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By D. W. Dew, D. M. Miller, P. C. van Aswegen

The bacterial oxidation (BIOX®) process for pre-treatment of refractory ores for gold recovery is marketed by BIOMIN Technologies S.A. The process was originally developed by GENMIN who are still providing testwork, design and commissioning assistance to BIOMIN. This process offers an alternative to the more conventional roasting or pressure oxidation techniques with the following advantages: • Greatly reduced capital costs for small to medium size plants. • A relatively flexible and easily controllable process requiring relatively unskilled labour for operation. • Improved gold recovery. • A process that is environmentally friendly. The principal disadvantage of bacterial oxidation is the relatively slow kinetics compared to pressure oxidation and roasting, a plant residence time of 4 to 5 days typically being required to obtain complete liberation of gold from refractory sulphide minerals. Bacterial activity is also slow to recover from disruptions such as air supply failure or contamination by toxic species such as cyanide. Optimum plant performance depends on judicious management and sound training of operators.

Jan 1, 1993

By W. E. Wallace, S. -G. Xing, M. J. Keane, J. C. Harrison

"SummaryDiesel-exhaust particles from two sources were dispersed in aqueous mixtures of dipalmitoyl phosphatidyl choline, a major component of pulmonary surfactant, and were tested for genotoxicity. Diesel samples from the same sources were extracted with dichloromethane and transferred into dimethyl sulfoxide and subjected to the same assays. Both types of extractions yielded similar results in both the Salmonella mutagenicity assay and the sister-chromatid exchange assay using V79 cells. After separation of the samples into supernatant and sediment fractions, the activity of both diesel samples was shown to reside exclusively in the supernatant fraction for the solvent-extracted samples, and exclusively in the sedimented fraction for surfactant dispersed samples. These findings indicate that genotoxic activity associated with diesel particles inhaled into the lung may be made bioavailable by virtue of the solubilization / dispersion properties of pulmonary surfactant components.While diesel engine emissions are associated primarily with transportation, they are also very common in the workplace. Estimates for the U.S. are that as many as 1.35 million workers in as many as 80 000 workplaces are exposed to the combustion products of diesel engines (NIOSH, 1988). These occupations include, but are not limited to mining, agriculture, motor vehicle maintenance, fork lift truck driving, truck driving, and tunnel and bridge operation."

Mar 1, 1992

By Paul Doherty

The offshore wind sector is booming on a global scale, with the U.S. becoming a front runner in this highly progressive market. The Global Wind Energy Council has highlighted the exponential growth in both fixed bottom and floating projects in the years ahead, with global installed capacity set to exceed 300 GW by 2030. This growth in installed capacity is primarily related to fixed bottom projects, which have dominated the market for the past 20 years. However by the tail end of this decade, floating projects are likely to become

Oct 1, 2022

By Asfahani. Jamal, Randa Mohamad

"Abstract - Electrical and structural characteristics of formations favorable for sulfur occurrences in northeast Syria are described using geo-electrical prospecting methods. Simple (VES) and combined (CVES) Schlumberger vertical electrical soundings and geo-electrical profiling using a Wenner configuration were applied to the Teshreen structure. Six profiles (A, B, C, D, E, and F) at the borders of anticlines, where positive and negative structures are joined and salt formations have a tendency to disappear, were studied.Secondary structures, characterized by high apparent resistivity exceeding 3000 Ohm.m were located on each profile using a Wenner profiling configuration. These secondary structures are demonstrated to be favorable for sulfur prospecting by both drilled wells and vertical electrical soundings. Traditional interpretation of the 84 VES measurments is supported by data from 14 CVES measurments. The CVES technique is a powerful tool, due to its improved resolution of the electrical boundaries.Thicknesses and resistivities of the Lower Al-Fares, Al-Garibeh, and Al-Dibbaneh formations were determined through the interpretation of VES measurments. The same VES measurments were then interpreted using the Pichgin method, whereby all the subsurface tectonic features were determined for depth penetration corresponding to AB/2 = 1000 m. The integration of the first and second VES phases creates a clear picture of the subsurface, including tectonic, geometric, and geoelectrical information. In summary, the sulfur occurrences in the research area are controlled by tectonic paths that are well defined by geo-electrical methods. These diverse geo-electrical methods could be used successfully for sulfur prospecting in similar environments."

