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By D. R. Hack, N. M. Sirakov, M. L. Feves, M. Iwanowski

This paper presents a new approach capable of volume calculation of 3D reconstructed geological objects. The method is based on a well-known concept that states the volume of an object can be computed as the limit of the sum of the area of infinite number of sections, which cut the 3Dobject. Since shortage of input data about the geological objects usually exists, Mathematical Morphology and polynomial interpolation are employed to generate a set of intermediate sections between the set of initial sections. A Mathematical Morphology tool is applied to compute the area of the two of sets initial and generated 2D sections. Regularities together with Delaunay Triangulation are employed to perform 3D reconstruction. A formula is developed on purpose of volume calculation of the reconstructed objects. A set of ten theoretical, electrical resistivity cross-sections were generated and used to perform an experiment to show the capability of our approach to estimate the volume of complex 3D geological object in case of sparse 2D sections. The volume determined using the morphological approach presented in this paper show good correlation with the volume of the original input object. Advantages and disadvantages of our volume calculation approach are discussed in the conclusion of this paper. Keywords: electrical resistivity, sparse 2D sections, geological objects, smooth 3D visualization and volume calculation.

Jan 1, 2003

By Xiangwen Wang

Electrodeposition of lead metal from high purity brine electrolytes containing lead chloride (PbCI,) was conducted so as to assess the feasibility of electrowinning lead-metal directly from aqueous chloride electrolytes. Tests were performed at 65 and 80°C (338 and 353°K). Characteristic features of the deposits, on both lead and graphite substrates, were correlated to operating parameters associated with: electrolyte temperature, current density and total lead- concentration. Photomicrographs of these morphological features were obtained by use of Scanning Electron Microscopy (SEM).

Jan 1, 1993

By A F. D C Varajpo, R C. Weba, C Volkmer-Ribeiro, C A. C Varajpo, N S. Gomes

This study relates to the spongillite deposits from the region of Jopo Pinheiro, in the north-west of the State of Minas Gerais, south-eastern Brazil. The deposits occur in shallow ponds (with a maximum depth of 3.5 m) on a karstic planation surface developed on rocks of the Spo Francisco Neoproterozoic Supergroup. Cenozoic detritic covers are associated with this surface. The field study of spongillite deposits from the Preguita and Avipo deposits revealed sedimentological and pedological similarities between the different deposits. They have a lenticular shape and contain different layers of sedimentary spicules intercalated with layers of quartz sand and clay minerals. Representative samples from the different layers investigated by X-ray diffraction, differential and gravimetric thermal analysis and infrared spectroscopy showed a range from three to 80 per cent of amorphous silica (opal) corresponding mostly to the sponge spicules in the sediments. Optical microscopic investigation determined that the spicules predominantly belong to the sponge Metania spinata. This species is represented by smooth megascleres (alpha type), prickly megascleres (beta type) measuring 240 to 450 mm in length, as well as the spiny microscleres; whereby the smooth megascleres are larger and thinner. The morphological variation of the spicules as well as the presence of more fragmented spicules towards the base of the deposits, portray a variation in texture and in the state of their preservation along the profile, suggesting environmental variations at the time of their formation and deposition.

Jan 1, 2008

By Guo Xueyi

The morphological characteristics of the nickel particles electrodeposited from chloride dominant aqueous solution was investigated. The effects of the electrolyte constituents, the parameters for the electro-deposition on the morphology of the nickel particles were addressed. It is evidenced that not only the particle size but also the morphology of the deposited nickel particles strongly depend on the electrolyte constituents and technical operation conditions. The electro-crystallization mechanism of the metallic nickel particles deposited at high current density was elucidated. The ultra-fine nickel particles with flake, nodular or dendrite shape may be produced by controlling the duration for electro-deposition.

Jan 1, 2003

By F. Ajersch, A. R. Hekmat

Apparent viscosities of hypo-eutectic (Al-7% Al) and hyper-eutectic (Al-35% Si) binary alloys were measured in the semi-solid state using a Couette type viscometer at variable shear rates. Analysis of the microstructural evolution demonstrates the differences in the rate and degree of attrition of the primary phase particles which are characteristic of the thixotropic nature of the semi-solid alloy. It was observed that the Si primary phase in the hyper-eutectic alloy is much more difficult to fragment than the dendritic a-Al phase in the hypo-eutectic alloy. For the case of the a-Al, the dendritic structure is broken down by attrition and fracture of the dendrite arms whereas the fracture of the Si hexagonal crystals in the hypereutectic alloy occurs along the {100} and {110} cleavage planes. Results are presented for fixed solid fractions of the primary phase at isotherm condition for each type of alloy.

