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By E Yll÷, O HyvSrinen

Outokumpu has developed a new chloride leach process, called HydroCopper«, to treat copper concentrates. Chalcopyrite is quite refractory in leaching and in sulfate milieu an autoclave of high temperature and pressure is required. However, in the HydroCopper«-process copper sulfides can effectively be leached in atmospheric pressure using strong, aggressive chloride solution and copper (II) ions as oxidant. Copper is precipitated from the purified pregnant leach solution as copper (I) oxide, which is filtered and reduced by hydrogen gas to metallic copper powder, which is melted and cast into copper product. Sodium chloride formed in precipitation is decomposed in a chlor-alkali electrolyser, the products of which are circulated back to the process: sodium hydroxide to copper (I) oxide precipitation, chlorine gas to leaching and hydrogen gas to the reduction of copper (I) oxide. During 2003 - 2004 the performance of the HydroCopper«-process was confirmed in a demonstration plant processing one tonne of copper per day. It has been found to be applicable for different kinds of concentrates and can also tolerate a wide range of impurities. A significant advantage of the process is that gold can be leached as a chloro-complex and recovered with active carbon. HydroCopper« can economically recover copper from concentrates and process to a cast copper product. The best utilisation of the process is in most cases achieved when the plant is situated at the mine site. Higher recoveries are attained by the optimisation of the whole operation chain from the mine and the concentrator to the HydroCopper« plant.

Jan 1, 2005

What is the best circuit to comminute primary crusher product to make beneficiation feed? Finding the best circuit to crush and grind minerals to beneficiation sizes is a complex problem that can lead to interminable discussion. Conclusions reached can be questioned. This will continue as long as the technology of comminution continues to expand, and is a mixture of many technical and economic factors in what is not a precise science. Laboratory and pilot plant procedures now exist that can help process engineers make sound decisions on which circuits are the best for crushing and grinding the specific ore being studied. It is the aim of this paper to discuss such procedures so a better under- standing of key decision parameters is avail- able, and to update comminution testing which has seen a. period of change in which new procedures have been introduced.

Jan 1, 1978

Some only types of bank finance are appropriate for mining development, with conventional fixed rate finance having significant limitations of flexibility. New, innovative and flexible instruments have recently been utilised within project financing packages. A strictly limited number of specialist project finance banks exists, with the necessary specialist personnel able to address project cost-competitiveness, cost and commodity forecasting, joint venture negotiations, and completion and sales undertakings. Different techniques of internal bank appraisal are applied, with the usual equity investment project valuation criteria being seldom useful for loan assessment purposes. Company attention paid to the preparation of a sensitively structured bankable presentation can prove most effective for securing development project finance. Substantial scope is possible for savings of time and money.

Jan 1, 1983

The Key Centre for Mines consists of the School of Mines of the University of New South Wales and the Departments of Geology and Civil and Mining Engineering of Wollongong University. The Key Centre for Mines/International promotes, markets and develops overseas activities in applied geology, mining engineering, mineral processing and extractive metallurgy specifically in response to the perceived needs in the region for mineral resource and other related earth-science based development. the Key Centre for Mines/International will be involved in the overseas marketing of formal courses; special training activities such as short courses and in-house programs; technical and educational consultancy; research and development projects, and in the establishment of regional links through twinning, exchange and various network arrangements with other organisations in the region. Activities which are now being developed include a training program for Korean mining engineers and geologists, teaching and curriculum development in the Mineral Resources Engineering Faculty of the University Sains Malaysia and a staff development proposal for the Department of Geotechnology of Khon Kaen University, Thailand

