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The nickel refinery at Yabulu consumes an average of 118,000 kg/h of low pressure steam in stripping operations to-recover ammonia and carbon dioxide from product liquor and ore tailings streams. The steam used in the stripping operations is produced from the 25 MW power generation plant at the refinery. The back pressure on the non condensing steam turbines is maintained at 60 kPa.Studies have been carried out to determine the optimum amount of steam required to be generated for stripping operations. When steam production is increased, the product liquor flow from thewashing thickeners can be increased. This results in improved washing efficiency of the thickeners and therefore improves the plant nickel recovery. A computer thickener wash model was used to predict nickel recoveries at varying steam consumption rates.The studies have shown that in most plant situations, it is not economical to-generate more steam than that already available from existing power production.The studies also highlighted the necessity to use all steam generated from power production at all times to maintain maximum nickel recovery.

Jan 1, 1985

By Koginmo V. I

The concentrator at Bougainville Copper Limited has an annual throughput of 48.2 million tonnes/year producing approximately 175,000 tonnes copper, 16.1 tonnes gold, and 50 tonnes silver. Conventional three stage crushing and screening are used to reduce run of mine ore to an average product d80 size of 6.7mm. The primary objective of the crush- ing plant is to provide a continuous supply of ore to the 12 primary grind- ing mills via an intermediate 300,000 tonnes capacity stockpile. Since ball mill performance improves with decreasing mill feed size, the crushing plant continually strives to produce the finest possible product for mill- ing. This has been achieved by increasing plant availability and total installed power, and improving crusher manganese liner life, screen cloth life, and plant operating practices. A recent innovation was the installa- tion of a 35 million tonnes/year preconcentration screening plant in Janu- ary 1987 to recover high grade fines from low grade run of mine ore types in which the mineralisation occurs preferentially along fracture planes in the parent rock.

Jan 1, 1988

A Feasibility Study to determine the future of ZC Mines was completed in mid 1987. Early in this study, which lasted two years, it was identified that significant reductions in treatment costs would result if the Zinc Corporation Concentrator was closed. All of the production from the existing two mines, The Zinc Corporation Limited (ZC) and New Broken Hill Consolidated Limited (NBHC), would then be treated in the concentrator at NBHC.After a partial upgrade of the NBHC concentrator, the ZC concentrator was finally closed and all of the equipment disposed of. This closure highlighted the need to concentrate all ore haulage in one shaft to further reduce operating costs and remove the cost of surface transport of ZC production to the improved NBHC concentrator. This paper outlines the changes that were made to improve the haulage system for ZC Mines. After a number of options were investigated, it was finally decided that the upgrade of the existing NBHC haulage shaft was the best option even though some production would be lost while the upgrade was in progress.

Jan 1, 1988

By Membrey W. B, Partridge A. C

Lower transportation costs, improved handling and better utilization efficiency are some of the reasons that make low moisture coal product desirable. There has been considerable interest in the development of effective coal dewatering techniques to achieve this result. One avenue of considerable merit for enhancing dewatering processes is by modification of the surface chemistry of the coalwater slurry system by chemical means, resulting in better performance of existing equipment. This paper reports the results of an investigation of the utility of surface active agents in the enhancement of fine coal dewatering. A large variety of proprietary dewatering agents have been studied in relation to their efficiency in enhancing the dewatering of a number of Australian coals. Properties of particular coals that make them amenable to improved dewatering by particular chemical agents have been identified. Surface studies, including surface tension and zeta potential measurements as a function of surfactant concentration, as well as dewatering assessments, were used. Particular attention was paid to filtration, but the results could be applied to other dewatering systems.

