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Cores of pre-Tertiary basement from ten oil exploration wells are related petrologically to the "axial", "marginal" and "shelf" facies of the New Zealand Geosyncline.A NW. Nelson-type basement is inferred beneath peninsular Taranaki and the western continental shelf. The terms Taranaki Basin and Wanganui Basin are re-defined and the terms North Wanganui Basin, South Wanganui Basin, Pipiriki High, Taranaki Fault, and Turakina Fault are proposed. Major faults are interpreted as of mainly transcurrent type and appear to form the western part of a splay at the northern end of the Alpine Fault. Evidence for a major Cook Strait Fault is reviewed.

Jan 1, 1967

By J Zhou, D M. Hunter, S M. Iveson, K P. Galvin

The recovery and concentration of ultra-fine iron ore can provide significant economic benefits. Presently, there are limited options available given the low settling rates achieved by conventional gravity separation and the relatively poor performance of reverse flotation. The Reflux Classifier is a new water-based gravity separation technology that consists of a set of parallel inclined channels positioned above a vertical fluidised section. This arrangement promotes a powerful throughput advantage compared to conventional fluidisation and a highly selective hydrodynamic basis for achieving sharp separations. A high shear rate develops within the inclined channels, which generates sufficient hydrodynamic lift to convey the lower-density particles (even if they are relatively coarse) to overflow while retaining the high-density particles (even those that are ultra-fine) for discharge to the underflow. The technology has previously been used around the world on particle sizes in excess of 0.1 mm. The present work, however, is concerned with density-based separations down to much finer particle sizes approaching 0.01 mm.A major advantage of the Reflux Classifier technology is the achievement of simultaneous gravity separation and desliming via a single-stage separation. A series of continuous experiments was conducted using an iron ore feed with head grade of 35 wt per cent FeT and nominal top size of 0.106 mm, with 59 wt per cent being below 0.038 mm in size. At a low throughput of 1.5 t/(m2 h), the Reflux Classifier produced high-grade products at a high recovery. For the entire feed, grades of 66.1 wt per cent FeT with Fe recoveries of 80 per cent were achieved in a single-stage separation. Within the 0.020–0.038 mm size fraction, grades of 68.8 per cent were achieved with iron recoveries of 94.7 per cent. Excellent recoveries of up to 57.0 per cent were achieved for the -0.020 mm size fraction. The ability of the inclined channels to retain the fine dense material further enhances the effectiveness of the Reflux Classifier by creating an autogenous dense medium effect within the vertical section. This helps to elevate large gangue particles up into the overflow.CITATION:Hunter, D M, Zhou, J, Iveson, S M and Galvin, K P, 2015. Gravity separation of ultra-fine iron ore in the reflux classifier, in Proceedings Iron Ore 2015, pp 143–148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M I. Pownceby, N A. S Webster, J R. Manuel, J M. F Clout, E Donskoi, N A. Ware

The relative influences of sinter mineralogy, sintering temperature, solid and pore macro- and microstructure on iron ore sinter physical strength are not yet fully understood. Whilst a range of analysis techniques have been used by researchers to evaluate sinter physical properties and sinter mineralogy, none have been able to directly link sinter mineralogy and physical strength under controlled conditions. CSIRO has developed a unique laboratory method to study the fundamental melting properties of fine iron ores in a laboratory furnace under a controlled temperature and gas atmosphere environment designed to simulate the industrial sintering process. Compacted tablet samples for a 0.41 per cent and a 2.5 per cent Al2O3 series were fired in a tube furnace at various temperatures, cooled, then tumbled using a modified Bond abrasion test apparatus to determine a relative tumble index (TI) at each temperature. Quantitative XRD (QXRD) analysis was then carried out on the tumbled samples and optical image analysis (OIA) was conducted on polished sections of a separately fired compact in each case. The amount of total SFCA was found to decrease with increasing firing temperature for both alumina series with the total amount of SFCA higher in the 2.5 per cent Al2O3 series compared to 0.41 per cent Al2O3 series samples. The increase in the amount of magnetite and hematite with increasing firing temperature was largely at the expense of a decrease in total SFCA. Overall, there was good agreement between the quantitative mineralogy determined from QXRD versus OIA for SFCA, hematite and magnetite. Qualitative analysis of high magnification images of the sinter correlated with both the OIA and QXRD results.

