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By Robert Uhley, Tsvi Meidav, LeRoy Scharon

Before National Lead built an industrial plant on its Fredricktown property, some 100 miles south of St. Louis, a 750x500-ft area on the proposed site was investigated by electrical resistivity, seismic refraction, and churn drilling. Data were accumulated to prepare an isopach map of the overburden and to determine soundness of the dolomite bed- rock and the depth to bedrock at fixed points. The site was on a gently sloping hillside. Elevations above sea level ranged from 760 ft in the northwest corner to 820 ft along the eastern edge, giving a total relief of 60 ft. There were no major drainage features, but in the northern part of the plant site there was an indicated depression area which later was interpreted as reflecting subsurface conditions in the bedrock. No rock was exposed in the entire plant site area; the surface was characterized by soil and overburden.

Jan 2, 1959

By H Y. Niu

The coal left in the goaf is easily submerged by groundwater damage. During the mining process of the underlying coal seam, it is necessary to drain the water in the overlying goaf. The coal sample is prone to spontaneous combustion after being soaked in water and air-dried. To explore the effect of micro-functional group transformation of water-immersed coal samples on the spontaneous combustion characteristics of coal samples during the low-temperature oxidation process. Using the experimental method of infrared spectroscopy, the migration law of special functional groups under different oxygen concentrations of water-soaked coal samples was analysed. By means of thermal analysis, the endothermic and exothermic properties of the functional groups in the water-soaked coal samples were studied. The results show that: the higher the oxygen concentration, the more oxygen-containing functional groups in the water-soaked coal sample, compared with the 18 per cent oxygen concentration, the 14 per cent oxygen concentration has a small increase, and the chain length is shortened. The temperature increase together with the oxygen concentration content determines the functional group content, the pyrolysis process produces some functional groups. The lower the oxygen concentration, endothermic rate decreases and endothermic temperature increases, the higher the ignition temperature of coal oxy-combustion, the lower the total heat release, the higher the burnout temperature, and the faster the oxygen-absorbing weight gain and the conversion of functional groups. Below 14 per cent oxygen concentration, the oxidative combustion process will be greatly reduced. The results provide a theoretical basis for preventing long-term water-soaked coal body oxidative spontaneous combustion in shallow buried coal seams.

Oct 12, 2022

By Erik Nygaard, Klaus Voges

ANFO is the most used industrial blasting agent in the world, and is often used as a reference for comparison of other explosives. It is known to work very well under dry conditions in large borehole diameters, whilst in small borehole diameters increasing amounts of toxic fumes (CO, NO and NOz) can be formed. In underground blasting, problems can also occur with reduced visibility caused by unreacted ammonium nitrate and overall composition of the detonation fumes. ANFO is made by mixing Ammonium Nitrate Porous Prills (AN-PP) and fuel oil. We have measured velocity of detonation (VOD), toxic fumes and visibility after blasting of ANFO in 54x2 mm steel tubes, and the differences are remarkable: By using an AN-PP grade developed for underground blasting and small diameters, the following can be obtained:

Jan 1, 2001

By Dirk van Zyl

Natural materials can be used successfully in the construction of heap leach pads. The use of these materials usually result in the least expensive approach for such facilities. Sufficient geotechnical experience has been gained in the design and construction of clay heap leach pads so that they can be used with confidence. A number of operators presently use clay pads in their heap leach facilities; these include Alligator Ridge, Ely, Nevada (gold), and Union Carbide, Gas Hills, Wyoming (uranium). This paper describes the construction and field investigation of a clay pad for the heap leaching of agglomerated precious tailings. The project is located in the Mojave Desert, Southern California. The design had to satisfy operational requirements as well as regulatory requirements. The California Water Quality Control Board (WQCB) was one of the agencies which had to issue a permit for the project. Their biggest concern was the discharge or escape of cyanide into the environment. Rather stringent requirements were therefore placed on the pad design criteria, especially in terms of permeability.

Jan 1, 1983

By Edson Ramos, Rony Choqueneira, Russel Lozada

El artículo refiere un trabajo de investigación que tuvo por objetivo analizar, mediante la electrocoagulación con un diseño de reactor de flujo continuo, la remoción de metales pesados (Pb, Cu y Zn) y turbidez presente en aguas del río Coata (Juliaca), destinadas para consumo y/o recreación. Se detallan las condiciones (2 celdas de flujo continuo conectadas por un canal de tubería), así como los procedimientos efectuados en esta experimentación, que ha obtenido buenos resultados (una eliminación superior al 50% en la primera celda y al 80%, en la segunda).

