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By C Tukel

Copper sulfate is traditionally used to activate various types of sulfide minerals. The list of users includes Falconbridge Sudbury operations, where copper sulfate solution is added to the pyrrhotite/pentlandite middlings at the scavenging stage. Results from some batch tests reported in the literature suggested that copper activation is helpful for the improvement of pentlandite recovery, especially in the difficult to float fine particle range. Any improvement in pentlandite recovery is important since it is the main nickel bearing sulfide mineral. The impact of copper sulfate for this function has been investigated. Since the focus of current investigation was the flotation behaviour of minerals at the scavenger stage, rougher flotation was kept as constant as possible at two different weight recoveries, namely 13.2 per cent and 15.5 per cent that is relevant to industrial practice. Samples taken during batch testing were extracted using DETA and flotation products from selected tests were analysed to determine the recovery by size behaviour in relation to the use of copper sulfate. Results provide significant evidence that the addition of copper sulfate to these middlings does not yield greater nickel recovery, either on an overall or specific particle size basis. It is concluded that copper sulfate is wasted in the process and that self activation behaviour of the ore at a slightly reduced pH is sufficiently significant to maintain the scavenger recovery of pyrrhotite and pentlandite at desirable levels. Results obtained from limited circuit trials have shown supporting evidence for this conclusion.

Jan 1, 2005

By K Edwards, A J. J Mouton

Hematite represents the vast majority of iron ore exported from Australia as the development and processing cost of magnetite is generally seen as a barrier to the development of vast magnetite resources. However, a number of magnetite projects have attracted a significant amount of interest and investment from large Chinese steelmakers.This paper compares the relative merits of the development of Australian magnetite and hematite ore from the point of view of the steelmaker, taking into account the factors that influence the capital costs of the development of the ore types and the relative costs of operating the process plants to treat these ores. By modelling the relative operating cost for the production of hot rolled coil in China for the two ore categories, the paper demonstrates the economic drivers behind the Chinese steelmakers’ large investments in the magnetite resources of Western Australia. It does this by estimating the potential value of magnetite concentrate to the steelmaker in the event that the maximum potential is realised by operating the blast furnace with a 100 per cent pellet burden.Under the conditions described, it was found that direct reduction (DR)-grade magnetite concentrate could command a price premium over 62 per cent Fe fines of up to 46 per cent (December 2014 on a cost and freight (CFR) basis). The corresponding premium for blast furnace (BF)-grade magnetite concentrate is 17 per cent, which demonstrates the dependency on grade.The capital expenses for a 14 Mt/a concentrate plant is estimated at US$3.1 B for BF-grade magnetite and US$3.35 B for DR-grade, with operating expenses at US$45 and US$50 respectively. The corresponding free on board price for a break-even net present value is calculated at US$82/t for BF-grade magnetite and US$90/t for DR-grade. The minimum long-term iron ore price (62 per cent Fe) that would be required to underpin such a project is estimated at US$78/t CFR for BF-grade magnetite and US$68/t CFR for DR-grade concentrate.Apart from the financial benefits, it is demonstrated that the use of magnetite concentrate in ironmaking has the potential to reduce CO2 emissions by approximately 400 kg per tonne of hot rolled coil.CITATION:Mouton, A J J and Edwards, K, 2015. Magnetite – a higher-grade blast furnace feed and its potential benefits for the ironmaker, in Proceedings Iron Ore 2015, pp 613–620 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

The Mt Sinivit gold project is located approximately 50km SSW of Rabaul in the Baining Mountains of the Gazelle Peninsula, East New Britain Province. The deposits were discovered in mid- 1983 and form part of a larger 26km long zone of variably aurif- erous quartz veining. There are no surface indications or previ- ous records of any prospecting activity or production from the region. The Mt Sinivit deposits consist of a series of oxide and sulphide reserves and resources contained in the Wild Dog (South- ern, Central and Northern oxide zones; Northern sulphide zone) and Kavursuki veins. The proposed exploitation of the oxide reserves by a series of small-medium sized open pits has been fostered by the PNG Department of Mining & Petroleum (DMP) as part of a government policy to encourage the development of a small-medium sized mining industry in the country. The aim of this paper is to document the steps and procedures involved in obtaining the grant of a Mining Lease emphasising the time and the expenditures required during each step of the approvals process for the Mt Sinivit project.

