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By C M. Stewart

Lithium battery electric powered vehicles and machines (BEVs) continue to gain traction inunderground mining use, with predictions they will dominate the underground light and heavy vehicle fleets for some mines within the next decade. There are clear advantages for ventilation systems through reduced heat output and the elimination of harmful exhaust gases and diesel particulates. However, the risks and effects of BEV fire emergencies for underground personnel and ventilationsystems are still largely in the early stages of analysis and understanding. This paper conducts an industry review of a selection of lithium battery fire incidents and research.A research paper review on lihthium fire behaviour, intensity and toxicity will be analysed and comparisons made with equivalent diesel machinery fires for context. Guidelines for mine firemodelling parameters will be offered to assist in predicting the behaviour, heat and emissions from BEV fires, and recommendations and conclusions will be drawn on the specific hazards of lithium battery fires compared to conventional diesel powered machines.

Oct 12, 2022

By C Xuan, J H. Park, Q Wang, C Shen, D Kumar, W Mu

Dissolution of non-metallic inclusions in the metallurgical slag is of vital importance for cleanliness control of the steel manufacturing. With the development of high temperature confocal laser scanning microscope (HT-CLSM), new insights have been obtained due to its in situ observation characteristics, higher resolution and precise control. However, HT-CLSM measurement has the limitation, eg the slag composition cannot include high amount of transition metal oxides. In addition, it is time consuming for the experimental procedure and not so simple to succeed for every measurement. It is known that digitalisation has made a significant progress in recent years. Machine learning (ML), a sub-domain of artificial intelligence (AI), is the key enabling technology for the digitalisation of the material science and industry. The database for ML model is collected using almost all available HT-CLSM experimental data and subsequently the established database is trained by different ML methods. Unseen data is used as the benchmark of the ML model. Al2O3 dissolution is the main process to be predicted in the current study. A good agreement between the HT-CLSM data and the ML model prediction results show the possibility to apply ML in process metallurgy.

Jun 19, 2024

By Md. Nafiul Haque, Murad Y. Abu-Farsakh, Chris Nickel

"This paper presents the results from a pile load testing program for a bridge construction project in Louisiana. The testing includes two 54-inch open-ended spun cast concrete cylinder piles (OECP), one 30-inch open-ended steel pile (OESP), and two (30-inch and 16-inch) square prestressed concrete (PSC) piles driven at two locations with very similar soil conditions. All the test piles were instrumented with vibrating wire strain gauges to measure the load distribution along the length of the test piles and the skin friction and the end bearing were derived from strain gauge measurements. High strain dynamic load tests (HSDLT) were performed on all test piles at different times after pile installations to quantify the amount of setup with time. Static load tests were also performed on the PSC and open-ended steel piles. Due to expected large pile capacities, the statnamic test method was used on the two open-ended cylinder piles. The pile capacities of these piles were evaluated using various CPT methods (such as Schmertmann, De Ruiter and Beringen, LCPC, COFS methods). The result showed that all the methods can estimate the skin friction with good accuracy; but not the end-bearing capacity. Setup was observed for all the piles, which was mainly attributed to increase in skin frictions. The setup rate parameters “A” [The “A” parameter is defined as the rate of increase of pile capacity ratio (Rt/Rto) per log cycle of elapsed time] were back-calculated for all the test piles and the values were between 0.31 and 0.41.INTRODUCTIONDue to greater efficiency (capacity to weight ratio) of the pipe piles, open-ended piles are a viable option to solid piles. However, the behavior of open-ended piles is more complicated compared to the close-ended piles owing to possible formation of “soil plug” inside the open-ended pile. Many researchers have analyzed the behavior of both types of piles for different purposes; however, very few studies in the literature offer the side-by-side comparison of the close-ended and open-ended piles."

Jan 1, 2017

By A Bax, G Wardell-Johnson, W P. Staunton, J McGrath, J J. Eksteen

Since 2001, the AMIRA P420 gold processing technology project series has been studying the recovery of gold using gravity devices, with particular emphasis on the centrifugal units, Knelson and Falcon concentrators. The work has entailed the surveying of operating gravity circuits in Australia, Africa and North and South America.This paper reviews some of the results and lessons of these studies, including common circuit operating and design factors, which limit gravity recovery; pointers towards effective modelling of gravity circuits; and the contribution of gravity to overall gold recovery.CITATION:Wardell-Johnson, G, Bax, A, Staunton, W P, McGrath, J and Eksteen, J J, 2013. A decade of gravity gold recovery, in Proceedings World Gold 2013 , pp 225-232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

