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By C. P. Shen, H. C. Tsai, Bennie Chu, Y. S. Hsieh

The Pinglin tunnels are situated within the fold-and-thrust belt structural region in Taiwan, due to continent-arc collision and plate tectonic setting. The pilot tunnel TBM (§=4.8m) became stuck ten times with the standstills to date. The westbound main tunnel TBM (§=11.74m) was buried in a collapsing calamity. The main tunnel TBM shall identify and overcome the adverse geology with high volume of ground water ingress itself. This paper presents our experience and methodology through the adverse geology with Pinglin large TBM.

Jan 1, 1999

Jan 1, 1933

By Craig C. Hustwit

A pilot-scale treatment study was conducted on a copper-zinc bearing metal mine drainage using a pipeline treatment system called the In-Line System (ILS). The objective of this U.S. Bureau of Mines study was to determine whether the ILS could be extended from the treatment of coal mine drainages to the treatment of metal mine drainages. Hydrated lime (Ca(OH)2), quick lime (CaO), and caustic soda (NaOH) were used to neutralize the drainage. A novel reagent slurry of Ca(OH)2 and type C fly ash was also evaluated. Except for Ca(OH)2-fly ash slurry, treatment performance was evaluated for all reagents at pH values of 7,8,9, and 10. The Ca(OH)2-fly ash slurry was evaluated at a pH of 10. All reagents tested neutralized the metal mine drainage and substantially reduced the dissolved metal concentrations. It was concluded that the ILS could be useful in the treatment of metal mine drainages.

Jan 1, 2010

By D Andrew, G Stanway, P Mahoney, C Griebel

The iron ore mining industry is currently going through an adjustment from high to more moderate growth as China’s economy transitions from capital-intensive investment to a more services-oriented economy. We are now witnessing a renewed focus on productivity improvements and cost savings as planned expansions are completed. Despite the scale and importance that the mining industry plays in the global economy, innovation literature is generally more targeted at faster-moving industries with shorter innovation timeframes and lower capital requirements. To fill this gap, VCI set out to understand the state of innovation in the mining industry in 2014. This State of Play report aims to give an objective appraisal of the strengths and weaknesses of innovation in mining. The report has three sections covering both the structure and delivery of innovation in mining:Ecosystem – focused on understanding how the iron ore mining innovation ecosystem system works, including the roles of large and small miners, service companies, researchers and governments. Our recommendations focus on what is required for the system to work well and improve the level and quality of innovation in the industry.Strategy – how do companies define their innovation strategy in relation to their corporate strategy? How are these related to prevailing global and industry trends? How do they communicate this with their business? How successful are they? These are among the questions that this section attempts to answer. Our recommendations are pitched at the executive leadership of iron ore mining and service companies.Delivery – focused on how companies develop and deliver innovation, looking at the success of different structural options, leadership and culture, partnerships and the best approaches to change. Recommendations are aimed at improving outcomes within the iron ore mining value chain, including the role that suppliers play.CITATION:Stanway, G, Mahoney, P, Andrew, D and Griebel, C, 2015. Understanding the state of innovation in the iron ore industry, in Proceedings Iron Ore 2015, pp 631–646 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By R. A. Flinn, R. D. Pehlke, D. R. Glass, P. O. Hays

