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By Hui Yongning

This paper presents a simulating test of constitutive relation of soil anchor in laboratory and puts forward a new plastoelastic mechanical model, on which a new calculating formula of elastic and plastic limit bearing capacity for soil anchor is suggested and two engineering projects verify that this method is adaptable.

Jan 1, 1991

By K. Wyper

"Gulf Minerals (Canada) Limited' s Rabbit Lake Uranium Operation is located in the northern portion of Saskatchewan, 198 miles southeast of Uranium City and 134 miles northwest of Lynn Lake Manitoba.This paper describes flow sheet changes to solve operating problems and briefly describes future changes to accommodate the new ""B"" Zone ore.The Rabbit Lake mill was designed to process 1600 dry tons per day of uranium ore, with an average grade of 0.370 percent u3o8. In 1981, the mill processed 2040 tons per day at a grade of 0.231 percent u3o8 . The process modifications and flow sheet changes that allowed this increase in tonnage will be discussed in relative chronological order. Mill feed was introduced on June 10, 1975, the original equipment consisted of an Ingersoll Rand hydraulic breaker mounted over a 24"" square grizzly. The - 24"" ore was fed to a 2011 X 6"" seflli autogenous grate discharge mill close circuited with 20"" cyclones, the mill discharge was screened on a tyler double deck screen with the undersize (8 rnesh) reporting to the cyclones, the screen oversize was returned by conveyor belt to the mill feed chute.The cyclone overflow (28 mesh) was thickened in a 100' diameter thickener to obtain 55 percent solids for the leach circuit.The leach circuit consisted of two slurry holding tanks and five leach tanks."

Jan 1, 1982

Jan 1, 1996

By Laura Mottola

Process Design and Change Management for Successful Deployment of Technology in Mining Over the last 30 years Canada has been successful in developing but not deploying hardrockmining automation. Our opinion is that the current lack of R&D investment and implementation capacity places Canada at risk as a future global mining leader A white elephant A burdensome possession; creating more trouble than it is worth. White (albino) elephants were regarded as holy in ancient times in Thailand and other Asian countries. Keeping a white elephant was a very expensive undertaking, since the owner had to provide the elephant with special food and provide access for people who wanted to worship it. If a Thai King became dissatisfied with a subordinate, he would give him a white elephant. The gift would, in most cases, ruin the recipient.

May 1, 2010

By C. A. Young

Cyanide is a fast-acting, highly toxic substance but, at the same time, is deemed essential for sustaining life as well as our standard of living. In this manuscript, the facts about cyanide are presented beginning with a brief history and definition and ending with a discussion on cyanide alternatives. Other topics include speciation, physical characteristics, toxicity, manufacturing, cyanogenics, cyanide cycle, separation, destruction, and markets including those outside the mining industry. Emphasis, of course, is placed on gold production by leaching and how it is influenced by ore type, mineral characteristics and economics as well as its advantages and disadvantages.

Jan 1, 2001

By G. Adderley, A. Wetherelt

The problems of poor drilling in underground operations have been highlighted on many occasions. Incorrect collaring and poor angular deviation can all lead to an increased block size, dilution, over-break adding to both cost and time, while in a tunnelling operation sidewall damage and a poor percentage pull from a blasted round has similar consequences. This paper sets out to further investigate the ability of the laser scanner method of obtaining drill hole deviations and collaring errors at the face as described by Wetherelt and Williams (2006). Tests were carried out to compare measured inter-hole burdens from this method in comparison to that obtained using a total station survey. To investigate the ability of these methods to accurately determine drilling errors, a field test was carried out through an analysis of a series of pre-drilled blast holes of known inclination and direction. A time-motion study was also conducted for a varied number of holes to assess the usability of each method. In line with current research into blast vibration being undertaken at the Camborne School of Mines, 6 cut blasts were carried out to establish the effect of poor drilling on a blasts success to see whether an increased burden at the toe of a hole had an influence on vibration.

