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By H Asche

The Melbourne Metro project has evolved from the Victorian Transport Plan. MM1 is the second major phase of the proposed separation of Melbourne’s radial railway system, creating a line that will operate independently across the metropolitan region. The central section will run beneath the inner suburbs and the central city. The initial project comprises nearly 8 km of twin bore tunnels, three cavern stations and two cut and cover stations, as well as a dive structure and connections with the existing rail system. This paper describes the development of the geological model, a modification of the rock mass classification system derived during the EastLink project and the influence of the geology on the design of the tunnels and stations for the Department of Transport’s business case.The majority of the tunnelling will be in the siltstone and sandstone bedrock. This material has been extensively folded, sheared and intersected by igneous intrusions. A revised rock mass classification system has been developed for the Melbourne Formation to assist in identifying the important engineering properties of the rock and to rationalise the support types required.The Metro’s tunnel alignment crosses the Yarra Delta deposits in the lower reaches of the Moonee Ponds Creek and again at the Yarra itself near Princes Bridge. These deposits vary in extent and thickness over very short distances. The investigation of these materials has been carried out using conventional drilling techniques in conjunction with sonic drilling methods.Over the central section of the Metro, the positions of the new station are determined largely by transport planning requirements and urban development opportunities. However, the stations, and the tunnels, have been the subject of studies, optimising exercises, and selection processes to arrive at the concept design. This paper describes the influence of the varied geology on the development of the design, and the identification and management of the risks in tunnelling under the centre of Melbourne.

Mar 8, 2011

Research on Universal Depressant of Talc and Serpentine

Sep 13, 2010

By Turker L

The leaching of Tellness (Norway) ilmenite concentrate in hydrochloric acid and mixed aqueous HCl-alcohol solutions at boiling temperatures was investigated. It was found that the alcohols methanol, ethanol and ethylene glycol all substantially increased the leach rate and in the case of methanol and ethanol this was achieved at lower boiling temperatures compared with aqueous HC.

Jan 1, 1986

The tangible effects of leakage are presented graphically, and a technique for quantifying the leakage characteristics of a ventilation column using the æSolveÆ capabilities of a common spreadsheet is demonstrated. A case study of a working decline in Western Australia is used to demonstrate the potential for more realistic design of development ventilating systems, and for more cost effective management of the condition of the duct.

Jan 1, 2002

Lead Removal from Contaminated Soils with Chelating Agents

Sep 13, 2010

The sudden. explosion of relatively inexpensive digital process control computers has accelerated interest in the possibilities of economic savings by their use. In particular the metalliferous industries have shown that they are willing and capable 6f grasping this new technology and putting it to good use. These industries have a number of problems which need special attention. In many cases the process is difficult to measure and a reaction is often controlled by measuring a secondary effect, computing its relationship to the reaction and then applying the necessary corrective action. This creates problems in building the process model, designing the computer to process interface and in the subsequent system development. Environmentally the metalliferous industries create conditions which severely test sophisticated electronic equipment. Care taken in locating and housing this equipment is a major factor in ensuring reliability in Operation.

Jan 1, 1977

Jan 1, 2004

Enhancing the Flotability of Gold-Bearing Ores by a Mixture of Collectors

Sep 13, 2010

Various methods and software have been trialled for simulation of Au grades at Boddington Mine. This covers in-house and public software as well as sequential and turning bands methods. The diversity of options was further expanded with comparison of point and direct block simulation. Some difficulties were encountered in incorporating high-grade restrictions. Altering parameters or software can make very significant differences and give results varying from estimations. This paper details a new simulation run with validation and tests for local calibration (or progressive correction) of the simulations to the estimations, focusing on reproduction of statistics. This approach brings to the forefront the question æwhat is the purpose of the simulations?Æ Results and some ideas for future applications at Boddington are summarised.

Sep 26, 2011

By W Assibey-Bonsu

The paper provides a brief review of the multivariate uniform conditioning and the localised multivariate uniform conditioning techniques and presents a case study based on a porphyry copper gold deposit in Peru. Two other important scenarios have been investigated and will be particularly emphasised: The recovered selective mining unit (SMU)s depend on a combination of copper and gold content, which can be expressed by means of ænet smelter returnsÆ (NSR). Two approaches are compared. Firstly, the application of a composite cut-off on NSR on the joint distribution of each grade and the application of uniform conditioning to three variables is investigated, ie for the first approach NSR is used as the main variable. The second approach considers copper as the main variable. In the case of multiple domains the procedure used to apply the technique to process mixed panels is clarified and recommendations are made.

