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By Rainer Antretter

The city of Garmisch-Partenkirchen in southern Germany is located at a main transit road to Tyrol in Austria and suffers of a very heavy traffic load. Therefore, the Kramertunnel as a by-pass tunnel is built to release/mitigate the traffic through the city centre. The 3,600 m long single tube road tunnel is designed with a parallel but smaller emergency tunnel and with cross passages, fitted with single- and doublesided emergency bays, a vent shaft, and an intermediate ceiling to separate fresh air supply from the road traffic. The tunnel, concrete lined along its entire length provided the challenge to find smart formwork solutions for quick set-up, repositioning, setup and pouring. Three particularly specific sections are discussed in this paper.

Jun 13, 2023

By A. Torkian

Process water from production of concentrates in Meydook copper sulfide mine is transferred to the 8.3 million m3 tailings dam and a water retention pond after initial thickening. Elevated concentrations of heavy metals, sulfate, and TDS and decrease in pH as well as seepage into the aquifers have been the concern of the regulatory agencies since the start of activities. In this paper the results of a 6-month monitoring program from 4 wells are presented. The wells were located approximately 1.5 km from downstream of tailing dam (0.4 km from water retention pond) as well as upstream background well (2.28 km from water retention pond and 1.27 km from tailings dam). The objective was to study possible effect of accumulated tailings on the groundwater resources. Water levels in sampled wells were on average between 20 and 40 m. Results showed high levels of lead (5 ppb), copper (0.17-0.46 ppm) and selenium (73.1- 29.1 ppb). High levels of selenium and lead were partly due to natural geological settings of the area with high levels present in unaffected soils in the vicinity including water wells of villages upstream of mining operations. High copper levels were attributed to both mining operations as well as deposition from particulate air deposition onto the soil and transport to ground water by rain.

Aug 1, 2013

By M. G. Zabetakis

Benzene and toluene are the first two members of an important homologous series whose general formula is CnH2n-6. The members of this series differ in composition from benzene by some integral multiple of CH2; they can all be prepared in the laboratory by the Wurtz-Fittig, Friedel-Crafts and Grignard syntheses. Because 'of the industrial importance of these-hydrocarbons, the limits of flammability of eight members of the series have been determined at 100° C.-(A temperature of 1000 C. was chosen because the determination of the upper limit of flammability of p-cymene requires an apparatus temperature. of at least 90° C. As elevated temperature data are available for other combustibles at 100° C. but not at 90° C., all data were taken at 100° C. in order to obtain comparable results.) Minimum ignition temperatures of these combustibles have been determined at laboratory-pressures.

Jan 1, 1951

By Arthur Notman

THE mineral industries in this country have now had about a year of national planning. Al. though the period is short, the volume of activity and legislation designed to make that planning effective has been nothing short of enormous. Those who have been privileged to see and study a few of the codes to regulate our mineral industry, such as those for oil, coal, steel, and copper, are driven to the conclusion that nothing was really known about the proper way to conduct those industries in this country prior to June, 1933; or if anything was known, nobody in actual practice made use of that knowledge. And yet those industries, in days gone by, helped to make this country the most prosperous in the world, and to maintain a standard of living even today higher than that of any other country. Without wishing to assume any first-hand knowledge of the Russian standard of living, I must confess that the evidence seems to indicate that even with dictatorial authority, national planning encounters unexpected difficulties. Perhaps what really wants

Jan 1, 1935

By Michael W. Hinds

X-ray Fluorescence Spectrometry (XRF) is used at various stages of gold refining. Initially, incoming impure gold is analysed for deleterious elements such as As, Cd, Hg, Se, and Te. Based on the levels of these impurities the material can be returned to the client or accepted for refining. XRF is also used to determine the metal concentrations after the impure gold has been melted and sampled. This information is used to assist the final Fire Assay determination of gold and silver. An energy dispersive XRF is used to determine the end point of chlorination refining step.

