Search Documents

Effects of Hydrated Mg2+ on KCl Flotation

Sep 13, 2010

The New Zealand Minerals Industry is small but growing. Over the next 10 years it will be facing stiff international competition for skills to support this growth, particularly from Australia who are forecasting that a further 70 000 people will be employed by 2015.   The value of commodities mined and quarried in NZ continues to increase; and the value of coal, metals and industrial minerals production reached $1.505 billion in 2006, an increase of 15 per cent on 2005. Production increases will continue à. Latest Crown Minerals statistics show that national prospecting and exploration expenditure rose to $29.9 million in the year ended March 31 2006 û an increase of 46 per cent from the $20.4 million spent in the March 2005 year. The equivalent 2001 year expenditure was only $2.48 million.   The industry already experiences difficulty in recruiting the people it needs with ongoing demand for skilled underground miners, trades people, and mining professionals. This discussion paper will outline the national context with regard to labour, skills and training. It will suggest options and provide an opportunity for conference participants to discuss the way forward.

Jan 1, 2007

Study on Oil Agglomeration Flotation for Deinking

Sep 13, 2010

Efficiency, Economics, Energy and Emissions - Emerging Criteria for Comminution Circuit Decision Making

Sep 13, 2010

By B Hiebl, J Martens, L Petzold

A research team at the Iron and Steelmaking department at Primetals Technologies has established new upgrading measures for improving the efficiency of the beneficiation process in ironmaking plants, relying largely on pre-existing equipment. After the upgrade, the iron content in the final iron ore concentrate was shown to be significantly higher. Remarkably, the costs for employing the respective measures are surprisingly low.This case study is based on a Kazakh iron and steel producer, whose beneficiation process is currently generating a magnetite concentrate with a final iron content of 65.65 per cent. The study shows that the implementation of Primetals Technologies’ intelligent modification measures to the current beneficiation process, the realisation of more effective dewatering, and the utilisation of an innovative binder lead to an increased iron content in the resulting pellets, reaching a concentration of 69.17 per cent (iron ore concentrate) and 66.5 per cent (pellets).The current operation consists of three closed circuit grinding stages, four stages of low intensity magnetic separation, vacuum disc filters and straight-grate pelletising. By dividing the slurry after the second stage of grinding and the third stage of low intensity magnetic separation, it is possible to divert the more iron-rich fines before they would enter the third grinding stage and the fourth stage of magnetic separation. This then reduces the load on the existing third stage ball mill. Afterwards, the ground material is treated in an additional low intensity magnetic separator and mixed with the previously diverted fraction of the fines. An improved filtration procedure, combined with the application of a highly sophisticated binder, further reduces the amount of additives needed, so that a genuine direct reduced (DR)-grade iron concentrate is produced as a result.All laboratory, pilot and pelletising test work was executed at Primetals Technologies’ laboratories in Austria.CITATION:Martens, J, Petzold, L and Hiebl, B, 2017. Enabling iron ore concentrate for the production of direct reduced iron with pre-existing beneficiation lines, in Proceedings Iron Ore 2017, pp 227–232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Recovery of Vanadium from Stone Coal Through an Environmentally Friendly Acid Leaching Technology

Sep 13, 2010

Pilot-Plant Testing of Ammoniacal-Cyanidation for Gold Recovery from Copper Gold-Bearing Ore The results of pilot-plant tested ammoniacal-cyanidation of gold recovery from copper gold-bearing ore are presented in this paper. This ore is from a deposit of Russian Federation with gold and copper grade 9.5 g/t and 0.4 per cent, respectively. Copper is largely present as malachite and azurite. The presence of chalcopyrite and bornite is also observed. In order to recover gold, gravity is recommended. Two options of ammoniacal-cyanidation using leaching of gravity tails, CIP and filtration, were tested. It was found that ammoniacal-cyanidation using filtration of leaching tailings and recycled solutions is the most optimal option. The proposed flow sheet provides for 89.7 per cent gold recovery from gravity tailings at the consumption of NaCN 0.9 kg/t and (NH4)2CO3 7.5 - 9 kg/t. Compared to conventional cyanidation, this technology decreases the consumption of sodium cyanide from 4 up to 0.9 kg/t at the same gold recovery. It can be recommended for the treatment of copper gold-bearing ores with the similar composition.

Sep 13, 2010

By R Byrnes, P Hensley

The outstanding environmental management initiatives undertaken by Novacoal at its Western Main Site near Lithgow in New South Wales over the past five years are detailed in this paper. These initiatives have been based on a combination of proven and innovative investigation and implementation techniques, close consultation with regulatory authorities and full support by colliery management. The results of these initiatives have enabled the colliery to exceed its pollution control obligations from a base well below industry standards. The initial poor condition of the mine was the result of over 50 years of traditional mining which paid little regard to environmental management. The transformation of the colliery within such a short period, with limited capital, is considered a model for the N.S.W. coal industry.

