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The mining production rate of two million tonnes per annum at Olympic Dam required greater servicing capacity than was available with the existing Whenan Shaft. To increase servicing capability a Service Decline was constructed from June 1986 to June 1987 extending 2000 m from the surface and linking up with inclining development from the existing Whenan Shaft workings. The decline was used for access of all men and materials during the construction phase of the ore handling system. During production, most mine servicing will be via the decline with hoisting of rock through Whenan Shaft.

Jan 1, 1988

By N Bianco, D Drinkwater

The professional skills shortage is intensifying, and commentators are predicting a shortfall in supply of qualified professionals for the mining industry, ranging from thousands to tens-of-thousands by 2020 (Tuckwell, 2011; Scoble, 2011; Laurence and Hebblewhite, 2011). Human resources are already stretched, and university graduates arriving in the workplace are often moved rapidly into management positions where there is limited scope to develop their engineering proficiency. This process may well be developing excellent young managers, but our industry is producing fewer excellent young engineers (Munro and Tilyard, 2009). Many believe that it is engineering excellence that is likely to be the key to our industryÆs success in the decade to come. An innovative in-house graduate development program has been created by specialists at the JK Centre in partnership with two mining companies. This program, known as MetSkill«, has been running throughout 2012. Groups of graduates have had to identify a process plant optimisation opportunity and embark on a structured program of data collection and analysis, facilitated by a æteaching teamÆ of researchers and consultants from the Julius Kruttschnitt Mineral Research Centre (JKMRC) and JKTech. This group project culminates in a report-back session to senior company officials. Along the way, a series of short workshops and other activities provide opportunities to work on specialist skills, and support is also offered by senior technical specialists from the companies involved.This paper outlines key features of the MetSkill« program, along with a report-card on progress in 2012 and plans for further program development in 2013.CITATION:Drinkwater, D and Bianco, N, 2012. Developing minerals industry leaders by encouraging metallurgical excellence, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 287-290 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By D R Van Eck

Western Deep Levels, a seismically active deep level told mine. stalled placing backfill in their narrow tabular workings as part of the regional support strategy in 1986. Over the years the percentage of working places being backfilled has been gradually increasing. At the end of 1995 the support efficiency and the labour productiveness relating to support installation were scrutinised to determine if resources were being optimised. Owing to financial, safety and productivity constraints it was decided to redesign stope support to be less labour intensive, safer and provide an integrated stope support system. This new integrated system will thus combine the previously used temporary, permanent and back area support consisting of mechanical props, hydraulic props and backfill respectively. Backfill previously formed an integral part of the regional support in conjunction with strike stabilising pillars. To design the integrated support system the backfill placement quality has to be exceptionally good and placement must be done as close as possible to the working face. The backfill to face distance was reduced by 30 per cent and in some areas by more than 50 per cent with an increase of square metres filled to increase the effect of the backfill even more. This paper addresses the design and successful implementation of an integrated stope support system based on the optimisation of backfill to he extent where installation of mechanical and hydraulic jacks could he Eliminated

Jan 1, 1998

By Masters I. M, Ozberk E, Chalkley M. E

The integration of iron rejection as hematite with the Sherritt two-stage zinc pressure leach process has been investigated on the laboratory scale. The two-stage pressure leach process is applicable for a greenfield zinc plant, or for replacement of the conventional roast-leach circuit in an existing zinc plant. An excess of zinc concentrate is used to accomplish acid neutralisation in the first stage of pressure leaching, and the residual concentrate in the first stage residue is treated with an excess of acid solution in the second stage of pressure leaching to yield high zinc extraction. Integration of hematite precipitation with this process allows for the potential sale of the iron residue, greatly decreasing the residue disposal problem. Two flowsheets containing the desirable features of both of these processes are described in this paper, along with laboratory Results.

Jan 1, 1993

By Baynes F. J, Bermingham A. G

The 6000m long King Headrace Tunnel will be driven through hard Owen Conglomerate in the Eastern third and feldspar porphyry in the Western two thirds, with the anticipated hardness up to 350MPa unconfined compressive strength. Since the Commission had not driven a long, large diameter tunnel for some twenty years, major research was undertaken to assess the current tunnelling trends. Tunnel boring machines were compared with drill and fire equipment. Rail equipment was compared with rubber tyred equipment. Tenders were called with tenderers invited to submit alternatives if desired. Commissioning and production excavation using the equipment is discussed with the final conclusion being that the individual items of equipment purchased combined to make an efficient hard rock drill and blast system capable of progressing through all rock conditions likely to be encountered on the King and Anthony Schemes.