Knowledge of the depth of penetralion of an oxygen jet into the bath of the oxygen converter and of the correlation of penetration with driuing pressuve, lance heighl, and nozzle throat area is vital to the understanding of converter operation. If the penetration is too shallow, then severe and hazardous slopping takes place. On the other hand, if the jel penetrates entirely Lhvough lhe bath for an apprcciublc period of time, bottom damage occurs. In addilion to measurement of the penetralion of the jel, knou~ledge of the circulatory movement in the bath is also of interest in order to evaluale various theories oj-concerter operating behavior which have been published. In this investigation, experimental converters were buill of IOU- , 300-, and 4000-lb capacity. Four independent methods were used to determine penelralion: the onset of bottom marking, a nitrogen bubbler probe, observation througlt an optical syslew built into the oxygen lance, and direcl viewing of the jet issuing from the bottom of the vessel. Good correlation zuas obtained, and empirical relalions for pvedicling perletration were found. These relations were conjzrmed by bottom marking tests in 55- and 110-ton vessels. Within the operaling conditions employed in these tests, the depth to which a single oxygen jet penetrated zuas found lo vary according to the relatiorl ThE technical literature is replete with data concerning the successful use of the basic oxygen furnace or converter in steelmaking. Experimental data are lacking, however, on the vital factors of the depth of penetration of the jet into the bath and the induced circulation. Commercial operating conditions usually have been the result of cut and try experiments in lance manipulation until satisfactory results were obtained. There have been, however, two hotly argued opposing theories concerning desirable depth of penetration and these are exemplified by the Schwarz and Miles patents1,2 on one hand and the Suess patent3 on the other. The Schwarz patent teaches that the jet, issuing from the nozzle at supersonic speed, penetrates deeply "so that the reactions between the iron and the oxygen and between the oxygen and the rest of the smelting components take place in the center of the bath". Specific operating suggestions are given by Miles.2 By contrast, the Suess patent calls for surface Circulalion was investigated by lour methods: by direct observation in 200-lb open baths, by the use of graphite rudders in the 300- and 4000-lb converlers, by direct observalion through an oplical system in the lance, and by various models al room temperature. All were in excellent agreement and indicated that the motion of the bath ulas up at the center, radially outluavd at the surface, and down at the sides. Experi-ments in small and in commercial vessels indicate that it is essential to operate with a jet penetration of approximately 50 pct of the bath depth. Surface blowing results in low oxygen eficienty and in hazardous conditions which may render the process inopeuable. RejYactory dartzage al the bottom of the vessel is only encountered when the jet penetrates to the bottom, and this can be avoided by properly applying the penetration formula. The application of this en/pirical formula in commercial peraations is best when limited to combinations of lance size, pressure, and height which are typically encounteved in the use of a single-hole lance. blowing so that "...the oxygen jet does not penetrate deeply into the molten metal bath and is confined to an impingement area at the central portion of the bath surface". These references are given merely to illustrate the basic differences between the two schools of thought and to point out the need for measurement of penetration for the sake of the operator. For example, it is shown later that inefficient and even dangerous conditions can arise if improper blowing conditions are used. Differences are also evident between the two schools of thought as to the mixing, circulation, and agitation which is to be accomplished by the jet. The Schwarz patent states that "surface contact is not sufficient in most cases to bring about quick reaction, the same as the blowing of the gas over the bath surface or the mere blowing of the gas onto the bath surface". The patent goes on to call for active mixing. In contrast the claims of the Suess patent call for "discharging a stream of oxygen ... to an extent to avoid material agitation of the bath by the oxygen stream". In this patent the circulation is said to be downward in the center and up at the sides of the vessel. A number of investigators4-12 have explored penetration and circulation in transparent models. In general, it is agreed in these tests that the circulation is upward at the center (along the sides of the jet cavity),

