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By G P. Taylor

Mining Lease SML 57 was registered to Mount Kasi on 5 January, 1995. The Mount Kasi gold mine is located in Vanua Levu, Fiji's second largest island and operated from 1932 to 1946 producing 261,000t of ore at an average grade of 7.5g/t Au. The deposit represents a structurally controlled style of high sulphidation copper gold mineralisation with peripheral low sulphidation mesothermal vein type gold mineralisation. The resource consists of 1,048,000 tonnes of residual soils (eluvium) containing 1.9 g/t Au at 0.5 g/t Au cut off and 1,240,000 tonnes of hard rock at 3.0 g/t Au and 1.0 g/t Au cut. 94 drill holes, 298 auger holes and 85 pits were modelled to outline the resource. 29% of the pits bottomed in mineralisation and it is likely the full thickness of eluvium has been understated. The pit is scheduled to produce 500,000 tonnes of ore per annum to yield 35,000 ounces of gold with an initial 2 years of eluvial ore followed by a further 2 years of hard rock ore. Total capital costs are estimated to be less than 10.0 million dollars with construction planned to commence in 1995. The likelihood of locating further ore is high.

Jan 1, 1995

By P R. L Browne

Study of geothermal systems in the Taupo Volcanic Zone (TVZ) has significantly advanced our understanding of the processes of epithermal mineralisation. The three main lessons learnt are: 1. knowledge of their chemical anatomy; 2. precious metal transport and deposition; and 3. hydrothermal alteration zoning. These are described in the context of ore formation and exploration.

Jan 1, 1997

Implementation of an Energy Efficient Dry Grinding Technology into an Anglo-American Zinc Beneficiation Process

Sep 13, 2010

The Martha Hill project operates with a nett surplus of water, due to the catchment of rainwater on the tailings dam and the requirement to de-water the open pit mine. It is necessary to discharge this surplus, treated as required, to the Ohinemuri River which flows past the process plant.   The treatment plant, adjacent to the process plant, handles all effluent from the Martha Hill operation including water pumped from the mine, excess water from the tailings decant, and seepage from the tailings dam underdrains. To-date the plant has treated and discharged over 800 000 tonnes of water.

Jan 1, 1991

By A P. Tinnelly

This paper explores the structural/physical and policy based issues that have lead to the apparent resource conflict between Forestry and Mining on the West Coast. Both industries are important to the West Coast and bear many similarities, particularly at the corporate end of the mining scale. However there are very distinct structural differences which set the scene for friction at the boundaries. Examples of how mining impacts upon forestry illustrate where some of the friction arises and provides some insight as to where some solutions are or may be found.

Jan 1, 1996

By M Boyd

The University of Wollongong was named University of the Year 2000, for its work in preparing students for the e-world. Computer facilitated learning is being introduced into subjects throughout the engineering course. First year mining engineering students are introduced to computers, e-communication, using the UniversityÆs web based information system, and web based subject delivery. Mining engineering students in the mid-years of the course use programming languages and numerical computation software such as MATLAB, while students in the final years use a range of commercially available professional engineering software such as TALPAC. Most of these subjects are offered as part of the UniversityÆs Learning Online program, co-ordinated by its Centre for Educational Development and Interactive Resources (CEDIR). Learning Online subjects are delivered using the Web Course Tools (WebCT) environment. WebCT allows all resources to be accessed through the web, allows email communication between lecturer and student, and allows discussion groups for the exchange of ideas. Students can submit their assignments through WebCT and receive immediate feedback. This paper describes how WebCT has been used to deliver a first year engineering computing subject, mid-year numerical computation subjects, a mining economics subject and mine planning subjects.

