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By J H. Park, M J. Lee

Because the environmental problems are occurred by greenhouse gases such as CO2, the industries have tried to increase electric motor efficiency to reduce CO2 emissions. A core material of electric motor is high-silicon electrical steel. The ferrosilicon (FeSi) alloy, a raw material for the production of electrical steel, affects the electric properties of silicon steel. The main impurities such as Ca, Al and Ti make inclusions or precipitates that causes core loss. The slag treatment has been widely used to remove impurity elements. Thermodynamic principles for the refining of several impurities, specifically Ca and Al, have been investigated, whereas thermodynamic behaviour of Ti has not been fully understood yet. Therefore, in the present study, the titanium distribution ratio () between ferrosilicon and CaO-SiO2-Al2O3 slag system at 1773 K was investigated. The results show that is influenced by both the basicity and stability of titanium ion in the slag. Specifically, exhibits a minimum value at about C/S=0.7 indicating a shift in the titanate structure unit from [TiO5]-square pyramid to [TiO4]-tetrahedron because of lack of Ca2+ ions in a C/S<0.8 region, contributing to an increase in titanate capacity and .

Jun 19, 2024

Australian coals tend to be young in geological age and high in ash by world standards; preparation of the coal before marketing is almost universal. On the basis of float and sink data from 39 locations in the Eastern Australian coalfields, the coals are placed in four categories representing increasing difliculty in their washability characteristics. These seem to be related neither to the geological age nor the geographical position of the deposit and Hunter Valley coals, for example, span all categories. The influence of crushing on the washability of Australian coals is briefly considered and from limited data it is concluded to be appreciably smaller than for British or North American coals. A strategy for the float and sink analysis of Australian coals is proposed and the influence of washability characteristics on current trends in the selection of separating processes for coking and steaming products is discussed.

Jan 1, 1979

By P Tzeferis

An exploratory laboratory work was carried out on microbial leaching of poor non-sulphide nickel ores, not amenable to conventional mineral processing operations. The results have shown that domestic low-grade lateritic ores of limonitic or haematitic type are amenable to bioleaching by fungal strains of Aspergillus sp and Penicillium sp. Maximum nickel and cobalt recoveries achieved were 60 per cent and 50 per cent respectively. Losses of soluble nickel in the fungal biomass were found in the range 3 - 11 per cent. Chemical analysis of the leach liquors showed the presence of significant amounts of citric, oxalic and other organic acids, indicating the role which certain metabolic products of fungal activity may play in the process. Possibilities for future investigations are discussed.

Jan 1, 1997

By G C. Sen

All mining and quarrying operations that employ blasting to fragment and move broken ground have a price to pay for æby-productsÆ such as vibration and noise. These æby-productsÆ cannot be eliminated but they can be controlled and modern blasting techniques have improved to the point that excessive environmental restrictions can be adhered to whilst maintaining acceptable production rates and quality. Accurate measurement is the key to control, and as the environmental limits are becoming tighter, the proper way to measure vibrations from blasting operations becomes an integral part of the mining or quarrying operations. The basic vibration monitoring system consists of a primary sensor connected to a data logger and computer software for the analysis of the signal received and recorded. Currently, as with all fields of measurement, much improvement has occurred over the past decade, and electronic devices are much more accurate and reliable. Data analysis has also improved considerably with the computing power that is available to field operatives today. Mounting the primary sensor has been often overlooked in supposed æstandardsÆ with procedures such as double sided tape, resting on a flat surface provided the vibration level is less than a given amount. But if it is worth going to the expense of the monitoring equipment and manpower, surely it is worth a little extra effort to ensure the primary sensor is coupled to the ground effectively. The primary sensor must move with the ground and measure this movement; so if the primary sensor is allowed to move without respect to the ground (ie poor coupling to the ground) then a false record of the physical event will be measured. This scenario can easily be a practical reality if the primary sensor coupling method to the ground is not effective. In this study a number of mounting methods were fabricated and connected to similar data monitors and a series of ænormalÆ production blasts were used as the vibration source. These mounting devices were measured against an in-house procedure (the æstandardÆ) and the relative merits compared. A laboratory investigation was also carried out to look at the physical parameters of the æsoil and their effect on vibration attenuation of the in-house standard method.

