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By M Simpson, K Brodie, J L. Mauk

Subaqueous water-rock reactions that occur at the pit wall/lake water interface can affect the pH of pit lakes. Many pit lake water chemistry models neglect subaqueous reactions, which may create inaccurate predictions over time. A mineral quantification method is presented that defines the wall rock mineralogy of active open pit mines, using samples collected from the Martha Mine, a low-sulfidation epithermal Au-Ag deposit in Waihi, New Zealand. The mineral quantification method has five components: field observations and sampling, X-ray diffraction analyses, selection of representative samples, geochemical analyses, and mineral accounting. Predicted mineral concentrations closely match observed mineral concentrations visually estimated using petrographic techniques. Results of the method can be incorporated into a geochemical model of long-range pit lake water quality resulting from subaqueous water-rock reactions.

Jan 1, 2003

By Bhattacharyya A. K

In this paper, the current methods for predicting surface subsidence due to underground coal mining are evaluated first. A single index, called a strata parameter (P), is then proposed to describe the overall character of the undermined strata in the context of surface subsidence. Based on the strata parameter, a method for predicting the maximum surface subsidence for various panel width (w)/depth (h) ratios is presented, which has been tested against specific empirical curves or data from several coalfields in different countries. From the data relating to several coalfields, a linear relationship between the reported average angle of draw and the strata parameter has been established. It has also been found that the strata parameter can be used for studying the locations of the inflection points and the shapes of transverse subsidence profiles.

Jan 1, 1995

By K Paki, K Parker, J F. Dupont

The Mount Charlotte grinding circuit at KCGMÆs Fimiston mill was recently equipped with three 650 mm CAVEX cyclones in order to improve the overflow P80, reduce the fines bypass to the underflow and improve the underflow density/recovery of water to the overflow. After the first two sets of surveys were conducted air core boosters (ACBs) were installed on the 650 mm CAVEX cyclones in an attempt to further increase their performance. JKTech was approached to assist with the examination of the data obtained from the surveys; this data was intensively modelled to determine, to a high degree of confidence, the impact the changes to the cyclones had on the classification and the benefits to the plant. This paper outlines the outcomes of the trial and the methods used to determine those outcomes.

Jan 1, 2007

Open pit mining at Bingham Canyon commenced in 1904 and about two billion tonnes of ore have been extracted since then. There remain just under one billion tonnes of ore in the pit and this will be mined by 2015. Because the porphyry system extends below the ultimate pit limits, Kennecott Utah Copper Corporation initiated a study in 1997 to determine the viability of underground mining. The study was initiated at that time because the results were to be used to compare the economics of a further pit expansion to that of an underground mine. If a pit expansion was viable then overburden removal would have to start in the near future. This paper is a summary of the work that was carried out for the underground study. Block cave mining was determined to be the most appropriate method to mine the deposit. Two block cave areas have been planned with a total production rate of 72 500 tpd. Additional sources of ore will come from skarn orebodies that are associated with the porphyry deposit. The geology of the deposits is described together with the geotechnical techniques that were used to characterise the rock in the absence of more detailed data that are normally available. A general description of the mine plan is given along with the reasons for selecting the particular methodology used. The study was completed at the end of 1998 and demonstrated the viability of underground mining at Bingham Canyon. Funds have been approved for further drilling and technical studies, which will lead up to a feasibility study in 2004/5.

Jan 1, 2000

By Rao SR, Finch JA

Sphalerite flotation without Cu activation in the presence of iron ions has been reported and studied as a function of pH, dissolved oxygen content and pulp potential with both single mineral and ore samples (Leroux, Rao and Finch, 1987; Xu et al, 1992; Zhang, Rao and Finch, 1992). The flotation was attributed to ferric hydroxy xanthate. As a prelude to surface analysis to try to identify the species responsible, bulk precipitates formed from iron salt and xanthate solutions under different conditions were obtained and analysed. Analysis techniques included ultraviolet spectroscopy,infrared spectroscopy, X-ray diffraction and Mossbauer spectroscopy. It is tentatively concluded that the bulk precipitates contain three ferric components, two hydroxy xanthates (Fe(OH)2X and Fe(OH)X2) and iron oxide (FeO.).