Jan 1, 1968

By Parsons A. E

The application of known pelletizing tech- nology was successful in the agglomeration of zinc concentrate into pellets of minus 6mm siz- ing using fine zinc calcine and sulphuric acid as binder. Subsequent roasting trials conducted in a 0.3 m diameter fluid bed reactor, showed that the pellets satisfactorily withstood hot physical abrasion during fluidization. Fines generation was low and the pellet calcine was hard, possessing excellent handling properties. Results of laboratory scale static pellet sinter- ing tests showed conclusively that the deterior- ation in sinter physical quality experienced with fine calcine was not apparent when the calcine was added to the mix in pellet form. Based on the results of small scale exper- imental work, a one tonne per hour pilot plant was constructed and operated. Several thousand tonne of pellets were produced-for fluid bed roasting in Badische Analin and Soda Fabrik (B.A.S.F.) turbulent layer (T.L.) roasters previously designed for roasting iron pyrite concentrate. Continuity of the T.L. fluid bed roasting operations was achieved when the waste heat boilers were replaced with atmospheric coolers and thus eliminated the problems of gas flow restrictions. Sinter plant trials were conducted over a period of two weeks with the addition of pellet calcine to the sinter feed. Results showed a marked improvement in sinter plant performance, and as a result of better bed permeability, increased sinter production was achieved, with- out significant deterioration in sinter quality.

Jan 1, 1974

By Y. Zhen, N. Topliffe, G. Shou

The typical service life for a long distance slurry pipeline is15 to 25 years. Determination of wear rate for a pipeline could have a high economic impact on the pipeline project. Wear is a combination of chemical corrosion and mechanical abrasion. The contribution of each factor has to be determined project by project. Normally, chemical corrosion dominates the pipe wear in fine slurry pipelines. These pipelines have been designed with a velocity between 1.5 m/s and 2.5 m/s. Solids are suspended with high homogeneity across the pipeline section. Bottom wear is not much greater than the top wear and not sensitive to velocity. The wear pattern in the pipeline transporting medium coarse solids, such as milled ore and tailings, is different. Wear concentrates on the bottom of pipeline and the outer bends, and is more sensitive to flow velocity. Wear distribution along the pipelines is similar.

Jan 1, 2007

By J. Elderton

"The combination of A C induction motor and flu id coupling, of either the fixed or variable filling type, constitutes a simple, low cost, highly reliable drive unit, with many applications in the mining field.The paper will, however, concentrate on the variable filling fluid coupling in three principal applications-conveyor starting, infinitely variable speed control for slurry and slimes pumping and dewatering pumps for deep mines. Fluid couplings can be used with standard or custom-built control gear equipment, ranging from the most simple, time-based open loop types, to those having the latest microprocessor techniques.IntroductionThe first industrial applications of fluid couplings included their use in the mining field as hydraulic slip regulators for flywheel generating sets. These installations, usually rated at around 1700 to 2500 hp, were located at mine shafts where the electrical grid transmission lines were not strong enough to cater for the peak power demands of the cage winding cycle. In Canada, the first two significant examples of variable filling fluid couplings for mining were on conveyor drives, at Steep Rock Mines Limited, closely followed by the major iron ore handling term inal on the St. Lawrence River at Sept-Iles. Successful and reliable operat ion of the fluid couplings at these two sites set the pattern for use on many subsequent mining projects throughout the Canadian Continent."

Jan 1, 1986

By M Grigorescu, J H. Hodgkinson

The expansive, open cut iron-ore mines in Western Australia typically experience few days of rain per annum, often amounting to less than 250 mm. Unlike mines where rainfall is frequent, they may be less prepared for extreme rainfall events. Such events can cause erosion, flooding and sedimentation, drainage alteration, spoil and stock heaps wetting and effect slope stability. Such impacts may threaten personnel safety, infrastructure, and production. The CRATER (‘Climate Related Adaptation from Terrain Evaluation Results’) framework collates and interprets a mine’s pre-existing data and semi-quantitative information to assess vulnerability to, and ultimately plan to avoid or minimise, flood-related hazard to infrastructure, people, downtime, environment and revenue. Outputs assist decision makers to design investment strategies for minimising mining operations’ vulnerability to climate. Previously developed for smaller, wetter mines in Queensland’s coal region, the outputs provide a hot-spot map, fault tree analysis and an assessment of the mine’s capacity to adapt. The multicriteria evaluation (MCE) within a geographic information system (GIS), equally suits iron-ore mines’ siteconditions (elevation, slope, drainage, soil and vegetation) to identify critical inundation areas. Hotspot results provide target zones for in-depth fault-tree analysis that, in turn, present a range of sitespecific adaptation options. Rainfall-intensity and the number of rain days since the 1970s have increased over central and eastern parts of the Pilbara Region. While tropical cyclones may become less frequent, they are projected to increase in intensity. Although some parts of the Hamersley Ranges receive more than 500 mm per annum, rainfall in the Pilbara is generally very low. Therefore, experience of the impacts of extreme rainfall events in the constantly changing topography of Western Australia’s iron ore region may be sparse. Minimising potential effects can be proactively assisted using CRATER.