One of the responsibilities of the Melbourne and Metropolitan Board of Works is to provide a sewerage system for the metropolis of Melbourne which now contains over 2.5 million people. In providing this sewerage system it was necessary for the Board to embark on a large tunnelling programme some 20 years ago. As a result of this extensive tunnel construction programme, tunnel boring machines and shaft sinking methods have been developed to cope with the soft ground and soft to medium rock found in the southern and eastern areas of Melbourne where the majority of the recent tunnelling has been carried out. While in the last few years radical changes in construction methods have not been made, development has continued and improvements have been made, which have enabled the Board to extend the limits of the ground conditions in which it can efficiently construct shafts and also tunnels with boring Machines.

Jan 1, 1976

By W. D. Blackburn

If there is a single key to managing a mineral extraction company, it is the control of productivity. American labor costs, in general, tend to be in the range of 10%-15% of total costs. American coal mining labor costs, however, exhibit ranges of 30%-60% of total costs. Is it any wonder that the industry finds itself at a competitive disadvantage? When labor costs take as much as sixty cents of every dollar of revenue, there is little room for profitability. The American coal mining industry must set as a long range goal the reduction of labor costs to the 10%-15% range of total costs in order to be competitive.

Jan 1, 1986

By Roger J. Goodman, Don Riva

"IntroductionCrows Nest Resources Limited (CNRL), a wholly-owned subsidiary of Shell Canada Resources Limited, is nearing completion of its first coal project, located in southeastern British Columbia. CNRL shipped over 700,000 tonnes of thermal coal to foreign markets in 1982. With the completion of the metallurgical coal plant in December, 1982, shipments of both thermal and metallurgical coal will increase substantially in 1983 and will approach the anticipated operating capacity of 3.0 million tonnes in 1985. The Line Creek Mine lies some 25 kilometres north of Sparwood in southeast British Columbia (Fig. 1). The open-pit mine is located on top of Line Creek Ridge, with coal being hauled 16 km to the thermal and metallurgical coal preparation plants, situated adjacent to the already existing Canadian Pacific Railway. Most of the coal is moved by 108 car unit trains by CP Rail to coal ports in Vancouver, where it is loaded onto vessels destined for overseas markets. Some smaller scale car load shipments are moved by rail to contiguous markets in the Pacific Northwest. History The southeastern British Columbia area, known as the East Kootenays, is steeped in a rich coal mining heritage, dating back to the latter part of the nineteenth century. Predecessors of Crows Nest Resources Limited were instrumental in developing the rich coal reserves in the area. In 1887, William Fernie, a pioneer-cum-prospector recognized the potential of coal deposits in the East Kootenays. Spurred by the relentless push west of the Canadian Pacific Railway through the Crows Nest Pass area, Fernie recognized that it was just a matter of time before the steam locomotives provided him with his required market. That time arrived in 1897 when Fernie helped to form the Crows Nest Pass Coal Company and coal mining commenced at Coal Creek, near his namesake town of Fernie. During its almost 70-year history, this company produced over 48 million tonnes of steam coal and 8 million tonnes of coking coal. In 1965, the Crows Nest Pass Coal Company was re-named Crows Nest Industries, to better reflect its expanded interests into forest products, and it is the latter company which Shell Canada Resources Limited acquired in 1978. The extensive coal resources of Shell, in both Alberta and British Columbia, were rationalized into one group with the birth of Crows Nest Resources Limited to manage and develop the coal holdings."

Jan 1, 1985

By N. Voennann

Stillwater Mining Company operates an electric furnace at its smelter in Columbus, Montana to treat a Ni-Cu-platinum group metal concentrate along with secondary PGM bearing materials. Hatch Associates has designed several improvements to this furnace, which was originally built by others. Implementation of these relatively low cost improvements has resulted in substantial increases in furnace availability and capacity, along with reduced unit costs. ? The improvements included: ? Installation of water-cooled copper cooling elements to stabilize refractory wear and increase furnace life.- ? Improved furnace 'bindings, to enhance the furnace's structural integrity by improving the contact between the refractory and cooling elements, and by promoting tight brick joints resistant to matte or slag leaks. ? Adjustment of the electrode regulator to allow higher furnace power levels. ? Installation of an automated air-slide (aeration conveyor) feed system to evenly distribute the furnace feed in an insulating layer on the bath surface. This "black-top" practice reduces unit energy costs and makes available additional smelting capacity.- ? Electrode seals to reduce ingress of air that absorbs heat before exiting the furnace in the off-gas stream. The saved energy can be used to smelt additional concentrate. This paper describes the above furnace modifications, and the benefits derived from their implementation.

