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By Webster SS

This paper uses computer modelling tech- niques to compare and contrast anomaly patterns obtained with fluxgate (vertical field) and proton precession (total field) magnetometers at typical latitudes in northern and southern Australia. The use of these modelling tech- niques is suggested as an aid to magnetic interpretation and field examples are included from Tasmania and the Northern Territory.

Jan 1, 1975

By R Shrimali, P Rajmeny, L Shekhawat, A Joshi

Rampura Agucha open pit mine has successfully been excavated to a depth of 320 m, incorporating multistage working. The key to success is the implementation of presplitting as control blast measures at every stage of mining, including intermediate cut backs, in addition to the final wall. The major challenges encountered in establishing presplitting in the hang wall as compared to the footwall of the mine are:reversely dipping foliation, ie dipping into the hang wall itselfstriking obliquely at an angle of 20–30° with regards to the general strike of the pit wallthe presence of numerous geological planes of weaknesses like major faults, slips, etc.Control blast parameters like hole inclination, spacing and stand-off with buffer row were chosen initially from the literature survey and were subsequently fine-tuned by field trials to the mine geo-mining conditions of the hang wall. Electronic initiation used for trim blasts along with double presplitting in fault-affected zones helped in getting better presplit performance and resultant stability of the hang wall.CITATION:Rajmeny, P, Shrimali, R, Shekhawat, L and Joshi, A, 2015. Establishing the design parameters of a control blast for long-term stability of the hang wall at Rampura Agucha Mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 437–446 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By A Cranley, A Giblett, S Thacker

The Newmont Tanami Operations are located in the Northern Territory, approximately 550 km north-west of Alice Springs. The Granites process plant commenced operations in 1986 as a 300?000 t/a ball mill / carbon-in-leach (CIL) plant and has undergone numerous expansions between that time and the current day, with project-to-date gold production exceeding 6.5 Moz. Annual plant throughput has exceeded 2.8 Mt/a while processing a blend of open pit material and ore from the Callie Deeps underground mine, with annual gold production exceeding 400 koz. In 2013 the operation processed 1.8 Mt of underground ore for the production of 323 koz of gold.This paper reviews the operation and expansion of The Granites process plant since the mid to late 1980s with particular focus on the gravity gold recovery circuit. The Tanami ores contain significant levels of free gold, and gravity recovery has long been an integral component of the metal recovery process at the Granites plant. The results of ten years of gravity circuit performance analysis and optimisation are presented.CITATION:Giblett, A, Cranley, A and Thacker, S, 2014. Three decades of gold production at the Newmont Tanami operations, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 209–216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

Blasting is a common practice in mining whereby solid rock is fractured, using explosives, to a more manageable size. The effectiveness of blasting influences a number of downstream activities such as shovel digability, crusher throughput and mill throughput. As the cost of explosives is relatively low compared to milling costs (mainly due to power consumption), blasting practices can be optimised so that the downstream processes are made more efficient, and an overall cost saving made. This is the basis of the Mine to Mill approach. The effectiveness of the blasting is influenced by two main factors, the blasting practices used (eg explosive amount and type) and the geology of the area. As the geology cannot be altered, the blasting practices must be refined to create optimum blasting. Kalgoorlie Consolidated Gold Mines (KCGM) Fimiston operation, located in the heart of the Kalgoorlie Goldfields is the largest gold mine in Australia. Mine to Mill at KCGM has had varied success, with initial positive indications being lessened by a number of factors, including the increase in the amount of voids.

Jan 1, 2003

By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By M Zanin, E Chan, D Xu

An experimental design has been developed to investigate the relative influence of distinct pulp and environmental properties on froth stability in the flotation of a typical porphyry copper ore. In particular, factors such as frother and collector type, feed particle size (P80), solids per cent, composition (chalcopyrite and pyrite content), as well as grinding environment (mild steel versus stainless steel, high and low pH) have been varied in a controlled manner, and the resulting froth stability evaluated. A previously developed froth stability column, based on the Bikerman approach, was used to measure the froth height and half-life in each test. The relative effect of each factor is presented here on a comparative basis. It is shown that frother type is the most important factor, with marked difference in froth stability when switching from methyl isobutyl carbinol (MIBC) to glycol based frothers. Solids per cent and particle size also play a significant role. The grinding environment had lesser effect on the resulting froth stability, although mild steel grinding gave higher froth stability compared to stainless steel grinding. The experimental evidence supports the hypothesis that in porphyry copper flotation the grinding environment influences surfaces oxidation, pyrite activation and the extent of hydrophobic particles reporting to the froth phase. This has an indirect effect on the resulting froth stability, which is however small if compared to the other factors. This work is still in progress, and extension to other mineral systems is planned. However, some insights are offered to operators on the parameters which are more likely to have an impact on froth stability in copper flotation plants.CITATION:Zanin, M, Chan, E and Xu, D, 2014. Empirical evaluation of factors affecting froth stability in copper flotation, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 193–200 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

