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By M Dean, M Nehring, P Knights, M S. Kizil

Integrated continuous mining techniques such as fully mobile in-pit crusher and conveyor (FMIPCC) systems offer inherent labour, energy and environmental benefits to deep pit metalliferous mines. However, before such systems become commonplace, a number of barriers must be overcome.This paper outlines a number of commonly perceived barriers to FMIPCC application, together with a number of suggested solutions. The paper advances a design approach for specifying FMIPCC systems for deep pit metalliferous applications. A novel FMIPCC configuration is advanced using a hydraulic excavator in backhoe configuration. Because of the requirement to minimise belt extensions, a mine planning approach is presented based on a series of parallel and radial belt conveyor moves.The FMIPCC system does not fully replace truck-shovel systems. In the proposed mine plan, sinking is undertaken with truck-shovel systems using a series of box cuts, whereas pit ‘widening’ activities are accomplished via the FMIPCC system. Because of inherent differences in mine sequencing, the net present value derived from the FMIPCC mine will differ markedly from that derived from traditional, nested-pit, truck-shovel mining approaches. Therefore, any comparison of the FMIPCC and truck-shovel approaches must take into account radically different mine planning approaches.CITATION:Dean, M, Knights, P, Kizil, M S and Nehring, M, 2015. Selection and planning of fully mobile in-pit crusher and conveyor systems for deep open pit metalliferous applications, in Proceedings Third International Future Mining Conference, pp 219–226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

The effectiveness of three different types of longwall chock under the three different types of geological conditions worked recently is outlined. Some provisional analyses of the variation of chock load under the shale roof con- dition are briefly discussed and some problems and solutions of gateway and road- head support outlined.

Jan 1, 1974

By P Cavieres, R Dunlop, S Gaete

El Teniente Mine started the exploitation of the primary rock in the beginning of the 1980s decade, using caving methods. Since the beginning the mining activities have induced seismicity including some occasional rockbursts. Owing to the relevant damages, the mining operations were stopped in some production sectors. This paper describes the concepts that have been used in order to control the induced seismicity based on the strategies for controlling the rockmass breaking process, which depend on mining parameters. It also presents the main concepts applied in the Teniente Sub6 sector design and the experience collected during its sector exploitation.

Jan 1, 2000

The mining industry is quite often faced with declining selling prices for its products in the face of rising prices for the input cost resources that it uses. Blasting is a key activity within the mining system and has a vital role to play within the Mine to MillTM concept. It is therefore important that blasting makes a positive contribution to mine profit and productivity. There are several variables involved in considering the profitability and productivity of blasting. The rock types and structures, the bench height, the blast hole drill rig specifications, hole diameter, spacing and burden, explosive loading and initiation and blast size fragmentation. Productivity accounting is a methodology which is used elsewhere to give additional insights into the productivity and pricing factors that drive the financial performance of a business. Miners know intuitively that productivity and pricing influence costs and profit, but only with productivity accounting can the dollars involved be calculated. Drilling and blasting are part of a chain of unit operations in a mine. For an owner-miner, drilling and blasting would be considered as cost centres and a productivity accounting cost model approach would be relevant. On the other hand a contractor is likely to consider drilling and blasting as a profit centre, in which case a productivity accounting profit model approach would be appropriate. Both of these will be explained. The paper provides a basic outline of deterministic productivity accounting and demonstrates its application to blasting. Drilling and blasting data from a mine was obtained for a two-month period. The change in productivity and prices was calculated to obtain the dollar contributions from them towards the change in cost. It was determined that although there had been productivity dollar gains these were offset by larger pricing dollar losses, the net effect being that total drilling and blasting costs increased. The productivity accounting analysis gives the facts and the mine is in a position to establish priorities based on knowing the dollar contributions of each input used.

