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By Dyson N. F

Mixed cobalt-nickel sulphides precipitated from ammoniacal process liquors derived from nickel sulphide concentrates, mattes, and reduced nickeliferous laterites have been characterized.The mixed sulphides are prone to oxidation on standing and are rapidly leached under relatively mild conditions. The kinetics of the leaching reactions are controlled principally by temperature and oxygen partial pressure. Although the samples have different CO:Ni ratios and have undergone varying degrees of oxidation, there is little difference in their leaching behaviour. The results suggest that a single plant would be able to process mixed sulphides of varying composition. Any copper and zinc present in the mixed sulphides as impurities also go into solution and must be removed prior to recovery of the cobalt and nickel in metallic form.

Jan 1, 1981

By A Jäger, J L. Lett, J Rachocki and B Mobilio

The Newcrest Mining Limited Cadia East Panel Cave mines near Orange, New South Wales, Australia commenced production 1200 m below the surface in May 2014. Understanding the mine-wide impact caving had on excavation stability was a primary objective to ensure a safe working environment as production ramped up in the Panel Cave 1 operation and establishment activities were implemented in Panel Cave 2. The impact of cave interaction between Panel Cave 1 and Panel Cave 2 and establishing monitoring systems to assist mine planning and production as both caves joined is explained in this paper. Monitoring tools such as a microseismic system, open holes, HI-cells, extensometers, fibre optic sensing, cave markers, closure monitoring, underground observations and damage mapping were used to characterise the performance and position of the cave back. The data and observations collected were compared to predictions from numerical and empirical methods and used to calibrate the numerical models for forward prediction and to develop site empirical design tools. The results and methodology for monitoring deep high-output caves are the key discussion points in this paper.CITATION:Lett, J L, Jäger, A, Thornhill, T, Rachocki, J and Mobilio, B, 2016. Geotechnical challenges in cave monitoring – a modern approach, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 203–216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By D Craw, J Pope

The Greenland Group, Westland, can be characterised with respect to environmental issues by the application of a GIS database (DAME), and specific sampling campaigns. Waters draining gold mineralised areas have a distinctive chemistry characterised by neutral pH and arsenic as a trace element. The acid neutralising capacity (ANC) from carbonates usually exceeds the maximum potential acidity (MPA) from sulphides resulting in circum-neutral pH. These waters are readily distinguishable from waters draining coal mine related areas, which commonly have low pH (~4) and low As concentrations (~0.1 ppm). In contrast, dissolved arsenic mobilised from Greenland Group historic gold mining areas is up to 2.4 ppm. This As mobilisation is controlled by the secondary As mineral, scorodite (FeAsO2+2H2O). Maximum dissolved As concentrations increase with increasing pH, corresponding to the increasing solubility of scorodite with increasing pH. Dissolved As is attenuated by dilution, precipitation of scorodite, and/or adsorption to iron oxyhydroxide (HFO). Adsorption to HFO is an important attenuation mechanism in and adjacent to many mine sites. HFO is abundant at mine sites where pyrite was abundant in fresh rock, such as where the mineralised zone is dominated by disseminated pyrite. Pyrite, and resulting HFO, are relatively rare where mineralisation occurred as well-defined quartz veins. Localised HFO occurs also where ankerite oxidises in host rocks. Arsenic output flux (ca. 25 g/day) from historic gold mine sites is commonly less than the natural background flux from mineralised rocks (>5000 g/day).

Jan 1, 2006

This article presents a proposal for the rehabilitation of the mined area of the Mogiana quarry. The Mogiana quarry produces material used in civil construction and is situated in the Brazilian State of Spo Paulo in the kilometre six of the Mogf Mirim - Itapira highway. The mineral exploitation in the Mogiana quarry provokes modifications in the environment such as alterations in the relief, vegetation, quality of the air, water and landscape. Through previous study of the area it was verified that after the closure of the exploitation the mine should be occupied mainly by pasturage. At the closing of the mine the exploitation benches, berms and slopes in general as well as the surrounding areas should be covered with a layer of soil and vegetated with native species in order to mitigate the negative impacts caused by the mine. The rehabilitation project of the area is based on the probable future use of the area, located between agricultural cultivations and cattle creation. The great alteration of the relief and soil would make future use of the area for agriculture difficult. It is more suitable t0 animal creation, mainly cattle. The high and thick rock slopes originated by the mining should be covered by vegetation, where possible, to reduce the negative visual impact. Obviously several measures will be necessary to reduce the impacts on the environment during mining. The final and definitive reclamation will only be possible after abandonment of the area. The main aspects of this reclamation process will be discussed in this paper.

