves the particle size distribution compared to TEA alone.. The grinding aids produced smooth rounded particles, which have a smaller specific surface area, enhancing the quality of the cement. XRD showed no significant structural distortion with or without grinding aids, and it was also found that the grinding aids helped decrease ball coating during grinding. The use of grinding aids can significantly improve clinker production and fineness while decreasing energy consumption, which can help reduce the costs and CO2 emissions associated with cement production.

Sep 6, 2023

By A.M. Wala

A new radioactive tracer method to measure airflow in inaccessible airways has been developed for situations when studies of the mine ventilation system are not possible using conventional flowmeters (anemometers). The new method has been tested in the ventilation laboratory at the University of Kentucky and in the Experimental Underground Coal Mine at the U.S. Bureau of Mines. This new tracer method has been utilized in leakage, dilution and flow velocity measurements in laboratory and field (mine) experiments.

Jan 1, 1996

By Rov G. Stott

In recent years there has been no loss of life from fires in the underground mines of the Lake Superior district, but numerous minor fires and several serious ones involving loss of property and production have occurred. The iron-ore-producing companies recognize that well-equipped mine rescue stations are a valuable asset against the ever-present ranger of mine fires or the possibility of hazardous atmospheric conditions underground. Prompt action by trained and properly equipped rescue teams is recognized as the prime essential in saving lives, property, and production when fires occur. To achieve this purpose, the mining companies have provided themselves with mine rescue equipment and maintain trained mine rescue crews. This circular describes how one progressive company has provided, maintained, and improved upon such protection for its underground iron-ore mines on the Marquette and Menominee iron ranges of Michigan's upper peninsula. SUMMARY The central mine rescue station of The Cleveland-Cliffs Iron Co. at Negaunee, Mich., has provided the company's mines with competent and well-equipped mine rescue teams. The new central mine rescue station at the Mather mine "B" shaft has the distinction of having underground training facilities provided as a part of the station. The company maintains the largest trained force in mine rescue in the Lake Superior district, and mine rescue training is employed as a part of the accident-and fire-prevention program. One of the most important results has been the promotion of closer cooperation and understanding between the management and the workmen. In addition to the service rendered to company mines, the station and its personnel have given assistance to others. The station and its equipment have also been used for training several nearby community volunteer fire departments. This mine rescue station and its personnel have been a dependable and valuable asset to the community in which it is located.

Jan 1, 1954

By Walter W. Kaufman

This report summarizes a study conducted to establish the nature and impact of regulations governing disposal of refuse from underground coal mines. The regulations affecting refuse disposal in eight major coal producing states are collected, summarized and reviewed. Federal regulations applicable to refuse generated by underground coal mines are also included. Common refuse disposal practices are discussed as are the refuse quantities generated annually in each study state. Technical requirements of regulations are discussed acid presented in appended tables. Economic implications are also assessed through cost analyses of three major types of disposal processes. The report also includes an assessment of future trends in regulation and refuse generation plus a series of recommendations concerning potential improvements in both the regulatory and refuse disposal processes.

Jan 1, 1978

By Charles A. Ashburner

DURING the early part of August, 1880, I was directed by Prof. J. P. Lesley, State Geologist, to assume charge of the geology and mapping. of the Second Geological Survey of the anthracite codfields. I visited the region uninaumbered by any instructions other than this,—that I should submit a plan for making the sur-

Jan 1, 1881

This paper gives a first-hand account of what a graduate mining engineer can learn by visiting Atlas Copco in Sweden and gives reasons why all mining engineering students should apply for this excellent scholarship. It will also (attempt to) refute the authorÆs mine managerÆs claim that the trip was a huge junket.

Jan 1, 2006

By H. E. Mussey

When the American Institute of Mining Engineers visited the Birmingham district in May, 1888, the four Ensley furnaces (Fig. 1) then completed were referred to as monumental.' Their dimensions are givcn in Table 1. Mr. Gordon stated, with considerable satisfaction, that on the preceding day one furnace had produced 165 tons. The blast was

Jan 1, 1925

By Blott S. F

The smelting plant and equipment at Mount Isa, as originally designed and built, was described by J. M. Callow (1) *.F. A. Forward (2) described alterations and additions to the plant and discussed the metallurgy of mixed carbonate-sulphide concentrates at Mount Isa, prior to 1933, in the Proceedings of this Institute.In 1933, A. F. McAskill (3) gave full mechanical details of the plant in a paper presented to the Institution of Engineers, Aust.FLOW SHEETSFig. No. 1 represents the present general flow sheet. Forward's (2) flow sheet is reproduced here as Fig. lA, and will serve for comparison in depicting subsequent deletions from, and alterations and additions to, the plant.Fig. No. 2 presents the daily tonnage flow sheet of 1939 practice.ALTERATIONS SINCE 1933General. Many changes in metallurgy and operation have taken place, particularly subsequent to March, 1935, when the treatment of a mixture of carbonate and sulphide ores was discontinued and the mill commenced operating on all-sulphide ore. This alteration brought about the elimination of gravity concentration-Jigs and Tables and resulted in the production of all-floatation concentrates of a very fine sizing. Refer Table No. 2, page?) Radical changes in the analyses and physical nature of concentrates also followed (see Table Nos. 1 & 2, page ?) and, similarly, radical changes in the smelting plant have been slowly brought about.