Jan 1, 1990

By L Whitbourn, K Yang, P C, E Ramanaidou

The potential of hyperspectral mineral mapping within a mine environment is demonstrated. Central to this capability has been the development of portable or vehicle-mounted, hyperspectral mine face-mapping systems. Data from these systems were used to detect subtle mineralogical variations and map their distribution across rock faces in a fashion that previously was not possible. In one study, the data usability was enhanced by ædrapingÆ the mineralogical determinations over a three-dimensional æmodelÆ of the rock-face. The eventual melding of the spectral mine face-mapping and three-dimensional spatial technologies will result in a new generation of mineralogical and structural information becoming available to mine geologists, engineers and metallurgists. Specific uses for spectrally-derived, mineral mapping data sets could include:ore grade mapping systems based on either direct detection of ore minerals themselves (eg iron and nickel oxides), or mineralogies that may be used as surrogates for ore-grade information (via various alteration minerals) after a suitable orientation survey; detecting mineralogies that have a deleterious effect on milling, metallurgical processing or have occupational health implications (talc, swelling clays, carbonates, asbestos, etc); selective mining and blending by collecting, processing and displaying such mineralogical images in near real-time to monitor ore grade and quality, and allow the separation of ore from waste during loading operations at the mine face; a mineral detection and mapping capability to assist in structural and geotechnical mine planning applications; and an enhanced geological detection and mapping capability for ore mineral species or alteration mineralogies that may be used to vector further mineralisation, update the existing mine ore model, or provide input to assist in the control of autonomous mining equipment. Within the Woodlawn open pit, Fe- and Mg-chlorites and phengitic- micas associated with sulfide mineralisation were detected and mapped. Subsequent studies using a second generation face-mapping system demonstrated the direct detection of ore-grade materials for iron-ore and nickel laterite mining activities. Satisfactory and meaningful results were extracted from data that were collected under a variety of challenging conditions. However, these non-ideal climatic and operational conditions would be expected under most operational situations in a mine environment. Development of a system using artificial illumination, permitting night-time (and eventually underground) operation and elimination of atmospheric absorption effects is underway.

Jan 1, 2006

A philosophy is presented that new graduates in mining and metallurgy should be equipped to use computers during their under- graduate courses, should be aware of the capabilities and costs of a wide range of computing equipment, and should receive sufficient stimulus to become involved in applying computers for the benefit of the mineral industry. A program is presented in which computer applications and "hands on" involvement with computers are integrated into the progressive stages of the undergraduate courses in Mining and Metallurgy. In this respect, the role of the computer is to assist the student by performing time consuming tasks, to demonstrate the industrial applications of computing, to extend the scope and complexity of the tutorial, assignment and project work which can be undertaken by the student, and to provide the essential first stepping stones toward continued useful involvement with computers during the graduate's working life.

Jan 1, 1977

Mining in the twenty-first century brings with it a new range of challenges, some unfamiliar to our industry. Skilled staff recruitment and retention is a significant issue. Equipment supply lead times are changing the risk profile under which we operate. And the new landscape of this century demands accountability at all levels while also requiring that we deliver more to our shareholders and our host communities. This paper draws on experiences in Waihi, addresses some of the challenges facing the modern mining industry and suggests some modest mitigation strategies.

Jan 1, 2007

By Henley S

The year 2000 is not very far ahead - only five years. It should not be hard to forecast what will happen between now and then, because the technologies that will be in practical use then should all be at least in embryo existence now. There has been a historical trend for the mining industry to work ever more difficult and ever more marginal deposits. There are clearly a few exceptions and major discoveries, but the industry is becoming heavily dependent, at both the exploration and the mining stages, on technological innovation to retain acceptable profit margins. With the new exploration and mining technologies come requirements for additional computing support. Computing technology further allows the potential integration of a wide variety of different types of data to help the explorationist to build and test exploration strategies, or to help the miner to design and schedule mining operations.

