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We are all no doubt aware that with today's high costs it is more important than ever to get the maximum possible return on capital invested in the mining industry. Screening is an important and often costly process in the size classification of industrial minerals and for this reason alone it is essential for both managers and operators to fully understand what type of screening equipment is best suited for a particular application and why. The advent of elastic materials such as rubber and polyurethane have added a new dimension to the process of screening. It is important to understand why the physical properties of these materials can be of benefit in the screening process, and recognise which type of screening applications best take advantage of these orooerties.

Jan 1, 1984

By L C. Thompson

BioLix is the term for a new class of biologically-derived lixiviants for precious metals (gold and silver) recovery. BioLix can be used as an alternative to cyanide on virgin and spent ores. The BioLix process is based on inducing microbial enzymatic reactions that generate organo-lixiviant chemicals. The bioprocess involves a two-stage culture strategy. First, specialty microorganisms are cultured to generate a high biomass. Then, a food-grade quality amendment is introduced that forces the microorganisms to produce the organo-lixiviant. The second-stage culture is applied to the ore where the microbial/lixiviant system acts on mineral surfaces to extract precious metals. The process operates at ambient temperatures and near neutral pH. This paper will examine the BioLix process through an extensive laboratory development and demonstration project. Laboratory development consisted of identifying and isolating specialty microorganisms and inducing agents for the production of the organo-lixiviant solutions. A demonstration was performed on low-grade and high-grade oxidised ore from the Buffalo Valley mine in Nevada, USA. Results indicate that the BioLix process was comparable to cyanide in terms of gold recovery and operated at near neutral pH and ambient temperatures. Applications for the BioLix process will be discussed including spent-ore re-leaching, cyanide replacement for virgin ore, and in situ mining.

Jan 1, 2004

By J Pearse, N Acosta, N McIntyre, M Angarita, L Camacho, C Huguet, D Arbelaez-Ruiz, J Ossa-Moreno, O Restrepo

Colombia is an example of a nation where mining makes a significant contribution to local and national economies. Due to the abundant resources present in the ground, there are good prospects for further development. However, the impacts of mining projects can include reduced access to good quality freshwater for other economic activities and/or biodiversity preservation (Ossa et al., 2018). As well as the water management challenges common to all mining regions globally, Colombia has particular challenges associated with its biophysical and socio-political traits. Land use change in many regions is dynamic including rapid development of agriculture and the development and abandonment of small scale mines. The value of ecosystem services provided by prospective mining regions also creates challenges in particular with regard to the páramos, the headwater wetlands from which about 70% of Colombia’s water supply has originated (Cleef 1981). Colombia also has particular challenges related to strong preconceptions about mining and its impacts on water. On the one hand, there is recognition that new large-scale mines are important for Colombia’s economy; on the other, there is deep distrust of the sector’s ability to operate with minimal adverse impacts (Gutiérrez-Gómez, 2017). Hence, any impact assessment is likely to face high levels of scepticism and scrutiny. Summarising the work of McIntyre et al. (2018), this abstract proposes a framework for assessing and communicating risks to regional water resources arising from the impacts of mines. The framework outputs aim to provide government and other stakeholder groups the scientific evidence needed to inform their viewpoints about mining development in the selected region, and a baseline from which to design a program of priority scientific research. CITATION:McIntyre, N, Angarita, M, Acosta, N, Camacho, L, Pearse, J, Huguet, C, Restrepo, O, Ossa-Moreno, J and Arbelaez-Ruiz, D, 2018. A framework for assessing and communicating water risks in prospective mining regions of Colombia, in Proceedings Life-of-Mine 2018, pp 49–51 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By T Perera, B Fan, S Thang, T Hsia