Jan 1, 2011

By Donald E. Ralston, A. T. Yu, Richard P. Killmeyer, Peter Phillips, R. W. Vander Laan, John N. Murphy, John R. Messineo, John Peters

Overview Coal production in the first half of 1982 remained near the high levels begun in mid-1981. Production then fell sharply during the latter part of the year due to recession-weakened demand. Even so, 1982 coal production was estimated at 756 Mt (833.4 million st), a record high that exceeded 1980's previous production record of 752.7 Mt (829.7 million st). Though 1982 coal production was substantially below industry expectations, the attained production represented a modest achievement in view of the recession's severity. In 1982, the gross national product declined 1.8%, its worst performance in 36 years. The recession, along with mild weather, improved energy efficiency, and conservation efforts caused the nation's energy use to drop 4.1%. With the iron and steel, construction, and auto industries experiencing production declines, industrial energy use fell 10.8%. The extent to which the nation's economic slump affected coal markets in 1982 varied: • total domestic coal use declined 3.4%; • exports remained strong for most of the year; • electric utility coal use declined for the first time in 25 years; • coal use at coke plants declined by one-third; and • coal use in other industrial sectors stayed surprisingly near the 1981 level. Coal Use Domestic coal use totaled 641.8 Mt (707.5 million st) in 1982,22 .9 Mt (25.2 million st) below the 1981 level. Nearly all the decline occurred at coke plants where use dropped to 37.1 Mt (40.9 million st) in 1982 from 55.3 Mt (61 million st) in 1981. The decline in all other industrial and electric utility coal markets was only 5.3 Mt (5.8 million st). Residential and commercial coal use increased 635 kt (700,000 st) to 7.3 Mt (8.1 million st) from 6.7 Mt (7.4 million st). Power generation decreased 2.3% in 1982, the first year since 1945 that output failed to increase. The decline was due to a drop in industrial demand. Electricity sales to residential, commercial, and other nonindustrial users increased slightly. But coal's competitive position stayed strong. Power generation from oil and natural gas fell 28.9% and 11.7%, respectively. Power generation from coal declined only 0.9%. Among the primary energy sources, coal fueled 53.2% of US electric power generated in 1982, compared with 52.4% in 1981. In 1982, US steel production declined to 66.1 Mt (72.9 million st), the lowest level in 50 years and down from 109.6 Mt (120.8 million st) in 1981. The reduced steel demand forced 13 coke plants to shut down. Coal Exports Coal exports in 1982 totaled 96.4 Mt (106.3 million st), 5.7 Mt (6.3 million st) less than in 1981. Despite the worldwide recession and above normal coal stockpiles in many countries, exports were higher than many expected. This showed the relatively strong US position in international coal trade. The US continued to export near-record coal tonnages despite increasingly competitive influences. These included an improvement in Australia's labor difficulties, the return of Polish coal to Western European markets, and lower oil prices. In 1982, US port facilities were improved and expanded, and more efficient methods for scheduling foreign vessels were implemented. As a result, high volume coal shipments to US ports were routinely loaded and dispatched unhampered by bottlenecks that plagued East Coast ports in 1981. Appalachian coalfield production declined 1.4% from 1981 output and 3.9% from 1980 output. The interior region of the US showed an increase of 7.8% in production. This was primarily because of a

Jan 5, 1983

By F. R. Morral

In 1964, mining education in the United States will celebrate a 100th anniversary-that of the founding of our first school of mines at Columbia University. Prior to that, curricula leading to degrees in mining and metallurgical engineering were offered in 1853 by the Polytechnic College of Pennsylvania in Philadelphia. But the New World's earliest achievements in mining and metallurgical education were those of the Spanish in what is now Mexico. American metallurgy probably goes back to Father Jose de Acosta, who in 1590 described the metallurgy of silver and mercury in the New World.' The Spanish priest and metallurgist Don Alvaro Alonso Barba Toscano (1569-1662), in his hook The Art of Metals, published in 1640, stated a need for a school of mining and metallurgical education in the New World. (The latest translation of this book was made by R. E. Douglas and E. P. Mathewson and published by J. Wiley & Sons, New York, in 1923.)

Jan 1, 1963

By J. A. Finch, J. Yiantatos, A. R. Laplante

This paper re-examines the mixing conditions in the collection zone of flotation columns. These have in the past been characterized with a single uniaxial dispersion coefficient, E. The relationship between E and column diameter, Dc, is examined based on residence time distributions (RTDs) in columns of Dc ranging from 5.lcm to 184cm. Results agree with published correlations in chemical engineering, i.e. E a Dc '" , Data explain why pilot columns display significant upgrading between the feed level and the interface, whereas plant columns do not. It also suggests that, for plant columns, the full collection zone (up to the interface) can be considered when calculating the residence time. A mathematical model considering two regions of different mixing was compared to the single E model. Both models adequately fitted measured age distributions inside the column and overall RTDs. Measured and simulated mixing characteristics are compared to those of flotation banks, using a tanks-in-series approach; banks of comparable mixing to columns are identified.