Dec 6, 2010

The Mount Lyell Mining Field is Australia's chief productive source of copper. It is situated near Queenstown, on the western flanks of the West Coast Ranges, about 20 miles from the west coast of Tasmania (Fig. 1).The following observations on the mineral composition of the copper ores of the Mount Lyell Field are based on a...

Jan 1, 1939

By J V. Lawless

Mineralisation processes in epithermal deposits in the North Island of New Zealand are best illustrated by considering the two most productive deposits: Waihi and the Thames Bonanza Zone (TBZ), which have different mineralogies and ore shoots geometries. These two deposits can be taken as typical of certain styles of epithermal deposits worldwide, and recognition of their differences can be used to develop mineralisation models of predictive value. Waihi, the major economic producer in the Coromandel Volcanic Zone (CVZ), has laterally near-continuous ore shoots over a vertical interval of 600 m which consist of quartz, chalcedony, pyrite, base metal sulphides and electrum. They are found in the foot wall of earlier quartz veins which contain quartz pseudomorphs after platy calcite and adularia. The Thames Bonanza Zone which was the second biggest producer in the CVZ has discrete near-vertical ore shoots over 300 m vertically, which consist of quartz, pyrite, base metal sulphides, electrum and in their upper parts barite, that are enclosed in veins of quartz.   The gold mineralisation in both deposits is considered to be a co-precipitate with pyrite, with that at Waihi produced by prolonged boiling in an upflow of a hydrothermal system. That at the TBZ was produced by mixing a deep water primed for gold deposition by prior limited boiling, with an oxidised condensate of the steam released by the boiling, in an outflow proximal to the system's upflow.

Jan 1, 1997

By Greaves M. C

X-ray fluorescence spectroscopy used for the analysis of mill samples results in improved control of flotation concentrators.Techniques and equipment for sampling pulp streams, filtration and drying, grinding, briquetting and X-ray fluorescence analysis of samples have been developed.The current methods in use permit the analysis for lead and zinc in six pulp samples within 30 min total elapsed from the start of sampling. The X-ray method gives a precision at least equal to the former routine wet-way assay methods.The equipment is used also for pilot plant control, as a means of solving complicated analytical problems and in the rapid qualitative analysis of exploration samples.INTRODUCTIONIn milling and concentrating operations, classical methods for the assay of lead and zinc have been mainly of use for accounting purposes and for the post-mortem examination of plant operations, but have been of little value for rapid mill control. Where attempts have been made to apply these methods to control assaying, it has been necessary to modify the procedures and introduce short cuts which have tended to reduce their reliability.Even with these shortened procedures, the time taken to obtain a limited amount of information rendered them of little value for the control of milling operations where sudden, large fluctuations can occur. In recent years, a number of new and rapid analytical techniques, based on physical rather than chemical principles, have been introduced.These include direct reading emission spectroscopy, x-ray fluorescence spectroscopy and atomic absorptionspectroscopy.

Jan 1, 1964

Possibilities and Working of the Specific Agglomeration of Fibrous Materials and Residues Plant based fibrous materials are becoming of increasing interest in a multitude of industrial applications. Main advantages are the specific lower energy demand and virtually closed CO2 cycle, excellent mechanical properties based on low density as well as a high level of recyclables. In contrast, processing and handling of such materials is associated with a number of challenges. These challenges are mainly related to specific morphological characteristics in correlation to fibre length and structure (branching and splices). Specific problems in further processing steps including transport, dosage or storage for natural fibre compounding, result from form-locking bonds leading to burling, clusters or plaits. Technologies of fibre processing are well known, but other than textile based technologies they generally result in intermediate goods which do not allow direct industrial application. The investigation to be presented is based on results of recent research activities and shows two possible technical solutions of innovative fibre agglomeration procedures. These methods allow the conversion of middle to long fibres into a form, which eases further processing and dosage significantly and therefore allows free flowing too. The procedures are based on the working principles of rolling and winding technology. Within the work, both of the patented methods and their respected lab-scaled devices will be described. Further, results will be shown for an up-scaled rolling agglomeration unit applying the developed principle and consisting of multiple process zones. Possible variations of the resulting product characteristics and the impact of different process parameters will be discussed based on the trials with natural fibre (hemp and flax) agglomeration. As a main outcome of the research, product qualities can be supplied according to the requirements of the specific application in correlation to agglomerate strength, porosity or form. In conclusion, recent developments for specific methods of characterization will be depicted.