Nov 8, 2021

By Mariana Alves de Carvalho

O desenvolvimento da indústria e a redução do ciclo de vida de eletroeletrônicos aumentam a geração dos chamados resíduos de equipamentos eletroeletrônicos (REEE). Dentre os REEE, as placas de circuito impresso (PCIs) apresentam um teor de metais em sua composição que as torna importante objeto de estudo visando a recuperação destes metais para fins econômicos e, por conseguinte, impede que sejam dispostos no meio ambiente. O presente trabalho tem por objetivos a caracterização de uma amostra de placa mãe de computadores obsoletos e posterior recuperação dos metais via duas rotas hidrometalúrgicas de lixiviação ácida e lixiviação ácida em meio oxidante. A primeira etapa foi realizada com ácido sulfúrico 2M por 18 horas e a 95°C; a segunda etapa, de lixiviação em meio oxidante, utilizou também o ácido sulfúrico 2M como agente lixiviante, e o peróxido de hidrogênio como agente redutor, por 6 horas e a 95°C. As duas rotas se diferenciaram entre si na proporção sólido-líquido, sendo a primeira de 1:10 e a segunda de 1:20. A rota com proporção 1:20 foi a que apresentou resultado mais positivo, com 100% de lixiviação de Ag, Al, Cu, Fe, Ni e Zn.

Oct 30, 2017

By Komar Kawatra, Joseph Halt

"Bentonite clay has been the traditional binder for iron ore pellets. However, bentonite increases pellets’ silica contents and is expensive. Researchers have proposed lowering bentonite doses by mixing it with other common binders. These mixtures may only be successful if the fundamental bonding mechanisms are understood. For example, what happens when bentonite (physical bonding) is mixed with fly-ash (chemical bonding)? What happens when bentonite is mixed with cornstarch (physical bonding)? In this paper, experiments are described where bentonite was mixed with various ratios of cornstarch and fly-ash, and pellets were agglomerated using 0.66 % w/w binder. Ca(OH)2 and CaCl2 were added as activator and accelerator, respectively, to the bentonite-fly ash mixture. Curves of pellet dry strength vs. bentonite-starch ratio were linear, suggesting the physical-physical bonding mechanisms were compatible - acceptable strengths (> 22 N) were produced at all bentonite-to-starch ratios. This was contrary to bentonite-fly ash mixtures, which displayed dry strength curves with a noticeable minimum due to competing binding mechanisms. Bentonite alone and fly ash alone produced acceptable strengths (> 22 N), but their mixtures resulted in weak pellets. Due to the positive results using cornstarch (CS) binders, the effects of CS solubility in water were investigated using two CS with high and low solubility (60 and 7.5 %). CS was premixed with bentonite at various ratios (0, 20, 40, 60, 80, 100 %). Pellets were agglomerated using 0.66 % w/w binder. The dry strength of pellets ranged from 50-300 N using the high solubility CS mixtures, and from 50-85 N using the low solubility CS mixtures. Fired strengths exceeded 2200 N/pellet at all bentonite-cornstarch ratios. This research showed that cornstarch solubility is an important factor in determining its effectiveness as a binder for iron ore concentrates, but significant work is still necessary before it can be used as a bentonite replacement."

