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A metallurgical balance drawn around a mineral processing plant or smelter must involve all process streams crossing the plant boundary. Modern sampling theory, as formulated by Gy, and sound statistical method can be used to determine the uncertainties in the observed assays for the set of balance analytes and in the mass flow rates of the process streams for the balance period. These uncertainties can then be used together with the material balance equations to arrive at adjusted component mass flows that satisfy the material balances exactly. To determine whether or not the data is consistent with the level of uncertainty in the data and with the material balance equations, a goodness of fit test is applied. This goodness of fit criterion is the principal tool to quantify the quality of the material balances. The mathematical structure of the statistical material balance problem poses a number of challenges. For example, while the variances of the adjusted component mass flows do not vanish, the variances of the sums of the adjusted component mass flows about each balance node do vanish, simply because the balancing computation demands that the balances close exactly. Even though it can be shown that the variances of the adjusted component mass flows are always lower than the estimates for the corresponding unadjusted component flows, it is still not possible to construct a confidence interval on the component mass flow into (and out of) a balance node using the adjusted component flows. On the face of it, such a confidence interval is exactly what is most desired from the balance calculations. The problem arises because the balance problem is a data adjustment rather than a parameter estimation problem. It is possible, however, to calculate the recovery of a component to a product stream and determine a confidence interval for the recovery value. It is also possible to calculate an uncertainty in the mass flow of any balance species in any process stream, before and after balancing.

Jan 1, 2005

By Andrews S. J

Century is a shale hosted zinc, lead, silver deposit developed within gently folded, Proterozoic Lawn Hill Formation shales and siltstones, approximately 250 kilometres north-northwest of Mount Isa, comprising 118 million tonnes of stratiform mineralisation, averaging 10.2 per cent ,,inc, 1.5 per cent lead and 36 grams per tonne silver. The deposit is largely overlain by Cambrian limestone and younger Proterozoic sedimentary rocks, outcropping at only two places. Small discordant lode lead-silver deposits formed the basis of relatively small scale mining activity in the area for almost 100 years, exploration tenement covering the deposit being granted to CRAE exactly 100 years after the first mining leases were pegged in the area in 1887.Stratiform mineralisation occurs within three distinct blocks, bounded by normal faults and the unconformity between Lawn Hill Formation and overlying Cambrian limestones. The Termite Range Fault, a major northwest trending, regional scale fault system occurs adjacent to the northeast deposit boundary, while the Magazine Hill Fault, possibly a component of the east trending Little Range Fault system, forms the southern boundary of the deposit.

Jan 1, 1993

By McConachy G. W, Wright J. V

During the 110 years since the discovery of the Broken Hill PbZnAg deposit six major mining companies have mined the ore body and explored the ore environment. Despite this activity, no new orebodies have been found at Broken Hill. The failure to discover large new resources cannot be attributed to a lack of activity because major companies have maintained substantial exploration commitments over many decades. This suggests that not only was a unique coincidence of conditions required to form the deposit but also that full recognition and definition of the critical parameters may not yet have been recognised. In an attempt to illuminate some of the more unusual and poorly studied characteristics of the ore environment some new areas of investigation are presented here which may contribute to understanding the ore deposit setting and focus exploration towards different and perhaps more productive targets. Sedimentological characteristics of the host succession of the Broken Hill deposit are apparently unique along the line of lode. An upward-coarsening megasequence reflected in the development of clastic psammites stratigraphically below the ore deposit is one important ingredient which has received little exploration focus. These psammites also host mineralisation and form part of a spectrum of quart-zrich rocks collectively referred to as gametiferous psammites, garnet quartzites and blue quartz lodes. Sedimentological data interpreted from outcrop, drill core and downhole geophysical well logs support a elastic origin for some of these rocks; an interpretation which is at variance with traditional interpretations favouring an exhalative origin. A clastic origin for many of the footwall psammites, and their close spatial association with the orebodies suggests their role in ore formation was important. It is interpreted as a critical part of the fluid flow architecture within the sedimentary basin, which focussed ore forming fluids into an unique environment favourable for trapping mineralisation. Detailed stratigraphic correlation near the deposit has also highlighted that quartzofeldspathic rocks (Potosi gneisses and lode pegmatites) have complex relationships with ore. Suites of stratabound quartzofeldspathic pegmatites have received limited study, but their distribution and voluminous development suggests they may be as important to ore formation as the psammitic lode rocks which host the orebodies. These associations are not in conflict with some recent ore forming models invoking deposition in a shallow water environments of deposition. The geochemistry of parts of the host sequence has been studied extensively in the past but this has not been merged with current stratigraphic subdivisions. A large drillhole data base now permits the geochemistry to be related to the sedimentary succession and reveals that a signature involving stratigraphic vectors best illustrated by changes in MnO, Na2O, Pb and Zn can be detected. This is interpreted to reflect sedimentary basin processes as opposed to a classical volcanic hydrothermal alteration pipe associated with seafloor venting. The stratigraphic setting together with characteristics of some of these poorly understood areas is discussed to emphasise that construction of sound models for exploration requires the total ore environment to be studied with attention directed to the geometry and setting of the full range of host rocks. Control of the greater portion of the line of lode by a single company, Pasminco Australia Limited, now permits disparate datasets and observations to be merged and presents new opportunities and encouragement for model refinement and exploration success.