Oct 30, 2019

By Ian M. Ritchie

Right across the universities of the developed world, the traditional disciplines of physics and chemistry are losing ground. Extractive metallurgy, which depends so heavily on chemistry, is also contracting despite a clear need for people with this kind of training in the mining industry. Reasons for this loss of popularity are discussed in this paper. High on the list is one of image. The extraction of metals is widely seen as a dirty, polluting, sunset industry which involves working in remote and uncomfortable corners of the earth for inadequate compensation. Ways in which the image problem can be overcome are considered. It is concluded that a concerted effort needs to be made by the universities and industry to redress this situation. The importance of extractive metallurgy, both now and in the future, when a greater emphasis will be placed on sustainability and recycling, needs to be stressed. In addition, courses need to incorporate training for a career path that leads on beyond extractive metallurgy.

Jan 1, 2003

By Y. Zhou, G. Chisakuta, P. Bwando, G. Mitshabu

A newly started copper hydrometallurgical plant was confronted with a manganese oxidation issue in electrowinning. This oxidation, in the absence of the amount of iron required to stabilise the electrolyte oxidation-reduction potential, is known to produce oxidants (MnO2, MnO4) that can cause accelerated degradation of the organic phase components in solvent extraction and corrosion of lead anodes in electrowinning. The overpotential required to build up the protection layer on new anodes causes an increased electrolyte potential that creates oxidized species in the electrowinning tankhouse, and these species come back to solventextraction plant with the recycled spent electrolyte. This paper discusses the impacts of manganese oxidants on the health of a plant organic phase. It also outlines the actions taken using iron scraps and sulfur dioxide to mitigate the problem that happened due to the lack of ferrous iron sulfate available on site, as recommended for better control.

Jan 1, 2023

By Cajsa Samuelsson, Theo Lehner

Converting and refining play a central role in the extraction of metals. Sweden has a long tradition as an experimental play ground for metallurgists, chemists and alchemists, developing new methods and technologies. Presenters of papers are usually happy in recording successful developments. But reporting failures can be as great a value as the former. In the paper experiments and experience in process development are illustrated, differences between ferrous and non-ferrous developments are highlighted and industrial learning curves are discussed. 53

Jan 1, 2009

By Andy Boeckmann

Engineers and owners widely recognize the benefits of foundation reuse - cost savings, reduced construction schedules and reduced environmental impacts, among others. Yet for many projects with existing foundations identified as reusable, reuse is an idea that is discussed at length before cold feet prevail. To address this disconnect, Deep Foundations Institute (DFI) formed the Foundation Reuse Task Force in 2021, which intends to promote reuse, leveraging experience among DFI members and collaborating across pertinent committees. Indeed, the task force includes about 40 members drawn from the Subsurface Characterization for Deep Foundations, Sustainability and Testing and Evaluation committees. One of the first orders of business for the task force was to create a database of successful reuse projects, developing short summary documents highlighting the database projects and recruiting reuse-focused presentations for the ITS Money program. Solid progress has been made on each front: the case history database includes 12 cases so far; the first three summary documents were recently published to DFI's website and foundation reuse projects have been well represented among the past year's ITS Money program. The reuse case history summary documents are available at www.dfi.org/foundation-reuse- case-histories; each of the three is also discussed below. The summary documents demonstrate the feasibility and benefits of foundation reuse. The documents are therefore a useful tool for foundation engineers to share with owners, structural engineers and anyone else who may be hesitant to pursue foundation reuse. The task force continues to welcome new members and anyone interested in joining can contact Andy Boeckmann. The task force is also eager to highlight additional reuse success stories. Anyone with case history information to share is also encouraged to contact Boeckmann.

Jul 1, 2022

By Cleland N. Conwell

The term "tender tundra" is a myth---a well-developed myth, but contrary to the fact. Any area that supports herbivores must have a plant base to supply food, In Alaska, herds of caribou migrate and live north of the Arctic Circle. And, if there is enough growth in the moss and lichens and arctic grass to support a caribou herd, the "tender tundra" can heal after it has been disturbed by mining. Another myth is that Alaska is an ice box. Actually, many areas In the state---particularly the Interior---have a high agricultural potential. Nevertheless, the fact remains: whether it is reclaimed by advancing the productivity from forest to agriculture or is allowed to remain a wild-life habitat, Alaskan land will revegetate. Reseeding speeds reclamation, but left to nature, native species will reclaim the land whether it was disturbed by forest fires, roads, villages, or mining. In fact, it is impossible to find many of the old gold mining camps.

