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By Louis A. Panek

INTRODUCTION Block caving is distinguished from other types of mining in its requirements that the mineral body to be extracted must cave after a relatively large tabular open¬ing is created underneath it, and that the caving must be predictable and controllable for both operating and safety reasons. A mineral body that caves readily may present special problems with respect to ground support in the mining access openings, where stability, rather than failure, is the desired objective. The complete ex¬traction of a caving block, which may measure 50 to 100 m on a side and 100 to 300 m in height, tends to create a large void, resulting in significant changes in the ground stress system and a migration of rock from all directions toward the void; these events begin very early in the life of the mine and lead to additional spe¬cial problems with respect to control of ground move¬ments in the mine working areas, in the rock adjacent to the caving stope, and on the subsiding surface above the mine. Thus, the mechanics of an undercut-cave operation involve a broad range of geotechnical subject matter, including the determination of the lithostatic earth stresses, the structural properties of a large jointed rock mass, the flow properties of the fragments after caving, the stability of tunnel-like openings, and the stability and displacements of the rock structure (1 to 2 km in size) that surrounds the ore body. The objectives are achieved by in-place measurement of rock properties, laboratory tests, theoretical structural analyses of the related prob¬lems, measurements of structural behavior in and above the mine, and comparison of theoretical predictions with actual performance in order to interpret and refine the predictive capability. Undercut-cave mining (Julin, et al., 1973) differs from most other methods in that the caving is an essen¬tial and inherent part of the excavation process and in¬volves the movements of millions of cubic meters of rock over distances of hundreds of meters, as compared to the gradual 2-m settling of the overburden typical of full¬caving longwall coal mining. Undercut-cave mining may involve a rock mass on the scale of a 1-km diam open¬pit mine, but mining is several times deeper than that in the open-pit mine; furthermore, a large portion of the rock mass is in a failed, rather than a stable, state. Ground-control problems are inevitable in a situa¬tion where ground movements are occurring on such a large scale, and where the rock mass is expected con¬veniently to cave at one location but to be stable at an¬other. To devise effective responses to these ground¬control problems, one needs to know first of all what is happening, not merely at the point where the symptoms are observed, but more broadly with respect to the be¬havior of the entire mine rock-mass structure over the total area of extraction, including the effects on the sur¬face as well as those underground. Monitoring structural behavior on this scale would require a sizable group of people, if they attempted to measure all the significant mining-induced changes of ground displacement and pressure, even on a 100-m grid of points. The practical approach is to conduct the mea¬surements activity by a judicious sampling, making in¬termittent, concentrated efforts in selected areas of lim¬ited extent to study problems of immediate importance; simultaneously a minimum level of surveillance is main¬tained over the total structure to delineate long-term be¬havior trends in the major structure, which provide the baseline reference data that are so essential for interpre¬tive purposes. Mine-structure behavior depends not only on the mine extraction configuration and sequence, but on the rock structural properties and how they change from one location to another in the mine. Increasing attention is being given to determinations of rock strength and de¬formation by performing mechanical properties tests in place and in the laboratory, and by drawing inferences from the mapping of geologic structure in mine openings as they are driven and from the logging of cores ob¬tained from exploration drilling that may be performed primarily for delineating ore reserves. Monitoring of mine-structure behavior and inter¬preting it in terms of the growing excavations and the structural properties of the rocks have significant im¬pacts on designing the major undercut-cave operations of undercutting and drawing the ore, supporting the ac¬cess openings, and controlling surface subsidence. The purpose of this chapter is to call attention to the com¬mon ground-control problems encountered in undercut¬cave mining, to relate them to the mining process, and to explain the geomechanical approaches to analyzing these problems with emphasis on methods that are most readily available to the mine staff. UNDERCUTTING, CAVING, AND DRAWING A distinguishing characteristic of an undercut-caving method of extraction is the objective that the rock mass fails of its own weight in a predictable and controllable manner, after it is undercut by excavating a tabular¬shaped void, horizontal or inclined. Induced or forced caving refers to procedures that may be resorted to when the ore will not self-cave over the desired span. Block caving, panel caving, and mass caving are terms used to denote the particular sequence of undercutting and ex¬tracting the total area of the ore body on a single min¬ing level. The discussion herein is not specialized to any of these variations; the word block as used does not imply anything as to sequence. CREATING THE UNDERCUT A common undercutting method is to drive a series of drifts and blast the intervening pillars. Theoretical structural analysis and practical experience show that ground-support problems in the undercutting drifts and in underlying access openings as well (the same princi¬ple applies even if undercutting is done by belling out drawpoints from the slusher drifts) are minimized by retreat-mining across the undercut slot according to a sequence such that the growing undercut area retains a