Jan 1, 1997

The paper reviews recent valuations of mineral properties, many of which are at an early stage of exploration. The various methods used are outlined. The problem of comparing, in terms of whether it is fair and reasonable, a highly subjective opinion of the present value of a portfolio of exploration tenements with a vendor consideration, the real value of which, in most cases, lies at some indeterminate time in the future because of the application by the Australian Stock Exchange (ASX) of escrow conditions, is highlighted. Examples are given of some of the questionable logic used by consultants in handling this difficult issue. A proposal for revision to current flotation and listing practice which, the author believes, would circumvent the problem and at the same time provide better protection for the investing public is offered for Consideration.

Jan 1, 1994

We operate a 50 cubic metre per hour mobile alluvial tin mine on small scattered deposits in the Irvinebank area. Wash is loaded by a Cat. 950 front end loader into the bin of a screening section and screen undersize is pumped to a separate jig unit. Both units are rubber tyre mounted and are shifted once a month when the haul distance gets to about 150 metres. The shift takes about 8 hours.The screening section is sited close to the face with a ramp for dumping in and a one metre drop for the screen oversize which is removed by the loader.A reciprocating plate feeder with variable rate hydraulic drive, feeds wash onto a horizontal 1.2 metre x 2.2 metre two deck Kinergy screen. Minus 10 millimetre undersize is pumped by a Warman 6/4 sand pump with a 37 kW variable speed Reeves Motordrive to the jig unit.The jigs are placed 20 to 70 metres away so that tailings will run back into previously mined ground. Reject stone is used to impound the sand and mud, allowing the water to filter through and return to the feed water pump.An MTE trapezoidal module is used as a primary jig. Hutch product is pumped to an eight cell clean-up jig which we developed ourselves along MTE lines. It has a trapezoidal shape and sawtooth stroke provided by cams. Clean tin is taken from the first four spigots. These consist of clear plastic tubes fitted with taps so that there is no water loss except when the tin is drawn off. Fine concentrate from the last four spigots is put over a curvilinear table which sits on a steel base packed with earth.

Jan 1, 1986

A series of petrological studies were carried out on the characteristics of alteration and mineralisation in mainly structural-controlled (Deep Star, Meikle, Deep Post) and predominantly lithological-controlled (Post-Betze-Screamer and West Leeville) gold deposits in the northern district of the Carlin trend, Nevada. Alteration and mineralisation in these deposits are hosted in a sequence of calcareous clastic units of the Devonian Popovich Formation, into which have been emplaced a number of Jurassic intrusions, and syn- to post-mineral Eocene dikes. Four hydrothermal events have been recognised in these deposits: an initial Devonian base metal system and early diagenesis; a Mississippian stage of alteration in conjunction with burial metamorphism; contact and hydrothermal alteration and base metal-gold mineralisation associated with the emplacement of the Jurassic intrusions; and a Carlin-style gold system related to Eocene magmatism.

Jan 1, 2004

By S C. Dominy

Grade control programs aim to deliver economic tonnes to the mill via accurate definition of ore and waste. The foundation of a successful program is high quality sampling supported by geology and a suitable data management and modelling system. Underground sampling methods include chip, channel and panel samples; grab/muck pile samples; and drill-based samples. Grade control strategy is related to mining method and orebody type. Sampling protocols must be designed to suit the style of mineralisation in question. Holistic studies focussing on ore mineralogy and gold particle deportment, size and distribution are required for sample collection and preparation protocol optimisation through ‘Theory of Sampling’ application. Where possible, such programs should be undertaken early in the life of a project. Appropriate assaying procedures are also required. Program implementation will require suitably skilled individuals to train and mentor staff, with ongoing Quality Assurance/Quality Control (QA/QC) monitoring and review will allow protocols and staff to be updated as required.