Jan 1, 1999

Tapira Mine (Tapira, MG, Brazil) is the largest phosphate ore and concentrate producer in Brazil. The mine is an open pit, which until recently operated with a large equipment fleet and now uses a smaller fleet operated by contractors. The annual production reaches 17 Mt of ore plus 14 Mt of waste at a stripping ratio of 0.82. Defining the geological boundaries and forecasting the annual production can be a difficult task if not performed on a reliable model. The geological model has been totally reviewed as well as the estimation process. Ordinary Kriging has been used to build the new block model with P2O5 and contaminant grades. After estimation, block model validation and classification criteria definition to assess resources and reserves, the result is given by the life-of-mine plan is defined after pit optimisation and design. The Lerchs-Grossmann algorithm implemented in the NPV Scheduler was used to define the long-term production targets based on the main parameters P2O5 and the contaminants that are just important to the beneficiation process.

May 1, 2010

Engineering availability of the 120/200 tonne Wabco haulpak fleet at Mt. Whaleback was in the mid fifties and unstable. The project to achieve a reliable 66% during 1980 highlighted "plannable" maintenance, short cycle scheduling, condition monitoring, backlog control, and, above all, the importance of involving all affected people. It is not sufficient for consultants to design systems and make them work. The people who use the system must understand it, support it and "own" it. In this way, they will develop it and improve results after the outside help has been withdrawn INTRODUCTION In early 1979, PA proposed a programme to improve engineering availability of the Mt. Newman Mining fleet of 70 Wabco haulpak trucks of which 53 were 120 tonne and 17 were 200 tonne units. (Subsequently five 200 tonne trucks from Hamersley Iron were added to the fleet). The ore truck workshop was also responsible for 75 tonne trucks used as water trucks and general purpose vehicles. The need for action was clear. The fleet was achieving availability in the "mid fifties" with wide variations indicating that the fleet was becoming unreliable. Projected tonnages required a reliable 66% availability to be

Jan 1, 1982

By C Kocsis, G Baiden, Y Bissiri

CANMET-MMSL and Penguin Automation Systems Inc have been exploring how process simulation and ventilation modelling software, when combined, can be used to optimise hard-rock/metal mine ventilation systems. In combination, it is anticipated that this methodology will facilitate the exploration of mine design options that affect ventilation requirements and ultimately cost. Such integrated mine design could limit, and possibly reverse, the drivers that under current practices would generally dictate increased ventilation, power consumption, cost and greenhouse gas emissions. It is believed that the mining industry needs such process models to develop better business cases. For example, the implementation of optimised ventilation systems will undoubtedly require significant investment and mines are often reluctant to try such conservational measures unless they can be proven cost-effective. In general, Canadian hard-rock mines know their ventilation systems are providing too much air and consuming power unnecessarily. This is because their systems are designed to provide maximum production flexibility, based upon peak demand, which may be at some future time, and operated continuously at that level regardless of actual need. Simplistic analyses have shown electrical energy savings can range from 30 per cent through to 90 per cent (Hardcastle, Gangal and Leung, 1998). These savings depend upon such factors as the intensity and continuity of the production schedule as opposed to non-productive time. Where these savings occur is also important, if limited to either the primary or auxiliary ventilation systems, they could be negligible in a mineÆs total energy consumption. The problem these mines face is determining what level of ventilation is required in real-time and then the relative benefits. Such parameters as varying electricity costs, heating fuel options, different design criteria and their complex inter-relationship can effect the selection of an optimal system, depending on whether energy, environment or cost is the prime driver. The use of process simulators in underground mining is in its infancy; to date they have been used to show the benefits over the life of a mine under different mining methods, such as a comparison of tele-remote mining from surface against conventional manned operation (Baiden, 2000). This ongoing development advances the use of such simulators into a new and potentially important area, namely modelling the life-cycle ventilation requirements of a mine. This paper shows how such a life-cycle analysis as opposed to peak demand can provide the basis for optimising the design of ventilation systems and their control.

Jan 1, 2005

By Sulanto J, Talonen T

In the mid 1960&apos;s Outokumpu considered building a lead Flash Smelter on the basis of Flash Smelting technology developed first in the late 1940s for smelting copper concentrates. Pilot scale tests were carried out and the process was found technically sound. The project was however not economically viable under Finnish conditions and it was cancelled. In 1981 pilot plant tests were restarted after many enquiries from the primary lead producers. All the know-how and development made in copper and nickel smelters was applied to the Lead Flash Smelting process and the tests were successful. Outokumpu has so far tested several types of lead concentrate with lead contents ranging from 28 to 75 per cent. The concentrate is oxidized and smelted to metallic lead and slag directly in the Flash Smelting Furnace using high oxygen enrichment of tonnage oxygen. Fossile fuel is used in the Flash Smelting Furnace in cases when the feed material does not contain enough latent heat to smelt the furnace products even though pure oxygen is used for oxidation. Thus the process results in a low consumption of extraneous energy. Use of oxygen results in a small gas flow but it is rich in sulphur dioxide. The gas treatment facilities and sulphur recovery plant will be small in size and low in investment cost. The process is flexible and can produce stable quality of products from different types of raw materials. Quality of lead bullion especially the sulphur content can be regulated over wide a range, from 0.1 per cent upwards according to the needs of the refinery.

