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Mining had a very considerable effect on the country's development. The visual evidence remaining is an integral part of New Zealand history. Early mining for manganese and copper in the 1840s was succeeded by alluvial gold rushes. These gave way to hard rock extraction, hydraulic elevation and dredging. Coal mining dating from the 1850s was fairly widespread. Other minerals were obtained on a small scale. Manufacture of mining' machinery stimulated industrial engineering enterprises. Schools of mines played a significant part in advancing technical skills and several remain as museums. Surviving mine structures and site relics are part of the industrial heritage signifying the technological and economic development of a small isolated nation. Some of these are described. Identification, recording and preservation where practicable is advocated.

Jan 1, 1990

By F Hungerford, T Ren

"Gas management has always been a major concern for the ventilation officer of any gassy mine. With an increase of mining depth and gas content, there is a great demand for the development of in-seam drilling sites where boreholes can be drilled for the pre-drainage of gas prior to longwall operation. The ventilation and gas management in the drilling site therefore becomes a critical component of mine safety. In this study, advanced computational fluid dynamics technology was adopted to investigate the aerodynamics of gas emitting from the drilling site and boreholes during normal drilling and, in the case of a sudden gas inrush, from the borehole. In addition, the impact of different ventilation controls on gas removal in the drilling site was investigated. Modelling results indicate that gas accumulation zones could be formed if the ventilation system fails to deliver sufficient airflow to the drill site, especially when a sudden gas inrush from a borehole occurs. The configurations of brattice, layout of ventilation tubes and the gas emission rate all have a significant effect on the gas distribution. Due to variations in site-specific conditions, it would be desirable to conduct modelling studies to assess the effects and efficiencies of a ventilation design for the varying environment on-site before carrying out drilling practice. CITATION: Ren, T, Hungerford, F and Wang, Z, 2015. Computational modelling studies of ventilation management for underground in-seam drilling sites, in Proceedings The Australian Mine Ventilation Conference, pp 239–250 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 31, 2015

By R Dimitrakopoulos, K Kawahata, L Montiel

A method that optimises mining complexes that are comprised of multiple processing destinations, open pits and underground operations is presented. Mining, blending, processing and transportation decision variables are simultaneously optimised while accounting for geological uncertainty. The method uses a simulated annealing algorithm at different decision levels to generate a stochastic-based extraction sequence and processing policies. A case study shows its ability to generate a higher net present value while facing a reduced amount of risk when compared to traditional optimisation methods.CITATION:Montiel, L, Dimitrakopoulos, R and Kawahata, K, 2014. Globally optimising open pit and underground mining operations under geological uncertainty, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 201–212 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

The Elgas Underground Storage Facility at Port Botany, Sydney, is the first purpose-built cavern of its kind in Australia and allows large capacity, safe and environmentally benign storage of Liquefied Petroleum Gas (LPG). The facility provides Elgas with the flexibility to source product at competitive prices and will ensure long-term security of supply. Construction has provided Orica Australia, formerly ICI Explosives, with a unique opportunity to provide a bulk explosive delivery system specifically designed to meet the exacting demands of the site (see Figure 1) and of the project.

