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By B Clements, G Lane

The operations and project environments are very different, but overlap in many areas. The development of mineral processing projects is goal oriented, is schedule focused and is a contractual environment. The operating environment for a mineral processing plant is oriented around longer-term commitments, focused on delivery against budget expectations, and an environment heavily influenced by long-term personal relationships, community relationships, and people issues.Further contrast is evident in the way expenditure is managed. Projects commit large amounts of money quickly to meet schedule-based objectives. Operations manage expenditure to minimise operating costs and are able to, or are forced to delay decisions on large expenditures. However, these two environments need to come together in many ways, ranging from greenfields plant handover to a new operations and maintenance crew, to day to day interaction and management of brownfields projects, often in close proximity.This paper considers the different perspectives people bring to projects and early operations, including the advantages and disadvantages of æoperationsÆ input to a project and models for managing value adding during project development, implementation and debottlenecking.CITATION:Lane, G and Clements, B, 2012. Operations versus projects - How do people think and what are the implications?, in Proceedings 11th AusIMM Mill OperatorsÆ Conference , pp 11-16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The knowledge in the field has been reviewed by literature studies, and using experience from personal research in sublevel caving. There is a lot of material regarding gravity flow of fine grained materials in bins, but the theory of flow for these materials are normally not applicable for coarse blasted rock. This study was therefore concentrated towards coarse rock fragments created after blasting in orebodies. The goal for this study was to make a report of known knowledge, and identify what we have to learn more about. The Bergmark-Roos theory, which was a paradigm shift in the science of gravity flow, is today the best mathematical theory for calculation of the drawbody for a homogenous material or when we wish to simulate the mean drawbody for a large number of draws. The Bergmark-Roos theory must however be improved, so it can take into account the flow pipe effect. When this is done it will be possible to construct a 3D computer model for calculation of ore extraction versus amount of loaded ore and waste. It is also necessary to find the 3D shape of the flow cone to be able to calculate the 3D ore rest that normally develops on footwalls. Calculations should be done for the draw on several sublevels including determination of the ore losses and temporary ore rests. First when this computer model is developed optimisation of ore recovery and waste rock dilution can start for a given orebody. The author points out the importance for international co-operation and standardisation of methods for determination of material properties. More field tests and model blasting tests should also be done. When enough knowledge is gathered, a handbook of the optimisation of sublevel and block caving should be written.

Jan 1, 2000

By F R. M Pires, R M. Carvalho

Supergene processes in banded iron formation (BIF) result in important dissolution, material transport and simultaneous disorder of the residual bands. The rock physical properties such as density, porosity and rheology change during the weathering attack. The itabirite, Paleoproterozoic metamorphic BIF from Quadrilßtero Ferrffero (QF) û Brazil, shows several weathered facies. Strong linking between topographic surface, rock density and iron grade occurs within the weathered zones. This linking is due to partial dissolution of silica and carbonate from itabirite and gravitational rotation and break of the remaining blades, generating kink-like slump structures. The original itabirite density, 3.7 t/m3, decrease at the first leaching steps, until 2.7 t/m3, and increase at the end of the leaching process until 3.6 t/m3. Iron grade increases from 38 per cent to 68 per cent and depressions (sinkhole), subsequently filled by Cenozoic basinal sediments, are developed over the enrichment zones. The formation of important supergene iron ore deposits of QF is intimately related to such a process. Several iron deposits at QF, such as Pico do Itabirito, Fßbrica Nova, Casa de Pedra, Tamanduß, -gua Claras, Cappo Xavier, etc., reveal the aspects related to the proposed evolution, implying that the formational process of the soft iron ores had a regional character. Granular medium model helped in the understanding of the development of the structure and the formation of the deposits. A numerical model has been developed in order to simulate a leaching system in a two-dimensional matrix, composed of two types of materials: leachable and unleachable. Equal volume proportion and vertical banding were considered. Drilling data was used as multipoint attractors to remove leachable matrix nodes.

