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Upgrading of MgO in Dolomite Ore by Froth Flotation

Sep 13, 2010

The Cooperative Research Centres (CRC) Program was established and is supported by the Australian Government at a total cost of $140 million per year. Six of these centres have been established to help Australia's mineral industry: three in exploration, one in mining and mineral processing and two in extractive metallurgy. Since the CRC Program has now been in operation for five years, it is a good time to ask whether the minerals industry is being served adequately by these centres. In this paper, the performance of one CRC, namely the A J Parker Cooperative Research Centre for Hydrometallurgy, will be discussed in terms of the objectives of the CRC Program. As will be shown, the Parker Centre has made considerable progress since its establishment in 1992.

Jan 1, 1996

By Eggleton T, Taylor G

The lateral and vertical distributions of gold and a wide range of other elements in the regolith, close to Au and Cu mineralisation have been investigated at Goonumbla, NSW. Open cut mining has exposed deeply weathered profiles which have been used for this investigation. Determination of secondary mineralogy and micromorphology of profiles have facilitated the broad interpretation of processes that determine element mobility and dispersion from primary mineralisation as a result of weathering. This in turn has led to better interpretation of geochemical data and enhanced understanding and knowledge of regolith geochemical processes which are invaluable in the formulation of improved exploration Procedures.

Jan 1, 1997

By A Turichshev

The synthetic rock mass (SRM) approach for modelling jointed and veined rock has been at the forefront of caving geomechanics research for years. A well-constructed and calibrated SRM model can capture the full rock behaviour at a macroscopic scale. Traditionally, SRM technology employed bonded particle models (BPM) due to their ability to model rock’s response to loading without prior specification of behaviour. The SRM modelling process requires the BPM to simulate intact rock and the subsequent introduction of fractures or veins by changing bonding characteristics between the particles. However, bonded particle materials have difficulty reproducing both the compressive and tensile strengths of intact rock. This and other limitations of BPM have been the driving force in exploring the potential of grain-based (2D) and bonded block (3D) models (BBM).This paper reports on recent work exploring the applicability of both BPMs and BBMs in 3D to the modelling of intact rock. The advantages and limitations of both BPMs and BBMs are addressed based on the results of numerical simulations using the PFC3D and 3DEC distinct element codes. The preliminary results suggest that BBMs are better suited for simulating intact rock behaviour than BPMs. Ongoing work aims to better qualify the applicability of BBMs under different conditions. This has significant implications for our understanding of rock mass behaviour in a caving environment.CITATION:Turichshev, A and Hadjigeorgiou, J, 2016. Simulating intact rock behaviour using bonded particle and bonded block models, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 453–460 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

In a previous study, various pyrite depressants were examined to improve the flotation performance of a copper-sulfide ore. Optimal results from this study were used to examine the effect of elevation on recovery and grade. Tests were conducted at elevations of 3350, 1735, 610 and -760 metres, consisted of five repetitive experiments for statistical analysis, and were performed both with and without airflow control. Tests were also performed in a glove box at Montana Tech to mimic the pressure conditions. Results indicate that both recovery and grade are dependent on pressure via bubble size and airflow suggesting that pressurised flotation cells should be considered for operations, particularly those at high elevation. Economics are extremely favourable for implementation because ensuing capital expenses are inconsequential with minimal time for return-on-investment.

Jan 1, 2005

By Noller B. N, Mine F. J

Modem open cut and underground mining in the tropics inevitably expose partially weathered and unweathered rocks to oxygen and water, leading to weathering and the release of solutes and often acidity as well. Historical monitoring data can demonstrate these phenomena. Three case studies from open cut mines in the north of the Northern Territory illustrate the deterioration in quality of pond water receiving drainage from waste rock dumps. The potential for deterioration of water quality was not recognised in many mine Environmental Impact Statements prepared and accepted in the 1980s. The examples documented indicate the importance of adequately planning for this near inevitable process. Retrofitting a mine water management system to 'no' or minimal release can be very difficult and expensive, and may not be feasible, leading to downstream pollution. The characterisation of acid and solute production potential of ore and waste rock, and improved dumping strategies and water management are very important to minimise the environmental impact of mining in the tropics.

