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By E. H. Cho

A current environmental concern is the cleanup and restoration of soil contaminated with low-level radionuclides at DOE sites including the Nevada Test Site. At the present, there is no applicable process to economically and effectively deal with the remediation of contaminated soils. This situation requires development of a selective flotation process to separate the radionuclides from contaminated soil efficiently and economically. In this study, a minus 200 mesh size fraction of pure cerium dioxide was used as a surrogate for plutonium oxide which is the major contaminant at the Nevada Test Site. A Hallimond flotation cell was utilized to examine the flotation behavior of cerium dioxide with oleic acid under various conditions of pH and collector concentration Mechanical cell tests were conducted to float the surrogate from a mixture with uncontaminated Nevada Test Site soil in the absence and presence of calcium carbonate as a carrier. Two different sizes of the carrier (minus 150 mesh and 65-150 mesh) were tested. It was found through the Hallimond cell flotation tests that the cerium dioxide could be floated well at pH's 4 and 9 with 10-3 molar oleic acid. It was also found that the addition of the carrier drastically enhanced the flotation recovery of cerium dioxide. The flotation recovery of the surrogate increased from 34 % to 65 % by adding only 0.5 % calcium carbonate (minus 150 mesh) in the feed and also increased to 95 % by adding 10 % of this carrier to the feed. The finer size fraction of calcium carbonate (minus 150 mesh) was more effective in recovering cerium dioxide than the coarser size fraction (65-150 mesh) The flotation method utilizing a carrier of calcium carbonate seems to provide a high potential to be used for the remediation of soil contaminated with radionuclides at various Department of Energy's nuclear weapon sites.

Jan 1, 1996

By R. F. Favreau, Patrice Favreau, Dennis Mahan

Cast blasting is becoming more and more popular, not only in coal mines but also in other operations which require excavation of an upper layer of waste rock to uncover temporarily and excavate a layer of ore, which may for example be material for the fertilizer industry.

Jan 1, 2014

By Andrea Biagi, Elisa Comis, Gianluca Bella, Enrico De Panicis, Guido Barbieri, Matteo Giani

The Sotra Link Project is a major infrastructure project in Norway involving the design, construction, financing and maintenance of several underground and surface structures between Sotra island and the city of Bergen, among them 23 tunnel portals, 12.5 km of tunnels and a 900 m long suspension bridge. This paper describes the benefits in applying a Building Information Modelling (BIM) approach to tunnelling, from Early Design to the Detail Design Phase. The BIM application to the Sotra Link Project resulted in several improvements, such as efficient handling of clashes and inconsistencies, deeper understanding of effective design choices (reduction of errors), more efficient communication between designers, enhanced control of project quantities and costs. The advantages of the BIM approach during the ongoing Construction Phase are also explained.

Jun 23, 2024

By Xuejing Xie, Tianxiang Ren

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). Standardised stream-sediment sampling procedures have been used in mountainous and hilly terrains. Special sampling procedures were developed for application in remote environments, such as high mountains, desert, semi-desert, karst and loess-covered regions. The diversified analytical methods used in more than 20 analytical laboratories participating in the project have been unified into two multi-element, multi-method analytical systems. A unified data monitoring procedure was developed based on primary and secondary standard samples. To date the project has covered about 4 000 000 km2 and the aim is to complete the coverage within the present decade

May 1, 1991

By Kenneth C. Ko

An engineering investigation was carried out on the technical and economic feasibility of implementing flexible liner/backpacking support systems In an advancing tailgate longwall mine. The system for a model mine consists of a circular tube constructed of liner plates and flyash backpacking. Flyash is pneumatically stowed into the tailgate. Small amounts of cement may be mixed to improve the support capability of the fill In difficult local ground conditions. Water is added inside the nozzle immediately prior to spraying. Results of theoretical analyses and a field test show that the designed system is technically feasible, can be cost-competitive, provides more stable ground conditions, and can Increase productivity and coal recovery, when compared with existing retreat longwall systems. In certain mine layouts, the new system can reduce the direct mining costs by a significant amount. The system would be particularly applicable to deeper coal beds with bad ground conditions.