Minerals are valuable resources and critical elements for a broad range of biological and technological applications, including technological developments to improve energy efficiency and the global movement to promote a low-carbon economy. However, in order to extract these critical metals, large amounts of waste and toxic chemicals are generated, as well as the use of high energy and large amounts of water consumption. Froth flotation is one of the most commonly used processes to separate and collect high-value minerals, but it still has some limitations, including low flotation efficiency performances using existing collectors and other reagents. Therefore, there is an urgent need to design and develop new metal-specific collectors to more efficiently separate and recover valuable minerals and to allow bulk water recovery from flocculated tailings. In this research, we propose to use our newly designed and synthesised novel collectors derived from a type of vitamin E (α-tocopherol), a relatively inexpensive and non-toxic natural molecule. As a potential collector-building block, α-tocopherol has a long hydrophobic carbon chain that facilitates the attachment to air bubbles during the froth flotation process. In addition, the phenol group of this molecule can be easily modified to incorporate various functional groups for targeting different types of minerals. Furthermore, α-tocopherol can be converted into a monomer for polymerisation by the reversible addition-fragmentation chain-transfer (RAFT) process, which can provide us with polymer based-collectors with high precision control of molecular weight and architecture. So far, small-scale qualitative experiments on α-tocopherol-based collectors have been performed with good results, which indicates the feasibility of these compounds as novel collectors for improved froth flotation processes.

Aug 24, 2022

By C Simpson

In 2011 the forecasted world demand for iron ore continues to grow, and during this time Australia is looked upon as a reliable supplier of high quality ore. The expansion of the current Australian mines is unlikely to meet the forecast demand. New mines are therefore being actively explored for and when discovered, are quickly being developed into mines in order to meet the world’s hunger for steel.The Solomon Project area is a large new iron ore discovery, located in the central Hamersley Ranges of the Pilbara province in Western Australia. The first Fortescue exploration drill holes commenced on the project in 2007 and to date three billion tonnes (Bt) of iron ore have been defi ned within the project area. Fortescue is fast-tracking the development of the ‘Solomon Stage 1’ project, with rail and mine construction commencing during 2011, and ore to be railed to Fortescue’s existing shipping operations at Port Hedland commencing in 2012. At a designed production rate of 60 Mt/a, the Solomon operation will be one of the biggest production centres of iron ore in the Pilbara.Deposit types include the three dominant mineralisation styles of the Pilbara province, being bedded iron deposits (BID), Channel iron deposits (CID) and detrital iron deposits (DID). All these mineralisation styles are present in large concentrations within the Solomon project area, and when mined will produce two product streams. These are a single product of CID, and a combined product from a blend of BID and DID material.This paper defines the geological characteristics of the Solomon iron deposits as recognised through the exploration and development of this vast resource over the three years since exploration commenced on the project.

Jul 11, 2011

By B Shi, Y Li, L Ma, F Zhou

Subsurface fires are a common threat to coal mining, as spontaneous combustion of coal can potentially result in gas combustion and explosion. Fire-proof techniques, such as grouting, foam, or colloid injection, are not in a position to function ideally, due to the limited coverage and stopping the extinguishment substance from reaching the fire location. Liquid nitrogen, as a kind of all-submerged fire prevention or extinguishing method, can rapidly extinguish fires, thus preventing gas explosion and minimising extinguishment time. Injecting liquid nitrogen through boreholes is an important way during the period of mine catastrophe. But liquid nitrogen is not effective enough in infusion; technical issues restrict the development and utilisation of liquid nitrogen fire prevention and extinguishing technology. Immediate infusion of liquid nitrogen is usually associated with ‘air slug’ (the balloons and bubbles in the pipeline which hinder the flow of low-temperature liquid), which blocks pipelines for liquid nitrogen injecting. Another issue is that the pipeline tends to be damaged due to freezing, which undermines the injecting efficiency of liquid nitrogen and its application result. In order to solve the problems of the low efficiency and some other related field issues in liquid nitrogen perfusion, the ground–underground high efficiency liquid nitrogen injection technology were developed. Implementation of liquid nitrogen infusion techniques in Chinese coalmines achieved the goals of fire prevention and air-cooling. The technique presented in this paper is efficient in absorbing heat, and consequently, displacing oxygen and combustible gases. Field tests at Rujigou and Yangchangwan Coalmine justified the efficiency of the technique. By using this technique, there was no waste left behind, which may impede the subsequent production. The presented technique is of great benefit to the social, economic, and environmental aspects of mining operations, and will have broad applications in fire prevention for large-scale coalmines.CITATION:Zhou, F, Shi, B, Li, Y and Ma, L, 2015. Key techniques and engineering applications of stereoscopic liquid nitrogen infusion for coalmine fire prevention, in Proceedings The Australian Mine Ventilation Conference, pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By M Yahyaei, F Reyes, R Lage, V Jokovic

