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By Geir M. Haarberg

Electrochemical techniques, mainly linear sweep voltammetry and potential step chronoamperometry, were used to study the behaviour of dissolved phosphorus species in cryolite-alumina melts, The presence of AIPO4 or Na3PO4 gave rise to voltammetric current waves due to electrode reactions involving phosphorus species at potentials where dissolved alumina is stable in cryolite melts, Diffusion kinetics for dissolved P(V) species were studied, Data from industrial cells were used to determine mass balances for phosphorus, For cells being fed with secondary alumina, more phosphorus tends to end up in the produced metal, Laboratory experiments to study the effect of phosphorus in the bath on the current efficiency for aluminium were also carried out.

Jan 1, 2004

By J. Bensabat, B. Figueiredo, A. Niemi, J. Rutqvist, C. F. Tsang

"A hydro-mechanical model was developed to study the interaction between mechanical deformation and fluid flow in the fault zones during CO2 injection and storage at the Heletz site which was chosen as a test site for CO2 injection experiments in the framework of the EU-MUSTANG project. The potential reservoir for CO2 storage at the Heletz site consists of three sand layers separated by lowpermeability shale layers. The potential consequences caused by fault reactivation, focusing on the shortterm integrity of CO2 storage, are evaluated. The difference in the results obtained by considering the three-layer as an equivalent layer storage formation is analyzed.INTRODUCTIONLarge-scale storage of CO2 in deep underground reservoirs may cause considerable pore-pressure perturbation as well as flux migration and concern has been raised over whether shear slip displacements may be induced in nearby faults, as a consequence of their reactivation. A state-of-the-art review can be found in Rutqvist (2012), which describes the various possible effects resulting from CO2 injection into a deep sedimentary basin, including those involved in reservoir stress–strain changes, micro-seismicity, caprock sealing performance, and potential fault reactivation. Moreover, several studies have recently shown how CO2 injection may produce seismic events both on major faults (i.e., large faults with large initial shear offset) (Cappa & Rutqvist, 2011a, b, 2012), and on minor faults that might have gone undetected during the site characterization, e.g., faults less than 1 km long and without detected initial offset (Mazzoldi et al., 2012).The present paper is concerned with the Heletz formation which was chosen as a test site for CO2 injection experiments in the framework of the EU-MUSTANG project. The Heletz site located at the southern Mediterranean coastal plain of Israel and the structure is an anticline fold with a crest of about 4 km by 2 km. The structure is gently dipping to the east, truncated by a pinch-out line to the west and subdivided into a number of blocks by transversal normal faults with small displacements. The water table is located at 300 m below the land surface. An areal sketch of the site with the elevation of the caprock and the location of the borehole that has been chosen for the CO2 injection experiment is presented in Figure 1."

Jan 1, 2015

By C. Denis Thibodeau

Outline Introduction 402 OB Mining Sequence Trial to Verify Sequence Change Monitoring Observations Numerical Modelling Conclusion

May 1, 2013

By A. A. Ruitenberg, S. C. Johnson, L. R. Fyffe

"Several types of stratiform and epigenetic gold deposits have been found in New Brunswick, It is the purpose of this paper to describe and classify the epigenetic deposits and demonstrate their relationship to tectonic evolution. The stratiform deposits are mostly volcanogenic massive sulphide deposits that are described elsewhere (Davies et al., 1985).The auriferous epigenetic deposits include quartz-carbonate veins and stockworks, polymetallic veins, contact metasomatic, porphyry copper and volcanic breccia (epithermal) deposits. These epigenetic deposits are concentrated in major fault zones that define or are close to the boundaries of tectonostratigraphic terranes or terranes and cover sequences. The host rocks of the deposits were subjected to extensive crustal thickening resulting from thrusting and/or high angle reverse faulting.The gold deposits north of the Avalon Terrane occur indilatent structures related to mainly dextral wrench faulting that postdated the episode of crustal thickening. The deposits along the southern margin of the Avalon Terrane occur in structures related to late phase thrusting."

