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By Mike Samuels, John Starkey

"This paper examines test results and grinding mill design for the recent Fortune Minerals’ NICO Project, located in the Northwest Territories. SAG milling and rod milling options are compared. Rod milling is clearly shown to be the best option because of the ore’s extreme resistance to breakage in a SAG mill environment.Surprisingly, the Bond Ball Mill Wi was 13 kWh/t for this ore. The Bond Rod Mill Wi was 20 kWh/t, whereas the SAG pinion energy to grind the ore to T80 1.7 mm was 30 kWh/t. The existence of ore with this ratio of SAG hardness to Bond BM Wi has not been previously observed. If not considered, this critical relationship may adversely impact the accuracy of mill design. This paper substantiates the significance of these findings to achieve successful grinding design on ore that is macro-competent during primary size reduction, but relatively normal during secondary grinding.INTRODUCTIONThe NICO Cobalt-Gold-Bismuth-Copper deposit is located 160 km northwest of the City of Yellowknife, Northwest Territories. It is the largest IOCG-type deposit (aka Olympic Dam-type) currently recognized in Canada with Mineral Reserves of 21.8 million tonnes contained within a larger 57 million tonne, lower-grade Mineral Resource. The project, owned 100% by Fortune Minerals Limited, has been assessed in a positive definitive feasibility study, subject to underground test mining and pilot plant testing, and is now in the permitting stage to develop a combined open pit and underground mine and process plant. An updated process flow sheet incorporates conventional crushing, grinding and bulk flotation, followed by filtration for shipment of a concentrate to a purpose-built refinery proposed to be built near Saskatoon, Saskatchewan. At the refinery, separate bismuth and cobalt concentrates will be produced following regrinding. The hydrometallurgical process methods include: pressure acid leach, precipitation, ion exchange, and electro-winning for recovery of cobalt as 99.8% cathode; solvent extraction and electro-winning of by-product copper cathode; ferric chloride leach and electro-winning for recovery of bismuth as 99.5% cathode; and cyanidation of the leach residues for recovery of gold as doré."

Jan 1, 2010

The Heavy Media Separation plant operated at Lidsdale siding, eight miles from Lithgow, by the N.S.W. Mining Co. is a product of the Western Machinery Company, of D.S.A.This mill, designed to use finely ground magnetite as the heavy medium, was prefabricated in America and shipped to Australia for erection.First operated early in December, 1951 it has worked on a two-shift basis since. Designed for an input rate of 330 tons per hour, this mill is capable of washing 4 in. x /u in. coal down to its inherent ash by removing all heavy material, including high-ash coal.The principle is quite simple. A stream of raw coal is fed into the separatory vessel which contains a liquid medium, the density of which is adjusted to produce the desired split between coal and refuse. In this bath the lightest coal floats, and all material heavier than the specific gravity of the medium sinks, and is removed separately. Such a system is,. ideally suited to Western coal, as there is no definite splitting point between coal and refuse. Inherent ash of the coal fed to the plant ranges from 8 to 25%, the corresponding density range being from 1.28 up to 1.8.Generally speaking, the higher the density the higher the ash content of the coal.The density in the separatory vessel (hereafter called the cone) can be quickly and easily adjusted throughout the above range to any desired value. Customer requirements, coupled with the economics of washing, dictate the proper specific gravity to be maintained. At present this is held at 1.52...

Jan 1, 1954

By Patrick E. Durnal

A joint venture of Ben C. Gerwick Inc., Sverdrup (now Jacobs) and DMJM (now DMJM Harris) designed the $779 mill seismic upgrade of the Richmond - San Rafael Bridge over the San Pablo Bay in the San Francisco Bay Area and provided construction support to Caltrans. Construction of the marine foundation retrofit was completed by a joint venture of Tudor Saliba/Tidewater/Koch-Skanska and their subcontractors: Pomeroy Precast Construction, AGRA Foundations, Dutra Construction and Vortex Divers. Construction management and inspection was performed by Caltrans with support of various consultants.

Jan 1, 2013

By Steve Kral

Good times make for happy miners. And the past few years have seen a lot of smiling mining engineers, geologists, metallurgists, corporate executives, analysts, investment bankers and shareholders. And nowhere was that more evident than at the 74th Prospectors and Developers Association of Canada’s (PDAC) annual meeting. The meeting, held in Toronto March 5-8, attracted a record 14,500 people. Of those, the PDAC said attendees came from an estimated 100 countries. And about 40 countries sent national delegations to the meeting. Argentina, for example, sent nearly 100 people. The PDAC meeting has always been a event where companies and individuals can get a look at numerous properties in all parts of the world that could potentially become major mines. And through the many receptions, hospitality suites and just sitting in the local restaurants and taverns, deals are usually made.

