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The main factors which influence disposal of mine waste under New Zealand conditions are identified and discussed: namely, geological conditions which produce soft weather-sensitive waste, wet and cold winters which affect productivity in such waste, elevated seismicity which affects stability and the need for water rights which involve public participation. The waste disposal scheme for the Martha Hill Project is described, thereby illustrating how these factors influence the planning of a current mine strippings and tailings disposal scheme.

Jan 1, 1986

By M Hino, Y Sasaki

Sustainable handling of municipal waste and sewage sludge has an important goal to recycle resources without supply of harmful substances to humans or the environment. The gasification mechanism of phosphorus from municipal waste and sewage sludge during the incineration process has been investigated to develop a phosphorus recovery system. Quadrupole mass spectrometer coupled to an electric furnace is applied to study the vaporisation behaviour of phosphorous gas phases from municipal solid waste (MSW) incinerator ash of sludge during solid-state reduction by carbon. Measurements are carried out in vacuum conditions of 2 x 10-6 Torrs and furnace temperature range 573 - 1773 K, at a heating rate of 7.22 K/minute. It has been found that most of the phosphorus is vaporised as PO2, P2 and P4, in agreement with thermodynamic estimation despite a shift in the temperature regimes.

Jan 1, 2006

By N Clarke, J Hunt, A Barros, N Guerrero, L Keeney

Grade Engineering® (GE) involves a range of integrated technologies and operating protocols for improving effective feed grade through early rejection of low value material prior to costly processing activities and has the potential to transform the economics of large, low grade, mining operations. Extensive GE test work by AngloGold Ashanti (AGA) and the Cooperative Resource Centre for Optimising Resource Extraction (CRCORE) determined that the Gramalote gold deposit in Colombia is highly amenable to implementation of grade-by-size screening to upgrade the ore at a production scale. To understand the relationships between geology and the upgrade response drill core and bulk samples were analysed at the Centre for Ore Deposit and Earth Sciences (CODES) as part of a larger CRCORE project to understand geological controls on grade-by-size deportment, i.e., the tendency for specific mineral phases to preferentially fractionate during breakage into different size fractions. This work is focussed on understanding the role of mineralogy and texture in influencing rock breakage and natural fractionation at a range of scales. Detailed logging of Gramalote drill core and mineralogical analyses including hyperspectral logging, portable and bench-scale X-ray fluorescence (XRF), plus low resolution Laser Ablation of intact drill core pieces, combined with data from site (drill logs, geochemistry, petrophysics) were used to evaluate the ore and alteration mineralogy, vein paragenesis and textural variability. This provided information on gold deportment and allowed the identification of favourable host veins. Bulk sample material from different ore grade zones was also analysed. A comparison with the results of GE testing shows that positive upgrade results are produced by rocks with abundant veins, particularly those associated with potassic and/or white mica alteration. This work indicates upgrade response can be predicted from drill core using data collected by a combination of automated systems including hyperspectral data, XRF, and detailed drill core logging.

Nov 10, 2020

By M J. Nugus, J G. McLellan, T G. Blenkinsop

High fluid pressures and deformation have been instrumental in the formation of high-grade gold lodes at the Archaean granite greenstone 12 Moz Sunrise Dam gold deposit in Western Australia. Historically, predicting the location of these lodes has been difficult due to the irregular nature and high-grade nugget characteristics of the deposit. Recent exploration successes and the discovery of the Vogue system have led to an improved knowledge of the deep extents of the mine. This new structural and gold distribution data has enabled a new 3D interpretation of the system and has provided a better insight into the links between deformation, fluid pressure evolution and gold deposition. Here we employ 3D geomechanical and coupled fluid flow modelling to better constrain areas of high strain partitioning, rheological failure and focused fluid flow, which provides a substantially increased predictive capacity for further within-mine exploration. The localisation of deformation in and around the main felsic porphyry and major shallow shear zones provides critical insights into fluid pathways that have contributed to the distribution of fracture networks and ultimately gold deposition during late stage deformation events. Understanding the relationship between deformation events, fluid pressure evolution and the partitioning of strain is paramount in understanding the distribution of gold and for focusing on future target areas.CITATION:McLellan, J G, Blenkinsop, T G and Nugus, M J, 2013. Fluid pressure, geomechanical evolution and predictive targeting of the Sunrise Dam gold deposit, Western Australia, in Proceedings World Gold 2013 , pp 419-426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Y K. Ji, B J. Chung

