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By Regina Rocha, Miguel Humpire

Uno de los retos dentro de las operaciones unitarias de minería es la voladura, la cual presenta un impacto importante aguas abajo en los siguientes procesos, es por eso que las compañías mineras aseguran los resultados del proceso de voladura a través un trabajo en conjunto con empresas especialistas en explosivos. En ese sentido, como parte de la excelencia operacional, se implementan sistemas de control y aseguramiento de calidad de todas las actividades que se producen en mina y conllevan a ejecutar la voladura en una mina de alta complejidad a fin de dar cumplimiento al diseño de carga.

Sep 30, 2022

By V. A. Ettel

Current practices in electrolytic winning and refining of copper , nickel and zinc are reviewed from the point of view of their respective energy requirements. The electrical energy requirements of these processes are broken down in to the individual components, which belong to two basic categories: (a) thermodynamic energy requirements (G of the desired reaction) : (b) energy losses (anode and cathode polarizations, ohmic drops in the electrolyte and in the cell hardware, energy losses due to unwanted side reactions and electrical shorts). The individual energy components are separately examined for each electrolytic process and the potential for energy saving in these processes is discussed. It is shown that many potential energy-saving measures are uneconomical at the present time, as they increase over-all operating costs. The discussion is focused on those approaches which hold most promise for the future.

Jan 1, 1977

De Beers? Finsch diamond mine began operation in the 1960s as a surface project using the latest technology available. During the 1990s, the operation, located about 160 km (100 miles) west of Kimberley, South Africa, began its move as an underground mine. The earlier stages (Blocks 1, 2 and 3) of underground work at Finsch used open stope mining methods, also using the latest in technology. The mine began developing Block 4 in 2004. How-ever, studies on this level showed that block caving was a more efficient mining method than open stoping. It was during those studies that De Beers determined that Block 4 would be a good candidate for testing Sandvik?s automated truck haulage technology.

Jan 1, 2008

By Jarc H

The steeply dipping silver/lead/zinc orebodies at Mount Isa mine have been extracted most recently by a combination of cut-and-fill and open stoping methods. Bench stoping was first used at Mount Isa Mine seven years ago to allow safe extraction of a highly stressed cut-and-fill stope. Subsequent benches have shown that the method offers significant cost and safety benefits through increased productivity and reduction in man exposure. The success of benching has lead to cut-and-fill mining being replaced at Mount Isa.Significant resources have been focussed to optimise benching. This paper describes the operational, planning, and research and development aspects which have contributed to the method to date. A brief look is also taken at the future direction of benching at Mount Isa.

Jan 1, 1992

By L. Andrews

Nickel is recovered as a by-product of the platinum-producing process operated by Anglo Platinum. The metal is mined mainly as sulphide minerals contained in platinum ores. These pass through the concentrating, smelting and converting process route and nickel is finally recovered by electrowinning. Smelting of the concentrated ore in the electric furnace produces a melt with a high slag to matte ratio. The resulting furnace slag is granulated and later milled and floated to recover matte. A project was initiated to investigate the distribution of nickel in the slag in order to improve recovery. Slag samples were examined using a combination of chemical and mineralogical techniques. The granulated slag was found to consist mainly of a silicate glass phase, which reflects the composition of the molten slag in the furnace. Nickel occurs as free matte granules, as matte phases locked inside the glass, and in the glass phase itself. Whereas nickel in the matte is as sulphide, most of the nickel in the glass phase appears to be oxide- bound(i.e. in solid solution). Milled slag as flotation feed showed recovery-limiting features such as free matte with oxidized surfaces and unliberated matte inclusions in the slag. The biggest nickel losses, assuming no tapping problems, are in the glass phase solid solution. Only around 40% of nickel would be recovered from the slag, even under ideal conditions. Spoon and pot slag samples were also examined to see if casting and crushing would improve recovery. Although larger and therefore more easily recovered matte phases formed, nickel partitioned into crystalline silicate phases, limiting the maximum theoretical nickel recovery to 70%.

Jan 1, 2004

By Brian P. Waagner

Construction law in general and the law of deep foundations in particular continues to develop rapidly, particularly in the areas of risk allocation. Public and private owners are increasingly using contractual disclaimers to shift the risk of differing site conditions to contractors, and courts are increasingly willing to enforce these contractual devices. Perhaps also in an effort to control costs, public and private owners are turning to design-build contracting techniques. While design-build offers many advantages over traditional project delivery systems, it does not answer all of the risk-allocation questions that frequently arise. Even in design-build, problems with unanticipated subsurface conditions and defective design are not easily addressed. Finally, developments in electronic commerce present the potential to transform the construction industry.