Jan 1, 1984

By J MacNeil, R Dimitrakopoulos

As open pit mining of a deposit deepens, the cost of extraction may increase up to a threshold where transitioning to mining through underground methods is more profitable. This paper provides an approach to identifying an optimal depth at which a mine should transition from open pit to underground mining. The value of a set of candidate transition depths is investigated by optimising the production schedules for each depth’s unique open pit and underground operations. By considering the sum of the open pit and underground mining portions’ value along with the cost of transitioning corresponding to each candidate transition depth, the optimal transition depth can be identified. The optimisation model presented is based on a stochastic integer program that integrates geological uncertainty. As an input, the stochastic integer program utilises a set of several stochastic simulations that represent equally probable scenarios of the mineral resource. This group of simulations describes the uncertainty in the deposit, while the optimiser aims to maximise value based on discounted profits of both the open pit and underground components of the deposit.CITATION:MacNeil, J and Dimitrakopoulos, R, 2014. A stochastic optimisation formulation for the transition from open pit to underground mining within the context of a mining complex, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 363–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

The Committee for Mineral Reserves International Reporting Standards (CRIRSCO) was formed in 1994 to promote development and adoption of international standards for estimation and reporting of exploration results, mineral resources and mineral reserves. The CRIRSCO standards have been accepted by most mining companies and professional societies worldwide. Market regulators from Australia, South Africa and Canada require that these standards be followed when releasing public information. Among these requirements is the use of specific definitions for what constitutes exploration results, mineral resources and mineral reserves. If such information is publicly disclosed in must be estimated by a Competent or Qualified Person. In the United States of America, public disclosures are regulated by the US Securities and Exchange Commission. The SEC does not recognise the CRIRSCO guidelines, and some of the SEC requirements for public release of information are materially different from those applicable in other countries. The CRIRSCO definitions and the Competent Person requirements are reviewed and compared with those of the SEC. The organisation of the SEC and its rule making process are briefly discussed. Ongoing efforts to bring the US regulatory requirements closer to those applicable in other countries are presented, as well as other activities that CRIRSCO is entertaining with the United Nations, the International Accounting Standard Board and other international organisations to reach the objective of worldwide standardisation of reporting procedures.

Jan 1, 2006

By H Plewes, A Bur, L Murray, J Pottie

Water recovery from tailings for reuse in mineral processing is essential to operation of mines in the Atacama Desert of Chile. With annual rainfall of 5 mm, the prudent and efficient use of available water resources is a major issue for the Escondida Mine and other mines in the area. The Escondida Mine is located at an altitude of 3100 m, in a very arid, seismically active part of the Atacama Desert of northern Chile. The site is located about 170 km from the coastal city of Antofagasta. From 1994 to 2002, tailings were discharged into the Hamburgo Tailings Facility, which comprises a series of æpaddiesÆ located near the open pit and mill. Because water in the region is only obtainable from groundwater sources, the paddy system incorporated a number of design features with the aim to maximise water recovery from the tailings. As part of the recent mill expansion to 237 500 metric tonnes per day, a new tailings facility, the Laguna Seca Tailings Facility, projected to be one of the largest tailings facilities in the world, was commissioned in 2002. Extensive studies were conducted for the design of the new facility to predict water recovery from the conventional wet disposal of tailings. The predictions were calibrated against the performance of the Hamburgo Tailings Facility and subsequently re-calibrated against actual performance during the first year of operation at the Laguna Seca Tailings Facility. Initial operation of the Laguna Seca Facility was marked by a coincidental change in tailings characteristics from design, which highlighted the need for thoroughly understanding tailings behaviour during deposition, and the parameters and deposition techniques that could enhance water recovery. Systems have been put in place to manage the tailings deposition and respond to changes in key parameters such that water recovery targets can be reliably achieved. This paper describes the background studies that were conducted to evaluate evaporation and tailings behaviour, summarises the water balance and then presents some observations from the commissioning and start-up of the facility.