Jan 1, 2002

By Shianny Cruz Vasquez

Peru is a country with a complex physiography due to the Andes uplift that expose the different ore deposits. Actually Peruvian mining produces a variety of metal commodities and has one of the world’s largest mining. It is the third-largest global producer of copper, silver, zinc and tin. Within Latin America is the largest producer of gold, zinc, tin and lead. The importance of this research was to determine the toxic elements source and the current state of surface water and groundwater all the way from the top until it empties into the Tambo River and assess their, that impact have the toxic contaminants on the environment and the human health of the surrounding Communities and provide a management and decision-making tool to prevent socioenvironmental conflicts.

Sep 1, 2017

By Jamey B. Rosen

As Project Information Management Systems (PIMS) technologies develop, the range of projects to which one can apply these technologies grows while the cost to apply them shrinks. In recent years, technologies previously limited to large “megaprojects” (e.g., major dam rehabilitations) owned by major entities (e.g., the United States Army Corps of Engineers) with large budgets have been applied to smaller projects with less stringent specifications and more modest budgets. This paper will describe applications of PIMS technologies to small projects with limited budgets, including examples from levee construction, small-scale grout curtain installation, and diaphragm and secant pile cut-off walls. We will include a demonstration of how PIMS technologies can effectively analyze verticality data from koden and hydromill data streams to automatically generate models and as-built drawings showing overlap and deviation along the depth of the foundation. INTRODUCTION This paper discusses the application of Project Information Management Systems (PIMS) technologies to geo-foundations projects, with a focus on technologies and examples that are in a lower cost range. PIMS technologies allow contractors and other stakeholders to perform efficient quality control on their data, generate quick or automatic reports and as-built drawings, perform analyses to better understand their construction, and ultimately use their data to increase the quality of their construction. As PIMS technologies are relatively new to the deep foundations industry, and owner specifications on their use are generally viewed as complex and limited to large scale projects, PIMS technologies are frequently viewed as an expensive component that is beyond the scope of a smaller or simpler project. However, the same principles and techniques generally associated with large projects can be applied to projects at smaller scale. Furthermore, as these technologies develop both in the deep foundations and other industries, the cost of application is decreasing quickly making them even more affordable for smaller projects. The remainder of this paper provides some justification for applying PIMS technologies, describes some scalable data management concepts and workflows and then provides some examples of “low cost” applications of these technologies.

Jan 1, 2019

By Yunqing Zhang

Weak shales refer to those with lower strength, thinly- laminated structure, sensitivity to moisture and weathering as well as significant time dependent behavior. It has been said that many future coal reserves with good quality have weak immediate roofs. Therefore their geo-mechanical properties and behavior must be known before an appropriate support plan can be designed. In this study, four types of shales collected from underground coal mines were tested in the laboratory. Their modes of failures in underground were observed and correlated with their lab behavior. The failure mechanisms of thinly-laminated weak shales were analyzed by the means of numerical modeling.

Jan 1, 2004

By Guido Venturini, Giorgio Martinotti, Luca Delle Piane, Paolo Perello

This paper presents a critical review of geo-structural mapping methodologies applied to deep tunneling projects in complex mountain chains such as the Alps. Geological forecastings are often a crucial part of tunneling projects, which should allow contractees or contractors to assume their own risks. Despite this, often adequate methodological criteria are not applied in the realization of these studies, with consequent increase of costs and delays. A discussion should hopefully start in the world of tunneling in order to define a correct approach.