Jan 1, 1993

By W J. Haylock, K Wasiel

PX4 Software Pty Ltd is a Brisbane-based company, which specialises in providing tenement management software to mining and exploration teams operating in Australia and several international jurisdictions, including the United States, Africa, and Canada. Whilst the company is experiencing substantial growth due to a demand from both the minerals and mining technology sector, there is a crucial gap in the market for critical minerals, which will be required to achieve the net-zero emissions goal set by the Paris Agreement for 2050. To help understand and address the technology gap identified by the unprecedented demand, PX4 Software undertook the Annual Survey of Technological Transformation in the Exploration Industry. This survey involved interviews with 12 very distinguished subject matter experts in the fields of Geoscience and Geology from across the globe. From this survey, we have defined eight major categories of exploration technologies. Notably, the most transformative of these technologies over the past 65 years falls into the Geophysical Methodology category, specifically focusing on image and signal processing of both airborne and downhole data. Advances in computing power during this period have significantly improved data processing quality, enhancing orebody modelling, and targeting. This has had a profound impact on the industry. Moreover, the survey reveals that future transformative technologies are expected to centre on the automation of existing processes through AI and Machine Learning techniques. This is expected to help facilitate the identification of critical mineral systems and thus enable the exploration industry to make more informed decisions based on data analysis using Machine Learning and AI.

Sep 1, 2024

By S H. Burgmans, B Anderson

This paper aims to define the specific challenges relating to dredging fine tailings from an above ground storage facility for transferral to a mined-out pit. In addition, it compares dredging and mining perspectives on dredging of fine tailings.

Jul 1, 2021

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

By T Wettainen, G Shekhar, M Stromsten, B Skawina

The aim of a transportation system in an underground mine is to move the rock masses from one location to another in the most preferable manner by minimising the long and short-term operational costs. A continuous improvement of material transportation systems used in mines generates a need for continuous investigation of the current and new underground transportation systems. In an underground mine, an orepass is a common system used to transfer the material to the lower levels. If this system loses the ability to transport or store the necessary material capacities, it would result in production disturbances. In this paper, discrete event simulation (DES) was utilised to analyse the material inflow and outflow of the orepass systems when subjected to the different conditions. The study presented in this paper is based on the Malmberget mine, the second largest underground sublevel caving (SLC) iron ore operation in the world.

Mar 15, 2021

By K T. Mandisodza, T J. Cartledge

The principal objective of Geotechnical Engineers supporting operating mines is to provide safe working conditions and ensure that pit designs are geotechnically optimised to site conditions and pre-defined stability requirements. Pit slope designs are delivered in advance of pit excavations. Making changes to these designs is usually slow to enact and involves a layered sign-off before implementation, leading to unwanted delays in their adoption and subsequently increased production pressures. When unexpected ground conditions are encountered during the mining process, or short-term mining schedule requirements demand it, changes to these designs may not be easily feasible in certain situations. It is when these scenarios arise that Geotechnical Engineers need to be proactive and consider unconventional options to deliver safe operating conditions while satisfying short-term requirements to the mine schedule. Essentially, the geotechnical short-term strategic designs double-pronged approach supports the mine schedule while providing safe conditions and minimising geotechnical risks for people and equipment. Common short-term strategic geotechnical designs include; slope buttressing, over-steepening cut slopes to increase reserve recovery through unplanned or emergency cutbacks, and accepting risk threat and operating under unstable slopes. When implementing strategic design options, the Geotechnical Engineer must consider the broader implications for such designs. They must think of the plan’s long-term effects on the mine schedule and pit wall stability. Initiating aggressive designs to recover additional reserves to satisfy a short-term scheduling demand could result in-pit wall instability or suboptimal pit layout. Before and during the implementation phase, the Geotechnical Engineer must communicate and engage with relevant stakeholders to ensure that the plan is executed accordingly and geotechnical risks are effectively managed. Proactiveness to ground response and implementation of risk management strategies will improve safety performance and optimise mining schedules.