Sep 13, 2010

By D Howe

The Athena gold deposit was discovered in 2007 by Gold Fields Australia Ltd, at the St Ives Gold Mine, 35 km southeast of Kambalda, Western Australia. Gold anomalism was identified in sheared Paringa Basalt as a result of a regional scale aircore drilling program, in association with geophysics. In the 18 months following discovery, the deposit was intensely drilled and by June 2009, it was announced that the Athena deposit contained an ore reserve of 1.7 Mt @ 5.6 g/t for 316 koz. This was followed by a feasibility study, and as a result mine development commenced in November 2009.The Athena mineralisation is hosted in a discrete, north-south striking, steep to moderately dipping shear zone within the southwest dipping Paringa Basalt. Vein intensity has a strong correlation to grade and vein type varies from early thin quartz-albite-sulfide (pyrite and/or pyrrhotite) shear parallel veins to strong brecciation and irregular veining with quartz-albite-actinolite-biotite-pyrrhotite infill. The geology preproduction process developed at the Argo mine was refined and improved following a business improvement project. The aim of the process is to construct detailed geological interpretations prior to development allowing informed mining decisions to be made. The process delivers significant cost savings and revenue enhancements.The development of macroscopic classification scheme was critical to determine ore or waste in the early phases of mining. The Style of Deformation, Alteration and Veining (SAV) Code was the result, and has been enhanced as greater geological knowledge is gained over time.

Aug 22, 2011

This paper deals with the application of table flotation to two unusual mineral dressing problems. Both problems involved the removal of interfering minerals at sizes too coarse to normal froth flotation.The first problem was the removal of arsenical minerals from Broken Hill gravity concentrates without further size reduction. Table flotation without grinding of the original concentrates gave almost complete rejection of the arsenic from the concentrates. A typical test result was a reduction of arsenic in jig concentrate from 0.75% arsenic to 0.007% arsenic.The second problem was to develop a method to produce a high grade calcium carbonate concentrate from coastal dune sands containing about 10% silica and about 80% calcium carbonate. The sands were about 30 mesh British Standard Screen (B.S.S.), and for economic and other reasons it was stipulated that the separation be made without grinding. Again, table flotation gave excellent results. A concentrate was produced containing 99.62% acid soluble material, representing a recovery of 98.69% of the calcium carbonate in the feed with a rejection of 96.44% of the silica.The investigations' were carried out at the Kalgoorlie Metallurgical Laboratory, under the Department of Mines...

Jan 1, 1954

The use of black and white and colour infrared film in remote sensing of natural resources is reviewed. In heavlly-forested areas such as New Zealand, the main value of the method is in surveying the vegetation cover to detect the existence of plant communities characteristic of specific geological formations. By contrast in arid areas of Australia where the vegetation cover is sparse and where rocks and soils are well exposed, the method can be used in detecting different rock types or other geological differences.

Jan 1, 1972

Open pit mining at Bingham Canyon commenced in 1904 and about two billion tonnes of ore have been extracted since then. There remain just under one billion tonnes of ore in the pit and this will be mined by 2015. Because the porphyry system extends below the ultimate pit limits, Kennecott Utah Copper Corporation initiated a study in 1997 to determine the viability of underground mining. The study was initiated at that time because the results were to be used to compare the economics of a further pit expansion to that of an underground mine. If a pit expansion was viable then overburden removal would have to start in the near future. This paper is a summary of the work that was carried out for the underground study. Block cave mining was determined to be the most appropriate method to mine the deposit. Two block cave areas have been planned with a total production rate of 72 500 tpd. Additional sources of ore will come from skarn orebodies that are associated with the porphyry deposit. The geology of the deposits is described together with the geotechnical techniques that were used to characterise the rock in the absence of more detailed data that are normally available. A general description of the mine plan is given along with the reasons for selecting the particular methodology used. The study was completed at the end of 1998 and demonstrated the viability of underground mining at Bingham Canyon. Funds have been approved for further drilling and technical studies, which will lead up to a feasibility study in 2004/5.

Jan 1, 2000

Silver is one of the three major metals produced from the Broken Hill mines. The accurate determination of the silver in these ores, therefore, is of economic importance.With due appreciation of the divergence of opinion of many who are interested in the subject of the determination of silver, the writer has been prompted to present the results of some recent experiments on silver losses during cupellation and conclusions from these experiments in the present paper. The losses of silver in the fire assay for this metal are due to silver retained in the slag during the fusion or scorification of the ore, and to silver volatilized from, and absorbed by the cupel during the process of cupellation.The literature describing the results of experimental work on silver losses due to the above causes is extensive, and the general conclusion of these experiments is that the silver lost in the slag is small, but that lost by cupellation is larger and more variable.The term cupellation loss in this paper refers to the total cupellation loss, no distinction being made between the absorption and volatilization losses.Volatilization loss is shown by King to be 0.5% of the total cupellation loss and, as it is generally accepted among assayers as being only a small fraction of the cupellation loss (3) (5), it will not receive further consideration in this paper.The factors causing the loss of silver by cupellation and the precautions to be obs~rved to reduce the loss in this operation are described in (1), (2), (3), (4) and (5). The...