Jan 1, 2002

By V Matousek, A Sellgren, R Visintainer, G McCall

A 4-component model for settling slurry pipe flow has been previously described by Wilson et al (2006) and Sellgren et al (2014) to predict pipeline friction loss (hydraulic pressure gradient) over a range of slurry compositions: from fine to coarse particle size, narrow to broad particle size distribution, and low to high solids concentration. The method applies a weighted average of established pipeline models for various settling slurry flow regimes, according to the volume fraction of solids falling within the applicable size range for each model. Further development of the model was undertaken by Visintainer et al (2017a, 2017b), based on a comprehensive set of laboratory tests in 203 mm (8 inch) and 103 mm (4 inch) pipelines, and it was also adapted to the modelling of slurry pump performance derates. However, this work was all performed with solids having a specific gravity near 2.65, as is typical for many mineral processing and dredging applications. The goal of the present work is to test the applicability of these models for settling slurries having a higher solids specific gravity, as may often be seen in the mineral processing of iron ore deposits. To that end, a test program was carried out in a 103 mm (4 inch) pipe loop using various compositions of an iron ore product having a solids specific gravity of 4.75 and containing both coarse and fine solids. By screening and flushing operations, a range of particle size distributions were created having different proportions of the coarse and fine elements. In all, 19 tests were performed with d50 particle sizes ranging from 50 μm to 3.2 mm and delivered solids concentrations from 10 per cent to 43 per cent by volume. Particle size distributions varied from very narrow to very broad, with d85/d50 ratios ranging from 1.75 to 26. Pipeline pressure gradient and pump performance data were collected and used to test the applicability of the previously developed 4- component models and to propose improvements to the models for the handling of high-density solids.

Nov 8, 2021

L&M have been involved on the Shotover since 1980 when we joined Jack and Barney Ryan, who had started in 1972 with gold at $45 per ounce after a successful career as roading and demolition contractors in Christchurch. The first 85 tonne plant was a typical NZ trammel-riffle table plant with an armour plated hull for surviving Shotover floods, and was fed by a 53 tonne UH20 excavator. All this gear had to be carted in over the Skippers road on a small truck or sledge for the heavy loads. This operation was successful and generated the cash flow to sample the lower section of river and plan a second plant. To reduce fine gold losses this was planned to be a jig recovery plant and also included a vibrating screen which saved space and weight over a trammel. There are five flowlines of primary jigs and one secondary, followed by two Knudsen bowls for cleanup.

Jan 1, 1985

By B Armstrong

The Proterozoic poly-metallic Trilogy deposit was discovered in 1997, and until recently, mining evaluation was stalled due to poor metallurgical performance. Unlocking the substantial economic value of the deposit required a coming together of geologists, mineralogists, metallurgists and mining engineers, who by working collaboratively, uncovered the detail necessary to allow the required metallurgical breakthroughs to occur. The deposit itself is described as a sedimentary exhalative (SEDEX), with an enriched lead-zinc-silver core surrounded by a broader envelope of copper-gold mineralisation. The geological domains were defined in broad terms based on the style of mineralisation, assay values and lithology. These domains, while adequate for the resource estimation process, failed to translate into representative metallurgical domains. Additional work with new techniques defined regions in the deposit with altered processing properties which could not be recognised by conventional geological logging. Such additional complexities could not be appreciated at the outset of the metallurgical test work program.These regions were defined by applying the EDTA analysis method for recognition of where the valuable sulfides, particularly galena, had been partially modified by oxidising conditions. Hence, the flotation response of the valuable sulfide minerals was diminished and the increased amount of heavy metal cations available in the system significantly reduced selectivity in the flotation process.Understanding the detail of this complexity was essential in determining representative metallurgical domains, which was the first step in the long road of development.

Sep 5, 2011

By E Widzyk-Capehart, C Hölck Teuber, S Steffen, V Rivero, O Fredes, E Sanchez, I Pedemonte, N Gonzalez

This paper summarises the research, development and initial application of a sensing platform that has the potential to monitor subsurface deformations, pore pressure and other variables simultaneously to gain a better understanding of rock mass behaviour. The platform is based on Networked Smart Markers (NSMs) devices, which, with their ability for wireless communication between individual sensors and the possibility of real-time data acquisition and processing, will assist in the development of predictive tools to better assess rock mass behaviour.A good opportunity to implement this technology is in the specific application of transitioning from an open pit mine to an underground caving operation. One of the key elements to maintaining the mining business during such a transition is having a good understanding of the unique geotechnical conditions of mutual influence created during the open pit to underground interaction. The knowledge acquisition will require the implementation of a robust platform for geotechnical monitoring, which could be enhanced by incorporating the NSMs. The integration of sensors within the NSMs would enable the collection of additional data about rock mass behaviour (ie caving propagation and crown pillar fracturing), which could be used to improve the management of mining operations and, specifically, allow the development of reliable predictive tools based on the data collected.CITATION:Widzyk-Capehart, E, Hölck Teuber, C, Fredes, O, Rivero, V, Sanchez, E, Pedemonte, I, Gonzalez, N and Steffen, S, 2016. Understanding rock mass behaviour through the development of an integrated sensing platform, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 275–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The Key Issues - An Overview Minerals industry needs Mining companies want technologies which are ò cost-effective, ò high likelihood of delivery (ie transfer existing technologies from other industries), ò highly useable, ò an evolutionary rather than revolutionary approach, and ò to be developed in partnership with the mine, supply groups and researchers, For example, `soft' systems for information collection to better manage the mining process rather than mechanical systems.