Jan 1, 1975

Jan 1, 1905

During a period of six months in FY2018, a series of trials were conducted to compare drilling accuracy using two different methodologies and the subsequent impact this had on ore dilution. Testing was conducted at Cracow underground gold mine in Queensland, Australia. The drill rig’s existing alignment process was compared to a new technology system with the following observations: - Using the existing alignment process only 20% of holes surveyed recorded toe points within the +/-300mm (11.8in) tolerance blast-hole deviation. - The new technology was proven to limit rig alignment error, reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160%. The increased accuracy reduced stope dilution by reducing over-break of subgrade ore: - Stopes drilled using the new technology recorded 62.6% less average dilution. - This contributed to an overall reduction in dilution for the full year (FY18) of 5 percentage points compared to FY17 - from 22% to 17% (a net decrease of 22.7%). A cost-benefit analysis extrapolated from the trials stipulates that if the new technology were in use for a full 12 months, when applied to FY17 full year data, a 10 percentage point reduction in dilution would represent a net 45.4% decrease, and would result in AUD8.2M (USD5.9) additional ore recovered, with AUD4.5M (USD3.2M) less spent on wasted cost of haulage and processing of diluted ore. As a result, return per tonne would increase 22%, from AUD87 (USD63) to AUD106 (USD77.1). INTRODUCTION Dilution – planned and unplanned – remains a significant cost impairment in the mining process. A series of trials were held over a six-month period in FY18 which established the cost-benefit of new technology as it applies to the alignment accuracy of production drilling rigs in underground mining, thus confirming its ability to limit drilling as one of the causes of dilution. The trials identified three underlying factors affecting drilling accuracy, measurable by blast-hole deviation surveys of planned vs actual toe data. These were; rig alignment error, collar location change/error, and in-hole deviation. The trials involved a comparison of existing rig setup processes and technology, with the new technology (Minnovare’s Production Optimiser system). The trials were undertaken in the same environment; an operating underground gold mine - Cracow Gold Mine. The comparison first revealed the extent to which rig alignment impacts blast-hole deviation. Secondly, the new technology was proven to limit rig alignment error, thereby reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160%.

Jan 1, 2019

By Kallam V. K. Reddy, VADAPALLI SANJANA, Veerendra Singh, Gajanan Kapure

This work describes a leaching process for the conversion of high-magnesium peridotite rock, which is a chromite ore overburden, into two valuable products: magnesium salts and micro silica. Under normal leaching conditions, residue remaining after leaching is of a gelatinous nature and thus hinders the filtration process. To address this issue, oxidative leaching with the addition of H2O2 was employed, and it significantly improved the filtration kinetics. Four different approaches for H2O2 addition were tried, and they all proved effective in controlling gelation. The optimum oxidative leaching condition was 70 °C, 2 h time, 2 M H2SO4, 0.5MH2O2 and 400 RPM; under these conditions, 92% magnesium leaching efficiency was achieved. After leaching, the leach liquor obtained was purified and dried into Mg(OH)2 and MgSO4 salts. The leach residue contained mainly silica particles, with size in the 10–30 μm range. This material thus represents an attractive candidate for the production of highperformance concrete for the construction industry. The oxidative leaching process described here enabled the complete conversion of peridotite into valuable products, magnesium salts and micro silica.