Jan 1, 2009

By J. S. Miller

The Bureau of Mines conducted surface tests to determine the feasibility of using liquid explosives for underground rock fracturing. The effects of configuration, confinement, length, critical layer thickness, and fracture-propping sand on detonation and explosive propagation velocity of desensitized nitroglycerin were studied, using polymethyl methacrylate and glass-plate reservoirs through lengths from 3 to 12 ft, with explosive-layer thicknesses from 0.1875 to 0.0312 in and in aluminum tubes 8 ft long with diameters from 2.000 to 0.125 in. Interval and continuous detonation velocity data were obtained. Under the test conditions detonation velocity was dependent upon explosive confinement and fracture-propping sand. The detonation velocity of a confined nitroglycerin explosion in aluminum tubes can be reduced by as much as 85 percent, when the tube contains fracture-propping sand. The shape of the reservoir, whether triangular or rectangular, has little effect on the detonation velocity or explosive propagation. The critical or minimum explosive-layer thickness between glass plates, capable of supporting propagation, was 0.0312 in. The presence of a fracture-propping sand in the sheetlike layers increased the critical explosive layer thickness to 0.0625 in. In nitroglycerin-filled and nitroglycerin-sand filled tubes, the minimum tube diameters successfully tested were 0.125 in and 0.375 in, respectively.

Jan 1, 1969

By Frank Yu, Bob Fukuhara

"The Stillwater mine is a 3,000 tons/day platinum/palladium underground mine and flotation concentrator located in the Beartooth mountain range in south-central Montana. The site elevation is 5,000 feet above sea level providing a climate with pleasant summers and cold winters. The winters are particularly characterized by very strong winds.The mining methods at Stillwater had been variations of overhand cut-and-fill and some blast-hole stoping. Until construction of the paste back-fill plant, mine back-filling was being practiced using classified hydraulic sand-fill methods. Where higher strengths were necessary, cement was added to the hydraulic fill, however, excessive quantities were necessary due to significant losses with the water drainage from the comparatively low-density fill. There was a need for higher strength back-fill with reduced cement content to augment the hydraulic-fill process.In early 1998, Stillwater Mining Co. commissioned AGRA Simons (then H.A. Simons) in a joint venture with The Industrial Company, TIC, to design and construct a treatment facility to re-process the mill flotation tailing, incorporating the following process alternatives:Produce 100 tph of low strength paste with unconfined compressive strength of 25 to 50 psi,Produce 100 tph of high strength paste with unconfined compressive strength of 100 to 125 psi,Direct all of the excess mill tailing to the sand-fill plant,While no paste is being produced, pump all of the mill tailing to the sand-fill plant,While no paste is being produced and the sand-fill silos are full, direct the mill tailing to the tailing pond.The paste backfill plant was therefore to be designed to produce the two different types of backfill paste as well as have the function of being the distribution center for the mill process tailing .Moderate to high slump pastes would be required because of the comparatively long horizontal transport distances, up to 8,000 feet, and the requirement for a low angle of repose to fill the stope evenly without numerous discharge points."

