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By S Wainio, P J. Beckett, T Miller

Lichens are a symbiosis of fungi and algae. Air borne elements and gases are absorbed very efficiently over the entire surface of the lichen, because they have no protective structures such as a waxy cuticle or stomata. A survey in 1977 (one year before the Sudbury Regreening program began), indicated that several Cladonia spp had invaded the soil in Sudbury’s open birch woodlands. Pollution sensitive species such as Cladonia rangiferina and C. mitis occurred 20–25 km from the smelters. It was anticipated that the improvements in air quality and reclamation efforts would allow a natural invasion of pollution sensitive species into what once was a lichen desert that surrounded the smelters. The purpose of this project was to study the invasion of terricolous (soil-inhabiting) communities of lichens and mosses on reclaimed land in the Sudbury region 45 years after commencement of the Sudbury Regreening Program.

Aug 2, 2023

The value of Australia's education services exports increased to over $15 billion dollars in 2009, placing education as the third overall export earner behind coal and iron ore; however there are concerns over the impact of emerging policies on the future of both the industry and the provision of mining education. Policies have impacts on the growing number of international rankings (or league tables) of mining jurisdictions and universities. A high position in such rankings might be used as a measure of perceived quality with benefit to those at the top and to the detriment to those lower down.    Top performing companies in the relatively new domain of sustainability have been shown to achieve better financial performance than their industry competitors, assisting them in attracting top quality committed staff, hence positioning themselves well for the future. The world's mining companies, jurisdictions and universities are now ranked with results in the public domain. It is argued as to the validity of the data or perceptions used in such rankings, but there is no doubt they are influential in determining the flow of dollars around the globe. By investing your pension fund assets in the shares of the top performing companies, by placing your exploration dollars in a country at the top of such a list of attractive jurisdictions, attending or recruiting from a University at the top of the rankings - risk must surely be reduced?   While savings and risk reduction can undoubtedly result from the introduction of new technologies developed through appropriate R&D (the other core activity of a university), the maintenance of a very high level of exploration and production performance through dedicated highly skilled staff every hour of every day quietly improves financial performance, while avoiding safety, environmental and/or community incidents (ie protects the 'triple bottom line'). As always risk reduction comes down to enabling quality people to do a quality job - through the actions of such people we can sustain the global mining industry and secure our social license to operate. However, there is global concern over where the numbers of such people, including those with the recently required skills in sustainability, are going to come from.   This presentation will discuss some of the complexity and interactions involved in the development of such rankings, the dangers inherent in their simple acceptance and use, plus indicate some of the directions mining educators might take to sustain and increase the supply of quality graduates to the global mining industry. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Jun 1, 2010

By Yin J, Sun H

A new technology has been introduced - the use of the High-Water Solidifying Material for providing pumped roadside supports to maintain a roadway for re-use in longwall retreating. As a gob edge support, its initial use at Hebi No. 1 Colliery was successful, providing acceptable performances in support and control of convergences and lateral closures of the gob-edge roadways. This acceptability applied to both first use and re-use when the roadway became a gateroad for the adjoining longwall, remaining stable throughout the associated loadings and convergences. The technology promises economic and social benefits.

Jan 1, 1992

By Theophili CN, Kapenis AP

Seismic tomographic imaging has been applied to determine the blast induced damage zones in bauxite pillars in underground mining. At the retreating stage, when pillar dimensions are reduced from 8 x 8 m to approximately 5 x 5 m, the' seismic tomographies reveal, through measurements of the P-wave velocities which is a measure of the degree of fracturation of the pillar rock mass, the presence of three zones within each pillar. In the external zone, where velocities recorded are below 750 m/s. extensive pillar damage occurs which is attributed to both the growth and coalescence of pre-existing cracks and even the creation of new cracks in the rock mass. This effect is in agreement with literature, when considering the peak particle velocity as a criterion for rock failure in tunnels. In the intermediate zone, where velocities range between 7S0-1000 m/s, damage to a much lesser extent occurs which is due mostly to growth of pre-existing cracks and widening of their apertures. The inner zone, where velocities exceed 1000 m/s, is considered to be unaffected by blasting. Simple remedial measures of low cost, which are based on blasting mechanics are proposed to minimise the blast induced damage zone and consequently the transition zone.