Jan 1, 1998

By Alessandro Molinari

In recent times, coke oven machines are acquiring a more prominent role in the coke making process. Apart from the traditional handling of the coal and coke flow, nowadays these machines are also deeply involved in all environmental and process control aspects. Paul Wurth coke oven machines have been developed by Schalke to meet the most recent requirements in terms of emissions control, automation, instrumentation, operability and maintainability. In CSP, Ceará, the new coke making plant represents the status of the art of the technologies applied to the whole coking process; starting from the Coke Oven Batteries and the Gas Treatment Plant developed by Paul Wurth up to the Coke Machines supplied by Schalker Eisenhütte, whose technology is now part of Paul Wurth coke making products portfolio. Present paper describes the plant configuration focusing on Coke Oven Machines and the key factors which are guarantying the success of the project.

Aug 16, 2017

By Diego José Inforzato

Hot tensile data were correlated with creep data, in Aluminum Alloy AL7475-T7351, as part of a broader research program, aiming at the validation of a methodology that proposes an equivalence between the two kind of results, for metallic materials in general. The methodology is based on a criterion that establishes correlation among the following parameters from each test: the strain rate, ultimate tensile stress, and time to reach the ultimate tensile stress, in tensile tests, are equivalent respectively to the: minimum strain rate, applied stress and rupture time, in creep tests, for a given test temperature. The present material was tested at 3 temperatures: 133,166 and 193ºC, using 3 nominal tensile strain rates in the hot tensile tests: 3.2x10-6, 1.6x10-4 and 6.4x10-3 s-1 and 9 applied stress levels in the creep tests, varying from 140 to 400 MPa. The conversion of the hot tensile data to creep-like data allowed performing the analysis of all the results together according to the traditional creep relations proposed by different authors, namely: Norton, Arrhenius, Zener-Hollomon and Monkman-Grant, with the determination of the corresponding parameters in each case. The equivalence between hot tensile and creep data is also confirmed for this aluminum alloy.

Aug 8, 2018

By Adrian Gygax, Sarah Gaib, Rod Kostaschuk

The British Columbia Ministry of Transportation and Infrastructure (Ministry) recently completed a slope stabilization project at Ten Mile Slide on Highway 99. The highway is an essential part of the road network connecting the British Columbia (BC) coast with the interior of the province. The landslide was first identified in the mid-1980s and has retrogressed more than 250 m upslope since then, leading to continual and expensive repairs to the highway. The Ministry engaged BGC Engineering Ltd. (BGC) and their structural sub-consultant Gygax Engineering Associates Ltd. (GEA) to develop a stabilization scheme that would halt the slide with an acceptable level of residual risk. The design required careful consideration of construction stages and the stresses induced in the structural components as the slide movement was progressively stopped as construction advanced. Four stabilization design options were shortlisted with the preferred option selected in Fall 2016. The selected solution comprised the construction of five rows of post-tensioned soil anchors upslope of the highway and a tied-back concrete tangent pile retaining wall for the roadway itself as well as reconstruction of the highway alignment, grade and drainage through the slide. Works were installed by top-down construction within defined time allowances stipulated in the contract. Significant engineering was undertaken beyond standard design processes for this complex project, such as comprehensive geotechnical investigations, aerial and terrestrial laser scanning and change detection analyses, pre-production test anchors, detailed geo-structural numerical modelling and due diligence activities to validate and optimize the design. The stabilization works have been very successful with the slide response being as predicted and the highway operating again as full two-lane service.

Oct 1, 2022

By David Corke

The paper presents the development of Federation of Piling Specialists (FPS) calculation of rig track loading, the production of the Building Research Establishment document “Working platforms for tracked plant” (BR 470), working platform testing and considerations of rig stability. The paper also discusses the importance of rigorous and well documented procedures and proposed future development of rapid working platform testing methods. Topics presented include the fundamental requirements and principles involved in the testing, design and maintenance of working platforms, rig track loading, the BRE design method and site testing analysis. The paper stresses the need for testing and design processes to be robust and simple and quick to perform as there is often little time between the award of a contract and the need to start work on site. Also, it is vital that all aspects of working platform design can be carried out with information that is available to the platform designer. Developments in the UK over the last two decades have resulted in improved quality and safety of working platforms that will hopefully be further enhanced as design and testing methods continue to improve.

