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By William A. Hustrulid

An overall summary and the individual reports of eight workshops to determine research and development needs in western mining ore presented. Problem areas are identified, and recommendations regarding priorities, funding sources, and prime movers are made. The objective of this contract was to identify research and development needs for advancing mining technology as well as health and safety measures for western U.S. Surface and underground mining. This was accomplished by convening a series of workshops where problems could be thrashed out by producers of trona, uranium, open pit copper, underground salt (from the Midwest and New York), underground metal and nonmetal, etc. In addition to problems, future priorities, funding, and the desicion as to who should be the prime mover on R & D were discussed.

Jan 1, 1976

By David Schlain

"IntroductionThe purpose of this investigation was to study the characteristics of the high-acid electrolytic manganese cell with the idea of fitting it into one of the flow sheets being worked out by the Metallurgical Division of the Bureau of Mines for the recovery of manganese from low-grade domestic ores.In construction, the high-acid cell 3/ differs from the low-acid type in that the cathode and anode compartments are separated by a diaphragm of relatively low porosity, such as alundum. This is necessary because in the high-acid cell the two electrolytes are circulated separately. The anolyte is 15 to 30 percent H2SO4. The catholyte consists of a solution of ammonium sulfate and manganese sulfate with a OH of 4 to 3. The only mixing of electrolytes is that resulting from flow through the diaphragms. In the low-acid cell the two electrolytes are not circulated separately and do not differ so widely in hydrogen-ion concentration. Hence, the canvas diaphragm is sufficient.During operation of the cell, manganese is deposited on the cathode, and sulfuric acid is produced in the anode compartments. Various other reactions take place in the cell. There is considerable decomposition of water; hydrogen is evolved at the cathode, and oxygen is liberated at the anode. When lead anodes are used, some hydrated oxides of manganese are formed at the anodes. The quantity of oxides formed is not as great as it is in the low-acid cell, because fewer Mn++ reach the vicinity of the anodes."

Jul 1, 1942

By Richard Hanke

Tunnel construction on the Brightwater Conveyance System?s East and Central contracts required ground modifications of the existing site soils, comprised of sandy alluvium to very dense glacial till, to assist with both hand-mined and TBM tunneling operations at vertical access shafts. The ground modification program was completed with a modified double fluid jet grouting system to construct continuous overlapping soilcrete columns to depths up to 94-ft below existing grade. This paper presents the sequence and methodology for the ground modification work and capabilities of jet grouting for structural support and groundwater control in the challenging soil profile present at the Brightwater Conveyance System Project.

Jan 1, 2008

By André van Wageningen

Long term mine scheduling is one of the most difficult optimization problems. The problem is said to be NP-complete in that the best possible solution cannot be found any quicker than checking all possible permutations and combinations. In current mining operations, it is important to report changes in long term plans as soon and as accurately as possible. Where geological data can change rapidly, such as in narrow vein deposits, the need to quickly identify and optimize different long term alternatives becomes a difficult task and can lead to many permutations of the long term mine plan. The question arises, is the new plan optimal or not? Can the company objectives be met while adhering to operational constraints? Although a number of optimization techniques have been used in the past, many include significant simplifications or fail to produce acceptable results within the required timeframe. Genetic Algorithms (GAs) are among the most promising optimization techniques within operations research. They are based on natural selection and evolution of solutions to complex problems. They have been known to quickly converge within a few percent of the optimal solution by examining only a fraction of the possible permutations. The GA itself contains very little problem specific information and, as such, in this study, has been linked to a discrete-event simulation (DES). The DES is able to evaluate each sequence proposed by the GA and determine the effectiveness and value of each schedule. The DES feeds information regarding the feasibility and quality of the solutions back to the GA during the optimization process. In this paper, GAs and DES are described and the coupling of the two methods is outlined. The GADES module is then used to ?optimize? a narrow vein theoretical case study and the results discussed in a broader mining context.