Jun 22, 2022

By T A. J Hopper, S Mukkisa, K-O Ott, D Palmer

RIG Technologies has developed new technology that can successfully acquire high quality natural gamma ray (GR) and hole deviations, downhole while drilling, on reverse circulation drills. This technology survives the hostile downhole environment with shocks of between 400–2500 g for 7– 10 days at a time. The Logging While Drilling (LWD) service eliminates the need to run in-rod surveys, either by the driller or by wireline trucks and crews. This time saving is in the middle of the drilling process, thus enabling drills to keep drilling and increase their productivity. Additional to the natural GR and directional survey, the downhole tool is equipped with sensors to measure the downhole dynamic response of the drilling system providing insights into rock hardness, density and potentially clay types. These parameters have never been acquired behind the hammer before and coupled with surface measurements from the drills themselves, form a rich data set for trainable machine learning algorithms shortening the time to receive advanced geophysical answer products from sometimes months, to live feeds directly from drills (Hopper, 2019). Alive, high speed, two-way data link between surface data acquisition systems and downhole geophysics tools has been established and incorporates calibrated surface measurements of dynamic forces directly on the drill string to match up with those measured downhole. Receiving live streams of natural GR and hole deviation surveys as the drill is drilling allows true remote decisionmaking with live data available anywhere in the world. The combined data from surface and downhole dynamics builds a data set that could begin to enable true optimisation of autonomous drilling processes.

Nov 8, 2021

By P Malkin, S Thomas, P M. Stone, D Kostyuk

In open pit mining, it is common that the bottleneck to productivity and profit lies in the truck-shovel mining operation, especially as strip ratios and mining intensity have increased with resource depletion and advances in mining equipment capabilities. This paper outlines a study of truck-shovel productivity using a new proprietary discrete event simulation platform for truck-shovel operations called MineDES. The study will specifically address the issue of whether truck queuing at shovels should be considered productive or not, and how mining engineers can determine the optimal truck fleet size for specific operational configurations.The MineDES simulation platform will be described and illustrated, highlighting the features that make it an appropriate tool for conducting the experiments at the heart of this study. The study encompasses a set of experiments, consisting of a number of simple truck-shovel operational scenarios for a benchmark open pit mining operation, which are simulated using MineDES. Each experiment is designed to highlight different factors, which are most important in calculating the ideal truck fleet size and for understanding the marginal productive impact of each additional truck added to the fleet. The scenarios will principally address the issues of how different types and levels of unscheduled equipment downtime and process variation, combined with the traffic delays/congestion arising in more intense mining operations, will affect productivity. The results of the experiments are interpreted using a simple fit-for-purpose cost and revenue model in order to highlight the indicative cost of over- or under-trucked configurations.The study has found that the optimal fleet size that maximises productivity and value will, in the presence of even small process variation, lead to non-zero trucks queuing at shovels on average. As process variations and unscheduled downtime events increase in the truck-shovel system, the required fleet size to optimise productivity and value increases. MineDES provides a convenient platform for quantifying this for real operations.CITATION:Kostyuk, D, Thomas, S, Malkin, P and Stone, P M, 2014. Is truck queuing productive?, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 267–274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

The Cadia Valley Operations currently hosts a large operational open pit, a large operational sublevel caving underground mine and two other underground projects at the study stage. This scenario creates an unusual situation for the evaluation and planning of a fifth major open pit project. The Cadia East Open Pit is a large gold-copper development located adjacent to the operational open pit and above one of the underground projects. A study team is conducting a comprehensive and robust analysis of the target orebody. Two key factors for this project include the existing and planned projects within the valley and the wide range of available mining methods. The aim for the study team is to present an optimal and practical case which suits the entire Cadia Valley Operation. A rigorous and robust analysis of the situation requires that each factor be properly evaluated. A modular system has been developed which allows the wide range of scenarios to be quickly and meaningfully considered. Sensitivities for each module drive the further development of that particular module. As each scenario progresses, an assessment is made evaluating its value, strategic value and practicality. In such a way, the number of scenarios is gradually reduced at each stage to produce a final short list of feasible cases. Each scenario on the shortlist is then assessed with regard to the existing operations and other projects. A qualitative and quantitative analysis is made. This ranking is used to provide the recommended case.

Jan 1, 2007

By M Freeman

In a visionary move, the Planning Commission and the Ministry for Planning in Western Australia decided to invite three extractive industry quarry operators, local government councils and State Government departments (Minerals and Energy, Environmental Protection, South West Development Commission) to contribute jointly to study the impacts of blasting on areas surrounding basalt quarries in the Bunbury region of WA. The results of the study will help establish suitable zones in which land uses will be controlled under a proposed Greater Bunbury Region Scheme and in local planning schemes, to minimise conflicting land uses. This paper discusses the blasting program conducted to characterise and model the vibration behaviour of the rock under the effects of pilot-scale and full production blasting, and highlights some of the benefits achievable when a thorough blasting impact program and assessment is conducted at the planning stages of land-use establishment.