Jan 1, 1994

By Kobe HW, Balance PF, Black PM, Sporli KB, Smith IEM, Locke CA

The Hauraki Goldfield consists of a large number of volcanic-associated epithermal gold deposits within the Coromandel Volcanic Zone (CVZ), North Island , New Zealand; it is the most accessible and most studied of the Southwest Pacific gold regions. The deposits occur generally as steeply dipping quartz veins and breccia sheets in faults and fractures.From a tectonic perspective, the CVZ is generally considered a Neogene convergent volcanic arc constructed under an extensional tectonic regime; the common tectonic setting for epithermal mineralisation. The gold deposits are mostly hosted in subaerial andesitic arc-type volcanic rocks. Temporally, however, mineralisation is associated with rhyolitic rocks of a bimodal volcanic suite that may represent a back-arc environment. Rifting and calderas may be important components of the latter regime, but this is not yet clear; the general structural framework controlling the location of CVZ gold deposits remains poorly understood. Geophysics, particularly aeromagnetics, has a role in mapping regional fault patterns in the CVZ

Jan 1, 1990

By J Manuel, N Ware

Ideal iron ore sinter is produced by optimising the balance between coarse (+2 mm), stable ore nuclei and a reactive matrix consisting largely of fluxed -1 mm fines. The authors have previously published work evaluating the matrix melting behaviour of a number of fine ores, using techniques developed by CSIRO. The focus of that work was to demonstrate the contribution of the matrix to overall sinter quality, with the results showing a direct correlation between melting point, matrix porosity and strength. CSIRO has also developed a complementary test to study the behaviour of coarse ore nucleus particles in contact with the sinter matrix and provide an evaluation of their reaction and assimilation properties. This test provides valuable fundamental information that can be used to better understand the role of specific ore types and optimise blend composition.The CSIRO laboratory-scale assimilation test is carried out by embedding particles of ores of specific sizes into a fluxed matrix of known sinter blend composition, using real ores and fluxes, in a laboratory test that directly relates to pot-grate and plant sintering conditions. Samples are fired under controlled conditions in a tube furnace using a standard heating profile and a constant, low-oxygen potential atmosphere. These conditions simulate the actual sintering process while removing the effects of the many locally-variable parameters (eg temperature, oxidation potential and localised chemistry) that exist in the actual process, meaning that trends in behaviour can be more clearly seen. Designed as a compromise between the industry-standard pot-grate sintering test and a more fundamental test using chemical reagents, the aim is to isolate and evaluate the nucleus behaviour of an individual blend component to allow an improved understanding of the role that an individual ore plays in a specific blend. Measured cross-sections of the resulting fired samples provide a semi-quantitative measure of reactivity, while accompanying photomicrographs allow a qualitative assessment of assimilation properties (eg volume and distribution of secondary porosity generated during reaction).In this paper, to complement the previous work published on melting behaviour, nucleus particles were selected from hematite, hematite-goethite and goethite ores and embedded in a simulated plant sinter matrix. Drilled core particles of two sizes were tested at fixed temperatures simulating low- (<1300°C) and high-temperature (>1300°C) sintering conditions. The resulting assimilation properties are compared and discussed as a function of particle size, temperature and ore/sinter mineralogy. The implications for the contribution of each component to the prediction of blend sinter quality are also discussed.CITATION:Ware, N and Manuel, J, 2015. Fundamental nucleus assimilation behaviour of hematite- and goethite-containing ores in iron ore sintering, in Proceedings Iron Ore 2015, pp 77–82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

High pressure (-1.2 GPa) Early Cretaceous granulite facies orthogneisses in Fiordland, New Zealand are in tectonic contact with a cover sequence comprising mid-Palaeozoic amphibolite facies metasediments, subordinate metavolcanic rocks and syntectonic granitic orthogneisses. This cover sequence and the underlying granulites constitute upper and lower crustal plates of a mid-Cretaceous metamorphic core complex whose emplacement was linked to continental rifting and the Late Mesozoic breakup of the Pacific margin of Gondwana. Exhumation of the lower plate granulites occurred in two stages. The first stage was associated with extreme attenuationand tectonic denudation of the cover sequence accompanying emplacement of the core complex, leading to rapid uplift of the granulites but without generating the large volumes of Fiordland-derived sedimentary detritus normally expected if uplift and erosion were the only factors involved in unroofing the granulites. Final uplift and exposure of the granulites at the surface occurred mainly during the last 10 Ma in response to transpression across the mid-Tertiary Alpine Fault and/or the obduction of Fiordland continental crust over oceanic crust of the Tasman Sea.

Jan 1, 1990

Maximising margins in today's competitive international commodity markets demands superior productivity. This requires more than selecting the best equipment. It requires continually improving the efficiency of production, commercial, marketing and administrative processes under the control of solid modern management systems.This paper introduces an integrated way of working that includes proven management systems for successfully changing work practices and attitudes, developing managers and increasing accountability. It introduces a proven methodology for systematically involving people in sustained true continuous improvement of processes for maximising productivity, safety and revenue while minimising costs.