Jan 1, 2002

By P Paredes, T Leaño, D Gajardo, C Tramón, S Peñaloza

The definition of an ore handling system and its consequent layout design is of crucial importance in cave mining projects. It not only represents the main driver in the production capacity and reliability of the mining system, it is also a fundamental variable in the footprint’s development time and cost.In recent decades, load-haul-dump (LHD) tramming distance optimisation through the allocation of several orepasses inside the footprint has been the most common practice in ore handling system layout definition at Codelco’s operations. Today, the improvement of existing technology, such as higher-capacity LHDs and jaw-gyratory crushers, and intensive preconditioning techniques to improve fragmentation allow the conceptualisation of simple and highly productive ore handling system layouts for wide caving areas that avoid the complexity and high cost of developing numerous orepasses inside the footprint.The initial macroblocks of the Chuquicamata underground mine project (PMCHS) consider an ore handling system layout in which LHDs dump into orepasses located inside the footprint area. The ore is then transferred into crusher chambers located below the production level, where it is crushed by jaw crushers and then conveyed to surface. In an effort to reduce development time and costs, a new ore handling system layout for the PMCHS experimental macroblocks was engineered using improved technologies and techniques in a simpler mining system. This paper compares the new ore handling system layout for the project’s experimental macroblocks with the traditional LHD-orepass layout in terms of production capacity, reliability, development time and cost.CITATION:Paredes, P, Gajardo, D, Leaño, T, Peñaloza, S and Tramón, C, 2016. Simplifying the ore handling system through the use of current technology at Chuquicamata underground mine project, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 571–584 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The ore milled from the Lead Lode of The Zinc Corporation leases consists of a fairly granular mixture of galena, marmatite, chalcopyrite, tetrahedrite, pyrrhotite, pyrite, and lollingite with a gangue association of calcite, quartz, bustamite, rhodonite, mangan-hedenbergite, garnet, fluorite, mangal1o-calcite and apatite. The silver content of the ore occurs in three minerals-tetrahedrite, dyscrasite, and pyrargyrite, the last two mentioned occurring in microscopic association only. Other metallic and gangue minerals are also present in this complex mineralogical association, but do not influence the milling operations. Fortunately, the silver minerals favour the galena and chalcopyrite as their host minerals, thus facilitating the recovery of both copper and silver in the lead concentrate. The ore from the Lead Lode assays from 14-18% lead; 3·0-4·5 oz. silver per ton, and 9·5-12·0% zinc.A parallel lode, known as the Zinc Lode, is well developed in The Zinc Corporation leases. This lode assays from 6-8% lead, 1·5 oz. silver per ton, 18-25% zinc with a siliceous gangue. The common Lead Lode gangue minerals-ealcite, rhodonite, bustamite-are very rare in present underground exposures. No metallurgical work was done on this ore during the pilot plant operations.The aim in the milling process is to produce: 1. A lead concentrate with the maximum economic recovery of lead, silver, gold, copper and antimony, and minimum zinc content.2. A zinc conc,entrate with the maximum economic recovery of zinc, cadmium, and cobalt, and minimum iron, arsenic and fluorine content.3. A waste residue containing sufficient granular material to be utilized as underground fill.In considering the economics of the milling practice the above three requirements plus consideration of the tariffs submitted by the purchasers of concentrates were the deciding factors in the evolution of the present milling practice.Towards the end of 1924 The Zinc Corporation Limited added to and adapted the old zinc tailings plant for the treatment of 5,000 tons of crude ore per week. This plant, which operated until January, 1936, was in general principles similar to the standard Broken Hill methods of ore concentration, whereby the galena was recovered by the gravity concentration methods of Hgging and tabling with selective flotation concentration of the residual galena and marmatite. One important difference from other Broken Hill plants was that the primary grinding of the jig tailing was performed with flint-loaded mills operating in closed circuit with revolving screens. Two primary grinding sections were installed, each...

Jan 1, 1941

The Century zinc-lead-silver deposit has a geological resource of 118 million tonnes averaging 10.2% zinc, 1.5% lead and 36 g/t silver. It lies approximately 250 krn NNW of Mt Isa in NW Queensland, Australia, and is hosted by middle Proterozoic age siltstones and shales of the Lawn Hill Formation. Within the orebody, most mineralisation occurs selectively within black shale units as fine grained sphalerite and galena lamellae with minor pyrite and siderite. The black shale units are separated by weakly mineralised sideritic siltstone horizons. The deposit is unmetamorphosed and only weakly deformed, displaying excellent lateral stratigraphic and grade continuity. The deposit is mostly overlain by younger Proterozoic sediments and later Cambrian age limestone cover and only a small proportion of the mineralisation crops out. Mineralisation has a subtle surface expression without a classic gossan profile, probably due to the low iron sulphide content of the ore. These factors contributed materially to the length of time between the first recognition of lead-zinc-silver mineralisation in the area by prospectors in the 1880s, to the discovery of the orebody by CRA Exploration Pty Ltd (CRAE) in April 1990.   Small scale prospecting and mining continued in the area from the date of the first mining lease in 1887. Post 1950, the deposit area was also included within nine separate regional exploration titles prior to CRAE's title acquisition in 1987. CRAE's original exploration strategy was partly pragmatically and partly conceptually inspired, but the eventual discovery only partly conformed to the original conceptual model. The deposit was found higher in the stratigraphy than the original target position, with unexpectedly low total sulphide content relative to other known deposits.   The discovery soil anomaly was located by the CRAE's first regional orientation traverse line in the area, but was not drill tested for three years. The discovery sequence at Century has strong elements of persistence, technical competence and some luck. It demonstrates that even in well explored terrains (by conventional standards) the exploration story can never be said to be over. The foreshadowed development of an economic resource at Century will hopefully inspire continued commitment to 'brownfields' exploration by mining companies, and demonstrate to external regulators the importance of genuine multiple land use strategies and the need for continued access to land for exploration and mining purposes.