Jan 1, 1940

By U König, N Norberg

To cope with varying raw material qualities and increasing prices for energy, a more frequent and accurate monitoring of the processing of iron ore became the focus in sinter plant operations. Traditionally, quality control in iron producing industries has relied on time-consuming wet chemistry or the analysis of the elemental composition. The mineralogy of a sinter that defines the properties and behaviour in the blast furnace is often not frequently monitored. One fast method to analyse the mineralogical composition of iron sinter, raw mixtures and iron ores is X-ray diffraction (XRD). Recently statistical methods such as similarity analysis or partial least square regression (PLSR) in combination with XRD raw data has become more and more popular in handling large amounts of data and correlating process-relevant parameters directly with an XRD measurement. PLSR can be used to correlate process parameters directly from the XRD pattern without investigating the mineral content. Hidden information that is present in the measurement but not determined with traditional methods can be used to improve the characterisation of the analysed materials.CITATION:König, U and Norberg, N, 2017. Iron sinter process control using X-ray diffraction – part : monitoring of low temperature degradation, in Proceedings Iron Ore 2017, pp 75–78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The use of walk-through inspections, approvals and ad hoc investigations to ensure risk is kept within acceptable levels is reaching its limits of effectiveness. Further improvement in occupational health and safety requires a systems approach, and the use of Quality Management principles is an obvious basis for this. SafeGuard, a æbest practiceÆ model health and safety management system and audit criteria based on AS/NZS ISO 9001:1994, has been produced by the Department of Mines and Energy. Quality style audits of mine and quarry health and safety systems are now being carried out by the Inspectorate.

Jan 1, 1998

Measurement of densities, susceptibilities, permanent magnetization, and calculation of demagnetization factors has allowed computer modelling of gravity and magnetic data over the Middleback Range iron formations of South Australia. As well as providing structural information, the study emphasizes the effects of weathering on the interpretation of magnetic data.

Jan 1, 1975

Modem mineral exploration and development takes place within a data-rich context underpinned by a wide range of data acquisition, processing and interpretation technologies. This leads to requirements for consistent and explicit methods by which the relative risks - or success probabilities - of exploration programs can be assessed and communicated. Bayesian risk assessment methods are outlined which provide a starting point for this more rigorous approach to exploration investment.   Effective governance of information technologies becomes a core function of the modem competitive Board. As such it becomes a component of any business audit and any assessment of the quality and success potential of a company. Limited data however suggest that the average Board may be under-represented in this increasingly critical skill area.

Jan 1, 1997

By J Cook

In this paper we present a case study of the challenges and opportunities associated with the development of cultural heritage management strategies at the Lihir gold mine in Papua New Guinea. We discuss the contextual drivers and constraints, and outline the ways in which Lihir Gold Limited is aiming to set new industry bench marks for the region through the development of values-based best practice cultural heritage management programs. This approach is largely based upon a compliance partnership with a local stakeholder group. We argue that such partnerships are a prudent means of mitigating company risk, while constituting a far more necessary tool for local people in the reconceptualisation and negotiation of the experiences of significant social change and modernisation experienced in the context of recent resource development.

Jan 1, 2009

By P. S. B. STEWART

As part of a continuing study of mechanisms of breakage, the grinding at Nairne Pyrites Pty. Ltd. was traced by the addition of barytes and the results compared with parallel small scale laboratory tests. It was confirmed that the same basic mathematical functions described the behaviour of the full scale ball mill as those established in the small scale mill. However, an additional classification function was required to define the behaviour for the rod mill and was evaluated as a function of size from the experimental data. The classification and grinding of the pyrites ore was assessed from steady state size distributions around the circuit.

Jan 1, 1971

ONE of the phases of mining wide ore-bodies, such as are found in Broken Hill, is the laying-out and design of the sill floor gangway timber, When, in the above operation, a detail has to be repeated frequently, it is desirable in the interests of efficiency that that detail should be standardized as far as possible. Before arriving at a standard design e.g., a crosscut layout-it would seem necessary to compare its strength with some other unit of timber and see that the general design is at least as strong as the unit that has been taken for comparative purposes, In these notes no attempt is made to calculate the stresses to which timber underground is subjected, but merely to draw a comparison between the relative strengths of the various cross sections of timber in common use underground.It has been assumed for the purposes of comparison that the milling exerts pressure in a vertical plane only, and is uniformly distributed over any area. A beam supported at both ends, and with a uniformly distributed load, has the maximum bending moment at a point midway between the points of support, and equals- WL2 8 where W = load per unit length. L = distance between points of support.The bending moment also equals M-, where y M = modulus of rupture of the material in question. I = moment of inertia of the section of the beam about a given axis.Y = distance of extreme fibre from that axis. WL2. I The formula -8- = MY- only holds good until the elastic limit...

Jan 1, 1923