Equipment wear is strongly related to the performance of grinding circuits. In particular, SAG mills are subjected to the wear of their shell liners and grates. Changes in lifter height and face angle impact mill performance, while classification at the mill discharge is also affected as grates wear out. Moreover, liner mass loss caused by wear affects how operators interpret readings of sensors such as load cells or bearings pressure. Automating and optimising grinding circuits under these constrain becomes challenging due to the nonlinear and dynamic nature of the system. The operation of SAG mill grinding circuits remains largely dependent on human intervention, which frequently results in inconsistencies in performance across shifts, reflecting the operator’s personal preferences, experience, and other human factors. The influence of human factors can be reduced by careful training of operators as well as by automation using advanced supervisory control. The latter approaches could benefit from the development of dynamic process models that consider the effects of wear on the performance of equipment over time. This paper presents detailed industrial data showing the effects of wear on SAG mill performance. Additionally, a dynamic SAG mill model that accounts for these phenomena is proposed and demonstrated in a simulated environment. This model is shown to mimic the effect of wear on the performance of industrial scale mills and the operational constraints they are subject to, thus extending traditional SAG mill models. Incorporating wear into modelling and simulation platforms can improve the understanding of the effects that wear can have on the performance of key assets in comminution circuits and may allow the development of more robust model-based advanced process control strategies.

Aug 24, 2022

Nuclear power stations to be installed in Australia will be fuelled from Australian resources of raw materials.This will require the establishment of new manufacturing industries and the eventual expansion of established activities, especially in uranium mining and the preparation of precision metal products.This paper presents some predictions of the possible growth of nuclear power installations in Australia.These might amount to 4000 MWE by 1985 and 11,500 MWE by 1990 and towards the end of the century, about 50 per cent of new generating plant might be nuclear.Predictions are given of the demands for materials (uranium and zirconium) and fuel manufacturing services for four reactor systems which might be considered in the programme.The availability of raw materials and technical capability place Australia in a particularly good position to undertake the manufacture of nuclear fuel; in addition to satisfying the domestic demand we should actively seek export markets for these products.

Jan 1, 1971

By D J. Robinson, L L. Kuhar

In-situ recovery (ISR) is accepted and applied across many geographies, and approximately 50% of the world’s uranium is currently extracted by using an ISR method (World Nuclear Association, 2014). The low environmental impact, the elimination of risk for mine workers and the fact that all of the lowest-cost producers of uranium use an ISR approach should raise interest from traditional miners (IAEA, 2014). However, the broader application of ISR to other commodities and mineral systems remains limited. A number of demonstration (experimental) copper projects have been undertaken (Sinclair and Thompson, 2015) with a few copper projects in Arizona being close to demonstration (Florence, 2018 and Gunnison, 2018). Evidence of very few economically operating ISR copper projects can be found (for example, the Russian, Uralgidromed OAO, built by the Russian Copper Company in 2005 and operated as an ISR facility from the Gumeshevskoye deposit (Russia Mining, 2018). A number of gold deposits, particularly paleochannel deposits, have also been considered for ISR, but, to the best of our knowledge, only limited demonstration and no commercial operations have been established, yet (Kuhar et al, 2018 and references therein).CITATION:Robinson, D J and Kuhar, L L, 2018. Extending mine life through application of an in situ recovery approach, in Proceedings Life-of-Mine 2018, pp 56–57 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By R W. Wilson, A R. Branch, T S. Pooe