In recent years, the utilisation of ultra-fine ore in ironmaking has gradually increased due to the depletion of high-quality iron ore. The use of ultra-fine ore in the ironmaking process is typically energy intensive and leads to high CO2 emissions. The improvement of sinter reducibility is one of the methods used to reduce the environmental impact of using fine ore.In this study, a high-strength and high-reducibility sinter manufacturing process was investigated by controlling the sintering reaction. The key technology used in this method is the manufacture of mini-pellets by selective granulation equipment. The mini-pellets consist of iron ore, limestone and burnt lime and are designed to melt at temperatures below 1200°C. The molar ratio of CaO to Fe2O3 of the mini-pellets is 0.25~0.75. The 2~5 mm diameter mini-pellets are manufactured with burnt lime as the binding material.During the sintering of mini-pellets, goethite, which has relatively high reducibility, should be retained as residual ore in the sinter cake. The strength of the sinter cake was kept by the bonding reaction of the mini-pellets, which have a low melting temperature. This is the main principle of the reaction-controlled sintering method.The reaction-controlled sintering method manufactures a high-strength and high-reducibility sinter cake and increases sinter productivity by around 15 per cent using ultra-fine iron ore.CITATION:Chung, B J and Ji, Y K, 2015. Production of high-quality sinter by controlling the sintering reaction, in Proceedings Iron Ore 2015, pp 21–28 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By J C. Koppe, L Vieira

One common problem for blasting in iron ore mines with significant weathering is the occurrence of large blocks of hard rock mixed with softer material. This situation causes a problem for blasting design and sometimes produces large boulders of rock that require a secondary blasting, as well as excavation difficulties. To minimise this situation, geophysical techniques were used to identify the hardest material amid the weathered material. To study the problem, seismic, ground penetrating radar (GPR), electrical resistivity and induced polarisation (IP) methods were used in an intensely weathered Brazilian iron ore deposit. The methods of GPR combined with IP, resistivity and seismic showed to be effective in modelling the contrast among hard, friable materials and soil. The results were used to improve the geological model and create more favourable conditions for the subsequent blast design. The blast design based on geophysical/geological models resulted in significant improvement in the fragmentation of the iron ore. This was achieved by the adoption of a specific drilling pattern for a given geological situation. With the new specialised blasting design the formation of boulders was eliminated.CITATION:Vieira, L and Koppe, J C, 2015. Geophysical techniques applied to blasting design, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 289–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M Jones

The past 100 years the mining industry can be characterised by a focus on increasing financial returns often to the detriment of social, human, manufactured and environmental capitals. Despite the sustainable development principles promoted by the International Council on Mining and Metals (ICMM), the Equator Principles and the African Mining Vision, which should have enhanced project promoters’ ‘licence to operate’ within a host community or nation, the industry has often failed to integrate proven innovations and best practices that enhance sustainability outcomes for mineral resource projects. This failure has led to delays, the abandonment of projects, with value destroyed for promoters, governments, host community and investors.The paper will outline the application of proven innovations, Enterprise Optimisation (EO), and Sustainable Operations (SUSOP®), during the pre-feasibility phase of a project. By determining the value of each capital before and after the application of proven innovations, the presentation will outline how and where value can be created across all five capitals over the life of a project or operation.The paper will demonstrate how the application of proven innovations significantly transforms the value-proposition of a mineral resource project or operation by generating additional value across all of the five capitals, reducing project risk, thus generating value for all stakeholders.CITATION:Jones, M, 2015. Fundamentally transforming the economic and sustainability signature of mining assets, in Proceedings Third International Future Mining Conference, pp 169–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