May 5, 2020

By W. D. Robertson, J. -P. Briant, M. Gell

The distribulion of dislocatiorls genevnted during the propagalion of hydrogen-induced cracks in Fe-Si cryslcrls was studied as a funclion of temperature f-110o lo 243°C) and silicorz conlenl (3.1 and 4.2 pct). It zoas found that the clislocntiotl densily and the size of the plctslic zone increased with increasing tempevalnre and decreasing silicon conlent. Furtheruvzove, there was a correlcrtion in the dislocalion patterns formed around cracks that propagated at different tempevattrt-es in cvyslals of diffevent silicon contents such that a 1 pcl itlcverise in silicon content was equivalent to a lemperaluore redziclion of approximately 120°C. The experimenlal YeSnllS were compaved with the results of an elastic-plastic wodel that relates the size of the pluslic .zone to the cvack length, internal pressure, and yield stress. it was found that the clzunges in the dislocctlion cryrays with lemperature and combosition can be e-kplaincd by the lemperatrnre and composilion dependence of the yield stress. An wmtsual feature of this study was the observation of low -temperature noncrystrrllogruphic cracks. PLASTIC relaxation can occur at the edge of a moving crack by the operation of pre-existing dislocation sources or by the creation of new sources in a region of perfect 1attice.l'2 The amount of relaxation in a given crystal depends on the crack velocity and the temperature, and can determine whether a crack propagates in a brittle or a ductile manner.1-3 Tetelman and Robertson4 observed microcracks m Fe-3 pct Si single crystals that formed on (100) planes by the precipitation of hydrogen gas during electrolytic charging at 23°C. The plastic deformation accompanying crack propagation was observed in the form of dislocation etch pits and an extensive analysis has been made of the size, shape, and crystallography of the dislocation arrays5-7 This paper describes the effect of temperature on the plastic deformation generated around hydrogen-induced cracks in Fe-3.1 pct Si and Fe-4.2 pct Si single crystals. The observations are compared with the results of an elastic-plastic model for yielding around a crack containing an internal pressure. 1) EXPERIMENTAL PROCEDURES The composition of the materials used in this study are given in Table I. Single crystals of alloy A and the 4.2 pct Si alloy were grown by the strain-anneal method; crystals of alloy B and the 5.1 pct Si alloy were cut from an ingot grown from the liquid. he ~ingle-cr~stal metallographic specimens had a Cross section of 0.100 by 0.050 in. with a length of at least 3/8 in. Specimens were annealed for 3 hr at

Jan 1, 1968

By Erwin Olivera, Federico Salazar

En Minera las Bambas se implementó un modelo integrado de gestión dentro del área de Entrenamiento Mina con el objetivo de preparar, fortalecer, monitorear y revalidar las capacidades teóricas y prácticas de los operadores de equipo pesado, a través de, un adecuado proceso de entrenamiento que utiliza estándares, infraestructura y tecnología de primer nivel, agregando valor al ciclo de minado. Entre los años 2017 y 2019, se incrementó los equipos de la flota de mina para el futuro desarrollo del tajo, generándose una necesidad de reclutar, formar y adecuar operadores locales y externos; para lo cual se diseñó un proceso de entrenamiento seguro y eficiente.

Sep 30, 2022

By Leon Orlowski

THE oil-bearing districts of Poland are found on the slopes of the Carpathian Mountains. The oil belt extends from Gorlice southeast to Stanislawow. It is approximately 250 miles long and 30 miles wide, and comprises four geological districts: the western, or Gorlice district; next, to the east, the Krosno district; the Boryslaw district; and, in the extreme southeast, the Stanislawow district. The amount of petroleum produced in Poland from the beginning of the oil industry scarcely totals 26,000,000 metric tons, or 15 per cent. of the estimated supply. Of this amount, 18,000,000 tons have been taken from the fields of Boryslaw within 25 years; and only about 8,000,000 tons from all other fields within a period twice as long, although some of these other fields represent just as good possibilities as did Boryslaw at the beginning of its development. The Polish oil industry was severely stricken by the war. The retreating Russian armies, in 1915, destroyed a large number, of the existing oil wells, nor was the post-war period favorable for the development of this industry;; the money and credit stringency interfered with the expansion of drilling. But since 1921 there has. been a slow steady increase in production and there is now every reason to believe that conditions in the industry will improve. In fact, an increase in new drillings has been reported for the current year. The production of crude oil in Poland, in 1913, amounted to 1,113,668 metric tons. In 1914, the production declined- to 655,600 metric tons. In 1921, the production was 705,596 tons; in 1922, 712,428 tons, and in 1923, 737,182 tons; or more than 5,000,000 bbl. But the fields have a much greater potential output, which could be realized were the capital available for prospecting and new drilling. The principal producing, and at present most exploited, fields are around Boryslaw and Schodnica. These fields were developed rapidly for in the first year of their modern exploitation the wells were gushers of moderate depth. However, as a result of heavy drilling, the shallow folds have been exhausted and oil can be reached now only by deep drilling. Wells of almost 5600 ft. have been drilled in Boryslaw. Because of these drilling conditions, a large number of engineers and workmen specially skilled in deep drilling are to be found in this field.

Jan 3, 1925

By Ricardo Huancaya

El sistema de apoyo a la gestión de flota de vehículos en mina a tajo abierto “GO Tracking”, es un sistema que permite la localización y rastreo de vehículos mediante el uso de la tecnología GPS". En ese sentido, el presente texto señala la implementación de estrategias de producción dirigidas a aumentar la eficiencia y disponibilidad de la flota en su conjunto. El proyecto fue gestionado siguiendo las directrices propuestas por el PMI, donde los riesgos de seguridad son mitigados mediante el monitoreo y alerta de exceso de velocidad, así como la proximidad de otros vehículos, evitando las colisiones.