Jan 1, 1995

By N Tuffs, R Peace, S Xue

Mine gas control is a major issue in most of the gassy underground coal mines, due to its direct impact on safety, production delays and cost of production. Analysis of the gas data, from different collieries in Australia showed that longwall gas emissions have increased substantially over the years. Simply increasing the number of goaf holes in the panel or decreasing goaf hole spacing seems not to be effective, in controlling high goaf gas emissions. A major research project has been undertaken by CSIRO in collaboration with mine sites to address this goaf gas control issue with the aim of developing effective and optimum goaf gas drainage strategies. The project has combined extensive field studies with computational fluid dynamics (CFD) models, to characterise goaf gas flow patterns and develop effective gas control strategies. The research work specifically involved review of gas control issues at field sites, goaf gas monitoring, tracer gas tests, CFD simulations and extensive field trials. Field demonstration studies of the new optimum strategies have been conducted at two collieries in Australia. The project results have shown that the optimum strategies were highly successful, in improving the overall efficiency of goaf gas drainage systems, at both the field sites. Results of the goaf gas flow characterisation studies and field demonstration studies are summarised in this paper.

Jan 1, 2005

The discovery of magmatic nickel sulfide mineralisation within the Musgrave Block of Central Australia, in a region which has received virtually no exploration since the early 1970s, promoted a pegging rush throughout the region and provided a significant boost to the investor interest in resources sector companies. The discovery proved a significant success for the application of generic models for major magmatic nickel-copper sulfide deposits. The entry of junior explorers to the region is the principal mechanism by which the region will be explored, although significant social and physical challenges will impact on the ability of explorers to maintain investor confidence in the region.

Jan 1, 2002

By Stephenson IM

Research to develop the use of L.D.slag as an aggregate in road construc-tion is described. The chemistry and mineralogy of L.D. slags are shown to be generally similar to S. Yorkshire arc furnace slags, which have been success-fully used for road construction for many years, although both free lime and iron contents were found to be higher. Physical and mechanical properties are good but the slags' high density will result in lower "covering capacity"."Weathering" in stock piles is shown to significantly reduce free lime levels fairly rapidly although around 50 per cent of the mean "fresh free lime" content is still present even after two years treatment.

Jan 1, 1979

By H W. Scriba

The development and improvement of computer-based process simulation packages over the past 20 years has provided process engineers with a powerful tool to use in the design of complex metallurgical plants. The use of such modelling tools has enabled the design of process plants that minimise operating and capital costs whilst optimising plant efficiency and recovery. Almost every new project developed in the current market is underpinned by a simulation of the process. In line with engineering best practice this simulation should be based on laboratory/pilot plant test work results and sound assumptions. Any errors that are not identified in the development of the process simulation may have significant effects on the final design and operation of the processing plant. Developing a simulation of the process in a comprehensive, logical and auditable manner is thus essential in ensuring the simulation accurately represents the expected process plant behaviour. A methodology that ensures these requirements are met has been developed by SNC-Lavalin Australia and is described in this paper. The methodology includes the major review stages of data collection, model planning, model building and optimisation, model review, scenario testing and options development, and model reporting. All of these stages should incorporate comprehensive client interaction and review by a suitably qualified representative. In applying these methodologies SNC-Lavalin Australia ensures that the process simulation model developed can be confidently utilised in the design of the process plant, and in the estimation of operating and capital costs, whilst ensuring that engineering best practices are met.

Jan 1, 2008

Mine haul road design at Bougainville Copper Limited has undergone significant changes since mine start-up. Selection of 95 tonne trucks and the subsequent replacement by 155 tonne units is discussed, with particular reference to haul conditions within the mine. Changes to haul road design and construction practices are detailed which have lead to improved standards and tyre life. INTRODUCTION Bougainville Copper Limited operates one of the largest copper mines in the world at Panguna, Bougainville Island, in the North Solomons group of Papua New Guinea. The mine commenced commercial operation in April, 1972 and current planned production is 198 000 tonnes of material per day, of which 115 000 tonnes is ore averaging 0.46% copper. Annual total planned production is 72 000 000 tonnes to yield approximately 150 000 tonnes of copper with significant quantities of gold and silver. The mine operations workforce now consists of national employees up to General Foreman level.