Jan 1, 2001

A series of petrological studies were carried out on the characteristics of alteration and mineralisation in mainly structural-controlled (Deep Star, Meikle, Deep Post) and predominantly lithological-controlled (Post-Betze-Screamer and West Leeville) gold deposits in the northern district of the Carlin trend, Nevada. Alteration and mineralisation in these deposits are hosted in a sequence of calcareous clastic units of the Devonian Popovich Formation, into which have been emplaced a number of Jurassic intrusions, and syn- to post-mineral Eocene dikes. Four hydrothermal events have been recognised in these deposits: an initial Devonian base metal system and early diagenesis; a Mississippian stage of alteration in conjunction with burial metamorphism; contact and hydrothermal alteration and base metal-gold mineralisation associated with the emplacement of the Jurassic intrusions; and a Carlin-style gold system related to Eocene magmatism.

Jan 1, 2004

By J Seppelt

The Kanmantoo Copper Project is owned and operated by Hillgrove Resources Limited and is situated in the Adelaide Hills region in South Australia. Mining in the area has taken place off and on over the last 140 years to recover metal from both copper and lead-zinc ores. This paper focuses on the commissioning, ramp up and future outlook for the copper concentrator at the Kanmantoo Copper Project with major focus on issues encountered and operating performance achieved to date.CITATION:Seppelt, J, 2012. Commissioning of the Kanmantoo Copper Concentrator, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 127-136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Laros T, Schoenbrunn F

Deep paste thickeners have been proven capable of consistently producing medium to low slump material for disposal without the need for filters. However, proper design of the entire system is critical for a paste project to he successful. Some of the factors that must be carefully considered in design of a paste system include thickener sizing, tailings inipoundineni design, underflow pumping, and control system.

Jan 1, 1998

At moderate depths this question is of relatively small importance, but at depths over 2,000 feet it becomes a matter of some consequence. The rate of increase of temperature with the depth varies in different localities, but as a rough average we may take it to be about 1° Fahr. for every 50 feet of depth. The variation of temperature of the earth's surface from summer to winter penetrates to a comparatively shallow depth. At 50 feet the variation becomes practically insensible, and the temperature of the strata will be about the mean temperature at the given locality, from 60° to 75° F. in this country or the comfort of men working in the mines it is desirable to maintain a temperature of about 70° F. in the workings, or approximately the temperature of the strata near the surface.In order to obtain some idea of the magnitude of the undertaking involved in cooling a mine, I have examined the effect of placing in a long drive an apparatus by means of which we can abstract heat at a uniform rate from the drive, keeping, thetemperature nearly the same at all points of the drive at any given time.The lowering of temperature 70 F. at any distance feet from the centre of the drive (treated as a cylinder of the same sectional area as the actual drive), after an interval of time days from the commencement of the operation is given by the formula...

Jan 1, 1907

By J Ferreira

To speed up multivariate geostatistical simulation it is common to transform the set of attributes into spatially uncorrelated factors that can be simulated independently. One decorrelation method is the method of minimum/maximum autocorrelation factors (MAF), where a two structure linear model of coregionalisation is assumed. The transformation decorrelates the theoretical model exactly, but the actual data are only approximately decorrelated. The MAF transformation can therefore be seen as a special case of a non-orthogonal approximate diagonaliser of a set of symmetric matrices. A more general approach for approximate joint diagonalisation (AJD) has been developed in the context of blind source separation. For these AJD algorithms no assumptions are made beyond symmetry of the individual matrices and so they can be applied to a family of experimental semivariogram matrices. In their application there are no restrictions on the number of structures in the linear model of coregionalisation (LMC) thus removing one of the conditions placed on the subsequent modelling of the spatial structure of the factors. In this paper the general background for the U-WEDGE AJD method is presented. It is shown that the U-WEDGE method achieves better spatial decorrelation than the MAF method. The factors derived from U-WEDGE are simulated using conditional turning bands simulation and then backtransformed to attribute space.

Sep 26, 2011

By D J. A Van Zyl, J C. Cunning

Technological advances associated with the expanded application of paste technology in underground mine backfilling are now stimulating an interest in the disposal of process tailings as paste in the surface environment. Concurrent with the development of alternative surface tailings disposal practices is the requirement to fully understand the consolidation behaviour of tailings in paste form, and to relate this understanding to the significant body of data and operating experience from decades of study of the performance of hydraulically placed tailings. One effective method for demonstrating the benefits derived from handling and placement of tailings as paste is to review tailings slurry consolidation theory from the perspective of the changes which take place in the material as it makes its transition from a loose slurry to a dense, stable deposit resulting from managed thin-layer deposition. For a typical process tailings, an example is provided which illustrates the effect which mechanical dewatering has in accelerating the consolidation process and thereby providing a range of benefits from the perspective of surface disposal. Increased rates of filling (rise), expanded use of upstream embankment construction methods and elimination of impounded surface solutions are some quantifiable benefits which can be assembled on a site-specific basis to allow for valid comparisons with more traditional approaches to tailings disposal.