Jan 1, 2000

By P. J. Williams, A. R. Foster

Petrographic studies, assay records, and laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS) analyses of major sulfides suggest nearly all of the gold at the Ernest Henry Cu-Au deposit occurs in the form of native gold or electrum (95-65 wt.% Au); sylvanite and dissolved gold in cobaltite, chalcopyrite, and pyrite make only minor contributions. LA-ICP-MS analyses of the gold contents of chalcopyrite gave from 8 to 139 ppb (mean = 56 ppb), more than an order of magnitude lower than those experimentally determined in chalcopyrite in equilibrium with native gold at the estimated mineralization temperatures (350°-450°C). Gold content is more variable in pyrite (1-400 ppb, mean = 77 ppb) and highest in narrow growth zones of a subordinate type of complexly zoned pyrite wherein it is associated with elevated As, Ag, Sn, Sb, Te, and Bi. Deposition of gold-electrum was closely associated with, but preceded some of the chalcopyrite deposition, as indicated by microtextures and lower bulk Au:Cu ratios in late-stage chalcopyrite-rich veins. Gold grains have maximum dimensions from <1 to 50 micrometers, and are heterogeneously distributed with most occurring in microscale clusters. Fifty-five out of 76 grains recorded in polished sections are in contact with both chalcopyrite and pyrite, and many of the rest are in sites where such a relationship could exist in the third dimension. The dominant textural sites are intergrowths with chalcopyrite in microveinlets cutting pyrite, and on faces of pyrite grains in contact with chalcopyrite. Scanning electron microscopy, electron microprobe analysis, and proton induced X-ray emission studies show that pyrite associated with gold includes complexly zoned, weakly zoned, arsenian, and arsenic-poor types. The textures are compatible with the possibility that most gold was deposited electrochemically as native metal on pyrite surfaces. The textural distribution of gold has important metallurgical implications given that the ore processing circuits at Ernest Henry and most other sulfide copper mines are designed to exclude pyrite (and arsenic) from concentrates.

Jan 1, 2007

By Gui DeReamer

Located on the Wabash River in the central portion of the state, the city of Lafayette, IN is relatively small compared to most cit-ies that incorporate tunnels into their combined sewer overflow (CSO) systems. The original CSO plan for the city was to replace two aging lift stations that were built in the 1950s. The original con-cept was to build a new sewer using conventional cut-and-cover construction to eliminate one of the lift stations ? the Parking Lot Lift Station ? and build a new regionalized one at the location of the Pearl River Lift Station. The initial sewer design was sized just to handle the flow that would eliminate the Parking Lot Lift Station. The planning for this project was being developed as part of the city?s CSO long-term control plan (LTCP) that focused on reducing the overflows from the city?s 14 overflow points. However, during the development of the CSO LTCP, a major industrial user indicated it would be increasing its flows to the system, which required additional conveyance capacity to meet the city?s CSO LTCP. After reviewing the design concepts with city representatives during the planning phase of the project, the mayor indicated that he wanted to minimize impacts to downtown businesses; therefore, trenchless alternatives were considered. The last piece of the puzzle that drove the project away from a small diameter pipeline was discovered during a flow monitoring program to collect flow data for the CSO LTCP project. This study revealed a major restriction in the 100-year-old Pearl River Trunk Sewer, located beneath four active railroad tracks. To eliminate this flow restriction, provide more overflow storage and reduce the impact to local businesses, a new 2.7- to 3.6-m- (9- to 12-ft-) diameter tunnel sewer became the most viable solution.

Jan 1, 2011

THE flotation plant at Mount Lyell was erected, primarily, for the treatment of ore from the Lyell Comstock mine. These workings are situated over a mile in a direct line north of the North Mount Lyell mine, and are connected with the Reduction Work at Queenstown by a 2-ft. gauge steel tramway via the Queen River valley a distance of 7 miles. The property was purchased from the Mount Lyell Comstock Copper Co. After the disastrous fire in the North Mount Lyell mine in October, 1912, steps were immediately taken to make Lyell Comstock ore available for treatment, in order to relieve distress caused by any prolonged stoppage of work, and subsequently 13,032 tons of ore, averaging 3.38 %copper, 0.28 oz. silver, and 0.034 oz. gold; were smelted. When operations were resumed at the North Mount Lyell mine, it was evident that there was no economic advantage in smelting Lyell Comstock ore as compared with the higher value North Mount Lyell ore, which was also a better flux for the Mount Lyell pyrites, and that the future of the Lyell Comstock ore depended upon cheap mining and successful concentration of the ore. Therefore, extensive trenching and diamond-drilling was carried out, and a sufficiently large quantity of ore proved available for cheap extraction by open-cut methods. At the same time bulk tests by flotation were carried out at the Minerals Separation testing plant in Melbourne on different classes of ore from the Mount Lyell Comstock mine proper, followed by laboratory tests at Queenstown on all classes of ore available. All these tests demonstrated that the ore was amenable to the process, provided that it was ground finely enough. Plant erection was delayed by the general dislocation of business at the outbreak of war, but finally it became...