Jan 1, 1995

A Sun SPARCstation based computer network is utilised to store and process mining data at the Macraes Gold Mine. Techbase and Medsystem software running on the SunOS unix platform is used to generate all data plans, sections and other design data required on a daily basis to run the mining operation. The Macraes site is regarded as a fully integrated site where all geological, grade control, exploration, orebody modelling, resource estimation, pit optimisation and mine design is undertaken on site by MacraesÆ professional staff. The methodologies employed are regarded as æstate-of-the-artÆ where computerisation allows the rapid and efficient evaluation of large quantities of mining data by a handful of professional personnel. Ore reserves are estimated using an indicator kriging method and roving cone pit optimisation, a complex process that would not have been achievable in pre-computing days.

Jan 1, 1992

By D Matthews

With a brownfield project comes control integration challenges. The Khumani Iron Ore Mine’s second phase expansion posed a number of challenges as there was substantial brownfields work conducted. The fi rst phase was the compilation of the modifi ed process functional specifications for the project. The second phase was an audit on all of the operational sequences; this included a comparison between the SCADA sequences, sequential starts analysed from the historian data (with the potential for improvements made by the plant operators in manual start-ups) and what was proposed in the process functional specification. Differences, inclusions and missing equipment were highlighted. The third phase was the comparison of interlocking and control in the PLC with the updated process functional specification; this was done during the coding process. Running parallel to the three phases was the SCADA integration; tie-ins to the existing SCADA were conducted on maintenance days and shutdowns, in many instances with ‘dummy’ equipment to get the operational staff accustomed to the new interface. This paper details each of the phases, the success of this methodology as well as the pitfalls experienced.

Jul 11, 2011

Adsorption of Alkylammoniums in the Interlayer of Montmorillonite and its Effect on the Viscosity of Organo-Montmorillonite Gels

Sep 13, 2010

Application of Discrete Element Method for Simulating Feeding Conditions and Size Reduction in Cone Crushers

Sep 13, 2010

The prospect of utilisation of phosphate ores which contain high P2O5 values associated with Al and Fe has produced a great deal of interest over many years. Processing options have generally been based on the utilisation of by-products which were required to offset the processing costs.   This paper presents a range of processing options which have been investigated at laboratory or technical scale on phosphate ores which predominantly consist of crandallite, CaAl3(PO4)2(OH)5.3H2O and millisite, Ca(NaK)Al6(PO4)4(OH)9.3H2O. Christmas Island (Indian Ocean) and Mt Weld (Western Australia) phosphate ores are good examples of such feedstocks. It is expected that these processes may also be applicable to such phosphate ores from other locations.

Jan 1, 1990

By D van der Wal, R Dobbe, K Moeller

"Ore mineralogy and texture are primary variables controlling mill recovery efficiency in flotation plants. However, tracking daily variations of key mineralogical characteristics such as species-by-species liberation is not possible with current on stream analysers and assay lab techniques. In addition, traditional plant mineralogical analysis limited by long data turn-around times from central analysis laboratories typically provides only a time-averaged view of mill performance, e.g. by means of monthly composite feed, con or tailings analysis.This paper presents the results of a development and first field test of an on-site Automated Mineralogy solution (MLA or QEMSCAN) with the specific goal of monitoring recovery variation, ore quality and flotation performance on a mineral species-by-species and day-by-day basis, from up to twelve million direct particle observations per month. The trial was performed at a Pb/Zn-Ag operation in the US from November 2012 to April 2013. The focus of the study was three-fold: to validate the robustness of equipment and operational procedures for daily use by mine site technicians at a remote mine site to develop a methodology to boil down hundred-thousands of Automated Mineralogy particle data from size-by-size con and tailings samples to a couple of numbers meaningful to chief metallurgists to monitor recovery trend changes and correlate these to changes in the feed properties and/or flotation efficiency.The study focused primarily on the Pb/Ag rougher-concentrator circuit. Ten polished blocks of two and three size fractions of con and tailings were prepared by mine site technicians during a daily twelve hour shift. Eight hours of daily measurement time by the instrument revealed an estimate of the dayÆs recovery performance, ore quality and flotation performance for Freibergite (Ag-species) and Galena (Pb-species), within 36 hours from initial sampling. Data quality was assessed by means of calculated versus measured assay reconciliation. Cumulative sum curves of recovery performance, ore quality and flotation performance reveal trend changes with a frequency of 1 to 4 weeks. These were correlated to cumulative sum curves of e.g. locked and slimed particle classes of the mineral species of interest, attempting to identify a possible root cause of recovery performance trend changes. Systematic over-grinding and flotation chemistry issues were the primary causes of below average plant operations during the trial.CITATION:van der Wal, D, Dobbe, R and Moeller, K, 2013. Development of an on-site mineralogy solution for metallurgists, in Proceedings MetPlant 2013, pp 126-132 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Peculiarities of Quartz Distribution in Zinc Flotation Products and their Influence to Mineral Processing

