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By Kelly GD

Prior to 1986, users of satellite based remotely sensed data were almost exclusively reliant on the United States Landsat series of satellites to monitor our Earth's resources. This situation changed when France, Belgium and Sweden launched SPOT-1 in 1986. The year of 1988 saw the Japanese also enter into the earth resource satellite business. The Japanese launched an earth resource monitoring satellite with an emphasis on marine resources, hence the name MOS-1 (Marine Observation Satellite). Many more remote sensing instruments are planned for launch by these nations and others in the next 10 years.

Jan 1, 1990

By B G. Lottermoser

Phosphate induced stabilisation has been used to create passive iron phosphate coatings on pyrite and pyrrhotite. The formation of solid phosphate coatings on sulfide grains thereby inhibits sulfide oxidation. The aims of the study were to determine whether phosphate induced stabilisation could control sulfide oxidation and metal mobility in partly oxidised, polymineralic, sulfidic mine wastes. Waste materials were obtained from the acid mine drainage generating, abandoned Montalbion silver mine site, far north Queensland, Australia. The waste consists of quartz, kaolinite/illite, sulfide minerals (galena, chalcopyrite, tetrahedrite, sphalerite, pyrite, arsenopyrite), and pre- and post-mining oxidation products (hydrated Fe, Cu, Pb and alkali mineral salts). SEM observations of waste material treated with potassium orthophosphate showed that metal, metal-alkali and alkali phosphate coatings developed on all sulfides (with the exception of tetrahedrite). The abundance of phosphate phases was dependant on the availability of cations in solution for complexation with the phosphate anion. In turn, the release of cations was dependent on sulfide oxidation or the dissolution of efflorescent mineral salts. Experiments aiming to dissolve these phosphate coatings û using a strongly oxidising solution û showed that the phosphate coatings remained stable, preventing acid generation and metal release. The results of this study demonstrate that liquid phosphate stabilisers can suppress sulfide oxidation and immobilise metals in partly oxidised, polymineralic mine wastes.

Jan 1, 2003

By Stump NW

Until a year ago all isotope on-stream analysis utilised flow cells similar to those designed for conventional X-ray on-stream analysis. These systems incorporated a fairly complex sampling system necessary to present a representa- tive air-free sample of the main process to the flow cell. Maintenance costs and capital costs associated with flow cells and sampling systems have been generally high. Costs can be greatly reduced and reliability greatly increased, by using isotopes incorporated in immersible on-stream analysis probes which actually dip into the main process stream eliminating the need for sampling. A bonus of other advantages associated with immersible probes includes temperature stability and ease of calibration. This paper discusses details and results of the probe systems, justifica- tion for installing on-stream analysis, comparison of conventional X-ray and isotope techniques, and a brief survey of methods of analysis using radio- isotopes in on-stream elemental determinations.

Jan 1, 1971

By J Hadjigeorgiou

Underground mines often rely on ore pass systems to ensure the transport of ore and waste. Consequently, it is important to ensure the smooth operation of such systems. Ore pass degradation that may require rehabilitation results in production delays and high operational costs. The occurrence of hang-ups within an ore pass also leads to disruption of ore production. There are important safety concerns when worker intervention is necessary to re-establish material flow in the ore pass. In order to facilitate the design of ore pass systems, mining operations often rely on past experience, or semi empirical guidelines. This paper describes recent efforts to establish a comprehensive database on current practices; encountered operational problems and solutions in ore pass design in Quebec underground mines.

Jan 1, 2003

The smelting operation associated with the production of aluminium has a voracious appetite for high grade carbon materials. Within the technical parameters of the Hall-Heroult process, the reduction of alumina to one tonne of aluminium results in the consumption of nearly 0.5 tonne of carbon at the anode of an electrolytic cell. This paper reviews the role of carbon and the basic quality requirements of carbon products in the production of aluminium, discusses the effects of certain physical and chemical specifications on smelting and related operations, and examines recent trends in the quality of these raw materials.

Jan 1, 1977

The methods used by the Anglo American Corporation for analysis of long-term metal markets and prices are described. The principal factors affecting the relationships between production costs and metal prices are analysed. These are firstly the type of market, - speculative or consumer commodity, free market or subject to price control; and secondly the rate of growth of demand for the metal. It is shown that virtually all metals will have relatively low rates of demand growth for the foreseeable future, due to market saturation, increased economisation, substitution and product obsolescence. Metal prices have a clear dependance on production costs, however forecasting future costs is by no means simple; amongst other things, account must be taken of changing exchange rates, inflation rates, and the potential for operating more efficiently. The paper concludes by giving brief assessments of the long-term future for aluminium, copper, zinc, nickel and tin.