Jan 1, 1999

By S Ellis, J McMullen, M Habner

A new leaching regime was implemented at Kalgoorlie Consolidated Gold MinesÆ (KCGM) Gidji plant on a cyanide leach of ultra-fine ground sulfide concentrate. High lime concentration and lead nitrate were used to overcome the refractoriness of the fine sulfides (high reactivity of fine sulfides with the presence of gold tellurides). The leach pretreatment stage was shown to be detrimental and was shut down. Lime titration was introduced as part of the process control. It was shown that the leach could be performed at low dissolved oxygen, (ie 3 - 5 ppm) to avoid sulfide oxidation and the associated high cyanide and lime consumption. Plant results showed reduced cyanide consumption (40 per cent) and an accelerated leaching rate, whereby most of the gold was dissolved in 24 hours compared to 72 hours used previously. Similar work was performed at KCGMÆs Fimiston plant, which leached a combined ultra-fine ground sulfide concentrate along with the slimes fraction from hydrocycloning the bulk flotation concentrate. The use of lead nitrate, high lime and carbon-in-leach generated a faster leaching rate and minimised adsorption of gold on fine pyrite particles. The grind, previously controlled with a P80, was replaced by a P98 to give a better operational indication of top size hydrocyclone performance. Before the implementation of the changes, average leach residues for slimes and UFG were respectively 4.0 g/t and 5.5 g/t. With the modifications to the leaching regime, average leach residues were lower by 1.5 - 2.0 g/t. Whilst significant improvements have been demonstrated, further work is progressing at KCGM to further reduce ultra-fine concentrate leach tail grades, and also to improve the understanding of concentrate refractoriness and the factors responsible for differences between laboratory and plant leach results. Estimated profits since the implementation of the new approach are in the range of $A3.5 million per year.

Jan 1, 2005

By L. R. MURPHY

This paper gives a general description of mining operations at the Rosebery Mine and a brief account of the older Hercules Mine. The more unusual aspects of the operations, such as the sinking of the inclined shaft, blast-hole experiments, diamond drilling practice, and proposed future developments are described in detail.The following main heads are used:Roseberry- General production Data.General Description of Ore-body, and Characteristics of Ore and Country Rock.Layout of MineMining Methods, Filling, etc.Blast Hole Stoping.Sinking Main Inclined Shaft.Mining Timber. Contract System.Diamond Drilling and Sampling.Surveying.Labour Force.New Developments, Sand Filling and Pumping.Hercules-Situation of Mine.Transport-Haulage and Aerial.Ore Bodies.Stoping Methods.Ore Handling.

Jan 1, 1949

By P Wood, S Leveritt

This paper will introduce some innovative strategies for simulator training that are intended to improve the level of safety and operational performance of heavy equipment operators. The key strategy is to design simulator training to deliver improved work performance outcomes. This strategy is underpinned by a process for engaging workers in knowledge discovery and transfer that has been developed as an outcome of an Australian Coal Association Research Program (ACARP) funded project conducted at open cut coal mines in Australia. The process is expected to deliver improvements in the safety and operational performance of heavy equipment operators by informing training content about how experienced operators manage unexpected situations around the site. Tapping into the tacit knowledge that experienced operators gather over time can provide site specific and timely information about situational cues used to manage the unexpected. This type of information complements basic skills training by helping the trainee understand the operational context in which the acquired skills will be applied. Inexperienced operators have traditionally gained experience through their own actions, observing the actions of others and by taking the advice of mentors who have æbeen there, done thatÆ and developed operational decision making skills for safe and productive work performance. Leadership and mentoring techniques that contribute to effective knowledge delivery will also be discussed.Other simulator training strategies include refresher training, change management, emergency response training and testing the usability of new equipment and technologies prior to their introduction on-site. A key challenge ahead for the resources sector is the development of knowledge elicitation techniques that suit the operational workforce. A challenge for simulation and modelling professionals is to develop and refine techniques that support cost-effective customisation and regular updates of simulator scenarios.CITATION:Leveritt, S and Wood, P, 2012. Raising the simulator training bar - Strategies for improved work performance and effective utilisation of site-based simulators, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 65-70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By Y-B Kang, W-Y Cha, Y-M Cho

