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Legislation up to the early 1950s prevented the mechanical extraction of pillars. The mines operating at that time had formed extensive areas of pillars. When permission for the mechanical extraction was gazetted, conventional equipment was employed for pillar extraction and generally using hand mining systems. The mid-fifty's saw the of continuous miners. These machines eliminated the disadvantages of conventional equipment and the necessity for multiple working places. Some new layouts for panels emerged; however, actual extraction methods of pillars still followed closely that of hand mining. During the early sixty's the extraction of standing or new formed pillars was undertaken by the "open-end lift" or a "split and lift" method.

Jan 1, 1974

The operators of the iron ore railroads in the Pilbara faced problems of excessive wear between rail and wheels as the tonnage hauled increased in the early 1970's. Joint research projects were begun between Hamersley Iron, Mt Newman Mining and the BHP Melbourne Research Laboratories to study these problems and recommend solutions. The particular problems of wheel rail interaction were solved by asymmetrical profile grinding of the rail and modifications to the machining of the wheels. Rail materials were improved through increasing yield strengths by alloying and by heat treatment. Wheel materials were improved by alloying. The economic benefits of these improvements have been demonstrated by much reduced re-rail requirements and other reduced maintenance costs.

Jan 1, 1986

By Merwin RA

The recent development of rare earth permanent magnets has revolutionised the field of magnetic separation. The advent of rare earth permanent magnets in the 1980s provided a magnetic energy product an order of magnitude greater than that of conventional ferrite magnets. This has allowed the design of high-intensity magnetic circuits operating energy free and surpassing the strength and effectiveness of electromagnets. New applications and design concepts focusing on the mineral and metal processing industries have evolved. This technology also led to the development of various magnetic separators specifically designed for mineral processing applications. Applications which were not previously considered are now being applied to primary mineral upgrading and recycling and secondary recovery.

Jan 1, 1993

By Barnett J. C

The arid and semi-arid region of Western Australia occupies about two-thirds of the State equivalent to an area of about 1.8 million sqkm. Groundwater demand in this area has historically been linked to the pastoral andmining industries commencing with the gold discoveries in the Eastern Goldfields some 100 years ago. Substantial increases in demand have occurred in the past two decades initially as a result of nickel discoveriesin the early 1970's and more recently the rapid resurgence of the gold mining industry. Mineral exploration and development in the Great Sandy Desert at Telfer (gold) and Kintyre (uranium) and in the Great Victoria Desert at MulgaRocks (uranium) has also been accompanied by detailed groundwater investigations.

Jan 1, 1988

The rnunber of Cenozoic volcanoes which has already been found in China surpasses 600. An ancient Chinese tourist, Xu Xiake (1587-1641 in the Ming Dynasty), mentioned in his travel notes the volcanoes and hot 'springs in Tengchong, a country of the Yunnan Province, 400 years ago. In 1927, the geologist, Yun Zhanli, expounded generally on the recent volcano distribution in China. In the '70's, China not only accomplished aerial photography and produced topographic and geological naps covering the whole country, but also obtained a new understanding of the geographic distribution and process of development of the Cenozoic volcanoes through Landsat imagery; interpretation and ground verification, together with C14 isotope dating and analysis of volcanic rocks.

Jan 1, 1987

Modelling of Synergistic Effect of Cyanex 302 and D2EHPA in Zinc Solvent Extraction A comprehensive model is presented to predict the synergistic effect of D2EHPA and Cyanex 302 on co-extraction of zinc and manganese. The experimental results indicated that pH, temperature and the extractants ratio have strong effects on the extraction process. Correlations were proposed to predict the distribution coefficient of zinc and manganese between two phases at different conditions by multiple linear regression. The correlations were simplified by eliminating less important terms by analysis of variance. Optimum conditions (ie pH, temperature, extractants ratio and aqueous to oil phase volumetric ratio) for obtaining maximum separation of zinc from manganese at different zinc concentrations and number of extraction stages were determined. For finding the optimum condition genetic algorithm was used. Comparison the model estimations and the experimental data show that the presented model has good ability to predict the behaviours of zinc extraction system over Cyanex 302 and D2EHPA.