Jan 1, 2006

By R. Roufail

In this paper, the effect of different operating parameters of high speed stirred mill on the particle breakage mode is addressed. Morphological features of broken particles is investigated and related to the types of forces generated in the mill using Discrete Element Method (DEM). The stress intensities generated in the mill are varied by changing the agitator speed. The investigated agitator speeds were 1000, 1500, and 2000 revolution per minute (rpm). The minerals considered in this study are hard minerals (quartz) and soft, sulphide minerals (galena). The morphological features examined are roughness, roundness and elongation, which shed light on the mode of breakage during the grinding process. Particles that are rough, less round and elongated would imply that they broke via fracture, along their grain boundaries. On the other hand, the smooth, less elongated particles would mean breakage occurred across the grain, which is abrasion mod. DEM study complemented the understanding of particle breakage mechanism via tracking the types of forces applied on the particles. Normal forces imply compressive loading, which is presumed to impose fracture breakage along the grain boundaries, whereas tangential forces imply abrasion loading. Stirred mill grinding has been regarded as an attrition/abrasion process, whereas, this study showed that about 60% of total particles that are morphologically analyzed for both minerals were rough particles. Such an observation indicates that the fine product, which contain a significant amount of progeny from the coarse fractions are consistently broken via fracture. The morphology results agreed with the DEM findings, which indicated that the agitator speed, mineral type, and residence time would dictate the type and mode of particle breakage. Keywords: DEM, high speed stirred mill

Sep 1, 2012

By Byung-Young Choi

Nitrogenated carbon films were deposited on the high-frequency induction hardened steels by ion beam assisted deposition. X-ray photoeleetron. spectroscopy and scanning electron microscopy were used to analyze the chemical content and the morphology of the coated steels. Rolling contact fatigue tests were performed using Polymet RCF-1 machine with a constant supply of lubricant. It was found that CNx films adherent to the steels substrates were formed by ion beam assisted deposition. It was also found in the rolling contact fatigued specimens that non-propagating crack was initiated in the white etching area indicating the maximum shear stressed, region, leading to surface failure.

Jan 1, 2000

By P. A. Mahanwar

Flyash were melt mixed with nylon 6 at a 30wt% concentration. TYZOR® TPT, a coupling agent, was used to facilitate the link between filler and matrix. The morphological characterization, using SEM, revealed sufficient matrix residue on the filler surfaces thus confirming the strong interfacial bonding between the filler and the matrix on treating. Tensile, impact and the flexural properties of the composites were also improved with the incorporation of coupling agent. As flyash particles tend to impart a grayish color to the plastic, TiO2 pigment was employed to make the formulations aesthetic. The pigment was added to the filled system in 0.1, 0.5, 1.0, 1.5, 2.0 wt/wt ratios. Scattering of incident light and spectral reflectance was higher for smaller particle size flyash. Moreover an increase in the scattering with increase in pigment concentration indicates better dispersion of the pigment, which again is due to the presence of coupling agent.