Jan 1, 1989

One of the most difficult places to ventil ate in any mine is the working face area of an advancing mine heading. With an ever changing configuration, continual modification and extension to the ventilation system is necess- ary to maintain an adequate supply of fresh air and to control mixing and recirculation. Methane emissions and high dust levels as coal is broken and removed from the face area can produce unhealthy and dangerous conditions if ventilat- ion is not adequately monitored. An understanding of the air flow patterns which develop through use of different face ven- tilation systems can be reached by undertaking underground measurements or through observations using physical models. Tests undertaken by the author to determine the adequacy of different system-configurations are discussed together with approaches adopted by others working in the United States. Various new methods have been proposed for improving face ventilation beyond that sustained using conventional brattice curtain or tubing systems. The adequacy of some advances adopted by mining companies to improve ventilation while maintaining output efficiency is discussed.

Jan 1, 1983

By M Franklin, C Puglisi, S Fitch

Implementation of a well planned and executed Management Operating System (MOS) can result in widespread improvements to operational performance but its success relies heavily on the investment by and engagement of the larger workforce with the project. Over the seven month period of the Telfer MOS project, significant improvements were achieved; a 20% increase in monthly hoisted tonnes from the open stope and sublevel cave operations and a 45% increase in square metres of ore extracted from the narrow vein operation. The Telfer MOS was undertaken with the intention that the project wasn’t solely about producing new tools, it hinged on the investment and behaviours of the personnel affected by these tools and alterations. To ensure that the project ran smoothly, the Byrnecut senior leadership team and their operators were heavily involved in the project’s development. In the initial stage, Telfer’s MOS project determined that the quality and accuracy of the information received in the form of radio calls to mine control and completed operator plods was questionable. This required an overhaul of the data collection and verification process in the form of altered operator plods, which was then cross referenced with the operator’s radio calls to mine control. Once the data collection and verification process was implemented, the Telfer team was then able to produce several tools with the aim of providing visibility to the data being captured and its implications. These tools allowed the mine foremen to determine whether equipment was being under-utilised and where they should focus their production efforts to meet monthly targets. Whilst the initial underground project is now complete, the implementation of MOS across the entire site is ongoing with significant operating improvements occurring.

Mar 15, 2021

The paper will review the marked upsurge in the installation of new continuous metal coating lines, both hot dip and electrodeposition. Although some of this new capacity has been replacement for obsolete facilities or directed at traditional markets, eg building products, consumer durables etc, by far the major portion is targeted at the automotive industry. The reasons for the rapid growth of coated automobile panels are discussed. A comparison of the installed capacity with projections for this market indicate that a severe over-supply situation has arisen. Many coatings are now available for the automotive industry, each with their own strengths and weaknesses, but none as yet wholly satisfactory. Coating development has mainly been cost driven. This favours hot dipped coatings, providing surface quality and pressing problems can be overcome. The high cost per unit thickness of electrodeposited coatings has also seen pure zinc coatings being replaced by thinner, more corrosion resistant alloy coatings such as zinc-nickel and zinc-iron. Recently resin overlays have been introduced to improve the performance of electrodeposited coatings. Developments in coatings for the more traditional markets will be described. The fastest growing market in the last decade has been prepainted product for the building industry. This has led to the installation of extra painting capacity and again it appears an excess capacity situation has occurred. Over the same period the traditional zinc coatings have continued to lose market share to the zinc/aluminium alloy coatings, Galvalume and Galfan. These have been joined recently by '1'aiyo Crack-Free which has been taken up by some metal coaters. Galvalume is now widely accepted as being the best available coating for unpainted applications. It is also suggested that 'spin-off' coatings from automotive developments might find a niche in the consumer durable market. The end users of coated products, particularly the automotive industry, have demanded improvements in quality, such as surface smoothness, formability, etc. At the same time the new coating lines have to process wider strip and run at faster speeds. To reconcile these somewhat incompatible needs has required numerous process improvements, many of which need in-line instrumentation and computer control. The more important of these changes are discussed briefly. Finally the paper will describe the recent developments which have occurred in continuous galvanising in Australia and put them into context with the rest of the world.

