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By N. A. D. Parlee, I. D. Shah, W. C. Phelps

THIS note reports on a continuation of a program on the thermodynamics of Fe-S-X systems in the "steel-burning" temperature range begun by Bock, Barloga, and parlee.' Small coils of 0.039-in.-diameter pure iron (Ferrovac-E) wire were equilibrated with Fe-S-0 melts in ingot iron crucibles under argon at 1324°C in the assembly shown in Fig. 1, the lower part of which was heated in a large Globar furnace. Fig. 1 shows (R) the coiled iron wire sample, (M) the Fe-S-0 melt prepared from desired proportions of ferrous sulfide and ferric oxide, (K) the iron crucible, (I) a mullite guide tube, (J) an alumina crucible, (L) alundum sand, (N) crushed mullite, (Q) hollow cylinders of K30 brick, (C) a steel rod, (B), (El, (F), (G), (P), and (O), details of brass water-cooled head, and (H) a mullite tube 2-3/4 in. ID and 26 in. long. The rod (C) bearing the sample could be removed at will and be replaced by a tube for sampling the melt, or by a thermocouple for comparing the melt temperature with a control thermocouple not far from the 2-3/4-in. mullite tube. After equilibration the iron coils were treated with acid to remove the outer layer of metal and then they were analyzed for sulfur by a standard combustion method. The melt samples were analyzed for oxygen by a variation of Lander's2 hydrogen-reduction method for mattes, and for sulfur by the ASTM combustion-iodometric method NO. E 30-47. When the results of some forty-two runs were examined it was found that the sulfur and oxygen contents of the equilibrated melts showed good consistency, in that the plotted compositions fell along the smooth curve shown in Fig. 2. The points on this curve represent the experimental compositions of melts in equilibrium with ?-iron (Fe-S-0) solid solutions. These solid solutions are saturated with sulfur and oxygen with respect to the melt and therefore have the same sulfur and oxygen activities as the melt. The curve drawn through the points therefore delineates the ? liquidus. It falls in such a position as to roughly confirm the liquidus curves of Hilty and crafts3 at 1200" and 1300°C which are

Jan 1, 1965

By J. A. McLennan, J. M. Ortiz

Nickel laterite deposits are typically formed from tropically weathered mafic-to-ultramafic complexes. The resulting nickel concentration is found within soil horizons and is mineable with regular dozer units. At the time of mining, digging elevations are needed at selective mining units (SMUs) or representative dozer regions (RDRs). Moreover, for mine planning, the costs due to dilution and lost ore require mining elevations to be specified. A conditional simulation approach is used to calculate “optimum” RDR mining elevations. Multiple realizations of the ore base surface are simulated. For a single bottom surface realization, dilution and lost ore costs are calculated over the entire vertical extent of each RDR. The optimum mining elevation is the elevation where the lowest summed cost of “accepting dilution” and “wasting ore” occurs. The reported RDR dilution is the cost of mining the volume of waste located below the bottom surface and above the optimum mining elevation. The reported RDR lost ore is the cost of not mining the volume of ore above the bottom surface and below the optimum mining elevation. For all ore bottom surface realizations, optimum RDR mining elevations and their associated dilution and lost ore costs are calculated and compiled to represent production uncertainty.

Jan 1, 2006

By William Reisz

Over the years as surface mining operations have become more sophisticated, angle drilling has become a more popular blast design technique, especially in areas where overburden and stripping ratios have increased. Another method of blast design is the staggered pattern, which greatly improves explosives distribution within the blast. While both methods present some engineering challenges, this paper will discuss how the two methods can be combined to enhance fragmentation, improve cast percentage, drill production ratios and highwall control. A practical engineering approach will be presented as well as a discussion on the discipline required to maintain a quality blasting plan.