Jan 1, 1993

Early theories of coal formation are outlined, with special emphasis on the arguments for allochthony and autochthony. Various aspects of the nature, growth, and decay of the characteristic vegetation of the brown coal peat moors, their conversion into coal, the origin of banding, and the influence of tectonics are discussed.A description of the banding in Victorian brown coals is followed by a discussion of their vitrain, fusain, and natural carbonized coal; and concludes with the nature of the coal resin and the possibilities of its extraction.The nature and derivation of inorganic matter in brown coal, based on Lessing's classification, is described. Assimilation of mineral substances in specific plants with variations due to environmental factorsare illustrated by analyses of present day trees. Consideration is then given to possible sources of salt, marcasite, and quartz in brown coal.It is shown that part of the inherent and extraneous ash may have been removed during and after coal formation. The nature and abundance of the organically combined substances in brown coal emphasizes the anomalies that may arise from estimating the total inorganic matter from ash contents.After classifying deposits on external heating surfaces of boilers, theoretical and practical aspects of slag formation, alkali matrix deposits, and the effect of sulphur and chlorine are considered.Analyses of deposits in boilers burning Victorian brown coal are tabulated.Slagging at the Yallourn power station from sand in the Yallourn open cut, and difficulties with Yallourn North Extension coal at the Maryvale paper mills are described.Tests carried out on Morwell and Yallourn coals showed that with the former, impacted deposits formed on boiler heating surfaces, and left a high percentage of chlorides on probes. Morwell briquettescompared with Yallourn briquettes also reduced the running time of a semi-industrial boiler through deposits with sodium sulphate as...

Jan 1, 1962

The mostly submerged New Zealand sub-continent has a complex geological history and an active oceanographic regime that provides opportunities and challenges for offshore mineral exploration. Known deposits include polymetallic Fe-Mn nodules and crusts, polymetallic massive sulfides, phosphatic nodules, titanomagnetitie ironsands and placer gold deposits. Currently exploration interest is high with some 3.5 per cent of the EEZ under prospecting permit or application.   Article 76 of the UNCLOS convention allows coastal states to have sovereign rights over areas of the seafloor that are natural prolongations of the landmass that constitute submerged parts of the continental margin as extended continental shelf. New Zealand has substantial areas of elevated ridges and plateaux beyond the 200 M EEZ that form extended continental shelf. New Zealand has nearly completed a ten year, $44.4 M programme to define its outer extended continental shelf. New Zealand will lodge its outer limits of the extended continental shelf with the UN-appointed Commission on the Limits of the Continental Shelf in 2006, which if accepted, will enclose ~1.8 million km2 beyond the existing EEZ. Ocean Survey 20/20 is a follow-on marine mapping programme to underpin resource exploration and environmental management of the EEZ and extended continental shelf.