Jan 1, 1993

This paper reports on the field results of using electronic detonators to improve blast outcomes. OricaÆs electronic detonator, the i-konTM Digital Energy Control System, allows exact and precise timing in 1 ms increments from 0 to 15 000 ms. This gives the blast engineer and shotfirer the ability to fire a blast using any possible desired sequence. In the three years that have followed the release of the i-konTM System, Orica has been re-exploring ways of initiating blasts using the abilities of electronic detonators to improve fragmentation, diggability and crusher throughput. This study began with revisiting fundamental blast theory, lead to generation of new state of the art computer fragmentation modelling and ended with many iterative field trials of i-konTM blasts across a wide selection of mining methods and rock types. At three sites a detailed measurement process was undertaken to compare the results of pyrotechnic blasts with i-konTM blasts. This paper will detail the significant improvements in fragmentation, diggability and crusher throughput that was found at these sites.

Jan 1, 2003

The coking coal produced by Utah Development Company in the Bowen Basin is processed by a dual system of dense media cyclones for the 30mm x 0.5mm feed and flotation for 0.5 x 0mm material. The basic metallurgy of these processes will be presented with emphasis on the operational characteristics which are peculiar to coal. Potential areas for process improvement by the application of more sophisticated control systems will also be discussed.

Jan 1, 1978

By P Oikkonen

Sprayed concrete has played an integral role in underground rock support for nearly a century. However, concrete is also considered to be one of the biggest environmental problems in construction and mining, largely because of the high carbon footprint of cement and aggregates production. This is driving the industry to find ways to cut concrete usage where possible. Improving sustainability by cutting concrete material consumption also reduces application time and costs. Improving concrete properties can make it possible to design thinner linings, but as awareness of safety and longer design lifetimes are driving developments in the opposite direction, it is not realistic to see this as a major factor in cutting concrete consumption. More accessible solutions are focusing on layer thickness control and minimising rebound and wastage. Digital technology and innovation offer excellent tools for improving sustainability while optimising other aspects of the spraying process at the same time. A digital layer thickness control system gives near-real-time information to the sprayer operator with full coverage of the sprayed surface. This enables the operator to achieve consistent layer thickness on the first pass, in comparison to the traditional methods of overspraying with the aim of achieving sufficient layer thickness, probe drilling after the concrete has set, and respraying at a later stage if needed. Operator competence is the single biggest variable in a successful sprayed concrete process, affecting rebound and wastage levels. Unfortunately, the learning curve to become a master sprayer is quite steep and training on a real sprayer and real concrete requires a significant amount of time and money. Training in a virtual reality (VR) environment enables operator training to be carried out in a low-risk environment and provides a way of measuring performance and assessing and certifying the operators. After the VR training period, a novice nozzle operator has the basic understanding to start working on a real sprayer, and an experienced nozzle operator can benefit from the possibility of assessing their performance.

Mar 29, 2023

By H Utama, hi, A Suw

PT. Indo Muro Kencana (PT.IMK) is gold and silver mine located in Central Kalimantan province, Indonesia. Mining activities in PT.IMK is conducted in Bantian pit area by applying surface mining method and using combination of excavator and hauler (articulated dump truck and rigid haul truck) as the transportation for ore to the crushing plant and waste material to the waste dump. Current blasting practice is ore-waste blasting. Ore-waste blasting is the term where the ore and waste rock are blasted in the same blasting process. Blasting is conducted by using nonel initiation system. By multiple pits operation, monthly powder factor is varied from 0.23 kg/t to 0.27 kg/t. Emulsion blend with density 1.15 g/cc is used as bulk explosive. At this stage, the concept of geoblast is proposed as an engineering tool for Drill and Blast engineering practice in PT.IMK. In addition, there is a need to maintain rock fragmentation by blasting, to maintain monthly powder factor, and to maintain excavator’s productivity. Next, the concept of scaled depth of burial (Chiappetta and Treleven, 1997) and the concept of blastability index (Lilly, 1986) are proposed as geoblast’s tools to improve blasting practice in PT.IMK. It is expected that rock fragmentation by blasting, explosive consumption and excavator’s productivity will be maintained by integration of geoblast and drill and blast engineering. Furthermore, the objective of this paper is to integrate geoblast and drill and blast engineering in order to create an engineering guideline in PT.IMK. Additionally, blasting trials with air decking application is proposed in order to support the geoblast’s improvement. It is planned that these blasting trials will be conducted in 2022. In conclusion, it can be seen that integration of geoblast and D&B engineering in PT.IMK is relevant to improve current drill and blast current practice and applicable to maintain rock fragmentation by blasting.