When lying over 200-250m depth, many seams and surrounding strata are gassy enough to create mining difficulties , particularly in highly productive longwalls as well as in their development headings. In addition to the gassiness of seams or stra- ta in the outgassing volume around working, the shape expansion and limits of this one influences much the intensity of gas emission. These charac- teristics of outgassing volume differ very much ac- cording to the permeabilities of the seams and strata encountered by their fracturation due to mi- ning. Moreover, the shape of the outgassing volume is very much modified by the rate of advance of the face. In nearly impermeable deposits, gas flows from a limited outgassing volume. When the rates of advance of a face are medium or low, the shape and dimensions of this volume do not change very much and outgassing volume is translated progressi- vely with the face advance. This explains why, in the past, it was observed that there was for each seam an average steady specific emission of gas, round which the volume of gas evolved per mined ton or per mined unit area, calculated over a cer- tain time, was oscillating. Combined with a statisti- cal irregularity coefficient, this allowed prediction gas of emission and thus to take decisions for air ventilation, drainage, and eventually production.

Jan 1, 1988

The first hydraulic roof supports were installed underground in 1950s and ever since that time engineering developments have improved the supports in many different ways. However. advances in three main areas, the roof support mechanical design, hydraulic engineering and electronics have ultimately led to the point where, 35 years after that first installation. automation has been achieved and is now commonplace.The history of roof support automation has involved the continual integration of high technology engineering. Thera ate further possibilities for the future which combine to give some idea of the likelihood of there ultimately being a completely manless face.

Jan 1, 1991

By D Macfarlane, T McMorran

  This paper describes the design and construction of the upper section of the Pike River Mine Access Road. The road extends 11 km from Logburn Road alongside Big River on the West Coast of the South Island of New Zealand up Pike Stream to the new mine portal on White Knight Stream (Figure 1). This new road starts on alluvial terraces, then partially follows an old logging road before entering virgin bush and traversing the true left bank of a steep sided gorge on Pike Stream some 50 - 100 m above the stream before dropping down to the mine entrance. Its development has been an extended process from route selection, consenting through to design and construction.   The paper focuses on the 1 km section of road between the Amenities Area (Figure 1) and the portal. This section of road is a steep section through the gorge, principally on Conservation estate, and has presented the most challenges and required the greatest effort to obtain the regulatory approvals, prepare the design and to construct. This paper outlines the history of the challenges faced and how the road was successfully developed.

Jan 1, 2007

By D R. Andrew, K T. Morrison, J F. Tiedgen

Waste blasting in iron ore operations can pose a number of technical challenges, including blasting through variable geology and blasting soft ground in wet conditions. Blast patterns are designed to be loaded with a specific range of explosives with unique characteristics and properties. Each explosive product will produce an optimal blast outcome for a given set of blast parameters and ground conditions. Sites characterised by softer rock typically require low-density, low-energy explosives. Historically, these products have contained a high ratio of porous ammonium nitrate prill and are only suitable for dry blastholes. When blastholes within a pattern are found to be unsuitable for such explosives due to wet, damp or muddy blasthole conditions, a new product is selected. While it is easy to switch products to match blasthole conditions, the different properties of the new non-ideal product can impact blast performance and increase loading times and costs.Flexigel™ is a solids-sensitised emulsion blend suitable for loading at variable densities and energies in dry, damp, muddy or wet blastholes. It is a universal product that can be loaded to match ground and blasthole conditions or complement other explosive products.At Fortescue Metals Group’s Cloudbreak site, Flexigel™ was trialled through a series of matched pair blasts in order to optimise blast outcomes in conditions that were non-ideal for existing explosive products and to reduce the overall cost of drill and blast operations. Flexigel™ yielded improved instantaneous dig rates and improved loading efficiency when compared to a traditional emulsion blend. The results also indicated that variable-density and variable-energy products afford greater flexibility for optimising blast outcomes across all ground and blasthole conditions trialled.Trials of Flexigel™ at Cloudbreak have shown that a variable-density solution is available for conditions where traditional explosive products are non-ideal. As such, Flexigel™ is able to fill a major void at any operation where the desired low-density, low-energy explosive product must be substituted for a more expensive traditional emulsion blend or heavy ammonium nitrate/fuel oil.CITATION:Andrew, D R, Morrison, K T and Tiedgen, J F, 2015. Flexigel™ – a variable-density solution, in Proceedings Iron Ore 2015, pp 413–418 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By A Bagis

