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Laboratory tests were conducted to study the effects of thrust or pull-down force and rotary speed on the vibration signatures of a particular drill in a known rock type, and to determine how the vibration signatures could be used to assess bit wear. The vibration signatures were analysed using a Wavelet Transform analysis technique, which decomposes the signals in multi-bands of frequency and presents the results simultaneously in time and frequency domain. Results show that as the bit wears, large fluctuations in amplitudes in the high frequency ranges occur, and prominent peaks in the low frequency ranges were observed for a worn bit. The Wavelet Transform technique provides an appropriate and effective metrics for monitoring and evaluating the state of wear as drilling progresses through the post-processing of wavelet coefficients. This study provides a basis for the development of an on-line detection technique of bit wear in rock drilling through Wavelet Transform technique or time-frequency analysis that can be used in real time.

Jan 1, 2000

By S Hapugoda, J Manuel, N Ware, A Dehghan-Manshadi

The effect of titania (TiO2 ) addition on the sintering performance of hematite iron ore has been studied by doping pure TiO2 into a sinter blend. The results of laboratory-scale compact sintering tests confirmed the considerable effect of TiO2 addition on sinter strength and mineralogy. The tumble index measurements confirmed an improvement in the strength of the sinter in response to TiO2 addition. The melting point of the sinter was also affected by increasing the TiO2 content, indicating a possible relationship between coke breeze consumption and TiO2 on industrial-scale sintering of Ti-bearing ores. Analysis of the sintered structures using optical and scanning electron microscopes confirmed a general improvement in the overall pore structure and sinter melt characteristics with the addition of TiO2 to the sinter blend. An important feature of the sinter structure was the formation of a perovskite phase (CaTiO3 ) and an increase in the proportion of this phase in the structure as TiO2 levels increase.CITATION:Dehghan-Manshadi, A, Manuel, J, Hapugoda, S, Ware, N and Donskoi, E, 2015. Effect of titania on the sintering performance of hematite iron ores, in Proceedings Iron Ore 2015, pp 29–34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M Cooksey, Z Zhu, N Langrené, W Chen, T Tarnopolskaya

"Dynamic decision-making can significantly increase the value of mining projects and deliver better sustainability outcomes under conditions of uncertainty. Despite its benefits, dynamic decision-making is rarely used by the mining industry, possibly because of the complexity of the algorithms used to make sequential decisions under uncertainty and difficulties in visualising the optimal strategies. To achieve better outcomes in practice, decision-makers in industry would benefit from a tool that would help them to understand and implement the results of the analysis.CSIRO is developing innovative dynamic decision support tools that include an intuitive graphical display of the boundaries between the regions of different optimal decisions, which would significantly assist optimal sequential decision-making under uncertainty. The dynamic decision support tool is based on novel stochastic optimal control methodologies that can be used to optimise decisions in situations with multiple uncertain variables and decisions (Tarnopolskaya, Chen and Bao, 2015; Chen et al, 2015; Langrené et al, 2015). The types of market uncertainties that can be considered include commodity prices, interest rates and exchange rate, while the key orebody uncertainties include the reserves, boundaries between ore types and even geometallurgical parameters.The dynamic decision support tools have a number of benefits and can be used to:construct optimal operational strategies and to optimally manage resources projectsgain insight into optimal strategies under different market conditions and project settings compare expected project values under different project settings and to select the setting that provides best sustainability outcomes.This extended abstract demonstrates the use and benefits of the dynamic decision support tools using a synthetic case study of a gold mine.CITATION:Chen, W, Langrené, N, Tarnopolskaya, T, Zhu, Z and Cooksey, M, 2016. Dynamic decisions under uncertainty – a case study on a gold mine, in Proceedings Life-of-Mine 2016 Conference, pp 20–23 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

The philosophy of computer control of grinding and flotation at ZC/NBHC is presented. The performance and reliability of the in- stalled systems are discussed.