Jan 1, 1995

The AusIMM is concerned about the longer tem sustainability of the minerals sector in Australasia. Our contention is that the sustainability of the sector is at risk if we do not:   ò encourage more exploration in Australasia by removing impediments and         increasing incentives; ò fund our university and research centres appropriately to increase both our   prospectivity, and our processing efficiencies; and ò manage our human resources better.   This paper will focus on how we can better manage our human resources to assist in ensuring sustainability of the sector in Australasia .   From a production point of view:   Economic output = f (Land, Labour, Capital, Environment) where Land refers to all of the natural resources used in production. As well as land itself it includes water, forest, fisheries, oil, gas and mineral deposits. Labour refers to the skills and capabilities used by humans in the production process. Capital describes all of the manufactured aids used in the process of production1. The challenge for management is to ensure maximum efficiency and effectiveness of labour in the production process whilst maintaining sustainable development.   The 1992 Rio Summit defined sustainable development as maintaining and enhancing:   ò natural capital û defined as all natural resources, both environmental and   those of traditional economic value; ò manufactured capital û made by human kind, including produced goods,     infrastructure and built environment; ò human capital û defined as the health, well being, intellectual capabilities and   spiritual welfare of individuals; and ò social capital û defined as social relations and consultations within and   between societies, their norms and functionality2.   The minerals sector in Australasia has successfully focused on the technical aspects of each of these components of sustainable development with primary attention applied to natural capital and efficient utilisation of manufactured capital. The technical aspects of human capital and social have also been addressed through an emphasis on occupational health and safety and interaction with local communities however I suggest that, to date, insufficient emphasis has been placed on labour (human capital) to maximise economic output1.   It has become increasingly common practice to identify land as natural capital, labour as human capital and capital as physical capital. That is labour has been treated as a commodity rather than an opportunity to create a comparative advantage and this will be the greatest challenge for mine management to show leadership over the next decade of the 21st Century.   This paper will outline characteristics of the sector which are relevant to the management and utilisation of labour, outline the outcomes of recent AusIMM surveys, review the reasons for the current and future anticipated skills shortages, some innovative responses to the challenges and finally, suggestions on how mine management can show leadership.

Jan 1, 2006

By C Bailey, T Kojovic, M M. Hilden, M S. Powell

The Julius Kruttschnitt semi-autogenous grinding (SAG) mill model was developed by Leung in the 1980s and extensively updated to the variable rates model by Morrell and Morrison in 1996. Since then only minor upgrades have been incorporated in the version distributed in the JKSimMet simulator. A number of improvements, developed over the course of the AMIRA P9 project and in recent independent work, have now been incorporated. These improvements are based on a power-based model that directly relates the degree of breakage with energy consumption. The new size-dependent breakage function has been incorporated. The upgrades include more accurate predictions for a wide range of mill fillings (ten - 40 per cent), slurry hold-up in the mill, pebble discharge rate and the influence of changes in feed size and ball load.The paper presents the status of progress in the model development. The upgraded model will greatly enhance its application to challenging design and optimisation studies required to optimise the performance of SAG milling circuits.CITATION:Kojovic, T, Hilden, M M, Powell, M S and Bailey, C, 2012. Updated Julius Kruttschnitt semi-autogenous grinding mill model, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 71-80 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By R Cox, S Pandey

The coal seam gas (CSG) industry is expanding rapidly in the Surat and Bowen basins. CSG production involves pumping water from the coal seams to release the gas adsorbed to coal particles. The reduction in water pressure in the coal seams will cause some reductions in water pressure in overlying and underlying aquifers because there will always be some interconnectivity between the formations. The Surat Basin is a sub-basin of the Great Artesian Basin, which contains aquifers of high economic, environmental and cultural value. The Condamine Alluvium is also an important water resource, which overlies parts of the eastern margin of the Surat Basin.Under the Queensland (Qld) regulatory framework, an area of intensive CSG development involving multiple CSG operators can be declared to be a cumulative management area. For such areas the Office of Groundwater Impact Assessment develops assessments of future impacts on aquifer water pressures and develops and manages arrangements. The results are published in underground water impact reports.The Surat underground water impact report (QWC, 2012) was approved in December 2012. This paper summarises the place of the report in the Queensland regulatory framework, the content of the report and progress in its implementation.CITATION:Cox, R and Pandey, S, 2013. Managing groundwater impacts in the Surat Basin, in Proceedings Water in Mining 2013 , pp 169-174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Gillies A. D S