Molten slag used in the secondary refining process (RH process) for the production of Ultra-Low C (ULC) steel is typically composed of CaO-Al2O3-MgOsat.-FetO with minor constituents. FetO in the RH slag is the main source of reoxidation of the molten ULC steel in the ladle by 2Al + 3(FetO) = (Al2O3) + 3Fe, thereby serving as the source of the alumina inclusions. On the other hand, FetO also enhances the fluidity of the slag, thereby increasing inclusion absorption capacity. Optimum slag chemistry design is therefore required to produce clear ULC steel. The reoxidation kinetics was investigated in the present study by employing high-temperature experiments and developing the reaction rate model. Initial compositions of slag ((% CaO)0/(% Al2O3)0 and (% FetO)0)) and reaction temperature were varied and change of [% Al] in the molten steel was measured. The rate-controlling step was analysed. It was found that the rate-controlling step in some cases changed during the reoxidation: from a mass transport of Al in the molten steel to a mixed transport including Al2O3 in the molten slag. The experimental data validated the reaction rate model based on the elucidated reaction mechanism and FactSage thermodynamic database. The model suggested that high (% CaO)0/(% Al2O3)0 suppresses the reoxidation only when (% FetO)0 is low (5 or lower in the present study).

Jun 19, 2024

By D A. Williams, P J. Chapman

Constructing upstream raises with tailings is an accepted and cost-effective practice in Western Australia, where the climatic conditions are favourable, desiccation (and hence overconsolidation) occurs rapidly due to air drying and there is a perceived low seismic risk. This is in contrast to many other settings, where there is either a positive water balance, high seismicity or a combination of both. In recent times, there has been an increased focus on seismicity in areas of Australia that have historically been considered to be of low seismic risk. The increased focus is driven by two recently published documents used by tailings practitioners and increased awareness from corporate entities, particularly those with mines in high-seismicity regions such as South-East Asia and South America (particularly Chile).The increased awareness has resulted in increased rigour being applied to seismic design of tailings storage facilities (TSFs) in general, and particularly upstream-raised TSFs. This paper compares the results of a seismic stability assessment for an upstream-raised TSF located in the Goldfields region of Western Australia, which has historically been considered a low seismic area, with a seismic stability assessment carried out for a crossvalley TSF containing similar tailings but located in a high-rainfall, high-seismic setting in South-East Asia. The influence of the adopted design earthquake values on the results of the assessments and the potential impact of the maximum design earthquake (MDE) on the design approach is presented for both cases. The results indicate that although the Western Australian site is located in an area thought to have low seismic risk, the screening level analyses suggest that the MDE could result in liquefaction of the tailings materials. Not surprisingly, liquefaction was also indicated for the South-East Asian site. The outcomes of the assessment are also presented.CITATION:Chapman, P J and Williams, D A, 2015. Seismic design of upstream-raised tailings storage facilities in a semi-arid, low-seismicity setting, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 157–162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By R McCarthy, P Darvall

FerrAus Limited's Robertson Range and Davidson Creek iron ore projects are located on the far eastern margin of the Hamersley Province, approximately 100 km to the east of Newman, Western Australia. The deposits are primarily formed of bedded haematite-goethite-limonite mineralisation within the Marra Mamba Formation, comprising a total combined resource of 164 Mt at 58.6 per cent Fe. The deposits represent relatively new discoveries for the Hamersley Province. The potential for mineralisation at Robertson Range was identified by Rio Tinto Exploration in 2000, while Davidson Creek remained untested until 2007. One of the main reasons for this is that these deposits are almost exclusively concealed beneath Tertiary sediments and recent transported cover making them difficult targets for conventional, prospecting style exploration. Since commencing exploration in the project area, FerrAus has collected nearly 20 000 stations of gravity data within the Robertson Range and Davidson Creek project areas, with most of this data collected at a 50 100 m station spacing. Gravity has proven itself to be an effective technique at predicting the position of the target host stratigraphy and has been a key driver in the exploration for concealed iron ore deposits. However, there is not always a perfect correlation between the position of gravity anomalies and concealed ore. The response of deep haematite bodies may be masked by low-density cover rocks, while other dense lithologies may be the cause of gravity anomalies which appear similar to the Marra Mamba targets. Hence, effective use of the gravity data requires interpretation in a geologic context with an understanding of the capabilities and limitations of the technique.

