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By Roger Ferreira da Silva

O método de ensaio não destrutivo baseado na análise do ruído magnético Barkhausen (RMB) possibilita a obtenção de informações a respeito da microestrutura do material examinado e do estado de tensões presente no mesmo. Devido às particularidades do método, as medições devem ser realizadas mantendo-se constante a geometria entre a sonda e o objeto examinado, de forma a assegurar a confiabilidade das mesmas. Quando realizado manualmente, o processo de medição é demorado e sujeito a erros de posicionamento da sonda. Em trabalhos industriais ou em laboratório, esses erros podem resultar em interpretações incorretas, devendo ser reduzidos ao mínimo possível. Visando à redução do tempo de execução das medições e de análise e a eliminação de possíveis erros de posicionamento da sonda de inspeção, este trabalho propõe a automação do processo de medição de RMB em corpos de prova do tipo chapa. Compreende a construção de um dispositivo de movimentação XYZ acionado por motores de passo e do software “Plate Barkhausen”, com uma interface amigável, para controle da movimentação e da medição, além da análise dos dados.

Jul 30, 2018

By J. Hadjigeorgiou, J. Wesseloo

Mining companies employ a multitude of risk management tools. The effectiveness of these tools for decision-making and communicating risk has not been addressed. This paper investigates the use of verbal probabilistic expressions in communicating geomechanical risk. Analysing survey data obtained from a group of mining geomechanics professionals, it identifies limitations of common probabilistic expressions. The paper concludes by making specific recommendations to avoid the use of certain expressions that may result in increased uncertainty, thus compromising the use of risk management tools.

Jan 30, 2026

By P Cherepanskiy, G Elphick, R Hus, C Perring

When an iron orebody nears its end of life, the extracted material can become increasingly problematic to handle. Higher moisture content occurs as larger portions of originally-below-water-table material is mined, which in some deposits is accompanied by further changes in physical and/or chemical properties present along the edges of the orebody. Plant delays related to problematic material have affected all of BHP’s mining hubs to various degrees. Following the recent successful work in Yandi, where the development of an index to quantify the handleability of channel iron ore deposits resulted in an increase in extracted volumes and an extension to the expected life-of-mine, the value of implementing similar indices for bedrock iron ore deposits has been recognised. A materials handling index has been developed by combining observed empirical relationships between material properties and processing plant performance. Indices for each deposit were further refined and optimised by implementing a back-testing strategy which facilitated an understanding of what weighting or scaling each of the contributing components should carry to yield the highest success rate of predicting actual delays at a given plant. Currently materials handling indices are deployed to all mine sites and are made available in block models as well as calculated for individual blasthole and production samples. Values in block models are obtained by predicting the required properties using machine learning models, whereas hyperspectral data is used to ‘measure’ some of those properties on a sample level. This paper discusses the work that has been undertaken to obtain materials handling indices, the testing that has been done to optimise them, and what processes have been developed to ensure the best metrics are being used in the different planning and scheduling horizons to optimise extraction.

Jun 22, 2022

The first mention of gold in Western Australia was in 1848 when some specimens of copper ore, which are believed to have come from the Murchison district, were sent to Adelaide for assay. Gold was present in these specimens, but no particular interest seemed to be attached to this fact as the search at that time was mainly concentrated on base metals and coal. Interest appeared to be shown in gold in 1852 when several parties moved out eastwards from York looking for goldbearing country. Though these parties inmany cases were very near to what is now known as the Yilgarn Goldfield, nothing was found.The next record of gold was reported in some specimens which were brought in from Cardup, some 25 miles from Fremantle. Though this area was investigated, it would appear that all the gold had been contained in the specimens and nothing further was found, though the report had been the cause of a small rush of people interested in gold.From time to time specimens had been brought in by various people from the district east of Northam, and in 1861 a reward emanating from private sources was offered for the finding of gold within a radius of 150 miles from Perth. The Government at this stage took an interest in exploration for gold and in the same year supplemented this privately offered reward on a £ for £ basis. The Government also, about this time, commissioned a practical miner, with prospecting experience in the Eastern States, to examine the country between Albany and Northam with a view to the possible existence of goldbearing veins in that area. His report, however, was entirely unfavourable and nothing further was done. In 1873 a quartz lode was discovered near Albany arid a company was formed to work...

