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By M I. Pownceby, C M. MacRae, A Torpy

Electron probe microanalysis (EPMA) and quantitative X-ray diffraction (QXRD) techniques are capable of providing high-quality quantitative information regarding the phase mineralogy and distribution of alumina within iron ore samples. The techniques, however, use different methodologies in determining the mineralogical information (ie structural versus chemical), which introduces some limitations. In this study, EPMA was used to identify and quantify the deportment of alumina within mineral phases in iron ore samples (-1 mm crushed) sourced from different suppliers. Results were directly compared with quantitative mineralogical data derived from QXRD to provide an evaluation of the relative merits of both techniques. The four ores studied contained alumina either in the form of gibbsite, aluminosilicates (eg kaolinite), or associated with goethite.For minor phases, gibbsite and kaolinite, the abundance trends measured via QXRD were generally reflected in the EPMA data. Agreement was less satisfactory for the more abundant goethite phase (both low- and high-Al forms). The discrepancy may be the result of sampling issues arising from textural features such as grain size, and also a systematic overestimate in the amount of Al-rich goethite when hematite and Al-bearing phases are finely intermixed and the EPMA step size is coarse. A second difference in the EPMA results compared to the QXRD data was in regard to quantification of low-Al and high-Al goethite phases. The sensitivity of the chemical-based EPMA was better for distinguishing between high- and low-Al goethite although the results remain overprinted by potential errors introduced via sampling.Care should be taken when directly comparing results from each method, although in general the data should be considered complementary, as each approach provides slightly different results and interpretations regarding the overall mineralogy.CITATION:Pownceby, M I, MacRae, C M and Torpy, A, 2017. A comparison of X-ray and electron-based analysis techniques for characterising the mineralogy and alumina distribution in iron ores, in Proceedings Iron Ore 2017, pp 593–598 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

This paper highlights the agricultural sector's primary concerns with mining in New Zealand: the information gap, land rehabilitation and compensation. It suggests how these issues can be resolved between the competing land uses in the interests of New Zealand.

Jan 1, 1981

By J Parr, P Ashworth, S Johns, C Yeats, A Littleboy

The ocean floor is increasingly being discussed in terms of its resource potential. New discoveries, improved knowledge and access to unexplored areas of the deep sea and continental shelf are some factors contributing to a renewed interest in the seafloor exploration and mining industry. The industry has been referred to as the ænext minerals frontierÆ. To date, much of the research has focused on proving economic and technical viability of the industry, with environmental issues addressed locally. However, there is limited research internationally, and none known in Australia that considers the social viability of the industry, addressing issues such as regulatory contexts, international precedence and public acceptability. Does the nascent seafloor exploration and mining industry have a social license to operate? Does it have support amongst the wider community? If not, why not? The Wealth from Oceans National Research Flagship explored these questions by scoping the social issues that would surround an expansion. Two desktop studies provide insight into the current level of activity in seafloor exploration and mining, recent developments and the regulatory regimes on which the industry is based. One study focused on the situation in Australia, while the other was internationally focused. A series of workshops were held with key stakeholders from government agencies, industry and other interested parties, such as environmental groups and the fisheries industry. These workshops identified and explored the different stakeholdersÆ perceptions of the benefits, concerns, opportunities and key questions associated with an expansion of the seafloor mining industry. The desktop studies revealed that Australia is one of only a few countries with legislation specific to seafloor exploration and mining. Nevertheless, barriers to licence approval exist because of lack of precedent in applying this legislation. Consequently, the decision process can be vulnerable to political issues and subjective judgements. The outcomes from the stakeholder workshops suggest this inconsistency may be influenced by the high levels of concern and uncertainty over environmental impacts. Uncertainty over environmental impacts can influence the acceptability of an environmental impact assessment (EIA) and also mean the perception of risk is variable. Overall, this research suggests that the future of the seafloor exploration and mining industry will be highly dependent on AustraliaÆs ability to:improve the knowledge-base underpinning the regulatory regime,generate open and transparent communications between stakeholders, andimprove the understanding of policy and regulatory processes.

Jan 1, 2008

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

The principal source of funding the working capital requirements of gold miners has traditionally been equity. However in the 1980s, with a substantial increase in activity in the exploration for, and the production of, gold the traditional sources of equity finance became no longer sufficient to meet demand. With the often high cost of raising equity, the need for developing alternative financing structures became critical, especially since the stockmarket crash of 1987 which at least until recently, adversely affected the amount of equity capital available for investment in mining.