Jan 1, 1982

By Michael Schultz, Gregory Sanders

In 2017, the North Texas Municipal Water District (NTMWD) initiated the design of the Sister Grove Regional Water Resource Recovery Facility (SGRWRRF) to provide additional treatment capacity for future population growth within the Lavon Lake watershed. To provide a discharge location for SGRWRRF approximately 4.5 miles of 2.4- meter (96-inch) internal diameter pipeline will be constructed, including 2.3-kilometer (7,800) feet and 487-meter (1,600 foot) long tunnel segments. This paper will discuss the anticipated geology of the two tunnel segments, selection of the tunnel alignment, the anticipated initial tunnel support requirements and other aspects of the project design

Jun 13, 2021

By Greg Sanders, Michael Gilbert, James G. Shaughnessy

"A new raw water intake from the South Holston River to the Kingsport water treatment plant is under construction. The exploration for the 335 meter long horseshoe shaped tunnel design took advantage of the site topography along the alignment to better define the complex geology consisting of Knox Limestone and Sevier Shale formations separated by a fault zone. To assess the geological conditions and to determine the extent of the fault zone, a 183 meter long horizontal boring and geophysical investigation was performed along a portion of the tunnel’s horizontal alignment. Explorations defined the fault zone width at approximately 5 meters and packer testing along the alignment provided a means of estimating groundwater inflows. As the tunnel excavation advances, comparisons of exploratory data versus encountered conditions will be made. This paper provides details on the geotechnical investigation, lessons learned, and the influence of the geology on the tunnel design. PROJECT OVERVIEW The Kingsport WTP is supplied with raw water via the South Holston River. The City of Kingsport (City) owns and operates the Kingsport Water Treatment Plant (WTP). The existing raw water intake system, consisting of pumps, power supply, raw water piping and appurtenant facilities has been determined to be vulnerable to failure. The original Raw Water Pump Station (RWPS) was constructed in 1928 as part of the original Kingsport WTP project. The 1928 RWPS operated until 1970 when it was replaced by the existing RWPS. This existing system still utilizes the 1928 piping and piping tunnel. Improvements to the RWPS hydraulics and capacity are required to meet the City’s future water treatment needs. The system extracts water from the South Fork of the Holsten River and coveys it via three pressure pipelines to the WTP. The conveyance piping exits the RWPS, ascends approximately 23 m up a near vertical rock outcropping then enters a 120 m long tunnel. Upon exiting the tunnel the piping continues underground to the WTP. The drill and blast tunnel is horseshoe shaped and nominally 3.3 m high by 3.3 m wide. The easternmost 62.3 m of the tunnel is without any type of support. The remainder is lined with concrete. According to the City of Kingsport, the concrete lining was installed in the 1970’s as part of upgrades to the facility. An evaluation of the current facilities concluded that the conveyance piping was in poor condition and required replacement."

Jan 1, 2016

By D. L. Johnson

A number of small but rich copper sulfide (chalcocite) ore deposits are located on Michigan's Keweenaw Peninsula. These deposits are considered too small to warrant the capital investment required for conventional mining. However, they are being considered for in-situ solution mining as a way to revitalize the area's once prosperous copper extraction industry. Geology, mineralogy and geohydrology of the deposits have been investigated to determine their suitability for leaching; Three conclusions were drawn from the work. First, the sulfide mineralization is found primarily in fractures (65%) and, therefore, is accessible to injected leach solutions. Second, the ores are shallow, occurring from surface exposure to about 200 meters depth; injection and recovery wells would not have to be excessively deep. Third, the rock was found to have low permeability, in the neighborhood of thirty millidarcys or less. However, preliminary hydraulic fracturing experiments indicate that this will be an effective method for permeability enhancement. In one experiment a permeability increase of 100 times was achieved using a very low injection pressure at shallow depth. Additionally, fracture aperture spacings measured from drill core were correlated with fair success to field permeabilities.