Nov 29, 2022

By B Putland, I Lovatt, D Schwann, A Cervillin

The Mount Carlton project in Queensland's North East sits on a high-sulphidation epithermal style deposit rich in gold, copper and silver. Mt Carlton is an open pit mining operation with ore processed using a primary crusher, single stage SAG mill and flotation to produce a concentrate for sale. Orway Mineral Consultants (OMC) was involved in the original design of the comminution circuit and the project was commissioned in late 2012, with first concentrate shipped in March 2013. When Evolution sought to optimise the project in 2015, OMC was invited to assist by undertaking a circuit review to identify opportunities for the optimisation. During 2016, the Mt Carlton site team implemented the optimisation strategies developed in conjunction with OMC. These included reconfiguring the SAG mill discharge arrangement, reducing the average ball diameter and allowing the mill to operate at higher speed and under more autogenous conditions. Cyclone operation was changed to constant pressure and the vortex finder size was decreased. The combined strategies improved energy efficiency and allowed higher SAG mill power utilisation. The additional power has been used to increase throughput by 2.4 per cent while achieving a 27µm reduction in product size (P80) to gain downstream recovery improvements. The reduction in grind size has been achieved with only 6.8 per cent increase in specific energy consumption because of a 6.5 per cent increase in grinding efficiency. The circuit product size is also notably more consistent due to the improvements made to the cyclones, providing benefit to the downstream flotation circuit. A significant decrease in ball consumption was also gained, saving hundreds of thousands of dollars a year in operating cost.This paper will discuss the circuit design, start up and will detail the changes made during the optimisation and why these were successful.CITATION:Putland, B, Lovatt, I, Cervillin, A and Schwann, D, 2018. Mount Carlton comminution circuit design, start-up and optimisation, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 517–528 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By C Laming, S Staude, D Hammond, S Sheppard, J Griffith, S Stanfield, S Marriott

Long Operations is located on the eastern slope of the Kambalda Dome in Western Australia. Kambalda hosts nickel deposits that are modelled to have formed from an exsolving sulfide melt from a parental komatiite melt. The nickel deposit model predicts a stratigraphical relationship where massive Fe-Ni-Cu-sulfides are deposited in troughs at the base of komatiite channels. The basal contact of the sulfides is generally tholeiitic basalt. The Kambalda geological sequence form a dome structure with a granodioritic core and have undergone tectonic and metamorphic overprinting, resulting in the formation of upper greenschist to lower amphibolite-facies units.On the basalt-ultramafic contact, within the Long Operations, there are two separate channels hosting seven different orebodies. The Moran orebody is the most undisturbed orebody at Long Operations, with many primary magmatic textures preserved, making it ideal for studies to improve the existing nickel sulfide formation model. Detailed exploration and production infill drilling and systematic sampling indicates consistent nickel tenor variations over the entire Moran orebody. This was also observed in other deposits in Western Australia and was explained as metamorphic variations. Similar variations are observed with some trace elements that cannot be explained by metamorphic overprint but with gravitational segregation in the liquid sulfide. Other more complex trace element patterns (eg Cr) require additional explanations and are partly originated from incorporation of underlain basalt and sediment and partly from gravitational segregation.From a mining perspective, the Moran orebody can be used as an example of modern high-speed mining, but at the same time preserving samples for the future and allowing knowledge from the geological context and geochemical signatures to improve future exploration.CITATION:Staude, S, Marriott, S, Griffith, J, Laming, C, Hammond, D, Stanfield, S and Sheppard, S, 2014. Improvement of existing ore-forming models due to systematic sampling during mining – an example from Kambalda, Western Australia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 341–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By R Shaw, R Williamson

