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By Jarc H

The steeply dipping silver/lead/zinc orebodies at Mount Isa mine have been extracted most recently by a combination of cut-and-fill and open stoping methods. Bench stoping was first used at Mount Isa Mine seven years ago to allow safe extraction of a highly stressed cut-and-fill stope. Subsequent benches have shown that the method offers significant cost and safety benefits through increased productivity and reduction in man exposure. The success of benching has lead to cut-and-fill mining being replaced at Mount Isa.Significant resources have been focussed to optimise benching. This paper describes the operational, planning, and research and development aspects which have contributed to the method to date. A brief look is also taken at the future direction of benching at Mount Isa.

Jan 1, 1992

Comparison of Industrial Cyanide Destruction Processes

Sep 13, 2010

Promoters for Soap Flotation of Phosphate Minerals

Sep 13, 2010

By L Forrester

The tube bundle system is an integral part of an underground coalmine’s gas monitoring system. The maintenance of these systems is vital to ensure the quality of the data produced. Integrity testing of the tube bundle lines is required monthly, as specified in Standards Australia AS/NZ 2290.3 (1990). The various forms of integrity testing are reviewed, including pressure testing and introduction of a known gas. This paper provides a recommended and standardised methodology for those techniques where none currently exists. A strengths, weaknesses, opportunities, threats (SWOT) analysis is performed. The parameters considered for the SWOT analysis include resourcing required by the mines, time for the testing to be performed, and quality of the results produced. The suitability of such integrity testing protocols to be used in a mine emergency situation is also evaluated.CITATION:Forrester, L, 2017. Tube bundle integrity testing methodologies, in Proceedings Australian Mine Vent Conference 2017, pp 129–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By G Akdogan, R V. R Handfield-Jones

The application of microwave energy as a substitute for conventional heating has drawn interest from many researchers in extractive metallurgy. Microwaves have a heating effect just as many other forms of radiant energy. Microwaves are able to penetrate the substance at which they are directed and in being absorbed heat the material from the inside. As a result of heat generated in the interior of a particle, microwaves can affect the rupture of a particle (in this case a host ore) and break down the matrix of the particle (host ore) and expose the recoverable mineral to the leaching reagent. Two series of leaching experiments were carried out at temperatures above 90????C using a conventional heater (hot plate) and a modified 850 W, 2.45 Ghz microwave oven. One series of tests was carried out at ambient temperature. A pyritic/arsenopyritic gold concentrate was leached with 3.3 kg/t to 6.8 kg/t NaCN for two hours. The extraction of gold at 6.8 kg/t NaCN was higher in microwave assisted leaching (59 per cent) than the extraction obtained in leaching at conventional heating (39 per cent) and ambient temperature (28 per cent). Extraction of gold was dependent on the size fraction used and was 48 per cent for û75 ¦m, 43 per cent for û90+75 ¦m and 37 per cent for û150 + 90 ¦m size ranges.

Jan 1, 2000

By R L. Brathwaite

In New Zealand, volcanogenic massive sulfide (VMS) deposits are found in three main geological environments associated with: 1.   ophiolitic basalts of Oligocene age in Northland and East Cape (eg Pupuke, Pakotai, Parakao and Lottin Point); 2.   with chert and pillow lava in greywacke sequences of Permian-Jurassic age (Torlesse and Waipapa terranes; eg Kawau Island, Te Kumi and Maharahara) and their metamorphic equivalents (Haast Schist; eg Moke Creek and Waitahuna); and 3.   with greenschists (metabasalts) and metaserpentinite of Permian-Triassic age (Ponamu Ultramafics) in Westland (eg Bowen and Wilberg ranges). The deposits consist of small lenses of disseminated to massive sulfide minerals, mainly pyrite and chalcopyrite. Small quantities of copper ore were mined from some deposits in the 1800s (eg Kawau Island from 1846), with the last mining at Parakao from 1961 to 1966. Several deposits have been recently examined for their gold potential with assays on sulfide rock samples as high as 75 g/t Au (Lottin Point).