May 1, 2022

By Jack Taggart, Chris Barker

Pile load testing strategies for large infrastructure projects and multi-phase building developments have historically justified cost and programme benefits for undertaking advance preliminary and working pile load testing. However, more recently piling and pile load testing strategies have included assessment of the embodied carbon to understand and present the carbon savings that can also be achieved. This paper gives an overview of the factors contributing to carbon and emissions in the construction of bored pile foundations and presents the methodology taken in assessing embodied carbon as part of the pile load testing strategy for a multi-phased building development in London. Potential embodied carbon savings for various bored pile types and load testing strategies are discussed alongside alternatives and other considerations including pile re-use and carbon offsetting to inform continual improvement for future projects.

May 1, 2022

By C. Roos, K. Jetmore

Developing a strategic underground mine plan is challenging and investigating multiple scenarios may take weeks. This process can be sped up using the Theory of Constraints to isolate the bottleneck mining activity and simplify the mine schedule process. This paper presents a technique to apply the Theory of Constraints to test multiple cutoff grade scenarios in Mineable Shape Optimiser and quickly produce many high-level production-based schedules that can be easily interpreted using stope-by-stope graphs, the Hill of Value, and through incremental return analysis.

Mar 2, 2022

By C Zschiesche, alam, A Abadias Llamas, A K

An integrated experimental and thermodynamic modelling study of the phase equilibria in the FeOFeO1.5- SbO1.5-SiO2 system in equilibrium with liquid Sb and Sb-Ag metal has been undertaken to develop thermodynamic model of the Na-Si-Fe-O slag system with S-Sn-Sb-Pb-As minor elements based on the experimental investigation of the selected sub-systems. New experimental phase equilibria data at 575–1600°C were obtained for this system using high-temperature equilibration of synthetic mixtures with predetermined compositions in sealed silica ampoules, Fe3O4 basket in sealed silica ampoule, or Re foils, a rapid quenching technique, and electron probe X-ray microanalysis of the equilibrated phase compositions. Experimental results on phase equilibria in the Fe-Sb-Si-O+Sb metal system obtained helped to produce initial set of model parameters in the slag. The primary phase fields of quartz/tridymite/cristobalite (SiO2), 2 high-SiO2 immiscible liquids, olivine (Fe2SiO4), wustite (FeO1+x), spinel (Fe3O4), schafarzikite (FeSb2O4) and valentinite/ senarmontite (Sb2O3) were identified in the binary Sb2O3-FeO, Sb2O3-SiO2 and ternary FeO-Sb2O3- SiO2 systems. Further refinement, particularly the distribution of excess Gibbs energy among the ‘FeO’-Sb2O3-SiO2 and ‘FeO1.5’-Sb2O3-SiO2 interactions, required the study at more oxidising conditions. Oxygen potential was increased using an inert metal (Ag) rather than using the gas flow due to the high volatility of Sb-containing gaseous species. Liquid Ag-Sb alloys with low concentrations of Sb of a few percent were used. At these conditions, the concentration of AgO0.5 in slag was below 1 mol per cent, which had a small effect on observed phase equilibria in the system. In addition, important information on the solubility of silver in slags is produced, which can be valuable when treating electronic recycling materials or primary silver-containing ores through the Pb process. Two main areas were addressed: the spinel-tridymite boundary (40–70 per cent SiO2 in slag) and spinel liquidus near 15 per cent SiO2 in slag. This allowed to deconvolute the separate contributions of the FeO-Sb2O3(-SiO2) and Fe2O3-Sb2O3(-SiO2) systems.

Jun 17, 2024

By B Taylor, S Evans

Bulk explosive technology for underground mining has not seen any significant technological advances since the widespread transition from ammonium nitrate fuel oil (ANFO) to ammonium nitrate emulsions (ANE) commencing in the 1980s. The in-hole energy profile that conventional ANE systems deliver is limited by the physics of chemical gassing and simple control systems. This compromises the range, precision, and accuracy of energy delivery into the blasthole, and in some cases limits the length of charge that can be delivered. Orica’s 4D™ bulk system removes many of these constraints, enabling better blasting performance across all underground mining methods. This paper reviews work completed at three mining operations across Australia, the United States, and Chile with a focus on how this system can improve mining operations and deliver sustained commercial and productivity benefits into the future. These benefits include improved ore recovery, reduced dilution from waste rock, and reduced overall explosives consumption. This paper also reviews how this new technology can be applied for planning future mining operations.

