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By M Lynch, B White

The historic city of Charters Towers in North Queensland is underlain by an extensive labyrinth of old mine workings in a large number of flat lying, subparallel, main and cross-cutting cross reefs extending of the order of 5 km along strike and down to a depth of 700 m in parts. These old workings produced over 6.6 million ounces of gold at a grade of over one ounce to the tonne prior to closure in 1920.Citigold is progressing the development of a modern, high productivity, low cost new mine to extract extensions of these reefs as well as other as yet un-mined reefs. To do this it is changing the paradigm for operating in such circumstances. This paper first briefly reviews the setting for the development and then discusses the philosophies and concepts that Citigold is proposing to use, harnessing technology to create a mine that exemplifies more productive and safer mining based on operating in the digital age.The paper addresses how a modern approach is being applied to the planning of a mechanised, deep, narrow vein, hard rock gold mine under a city. It also describes briefly the successful æexperimentationÆ with longhole open stoping methods developed at the companyÆs small underground operation (the Imperial Mine) to the south of the city, which will also be expanded substantially as part of the Charters Towers Gold Project.The paper also addresses the development of new and/or modified technologies in the venture, with the objective of pursuing continuous and autonomous mining methods. The company is adopting a holistic systems approach, addressing people, process and technology in order to efficiently identify and locate the high-grade ore zones and then extract them effectively at a high grade by minimising waste development and haulage, dilution and energy consumption, and with minimal environmental impact.CITATION:Lynch, M and White, B, 2013. Brave new world autonomous mining systems, in Proceedings World Gold 2013 , pp 157-166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By N Cusworth, W R. Mackenzie

"In 2007, the authors presented a framework for the conduct of resource project feasibility studies and provided guidance on minimum standards and best practice (Mackenzie and Cusworth, 2007).This paper will present the authors’ observations in relation to feasibility studies undertaken to support investments made during the unprecedented period of resource project capital investment since 2007. It will also provide comments on general trends in the mining industry’s approach to project assessment and update recommendations on best practice.CITATION:Mackenzie, W R and Cusworth, N, 2016. The use and abuse of feasibility studies – has anything changed?, in Proceedings Project Evaluation 2016, pp 133–148 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By P K. Banerjee, S Kumar

Indian iron ores with less than 62 per cent Fe are currently unexploited, except for a few sectors which export them to foreign countries. It is anticipated that by 2012 the countryÆs domestic steel production is likely to rise to the tune of 60 million tonnes per annum. To meet this requirement, it is necessary to utilise not only the existing high-grade deposits but it is also necessary to look into exploiting the leftover iron ores of lower grades. Hence, reserves with Fe content 62 per cent and below (particularly the ores with In the present paper, an attempt has been made to beneficiate three different types of low-grade iron ores selected from three different parts (states) of the country. In the paper, alternative routes for beneficiation and effective utilisation have been tested using different techniques in the laboratory in an attempt to match their (Al2O3/SiO2) ratio after thorough characterisation and liberation studies. The paper also encompasses the geological formations, occurrences and distribution of Indian iron ores as well as highlighting the problems associated with the fines, possible metallurgical routes, and their market segregation from the perspective of end users.

Jan 1, 2007

By E Beltran, S Ngunz, F Orrante, F van Zyl, M Westcott

"The primary control objective of the project is to achieve milling optimisation by ensuring that the energy available for rock breakage is used as efficiently as possible. This is achieved by increasing the level of mill filing until a process constraint is reached. Stable operation against this limiting constraint is then maintained to ensure long-term optimised operation.Semi-autogenous grinding (SAG) mill control optimisation presents a number of challenges. SAG mills have multiple inputs that are used to control multiple outputs (MIMO process). Secondly, the SAG mill loading process is a ‘high inertia’ process that can be approximated as an integrating process. This means that it is open-loop unstable. The hybrid control strategy presented implements an advanced ‘load stabiliser’, which transforms this integrator process into a more manageable first order process, which can be steered stably against the constraints. This SGS hybrid Expert control strategy implemented on both SAG mills at the Porgera concentrator therefore consists of two integrated parts responsible for:stabilising the mill load to a targetdriving the mill load target to the maximum determined by the process constraints (eg maximum power draw) to maximise efficiency and throughput. A comparative study is done between the operation of the plant for a period of a month before and a month after the implementation of this strategy. The results indicated a significant improvement in the SAG mills’ stability and operation as well as a reduction of overload situations leading to a loss of throughput.Citation:Ngunz, S, van Zyl, F, Orrante, F, Beltran, E, Westcott, M and Wilson, S, 2016. Simplified Hybrid Semi-autogenous Grinding Mill Control - Explanation and Practical Results at the Porgera Concentrator, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 313–320 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By G Smart, D Ward, J Grace