Jan 1, 2003

By W Patton

Investment decisions in the mineral resources sector are made on the basis of an assessment of the economic potential for a mineral deposit. Given the supporting information for the location, scale, and quantity of the commodity of interest, miners and investors aim to make risk-informed decisions when considering further investment. The objective of resource classification is the synthesis of various types and quantities of geologic information used in resource model construction to assign confidence categories to the estimated mineral resources, which can then be used to support informed economic decisions. In this paper a risk-based classification scheme for iron ore mineral resources using conditional simulations is presented. The method involves categorisation of each block according to a confidence level, considering expected recoveries from a kriging model over mining production volumes. The realisations of the simulated model are used to assign risk-based confidence categories to zones of the ore deposit. One motivation for this work is to assess the sensitivity of the scheme to geologic uncertainties. Specifically, that which uncertainty in the layout of mineralising alterations and weathering overprints influence variabilities of associated rock properties and the likelihood of obtaining expected ore recoveries. It is shown these risks have material implications for a project’s economic potential. How the scheme can be extended to the grade control context and the value subsequent grade control activities is also quantified.

May 24, 2023

By Sneddon NW

Aberdare North Colliery is situated on the eastern boundary of the City of Cessnock in the Hunter Valley, New South Wales. Although the area is now noted for its wines and vineyards, the district has a long history based on coal mining. The richest coal seam in the Cessnock district is the Greta Seam, a low ash, high volatile steaming or gas making coal. The seam, up to 10 metres thick, extends over a large area surrounding the city of Cessnock and neighbouring townships such as Bellbird, Aber- dare, Kearsley, Neath, Ellalong, Kurri Kurri and Stanford Merthyr. The Aberdare Colliery, leases, which extend under Aberdare and Cessnock townships, were first worked in 1905 and continued developing pillar panels until the mine closed on 11 Nov- ember, 1960. Coal mining to this time consisted mainly of developing pillars to the 2.4 metre parting and, in some areas, dropping the top coal to the 6 metre parting, thus leaving the pillars intact, the top 1.8 metr-es of coal be- ing left untouched due to the high sulphur content. Aberdare North Colliery was opened in 1956 in order to recover and extract the pillar coal and tops left standing for over 40 years. During the pillar extraction phase the occurr

Jan 1, 1981

By K L. C Gontalves

In 1999, the Mineral Development Centre of CVRD (CDM) acquired a flotation device referred to as Mini Pilot Plant (MPP), which is able to run continuous flotation tests with drill core samples. Since then this equipment has been used to define the flotation circuit and process conditions during the pre-feasibility phase of CVRDÆs copper sulfide projects. Until now, the MPP results had not been validated for an industrial flotation operation. The present work consists of a comparison and correlation of the results from a flotation MPP and an industrial plant. In order to make this comparison, an industrial plant was completely sampled and the feed ore was tested on bench scale and on a MPP. The metallurgical and mass balances of each test were used for the comparison.

Jan 1, 2005

Old Copper Flotation Tailings Waste Reprocessing

Sep 13, 2010

By B Kretschmer, G Bartel, B de Villiers, W Watt

"The Nyrstar Port Pirie Smelter, located on the eastern shore of the Upper Spencer Gulf in South Australia 230km north of Adelaide, began operation in 1889 to process lead concentrate from the Broken Hill lead and silver mines. The site still operates an updraft sinter machine, commissioned in 1955, with the product fed into a blast furnace. While sinter plant technology has changed and improved since 1955, development has reached the stage where further enhancements are not possible or economic. High purity lead concentrates command lower margins and for the smelter to remain economically viable a wider range of higher value materials must be treated. The current flowsheet cannot meet this demand. Additionally, community blood lead levels particularly in children below four years of age, are a critical indicator used to measure the site’s environmental performance. The smelter’s environmental licence to operate is dependent on meeting future community and regulatory expectations. To achieve this a major step change in the emission performance of the smelter is required. Since 2008 pre-feasibility work has been undertaken to develop a new flowsheet and business model to allow Port Pirie to operate sustainably into the future. The main requirements were for the smelter to reduce lead and sulfur dioxide emissions that impact on the local environment and community to meet current and future environmental expectations, as well as dramatically reducing current feed constraints and change the business case from a marginal business to a sustainable profitable business. After reviewing all practical options a decision was made to replace the sinter plant with an Outotec Top Submerged Lance (TSL) furnace. This paper describes how the new furnace technology was selected and how it will be integrated into the present flowsheet; the unique funding arrangements that are in place to deliver the redeveloped site; and future opportunities that are associated with the implementation of the new flowsheet. CITATION: De Villiers, B, Bartel, G, Watt, W and Kretschmer, B, 2015. Nyrstar Port Pirie redevelopment, in Proceedings MetPlant 2015, pp 325–337 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 7, 2015