Jan 1, 1990

By F. Habashi

"Extractive metallurgy was divided into the three sectors pyro-, hydro-, and electrometallurgy in 1959 when Professor Joseph Newton at the Idaho School of Mines in Moscow mentioned this in his book Extractive Metallurgy. Pioneer hydrometallurgists who built this discipline can be traced to the alchemists in the ninth century. It is now a mature subject of great importance in which pressure plays a vital role. Short biographies of some hydrometallurgists and the processes they invented are briefly outlined.INTRODUCTIONHydrometallurgy is the use of aqueous solutions to recover metals from ores. It is a relatively new discipline when compared with pyrometallurgy the use of fire to melt ores and recover metals which was practiced in ancient times. Hydrometallurgy can be traced to the time of alchemists whose concern was the transmutation of base metals into gold. Although alchemists did not succeed in their venture yet they described many reagents that are useful today. For example, they prepared sulfuric acid by distillation of iron vitriol, muriatic acid by distillation of sulfuric acid with salt, and nitric acid by reaction of sulfuric acid by reaction of sulfuric acid with salpeter. Jabir Ibn Hayyan the Muslim alchemist who lived in the ninth century (Figure 1) described aqua regia a mixture of nitric and hydrochloric acid that can dissolve gold although either acid has no action on gold. THE MIDDLE AGESIn the Middle Ages, it was reported that copper was recovered at Rio Tinto in Spain by allowing copper-containing pyrite to be exposed in piles to the action of air and rain. Copper sulfate solution obtained was treated with pieces of iron to precipitate metallic copper—a process that was called cementation. Georgius Agricola (1494–1555) (Figure 2) a medical doctor in Saxony who used to visit mines and smelters to examine miners and metal workers, described in his book De Re Metallica the parting of gold, i.e., separating of silver from gold by acids."

Jan 1, 2016

By I. Imris

The chemical industries are using different type of catalysts, which after application usually produced many tons heap of residues. One of them is cupric oxide catalyst with high content of copper and silica. The recovery of copper from the waste has become major interest from a viewpoint of environmental protection and recycling of resources. The thermodynamic analysis and experimental results suggest that the copper from cupric oxide catalyst can be extracted by plasma reduction process. By plasma reduction process the inert slag and copper with following chemical composition: 99.04 % Cu, 0,042 % Fe could be obtained.

Jan 1, 2007

By B. A. McKee, T. Adamcewicz

For a capital expenditure of only $46,000, Caland Ore Company has successfully converted its three dry grinding center peripheral discharge rod mills to dry grinding ball mills. The conversion has resulted in a significant capacity increase, operating cost reductions and in-plant environmental improvements. This paper describes why and how• the conversion was made.

Jan 1, 1972

By Per Hedvall, Jan-Eric Ståhl

"The main objective of this study is to introduce the new Sandvik’s production cost-model within Crushing & Screening (C&S) technology. So far, there have been different ways of determining different production costs in the industry, however, the previously published and presented methods have not been very efficient in calculating the costs per product and metric ton. Accordingly, the current study has been planned and started in collaboration with Lund University to provide an accurate and easy to implement cost estimation program to determine the costs for crushing and screening plants worldwide.The proposed model has been adapted to fit the C&S processes of different rocks/ores fractions. The result is presented as cost per ton of the end product(s).Within this paper the cost estimation results for 3 different crushing and screening plants are presented based on the information obtained from the following sources: a) documents at Sandvik SRP, b) Sandvik’s crushing & screening internal/external machines/plants data and information, c) literature studies, including the use of Sandvik’s internal/external simulation and software programs, d), visiting the crushing and screening plants ,e) interviews, information systems’ data, and, f) testing and observations by ourselves.In order to improve the level of accuracy and the validity of the attained results, simplistic Monte-Carlo simulations have been used, where needed. The achieved results, so far, have proven the reliability of the model. The calculated cost estimations have shown an accuracy over 80% when they compared with real cost data obtained from plant practices.The current cost calculation model, will offer the possibility of:•,Calculating the production costs in proposed and/or existing C&S plant.•,Making detailed cost analyses for the end product(s) in proposed and/or existing C&S plants.•,Determining the profitability of each finished product when it’s required.•,Cost optimization by potentially cutting the cost for part of C&S plant with an existing plant practice"

Jan 1, 2016

By H. R. Taylor

The history and development of this property is more or less familiar to nearly everyone connected with the mining industry, so that only a brief outline of the more important facts will be given in this article. In 1916, a small pilot mill was constructed by the British Columbia Copper Company at Copper Mountain, and during 1916 and 1917 test work was conducted to determine the possibility of concentrating the ore and also to work out a suitable flow-sheet. In the spring of 1917, the location of a mill site at Allen by, which is about 8,% miles from Copper Mountain, and near the Similkameen river, was decided on, and the designing of a 2,000-ton plant was then worked out by Bradley, Bruff and Labarthe. Early in 1918, the actual construction of the concentrator began, and, after considerable labour difficulties, it was completed in 1920. During this period of construction, the West Kootenay Power Company ran a 60,000-volt power line over from Greenwood, a distance of 102 miles, and also built a sub-station at Allenby to take care of the mine and mill. The concentrator was started up on October 20th, 1920, and ran until December 11th, 1920, a total of 18,354 tons of ore being milled. The results of this short period of operation were encouraging, but, due to tlie prevailing low price of copper and high wages, it was necessary to shut down until a more favourable time. During the latter half of 1923, some work was done on remodelling the mill. This work continued until January 8th, 1924, when it was suspended.