Sep 13, 2010

By K Knorr

Desktop X-ray powder diffraction using a D2 PHASER equipped with fast linear detector was performed on several iron ore and mill scale samples. Data were analysed using cluster analysis and Rietveld quantitative phase analysis. The quantitative mineralogy of both materials could be established. Thus the input is provided for understanding the energy consumption and the CO2 emission during iron production. Furthermore, tabletop XRD allows to distinguish iron ore from mill scales and to quantify their mixtures.

Jul 11, 2011

By M Zanin, E Chan, D Xu

An experimental design has been developed to investigate the relative influence of distinct pulp and environmental properties on froth stability in the flotation of a typical porphyry copper ore. In particular, factors such as frother and collector type, feed particle size (P80), solids per cent, composition (chalcopyrite and pyrite content), as well as grinding environment (mild steel versus stainless steel, high and low pH) have been varied in a controlled manner, and the resulting froth stability evaluated. A previously developed froth stability column, based on the Bikerman approach, was used to measure the froth height and half-life in each test. The relative effect of each factor is presented here on a comparative basis. It is shown that frother type is the most important factor, with marked difference in froth stability when switching from methyl isobutyl carbinol (MIBC) to glycol based frothers. Solids per cent and particle size also play a significant role. The grinding environment had lesser effect on the resulting froth stability, although mild steel grinding gave higher froth stability compared to stainless steel grinding. The experimental evidence supports the hypothesis that in porphyry copper flotation the grinding environment influences surfaces oxidation, pyrite activation and the extent of hydrophobic particles reporting to the froth phase. This has an indirect effect on the resulting froth stability, which is however small if compared to the other factors. This work is still in progress, and extension to other mineral systems is planned. However, some insights are offered to operators on the parameters which are more likely to have an impact on froth stability in copper flotation plants.CITATION:Zanin, M, Chan, E and Xu, D, 2014. Empirical evaluation of factors affecting froth stability in copper flotation, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 193–200 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By F Brenguier, R A. Lynch, G Olivier

The seismic velocities of intact rock are dependent on the applied stress. Unfortunately, the low susceptibility of seismic velocity to stress changes mean that changes in seismic velocity have to be measured extremely accurately to infer stress changes from them. Previously, it was thought that measurements of this accuracy could only be made with active sources or repeating earthquakes. In this paper, we show that the noise generated by mining activity can be used to construct virtual seismic signals with which we can measure changes in seismic velocity accurately enough to see the short- and long-term effects of a production blast on the surrounding medium. The time-dependent velocity variations achieved with this method show that the blast caused weakening of the rock mass for the rock within a radius of 200 m of the blast. The weakening is healed by confining stresses over a period of five days, after which permanent changes in the seismic velocity can be seen. The size and spatial distribution of the seismic velocity changes were compared to modelled changes in static volumetric stress, which supported the notion that seismic velocity changes can be used to measure the redistribution of stress after a blast. The results of this study indicate that this method can be a powerful tool to evaluate the evolution of stress in a mine at a relatively low cost as the data that it uses would normally be discarded.CITATION:Olivier, G, Lynch, R A and Brenguier, F, 2016. Measuring the redistribution of stresses resulting from new excavations with ambient seismic noise correlations, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 873–878 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By I J. Holland