The original bulk air cooling system at this particular mine made use of two water chilling refrigeration machines to produce peak cooling of approximately 12 MWR with a downcast air temperature of about 7°C; however, as the shaft is not used for transporting personnel, the opportunity existed to supply more cooling to the mine by lowering the downcast air temperature. An ice storage facility has been constructed and provides a range of opportunities in operating the system: colder air temperature sent to the shaft, enabled by using near-zero degree water produced by melting ice to cool the air; electricity time-of-use management, by shifting electricity usage out of peak tariff periods; and increased peak cooling capacity, by melting ice while chilling water. Ice is created in the storage facility at night while the ambient air temperature is low and then melted to produce cold water when required by the cooling process. An ice dam was constructed and serpentine stainless steel coils installed where the ice is produced; one of the refrigeration machines was converted to chill a glycol solution to subzero temperatures to create the ice on the coils; a plate heat exchanger was installed to allow the glycol chiller to act as a water chiller as well; and a third spray stage was added to the bulk air cooler to utilise the near-zero water. This paper describes the thermodynamic design, construction and performance assessment of the new system, which is unique, novel and represents the state-of-the-art of this type of cooling system and energy management.CITATION:Branch, A R, Wilson, R W and Pooe, T S, 2015. Novel use of ice thermal storage for energy management on a mine refrigeration plant, in Proceedings The Australian Mine Ventilation Conference, pp 185–192 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By B Taylor

Although the underground mining environment is arguably safer now than at any time in history, as underground mining operations across the globe increase in-depth, magnitude, and complexity, protecting workers from harm becomes increasingly challenging. In deep, stressed, seismic mines the development face is one of the most hazardous work areas. The active face is usually the furthest extent of the underground workings, so ventilation can be difficult to maintain, exposing workers to high temperature and humidity while working on foot and doing manual labour. While mechanisation has made many tasks easier in modern times, the reality of underground mining is that development charge-up workers still spend long periods directly exposed hazards at the face. In 2019, Orica and Epiroc partnered to co-develop the world’s first fully mechanised development charging unit using fully wireless initiation, called Avatel™. Built on Epiroc’s M2 Boomer carrier platform, the system is designed to allow one person to charge a development face from the safety of a fully enclosed cabin, thereby reducing exposure to hazards at the face. The system was prototyped in Europe before entering commercial introduction in 2022. This paper reviews earlier attempts to mechanise underground charge-up and describes the development journey and engineering challenges of building a mechanised development charging machine.

Mar 29, 2023

By S Munn

Today, it can be said that the majority of mines utilise communications equipment in one form or another. Either for communications between staff making their day-to-day operations more efficient, or for emergency communications, as well as linking computer based mine management systems, and providing remote control over complex mobile and fixed machinery. With the advances in technology now available, we are moving into the next generation of mine communications equipment, using digital communications in the underground mine environment. It is a proven fact that an efficient underground mine communications system can help maximise production, by providing major gains in areas such as equipment and manpower utilisation, staff and vehicle tracking, reaction times to break downs and emergencies. In this paper we will describe some of the facilities that are currently available, as well as what will soon be available to mining and tunnelling companies around the world.

Jan 1, 1999

By L Huang

"Successful rehabilitation of tailings landforms of tens to thousands of hectares in size at base metal mines is critical to mining companies’ ‘social licence to operate’. Rehabilitation technology used is closely related to both the economic sustainability of the mining company and the ecological sustainability of the mined environment. Conventional technology to rehabilitate mine waste landforms is costly and constrained by the availability of soil (to reconstruct root zones) and clay materials (to reconstruct compressed layer). Depending on mine waste properties and site-specific resource availability, it is not uncommon to cost A$0.1–0.5 M/ha for the establishment of conventional cover systems over mine waste domains, which often accounts for large proportion of the total closure costs. This can lead to costs approaching several hundred millions dollars for rehabilitating larger tailings and acidic waste rock using conventional cover systems.The present extended abstract proposes a suite of new technologies to tackle the problems outlined above and discusses critical factors in successful rehabilitation from substrate levels to the whole landform performance, in two key aspects:in situ engineering of tailings soil to offset/reduce materials requiredin situ chemical engineering of massive hardpan layer through alkali-activation and mineral gel cross-linking network mechanisms to encapsulate reactive tailings and achieving sustainable hydro-geochemical stability in root zones.This aims at functionally replacing the roles of the compressed clay layer and capillary breaks in conventional covers. These technologies would improve both the economic and ecological sustainability of mine waste rehabilitation, thus addressing the triple-bottom line of mining and mineral processing industries not only in Australia but other countries.CITATION:Huang, L, 2016. Emerging technology for economic and ecological sustainability in the rehabilitation of metal mine tailings, in Proceedings Life-of-Mine 2016 Conference, pp 128–131 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