Jan 1, 2001

By A Keogh, P Allen, P Stoker

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Private equity (PE) firms are comparatively free of mandatory requirements for the level and scope of due diligence applied prior to making investment decisions in minerals projects when compared to listed entities, sovereign funds or financial institutions adopting the Equator Principles (Equator Principles Association, 2013). While this freedom allows for flexibility, agility and innovation in making investment decisions, it can also expose PE firms to material risks that may impact their ability to successfully list the projects or attract later financing.Financial institutions and investors with mandatory due diligence and disclosure standards may refrain from investment in or acquisition of a project if it fails to meet various performance requirements. There are many high-profile projects that have suffered significant write-downs on book value after acquisition because specific non-mining issues were not adequately assessed. Thus, a PE firm may be left with an asset that is difficult to divest and incapable of securing development finance.PE firms can manage this risk by being aware of the growth trend in the adoption of ‘international standards’ in addition to host nation standards and legislative requirements. This paper outlines key issues for PE firms to address to maximise the chances of obtaining funding or successfully taking an exploration or mining project through to listing or divestment. Two steps are required: identification of gaps in performance and priority matters of interest to financial institutions and development of action plans to ensure that the priority requirements are met or capable of being met.A PE firm can set its project for success by understanding the social and environmental performance requirements of international standard financiers and by setting the project on the right path to meeting these requirements, and thus making it an attractive investment.CITATION:Allen, P, Stoker, P and Keogh, A, 2015. Setting for success – private equity exploration and mining project buy-in to listing and divestment , in Proceedings PACRIM 2015 Congress, pp 93–100 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By A Vakili

Dilution is associated with considerable direct and indirect costs in underground open stoping operations. As shown in previous works, an improved ability to predict dilution enables the economic risks associated with unplanned dilution to be reduced. Depending on the width of the orebody and depth of mining, the economic performance of an open stoping operation can become even more sensitive to dilution. It is shown in several well-documented studies that as little as 1 per cent of additional dilution can impose millions of dollars of lost profits per annum. Optimisation of a stoping operation is therefore largely dependent on the ability of the operation to minimise dilution. This can only be achieved through sensible analysis of past and future performance of mined stopes using the most appropriate recent available technologies and tools. This article presents a new design process that utilises advanced geotechnical numerical modelling and various other analytical tools to assist with a more robust mine design of open stoping operations. The focus of this design process is on geotechnical factors affecting dilution during the life-of-mine. A recent application of this optimisation method for a mining operation is presented in this paper as a case study. Through the application of this method and various other operational improvements, the mine was able to deliver more consistent production and lower operating costs over its life-ofmine outlook and was able to reduce dilution by up to 50 per cent and achieve sustainable record high production rates.

Mar 29, 2023

By R M. Lonsdale, M D. Goodz

"With an ever-increasing dynamic business environment, successful stakeholder engagement is becoming more fundamental to achieving desired outcomes in today’s mineral resource industries. It is imperative to be proactive in correctly identifying all stakeholders and initiating early contact. This builds trust relationships, which are essential to ensure future decision-making processes are streamlined.Often neglected is a company’s obligation to select the correct team to represent its values and mission. The company requires representation that demonstrates an understanding and commitment to its operations and people, the safety and health of the community and environment, and most importantly, represents the decision makers. Stakeholders need to believe that the engagement process is genuine and that the company representatives are aligned towards targeted outcomes that will benefit all stakeholders in some way.Among others, stakeholders include shareholders, staff, families, community, service and supply providers, regulators, land managers and the political/financial framework. Depending upon the mineral product, stakeholders may include ports, international offtake clients and those along the route. New stakeholders continually evolve during mine life, and the engagement process requires an investor–community–public relations (IR/CR/PR) team to anticipate change and actively scan perception and chatter.Successful communication is more than delivering a message; it is about engaging stakeholders and confirming the feedback loop to ensure the correct message is communicated and the relationship is strengthened.The nature of the mining company’s branding and the public’s perception of company intentions will dictate whether there is willingness to allow the company to follow its desired path. This in turn controls the company’s most scarce resource – time. Timing is fundamental to achieving targeted outcomes with minimal cost and delays, marketing in a peak cycle and acquiring critical capital for development and growth.Branding and stakeholder engagement effectively controls and extends to the company its social licence to operate.CITATION:Goodz, M D and Lonsdale, R M, 2016. Stakeholder engagement – who are you, what do you stand for and why? In Proceedings International Mine Management Conference, pp 239-248 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 22, 2016