Jan 1, 1995

By Rao S. B, Baafi E. Y

A venturi based multi-scrubber air cleaning system has been developed for dust control along a longwall face in coal mines. The system consists of a number of scrubbers. strategically placed along the wall face which deliver cleaned air at high exhaust velocity into the middle section of the longwall cross-section thus dividing it into two zones. The aim is to maintain the walkway on the powered support side as a zone of relatively clean air. Laboratory studies have shown that the scrubber's average efficiency is 90 per cent. Field trials in three longwall faces have shown that. under normal operating conditions. 40 to 50 per cent average protection efficiency can be achieved within 3 m to 4 m downstream of the scrubber. A three-dimensional finite element computational fluid dynamic model. FIDAP. was used to simulate the airflow patterns the dust concentration and the scrubber dust control technique at a typical longwall face. Results of simulations tally very well with the field results.

Jan 1, 1995

By E Shilov, R Dixon, L Tovey

BHP Western Australian Iron Ore (WAIO) operations use a suite of slope monitoring systems which are deployed to operational areas based on the ground control risk. Slope Radars are one system used within WAIO, having recently deployed and integrated a network of 22 radar systems across the operations. The integration required the development of supporting network architecture, infrastructure, virtualised hosting, security protocols and a technology support model. This has enabled data transfer between the physical radar systems located in open pits, to on-site offices, a vendor supported remote control room in Indonesia and the WAIO Integrated Remote Operations Centre for data analysis and monitoring of system and displacement alarms 24/7. The typical technical skillset of a Geotechnical Engineer does not include the knowledge and capability to understand and develop the supporting IT infrastructure required for establishing an integrated radar monitoring network. This paper will provide a discussion of the technology considerations for integrating radar systems and highlight the importance of the developed partnerships between internal geotechnical and technology teams and the external vendor team to ensure a reliable, robust and scalable slope monitoring solution.

Nov 29, 2022

By D Cohen, A Wurster

Many Southern African mining operations produce mine water which is beneficially and productively utilised on the mine sites and to support other water uses. Mine water treatment typically takes place within the context of integrated mine water management involving pollution prevention, waste minimisation, recycling and reuse as well as river discharges. Development of new and improved mine water treatment has focused on the neutralisation of metals removal, desalination of high sulfate waters and passive treatment. Mine water neutralisation processes now incorporate a combination of natural limestone and lime treatment, as well as features to maximise gypsum precipitation. The South African CSIR developed a suite of limestone-based neutralisation processes, which include reuse of CO2 and CaCO3 generated in the process. Desalination of high sulfate mine water is typically done using one of the following technologies:biological sulfate removal with different approaches to the handling of the sulfide generated in the process, and ultrafiltration (UF)/reverse osmosis (RO) treatment with different approaches to the handling and disposal of the brine. The current research and development focus is the separation and recovery of saleable products from the treatment residues and brine streams.

Jan 1, 2006

The Rio Tinto Iron Ore group currently estimates grade attributes for mineral resources using ordinary kriging (OK). OK produces a smoothed globally unbiased estimate, but does not capture local variability, which can have significant impact on mine planning and scheduling. The dimensions and the multivariate nature of iron ore deposits make point simulations of whole deposits impractical. With a direct block simulation method the size and speed limitations of point simulations can potentially be overcome, resulting in a viable method for capturing local variability and for providing risk measures into the mine plan and schedules. Some iron ore deposits are highly folded (post mineralisation) and require preprocessing using an unfolding algorithm to properly define the continuity parameters and directions of anisotropy before simulation can proceed. Block co-simulation proceeds in unfolded space and since mine planning require a block-model with regular block-sizes; a regular block-model is unfolded first. This paper discusses a block co-simulation approach that can be used to simulate the irregular blocks resulting from the unfolding process. A section of an iron ore deposit is used for testing the block co-simulation algorithm and the simulation results are compared against the Isatis direct block simulation method. Available blasthole data is also used to validate the behaviour of the block co-simulation algorithm.

Sep 26, 2011

In dense medium processes for the beneficiation of minerals the consumption of medium (generally ferrosilicon) represents a major component of the operating cost. This provides a strong incentive for improvements in heavy medium recovery circuit design and operation. A major thrust in heavy medium plant design over the past decade has therefore been towards circuits which reduce medium losses. In this paper recent trends in plant design are examined in relation to the factors infl uencing circuit performance and medium losses. Operational details ' which have a significant effect on losses are discussed and illustrated by means of plant and pilot plant test data, with particular emphasis on the performance of wet drum magnetic separators. While the emphasis is on reducing the consumption of the high-cost ferrosilicon medium used in minerals beneficiation, most of the principles described in this paper are equally relevant to the design and operation of magnetite recovery circuits for coal preparation plants.