Jan 1, 2014

By Oliver Bowles

THE most important non-metallic mineral industries from a tonnage standpoint are those that are allied with the construction industries and are engaged in handling sand and gravel, crushed stone, building stone, cement, lime and gypsum. The greatest problem facing a number of these industries at this time is over-production. They have experienced un- usual, and in some instances phenomenal, growth during recent years, stinlulated by extensive highway and building construction, but in some localities expansion of producing plants has far outstripped industrial needs. The cement industry is operating at about two- thirds capacity. Over-production tends toward price- cutting and unprofitable and interrupted operation, involving maintenance expenses for idle plants and disorganization of working forces. This condition has encouraged active efforts toward reducing production costs by the introduction of labor-saving equipment. Also, there is a tendency toward the location of manufacturing plants, wherever possible, near the centers of consumption rather than at points of production of raw materials. In order to reduce overhead expense, or for other reasons, many consolidations of companies into larger units have taken place. An economic study of conditions in these industries is highly desirable. The U. S. Bureau of Mines has taken one step forward in this direction in the issuance of Economic Paper 7, entitled "Economics of New Sand and Gravel Developments." Briefly, this report emphasizes the importance of making a thorough study of all the economic factors involved before undertaking new .enterprises.

Jan 1, 1930

By N M. Player, R P. Varden, E Jones

"An effective geotechnical design provides an accurate and appropriate assessment, balanced with a mining company’s risk profile. Justifying the cost of slope assessment requires an understanding of the input sensitivities, and resultant risk, to achieve a slope of a required functionality. As a project progresses from Scoping to Feasibility, the geotechnical risk becomes better resolved through increased expenditure on drilling, testing, analysis and modelling as long as the input data is appropriately spatially distributed. Providing accurate and appropriate geotechnical assessments in the early stages provides confidence in all following stages, especially where initial analysis indicates difficult geotechnical conditions. It is also in the early stages of project definition that there is most opportunity to maximise the value of the deposit through investigations into optimal mining methods.This paper examines the advantages of geotechnical engineering input through a project study period. Early geotechnical involvement allows the Scoping and Pre-Feasibility Studies to be more effective. Operational risks can then be better understood and dealt within the Feasibility Study phase, also ensuring that the correct risks and management controls are put in place.With commodity price pressure and cost of resource recovery in a downturned industry, reducing the risk to cash flow, resource recovery and safety should be a primary goal for all mining companies. Reduced risk can be effectively achieved through geotechnical design of slopes to achieve a required performance as part of an integrated study to the Reserve definition and mine design.Citation:Varden, R P, Player, J R, Player, N M and Jones, E, 2016. Justifying Slope Design Risks and Costs, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 185–201 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By Jose Castro

The growing demand of scrap to supply the electric arc furnace has driven to search for new alternatives of raw material. The DRI produced using self-reducing pellets has become competitive due to the potential use of a wide range of carbonaceous materials such as coal, charcoal, biomass etc. In this context, the rotary kiln process using improved technologies such as post-combustion and self-reducing burden is a promising source of high quality raw materials. This paper presents a mathematical model of the rotary kiln process designed for self-reducing pellets and post-combustion. The model is based on the transport equation of two-phase flow, energy and mass transfer. The solid material is composed of a typical self-reducing pellet. The model considers the solid phase (C, volatiles, Fe2O3, Fe3O4, FeO, Fe, H2O, SiO2, Al2O3, MgO, P2O5, K2O, Na2O, FeS, CaO and gangue) and the gas phase (N2, O2, CO, CO2, H2, H2O, SO, SO2 and SiO). For each of the above components a conservation equation is solved and the mass and energy transport is accounted. The set of differential equations are coupled by the rate equations describing the kinetics of the several reactions, which take place within the rotary kiln. All the conservation equations are solved based on the finite volume method applied for a three-dimensional cylindrical coordinate system. Simulation results are presented for global parameters such as metallization degree, productivity, gas utilization ratio and calorific value. Inner conditions such as three-dimensional gas and solid temperature patter and compositions are discussed.