Jan 1, 2002

By A H. Clemens, P Lindsay

Acid producing potential static tests have been undertaken on sample lithologies from New Zealand coal mines, to rank the lithogies into acid producing waste rock and stable non-acid producing waste rock. Results indicated that the main acid producing waste rock in the Waikato coal region are the marine Whaingaroa siltstone and the Glen Massey formations and the main alkaline producing lithologies were the Tauranga group volcanic-derived sediments (A & D) and the Mesozoic basement. Coal ash analysis of 28 samples from 28 mines have also been analysed for reactive S percentage and their base potential has been quantified by the chemical index of alteration (CIA). The results provide mine management in the Waikato Coal region with a classification of problematic and stable waste rock types. XRF and CIA values determined from wash drill cuttings would provide a method of determining waste rock volumes and magnitude of palaeo-weathering underground.

Jan 1, 1999

By A T. Job, P R. McAree

There is significant value at stake in the mining industry from the implementation of new technologies that support the enhanced profitability and sustainability of mines. However, in order to realise this value, new technology must be implemented in a way that is both effective and sustainable. The industry has a mixed history for technology implementation that provides fertile ground for understanding what is necessary for innovation to deliver value. This paper describes early stage research investigating why this is so, with the aim of improving how to deliver value. Several case studies are provided covering both successful and unsuccessful technology interventions. The paper identifies the common factors that emerge from the case studies, and offers a path forward for further research in this area.CITATION:Job, A T and McAree, P R, 2017. Three case studies on the implementation of new technology in the mining industry, in Proceedings Iron Ore 2017, pp 407–414 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Collaboration between education providers is the key to long-term sustainability and improved quality in mining education. The mining industry is now, more than ever, an industry doing business on a global basis. Staff are recruited by global mining companies in many different countries and can find themselves deployed anywhere in the world. The mining engineer of tomorrow must be willing to take on this international challenge, and must be educated to a level where he or she has a comprehensive grounding in technical aspects of mining engineering, but also a well-founded appreciation of management, social, environmental and cultural issues that may be encountered around the world. In order to deliver such an education, academic providers must collaborate at both a national and international level. This paper provides an overview of progress that has been made in Australia through the national joint venture ? Min¬ing Education Australia (MEA). Supported by the mining industry in Australia, through the Minerals Council of Australia (MCA), MEA has been operational since 2007 and is seeing the development of a range of innovative courses and delivery methods, together with a high level of staff cooperation across the country. MEA has also commenced some international teaching initiatives that are seen as a catalyst for a far greater degree of international collaboration in the future. Such activity is not only to the benefit of the students who are taught by experts from around the world, but it also ensures that individual univer¬sity programs remain viable in terms of staffing numbers and financial performance. The paper also presents some statistics on recent upward trends in mining engineering student numbers from around the world, in response to the global shortage of mining engineers.

Jan 2, 2010

"The Ernest Henry Mining (EHM) ore body is an iron oxide copper gold deposit with an average grade of 1.1 percent copper, 0.5 g/tonne gold and 22 percent magnetite. At the end of 2009, EHM converted the ball mill media charge from forged steel to high chrome media. At high pH values (above 10.5), forged media is passivated, so as the pH of the system drops the media corrosion rate increases and floods the system with corrosion products, affecting flotation. As the high chrome media is much more inert, pH has less of an effect on copper flotation response. Given this, the pH in the roughers was dropped from 10.6 to 9.6 and it was found that there was a slight increase in copper recovery and no statistical change in either the rougher or final copper concentrate grades for copper and gold. With the reduction in pH, there was a noticeable reduction in lime usage from 0.85 kg of lime per tonne of ore processed to 0.55 kg/t. This reduction in lime is equivalent to approximately $700,000 per annum at current production rates.INTRODUCTION The Xstrata Copper Ernest Henry Mine (EHM) is situated 38 km north east of Cloncurry, Australia. The mine began as an open-cut operation in 1998 and transitioned to a multi-sourced operation in December of 2011, utilising ore from the newly completed underground mine in addition to ore mined from the Mount Margaret Mining operations. EHM produces a combined copper gold concentrate containing 25 000 t of copper and 35 000 oz of gold annually, utilising a three stage grinding circuit along with a four stage flotation circuit. In addition to this EHM also produces 1 000 000 t of magnetite concentrate annually via a further grinding and three stage magnetic separation circuit. Based on metallurgical test work performed by Magotteaux between 2002 and 2008, the step to change from forged steel media to 18 percent chrome media was taken in 2009 in a bid to alter the pulp chemistry to improve the flotation performance in the plant (Greet, Kinal, Twomey, & Peatey, 2010). This plant trial resulted in: • Increased dissolved oxygen levels within the pulp, • A ball mill discharge Eh shift of 25 mV to more oxidising pulp potentials, and • An EDTA extractable iron percentage reduction. These improvements in the pulp chemistry resulted in an increase of 1.7 ± 0.6 percent in copper recovery and an increase of 2.9 ± 1.7 percent in gold recovery. As the plant trial using high chrome media was successful, the use of the media was adopted as the standard for the ball mill. This implementation opened the door for further process improvements around the flotation circuit."