Jan 1, 1920

New Bio-Adsorber with Activated Carbon and Nano Tube Carbon for Separation of Nickel and Cadmium

Sep 13, 2010

By L. R. Stace

Arguably, one of the most significant technological breakthroughs that had been experienced during the period when British Coal was the major coalmine operating company in the UK, the use of rockbolts as principal support in underground roadways brought with it the need to re-assess the technical knowledge, management controls and legislative frameworks associated with the support of mine workings. Following a major roof fall in a roadway supported principally using rockbolts in which fatalities occurred, the process of the design of rockbolted support and the systems and procedures that had been put in place to control its use in the UK were further reviewed. The paper discusses the outcome of these reviews, and how the incident initiated a major new interest in strata control research in the UK against the background of the fragmentation of the ownership of the mines following the sale of the former British Coal assets at the end of 1994, together with the proposed introduction of new strata control legislation in 1996.

Jan 1, 1996

By A. Nkolele

Paper written on project work carried out in partial fulfilment of B. Tech (Metallurgical Engineering) degree Fine coal of the Goedehoop Colliery is dewatered by centrifuging before being sold. Full-scale plant tests were carried out to reduce residual cake moisture by the addition of surfactants. It is believed that by modifying the interface between the coal surface and the adherent surface water, as well as the water occluded in the cake voids, drainage is improved. Two anionic surfactants at concentrations up to 150 g/t were tested on coal of <0.5 mm size. The results demonstrate that quite high additions of surfactant (80 g/t)were needed to reduce moisture from 20 to about 17?18%. It was observed that when increasing surfactant additions at low levels, within a very narrow concentration range, the retained moisture first increased sharply only to decrease sharply immediately thereafter; this effect points to a critical surfactant concentration. Based on the obtained results, the use of surfactants cannot be recommended at this stage; further investigations under more controlled conditions are required.

Jan 1, 2004

By Stavros H. Constantopoulos

Mediterranean regions such as Greece, Turkey, Cyprus, Corsica and New Caledonia have experienced epidemics of malignant mesothelioma as a result of non-occupational, ??domestic?? exposure to tremolite asbestos and fibrous erionite. This exposure to tremolite asbestos and fibrous erionite is typified ??domestic?? due to its prevalence in regions with natural deposits of tremolite asbestos (or fibrous erionite) where the material from tremolite asbestos or fibrous erionite is used for domestic applications such as whitewashing. However, these exposures may be useful in examining the potential consequences of even small amounts of amphibole asbestos fibers in the ambient air. It can also elucidate the effects of fibers that behave like amphibole asbestos. However, this type of exposure is not useful for studying the potential effects of small amounts of asbestos in the ambient air of big cities due to the differing nature of the fiber types and modes of exposure between the regions. © 2008 Published by Elsevier Inc. Keywords: Tremolite asbestos; Erionite; Domestic; Environmental; Exposure

Jan 1, 2007

By Martin Stone

Industrialized countries, particularly the United States and the United Kingdom, remain at the forefront of international efforts to control the potential disruption from computer malfunctions caused by the date change from1999 to 2000 — widely known as the millennium bug or Y2K. Disruption is least likely in the developed world, including the United States, Canada, western Europe, Japan and Australasia. However, the picture is potentially different in developing countries where many mining companies operate. The less developed the country, the greater the chance of some form of Y2K-linked disruption.