Jan 1, 2005

Beneficiation of Iron Ore - Washing with Surface-Active Agent The stability of the dispersed phase in 10 wt per cent slurry of iron ore slime and fines was studied at pH 5 and different concentrations of surface-active agents. The behaviour of the dispersed phase of iron ore slime and fines is different for different surface-active agents. The improvement of iron value of slime and fines in the presence of surface-active agent is best realized at pH 8, where the Al2O3/Fe and Al2O3/SiO2 ratios in the concentrates are appreciably reduced. The polar functional group like -COO- interacts with hematite surfaces and forms outer- and inner-sphere surface complexes depending on the suspension pH and adsorbate.

Sep 13, 2010

Laboratory scale flotation tests were done on mineral hematite and aspecular hematite ore using oleic acid and sodium oleate as collectors. The mineral hematite floated strongly in the neutral pH region, with an increased pH range of flotation at higher oleate additions. Concentrates with sufficient hematite grade to meet the paint pigment specification were produced using oleic acid and sodium oleate as hematite collectors on the specular hematite ore. Hematite recoveries of 70 per cent at 60 per cent Fe grade were obtained using stagewise roughing. The interaction between hematite and oleate was confirmed as chemisorption but the exact mechanism could not be determined, as two independent phenomena can be used to explain the fact that the pH of maximum grade increased with increasing oleate addition.

Jan 1, 1999

The resource industry must prepare for the inevitable shift towards automation as an operational objective. Although this may seem like a distant concern, many mining companies and equipment manufacturers are already conducting full-scale automation trials. The necessary technology is advancing at a rapid pace yet the training of people to support it at the trade level lags far behind. Those given the responsibility of installing and maintaining automated equipment in the mining environment require a unique set of skills and knowledge. These training needs demand attention to ensure that the wider uptake of automation is sustainable and achieves its full potential.   This paper documents work undertaken by CRCMining and the Mining Industry Skills Centre towards establishing a training framework seeking to address the needs of trade level personnel tasked with the support of automation equipment. A comprehensive definition of the skills and knowledge required by the hypothetical automation-specialised tradesperson is presented. The training pathway identified for these personnel is also described. This work forms part of the Mining Industry Skills Centre's Automation Skills Formation Strategy, funded by the Queensland Department of Education and Training.

Jun 1, 2010

Technologies are receiving a lot of 'press' - and rightly so; as they are seen as the means for achieving quantum leaps in productivity and cost reductions. A point of concern for Caterpillar is that we do not believe there is enough understanding of the infrastructure needed to support some of the future technologies, as well there is not enough utilisation of the current systems.

Jan 1, 1997

By J Fisher, M Castro, A Hariyadi

The train haulage system being designed for PT Freeport Indonesia’s Grasberg Block Cave (GBC) will be located within the mine at an elevation of almost 3000 m above sea level on the west side of the island of Papua, Indonesia. The developing block cave is beneath the active Grasberg Open Pit and will transport 160 000 t of ore per day from multiple chute galleries to the underground crushing plants. The design entails 28 km of rail and 119 ore chutes, which will be brought online over the course of ten years.The train haulage system will be driverless and fully automated. Sequentially, the system includes remote controlled rock breakers at the top of the chute grizzlies, followed by remote controlled chute loading of the trains, then autonomous train haulage and autonomous unloading. An overhead catenary system (OCS) will power the locomotives, which are equipped with on-board batteries to drive through the loading and unloading sections. Service locomotives with drivers move material-laden freight cars in and out of the service shaft, destined for workshops, the magazine and batch plants. Service locomotives are also used for haulage level maintenance. Highly reliable and redundant control and communications systems are required to manage 12 trains in simultaneous operation.This paper provides an overview of the train haulage system’s technical complexities and the associated support systems interactions. The paper also highlights the project management issues and successes of this globally sourced project.CITATION:Hariyadi, A, Castro, M and Fisher, J, 2016. Automated train ore transport, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 563–570 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Neither the copper orebodies nor the zinc-lead-silver orebodies at Mount Isa were formed syntectonically as has been claimed for the last 20 and 10 years respectively. Both orebody types were cogenetic, coeval, and formed early during the sedimentation and diagenesis of the host formation. The copper orebodies are interpreted as having formed diagenetically at hand specimen scale, syngenetically at formation scale. The zinc-lead-silver orebodies are interpreted as having formed primarily by sedimentary means at both hand specimen and formation scales.