Ridgeway Gold Mine is part of Cadia Valley Operations which is wholly owned and managed by Newcrest Mining Limited. It is an underground sublevel cave (SLC) operation mining approximately 5 Mt per annum. Ore control systems at Ridgeway have been designed to deliver gold and copper metal production through focussing on the ore characteristics that impact on mine and mill performance and ultimately metal delivery. This is achieved using data collection and management systems which allow data to be collected digitally with æat captureÆ validation routines. These data form the basis for forecasting and on-going systems analysis which aim to accurately assess local in situ and drawn ore characteristics. Physical attributes of ore such as draw characteristics, brow conditions, visual grade estimates and draw point sampling are routinely recorded. Ore tracking and accounting systems monitor gold and copper grades, copper mineralogy, host lithology and ore sizing. These factors have material impacts on concentrator throughput and metal recovery. Draw point recovered grades are routinely reconciled back to design data to monitor and assess draw performance. Statistical variance controls are also employed to analyse mine and plant performance and guide actions.

Jan 1, 2003

By M P. Sandy, V Louchnikov, V Eremenko, M Orunesu, O Watson

"Surface support is a key component of most ground support systems which are applied as a means of reducing the risk of rockfall occurrence and maintaining serviceability of mine development. Surface support has two primary functions: distributing the applied load throughout the system by providing connection between rock bolts retaining smaller rocks that unravel between rock bolts.Confinement is also provided to the rock mass, which may increase its capacity to resist further degradation or loosening.Surface support has been routinely installed in most underground mines around the world for many years, yet the operators are still not always certain which type is best suited for deformable ground conditions. A number of factors need to be taken into consideration prior to selecting the type of surface support liner, such as its capacity, availability, practicality of installation, manual handling and loading conditions (static or dynamic) to ensure the system’s optimal performance in terms of safety and costs.This paper presents an overview of the surface support types currently used in underground mines in Australia. Shotcrete, weld mesh, high-tensile chainlink mesh, reinforced weld mesh and high energy absorption (HEA) mesh are discussed. A detailed description of each system is provided in terms of capacity, energy absorption, installation cycle and costs. The cost of each system has been normalised to the units of energy absorbed. The information presented in this paper can be used by underground operators as a reference guide when deciding on suitable surface support type for deformable ground conditions.CITATION:Louchnikov, V, Sandy, M P, Watson, O, Orunesu, M and Eremenko, V, 2014. An overview of surface rock support for deformable ground conditions, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 57–66 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

By P Esteves, J L. Bechir, R Galery, C Senna, V Souto

The current moment experienced by the mineral industry is marked by a series of economic, social and environmental challenges. Among the main challenges, it is important to highlight the decreasing in ore grades with the gradual depletion of the existing deposits, the high volatility in international commodity prices and the operational inefficiencies in the mine, beneficiation, and metallurgical plants. In this context, mining companies are continuously looking for alternatives that minimize production costs and maximize overall production. In addition, recent tragedies involving tailings dam collapses in Brazil, reinforced the need for a more responsible, sustainable, and conscious mining, such as aiming the preservation and rehabilitation of the land environment. In this scenario, the Sensor-Based Sorting (SBS) technology is currently getting more space into the mining market. This separation technology aims the removal of gangue material in coarse particle size fractions, prior to comminution and concentration stages. As a consequence, the technology allows a smaller consumption of energy, water, chemical reagents and other inputs. Moreover, the sensor-based sorting is a dry processing technology and favors the reduction of fine material to be sent to the tailings. The aim of this paper is to provide information regarding the technical and economical evaluation of SBS technology applicability to a zinc silicate mining in Brazil. The project evaluation was performed in two stages: laboratory test work and the execution of a pilot plant. The execution of a pilot plant allowed the technology optimization, quantification of downstream process effects, such as a proper economic evaluation about the technology benefits. Keywords: Sensor-Based Sorting; Particle Sorting; Ore Sorting; Preconcentration; capital expenditure (CAPEX); operating expenditure (OPEX); zinc; comminution; dry processing.