Located in North West Queensland, XstrataÆs Mount Isa Copper Operations (MICO) is one of the largest underground mines in Australia with annual production exceeding six million tonnes of ore with average copper grades of three per cent. As at 30 June 2006, the Ore Reserve inventory totalled 87 Mt, with annual diamond drilling planned at >40 000 m in order to convert existing resources and test and define exploration targets. The role of the geology department within MICO is to collect, interpret and communicate relevant geological information to ensure the optimal extraction of ore. Routine underground inspections across multiple ore sources are undertaken and the information derived is then distributed to a range of professionals, operational personnel and management. The information is a æreal-timeÆ geological view for the stakeholders. Ongoing data collection and interpretation has developed a strong geological input to all mine planning processes within MICO. This has created strong synergies between mine planning professionals and a throughput benefit has been seen all the way to the concentrator. The MICO geological framework also provides avenues for a geological focus away from short-term production requirements, and as a result significant orebody scale observations and patterns have been realised that have led to an increase in the accuracy of geological and resource models. This has provided practical benefits for short-term scheduling and production, whilst enabling the realisation of long-term benefits that have a strong potential to increase the volume and value of the MICO resource. This paper will discuss the various mine geology contributions at MICO and illustrate some examples where mine geological input from graduate level has added significant value to the MICO business.

Jan 1, 2007

By M D. Sussman

A large number of countries in the world now have some regulation for labelling the presence of genetically modified organisms (GMO) in food. For the last ten years, ISO/TC 34/SC 16 has been providing methods, guidelines and requirements concerning the evaluation of molecular biomarkers including GMOs. This activity makes sure that stakeholders on all sides of commercial transactions are satisfied and their marketing or regulatory needs are met. Developing and maintaining a transparent, science-based environment for users of horizontal methods for molecular biomarker analysis is a high priority. Sampling and analysis of molecular biomarkers has become critically important for food and agricultural organisations developing, producing, distributing and selling genetically engineered, non-genetically engineered, identity preserved and/or organic crops and their derived products and preventing their respective destructive diseases. To aid in international harmonisation, a new work item proposal to develop an ISO type A management system standard (MSS) for organisations including laboratories using molecular biomarker analysis and sampling has been submitted to ISO/TC 34/SC 16. The purpose of this MSS is ensuring that determination of the presence, absence or quantification of a particular biomarker with a relationship to a product quality determinant, a marketing claim, a regulation or a plant pathogen is carried out under a suitable quality assurance / quality control system. This MSS will provide an overarching system to apply and manage molecular biomarker analysis and sampling for any organisation large, medium or small in a private, government or academic setting.CITATION:Sussman, M D, 2017. ISO/TC 34/SC 16 horizontal methods for molecular biomarker analysis – molecular biomarker analysis and sampling management system, in Proceedings Eighth World Conference on Sampling and Blending , pp 295–302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

Conventional narrow vein mining, utilising hand held methods, is expensive and requires specialised miners who are becoming a rarity. Hand held mining techniques (shrinkage stoping, leading stoping and cut and fill) have the advantage that they can be selective. The methods allow continued sampling of the face, control of hanging wall conditions and are adaptable to changes in strike and dip. On the other hand, more productive longhole stoping methods can allow excessive dilution due to drill hole deviations and changes in orebody dip and can be subject to unexpected hanging wall or footwall failures. Development of small scale equipment (as narrow as 0.8m wide) used for drilling or bogging very smallaccess drives has been ongoing over the past decade. In this paper, types of equipment are examined and compared, particularly with respect to their produc- tivity, size, and working environment. The introduction of electric hydraulic equipment has provided a better working environment with reduced noise, exhaust fumes and heat. The concept of the "hydraulic cherry picker" may have application in mining steeply dipping orebodies. The system requires orebodies to be reasonably consistent in dip over 15 metre sub-level intervals. The system involves the basic concept and skills of machine and airleg mining, combined with the safety and productivity of a mechanized work platform. The platform or basket is stabilized between the hanging wall and foot- wall by hydraulic rams and is extended by a tilting hydraulic boom mounted to a small prime mover or trailer. Design concepts (including remote controlled charging of explosives, adaptation to the boom for rock cutting and the overall electric hydraulic mining concept) are put forward in the paper as a view as to how narrow vein mines will be mined in the future.