Jan 1, 2006

By Greg Wyartt

In the Pilbara region of Western Australia, an iron ore mine is undertaking a high wall cut-back to improve stability and allow access to deeper ore deposits. Several sections of the wall have been classified geologically sensitive due to unstable localised geology, and therefore an engineered approach to vibration critical blasting was required. The use of electronic detonators allowed multiple signature (seed) holes to be incorporated into a production blast adjacent to the geologically sensitive area, therefore providing baseline vibration data to be used for future modelling with the added advantage of eliminating unnecessary pit closure downtime typically associated with a signature hole program. All subsequent blast patterns also incorporated multiple signature holes to provide additional data and allow continual updating – and therefore improved accuracy - of the blast prediction model.

Jan 1, 2018

By Jean-François Lessard

The performance of rock pass systems has a significant contribution to the economics of underground mines. Operational concerns include hang-ups due to arching of material, blockage and degradation of the rock pass. This papers presents the preliminary results of a comprehensive rock pass database on the engineering and operation of rock pass systems in Quebec underground mines.

May 1, 2002

By Payman Roonasi

Having knowledge of mechanism of magnetite formation is essential in a number of industrial processes including magnetite synthesis and corrosion of iron. In this study, magnetite nanoparticle was synthesized via two different ways; coprecipitation of iron (II) and (III) and oxidation of ferrous hydroxide. The samples were characterized using X-ray diffraction (XRD), Mid-Far IR spectroscopy, scanning electron microscopy (SEM), chemical analysis for determination of Fe II/Fe III ratio and ICP-MS for iron isotopic ratio (56Fe/54Fe) measurement. Since fractionation of iron isotopes depends on reaction rate and bonding strength, interpretation of the isotopic data with respect to the possible mechanisms is discussed. No fractionation of iron isotopes was observed for the magnetite synthesized by coprecipitation, whilst magnetite formed from ferrous hydroxide showed higher abundance of 54Fe compared to 56Fe in the beginning of reaction, implying the significance of the following reaction:

Jan 1, 2009

By Kazimierz Gwizdala

In recent years, in Poland the ATLAS piles have been successfully applied for some constructions near Gdansk. The piles have been used as foundations for housing and another areas of civil engineering, in delta Vistula geotechnical region, characterized by weak, highly compressible soils represented by mud and peat, lying in sub-surface layers, several meters thick. Usually below are dense sandy soils or gravel. In all cases, the base of ATLAS piles rested on sandy soils. The analysis of pile bearing capacity has been discussed and verified by static pile load tests (SPLT). The load-settlements characteristics obtained were satisfactory. In the paper, the results of geotechnical investigations as well as calculations and load tests are shown. The ecological aspects of ATLAS piles application within highly urban areas of the cities and complex geotechnical conditions are emphasized.

Jan 1, 2006

By Shimi Tzobery, Jay Davenport, Raymond Henn, Sam Bandimere

Over the past several decades, the use of cement-based grouts using ultra fine cement as a replacement for portland cement has begun to gain acceptance as an alternative to chemical solution grouts used in permeation grouting. The amount of information currently available on grouts made with ultrafine cement is limited. The authors used a previously developed field testing program to perform additional tests to evaluate the permeation performance of portland and ultrafine cement-based grouts. For the first time, the 2003 testing program included an attempt to determine the 28 day compressive strength of the sand permeated by the grout.

Jan 1, 2005

The early development patterns of both Australia and New Zealand were substantially in parallel and both were heavily indebted to gold mining for, providing the stimulus to growth. However, since the mining boom, of 1895 - 1899, the mining sector in New Zealand has progressively declined, while in Australia it has assumed an increasing importance in the economy. The continued dominance of minerals in Australian trade, and the fact that eight out of the top ten companies in Australia are directly involved in mineral exploration and production, has strongly influenced government and public attitude's to the minerals sector. Although the legal framework of mining and exploration Acts and Regulations are similar it is in, the method of administration, particularly in regard to exploration and prospecting licences, that the gulf across, the Tasman is apparent. Despite the relative ease of application and granting of licences in Australia, in the more settled south eastern part of the continent we are finding more and more land is being zoned unavailable for exploration. In the remote areas, the Aboriginals now control nearly ten per cent of the land area of Australia, virtually with drawing that portion from exploration. The concept of 'Australianisation' has softened a hardening attitude against foreign investment in mining on the part of the bureaucracy. This anti-mining attitude is fortunately, not shared by the public, and we can but hope that the will of the Australian people can filter through to our masters in Canberra, and ease the rapid increase in the number of regulatory bodies which does so much to inhibit the normal conduct of business. The delays caused by interminable hearings and committee investigations all cost money. This cost can only rebound back on the end consumer, who after all is a voter.