Nov 10, 2020

By B Olsson, B Reynolds, R Norman

An unprecedented growth in demand for coal exports has placed pressure on multi-user coal chains to guarantee that their capacity expansion projects will meet the required demand. These projects, however, are taking place in an increasingly complex commercial and technical environment - competing rail and coal terminal service providers as well as a myriad of competing mine operators, all needing to operate in an increasingly integrated manner to get the most out of expensive shared assets.Increasing system complexity and integration has driven the need for more holistic and sophisticated analysis tools. The capacity of coal chain subsystems, such as mine, rail and port, can no longer be determined effectively in isolation. Understanding the nature of the interactions between these subsystems, their sensitivity to uncertainty and the resultant capacity of the integrated system is the key to both maximising value and minimising risk.Recently, TSG has worked closely together with the Integrated Logistics Company and a number of key stakeholders in the Dalrymple Bay Coal Chain to develop independent system master plans. These master plans have provided a quantitative and rational assessment of coal chain capacity in its current state and a prediction of its capacity once a pipeline of committed capacity improvements is in place. This paper provides an overview of the study and a comprehensive guide to the process required to effectively achieve valuable strategic insights in a challenging multi-user stakeholder environment.CITATION:Reynolds, B, Olsson, B and Norman, R, 2012. Using independent system simulation to mitigate risk in the Dalrymple Bay Coal Chain, in Proceedings Project Evaluation 2012 , pp 77-84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By Lorenzen L

In South Africa, as in many other countries, the young engineering graduate is promoted quite soon to a management position where he uses less technical skills and more people-oriented skills. In the standard undergraduate curriculum for engineering, little attention is paid to the non-technical issues of the profession. An undergraduate course in management techniques cannot be a substitute for a MBA or Masters degree in engineering management, but can at least create an awareness of the practical problems facing the engineering manager. The aim of this paper is to provide an outline of such a course structure at the University of Stellenbosch. A survey is also presented on management training in the South African and Australian mineral industries. Feedback from students and graduates indicates that the fresh graduate does not fully appreciate the value of such a course until he/she achieves a position of responsibility after two or three years. Nevertheless, the management course appears to be successful in widening the perspectives of the engineer. As explained frequently in management journals, the technically oriented person (the engineer) has a convergent thought pattern, which could be in conflict with the more divergent thought pattern of the top, personnel or marketing manager. It becomes increasingly imperative for the young minerals engineer to be externally oriented instead of the traditional internal focus of engineering. The engineer should not only be aware of environmental issues in the technical design and operation of plants, but should also understand the inter-relationship between public relations, political pressures and environmental perceptions vis-d-vis technical facts.

Jan 1, 1993

By King RP, Kientzler P

In recent years, ultrasonic comminution technology has been developed at the Utah Comminution Center. An ultrasonic grinding device was assembled and investigated. An ultrasonic transducer system has been significantly improved by using a special type of piezoelectric ceramic and preloading to 4.1 x le kPa to obtain maximum strength. The improved system provides constant and rapid vibratory promotion of fatigue fracture resulting in more effective breakage. The design principles for an ultrasonic mill are developed in this paper. Size reduction was successfully achieved in the ultrasonic nip-roll device for a variety of materials. Ultrasonic comminution has repeatedly demonstrated the capability of producing fine particles from a variety of materials. A comparison between ultrasonic grinding and dry ball milling of limestone showed that the ultrasonic device produced much narrower size distributions than the ball mill. This trend is especially obvious in the coarse size range where few particles remain, and in the fine size range where overgrinding is prevented. This behavior might have some interesting applications in areas other than mineral processing like powder metallurgy or material science where narrow and controlled product sizes are required for the successful elaboration of high-technology ceramics and glasses. Ultrasonic comminution has a significant advantage in the accurate control of the product size.