The ERMS Process was developed during four years of testwork by Austpac Gold NL to overcome the severe metallurgical problems of the ilmenite atWestport, in the South Island. These deposits have been known for about one hundred years. They were originally mined for gold, and only later attracted attention as a possible source of titanium minerals.   The resource is of world scale and may exceed 20 million tonnes of contained ilmenite. Similar deposits occur at Barrytown further south and together these areas would constitute an important opportunity for export-oriented mineral development, if a viable beneficiation technology were available. Further processing is essential, as the composition of the ilmenite is well below market specifications.

Jan 1, 1993

By E Mroczek, M Climo, B Carey, M P. Simpson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The composition and volume of geothermal fluids in New Zealand offers considerable potential for the extraction of various metals and minerals, as well as being a source of heat energy, steam and gases, and for use in generating electricity. While extracting products from geothermal fluids is technically feasible, positive economics is the key driver for commercial success; however, there is no assessment of this opportunity that identifies simple, cost-effective processing technologies and provides a greater understanding of the economic viability and barriers for implementing such technologies. The methodology that will be used to evaluate the commercial opportunities for New Zealand is discussed.CITATION:Mroczek, E, Simpson, M P, Climo, M and Carey, B, 2015. From waste to wealth – mineral extraction from geothermal brines, in Proceedings PACRIM 2015 Congress, pp 133–138 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

THIS paper is not intended to be a detailed description of the lead, smelting plant at Cockle Creek, as this has been covered in previous papers for the Institute in 1918, Proceedings No. 31, by other members of the staff; but the idea is to give some of the practices and conditions peculiar to these works, also to give some experiments carried out and the conclusions arrived at. Unfortunately, owing to the closing down of the smelting and refinery plant at these works, sone of the experiments could not be carried to a more definite and commercial basis, but they are given in the hope that they may be of interest to members, and may perhaps suggest further thought along the lines indicated.ROASTING AND SINTERINGThe greater part of the ore treated at these works came from the Central mine, Broken Hill, but, in addition, a large quantity was purchased from other parts of New South Wales and from Tasmania. This purchased ore was seldom received in the form of a concentrate, but initially in its crude state, and therefore had to be crushed. The crushing was done in a Krupp mill, and the ore then added to the roasting mixture. This addition of crude ore was one of the main...

Jan 1, 1923

By M Dusci, A Trueman, S Poos, R Baumgartner, M Brittan

The Canahuire epithermal Au-Cu-Ag deposit in southern Peru is a complex and challenging deposit for metallurgical studies. It has issues of gold locking in sulfides and non-sulfides, deleterious elements and acid rock drainage (ARD). From scoping study to feasibility study, there has been considerable improvement in the understanding of the important geometallurgical characteristics that need to be measured and modelled. This paper presents the current understanding and the requirements to continue to provide optimal models for mining studies.Significant effort has been put into understanding the genesis of the deposit. Improved spatial and temporal understanding of lithology, alteration, structure and mineralogy was used to build a geological and alteration model of the deposit.Early metallurgical programs quantified the effect of head grade on process plant recoveries, but the geometallurgical and statistical analyses did not identify other physical characteristics that influence these recoveries. The studies improved the understanding of the nature of locked gold which can occur as minute inclusions (< 5 ¦m) in sulfides (primarily pyrite with lesser arsenopyrite, pyrite being 100 times more abundant than arsenopyrite) and gangue minerals (quartz and carbonates) as well as solid solution in arsenopyrite and pyrite.The presence of pyrite and the limited buffering capacity of waste rocks increases the potential ARD, which will require mitigation costs before, during and after operations. Waste rock ARD potential has been classified and incorporated in the geometallurgical model. The current classification of waste rock at Canahuire, using international classification standards, is limited due to the complexity of the deposit.Complex deposit metallurgy necessitates a complex process flow sheet, including flotation and cyanidation. Economic recovery will be constrained by the relationships between economic variable grade, other elements and mineralogy. These constraints and inter-relationships are difficult to establish throughout the deposit with a single test. A follow-up geometallurgical program is under investigation and will attempt, with the help of additional test work, to map areas of higher and lower recoveries. It is hoped that metallurgical response can be linked to measurable parameters other than head grade. If this is possible, these factors can be incorporated into future geometallurgical models.CITATION:Baumgartner, R, Dusci, M, Trueman, A, Brittan, M and Poos, S, 2013. Building a geometallurgical model for the Canahuire Epithermal Au-Cu-Ag Deposit, Southern Peru - past, present and future, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 51-58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

