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By M Kizil

Mining Engineering Degree programs have traditionally had a practical emphasis and have been highly vocational in nature. However, over the years, there has been an increasing attention to the more scientific aspects of the discipline. More recently, the professional institutions, the industry and the community at large have placed increasing emphasis on the broader aspects of the professions: management, finance, humanity, environment and social issues. Notwithstanding this, there has been a continuing emphasis on the practicalities, and most Mining Engineering programs are still strongly vocational in nature. But employers of new graduates complain about the graduatesÆ lack of practicality and readiness for employment æat the sharp endÆ on the mine site.This paper briefly describes some of the more recent developments in the Mining Engineering Degree program at the University of Queensland that attempt to address the problem. Particular attention is paid to alternative learning programs, including applications of virtual reality, practical experience at the University Experimental Mine (UQEM), and the Undergraduate Site Learning Program (USLP).

Jan 1, 2002

The green field discovery of a two million ounce high-grade refractory gold ore deposit in the Indonesian Province of Sulawesi Utara, led Newmont to utilise its proven technical expertise in dry grinding and whole ore roasting to develop a 2000 tonne per day, 160 000 ounce per year operation in this remote and picturesque location.Located at an elevation of 250 in above sea level and ten kilometres to a deep water natural harbour, the hard rock open pit mine, process plant and infrastructure facilities were built to budget at a capital cost of US$132 million. The plant was commissioned with oxide ore, with the first gold poured in March 1996 and with refractory ore in January 1997. The operation rapidly met its production targets because of extensive forward planning and training programs developed for the local workforce. The presence of steep topography, fertile coastal plains, high rainfall, high seismicity of this location led to the decision to dispose of neutralised tailings in deep water off the coast instead of impounding tailings in a dam. This paper describes the development of the project and the challenges in developing a gold operation in a remote location which lacked infrastructure, the steps taken to ensure a smooth commissioning, and the selection of the workforce to operate a technically sophisticated facility.

Jan 1, 1997

By J Krahn

In designing climate exposed soil structures such as caps and covers over mine waste it is necessary to include the wetting and drying influences of the local climate in order to accurately predict the net water, vapour and oxygen fluxes across the ground surface and through the base of the covers. The most advanced evaporative flux modelling tools currently available to practitioners have been limited to rigorous one-dimensional models (ie SoilCover) or semi-empirical two-dimensional models (ie Hydrus-2D). It is common practice to use the rigorous one-dimensional evaporative flux model results to develop a surface boundary function that can then be applied within a saturated/unsaturated two-dimensional model. However, this is not an ideal situation and results in a further approximation of the real system being modelled. This paper will highlight the use of a new modelling tool, VADOSE/W, which brings existing, rigorously formulated evaporative flux theory into the familiar setting of a two-dimensional model. The model is enhanced for simultaneous two-dimensional oxygen gas transport analysis, which has direct application in the mine waste industry. A key focus of the paper will be addressing the limitations of one-dimensional analysis for cover systems on sloping and hummocky terrain.

Jan 1, 2003

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high-speed photography to better understand the mechanisms of fracture and fragmentation.CITATION:Fourney, W L, 2015. The role of stress waves and fracture mechanics in fragmentation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 27–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By D B, M A. Sares, D W. Coulter, D C. Peters