Jan 1, 1993

By R Herbert, M E. Malmstr÷, S U. Salmon

The study focuses on sulfide oxidation processes in unweathered pyrite-rich mine tailings from a soil-covered impoundment in northern Sweden. To simulate the oxygen-limited conditions in water saturated tailings two long-term column experiments were performed. Results are presented for the first 11 months of the experiments at room temperature. The tailings used in the experiments were of two different grain sizes (one coarse grained, in the range 0.02 - 0.6 mm with a grain surface area of 1.86 m2 g-1, and one fine-grained, in the range 0.0015 - 0.06 mm with a grain surface area of 10.00 m2 g-1) and with slightly different mineralogical composition. The S:Fe molar ratio in the leachates (1.0 - 1.5) indicates either that pyrrhotite is the main iron sulfide undergoing oxidation in our experiments, or, alternatively that the S:Fe molar ratio in the leachate is determined by pyrite weathering in conjunction with other processes releasing iron or immobilising sulfate. However, speciation modelling of the leachates indicates that ferrihydrite was close to saturation, suggesting that a ferric oxyhydroxide may have dissolved/ precipitated during the experimental period, thereby affecting the S:Fe molar ratio. Pyrite oxidation rates obtained from the two column experiments during æsteady-stateÆ were 2.25 + 10-13 and 8.45 + 10-14 mol m-2 s-1 in the coarse and fine tailings, respectively. Pyrrhotite oxidation rates, as an alternative, were 2.31 + 10-12 and 1.24 + 10-11 mol m-2 s-1 in the coarse and fine tailings, respectively. Natural microbial activity was confirmed in both the tailings and the leachates; therefore, the obtained oxidation rates are not strictly abiotic. It is thus concluded, based on the experimental results, that tailing heterogeneity will result in zones with different oxidation rates, related to their physical and chemical properties.

Jan 1, 2003

By I P. Hodkinson

SMC Resources Limited is implementing a selective mining approach at the Hadleigh Castle mine, formerly operated by Aurora Gold Limited. The main ore zone has a length of 250 metres and dips at 40 - 45¦ to the south. Gold mineralisation occurs in a variety of quartz-sulphide lodes in sericitised granodiorite. Shallow dips, alteration intensity and mineralisation style combine to make mining relatively difficult. Previously unworked, high-grade, shallow dipping (30 - 45¦), narrow quartz-sulphide lodes within the hanging-wall of the deposit are also being selectively exploited. Annual production of 35 000 oz Au is forecast from 185 000 tpa ore grading 6.5 g/t Au over a currently envisaged mine life of six years. Operations completed to-date include deepening the decline and access development of the first two levels beneath the previous workings. Longhole stoping operations have commenced in the main ore zone with air leg stoping also underway in the hanging wall lodes.

Jan 1, 1998

By P D. Munro

"This is a reprise of the paper ‘Back to the Future – Why Change Doesn’t Necessarily Mean Progress’ presented to the Tenth Mill Operators’ Conference in 2009. It was observed that the ‘boom and bust’ cycles of the industry, together with trends in tertiary education and the effects of fly-in fly-out (FIFO) operations raised serious questions about the sustainability of human capital in the mineral processing sector.In 2016 we find ourselves in a ‘bust’ after enjoying a decade of the longest commodity price ‘boom’ in a century. In the ‘boom’ did we:make any technological breakthroughs?put measures in place to improve our human capital, especially in the area of ‘professional formation’?The paper makes observations on the current performance of mineral processing engineers and the organisational milieu in which they operate. It questions whether mineral processing engineers are actually ‘adding value’ at some sites given their organisational and operational practices.Some technical trends are examined and what it might mean for mineral processing engineers.Given the above and demographic trends for mineral industry professionals, changes to the seemingly current laissez-faire model of professional development are proposed.Citation:Munro, P D, 2016. Back to the Future - Still on the Dark Side, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 341–348 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By K L. Brown

Sampling and analyses of deep waters from Wairakei and Rotokawa geothermal systems indicate a wide range of precious metal concentrations (<0.1 to 23 ppb Au; 6 to 2400 ppb Ag), suggesting that eastern ôandesiticö TVZ geothermal systems (eg Rotokawa) have higher aqueous gold and silver than western ôbasalticö geothermal systems (eg Wairakei); this interpretation is consistent with known occurrences of high grade precipitates in wells from eastern systems. The fact that the deep waters are undersaturated in gold further suggests that the aqueous gold concentrations of deep waters are limited by metal availability. The flux of gold for the two systems ranges from ~1 to 50 kg Au/yr, and the flux of silver ranges from 65 to 6900 kg Ag/yr. At Rotokawa, it only takes ~600 years to flux one million oz of Au and >100 million oz of Ag. The supply of hydrothermal gold and silver is obviously important during genesis of an epithermal deposit, but ore formation also depends on the existence of a suitable ôtrapö that efficiently extracts metal from solution in a small volume of rock. Such traps seem to have been poorly developed until geothermal drilling in the TVZ.

