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Methods for Improving the Flotation Recovery of the Coarse Fraction of a Nickel Ore

Sep 13, 2010

Old Copper Flotation Tailings Waste Reprocessing

Sep 13, 2010

The Ministry of Economic Development has as its slogan æTogether making the differenceÆ. The Ministry is required to work in partnership with the private sector, local authorities, Maori economic entities, trade unions and community groups to transform New Zealand's industrial and economic base. The Government is seeking to achieve sustainable and balanced economic development by: being more actively involved in economic management; working in partnership with the public and private sector and with worker and business interests; focusing on adding value in industries (including primary industries) with long term potential; and bringing the tools of economic policy together in a coordinated way. The Ministry, particularly through its operating group Crown Minerals, is committed to working with industry to achieve mutual goals and to obtain continuing investment in minerals and coal exploration and mining and an active New Zealand minerals industry.

Jan 1, 2000

The Golden Cross mine is a Joint Venture between Coeur Gold New Zealand Limited, as Manager, and Viking Mining Limited. The mine is targeting Zero Lost Time Accidents as a goal.   The Golden Cross operation produces gold and silver from both underground and open pit. The mine is based on an epithermal gold-silver deposit. Treatment of ore is on a campaign basis for each ore type (i.e. underground or open pit). Milling is conventional SAG Mill and Ball Mill grinding circuit followed by carbon in pulp recovery of gold and silver. All tailing materials are treated through the Cyanisorb process to reduce cyanide levels prior to being discharged into the tailings dam.

Jan 1, 1995

Open pit mining has considerable damaging effects on the environment of the mining region. These harmful influences have to be controlled during mining operation until mine closure. Different sections of mined land, such as; pit(s), waste dump(s), tailing pond(s), roads, areas for onsite facilities and free land zones which are not mined, have to be reclaimed through treatment of environmental pollution and implementation of a permanent post mining land use (PMLU) after mine closure. Implementation of a permanent optimal post mining land use (OPMLU) is one the most decisive criterion which effects on reclamation procedure, mine closure and their costs. Therefore to define ultimate pit limit (UPL), mine closure and reclamation costs should be entered in the calculation iterations same as the other variable costs of the projects. Estimation of closure and reclamation costs of a mining project is carried out based on the attained OPMLU and the specifications of the mine site. In this paper, a model is developed to provide OPMLU for pit area through fuzzy multi-attribute decision making (FMADM) technique. The model was implemented on a hypothetical copper mine in northwest of Iran as a case study. Lumber production was selected as OPMLU for the pit area. It is finally concluded that through the developed model, OPMLU for different sections of mined land in an open pit mine project is defined. Also closure and reclamation costs are estimated based on the defined OPMLU to achieve a more accurate UPL.

Dec 6, 2010

The paper outlines the history and current status of the VALMIN Code and sets out the background, methodology, results and recommendations of the Independent Review of the VALMIN Code undertaken during 2001 under the Chairmanship of Ian Goddard. The paper is based on the final report of the Taskforce, which was submitted to the Board of The AusIMM for consideration.

Jan 1, 2002

Generation and Attachment of Submicron Size Bubbles to Colloidal Solids

Sep 13, 2010

In November 1969, New Zealand Steel Ltd pioneered the commercial use of the SL/RN solid fuel direct reduction process to make sponge iron as a feed material for electric arc furnaces. Serious process problems with the use of green balls and coal injection were progressively overcome. The process was developed by New Zealand Steel along a radical route, of feeding the fine grained raw ironsand concentrate and coal directly to the kiln. Contemporaneously with this development of direct reduction, steelmaking process innovations were made that enabled the arc furnaces to operate successfully with the high volumes of acid slag. The further expansion of New Zealand Steel's primary steelmaking capacity to replace the currently imported hot and cold flat rolled products is under consideration. The requirement to produce about 600 000 tonnes of steel slabs will be an opportunity to further modify iron and steel making plant and processes to optimise the economics. The conceptual and preliminary engineering selection of options is described.