Jan 1, 2009

By S Schwarz, D Alexander

The mining industry, and in fact the world, has undergone significant changes in the past five to ten years, ranging from the metals boom, the global financial crisis and the rise and fall of national economies, to name just a few. There has been a focus on sustainable development for projects and operations in the mining industry, mainly pushed onto the industry by communities, governments and other agencies. While sustainable development and operation is a worthy priority for mining operations, discussions with mining industry personnel (with a strong slant on the mineral processing perspective) have shown other issues have surpassed the typical issues of water resources, energy availability and the environment. These include staff turnover and skills shortages, extracting metal from more complex orebodies and the uptake of new step-change technology.A number of key operating mineral processing personnel were interviewed to determine their perspective on the current issues facing the mining industry. This paper details the findings of this survey and highlights some of the topics that have been identified as the top issues from a mineral processing perspective.CITATION:Schwarz, S and Alexander, D, 2012. Current issues in the mining industry - From the operational mineral processorÆs perspective, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 369-372 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By R McIlwraith, B Breul

"This paper discusses the successful use of bituminous geomembranes (BGMs) in mining applications since their development in 1974. It explains and illustrates the structure of a BGM composite, which is a geomembrane manufactured by impregnating a polyester geotextile with a compound of bitumen, elastomer and filler. Examples of applications of BGMs in the mining industry are also presented in the following contexts.Storage of solid waste: storage of mining waste at mines in Canada heap leach pads in France, Peru, Chile and Turkey at the base of a mining waste landfill in Brazil capping of solid mining waste in Chile and Canada temporary capping of mining stockpiles in Australia (with possible reuse of the BGM for other works).Examples of the application of BGMs for the storage of liquid waste in mining containment reservoirs in Canada, Guatemala and Peru will also be given.For each example given, reasons are supplied that supported the choice of BGMs by the clients and consultants, drawn from the following advantages of the BGM:BGMs have excellent puncture strength, due to the internal polyester reinforcement, as well as excellent ultraviolet resistance. This often eliminates the need for a cushion geotextile or cover soil over the BGM.BGMs have a very long life expectancy, in excess of 300 years, in subsoil conditions (Breul et al, 2004).BGMs can be installed in very harsh climatic conditions. They are suitable for high wind environments as their heavy mass per square metre makes them resistant to wind uplift. The low coefficient of thermal expansion means that BGMs are suitable for installation in mines where very low or very high temperatures are expected. This reduces construction delays and allows for a quicker use of the mining facility.The fact that the BGM can be installed by the mine’s own workforce, after appropriate training from the BGM manufacturer, allows for a more flexible construction sequence on the mine.Ability of the BGM to connect to other materials such as concrete, steel, rock and other geomembranes that may be on the mine site.The technical advantages of a BGM enabled the engineering consultants to prepare solutions for their mining clients that had a lower environmental risk, had a faster completion schedule and were overall a cheaper option than with a polymeric geomembrane.CITATION:Breul, B and McIlwraith, R, 2015. Bituminous geomembranes in mine construction, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 289–296 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 27, 2015

By D Chalmers, C C. Harb

The detection and control of gas levels in mining is a continuing challenge for the industry. Standard detectors have many problems that could be overcome with laser based spectroscopic instruments, but to date these systems have not been suitable for mining conditions. This paper reports the development of a new digital data extraction scheme to modernise traditional cavity ring down spectroscopy (CRDS). CRDS is a direct cavity enhanced laser based absorption technique, which is used to allow the identification of an unknown substance by their molecular fingerprint; this unknown substance is identified by analysing the ring downtime of the light exiting the optical cavity. Traditional CRDS has many issues when analysing substances in hostile environments, or when multiple species may be present. This presents an alternative approach, called real-time CRDS (rtCRDS) that has the potential to overcome many of these issues and produces systems that could be used in the mining industry. The system utilises newly developed widely tuning quantum cascade lasers combined with improved optical cavities and novel digital data extraction to produce spectra over a 1500 nm range in a few seconds. The ring downtime measurements produced are accurate and have high sensitivity and maximum signal to noise ratio. This paper discusses the technique, illustrating the advantages compared to traditional systems and show real-time spectra for a set of molecules of interest to the mining industry. This paper also provided an analogy between this approach and that used in digital communications systems, and shows that this scheme is ideally suited to provide a network of sensors in hostile environments.CITATION:Harb, C C and Chalmers, D, 2015. Real-time methane detection – modern digital laser spectroscopy for hostile environments, in Proceedings The Australian Mine Ventilation Conference, pp 161–166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By McQuade C. V