Jan 1, 1994

By C Haughy, F F. Pitard

Blue Mountain Minerals is a large supplier of calcium carbonate products used by various manufacturers as a major raw material. Very small amounts of free carbon in the rock can have a huge impact in carbon-sensitive applications. The marble in the deposit at Blue Mountain Minerals contains variable amounts of free carbon in the form of trace amounts of the mineral graphite.To make quality improvements, variography was used to measure the impact of non-ideal sampling practices at the Blue Mountain Minerals operations in Columbia, California in the United States. A major investment in correct sampling systems and sampling protocols was implemented over a one-year period. Subsequent variography was used to measure the improvement on the predictability of the graphite content in marble produced by the quarry and as it is processed as an acceptable raw material for extremely carbon-sensitive applications. The improvements of the sampling protocols, control of long-range changes and better knowledge of process cycles are easily noticeable on variograms when they happen to exist. The economic impacts are discussed.CITATION:Haughy, C and Pitard, F F, 2017. Use of variography to measure improvement of sampling practices for the quality control of graphite consistency in marble used for carbon-sensitive applications, in Proceedings Eighth World Conference on Sampling and Blending , pp 255–260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

For establishing sustainable material cycle process in human system, a brand new concept should be created, which could recycle the waste materials, which are land-filled and discarded under present economical situation. The concept of 'RtoS' (Reserve (of waste) to Stock) to create 'artificial deposit' of the materials concentrate is one of the best ideas to be applied. From this viewpoint, separation technology, in especial, solid phase separation such as mineral processing technology contributes much to the concentration, making 'artificial deposit' with less energy consumption compared with melting and/or dissolving technologies. Results of rare metals concentration in the e-waste are also introduced as an example with combining novel comminution and parts/powder separation.

Sep 13, 2010

The Beckman Air Comparison Pycnometer is as accurate as the specific gravity bottle for the determination of the volume of fine powders, or particles, up to 50 c.c. in volume. The determination using the air comparison pycnometer is performed in a much shorter time.A graph of density versus iron content for samples from four different iron ore deposits shows that iron contents can be obtained to within 4 per cent iron. Field geologists should be able to obtain quick and relatively accurate iron contents of ore samples using the air comparison pycnometer at these deposits.INTRODUCTIONA Beckman Model 930 Air Comparison Pycnometer was purchased to decrease the time required for the determination of the volume of stones and powders. The liquid displacement method was used previously and the time required per determination varied from a few minutes for stones to half an hour, or more for fine powders. With the air comparison pycnometer, the determination takes approximately 2 min and can be quickly checked for accuracy by a further determination. The total time for weighing, determining, and checking the volume is no more than 5 min.DESCRIPTION AND PRINCIPLE OF OPERATION OF PYCNOMETERDescriptionThe air comparison pycnometer measures the volume of materials, in c.c., by determining the amount of air displaced.A diagram of the main components is given in Fig. l.Cylinders A and B are equal in volume and each has a piston which is moved by turning a handwheel attached to a geared shaft. The measuring piston shaft is geared to a 5...

Jan 1, 1963

Longwall mining originated in the early 18th century in the county of Shropshire in England, where it was known as the longway method. Its name implies the extraction of the seam over a long continuous length or wall of exposed coal. Until the late 19608 and early 1970s the use of the longwall system with a few exceptions was confined to the United Kingdom and Europe. It was not until the early 19708 that the highly productive longwall faces we now know, were developed and the application of the longwall system extended to Australia, South Africa, United states of America and other parts of the world. The modern longwall face has three major components, namely: +         the machine to break and load the coal +         the face conveyor; +         and a system of roof support.   This paper reviews the development of longwall mining technology. The parameters directly influencing the production 'of a modern longwall face are considered, as are the possible constraints to the further development of the longwall system.

Jan 1, 1991

By B Vernon, M Whiteley, T Robinson

The Western Australian gold industry has approximately 100 operating plahts, mainly CIP/CIL. The nature of the State's rapidly expanding gold industry gave rise to concerns over management of the  cyanide hazard, in that most plants are remote from major population centres, have a workforce with a high tum over and use highly saline process water. Approximately 4500 workers in the industry have the potential to be exposed to cyanide in the course of their normal work.   This paper outlines the risk management strategy developed by Government and industry to monitor atmospheric HCN gas in the work environment and the role of continuing education and training along with regular site inspections by Department of Mines Inspectors.