Global iron ore demand, sparked by ChinaÆs rapid industrialisation and emergence as the worldÆs newest steel market, has seen iron ore groups investing heavily in production capacity as well as infrastructure. The success of these new projects depends heavily on reliability, competitiveness and quality control in an increasingly demanding trading environment. Furthermore, the iron ore industry continues to improve its competitiveness in mining practices, technology innovation and management processes. The continued fine tuning of these sectors will be critical to the success of the industry in the years ahead, and this mining sector will continue to demand process improvements from their service suppliers to maintain competitiveness. Automation offers a real solution to these demands. A crucial quality control element in mining, beneficiation, stockpiling and shipping stages is ensuring representative samples of ore are taken along each step of the process. When these samples reach the laboratory it is imperative that the sample is representative of the entire stream and that no induced errors occur. Examples of automation start with mechanical primary and secondary samplers in the run-of-mine processes through to sample tower and laboratory crushers, dividers and collectors. Automation is widely used in many forms to provide reliable and repeatable samples for analysis whilst providing a safer working environment. Laboratory automation systems in use today vary from simple linear systems to sophisticated robotic cells. Sample automation in the iron ore industry has resulted in many benefits for both producers and their customers. The most significant benefits have come in the form of higher safety standards whilst reducing sample error, sample handling and sample contamination during collection. These benefits have been further augmented by reliability and repeatability of automating the final sample preparation and analysis stage. Today these benefits are reflected in reduced costs of sampling and improvement in both turnaround time and quality of results, whilst complying with Australian safety and ISO sampling standards.

Jan 1, 2007

By R J. Wood

Raise drilling (or raise boring) is not a new technology or methodology. The first raise drilling machine was developed by The Robbins Company (TRC) of the USA in 1962. TRC manufactured the first tunnel boring machine (TBM) in 1952 and Jim Robbins, the founder of the company wanted to ‘turn the TBM concept on its head’ so to speak.Many improvements have ensued in the 50 years since the first machine. Such improvements include advances in the drill rod and thread design, cutters and reaming heads. Raise boring would not have been possible without the development of the tungsten carbide insert cutters and there have been big advances in both the carbide technology and in the mechanical design of the cutters.Over time mines have developed deeper with a greater use of diesel equipment resulting in greater ventilation requirements. This in turn means larger and deeper ventilation shafts. There have also been improvements in directional drilling techniques. This all combines with the need and ability to construct larger shafts using the safe method of raise drilling. With suitable geotechnical conditions the RBR900VF is capable of drilling shafts to a diameter and depth of greater than 8 m and 2000 m respectively. Greater diameters are possible over shorter lengths with suitable ground conditions.The RBR900VF was designed and manufactured to specifications developed by Macmahon. This machine has the greatest thrust and torque capability of any machine in the world. It enables cutters to be more heavily loaded in the larger diameter heads and this is essential for efficient rock excavation. Additional features of the new machine include minimal manual handling to provide a safer working environment and higher strength steel for the drill rods providing additional safety margin.CITATION:Wood, R J, 2014. A revolution in raise boring – the development of the RBR900VF, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 171–178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By P Cameron