This presentation discusses NASA-funded research on the ability of hyperspectral remote sensing to map diagnostic acid rock drainage (ARD) mineralogy that adversely affects water quality within watershed and to determine the relative contributions of natural ARD sources of metals and acidity to that drainage. Ground-based reflectance spectroscopy, combined with water chemistry, is used to identify mineralogical and chemical variations throughout a watershed. Integrated with hyperspectral data acquired from airborne remote sensing platforms, such as the NASA Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, a methodology has been developed that should improve environmental assessments and tracking of impacts on and from drainages. Phase I of this project focuses on a drainage basin (Lake Creek), tributary to the upper Arkansas River in central Colorado, which is impacted by natural acid rock drainage from areas of high-sulfide hydrothermal alteration. This project builds upon research and inventory efforts by the Colorado Geological Survey (CGS) to identify hydrothermal alteration that is the primary source or is contributing to acidic and toxic drainage in Colorado. This presentation will cover ground and airborne hyperspectral remote sensing techniques and results and water analyses for seasonal high-flow and low-flow conditions in Lake Creek. Identifying correlations between mineralogy, especially mineralogy that can be identified through airborne remote sensing, and water chemistry is a key focus of this project. Of particular interest are low-pH iron phases such as jarosite, ferrihydrite, schwertmannite, copiapite, and transitional amorphous phases as well as AlOH phases from higher, although still acidic, pH environments which are observed to mix with the iron precipitates within the streams draining from the hydrothermal systems. Drainage in the Lake Creek watershed derives from the Grizzly Peak caldera (Oligocene), which exhibits extensive hydrothermal alteration. Alteration types include silicic, quartz-sericite, quartz-sericite-pyrite, advanced argillic, and argillic. By understanding the chemistry of a naturally impacted drainage and its relationship to the surrounding geology, the project goal is to allow more efficient and complete identification of such sources in mineralised terranes through remote sensing technology.

Jan 1, 2003

By N Bianco, D Drinkwater

The professional skills shortage is intensifying, and commentators are predicting a shortfall in supply of qualified professionals for the mining industry, ranging from thousands to tens-of-thousands by 2020 (Tuckwell, 2011; Scoble, 2011; Laurence and Hebblewhite, 2011). Human resources are already stretched, and university graduates arriving in the workplace are often moved rapidly into management positions where there is limited scope to develop their engineering proficiency. This process may well be developing excellent young managers, but our industry is producing fewer excellent young engineers (Munro and Tilyard, 2009). Many believe that it is engineering excellence that is likely to be the key to our industryÆs success in the decade to come. An innovative in-house graduate development program has been created by specialists at the JK Centre in partnership with two mining companies. This program, known as MetSkill«, has been running throughout 2012. Groups of graduates have had to identify a process plant optimisation opportunity and embark on a structured program of data collection and analysis, facilitated by a æteaching teamÆ of researchers and consultants from the Julius Kruttschnitt Mineral Research Centre (JKMRC) and JKTech. This group project culminates in a report-back session to senior company officials. Along the way, a series of short workshops and other activities provide opportunities to work on specialist skills, and support is also offered by senior technical specialists from the companies involved.This paper outlines key features of the MetSkill« program, along with a report-card on progress in 2012 and plans for further program development in 2013.CITATION:Drinkwater, D and Bianco, N, 2012. Developing minerals industry leaders by encouraging metallurgical excellence, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 287-290 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

Nippon Telegraph and Telephone Corporation (NTT) developed a new construction method (the M-2 method) that could drive a long, curved small-diameter tunnel (4>1.2 m) without human labor. This method employs the cast-in-place lining system, using quick-hardening resin mortar, so that it can greatly increase the driving distance and execute both long distance driving (longer than 500 m) and curved driving with a radius of curvature of 200 m. Furthermore, the central control system with a mini-computer in a vertical shaft enables all work in a small-diameter tunnel, i.e., excavation, lining, and transportation of excavated soil and materials, without human labor. NTT conducted several field tests and a Practical Application Test (P.A.T.) under a public road bearing great traffic. Good results were obtained and the practicability of this method was demonstrated. Therefore, from now on, NTT will apply this ii-2 method to drive telecommunication cable tunnels in urban areas. This method will also be applicable to constructing public tunnel facilities, such as for water, sewage, electricity and gas.

