Search Documents

By C Czerny, T Elkington, L Lorenzen

The Dutwa Nickel Project is a nickel laterite atmospheric leach project located in Tanzania that has been under development by African Eagle Resources plc (2012). A bankable feasibility study (BFS) has been progressed to evaluate mining of the resource (107 Mt at 0.92 per cent Ni) followed by hydrometallurgical processing on-site to make a mixed nickel-cobalt intermediate product. The unique relatively high silica contents in the Dutwa deposits, as opposed to limonite, which is more commonly occurring in nickel laterites, presented the possibility for beneficiation of the ores to enhance the leach feed nickel grades and provide economic benefits in terms of operating and capital cost efficiencies.Geometallurgical relationships, based on the results of an extensive variability metallurgical test work program for beneficiation and leaching, were developed for the BFS, which resulted in an improved understanding of ore classifications within the deposit and their responses. The geometallurgical information obtained has been instrumental in making key preliminary techno-economic decisions, such as forecasting whether or not mined material should be beneficiated and was ultimately used to drive the mine plan towards the prioritisation of areas within the deposits that delivered the best cost efficiencies and overall project economic outcomes.CITATION:Elkington, T, Lorenzen, L and Czerny, C, 2013. The use of geometallurgical relationships in process route selection and mine plan optimisation for the Dutwa Nickel Project, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 207-216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

BHP Billiton Olympic Dam produces copper cathode, uranium oxide concentrate and refined gold and silver. The operation is comprised of an underground Mine and Processing Plant and is located 560 km north of Adelaide. Water for the operation is sourced from two wellfields located 120 and 200 km from the operation in the Great Artesian Basin (GAB) at a rate of approximately 36 ML/d. Regulatory drawdown limits were established to protect regional GAB springs and are monitored at compliance bores. Drawdown was predicted in the æOlympic Dam Environmental Impact StudyÆ (Kinhill, 1997); however, pumping at higher volumes may have the potential for increased drawdown resulting in a trend towards the compliance limits. In recent years increased usage of water in the Concentrator and Hydromet sections of the Processing Plant has caused excess process water reporting to the Tailings Retention System (TRS). This has resulted in excessive amounts of liquor ponding on the tailings cells with a potential impact being contamination due to seepage of liquor to groundwater. Effective management of water by the operation is necessary to both reduce GAB drawdown and reduce the amount of liquor on the tailings cells. A site working-group has been established to investigate and pursue opportunities to improve the water use efficiency of the operation. This paper will highlight the issue of water management at Olympic Dam and discuss the various options currently being investigated to improve management of this important resource.

Jan 1, 2006

By D Piason

Newstan Mine commenced mining operations in 1887 and has since undertaken extensive mining within the Young Wallsend, Great Northern, Fassifern, Borehole and West Borehole coal seams using a range of mining methods including board and pillar mining and longwall mining.Newstan Mine is planning to extend the existing mine workings using longwall and miniwall mining methods to produce up to 4.5 Mt/a of run-of-mine (ROM) coal for at least 25 years. The planned extension in the Main East and South West sections will involve developing new longwall panels and related mains headings. The new area contains higher specific gas emissions (SGE) than previously experienced at Newstan Mine. To achieve the optimum ventilation requirements for the longwall operation in this new area, a new ventilation shaft was designed to be constructed using the blind boring method in the South West Headings section.This paper presents the shaft design parameters and selection criteria for the construction of the new ventilation shaft, including the construction phase and the holing process to connect the shaft to the underground workings. The paper also discusses future ventilation requirements for Newstan Mine.CITATION:Piason, D, 2015. South-west ventilation shaft project at Newstan Mine, in Proceedings The Australian Mine Ventilation Conference, pp 229–238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Y Li, D J. Williams, E Topal