Jan 1, 1987

By Draper J. J, Jell J. S

The Burdekin Basin in the Townsville hinterland is an intracratonic extensional basin which contains up to 4500 m of marine and continental siliciclastics and carbonates. The basin sequence is recognised as having accumulated during five major episodes of deposition. Facies analyses of these show that each consists of one or more transgressive or regressive phases. Each episode led to the accumulation of thick sequences in several half-grabens in a transtensional back-arc setting. The depositional episodes can be recognised in comparable sequences in the Broken River Province to the west and Drummond Basin to the south.An Early Devonian episode resulted in the deposi-tion of dominantly marine facies, currently mapped as Fanning River Group, in the northern part of the Burdekin Basin. Two transgressive phases are recorded there, firstly in the Pragian, then later in the late Emsian to early Eifelian. A Middle Devonian episode is represented by dominantly marine facies of the Fanning River Group, representing the peak of a widespread late Eifelian to Givetian transgressive phase. A Late Devonian episode is characterised by continental facies of the Dotswood Group. Deposition occurred during a major regressive phase in response to regional uplift of surrounding areas, and the onset of acid-intermediate volcanism to the south. A Late Devonian to Early Carboniferous episode followed, which was a period of alternating marine transgressions and non-marine regressions that resulted in the deposition of the Keelbottom Group. A final Early Carboniferous episode, marked by the deposition of calc-alkaline volcanics and non-marine faciesòof the Glenrock Group, was a direct outcome of Early Carboniferous subduction further to the east. Compression of the basin followed in the Late Carboniferous, resulting in folding and reactivation of basement faults.

Jan 1, 1990

By M Behrens, A McPhee, B D. Hegan

This paper describes the design and construction of twin 400 m long road tunnels as part of the Northern Motorway Extension Project in Auckland, New Zealand. Construction of the tunnel civil works is now completed and installation of mechanical and electrical systems is well underway. The tunnels are expected to be open for traffic at the end of 2008. The paper will address the design aspects of the project including: tunnel alignment and cross-section, geotechnical conditions and rock support, waterproofing and concrete lining and fire and life safety. The paper will cover the bored tunnel section, the cut-and-cover tunnel section, cross passages and portal structures. The design brief included a requirement for the tunnels to be a gateway to Auckland and this required particular attention to be given to the visual appearance of the finished tunnel structure. The final arrangement of the portal structures and a requirement for recesses in the concrete lining for emergency cabinets, deluge pipework and cable runs, reflects these requirements. The tunnels were excavated by a roadheader and road planer using a heading and bench. Initial support was provided by a combination of lattice girders, cement grouted rock bolts and steel fibre reinforced shotcrete. The permanent lining consisted of installation of a drainage geotextile and waterproof membrane, followed by cast in situ unreinforced concrete. Each portal consists of a cut-and-cover section. This paper describes the tunnel construction methods, including the particular requirements for safety, the environment and community relations. The tunnel is fitted with a compartmentalised deluge system for fire fighting purposes. The tunnel control centre is incorporated into the control centre for Auckland Harbour Bridge, some 30 km from the tunnel location.