Jan 1, 1989

By M J. Dunn

The geotechnical model is the cornerstone of any mining geotechnical design and as such the confidence level and reliability of the geotechnical model is paramount. The geotechnical model confidence level needs to be commensurate with the level of design that is being applied or study that is being undertaken. The geotechnical model is made up of several components and the reliability of the data underlying these components ultimately determines the reliability of the geotechnical model.Data reliability is linked to the quantity of data collected, the spatial distribution of the data collected, quality of the data collection and the interpretation of the data. In a typical project, there is an opportunity to improve data reliability through the scoping, prefeasibility, feasibility and final design and implementation stages.Currently, very little quantitative guidance exists in the literature on assessing the confidence level of geotechnical studies, although there have been attempts by various authors (Haile, 2004; Haines, Swart and Kruger, 2006; Read and Stacey, 2009; Dunn, Basson and Parrott, 2011) to qualitatively describe what level of geotechnical data is required. Recently a number of authors (Read, 2013; Fillion and Hadjigeorgiou, 2013; Thomas, 2013) have outlined methods that could be applied to assess the reliability of some types of geotechnical data that are used in the development of geotechnical models.This paper briefly discusses some of the factors influencing data reliability and the geotechnical model confidence and some of the tools available.CITATION:Dunn, M J, 2014. Geotechnical models and data confidence in mining geotechnical design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 127–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Jakub Szary

Excavation and shoring adjacent to the above-grade Gilmore train station and elevated guideway was undertaken in 2019. A perimeter secant pile cut-off wall was constructed to a depth 37 m (121 ft) below ground surface consisting of 1.0 m (3.3 ft) diameter drilled piles spaced 750 mm (2.5 ft) on-center, tied back with soil anchors, and reinforced with W610 steel sections every 4th pile. A bracing/jacking system was also constructed to support 3 free-standing guideway caissons within the excavation. An automated instrumentation program was installed to monitor movements of shoring walls and train infrastructure in real time and consisted of a robotic total station, inclinometers, tiltmeters, strain gauges, extensometers, and anchor load cells. Baseline monitoring was able to establish diurnal and seasonal movements within the structure, strongly correlated with temperature. The system actively monitored various shoring elements and train infrastructure in real time and alerted the project team when values exceeded predetermined threshold values. Remote reconfiguration of the automated system allowed for more frequent monitoring during jacking of Pier 29 in March 2022. Monitoring data was in agreeance with on-site manual surveying results and jacking dial gauges, and proved to be a reliable monitoring system for construction applications.

Sep 1, 2022

The need for formalised geotechnical reporting has not been fully explored at many operations. With the continuing need to provide safer and more efficient workplaces, the requirement for good geotechnical reporting systems (as with other reporting systems) has become of greater importance.Historically, the risk from rockfalls has been the largest cause of fatal injuries in the underground mining industry. The response of the ground to mining is generally poorly documented at many mines. At Olympic Dam, it was found that the existing corporate hazard and incident reporting (HIR) procedure did not record enough specifics about geotechnical issues. A separate and more specific geotechnical reporting process was set up to address this problem.This paper examines the role that geotechnical reporting plays at the WMC Resources Olympic Dam Mine; from reporting and rectifying day-to-day geotechnical issues that affect the operation to documenting and analysing longer term trends.