Jan 1, 1986

Present knowledge of the Pacific floor in- dicates: Postulated subduction zones and/or moving basements overlain by undisturbed sediments. Contiguous mantle convections of conflict ing directions and variable rates. Disharmony between transform faults and mantle convections. =hese features are shown to be difficult to reconcile with conventional hypotheses of sea f 1mr spreading and cast the model into serious doubt.

Jan 1, 1987

By Lo YC, Pate WT

In recent years there has been a great deal of interest in ways to optimise the performance of mineral processing plants. This paper describes a methodology developed for optimisation of autogenous and semiautogenous mills. The methodology involves plant sampling, batch testing, modelling, computer simulation, control strategy evaluation and implementation. The models have been tested in plant operations to verify the research findings and predictions. Two example applications of this approach to plant optimisation are presented. Benefits reported in these two examples are in the range of four - eight per cent increase in size reduction efficiency.

Jan 1, 1993

Iron formation-hosted iron ore deposits account for the majority of current world iron ore production and consist of three classes: unenriched primary iron formation with typically 25 to 45 wt per cent Fe; martite-goethite ore formed by supergene processes, with abundant hydrous iron oxides containing 60 to 63 wt per cent Fe; and high-grade hematite ores thought to be of hypogene or metamorphic origin overprinted by subsequent supergene enrichment with 60 to 68 wt per cent Fe.Individual iron ore deposits range from a few millions of tonnes to over two billion tonnes at >64 wt per cent Fe, although most are within the range of 200 to 500 Mt. In the Hamersley Province of Western Australia, martite-goethite ores are largely developed in the Marra Mamba Iron Formation, although high (>0.08 per cent P) phosphorous mineralisation is also well developed in the stratigraphically higher Brockman Iron Formation. Whilst the vast majority of high-grade microplaty hematite ore is best developed in the Brockman Iron Formation, this paper provides the first textural evidence of locally significant microplaty hematite mineralisation in the Nammuldi Member of the Marra Mamba Iron Formation, in the Chichester Ranges at the Christmas Creek, Cloud Break and Mount Nicholas prospects. Petrographic studies have identified a high-grade Fe texture composed of nanometre scale plates of hematite in mineralised sections of primary microplaty hematite deposits in the Pilbara and elsewhere, well below the normal depth of weathering or dehydration. The population of nanometre to micrometre scale hematite plates is interpreted to represent various stages of nucleation, crystallisation and progressive growth of hematite from the primary ore-forming fluid in areas that were once iron-rich carbonates or silicates in the BIF.

Jan 1, 2005

By Segnit ER, Jensen G

The decoppering of soft and hard leads was investigated by stirring in an open pot, using sulfur or sulfur plus pyrites, or sulfur plus pyrrhotite, as reagents. Lead samples taken during the process were analysed for copper. Dross samples were examined by optical micro- scope, SEM and XRD. Soft lead containing silver can be decoppered satisfactorily by stirring with 0.1% S at low temperatures - close to 330¦C. Soft lead, whether containing silver or not, can be decoppered satisfactorily at higher temperatures by stirring with 0.1% S plus 0.4% pyrites. Then CuFeS2, Cu5FeS4 and PbS are formed, instead of Cu2S, CuS and PbS when using S alone. Hard lead containing tin can be decoppered satisfactorily by stirring with 0.1% S at temperatures from 320-400¦C. When stirring with 0.1% S plus 0.4% pyrites, reversion of copper from dross to lead on prolonged stirring does not occur. Hard lead without tin can be decoppered with S plus pyrites better than with S alone, but the presence of antimony hinders the decoppering, which is less effective on lead with 5.5% Sb than with 2.3% Sb.