Jan 1, 2014

By D N. B Skinner

Changes in the configuration of late Cenozoic volcanic arcs related to Pacific-Australian plate convergence in northern New Zealand may have localised large-scale epithermal gold-silver mineralisation to a particular part of the volcanic arc system, the Coromandel Volcanic Zone (CVZ). The history of arc-type volcanism in northern New Zealand began with the development of the continental margin Northland Volcanic Arc from early-mid Miocene (26-15 Ma). From 18-15 Ma the Northland Volcanic Arc extended south into the northern and western part of the CVZ where it is dominantly composed of andesite with lesser dacite and very minor rhyodacite. In the south, centre and east of the CVZ, younger andesite-dacite volcanism overlapped in space and time (14-5 Ma) with voluminous rhyolitic volcanism associated with rift-hosted calderas and minor basaltic eruptions. This change to bimodal rhyolitic-basaltic volcanism and extensional tectonics was a result of southwest (SW)-directed propagation of the Colville-Lau oceanic island+ arc into the north-northwest (NNW) trending Northland Volcanic Arc and its underlying continental crust. The extensional tectonic regime created in the collision zone between the two arcs is also the site of the 14-6 Ma Coromandel epithermal gold-silver province, which contains some 50 separate deposits and has a production (1862-1996) of about 300 t Au and 1150 t Ag. Extensional tectonics facilitated the emplacement of silicic magma at shallow crustal level and led to reactivation of deep basement faults. The resulting enhanced heat flow and fault-focused fluid flow localised large hydrothermal systems and associated extensive low-sulphidation epithermal gold-silver deposits in the southern part of the province, as at Waihi, Golden Cross and Karangahake.

Jan 1, 1997

Authors have been conducting research on autonomous loading operation by wheel loader. Autonomous loading cycles has been demonstrated with real size experimental model. In V shape loading operation, travelling between scooping point and dumping point is dominant factor for cycle time of the operation. The positions of scooping point and dumping point changes with advancing the operation. In the developed system, path planning is performed at the beginning of every cycle. The path is formed by combination of curve and straight path elements. During travelling on the planned path, path following control is applied on the loader to keep position error in narrow range. Positioning of the loader is based on dead reckoning with correction by global positioning system (GPS) data. In a process of path following control, control value for steering angle is determined based on position error in lateral direction. Proposed method of path planning and position control is installed and tested in the real size experimental model. The detail and results will be described in the paper.

Dec 6, 2010

By H. B. Menardi

The history, geology, ore deposits and current mining operations of the Huitzuco district have been described by C. W. Vaupelll and the current mill operations by David Segura.2 This paper completes the story of Huitzuco with a description of the reduction of the flotation concentrates. The predominant ore mineral in the Huitzuco deposit is livingstonite, a rare, mercury-antimony sulphide (HgS.2Sb2S3). Other associated minerals include cinnabar, stibnite and elemental sulphur. The gangue is largely limestone and gypsum. Former operators mined a selected grade of ore, from which the mercury was recovered by an expensive, inefficient operation. A considerable tonnage of rejects and fills, carrying mercury and antimony, was left in the mine. In order to recover both mercury and antimony from these fills and also from newly developed ore, a combination method has been developed, by means of which the livingstonite is concentrated by flotation and the flotation concentrates subsequently reduced to metallic mercury and antimony. An essential part of the flotation treatment, as developed by Segura, is the use of copper sulphate as an activating agent. A typical analysis of concentrates now being produced at the property is as follows: Hg, 7.73 per cent; Sb, 26.40; Fe, 1.20; S, 29.68; CaO, 11.50; MgO, 7.25; SiOz, 1.63; A1203, 0.65. PRocess foR Treatment op Concentrates In the development of a process for treatment of these concentrates, three different methods were investigated: (1) roasting in a Dwight-Lloyd sintering machine with an excess of air; (2) separation of mercury and antimony by distillation in a reducing atmosphere; (3) a third method, which ultimately developed into the present process. The third method involved a slow calcination at a closely regulated temperature with a limited admission of air, which separated the mercury and antimony, the raeroury passing out of the kiln with the furnace gases and the antimony remaining in the calcine or "sinter."