Jan 1, 1929

By Minoru Fujita, Ian M. Johnson

"A helicopter-borne geophysical survey was flown in 1978 over selected areas on Kyushu Island, Japan. The principal sensors were a moving source electro-magnetic system and a magnetometer. Maps of apparent resistivity were generated from the EM data. Based on the resistivity signature of known deposits within the survey areas, targets were selected for ground follow-up. Drilling of one such target in late 1980 resulted in the discovery of a gold deposit from which full production will begin in the summer of 1985. The deposit contains a minimum 120 tonnes (3.86 million ounces) of recoverable gold and is the largest in Japanese history. The deposit is in a geological setting previously unsuspected of hosting precious metal deposits. The case history suggests a preferred exploration strategy which might be employed in other similar geological environments.IntroductionThe Hishikari area is located some forty-five kilometres north of Kagoshima city, Kagoshima Prefecture, Kyushu Island, Japan (Fig. I). The area and its environs is one with a number of gold deposits which have been worked with varying results since the late 1800s. The large st deposit in terms of recovered gold is the Ohkuchi (or Oguchi) Mine (Fig . 2) which was recently closed due to exhaustion of reserves. The Ohkuchi Mine started production in 1896. A total of 22.2 tonnes (714 ,000 ounces) of gold, with an average ore grade of 13.6 grams/tonne (0.39 ounces/ton), was extracted over the Life of the mine.In an attempt to discover new deposits , the Metal Mining Agency of Japan (MMAJ) carried out a regional geologic mapping program of the area between 1975 and 1977. This was followed by a helicopter-borne electromagnetic and magnetic survey. The airborne survey was flown by Scintrex and the compiled results presented to MMAJ in early 1979."

Jan 1, 1985

By Michio Okada

Dissociative adsorption of hydrogen (deuterium) on thin gold films grown on Ir{111} surface has been studied with temperature-programmed desorption using a quadrupole mass spectrometer and nuclear reaction analysis. Thin Au{111} films are epitaxially grown on Ir{111}. Surprisingly, H2 (D2) can dissociatively adsorb on these Au{111} films, although it is well known that Au surfaces are noble enough not to dissociate hydrogen molecules [B. Hammer and J.K. Nørskov, Nature 376, (1995) 238]. We attribute this to the sensitivity of hydrogen to changes in the local surface properties, e.g., electron localization (the narrowing of the s-band, the s-band center model), which could explain the upto now unexpected high for the reactivity of a thin Au{111} surface. Moreover, we found that H (D) atoms can be confined into a Au thin film and/or the interface between an Ir surface and the thin Au film. We demonstrate how anomalously reactive thin Au films grown on an Ir surface are, and also compare the Au films with Ag films grown on Ir to test the validity/generality of our proposed s-band center model.

Oct 1, 2003

By T. Patching

"Introduction The occurrence of coal was first reported in the Drumheller area in 1793 but it was not until 1912 that production of coal was recorded. In that year 13,000 tonnes were mined in the Drumheller area. Three years later the Drumheller mines ranked next in the Province to those in the Crowsnest and Lethbridge districts, with an output of 225,000 tonnes. By 1917 production had increased to 600,000 tonnes, moving Drumheller to second place in output in the province, second only to the Crowsnest district. It held this rank until 1960. Production, almost all from underground mining, rose to over a million tonnes a year by 1920 and remained between one and two million tonnes per year until 1954. Competition from newly discovered oil and natural gas, beginning around 1950 caused a steady loss of domestic coal markets, especially from underground mines. By 1960 Drumheller's production had fallen below a half a million tonnes per year and the field ranked third in output in the province, being surpassed by new stripping operations in the Castor field. By 1965 only a couple of producing mines remained in the Drumheller valley, and output was only about a quarter of a million tonnes per year(1). Throughout the life of the field production was seasonal, depending mainly on the domestic heating market. In 1979 the last mine ceased production. For the last several years of its operation it had remained open in the summers to provide tours for visitors(2). The Drumheller mining operations were located along or near the Red Deer River valley which is 300 to 400 feet deep, and extended from a few miles above the city of Drumheller to East Coulee, about 13 miles down the river in a south-easterly direction. Intervening mining communities existed for some years at Wayne and Rosedale. During the peak years of production some 2000 to 2500 miners and their families lived in these communities and the surrounding areas."