Jan 1, 1997

On the Kinetics and Equilibrium Models for Biosorption of Ni(II) onto a Gram-Positive Bacteria Strain, Rhodococcus opacus, for Environmental Applications The aim of this fundamental study was to evaluate the biosorption of Ni(II) from aqueous solution streams onto a Rhodococcus opacus strain through kinetics and equilibrium isotherms studies. The biosorption of nickel achieved its highest value in a pH around 5. The experimental data evaluation was carried out focusing three two-parameter models, as: Langmuir, Freundlich, Dubinin - Radushkevich. In order to determine the best isotherm fit, three error analysis methods were used to assess the data: correlation coefficient (R2), residual root mean square error (RMSE) and Chi-square test. The error analysis established that the Freundlich model fits better the nickel biosorption data. Maximum uptake capacity of nickel reached a value around 7.63 mg.g-1 for R. opacus. The biosorption rate was fast and achieved a removal of around 79 per cent of Ni(II) in the first 5 minutes at room temperature (25 ¦ 2¦C). The experimental kinetics data was evaluated considering two models (pseudo-second order and pseudo-first order). The error analysis established that the pseudo-second order model better fits the data.

Sep 13, 2010

By G Phillips

The Merlin project is situated 130 km south of Cloncurry in North West Queensland, Australia. It is located within the Pre-Cambrian Mt Isa Inlier and is grouped within the Eastern Fold Belt. The host rocks are metasedimentary rocks of the Proterozoic Kuridala and Staveley Formations adjacent to the Mount Dore Granite.Merlin zone represents part of the Mount Dore polymetallic deposit containing copper, zinc, silver, gold, lead, cobalt and most recently has been found to host molybdenum mineralisation. This is intimately associated with economic grades of rhenium, a naturally occurring metal that is an important component of high temperature aircraft engines. The host rock sequence is a 200 m thick zone of metasediments sandwiched between competent granite in the hanging wall and brittle quartzite in the foot wall. A distinct shear marks the contact between the granite and metasediments. The host rocks are comprised of three main rock types: black shale, phyllite and altered banded calc-silicate.Mineralisation dips to the east at approximately 45° in a package of fine grained pelites and banded calc-silicates. The top 150 m of the sequence is typified by black shale and phyllite. The lower 50 m is typified by pink banded calc-silicate. The main molybdenite zone is located at and parallel to the pelite-calc-silicate contact. Down dip, the zone splits into two or three veins hosted by the calc-silicate rock suite and haloed by thin, steep dipping, stylolitic molybdenite veinlets.The deposit was discovered in 2008 by routine infill reverse circulation sampling conducted for the Mount Dore copper deposit. One hole penetrated below the main target Cu horizon and intersected visible molybdenite. During 2009 and 2010 a 50 × 50 m diamond drill pattern delineated a total mineral resource of 6.7 Mt @ 1.3 per cent Mo, 23g/t Re, 0.3 per cent Cu (mostly Indicated Mineral Resource with minor Inferred Mineral Resource). The resource has been estimated using ordinary kriging within grade domains. Access to the deposit has commenced via a decline and production through the nearby Osborne flotation concentrator (70 km south) is expected in 2012. All facilities and resources are fully owned and operated by Ivanhoe Australia Limited, a public listed company on the Australian and Toronto stock exchanges.

Aug 22, 2011

By A J. Weston

Block or panel caving technology is far removed from that of the top slicing and block caving of the late nineteenth or early twentieth centuries. The rapid mechanisation and expansion of these methods in the late twentieth century was as much a result of the change of the technology of the unit operations of development, ground support, drilling and blasting and transport as it was of the advances in geotechnical understanding and practice. The small footprint gravity and scraper block caving mines with boundary weakening, rail transport and shaft hoisting of the early to mid-twentieth century have been replaced by massive high lift panel caves using preconditioning of the ore, large load-haul-dump units, adjacent crushers and conveyors to surface. The technology changes in the unit operations are described and the drivers for these changes examined.CITATION:Weston, A J, 2016. The evolution of block caving technology, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 265–274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The Bayswater seam of the Singleton Coal Measures is discussed in relation to its field occurrence and related li~hotype profiles. The seam is correlated throughout widely separated areas of the Hunter Valley with the Farrells Creek seam at Howick, Broke seam at Broke, and Saddlers Creek seam at Mt. Arthur. The unusual features of composition of the seam in relation to adjacent seams is dealt with in terms of the seam environment, particular attention being given to the sandstone at the base of .the seam. Petrographic and other data are used to support the arguments submitted.