Jan 1, 1978

The Mount Kasi gold deposit in Vanua Levu represents an epithermal, high sulphur, gold-enargite system occurring within a volcanic caldera of Middle to Upper Miocene age. High level breccia pipes flare upward and form flat lying, near surface, mushroom shaped sheets parallel and near to the present land surface. The upper portions of the pipes contain explosion breccias which are capped by sandy siliceous sinter-like beds and are cut by alunite veins. Outlying intercalated scoriasceous lavas and breccia sheets show evidence of subsidence within a shallow basin. Detailed mapping of breccia types, intensity of silicification and the presence of multiple quartz veining and enargite abundance outlined blocks of more consistent gold mineralization within the breccias. This work has provided a model for mineralization which will aid future exploration and ore reserve estimations. A significant eluvial concentration of gold occurs in soils overlying the breccia sheet.

Jan 1, 1987

The importance of proper planning, preparation, and execution of a steady state sampling campaign for metallurgical plant assessment must not be underestimated. Careful planning can increase the amount and reliability of information from an optimum number of samples and fully utilize available plant data. It requires specification of the data required, determination of run duration sampling frequency, the selection, modification and testing of sample points and cutters, as well as organisation and briefing of plant and sampling personnel. Preparation immediately prior to sampling, the conduct of the sampling campaign itself and procedures to handle the collected samples and information are discussed. Cutter design, fabrication and use are described in detail, and typical sampling situations, for ball mills, classifiers, pipes, launders, flotation cells and thickeners are considered individually. Measurement of pulp flow rate can often resolve difficult mass balance problems, and discussion of convenient techniques is included.

Jan 1, 1976

By N Madani, N Battalgazy

Geostatistical simulation has been widely used in mineral resource classification of metalliferous deposits based on international standards such as JORC code which is one of the most extensively used around the world for reporting the mineral resources and ore reserves alongside with objectives of the companies (Sadeghi, Madani and Carranza, 2015). However, the modeling process becomes challenging whenever the relationship between the variables of interest is complicated and cumbersome to model. This characteristic sometimes manifests itself in complex spatial and global cross-correlation measures, deeply depending on the formation and genesis of the deposit. The objective then is to generate the models that not only reproduces these significant characteristics, but also, it leads to a better understanding of a mineral resource estimation and successive decision-makings. In this respect, there are different approaches taking into account the spatial correlation structures, for which can be classified as independent simulation, co-simulation, and factor-based methodologies. In this paper, three techniques: Turning Bands Independent Simulation (TBSIM), Turning Bands Co-Simulation (TBCOSIM) and Projection Pursuit Multivariate Transform (PPMT); from those aforementioned approaches are selected to model two cross-correlated variables (Iron and Aluminum Oxide) belonging to an Iron ore deposit located in Brazil, in order to examine which methodology better reproduces the corresponding complexity in terms of local correlation measure. CITATION: Battalgazy, N and Madani, N, 2018. Mineral resource assessment in complex ore deposits based on international standards, in Proceedings Complex Orebodies Conference 2018, pp 79–81 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Crawford M

During the initial development of Mount Isa Mines power was supplied from a temporary power plant situated near the Man & Supply Shaft. The main power plant was placed in service early in 1931 and then comprised two Babcock and Willcox boilers, fired by pulverised fuel, and two British General Electric Company's turbo-alternators of 5,000 kW. each. Both plants have been described by A. F. McAskill in the Journal of the Institution of Engineers, Australia.From 1931 power demand progressively increased due to greater production, further mine development in the harder sulphides increased pumping for mine drainage and additions to mill and smelter until, by 1935, the plant was inadequate for further output commensurate with a reasonable safety margin.Coincident with the added power demand, operating conditions involved a fuel problem which could not have been anticipated. The ash content of the fuel supplied gradually increased from 13% to 16-5%, while the melting point of the ash decreased with higher pyrite content.Temperature conditions in the furnace required careful control to cope with ash formation and slag accretions.Consequently brickwork, excessively stressed on water walls, was constantly under repair, and required suspension periods of 50% of operating time for cleaning and overhaul.Load conditions varied continually, therefore the high heat liberations in the furnace, necessary to accommodate peaks in fluctuating output, resulted in ash fusion.