Jan 1, 2006

By I M. Platten, S C. Dominy

The Clogau St DavidÆs gold mine has a recorded production of around 81 000 oz Au and it is the largest mine in the Dolgellau gold-belt and BritainÆs most prolific historical producer. The original mine was first worked for copper, however; in 1854, gold was found in waste material from the St DavidÆs section. In recent times the mine has operated intermittently between 1983 - 2007. The principal black shale-hosted gold-bearing reef (Main Reef) can be traced for about 3 km, striking approximately NE-SW and dipping steeply between 60¦ - 90¦ SE. The reef system pinches and swells, changes strike and splits into a number of smaller branches. Reef width is variable, ranging from over 6 m to a few cm and in places reducing to small irregular blobs. The reef is internally complex and composed of swarms of narrow (1 - 300 mm) subparallel veins separated by country rock sheets. The gold-bearing veins within the reef package are discontinuous; though generally possess bonanza grades running 10s - 100s oz/t Au. It has historically been shown that some gold-rich vein segments can grade up to 300 oz/t Au. The predictability of the gold-rich segments is poor, but has been shown to be related to presence of the Clogau (black shale) Formation, and/or the mechanical interactions of the reef with greenstone sills, reef branching and splitting and/or cross-fractures to form ore shoots. The mine is currently being re-evaluated as a potential small-scale selective operation.CITATION:Dominy, S C and Platten, I M, 2012. Geology, mineralisation and potential of the Clogau St DavidÆs mine, Dolgellau gold-belt, Gwynedd, Wales, in Proceedings Narrow Vein Mining 2012 , pp 101-120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By J Addai-Mensah, W Skinner, C Kelsey, J R. Kelly, E Baawuah

Comminution continues to be the most capital-intensive unit operation in mineral processing. The fundamental purpose of comminution is to liberate the valuable minerals so that they can be economically concentrated into saleable products. Declining ore quality characterised by lower grade and increased complexity requires significant energy consumption for comminution. Low-grade magnetite ores are typically fine-grained and require fine to ultra-fine grinding (P80 ~ 30 - 40 µm) to enhance its liberation from the typically siliceous gangue matrix. Historically, this has been achieved using multi-stage crushing and grinding technologies, which require high energy consumption with low energy efficiency. This motivated innovations in energy efficient technologies for comminution. Such technology has been developed in the IMPTEC super-fine crusher. It is an innovative, dry (with the potential to be operated wet), media-free, energy efficient crusher that can to reduce 10 mm feed particles to 19 – 30 µm with very low recycle loads. In this study, the mineralogical and physicochemical characteristics of crushed magnetite ore using the IMPTEC super-fine crusher have been investigated in comparison with those of rod milling. The super-fine crusher generated higher liberated magnetite minerals in the – 300 + 212 µm and < 45 µm size fractions compared to rod mill. Both comminution devices generated large low-grade hematite and goethite middlings. However, the rod mill produced higher locked/unliberated hematite and goethite compared to that of the super-fine crusher. Quartz mineral had the highest liberation irrespective of the comminution device used. The super-fine crusher generated higher entrapment of other minerals within the silica matrix compared to the rod mill. The breakage mechanism of the super-fine crusher which is predominantly through high compression with shear, generated improved mineral liberation in the coarse size fractions compared to the predominant abrasion and attrition breakage mechanisms of rod milling. The higher mineral liberation generated by the rod mill is potentially due to the prolonged batch milling of the ore compared to the single-pass open circuit of the super-fine crusher.CITATION:Baawuah, E, Kelsey, C, Kelly, J R, Addai-Mensah, J and Skinner, W, 2018. Mineral liberation studies of IMPTEC super-fine crusher – 130 crushed product, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 313–326 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By E J. B van Etten

This paper reports on the results of several years of monitoring rehabilitation at a silica sand mine on the Swan Coastal Plain, south of Perth. Mining here occurs below the regional watertable and leaves a post-mine landscape of dredge pond voids (pit lakes) with surrounding battered slopes. The restoration we recommended was to develop the pit lakes as wetlands of regional analogue and value. Several different restoration techniques have been applied to re-vegetate pit lake slopes over many years which have enabled an evaluation of reasons for success/failure of different restoration approaches. Learning acquired clearly showed the benefits of using fresh topsoil for restoration over topsoil that has been stockpiled for several years. Most topsoil used in restoration was from seasonal wetlands and consequently restoration was most successful in the riparian zone from the edge of pit lakes to about 2 m vertically above the water table. Topsoil restored areas above this level remained poor in plant species and cover. Conversely, remedial seeding/planting proved largely unsuccessful. Permanently and seasonally flooded pit lake margins recolonised relatively quickly and successfully with native sedges and rushes. Development of rehabilitated upper slope plant communities over time was evident with loss of typical wetland species and greater growth and survivorship of upland and dampland plant species on mid to upper rehabilitated slopes. Plant communities of lower slopes showed a converse pattern of development, with a shift towards a more typical wetland composition. We believe matching topsoil to site and development of topographic profiles similar to natural wetlands of the region are the keys to optimising restoration success of sand mines with shallow water tables.