Jan 1, 2006

Gold rush histories are usually written as though they were unique events in the development of a region or nation. While this is a valid way of looking at gold rushes, it is not the only way. This paper is a brief attempt to relate the West Coast rushes to a wider context. During the second half of the nineteenth century the lure of gold transformed the Pacific Rim. Gold rushes drew more than half a million Europeans and Americans to lands bordering the Pacific. By 1900 a chain of mining, industrial and urban centres ran from California to Alaska; from Ballarat to New Guinea, and on to Western Australia. The New Zealand rushes were a significant chapter in this story. People, cargo and information passed from rush to rush. Techniques learned on earlier goldfields were imported; those developed in New Zealand were, in turn, taken up elsewhere. Administrative systems and regulations developed in Australia were implemented in New Zealand, improved and passed on to Canada. This interconnectedness was so strong that gold-seekers thought of the mining regions as a distinct culture, 'the whole digging world'. Much can be made of the similarities shared by rushes. But comparison can also highlight the individuality of each rush. +The early days of the West Coast rushes were perhaps the strongest assertion of a diggers' culture. A brief period in which a remarkable orderliness was created through mateship, self-regulation, and the occasional threat of rough justice. The West Coast rushes were both a unique experience and an integral part of a process which transformed the Pacific Rim during the nineteenth century. Understanding their part in that bigger story highlights just how unique they were.

Jan 1, 1996

By S. B. Christy

The practice of the cyanide-process of gold-extraction has brought to light many important contradictions of familiar chemical analogies, which still obscure both the theory and the practice of the art with distinctions subtler and more difficult to make or follow than those which delighted the heart of the old-time metaphysician. Yet Nature herself has drawn these distinctions; and if we hope to succeed in this modern search for the Golden Fleece, we must be able to follow her through the winding labyrinth. There are so many phases of this question that I shall attempt to touch on only one of them at this time, but it is one that lies at the root of many others. In reviewing my paper on " The Solution and Precipitation of Cyanide of Gold,"* Mr. E. B. Wilson contends† that" in the solution of gold by means of alkaline cyanides the various reactions are determined, as to their order and intensity, by the relative position of the elements concerned in the electro-chemical series, or series of voltaic tension." In a modified form this statement is probably true. That is to say, the difference of electrical potential in any closed electrical circuit determines the nature of the reactions which ensue. But the matter is not so simple as Mr. Wilson assumes. Recent investigations show that the order of the metals in the electro-chemical series depends not only on the nature of the elements themselves, but also on the chemical composition of the solution in which they are placed; its degree of concentration; its temperature; and, in the case of gases, on the pressure. Unless all these conditions are taken into account, inferences drawn from the electro-chemical series are likely to prove more

Jan 1, 1901

By Ted C. Briggs

A special high-pressure Burnett-type compressibility apparatus was constructed and used to determine compressibility factors for pure helium, pure nitrogen, and nine helium-nitrogen mixtures containing 89.47, 79.04, 69.69, 60.09, 49.24, 41.02, 30.99, 20.53, and 10.67 mole-percent helium. A total of 161 runs were made consisting of 2,355 observed pressures. Data were obtained at 0°, 25°, and 50° C and at pressures to 1,000 atmospheres. A power series in the reciprocal volume, commonly called a Leiden series, is used to represent the compressibility factors. Three parameters in the series are required to represent helium, five parameters to represent nitrogen, and from three to five parameters to represent the mixtures. Compressibility factors are believed to be accurate to better than 0.1 percent over the entire pressure, temperature, and composition range.