Jan 1, 2004

By Peter Zhang, Dan Neilans, Scott Peterson, Scott Wade, Joe Pugh, Ryan Mcgrady

"A coal outburst is a severe safety hazard in room-and-pillar mining under deep cover. It is more likely to occur during pillar retreating. Multi-seam mining dramatically increases the risk of coal outburst within the influence zones created by remnant pillars and gob-solid boundaries. Though coal outburst is generally associated with heavy loading of coal pillars, its occurrence is difficult to predict. Risk management provides a proactive tool to minimize coal outburst in room-and-pillar mining under deep cover. Risk assessment is the first step in identifying and quantifying outburst risk factors. The primary risk factors for coal outburst are overburden depth, roof and floor strength, geological anomalies, mining type, multi-seam mining, and panel width. A risk assessment chart can be used to proactively screen out mining sections with high risk of coal outburst for further analysis. Gob-solid boundaries and remnant pillars are critical factors in evaluation of the coal outburst risk of multi-seam mining. Risk identification, risk assessment, geologic influence mapping, geotechnical evaluation, risk analysis, risk mitigation, and monitoring are essential elements of coal outburst risk management process. Training is an integral part of risk management for risk identification and communication between all the stakeholders including management, technical and safety personnel, and miners.INTRODUCTIONA coal outburst is a sudden violent burst of coal from a pillar with broken coal or blocks of coal forcibly ejected into open entries. A coal outburst is a severe safety hazard as the mining crew is highly exposed at the site when the event occurs. Though deep cover and strong roof and floor are underlying geologic conditions of a potential burst incident, its real occurrence is also the result of additional mining factors. In room-and-pillar mining, a coal outburst could occur during both development and pillar retreating, but the latter greatly increases the risk of outburst. The other risk factors of coal outburst also include mining layout, multi-seam mining, presence of adjacent gob, cutting sequence, and local abnormal geologic conditions. Over the years, the cases of coal outbursts have been studied by many researchers and mining practitioners(Peng, 2008; Newman, 2008; Iannacchione and Tadolini, 2008; Gauna and Phillipson, 2008; Hoelle, 2008; and Newman, 2002). It is commonly believed that the coal outburst is the result of a sudden release of elastic strain energy stored in coal pillars and is highly associated with cutting into heavily loaded coal pillars, but its occurrence is a rare event and is difficult to predict. A number of engineering controls have been recommended to mitigate outburst potential. For room-and-pillar mining, sufficient pillar sizes have been the primary control for coal outburst prevention. The pillar design tools such as ARMPS and AMSS developed by NIOSH have played an important role in the design of stable pillars to prevent pillar collapse and squeezing as well as coal outbursts. In fact, with the implementation of pillar design using proper stability factors, pillar collapse and squeezing have been almost eliminated, and the number of coal outbursts has been greatly reduced in the US over the past decade. However, after a few outbursts occurred during pillar retreating in the US over the past a few years (MSHA, 1996; MSHA, 2014; MSHA, 2013), it has been realized that sufficient pillar size is still not enough to prevent coal outbursts. The investigations of the incidents showed that other factors such as multi-seam mining, panel layout, cutting sequence, and local geologic factors also seemed critical in causing the events. Therefore, it has become imperative that additional proactive measures beyond proper pillar design be implemented to prevent coal outbursts."

Jan 1, 2015

By Tyler Acorn

In December of 2009 an estimated one million ton slope failure activated a 10 million ton mass impacting use of the main ramp system in the Newmont Gold Quarry pit. The failure left behind a 400 foot (122 meters), vertical to sub vertical scarp feature and shut down production in the lower benches of the pit.