Oct 5, 2011

By P K. Singh

Recent advancements in understanding the detonation process are noteworthy, but they are still based on somewhat hypothetical situations. The actual variables that are essential parts of normal blasting practice have not yet been taken into account in such treatments. These include the various initiation practices employed to detonate a column of explosive, from single point initiation to multi-point initiation in blast holes, and the effect on detonation characteristics of both detonators and explosives under multi-deck and multi-hole blasting conditions. The in-the-hole velocity of detonation (VOD) of an industrial explosive is dependent on explosive’s charge diameter and blasthole diameter. The relationship between blasthole diameter and VOD provides a fundamental guideline to the rate of energy conversion and energy release within the detonation front on the interaction of explosives with the confining medium.The in-the-hole VOD of explosives was measured at four experimental sites in India for different blasthole diameters, ie 150 mm to 311 mm, but for identical explosive composition being same particle size, density, viscosity and loaded into blastholes with the same degree of confinement. The results of the studies demonstrated that there is definite relationship in in-the-hole VOD of the explosive and the diameter of the blast hole. The study also confirmed that the explosives initiated with concentrated boosters yielded higher VOD in comparison to those explosives that were initiated with multi-point priming. The measured increase in VOD of explosives for increasing diameter of holes was up to 24 per cent. The rate of change in in-the-hole VOD of explosives increases with increasing blasthole diameter. It can be further stated that the in-the-hole VOD of the explosive reaches a fairly constant value after reaching a limiting/threshold diameter of 311 mm.

Nov 8, 2011

By A Horne, Z Graszkiewicz, D Dettrick, R Evan, B Neal

"Most of VictoriaÆs rivers and aquifers are already fully allocated or reaching full allocation. In regions without a well-established water market, access to water entitlements to facilitate new development is limited. In areas with established water markets, mine developers face an undue cost burden in circumstances where they are only planning to consume a fraction of the water entitlements that they purchase. The challenge for water managers is to ensure protection of water resources and other water users without creating an unnecessary disincentive for those types of developments that return most of the water that they take from water sources. The opportunity for development of a mine is explicitly linked to a particular location and must be developed where a resource is located or it cannot be exploited at all. Regulatory arrangements that facilitate development may have a positive impact on economic development, particularly where water availability is a potentially limiting factor. Net volume licensing has the potential to allow increased economic outcomes through improved licensing of access to water. Net volume licensing differs from traditional water licensing in that it authorises access to water on the basis of ænet useÆ rather than æthe gross volume takenÆ. This paper asks under what conditions net volume licensing is likely to be feasible and effective. In particular, the paper examines the information and accuracy requirements to allow net volume licensing decisions to be made. This work is based around five case studies in Victoria that were used to examine the potential for net volume licensing for mines and quarries. Assessing a potential net volume licensing arrangement requires the regulating authority to have an understanding of the inputs and outputs of water to a site. In contrast, assessment of take and use licences consider only a single input. It was concluded that the conditions that lend themselves to net volume licensing include: well understood water inputs and outputs, including appropriate accuracy of information where the location of site water inputs and outputs are the same where the timing of extraction and discharge can be managed to minimise impact on the water resource.A key remaining challenge is establishing an accounting framework that allows net volume licensing under current water resource limits. CITATION:Graszkiewicz, Z, Horne, A, Neal, B, Evan, R and Dettrick, D, 2013. The practicalities of implementing net volume licensing of water use in mines and quarries - a discussion based on Victorian case studies, in Proceedings Water in Mining 2013, pp 241-250 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By B Kilgariff

Flotation has been in use at Broken Hill for nearly 100 years, and the process has gone through many different optimisation studies over that time. This paper reviews the current flotation practice at the Perilya Broken Hill Mine, and details one of the recent optimisation studies conducted using mathematical modelling and simulation tools. The optimisation study consisted of surveys of the lead and zinc circuits, mapping of the floatability components of the ore and developing models of the lead and zinc circuits. The models were then used to conduct simulations to simplify the circuit. The study allowed plant personnel to identify optimum operating conditions for their current flotation cells, as well as possible improvements in circuit configuration and cell capacity.

Jan 1, 2005