Aug 22, 2011

By E de Necker, F D. I Hodg, L-M Cruywagen

The acid mine drainage (AMD) situation at three opencast collieries in the Witbank Coalfield, South Africa, was evaluated from different perspectives. Twenty-seven test pits were dug into the spoils of these collieries to characterise the in situ conditions of spoils of varying age. Detailed static testing was done on surrounding drill holes and additional samples were taken from the test pits. Selected samples were tested using different techniques, namely ABA, mineralogy and kinetic tests. Groundwater monitoring boreholes from the areas surrounding these spoils were also used for characterisation. The ABA results compared favourably with the in situ determinations; acidic test pits proved to be potentially acid-generating from ABA, even when the samples had neutral paste pH. Kinetic test results showed these samples to yield low pH leachate over the test period. In several of these results, the theoretical depletion of neutralising potential and the onset of acidity were well matched. NAG pH-values and final observed water chemistry corresponded for the cells predicted by ABA to acidify, but compared poorly in cells that did not acidify. Results from the non-acidic spoils were consistent with the in situ observations. Alternative kinetic test methodologies were also employed. Duplicate samples were tested in humidity cells and in aerated trays that were manually wetted on a regular basis. Results from these tests showed an excellent correlation. Detailed mineralogical determinations using XRD and XRF were used for comparison to the ABA and, in some cases, humidity cell results. These comparisons show that the ABA results are consistent with the results expected from the mineralogy. The conclusion from these assessments is that ABA, in most cases, provides information that can be correlated to the field, mineralogy and to humidity cells. The use of multiple techniques leads to a higher degree of confidence in the use of the data.

Jan 1, 2003

By K Aikawa, M Ito, K Mitsuhashi, Y Ebisu, J V. Satur, I Park, N Hiroyoshi, T Suto

Copper concentration using flotation is becoming more difficult, because of an increase in ore complexity accompanied by smaller grain sizes of copper minerals than usual, requiring finer grinding in order to liberate them. Project Arqueros, located at the mid northern part of Chile, is a copper mine project with an orebody consisting of various sulfides such as chalcopyrite, chalcocite, and bornite. Some of the copper minerals in Arqueros show low floatability mainly because of their fine grain size and resulted fine grinding size, and also because of the complex mineralogical composition. For example, chalcopyrite in Arqueros floats less than the other copper sulfide minerals. In this study we carried out some kinetic flotation tests with the Arqueros ore using a laboratory-scale forced air type flotation machine by varying the regrinding size. The products were assayed and mineralogically analysed to compare the minerals in their flotation behaviour with respect to size classes and liberation classes. The results were compared with a model calculation according to bubble size measurement. From the flotation testing and mineralogical analysis, it was found that copper minerals of the same size and liberation class floated at the same rate even with different regrinding size. At the same time the comparison between experiment and calculation showed that the fine particles of less than 5 µm size floated faster in actual than in the model applied. These results suggested that interactions among minerals of different species and of different sizes had positive impacts on the flotation rate of the fine particles. It indicates that this phenomenon can be applied to improve copper recovery in the project.

Aug 24, 2022

By J Manuel, A Trudu

Regulations on the emission of particulates from sinter plant stacks are becoming increasingly stringent and reducing these emissions by improving gas cleaning systems is a significant cost to the sinter plants. This paper describes an investigation into the emission of particulate matter from an iron ore sinter bed during the sintering of a Japanese Steel Mill (JSM) style ore blend in a 300 mm diameter pot grate test facility. Several techniques were trialled to determine a reliable method to sample the quantity of dust emitted and determine the mechanism of dust emission from the sinter bed. The nature of the dust was also examined using chemical and size analysis as well as optical and scanning electron microscopy. The paper discusses the techniques used to carry out the program as well as results on dust loading measured during sintering and the nature of the dust captured.