Jan 1, 2006

The Calypso geothermal field, mapped by the R V Sonne (cruise SO-135) in 1998, includes four main sites, the Northern Vent Area (centred on 37¦ 36.7'S, 177¦ 06.2'E, area 1.5 km2), Central Vent Area (37¦ 39.4'S, 177¦ 05.2'E, 1 km2), Southern Vent Area (37¦ 41.7'S, 177¦ 06.0'E, 1 km2) and Mercury Vent Area (37¦ 41.3'S, 177¦ 07.3 'E, 0.5 km2). Hydrothermal activity at the vent sites is controlled by minor, sub-parallel NE-trending normal faults. Gas bubble trails (C02) and shimmering hot water vent from fractures and joints between large blocks of silicified volcaniclastics and in depressions in the sediments at the base of these outcrops. Measured maximum vent temperatures are between 180¦C and 201¦C. Venting fluids are at, or just below, boiling for water depths of 200 m. Rock samples recovered by dredge from the sites include massive anhydrite, clay-altered pumiceous ash, silicified volcaniclastic sediments and volcaniclastic breccias cemented by sulphur. Clay-altered samples, dominated by randomly interstratified illite-smectite and accessory chlorite, indicate formation environments of 70¦C to 90 ¦C. Native sulphur is abundant throughout the samples. Fine-grained (<1 mm) disseminated pyrite and vein pyrite occurs in the clay-altered pumiceous volcaniclastics and argillites. In the Southern and Mercury Vent Areas, fine-grained orpiment, realgar and cinnabar have deposited in the sandy matrix of volcaniclastic breccias. Amongst the cinnabar, small (<2 mm) beads of native Hg formed on the surface of several rocks following their recovery. These samples also contained abundant light hydrocarbons, which coat the rocks with an oily sheen.

Jan 1, 1999

By Jae R. Lee

Keywords: Self-propagating high temperature synthesis, AlN, Powder synthesis The particle size and shape effects of starting raw powders on the synthesis of aluminum nitride by self-propagating high temperature technique under high nitrogen pressure were investigated with various AlN diluents and Al reactants. It was found that the structure of beds of the starting raw particles largely affected the pore channels for nitrogen gas infiltration as well as the passages for combustion propagation before and during the reaction, resulting in the morphology and purity changes of the synthesized products. The AlN product of purity over 98% with about 30 microns was obtained.

Jan 1, 2005

By J. W. Ahn

Calcined calcium oxide from limestone is hydrated to manufacture calcium hydroxide, and then precipitated calcium carbonate is synthesized from calcium hydroxide. Precipitated calcium carbonate of various morphologies is obtained by controlled conditions of each step and characteristics of limestone, calcium oxide and calcium hydroxide. Especially characteristics of calcium hydroxide have the most influence on morphology of precipitated calcium carbonate character. In this study, therefore, it is investigated the specific surface area of calcium hydroxide and morphology of precipitated calcium carbonate according to hydration temperature. Calcium hydroxide hydrated at high initial temperature has larger particle size than that hydrated at low initial temperature. And formation yield of aragonite precipitated calcium carbonate has improved by using calcium hydroxide had larger particle size (hydrated at high initial temperature).

Jan 1, 2014

By Kikuo Okuyama, I. Wuled Lenggoro, Manabu Shimada

"Aerosol processing of materials such as (i) gas-to-particle conversion process (e.g., Chemical Vapor Deposition (CVD) method) and (ii) liquid (or droplet)-to-particle conversion process (e.g., spray pyrolysis) has become of major interest to produce novel submicron- or nanometer-sized particulate material used in electronic and chemical industries. After reviewing recent theoretical and experimental researches on the evaluation of properties and morphology of fine particles by the CVD and spray pyrolysis methods, the importance of the process engineering approach· for aerosol processing of materials and the use of advanced aerosol measurement technology have been pointed out.IntroductionMaterial synthesis via aerosol processing offers a route to producing nanometer-sized and submicrometer-sized particles of high purity with specifically tailored chemical and physical properties. Especially, single nanometer-sized particles (nanoparticle materials) are considered to play an important role in the synthesis of nanostructured materials as well as in nanotechnology in 21st century due to their quantum effect and so on.However, the transformation of gaseous or liquid precursors to the final functional particulate matters consists of various complex chemical and physical processes. In order to control the size distribution and morphology of produced particles, it is important to analyze and model various phenomena, such as gas-phase or liquid-phase chemical reaction, nucleation, condensation, agglomeration and sintering that occur simultaneously in aerosol material processing. By introducing the Aerosol Science and Materials Science, the authors have been trying to model the changes in particle properties and morphology by gas-to-particle conversion and droplet-to-particle conversion processes. The authors have also been trying to obtain the experimental data on the particles properties as accurate as possible."