Jan 1, 1982

By Todd M. Ruff

This report summarizes ongoing research at the National Institute for Occupational Safety and Health, Spokane Research Laboratory, in which collision warning systems for surface mining dump trucks are being evaluated. Common accidents involve these large trucks running over smaller vehicles or pedestrian workers. Collision warning systems currently use one of several methods, including radar, radio-frequency-signal detection, or ultrasonic signals, to detect and warn of the presence of an object or person in the blind spots of the mining equipment. Most available systems have not been tested on large off-highway dump trucks. This report evaluates several systems on two sizes of trucks, a 50-ton-capacity truck commonly used in quarries and construction and a 240-ton-capacity truck commonly used in open-pit mines. Tests were conducted to determine false alarm rates, alarm effectiveness, and reliable detection zones for a person and a pickup truck. The results indicate that radar and radio-frequency identification systems show promise for this application and that several of the improved systems are ready for extensive field tests. However, challenges still exist in applying these technologies to large trucks.

Jan 11, 2000

By J F. Seale

The design of the settling pond for the Malvern Hills opencast coal project was based on a primary requirement to control runoff and sediment generated from the immediate 6 ha mine catchment, which included two seepages from old underground workings. The pond has been particularly effective in controlling turbidity in the outflow water, with the consent limit of 50 NTU being met on all but one occasion and normal levels of discharge less than 10 NTU. Water quality testing carried out at the time of consenting indicated that there were no acid-generation issues with the proposed mine site in dominant mudstone strata of the Broken River Formation, and that water from the old mine workings was near-neutral in terms of pH and well-buffered. However, it became apparent over the very dry summer of 2003 - 2004 that slaking of the exposed mudrocks in the mine batters was resulting in significant acidity generation, and outflow pH levels were well below the consent limit of 6.5 during and following periods of rainfall. Although these acidity problems have been remediated in the short-term by the use of lime products, it is clear that a programme of lithotype characterisation for AMD should have been undertaken and this has now been implemented. Design of long-term acid drainage control measures is being carried out, and will probably be based around the use of hydrated lime for pH control with enhancement of natural wetlands.

Jan 1, 2004

By Forrest T. Moyer

INJURY experience and related employment information are presented in the chapter for the coal-mining, coking, oil and gas, peat, and native asphalt industries in the United States for 1964. No attempt has been made to combine these data and present injury-frequency rates reflecting the mineral-fuel industries because the hazards of the separate industries are not comparable. All rates in the text are calculated separately on data before rounding, hence component rates may not add to the total rates shown in the tables. Tabulations showing the trend of injuries and employment for all mineral industries are presented in Volume III. COAL Injury experience of the coal mining industry was improved in 1964, as measured by the declines of 1 and 14 percent, respectively, in the frequency and severity rates. Although the total number of injuries increased in 1964, a slightly greater proportional increase in man-hours worked caused the frequency rate to drop to 44.65 per million man-hours. The injury-severity rate in 1964 was 7,832 days lost per million man-hours of exposure. Employment and injury data for 1964 are based on final data for anthracite mines and preliminary data for bituminous coal and lignite mines. Fatality experience improved significantly with a record low number of 240 deaths in 1964. This total was 44 less than in 1963. The Nation's coal mines during 1964 were free of major disasters (a single accident resulting in the death of five men or more) for the first time since 1956. The

Jan 1, 1965

While SME is hosting its Annual Meeting at the Phoenix Convention Center, Feb. 28 to March 3, one of the finest collections of mining history will be on display just 15 blocks away at the Arizona Mining and Mineral Museum. Inside the museum, visitors will be treated to a treasure trove of minerals, gems, me¬teorites, rocks, fossils, mining artifacts, historical exhibits and interactive displays on modern mining. The museum is located at 1502 West Washington. For SME Annual Meeting attendees, this is a free, eight-minute Dash bus ride 15 blocks west of the Phoenix Convention Center.

Jan 1, 2010

By D. Witchard, G. C. Penny

An important conclusion of the study is that altering the properties of the granulation water is a practical way of improving the sintering performance of blends that contain porous ores, and more work is under way to investigate other additives. Previous studies of iron ore blends containing pisolite ore showed that losses in sintering productivity were a result of deteriorating green-bed permeability. Pisolite ores are extremely porous and absorb a proportion of the water added during granulation. Although increased water addition could be used to counteract losses in productivity, the current study examined methods of inhibiting water absorption by pisolite ore as a means of improving productivity. Additives were used to alter the properties of the granulating water. With no increase in mix moisture contents pilot-scale sintering studies showed that sugar-based additives gave productivities that are higher than those obtained for a comparable ore blend containing haematite rather than the pisolitic ore. Several techniques of adding the sugar to the sinter mix were examined and found to increase productivity to varying degrees. Theoretical considerations, in some cases supported by experimental results, indicate that sugar-based additives not only inhibited water absorption by porous ore particles but also improved the permeability of the sintering bed. The study also suggested that, contrary to some commonly held views, the highly reactive nature of Yandi ore from Western Australia is beneficial for sintering. Porous ores enabled the formation of a strong sinter at fast flame-front speeds-both good strength and a short sintering time are requirements for high-productivity operation