Oct 21, 2015

By R. C. Miranda

Artificial vision systems are increasingly used to assist humans to perform different tasks in different areas. These systems are able to recognize patterns in complex images, which can provide multiple data. Currently, vision systems are used in both; monitoring traffic - which uses radars for vehicular plate recognition- as in metallurgical and food industries for strict quality inspections. Their use in mining occurs in measuring the speed of froth over the lip of a cell, in determining the shape and size of pellets, in obtaining from the tendency of mineral content and as a replacement for laboratory analysis of particle size. With this advanced tool, it is possible to achieve significant improvements in quality, productivity, and especially in reducing costs in pelletizing plant of iron ore. The objective of this paper is to contemplate the current situation of image analysis in the pelleting plants and glimpse at the potential applications that are being developed. This paper also presents the conception and implementation of an automatic control system of the pellets size distribution applied on a pelletizing plant of iron ore. The article demonstrates the strategy used for measuring the size distribution of the iron ore pellets, based on image analysis and the strategy implemented on advanced process control, which shows substantial gain on plant performance.

Sep 1, 2012

J. M. Wadsworth,' Okmulgee, Okla. (written discussion).—It seems to me that thc young man must first be absolutely sure that the work he has taken up is to his liking and then I would advise that he get into the practical end of it and learn as much about it as he can as fast as he can. For instance, in the refinery business the college man, graduated in chemical engineering, should ground himself by going through the various departments in a refinery and working in them until he is thoroughly familiar with the operating problems. In a short time he would be able to apply many things which appear in the abstract form in his college work and this would opcn up an opportunity for him to capitalize on them, promoting his own interest. I do not criticize the present-day college men as a class, but I have found that many of them come into your plant with the idea that mere possession of a diploma should insure rapid promotion; in a short time they are impatient and usually leave. We have found in employing men that the single attribute most difficult to find in them is a lot of energy and whole-hearted interest in the work at hand, and it seems to me that if a man combines these with a careful technical training he should be fairly well equipped to gamble on his future. They must learn that the biggest satisfaction to be gained in life is in their work. Procedure for Attaining Objective of Young Petroleum Engineer H. B. Fell,+ Ardmore, Okla. (written discussion).—Of course, the first thing to be ronsidered in any proposition is the ultimate objective that is desired to be attained. 1 presume that the desired objective of most of the young men graduating in petroleum engineering will be that of chief executive of one of the companies in the petroleum industry, or one of the allied industries, or to become an independent oil producer, or oil refiner, or possibly an oil distributor. The next phase then to be considered is the procedure which should most logically be followed to attain the objeckive of the indivitlual, since in these cases these young men will have been trained in a course in petroleum engineering and it would logically be presumed that the attainment of their objective should be through the operating end of the branch of the business with which they are connected. The operating end is, of course, the department of each branch of the business that develops the resources, or refines the products, or distributes the products, from which the profits are derived, and is a part of any business which is filled with enough interesting work to appease the desires of the most ambitious young men. In order to get the best possible training it would appear to me that the place for a young man to start after graduation would be at the bottom of that branch of the industry which he expects to follow. For example, if he is going in the producing end he can gct no better training than is secured by starting as a roustabout in the ficltl, where he romes in constant rontact with the character of work that is necessary

Jan 1, 1928

By J Ta’ala, M Handyside

Mechanical sampling from conveyors has historically been a staple in the iron ore industry when information related to chemistry, sizing and moisture is required. In order to comply with ISO 3082:2009, samples can be taken either on a mass or time basis provided no bias is introduced by periodical variation in quality or quantity. With the introduction of mechanical sample carousels, you also have the opportunity to collect samples on a mass or time basis. In order to optimise automatic sample stations in a changing production environment, BHP Billiton Iron Ore (BHPBIO) has developed a simulation model that enables the various combinations of mass–mass, mass–time, time–time and time–mass to be investigated.The sample station model can utilise actual (variable) feed rates to achieve high resolution and enables the simulation of sample size variation. Cutter speeds and other settings can then be adjusted to better optimise the performance of the sample station with regards to optimal sample size as well as ensuring the sample station is in compliance with ISO 3082. The model can also assist process engineers in adjusting settings to better optimise the sample station and reduce unwanted events such as blockages. The model can be easily modified to conform to various sample station designs. This paper demonstrates the use of the model and the benefits that can be achieved.CITATION:Handyside, M and Ta’ala, J, 2014. Simulating time versus mass basis?sampling, in Proceedings Sampling 2014 , pp 155–164 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014