Jan 1, 1980

By Dutton D

In the British coal mining industry, during the last decade, a great deal of environmental monitoring experience was acquired, particularly in the Doncaster Area of the Yorkshire coal- field, which had a long history of spontaneous combustion and gas emission problems. This paper summarises the experience obtained and shows how the introduction and operation of these systems has resulted in improved techniqu- es for fire detection and control. Some of these systems are described in detail with emphasis placed on the uses to which output data are put, and their impact upon management at colliery level. Reference is also made to the problems encountered in the development of such systems and how they were solved. The paper also makes reference to the recent Research and Development work of the NCB's Scientific Department and Mining Res- earch Development Establishment (MRDE), which was directed to the design and application of a range of underground sensors, and so ensured continuing progress in this field. The paper refers briefly to a new comprehensive monitoring unit and an integrated fire detection and data transmitting system which are currently being assessed in the Yorkshire coalfield.

Jan 1, 1983

By P Minkkinen

"Pierre Gy showed in his early works that the results in estimating the variance of the mean value of continuous lots depends on sampling mode (random, stratified or systematic), except in the theoretical case that the measurand is randomly distributed in the lot. The experimental variance estimate calculated from samples taken from the lot is independent of sampling mode but depends on sample size and the type of the lot heterogeneity. Variography can be used to estimate the variance of the lot mean for different sampling modes.Gy also defined weighting error, which is made if a simple average is calculated from the assays of samples taken from a continuous object (eg from a process stream) where the flow rate varies with time and is correlated with the concentration of the analyte in the stream.The effect on sampling uncertainty of the three sampling modes and their interaction with the following factors in estimating the uncertainty of the mean concentration is studied using simulated lots, and lots having heterogeneity patterns similar to those of real data sets, including the effect of: the type of heterogeneity (random, grading and clustered heterogeneity patterns) increment size and number employing composite sampling weighting error. CITATION:Minkkinen, P, 2017. Dependence of the variance of lot average on the sampling mode and heterogeneity type of the lot, in Proceedings Eighth World Conference on Sampling and Blending, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 9, 2017

By Baafi EY, Chatterjee PK

The quality of mine planning decisions ultimately depends on reliable estimates of the characteristics of the orebody. The quant- ifiable factors such as grades or thickness can be estimated from field data gathered from outcrops or exploratory drillholes. Since outcrop data is necessarily limited to the periphery of a deposit, extensive drilling generally is required. This paper outlines a method for selecting the number and location of additional exploratory boreholes using an iterative procedure based on a mathematical optimization concept called fixed point theory. The method is illustrated through its application to an exploratory drilling program for a coal mine where optimized locations gave a lower estimate of regional and block variances than a manual Choice.

Jan 1, 1986

By Stewart R

Potential acid rock drainage from the destruction of metalliferous sulph-ides is recognised as a critical factor in the design and economics of any mining venture. While this realisation is relatively new, mining companies have embraced the issue with the aim of scientifically quantifying the magnit-ude of the problem, specific to indiv-idual properties.Coinciding with the development of the open pit mine at Porgera, a comprehensive assessment of the potent-ial for the formation of acid rock drainage was initiated in 1991. Detail-ed study of the mineralogical charact-eristics of all rock types, along with extensive test work to determine the maximum potential of rocks to generate and consume acid (known as acid base accounting or ABA), has been conducted. Correlating this with the known and interpreted geology of the open pit has indicated a strong relationship between rock type, sulphur content and the acid base character. This relationship is used daily as a simple, cost effective means for classification and management of the variety of material types produced from the minincx operation.

Jan 1, 1994

By Ritchie IM

The Parker Centre was formally established by the Australian Government's Co-operative Research Centre (CRC) Program in 1992 and is one of over 60 such centres encompassing a wide-range of applied scientific and resource based disciplines. Government funding for the CRC Program is currently around $A140 million per annum and the Parker Centre receives $A1.8 million per annum to support its core research and education activities.

Jan 1, 1997

By Cortes JP

In a dynamic environment such as the Star Mountains of Papua New Guinea Geotechnical Engineering for the Ok Tedi Project must be described as both interesting and challenging. To be effective a reasonable sized team of dedicated people is required with occasional supplementation by specialist consultants and an annual review process. Ok Tedi Mining Limited's (OTML) Geotechnical Section has a vision to be recognised as the leading mine-based geotechnical engineering section in PNG and to be world class by any international standards. This paper deals with the organisational and operational duties of the Geotechnical Section at the Ok Tedi Mine. One of our major roles is in the area of safety, and in particular in the early warning of natural and mining induced geological hazards that may affect safety and/or productivity. The major activities in- clude geotechnical inspections (pit, waste dumps, tunnels, re- gional), data collection activities and database management, geotechnical design and control work.