Jan 1, 1939

The following thesis is an outcome of an investigation undertaken by the writer, at the suggestion of Professor Skeats, of the dykes and associated auriferous reefs of the Walhalla-Wood's Point belt, with the view of determining what relation, if any, existed between the petrological nature and the extent of llietasomatic alteration undergone by the dykes, and the genesis and localization of the gold.Although the greater part of the writer's time in the field and laboratory was occupied in studying the dykes and auriferous occurrences, a study was also made of the general geology as a basis for the special investigation. In addition, it soon became evident in the field that secondary enrichment had played a marked part in re-concentrating the gold and some interesting data in this connection have been collected. For example, indubitable evidence has been found of nuggets of gold having been formed by secondary processes.

Jan 1, 1920

Gold mineralisation at Wapolu lies within an exposed arcuate zone at the decollement contact between a basement dome of high grade metamorphics and an overlying ophiolite sequence. This contact was originally a thrust fault which has since become a decollement zone for gravity sliding in association with basement doming. Hydrothermal models for the gold mineralisation postulate an epithermal system in which fluids were channelled up the decollement with boiling of those fluids causing hydrothermal brecciation and subsequent gold deposition. The alteration assemblages, fluid inclusion data and geochemistry indicate that the upper levels of the system are exposed.

Jan 1, 1987

Brisbane based and listed on the ASX, Eastern Corp is pursuing the development of coal projects in New Zealand. There are various reasons why New Zealand coals are of interest û substantial resources, stable political/economic environment, close to Asian markets. In just over 12 months, Eastern has secured an operating coal mine (Cascade) and a prospective exploration area (Whareatea West), both on the Denniston plateau region, on the south islandÆs west coast. A key focus of activities is the development of relationships with key stakeholders and the promotion of the local economy.   Certain barriers may exist to the entrance by foreign companies into the New Zealand coal mining sector. These include geological challenges provided by the heavy faulting of the coals, port and rail infrastructure constraints, and the ægreenÆ factor.

Jan 1, 2005

By T C. Hughes, R Hughes

Ausmelt has developed and commercialised high temperature reactor technology that has been applied to waste processing in the form of a catalytic waste converter (CWC). Ausmelt Technology uses a top submerged lance system within a versatile converter containing an oxidised molten siliceous slag. Metals and other valuable products can be extracted from wastes for recycle into the community. Non-valuable components such as toxic organochlorinated compounds are destroyed and prevented from reforming. The slag produced is inert and can be safely used in building and concreting. The CWC can be applied to practically all types of wastes and examples from Ni-Cd batteries to toxic wastes are discussed. Additional benefits can be derived from large-scale operations if the surplus heat generated is exploited to produce steam and electricity.

Jan 1, 2000

By Kubik K

This paper reviews the historical data on relative height changes of landmasses with respect to sea level for Pacific Rim countries.It discusses existing theories of the Greenhouse effect, and the interaction with the vertical movements of the continental plates which leads to different effects for different places. Possible future scenarios are described and directions for future research and measurement programs are given.Relative sea levels are governed not only the increase of water from deglaciation but also by a range of other factors such as variable water storage in lakes and the atmosphere, thermal expansion of the ocean, ocean currents, and the shape of the ocean and the continents. Sea floor spreading, for example, is ultimately more significant than deglaciation in sea level control but is generally much slower.

Jan 1, 1990

This session comprises six papers: One paper is specifically on advances in drilling techniques, a paper presents a classification for water inrush rich with corresponding guidelines for protection, two papers are concerned with mining impacts in integrated catchment management - one from the quality viewpoint and the other from the quality viewpoint, and the final two papers are case studies of mine dewatering - one for an underground mine threatened by a karst limestone aquifer and the other of an open-cut mine threatened by interbedded sand aquifers. The paper entitled, Practical mine dewatering by means of surface drilled wells by Sides is innovative in presenting the case for wells as cost effective and appropriate for a number of purposes including exploration, re-opening old mines, dewatering, grout emplacement and monitoring.