The pyroclastic-filled Voorspoed kimberlite pipe has a low grade due to significant internal dilution which translates to a marginal business case. The site, with excavations, tailings dumps and buildings remnant of mining from 1906 to 1912 is to become De BeersÆ benchmark mine in South Africa. In a climate of skills shortages and lean structures, a geological service to optimise exploitation of this complex resource was established. As historical mining removed the higher-grade centre of the pipe, initial production was in the weathered upper benches along brecciated pipe margins. Trenching and blasthole logging before blasts helped to mitigate the effects of the drastic contact deviations that occur when working with an inferred geological model. However, identification of unfamiliar weathered kimberlite and delineation of unmodelled internal waste posed challenges. Efficient grade control by demarcation and allocation of individual truck loads will be vital to continue profitable mining at Voorspoed. Further challenges arose across disciplines. The first yearÆs planned production of mostly weathered kimberlite was processed through a plant designed for VoorspoedÆs unusually competent ore. The high clay content of the weathered material led to clogged chutes and overloaded fines disposal, hampering efforts to commission the plant. Resolving this problem involved mining æout of planÆ to provide a blend of fresh and weathered kimberlite. The calculation of an accurate mine call factor was hindered by a lack of haul truck monitoring, process stoppages and stockpiling in the plant during commissioning. Updating of the geological model to incorporate the contact changes observed in the pit was slowed by the need to first understand how 40 years of exploration data was integrated to create the model. A plan, involving focused mine geology practices, is in place to upgrade a portion of the resource from Inferred to Indicated level of confidence. These challenges are not limited to new mines but will be ongoing as new information is constantly gained at Voorspoed and many mining operations.

Jan 1, 2009

By R Buerger, D Barrett, P Hodkiewicz

The Emily Ann nickel mine is owned and operated by LionOre Mining International Ltd. The deposit was discovered during 1997 and is blind, concealed beneath 25 m of transported cover and a further 100 m of unmineralised Archaean felsic rocks. Nickel sulfide mineralisation is hosted predominantly in strongly deformed, altered and metamorphosed Archaean komatiitic ultramafic rocks. Subordinate felsic-hosted, remobilised mineralisation is also present. Mining of ore commenced during late-2001. Since the early days of exploration drilling, through feasibility delineation drilling and subsequent mining, a geological model involving thrusting and folding of a komatiitic-hosted nickel sulfide deposit has been an evolving theme. Development of appropriate mine geology procedures, including detailed mapping, significantly increased the confidence of mine-site geology and engineering staff in the geological model and improved operational efficiencies during start-up. This also allowed the engineering and mining team to develop a tolerance for the large fluctuations in daily production grade, with an understanding that budgeted production targets, on a level-by-level basis, were achievable. This paper describes the development of the current interpretation of the deposit and emphasises the importance of a sound understanding of deposit geology. The direct benefits at Emily Ann included improvements in drill targeting, resource estimation and mine planning.