Oct 1, 2004

The Functional Performance Equation for ball milling circuits allows us to isolate the circuit classification system efficiency (CSE) from the mill?s grinding performance. The factors which affect circuit CSE are reviewed, with emphasis on water usage at the classifiers. It is shown that manipulation of such water usage can be carried out to improve plant grinding circuit efficiency, at times by more than 30 percent.

Jan 1, 2009

By W. Greuer

The objective of this paper is to demonstrate how site-specific slope stability analysis can be performed entirely from the desktop with satellite images, Geographic Information Systems (GIS), and slope stability software packages. This type of analysis would effectively eliminate or restrict the need for expensive field testing of geotechnical properties of a hillside, pit wall, berm, or embankment, and would be particularly useful for slope failure mitigation at remote or otherwise inaccessible locations.

Jul 17, 2000

By Barry L. Warner

This program involves the evaluation of means for suppressing fires on underground coal mine conveyor belts. Full scale conveyor belt fire tests were conducted to determine the requirements of automatically actuated water sprinkler, high expansion foam, and multi-purpose dry powder extinguishing systems, and of various fire detection devices, necessary to adequately protect underground belt heads. The program included the development of a suitable MI scale conveyor belt test fire, conducting of fire tests in which extinguishing and detection systems and equipment were evaluated, and testing to evaluate the effects of the coal mine environment on detection equipment. Preliminary testing conducted to develop a suitable test fire revealed that fire can propagate on some conveyor belting classified as fire-resistant. New fire-resistant PVC and new non-fire resistant rubber belts were used in the full scale fire tests. These tests indicated that a single branch line sprinkler system with relatively low water pressure provides adequate belt head protection. High expansion foam and multi-"purpose dry powder extinguishing systems as presently specified by regulation were found to be suitable for belt head protection, although care is required with powder systems to assure adequate distribution. Thermal type detection devices were found to be most practical for conveyor belt protection, with combustion products and optical detection methods having serious disadvantages.

Jan 1, 1974

By Hernán Parra

El presente trabajo señala la fase de tratamiento metalúrgico de pirrotitas que contienen oro, donde en la concentración por flotación se encontró un esquema adecuado para tratar pirrotitas auríferas considerando las restricciones ambientales que no permitieron incorporar técnicas de cianuración directa, que es como suelen tratarse es-tos minerales en el mundo. Asimismo, se propuso el uso de concentradores centrífugos para recuperar el oro libre fino en una primera etapa gravimé-trica, y concentradores de mesa Gemeni para obtener concentrados de alta cali-dad disponibles para fundición.

Sep 9, 2007

By F. M. Doyle

Metal removal kinetics and metal ion selectivity in ion flotation were studied from a thermodynamic perspective. Surface tension data could be used with the Gibbs adsorption equation to quantitatively predict the metal ion removal kinetics in alkylsulfate-Cu systems. However, surface tensions predicted cation selectivity coefficients in the sodium dodecyl-sulfate (SDS)-Cu-Ca and SDS-Cu-Pb systems rather poorly, although the predicted order of the selectivity (Cu2+<Ca2+<Pb2+) was correct. Another thermodynamic selectivity model, which used the Grahame adsorption equation and a geometrical analysis, predicted cation selectivity coefficients that agreed very well with experimentally measured values.