Jan 1, 1973

Inhibition of Bubble Coalescence by Salts and Sugars

Sep 13, 2010

By M Ranjan, C R. Borra, P Palai, P P. Sahoo

Change in mould slag composition during casting of medium alloy steel is caused by the redox reaction between molten steel and mould flux. Mould flux generally contains a certain amount of SiO2, but elements such as Al, Mn and Ti in high/medium alloy steels reduce SiO2 in the mould flux, causing remarkable changes in the composition of the mould slag. As a result, the properties of the mould slag change greatly as continuous casting proceeds. This causes casting instability, process abnormality and casting defects. Effect of Ti as an alloying element in steel on mould slag is studied extensively through high temperature laboratory measurements and plant measurements. TiO2 gets picked up by the mould slag up to 3 per cent during casting a steel grade containing 0.1 per cent Ti. This changes the mould slag composition and results in decreasing the slag viscosity by up to 10 per cent and decreases slag break temperature by 30–40°C.

Aug 21, 2024

Permitting, engineering and evaluation, detailed design and construction aspects of the Golden Cross goldmining project in New Zealand are briefly reviewed. The extremely lengthy and complicated governmental approval process together with the delaying tactics of opponents of the project are outlined and comment is made on aspects of the draft legislation proposed as part of the overhaul of New Zealand's resource management laws.

Jan 1, 1990

Suddenly, mining has been thrust into the limelight. It has a large image that casts its shadow over New Zealand. Is it any wonder that resistance has heightened and that an almost unprepared populous is currently struggling to protect the very land they hold dear. Next to the atomic bomb, mining has the demonstrated power to massively change the land and its side effects can pollute many miles beyond the operation. During the past year, New Zealand concern over the possible effects of the mining proposals has become acute. This was specially so in the areas of special environmental quality, such as the Coromandel, and here a very unhappy situation has arisen.

Jan 1, 1981

Solid Energy New Zealand Limited has grown significantly since becoming a State Owned Enterprise in 1987. Exports, profit, turnover, output per employee are all trending upwards. The company has identified the management of Health and Safety as a key capability to sustain future growth, and to add value to the business. It has set a target of being the best practice in managing Health and Safety.   This paper examines the company's activities in the Health and Safety area, and how it sees that value can be added by preventing and containing losses through accidents involving people, property, process and the environment. Solid Energy is confident that a Planned approach to managing Health and Safety can achieve this. It will explore historical events, strategic changes, Health and Safety systems, Benchmarking, Performance Measures, initiatives, progress to date and challenges for the future.

Jan 1, 1997

By C E. Davies

At present the source of virgin iron for steel produced in New Zealand is titanomagnetite extracted from titaniferous beachsands. Some of these beachsand deposits contain extractable quantities of ilmenite as well as titanomagnetite and both minerals represent challenging sources of vanadium and titanium products in addition to iron. This study looks at some theoretical aspects of smelting these ores directly with coal rather than with electric power, and takes into consideration the properties of the raw materials, the thermodynamics of possible process routes and the background of the economics involved.

Jan 1, 1980

Earnest Advocacy - A Key to Sustainable Minerals Industry Education - A Philippine Experience

Sep 13, 2010

By T Angerer, N H. Maund, S Hagemann, D R. Cowan

Cliffs Natural Resources Pty Ltd - Asia Pacific Iron Ore's (formerly Portman Iron Ore Limited) K deposit (Dowd's Hill), at its Koolyanobbing operation in Western Australia, hosts enriched magnetite mineralisation below the presently mined haematite-goethite ore zone. Two distinct northwest-southeast elongated, highly magnetic anomalous bodies that dip to the north-east appear to be sourced by this deeper mineralisation. Magnetic modelling indicates significant remanent magnetisation with Qratios around 1.5, directed shallow down. The north-west anomaly is overlain by a ridge of uneconomic banded iron formation (BIF) and the present waste dump, whereas the south-east body was partly exposed during ongoing mining of overlying haematite-goethite ore. Sections of the magnetite mineralisation in this south-east anomaly were intersected previously by diamond drill holes. Review of the historic cores identified potential magnetite enrichment, with grades and mineralogy that might be amenable to beneficiation. A first-phase reverse circulation drilling program was designed to further delineate the trend and extent of the two anomalies. The following magnetite mineralisation assemblages are recognised from cores, reverse circulation (RC) drill cuttings and pit mapping of the south-east magnetic body: higher-grade magnetite-haematite ¦ goethite and magnetite ¦ pyrite and lower-grade, recrystallised magnetite-quartz (BIF), magnetite-carbonate, magnetite-talc and minor magnetite-bearing mafic schist. Disseminated specularite is locally present in theassemblages. Talc-schist and massive pyrite occur along the footwall contact. Magnetic susceptibility measured from drill chips within the magnetite-enriched zones reveals an apparent susceptibility values range of 0.2 to 1.3 SI. Preliminary results from Satmagan and Davis tube recovery analysis shows that the magnetite content in these mineralised zones correlate well with existing geophysical data and magnetic susceptibility measurements.

Jan 1, 2009