Jan 1, 1982

By C Catania

Mining companies and operations across the globe typically target best practice financial management, along with a focus on economically driven mine plans. Not only is this inherent in running a successful mining business, but also critical in addressing investor scrutiny. The standards for social and environmental practices is less consistent than this, with most companies adopting standards that are driven through legislative and compliance requirements of the nations in which they operate. Although there is still room for improvement, Australian is a country that stands at the forefront of social and environmental legislation, driving more sustainable planning practices for mining operations, with an ever-increasing focus on mine closure considerations. Of the many nations yet to reach such a legislative position, Kazakhstan is a place where some companies are driving towards world class standards beyond what is government mandated. CITATION:Catania, C, 2018. World-class mine planning for a sustainable future in Kazakhstan Mining, in Proceedings Life-of-Mine 2018, pp 6–7 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By Koppe JC, Strieder AJ

The Rivera Crystalline Island (RCI) is an erosional window of the intracontinental Parana Basin that outcrops in the Rivera Department, north of Uruguay. RCI is made up mainly by Precambrian granites, metasediments and granite-gneisses. This island is crosscut by a dextral transcurrent shear zone system, the Rivera Shear System (RSS). The bulk strain ellipsoid was defined by previous work and has allowed the evaluation of shear dynamics. The geometry of the shear system is made up of two shear directions: E-W (P-shear), which turn right to NW-SE direction (R-shear), leading to the development of extensional bends. The shear zone system was developed in brittle-ductile to brittle regimes, under temperature conditions compatible with greenschist facies metamorphism. The shear zones are marked by an intensive fracture cleavage development. Mylonites develop only in narrow, discontinuous higher strain zones. Internally, the shear zones are dominated by intrusive rocks, mainly granites, dacites and diorites. Hydrothermal alteration has been developed in several areas.The economic significance of RCI is given by several small gold deposits, which have been exploited since 1869. One major new gold mine is under development, the San Gregorio Gold Mine. This gold deposit is locally controlled by a dilatant site where R-shear turns right to P-shear. Mine lithologies were deeply altered by hydrothermal fluids in the dilatant structure. This work presents the lineament-structural analysis carried out to identify similar structural patterns in all RCI sites favourable to host other gold deposits. The exploration program also considered remote sensing, geology, geophysical and geochemical survey.

Jan 1, 1997

By K Buda, W Staunton, M Hill, V Tjandrawan

One of the challenges facing the gold industry in the 21st century is the continuing need to identify new reserves of economically treatable ores. Discoveries of large, metallurgically simple orebodies are becoming increasingly rarer, forcing companies to investigate options for the processing of ores which may present recovery, economic and/or environmental issues, requiring innovative approaches to their treatment. Ores which contain naturally occurring carbonaceous material (æpreg-robbing oresÆ) are an example of one such ore type. NewmontÆs Jundee operation contains zones of carbonaceous ore within the oxidised orebody. A program consisting of detailed laboratory work and extensive plant trials has been undertaken to assess the options of the processing of this material. Laboratory tests demonstrated the advantage of carbon-in-leach (CIL) over direct cyanide leaching and carbon-in-pulp (CIP) for treatment of these ores. The laboratory program identified several factors which would enhance overall gold recoveries where preg-robbing ore was being processed, including: keeping preg-robbing ore separate from non-graphitic ore; maximising gravity recovery; and ensuring the plant operates in æpureÆ CIL mode, ie no leaching prior to first adsorption tank. Several plant trials were undertaken to assess the economic sustainability of treating moderate preg-robbing ores through a modified gravity/leach/adsorption circuit. Results indicated that where good operational control of the circuit was maintained to ensure high gravity recovery, minimal leaching prior to carbon contact, and maintenance of good, active carbon inventory, then acceptable and sustainable overall gold recoveries could be obtained. Using these relatively simple plant modifications potentially allows a plant to treat ores with preg-robbing index (PRI) values up to one. When PRI values rise to 1.3 - 1.6, leach recoveries can drop from >85 per cent to