Jan 1, 2002

By Zani J. A, Jackson W. D

Bauxite was discovered in the Kimberley in 1965 by an Amax field crew. Reserves of 230 million tons, of bauxite. averaging 47% total alumina on Mitchell Plateau and 980 million tons averaging 36% total alumina on Cape Bougainville have been indicated by the results of drilling and bulk sampling. Laterite which contains the bauxite deposits caps basalt and interbedded sandstone and siltstone of the Carson Volcanics formation. Bauxite on Mitchell Plateau is 3.2 metres thick on average and is underlain successively by nodular ironstone, clay and basalt. The major components of the bauxite are gibbsite,boehmite, hematite and goethite containing some alumina, anatase and clay minerals. Quartz and vanadium oxide are minor constituents. Boehmite and hematite are concentrated near the surface, whereas gibbsite and goethite predominate at depth. The bauxite profile consists of ferru- ginous, pisolitic and gibbsitic zones with increasing depth. Cape Bougainville bauxite is 8.6 metres thick on average and of tubular structure; its mineralogy is relatively uniform..

Jan 1, 1973

By P K. Banerjee, S Kumar

Indian iron ores with less than 62 per cent Fe are currently unexploited, except for a few sectors which export them to foreign countries. It is anticipated that by 2012 the countryÆs domestic steel production is likely to rise to the tune of 60 million tonnes per annum. To meet this requirement, it is necessary to utilise not only the existing high-grade deposits but it is also necessary to look into exploiting the leftover iron ores of lower grades. Hence, reserves with Fe content 62 per cent and below (particularly the ores with In the present paper, an attempt has been made to beneficiate three different types of low-grade iron ores selected from three different parts (states) of the country. In the paper, alternative routes for beneficiation and effective utilisation have been tested using different techniques in the laboratory in an attempt to match their (Al2O3/SiO2) ratio after thorough characterisation and liberation studies. The paper also encompasses the geological formations, occurrences and distribution of Indian iron ores as well as highlighting the problems associated with the fines, possible metallurgical routes, and their market segregation from the perspective of end users.

Jan 1, 2007

By A C. Edwards

The Mesozoides of North-Eastern Asia represent a collage of exotic terranes which were accreted to the margins of the Siberian continent. In the Late Precambrian and Phanerozoic, the passive margin of the Siberian continent (the current north-east) broke up into a number of discrete fragments as a result of rifting events in the Riphean, Early and Middle Paleozoic. Rift related mineralisation includes stratiform and stratabound copper and base metal mineralisation in the structures of the Omulevka, Okhotsk and Prikolyma basement terranes, as well as along the edge of the Siberian continent in the Paleozoic sediments of the Verkhoyansk passive margin. During the Late Mesozoic the terranes were reassembled in a series of accretionary events. At the end of the Jurassic, the velocity of the Kula plate increased, and the opening of the Canadian Basin in the Arctic commenced, changing the vectors along which the Siberian and North American plates moved. Island arcs terranes were pushed back onto the Omolon super-terrane which was in turn pushed onto the Siberian Craton in a series of massive collisional events that resulted in the restructuring of the whole region. Numerous granitoids characterised by collisional and island arc chemistries with Au and accompanying Sn, and W mineralisation were emplaced. Mesothermal gold-quartz mineralisation was emplaced in a series of narrow belts that adjoin major crustal sutures and that spatially overlap belts of granitoids and zones of subgreenschist metamorphism. Each of these gold-quartz vein belts corresponds with a specific collisional phase. In the middle Cretaceous, the Okhotsk-Chukotka volcanic belt developed along the paleo-Pacific margin of the Siberian continent. Epithermal Au-Ag developed in the volcanics and shallow mesothermal Au-Ag-quartz and Au-Sb mineralisation developed in the Mesozoides. Porphyry and skarn style mineralisation developed in both the island arcs and in the continental Okhotsk-Chukotka Volcanic Belt.