Jan 1, 1988

Sasol Roche Blasting Services (SRBS) and its former owners have been in the process of developing and utilising low-density explosives over the last ten years. Many blasts have been fired in varying strata types in a number of mining operations. This has led to a good understanding of the product and the best methods to exploit its characteristics when designing blasts. Unlike some other low-density products, SoftLOAD« is a homogeneous mix that is easily handled and able to be loaded at high load rates. This paper discusses the physics of SoftLOAD« low-density explosives and how through correct utilisation, blasting outcomes can be significantly improved. It also touches on the various side benefits that can provide the blast designer with a more controlled blast.

Jan 1, 2004

The word "mine" means different things to different people. To a professional in the mining industry, it may mean trucks and shovels, overburden dumps, headframes, mill buildings, and the other conventional nuts and bolts that constitute an operating mine. To an environmental- ist it may mean bulldozed trees and tailings dams. To a mining engineer who has spent a significant proportion of his career in mine and prospect evaluation, it can mean a hole in the ground with a liar at the top. The liar in this case is frequently not so through design but through ignorance. The purpose of this paper is to contribute in a small way to en- lightening that ignorance. In doing so, it will foster more effective deployment of the pool of risk capital available to the industry.

Jan 1, 1982

The aspect ratio (mill diameter/mill length) of autogenous and semi autogenous mills varies widely and can be as high as three or as low as 0.5. The literature on the subject of what effect aspect ratio has on grinding mill performance or energy efficiency is almost non-existent. However, at the design stage of many grinding circuits the subject is often vigorously debated amongst metallurgists. In this paper the performance characteristics of mills with different aspect ratios are examined to determine whether process performance characteristics are a function of aspect ratio and whether high aspect ratio mills are any more or less energy efficient than low aspect ratio units. Data from both pilot and full-scale mills are used for this purpose in open and closed circuit configurations.

Jan 1, 2007

The mineral sands industry in Australia can contribute much more sig- nificantly to economic development beyond the year 2000 by increased production of constituent minerals such as ilmenite, zircon, rutile, leu- coxene and monazite from existing and new resources, and especially from downstream processing to intermediate and finished products based on these resources. The end-use areas for mineral sand-based products include those products whose demand is tied to general economic growth, such as paints and plastics, and refractory bricks for the steel industry. High techno- logy applications such as zirconia ceramics and super-magnets are indica- tive of new developments in technology which provide considerable scope for expansion at higher rates than overall western world economic growth. An optimistic outlook for the industry is outlined, based upon a brief review of opportunities.

Jan 1, 1988

The exploration methods used by the British Coal Corporation in 1990 improve the geological reliability of underground coal production. Although some of the techniques in common use have been proved to be effective, their limitations are recognised and concentration has been on the increasing integration of direct and remote sensing techniques. Attention is focussed onto first seam workings in sections of at least 2 metres in the depth range of 400-1200 metres and covers both surface and underground exploration. The case studies of exploration techniques and their effect on mine design at several existing collieries are representative of a wide range of geological environments within the more productive British coalfields. Notwithstanding such improvements in exploration and geological reliability, further new exploration technology is currently being investigated or trialled by British Coal.

Jan 1, 1991

By Anderson D

Investigation of a water inflow into Wongawilli Mine in the Southern Coalfield of New South Wales included algal analysis. The determination of algae in the water suggested an external water source. An alternative hypothesis proposed that algae are inherent in a coal mine environment. Investigations to determine the validity of these hypotheses and provide information on the viability and longevity of algae under adverse conditions were conducted in the mine and the laboratory. Results indicated that a mine environment is not natural to algae and is not conducive to their growth. These findings support the hypothesis of introduction of surface water to the mine workings. They indicate that, in the absence of other available techniques, algae can be an effective tracer for use in the determination of a water source.

Jan 1, 1988