Jan 1, 2005

Gold mineralisation at Wapolu lies within an exposed arcuate zone at the decollement contact between a basement dome of high grade metamorphics and an overlying ophiolite sequence. This contact was originally a thrust fault which has since become a decollement zone for gravity sliding in association with basement doming. Hydrothermal models for the gold mineralisation postulate an epithermal system in which fluids were channelled up the decollement with boiling of those fluids causing hydrothermal brecciation and subsequent gold deposition. The alteration assemblages, fluid inclusion data and geochemistry indicate that the upper levels of the system are exposed.

Jan 1, 1987

TasmaniaÆs mineral endowment has resulted in 600 abandoned mines. Commonly occurring sulfide minerals such as pyrite and pyrrhotite can generate acid drainage and also mobilise heavy metals. Due to the StateÆs steep topography and high rainfall the risk to water quality in the receiving environments is significant. Surface waters impacted by abandoned mine sites typically showed high sulfate and metal distribution at pH range of 2.0 to 5.0. The impacted waters generally showed metal distribution in the high acid/extreme metal to low acid/low metal range. A similar trend was shown by sulfate distribution. Elevated levels of metals and sulfate downstream from several abandoned mine sites indicated that active sulfide oxidation is occurring and these sites may be potential point sources of metal pollution in the receiving environment. High correlation between metal and sulfate distribution suggests that sulfate distribution in surface waters may be used as a cost-effective investigation tool for preliminary assessment of acid drainage.

Jan 1, 2003

By W Ilahi

Underground metalliferous mining methods often result in the formation of vertical openings to facilitate the extraction of orebodies. These development and production techniques can result in the creation of vertical open voids, which include stopes, orepasses, ventilation raises and other excavations. There are risks associated with the use of mobile plant in the vicinity of these voids, especially during backfilling and when bunds are constructed at the edge of a stope or void. These voids can present unacceptable risks if not adequately managed.

May 5, 2022

The Honourable Neil Pickard has been in Parliament for something like sixteen years. He was Minister for Education in 1976, served as Shadow Minister in a number of portfolio areas while his party was in opposition, and since their return to power in 1988, he has been the Minister for Minerals and Energy. Ladies and gentlemen, I ask you to welcome the Minister, the Honourable Neil Pickard.

Jan 1, 1989

In the current climate, there is a real need to bridge the gap between theory and the real world mining considerations, and develop viable, cost-effective, high performance thickeners. With a greater need to extract profits from both difficult-to-process ores and lower grade orebodies, coupled with the necessity to produce 'greener', less water intensive technologies, suppliers need to take current thickener designs to the next level and into the 21st century. The complexity of 'getting it right' within a thickenerÆs feedwell, the 'nerve centre' of the thickener, is no small task. Delivering dilution water and mixing this water with incoming feed slurry, addition of flocculant, maximising flocculant-slurry interaction to build aggregate size, minimising unabsorbed flocculant percentage, volume average of solids volume fraction, momentum dissipation ratio, dilution recycle ratio, volume average shear, maximum shear rate at exit, aggregate size on exit, uniform discharge profile and more ù all of these need to occur in the right order and in the right proportions within the feedwell. This paper discusses the genesis and evolution of a new feedwell design, the first major innovation in the thickening industry in over 15 years.

Jan 1, 2008

By A Prill

Safety First and zero accidents are the targets most mines in Australia are aiming for, but manual processes and procedures limit the capabilities and response time in emergency situations. Even with a high safety focus, accidents and incidents still happen, too often with tragic outcomes. Dangerous areas, narrow roads and winding curves are all daily obstacles that threaten workforce safety. Every unforeseen event, such as traffic collisions and other accidents, puts lives in danger and weakens production. Safety must be guaranteed.