Jan 1, 2000

By Franklin M. Grynkewicz

The subject of bearing pile performance installed by vibratory hammers has been a matter of increasing study and continued controversy. A recent case study from a major bridge replacement project is discussed which provides encouraging data on the use of vibratory pile hammers as a primary means of pile installation and also presents the problems associated with its general acceptance. The bridge project case study foundations consisted of HP 14 x 89 pile sections, designed to develop capacity primarily in friction. Preliminary tip elevations were determined by traditional static analyses. Production pile installation was performed using an IHC S-70 Hydro-Hammer. Driving criteria and final production pile tip elevations were determined after preliminary indicator pile drive tests and static load test results at bridge pier cofferdam locations. Based on impact driven production pile performance, the Contractor wished to investigate vibratory driven piles as a means to accelerate construction schedule. Dynamic pile testing procedures were used as the primary measurement tool and test results were compared to the production pile drive records and prior static load tests. Field testing consisted of driving and monitoring with the PDA impact driven piles to the design tip elevation. Three vibratory driven piles were installed to the same tip elevation and immediately subjected to impact driving and dynamic testing to compare dynamic pile resistance. The results indicated that the site soil conditions were favorable for vibratory pile hammer installation. Recommendations and procedures for proceeding with vibratory hammer pile installation were presented to the Owner. These procedures included quality control in conformance with latest AASHTO recommendations. The Owner, in spite of the site specific data base and QA/QC procedures, would not accept vibratory pile hammer installation, due to the absence of precedence. It is concluded that for vibratory methods to become accepted a rational method of analysis, design and field QA/QC procedures requires development. In addition, the engineering community and Owners/Agencies must be more open to alternate methods of foundation construction. The continued development of dynamic methods of monitoring vibratory pile installation is considered to be key to the general acceptance of this installation procedure.

Jan 1, 1991

By J. -C. Tricket, W. A. Düweke, S. Kock

The high-resolution three-dimensional (3-D) seismic reflection data acquired for Impala Platinum between 1998 and 2002 in the western Bushveld Igneous Complex form an integral part of Impala?s mine planning and development programme. These data are of sufficiently high quality to provide unprecedented 3-D models of the geological structure of the Merensky Reef and UG2Chromitite Reef, from which the mine deduces the size, geometry and distribution of mineable blocks. Conversely, the seismic data details zones of un-mineable ground caused by structural disturbances in the form of potholes, fault zones and pegmatoid intrusions. Furthermore, variations in dip and strike are well imaged, allowing the mine planners to optimize the mine design and layout. Current interpretation work is focused on enhancing the accuracy of these geological model seven further through the analysis of ?seismic trace attributes.? Preliminary testing on the Impala Platinum 3-D seismic volume has shown that attribute analysis has the potential to illuminate a number of geological reef disturbances that are otherwise ?invisible? in the original seismic time volume. Potential areas of improvement include inter alia: ?Improved definition of major fault zones ?Improved definition of zones of reef depression (?slumping?) ?Identification of reef terracing and/or reverse dip.. Keywords: 3D reflection seismics; Impala Platinum Ltd; seismic attribute analysis; Seismic Micro Technology (SMT); rock solid attributes; dip-azimuth; instantaneous phase and similarity.

Jan 1, 2004

By R. C. D. Phillis

The management of critical resource inventories is an important productivity lever and a significant risk factor?risk in the sense that poor resource availability lends itself to disempowerment of workers, unsafe work practices, wasted spending (high unit costs),and poor quality of work (including mining waste/rework). Most underground platinum mines experience lost blasts that directly lead to reduced productivity. In most surveyed shafts, 30% of lost blasts can be attributed to shortages of critical material and/or equipment. The problem is prevalent despite the existence of conventional transitory surface and underground stores. This paper discusses the introduction of buffer stores as a complementary materials storage system in order to improve health and safety in mines as well as reduce lost blasts. Both quantitative and qualitative results have shown that buffer stores result in dramatic improvements in productivity and are readily acceptable by stakeholders. Keywords Buffer stores, lost blast.

Jan 1, 2011

By D. Brün, T. W. Nattkemper, T. Kuhn, T. Schoening

Underwater exploration for marine resources using camera-equipped devices (OFOS, ROV, AUV) is receiving growing attention. This development is creating a continuously growing pile of digital underwater images leading to a serious bottleneck in the analysis. However, any harvesting strategy must be coupled to an efficient and effective assessment of the biodiversity in the area of interest and in nearby control areas. To integrate manual image and computational image interpretation on different levels (i.e. regarding geology and environmental sciences and taxonomy), sophisticated software support is required, which is not yet offered explicitly, neither by commercial software companies nor by academic or other publicly founded institutions. Here, we present the first version of a new digital asset management system that offers functionalities for easy data management, sharing, manual annotation and integration of computational modules for image enhancement/pre-processing and interpretation. The functionality is demonstrated with data from the CCZ provided by the BGR Hannover.