Sep 13, 2010

Conservation and environmental issues are raising their profile with respect to both demand restraint and electricity supply options. In New Zealand, conservation pressures and energy efficiency need to be seen in relation to the supply system currently in place which has capacity for economic supply of electricity in quantities substantially in excess of the current market. Consequently, energy efficiency and conservation need to be interpreted in relation to the supply system as well as in relation to end use. The relationship between the environment and conservation is strongest when new generation is required. New Zealand's electricity supply system consists of a large proportion of hydro production and this has significant environmental benefits when considered in relation to concerns of global wanning and the greenhouse effect. However, environmental trade-offs in supply options need to take account of both the efficiency of electricity end use, the trade-off between hydro and thermal generation and the inter-regional effects of shifting development options from one region to another. The Electricity Corporation has a high level of consciousness with respect to environmental and conservation issues and this paper demonstrates its own moves to maximise energy efficiency and illustrate the environmental trade-offs for supply.

Jan 1, 1990

By S Jackson, I Arbuthnot

The use of High Rate Thickeners has gained wide acceptance in the mineral treatment industries. The design of these units is characterized by an efficient deaeration and flocculation chamber, and introduction of the flocculated feed solids into a preformed floc bed zone. By these means the settling process is accelerated and consequently High Rate Thickeners achieve a significantly higher throughput per unit area than conventional thickeners.   The object of a control system on a High Rate Thickener (HRT), as on a conventional thickener, is to obtain the required underflow density and overflow clarity at all feed conditions. The feed conditions which may vary include volumetric and mass feed rate, pulp density, particle size and particle type. A conventional thickener has a large volume and cross sectional area, and changes in performance occur slowly û the operator has time to observe and react to these changes to maintain control. On a HRT, there is a much reduced residence time and therefore control parameters need to be reset more frequently. Although manual control is possible, the use of automatic control systems is therefore desirable to avoid excessive operator attention, while optimizing control of density and clarity. Automatic control of a conventional thickener is usually achieved by an underflow density loop which regulates the rate of withdrawal of underflow. A turbidity meter is sometimes used to measure overflow clarity and regulate the addition of a coagulant or polymer flocculant. These measures are not adequate on a HRT, because they would not give optimum control and could lead to excessive flocculant use. To achieve optimum operation in a HRT, the floc bed level should be maintained above the feed inlet point in the thickener. This bed level has become the key variable around which most control systems have been designed. However, a number of problems have occurred which has resulted in poor control, or only partial control of thickener performance. We will describe some of these problems, and a solution which is simple and effective.

Jan 1, 1990

By D Connelly

There is now a new generation of mobile crushing and screening plant systems available which have been developed based on the motivation of reducing truck haulage. Newly designed mobile crushing and screening plant systems have the advantages of mobility, flexibility, economy and reliable performance, making this system very appealing for small- to medium-sized projects or projects where a number of resources are separated by distance.A brief review of the past history and experience with transportable crushing plants provides an insight into some of the issues with transportable plants in mineral processing. A closer look at a simple model based on exploiting small but high-grade orebodies suggests the concept has merit, however there are many more engineering, logistics, legal, technical and management aspects which have limited the application of such a concept in the resource sector. This paper explores the concept in detail and endeavours to analyse the preferred commodities and scenarios under which the concept could be used and the economic and logistical limitations for iron ore. The paper also looks at the risk assessment criteria to be applied in selecting the type of resource projects where the model could be applied successfully. Other aspects considered in this paper are the project planning requirements, technical and economic feasibility, bankability and operability. Reference is made to the operating experience of contractors at a number of sites and feedback from the resource companies as managers of the projects.CITATION:Connelly, D, 2013. Mobile crushing and screening plant applications for small- to medium-sized iron ore projects, in Proceedings Iron Ore 20 13, pp 349-354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Copper Extraction from Scrap Cables by Biotechnological Means

Sep 13, 2010