Jan 1, 1987

By Williams C

A stibnite concentrate from Golden Spec (WA) was subjected to a series of tests involving high pressure cyanidation and pressure oxidation followed by conventional cyanidation. The concentrate, whose gold content was 18.1 g/t, yielded only eight per cent of the gold when leached directly by a standard 24-hour cyanidation test. The recovery was increased to only 15 per cent when pressure cyanided under the following conditions: ambient temperature, 2000 kPa oxygen pressure, two hour retention time and 30 per cent w/w solids pulp density. This poor response to pressure cyanidation emphasised the refractoriness of the material. Evidence of the fine distribution of the gold through the concentrate, from measurements of the particle sizing distribution and the gold analyses of the individual fractions, also suggested that this concentrate was highly refractory. Pressure oxidation of the concentrate at elevated temperatures followed by cyanidation yielded recoveries as high as 94 per cent. However a preoxidation treatment under the following conditions was necessary: 230¦C, 2000 kPa oxygen pressure for a period of four hours.

Jan 1, 1992

Block caving is the lowest cost underground mining method but it has relatively high risks and a high up-front capital and development cost. It has application to large, often lower-grade orebodies where high production rates can provide good returns on the investment. However, it has a range of technical risks that are peculiar to block caving and the usual financial, political and environmental risks that may be exacerbated by the long lead-in times associated with the development of a block cave operation. With initial development costs that may be $100 M to $1000 M when the building of a treatment plant is also required, it is obviously important to minimise and manage the risks. In a greenfield project, commitment to a substantial proportion of the capital expenditure may be required to gain access to the deposit, and the decision to proceed at this stage would be based very largely on interpretations of drill hole data. In established mines the data may be supplemented by geological mapping and past experience, etc. The quality of this data is critical and yet it is frequently degraded through poor techniques and avoidable omissions. The final decision to proceed would be assessed on projected commodity prices, mining capital and operating costs, dilution and run of mine ore grades. The latter will vary over the life of the project and these can be estimated with drawdown or draw control modelling techniques. In this modelling, there are further risks in the assumed modelling parameters or that the modelling technique may not be applicable or appropriate. The paper addresses the most critical technical and operational risk areas and provides some practical precautions that can be taken to reduce these and improve the reliability of the geological and geotechnical models.

Jan 1, 2000

By R A. Pax

Electrostatic separation is a core requirement for the beneficiation of mineral sands suites to provide valuable product. Although the basis of electrostatic separation has been understood for some time, the details required to be able to calculate the metallurgical performance of a separator has not previously been achieved from a mechanistic perspective. Empirical models have had some success but require extensive test work. Traditionally, performance of an electrostatic separator is determined by careful experimental work using the target mineral suite. Although electrostatic separation was invented at the end of the 19th century, very little modification of the basic equipment occurred until relatively recently, with the addition of a plate electrode to aid separation. Previously, the author has presented results, calculated using finite element modelling (FEM), of the electric fields present in an electrostatic separator in various configurations. This paper will present some new mathematical modelling work, which uses the FEM determined electric field configurations but also incorporates some fundamental physical processes that provide insight as to the limitations and opportunities for this important separation technique.