Jan 1, 1987

To help meet the challenge of mine finding at the start of the 21st century, the exploration geophysicist will have at his command a powerful range of tools, some new, some improved, and some which already exist today but are as yet little used. Remote sensing, using satellite and aircraft-based multi-spectral scanners, will provide the means for routinely mapping the surface distribution of certain carbonate rocks, clay and ferrous alteration minerals, based on the analysis of solar reflectance spectra. Time and emission-spectral resolved laser-induced fluorescence will likewise map the distribution of certain ore and pathfinder minerals, as well as certain skarn zones, all potentially related to ore deposits. The GPS (Global Positioning System), based on 18 orbitting satellites, will provide a universal, three dimensional, all weather navigation system which will completely supplant all existing aerial navigation systems, and greatly facilitate aerial surveying and automated processing and presentation of the data. Aeromagnetic gradiometer measurements will provide higher geometric resolution which will yield better definition of individual geological units. Multi-method ground geophysical surveys will be greatly expedited through the use of portable microcomputer-based, multi-sensor instruments. These instruments will interface with other intelligent devices for automated processing, presentation and interpretation of the ground field data. Borehole geophysics will come into more general use, both for at-hole measurements, especially using active nuclear techniques for grade determination, and for remote detection using a variety of electrical, magnetic, seismic and other methods.

Jan 1, 1986

By V Matousek, A Sellgren, R Visintainer, G McCall

A 4-component model for settling slurry pipe flow has been previously described by Wilson et al (2006) and Sellgren et al (2014) to predict pipeline friction loss (hydraulic pressure gradient) over a range of slurry compositions: from fine to coarse particle size, narrow to broad particle size distribution, and low to high solids concentration. The method applies a weighted average of established pipeline models for various settling slurry flow regimes, according to the volume fraction of solids falling within the applicable size range for each model. Further development of the model was undertaken by Visintainer et al (2017a, 2017b), based on a comprehensive set of laboratory tests in 203 mm (8 inch) and 103 mm (4 inch) pipelines, and it was also adapted to the modelling of slurry pump performance derates. However, this work was all performed with solids having a specific gravity near 2.65, as is typical for many mineral processing and dredging applications. The goal of the present work is to test the applicability of these models for settling slurries having a higher solids specific gravity, as may often be seen in the mineral processing of iron ore deposits. To that end, a test program was carried out in a 103 mm (4 inch) pipe loop using various compositions of an iron ore product having a solids specific gravity of 4.75 and containing both coarse and fine solids. By screening and flushing operations, a range of particle size distributions were created having different proportions of the coarse and fine elements. In all, 19 tests were performed with d50 particle sizes ranging from 50 μm to 3.2 mm and delivered solids concentrations from 10 per cent to 43 per cent by volume. Particle size distributions varied from very narrow to very broad, with d85/d50 ratios ranging from 1.75 to 26. Pipeline pressure gradient and pump performance data were collected and used to test the applicability of the previously developed 4- component models and to propose improvements to the models for the handling of high-density solids.

Nov 8, 2021

By Blockley J. G, Laeter J. R

The history of the Ph-Cu-Zn mineralisation in the orthampton Block of Western Australia has been further investigated. It was hoped that (1) Rh-Sr studies on partially-remelled granulites, wall-rocks to the dolerite dykes, should date the dolerite intrusion, (2) Rh-Sr data on hydrothermally-altered dolerite should date the sulphide mineralisation, (3) Pb model ages on the galenas might provide an independent dating of the mineralisation, in addition to any geochemical information that might be derived. Only the second dating aim was fulfilled, but the Pb isotope data, when combined with the Rh-Sr data, have permitted deductions about U, Th and Pb abundance changes during the regional metamorphism, and about a possible source of the ore Pb. In detail the following has been found. (1) The partially-remelted granulitic wall rocks yield a scattered whole-rock Rh-Sr isochron which seems not to have been reset by the dyke intrusion (age 1037 ± 146 Ma, with initial Sr ratio 0.7171 ± 0·0054, MSWD = 111). This date agrees well with that reported previously for granulites from another locality; together theyestablish the time the metamorphic period closed. (2) The hydrothermally-altered dolerites yield a Rh-Sr whole-rock date 434 ± 16 Ma, with initial Sr ratio 0.7072 ± 0·0029 and MSWD = 31, taken as referring to the time of Ph-Zn mineralisation. This contrasts with a report of much older palaeomagnetic and K-Ar datings of the dolerite (not less than 550 Ma, possibly older) and suggests that neither the dolerites nor their heat have had any connection with the mobilisation of the Pbscavenging solutions. (3) The Pb isotope ratios of galenas from the ores yield a well-correlated regression which is not amenable to any of the model-age calculations. (4) The Pb-isotopic trends negate any genetic connection between dolerite and mineralisation, but the country-rock granulites could be the Pb source. (5) Combination of the Rh-Sr dates and the Pb data in a "simultaneous isochrons" construct permits the inference of major losses from the system during the regional metamorphism, in the order U>Pb>Th, with substantial homogenisation of the remaining Pb. This left a wide range in local UlPb and Th/U among the source rocks which eventually were scavenged by the mineralising solutions. (6) These geochemical deductions are shown to be compatible with previously-published information on the abundance ofU and Th in the Northampton Block granulites, which are thus seen to be credible as source rocks for the ore lead.