Jan 1, 1980

By G K. N Subasinghe

Metallurgists operating Knelson Concentrators (KC) often rely on manufacturerÆs recommendations for selecting operating parameters, such as fluidising water flow rate and cycle time. Recent studies have shown that these parameters are not only dependent on the machine parameters but also on the feed characteristics, such as size distribution of the gold and gangue particles and the composition of its constituent minerals. It is known that a particle entering a KC initially traverses a circular path within the bowl. For a particle to maintain a given orbit, the required centripetal force must be supplied by external means. It has been argued that this centripetal force, which is dependent on the mass of the particle, its radial position and the rotational speed of the bowl, is provided by the fluid drag force created by inwardly moving fluidising water and the BagnoldÆs force created by the particle/particle collisions. Depending on the fluidising water flow rate, one of two situations can occur where the porosity of the bed increases or decreases, which influences the amount of material retained within the bowl. The amount of material of a given size and density retained in the bowl is thus dependent on the extent of the centripetal force provided. Based on the above concept, a criterion that can be used to predict the amount of material recovered in the bowl has been derived and validated by experimental data. It may also be construed that this criterion demarcates the transition of the bed from a packed-bed state to a fluidised state. By identifying the transition values for the different constituent mineral particles in the feed, it is possible to estimate the optimal fluidising water flow rate that would maximise gold recovery while minimising gangue recovery. In addition, the kinetics of gangue displacement by incoming heavy mineral particles were also studied using synthetic mineral mixtures. The experimental data suggests that this process follows first order kinetics and that the build-up of heavy mineral reaches a maximum. A model has been proposed to predict the optimal batch cycle time for a KC in terms of the feed characteristics and machine operating parameters.

Jan 1, 2006

By C J. Hogan

Increasing demand for fine grinding to improve mineral liberation and metal recovery and the need for stricter control of the environmental impact of tailings deposition poses problems for tailings disposal. This has led to an increasing number of investigations of properties of tailings and their disposal. This paper describes laboratory model testing undertaken on Macraes mine flotation tailings to provide information on tailings behaviour under conditions of subaerial deposition. The in-place density or 'dry density' of the impounded tailings and the impoundment depth relationship are important for utilisation of the available impoundment storage facility and results of dry density to depth relationships are given for the Macraes mine tailings impoundment.

Jan 1, 1993

By G E. Ho, M Anda, S Dallas

Water auditing and water conservation measures are fast becoming the quantitative tools for water balance reporting in the mining and minerals processing sector. Therefore, this paper was written to describe the process of water auditing in a goldmining environment and to contribute towards building an appropriate water management framework for The Cooperative Research Centre (CRC) for sustainable resource processing (CSRP). The research will assist with the assessment of water balances in mining and hydrometallurgical processes and ongoing probabilistic modelling for Newmont Mining Corporation, its wholly owned gold mines, and its joint venture operation of Kalgoorlie Consolidated Gold Mines (KCGM). Kalgold or KCGM are the managers of a joint venture project between Barrick Australia (50 per cent) and Newmont Mining Corporation (50 per cent) at Kalgoorlie, Western Australia (WA). Boddington Gold Mine (BGM), Western Australia, will commence operations this year and manage the new goldmine expansion project. BGM is 100 per cent Newmont owned and will operate to continue mining gold and copper from the existing (BGM) site that was decommissioned in 2001.

Jan 1, 2009

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

By K Williams, W Chen, J Miller

The flow function of an iron ore material governs its flowability characteristics in material handling chains within the resource industry. A uniaxial compression test is able to obtain a flow function more rapidly comparing to the Jenike direct shear test; nevertheless, the results often exhibit lower rankings using the former method. This study aims to investigate the fundamental stress states within the test specimen that lead to this phenomenon, and to introduce a new uniform density specimen preparation method for a uniaxial compression test, in order to achieve comparative flow functions as for a Jenike direct shear test. The minimisation of the wall friction effect and achievement of the critical state when preparing a uniaxial specimen are explicitly discussed. Experimental investigations on flow functions of a suite of Australian iron ore samples were conducted using both the uniform density uniaxial compression test and the Jenike direct shear test. Results from both methods were found to be comparable, providing the specimen exhibits cohesive flow behaviours. The outcome of this research enabled development of a rapid and reliable flow function testing method for cohesive iron ore materials.CITATION:Chen, W, Williams, K, Roberts, A and Miller, J, 2017. Rapid and reliable flow property testing – a modified uniaxial approach, in Proceedings Iron Ore 2017, pp 149–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By D Craw, C Smith, C Rufaut

Oceana Gold (NZ) LtdÆs, Macraes Gold Operation currently has two tailings impoundments, the larger of which covers approximately 75 ha. When an impoundment is temporarily out of use, the surface dries and dust can be blown from the surface to the surrounding area. At present water spraying is used to stabilise the surface, but this is not ideal as Macraes mine can experience water shortages during the summer. This paper examines an alternative method of surface stabilisation using vegetation as a ground cover. The tailings have a low natural fertility, so it is important to determine what will actually grow in the tailings, and whether amendments are necessary. Also important is the effect of the amendments on arsenic mobility in the tailings as the schist rock at Macraes has naturally elevated levels of arsenic. Three plants species, rye corn, barley, and lupin, were grown in metre-deep lysimeters at Macraes mine site. The plants were grown in unaltered tailings, and tailings with one of two amendments added: Bioboost (an organic fertiliser containing biosolids), and superphosphate fertiliser. The leachate from each lysimeter was collected and analysed monthly to determine the extent of arsenic mobility. In addition, laboratory experiments were set up to determine arsenic mobility in tailings with amendments at the centimetre scale.   All plants grew best with the fertiliser amendment, with rye corn growing the best overall. Plants growing in unaltered tailings either barely survived (rye corn, barley) or died (lupin). Plants in the Bioboost amended tailings grew only slightly better than in the unamended tailings. Laboratory experiments indicate that the addition of phosphate fertiliser greatly increases arsenic leaching at the centimetre scale when compared to unamended tailings. The addition of Bioboost only marginally increases arsenic leaching, compared to unamended tailings. This trend has not been repeated in the lysimeter trials on the metre scale over four months. Current results suggest that of the plant types trialed and amendments used, rye corn with superphosphate is the most practical short-term tailings stabilisation method at Macraes.