Oct 5, 2011

By P Moser, P Schimek, F Ouchterlony

This paper summarises the findings of 27 model-scale bench blasts in magnetic mortar, which were conducted from 2011 to 2014 at the blasting site of the Montanuniversitaet Leoben.The aim of the study was the investigation of the influence of blasthole delay times in small-scale bench blasts on the face characteristics and cracking damage created in the surrounding rock, which affects the fragmentation in subsequent rows.The test specimens or blocks, which were produced out of magnetite concrete, were roughly 1:100 in scale to normal bench blasts. The confinement of the testing blocks at the sides and back ensured the similarity to normal bench blasts with regard to the wave transmission into the surrounding rock. The specimen contained three or four rows with five blastholes each and were shot row by row, with virgin (undamaged) material in row 1 and increasingly damaged or preconditioned material in the following rows.The tested delay times varied between 0, 28, 73 and 140 µs, which corresponds to 0, 0.4, 1.0 and 2.0 ms/m of burden.The evaluation of the material properties showed that the use of magnetite concrete eliminated the inhomogeneous behaviour of rock, but some unexpected differences of the individual production cycles were still detected.The characteristics of the bench after each blast was evaluated along three horizontal lines out of a 3D model of the bench face. The tested delay time sequences of the virgin (first row) and single preconditioned blasts (second row) produced more overbreak for longer delays, while the third-row shots resulted in a smoothened surface independent of the chosen delay.The introduced damage after every blast was evaluated by an observation of irregularities on the newly blasted bench face. The visible cracks at the top of the testing blocks were documented and divided into several crack families according to their angle, length and origin. The remaining block was broken out of the blasting site after blasting, cut into several horizontal and vertical slices and dye penetrant spray was used to visualise the cracks created. Some of the detected crack families showed an influence of the delay time. The calculated mean crack density and mean crack intersection density showed that longer delays resulted in a higher degree of damage.The fragmentation results were well reproduced by the basic three-parameter Swebrec function. The observed improvement of fragmentation in the second- and third-row blasts was linked to the preconditioning of the burden for the following row while blasting the actual row. With the exception of the simultaneously initiated blastholes, the blasts showed coarser fragmentation for the shortest delays, while the longest delays generated the finest fragmentation.CITATION:Schimek, P, Ouchterlony, F and Moser, P, 2015. Influence of blasthole delay times on fragmentation as well as characteristics of and blast damage behind a remaining bench face through model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 257–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Holcombe R. J, Dobos S. K, Little T. R

Blue amphibole-bearing rocks in the North D'aguilar Block of southeast Queensland occur either as relict pods and lenses within regionally extensive greenschist facies phyllites and schists or as blocks entrained in serpentinite-matrix melange. Epidote + crossite-bearing varieties predominate and formed under conditions consistent with underplating and high P:T metamorphism in a subduction-related tectonic environment. Neither lawsonite nor jadeite has been observed and metamorphic conditions are estimated at 380-4500C for pressures of 0.5-0.8 GPa. High P:T metamorphism occurred during the earliest stages of deformation and was superimposed upon protoliths of inferred Late Devonian - Early Carboniferous age, including mafic volcanics, tuffs and coarse volcaniclastic breccias as well as pelagic and henipelagic sediments, all of which have undergone varying degrees of over-printing to the greenschist facies. Greenschist facies metamorphism occurred during the second phase of deformation and was associated with the formation of mainly flat-lying or subhorizontal structures; it followed the cessation of subduction and occurred in response to either thermal relaxation during uplift or the imposition of regional heating induced by crustal thickening and/or synkinanatic granite emplacement. Uplift and cooling of the high P:T rocks was completed by 260-265 Ma and may have occurred in response to the same extensional processes which gave rise to the onset of rifting in the adjacent Esk Trough.

Jan 1, 1990

By M Yahyaei, P Knights, M S. Kizil, J Qu

Digital Twins (DTs) are transforming business operations across many industries through their accurate representations of physical entities enabled by IoT technologies.

Sep 1, 2024

By P C. Hagan, J Chen, S Saydam

Fully grouted cable bolts have been used in underground mining industry for more than 40 years and are becoming more and more popular especially when severe geological conditions are encountered, such as high stresses and large cross-section excavations. The axial performance of cable bolts are mainly relied on the load transfer process between the cables themselves and surrounding rock masses via grout annulus. Therefore, the selected grouts play a significant role in determining the reinforcement quality for underground openings. In order to better understand the mechanical properties of Stratabinder HP grout, which is one type of cementitious grouts commonly used in Australian underground coalmines, plenty of unconfined compressive tests are conducted on it. Following diverse standards, two different kinds of samples are prepared and tested with the w/c ratio ranging from 0.35 to 0.45. During the test important mechanical properties including uniaxial compressive strength (UCS) values, Young’s modulus, Poisson’s ratios and so forth are recorded. Based on experimental results, the effect of w/c ratio on the mechanical properties of Stratabinder HP grout is studied. Beyond that, influences of sample size on the failure mode, peak strength as well as residual strength of this kind of grout are summarised and analysed.CITATION:Chen, J, Hagan, P C and Saydam, S, 2014. Mechanical properties of cementitious grout serving in fully grouted cable bolting systems, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 269–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By M Fuchs