Jan 1, 1985

By Cocker J, Urosevic M

Seismic methods have become common for the detection of low-throw faults ahead of underground coal mining. Surface seismic methods cannot theoretically be used where dykes occur, because seismic waves transmit from the surface down to the seams, and reflect back to the surface. Consequently, where sub-vertical structure such as dykes occurs, the surface seismic method fails.The ability of seismic methods to image dykes depends on the geometry used, the dyke thickness and the seismic wave propagation mode in relation to dyke composition and internal structure. Surface seismic methods find it difficult to distinguish between faults/fractures and very thin dykes (1-2m in thickness) when the dyke's thickness is less than the seismic wavelength. Consequently, borehole seismic methods have to be used to detect the presence of such thin dykes.

Jan 1, 1998

By Leahy G. J, Moxon N. T, Nicol S. K

Experimental work is described in which extremely dilute aurocyanide liquors are treated with novel surface-active complexing agents to produce a hydrophobic aurocyanide species. Subsequent aeration of these liquors causes accumulation of such species at the air-water interface and the aurocyanide complex is transferred to a froth concentrate. A detailed performance assessment of this process is made and this knowledge used in the design of a pilot plant facility. Early results indicate the feasibility of the selective recovery of aurocyanide ions from reclaimed residue dam water (approximately 0.2ppm Au) with upgrade ratios of the order 180:1. A further study was made applying ion flotation to the recovery of gold from a carbon-in-pulp (CIL) feed liquor (approximately 1.0ppm Au). The probable economics of this process compared to conventional CIL processing is also described. Successful development of countercurrent ion flotation for concentrating solids-free gold solutions may offer a lower cost alternative to existing gold ore processing technologies, or in more secondary applications such as concentrating dilute gold solutions or heap leach runoff. The technology may also have more generalised applications to other heavy metal process- Ing.

Jan 1, 1991

By G Gilchrist, S C. Dominy, T Jashashvili, R C. A Minnitt

The grouping and segregation error is one of Gy’s seven errors that cannot be measured in any qualitative manner because of its transient and changing characteristics each time the sample is handled mechanically. Attempts to calculate the mean and variance of the segregation error is considered by some as ‘an exercise in futility’ that would not help us achieve representative sampling. This research is aimed at understanding the process of segregation of dense, finely divided and dilute particulate materials supported in a clean quartz substrate during intense agitation. Several mixtures of fine-grained materials including steel, tungsten carbide and gold grains were used in these experiments. Four hundred grains of each of the minerals and metals at a top size of 2 mm were mixed with approximately 600 g of finely ground quartz material (95 per cent passing 2000 microns) in a 500 ml plastic jar with a sealable lid. The mineral–?metal mixtures were analysed in three steps using microfocus X-ray computed tomography. Step one consisted of rolling the containers on a flat surface in an attempt to concentrate the mineral and metal grains in the core of the supporting substrate; this is a base case that can be reconstructed after each session of analysis. The second step involved gentle and vigorous shaking of the mixtures in order to segregate the denser minerals and metals from the supporting quartz substrate. In some cases, a third step involved splitting the sample through a riffle splitter. Three-?dimensional images of the surface of each grain, its volume and its X-, Y- and Z-coordinates, before and after intense agitation of the container, were interpreted from the reconstruction of the tomographic X-ray data. The spatial analysis of grains using cell declustering and 3D variography provided a useful means of characterising the distribution of the grains in space and the extent to which they had become segregated during the process of agitation. Spatial analysis indicates that in general, grouping and continuity of grains is weakly developed. The modelled nugget effect remains high for most tests, indicating that grains of similar size did not group together strongly. Agitation through rolling provided the best continuity, although not consistently in the long axis of the plastic jar. The nugget effect was consistently highest, and the range of continuity shortest in samples that had been split, indicating that the grouping and continuity were reduced through splitting the sample. Initial results indicate that very little segregation of the minerals and metals occurs in the quartz substrate. This is somewhat counter-intuitive, but suggests that the effects of agitation on mixtures of dense minerals and metals in substrates of lower density do not lead to excessive segregation. Differences in behaviour between dense materials in response to agitation are evident. Grains of different composition and shape did not group and segregate in a predictable manner in response to the agitation methods. Initial results indicate that the degree to which a material groups and segregates relates more to the characteristics of the denser material itself, rather than the agitation method employed.CITATION:Minnitt, R C A, Jashashvili, T, Gilchrist, G and Dominy, S C, 2017. Quantifying segregation of minerals and metals in particulate materials using computed X-ray tomography and variography, in Proceedings Eighth World Conference on Sampling and Blending , pp 173–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