Jan 1, 2000

By M. Al Mukhtar, D. Hoxha, X. Brunetaud, D. P. Do, C. Auvray, L. Michel

"Mechanical behavior of rock joints is often the key factor governing the response of complex structures constructed in fractured rock masses such as underground openings or of objects assembling various stones blocks such as historical building walls or damaged marble statues. This paper aims at developing a theoretical model to describe the behavior of fresh joints based on the description of their morphology. The main idea of the model is to establish a link between the effective contact surface of joints and the frictional coefficient. Beginning from a chosen level of joint surface description where a joint is considered as “smooth”, the model describes the added friction with respect to the increase of the contact surface of the joints and the distribution of stress in these contacts. The model developed initially for asperities with regular geometry is firstly compared with existing models and then applied on fresh artificial joints. For that, healthy artificial joints have been characterised using in one hand classical CNL shearing tests and in another hand the morphology of joints. The joints surfaces are digitized before testing using a high resolution laser scanner (Konica Minelota Vivid 910) allowing to obtain a precision up to 10µm. From these scanned surfaces the morphology of joints is characterised on the profiles running in the direction of shearing and a mean value of friction is calculated using the developed model. This calculated value is then compared with that obtained from CNL shearing test and a good approximation is notedINTRODUCTIONThe role of the mechanical behavior of rock joints on the overall response of fractured rock masses is well established in many fields of engineering activity going from the stability of underground constructions (Souley M, Hoxha D, Homand F 1999), rock slope stability (Einstein H.H. Veneziano D., Baecher GB., O’Reilly K.J, 1983, Jaeger 1971), various rehabilitation of masonry construction, damaged stone artworks restoration (Michel L., Do D.P, Coignard B, Hoxha, 2014) and so on. In the same time the characterisation of the behavior of joints and their modeling is nowadays a dynamic field of research or/and investigations and many alternative approaches have been proposed (Barton, N.R. and Choubey, V. 1977, Tatone, S.A. Bryan, Grasselli Giovanni 2010, William C E. 2007). While empirical relations of shear strength with various parameters of the joint morphology are the most used in practice because of their simplicity (Barton. and Choubey, 1977, Barton 1973, Bandis S., Lumsden A. C. and Barton N. R. 1983) many other models of joint strength are developed based on mechanistic considerations (Haberfield CM, Johnston IW. 1994), multiscale approaches (Yang Z.Y., Di C.C., Yen K.C. 2001, Fardin N., O. Stephansson, Lanru Jing 2001) or micromechanical ones (A. Serrano, C. Olalla, R.A. Galindo 2014) to mention just a few of research trends on rock joints modeling."

Jan 1, 2015

The morphology of environmentally assisted cracks in stressed pipeline steel has been investigated, For a dilute and neutral solution (NS4) simulating ground water in contact with the steel, semi-elliptical cracks grow faster on the surface (2c) than in the depth (a), hence, the aspect ratio (a/c) decreases, This is explained using a deterministic concept since corrosion is dominant and the primary constraint is the conservation of charge, By contrast, when mechanistic conditions prevail, significant growth occurs in the depth, When underloads are imposed in the loading history, temporary accelerations in crack growth occur because corrosion rather than mechanical effects become dominant.

Jan 1, 2005

By A. Plumtree

The morphology of environmentally assisted cracks in stressed pipeline steel has been investigated. For a dilute and neutral solution (NS4) simulating ground water in contact with the steel, semi-elliptical cracks grow faster on the surface (2c) than in the depth (a), hence, the aspect ratio (a/c) decreases. This is explained using a deterministic concept since corrosion is dominant and the primary constraint is the conservation of charge. By contrast, when mechanistic conditions prevail, significant growth occurs in the depth. When underloads are imposed in the loading history, temporary accelerations in crack growth occur because corrosion rather than mechanical effects become dominant.