Roadheaders were introduced to mining and tunnelling in the early-1960s. Since this period their main field of application has been for roadway drivages in coal mines and for mineral production, for instance in coal, rocksalt, potash and gypsum mines. Their main field of application in tunnelling is in softer and partly friable rock formations, a suitable area for non-blasting excavation. However, in longer tunnel sections excavators with high ripping forces have replaced roadheaders in many situations. The main arguments against roadheaders have been and still are:a sharp increase in excavation cost with increasing rock strength and increasing abrasivity; and greater risks in conditions which have not been, or could not be, investigated to a sufficient extent. These arguments have, to a great extent, restricted practical roadheader application in production mining and in a lot of æstandardÆ tunnel projects. To address these limitations, factors which could make roadheaders attractive for such conditions and could overcome existing technological difficulties have been investigated. Extension of the economic field of application in hard rock was found to be the most important and the most effective step forward.

Jan 1, 2002

By C Rizos, A Ng

Land surface deformation can be caused by underground mining activities. The maximum subsidence normally occurs directly above the location of the excavation of the coal seam. In the case where the longwall mining technique is applied, the magnitude and shape of the subsidence bowl are constrained by the longwall structure (pillar). This paper describes the use of satellite radar interferometry for monitoring surface subsidence due to underground mining, as a cost-effective geodetic technique and complementary to conventional ground surveying techniques. This paper uses data acquired by the current generation of SAR satellites û the European ENVISAT and the Japanese ALOS û to monitor ground subsidence in the southern highland coalfield in New South Wales, Australia. An accumulated DInSAR subsidence mine map is produced using six successive ALOS acquisitions. The results are post-analysed with the aid of geographic information systems (GIS) and validated using ground survey data.

Jan 1, 2008

By B P. Wrench, N R. Steward, C Wu

A gold mine in southern China has transitioned from an open pit operation to a fully underground mine. An overhand mining method is used which requires the mined stopes to be filled with backfill having an unconfined compressive strength of at least 0.35MPa. Tailings from the process plant is deposited into separate flotation and Carbon in Leach (CIL) tailings storage facilities. The tailings has a high fines content and the thickener on site could only produce a dilute flotation tailings at a solids content of about 30 wt%. This resulted in two undesirable outcomes: the density of flotation tailings in the Tailings Storage Facility (TSF) was significantly lower than planned so that the TSF could not store the life of mine tailings and that the backfill product had to include a high percentage of manufactured aggregate and increased cement content to achieve the required strength. This paper presents results of a tailings study which identified that the flotation TSF would be capable of storing the remaining life of mine tailings if an amended backfill product made up of 100% of flotation tailings could be introduced. A 100% tailings backfill with the addition of 8% cement was developed by classifying the tailings and using the coarser fraction in the backfill. This backfill allowed 60% of the flotation tailings to be placed underground and only the remaining 40% in the flotation TSF. A new thickener was designed and installed to thicken the tailings and rheological testing of the tailings, using a closed loop pilot plant, provided parameters to upgrade the underground reticulation system to deliver cemented backfill to stopes throughout the mine and to deliver thickened tailings to the TSF. The revised design was implemented and has resulted in considerable cost savings. CITATION:Steward, N R, Wrench, B P and Wu, C, 2018. Optimisation of surface tailings storage and tailings backfill – a case study, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 454–464 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By N Steenkamp, L Furstenberg, W Cele, M Richter