Jan 1, 1998

By B Wu, B W. Lei, B J. Duan

When a coalmine fire occurs, it is crucial to judge the developing trends inside the fire area by analysing the changes of gas concentration in order to formulate the proper rescue measures. At present, few researchers have focused on the relationship between the changing trend of gas product and basic characteristics of fire in the coal fire extinguishing process. To study the relationship of basic characteristics of coalmine fire during the extinguishing process, an experimental platform for coal combustion in a confined space was built, and gas production, flame image and coal temperature during the extinguishing process were monitored and analysed by an online continuous gas analysis instrument, camera and thermocouple. Research shows that during the burning phase of the coal sample in the confined space, the flame zone decreases gradually due to insufficient gas supply. The size of the flame zone fluctuates and shares a positive correlation with CO concentration, while sharing a negative correlation with O2 and CO2 concentrations. Then, in the extinguishing phase, the increasing rate of CO2 concentration and the decreasing rate of O2 concentration both decrease gradually, but CO concentration would rise for a period before it eventually decreases. Coal temperature continues to rise in the open flame stage and does not go down until the flame is extinguished.CITATION:Lei, B W, Wu, B and Duan, B J, 2015. Experimental study on extinguishing characteristics of coal fire in confined space, in Proceedings The Australian Mine Ventilation Conference, pp 279–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By D Sibthorpe

The employment of a tunnel boring machine (TBM) is the default delivery method for the realisation of traffic, utility and primary resource underground space worldwide, with hundreds of kilometres completed safely each year. This is not yet the case for the mining sector in Australia, specifically underground coal mining. The safety advantages of TBM delivery when compared to New Austrian Tunnelling Method (NATM) delivery, or that of drill and blast, remains unrealised.With coal access drifts ranging between 1000?m and 3000?m in length, the construction of these facilities using TBMs could be done in a fraction of the time when compared to current practice. TBM world records currently stand at 435?m/week or 1600?m/month for the 7.0?m to 10.0?m range. Resource owners and developers should embrace the opportunity to deliver access to their orebodies in only a few months, excluding machine assembly and disassembly time.There are challenges in utilising TBMs for construction of Coal access drifts, such as; TBMs generally being bespoke design, maximising capital efficiency for drift development, and geotechnical variances between projects. This paper explores safer and more cost-effective options. This paper also provides detail of how the configuration within a completed drift could be optimised to ensure all site specific needs are met with regard to future use of the drift. The paper also includes descriptions of the engineering solutions that are available for physical and atmospheric challenges specific to coal drift applications and how the TBM manufactures are adapting to the regulatory requirements are also covered.Due to downward pressure on high cost bases and ever increasing safety requirements the popularity of TBMs in the Australian mining sector can be expected to increase and eventually become the default delivery method for coal drift construction, building them cheaper, faster and?safer.CITATION:Sibthorpe, D, 2014. Coal drift construction by tunnel boring machine, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 671–682 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

Jan 1, 2004

By L Y. Yang, Z Wang

This work presents the fundamental properties of CITIC magnetite concentrate and its performance in pelletising and sintering. CITIC concentrate has been widely used in pelletising to produce pellets for blast furnaces. It is also used in sintering to benefit from its sintering performance. CITIC concentrate has excellent balling properties owing to its size distribution, particle surface properties, large specific surface area and balling index, leading to strong green pellets and product pellets. When used in sintering at appropriate levels, sinter bed permeability improves, productivity is increased while coke consumption reduces, and sinter strength improves.