Jan 1, 2003

By Ivo Dreiseitl

Bottom sediment sampling by means of a box corer, as a direct method of deep seabed exploration for polymetallic nodules, is the most comprehensive way to obtain various types of geological information on points forming a network of stations. However, direct information is lacking from areas separating those stations and has to be approximated by interpolation or extrapolation, which leads to uncertainties. Sediment sampling with a gravity or piston corer can provide information on the superficial, up to 4 m thick, part of the sedimentary cover. As opposed to box coring, gravity or piston coring provides no information on nodule abundance. Information for unsampled areas can be gained by application of remote techniques of exploration. The techniques of choice in visualising nodule-rich fields, nodule-free areas, hard rock outcrops and other obstacles for seafloor mining involve using sonar and continuous deep sea (CDS) camera. Seafloor mapping can be rendered with two major sonar types: the side scan sonar used to obtain seafloor imagery and multibeam sonar for bathymetric data; the two types are usually combined and work with an intermediate frequency profiler. Photo-profiling by means of a deep sea towed camera provides a series of seafloor photographs, each supplemented with information on the area covered by each frame, including the nodule abundance. Remote techniques have been quite frequently applied by the Interoceanmetal Joint Organization (IOM) in nodule field exploration. Recently, geoacoustic techniques (side scan sonar + profiler) and CDS were applied for exploration of IOM?s first prime area H11 (5372 km2) on 6 transects. During the IOM-2009 cruise, a total of 295 km of geoacoustic transects and 344 km of photo-transects were surveyed. The data obtained were processed with the aid of earlier information produced by multibeam sonar surveys. The aim of this paper is to demonstrate the advantages of remote techniques, particularly with regard to application of the towfish device, for geological and geotechnical applications in exploration for polymetallic nodules.

Sep 14, 2011

By Luis Anderson Orna Berrospi

El presente texto describe la función de los robots en la colocación de explosivos -en tanto apoyan el proceso de voladura en la mina o acceden hacia áreas donde es imposible para los seres humanos trabajar o sobrevivir, de forma que utilizan las nuevas técnicas de Inteligencia Artificial. Asimismo, estos realizan tareas operativas en menor tiempo que buscan optimizar el trabajo de los mineros y reducir los costos de producción.

Sep 1, 2015

By N. M. Cheimanoff

GEOCAD is an ambitious research program aimed at the development of a computer based system assisting the geologist and the production or planning engineer. BONANZA, its mining part, is a computer production scheduling tool (short to medium term) of particular relevance to complex orebodies. The principle is to simultaneously use a powerful information management system (CAD potentialities) and small expert modules integrating the exploitation context and the engineer's knowledge (Artificial Intelligence tecniques). As an illustration, a module of mineable block determination for underground exploitation is discussed.

Jan 1, 1989

By William Hanco Mamani

El presente trabajo describe la implementación del GEOCATMIN en el Instituto Geológico Minero y Metalúrgico (INGEMMET). La labor del INGEMMET estriba en otorgar información de manera fácil, rápida y sobre los trabajos técnicos de INEM, MTC, MINAM, INEI, COFOPRI, SERNANP, geología y minería, productos geológicos entre mapas y boletines, etc. De forma, que esta información contribuye a una serie de procesos de cambio que el Gobierno impulsa, con el objetivo de mejorar la calidad de vida de los peruanos, promoviendo las inversiones, la inclusión social, el ordenamiento territorial, la zonificación ecológica económica, identificación de zonas de riesgo para la prevención de desastres, información geológica y minera, etc.

Sep 21, 2013

By William Hanco Mamani

El Perú es el primer destino de inversión minera en Latinoamérica y el tercero a nivel mundial. Como tal, ha generado una creciente demanda de información referida al catastro minero y al tema geológico, vital para la identificación de los recursos minerales. Por ello, el inversionista necesita contar con información actualizada, accesible y de una fuente confiable para poder planificar sus actividades. En este sentido, el presente texto describe la importancia de Geotmin en la industría minera -en tanto sistema de información geográfica de última tecnología que desarrolla la interactividad de fácil manejo y compresión de la estructura de capas presentadas en el sistema, donde su principal base de datos se basa en un geodatabase con más de 40 capas de información.

Sep 12, 2011

By Rolland L. Blake

The Bureau of Mines is investigating the potential for in situ leach mining "(ISM) of gold and silver mineralization. This preliminary study examined samples from several types of deposits using light optical microscopy and the electron microprobe to characterize the ore and gangue minerals and their microscopic characteristics, including the spacial relations between the target minerals and likely natural fluid channelways. Low grade disseminated deposit types from the western U.S. were found to contain fracture-hosted or matrix-hosted gold and silver minerals, some of which are encapsulated by quartz or pyrite. Geologic features readily observed microscopically include ore and gangue mineral identity, size, and their association with each other and with fractures. Successful ISM application to gold and silver deposits needs this data to: (1) select the proper lixiviant based on chemical reactivity of the host rock, ore, and gangue minerals, (2) determine potential permeability characteristics when designing lixiviant flow patterns, and (3) understand potential problems of the lixiviant reaching encapsulated ore minerals. Careful examination of the geologic characteristics of each ore body is required because of the observed diversity of characteristics in deposits from the same "class" and even within the deposit itself.