By S Tjerry, S Szylkarski, B Willis-Jones, I Dubinski

Achieving relinquishment of mining sites is becoming increasingly difficult, with a study by Byrne (2013) estimating that out of a set of 73 mining and metals sites around the world, less than ten per cent had achieved relinquishment over the last 50 years. The median forecast duration of time allocated for water management in the closure plans studied was approximately ten years, while the reality at the actual sites was a median duration of 22 years to date and growing.One of many challenges in mine closure planning is managing geomorphic stability of stream diversions. The challenge is to be able to demonstrate to regulators and the community that a proposed rehabilitation solution will be stable over the long term.During the mining operations, local watercourses and surface drainage can be diverted and managed using engineered channels and drainage structures. However, during the post-operations stage, the engineered channel and drainage may require modification to a more natural condition that will facilitate long-term environmental sustainability. Achieving geomorphic stability of a diverted watercourse is difficult, with the majority of stream diversions in Australia failing to meet expected design performance (White et al, 2013). Geomorphic stability is a complex process that is controlled by a combination of factors, including hydraulic flow conditions, geotechnical conditions and vegetation.This paper proposes that a fully dynamic and deterministic geomorphological model can be used to supplement the traditional empirical approaches to assess long-term geomorphic stability. The paper provides an overview of the geomorphological models and how they have been applied in engineering studies for forecasting future evolution of stream systems. The paper discusses the potential application of these models in the mining industry for forecasting and optimising surface water structures for the operations and post-operations stages of the mining cycle.CITATION:Szylkarski, S, Willis-Jones, B, Tjerry, S and Dubinski, I, 2016. Improving the reliability of stream diversion designs in mine closure plans using a morphological tool, in Proceedings Life-of-Mine 2016 Conference, pp 212–215 (The Australasian Institute of Mining and Metallurgy: Melbourne)

Jun 28, 2016

By Baafi EY

Deposits of gold, silver and other precious metals often display a high variability of grade values, usually a very low average metal content and are frequently not easy to sample reliably. The characteristics, together with the volatility of precious metal prices, make evaluations of precious metal deposits extremely difficult to make. Geostatistical estimation techniques can be used to make grade estimates of precious metals and to assess the reliability of these estimates. Two case studies are presented.

Jan 1, 1987

By C Fearon

This paper discusses the implementation of an underground rail haulage system during a major expansion of the Olympic Dam mine in 1998. The factors affecting the selection of rail haulage are discussed and details are provided on the rail system, which is designed to transport more than 10.5 million tonnes per annum (Mtpa). The reliability of the system during commissioning is discussed, including the decision to manufacture a ædummyÆ locomotive in order to keep the system operational. Finally, reliability improvements made both during and after commissioning are discussed with comments provided on the effectiveness of the system as it operates today.

Jan 1, 2005

Alkaline leaching with sodium carbonate solution adjusted to pH 9&#183;5 to 10&#183;0 preferentially dissolves thorium from a mixture of rare earth and thorium hydroxides. Rare earth sodium carbonates form in the alkaline leaching stage.These are converted to rare earth oxides for use as optical and ophthalmic polishing agents. Quadrivalent cerium is extracted under similar alkaline leaching conditions.INTRODUCTIONAustralia has made significant contributions to mineral chemistry and mineral dressing. As often happens with an industrially immature country, research investigations often outstrip the ability or desire of commerce to exploit them. It is wrong to think exclusively in terms of export of raw materials. Imagination assists in developing world trends. The chemical utilization of mineral sands has interested a group of investigators, chiefly at the Commonwealth Scientific and Industrial Research Organization (C.S.I.R.O.) and, more recently, in the mining industry itself. From an international point of view the highlight of this work was Newnham&apos;s (1960) process for the separation of hafnium from zirconium. Earlier work at C.S.I.R.O. investigated the chlorination of rutile, zircon, and monazite. Assuming that titanium tetrachloride would be available in large quantities in the post war years, extensive work was done by Kraitzer, McTaggart, and Winter (1948) on organic compounds of titanium. This work led to the development of heat resistant paints, plastic compositions, and improved organic protective coatings that predated overseas work by up to seven years. (Post, Shiihara and Schwartz, 1961; Anon, 1955). Contributions were made to the production of refractory hard metals (Kraitzer, 1949; Kraitzer and Newnham, 1956). Pilkington and Wylie (1947) and Urie (1947) investigated the production of rare earths from monazite by an acid process.

Jan 1, 1963