Jan 1, 1998

Excavation through fill material in underground metalliferous mines is usually avoided where possible, unlike in Civil Engineering application where excavation through soft ground is normally a matter of course. In the mining situation, where excavation is normally for access only, then excavation designs are engineered for mining in hard rock, except where previous lack of forward planning has made such excavation inevitable or a mining strategy sequence necessitates some mining through fill in order to achieve optimum recovery of ore. Historically, this has been the case, because of the lack of knowledge of the support characteristics of the fill material placed underground and the lack of knowledge of the composition of the fill material as placed. The expertise and experience available from mechanised excavation techniques in Civil Engineering application (shield jacking, forepoling, spiling, and soft tunnel boring, to name a few) are available for application to the underground mining situation if the need ever arises. This paper describes the situations in underground mining development where mining through fill material is required, the different types of fill material encountered and the types of support available

Jan 1, 1981

By L Clarke, R N. Campbell, F Bourke, J Anderson

Lithological units have been classified geotechnically with mechanical tests and discontinuity measurements from the GRD Macraes Limited, Macraes Gold Project and Rotowaro coal mine open pits, New Zealand. Using these measurements slope stability probability classifications (SSPC) have been quantified based on an adaption of Hack's (1998) SSPC system which places less influence on rock quality designation and unconfined compressive strength than previous slope/rock mass rating systems. The Hack weathering susceptibility rating has been modified by using the chemical index of alteration values from XRF major element analysis. Slaking and weathering is an important parameter in slope stability in the Waikato Coal Measures and Otago schist lithologies and hence a non-subjective method of assessing slaking/weathering in relation to the chemical index of alteration has been introduced. Other major components of this adapted SSPC system are the inclusion of rock moisture content and rock strength anisotropy effects on slope stability. This paper explains the systematic approach of using the adapted SSPC system to classify slope stability probability. The main modifications of Hack's SSPC system are the introduction of rock intact strength derived from Mohr-Coulomb failure criteria which has been adapted for varying moisture content, weathering state and confining pressure. It is suggested that the subjectivity in assessing intact rock strength within broad bands in the initial SSPC system is a major weakness of the initial system. Initial comparison of rock mass friction angles, cohesion and strengths derived from the adapted SSPC are compared with results derived from modified Hoek-Brown criteria, MRMR and SMR classification systems. The advantage of the modified SSPC system is that slope stability probability, maximum batter and overall slope height and overall slope angle for open pit walls can be predicted in addition to orientation dependent and orientation independent stability. Examples are provided, using the modified SSPC system to predict initial optimum pit slope designs in proposed greenfield mine sites.

Jan 1, 2000

By Groudeva VI

The biohydrometallurgy of gold is based on different processes which could be grouped into four main groups (Attia, Litchfield and Vaaler, 1985; Karavaiko et al, 1988; Groudev, 1990): 1. bacterial oxidation of gold-bearing sulphide minerals by chemolithotrophic bacteria to facilitate the subsequent chemical extraction of gold; 2. solubilisation of gold from oxide ores by means of heterotrophic bacteria; 3. recovery of gold from solutions by biosorption; and 4. microbial modifications of the surface of gold-bearing sulphide minerals to improve the subsequent gold concentration by physical dressing methods (eg flotation, oil agglomeration).

Jan 1, 1993

China has large amounts of iron ore reserves, but iron ore in China, with low-grade, small disseminated particles and many other associated minerals, is difficult to dress. In recent years, with the fast development of China's steel industry, the demand for iron ore has increased markedly. The new technologies in iron ore dressing in China are very effective in processing haematite and other difficult to dress iron ores. The iron ore grade and recovery rate has been improved. This result alleviates the difficulty in iron ore supply in China.

Jan 1, 2007

Knelson concentrators are commonly used to recover fine liberated gold in gold processing plants. The decision to employ a gravity gold circuit consisting of centrifugal devices such as Knelsons is primarily taken on the results of GRG tests, among other considerations. While the GRG test is considered a material characterisation test, which is useful in the design stages, its use in evaluating the performance of an existing unit is questionable. The problem is exacerbated by the fact that it is time consuming and costly. This paper examines the validity of the GRG test for performance evaluation and discusses alternative test work that can be performed to evaluate the performance characteristics of an operating machine. Principles that are useful in selecting optimal operating parameters, such as optimal fluidising water flow rate for a given ore/machine combination, are also discussed and illustrated with laboratory and plant data.