Jun 18, 1905

By W. Banda

Paper written on project work carried out in partial fulfilment of Phd. (Process Engineering) degree* The recovery of cobalt and copper from waste slag was studied in a plasma DC-arc furnace in reducing conditions. Three fluxes, CaO,CaF2, and TiO2, were investigated for their influence on selective recovery of cobalt into an iron-rich alloy. A further investigation on the influence of furnace power on the reduction of slag to recover cobalt to the alloy showed that a change in power setting had an unexpected effect on the recovery of metals to the alloy, in that selectivity of base metal recovery over iron recovery decreased at an increased power level. Keywords: DC-furnace, reduction, nonferrous, slags

Jan 1, 2004

By G. M. Steed, A. O. Oyinloye

The deposit lies in amphibolite-facies biotite granite-gneisses of Proterozoic age, 4 km east of a major crustal break known as the Ifewara-Zungeru fault. Gold mineralisation is contained in a zone of quartz-carbonate (mainly calcite) veins and hydrothermally altered gneisses with associated small-scale intrusions along a steeply dipping second-order fault zone that roughly parallels the main fault. Gold is present mainly at grain boundaries between quartz and carbonate as discrete particles up to 100 micrometres in size, in general association with sparse, scattered pyrite, pyrrhotite and some base metal sulphides. Adjacent to the gold-bearing zone the granite-gneisses have been hydrothermally altered with minor volume increase, most notable enrichment being in K2O, S, Pb and Cu (and Au). High concentrations of Th, Y, Ce and Zr in the granite-gneisses imply derivation from S-type granites. It is likely that their high heat production capacity maintained the high temperatures needed to transport gold in the hydrothermal systems. It is most probable that the mineralisation dates from the Pan-African orogeny (650-450 Ma)

Apr 1, 1996

By Tad S. Golosinski, R. Larry Grayson

Online education is not new. During the last decade, it has reached the stage where many universities offer a variety of courses, degrees and programs without any associated residency requirements. The most successful of the online universities, University of Phoenix, offers hundreds of accredited programs for close to 100,000 students throughout the world (www.phoenix.edu). Online education is considered to be a valid equivalent to traditional, classroom-based education. It is best suited to the needs of mature students with full-time jobs and a desire to deepen their knowledge. While most of the e-business has experienced severe setbacks during the last two years, e-education shows no signs of slowing down. On the contrary, the number of students and institutions offering online education keeps growing. The value of e-education associated expenditures was expected to reach $300 billion in 2001 (Sanoff,2001), making it a serious and mature industry.

Jan 1, 2002

By Peter Grundy

La eficiencia de los recursos en los procesos transparentes de gestión de las empresas permite aumentar el valor de los accionistas. En ese sentido, el presente texto señala el uso de la RCM como estrategia en el funcionamiento de un equipo que se centra en la confiabilidad. RCM es un proceso lógico que involucra aspectos técnicos y de negocio, capaz de producir resultados a muy corto plazo. Este proceso concluye con una recopilación de documentos fiables y totalmente óptimos para el desarrollo de las funciones de mantenimiento. Su uso correcto en la evaluación de los requisitos de mantenimiento de los equipos existentes, genera un mantenimiento menos costoso, confiable y eficaz. Asimismo se disminuye los costos de mantenimiento y se relaciona los aspectos ambientales y de seguridad.

Jul 17, 2000

By A. T. Iannacchione

Underground limestone mines typically use the room-and-pillar method of mining in the generally flat-lying limestone formations. In some cases the dip may exceed 5° which can result in unique roof instability problems. Stability may be further exacerbated by the presence of horizontal tectonic stresses. Field studies and numerical model analyses are combined to assess the affect of the dip in various stress conditions. The results showed that where the horizontal tectonic stresses are sufficient to cause intact rock failure, increasing dip results in increased failure potential. The effect of the dip is greater when the maximum horizontal stress is parallel to the dip. Two case studies are presented and evaluated against the findings of stress analysis results. The study showed that the empirical rules of orienting headings parallel to the maximum stress are generally applicable to dipping excavations, except when mining in the up-dip direction. The importance of accurately determining the orientation of the maximum horizontal stress is emphasized because the window of favorable orientations relative to the stress is small.