By S Talu, E Savage, P Sturm, A van As

It is estimated that substandard ground support installations and elements cost the Rio Tinto Copper Group millions of dollars between 2000 and 2014. These issues have also created significant safety and financial risks in Rio Tinto mines. As a result, Rio Tinto Copper has developed CaveCAD, an integrated system to collect, store and analyse all ground support-related data. The CaveCAD system stores geotechnical data and has the ability to automatically import data, collect data through tablet applications, report processed/analysed data and present this data through 3D visualisation software.The CaveCAD Ground Support module closes the design–implementation–verification loop by providing a method of verifying the compliance of all installed ground support, recording manufacturer specifications, recording quality control test compliance and rectifying any non-conformant areas. The module uses innovative technology to create value through cost saving, safety improvements and data collection efficiency. Cost savings will be achieved by a decreased need for excavation rehabilitation, less ‘waste’ due to faulty installation and quality assurance checks reducing the likelihood of substandard support units being used. Data collection will be improved through the use of a mobile tablet application that can be used underground in ‘off-line’ environments.CITATION:Savage, E, Talu, S, Sturm, P and Van As, A, 2016. Development and implementation of the CaveCAD ground support module for cost and safety improvements in block cave mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 769–772 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By J Field

Many aspects of water use in mining are driven by the technical requirements for water. There has been little consideration given to both the safety and the health requirements. Workers in the mining industry are exposed to water from a range of treated and untreated sources. The intended use of this water dictates the required quality of the water, sometimes with limited consideration for contact with miners. Particularly for underground workers, there is exposure while working in and walking through groundwater possibly contaminated by hazardous substances. Where controls are inadequate the outcomes of this exposure can result in disease, illness and injury û the costs of which can be significant. The situation could also arise where, due to the lack of human exposure, the controls are unwarranted and the financial cost unjustified from a health perspective but warranted from an equipment management standpoint. In addition to the health aspects, water can impact on a range of safety issues resulting from high pressure usage, dust suppression, fire fighting and other processes. The protocols and procedures in place need to consider the safety issues in addition to managing water usage. The current state of water management in mines from an occupational health and safety perspective has been ascertained from a survey targeting underground and surface coal and metalliferous mines. This survey considered the health and safety issues associated with water use, the types of surveillance, control protocols and the strategies that the mines have in place to manage the health and safety risks associated with water systems. The results assisted in the identification of potential occupational health and safety risks associated with water systems and the management processes that may be appropriate from a risk management perspective. Health and safety issues are often neglected but remain critical issues affecting the value of water to the mining industry.

Jan 1, 2006

SASOL Synthetic Fuels has recently completed the design of sampling systems for raw and blended coal feeding the gasifiers at Secunda, South Africa. The new systems will replace manual, stopped belt sampling and have been designed to achieve specific accuracy targets on a daily basis. The sampling system is unusual in the coal industry in that the fines content (-5.5 mm nominal) of the coal is very critical and is to be determined with high accuracy.The sampling system was designed to meet carefully considered target accuracies using methods of modern sampling theory. The heterogeneity of the coal streams involved with respect to the critical analytes was determined by appropriate sampling and sample analysis. The statistical characterisation of the time variation of analytes in the process streams was based on variograms derived from on-line ash gauges. From this point, the design was completed using fundamental statistical sampling theory and some simulation studies. The paper discusses the development of the sampling system design in detail as well as the plans to use the data stream to provide timely alarms when the coal quality deviates from the target specification.