A mine waste rock dump does not have any intrinsic value, yet is an inevitable structure in surface mining operations. Since the purpose of mining is to maximise profit, possible expenditure reduction in hauling waste rock to the dump, which can represent up to 50 per cent of the total operating cost, is highly desirable. Apart from cost, potential acid mine drainage (AMD), due to seepage from surface waste rock dumps containing reactive waste rock, could threaten the ecological balance, drinking water supplies and irrigation systems downstream from a mine site. In order to minimise these potential risks, selective placement of benign and reactive waste rock, and the encapsulation of reactive waste rock by benign waste rock, need to be carried out during the construction of the rock dump.In this paper, a new methodology, based on mixed integer programming (MIP) is developed to manage waste rock dumping. The model aims to minimise waste rock haulage costs by locating the optimum destination(s) for each waste rock block, while at the same time controlling the placement of reactive waste rock to minimise the potential for AMD. Tests on small-scale virtual data demonstrated that the model is capable of dealing with selective placement of different waste rock types, encapsulating reactive, potentially acid forming (PAF) waste rock, and stockpiling benign waste rock for encapsulation and rehabilitation purposes. The solution time for the MIP model is far less than the traditional manual approach, and the resulting schedule is up to 46 per cent more cost effective.CITATION:Li, Y, Topal, E and Williams, D J, 2012. Mathematical approach for better mine waste rock dumping management, in Proceedings Life-of-Mine 2012 , pp 207-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By H Benzer

Grinding clinker to finished cement consumes more energy than any other comminution process. World production of cement in 2009 was 2840 million tonnes and the energy required for comminution was 40-60 kWh/tonne depending on the clinker characteristics and the fineness of the finished cement. Machines used include single and multi compartment ball mills, HPGRs, vertical roller mills, centrifugal air separators, V separators, screens and crushers. The circuit most commonly used consists of a closed circuit HPGR followed by a single compartment ball mill and an air separator, and in operation the variables are adjusted to obtain maximum throughput with no loss of quality of the separator fines.A common objective in cement plants is to reduce energy consumption without affecting the particle size in the finished cement and simulation is used as one procedure to achieve this. Models are now available for all the machines commonly used in clinker circuits and circuit optimisation studies using simulation have been carried out in many plants leading to decrease in energy consumption per tonne of cement. In this paper the models used will be discussed briefly and several case studies will be reviewed which will highlight the effect of change in ball size in a two compartment mill, the role of the HPGR in an HPGR – ball mill – air separator circuit, and the use of a high intensity vibrating mill for producing finished cement with high additive ratio.

Aug 8, 2011

By H S. Pescini

A material aim when feeding ore blends into a processing facility is to reduce the variability of the properties of the feed material and to maximise the output, or throughput. At the Mining Geology conference of 2019, we presented a paper on optimal blending of coking coal given geological variability. The paper introduced integer-programming techniques to both maximise value and minimise feed or product variability. We discussed an application where the geological uncertainty is characterised using a normal distribution and exact solutions are readily obtainable using second order conic constraints in the mathematical model. Geological uncertainty is not always normally distributed, many properties will be characterised as log normal or some other skewed distribution. For example, copper can be some form of lognormal and Fe in Iron ore has a left skewed distribution. In this paper, we discuss some distribution free techniques to optimise the blends of plant feed or output given a quantified geological uncertainty. We discuss the sample average approximation method and how to set-up and apply the method to an ore blending problem. Evaluating a case study demonstrates that the explicit use of non-normally distributed geological uncertainty can better optimise feed into an ore processing facility and potentially add significant value. The approach is equally applicable to all mining and processing operations that blend material into a processing facility or directly into a saleable product.