Jan 1, 1985

By M. Medraj, M. A. Arafin, D. P. Turner, P. Bocher

In this study, the kinetics of isothermal solidification during TLP bonding of Inconel 625 and 718 superalloys with nickel based multi-component filler alloy BNi-2 have been studied through a combination of direct experimentation and mathematical modeling in order to determine the effect of process variables and, thus, to optimize the process. The predicted isothermal solidification completion times from the boron diffusion model and migrating solid/liquid interface model were in good agreement with the experimentally determined values and, they were found to be significantly less than those of other nickel superalloys with different nickel based filler alloys. Further, significant reduction of holding time was observed with increasing bonding temperature and with decreasing joint gap. No significant grain growth in the base metals has been observed in the temperature range being investigated (1325 - 1394K).

Jan 1, 2006

By Sabine Noelte, Mikko Petteri Rantamäki, Christopher Robben, Anssi Takala, Karl-Erik Rånman

"Sensor-based ore sorting is on its way to establish as a standard option for physical separation. The increasing number of installations in coal, iron ore, industrial minerals and hard-rock metal mining segments underlines the technological and financial potential that is beginning to be untapped. The Ma’aden Phosphate installation with 1.650 t/h sensor-based ore sorter feed sets a new benchmark for the possible capacity of stationary installations. Besides stationary installations, including multiple sorters parallel in different size ranges and multiple stages, containerised semi-mobile plants are applied. These offer two advantages, first being the reduction of transport costs when applied close to the mining face. The second is that semi-mobile systems enable processing of tens of thousands of tonnes of ore in a piloting phase with an approximate duration of 0.5 to six months, verifying the results laboratory mini-bulk tests on 5–10 tonnes of sample. This is especially important for low-grade metal ores because of the inherent Fundamental Sampling Error, as well as the Grouping and Segregation Error. The paper elaborates the results achieved within the I2MINE project, treating polymetallic ore at the Boliden Concentrator in Sweden.INTRODUCTIONSensor-based ore sorting (SBS) is becoming a standard option for physical separation, applied in all segments of mineral production. The Umm Wu’al project sets the bar for stationary SBS installations with 1,650 t/h feed (TOMRA, 2015). TOMRA Sorting Solutions has finalised an agreement in cooperation with Outotec to supply Outotec-branded sorting solutions for the mining and metallurgical industry (TOMRA, 2014). Especially for low-grade hard rock metal ores, an interdisciplinary approach is necessary applying experts for all aspects of mineral production. Due to the impact on the whole process stream, it is important on the end user side to have high level managerial support and involve all disciplines to ensure that all stake holders are involved in the analysis."

Jan 1, 2016

By Xu Feng, Han Shufeng, Zhu Bin, Wang Mingming

Due to urban subway tunnels mostly built in the cities with highly density buildings, the geological and construction conditions is complex, especially certain sections of the subway tunnel will pass through from the foundation of the overpass, therefore the stability and surface deformation control of that section’s tunnel excavation is particularly important. Taking Xi'an Metro Line Three interval tunnel as a research object, we have used FLAC3D simulation to analyze the tunnel’s surrounding soil deformation and tunnel lining stress distribution under bridge foundation with shallow buried covered excavation method. Analysis results show: (1) After the excavation of the tunnel right line, due to the bias of the upper bridge foundation the right of the tunnel showed relatively large deformation. In order to ensure the construction safety, we recommended using the grouting anchor reinforcement on the right side wall to further control the deformation zone. (2) The maximum vertical displacement of the ground occurred in the right wall of the tunnel portion which was due to the intensity of soil outside the grouting range of the arch is low, as a result the deformation is larger; this position requires special attention, strengthening the monitoring measurements of this part is necessary to avoid the large deformation and other adverse effects of the upper portion of bridge foundation. (3) The maximum vertical force area of the initial lining of the tunnel is in the middle of the side wall, while the second lining in this part of forces is smaller, thus at the beginning of the construction of the liner, attention should be paid to this area. On-site grouting or steel bracing reinforce support may be used if necessary.