Sep 1, 2024

By Andrew J. Petruska, Rik Banerjee

This study explores implementing a machine learningbased system to generate a 3D surface repre- sentation of the roof and support straps in the mine. Event cameras have been chosen for their performance in high-dynamic-range lighting conditions and for their low latency. To enable automated drilling and bolting, 3D vision using eventbased cameras has been developed. A ground-truth set is created using two, time-synced event cameras and a LiDAR camera. These sensors are used to construct a ground-truth dataset of corresponding event- camera images and surface maps from the LiDAR. The network is tested with stereopairs of event images and produces a depth image with ±5 mm RMS error on average across 1000 test images.

Feb 1, 2024

By S. Simske, K. Boakye, D. Winters

The application of digitization to operations and logistics is commonplace. From advanced data analytics to intelligent networks, digitization offers tremendous opportunities to create value, raise the efficiency of production processes, and reduce emissions. Several manufacturing industries have already implemented solutions to good effect by using digitization. Mining companies, for example, are using historical data about equipment health to predict potential failures, while aeronautics and automotive companies are using robotics and end-to-end digital twins to improve their design and production processes. Not surprisingly, first adopters of digitization in many industries have gained an edge over their competition. The cement and aggregate industry can better manage the enormous energy consumption, rising cost challenges, inefficient uses of raw material, logistic problems, emissions, and overall process complexity that are inherent in their operations by doing the same. This paper presents the results of a literature review and analysis and conveys the challenges for adaptation and implementation of digitization and artificial intelligence (AI) in the cement and aggregate production industry.

Mar 2, 2022

By Michael G. Batten, Brian D. Keaney

]The Virginia Department of Transportation (VDOT) and the harbors on the James River routinely use precast concrete piles founded in the Yorktown formation to support bridges and other coastal structures. However, axial pile resistances for large diameter piles in this area have been historically overestimated on past projects. This may be due to a common assumption that very large unit end bearing resistance will be developed for a large diameter displacement pile that is driven a significant depth. This assumption is integrated in the Nordlund (1963; 1979) method which is commonly used to estimate axial pile resistance for bridge foundations. A static and dynamic pile load testing program was implemented as part of the Hampton Roads Bridge and Tunnel Expansion project in Norfolk, VA in the James River. A primary objective of this program was to calibrate an axial resistance calculation method against the measured load test results. A method developed by Eslami and Fellenius (1997) that uses CPTu data directly was effective at calibrating to the measured load test results, and allowed for clearer interpretation of the unit resistance values than indirect, semi-empirical methods that require interpretation of soil friction angle and undrained shear strength.

Sep 8, 2021

By Jeffrey C. Schuh, Logan Bloemer, Daniel P. Dietzler

Over the past 30 years, the authors have encountered numerous projects where recognizing the geology, soil properties and groundwater conditions, and considering alternative construction techniques have promoted efficient and cost-saving construction. The construction documents for these projects, produced by various engineering firms, provided basic information on geotechnical conditions. The authors became involved in each project either because there was a problem during design or construction or, as a contractor, won the project because they saw a value engineering opportunity to take advantage of the geologic setting of the project to design and build alternatives to what the designer depicted. Understanding the geologic setting is critical before planning and designing begins. Being able to work with the geology and the materials on site is preferred before specifying more costly and complex solutions, which often require the importing of materials and adherence to unnecessary and/or inappropriate specifications. Failing to understand the geology or not knowing all the techniques available for construction can lead designers to develop solutions that could be inappropriate. This paper presents several examples of value engineering and project performance enhancements developed through knowledge of basic soil mechanics and implementing innovative solutions. History and Background Most people attend DFI meetings, present their experiences, listen to others, and read articles and papers with the hope they can learn from others. Geotechnical engineers and contractors often interface with others in the execution of projects who have, at best, a rudimentary knowledge of geology and soil mechanics. Of course, there is a need for architects, bankers, and regulators, etc., but they typically do not have much interest in the nuances of geotechnical engineering, which relies on both art and science. Thus, significant time is spent educating counterparts in the need for comprehensive subsurface investigation programs and the intricacies of construction in the “dirt,” as they typically refer to soil and rock.

Jan 1, 2019