Jan 1, 2007

Underground excavations are subjected to complex stress changes caused by nearby mining, but may also be affected by repeated dynamic loading from blasting and seismic events. In some cases, the combined, cumulative effects can lead to unforeseen damage, displacement and instability. Simulating dynamic loading of an underground excavation is a very complex task. The state of rock mass stress, damage and deformation must first be simulated sufficiently requiring small-scale structures to be explicitly modelled. Supporting elements must be represented with high similitude and then the dynamic event must be applied to the system in the case of blasts, or evolve as a consequence of rock mass instability for seismic events. A special case is for the effect of pit blasting on underground excavations - discontinuous rock phenomena at scales from mine, to bench, to pillar, to tunnel need to be captured and this represents one of the most computationally intensive tasks in mine simulation. Recent advances in computer power allow these tasks to be completed at a mine scale, incorporating discontinuities and geological detail matching the best practice for static Finite Element analyses. The results are a worthwhile contribution to mine decision-making, but require careful interpretation and thoughtful inputs - even more so than quasi-static analysis - as the cumulative effects of unfavourable modeling practices are greater. Some learnings from experiences with mine scale, discontinuum dynamic simulation are summarised, including a discussion of considerations of scale and similitude for this type of analysis.

Nov 25, 2010

By Lawrence PR, Hoffman W

The dissolution of gold from various ore-bodies is discussed in terms of extraction rates and reagent consumptions during leaching. Gold dissolves slowly in cyanide but reagent consumptions are usually satisfactory. In almost all cases where excessive cyanide consumptions occur, similar high consumptions result with other lixiviants. Recovery of gold from cyanide solution is well established and comparatively simple technology.Gold dissolution in thiourea is faster than cyanide but significant consumptions of thiourea, due to both adsorption and oxidation, occur. Gold recovery from thiourea solutions is likely to be more difficult than from cyanide.Chlorination of gold is very fast in acidic conditions but excessive consumption of chlorine occurs for ores containing greater than 0.5% S. Reprecipitation of gold and handling of acidic chlorine solutions are both significant problems. The mechanism of gold reduction onto activated carbon creates difficulties in the carbon in pulp process for recovery of gold but means a simplification in the production of bullion from loaded carbon.

Jan 1, 1984

By Eddy B. W, Washusen J. A, Wulff R. T

The State Electricity Commission of Victoria (SECV) has been con- tinuously involved in the extraction of brown coal from open cut mines in Victoria's Latrobe Valley for over 60 years, but have not completed a major mine. Detailed consideration for rehabilitation at this stage has only been able to be given to overburden disposal areas. Increasing interest in rehabilitation in the 1980's led the SECV to review its existing policies and practices and to embark in 1985 on a public consultation process to establish an agreed and accepted policy. This was extended in 1986 to the consultation process for the rehabilitation planning for the Mor- well Open Cut External Overburden Dump. This paper covers the con- sultative process developed and the lessons learned by the participants.

Jan 1, 1989

By Merritt RR

The equilibrium phase relations in the Fe- Mn-Ti-0-S system were established at 1380 and 1485 K. The elemental distributions between the equilibrium phases were obtained by chemical- ly analysing selected samples from the phase study. The results are considered in relation to the coal reduction process for upgrading ilmenite. The beneficial effect of adding sulfur to a kiln that uses a manganese-rich feed is ex- plained by the formation of a metal-sulfide solid-solution phase that removes part of the manganese from the oxide system. The optimum conditions for operating the reduction kiln are determined, and the practical need to operate the kiln at other than optimum conditions is explained. It is shown how the experimental data can be used to predict the best compromise conditions for reduction and the resultant purity of the product.

Jan 1, 1980