Sep 1, 2014

By Geoffrey Brooks, Mehedi Bin Mohammad, M. Akbar Rhamdhani

Molten alkali nitrates are used commercially as thermal storage fluids (HTF) for solar thermal electricity generation. Their range of operation is limited by the thermal stability and this limits the energy (steam-Rankine cycle) efficiency of these processes. In this study, the effect of atmosphere on the thermal stability of nitrates was investigated using simultaneous thermal analysis techniques (STA). The use of oxygen (O2) as a blanket gas was found to delay the decomposition point of the ternary NaNO3–KNO3–LiNO3 (13.23–57.14–29.63 weight ratio) mixture by 55 °C. By which operating range will increase 65 °C more compared to the binary solar salt. Higher heating rates increased the decomposition point but had less effect on premelting and melting properties. Nitrogen monoxide, and O2 evolution after melting indicates concurrent reversible reactions. Similar phenomena were observed for single and binary nitrates. The eutectic melting point of ternary nitrate obtained from the STA agreed well with FactSage eutectic composition prediction.

Mar 1, 2017

1. In 2002, a total of 2,820 contracting companies reported employment at coal mines to MSHA.

Jan 1, 2004

By David Caiden, Geoffrey Fosbrook, Jaidev Sankar, Donald Phillips, Jon Hurt, Anil Parikh

This paper will cover the progress being made on Phase 1 of New York’s Second Avenue Subway line. It will include a description of construction progress on the first contract to be let, which consists of a 248 m (815 ft) long launch box, 3.9 km(2.4 miles) of TBM tunnels and a tunnel sump; the packaging strategy for the remaining work; and the progress through Final Design of the remaining packages, including the two large span rock cavern stations.

Jan 1, 2007

By A Paz, H Lehto, M +stholm, I Roitto

Nowadays, the demand for a finer grind in minerals processing has set new challenges within the industry, particularly for grinding technology. Apart from a finer grind, energy efficiency is also a key driver in optimising comminution technology.Stirred milling technology, already proven in many other industries, delivers a modern, sophisticated, flexible and energy efficient grinding solution for fine and ultra fine grinding in minerals processing. Fine grinding technology is utilised particularly in concentrate regrinding to complete the liberation of valuable minerals after the first stage of concentration. Maintaining the correct particle and particle size distribution of the regrind product is crucial for downstream process performance. Stirred milling technology offers the unique possibility for online control and optimisation of the regrind product particle size. This paper describes the basis of this online control possibility and discusses the implementation of stirred milling technology in minerals processing, particularly in regrinding applications. The paper will also outline management and control of fluctuations in feed rate tonnages as well as particle size fluctuations in concentrate regrinding.CITATION:Roitto, I, Lehto, H, Paz, A and +stholm, M, 2013. Stirred milling technology - A new concept in fine grinding, in Proceedings MetPlant 2013 , pp 190-201 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By M. Steyn

[Zr(C9H6NO)4]?(HCON(CH3)2)?(H2O), where (C9H6NO) = 8-hydroxy quinoline (oxH), was synthesized and characterized. This tetrakis-coordinated zirconium complex crystallized in the triclinic crystal system (Pi, Z=2) along with water and N,N?-dimethylformamide(DMF) solvate in the asymmetric unit. The metal atom is surrounded by four N,O-donating bidentate ox-ligands that are arranged around the metal centre to give a square antiprismatic coordination polyhedron with a small distortion towards a dodecahedral geometry. Crystal packing is stabilized by intermolecular interactions of adjacent oxine ring systems in neighbouring molecules, as well as hydrogen bonding of the aqua and DMF solvate molecules, linking the molecular entities into a supramolecular three-dimensional network.