Sep 26, 2011

PIP is regularly engaged in businesses where Greenfield Capital Projects are under- delivering on the expected business case. In most of these projects, we can identify that rigorous review has been carried out on the design and financial cost elements and substantial reporting is maintained to Boards on progress versus plan of project completion and cost. However, in all sites of this nature that we have worked at, the planning, design and execution of the operational elements or æwiringÆ of the organisation have fallen short and resulted in significant extra cost or opportunity cost (lost tonnage or quality) during start-up. When compared to the amount of planning and resources that have been poured into the capital side, the ledger on the æwiringÆ side is typically fairly sparse. This presentation outlines the importance of running a disciplined, rigorous process to prepare the human and wiring side of a start-up to ensure rapid start-ups and put the site on the pathway to high performance. It gives an outline of the rigorous process PIP has used with projects to ensure excellent start-ups.

Jan 1, 2006

Extraction and Characterisation of Extracellular Polymeric Substances from the Mineral Surface During Bioleaching of Chalcopyrite Concentrate A mixed culture of moderately thermophilic microorganisms was used to bioleach chalcopyrite concentrate in a stirred tank reactor. The results show that up to 84.7 per cent of copper extraction could be achieved in 24 days at a pulp density of 6 per cent. The leaching rate of chalcopyrite concentrate tended to increase with an increase of dissolved total iron concentration. Furthermore, the extracellular polymeric substance (EPS) on the surface of the chalcopyrite concentrate was extracted and analysed. EPS was extracted at the first, third, eighth, 16th and 24th day during bioleaching, which mainly consisted of proteins, lipids, sugars and ferric irons. After the eighth day the total amount of EPS remained relatively constant. However, the amount of ferric iron in the EPS decreased in a large scale. The ore residue analysis indicates that the decrease of ferric iron was mainly due to the formation of jarosite on the mineral surface.

Sep 13, 2010

By J J. Van Wijk, A R. Penney

Successful management of geotechnical risk at a mining operation is more than just having a good ground control management plan or using advanced numerical modelling and the latest monitoring technologies. The fundamental requirements for effective geotechnical risk management include identification of potential failure modes, identifying and implementing appropriate controls, and demonstrating the effectiveness of those controls. Effective geotechnical risk management requires an integrated approach by confirming that appropriate risk management systems have been identified and implemented (management plans, procedures etc), and that these systems are executed consistently in the field across all working areas. Development of a thorough integrated auditing process executed by an experienced team of technical subject matter experts with substantial operational knowledge, provides a more complete picture of catastrophic hazard management. Following consistent evaluation criteria allows benchmarking of systems and implementation compliance between the sites being audited, and the results can then be ranked against other operations in an industry database.

Nov 29, 2022

By R Bearman

The importance of crushers in the mining industry declined with the introduction and resultant dominance of AG and SAG based circuits, but the recent move to consider more energy efficient circuits has caused the industry to re-consider the role of crushers.Different types of comminution equipment have different efficiency in the way the energy is applied in the size reduction process. Because of the general trend towards more sustainable production processes and emission of carbon dioxide, energy use has become more important. To fully understand how crushers can contribute to optimising the energy application in comminution circuits, detailed models of process performance are required. Such models need to take into account the mechanical design factors and how the crusher performance changes in response to feed conditions, the control strategy utilised and the wear of the crusher liners.It is also critical to analyse the total circuit, not just the individual crushers. To fully understand the performance of the entire circuit, dynamic simulation should be applied. Without the holistic understanding of the total circuit and the incorporation of transient effects, the full circuit performance cannot be adequately determined and the true energy picture will not be quantified.Based on detailed mechanistic modelling of crushers by the authors and the application of dynamic simulation, the opportunities to optimise the use of crushers for energy efficiency are examined.

Aug 8, 2011

Adsorption Effect on Multi-Heavy Metal Ions in Wastewater by Water-Washing Waste Saccharomyces cerevisiae

Sep 13, 2010

By R M. Yanamandra, S K. Tripathy, N Mangadoddy, P Sudikondala, P Ankireddy

Spiral concentrator is one of the most commonly used gravity concentration devices in mineral processing. The particles are classified based on their specific gravity and size. The present work analyses the experimental and numerical investigations of the water flow field, such as fluid depth and free surface primary velocity of two high gravity spiral concentrators at different flow rates. The measurement techniques use a flow depth gauge and flow visualisation technique adapting lycopodium powder as the tracer. Flow features in terms of liquid depth and primary velocity at the free surface of the flow are captured across the trough in two different high gravity spirals. A highspeed motion camera with an imaging frequency of 5400 frames per second and 768 × 768 pixel resolution is utilised to track the tracer particles in the liquid flow on the dark surface background. Further, the two-phase flow is studied numerically on high gravity spirals based on the volume of fluid (VOF) approach utilising the RNG k-ε model and Reynolds Stress Model (RSM) for predicting the fluid flow on trough surfaces such as water depth and free surface primary velocity. The CFD predictions of the flow field for the two spirals are attempted to validate against experimental data. The high gravity spiral concentrators show lower flow depths and free surface primary velocities but steep velocities on the outer trough zone compared to that of low gravity spiral concentrators (conventional coal spirals). Among the computationally tested high gravity spirals, higher pitch and higher secondary slope design shows greater flow characteristics.