Jan 1, 2011

By Marc Raithel, Sven Schröer, Lilma Schimmel, Dimiter Alexiew

"The Geotextile Encased Columns (GEC) deep foundation system for embankments and dikes on soft soils was introduced some 20 years ago and is now considered State-of-the-art in Germany, Europe and, step by step, worldwide. The GECs consist of compacted non-cohesive granular fill similar e.g. to common gravel columns with one decisive difference: they are confined in a high-strength, high-modulus, flexible geotextile “cylinder” (encasement). This engineered element with parameters being adaptable in a wide range provides a decisive tool to control and optimize the behavior of the GEC foundation system. Consequently, the GECs work properly even in extremely soft soils, and a wide range of fills inclusive of sands can be used. In the meantime vast design and technological experience is available and codified design methods exist. Initially the paper briefly describes the general idea, the basics and specifics of design, construction technology, materials, restrictions and optimal application areas. Then it focuses on three informative case studies. They are briefly presented focusing for brevity only on the most important facts and experience inclusive of the most meaningful data of short- and long-term measurement programs.INTRODUCTIONWhen considering embankments on soft soils, generally two groups of solutions exist:Unsupported embankments; there are four main options:a) build up embankment extremely slowly waiting for sufficient consolidation after every stage;b) replace the soft soil partially or totally;c) install a high-strength basal reinforcement providing overall and local stability and allowing much faster embankment construction;d) combine c) with strip drains to accelerate consolidation and thus the construction process additionally (Fig. 1, left).Today, practically only option ""d"" is of practical relevance. Despite all the pros and cons, the common attribute of all non-supported options is that local and overall stability (Ultimate Limit State-ULS) can be achieved and controlled, but not the short- and long-term settlements (Serviceability Limit State-SLS). The latter can be significant, e.g. up to 30% of the nominal planned embankment height. Supported embankments (Fig. 1, right): the main common idea is to over-bridge the soft soil layers by supporting vertical elements of different types: rigid piles, trench walls etc. or by ""softer"" solutions of different column types (compacted, cemented, mixed-in-place etc.). Herein the borderlines between “piles”, ""pile-similar elements"" and ""soil improvement” are fluent and depend on country, traditions, codes etc. The common attribute of the “supported” schemes is a minimized settlement. Twenty years ago a new specific solution was launched: the Geotextile Encased Columns (GEC), which is discussed in more detail below."

Jan 1, 2017

By Mark C. L. Patterson

Hydrothermal brines are extracted from significant depths below the surface of the earth and arrive at the surface at elevated pressure and temperature. The exact chemistry and conditions of these brines depends upon the rock formations through which the water travels, but many of the brines are rich in dissolved minerals especially silica which is often saturated in the brine. At pressure and temperature the minerals remain in solution but in order to extract heat from the brines, they need to be cooled and during which many of the minerals precipitate causing problems. Where precipitation is a problem in the downstream processing, the brines are maintained at a high enough temperature and pressure so as to avoid precipitation and injected back into the geothermal formation. This results in a significant loss in potential energy that could be recovered from the geothermal brines. If left to precipitate in an uncontrolled manner, many of the minerals will precipitate as gels, in a high surface area form which is difficult to extract from the liquor and which can causes problems. Precipitation in this manner often builds up on the inside of pipes, reducing the pipe cross-section available for fluid flow and reducing the overall efficiency of the plant. If the brines are seeded at the appropriate time or the precipitation conditions are changed, mineral particles can be grown and separated more easily from the brine. During this precipitation and growth phase the chemistry of the local environment can also be altered to grow more valuable particulates. Some of the specific chemistries will be discussed with reference to known geothermal brines and what needs to be done to precipitate value added products. A theoretical approach to the complete extraction of minerals from geothermal brines is also discussed with the goal of extracting more heat from the brine prior to reinjection into the well.

Jan 1, 2006

By Alan Jessop

A small group has been set up at the Dominion Observatory, Ottawa, to make a survey of terrestrial heat flow throughout Canada. Terrestrial heat flow is the heat rising from the interior of the earth and escaping at the surface, and is calculated from a knowledge of under-ground temperature distribution and the thermal conductivity of rocks. A small number of diamond drill holes are being sunk for the purpose of measuring temperatures below the surface, but the program is inadequate for a thorough survey. Mines and holes drilled for other purposes are being sought by the Dominion Observatory group to supplement their own drilling program. F ROM January, 1.962, to December, 1964, geo-physicists of many nations will be cooperating in the "International Upper Mantle Project." Unlike tl1e International Geophysical Year, which was mainly concerned with the fluid layers surrounding the earth, the Upper Mantle Project is an intensive study of the solid earth. Canada, with its large land area and extensive Precambrian Shield, is an active participant in the project.