Mining is an activity which has, in the past, been regarded as often leaving land in a condition unfit for further use. As the need for development that is both economic and ecologically sustainable has grown, so the issue of re-use of land after mining has become significant. During operation it is usual that mine environmental conditions which minimise unnecessary or avoidable environmental impact are agreed with the regulatory authorities . These conditions are usually set down in such a way that they can be interpreted reasonably well by both miners and regulators. However, the conditions to be met by a mining company before it can be absolved of responsibility of a site are often less clear. The close-out criteria by which the success of rehabilitation programs will be judged have received little attention in the past. These conditions are now growing in importance as the costs of rehabilitation of a mine site to an agreed post-mining land use assume greater significance in the economics of mining. This paper briefly describes the status of close-out criteria presently being applied across Australia. A comparison is made with similar guidelines from other countries.

Jan 1, 1994

By S Carr-Cornish, K Moffat

Social licence to operate is developed and kept through managing both operational impacts and the relationship between local community and company. However, CSIRO research has demonstrated that in determining how accepting community members are of a mining operation, relational factors, such as procedural fairness and trust, are much more important than operational impacts, such as impacts on employment and the environment (Moffat and Zhang, 2015). Companies seek to develop relational factors through their engagement with local community; such engagement has many aspects, including, initially identifying stakeholders and positioning the company as part of the local community (Lacey et al, in prep; Thomson and Boutlier, 2011). These relational factors involve the social identities of people living in the community. Social identities are a part of people that shape their beliefs, based on their connections with various groups in their lives (Hogg et al, 2004).An engagement process, intentionally or not, inevitably interacts with the social identities of stakeholders (Crane and Ruebottom, 2011). For example, traditionally, at the very beginning of engagement processes, community members are assigned to categories using conventional stakeholder mapping and categorisation methods, often based on assumptions about stakeholders’ interests, which equates to assumptions about stakeholders’ social identities (Colvin, Witt and Lacey, 2016; International Council on Mining and Metals, 2012). Yet, there has been limited empirical inquiry into whether such categories reflect the social identities of stakeholders and if there is a bearing on relational factors, including, the perceived fairness of consultations and trust in mining companies (Crane and Ruebottom, 2011). Also at this time, companies commonly seek to create a presence in communities, for example, joining Chambers of Commerce and participating alongside community members. Again, there has been limited empirical inquiry into whether community members and companies identifying with the same overarching group and thus sharing aspects of social identity, influences relational factors (Crane and Ruebottom, 2011). In this study, we examined the effects of changing aspects of social identity by changing how stakeholders were identified and companies were positioned, on how stakeholders’ perceived a new mining operation, specifically how they perceived the procedural fairness of the proposed consultation process and trusted the company, two factors that underlie a company’s social licence to operate.CITATION:Carr-Cornish, S and Moffat, K, 2016. Out of the box – the power of social identities in engagement processes, in Proceedings Life-of-Mine 2016 Conference, pp 180–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By P Dowd, A Adeli, C Xu, X Emery