Mar 22, 2022

By A Batnasan, K Haga, A Shibayama, K Higuchi, H Takeuchi

High silica (SiO2), alumina (Al2O3), and phosphorus (P) contents in iron ore adversely affect the quality of iron products. The removal of those impurities from iron ore is an essential point in further iron ore processing. In this paper, the removal of P, SiO2 and Al2O3 impurities from iron ore by alkaline drying followed by reverse cationic flotation is discussed. The reverse cationic flotation experiments are performed using the iron ore samples without and with alkaline drying pretreatment. All other flotation conditions except pulp pH (4–12) and particle size distributions (-45 to -250 μm) are held constant. A typical collector and frother, such as dodecylamine acetate (DAA) and methylisobutylcarbinol (MIBC), are used in the flotation experiments. Alkaline treatment is conducted before flotation using sodium hydroxide at fixed conditions. The impact of alkaline drying on the performance of iron ore flotation is evaluated based on the removal rates of P and SiO2 + Al2O3, iron grade, and iron recovery compared with the iron ore flotation without alkaline drying (direct flotation). X-ray diffraction (XRD) analysis indicates hematite and goethite are the main minerals in the iron ore, which assays 62.8 mass per cent Fe, 0.232 mass per cent P, 7.1 mass per cent SiO2 + Al2O3 (total) determined by X-ray fluorescence analysis (XRF). Results indicate that a combined approach is more effective for removing P and SiO2 + Al2O3 impurities from iron ore than the direct processing technique because the maximum removal rates of P and SiO2 + Al2O3 are 48.2 per cent and 66.5 per cent from the alkaline dried iron ore when 8.4 per cent and 13.1 per cent from the non-alkaline dried iron ore.

Sep 18, 2023

By Hoffmann CF

Thermal conditions at depths of several k.i'-.r.,etres in hydrothermal systems are a major (actor controlling gold transport into the epithermal environment. Understanding of the coupling of thermal, metal and ligand (HZZ S) sources in the root zones of hydrothermal systems therefore becomes important for the application of tectonic and igneous petrochem- ical studies to regional scale precious metal exploration. The evaluation of favourable conditions in this source zone and application to explor- ation rests on a detailed knowledge of the gases, H2S, CO2 hydrocarbons and other trace components preserved in fluid inclusions. Recent developments in analytical techniques now permit examination of these components and the recognition of complex hydrocarbons in rluid inclusions from epithermal and other lydrothermal systems appears promising for ieoosit-source correlation.

Jan 1, 1987

Simple parameters, capable of easy observation on-site under operating conditions without interruption to production, are outlined for the operational assessment of underground conveyor systems. Recording techniques, methods of analysis and deduction of operational characteristics are discussed for batch inputs to several points of a multiple belt conveyor system with limited inter-belt storage capacity. Particular attention is given to input and output load- time distributions, utilisation of inter-belt storage capability and system shutdown behaviour. Actual data, observed for a transfer feeder located between two trunk conveyor belts in an underground coal mine, is used to illustrate the operational assessment of an underground system. Load sensitive feedback systems-are briefly considered.

Jan 1, 1982

Research cruises dedicated to seafloor hydrothermal activity along the Kermadec arc first began with the Sonne-135 expedition in 1998. This was followed by the worldÆs first systematic survey for venting along an arc during the 1999 NZAPLUME I expedition. Since then, cruises dedicated to mapping plumes along the Kermadec arc include NZAPLUME II (2002), NZAPLUME III (2004) and ROVARK (2007). In addition, the manned submersible cruises SWEEP Vents (2004) and NZASRoF (2005) utilised the Shinaki 6500 and Pisces V, respectively, to sample in detail select hydrothermalsystems for mineralised samples, rocks and vent fluids. The ROVARK (2007) cruise was the first to deploy an autonomous underwater vehicle (ABE) along the arc which surveyed Brothers volcano at a far greater resolution than had been done previously by ships on the sea surface. While these expeditions have largely been led by GNS Science, together with its collaborators from National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory (NOAA/PMEL), significant contributions have been made by other groups from various nations, exemplifying the global interest in seafloor hydrothermal activity associated with intraoceanic arcs. This is an ASTRACT only. A full-length paper was not prepared for this presentation.