Nov 8, 2021

By D Carroll

Mining of the zinc, lead and silver deposit at the Broken Hill Southern Operations site has been occurring for over 100 years. As a result of this, a significant amount of high-grade ore is now taken from narrow remnant pillars left between old stopes and zones of previously mined ground. Stopes have been filled with either hydraulic fill (also known as ‘sandfill’), cemented hydraulic fill (cemented sandfill), waste rock backfill or a mixture of these fill types.In the last ten years, there has been considerable success mining through narrow pillars where sandfill is exposed in the development face and/or walls using a ‘shell’ support regime, wherein a layer of bolted mesh is sandwiched between two layers of sprayed fibrecrete (25 mm fibrecrete, then mesh and bolt, followed by a final 50 mm layer of fibrecrete). Shell support is also used in very poor, broken, relaxed ground conditions and in areas filled with cemented fill (sandfill with a minimum four per cent cement content).The next stage of innovation has been to develop a technique for mining through old stope voids filled with uncemented sandfill, known locally as ‘contours’ (old cut-and-fill working), an activity where unconsolidated sandfill can run at the face and from the backs. The challenge is to prevent exposed sandfill in the face and the backs from failing before it can be supported.To achieve this, the Southern Operations mine has implemented a technique in which 6 m long spiling bars are used to strengthen and stabilise the sandfill in front of the face. The hollow steel bars are driven in around the heading perimeter in a closely spaced pattern then pumped full of grout. The bars and the grout stabilise the sandfill in front of the face, preventing it from failing into the drive during excavation and prior to further support being installed.A final support system consisting of shotcrete, mesh, bolts and steel girders is installed as excavation progresses. Both the initial and final support systems are essentially passive support systems designed for a low-stress environment (as the stress originates mostly from the mass of unconsolidated sandfill).This process is slow and labour intensive. Fifteen separate cycles of people/machinery are needed to progress one equivalent heading cut (compared to six for a standard fibrecrete- and bolt pattern-supported rock face heading). This slow pace introduces scheduling challenges, but the process opens up parts of the orebody that were previously uneconomical to mine.CITATION:Carroll, D, 2014. Mining through sandfill using spiling bars, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 95–100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By S Harrison

Work health and safety duties around Australia include duties to manage psychosocial health and safety (mental health) of workers engaged by businesses or undertakings and of other persons impacted by the operations of the business or undertaking. Persons conducting a businesses or undertakings must develop systems of work and policies and procedures for ensuring, so far as is reasonably practicable, the safety and health of workers and other persons. Officers have a duty to exercise due diligence and to ensure effective systems are developed, implemented and resourced. The developed systems will only be effective with worker’s co-operation and engagement. The duties placed on workers by work health and safety laws are an important part of the safety matrix of obligations. Supervisors and Leaders are workers and they play a critical role in delivering health and safety outcomes. To deliver these health and safety outcomes with respect to psychosocial safety Supervisors and Leaders need to understand their obligations and have a framework to use to assist them in understanding what workers require and what steps need to be taken to meet their duties. They also need to take steps to assist those workers that they supervise to meet their duties.

Apr 16, 2024

By D Kentwell

This extended abstract and associated presentation provide a series of real examples of the complex interactions between the numerous input parameters, both geological and mathematical, that are required for resource estimation. Many of these parameters can contain a large degree of uncertainty at the initial resource stage. The resource tonnages and grades at economic cut offs of some types of deposits are relatively robust to these initial uncertainties while others exhibit significant sensitivity. In some cases, changes in parameters can result in counter-intuitive outcomes. Grades and confidence levels are inseparable; as the parameters change the confidence changes and so does the grade estimate. The extended abstract and associated presentation also discuss the question of whether or not a single solution is still an acceptable outcome for an estimate or if even a set of simulations based on a single fixed set of parameters is acceptable.CITATION: Kentwell, D, 2018. Sensitive dependence on initial conditions in resource estimation, in Proceedings Complex Orebodies Conference 2018, pp 28–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By D A. Sketchley