Jan 1, 1988

By Anton Sroka

The dimensioning of shaft safety zones is a substantial task of mining subsidence engineering. On the one hand, the coal reserves in shaft proximity are to be mined as complete as possible, because they can be made accessible economically. On the other hand, the maintenance of the shaft operation is to be ensured at each time, since shafts represent the most important link between underground and aboveground. Regarding these two criteria, this publication presents a model for the optimization of shaft safety zones. Beyond that, extraction methods in shaft safety zones are described, in particular with consideration of minimized mining influences on the shaft.

Jan 1, 2005

By Hans von Michaelis

The current exploration boom in Central and South America shows no sign of abating and, if anything, is growing. This is despite an inevitable cooling in the recent frenzied buying of resource stocks on the Canadian exchanges which have funded much of the Latin American exploration. Several factors appear to be driving the boom. Firstly, the resource potentials in this vast under-explored regions are nothing short of phenomenal. Secondly, after decades of stifling nationalization and restrictions that stood in the way of foreign investment, especially in mining, emerging nations the world over now suddenly find themselves competing with each other to be the most attractive.

Jan 1, 1995

This paper has been prepared to challenge the thinking of new leaders entering the mining industry in two areas. First, what is the worldÆs perception of mining and what does this mean to those entering the industry? Second, what is the future of learning in the mining industry and how can the industry attract and retain the best people?Then in closing, how can mining companies turn these challenges into opportunities and specifically how is BHP Billiton meeting these challenges.

Jan 1, 2004

By Renato G. Bautista, KNona C. Liddell

A model of the reaction of chalcopyrite, CuFeS2, with Fe3+ and with 02 is considered. Homogeneous solution phase reactions are assumed to be always at equilibrium throughout the dissolution of the mineral. The dissociation of USOb- and several complexation reactions involving cu2+, Fez+ and Fe3+ are incorporated in the model equations. The relative importance of Fe3+, 02, and H+ as oxidants and the role of solution equilibria are assessed and the implications for leaching practice discussed.

Jan 1, 1981

By J. Abbott

This paper gives a brief description of the Compania Ninera del Pacifico (CNP) a subsidiary of the Campania Acero del Pacifico (CAP), its participation in the Chilean Iron Ore mining and the gradual development of its activities. mainly in this paper, it is explained the CNP experience in the production of 34 million tons of self-fluxing pellets for Blast Furnace in a period of ten years in its Huasco Pellets Plant.

Jan 1, 1989

By Don Phelps, Christopher Tattersall, David McAllister

Located south of downtown Seattle, the Beacon Hill Station & Tunnels is the key section of the southern segment of Sound Transit’s proposed new LINK light rail system. This paper presents an overview of the design, which includes 4,300 ft of segmentally-lined bore twin tunnels and a deep mined station. With platforms located156 feet below grade, the station itself is only the second large-scale mined station in soil the US. Its complex geometry combined with variable soil conditions—sands, silt sand clays with slickensides—challenged the designer’s to come up with a SEM-based design that addresses the owner’s risk, cost and schedule concerns.

Jan 1, 2003

Three main divisions of the. Proterozoic are recognised in the North- West of Western Australia. These are referred to, in order of decreasing age as the Mt. Bruce Supergroup, the Bresnahan Group and the Bangemall Group. The stratigraphy and distribution of each is described, their relative ages discussed and a brief geological history of the whole area is Presented.