The active history of foreign investment in the mining industry has resulted in Australia emerging as a major world producer of a range of mineral commodities. The current contribution to the national economy represented by mineral production and export revenues would not have occurred without both capital and expertise provided by foreign investors in the past. The initial foreign investment has led to the formation of Australian majority owned and controlled multi-national mining groups such as BHP Limited, CRA Limited and MIM Holdings Limited. These Australian companies, and others, are playing a significant part as foreign investors in the mining industries of Papua New Guinea (PNG) and Indonesia. The study examines issues of importance in foreign investment in each of the countries. It concludes that in Indonesia, the nationalisation of the Dutch mining industry in 1957 did much to deter foreign investment. The remarkable degree of policy stability brought about by the Contract of Works system since 1967 has gone a long way to restoring that confidence. The level of investment in the Indonesian mining sector is steadily increasing. Its attraction to Australian investors is a combination of policy stability, favourable fiscal terms, geological prospectivity for a range of commodities and proximity to Asian markets to the north. PNG has a stable policy regime which until recently has been free from political interference at the administrative level. As such, investors were developing confidence in the system and investment was progressively increasing as evidenced by growing exploration expenditures up to 1988. The 1989 Bougainville revolution caused a re-assessment of PNG's investment and country risk. The recent Mt Kare incident has further raised concerns over the government's ability to guarantee internal security. Foreign investors are faced with weighing concerns with the risks of operation in PNG against the undoubted geological prospectivity of the country. The fiscal regimes of Australia, Indonesia and PNG were compared by means of a simulated open pit gold mine in each country. The effect of taxation is examined by reference to the relative change in project internal rates of return (IRR). The comparison of the relative differences between pre-tax and post-tax IRRs provides a measure of the relative attractiveness of each fiscal regime.

Jan 1, 1994

In most surface mining operations, overall project economics is driven to a significant extent by the slope angles that can be achieved within the rock masses present. This is particularly true of precious metal pits in which stripping ratios can be relatively high, although examples from other non-precious metal operations (such as large iron ore and copper pits) can also be found. As a consequence, it is not surprising that in most large (deep) open pit mines, relatively small changes in slope angle (of the order of two or three degrees can translate into changes in project value measured in the tens or even hundreds of millions of dollars. Understanding how this potential value can be realised, and quantifying the associated risks, should be one of the key outcomes of modern slope engineering practice. In striving for optimised slope angles, therefore, mining companies and their specialist consultants are increasingly turning to more sophisticated methods of engineering open pit walls. This paper summarises contemporary slope engineering practice as well as some of the key technical issues that are either currently being researched or will need to be researched in the future. It is written in the context of the slope engineering process; namely, data collection and analysis, failure mode identification and stability assessment, slope design, slope formation, and slope (face) mapping and monitoring (the latter two activities being the primary on-going data collection functions that close the design loop).

Jan 1, 2002

Adsorption of Starch on Kaolinite Surfaces

Sep 13, 2010

By N Hungerford, A Coote, S Doyle, D Henderson, F Della-Pasqua

A systematic, detailed airborne geophysical programme carried out in the Taupo Volcanic Region (TVR) in 2005 by Glass Earth NZ Ltd culminated in the identification of 21 epithermal gold targets. In this paper we present the follow up ground-truthing results from the first target drilled, Tahunaatara (TAH).   The Tahunaatara target was identified by means of a multi-disciplinary integrated approach (ôdata interventionö) that defined and ranked the target as being highly prospective for epithermal gold mineralisation. A follow-up ground resistivity survey over the target area revealed the presence of a ôresistorö buried beneath an extensive cover of recent volcaniclastic material. Geochemical soil sampling carried out in conjunction with the resistivity survey yielded anomalous gold values.   The host unit at TAH consists primarily of flow banded rhyolitic lavas, volcaniclastic deposits and tuffs of the Ohakuri Ignimbrite with small outcrops of silicified bedded breccias forming local topographic highs. Results from the first orientation drill hole show wide zones of intense silicification, clay alteration and mineralisation. Sulphide mineralisation is disseminated throughout the core in association with hydrothermal replacement and also occurs in association with quartz veins and infill in fractures (sulphide-only veinlets as opposed to quartz + sulphide veinlets). Textural evidence from drill core indicates that hydrothermal fluid flow was multi-staged with potential for multi-stage gold, and other elements. The presence of polymictic hydrothermal eruptive breccias indicates a hydrothermal vent system.   Alteration varies from argillic to silicic, with pervasive adularia and vuggy silicification also present. Chlorite is minor and associated with quartz, illitic clay and adularia. Assay results currently available confirm the presence of anomalous gold values in association with zones of vuggy silica deposition and intense silicification.