Road tunnels are an accepted and effective transportation solution in urban areas to mitigate increasing traffic congestion and facilitate improved urban connectivity in a cost effective manner while meeting societal goals to reduce the impact of construction. In designing a tunnel system, there is a requirement to achieve an acceptable level of in-tunnel air quality, as well as meeting ambient air quality goals. In Australia, there is also a requirement for zero portal emissions which means that all pollutants must be emitted to the atmosphere via a ventilation stack.Traditionally, effective pollutant dispersion has been achieved by constructing tall ventilation stacks which disperse pollutants into the atmosphere at a high level. The dominant variable parameters in the effectiveness of the dispersion under the ventilation engineers control are the efflux velocity, the height of the ventilation outlet and the concentration of pollutants at the point of discharge. During off-peak operations the required ventilation exhaust rate can be reduced due to the decrease in traffic. This can lead to a drop in the efflux velocity from the stack and therefore the effectiveness of the dispersion. This potentially drives the need for a higher outlet, or an increased exhaust rate to achieve a higher efflux velocity with consequent effects on energy consumption.The paper proposes a method of varying the cross-sectional area of the ventilation stack with the use of motorised control dampers, thereby maintaining a sufficiently high efflux velocity throughout the 24 hour period independent of traffic conditions. This allows the use of a potentially shorter ventilation stack.

Mar 8, 2011

By Murakami T, Tamiya M, Mizokawa T, Matsumoto T

In the expansion program of the iron ore pelletizing plant at Kakogawa Works of Kobe Steel Ltd., an automatic computer control of products fineness on grinding department is practised. The main problem of the process control of a grinding system is scattering of measured fineness values of products. The scattering comes from the inherent nature of grinding systems, sampled powders and measuring systems. A method is developed to presume the exact status of the plant from scattering products (fineness values and to achieve a stable con trollability of the plant by utilizing the computer. An on-line fineness analyzer, an automatic sampling device and vari-speed air separators are also developed to compose the automatic grinding plant. This report introduces the fundamental epts and results of the automatic fineness rol system of the grinding plant.

Jan 1, 1977

By T Roesch, M Neurohr, S Stratton

"Dwindling commodity prices are forcing today’s mining operations to increase output. Sometimes the solution is to upgrade the existing infrastructure; however, in most cases it has to be achieved with the same or reduced workforce and with the same equipment capacity through improved process efficiency and higher uptime.Measure, Manage and Improveis the mantra for this years’ Mill Operators’ Conference and while this in most cases relates to the above process efficiency, Siemens has set its focus on the availability and uptime aspect since unscheduled downtime is one of the biggest threats to any grinding operation. Pinion misalignments, resonance, unbalance and bearing and gear meshing faults in geared trains, as well as long-term changes in the condition of the mechanical components or structures and auxiliary systems in gearless systems are the main reasons for unscheduled downtimes in today’s mill drive trains. Our paper outlines the efforts that have gone into adapting conventional condition monitoring methods in conventional, pinion driven mill drive trains as well as gearless systems to capture the gradual deterioration of wearing parts or structural changes in the drive train not only on fixed speed application but also on variable speed applications with multiple operating points. The paper further explores the use of condition monitoring systems as a tool to assess spare thermal motor capacity to potentially push equipment beyond its nameplate rating, along with the process that was followed to correlate measured frequency spectra and envelopes to ambient and load data to understand the kinematics of the drive train.Citation:Neurohr, M, Stratton, S and Roesch, T, 2016. Advancements in Condition Monitoring on Mill Drive Trains for Proactive Maintenance and Early Fault Detection Purposes, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 263–272 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By G W. Scott, H M. Lukey