May 5, 2022

By S Johnston, L Howe, S Stevens

Regulators have an important role to play in fostering and enabling reliable, effective, environmental management. Given this, it is perhaps surprising that there has been relatively little debate on exactly how regulators can enhance their own approaches, in order to promote improved outcomes overall. The authors argue that applying research on High Reliability Organisations, as well as the University of Pennsylvania’s Penn Program Framework for Regulatory Excellence, to regulators has the potential to facilitate positive environmental results across the mine life cycle.

Aug 2, 2023

By M Nehring, M Kizil, P Knights

Mining and beneficiation can be described as sequential processes of separation of valuable minerals from waste. There is a great deal of interest in how the industry can be more effective – and efficient – with these processes. In particular, many mining companies are looking towards digital technologies to improve precision mining practices; that is, the targeted identification and separation of valuable ore from waste during the mining process. Greater precision will help unlock the value in many complex orebodies that are currently considered Tier 2 or 3 deposits. CITATION: Knights, P, Kizil, M and Nehring, M, 2018. Selection of precision surface mining methods for complex metalliferous orebodies, in Proceedings Complex Orebodies Conference 2018, pp 31–34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By K Baker, J Purtill

One of the key challenges for the mining industry globally is the rehabilitation of mine waste, and Queensland is no exception. Out of pit waste structures including waste rock dumps and tailings storage facilities, create novel landforms which require ongoing maintenance and pose risks to the environment and sometimes to communities. Where multiple mines co-exist, such as parts of Queensland’s Bowen Basin, individual mines can often be constrained by adjoining operations. This presents opportunities for broader rehabilitation strategies to be considered, more than the current single mine focus, that may provide better environmental outcomes for a region. Given recent global disasters involving tailings storage facilities, and our team’s endeavours to drive Queensland to achieve leading practice in mined land rehabilitation, we are exploring the potential to maximise in-pit tailings disposal opportunities for coalmines through shared waste management strategies. A shared waste management strategy is where two (or more) mines, owned by different companies and operated under different environmental permits, transport tailings from one mine to the other in close proximity, for disposal in a disused pit. This would reduce the number of waste structures to be built, operated, rehabilitated, and managed in perpetuity. Our objectives are to identify and remove barriers to tailings transfers between sites to:  minimise environmental risk  minimise long-term liability of managing mining waste and associated structures  support improved outcomes for the local community. To determine the scale of coal waste disposal practices in Queensland, internal data and publicly available imagery was analysed by the Department of Environment and Science in 2022. Approximately 6500 ha of land in Queensland is utilised for coalmine tailings storage facilities or codisposal areas, with ≈ 3700 ha of this being out of pit.

Aug 2, 2023

By I Levy

At our Monkland Mine at Gympie, we operate a deep, narrow vein gold mine using hand held equipment, rail mounted haulage and narrow shafts. This is in many respects the old-fashioned way and is well suited most of the orebody geometry exposed to-date. We have also commenced some long hole stoping and we use alimaks for some jobs. The heart of our particular mining style is the employment and retention of experienced miners with remuneration based on productivity. We do our planning/monitoring/supervision down to the level of daily individual productivity. In focussing on cycles per se, we have chosen not to talk about drill and blast cycles or cycles for mine development, stope preparation or drawdown and haulage. Instead we have stepped right back from the operation as presently run and have adopted a very broad view of the mining cycle. We will in this presentation intertwine the ebb and flow of, exploration, project sponsorship, development, production and cash returns to owners. The time line considered spans both history and predicted future.

Jan 1, 1998

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

The following thesis is an outcome of an investigation undertaken by the writer, at the suggestion of Professor Skeats, of the dykes and associated auriferous reefs of the Walhalla-Wood's Point belt, with the view of determining what relation, if any, existed between the petrological nature and the extent of llietasomatic alteration undergone by the dykes, and the genesis and localization of the gold.Although the greater part of the writer's time in the field and laboratory was occupied in studying the dykes and auriferous occurrences, a study was also made of the general geology as a basis for the special investigation. In addition, it soon became evident in the field that secondary enrichment had played a marked part in re-concentrating the gold and some interesting data in this connection have been collected. For example, indubitable evidence has been found of nuggets of gold having been formed by secondary processes.