Jan 1, 2004

By N E. Whitehead

An application to mine an ilmenite-rich sand deposit in Westland led to public concern about potential radioactive hazards should the ore be further processed to recover zircon or monazite. A review recommended that any material involved in the heavy mineral sand industry containing more than 0.05% thorium, uranium or their mixture should be considered a radioactive substance and, for mining purposes, a notifiable product. Safeguards for those occupationally exposed would operate via the Radiation Protection Regulations. The major safety requirement would be the minimisation of dust in certain operations.

Jan 1, 1993

By C A. Locke

Geophysical signatures of the Taranaki and Tongariro volcanoes reflect similarities in their age, composition and hydrothermal histories, but also reflect differences in host rock settings and edifice evolution. The Taranaki volcanoes have strong positive gravity anomalies showing that their edifices largely consist of dense andesite which reflects substantial lava production or dyke injection during construction and that large sub-edifice dyke/stock complexes occur. In contrast, the Tongariro volcanoes have strong negative gravity anomalies indicating low density edifices of volcaniclastic material; no sub-edifice intrusions can be identified, probably because of the lack of density contrast with host basement rocks. Strong positive magnetic anomalies over the younger cones can mainly be attributed to near-surface andesite lavas or dykes whereas subdued magnetic effects are associated with hydrothermally altered zones within both edifices and sub-edifice intrusions.  

Jan 1, 1995

Research and Tests on Improving the Technology of Enrichment of the Copper-Molybdenum Ore

Sep 13, 2010

By T Albinson

Mexican epithermal deposits can be broadly grouped into two types based on their contained metals, distribution, associated igneous rocks and fluid inclusion compositions. Silver-gold deposits (eg Tayoltita) mostly occur in the western part of northernMexico where host rocks consist of Eocene, intermediate composition volcanic and intrusive rocks; fluid inclusion studies indicate that mineralising fluids were <300¦C and dilute (=3 eq. wt. % NaCl). In contrast, silver-lead-zinc deposits (eg Fresnillo) mostly occur in the central part of northern Mexico where they are temporally associated with Oligocene-Miocene volcanic rocks and intrusions of felsic composition, but commonly hosted within underlying Paleozoic-Mesozoic sedimentary rocks; fluid inclusion studies indicate that mineralizing fluids ranged from 200 to 400 ¦C and were saline (=10 eq. wt. % NaCl). The distribution of these two deposit types, crosscutting major crustal sutures, and the close spatial-temporal relationships between mineralisation and magmatism, together suggest that magmatic processes were more important in the formation of mineralising solutions, as a source of both ligands and metals, than the segments of crust hosting deposits.

Jan 1, 1995

In the context of sustainable development, the Minerals Council of Australia (2010) states that 'investments in minerals projects should be financially profitable, technically appropriate, environmentally sound and socially responsible'. In other words, the business of mining can only be sustained if these criteria are met.   Science and technology plays a major role in all four of these criteria. This paper will present the technology and innovation emerging from the Minerals Down Under National Research Flagship which brings together CSIRO and more than ten of Australia's leading universities to work with industry to drive efficiency, productivity and environmental performance. This work is required if the Australian minerals sector is to thrive and continue to deliver national benefit in the face of increased global competition, declining ore grades, depleting ore deposits, increasingly constrained national resources (land, energy, water and people) and changing societal expectations.   Science and technology to reduce emissions and water use, discover greenfields resources, enable deeper mining operations and transform mineral processing are described. Technology is presented as an enabler of sustainability: a means to this end but not as an end in its own right.

Jun 1, 2010

A magnetometer survey 'was the Darkes Forest area between 1968. The instrument used was model MZ4 with sensitivity 9.4 conducted over part of 30th April and 3rd May, an ABEM torsion magnetometer gammas per scale division. The survey consisted of a closed magnetometer loop along lines cut for a previous magnetometer and seismic reflection survey by Wongela Geophysical in March, 1968. The magnetic results of the previous survey were not satisfactory in some areas and are presented as a comparison in instrumentation. Station separation in the present survey was 100 feet with tie-in readings at shot points of the previous survey (usually 1320 feet apart)

Jan 1, 1969