Jan 1, 1999

By L B. Zhou, S Li, B L. Wang, S B. Li, Q Wang

The rapid development in ChinaÆs metal mine resources has caused a series of mine environment problems such as serious ecological damage and environment pollution, and secondary geological disasters. The paper has reviewed ChinaÆs metal mine development, including current status and environmental situation, analysed existing problems in mine development and environmental management, and proposed corresponding countermeasures and suggestions.CITATION:Wang, B L, Li, S B, Li, S, Zhou, L B and Wang, Q, 2012. Current situations, problems, countermeasures and suggestions for ChinaÆs metal mine development, in Proceedings Life-of-Mine 2012 , pp 353-356 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By M G. Shaw, M A. Rhamdhani, S P. Singh, A R. Duffy, B Eisenbart, A K. Shukla, G A. Brooks

The field of astrometallurgy is a growing area of study. Metal production on the Moon is likely to begin in less than a decade as major space agencies such as NASA (National Aeronautics and Space Administration) and CNSA (China National Space Administration) are preparing to construct permanent lunar bases. The utilisation of regolith to generate oxygen and metals is expected to be important in the development of a sustainable lunar habitat. This paper provides an overview of potential metallurgical processing methods for lunar conditions, emphasising the impact of lunar factors on slag chemistry. The interaction between regolith and the extracted metals, as well as their impact on slag composition and refractory performance, are critical considerations in metal production on the lunar surface. The initial research on lunar metallurgical technologies is focused on oxygen extraction and Fe-Si alloys are reported as the by-products of these processes. This paper delves into the fundamental thermodynamics associated with the carbothermic reduction of lunar regolith. Thermodynamic analysis using the FactSage™ ver 8.2 software package indicates that the Fe-Si alloy can be produced as a metallic product from the lunar regolith at temperatures ranging from 1400°C to 1600°C under terrestrial conditions. However, under ultra-high vacuum conditions (3 × 10-15 bar) on the Moon, the required operating temperature for producing ferrosilicon would be significantly reduced. Thermodynamic modelling results indicate that under lunar vacuum conditions, Fe-Si alloys only exist as solid phases at lower temperatures below 650°C. At higher temperatures, both Fe and Si are expected to be present in the gas phase. In this work, the carbothermic reduction of the Lunar Mare Simulant (LMS-1) is conducted under terrestrial conditions. The findings indicate that the process can readily yield Fe-Si alloys with 7–10 wt per cent Si at 1600°C. Additionally, energy dispersive spectroscopy (EDS) analysis of the resulting Fe-Si alloy indicates the presence of phosphorus up to 1 wt per cent.

Aug 21, 2024

By P Collins, C Sheriff

The Sand Queen gold mine is a typical Archaean narrow, high-grade gold quartz lode deposit within a shear hosted system. Initial mining during 1904 - 1948 produced 181 659 ounces of gold from 248 564 tonnes of ore milled at an average production grade of 22.7 g/t Au, which equates to a minimum of 750 ounces per vertical metre. The current mining operation is using the old Sand Queen main shaft to access the Sand George deposit, which is a narrow quartz lode system discovered in the same shear structure along strike to the south of the Sand Queen mine workings. Current underground resources contain 360 200 tonnes at a grade of 11.8 g/t Au for 136 500 ounces. Mining is scheduled to produce 20 000 ounces of gold annually. Re-opening of the Sand Queen mine and underground development of the Sand George lodes has revived several grade control issues relevant to a narrow, ænuggettyÆ gold lode mining environment. These include the dependence of assay grade of individual samples upon a number of factors, including how and where a sample is collected, how and where it is analysed, and how grade data is used to estimate an æaverageÆ grade. Ideally, the only way to achieve an acceptable estimate of ætrue gradeÆ is to mine and mill a large parcel of ore (eg >100 tonnes) from each lode or ore type. In a mining operation producing relatively small tonnages from a number of separate ænuggettyÆ gold lodes, availability of resources and operational constraints may preclude intensive sampling for predictive grade control. At the Sand Queen mine, one of the key issues has been to establish a reliable system for estimation of gold grade with which to reconcile milling data. Extensive use has been made of detailed geological data to understand the grade distribution within individual lodes and between lodes, so as not to rely solely on assay results.