Many products and technologies have been developed from outcomes of research projects carried out by the Julius Kruttschnitt Mineral Research Centre (JKMRC). When these products and technologies are applied to the design and optimisation of blasting, comminution and separation, improvements in profitability can be realised. In 1970 Alban Lynch promoted two practical ideas to improve plant operations: Ore and equipment properties can be separated allowing experience with one type of ore or equipment to be transferred to other types of ore and equipment. If this experience was encapsulated in a mathematical model, then these properties could be combined and used to simulate (ie to design and to optimise) complete mineral processing circuits. Many problems associated with scale-up from laboratory to industrial equipment could be eliminated by experimental work on full-scale equipment in the plant. Many JKMRC research projects have focussed on the development of models of unit operations in mineral processing and their application to process simulation. Models of comminution and classification developed at the JKMRC have been used since the early-1980s. Ore characterisation techniques developed to support these models are licensed world wide through JKTech. The application of comminution modelling techniques to blasting, which optimises the process feed size distribution is used in Mine-to-Mill? projects. The advances in the understanding and modelling of froth flotation over recent years have provided the opportunity for integrated ore characterisation and process optimisation from resource to product. JKMRC project outcomes often provide proven opportunities for the mineral industry to improve performance and productivity. JKTech was established in 1986 to commercialise and market the most promising outcomes and thus ensure their continuing availability to the mineral industry. These include: commercial software (JKSimMet, JKSimBlast and JKMetAccount); monographs (Comminution and Blasting); technologies (Mine-to-Mill? and flotation optimisation); and hardware products (JKFrothCam, JKJetLift? and the Mineral Liberation Analyser). This paper summarises these technologies and their benefits.

Jan 1, 2002

By Montagnon P, Dagois G

The use of activated carbon for gold recovery has been known for years, but came industrially on stream since the years seventies.Despite several years of experience, the criteria for selecting a carbon have not been clearly determined so far.This paper will try to highlight the user through his experience, on the most important factors which should affect his decision.We will develop:- Physical characteristics - Adsorption characteristicsand try to show that slight variations on these characteristics may have important consequences on the plant design and profitability.

Jan 1, 1984

A survey of leaching systems for the dissolution of gold has been undertaken and their advantages and disadvantages evaluated both from their effectiveness at leaching and their compatibility with carbon- in-pulp (CIP) and resin-in-pulp recovery. In the near future it is almost certain that cyanidation in some form will remain the leaching system of.choice although economic and environmental pressures could see the introduction of other leaching systems particularly for treating refractory gold ores. The most likely alternative leaching systems appear to be acid chlorine, acid thiourea and ammoniacal thiosulphate. INTRODUCTION High grade reserves of readily recoverable gold ores are gradually being depleted which, inevitably, must create a greater awareness amongst gold producers, of the efficiency and, in some cases, the suitability of present day metallurgical processes for treating low grade, complex and refractory deposits. One of the key steps in the extraction of gold is the dissolution of the metal using chemical reagents which, ideally, should be cheap or recyclable, selective, non-toxic and compatible with down-stream recovery processes. In practice, meeting all these critera is difficult - if not impossible - particularly in view of the stringent environmental impact requirements which must be met Nowadays.

Jan 1, 1982

Structural geological information is widely used at the Mt Whaleback Mine, Newman, WA. Recent improvements in the structural understanding of Mt Whaleback are providing a very cost-effective way of reducing geological risk, improving the economics of mining, optimising pit design and addressing safety problems. The structure of the Mt Whaleback orebody is highly complex and has a significant influence not only on iron ore genesis but also on pit wall stability. A team approach between the Structural Geology and Geomechanics Groups has been providing excellent results to reduce geological risk at Mt Whaleback.

Jan 1, 1994

By Karlson R, Rispin M

Chemical admixtures are not commonly included in the variety of backfill mixes used in the mining industry. This may be attributed to several reasons including, but not limited to: the perceived high added cost, 2. the lack of awareness about their proper use, and 3. the lack of knowledge about their features and benefits. In the construction industry today, however, chemical admixtures are used in the majority of the concrete produced, enabling concrete to become a more cost-effective building material. They also enable construction crews to meet demands for year-round construction, quicker completion of construction projects, and improved concrete properties. The high demand for chemical admixtures in the construction industry has led to numerous innovations in admixture technology in recent years. Some of these chemical admixtures have been found to enhance the production, transport, placement, and in situ properties of backfill mixes. Others have been found to reduce the cost of such mixes while maintaining, and in some cases improving, their physical properties. In this paper, a few of such innovative admixture technologies are discussed. The benefits, imparted by these technologies to backfill mixes as well as performance data on their use in several backfill applications at various mines, are presented.

Jan 1, 1998