Jan 1, 1956

By G. S. Austin

The St. Cloud Mining Company extracts clinoptilolite about 6.5 km south of Winston, Sierra County, New Mexico. Production is about 18,000 mt/year. Natural zeolites are good adsorbents for positively charged solutes such as ammonium. St. Cloud’s production is used in animal hygiene, animal feed, environmental mitigation, air and water filtration, and other applications. By a simple chemical treatment with a surfactant, zeolites can also be modified to adsorb negatively charged solutes such as nitrate and arsentate, and neutral organics such as solvents and fuel components. These surfactant-modified zeolites are used in treating groundwater contamination, stormwater runoff, and solvent vapors from painting operations.

Jan 1, 2002

By Jorge Cardenas, David Martinez

Blasting-induced vibrations can be predicted with high precision, allowing for the optimization of sequence design, delay timing, and charge configurations to minimize their indirect impact on rock masses. This optimization leads to a reduction in peak particle velocity (PPV) and dominant frequency at monitoring points. However, a crucial aspect of slope safety is estimating the degree to which vibrations influence stability through numerical modeling of the dynamic response. Slope stability is closely linked to rock mass strength, the predominant failure mechanism based on discontinuity orientation relative to the slope face, and the pre-existing stability conditions before dynamic alterations occur. Blocks, wedges, and planar failures tend to slide under lower vibration levels and are more susceptible to resonance, particularly in fractured and low-strength rock masses. To evaluate the interaction between rock mass and vibrations, photogrammetry and artificial intelligence were employed to identify discontinuity families at vibration monitoring sites. This data facilitated the development of artificial discontinuity networks (DFN), which replicated a discontinuous medium within a numerical finite element model. The input signal was recorded at the slope base using triaxial geophones and incorporated into a discontinuous numerical model. The output signal was estimated through finite element analysis and subsequently compared with geophone measurements taken at the same location. Based on real-world output signals, damping parameters and the model’s natural frequency were adjusted to align both frequency spectra. Using the calibrated parameters, vibration records from various blasting projects at different distances were applied as input signals until slope failure was induced, thereby defining maximum allowable vibration limits in terms of PPV and frequency at the monitoring point. This approach provided a framework for optimizing sequence designs, charge configurations, and delay timings to enhance slope safety and prevent failure due to blasting-induced vibrations.

Jan 26, 2026

Due to complex mineralogical and chemical interactions of the value and gangue mineral phases present in uranium-containing lateritic ores, deleterious pulp gelation which impacts on value metal recovery sometimes occur during atmospheric leaching. In this study, the leaching behavior and particle interactions of selected oxide (hematite, quartz) and clay minerals (muscovite, chlorite), which constitute predominant host gangue phases of typical lateritic uranium ores are investigated to provide basic, mechanistic understanding of temporal pulp gelation phenomenon. Isothermal, batch leaching with H2SO4 was carried out on concentrated dispersions (30 ? 57 wt.%) of single minerals at pH 1 and 25 or 70 °C and their concomitant solution, speciation and rheology (shear yield stress, viscosity) were characterized. It is clearly shown that despite the high oxide content of lateritic ores, the pulp chemistry and rheology is largely affected by the incongruent leaching behavior of more reactive, acid-consuming aluminosilicate clays. Furthermore, time- and temperature-dependent alumino-silicate species polycondensation interfacial reactions are shown to be responsible for the enhanced particle interactions, reflecting strong pulp rheology in agitation and pumping. If not properly mitigated, high pulp shear yield stress and viscosity have a striking impact on processability and hence, value metal recovery.