Jan 1, 1990

Various influences determine how an Environmental Management System (EMS) for a mining or petroleum project is developed and administered. These influences include the environmental and resource legislation applying to the project, the culture of the organisation, the environmental sensitivity of the area, and the administrative policies of the regulatory agencies involved. While financial penalties and even imprisonment may be imposed for non-compliance with environmental legislation, there are other compelling reasons for the establishment of an effective EMS. If a company wishes to be considered by Governments for the grant of exploration or mining rights, it is important that it can demonstrate environmentally responsible operations at existing facilities. The development of an effective EMS requires commitment from the Board of the company and the issue of an Environmental Policy to empower all levels of the staff and workforce to achieve environmentally responsible operations. This must be supported by the provision of appropriate human and financial resources, and environmental training of staff at all levels from the Board to the mine site, workshop and office. A regular environmental auditing programme is essential to ensure that the EMS is in place and is effective in achieving compliance with regulatory requirements, corporate policies and protection of the environment. An EMS can be developed on the basis of existing management systems, quality management systems, existing and emerging environmental management standards (such as BS7750 and ISOI4000), or sophisticated computerised systems which may incorporate international experience, standards, and codes of practice.

Jan 1, 1995

By Misra V. N

Upgrading of a Koolanooka magnetite iron ore sample provided by Kingstream Steel Ltd was investigated using low intensity magnetic separation (LIMS) and reverse flotation. The ore contained 38.6 per cent iron, 37.8 per cent silica, 6.5 per cent magnesia and 0.54 per cent alumina, with the main minerals in the ore being amphibole (42 per cent), magnetite (39 per cent) and quartz (14 per cent). The concentrate obtained after low intensity magnetic separation contained 66.6 per cent iron and 6.34 per cent silica with an iron recovery of 72 per cent. This concentrate was further treated by reverse flotation to increase the iron content and reduce the silica content to meet the requirements for direct reduction iron (DRI) feed grade.

Jan 1, 1999

The Australian Centre for Minesite Rehabilitation Research (ACMRR) was established through a mining industry initiative to meet the need of industry, governments and the community for sustainable systems for land affected by exploration, mining and mineral processing activities. The Centre, which is a consortium of the major groups associated with mining rehabilitation research in Australia, has a focus on both strategic research and technology transfer and combines a wide range of multidisciplinary skills covering engineering and the physical and biological sciences. The paper briefly describes the goals, structure, expertise and research and technology transfer activities of the Centre. The major research program areas of waste rock dump and final void stability, acid mine drainage, tailings disposal, and remediation of ecosystem reconstruction are described in the context of national priorities.

Jan 1, 1995

The addition of cement to underground backfill at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited, Broken Hill commenced in 1967. A deterioration in metallurgical performance at each concentrator occurred as a result, with increased loss of lead and zinc to residues. Investigations to determine the reasons for this problem and methods to counteract it have been undertaken. This paper outlines the effects of cement on lead-zinc beneficiation at Broken Hill and presents an interim report on attempts to overcome the metallurgical deterioration.

Jan 1, 1971

By L Langer, R Simcock, M Davis

Rehabilitation of mining sites helps to achieve the purpose 5(2c) of The Resource Management Act 1991 û æavoiding, remedying, or mitigating any adverse effects of activities on the environmentÆ. The environmental outcomes for recent and current mining operations on the West Coast are variable. There are some exemplary mining operations which are restoring or even improving land use and environmental factors in the region, particularly those operated by the larger mining companies. There are also examples of an exploitative mentality where the environment and land have been severely degraded by mining activities. Technology has been developed to prevent a repetition of the historical destruction of the environment through mining. Failure to rehabilitate mined land is no longer acceptable to the New Zealand public in the 1990s and damages the credibility of the mining industry. Examples of successful mine site rehabilitation to pastoral farming and to production or plantation forestry are illustrated from the alluvial gold mining industry. Planning, sequencing of operations, the utilization of sailor plant growth materials, and aftercare are key factors in successful land rehabilitation to these productive uses. There is also a recent focus on restoring indigenous forests and wetlands at both coal and gold mining sites, particularly for mines on or adjacent to the conservation estate. The results of scientific research and efforts by the industry on techniques for rehabilitating rainforest and pakihi wetland after mining are presented, particularly from the Giles Creek Dunoille Coal Mine. There is a need for further research and trials to apply and extend rehabilitation techniques to other geological and environmental situations, particularly to mines in mountainous areas and to difficult environments like the coal measures ecosystems of the plateaux above Westport.