Jan 1, 1939

By Diego Ruben Martin

Este trabalho objetivou comparar, por meio de experimentos desenvolvidos em uma fundição, através da adição de três inoculantes diferentes (IM-22 com FeSi-Ba/Zr, G 20 com FeSi-Ba) e IMSR 75 com FeSi-Sr), para observar as características da vida util de ferramentas na usinabilidade das peças, microestrutura e propriedade mecânica. A metodologia da pesquisa se baseou em analisar principalmente pelo processo de fresamento o ferro fundido cinzento GG-25 inoculado diferentemente, denominado de acordo com a Norma DIN EN 1561. As formas de avaliação dos resultados terão como base uma análise quanto ao desgaste da ferramenta, acabamento superficial, análise microestrutural, composição química e propriedades mecânicas do material da peça. Os resultados mostraram que dentre os inoculantes aplicados o com Sulfeto de Estrôncio (SrS) apresentou-se mais estável termodinamicamente que as amostras inoculadas com os outros dois inoculantes, pois ele levou a uma variação da energia livre de Gibbs mais negativa e portanto mais favorável a formação de núcleos com raio crítico (rc) maiores, o que permitirá uma solidificação com nucleação heterogênea. Todavia o respectivo inoculante também foi mais eficiente na formação de uma microestrutura mais estável, com maiores quantidades de células eutéticas e vida útil do inserto mais longa quando usinado.

Aug 16, 2017

By R J. Merchant

The Hauraki goldfield is located east of Auckland in the North Island of New Zealand. It includes Great Barrier Island, the Coromandel Peninsula and the Coromandel and Kaimai Ranges as far south as the town of Te Aroha and south east to Te Puke. It has a total north-south extent of about 180 km and an area of 3000 km2. The goldfield is the most productive in New Zealand, and while production at present is negligible, the area has undergone continuous exploration over the last seven years.

Jan 1, 1984

By J. M. Wempen

Booster fans, large underground fans, can increase the volumetric efficiency of ventilation systems by helping to balance the pressure and quantity distribution throughout a mine, reducing leakage and reducing the total power requirement. However, in ventilation systems that use booster fans there is a potential for system recirculation, the leakage of return air to intake air, and also for localized recirculation near the fan through the bulkhead and airlock doors. Air that is recirculated locally decreases the system efficiency because the quantity of air flow through the fan increases without increasing the airflow throughout the system. To understand the detailed flow characteristics of a ventilation system with a booster fan, two-dimensional computational fluid dynamics (CFD) models were developed using the software Ansys-FLUENT. Though two-dimensional models do not represent the full complexity of the flow dynamics, they do provide a good representation of the flow characteristics and they allow for a qualitative analysis of how the flow dynamics are affected by the system characteristics. The CFD models were used to evaluate how the number of booster fans, the booster fan placement, the location and geometry of the fan installation and the construction of the airlock system affect the flow characteristics and the localized efficiency of the ventilation system.

Feb 27, 2013

By Tony Peach

Project Description The Ok Tedi Mine is located approximately 18 km east of the Papua and New Guinea-Indonesia border, on the southernmost extremity of the Star Mountains Range, it is situated almost equidistant from the north and south coastlines. The headwaters of the Fly River system are in the Star Mountains. The open pit mining activities are on Mt Fubilan with a (pre-mining) elevation of 2,095 metres (6,871 Feet) in the Western Province. The mine is in an area characterised by very steep topography and dense tropical rainforest. The pit has been free draining but will cease to be so in the first quarter of 2009. Ok Tedi Mining Limited (OTML) required a drainage tunnel to be driven under the mine, if possible before free drainage was no longer possible. The tunnel was required to be at least 5 m in diameter and 4,200 m (13,776 ft) long, with a possible extension of 1,100 m (3,608 Feet) if the mine decided it was required for additional drainage and underground exploration. The tunnel is being driven up grade at 0.67%, and will be connected to the pit by the raising boring of two 1.1 m (3 Ft. 6 In.) diameter shafts from the tunnel level 250 m (820 Feet) below to the pit. In Tabubil, the adjacent township at an elevation of 640 m (2,100 feet), air temperatures range from a mean at night of 20 (68°F) degrees centigrade to a daytime aver-age of 27 (81°F) degrees. Extremes of 12 and 39 (54°F?102°F) degrees centigrade have been recorded. Rain falls, on average, 339 days each year and totals 8,000 mm (315 inches), and have been known to approach 12,000 mm (472 inches) making the area one of the wettest places on earth. The portal site is at an elevation of 1,200 m or 4,000 ft and the air temperatures are a little cooler and the rainfall a little greater. Access to the mine is by air for personnel and light freight and by ship for heavier goods and materials. The port is at Kiunga on the Fly River 153 km from the portal site. The program for the project was tight, the decision to purchase the required TBM was made in July 2007 and the final decision to go ahead with the construction of the tunnel was made in November 2007.

By J. Piper

Markets and Production Beryllium (Be), an extremely light metal, is used in many specialty applications. It the lightest element in Group 2A of the periodic table, with a specific gravity of 1.85 gm/cc, and a high melting point of 12850C (Calvert, 2004). The functional properties of beryllium are stiffness, strength, dimensional stability, resistance to corrosion from acids, and electrical and thermal conductivity. The ability to reflect neutrons and transmit x-rays, makes beryllium irreplaceable in uses such as precision optical components, inertial guidance systems, and in nuclear reactors (Anon, 1993). Beryllium is used in Cu alloys to strengthen and reduce corrosion in copper wire, and in lightweight oxide ceramics that are used as heat sinks, and as electrical insulators. The market revenue of beryllium can be broken down into the seven major groups below, and are plotted on the pie chart in Figure 1 (Anon, 2005). 1.) Telecommunications & Computer 2.) Magnetic & Optical Data Storage 3.) Aerospace and Defense 4.) Automotive Electronics 5.) Industrial Components 6.) Appliance, and 7.) Other.

Jan 1, 2007