Jan 1, 2008

This paper presents a review of computer techniques for the automatic contouring of geological and geophysical data with output as interactive display on graph plotters or graphics terminals and passive display on automatic drafting tables. The advantages of the method of fitting a triangulated surface to randomly distributed data using an advancing front algorithm are described, as well as the technique for determining interpolated values for the production of contour line segments and a contour smoothing algorithm. This contouring method is employed by the Geological Survey of Queensland and is implemented as an interactive system. An alternative method ideally suited to randomly distributed data involves the use of piecewise parametric cubic splines. This method which is ideal for sharp variations in magnitude and areal extent typical of geophysical anomalies is discussed. The mathematics of surface interpolation using non-parametric splines and an explicit piecewise surface fitting technique are discussed. Curve tracing techniques which are suitable for automatic contouring are also presented and the inherent advantages of interactive contouring using on-line plotters and graphics terminals for previewing of displays are described.

Jan 1, 1977

By M Freeman

In a visionary move, the Planning Commission and the Ministry for Planning in Western Australia decided to invite three extractive industry quarry operators, local government councils and State Government departments (Minerals and Energy, Environmental Protection, South West Development Commission) to contribute jointly to study the impacts of blasting on areas surrounding basalt quarries in the Bunbury region of WA. The results of the study will help establish suitable zones in which land uses will be controlled under a proposed Greater Bunbury Region Scheme and in local planning schemes, to minimise conflicting land uses. This paper discusses the blasting program conducted to characterise and model the vibration behaviour of the rock under the effects of pilot-scale and full production blasting, and highlights some of the benefits achievable when a thorough blasting impact program and assessment is conducted at the planning stages of land-use establishment.

Jan 1, 2001

The Gold Ridge Mine is an open-cut gold mine in the Solomon Islands. The mine is owned and operated by Gold Ridge Mining Limited, a wholly owned subsidiary of Ross Mining NL. At the invitation of the Solomon Island Government, project construction commenced in July 1997 and gold production commenced in August 1998. The mine is the countryÆs first, and represents a major milestone in the development of the Solomon Islands. At the time of project approval and construction, there was a growing awareness in the country of the potential impacts of mining in the tropics, partly due to unfavourable publicity surrounding a number of other mining operations in the Pacific region. The management of environmental impacts was therefore an important consideration in the approval of the project, and continues to receive a high level of attention from the Government and community. Ross Mining did not commit to the Gold Ridge Project until it had satisfied itself that all waste rock and tailings could be safely contained on-site, and that the standards normally expected of a mine in Australia could be met. Ross Mining approached the approval, construction, and operation of the Gold Ridge Mine with a set of operating principles that met Government and community concerns. These were:best practice environmental management; operation of the mine in accordance with standards expected of mining operations in Australia; independent peer review of key technical aspects; on-going consultation with Government and community; and equitable transfer of wealth to landowners and the local community. As a consequence, the Gold Ridge Mine has developed into a successful mining operation with a high level of support from local landowners, the general community and the Central and Provincial Governments of the Solomon Islands.

Jan 1, 1999

By M Wortley, J McKay, D La Rosa, O Guyo

It has been a generally held concept that crushing operations were, by their nature, too simple to benefit from the implementation of advanced process control. The commissioning of an OCS¬ expert control system and image-based oversize detection system, VisioRock, at the Pilbara Iron Tom Price facility are dispelling these notions. A constraint-based OCS¬ expert control system has been designed and commissioned on the high-grade crushing and screening plant along with a vision-based oversize detection system functioning on six product conveyor belts. To date, the expert control has demonstrated the ability to increase production by maximising dynamic constraint utilisation. Dynamic constraint utilisation is a concept developed by Rio Tinto Technical Services for effectively evaluating constraint-based control logic performance. The VisioRock system has been installed and configured and has been operating for a period of several months. Currently, Tom Price and Metso personnel are working to define correct oversize detection thresholds. Details of the plant implementation are discussed.