Western Mining Corporation has grown from a small gold exploration and mining company, funded by large established mining companies, into a large multi-commodity and multi-national mining company with shareholders who no longer have the same understanding of mining as the founders. Ore reserve calculation methods and reporting procedures have gradually changed throughout the group during this growth. These changes have been led by the newer mines, in particular the Kambalda nickel mines, where the need for more global, less conservative reserves were required to justify capital and forward sales contracts and to inform shareholders of the true worth of their company. This change in attitude to reserves has flowed back to the gold mines and has allowed a better informed management and investing public to plan for the future. Management of the calculation of reserves remains the responsibility of individual mining operations, but a corporate reporting and management structure exists through the office of the Director of Exploration and divisional chief geologists who strive to maintain standards of calculation and reporting. Specialist ore reserve geologists are starting to justify their place in the organisation, particularly at the larger operations. Reporting to the new AusIMM Standards is fully supported, although the amount of supplementary information requested will need to be considered carefully because of the large number of factors that make up even the simplest reserve.

Jan 1, 1990

The South Junction deposit of St Barbara Mines Limited was discovered in 1989 by the geologists of Ross Atkins Mining.The deposit occurs in the lower part of the Gabanintha Formation of the Lukes Creek Group in the Mt Magnet -Meekatharra greenstone belt. Country rock is predominantly talc-chlorite schist. Gold mineralisation is associated with north-south shear zones, quartz-carbonate-fuchsite alteration of the ultramafic rocks and in particular close to deeply weathered quartz-albite porphyry. For a detailed description of the geology of the South Junction Deposit see Fiala (1992).

Jan 1, 1993

A review of the factors controlling stope wall behaviour such as excavation geometry, rockmass strength, induced stress, ground support, blast damage and drill drive layout is undertaken. In addition, the advantages and disadvantages of single lift stope geometries linked to vertical crater retreat are also analysed. Finally, key components of multiple lift stoping such as cut-off slots, production rings, stope undercuts and drawpoints are studied in detail.

Jan 1, 2000

Pyrrhotite is the predominant gangue mineral at Renison comprising about 60 percent of the sulphides in an average ore blend. It exists as two crystal structures - monoclinic and hexagonal. Monoclinic pyrrhotite is the slowest floating of all minerals but is ferromagnetic and hence recoverable more efficiently by low intensity magnetic wet drum separators than flotation. This paper discusses the installation and commissioning of four 0.915 m x 3.0 m, 0.1 Tesla permanent magnet, wet drum separators prior to sulphide roughing flotation. Planned circuit and process control modifications to better accommodate magnetic separation into Renison's flowsheet will be Discussed.

Jan 1, 1991

Mineral deposits in New Zealand whose origin can be ascribed to primary magmatic segregations are associated with mafic-ultra- mafic complexes related to two orogenic episodes which took place during Paleozoic and Mesozoic times. These mafic-ultramafic complexes are essentially of two types. One is ophiolitic and has podiform chromite mineralisation presumably formed below a spreading ridge. The other type occurs as intraplate layered intrusions in which Fe-Cu-Ni sulphides and Fe- Ti-V oxides have formed as a result of liquid immiscibility with the host magma, and have subsequently accumulated by gravity means. Generalised descriptions are given for some deposits in NW Nelson, Fiordland and Marlborough districts.

Jan 1, 1980