Jan 1, 2003

By J Hunt

A critical aspect of geometallurgy is quantifying mineralogical and textural relationships that affect mineral processing (eg, liberation and recovery). However, to date, this has been an expensive and time consuming venture and only minimal amounts of this type of data are typically available to be included in the mine planning process. Our research is focused on developing methods that will produce the required mineralogical and textural data rapidly and inexpensively. New methods of characterising liberation potential from image analysis of coarse particulate material and direct small-scale flotation measurement are compared with measurement of liberation at final grind size (ie conventional tests on MLA). The new tests are designed to rank the liberation potential of samples in order to classify an ore deposit into domains of low, medium and high liberation potential. This parameter can then be used to adjust the cutoff used to differentiate ore from waste. Results to date show that all tests provide the same ranking for the samples. The measurement based on coarse particulate material compares favourably to the results from MLA analyses on the same samples. Further work is being carried out to determine which of the tests will be the most effective in terms of time, effort and cost

Sep 5, 2011

By Ishikawa K, Kikuchi T, Tokairin Y

Roadheader, developed from coal cutting machines, is generally classified as a tunnel excavation machine for soft rocks in respect to excavation mechanism, machine structure, weight, engine output and so on. In recent tunnel works, however, there is an increasing demand for changing from blasting to mechanical excavation by roadheaders to avoid environmental problems such as noise and vibration. But there exist various difficulties in excavation of harder rocks by roadheaders. In order to explore the possibilities of roadheader excavation, we performed field and laboratory experiments. In the field experiment, roadheader model S-125 (Mitui Miike Machinery Co.,Ltd.) was tested for various rocks of wide range of hardness, and excavation capacity and wear of picks were measured. In the laboratory test, cutting performance of the picks was tested by our cutter testing machine. This report describes thr: of these experiments and discussions :n possibility of applying boom-type tunnelling machines to hard rock excavation based on these experimental data.

Jan 1, 1987

By Grainger A, Dawkins G, Lysaght A, Kennedy R

Maintenance management improvement projects were undertaken at several BHP Collieries Division mines pursuing.the objective of achieving better structured maintenance procedures. Efficiently structured maintenance and optimum asset use are interdependent and productivity and computer models assist towards that objective. Definition of aspects of maintenance and analysis of the nature of equipment and materials, workloads and tasks, lead to more effective planning and scheduling of maintenance. The quality, standards and procedures of records must be suitable and adequate for storage and future retrieval. Total Quality Control initiatives and improvement projects even extend into spheres of customer/supplier relationships and problem solving teams as well as the more recognisable standards of management and performance factors in maintenance. All such factors contribute to a Maintenance Management Matrix to provide a better structured approach to economic maintenance management in the capital intensive coal mining industry.

Jan 1, 1991

An examination has been made of the rate and extent of removal of carbon from scrap metal charges when the melt is exposed to atmospheres which are reducing or oxidising with respect to FeO at unit activity. The mechanisms of decarburisation of molten Fe-C-S- P-Mn-Si alloys with H2/CO/H20/C02 gas mixtures with controlled compositions at high or low concentrations of carbon in the melt in the presence and in the absence of sponge iron, in both slag free melts and in the presence of various slag forming additives are discussed. A significant quantity of carbon can be removed from the metal during the melting stage and under optimum conditions, a high percentage of metal recovery and low carbon can be obtained after exposure of melt to the above gas mixture with controlled compositions. The presence of ferrous oxide provided by poorly reduced ore in the charge and the use of controlled atmospheres facilitated the removal of carbon to very low level during the melting period.

Jan 1, 1984

Mathematical economic models for assess ment of technological progress in the mining industry in the USSR are discussed. The models are based on a simple index, TT which approxi- mates the rate of growth of the people's living standards. However, for application in the mining industry it is necessary to incorporate various parameters to account for the dynamic charges in the geological, mining and other technological conditions. Derivations of the models are shown and examples of results are Included.