Sep 18, 2023

By J E. Moffatt, N A. Spooner, T J. de Prinse, D J. Ottaway, E Klantsataya, L d. S Teixeira, B W. Smith, T B. Payten, G Tsiminis

Single wavelength fluorescence sensing has been used in the preconcentration of ores for many years in situations where it is typically specific to the mineral of interest. Examples of fluorescence sensing include the sorting of diamonds in diamond mines and the sorting of scheelite in tungsten ores. However, the number of minerals that show useful single wavelength fluorescence properties in the visible spectrum is relatively small, so the application of fluorescence sensing is currently limited to niche application in the minerals industry. Recent developments at the University of Adelaide have focussed upon extending fluorescence signal measurements into the infrared spectrum, as well as investigating multi-wavelength fluorescence known as up-conversion fluorescence. These techniques may not only significantly increase the number of minerals that exhibit fluorescence properties suitable for both identification and sensor-based sorting, but also provide mineral-specific signatures of higher quality than previously attainable. This paper details the research work carried out by the University of Adelaide and funded by CRC ORE to develop a mineral-specific fluorescence sensor. The sensor targets two fluorine bearing minerals, fluorite and fluorapatite, that are common in many base metal ores such as porphyry copper ores and silver/lead/zinc ores. Fluorine is a known penalty element in mineral products derived from these ores, so mining companies need to monitor and control the amount of fluorine in their final product to keep it below commercially agreed specifications. Currently there is no real time sensor capable of monitoring fluorine in the ore feed so monitoring and control is carried out using time-consuming standard sampling and off-line laboratory measurements. The development and application of a real time fluorine sensor will enable the mining companies to monitor and control fluorine levels in the plant, greatly reducing the time and cost associated with producing their mineral concentrates within the prescribed specifications.

Nov 10, 2020

By Liu Q, Siefken T. C, Misra V. N

The bubble size was measured in a laboratory flotation column. The effect of variables such as air flowrate, frother dosage and type, pulp density, particle size and water column height on the bubble size was investigated. The results show that an increase in either air flowrate or pulp density cause the bubble size to increase, while increases in water column height, frother dosage, surface tension or solid particle size cause the bubble size to reduce. Among the frother types tested, MIBC was found to be the most effective in reducing the bubble size.

Jan 1, 1992

By Clark K. N

The need for and advantages of simulators in iron ore pellet induration research are described. The approaches to simulation and the techniques to carry it out are discussed in detail covering drying and firing for the straight grate process. The CSIRO simulator design is described and some errors in simulation are discussed.

Jan 1, 1974

The structural pattern of Victoria shows the presence of EW, NW, NE as well as the more readily recognised NNW factors commonly associated with the goldfields. ENE and WNW trends are also present. This structural lattice affects all rocks of the State. Landsat imagery shows that the EW, NW and NE structural elements are closely related spatially to the distribution of Palaeozoic igneous intrusives, Cainozoic volcanic vents as well as all historically important gold mines. It is suggested that the EW, NW and NE structural grid visible on landsat imagery is a reflection of the structure of a mid-crustal layer situated between 3.5 and 17 kms below the surface. The points of intersection of the structural elements of the mid-crustal layer offer most favourable loci for the escape of energy in the form of heat. The correlation between the distribution of igneous plutons, volcanic vents and centres of mineralisation, all reliant on high levels of energy for their formation, indicates the stability of the structures of the mid-crustal layer since early Palaeozoic times. The deep level crustal structures are believed to be, related to the release of stresses placed on the crust since early Palaeozoic times by the rotation of the Earth. A geological model that accommodates the presence of a mid-crustal layer as well as the complexities of the recognised orogenic cycles of southeast Australia is suggested. All 1 000 kg Au reef and deep lead mines fall within 1.5 and 2.5 km respectively of strong linears associated intimately with plutons and volcanic vents. Future exploration of the State is more likely to meet with success if it too is confined to the evaluation of these and similar linears. The mode of mineralisation of any one centre will depend upon the temperature, pressure and geochemical gradients operating on the migrating mineralising fluids as well as the structures in the host rocks. These factors are likely to have varied considerably from one centre of mineralisation to the next and consistency of mineral isation form and depth should not be expected along the length of any single Linear.

Jan 1, 1986

By Player R. L

Measurements of the rate of PbO reduction from high lead metallurgical slags were made under laboratory conditions using graphite, a CO-50%CO2 gas mixture and metallic iron as reductants. The results show a transition in rate-controlling step at low PbO contents (i.e. 6 wt.% PbO). At medium to high PbO contents in the slag, the reduction rate was found to be strongly affected by the slag chemistry, temperature and reductant type. The effect of stirring and hence mass transfer in the slag phase on the reduction rate of PbO was found to be insignificant at medium-high PbO contents. Attention is drawn to the importance of chemically controlled reaction rates at the slag-gas interface. Parallels between these results and test work on a 5 tph scale have been briefly drawn.