Jan 1, 1964

By Gerd L. Klinkenborg

Ever see a curvaceous conveyor belt? Reports from Europe indicate appreciable interest in a relatively new system that has revamped some of the concepts of what single-belt conveyors can and cannot do. Invented about ten years ago by two German engineers, the so-called "Serpentix" single-belt conveyor, patented by the firm of Albert Stuebbe, is now operating at more than 100 foreign installations. The system boasts of three unique capabilities-climbing, turning and side discharge of load-which give it, the advantages of a multiple-unit system. The new conveyor needs only one drive station (which may be combined with tensioning), and except for the immediate area of the drive, is capable of conveying loads over a non-linear route. Transfer points are eliminated, and discharge points, which may be located anywhere along the route, may be operated automatically or manually, by direct or remote control.

Jan 1, 1962

By Paul M. Tyler

NOW that the dust of World War II has settled and we and our allies are faced with extravagant losses of men, money, and materials, virtually the only hope that the United States and Britain have in the way of reparations lies in the capture of industrial, technical, and scientific secrets. Even during the war American and British scientists and technicians gained access to German factories, questioned German personnel, studied German documents, and endeavored generally to keep pace with new discoveries in science, industrial technology, and process development. Under various agencies this work continued for two years after the war. Altogether at least 600 American scientists and industrialists have gone to Germany and brought back reports and several times as many British, Canadian, and. Australian investigators have been similarly engaged under co-operative arrangements designed to assure the maximum of coverage with a minimum duplication of effort. As a result of these investigations and document studies, about 500 or 600 reports have been prepared on metallurgical and allied subjects. Those by American authors or joint teams have been listed in the annotated Bibliography of Scientific and Industrial Reports, issued by the Office of Technical Services in the U. S. Department of Commerce. Many of the British reports are also available in this country through the same office or through a British representative in New York. Since it was my duty to read most of these reports for

Jan 1, 1948

By James T. Kemp

SOME interesting and, to American eyes, rather unusual processes for refining impure aluminum derived from scraps were found by American and British investigators who went into Germany in 1945 for the Technical Industrial Intelligence Committee Of the Joint Chiefs of Staff. What was found was recorded in a series of reports (see page 14), many of which have been released for general reading. This paper gathers under one title and summarizes the German work in refining light metal scrap. Reference must be made to the original reports for greater detail. Basically, the occasion and stimulus for the German developments in treating light metal scrap were hard necessity. Germany needed the metal for a rapacious war industry. Adequate supplies of new aluminum from reduction works were not assured. Great quantities of airplane and other light metal war scraps were forecast. It was evident that the scrap metal would have to be reabsorbed by the producing industry and would have to be kept of good quality. The normal current production of manufacturing scrap was being and could be consumed as generated. It offered no technical problem. The mixed scraps, especially those arising from crashed and decommissioned airplanes, however, presented problems of another kind. AIRPLANE SCRAP The recovery of usable aluminum alloy from the mixed assemblies that made up the piles of airplane scrap was attacked in different ways by different groups and with differing degrees of success. Three procedures actually were used On a commercial scale, one was in pilot-plant stage and another had come to a halt in the laboratory a year before Germany collapsed. Four of these five processes actually involved "refining"; that is, some measure of purification of the metal after melting. SORTING AND SEPARATION ON A SLOPING HEARTH The simplest procedure for utilizing airplane scrap involved no refining in the strict sense of the word. This was the practice adopted by two representative plants visited by the author, the Leipziger Leichtmetalle Werke, Rackwitz, Saxony, and the Vereinigte Leichtmetalle Werke, Hanover. These firms did essentially the same thing that was done in England but not with equal success, to judge by their shorter experience, the smaller tonnage handled and by the number and quality of alloys produced. The two German firms named rough-sorted scraps by their easily recognizable alloys, essentially by part and shape. They used hand labor to chop and hack and tear apart. The easily separated heavy metal and nonmetallic scraps were discarded as they were found. Steel and the higher-melting-point metal parts riveted to aluminum or built into