Jan 1, 2005

By Y Akiti, J Moller, E Esper, R Rugolo, A Pains

"Morro do Ouro Mine is a high tonnage/low-grade mine located in Paracatu, Minas Gerais State, Brazil. The mines move around 55 Mt of ore per year at an average grade of 0.4 g/t. The auriferous mineralisation of Morro do Ouro is related to hydrothermal fluids rich in arsenic (As), gold (Au), lead (Pb) and zinc (Zn). These percolated along favourable structures contained within phyllites of Upper Proterozoic age and defined a mineralised megaboudin which outcropped with 4 km extension and up to 2 km in width. The litologies in the interior of this structure are typically more deformed, sericitised and sulfidised, and exhibit the development of quartz boudins in the centre of the more deformed zones where are found the higher Au grades and the coarser sulfide crystals. Gold is preferentially associated with arsenopyrite, mainly occurring in fractures or aggregations of crystals and is rarely in solid solution or refractory. Over 90 per cent of the gold contained in the sulfide ore is free or extractable by cyanidisation. The current mineral reserve is 17.9 Mt at 0.403 g/t published at the end of 2012.In order to get a good grade estimation that represents the orebody more accurately a solids methodology was used to distinguish the different orebodies. Before 2011 the orebodies were worked with two domains relating to the weathered mantle. The B1 ore, which is oxidised, is located at the top of mineralisation, and is used to feed Plant 1. Underneath B2 ore, which is fresh sulfide bearing, represents over 30 years of production in Plant 2.In order to improve the predictability of gold grade estimation in geological modelling and to get a better predicting behaviour of each domain on the deposit, studies were carried out in which it was possible to show a correlation between elements and the mineralisation. One strong correlation and spatial distribution between Au and As, As and sulfur (S), Au and Pb, Au and Zn were found.Based on geochemistry, mineral correlations, amount of sulfide, structural deformation, texture of sulfides and the daily experience of the mine, it was possible to create solids that individualised bodies with similar mineralogical and chemical characteristics using the parameters listed above.After 2011, a new modelling concept was proposed and built with 11 different domains, compared with the previous, and with two more parameters: recovery acid neutralised capacity (ANC).Each of these bodies have different behaviours in mineral processing, like flotation and metallurgy. For example, bodies with pyrrhotite bring problems in the flotation, bodies with high arsenic do not recover well, bodies with high As with coarse texture have good recovery, bodies with fine texture do not have good adherence in production.In the present state of knowledge, protocols are being developed for bench testing to predict the recovery of each geochemical domain aiming to include these in the geological model for the parameter recovery. It is intended to create a field throughput in the model of ounces per hour, from each block of each domain to better predict the production, using the parameter recovery, Au and Bond Work Index (BWI).CITATION:Esper, E, Rugolo, R, Moller, J, Akiti, Y and Pains, A, 2013. Morro do Ouro geological model with a metallurgical view, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 67-74 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By Richard J. Waxweiler, Frank E. Lundin, Robert J. Roscoe, Victor E. Archer, Michael J. Thun, Joseph K. Wagoner

[Introduction] Since excess lung cancer mortality was first noted in the late 1800's among Joachimsthal-Schneeberg miners, there have been a number of studies of the long term health effects among various types of miners exposed to elevated levels of radon and its radioactive decay daughters. Substantial excesses of lung cancer have been noted among miners in the Joachimsthal mines (Sevc, 1976) , lead-zinc miners in Sweden (Axelson, 1979) , fluorspar miners in Canada (DeVilliers, 1971) , iron miners in Sweden (Renard, 1974) , uranium miners in Canada (Hewitt, 1976), and metal (Wagoner, 1963) and uranium miners in the United States (Lundin, 1971; Archer, 1976). The latter prospective cohort has also been shown to be at an excess risk of death due to tuberculosis, nonmalignant respiratory disease, and accidents when followed through September 30, 1974 (Archer, 1976). This report extends the followup of this cohort of miners through December 31, 1977 and expands the mortality analysis to investigate more cause-specific categories. [Methods] During the decade beginning with July, 1950, medical teams from the United States Public Health Service (USPHS) examined 3362 white and approximately 780 nonwhite males who had worked underground in uranium mines in the Colorado Plateau at least one month by January 1, 1964. Occupational, medical, and smoking histories were obtained during the examinations and often updated/confirmed during subsequent annual censuses of the miners conducted by the USPHS. The white miners now have been followed-up through December 31, 1977 using the Social Security Administration, Internal Revenue Service, direct telephoning and various other sources. Death certificates were obtained for the deceased and coded directly into the Seventh Revision of the International Classification of Diseases, Adapted, using the rules in effect at the time of death. Deceased miners for whom no certificate has yet been located were assumed dead on the date specified by the reporting agency, cause of death unknown. The uranium miners cohort was analyzed using a modified life-table system developed by the National Institute for Occupational Safety and Health (NIOSH). Person-years at risk of dying (PYAR) were calculated for each miner from his first USPHS medical examination date or date upon completion of one month of underground uranium mining if that was later. PYAR were calculated specific for five-year age groups, calendar periods, and periods after first underground uranium mining. The numbers of cause-specific observed deaths among the cohort occurring by December 31, 1977 were compared to the numbers of expected deaths. The expected deaths were calculated by multiplying the appropriate PYAR by the United States death rates for white males specific for five-year age groups, five-year calendar periods, and cause. The results were summed over the age and calendar period specific categories to obtain the total expected deaths for each cause. Standardized Mortality Ratios (SMR's) were calculated for each cause by dividing the observed number of deaths by the expected number of deaths and multiplying by 100. In some tables, two-sided 95% confidence intervals for the SMR's were computed using either Fisher exact confidence limits, if the observed frequency was less than eight, or approximate confidence limits, if the observed frequency was eight or greater, to indicate statistical significance. Because a priori hypotheses had been well established, one-sided lower confidence limits were used for tuberculosis, lung cancer, other nonmalignant respiratory disease (ONMRD), accidents, and total mortality. [Results] The cohort included 589 miners first examined in either 1950, 1951 or 1953; 753 first examined in 1954; 1235 first examined in 1957; 5 first examined in 1958; and 782 first examined in 1960. In Figure 1 the distribution of the cohort by first year of underground uranium mining indicates that 13.7% started before 1947 and would have thus had an opportunity to be followed beyond 30 years