Jan 1, 2002

By Marco D. Boscardin

Control and mitigation of building response to construction activities are assuming a greater role in design decisions for underground construction. Alternatives for controlling building response have multiplied with the continued development of ground modification methods, better control of construction activities that cause ground movements, and increased understanding of building behavior and response. This paper describes approaches to estimating building response to construction-related ground displacements caused by adjacent excavation and highlights the discussion with several case history examples. Examples discussed includes experiences with two, seven-story historic structures, supported by timber piles with granite block pile caps, which were underpinned in preparation for ground-freezing ground stabilization and tunnel construction beneath the buildings. The elevation of each building column was monitored and elevation adjustments were actively performed during construction. The second example examines the performance of a slurry wall braced cut, 45 to 50 feet deep penetrating through a stiff crust into a soft clay layer and associated building response. This cut was immediately adjacent to two, approximately 15-story office buildings, which were supported by deep foundations founded in the stiff crust.

Jan 1, 2003

By Efrén Peña Pino

El presente texto señala la aplicación del sistema SAP en la minería subterránea de Minsur. Este sistema operativo maneja las propiedades y procesos de la Sociedad Minsur, el cual cuenta con tres Centros, dos de los cuales son operativos (San Rafael y Pisco) al margen de la central de administración (Lima) y permite la planificación de todos los recursos de la empresa de manera integral, evitando imprevistos y una mejora de decisiones.

Jul 31, 2003

By Masaomi Kurihara, Seiya Kawano, Norihiro Yamaji, Satoshi Shiokawa, Nobuyuki Okamoto, Hironobu Sakurai

Seafloor polymetallic sulphides are distributed in the EEZ of Japan, including substantial deposits in the Okinawa Trough and Izu-Bonin back-arc basin. In this new frontier, the successful development of these resources in Japan is expected to bring about a new domestic supply of mineral resources. The initial stages of this development are authorized by the Basic Plan on Ocean Policy, approved by the Japanese Cabinet on April 26, 2013, and the Plan for the Development of Marine Energy and Mineral Resources, formulated by the Ministry of Economy, Trade and Industry (METI) on December 24, 2013. In 2008, the Japan Oil, Gas and Metals National Corporation (JOGMEC), commissioned by METI, began a survey and technological development programme for the development of the seafloor polymetallc sulphides (PMS) based on these Plans. The examination of four different fields: the evaluation of the amount of the resource, environmental assessment, mining technology, and processing & smelting technology, are concurrently promoted, aiming for commercialization as soon as possible. Based on the results of research for properties of geomorphology and marine environments of the target test sites in the Okinawa trough, which have been ongoing for several years, the preparation of the pilot lifting test included an in-situ excavation and crushing test conducted using test excavating and crushing systems.

Jan 1, 2018

By Fookes R. A, Gardner K. J, Gravitis V. L, Watt J. S, Steffner E. J

Two radioisotope techniques suitable for the rapid laboratory determination of the ash content of coal have been tested ou unwashed coal samples from four Australian coal seams. In one techniqne, measurements of backscattered 238Pu L X-rays and iron K X-rays from finely ground coal samples have been combined to determine ash content in uuwashed coals to ±0.5 weight per ce111 ash (ls) for three seams and 0.9 weight per cent ash for the fourth.The second technique, which involves measurements of the transmission by the coal of narrow beams of 241Am 60 keV and 123Ba 356 keV ? rays, requires less sample preparat ion. The ash was determined to within the range of 0.8 to 2.6 weight per cent for the four seams (unwashed coal). For washed coals, errors are expected to be < ±0.5 weight per cent ash.

Jan 1, 1982

By Fredrick Fränding

In mining and quarrying operations, electric motors can fail for a variety of reasons. Some failures are directly linked to demanding production requirements and contaminant-laden environments and, consequently, are difficult to prevent. A sizeable number, however, are caused by ?offline? factors that have nothing to do with production. These include inadequate or substandard motor repair practices and improper motor shipping, storage and installation. The fact that failures are at times attributable to repair- or rebuild-related errors and problems raises the stakes when selecting an electric motor repair provider. Teaming with high-quality electric motor shops can help a company reduce failures due to offline factors, improving motor reliability and cutting downtime costs. Regardless of location or annual revenues, the best motor shops have similar business cultures and share many of the same characteristics.