Geometallurgical modelling is increasingly being incorporated into mineral resource modelling and estimation as a means of increasing efficiency, decreasing operating costs and reducing risk in mining operations. Traditional geostatistical workflows for geometallurgical modelling face several difficulties, in particular, related to the non-additivity of process response variables, to highly heterotopic data sets and/or to preferential sampling designs, all of which may explain why most attempts to estimate geometallurgical response variables from assay data and mineralogy are still based on statistics and machine learning. The aim of the work presented here is to demonstrate the applicability of geostatistics to estimate copper recovery from copper sulfide ores at the Prominent Hill Iron Oxide Copper-Gold (IOCG) deposit in Australia. As recovery is non-additive, the preferred workflow is the joint estimation of the masses of metal in the feed and in the concentrate, both of which are additive variables. While the mass of metal in the feed can be estimated from abundant online assay analyses, the mass of metal in the concentrate can only be estimated from a very limited number of laboratory-scale batch flotation tests. Traditional approaches to estimating the masses of metal in the feed and in the concentrate, such as simple and ordinary co-kriging, are described and discussed. A modified version of co-kriging is introduced, which incorporates linear relationships between the mean values of the input variables, in addition to a spatial correlation model. Co-kriging with related means is shown to outperform traditional simple and ordinary co-kriging in terms of precision, accuracy and consistency of the estimates, and offers a practical and efficient tool to deal with highly heterotopic and preferential sampling designs.

May 24, 2023

By M Scamardella

The CSA Mine is located at Cobar, New South Wales, where it was in continuous operation from 1966 to the time it went into receivership on 29 January 1998. When it closed it was under the ownership of Golden Shamrock. Glencore International, in conjunction with Mt Lyell Mining, undertook a due diligence study to determine the feasibility to re-open the mine. This envisaged operating CSA Mine as a low-cost, copper concentrate producer under the direction of Cobar Management Pty Ltd (CMPL). The new workforce would consist of contractor trades people in operating functions under the co-ordination of CMPL staff, both on the surface and underground. This was the key to establishing the new culture in the workforce. The orebodies at CSA Mine are steeply dipping with copper-lead-zinc mineralisation in zones of strong alterations in a fine-grained siltstone host sequence. The predominant economic minerals are chalcopyrite, sphalerite and galena. The major gauge minerals are pyrrhotite, pyrite, chlorite, sericite and quartz. Ore for the project is being developed and mined from two high grade copper lenses within the QTS North system. Chalcopyrite occurs in two forms. The first consists of coarse chalcopyrite grains in association with pyrrhotite or pyrite. The second form consists of chalcopyrite grains intergrown with pyrrhotite grains. This form of chalcopyrite is quite rare. It allows electrochemical interactions between grains, resulting in rapid oxidation of the chalcopyrite surface. Physically this ore looks like, and has been mistaken for æpeacock oreÆ, ie bornite, but is infact oxidised chalcopyrite.

Jan 1, 2000

By L Dawson, S Carr-Cornish, N Boughen, K Moffat, S Masterson

The risk and consequences of community rejection and loss of a social licence to operate is well articulated (Moffat et al 2018), however, the means for systematically managing this risk are less established. At the local scale, a mining operation is said to have a social licence to operate (SLO) when it achieves ongoing acceptance or approval from the local community and other stakeholders who can affect its profitability (Graafland, 2002). Without this social acceptance, it is very difficult for a business to operate effectively or profitably. It is well understood that social (or community) acceptance of a mine and its associated operations is a reflection of the quality of the relationship a company has with their host community (Thomson & Boutilier, 2011; Lacey & Lamont, 2014; Parsons et al., 2014; Moffat et al., 2015). Community relations are an integral part of successful mining operations and where these interactions are effective, they tend to foster mutual understanding, trust and support between a company and the host community (Kemp et al., 2006; Holley & Mitcham, 2016). Research further demonstrates that where such interactions are perceived to be procedurally fair, the increased trust created in these company-community interactions tends to lead to higher levels of acceptance of mining operations (Moffat & Zhang, 2014; Lacey et al., 2017).The challenge, however, is how to listen systematically to communities that mining and associated operations; communities that are often located across vast geographic areas and with diverse demographics. To date, traditional methods deployed to both guide and evaluate community engagement and social investment activities have been challenged to reflect the nature of the phenomenon they seek to observe, the voice of community. For example, detailed baseline surveys of community attitudes every three years by companies, as is the requirement within the policy frameworks of most large miners, provide rich insights but do not reflect the dynamic, temporal nature of the relationships that underpins their SLO. These processes typically are largely opaque to communities and distinct from the company’s engagement activities. The CSIRO Local Voices project was developed with Rio Tinto to go some way towards meeting this challenge of how to listen to the voice of community systematically. CITATION:Moffat, K, Dawson, L, Carr-Cornish, S, Boughen, N and Masterson, S, 2018. Listening to Local Voices – a systematic approach for understanding what a social licence to operate means for Rio Tinto in the Pilbara, in Proceedings Life-of-Mine 2018, pp 8–11 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By G Reynolds, N A. Ware, L Lu