The Lake Superior Region has been a producer of iron ore for over 150 years. Early mining operations concentrated on direct shipping ores, which are the result of post-depositional upgrading principally by deep weathering. As direct shipping ore reserves became depleted, the focus changed to the production of iron ore pellets from taconite. The post-depositional processes responsible for upgrading taconite are regional metamorphism, contact metamorphism and hydrothermal processes (Clout and Simonson, 2005). While these processes are important in iron ore genesis they can also contribute to liberation problems and in some instances reduced pellet quality (Han, 2004). Low-grade metamorphic mineral assemblages can negatively impact liberation and pellet quality. Low-grade iron formation may contain a suite of carbonate minerals including ankerite, dolomite, kutnohorite, siderite and magnesiosiderite. Variation in the distribution and composition of siderite and magnesiosiderite makes controlling the MgO content of pellets difficult. Carbonate minerals also require calcination in the pellet induration process, which requires additional heat to be added to the system, slowing down the induration process and reducing throughput. Prediction of carbonate mineralogy and carbonate mineral chemistry is an important goal of ore characterisation for pelletising properties. Contact metamorphism causes changes in mineralogy and grain size (Klein, 1973; Gunderson and Schwartz, 1962). Increasing the grain size of magnetite should improve its liberation characteristics. However, plant grinding targets may not allow the coarse-grained, more easily liberating magnetite ores to increase throughput and can actually result in decreased throughput due to recirculation. While magnetite and martite ores are well understood (Lukey, Johnson and Scott, 2007) late open-space filling microplaty haematite ores are not. These ores, while composed of similar minerals, have a unique genesis that results in fine grain size and complex textures that present liberation challenges and often make interpreting laboratory metallurgical test results more difficult.

Jan 1, 2007

By A Weeks, W J. Shaw, A Kuk

Grade control is a process that requires the interaction between many components of the mining operation and successful grade control is only realised through good data, robust systems, and a well-trained, motivated and disciplined workforce.The Mt Magnet Gold Project Pty Ltd (MMGP), a wholly owned subsidiary of Ramelius Resources Limited, started mining at Mt Magnet in February 2012 with high expectations for success. Positive cash flow would fund an aggressive exploration and mine development program in the area to increase mine life. Disappointment followed when after start-up the operation had issues achieving budget grade and realising the predicted grade of the mined ore. In January 2013, things started to improve. During the next six months, gold production steadily increased with successive months achieving record production. What had changed?Improvements started following the realisation that controlling grade was not the sole responsibility of the mining geologist and that everyone on-site has a role to play. This paper examines the factors that delivered success for MMGP.CITATION:Weeks, A, Shaw, W J and Kuk, A, 2014. Who is responsible for grade? – an evaluation of the value chain at Mt Magnet Gold Project, Western Australia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 477–482 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By T Kilpatrick

Managing heat stress on Australian mine sites is a complex and enduring challenge due to the combined and variable contribution of environmental conditions, physical activities, and protective equipment. Inappropriately managed, heat stress can place significant physical strain on workers, leading to serious and chronic health issues. Additionally, excessive heat stress can dramatically reduce productivity, with 30 per cent of workers reporting a loss of productivity due to occupational heat strain. In Australia, due to increased absenteeism and reduced work performance, heat strain is estimated to have an annual economic burden of over $8 billion.

May 5, 2022

The Coal Corporation of New Zealand Ltd (CoalCorp) is the largest coal producer in New Zealand, with extensive properties in both the North and South Islands. CoalCorp's North Island operations are kilcmetres to the south of Auckland. opencasts, are located in the catchment wildlife, historical and scenic values. in this catchment is the single most mining operations. centred on Huntly, a town some 80 Five coal mines, four of which are of Lake Waahi, a lake with significant The discharges of mine lodgement water important environmental constraint on Throughout New Zealand the use of water is controlled by a statute called the Water and Soil Conservation Act 1967. All industrial water users are required to hold Water Rights, which are in effect licences to take, use, dam, divert or discharge water. Water Rights are obtained through a legally defined process and any potentially affected party has the per to object to their granting. A special tribunal hears the evidence for and against an application, and issues its decision, which is reviewable in a higher court on Appeal. Rights, if granted, are issued subject to conditions and, in the case of mining discharges, limits would be set on flaw rate, suspended solids concentrations, turbidity, pH and the concentrations of any potential toxicants. This paper presents a case study of an integrated, catchment wide water management plan for Lake Waahi, that was prepared by the author, and others while the author was in the employ of CoalCorp, and its predecessor, State Coal Mines. The author is grateful to CoalCorp for their permission to submit this paper.