Jan 1, 1980

By A. Vien

Over the past several years, Svedala has developed a continuous charge monitor (CCM) for tumbling mills. It consists of a strain gauge embedded into a rubber lifter and associated electronics. This paper describes the results of a research program to evaluate the technical and economical merits of such a device on a SAG mill. The evaluation includes validation through discrete element modelling and comparison to measured static volumetric load. Inclusion of the measurement into a control strategy and its potential for condition monitoring is discussed.

Jan 1, 2001

By G. E. Geiger

The purpose of this research was to develop a computer simulator fur predicting the air quality in existing coal mines as well as a design aid for developing new mines. In addition to the air quantity flow, the other variables of tempera Lure, moisture, methane and respirable dust are necessary to determine the air quality. An additional feature of this simulator is that it allows parametric studies of these variables to explore the effect that these variables have on the air quality of an operating mine system. The research has also pointed out arias where more research is needed, and promote better and more systematic data taking techniques. Wang and Hartman (see Reference 9, on page 1-98 of Section 1) had already published a computer program to determine the ventilation of large mines, and Wang and Saperstein (see Reference 10 on page 1-98 of Section 1) later published a refinement of the work in the previous reference. These references were the starting point of the simulator developed by this present research effort, and Section 1 of this report is a slightly modified version of the original vent elation program. The modifications were necessary to permit the additional programs of temperature-moisture, methane and dust to be

Jan 1, 1972

By H. Lowers, B. Van Gosen

The Iron Hill (Powderhorn) carbonatite complex is a 31 km2 alkalic intrusion located about 35 km south-southwest of Gunnison, Colorado. The intrusion has been well studied and described because of its classic petrology and architecture of a carbonatite-alkalic complex. The complex is also noteworthy because it contains enrichments of titanium, rare earth elements, thorium, niobium (columbium), vanadium, and deposits of vermiculite and nepheline syenite. In particular, the complex is thought to host the largest titanium and niobium resources in the United States, although neither has been developed. It may be economic to extract multiple resources from this complex with a well coordinated mine and mill plan.

Jan 1, 2007

By A. H. Srnallbone

Over the past few years the rising production costs, shortage of skilled labor, and increased use of lower grade ore bodies have all added justification for the use of on-stream analysis. A rise in the number of on-stream units indicates that this type of assay is now being accepted as a necessity. On-stream analysis is a much more rapid means of obtaining true assays of a flowing product when compared to wet chemistry or "grab" samples dried, briquetted and assayed by x-ray. In contrast, on-stream analysis uses real time samples assayed every 30 seconds while each stream is assayed every 5 to 15 minutes. It is very important not only to know that a change has occurred in the process, but to know what caused the change and how to correct for the change. For example, in a tailing sample the elements of interest comprise between 1% and 10% of the sample. The remainder is water and gangue. Previously the gangue was not assayed nor were the low atomic number elements used for corrections. In addition to the demand for higher accuracies some concentrators were being penalized for excessive Ca or in some cases 5i in their concentrates. This penalty was being imposed by the smelter in order that they could better cope with pollution problems and prolong the life of their furnaces. But until Ca, 5i, and S are measured on-line, nothing can be done about their control. By accurately measuring these light elements on-line, a complete assay is obtained of the total sample providing improved accuracy for the important products. The justification for complete accuracy assays is now even more obvious because they are possible at very 1ittle increased cost and at no increase in analytical time.

Jan 1, 1977

By D E. Thorp

The mining and concentration operations of New Zealand Steel have been carried out initially from the Waikato North Head (WNH) deposit since 1969 and subsequently from the Taharoa deposit since 1972. Over the years the WNH operation has produced about 1.2 million tonnes of concentrate which has been converted into steel, while total exports to the Japanese Steel Industry from Taharoa reached five million tonnes in February of this year. Recent expansion plans both in domestic steel production and in the ironsand concentrate export market have made it necessary for the company to look closely at, among other areas, the mineral processing of the titaniferous ironsands in both deposits. This paper deals with the recent test work carried out at WNH and Taharoa on the use of the cone concentrator unit as a primary gravity concentrating unit ahead of the magnetic separation stages and as a cleaner concentrator following the primary magnetic separation.