Jan 1, 2007

By Wilson T, Stone M, Mattiazzo R

The regulation of environmental management in the minerals and petroleum industries has been undergoing considerable change over the past decade. In recent years, there has been a distinct trend towards smaller government and increased environmental awareness. Current regulatory systems have generally neither responded to these trends nor effectively dealt with the demands placed on them. There is a need to develop a more effective means of providing assurance to Government and the community that its environmental objectives are being met. These means must also enable industry to have an effective environmental management process.

Jan 1, 1993

By A E. C Peres, P R. M Viana

The role of flotation columns in comparison with conventional mechanical flotation cells is discussed under the scenario of Brazilian flotation technology. All iron ore concentrator circuits commissioned since 1990 incorporated column only flotation technology in rougher, cleaner, scavenger configuration. Columns were also added to existing circuits, especially at the cleaner stage. Columns were also incorporated to phosphate ore flotation circuits operating mechanical cells. In two phosphate concentrators, columns substituted for all mechanical cells. Columns perform the cleaning stage in a large sulfide copper concentrator, following rougher flotation in tank cells. Scavenger of the cleaner tailings is performed in tank cells at this plant. Other ores that are concentrated in flotation columns include graphite, talc, lead-zinc sulfide, and a zinc hydrometallurgical residue for silver recovery.

Jan 1, 2005

The first stage in process design for coal preparation is a study of the coal seam and its associated features followed by an examination of the mining method to.be employed and the coal market requirements. Normally benefication is based upon the differences in relative densities of the coal constituents and asso- ciated ash forming components. Since initial liberation is obtained at a relatively large particle size, the size to which coal is crushed is more subject to the market requirements than to liberation studies. It is possible to estimate energy requirements for comminution and recoveries and product grades can be cal- culated following the interpretation of standard laboratory tests. Numerous units are available for the separation and concentration of the components of run of mine coal in- cluding jigging, dense media separators, and for the finer particle size fractions, flowing film separators, dense media cyclones and froth flotation.

Jan 1, 1975

By R Forster

Direct ship iron ore (DSO) operations at Extension Hill in Western Australia’s Midwest region have commenced, with fi rst product railed to the port of Geraldton in July 2011. Reserves are 14.8 million tonnes (Mt) of haematite-goethite ore overlying an Archaean BIF-hosted larger magnetite deposit which Mount Gibson Iron Limited (MGI) sold to other parties in 2006.Some unique geological aspects of the deposit shape DSO mining and processing operations. Owner-operator selective mining, blending, crushing and screening on site will produce three million tonnes per year (Mt/a) of Lump and Fines product to be trucked 86 km to Perenjori, railed 232 km to Geraldton, and loaded aboard Panamax-sized ships through the dedicated iron ore shiploader at the Geraldton Port Authority’s Berth 5 facility.The statutory approvals process for this project formally began in 2004, dominating delays in a predevelopment phase which extended over a longer period than the likely life of DSO operations. The lack of transparency, uncertainties and costs inherent in state government processes have influenced decisions made by MGI while assessing other development opportunities in Western Australia. Potential for additional Reserves exists at Extension Hill, however MGI’s ability to extend the mine life will hinge on statutory approval to explore for and evaluate other DSO resources on surrounding granted mining leases.The nature of the resource and use of existing infrastructure for product transport have enabled MGI to keep operating costs and capital intensity of this project relatively low. A tenacious development approach by MGI and robust project economics have fi nally enabled this site to take its place as a revenue earner beside the company’s other DSO operations at Tallering Peak and Koolan Island.

Jul 11, 2011

By Ramani R. V

In this paper, a comparative performance evaluation of geostatistical, spectral, and fractal methods is made for short-scale variability prediction. The algorithms compared are: sequential Gaussian simulation method; a random fractal algorithm based on the generalised stochastic subdivision method; and a spectral simulation approach adopted for direct multi-dimensional simulation. The data for this study have been obtained from a mined out coal property. As this property was being mined, a 7315 m by 7315 m (24000 ft by 24000 ft) coal block was extensively sampled at an approximate spacing of 107 m (350 ft) and the 60-ton samples were analysed for sulphur in the 1.50 float gravity fraction. This data set is used here with the three methods to generate the simulated realisations, which are analysed for semivariogram reproduction and for simulation errors. Although all three methods converge to the true semivariogram in an average sense, the coefficient of variation of the average semivariogram for the Fourier integral method is minimum. The realisations generated by the sequential Gaussian method have minimum mean simulation error. The choice of a simulation method based on variability reproduction and simulation errors remains difficult.

Jan 1, 1995