Jan 1, 2000

Electrochemistry Measurement, Using Chena Analyser, to Investigate Selective Separation of Pentlandite and Pyrrhotite

Sep 13, 2010

By Y Chen, G Xu, B Albijanic

High concentrations of airborne coal particles is the main reason leading to health and safety hazards in underground coalmines. Water spray is one of the effective methods to suppress coal particles in mine sites, but the use of plain water is not effective enough to capture coal particles. By adding surfactants, coal wettability can be improved which will increase the coal dust suppression efficiency. In this study, a modified sink test was employed to evaluate coal wettability in the presence of two anionic surfactants: sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS). Sink rates were calculated by measuring sink weight over test time. Different surfactant concentrations (0.01 per cent, 0.05 per cent, 0.1 per cent, 0.2 per cent and 0.4 per cent) and two types of water (tap water and deionised water) were selected to investigate coal wettability over three size ranges (0–38, 53–75 and 75–90 µm). The results show that both SDS and SDBS surfactants can lower the water surface tension and improve coal wetting performance. Sink rates increased as the surfactant concentration increased, and surfactant solutions prepared by tap water performed better than deionised water in enhancing coal wettability. Also, coal wettability varied for different coal particle sizes; the smaller coal particles were, the worse the wettability they possessed.CITATION:Chen, Y, Xu, G, Wang, R and Albijanic, B, 2017. Study on coal wettability for dust suppression in the presence of surfactants by sink test, in Proceedings Australian Mine Vent Conference 2017, pp 105–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By T Graham

Traditional iron ore wet beneficiation plants are large multilevel structures, often integrated into centralised processing plants. They are characterised by sizeable footprints, substantial water and power consumption, inflexible design and low scalability. Significant design changes that address these issues need to be made before relocatable modular plants become feasible. Firstly, large amounts of processing water are required in standard wet plants, so it is vital that water consumption is reduced to an absolute minimum. Secondly, the process of depositing tailings into tailings storage facilities (TSFs) is environmentally destructive, consumes significant power and requires lengthy approvals to be completed. Thirdly, modules need to be easily and quickly relocatable.The solution to reducing water usage and eliminating TSF requirements is accomplished by providing a tailings dewatering and dry-stacking capability into a separate module. This equipment needs to dewater tailings to a point (typically below 20 per cent moisture) where dry stacking becomes possible – design is mainly driven by material rheology and particle size distribution (PSD). In this respect, a flexible and scalable strategy is employed to dewatering modules, allowing a variety of components such as dewatering cyclone clusters, paste thickeners, fine mesh vibrating screens and filter presses to be used to achieve the necessary moisture level, enabling the final dry stacking to be accomplished by a simple telescopic stacking system. Plant relocatability also requires modules to comply with mass and dimensional constraints, as well as ‘plug and play’ ease-of-use features.For coarse particle upgrade, jigs provide a low-cost and effective solution, whereas fine and ultra-fine Fe units can be recovered using Wet High Intensity Magnetic Separation (WHIMS). Recently, sensor sorting – a dry process using X-ray fluorescence, X-ray transmission, laser or other sensors – has begun to make an impact in coarse particle separation, although capacities are still low. The overall objective of a plant is to provide an Fe upgrade of four to five per cent with a feed of up to 4 Mt/a and a recovery of approximately 50 per cent.CITATION:Graham, T, 2017. Relocatable modular beneficiation creates value from waste, in Proceedings Iron Ore 2017, pp 167–172 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By L Olivier, R J. Lowther, J L. Lett, I Brunton