Jan 1, 1981

THE following statement is contained in an article entitled "Mortgaging the Future." by Walter C. Teagle, president of the Standard Oil Co. of New Jer-sey, appearing in the current issue of the Lamp, the official organ of the Standard Oil Co.: "During the last eight months the domestic daily production. of crude oil has risen 300,000 bbl.. which means that no less a volume than 2,500,000 bbl. now are coming to market each day. . . . Every twenty-four hours 250,000 bbl. more than the consumer required are being added to our surplus oil storage. The temporary advantage of cheap petroleum products and the availability of fuel .oil, for a widespread use as a substitute for coal are not being weighed against the time when scarcity may follow on the heels of plenty and the public of tomor-row may have to pay for today's excesses. The over-production of crude and its consequences constitute a problem of national import which far outweighs the temporary advantages either to a part of the industry or to sections of the public.

Jan 8, 1927

By C. Sima, M. Legoabe

Keywords: Pyrometallurgy, furnace, platinum Mortimer Smelter is one of the three smelting operations in the Anglo Platinum Group. It is located in the Limpopo Province, approximately 100 km north of Rustenburg, and approximately 15 km west of Northam. The smelter operation is the smallest of the three smelting operations in the group, with a smelting capacity of 170 kt/annum. The operation consists of a Larox filtration plant, a Drytech flash drying plant, a modified Elkem / Hatch 19.5 MVA furnace, and a 60 t/h matte crushing plant. The operation does not convert its furnace matte, and hence the final sulphide rich matte is transported to and processed further at the Anglo Platinum Converting Process (ACP) within the Waterval Smelter Complex in Rustenburg. Furnace slag is granulated, and processed through a slag mill, or transported to a slag dump.

Jan 1, 2006

By Brimblecombe P

Morwell Open Cut is a continuous mining operation employing 5 buck- etwheel excavators, I bucket chain excavator and 54 conveyors. The combined bunkering capacity at both client Power Stations represents less than 12 hours maximum coal demand. This creates an extremely dynamic operating environment, which is further complicated with significant variations in both excavating and transportation plant capabilities. To achieve set objectives, including- I adequate reserves, 2 coal supply reliability, 3 cyclic plant maintenance, 4 minimal cost of coal, scheduling of the operation requires constant monitoring and reappraisal. Investigations are in progress to develop a computer based scheduling tool capable of simulating the complex operating environment. A review of computer scheduling packages currently available within the State Electricity Commission of Victoria has found limitations making most unsuitable for the task. The type of package found to be most suited is a knowledge based system ('Expert System')capable of operating within a set of rules defined by the user. Work is proceeding on the development of a knowledge base to test the effectiveness of Personal Computer based `Expert Systems'.

Jan 1, 1989