Jan 1, 2008

By Savidis G

The characteristics of 'Z' (Back-over run) and 'R' (Reverse) ventilation systems are dis- cussed in relation to their suitability for longwall mining. Experience in European mines has been described as a basis for comparison with Australian conditions. In assessing the merits of each ventilat- ion system, such factors as longwall layout (pillar design, number of headings and gateroad stability), the need for gas drainage and bleed- er systems, as well as the influence of seam dip have been considered relevant. The R system is generally applicable for single and two heading development in seams where gas emission is a less serious problem. In contrast, the lower extraction to development ratio of the Z system (which arises from using three or more heading layouts) is considered more favourable where high gas emission occurs. The Z system provides greater flexibility with respect to the provision of refreshing air at the tailgate end, access of men and materials, installation and retrieval of gas drainage systems and the ability to interchange main- gate and tailgate roadways in cases where roof strata loads are difficult to control, or where cpam in hac an influrnra

Jan 1, 1983

By M Berndt

Four siltite-argillite rock samples were characterised (particle size, chemistry, mineralogy) and subjected to laboratory dissolution testing for 36 to 298 weeks. In two samples sulfur (0.99, 1.69 wt per cent) occurred largely as pyrite, and in the other two samples sulfur (0.96, 1.93 wt per cent) occurred predominately as potassium jarosite. The observed rate of sulfate release from the pyritic samples was one to two orders of magnitude greater than that from samples containing potassium jarosite. Drainage pH values from the pyritic samples were one to two units lower and acidities were ten to 70 times higher than associated values from the potassium jarosite samples. Geochemical modelling supported the hypothesis that pH and concentrations of sulfate and potassium in drainage from the potassium jarosite samples were controlled by the limited solubility of potassium jarosite. This dissolution produced an iron-dominated mineral phase, but iron concentrations in the drainage were well below those predicted by ferrihydrite solubility.

Jan 1, 2003

By R-H Yoon

A turbulent flotation model has been developed by considering the subprocesses of collision, attachment, detachment, and froth recovery. AbrahamsonÆs model (1975) of infinite Stokes number is used to model collision, while the attachment and detachment subprocesses are modelled by considering the kinetic energies required to overcome the energy barriers and the work of adhesion, respectively. The energy barriers are determined by considering various surface forces, including electrostatic, dispersion and hydrophobic forces, while the kinetic energies are determined from the particle velocities at close separation distances from air bubbles. The latter has been determined by modifying the turbulent root-mean-square (RMS) velocities of Liepe and Moeckel (1976) and Schubert (1999) in view of a lubrication theory. In calculating the RMS velocities, it is assumed that a flotation cell is subdivided into low and high energy dissipation zones. The model predictions made by varying various hydrodynamic and surface chemistry parameters are consistent with flotation practice.

Jan 1, 2005

By T Raynlyn, S Hapugoda, V Nunna

The predominant phase in most Marra Mamba, channel iron deposits and detrital iron ore deposits is goethite. Goethite abundant iron ore fines tend to have complex mineralogical associations and fine dissemination of gangue material. These ores are typically challenging to process using conventional beneficiation methods. With declining ore grades, there is a need to develop new processing routes for low-grade goethitic ores/fines.Comparative process amenability studies were carried out using two different processing options to recover iron with low alumina and silica content from a low-grade goethite-abundant iron ore fines (-2 mm) sample from the Pilbara region of Western Australia. The first option involved dehydroxylation at 350°C and 400°C, followed by grinding dehydroxylated samples to 100 per cent passing 106 µm and magnetic separation. The second option was processing raw sample by gravity separation using a Floatex density separator. The performances of the two processes are discussed in terms of the iron grade-recovery responses, and an optimal processing route is proposed based on the findings from these tests.CITATION:Nunna, V, Hapugoda, S and Raynlyn, T, 2015. Process amenability studies on goethite-abundant iron ore fines, in Proceedings Iron Ore 2015, pp 165–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015