Jan 1, 2006

By G Turner-Saad

An improvement to cut-off grade optimisation theory based on geometallurgy has been completed. The improvement fundamentally consisted of taking into account mineralogical and textural characteristics instead of grades. These characteristics are related to the spatial variability of mineral abundance, association, particle size and liberation properties. Additionally, the improve- ment considered the spatial variability of mineral processing liberation and selectivity properties associated with mineralogy and texture. The enhanced optimisation enables estimation of the economic value of mining operations based on an optimum cut-off policy attributed to liberated and selected ore minerals.The enhanced optimisation was developed as an essential component of a joint cut-and-fill mining and mineral processing methodology based on mixed integer mathematical programming. The formulation considers static and dynamic modifying factors that vary over the projected life of mining. The objective function of the mathematical formulation consists of maximising the realistic expected economic value of concentrates or products of liberated and selected ore minerals, whilst minimises liberated and selected gangue minerals. The optimal solution is obtained when the objective function is subject to geological, mining, processing, marketing, smelting, refining, environmental and financial constraints. The methodology accesses geometallurgical multivariate resource models, which integrate the spatial variability of mineralogical and textural characteristics and mineral processing liberation and selectivity properties.The geometallurgical process concurrently optimises stope geometries, ore reserves, mining sequences, and mining and mineral processing production based on the enhanced cut-off of liberated and selected ore minerals. In addition, the process considers additive and non-additive transfer functions associated to mutually exclusive geometallurgical spatial domains. The transfer functions also take into consideration the blending of mineralogical and textural characteristics with mineral processing liberation and selectivity properties.This contribution presents an example of cut-off grade optimisation via mineralogical and textural characteristic, and liberation and selectivity processing parameter optimisation for a spatially variable orebody.

Sep 5, 2011

By S Russell

The completion of the $1.1 B Cape Lambert Upgrade project is the second ‘pillar’ in Rio Tinto Iron Ore’s expansion program that has enabled Rio Tinto Iron Ore to effectively double iron ore shipping capacity from the Pilbara between 2003 and 2009 to 220 million tonnes per annum (Mt/a), following the successful completion of the Dampier Port upgrade project two years earlier.The Cape Lambert Upgrade has built on and enhanced many of the engineering achievements of the Dampier Port upgrade project, as well as developing innovative and unique engineering solutions for this complex ‘brownfields’ project that presented its own challenges, particularly in this distinctive open-water port environment.The project was implemented in two phases to achieve an increase in port shipping capacity from 55 to 80 Mt/a – an enhancement phase and an expansion phase.The initial enhancement phase, which provided an increase to shipping capacity from 55 to 60 Mt/a, focused on increasing the utilisation and effi ciency of existing plant and equipment with a relatively small capital expenditure.The expansion phase, which provided the increase in shipping capacity to 80 Mt/a, included extending the existing iron ore wharf by 256 m to create four shipping berths, a new shiploader, an expanded stockyard (including a new fourth bucket wheel reclaimer) and a new surge bin facility to maximise outloading tonnage rates.The Cape Lambert Upgrade project was implemented whilst the port remained fully operational and continued to ship record tonnages of iron ore throughout the project duration. This achievement required signifi cant upfront planning and sequencing of construction activities to support the operation of the port. Innovative design and construction techniques were used to mitigate the impact and enable construction activities in and around the operating plant.Throughout the project, new benchmarks in engineering design and construction practices were established, which have since been adopted for new iron ore port facilities currently in planning phases.

Jul 11, 2011

By R A. Anand, N N. Viswanathan, M M. Pande

Slags are the most voluminous solid by-products generated in pyrometallurgical operations, and, as such, finding an application for these oxidic materials is pertinent to maintaining resource efficiency. In particular, pyrometallurgical copper production is associated with high slag rates, typically ranging from 2.2 to 3.0 tons of slag per ton produced copper, which necessitates slag valourisation. A possible application for these iron silicate slags is as supplementary cementitious materials (SCMs), which effectively lowers the CO2 emissions per ton of cementitious material. Although utilising iron silicate slags as SCMs has been studied in previous work, the scientific literature has limited data on the effect of composition on the inherent reactivity in cementitious systems. More specifically, no reports on the impact of FeO/SiO2 ratio have been presented in previous publications. Therefore, the present study aimed to isolate this parameter in a synthetic FeO-SiO2-Al2O3-CaO-MgO-Cr2O3 system. Since the amorphous content is a pertinent parameter for SCMs, a high-temperature confocal laser scanning microscope (HT-CLSM) was utilised to assess the crystallisation behaviour at continuous cooling conditions. Furthermore, high-temperature rheological experiments were conducted to measure the viscosities of the slags in relation to the crystallisation behaviour. The experiments showed that depolymerising the slag by increasing the FeO/SiO2 ratio generated a less viscous slag, which showed higher tendencies for crystallisation. Furthermore, experiments assessing the inherent reactivity as an SCM showed that depolymerising the slag by increasing the FeO/SiO2 ratio as the sole independent parameter generated an initially more reactive slag. However, replacing SiO2 with FeO was found to negatively affect the reactivity as measured over seven days within the tested compositional range.