Jan 1, 2013

By Joseph T. Singewald

The possible value of the red hematite iron ore of the southern Appalachian States, if some practicable method of concentrating it could be devised, has long been recognized. The ore is very low grade, and although in enormous quantities, particularly in the States of Alabama, Tennessee, and Georgia, is only at a few points rich enough to work, and even the best of it ranks among the lowest grade iron ores being mined in the United States. A cheap method of beneficiating this ore would make enormous quantities available and vastly increase the iron-ore resources of the country. However, this low-grade ore in effect constitutes a potential iron reserve, and as long as ample quantities of ore can be obtained elsewhere the question of its utilization does not demand immediate notice. Where these ores are in part of workable grade, however, a problem of more immediate importance arises which, from considerations of economy and prevention of waste in their mining, ought to be solved or, at least, attacked as quickly as possible. Where these ores are being worked they are usually intimately associated with lowergrade material that in mining is left behind. The difficulty and expense of going into ground broken by old workings makes the recovery of this lower-grade ore practically impossible and it is lost forever. Success in concentrating the red ores, therefore, would save material that is now being irretrievably lost. The successful largescale concentration of low-grade ore in the last few years on the Lake Superior iron ranges should encourage the attack of similar problems in the Birmingham district. While studying iron-mining methods in the United States for the Bureau of Mines, Dwight E. Woodbridge, consulting mining engineer of the bureau, was impressed with the importance of this problem, and believed it merited the attention of the bureau. Accordingly, Mr. Woodbridge had Mr. W. J. Penhallegon, general superintendent of ore mines and quarries of the Republic Iron & Steel Co., of Birmingham, send the author of this report five samples of the unworkable siliceous ores of the district. The results of concentration experiments with these ores made a more thorough 'and systematic investigation desirable. In consequence, the author subsequently collected samples in the district, and these became the basis of the experimental work described in this report. The results are published by the Bureau of Mines as a part of its efforts to increase efficiency in the utilization of mineral resources. The experiments were conducted in the geological laboratory of the Johns Hopkins University, Baltimore, Md., with the aid of Raymond Leibensperger, mining assistant. The chemical analyses were made by A. C. Fieldner, chemist, of the Bureau of Mines. The author wishes to express his appreciation of the courtesies extended to him by the mining companies of the district, and particularly to Mr. W. J. Penhallegon, of the Republic Iron & Steel Co. Thanks are also due Prof. W. B. Clark, director of the geological laboratory of the Johns Hopkins University, the unrestricted use of the facilities of the laboratory.

Jan 1, 1917

By Terry R. Neumann

During 1983, U.S. Bureau of Mines personnel examined mines, prospects, and mineralized zones to evaluate the mineral resources and potential of the Funeral Mountains Wilderness Study Area (WSA), Inyo County, California. Eleven mineral properties and two mineralized zones were examined during this study. Of these, six are within the study area and seven adjacent. There are no active mines, in the WSA, nor is there evidence of past production from any claim within the study area. The WSA contains no identified mineral resources. However, occurrences of bentonite, zeolites, and strontium were found in the area. There is little likelihood for resource development of any occurrence in the WSA. The area, in the Basin and Range Physiographic Province, is dominated by a Paleozoic marine sequence. Segments of Tertiary continental fluviolacustrine sediments, including volcaniclastic rocks, abut and overlie the Paleozoic rocks in fault controlled basin areas. Significant concentrations of bentonitic clay and zeolites occur as alteration products in Tertiary tuffaceous sedimentary rocks. However, they are generally low-grade, thin, and discontinuous, precluding commercial development. Limestone, quartzite, and sand and gravel in the area are suitable for many types of construction uses, but similar deposits outside the WSA are closer to markets. No energy resources have been identified in the WSA.

Jan 1, 1984