Sep 1, 2012

By T Baumgartl, C Gonzales, A Soliman, M Edraki

A soil cover isolates potentially acid-forming (PAF) mine wastes from atmospheric interaction and thereby mitigates acid mine drainage. As a cover that comprises either a single layer or a composite barrier, it essentially manages percolating rain water from flowing into these PAF materials and minimises air flow as oxygen has low diffusivity in saturated soils. However, the availability of suitable soils as cover materials is limited, especially in arid and semi-arid regions where weathering rates are low.This paper investigates the potential use of mine wastes as cover materials in a water-shedding soil cover in north-west Queensland. Four cover trial plots were built using mine wastes as cover materials. Each 2.3 m cover trial plot consisted of a 1.5 m soil cover made up of waste rocks and fines, a 0.5 m drainage layer that consisted of 0.1 m waste rock aggregates and a base layer made up of blended mine tailings. The hydrologic properties of cover materials were determined by in situ measurements and laboratory experiments, which, in turn, were used as input in a numerical model that described the cover’s transient soil moisture profile. The successful performance of the cover is reliant on the long-term stable geochemical behaviour of the substrate used as cover material. Therefore, investigations were carried out to determine the geochemical properties of the cover materials constructed from benign waste rock using static and kinetic tests, with the objective to increase the level of certainty of the material’s benign characteristics. Consequently, the long-term performance of this water-shedding cover design is described in terms of the physico-chemical characteristics of its outflows.CITATION:Gonzales, C, Baumgartl, T, Edraki, M and Soliman, A, ?2014. Mine wastes as cover materials in a water-shedding soil cover in north-west Queensland, in Proceedings Life-of-Mine 2014 , pp 261–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By R. S. Dean

The function of the Metallurgical Division is to conduct investigations relating to the treatment of mineral products from the state in which they are mined to the refined metal or other unfabricated product. These investigations include scientific and practical studies of ore dressing, covering the crushing and grinding of ores, separation by gravity, flotation. and magnetic methods; the hydrometallurgical treatment of ores, including cyanidation and amalgamation of the precious metals; the smelting and refining of copper, lead, and zinc, as well as the rare metals; and steel-melting practices from the raw ore to the finished steel. The object of this work is to conserve natural resources and eliminate waste by furnishing information on current methods of metallurgical practice. making fundamental studies of metallurgical processes, and developing new processes to the point of demonstrating their practicability. The Division is made up of sections devoted to the several phases of this work, each section being headed by an investigator capable of supervising his particular work. The work is carried on at the experiment stations and field offices or in the field, whichever seems best suited for the work in hand. The following, projects should be mentioned as particularly outstanding among those consummated successfully during the year: 1. Application of the type of chemicals known in the textile industry as wetting-out agents to flotation and agglomeration of ores, particulary soluble salts such as sodium and potassium chloride which must be treated in saturated brine. 2. Demonstration or a linear relation between surface and coercive force in magnetic minerals and Its application to magnetic separation and to the determination of grinding efficiencies and other metallurgical data which require surface determination at very fine sizes. 3. Pilot-plant demonstration of the practicability of the reduction of iron ore by natural gas and conversion of this direct iron into steel by direct melting and by forging and rolling before melting. The structure and properties of the iron so produced were studied in detail. This report covers the fiscal year July 1. 1934, to June 30, 1935.

Jan 1, 1936

By D. Hodouin

Jan 1, 1978

By Martin Herrenknecht

After the successful breakthrough at the end of 2006 of both TBMs into the multifunctional site Faido (MFS), in the middle of 2007 the two tunnel boring machines resumed the 12 km long section between Faido and Sedrun. In the roughly a 10 month interval both approximately 465 m long tunnel boring machines were partly dismantled, pushed through the 2.5 km long MFS, rebuilt for the new larger diameter of 9.5 m and reassembled to be ready for operation. In the rebuilding phase, improvements were made to the equipment, especially as a result of experience gained from the previous 14 km long drive in the section Bodio and taking into account the latest information regarding the upcoming 14 km section Faido. Both TBM drives are currently in the rock formations of the Lucomagno gneiss, which stretch over a section of 3.5 km from the MFS Faido to the predicted Piora Syncline. This section is divided into two fold axes of the Chièra Synform, where the Lucomagno gneiss pass from a sub-horizontal into vertical bedding. The drives, with current rock overburdens exceeding 1,500 m and, as known from the excavation phase of the MFS, in part highly disturbed rock formations, are characterized by the locally intense rock squeezing conditions with large convergences in the vicinity of the driving TBM as well as backwards due to the interaction of the two drives. High expenditure for the support measures, reduced driving performances together with extensive extra work associated with deadlines and increased costs are the result. In the paper the previous experience with the TBM drives in the section Faido and the challenges still awaiting us are presented and discussed.