Jan 1, 1972

By R. J. Reynik, F. R. Meeks

IN the classical paper1 of Mehl and Rhines entitled "The Rates of Diffusion in the Alpha Solid Solutions of Copper", the authors state: "It has been mathematically demonstrated that the treatment of the data as though the diffusion were taking place between two flat plates instead of radially in a cylinder has no appreciable effect upon the results. Were the bars of a much smaller diameter, a modification of the analytical treatment would have been required." Unfortunately, the errors in the reported concentrations are much too large to neglect, as shown in the results below. A planar treatment of diffusion data assumes that the reference planes separated by a nominal distance (AX) have identical areas. An adjustment must be made on the concentration data should the successive diffusion planes differ in area. The Mehl-Rhines' diffusion samples were cylindrical with copper electroplated onto copper-based alloys. Successive surface areas through which diffusion occurs are in the ratio ri/r1, where ri is the radial distance between the center of the sample and the center of the i th shell to which the host (alloy) atoms diffuse, and r1 is the radial distance between the center of the sample and the center of the innermost (i = 1) experimentally reported shell from which the alloy atoms diffuse. Hence, ri/r1 (i = 1, ..., n layers) is a dimensionless correction factor to be multiplied by the reported concentration data before planar-data analysis is attempted. In the forty-seven samples reported, the original interface between the copper alloys and the electroplated copper was located at a mean distance of 8.255 mm from the center of the samples. The successive layers, machined off the samples, were approximately 0.0762 mm thick. The distance (xi) at which concentration (ci) was reported was always a distance measured with respect to the original interface, that is, with respect to the fixed distance of 8.255 mm. Hence, the as yet undiscovered Kirkendall Effect was precompensated. The values of ri and r1 are therefore given by ri = 8.255 + xi and Y, = 8.255 + x,. The illustrative table below lists the position xi (mm), ri (mm), the value of ri/r1, the reported concentration (ci) in weight percent (only valid for radial analysis of data), and the corrected concentration [c'i = (ri/r1)ci] in weight percent (only valid for planar analysis of data). Similar tables can be constructed for the remaining forty-six samples. The corrected data can be used to re-evaluate the diffusion coefficients for the reported systems.

Jan 1, 1965

By R Stefansen, T Wisdom, A Nicholson, K Rahal

The challenges of increasingly scarce water resources and the risk of dam failures has seen the mining industry turn to sustainable tailings management solutions such as dewatering and dry stacking. Filtering tailings has been seen in the past as a cost-prohibitive process for larger throughput mines. However, as larger pressure filters are developed, the economic case for filtered tailings has gained traction.Focus has largely been placed on the correct design and operation of the filters. It is critical, however, that the material handling portion of the disposal system is also properly designed and operated. Thorough testing at laboratory and pilot scale to determine the conveying properties of the filtered material needs to be conducted. This testing will insure the material handling system meets the important availability needs of the mine even during periods of variability in the upstream processes and mine plan.The control system must also be robust and flexible in design to compensate for this upstream process variability. The control system needs to allow for different flowsheets including straight filtered tails as well as EcoTails™, a low-energy solution for co-mingling waste rock and filter cake.This paper will present case studies of different material handling solutions, the testing required for them and the lessons learned from each.CITATION:Rahal, K, Nicholson, A, Stefansen, R and Wisdom, T, 2018. Material handling testing and control system requirements for dry stack tailings, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 361–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Jeff Hammer, John McGregor

"The Twin Tunnels, originally constructed in 1964, have become a major choking point for trafficheading up to and returning from the Colorado high country along the I-70 corridor. To increase traffic flow, the Colorado Department of Transportation undertook the first widening of the East Bound Tunnel in 2013. After the successful completion of that project, CDOT began the widening of the West Bound Tunnel in 2014. Both projects had a limited schedule for tunnel construction of just nine months. The innovative blasting and demolition of the existing tunnel lining was a crucial component to the success of both projects. During the construction of the West Bound project in 2014 a large amount of surface bench blasting using conventional methods ran concurrently to the West Bound tunnel excavation to allow for enough room for the new tunnel portals."

Jan 1, 2016