Jan 1, 1977

By J Centofanti, D Conti, R Riske, C Morley, A Cook

Why is it so difficult? Why are there differences throughout the resources industry in how reconciliation factors are reported and calculated? Why is there no standard formula to use? These are common questions asked when mining companies try to compare reconciliation results across operations or attempt to undertake internal or corporate governance reporting processes. For many mining companies the calculation of reconciliation factors is often a very time and resource intensive part of mandatory reconciliation reporting. Some major mining companies, that move millions of tonnes of material per annum, dedicate full time resources to the calculation of reconciliation factors. The willingness of these companies to set aside resources demonstrates the value that operations place on good reconciliation reporting. Reconciliation is about measuring the variance between two like measures at different points along the mining sequence. It can be undertaken between predictive models, forecast plans and actual measured performance. Calculations are used to derive a variance between two sections within the mining sequence, with the result being commonly known in the resources industry as a æfactorÆ. Mining companies use the calculation of reconciliation factors as key performance indices (KPIs) to provide a æhealth checkÆ of their operation, with variances often pointing to issues either with the accuracy of the original estimate or the quality of the measurement being used in the comparison. There are many reconciliation factors that can be calculated and reported. This paper will set out, clarify and provide a recommended standard means of calculating each specific factor that, where adopted by a company, will ensure compliance with the international reporting codes, such as JORC. Using case studies from Rio Tinto Group (Rio Tinto) and BHP Billiton Mitsubishi Alliance (æBMAÆ), and the authors experience across a wide range of mine sites, the outline of a generic solution for tracking a parcel of material from the pit through to the port along with appropriate reconciliation factors is provided. The intention of proposing standardised reconciliation factor terminology and methodology is to provide the foundations of a system to enable communication and comparison across different commodities, companies and mines sites.

Jan 1, 2009

By P J. Howard, P Darvall, J H. Mainwaring

In less than a year, Atlas Iron’s Corunna Downs Project has moved from a new discovery to a substantial resource of high quality in an underexplored greenstone belt. Located approximately 170 km south-east of Port Hedland and 40 km south-west of Marble Bar, in the Pilbara Region of Western Australia, Atlas Iron Ltd (Atlas) has conducted extensive exploration work at Split Rock, Razorback, Runway and Shark Gully, consisting of geophysical surveying, field mapping, 464 reverse circulation and 16 diamond drill holes resulting in a current resource of 51 Mt at 57.3 per cent Fe (Atlas, 2014b).The Corunna Downs Project is interpreted to be hosted within the Cleaverville Formation of the Archaean Gorge Creek Group. Within the project area these rocks outcrop as subvertically dipping banded iron-formations (BIFs) and jaspilites, cherts, minor shales and meta-sediments forming a north–south trending plateau.Primary hematite-martite iron mineralisation is overprinted in the near surface environment by supergene goethite, and frequently capped with a thin laterite cover. The strongest enrichment areas have been discovered within topographic lows, proximal to fault zones, which coincide with a geophysical anolmaly. These characteristics were targeted, and the subsequent areas mapped in greater detail, allowing for efficient resource definition.Although first explored for iron in the late 1960s, it wasn’t until Atlas’ acquisition of the project in October 2012, that major strides were made to defining an economic resource. At present, Corunna Downs is Atlas’ best greenfields exploration discovery, both in terms of the potential scale of the resource and its blending capacity.The Corunna Downs prospect is emerging as a major new iron ore province in the Pilbara and includes 80 km of potential host stratigraphy. Corunna Downs sits strategically between Atlas’ Mt Webber and McPhee Creek tenements, and can play an important part in Atlas’ growth strategy as iron ore market conditions become more volatile and challenging.CITATION:Mainwaring, J H, Howard, P J and Darvall, P, 2015. Discovery of the Corunna Downs deposits, in Proceedings Iron Ore 2015, pp 305–312 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015