Jan 1, 2015

By A. W. Jacob

THE shatter cut, or burn cut as it is often called, is one in which the centre of the round is almost reamed out by drilling holes so close together that the blasting of a few holes shatters the rock embraced by all of them. The idea of shattering the centre of a face by shooting holes drilled parallel to one another is not new. Some miners have used this method for years past, when drilling quartz or a face near timber. But, they followed the age-old practice of first blasting the cut, then the square-up. It was not thought possible to shoot both together. In the case of machine men, the two largest contributors to silicosis are dust from drilling and dust from blasting. It follows, then, that material reduction of exposure to either constitutes an important step in lessening the incidence o silicosis. It was? the hope of being able to do away with the necessity of the men having to return early to a face, through dust concentrations of 60,000 to 80,000 particles per cubic centimeter, that aroused interest "in the shatter cut at McIntyre. Efforts to this end were successful. Now, with this kind of cut, all holes of a round are shot simultaneously.

Jan 1, 1942

By T H. Clark, R P. Doig, V. A. Saull, R B. Butler

Terrestrial heat flow has been determined for four boreholes in the Montreal area. The mean value of the results (uncorrected for glacial effects) is 0.790 ± 0.053 x 10-6 cal/ cm2/sec (95 per cent confidence limits). Thermal gradients were determined using a thermistor probe and d-c bridge, and also by a new method using a probe-contained phase-shift oscillator, the output frequency of the oscillator being a function of probe temperature. Thermal conductivity determinations were made on core from the boreholes, using a divided bar apparatus. INTRODUCTION T HIS paper concerns the terrestrial heat flow in the St. Lawrence lowland of Quebec, as determined from measurements on four of the numerous boreholes drilled in this region for gas and oil. The work has been supported by Geological Survey of Canada Re-search Grant 3-58, awarded to T. H. Clark and V. A. Saull. This sup-port is hereby gratefully acknowledged.

Jan 1, 1962

By Chris V. Sellathamby

Condition-based maintenance is replacing preventive maintenance in many industrial operations as a result of gains in productivity. Preventive maintenance is strictly time-based which means that as long as the prescribed time is sufficiently short, failures are prevented. The trade-offs between shorter cycles and increased downtime is a fine balancing act. Condition-based maintenance is gaining momentum as the more cost-effective and green solution to finding the optimal maintenance cycle and improving overall productivity. In the mining industry, various parameters of heavy equipment are monitored continuously to provide feedback for maintenance events. However, strain, shock, and vibration, key factors which lead to yielding and fatigue of metal parts, are not generally monitored by built-in systems, mainly due to the complexity of sensor installation and computational intensity of data processing. Scanimetrics has developed a stand-alone, add-on wireless system for measuring strain, shock, and vibration in heavy equipment and components, the data from which can be directly used to trigger maintenance events. The present system is being deployed in tar sands mining equipment. The system consists of a portable display and control unit, a software platform consisting of data management, sensor instrumentation and data analysis, and wireless strain sensor units, which can be easily installed on equipment. Data from the sensors can be gathered throughout the mine site, processed instantly, and used to generate condition-based maintenance events, improving overall uptime of the equipment and overall productivity of the mining operation.

Oct 1, 2010

By K. Bowes, M. D. Maley, R. J. Ring

The Honeymoon Uranium Project is an acid In-Situ Recovery (ISR) mine in South Australia. It was previously operated for approximately 18 months before being placed on care and maintenance in 2014, it was then acquired by Boss Resources in 2015. Boss has been performing a number of studies to plan for reopening of the mine, including a successful field leach trial (FLT) in 2017. The current configuration for uranium precipitation at Honeymoon is a batch process. Whilst this achieves effective uranium recovery, the precipitates produced are often very fine, with poor settling and solid/liquid separation characteristics. Continuous precipitation, involving recycling of solids, has reportedly been successfully utilised in other operations to increase the particle size and density of the product, leading to solids that can be more readily dewatered, dried and drummed, with less fines and dust generation. However, no operational data are available from such operations.

Jan 1, 2020

By M. Mirzazadeh

Air cooled crackable and conventional forged steel specimens were tested under reversed push-pull conditions to examine the effect of shot-peening on their high cycle fatigue behaviour (-106 cycles). The steels were tested in the normalized as well as shot-peened conditions. The results showed that shot-peening smooth specimens had little effect on the fatigue limit of the air cooled forged steels and the detrimental effect of the rougher peened surface was not apparent. Microhardness profiles indicated that the shot peening produced a gradient of compressive residual stresses that was greater than that of the loading stresses, suppressing the anticipated beneficial effect on fatigue life. Crack initiation was more likely to occur below the surface. The results indicate that the surface roughness was not a significant factor in controlling the fatigue lives, since they were essentially the same for the non shot-peened and shot-peened steels.

Jan 1, 2010