Jan 1, 2009

By Ray Brandon

The recent introduction of polymer geogrids for ground control purposes in underground mines allows mine operators more flexibility in choosing improved products for several applications. This is evidenced most clearly in longwall recovery operations. Since November, 1994, many mine operators have chosen Fortrac geogrid assemblies for the purpose of securing longwall recovery areas prior to shield removal. Fortrac is a lightweight, strong, and flexible polyester geogrid available in many strengths. Utilizing the "diamond" seaming method, different strengths of Fortrac geogrids are easily fastened together so stronger geogrids may be placed in the most critical areas and lighter geogrids in less critical areas.

Jan 1, 1996

By W. H. Dickinson

The performance of seven antiscalants spanning a range of chemistries was evaluated for control of calcium carbonate (CaCO3) formation in gold processing applications. Three preferred chemistries were identified which provided up to 100 percent inhibition in static jar tests when applied at 30 ppm dosage. The three products were further evaluated using a model carbon extraction circuit developed for this application. The test circuit enabled direct measurement of calcium carbonate formed on the carbon from a supersaturated solution under dynamic conditions. The antiscalants lowered CaCO3 buildup on the columns by 15 - 26 percent compared to untreated controls. Impact of the antiscalants on the rate and extent of gold loading onto a carbon adsorbent was evaluated in laboratory carbon-in-pulp (CIP) studies. The antiscalants generated a 25 - 35% increase in gold loading at gold extraction efficiencies up to 65%. On-site testing at a gold processing facility demonstrated that 10 ppm of the preferred antiscalant was able to fully suppressCaCO3formation in thickener overflow water.

Feb 27, 2013

By G. Deschênes

Following a successful investigation on the Central Zone sample, a cyanidation study was conducted on an ore sample from the AD-MW Zone of Clarence Stream Property, owned by Freewest Resources Canada, to develop a leaching strategy to extract gold. At a grade of 6.48 g/t, gold is present in the forms of aurostibite, free gold and electrum. The ore contains 4.3% berthierite/gudmundite, 1.3% pyrrhotite, 0.7% pyrite, 0.07% stibnite and 0.9% arsenopyrite. Similar to the Central Zone, the extraction of gold from the AD-MW Zone can be performed at atmospheric pressure, pH 10.5 and with a low concentration of cyanide. The grind size had no effect on gold extraction between a P80 of 28 to 71 µm. The oxygen and cyanide requirement significantly increased with a ?ner grind. Consequently, a very close control of cyanide addition is required to minimize passivation of gold. Lead nitrate, added in the pretreatment, increased the extraction of gold by 2.3%. Leaching at pH < 10 improved gold extraction but increased the cyanide consumption by 5%. Passivation of gold occurred when the pretreatment was longer than 2 hours. A longer pretreatment reduced the cyanide consumption by 5%. Mineralogical characterization of the leach residue with no gravity pretreatment prior to leaching indicated the presence of unleached gold grains and passivated gold grains. Removal of coarse gold by gravity increased the extraction by 2.8% (leach residue at 0.74 g/t Au). Increasing the DO to 16 ppm or the lead nitrate from 500 to 1,000 g/t increased the overall gold extraction to 90.4% (leach residue at 0.62 g/t), which is the maximum gold extraction obtained. The leaching parameters were 800 ppm NaCN, DO 16 ppm and pH 10.5 for a duration of 120 hours. The associated cyanide consumption was 4.0 kg/t. Gold leaching was not sensitive to cyanide concentration. Reducing the cyanide concentration to 250 ppm resulted in a gold extraction of 89.5% with a cyanide consumption of 2.6 kg/t.