By Erik Sundström, Magnus Nygren

The study explores the influence and consequences of safety initiatives on the development of safety cultures in the Swedish mining industry. It involves interviews with experts from four mining organizations, highlighting themes such as organizational structures, safety leadership, feedback, and communication.

Nov 1, 2023

By T. J. Rohrbacher

This report presents a U.S. Bureau of Mines methodology developed to incorporate factors of coal production (mining and cleaning methods, recoveries, economics, etc.) into the definition of recover-ability of a coal resource. Project procedures and computer models that were developed to include mine and preparation plant production rates, recoveries, and costs are explained. The results of these procedures and models are reviewed and compared to the Energy Information Administration estimate of U.S. coal resources-the "demonstrated reserve base." The Matewan 7-1/2-minute quadrangle in eastern Kentucky was selected to demonstrate the methodology.

Jan 1, 1993

Plan de l?exposé ?? Présentation du site de la mine Restigouche et du mandat confié à Genivar ??Dénoyage de la mine ??Processus d?enlèvement des boues au fond de la fosse ??Utilisation de Géotubes dans le procédé à l?usine de traitement des eaux.

Feb 1, 2008

By D Tucker, K Harney

Hatch forecasts that an increasing share of seaborne traded iron ore will be ultrafine, being either concentrate or pellet feed. This provides several challenges for the iron and steel industries, but the principal concern is: how much ultrafine iron ore can be consumed on sinter strands and with a minimal effect on productivity?This paper will identify new supply by project through 2020. Demand will be estimated for sinter production and practical steps will be identified to increase ultrafine consumption in sinter strands. The long-term iron ore price will be forecast to balance supply and demand. The paper will conclude by assessing how the pricing of ultrafine ore will develop relative to the Chinese iron ore indices.CITATION:Tucker, D and Harney, K, 2015. Iron ore ultrafines challenges and opportunities, in Proceedings Iron Ore 2015, pp 501–504 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By T. Thriveni, Ji Whan Ahn

"The current advanced technologies for the manufacture of light weight metals processing significantly increasing and attributes to the safety, performance, recyclability and economy. Still lack of technologies developed for light weight metals processing waste utilization and application. Environmentally friendly methods need to develop for better understanding the processing waste utilization. Alumina and aluminium processing creates a wide range of waste products, the most significant being is red mud. Bauxite residue is a high volume hazardous waste and nearly 3 billion tons have been dumped worldwide. Approximately, 120 Million tons/yr of red mud being produced without any environmental sustainable solution. Currently the most significant technology is waste utilization. The bauxite residue is suitable for road base construction, golf bunker sand, back fill and, general fill. Sustainable recycling technologies are necessary for the bauxite residue utilization for the recovery of rare earth elements and cement materials. Carbonation or CO2 sequestration of carbon dioxide is a method pioneered for the bauxite residue is modified to reduce alkalinity. The carbonation of alkaline material is an inexpensive and safe process that leads to the formation of thermodynamically stable products. The use of the carbonation can be an advantageous solution for environmental climate change and sustainability problems in the new century.INTRODUCTIONIn 2014, bauxite consumption was estimated to be 9.6 million tons, nearly all of which was imported, worth an estimated 269 million dollars. More than 95% of the bauxite was converted to alumina, and the remaining 5% went to non-metallurgical products, such as abrasives, chemicals, proppants, and refractories. Global aluminum demand is growing steadily spurred by growth in India and China (RBCAluminum Market Outlook, 2013) (Figure 1). Aluminum consumption is expected to rise 5% annually through the end of the decade, reaching 67 million tons per year by 2020. Global bauxite production decreased by 17% from that of 2013, principally owing to lower production in Indonesia. In response to a Government ban on exporting bauxite and other unprocessed mineral ores that took effect on January 12, 2014, bauxite mines throughout Indonesia shut down and production decreased from 55.7 million tons in 2013 to an estimated 500,000 tons in 2014. The ban was part of a mining law that was instituted in 2009 to increase development of downstream processing facilities in Indonesia."