Hydraulic fracturing to precondition the orebody to enhance rock mass cavability is gaining acceptance in underground cave mining applications. Assisting cavability is becoming important as an increasing number of cave mines are being implemented in hard, deep and competent rock masses where clamping stresses are higher and cave column heights may be in excess of 1000 m. Propagating large caves to surface in such conditions can be challenging as risks such as slowed propagation and air gaps can develop during the process.Underground-based hydraulic fracturing is routinely used at Cadia East as a means of preconditioning the orebody to assist in cave propagation, fragmentation and seismicity reduction. This paper presents a summary of a surface-based hydraulic fracture program that was successfully implemented to assist in the propagation of the Cadia East Panel Cave 1 (CE-PC1) cave to surface through competent overlying rock masses. In this case study, the propagation of the CE-PC1 cave slowed as the cave grew past 750 m in height, initiating a Trigger Action Response Plan regarding the cave propagation rate. Surface-based hydraulic fracturing was subsequently used to stimulate the cave to propagate through the final 450 m to surface. The paper details the equipment, strategy, implementation and risk management involved in the program as well as the key learnings.CITATION:Lowther, R J, Olivier, L, Lett, J L and Brunton, I, 2016. Implementation of a surface-based hydraulic fracturing program to successfully propagate a large cave through hard, competent near-surface rock masses to achieve breakthrough, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 83–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Goldfields (Tasmania) Limited operates a small, high-grade underground gold mine on the West Coast of Tasmania, 30 kilometres north of Queenstown. The main orebody, Zone 96, was discovered in 1989, with major development work commencing in 1993. The mine was officially opened in July, 1996. Initial production came from a shallow orebody known as the Sill Zone, some 50 - 150 m below surface, which was accessed by a 1 in 8 decline. Zone 96 lies between 350 m and 550 m below the surface and is accessed by a 402 m deep, 3.2 m diameter internal shaft from the collar level located 100 m below surface. The main ore extraction system in Zone 96 is mechanised cut and fill, using high density paste fill. Run of mine ore and waste are hoisted in a single 5.5 tonne overturning skip, then trucked from the underground collar to the gold plant ROM pad or waste dump, respectively. Ground conditions in the mine vary with orientation and proximity to major faults. The gold is contained in a sequence of strongly altered volcanic rocks adjacent to the Henty Fault. Most of the gold is contained in massive quartz, ranging in width from 0.5 m to 7 m, which has been subjected to substantial faulting. Average mineable grade is about 27 grams gold per tonne. Ore reserves in 1996 proved an initial mine life of approximately 4.5 years at 90 000 ounces gold per annum, with significant potential for additional resources from extensions to Zone 96 and adjacent zones. The lease is located in an environmentally sensitive area and a very high standard of environmental management is an essential part of the operation. This paper describes the relevant aspects of mining at Henty including grade control, ground support, backfill placement and environmental management.

Jan 1, 1998

By S Q. Zhao, J H. Wei, Z X Zhao, S N. Liang

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The degree of regional denudation is one of the most important factors for judging the preservation potential of ore deposits as it can be used in a predictive manner to help guide exploration. There are many methods available to judge the denudation degrees of mineral deposits. These include regional geochemical assessment methods, the characterisation of primary lithogeochemical halos, the thermoelectricity of pyrite and apatite fission-track methods. Each method has its specific principles, application scopes, limitations and successful cases. Based on previous studies, this paper discusses the research progress on assessments of ore deposit denudation in China and provides a summary and discussion of various methods that can be employed.CITATION:Liang, S N, Wei, J H, Zhao, Z X and Zhao, S Q, 2015. Review on the ore deposit denudation degree, in Proceedings PACRIM 2015 Congress, pp 65–68 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Investigation on Multicomponent Semi-Autogenous Grinding

Sep 13, 2010

Efficacy of Enhanced Gravity Separator in Processing Indian Iron Ore Slime The slime sample was subjected to concentration using Falcon concentrator for their enrichment. The effects of three important variables, eg bowl rotation frequency, back water flow rate and per cent solid were studied on the process performance. Increasing the rotation of the Falcon bowl, enable more material to the underflow by increasing the yield, whereas, the iron content decreases steadily with increasing the rotation of the bowl. The increase in the back water flow effectively removes the clay materials from the underflow at the expense of the yield. Similarly, increasing the per cent solid concentration in the feed produces a better product both in terms of yield and Fe content. Results show that EGS/Falcon can be used for processing Indian iron ore slime and producing pellet grade concentrate.

Sep 13, 2010