Jan 1, 1944

By T. Gupta, T. Ghosh

Rare earth elements (REEs) and their compounds are essential in a multitude of mundane and sophisticated applications such as renewable energy technologies, catalysts, medicine, and defense applications. The global supply deficit could be attributed to the destabilization of REE market that has, as a result, incentivized indigenous production of REEs. Cost-effective and environmentally benign opportunities are being explored for the production of REEs from non-conventional mineral sources including coal and coal by-products to stabilize the supply chain. Coal from Healy coal mine and Wishbone Hill deposits in Alaska have been quantified for REEs and were found to possess elevated total REE concentrations as compared to world average levels (60– 70 ppm). The objective of the study was to concentrate the REEs in the froth phase by froth-flotation of the fine size fraction (< 75 μm). A Box-Behnken design of experiment was employed to ascertain the main and interaction effects of operational parameters on response variable by analyzing 3D response surfaces. Experiments were carried out to maximize REE recovery and concentration by modeling and optimization of three operating variables (frother dosage, pulp density (% solids), and collector dosage). Based on the results, the optimum flotation conditions for maximum recovery at an elevated concentration of REEs in the froth fraction was obtained at 4.2% solids and 32.7 ppm of frother dosage for Healy sample and 10% solids and 37.9 ppm of frother dosage for Wishbone Hill coal sample. The quadratic relationship between the input and response variable was found to be independent of collector dosage suggesting good surface hydrophobicity and floatability of the two coal samples.

By Dianne C. Marozas

The U.S. Bureau of Mines is conducting research to evaluate the potential for developing an in situ leach mining process that will selectively extract manganese from oxide ores, leaving gangue relatively undisturbed. To accomplish this, a geochemical approach, based on deposit-specific information such as mineralogy and geology, is used to constrain the operating parameters of the system. Among the studies being conducted are (1) leaching experiments to define reaction mechanisms and kinetics, (2) detailed petrologic characterization at the microscopic scale to assess Mn distribution and leaching efficiencies, (3) deposit characterization and evaluation, and (4) development of potential Mn recovery schemes. Data from these studies are being used to develop engineering design information for an in situ mining process. Specific details of the Bureau&apos;s research project are discussed, including results obtained to date.

Jan 1, 1991

By Nikhil Dhawan, Shrey Agrawal, Veeranjaneyulu Rayapudi

India’s steel vision of 2030 requires a huge amount of quality iron ore. The utilization of low-grade iron ores such as banded iron ores will play an important role to achieve the same production. The absence of alumina impurities in the banded hematite jasper (BHJ) ore provides it an edge over other low-grade iron ores. The conventional beneficiation techniques such as magnetic separation and washing were found to be ineffective to produce suitable feed (Fe ~ 60%) for the blast furnace. It was found that microwave exposure provides significant enrichment to the low-grade iron ore and can be used as a pretreatment step in the beneficiation of similar low-grade iron ores. The above study reveals that hematite phase is susceptible to microwave exposure which enhances the separation of iron values from impurities. Under optimum conditions, an iron-enriched concentrate with 61% Fe, 85% Fe recovery at 50% yield can be achieved from BHJ feed ~ 38% Fe. The pretreatment process for BHJ beneficiation includes only microwave exposure without any chemical additive and may prove economical and industrially feasible.