Jan 1, 1989

By D. III Earley, R. L. Blake

The Bureau of Mines is investigating the potential for in situ mining (ISM) of gold and silver mineralization. This preliminary study examined samples from several types of deposits. It used light optical microscopy and the electron microprobe to characterize the ore and gangue minerals and textural features of these samples. This included the spacial relations between the target minerals and likely natural fluid channel ways. Low-grade disseminated deposit types from the western US were found to contain fracture- hosted or matrix-hosted gold and silver minerals, some of which are encapsulated by quartz or pyrite. Successful ISM application to gold and silver deposits needs this data in order to understand potential problems of the lixiviant reaching the ore minerals.

Jan 1, 1991

A number of small copper deposits occur in the Pernatty Lagoon-Mt. Gunson area. Textural and mineralogical differences distinguished the lagoon sulphide deposits, which occur in a water filled basin of permeable bedrock immediately under the lagoon floor, from the largely oxidized deposits which occur in the low hills adjacent to the lagoon deposits.Groundwaters are carrying copper, and to a lesser extent zinc, downstream to the lagoon. Several species of sulphate-reducing bacteria are widespread in the groundwaters and lagoon muds.It is suggested that copper sulphides were first deposited at the same time as, or soon after, the host Proterozoic sediments, and that during the present cycle of erosion the lagoon deposits may have been enriched, or largely formed, by bacterial precipitation of copper sulphides from laterally migrating cupriferous groundwaters.

Jan 1, 1971

By A. Philipp, A. S. Middleton, G. A. Harron, A. B. Durham

"Basal till sampling techniques were used to search for gold mineralization in the Timmins, Ontario area. During 1978 and 1979, approximately 90 overburden sampling drill holes were completed in Murphy and Hoyle Townships to test specific geophysically defined target areas. A conventional tricone dual tube drill system, and a unique retractable tricone/rock coring system were used to various advantages.First pass till sampling at 800 to 1200 ft intervals perpendicular to ice transport direction yielded anomalous gold values in till and carbonatized quartz pyrite-rich bedrock chips, and lateritic soil. Subsequent induced polarization-resistivity surveys defined the areal extent of a pyritic carbonate alteration zone. A second pass till sampling/limited rock coring program evaluated the gold mineralization potential of the alteration zone. Diamond drilling has substantiated the till and bedrock gold anomalies. Further evaluation of this mineralization is currently in progress. IntroductionThis paper describes an integrated geochemical/geophysical gold mineralization discovery case history in Hoyle Township. This discovery is on a property jointly owned (I983) by Canamax Resources Inc. and Du Pont of Canada Exploration Limited. Exploration of the property began in 1978 by Rosario Resources Canada Ltd. and in 1979 a joint venture agreement was signed with Du Pont of Canada Exploration Limited. Rosario Resources Canada Ltd. was taken over by Amax Minerals Exploration in 1981, which became Canamax Resources Inc. in 1982.The work described in this paper deals with a gold mineralization discovery located three-quarters of a mile northwest of the gold deposit currently being readied for underground exploration and development. Further drilling is required to investigate the economic potential of the gold mineralization herein described."

Jan 1, 1987

By H. L. Ramandi, P. Moore

"The corrosion of support bolts in underground mines has become an increasingly prevalent issue over the past two decades. With an increase of premature failures due to Stress Corrosion Cracking (SCC), it is evident that understanding the environmental factor influencing the cable bolt corrosion is critical for maintaining effective ground support hence the safety and productivity of underground spaces. Experimental testing of rock and cable bolts were accomplished in a variety of packings, including saturated clay, saturated coal, mine water and grout/cement to investigate their corrosion behaviours. Water samples were obtained and analysed for pH and electrical conductivity (EC) during the experiment. After a period of 76 days the bolts were retrieved and analysed visually. Primary factors were found to be the presence of geological materials and the aeration of the bolts, i.e. the vicinity to air and air flow, while secondary factors were observed to be pH levels and EC. It was also found that the coal/clay interfaces and the water/grout/cement interfaces are non-relevant to corrosion of rockbolts and cable bolts. The proposed framework can be applied to other reinforcement materials used in underground spaces for improved understanding of corrosion environment.INTRODUCTION Rock bolts and cable bolts are the major reinforcement elements used in mining industry to improve the rockmass properties for safe and productive mining. They are normally used to pin large beams or blocks of rock in underground mines to stabilise the rockmass in the roof (strata) against collapse. The rockbolts are typically low cost hot rolled rebar while cable bolts are composed of strands of wire, normally wound together around a central king wire (Hyett and Bawden, 1993; Vandermaat, 2014). The typical length of the bolts in underground mines is 2.4 m and 4–12 m for rockbolts and cable bolts, respectively (Vandermaat, 2014; Windsor and Thompson, 1997). Cable bolts are much more flexible and usually offer a much higher load capacity than rigid rockbolts. Their increased length and flexibility allows cable bolts longer than the height of a roadway to be used in underground mines."