Jan 1, 1977

In today?s high tech world, systems are getting bigger, faster, better. To remain at the leading edge, in any business, depends on accurate but flexible design thereby allowing operational managers to provide alternatives to improve their operations. The ultimate goal is to deliver to plan, with optimum economics. Mining is no different, with falling prices and escalating costs, improved margins become the focal objective. There are many ways to achieve this, ranging from operational efficiency improvements through production scenarios to planning initiatives. Of all, planning usually receives the least attention, yet it is the area of most influence on the NPV of the reserve. With computer technology, numerous concepts and iterations are possible thereby closing the gap between optimal and actual design. This paper discusses the application of the split shell design at the De Beers Venetia open pit in South Africa.

Jan 1, 2001

By Vahid Tajdar

The behavior similarity between pile and cone penetration test, has guided the researchers to use the CPT results in prediction of piles bearing capacity. In this article, artificial neural networks have been used to study about relation between cone tip and sleeve friction strength obtained from cone penetration test and ultimate pile bearing capacity, obtained from static pile load test. Artificial neural networks "ANNS" is a form of artificial intelligence. ANN tries to dramatize the human nerves & brain system biology structure in self-structure. In this article, the results of relevant studies about the prediction of ultimate pile bearing capacity in especial area of soils are presented by use of back - propagation neural networks. The results of static pile load test up to failure on 63 piles with closed end and CPT test results in the place of construction these piles use in order to confirm and creation ANN model. Comparing predicted ultimate pile bearing capacity by utilizing ANN with the numbers which are predicted by 5 common traditional methods shows that using of artificial neural networks is a suitable method for predicted ultimate pile bearing capacity in identified area of texture of soil moreover it has a better operation in comparison with common traditional methods.

Jan 1, 2006

By B. Ulrich

The basis of this paper is a compilation of work in the design and construction of copper heap leach facilities, and interviews with various heap leach operations personnel in Chile and Peru. The purpose is not to highlight specific mines and their performance, but rather to discuss geotechnical/civil features of copper heap leach facilities that function well, as well as features that do not. During the 1990s several copper heap leach facilities were brought on-line in South America. Many of these facilities have now been operational for a number of years during which time the operators have been able to monitor the performance of their heaps. This paper serves as a compilation of operators? experiences, and provides a discussion of the lessons learnt over the past decade. Several key geotechnical issues are examined, focusing upon the integrity of the ore, drainage material and pipe network, along with the success of inter-lift liners. This conference provides a timely update of the original paper (Burkhalter et al, 2002).

Jan 1, 2003

By Peter Kondos

The need for a sustainable development of ore deposits makes it imperative to be innovative and mindful in creating an economically and environmentally viable operation, while maintaining a good working relationship with the various stakeholders involved in developing and operating a large and complex mining project. This is becoming immensely important as gold ore deposits are becoming more mineralogically complex along with lower grades presenting both metallurgical and environmental challenges that need to be addressed in mitigating risks and improving project economics. This paper presents Barrick?s approach to development of strategic technologies for our long-term sustainable growth through conversion of valuable resources into reserves for both our green-field development projects and the expansion of our existing mining operations. Some of the key strategic solutions, including mineral processing, metallurgical and energy technologies, developed by Barrick and their impact on some of our complex gold and copper-gold ores will also be discussed in this paper. Keywords: gold ores, copper-gold ores, processing, breakthrough technologies

Sep 1, 2012

By Mariana Beatriz dos Reis Silva

A influência do tempo entre passes na evolução microestrutural de dois aços austeníticos, F138 (sem nióbio) e ISO 5832-9 (com nióbio), foi investigada através ensaios de torção a quente em condições industriais. Análises foram realizadas através de microscopia ótica e eletrônica de transmissão, EBSD e microdureza. Menores tempos entre passes produziram menores tamanhos de grãos e de precipitados. Microestruturas mais refinadas induziram a maiores microdurezas. O aço ISO 5832-9 apresentou maior resistência que o F138. Precipitações de TiNbN, após o encharque, e de NbCrN e NbN (5%), durante o processamento, foram observadas no aço ISO 5832-9. Ambos os materiais sofrem recristalização dinâmica, partículas grosseiras (> 200 nm) atuaram como partículas de reforço e partículas menores (< 50 nm) no ancoramento dos contornos de grãos e discordâncias no ISO.