Jan 1, 2009

Drilling and blasting are an essential part of most mining operations, and are commonly major operating cost centres. The effectiveness of blasting can have a significant influence on all subsequent activities, and hence overall operating costs. Drilling and blasting systems must be compatible with the overall mining method, to minimise total costs and ensure operational efficiency. Selection of suitable equipment and techniques requires an understanding of the total operation, plus current skills in specialised technologies. This paper examines the contribution of drilling and blasting to total costs, including the balance between capital and operating costs. The use of computer modelling is discussed, to demonstrate how blast performance and costs can be predicted and alternatives analysed. Case studies illustrate how cost savings can be made in operating mines, and alternative systems evaluated to optimise new projects.

Jan 1, 1990

By E. Laine

Rock density determinations are necessary for ore resource evaluations from estimated block grades in g/t. Rock density depends on the mineral composition and, thus, it is specific for each rock type. The rock density distributions for different rock types are often symmetric. Hence, the arithmetic mean is a good approximation for the average density for lithological units. However, there may exist spatial variation in density values due to alteration, fracturing and original heterogeneities such as layering. This study compares the kriged density model with the one with constant density values for different lithological units in the evaluation of metal amounts in rock blocks. The case study consisted of rock densities measured from the drill cores at Ahmavaara PGE deposit in northern Finland. The used Ni contents were simulated in accordance with the spatial distribution of rock densities. The Ni amounts in 2x2x2 m3blocks are higher for the kriged densities than for the average densities. The difference is increasing with the increasing metal amounts due to the nonlinear correlation between Ni content and rock density. The final effect on the resource estimation depends on the cutt off grade and prices of the metal, for example, for a very valuable metal the small differences are significant

Jan 1, 2003

By S Hapugoda, J R. Manuel, M J. Peterson

Microindentation testing using the square–pyramid–shaped Vickers indenter is a well-established technique to determine the microhardness of minerals and materials. However there is a paucity of published microhardness data from Fe ore samples. It is acknowledged that an iron ore’s particle mineralogy and texture is critical to its processing properties, and it is therefore considered that the microhardness of different mineralogical/textural types may also relate to these properties. Mineral microhardness potentially provides inputs to the modelling of breakage characteristics during comminution, as well as the relationship between mineral chemistry and microhardness, and mineral microporosity and microhardness. Microhardness can be determined as single crystal microhardness, for more coarsely microcrystalline samples, or as ‘aggregate microhardness’ for cryptocrystalline or finely microcrystalline samples.Variations in the texture and mineral chemistry of common Fe ore minerals (eg martite and microplaty hematite, ochreous and vitreous goethite etc) are well established and this study provides microhardness data on different textural forms of Fe (oxyhydr)oxides from a variety of different Fe ore deposits. The data indicated that in general, the mineral grain size, microporosity and texture were the main influences on Fe (oxyhydr)oxide microhardness. There were no apparent systematic variations between microhardness and minor element mineral chemistry, with the possible exception of Al content in goethite (for goethites with Al content &gt;0.5 wt per cent), and for goethite total element contents &gt;90 wt per cent (determined by electron probe microanalysis, EPMA). Higher Al concentrations and lower total element concentrations in goethite EPMA analyses correlated with lower goethite microhardness. Microporosity and grain size were more important than texture to hematite microhardness. Different textural forms of dense hematite (eg martite, recrystallised interlocking hematite and specular hematite) with similar grain size exhibited comparable microhardness. Microhardness values for hematite and hydrohematite with little or no evident microporosity were also similar, whereas more porous forms of martite, microplaty hematite or hydrohematite exhibited lower microhardness.CITATION:Peterson, M J, Manuel, J R and Hapugoda, S, 2017. Microhardness testing of hematite-goethite Fe ores – implications for their textural characterisation and geometallurgy, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Ketan H. Trivedi

This paper describes the method of analyses used for the design of temporary and permanent Secant Pile Walls, describes various aspects of construction including, guide walls, sequence of pile installation, plan alignment and verticality tolerance, methods of drilling (auger, wash boring, cased and open holes), lateral bracing for secant piles, cutting of keys in secant pile walls for the connection of permanent floor slabs, sealing of water leaks and waterproofing. The paper concludes with a brief case history of a secant pile wall project recently constructed in New York City.