Jan 1, 2017

By S Henderson

The Thames gold-silver deposits are part of the Hauraki goldfield, situated within the Miocene to Pliocene calc-alkaline Coromandel Volcanic Zone (CVZ). The Waitangi vein system is one of the mineralised ore shoots in the Thames district. The Thames gold deposits are characterised by shallow level epithermal vein mineralisation with phyllic to advanced argillic alteration assemblages and abundant sulphide minerals including pyrite, arsenopyrite, chalcopyrite, galena and sphalerite. Gold occurs as electrum in association with sulphide minerals. Microprobe analyses.of sphalerite grains from the Waitangi deposit mostly range from 0.8 to 1.5 mole % FeS, although one sample contains 9.5 mole % FeS. Arsenopyrite from Waitangi yields a range from 33.1 to 34.6 atomic As (%). There is no discernible correlation between the FeS content of sphalerite and gold grade in the Waitangi deposit suggesting that gold deposition is probably not controlled by changes in temperature and activity of sulphur aS2 that control the FeS content of sphalerite. The possible causes for gold deposition are thought to be boiling, mixing and changes in pH. Sulphur isotope analyses of mixed sphalerite-galena and sphalerite-galena-ehalcopyrite samples yield a narrow range of d34SCDT values (-1.0 to 0.9 ë;n=5), whereas late spongy pyrite gives unusually light sulphur isotope values (-16.7 to -27.9 ë; n=4). The sulphur isotopic values of base metal sulphides from Waitangi suggest that the sulphur was derived from a magmatic source. However, the source of light sulphur in the late pyrite grains is not known. Preliminary fluid inclusion+studies indicate homogenisation temperatures between 173¦ and 284¦C and salinities of 0.23.0 NaCI equiv. wt % (uncorrected for C02). Vein quartz at Waitangi yields d18OSMOW values from 6.8 to 12.7 ë (n=23). The calculated oxygen isotopic composition of ore fluids is between -2.1 to 3.8 ë at 250¦C and -0.1-5.8 ë at 300¦C. Oxygen isotope analyses have revealed significant variations in d18O values with elevation and gold grades. Zones of gold enrichment coincide with a zone of variable oxygen isotope values at the top of the vein system, where boiling and/or fluid mixing most likely occurred. Oxygen isotope values varying with gold grades within the Waitangi conduits suggest that d18O values may be useful in targeting bonanza grade gold mineralisation in epithermal vein systems.

Jan 1, 1993

By S M. Roscoe

Relationships of Noranda sulphide deposits to volcanic rocks are reviewed and chemical variations within the volcanic sequence are described. The assemblages of minor elements in the pyrites and pyrrhotites of the Noranda and l\llatagami deposits are similar and are characterized by a high content of cobalt, tin and other elements. Isotopic compositions of lead, other geochronological data and stratigraphically disposed zonal distributions of sulphides and minor elements indicate that the deposits were formed prior to folding and metamorphism. Lead isotope data indicate that the Matagami deposits, and several others, were probably formed about 2.95 x 109 years ago and that the Noranda deposits may be about 50 million years younger. The volcanic sequence at Noranda is younger than the thick sequences bordering it on the east and on the west. The relationships are consistent with the hypothesis that these strata-bound sul1>hide de-posits are coeval with their associated volcanic rocks. T HE writer has been engaged in a metallogenic study of the region between Sault Ste. Marie and Chibougamau. An essential objective of this study is the classification of mineral deposits with regard to their composition, form, geological

Jan 1, 1965