Jan 16, 2018

By T. Lindstad, V. Myrvågnes

In the production of high silicon alloys, carbonaceous materials like coal, coke, charcoal and woodchips are utilized as reducing agents. Primarily based on historical prices of charcoal compared to fossil reduction materials, the Norwegian Ferroalloy Industry has mostly been using coal and coke (char) as carbon source. The most important role of the carbonaceous material is to react with the SiO gas to produce SiC. The ability of the reduction materials to bind SiO gas can be measured and the value is recognised as the reactivity of the carbon source. This reactivity is one of the most important parameters in the smelting process in order to obtain a high yield of metal. The reactivity of the carbon materials is directly correlated to the material properties. It is known that the rank of the coal influences the SiO reactivity where low rank is beneficial. Coals of the same rank have however proven to have varying reactivity. In order to investigate how the micro-constituents of coal influence the reactivity towards SiO gas, three single seam unwashed coals of different origin which fulfil the requirements of the Norwegian Ferroalloy producers have been chosen. As the structure in the carbonized product is a function of petrographic constitution and carbonization parameters, the coals have been separated into different density fractions. The various density fractions of the same coals proved to have significantly different petrographic composition. The coals were carbonized according to a procedure simulating the conditions the coals experience when charged to an industrial furnace. Chemical-, physical- and petrographical properties of both the coals and the resultant chars have been thoroughly examined and correlated towards the SiO reactivity.

Jan 1, 2007

By I Lourel

In evaluating the installation of an in-pit crushing and conveying (IPCC) system for any mine, a number of options are available for each of the dig side, transport and dump side operations. Some of them are moreappropriate than others; given the pit arrangement, the material being handled and the rates at which it needs to be moved. This paper seeks to document the options that might be employed, and to rank them in terms of their applicability at any mine and their practicality overall, with a view to nominating those that would be most suitable for further study.

Jan 1, 2009

By Haskiel R. Shell

Methods of chemical analysis of clays for the following constituents are presented: moisture, ignition loss Fe2O3, TiO2, P2O5, CaO, MgO, Na2O, K2O, total. carbon, carbonate carbon total sulfur, soluble salts, and soluble sulfate. In these procedures the attainment of accuracy has been the primary consideration sample was taken to insure accuracy, with ordinary precautions. The procedures may therefore be somewhat somewhat and will not be suited for routine work on samples for which the approximate analysis is already known and in which the need for accuracy is not very exacting. However, the method shod be as a set of detailed directions, that have been tested and shown to yield accurate results with clays and other aluminum silicate minerals. Among these minerals are clays of all types, bentonite bauxite, shale, brick; soil, calcined refractory, and sand. Although some of the methods are Unusual, no particular claim is laid to originality. The material was drawn frail many sources, put together and tested.

Jan 1, 1949

By G. A. Gamble

Fans used to ventilate subway, passenger rail and vehicular tunnels are similar to the fans used to ventilate underground mines. However, tunnel ventilation fan systems are typically designed to meet NFPA 130 or 502 standards, while mine ventilation fan systems must comply with the appropriate federal mine safety regulations. As a result, fan operation requirements and performance criteria, as well as typical fan and duct configurations differ significantly for tunnel and mine ventilation applications. Variations in environmental conditions in tunnels as compared to mines also result in differences in fan performance and material specifications. The need to enclose tunnel fans within building structures creates space restrictions impacting fan size selection that are not commonly encountered in mine fan installations, resulting in different approaches to selecting fans for the two types of tunnels. This paper discusses the various similarities and differences in design considerations for tunnel and mine ventilation fans.

Jan 1, 2009

By L. Andrews

Electron microbeam analysis of metallurgical samples covers abroad field and has applications in the areas of minerals processing, hydrometallurgy, pyrometallurgy, physical metallurgy and corrosion. Some idea of the possibilities of microbeam techniques can be illustrated by examining the following example of a run of mine gold ore sample. Milling and bulk chemical analysis of the ore will provide major and minor element analysis as well as the gold grade. More detailed chemistry can also reveal the presence of trace elements that may be advantageous or deleterious to downstream processing. Electron microbeam analysis can provide additional information in the form of size, liberation, association and composition of the gold, the percentage of refractory gold, the size, liberation, association and composition of enclosing sulphide or arsenide phases and the levels and association of the trace elements that may affect processing. In most cases electron microbeam analysis complements bulk chemistry, and does not replace it. Both techniques should be used in parallel for maximum effect. This paper touches on the origin and history of electron microbeam techniques, as well as the theory behind microbeam analysis and processing. The more common types of instruments and their applications will also be dealt with briefly.

Jan 1, 2007