Queensland Pacific Metals (QPM) is progressing its Townsville Energy Chemicals Hub (TECH) project to produce nickel and cobalt sulfates for advanced battery materials. Apart from the nickel and cobalt sulfates, the process also generates a hematite by-product (~640 ktpa). The hematite byproduct precipitated from the process, hereafter ‘hematite precipitate’, is high in Fe and particularly low in impurities. However, it is a fine <20 μm crystalline, hydrometallurgical precipitate and is produced as a filter cake containing a high moisture content of about 15 per cent. This is considerably different from natural hematite ore and is expected to change its performance during sintering. In the present study, laboratory scale sintering tests were undertaken to evaluate the potential impacts of substitution of the hematite precipitate for traditional magnetite concentrates and further for Australian hematite-goethite ores in a simulated industry base blend. Substitution of hematite precipitate for magnetite concentrates was found to slightly increase the sintering temperature required to achieve the strength of laboratory sinters. However, further substitution of hematite precipitate for Australian hematite-goethite ores slightly reduced the sintering temperature required to achieve the laboratory sinter strength. These results reflect the reduction in Al2O3 contents of the blends and are consistent with the trend observed in industry and pilot scale facilities. The reduction in sintering temperature generally correlates to a reduction in fuel rate in the larger scale sintering process. The pore structure of selected laboratory sinters was further examined and discussed in conjunction with sinter strength. The pore structure images highlighted the relative difference between the blends with the most obvious difference being seen at 1290°C which correlates well with the laboratory tumble index (TI). The laboratory sinter samples showed an increase in porosity and irregularity of pore shape, as hematite substitution increased demonstrating the correlation between a more porous structure and a lower TI.

Sep 18, 2023

In recent years there have been many changes in mine ownership due to the on-going rationalisation towards larger mining companies. Larger companies inevitably find it hard to manage small mining operations and in many cases smaller mines do not fit corporate resource, production and profit criteria. Smaller companies are more suited to managing these medium or small scale mines and are tendering for the purchase or lease of mines that larger companies wish to dispose of. In addition to these factors there has also been a trend (especially in Western Australia) for mines to continue operating at ever increasing depths. This in turn has led to more mines operating in high stress environments and experiencing damaging seismicity. Assessing the viability of seismically active mines from a takeover or purchase point of view should involve analysing the risk profile of every aspect on mining that could be affected by adverse seismicity. This includes assessing current and alternative mining methods, mine designs, support systems, extraction sequencing, monitoring and blasting. This paper includes discussion on items that need to be assessed when considering the purchase of seismically active mines, with experience gained from some recent studies in Western Australia. In these cases it was apparent that quantification of previous seismic history on itÆs own was a totally inadequate method of assessing minewide seismic risk potential. A more holistic approach is required, taking into account all aspects of relevant data, all the minewide effects of seismic activity and all possible means of mitigating those effects.

Jan 1, 2002