Jan 1, 1989

The selection of the ore haulage system is one of the most crucial decisions made in the development of an underground mining project. The haulage system is, once selected, one of the components of a mine that defines its ability to respond to changes in mining inventory and the market conditions for its products. Over the last decade, in Australia at least, this selection process has largely centred on the debate over the merits of shaft and decline truck haulage. Little attention, if any, was given to the application of inclined conveyor haulage as a real alternative to the shaft and truck haulage. This is despite well established precedents for its application in the underground coal industry and some limited applications in underground metalliferous mines. This paper seeks to explore the case for the application of inclined conveyors as a legitimate ore haulage system for underground mines. The case for conveyor haulage is illustrated by an overview of the application of conveyors at some existing operations, and discussion of what conveyors have to offer as a mine haulage system and the issues that are associated with them. Material drawn from the feasibility studies for NewcrestÆs Ridgeway mine and Telfer Deeps Project is presented as case studies that considered selection of inclined conveyor haulage. The purpose of these case studies is to highlight the value of impartially approaching tasks of this type with a robust plan. This plan should be able to respond to issues identified as the task progresses towards the objective of finding the right solution for an ore haulage system.

Jan 1, 2005

By D Kentwell

This extended abstract and associated presentation provide a series of real examples of the complex interactions between the numerous input parameters, both geological and mathematical, that are required for resource estimation. Many of these parameters can contain a large degree of uncertainty at the initial resource stage. The resource tonnages and grades at economic cut offs of some types of deposits are relatively robust to these initial uncertainties while others exhibit significant sensitivity. In some cases, changes in parameters can result in counter-intuitive outcomes. Grades and confidence levels are inseparable; as the parameters change the confidence changes and so does the grade estimate. The extended abstract and associated presentation also discuss the question of whether or not a single solution is still an acceptable outcome for an estimate or if even a set of simulations based on a single fixed set of parameters is acceptable.CITATION: Kentwell, D, 2018. Sensitive dependence on initial conditions in resource estimation, in Proceedings Complex Orebodies Conference 2018, pp 28–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By A Sadri, S Smith

In the metal and mineral industry, different empirical techniques are used to estimate the remaining thickness of the lining within an operating furnace. The disadvantage and costly factor when using these methods is that production needs to be halted. Hatch has developed an accurate and reliable technique based on stress wave propagation principles to determine the condition of the remaining lining whilst the furnace remains online and operational.The technique involves test data collected and compiled to generate 3D imagery used to assist operators and maintenance planning personnel with valuable information showing areas of metal penetration in the lining, remaining lining thickness, exact location of voids, cracks, poor contacts and deterioration due to chemical attack. In this paper, the principals of the AU-E technique will be explained both theoretically and practically. In addition, the use of ultrasound technology for determining the condition of copper cooling elements will be briefly addressed.

Jan 1, 2006

By Lunarzewski L, Truong D

Although there are sound principles used in the world recognised methods of gas emission prediction, results based on these methods applied to several Australian longwall extractions have yielded unacceptably high discrepancies. With the development of mining in new seams and at higher rates of extraction, the need has grown for a methodical approach to predicting gas emission levels specifically for local Australian mining conditions. Such an approach is developed from results of recorded emission readings during longwall mining at Appin and Pacific Collieries over the past 6 years.

Jan 1, 1988

This paper discusses the implementation and potential limitations of the method for estimating sampling and analytical errors of multiple source mine output blended into a shipping product, described by Everett and Ziegelaar (2010). The practice of quality measurement varies between iron ore miners. The common objective is to monitor effective resource utilisation and control of product quality to customers. A flow diagram is given presenting the various options used by iron ore mine operators and the merits of the different options are discussed.

Mar 1, 2010

By I Mason, M van de Werken, B Zhou, J Hargreaves, W Stasinowsky

A critical step in open cut coal mining is clean removal of the overburden. This is usually achieved by drilling, blasting and digging. A key part of this process being successful is to stop drilling at the correct blast ‘stand-off distance’. The stand-off distance is the distance between the base of the drilled blasthole and the top of the coal horizon to be mined. Having this correct provides a protective cap of rock above the coal horizon so that the blast will fracture all the overburden without damaging the coal horizon or mixing it with the overburden. Drilling beyond the correct stand-off distance causes the blast to continue into the coal horizon, damaging it and mixing it with the overburden, leading to significant losses of coal product. Conversely, drilling short of the correct stand-off distance results in additional work to remove the intact overburden.