Jan 1, 1988

By J Tibbett, A Colebourn, B Hebblewhite, F Suorineni

The concept of Big Data refers to data sets that are so large, variable and/or complex that traditional data processing applications struggle to integrate the data for effective investigation, analysis and value generation. With advances in sensor technology and smarter equipment, the mining industry is experiencing Big Data, and in a different way to how the intelligence and marketing communities experience Big Data. Future mining will bring larger, more complicated and diverse data sets increasing the strain on traditional data integration and investigation techniques. Block caving is an important mining method for the extraction of massive, low-grade ore deposits due to its low operating cost and high production potential, given the right orebody geometry and ground conditions. This paper focuses on block caving due to its increasing popularity and importance in the future economic extraction of multiple commodities. The block cave mining system (BCMS) is a complex interrelation of factors, and due to the reliance on natural processes within the system, it is one of the least understood mining methods. Obtaining information on the factors within the BCMS generates large, complex data sets on various time scales. Each sensor network within the BCMS combines spatial and temporal information with tens to hundreds of recorded parameters. Data sets are quickly moving from multidimensional to n-dimensional. Optimisation of the BCMS is only possible through a holistic analysis approach, thus involving the integration of multiple, diverse, n-dimensional data sets (Big Data). This paper presents a current example BCMS Big Data situation involving 12 sources of information with differences in volume, data format and frequency of data generation. This suitability of virtual reality scientific visualisation (VRSV) as a solution to BCMS Big Data interpretation difficulties is then discussed. These 12 data sets can be effectively integrated using VRSV for intuitive and accelerated investigation of the BCMS. Potential future Big Data within the BCMS is presented involving 20 sources of information resulting from our increased need for monitoring and advancements in technology. Current methods of defining queries may not be suitable within these future complex, multidimensional data sets, and the potential of artificial intelligence algorithms within this system is discussed. These advancements in technology and machine learning lead to the requirement of live data acquisition and analysis. VRSV is identified as a suitable technology to satisfy the needs of real-time insight into the performance of these future caves for optimised management and reduced risk.CITATION:Tibbett, J, Suorineni, F, Hebblewhite, B and Colebourn, A, 2015. Virtual reality scientific visualisation – a solution for big data analysis of the block cave mining system, in Proceedings Third International Future Mining Conference, pp 109–116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Mousset-Jones P, McPherson M. J

Underground airways are characterized by irregular shape and uneven surfaces including large-scale natural roughness, fractures, and a super-imposed sand roughness. Swirls in the grooves of the wall and separation because of the periodic variation of the open cross sec- tion, due to the blasting patterns, make it almost impossible to calculate average con- vective heat transfer computationally on the bases of the geometrical description of the surface. However, dimensionless friction factors can be used to characterize the surface effect of an airway and an analogy between heat and momentum transfer can be applied to calcu- late an average convective heat transfer Coefficient.

Jan 1, 1988

By Miles M. J, Sandy D. A

It has long been known that drilling and blasting operations have a direct influence over productivity and costs of subsequent operations. If mine management is to effectively optimise blasting operations, good information is required on the operating costs of each of the affected operations, together with knowledge of how they are influenced by blasting. In practice it is not possible to do enough repeats of a full scale production blasting experiment to make a statistically significant analysis of the results. By monitoring each blast and subsequent operations in as much detail as possible, enough data will be available to effectively measure the effect of blasting on costs. This gives management an insight into the blast performance and is the first step towards optimisation. An Integrated Blast-related Cost Reporting System has been developed at the Rossing Mine Open Pit, which calculates the total mining cost for each blast. In assessing the total mining cost for each blast, use was made of an.integrated planning and management information system to collect relevant production variables, current operating costs and survey data. An automatic image analysis system was employed to measure the fragmentation of the blasted material in the back of haul trucks. A shovel monitoring system is also under development for use in assessing the muckpile diggability and, in conjunction with an appraisal of shovel component reliability, to estimate the maintenance cost under various digging conditions.

Jan 1, 1990