The Merlin Zone, a 2008 high-grade Mo-Re discovery, is a part of the Mount Dore Deposit in the Eastern Succession of the Mount Isa Inlier in Queensland, Australia. Hosted by carbonaceous metapelites and phyllites, the Merlin mineralisation comprises molybdenite veins, breccia infillings, stylolitic fracture fillings, and disseminations. Because rhenium is geochemically similar to molybdenum and commonly associated with it, global production of rhenium has been mostly a by-product of molybdenum refining. The high-grade rhenium in the Merlin Zone is an exciting discovery that is expected to become a direct source of rhenium. At the time of discovery, quality assurance (QA) procedures for rhenium were not in place at the Merlin Zone; therefore, they needed to be developed.The Merlin Zone was discovered using reverse circulation drilling, which led to concerns about molybdenite loss due to poor sample recovery. The twinning of the discovery hole with diamond core demonstrated a two-fold increase in molybdenum grade over several tens of metres. Consequently, the resources of the Merlin Zone were defined using assays from diamond drill core.Early analytical work, which was initially done only for molybdenum, comprised geochemical analysis with an aqua regia digestion, which have poor precision and can be biased low. Although initial testing for rhenium used similar procedures to those for molybdenum, a scarcity of commercial rhenium reference materials led to a validation process using neutron activation analyses and different digestions. This resulted in introduction of four-acid digestion assays, development of matrix-matched reference materials, and improvements to the quality of molybdenum and rhenium assays for reporting resources. Coarse and pulp duplicates were used to check for sampling bias and to ensure that levels of precision were adequate for the style of mineralisation and analytical methods. In addition, the direct and consistent geochemical correlation between molybdenum and rhenium provided another method for checking analyses.

Aug 22, 2011

By R Carreau

The results of a detailed acid rock drainage (ARD) prediction program were used to revise the waste rock segregation criteria at the Restigouche open pit mine. Waste rock at the site was predominately derived from altered volcanic rocks that hosted a massive sulfide lead/zinc orebody. The program assessed the five years of drainage chemistry from both the potentially acid generating and the non-acid generating waste rock storage facilities in addition to laboratory-based kinetic test results. Material-specific leaching characteristics including relative metal-release rates and neutralisation potential depletion rates were determined from 12 laboratory-based kinetic tests. Solid-phase analyses indicated that, although pyrite was typically the most abundant sulfide mineral in the waste rock, its abundance varied significantly as documented by total sulfur contents ranging from 4.0 per cent. Kinetic test results were used to establish revised waste rock segregation criteria based on total sulfur content and neutralisation potential. The revised criteria maintain that waste material with a total sulfur content 4.0 per cent as potentially acid generating. When present in sufficient quantities, ankerite provided an effective source of neutralisation potential for the range of observed sulfide oxidation rates. Kinetic testing documented that up to 6 kg CaCO3/t was ineffective at neutralising acidity in samples that contained >4 per cent S. The carbonate molar ratio measured from the humidity cells was adjusted to reflect the stoichiometry of the ankerite and applied as an NP/AP criteria for waste rock containing 0.1 <S per cent <4.0.

Jan 1, 2003

By P Jere

Mechanically coupled rock bolts encapsulated in cementitious or polyester cartridge resin grouts have been widely adopted for various underground rock reinforcement applications. Resin grouts are considered a superior product, however, both systems have their advantages and limitations, with the relative performance, quality installation cost and cycle time as the most notable parameters. Both applications have optimal rock bolt combinations and preferred ground conditions. Cementitious grouts are favourable for use with secondary deep embedment anchors. These are installed using various equipment with a series of autonomous tasks required to complete the installation cycle. The cartridge resin system can be utilised by a bolting or face boring rock drill to complete the full support installation cycle. This reduction in equipment changeouts mid-cycle generally deems it the more practical application and popular choice for primary support. Self-drilling anchors (SDAs) and hollow bolts have been a viable alternative to traditional rock reinforcement in variable and challenging ground conditions. Using a pumpable post installation grouting system, SDAs have proven to aid the quality of installation, but due to the additional equipment and cycle steps associated with application, the cycle time is increased. In recent years, fully mechanised bolting equipment designed to utilise a combination of self-drilling anchors and a thixotropic pumpable resin installed in a single pass has entered the market. This innovation is anticipated to deliver the advantages described above, with fewer limitations, and significantly improved development and rehabilitation rates. St Barbara Mining and Byrnecut Australia, supported by Master Builders Solutions, were first to conduct extensive trials and implement this rock bolting approach in an Australian hard rock underground mine and record the actual performance.

Mar 29, 2023