Jan 1, 1999

When the 2008 Olympic Games begin in Beijing, China is September it will not only mark the end of the journey for the Olympic torch and the thou-sands of participating athletes, but the games will also mark the culmination of a massive amount of construction in the city. On display for the world to see will be 31 new and refurbished venues including the 91,000-seat National Stadium called the ?Bird?s Nest? and the aquatics center, called the Water Cube. What will not be featured as prominently on the television cameras broadcasting the games around the world will be the network of tunnels built beneath the city. But that infrastructure of rail lines will be of critical importance to the games. While preparing to host the world, China added a subway tunnel that will include four stops in the Olympic Park. The 4.4-km (2.7-mile) subway line that runs through the complex of stadiums, gymnasiums and parks began trial operations in June. Prior to the opening of that line, Beijing&apos;s No. 5 subway line, which runs through the heart of the city from north to south, opened in October. That 27.6-km (17-mile) line took nearly five years to build and includes 23

Jan 1, 2008

By H Matsuno, N Oyama, T Yamamoto, K Nakajima, Y Iwami, N Saito

Recently, the quality of sinter feed ore used in sintering process has deteriorated. In particular, Fe has decreased and gangue component has increased in the sinter feed ore. Increase of gangue is not only the factor to influence sinter qualities, but also the factor to increase coke ratio in the blast furnace operation as the increase of slag ratio. Therefore, to cope with the deterioration of iron ore qualities, studies on alternative iron ore resources and development of its utilisation technology have been required.In that kind of new iron ore resources, authors focus on high-grade magnetite fine. High-grade magnetite fine decreases sinter productivity by the decrease of permeability of sintering bed. Therefore a new study for using large amount of magnetite fine is required. In the past, there are some studies about the effect of mixing ratio and size of magnetite fine on productivity and quality, but there are few studies about magnetite fine segregation in charging.In this research, the melting behaviour and interfacial reaction calcium-ferrite, which has important role as bonding agent among iron ores, melts into hematite substrate and magnetite substrate was studied. As the results, it was defined that upper segregation of high-grade magnetite fine is suitable for productivity of sintered ore. Based on this knowledge, the control method of high-grade magnetite fine segregation by magnetic force at charging was studied with DEM (discrete element method) and its verification experiments for magnetic segregation control was conducted in the laboratory.CITATION:Iwami, Y, Yamamoto, T, Oyama, N, Matsuno, H, Saito, N and Nakajima, K, 2017. Improvement of sinter productivity by control of magnetite ore segregation in sintering bed, in Proceedings Iron Ore 2017, pp 61–68 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Osama El-Fiky

There are many types of deep foundations currently being used in the San Francisco Bay Area, one of the most common being driven precast, prestressed concrete (PC/PS) piles. PC/PS piles are frequently selected for use due to of ease of installation, availability, and relatively low cost. Disadvantages of using PC/PS piles are noise, vibrations, pollution, front-end delays due to indicator pile programs, and reduced flexibility. An acceptable alternative to driven PC/PS piles was selected for construction of foundations for the heavy housing and administrative buildings at the San Francisco County Jail #3 replacement project in San Bruno, California. The pile type selected, the Auger Pressure Grouted Displacement (APGD) pile, was chosen to reduce noise, vibrations, installation time, and cost, and to allow for greater flexibility of installed pile lengths. This paper presents a case history of the use of APGD piles that were substituted for driven PC/PS concrete piles for the subject project. Standard and quick loading pile load tests were performed to confirm adherence with the design criteria originally used for the driven PC/PS concrete piles. The APGD piles were found to increase shear strength around the piles similarly to driven displacement piles. In addition, this paper presents the methodology used in monitoring APGD pile installation.

Jan 1, 2002

By Bobby Dupree

I remember a big problem with a seismograph in the winter two years ago. In response to a citizen’s complaint I placed a transducer near the corner of a two-story home. It was a pretty nice day for the winter months, the people were pleasant, and I had no problems digging a hole to place the transducer.

Jan 1, 2004