Jan 1, 1947

By Roy J. M. van Lier

In industrial aqueous solutions, germanium generally occurs in trace amounts amid high concentrations of other metals, such as zinc, copper and iron. Separation of germanium from these metals as well as its isolation from gallium and indium pose a real challenge to the hydrometallurgist. After a brief discussion of the aqueous chemistry of germanium, this paper reviews the flowsheet of the Apex Mine in Utah. The Apex property was the only mine in the world to be operated primarily for production of gallium and germanium, but apparently closed due to great operating difficulties. Several process variants proposed for the treatment of the Apex ore, including bioleaching methods, are addressed. Following a more general description of the behavior of germanium in hydrometallurgical zinc processing streams, available technology for its recovery from aqueous solutions is summarized. Precipitation, solvent extraction, ion exchange, electrowinning, ion flotation and liquid-membrane separation are all outlined in terms of the aqueous chemistry of germanium. Finally, the production of high purity germanium dioxide and metal is briefly discussed

Jan 1, 1995

By A. J. W. Headlee

RECENT interest in germanium centers around its use as a semi-conductor of electricity in electronic devices. It is generally believed that germanium transistors, diodes, triodes, photocells, and rectifiers will largely replace the present-day vacuum tubes. The germanium electronic devices are much smaller, lighter, and more resistant to shock, and they require only a small fraction of current required for conventional devices. Hence only a small amount of heat is given off by the equipment. This development will require many times the quantity of germanium now being produced, which in 1948 was approximately 1000 lb1 and was obtained almost entirely from zinc ores in Missouri, Kansas, and Oklahoma. No one knows with certainty what the demand will be for germanium by 1956. It may be 40,000 lb.1 Known concentrations in zinc ores are not sufficient to

Jan 10, 1953

By AIME AIME

AMONG the European nations Germany is the center of interest economically as well as politically, and of prime importance for Europe as a whole is Germany's capacity to produce mineral products for armament and for export in exchange for the import of the essential supplies to maintain its industries. So far as minerals are concerned, Germany is worse off than any other great power except Italy, and deficiencies are being met by attempts to increase output from local deposits and by greater use of substitutes derived from domestic raw materials to replace imported metals, petroleum products, and other minerals.

Jan 1, 1939

By Harold Gibson, Ulrich Schwarz-Schampera, Ralf Freitag, Hendrik Mueller

INTRODUCTION Germany has a long history in marine research in the Indian Ocean. The first German scientific cruise started in 1964, followed by a series of state-sponsored research cruises between 1983 and 1995 leading to the first finding of polymetallic sulfides in the Indian Ocean. The research included regional bathymetric, geological, structural, volcanological, petrological and hydrothermal investigations along the Carlsberg Ridge and the Central Indian Ridge (CIR). Early environmental base line studies covered oceanographic and sedimentology aspects. In 2010, BGR took the initiative for the preparation of a license application for the exploration of polymetallic sulfides with the International Seabed Authority (ISA), and prospecting started in 2011 along the southern Central (CIR) and the northern Southeast Indian Ridge (SEIR) in the southwestern Indian Ocean (cruises INDEX 2011 on board R/V Sonne), INDEX 2012 (R/V Fugro Gauss), INDEX 2013/1-2 (R/V Sonne) and INDEX 2014 (R/V Pelagia). After three years of resource-oriented and environmental base line studies, BGR, in order for the Federal Ministry for Economic Affairs and Energy (BMWi), applied for an exploration license which was approved by and subsequently signed with the ISA in 2015. The license gave permission to start a detailed exclusive resource-oriented exploration program in the license area. The program includes the outline of potential ore deposits and a resource assessment but also extensive and detailed base line studies for the sustainable protection of the marine environment in the license area. The license contract has a fifteen years lifetime and may allow the application for a subsequent mining license. The exploration aims at the identification of inactive polymetallic sulfide deposits, formed below former discharge zones of hot hydrothermal fluids on the ocean floor (“black smoker” systems), by advanced and modern exploration techniques.

Jan 1, 2018

By David Roncalla, Emma Flores, Juan Pérez

Se ha co creado a Rurana, Centro de Innovación Social de Asociación Pataz, para coadyuvar en el abordaje de los desafíos de triple impacto, basados en la innovación como un evento sistémico con direccionalidad de largo plazo, pero con pasos de corto y mediano plazo para desarrollar las capacidades requeridas para el logro de Misiones, propósitos de gran impacto enmarcados en la teoría de Mariana Mazzucato.

Sep 29, 2023