Jan 1, 2006

By P Toor

Mill filling is an important operational parameter in a SAG mill circuit and by its control and optimisation it can produce significant improvements in production capacity and energy efficiency. However, it is industry practice to report mill load as the total output given by load cells, or kPa for systems based on lubrication bearing back pressure, rather than the actual percent total mill filling.Ball trajectory is another critical parameter as overthrow can result in accelerated liner wear and possibly liner failure whilst underthrow can result in reduced grinding action. The assessment of ball trajectory cannot be done in isolation as the toe of the charge needs to be determined to make any meaningful assessment. Thus both total percent mill filling and mill trajectory are critical parameters; however neither is reported or available to metallurgy or processing teams in real time or a regular basis.In this study the performance of a fixed speed SAG mill was assessed and optimised by employing mill trajectory models and using the JKMRC power model to calculate percent total mill filling. Power Curves, which correlate ball filling, mill filling and mill power, were also developed. The Power Curves, with additional knowledge from the trajectory models allowed for the identification of optimal operating regions for the mill.CITATION:Toor, P, 2015. Optimisation of a semi-autogenous grinding mill through trajectory and power modelling, in Proceedings MetPlant 2015, pp 142–149 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

In eastern China, most of the copper skarn deposits occur in folded troughs which are controlled by the EW-trending faulted fold systems (the Pal-Asian geotectonic domain), and the NNE-trending rift or fault zones (the Marginal-Pacific geotectonic domain), particularly the later. From the north to the south, there are four troughs hosting the main copper skarn deposits in eastern China: the Yanliao Trough, the Yangzi River Trough, The Qiantang-Yuanshui Trough and the Zichen Trough. There are more than 30 copper skarn deposits in eastern China, and ore reserves of each deposit are between 30 to 100 Mt with average grades over 1% Cu.    Most of the large copper skarn deposit-related intrusions are Mesozoic in age (170 to 100 Ma) and were emplaced during the Yanshanian Movement. Outwards from the intrusion bodies, both the skarn alteration and mineralisation show certain patterns of zonation. Mineral assemblages indicate a relatively high oxidisation state during metasomatic alteration and mineralisation. Sulphur isotopic work indicates that most d34S values of the sulphides are between ~4 to 3ë suggesting a common magmatic sulphur source. Fluid inclusion and oxygen isotopic studies suggest that early-stage fluid shows magma-related fluid characteristics although meteoric water was involved during late-stage alteration.

Jan 1, 1995

By R Garzon

For resources projects with healthy net present value (NPV) and low cash flow volatility, conventional discounted cash flow (DCF) analysis will continue to provide the dominant investment decision-making criteria. However, DCF analysis can be biased because it often applies a single risk-adjusted discount rate (RADR) to compare the value of projects with different risk characteristics. Many of the difficulties with DCF modelling arise from analystsÆ inability to determine appropriate risk discounts and to estimate expected spot prices inputs for the commodities produced over the life of the project. Modern asset pricing (MAP) is a very valuable complement to DCF analysis in addressing some of these issues. Most papers dealing with MAP, however, while academically rigorous, tend not to be explicit in terms of practical application of this methodology in routine project evaluation. This paper has the objective of reviewing the MAP methodology and of demystifying its complexity, by providing a simple but realistic step-by-step evaluation of a mining project, comparing its DCF and MAP NPV values. The paper concludes that MAP provides a minimum, risk-adjusted æfloorÆ value, thus representing a valuable complement to any DCF valuation.

Jan 1, 2007

By R Long

The founder of social psychology is sometimes identified as Kurt Lewin. In a 1947 article, Kurt Lewin coined the term ‘group dynamics’. He described this notion as the way that groups and individuals act and react to changing circumstances. Lewin theorised that when a group is established it becomes a unified system with unique dynamics that cannot be understood by evaluating members individually. The discipline of social psychology really emerged out of World War II and tackled questions associated with human judgement and decision-making by the Nazis. For a comprehensive look at the development of social psychology look at Abelson, Frey and Gregg (2004).Social psychology is concerned with the way social arrangements affect human judgement and decision-making. What the author has done is apply the knowledge of this new discipline to an understanding of risk, safety and leadership. This paper will explain some of the developments in social psychology, such as the discovery of the bystander effect, Groupthink, bounded rationality, heuristics, risk homeostasis and the Milgram effect.The social psychology of risk tackles the way decisions are made about risk in their social context. Unless organisations understand that decision-making is socially conditioned, they are unlikely to be able to tackle the complexities of culture change or the development of risk maturity.The paper will offer a new understanding of why people do what they do, how risk makes sense and why a ‘dumb down’ approach to safety is dangerous. A model will also be presented that shows the pathway to risk maturity.CITATION:Long, R, 2016. The social psychology of risk, safety and leadership maturity, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 31–42 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

A New Online Detection Method for Arsenic Minerals in Process Streams

Sep 13, 2010