Managing productivity and improving efficiency for a healthy return on capital employed have become key mining industry strategies under prevailing tough global market conditions. However, achieving this in a multisystem environment such as a mining operation can be daunting. The field of discrete event simulation offers some relief, giving engineering teams insight into multivariable systems and stochastic processes. It allows for integrated system thinking and domain expertise to be woven into project thinking fibre. Directed system optimisation and therefore improved efficiency becomes possible. Furthermore, capital discipline accrues from optimal upgrade investments. This paper illustrates the practical application of this approach by reviewing a typical case study for a direct shipping iron ore operation. Dynamic simulation was used to establish maximum processing plant capacity under varying material characteristics and identify capital-efficient upgrades for increasing production.The study started with descriptive statistical analysis of existing data. Discrete equipment and system capacities were defined, followed by static plant mass balance calculations to establish bottlenecks and overall static capacity. Equipment ‘uptime’ and ‘downtime’ analyses established system and overall plant availability and utilisation. From this information, a dynamic simulation model could then be developed and initially calibrated against actual plant performance to verify its robustness. Once confirmed to accurately represent existing plant dynamics, system capacity response to variable changes could be tested to ultimately determine maximum plant capacity. Additionally, plant optimisation was incorporated to arrive at optimal upgrade points. Maximum capacity and necessary upgrades were established as a function primarily of feed size distribution. Additionally, the interfacing effects of rehandling feed material to the final product grade and potentially to life-of-mine were established as important outcomes. The results of the study illustrate the value of using dynamic simulation models to realistically and cost-effectively increase throughput.CITATION:Cele, W, Furstenberg, L, Richter, M and Steenkamp, N, 2015. Capacity evaluation of iron ore processing facilities utilising dynamic simulations, in Proceedings Iron Ore 2015, pp 597–604 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By B Roach, P M. Ashley, B Hooper

Mineral occurrences of the Hillgrove Au-Sb-W district are hosted in late Palaeozoic polydeformed, hornfelsed metasediments and Permo-Carboniferous granitoids of the NewEngland Orogen. In excess of 204 individual occurrences have been identified to date with the mineralisation developed as strike extensive (>20 km of known veining) and potentially depth extensive steeply dipping fissures. These are contained within an elongate area measuring some 9 km by 6 km in surface dimensions. Recorded gold production of 720 000 ounces along with current resources in the order of 340 000 ounces highlight the significance of this district. Historical antimony production is estimated at in excess of 50 000 metric tonnes. Significant tungsten of over 2000 t in the form of scheelite has also been produced from the field. Mineralisation is developed in veins, vein breccias, sheeted veins, network stockworks and as alteration sulfide haloes to the main structures. The vast majority of fissures are subvertical and vary in widths of up to 20 m in places. Paragenetic studies have previously indicated that the earliest mineralising event was a scheelite-bearing phase of quartz veining. Subsequent phases of arsenopyrite-pyrite-quartz-carbonate veining were accompanied by gold and minor base metal sulfides. Alteration is typically sericite-ankerite-quartz. Overprinting stibnite-quartz veining with gold-electrum, aurostibite and arsenopyrite form an important subsequent phase. Veining can be inferred from historical records to extend for vertical depths of over 1 km.

Jan 1, 2004

BHP-Utah Coal Limited operates 33 draglines of varying sizes in the Bowen Basin of Central Queensland. The group's operations with draglines commenced in 1963 with the establishment of opencut operations at the then TPM Moura Mine and continued through expansion of that mine, the commissioning of the Utah Development Company Blackwater Mine in 1968, and the subsequent establishment of six (6) other large opencut mines, all in the general area over the next fourteen years. These operations generally commenced with boxcuts on the sub-crop at depths of 15 to 25 metres. Over the years, depths have increased so that average depths now are in the 45 to 50m range. It was soon realised that dragline operations would have to be supplemented with additional stripping equipment. In 1981, a symposium "45m and Beyond" was held in Rockhampton to assess the problems associated with such "deep" stripping. Subsequently, dragline operations have continued and although addi- tional stripping capacity has been added, in many instances, draglines have been used and are being used to dig depths greater than 45m, some- times as much as 65 to 70m.

Jan 1, 1989