Jan 1, 1964

By Neil E. Izatt, M. Andre de Ruijter, Ronald L. Bruening, Wesley Young

IBC Advanced Technologies, Inc. has developed ligands, ?amed SuperLig®, which have specific applications in the gold mdustry. These ligands use molecular recognition technology (MRT). One ligand has been developed to selectively recover gold and silver from tailings solutions and from pregnant Merrill-Crowe solutions. Another ligand removes free cyanide, _ th10cyanate, other cyanide species, as well as copper and other base metal cyanide complexes from leached gold-ore solutions. The development of these "species selective'' SuperLig® prod­ucts allows for the more efficient operation of gold recovery processes and opens up the possibility of the economic devel­opment of high-copper gold ores. The resulting gold eluate is a high grade and a high purity stream which will simplify the need for further refming. Engineered systems based on MRT consist of a few unit operations utilizing standard equipment and mate­rials of construction. The process is simple to operate, thereby lending itself to automated modular design, which is both eco­nomic to manufacture and to operate. Test results for the gold and cyanide-copper systems are presented in order to demonstrate the high selectivity and effi­ciency of MRT technology in recovering these species from solution. . IBC Advanced Technologies, Inc. (IBC) and Fluor Daniel, Inc. formed a strategic alliance in late 1994. The goal of the alliance is to combine IBC's scientific expertise in the MRT field with Fluor Daniel's engineering capabilities in the metal­lurgical industry. IBC has its headquarters in American Fork, Utah, USA, where research, development and manufacturing are conducted. Fluor Daniel is an international engineering and construction firm with head offices in Irvine, California, USA. Engineering efforts for the alliance are centered in the Fluor Daniel Mining and Metals Operating Company office in Vancouver, B.C., Canada.

Jan 1, 1996

By Riqing Ye

Laser Engineered Net-shaping (LENS TM) is an emerging manufacturing technique that ensures significant reduction of process time between initial design and final components. The fabrication of fully dense parts with appropriate properties using LENS TM process requires an in-depth understanding of the entire thermal behavior of process. In this paper, the thermal behavior during LENSTM processing of 316 stainless steel was studied both numerically and experimentally. Temperature distribution and gradient in the fabricated 316 stainless steel part were obtained by Finite Element Method (FEM) simulation. The numerical results are in good agreement with the experimental observations. The numerical method may be used to optirnize process parameters and predict the thermal response of LENSTM fabricated components. Key words: Laser Engineered Net-shaping, Thermal Behavior, Finite Element Analysis

Jan 1, 2003

By T. H. Phillips

The Mission Mine is an open-pit copper mine located 18 miles south of Tucson, Arizona in the eastern foothills of the Sierrita Mountains. Mining is done on 40 foot benches using P & H 2100 shovels and 170-ton Terex trucks. Drilling is accomplished With two (2) Bucyrus-Erie 45R?s, one (1) Bucyrus-Erie 60R and two (2) Ingersoll Rand T-5?s. For secondary drilling. a Joy VCR-ISO truck mounted drill is used. The mine is currently operating 3 shifts/day, 7 days/week at 59,100 tons per day, with the mill receiving 28,500 tons per day. The management of the drilling and blasting program requires extensive record keeping in all phases of the operation. This is essential in order to evaluate different products and procedures.

Jan 1, 1988

A method, based on the macroscopic population balance equation allowing the dynamic simulation of a multistage adsorption plant given an arbitrary rate expression, is described. The partial differential equations resulting from this method are simplified using the method of characteristics. The simplified equations can then be solved using standard ODE integration techniques. The procedure is illustrated by means of data typical of a CIP application. Requirements for data structures which allow the incorporation of the carbon-in-pulp (CIP) model (and other unit models) into a general metallurgical simulator are described. Based on these considerations, it is concluded that more generality in the description of distributed quantities such as loading and particle size is provided by the use of mass density at fixed class boundaries, rather than discrete masses within fixed classes as has hitherto been used by ore-dressing simulators.

Jan 1, 1987

By J. E. Lawver, J. D. Raulerson, J. P. Bernardi, R. S. Hearon, D. Lynch, G. F. McKereghan

Despite recent economic problems, the future of the Florida phosphate industry appears optimistic. Florida has enormous reserves and will continue to produce a third of the world's phosphate supply simply by making changes in the present system of mining, beneficiation, waste disposal, and land reclamation. The geology and mineralogy of future deposits are discussed with reference to specific deposits. Lower ore grades, increasing power costs, and environmental regulations are necessitating development of new concepts of mining and matrix transportation. Because one of the ores to be mined in the future contains appreciable amounts of dolomite, research and development efforts are being concentrated on new techniques in beneficiation. Changes are being made in plant design to meet environmental and regulation standards. However, the expected new technology outlined for the industry depends on the geology and mineralogy of future reserves.

Jan 1, 1985