Aug 24, 2022

By L Bertoss, D Carvalho

In the last decade, the use of advanced implicit modelling software/algorithms in mineral resource workflows has become a best practice in the mining industry. In most cases, these workflows can easily replicate the level of detail of explicitly modelled geometries, even for very complex deposits. These techniques are flexible and can produce fast results since software is responsible for generating 3D surfaces and solids based on geological and interpretation data. Nevertheless, depending on how unique and complex some deposits are, intense manual editing and input are required to honour the geological context and produce the desired outcome. The current geological modelling workflow at George Fisher Mine (GFM) is based on the semi-automatic built-in tool that generates stratigraphic sequences (stacked lithology layers) based on logging and mapping data. This tool (stratigraphic sequence from Leapfrog Geo™) works for the majority of areas in the mine but fails to capture observed mineralisation pinch-outs in operational areas and at extrapolated boundaries of the deposit. These pinch-outs have the potential to negatively impact grade forecasts if not resolved manually. Using built-in software tools only, the alternative for a more accurate model is to generate each individual layer and adding tens of thousands of manual interpretation points to honour pinch-outs (based on the amount of existing drilling in the mine and number of layers). This approach would require an estimated minimum of two to four years of a full-time employee (FTE) to be exhaustively completed. This study presents an automated approach to generate pinch-out points using a set of Python scripts that only take a few minutes to run. The newly generated points are then combined into the commercial software workflow as interpretation points, honouring observed pinch-outs. The remarkable time difference between approaches removes chance of manual errors and allows mine geologists to spend valuable time in validation and testing of scenarios, ensuring they are more representative of the deposit’s geology.

May 24, 2023

By J Whittle

This paper describes what is involved in carrying out a comprehensive optimisation of a long-term operating schedule for a mining complex. It details the data that must be assembled and discusses the different approaches to optimisation and what limitations they put on the variables and constraints that can be handled.CITATION:Whittle, J, 2014. Not for the faint-hearted, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 3–6 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By Ring R. J, Waters D. J, Vautier F. E, Fulton E. J

Laboratory leach tests have been carried out by the Australian Atomic Energy Commission to compare the effectiveness of Caro's acid (permonosulphuric acid) as an alternative oxidant to pyrolusite in the leaching of uranium ores. Results demonstrated that Caro's acid reduced acid consumption in leaching and the lime required for neutralisation of tailings liquor. The uranium extraction was unaffected by choice of oxidant.Following this study, Interox Chemicals Pty Ltd arranged a plant trial using Caro's acid at the Nabarlek uranium mill of Queensland Mines Ltd. The trial confirmed that significant savings in acid and lime usage can be achieved under plant conditions.Plant operations also demonstrated that Caro's acid has a number of significant operating advantages over pyrolusite.Queensland Mines Ltd have recently decided to convert their leaching process from pyrolusite to Caro's acid. The new system is expected to be fully operational by mid 1983.

Jan 1, 1983

This paper will first discuss the fundamental requirements for reliable discharge of backfill by gravity alone at high per cent solids. This discussion will include brief mention of the underlying principles of saturated solids flow contrasted to that of stirred tank or dilute discharge systems. Here the need to possess full knowledge of the flow properties of the stored material will be highlighted. In addition proper account must be made of the silo overflow weir and settling capacity to match plant throughput. Here opportunity will be taken to highlight the complexity of this multi-phase flow situation as well as the general yet paramount requirements for reliable solids flow. It will be shown that by proper attention to the multi-phase considerations gravity discharge of slurries as a consolidated bed with minimal water content is possible. Such high solids discharge results in greatly reduced demand for process water. In addition pumping costs are reduced as is the delay time associated with the mine drainage operation. Confirmation of successful applications will be highlighted by reference to several recent case studies. In the concluding phase mention will be made of the key yet very simple and effective operation techniques which enhance reliable discharge. The simplicity and reliability of properly designed gravity discharge backfill tank systems suggests increased application of this technology by the mining industry.

Jan 1, 1998