Jan 1, 2016

By Hanlong Liu

The construction process and load-bearing behaviors of Cast-in-place Concrete Thin-wall Pipe Piles are analyzed based on its application on Yan-Tong Expressway project. The low strain test, static load test and field excavation are also carried out. It can be concluded that the new type of pile is convenient to construction with high bearing capacity and reliable quality, which has great potential in practical engineering.

Jan 1, 2006

By R. Pretorius, N. Mautsa

In a cobalt precipitation plant, phosphoric acid is used to eliminate excess uranium from the pregnant leach solution, resulting in a cobalt hydroxide product that has little uranium contamination. However, the amount of phosphoric acid added must be monitored and controlled to avoid financial and sustainability impacts and to prevent negative impacts on the final product quality. One possible solution to this problem is the use of online residual phosphorus measurement techniques to regulate the addition. By continuously monitoring the residual phosphorus levels in the solution, the plant can adjust dosing in real time to maintain the target residual phosphorus level. As a result, the cobalt precipitation plant can improve phosphorus level control, lowering the risk of overdosing, and ensuring consistent product quality. This approach can also improve process efficiency, reduce operational costs, and have a positive environmental impact

Jan 1, 2023

By André R. Laplante

"This presentation reviews three continuous centrifuge separators, the Falcon-C, Kelsey Jig and Multi-Gravity Separator, two units with possible synergies with centrifuges, the In-Line Pressure Jig and InLine Leach Reactor, and two centrifuge prototypes, the continuous Knelson and the Altair Jig. Typical applications, potential problems, promising synergies and general concentration mechanisms are discussed. A general discussion on the sources of information, the nature of the fluidization water flow, test work for potential centrifuge separations and the early life cycle of new technology, using centrifuge separators as an example, follows. ResumeCette présentation fait le point sur trois appareils de séparation centrifuge, le Falcon-C, bac oscillant Kelsey et Multi-Gravity Separator; deux appareils qui présentent des synergies possibles avec les centrifuges, le bac oscillant In-Line Pressure Jig et le système InLine Leach Reactor; et deux prototypes centrifuges, le Knelson continu et le bac oscillant Altair. On y présente des applications typiques, les problèmes d’opération les plus usuels, les synergies les plus intéressantes. On discute également des sources d’information disponibles pour le minérallurgiste, de l’impact du mode d’ addition de l’eau de fluidisation, de la démarche expérimentale a faire avant d’installer un centrifuge, et du cycle de développement de nouveaux équipements, en utilisant les centrifuges comme exemple.IntroductionGravity separation has undergone a renewal in the past 20 years, much of it attributed to centrifuge units. The semi-batch Knelson Concentrator has probably received the most exposure, but it is rather because of the shear number of units sold than the width and breath of its applicability. It excels at recovery very dense minerals in very small concentrations, and has become a workhorse of the gold industry. Falcon’s Super-Bowl comes a distant second, with very similar applications. A number of copycats are available, and are generically identified as “Knelsons.” This presentation will not address these units explicitly, but as possible synergies."

Jan 1, 2000

By Guy T. McBride

Mr. Chairman, Fellow Keynoters, Ladies, and Gentlemen: It is purposed to consider the theme of this meeting, "The 1970's - Pivotal Decade for the Mineral Industries," from the particular -- some would say peculiar -- point of view of one engaged in mineral engineering education, and this coign of vantage prompts the textbookish subtitle, "Problems and Solutions (?) in Undergraduate Mineral Engineering Education." Three interrelated problems, or problem areas, will be presented and discussed, and where solutions seem to be emerging or seem worthy to be suggested, they will be identified. The three problems are: 1. The goals, and therefore the course requirements, of the undergraduate curricula are in question, 2. The unit costs of undergraduate education appear excessive to those who bear the charges, and 3. The social ambience of the day affects for the worse the work attitudes and the career motivation of both prospective and in-course students. The Need. - Any discussion of these problems must bottom upon recognized national needs for minerals and a technologically sound minerals industry staffed by competent engineers, particularly at the exploration, development, and production levels, Fortunately, these needs have been recognized and to some extent quantified, and they are even now under further intensive study by some of the most competent members of our society and profession. The latter reference is, of course, to the current work of the National Commission on Materials Policy (U.S.A.) under the executive directorship of Dr. James Boyd. Predating this, and perhaps to some extent

Jan 1, 1972