Jan 1, 1996

By S Kasaneva

TheSan Cristobal gold district is located 110 km east of the port of Antofagasta, Chile. It contains the San Cristobal gold mine, where Niugini Mining Ltd. commenced a heap leach operation, with initial reserves of 10.1 million tonnes grading 1.34 g/t Au, in December, 1990. The San Cristobal district occurs within an upper Cretaceous-lower Tertiary magmatic arc. The main mineralisation occurs within a northwest trending subvertical zone, 1km long and 70 - 100 m wide, which contains rhyolite porphyry and minor breccia, and is locally termed the 'subvolcanic complex'. At the San Cristobal mine, most gold mineralisation occurs in subvertical quartz-pyrite veins which were emplaced in dilational sections of an imbricate fault system. The bulk gold resource comprises four ore shoots which formed where the vein system intersects the subvolcanic complex. Gold-bearing quartz-pyrite veins also occur at separate prospects, the Three Sisters and Sol prospects, west and south of the San Cristobal mine.   Hydrothermal alteration consists of potassic and propylitic assemblages related to intrusion of the subvolcanic complex. This alteration is overprinted by a phyllic stage which is associated with the emplacement of the quartz-pyrite veins. The oxide zone is 180 m thick, and contains native gold, electrum, limonite, and manganocarbonates. The underlying hypogene zone contains pyrite with minor chalcopyrite, sphalerite, galena, covellite, bornite, chalcocite, and arsenopyrite. Fluid inclusion studies indicate that the deposit formed at approximately 270¦C, and the mean salinity of the fluid was 4% NaCl equivalent. These observations enable the San Cristobal deposit to be classed as a porphyry- related, mesothermal quartz-vein system of the low sulphidation type.

Jan 1, 1995

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

By C A. Feebrey, R A. Duncan

The Ebor Volcano in north eastern New South Wales is an eroded example of a central-type intraplate volcanic-intrusive complex. It is of Miocene age (19 - 20 Ma) and has similarities to other central-type volcanoes in eastern Australia which may represent manifestations of sub-lithospheric hotspot activity. Thick lava flows are exposed around the Great Escarpment and are dominated by a tholeiitic basaltic suite, ranging from ol-tholeiite to qz-tholeiite to icelandite with ages of 19.2 - 19.6 Ma. On its western edge, the tholeiitic lava suite probably overlies remnants of basanite flows belonging to the Eocene (~48 Ma) Doughboy province, but elsewhere, minor alkaline basaltic lavas may be coeval with the tholeiitic suite. Several felsic bodies were emplaced into the volcano at ~19.0 - 19.2 Ma and include subalkaline and peralkaline types. The Crescent Complex is a Miocene-age, strongly differentiated mafic to felsic intrusion in basement rocks and centrally located in pre-erosion reconstructions of the Ebor Volcano. It is interpreted to be a major feeder for the tholeiitic lavas based on age and composition. Evolution of the dominant tholeiitic suite proceeded from a parental ol-tholeiite magma, through qz-tholeiite, icelandite and small volumes of felsic rocks by fractionation of plagioclase, olivine, clinopyroxene and titanomagnetite, accompanied by enrichmentof SiO2, SFeOlMgO, alkalies and HFSE.

Jan 1, 1995

Project developent proceeds by increasingly detailed studies addressing overall project returns through an analysis of the substance, risks and costs associated with the following elements: ò Reserves ò Mining ò Processing ò Infrastructure ò Environmental Impact ò Product Market Computer-based expertise has a potential to ò Capture perishable expertise, making this available for shared access and so reducing the cost of human experience ò Consolidate know-how for optimising process operations, bringing consistency of judgement and advice to decision- making by making the rules, facts and preferences explicit ò Allow assignment of the basis and authority of decisions, so experts can pass routine expertise down the line, freeing their time to generate more. ò Force a review of expertise when creating the knowledge base.

Jan 1, 1989

Experimental Validation of a Flotation Cell Model

Sep 13, 2010