Sep 1, 2024

By C Ward, U Mueller

Compositional geostatistics is an approach developed to ensure that the constant sum constraint induced by geochemical iron ore analysis is respected in estimation and simulation. Jack-knifing and cross-validation were used within this framework to compare the results from ordinary cokriging of the additive log ratio (alr) variables with those from conventional ordinary cokriging. Two methods were used to back-transform the alr estimates: the crude additive generalised logistic back transformation and numerical integration via Gauss-Hermite quadrature. Previous work on a blasthole data set from a Yilgarn iron ore mine showed promising results, with the Gauss-Hermite quadrature method returning results comparable to ordinary cokriging from the point of view of bias, but superior in that the constant sum constraint imposed by geochemistry of the data was honoured. Other practitioners have noted that the linear interpolation of non-linear log ratio transformations will result in biased results, and that this bias can be masked in a (grade control) setting where the spatial density is high. To test this assertion, the methodology has been extended to successively lower spatial density data sets. The results and applicability to routine iron estimation are discussed.CITATION:Ward, C and Mueller, U, 2013. Compositions, log ratios and bias - from grade control to resource definition, in Proceedings Iron Ore 2013 , pp 313-320 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Rowe P, Rogers D, Warren M

Pressure cyanidation of the minus 10 micron slimes fraction of the Fimiston flotation concentrates for the recovery of gold values has been evaluated as an alternative processing route to the roasting and atmospheric cyanide leaching of the calcine. Laboratory and pilot trials have demonstrated that gold extractions of greater than 94 per cent can be achieved at cyanide consumptions of 12-24 kg/t and oxygen consumptions of 0.1-0.3 Nm3/t with total pressures of 1000-2000 kPa. Economic and operational assessment of several reactor configurations suggests autoclaves may be preferred over pipe reactors at treatment rates of 10 t concentrate/h.

Jan 1, 1996

By M Wagner, H Assimi, F Neumann, C Garcia, B Koch

Run-of-Mine (ROM) stockpiles are the inventory of valuable materials extracted from the mine. Depending on the customer requests, a selective addition of ore from stockyards should be selected at the required tonnage. In the stockyard, stackers and reclaimers are the machines which load and unload ore, respectively. Currently, humans determine the reclaiming/stacking planning sequence in the stockyard by rules of thumb. However, this is a complex task subject to multiple operational constraints, such as where undesirable mineral properties should not exceed certain limits in a request. Human planning can lead to limited decision support and lower ability to consider the upcoming blends and requests. This kind of decision making can cause perturbations in the assumed profit and unexpected loss in practice. Therefore, an intelligent decision-maker and sequence planner would be highly valuable to automate stacking and reclaiming operations in practice. The benefits are reducing variability in decision-making and operation costs. This paper considers a stockyard with available mineral information in the stockpiles using load and dump locations from GPS data feeds. We present an optimisation problem to find a solution which results in reclaiming more ore in a shorter time. To solve the problem, we develop an automatic search strategy based on the greedy search algorithm independent of the type of machine used in reclaiming. The proposed method plans a sequence for stockyard recovery blend optimisation to meet multiple customer demands in a timeframe. Blend optimisation is subject to various constraints such as the elemental composition of the valuable materials and penalty elements. We present three case studies using EKA’s simulator, to fulfil two to four requests from four stockpiles. We compare the obtained results with a pilgrim step reclaiming heuristic and we show how our proposed search strategy outperforms the current strategy used in practice.

Nov 10, 2020

The prevention of silicosis by metallic aluminium has been reported by Denny, Robson, and Irwin in two papers. The first was published in 1937; the second, in 1939. The results definitely established that silicosis was prevented in animals by the inhalation of small quantities of aluminium. The present communication records subsequent progress in this field of research.

Jan 1, 1944

By R Pax

Feed ore variability, the major disturbance into a mineral processing plant receives considerable attention operationally, and at research and strategic levels to ensure that the throughput of the ore are maintained at all times whilst encouraging a sustainable approach to recovering the valuable minerals from ore bodies. Effort and insights from mineralogical and processing characterisation (eg. ore hardness) of sub-ore body domains allows sequencing for processing to ensure consistency and throughput for the size sensitive grinding unit processes. Optimising the blast fragmentation has benefit as does pre-concentration using ore sorting. Blending of ore domains with different characteristics is common for operations. In recent years a number of technologies have become available for on-line and more rapid assessment of ore and have been discussed in a recent paper by Cameron et.al. (2016) as an opportunity for further utilisation of mine-to-mill (and mine to product) strategies. Current concepts have focused on extensive characterisation of ores so that current control practices can be realised and made more effective with relatively slow measurements and actuation. CITATION: Pax, R, 2018. Dynamic concepts for mine to mill operation and optimisation, in Proceedings Complex Orebodies Conference 2018, pp 124–125 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By J Wheeler

The benefits of fine size separation in magnetite concentration are detailed focusing on published research from various iron ore producers. Basic principles of fine sizing and advancements in screening technology are addressed. A chronological review of research is used to show the evolution of fine sizing applications in the industry, starting with studies that demonstrated the benefit of using fine screens to produce consistent lower silica concentrates, followed by improvements in fine sizing equipment that have made effi cient screen classification in ball mill circuits practical. Case studies are used to demonstrate how positive sizing with screens can be used to significantly shift concentrate ‘grind/grade’ relationships.

Jul 11, 2011