Jun 19, 2024

By Y Wang

Inadequate goaf gas control may lead to gas exceedances in the ventilation return air, which will trip power in longwalls and cause production stoppage. To effectively control gas emissions, Australian mines heavily rely on drilling vertical goaf holes to capture coalmine methane before it migrates to mine openings. The wide application of goaf gas drainage may change the goaf pressure distribution, lead to more ventilation air leakage, and consequently increase gas explosion and spontaneous combustion risks. This paper focuses on analysing goaf gas drainage production data from a case study longwall mine in Australia. The correlation between suction pressure, total flow rate, gas flow rate and air leakage rate were analysed in detail as the face-to-hole distance changes. Suction pressure is found to be positively correlated with total flow rate, and their correlation also varies at different goaf locations due to various goaf compaction and flow resistance. This paper also proposed a theoretical method to calculate the goaf resistance of ventilation air leakage pathways. Based on several basic assumptions and different goaf drainage scenarios, the leakage airflow pathway resistance in the goaf at different face-to-hole distances can be calculated. The model results suggested that the resistance of air leakage pathways from the working face to individual goaf holes increased with the face-to-hole distance. The resistance results can also be used to calculate the corresponding permeability at the same position, which can be used as input data for CFD or Ventsim models.

Oct 12, 2022

By I Jabou, D G. Blazak, L C. S Hogarth

The R70 test is a good indicator of coal reactivity to oxygen and is commonly used to provide a rating of propensity for self-heating. Tests performed by The University of Queensland Spontaneous Combustion Testing Laboratory have resulted in the development of a large database that shows the impact of coal quality on this parameter. From these results it is possible to infer an R70 value, which can be used to gain an appreciation of the intrinsic coal reactivity before it is even tested. However, any interpretation of R70 values must consider the influences of coal rank, mineral matter and moisture content to provide a better understanding of the spontaneous combustion risk of a particular coal.

Jan 1, 2005

By M S. Fenzel

Increased environmental regulations and pressures have created changing and new demands for tailings management strategies in a variety of mining applications. Critical among these items is the disposal of tailings as the pursuit of increased yields and lower costs have driven the application of different process technologies. With a number of technologies having a niche application focus, the belt filter press has been utilised for decades as a cost-effective and versatile option for dewatering different types of mineral tailings and other waste process streams. One of the critical advantages of the belt filter press is the technology’s ability to adapt and work in numerous plant designs, operating conditions and applications. As permitting and disposal options have become more stringent, plant designers, operators and equipment suppliers must develop comprehensive and site-specific economic, design and process evaluation techniques to ensure proper equipment selection and system design for belt filter presses or any other dewatering technologies. This paper will explore these techniques in relation to belt filter presses (with reference to other technologies) in a variety of different applications, along with other considerations to ensure a successful tailings dewatering system and disposal design. Summaries of equipment performance characteristics, operating and maintenance strategies and optimisation techniques will also be addressed in conjunction with the belt filter press’s adaptability to different plant designs and the resulting tailings characteristics.CITATION:Fenzel, M S, 2015. Analysis and adaptability of belt filter presses and other technologies for tailings dewatering over a range of mineral processes, plant designs, conditions, regions and operating philosophies, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 35–44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015