By G D. Matthews, M E. Haylett, S Khosrowshahi, A Weeks

In narrow orebodies the use of ordinary kriging (OK) may pose certain limitations when used for grade control modelling. The smoothing effect of kriging, by its very nature, cannot retain or accurately characterise the dispersion (variability) that is inherent in gold deposits. This dispersion is a critical component of determining the desired level of ore loss and dilution.Fixed block model positions used in OK, and all estimation approaches, within a grade control process may never align with the ‘true’ ore boundary. This may lead to excessive ore loss and dilution, especially within narrow lodes.Using a risk-based approach to ore block design based on the geostatistical method of conditional simulation (CS) can highlight the differences achieved when an alternative method to OK is used for grade control modelling. By using a mesh of nodes and the application of a ‘transfer function’ to the simulation models, the position for ore contacts can be better assessed than when using fixed blocks in OK. Therefore, the value of various ore block boundaries can be better analysed by objective assessment of ore loss and dilution for a given minimum mining selectivity (selective mining unit or SMU), even in narrow lodes.A case study of a narrow vein gold deposit, comparing the results from an OK model and a CS model shows that whilst both models show similar trends – waste, low-grade, and high-grade regions are the same in both cases – the simulation model can provide greater insight for optimal definition of the mineralisation boundary.CITATION:Haylett, M E, Weeks, A, Matthews, G D and Khosrowshahi, S, 2014. Ore block design in narrow vein gold deposits – estimate or simulate?, in Proceedings Ninth International Mining Geology Conference 2014 , pp 421–424 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By D Phillpotts, S M. Mantsho, P Strobos

A challenge on many industrial flotation circuits is controlling concentrate mineral grades using measurements that are provided infrequently. The mineral grades in concentrate streams are a critical performance indicator in any industrial flotation circuit. Failure to achieve concentrate mineral grade targets has significant financial consequences on a flotation operation. A violation of a gangue mineral grade limits by the concentrator may also result in significant penalties. Online grade analysers which can provide reliable real-time grade measurements are essential for effective grade optimisation. The Blue Cube MQi analyser (by Blue Cube Systems) has recently come to prominence for its ability to rapidly determine mineral concentrate grades online and in-stream. This has provided excellent insight into the actual process dynamics in the flotation circuit, and hence enabled real-time control and optimisation of concentrate mineral grades. MintekÆs Measurement and Control division, specialising in advanced control solutions for mineral and metallurgical industries, has had the opportunity to link the FloatStar Grade-Recovery Optimiser to the measurements provided by the Blue Cube system at a nickel concentrator plant. The project initially focused on stabilising the final concentrate grade without directly accounting for nickel recovery. The site later procured additional Blue Cube MQi analysers, resulting in the expansion of the FloatStar Grade-Recovery Optimiser to incorporate recovery component in the performance. This site already had the FloatStar Grade-Recovery Optimiser for several years, but the original grade measurement device was unreliable and ultimately failed. The system was reactivated once the Blue Cube system was installed, replacing the old analyser.CITATION:Mantsho, S M, Phillpotts, D and Strobos, P, 2012. The implementation of FloatStar grade-recovery optimisation control solutions using Blue Cube online grade analysers on industrial flotation circuits, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 363-368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By J Nortier, J Dray

There is no single factor that determines the appropriate capacity for a mining project. It is driven by the size of the resource, the capacity of the market, the availability of capital, the availability of power, the availability of water, and a myriad of other considerations. There is also no single solution to the question of how big the project should be. However, to develop a project, the study team needs to select the configuration options that it regards as the best for the project. To be able to make this selection, the study team should consider the range of available options and do so at a level of detail that gives it confidence in the conclusion but does not lead to multiple detailed design exercises. Having considered the range of options, and with a clear definition of the project owner’s objectives and constraints, the work to be carried into feasibility studies can be focused appropriately. This paper discusses the process of completing strategic mine planning to identify project configuration options to assist in the selection of the processing plant throughput rate (Capacity Study) for a large greenfield open pit mine. The processes described in this paper allow for the basis of design to be set for subsequent studies that meets the objectives at a risk profile acceptable to the owner.

Jun 22, 2022