Jan 1, 2002

By J Levett, O Rondon, I Glacken

Reporting Codes are not prescriptive on methodologies to report or classify Mineral Resource Estimation results, but the assessment of risk and uncertainty is required, and is likely to be increasingly important in future Code updates. The 2012 JORC Code indicates that relative confidence in tonnage-grade estimations should be considered for classification, and that there should be a discussion of relative accuracy and confidence levels in the Mineral Resource Estimate. These considerations are also relevant to the drill hole spacing required for various classification categories, along with other geological and data quality criteria. This paper summarises the theory, principles and current practice of various drill hole spacing analysis techniques for both achieving a desired level of resource categorisation and for optimising grade control or resource drill-out costs. The authors provide practitioners with a guide in their use to assess uncertainty and relative accuracy, as illustrated by a number of case studies. While all drill hole spacing studies rely on the assumption of consistency of the continuity model from current to future drilling, the range of methods available provide much more objective outcomes than previously adopted ‘rules-of-thumb’.

May 24, 2023

Anglo Platinum recognised with its expanded operations the need to change its evaluation strategy due to increased sample volumes and the pressure it created at laboratories. The sender/receiver analytical scenarios had to change in order to curb costs and to prevent substantial investments in new sampling and analytical facilities. Given the high cost associated with correct sampling systems and sampling protocols and the shortage of technical resources a strategy of single point sampling and analysis was introduced. The analysis was then done at an ISO17025 accredited laboratory with ten per cent checks, subjected to careful statistical scrutiny. Logistical problems increased with respect to weighbridge congestion, maintaining sampling quality, throughput of samples in the sample preparation areas, manual quality control systems in place, audit trails and analytical capacity throughout all operations. This required the expedited improvement of existing sampling practices and the development of new sampling methods and equipment. Anglo Platinum is classifying and standardising sampling equipment, sample preparation and analytical procedures for all process streams with the view to minimise overall uncertainties. Major investments were made into a customised LIMS and automated equipment for data management, reduction of manual transcription errors and streamlining of sample processing. Anglo Platinum is committed in rolling out the enhancements to all sites as priority dictates.

Jan 1, 2008

By Y L. Ma, Y Yang, M Chen, W Bruckard

To improve the understanding of the reactions and mechanisms occurring during the leaching of sulfide ores at high temperatures a range of advanced characterisation and sensing tools have been combined to provide a sophisticated and powerful methodology to examine sulfide leaching systems. These include advanced electrochemical methods, surface chemistry and materials characterisation techniques such as synchrotron X-Ray Absorption Spectroscopy (XAS), X-Ray Photoelectron Spectroscopy (XPS), Scanning Electrochemical Microscopy (SECM), and in situ X-ray diffraction (XRD), together with new robust solid state chemical sensors for in situ real time monitoring of key aqueous chemical parameters. The methodology was employed to investigate various sulfide mineral leaching processes. For example, oxidation of arsenopyrite at elevated temperature involves complicated multiple reactions and the process is strongly influenced by the solution conditions, component speciation and mineralogy. The methodology was used to study this system both ex situ and in situ to gain a detailed understanding of the complex chemical reaction mechanisms operating. These mechanisms are discussed in terms of the observed leaching efficiency. The application of this methodology enables complex sulfide leaching systems to be understood more fully such that process efficiency can be improved.

Aug 24, 2022

By B G. Blacka, O Salisbury, K W. Mills, R G. Jeffrey

Whitehaven Coal Limited operates an underground longwall mine near Narrabri, New South Wales. The mining horizon in the Hoskissons Seam is overlain by a 16–20 m thick unit known as the Digby Conglomerate, a unit that is sufficiently massive to have potential to cause a windblast during first caving at the start of each longwall panel and periodic weighting throughout the panel. A program of hydraulic fracturing has been successfully used to precondition the conglomerate strata to increase its caveability at the start of each panel. This paper presents a system of temperature monitoring that was used successfully to measure hydraulic fractures at Whitehaven confirming their rate of growth, orientation and interaction with previously placed hydraulic fractures.CITATION:Mills, K W, Blacka, B G, Jeffrey, R G and Salisbury, O, 2014. Temperature monitoring of hydraulic fractures used for preconditioning massive conglomerate strata to reduce windblast, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 189–194 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014