Jan 1, 1920

By J Johansson, E Lund, J Lööw, A Pekkari

Technological development is accelerating in the mining industry (Abrahamsson and Johansson, 2021) and in large parts of the world there is an increased environmental awareness (United Nations, 2015). This can mean both challenges and opportunities. The mining industry has long been criticized for its adverse environmental effects. However, there is now a lively discourse about the role of mining in facilitating the green transition towards sustainable development. Mining is increasingly recognised as a prerequisite for the green transition, by supplying key raw materials to enable, for example, digitisation and batteries for electric vehicles. The green transition not only amplifies the demand for metals and minerals but also intensifies pressure on the mining sector to assume greater responsibility for environmental and societal welfare (Dehaine et al, 2020). New technology, such as digitisation, automation, and remote control, play a crucial role in advancing towards more sustainable mining practices. Despite the expanding role of advanced technology, human involvement will remain important in the extraction process (Rogers et al, 2019), but new technology will change how miners do their work, which in turn will lead to changed competence requirements for miners (Herbert and Hidalgo, 2021) and increased need for further education. Given the significant shift towards sustainable mining, it is important to study how these changes may affect the work, competences, further education and skills of miners as human expertise will continue to be critical in the extraction process. Consequently, there is a need for proactive research to prepare for the inevitable changes and implement measures to support miners through this changeable period to ensure a smooth transition that protects miners’ safety and working environment. This extended abstract explores how new technology will affect the need for further education of miners in the future.

Sep 1, 2024

By Rashchenko AF, Voiloshnikov GI, Elshin VV, Khomutov VV

The sorption method for the precious metals recovery fromsolutions and pulps are a perspective trend of modernhydrometallurgy. Russian gold mining industry uses thesemethods, anion-exchange resins being applied as sorbents. Theanion exchange resins allow effective recovery of preciousmetals, however, they have several drawbacks as compared withactivated carbons: high cost of sorbents; difficulties arisingduring treatment of pulps with complex ion composition;necessity of using titanic equipment and thiourea for gold elutionfrom loaded anion-exchange resin and its regeneration.

Jan 1, 1993

By R H. Yoon, M Gupta, A Noble, K Huang

Froth flotation is the most commonly used separation technology in the mineral industries. Given the complexity of the pulp and froth phases as well as the multitude of operational parameters that influence flotation performance, purely fundamental models with strong predictive capacity are limited. As a result, accurately modelling modifications to an existing flotation circuit are challenging, particularly when using empirically-derived models from a different operating configuration. Despite these complexities, a recent publication by the authors (Huang et al, 2022) has shown that flotation rates can be accurately predicted from a first-principles model that incorporates hydrodynamic parameters (eg pulp density, superficial gas velocity, feed flow rates etc), surface chemistry parameters (eg contact angle, zeta potentials and surface tension), and size-by-class liberation data. Circuit simulations using this model were shown to be effective in predicting experimental graderecovery curves from the size-by-class mineral liberation matrix. Since the model is derived from fundamental characteristics of the flotation system, it can be used to simulate alternative circuit configurations with varying degrees of recycle. Conventional flotation circuits are operated in a closed-circuit configuration by routing the cleaner scavenger tails (CST) back to the rougher feed to provide an additional opportunity to recover the slow-floating particles. This widely-used flotation strategy has been under constant debate, and several researchers have provided evidence that open circuit configurations provide higher separation and better circuit control (Konigsman, 1985; Bulatovic et al, 1998; Thompson, 2016). Recently, Finch and Tan (2021), used linear circuit analysis to show that open circuit configurations have a fundamental advantage when stage recoveries are high. Given the limitations of these prior studies, the objective of the current work is to further evaluate the merits of the open circuit configuration through a detailed circuit analysis and simulation study incorporating the first principles model described above.

Aug 24, 2022