Jan 1, 2008

By B, R E. Browner, H R. Watling

A number of hydrometallurgical treatment methods are being developed to extract copper from chalcopyrite flotation concentrate including microbial leaching and ferric sulfate leaching. However, chalcopyrite is difficult to process efficiently by hydrometallurgical methods as it exhibits slow reaction kinetics. Comparative leaching tests do not always satisfactorily explain or predict observed copper recovery, acid consumption, or differential leaching of minerals. This is especially true when reactive gangue constituents are present. The aim of this study was to determine how the leaching regime (microbial versus ferric sulfate) affects both the extraction of copper and residue mineralogy. Chalcopyrite flotation concentrate was leached at 30¦C and 65¦C using a pure culture of Acidithiobacillus ferrooxidans and a mixed consortium of thermophiles, respectively. In addition, the concentrate was leached at the same temperatures using 0.1 M ferric sulfate. Microbial leaching of chalcopyrite extracted more copper than ferric sulfate oxidation of chalcopyrite at 30¦C, demonstrating that the microbes promoted the solubilisation of copper at this temperature. This result was confirmed by leach solution analyses and residue analysis using quantitative X-ray diffraction (QXRD). More chalcopyrite was oxidized with ferric sulfate at 65¦C than at 30¦C (as expected). QXRD confirmed that pyrite reacted during ferric sulfate leaching at 65¦C but was relatively unreactive during lower temperature leaching. The high ferric ion concentration in the ferric sulfate leach at 65¦C led to significant precipitation of jarosite. This phase was only detected in small amounts at 30¦C in both the microbial and ferric leached residues. Sulfur also precipitated in the ferric leaching at 65¦C whereas no sulfur was detected in the microbial leached residue. Quartz was a relatively unreactive mineral phase regardless of the leaching medium and temperature. QXRD analysis indicated the residue mineralogy differed with different leaching regime.

Jan 1, 2004

By Heyes GW, Orrock GI

The fine grained complex orebody at Elura contains galena, silver and sphalerite in a matrix which is mostly pyrite; sulphides account for about 90% of the orebody. A differential flotation circuit is operated to con- centrate lead and silver in the first section and zinc in the second. The metallurgical performance to date indicates the need for improvement. The lead section has been sampled in detail to comprehensively assess its overall performance and to define problems associated with lead and silver flotation. The substantial amount of pyrite in the feed dominated the perfor- mance of each stage of the separation. It was responsible for extensive dilution of all concentrates and, as a consequence, for very large circulating loads. The rougher concentrate contained 68% pyrite some of which was rejected through the three stages of cleaning to 39% in the final concen- trate. However, this was still sufficient to hold the assay of this product below 45% Pb. Size by size behaviour shows that flotation rates of the valuable minerals, as characterised by their rate coefficients, were low through- out the circuit. There was a significant deterioration in these rates between rougher and cleaner I stages which resulted in large circulating loads between these stages. There was practically no recovery of coarse valu- able minerals to the final concentrate. The dilution of the final concen- trate by non-sulphide gangue was not a major problem. If the recovery of the galena and silver in the +38¦m size range could be raised to that of the - 381Lm size range, galena recovery would rise from 78% to 86% and silver recovery would improve from 46% to 59%. The Pb grade of the final concentrate would remain the same.

Jan 1, 1988

By D Craw

Quaternary warping and uplift of antiformal schist ranges in Central Otago, New Zealand, has resulted in recycling of alluvial gold from widespread, generally weakly auriferous, Miocene fluvial gravels that unconformably overlie the schist, into aprons of fan sediments along the range margins. Basement erosion during uplift has been limited and so gold input from sparse gold-bearing quartz veins in the schist has been relatively minor. In an eluvial cycle on the slopes of the ranges, chemical remobilization of gold occurs during oxidation and erosion of the Miocene sediments. The typically fine-grained (300 - 400 ¦m) gold undergoes chemical modification and grain size enhancement of up to two orders of magnitude, and much of it is redeposited in a large number of relatively small alluvial fans along the range margins. Groundwater mobility within the fans results in minor additional gold mobility and grain size enhancement. During range uplift, a small number of relatively large axial streams and rivers have developed in structural lows between growing antiformal folds. Axial streams 'gather' their flow from consequent streams draining the folds, and flow parallel to a range axis for some distance before cutting across it in an antecedent gorge. The axial streams rework alluvial fan sediments along the range margins, and transport mainly fine-grained gold from the fans along the ranges. This gold is redeposited where the axial streams emerge from a range in the neighbouring structural basin. Axial streams drain relatively large areas of range surface, and thus reconcentrate significant quantities of gold in a small number of relatively large fans and fluvial deposits. The processes of gold collection and re-deposition by axial streams are essentially the same, regardless of stream size. Coarse-grained gold produced by chemical remobilization, is more difficult to transport in fluvial systems, and thus remains in close proximity to eluvial environment where it was formed.