Jan 1, 1997

By Yianatos J. B

The advances in the study of control alternatives for flotation columns are reviewed. An integral solution to the control problem has to deal with problems associated with instrumentation, process modelling, control strategies and control algorithms. The term hierarchical control is used here to mean the intelligent integration of available knowledge, control algorithms and logic rules of decision. The selection of information, algorithms and rules is based on the experimental and theoretical knowledge of the column flotation process. The software support was designed and implemented in object oriented computer programs. This technique allowed the implementation of a combination of control techniques, algorithmics and heuristics, in the form of a control strategy. This strategy has shown to fit well with processes exhibiting complex dynamic characteristics. The hierarchical control was implemented in a pilot column and included the following general aspects: co-ordination of distributed conventional control loops, use of sets of control parameters for the froth depth control loop according to the froth depth state, verification and diagnosis of sensors, on-line predictive estimation of gas hold-up, diagnosis of common operating problems and the use of predictive control to account for feed flowrate changes.

Jan 1, 1995

By M R. Davidson, M P. Schwarz

A model for column bioleaching is investigated to identify and understand aspects of bacteria in bioleaching applications, which have implications in heap bioleaching operations. The model is used to simulate scenarios that would otherwise be time consuming to perform experimentally. This study uses a model of bacterial transport and attachment/detachment to ore particles, with a bioleaching model for the depletion of a copper-sulfide, also accounting for liquid and gas flow and gas/liquid oxygen mass transfer. The model includes aspects such as oxygen and ferrous ion consumption, coupled with leaching of a copper-sulfide via the shrinking core model. The model is used to investigate how the rate of leaching is affected by the bacterial concentration in the columns, by the bacterial regeneration of the leaching oxidant ferric ions. The model is also used to assess the impact of oxygen limitation and inoculation method on the copper leaching. Some comparison of the model with experimental data will be shown.

Jan 1, 2004

By T Higuchi, K Fukada, K Takehara, Y Iwami, S Fujiwara

Following the Paris Agreement adopted in 2015 and the SDGs, reduction of CO2 emissions has been taken up as an issue worldwide, and the steel industry, which has a particularly large emission, is required to significantly reduce it. Most of the CO2 generated in the steel industry is generated from the ironmaking process, due to the use of coke and its raw material coal in the ironmaking process. JFE Steel Corporation has been considering the use of hydrocarbon-based gaseous fuels and liquid fuels as a partial alternative to coke breeze used in the sintering process since 2006, immediately after the Kyoto Protocol came into effect in 2005. In a laboratory study, a pot test was used to investigate the effect of the type of fuel, its amount and its injection method on the heat pattern in sinter bed. As a result, the authors developed a technology, in which a predetermined amount of gas fuel or liquid fuel was injected from the surface of sintering bed to extend the holding time of 1200°C or higher at which liquid phase sintering occurs in the layer, to improve the sinter strength while reducing the amount of coke breeze. The authors succeeded in putting this technology to practical use using hydrocarbon-based gas fuel in 2009 and achieved a maximum annual reduction of 60 000 tons of CO2 per sintering machine. In this report, the authors introduce the results of laboratory studies on the use of various energy sources, the practical application of the technology for injecting hydrocarbon-based gaseous fuel into the sintering machine, and the operational results.

Nov 8, 2021

By McKenzie C. K, Stewart R. S, Simpson J

Blast control in small scale underground mining leads to improved fragmentation control, improved control over overbreak and dilution, and the optimisation of drilling and charging operations. Greatly improved control can be achieved through blast monitoring, to confirm proper implementation of blast designs and blasthole charging. Further improvements can be achieved through simple modelling, enabling blastholes to be placed in the correct locations and charged with the correct weight and strength of explosive. Improved design can be shown to significantly reduce overbreak and dilution, and even ground support costs. In one mine in Quebec, open stopes of widths varying from 2.5 metres to four metres and dipping at 36¦ to 38¦ were designed to achieve zero dilution using open sloping blasting practices. The first stope designed in this manner was monitored in detail and achieved its objective.A method for contouring damage around blastholes is presented as a basis for selection of drilling patterns, with particular application to the control of overbreak and dilution. Contouring can be used to provide reliable estimates of either overbreak or damage (where rock is broken het reynainc in nlarr)

Jan 1, 1993