Jan 1, 2006

By Andrew K. hg` Officer, A. L. Griffiths, J. Andrew Hindmarch, Gert Wittneben

Durban Harbour in South Africa is one of the continent’s busiest ports however the harbor entrance is currently too small for the new generation of container ships. There-fore it is to be deepened and widened by the National Ports Authority in the near future. An existing immersed tube tunnel carrying major sewer, water and other utilities under the harbor first needs to be removed and replaced by a deeper 4.4 m ID ser-vices tunnel. Construction of the deeper tunnel saw the first use of a slurry machine in South Africa and was required to negotiate grades up to 20%.

Jan 1, 2007

By Don Peel

Mineral aggregate, the most widely used mineral resource globally, has attracted little academic or public interest. Of all mining developments, the aggregate resource is seldom factored into resource management decisions. This lack of recognition to the strategic aggregate resource has significant economic, environmental, and social implications. Impact to the economics, the environment, and the community coincide with the key elements of the United Nations concept of ?sustainable development?. To build on the concept, the mining sector contracted the International Institute for Environment and Development to assess how mining activity contributes to sustainability. As a result, a useful assessment process was developed by the Mining, Minerals and Sustainable Development (MMSD) Task Group entitled ?Seven Questions to Sustainability: How to Assess the Contribution of Mining and Mineral Activities.? In Alberta, recent opposition to mineral resource development by community residents offers an opportunity to employ the MMSD?s assessment procedure. The public opposition to the mining activity was addressed through a stakeholder planning process initiated by the municipal council of Sturgeon County, Alberta. As a result the Calahoo/Villeneuve Area Structure Plan (CASP) was formulated and adopted. To measure the effectiveness of the CASP planning process in terms of sustainability, this paper applies the MMSD?s Seven Question assessment to the Calahoo/Villeneuve Area Structure Plan.

May 1, 2004

By G. S. Takenaka

When Bridger Coal Company transformed their operations from surface mining to an underground longwall operation their plans included not only the addition of new mining equipment but also surface fans for a blowing (supply) air ventilation system. The original system concept included a propane gas fired air heater to preheat the intake air during cold weather and a dual parallel fan and duct system. One fan operated to ventilate the mine while the other fan was for stand-by emergency operation. Equipment proposals were submitted in March, 2005 based on the dual parallel fan system. Discussions conducted during the equipment selection process revealed that several alternative system design concepts were available. The alternative concepts included innovation features that not only saved space and cost but also reduced operating expense as well. Many of the features were incorporated into the final design of the system. A comparison of the original system concept and final installation design are presented in the paper in addition to details of the features and the derived benefits.

Jan 1, 2009

Cobalt mostly occurs as a minor, but valuable, constituent in most nickel and a few copper ores, however it is not generally found alone in commercially viable deposits. Its concentration and extraction are therefore intimately linked to the recovery of the primary metals and the major task for the metallurgist is to extract cobalt of commercial grade from a much larger mass of either nickel or copper and sometimes both. With a particular focus on Vale Inco?s operations, this paper provides a brief overview of the mineralogy of the main deposits being currently exploited that contain cobalt as a co or by-product. The concentration and then extraction to metal are reviewed and some advances released into the public domain are discussed.

May 1, 2009

By William F. Hahn

The Bureau Of Mines recognized the desireability of illuminating working places in trona mines. This report describes two illumination system designs, their demonstration and evaluation on a Jeffrey 120HR continuous mining machine in an active working trona mine in Wyoming.

Jan 1, 1980