Jan 1, 1995

By J Zanganeh, M Ajrash, B Moghtaderi

Application of thermal oxidation is considered a promising technique in reducing fugitive methane gas from ventilation air methane (VAM). A typical thermal oxidiser operates with diluted methane and converts it to less potent greenhouse gases. However, having a thermal oxidiser in the vicinity of the coalmine exhaust shaft is a major safety concern as its high operation temperature increases the likelihood of accidental fire and explosion. The aim of this study is to investigate the application and effectiveness of side venting technique in reduction of deflagration consequences caused by methane gas. To address this importance a series of experiments were conducted on a detonation tube designed and fabricated as part of larger scale VAM Abatement safety project. The experimental work was carried out into two stages: examine the flame and explosion properties in a large-scale detonation tube to get reliable data; and then design and employ a venting system into the detonation tube to verify the effectiveness and performance of the venting against the flame and explosion.Results corresponding to this study show that the side vent duct with venting coefficient magnitude of 37 had a significant influence on methane flame deflagration and the explosion characteristics. The maximum pressure rise at the detonation tube reduced approximately 20 per cent to 32 per cent by applying the side venting duct. Also, the data shows that the venting damped the pressure oscillation after the flame deflagration which eventually reduced the system instability. Finally, by applying the venting technique the expected level of damage due to the dynamic pressure reduced to the level of limited building damage.CITATION:Ajrash, M, Zanganeh, J and Moghtaderi, B, 2017. Application of side venting technique in mitigation of methane – air explosion and flame deflagration in ventilation air methane, in Proceedings Australian Mine Vent Conference 2017, pp 153–258 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

On Wednesday 11th November, 1970, a series of violent explosions occur-- red within No.1 Basic Oxygen Steelmak- ing (B.O.S.) furnace at the Whyalla Works of the Broken Hill Proprietary Co. Ltd., (B.H.P.) when the furnace was moved immediately prior to tapping. Water from a burnt out flux chute had flooded the bath while the furnace was tilted slightly towards the tapping side waiting to tap. Although no one was injured, dam- age in excess of $54 000 was caused to the hood and superstructure. The water hydrated the burnt dolomite refractory lining some of which sub- sequently collapsed exposing bare fur- nace shell over part of the cone.

Jan 1, 1975

By L Huang

"Successful rehabilitation of tailings landforms of tens to thousands of hectares in size at base metal mines is critical to mining companies’ ‘social licence to operate’. Rehabilitation technology used is closely related to both the economic sustainability of the mining company and the ecological sustainability of the mined environment. Conventional technology to rehabilitate mine waste landforms is costly and constrained by the availability of soil (to reconstruct root zones) and clay materials (to reconstruct compressed layer). Depending on mine waste properties and site-specific resource availability, it is not uncommon to cost A$0.1–0.5 M/ha for the establishment of conventional cover systems over mine waste domains, which often accounts for large proportion of the total closure costs. This can lead to costs approaching several hundred millions dollars for rehabilitating larger tailings and acidic waste rock using conventional cover systems.The present extended abstract proposes a suite of new technologies to tackle the problems outlined above and discusses critical factors in successful rehabilitation from substrate levels to the whole landform performance, in two key aspects:in situ engineering of tailings soil to offset/reduce materials requiredin situ chemical engineering of massive hardpan layer through alkali-activation and mineral gel cross-linking network mechanisms to encapsulate reactive tailings and achieving sustainable hydro-geochemical stability in root zones.This aims at functionally replacing the roles of the compressed clay layer and capillary breaks in conventional covers. These technologies would improve both the economic and ecological sustainability of mine waste rehabilitation, thus addressing the triple-bottom line of mining and mineral processing industries not only in Australia but other countries.CITATION:Huang, L, 2016. Emerging technology for economic and ecological sustainability in the rehabilitation of metal mine tailings, in Proceedings Life-of-Mine 2016 Conference, pp 128–131 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016