By R. C. A. Thurston

"The lack of notch ductility in structural steel in general, and in ship plate in particular, has been the object of widespread attention in the metallurgical world since the spectacular collapse of the ill-fated S.S. Schenectady in 1943. Numerous investigations have been carried out, many new tests have been developed, and a vast amount of useful data has been published, with the result that our knowledge is now far more advanced than it was at the time of this disaster. Interest has focused largely on the medium strength steels, and the various factors which cause a normally ductile steel to behave in a brittle manner in the presence of a notch and at relatively .low temperatures have been thoroughly studied.The literature available on high-tensile steels, however, is less extensive and the present paper is intended to supplement this information. Notch toughness tests have been carried out, at the request of the R.C.N., on a high-tensile manganese steel in the form of commercial ship plate. One of the newer tests, the tear test, and the Charpy V-notch impact test, were used to examine the characteristics of plate for the construction of an ice-breaker. About 250 plates, mainly in the thickness range from 11,4 in. to 1 % in., were tested. An an-alysis of the results obtained is presented, certain aspects of the tear test are discussed, and the correlation between the two types of test is studied. On the basis of information available from casualty ships, the plates, with few exceptions, were considered to be satisfactory."

Jan 1, 1959

By M. L. Harris

In underground mines, coal dust explosions are prevented by the addition of rock dust sufficient to render the coal dust inert. The National Institute for Occupational Safety and Health (NIOSH) has developed a hand-held instrument that uses optical reflectance to measure the explosibility of a rock dust and coal dust mixture. This instrument is called the Coal Dust Explosibility Meter (CDEM). In this study, NIOSH personnel accompanied Mine Safety and Health Administration (MSHA) inspectors on their routine band surveys in five and three underground coal mines in MSHA District 2 (PA) and District 11 (AL), respectively. While underground, NIOSH personnel and MSHA inspectors used the CDEM to assess the explosibilities of the dust samples. The values of percent incombustible content (% IC) determined by the CDEM agreed well with those obtained later by low temperature ashing (LTA) in both MSHA and NIOSH laboratories. Further, the meter identified some samples as potentially explosible that LTA analysis had found to possess sufficient rock dust for inerting. The CDEM provides more information on the hazards in the mine. Rapid identification of areas with explosible dust mixtures using the CDEM allows for immediate intervention rather than a wait of several weeks for laboratory analysis.

Jan 1, 2008

By Ning Wang, Tengfei Guo, Wanyan Li, Hanjie Wen, Hannian Gu, Zehai Li

Bauxite residue (red mud) is an alkaline waste derived from the industrial process for extraction of alumina from bauxite ore. Some bauxite residues contain considerable concentrations of critical metals, for example, rare earth elements. Lithium in red mud was also reported as a potential resource. In the current study, a Li-rich red mud was leached using acetic acid to investigate the leaching behavior of lithium followed by neutralizing with hydrochloric or oxalic acid. By neutralizing red mud using diluted hydrochloric acid (0.01 mol/L), 58.04–60.27% of lithium was leached using 25% acetic acid at 95 °C for 60 min. In the meantime, more than 95% of sodium and 85% of calcium were also dissolved in the leachate solution. While oxalic acid (0.5 mol/L) was used to neutralize red mud prior to acetic acid leaching, lithium performed lower leaching efficiencies (42.41–46.88%) in comparison of using of hydrochloric acid–neutralized red mud. Nevertheless, these leaching efficiencies of lithium were close to that of calcium and much higher than those of sodium under the condition. In this study, 25% (v/v) of acetic acid, at 85 °C for 60 min, was demonstrated as optimum conditions for lithium extraction from oxalic acid–neutralized red mud using acetic acid. The results would be useful and of interest for lithium recovery and purification from red mud.

By Hibbert W. D, Lottrey A

The behaviour of coal in a process is a function of both the coal properties and the processing conditions. In the case of the Loy Yang coal deposit, extensive testing has been undertaken to determine: ò the extent, distribution and structure of the coal resource; ò the variations in properties throughout the resource; and ò evaluation of the behaviour of the coal during processing. This has involved the conduct of an extensive borehole drilling program, backed by geological modelling and material characterisation (chemical, physico-chemical and petrological). Evaluation of the behaviour of the coal during processing has ranged from theoretical modelling, laboratory-scale investigations through to pilot scale and full-scale tests. Until recently, the bulk of the work was directed at evaluating the behaviour of the coal for existing pulverised fuel (pf) firing/steam boiler technology and a high level of understanding has been developed of both the coal resource and its behaviour within these systems. More recent efforts have been directed towards the evaluation of new technologies directed towards cheaper and more efficient power generation using this coal. Loy Yang coal has been evaluated in the following technologies: ò Hydrothermal dewatering/direct coal-fired gas turbine; ò Steam fluidised bed drying; ò Solar drying/densification; ò Briquetting; and ò Gasification.

Jan 1, 1992