Jan 1, 1987

By X Hu, J Björkvall, L Sundqvist Ökvist

The metal production industry is a significant contributor to global CO2 emissions due to the use of fossil fuels such as coal and coke. To mitigate these emissions and meet climate goals, innovative and sustainable technologies are required. Molten salt electrolysis is a promising technology that directly produces metals from their precursor sulfides or oxides using electricity. When combined with renewable electricity and an inert anode, the electrolysis process can be carbon neutral. This paper presents the results of two pilot-scale studies on the electrolytic reduction of metal oxides and sulfides in molten salts. The first study focuses on the electrolytic reduction of chalcopyrite in molten NaCl-KCl salt. The results demonstrate that in situ separation of copper, iron, and sulfur is possible, enabling the extraction of all valuable elements without CO2 emissions. Furthermore, the findings underscore the capability to eliminate impurities like zinc, antimony, arsenic, and mercury from the electrolysis product. The second study investigates the electrolytic reduction of pure/synthetic chemicals of wüstite, hematite, and magnetite, as well as a magnetite-type iron ore in molten NaOH salt. The findings reveal a stepwise reduction of iron oxides from high valence to low valence, ultimately leading to the production of metallic iron electrolytically. Notably, this study underscores the challenges associated with the selection of an economically viable and durable inert anode material for efficient oxygen generation. These results indicate that molten salt electrolysis provides a sustainable and green route for base metal production. The use of this technology has the potential to significantly reduce CO2 emissions in the metal production industry, contributing to achieving climate goals.

Jun 19, 2024

By Somasundaran P

Controlled modification of mineral/liquid interfacial properties by adsorption is critical for mineral processing operations such as flotation, filtration, dispersion and flocculation. Ionic/nonionic surfactant mixtures usually show enhanced surface activity and salt tolerance over ionic surfactants, and this is especially beneficial for flotation of salt type minerals in which case dissolved multivalent cations in high concentrations usually cause loss of anionic surfactants by precipitation. Adsorption of nonionic/anionic surfactant mixtures on kaolinite has been studied with sodium dodecylsulfate as the anionic surfactant and octaethyleneglycol mono-n-dodecylether as the nonionic surfactant. Synergistic interaction between these surfactants was found to cause adsorption of the nonionic surfactant with its hydrophilic chains protruding into the bulk, leading to substantial changes in flotability and dispersion characteristics of kaolinite. Similarly, hydrophobicity changes are observed also' for silica particles upon adsorption of nonionic ethoxylated alcohols owing to possible changes in the orientation of the adsorbed surfactant species at the interface. Also, based on the results obtained with surfactant adsorption, a hydrophobically modified polymer was used successfully to disperse graphite particles in aqueous solution.

Jan 1, 1993

By G Lind

Bridging of production stopes in narrow vein gold deposits contributes to significant financial losses and production delays. Bridging is caused when underbreak in the stope production blast occurs, resulting in less than the designed stope blast volume breaking out during blasting. Jundee Operations in the Northern Goldfields of Western Australia extracts ore from its expansive narrow vein orebodies utilising longhole open stoping. In 2006 it experienced bridging in ten panels, or 8.77 per cent of all panels, as well as multiple bridging in 30 per cent of these bridged panels. The Jundee orebodies are west dipping with the bridged panels dipping between 44¦ and 62¦. This paper examines some solutions from the drill and blast design perspective to minimise bridging occurrences. It was found that the then current drill patterns and number of holes were adequate from a longhole stope design perspective. However, changes to the blasting design, specifically modifications to the blast delay initiation sequencing, primer positioning and blasthole dump combined with timely stope surveying and back analysis, were implemented with the aim of preventing bridging in this narrow vein operation.

Jan 1, 2008

In Munich's peculiar hydrogeological conditions (water bearing sand strata between layers of impermeable clay, silt or marl) are proper functioning groundwater lowering methods of decisive importance for underground construc- tion. Shield tunnelling with compressed air has al- ready proved to be successful. In view of growing application of shotcrete tunnelling it was obvious to consider the use of compressed air even here. After a preliminary research-project the first subway section "shotcrete under compressed air" was 1979 awarded in Munich and since that time five sections have been awarded, respectively completed. On the basis of the experiences meanwhile obtained reports will be given stating the frame conditions in which this new construction method can be applied. The tunnels consist of two shells. The outer ist driven by shotcrete under compressed air. In order to keep the air overpressure low, the groundwater often is previously detensioned or partially lowered. The inner shell of watertight concrete is built under atmosperic pressure.

Jan 1, 1987

By N J. Beukes, J Gutzmer, C Reinke, M Bau

In this study the light sparse phase search (SPL_Lt) mode on the Mineral Liberation Analyser (MLA) was successfully used to identify and quantify the abundance of rare earth element (REE) phosphates in Precambrian iron formations. Monazite (light REE phosphate) and xenotime (Y and heavy REE phosphate) are identified and data from the MLA combined with the mineral chemistry of the two minerals are used to calculate and model the expected REE concentration and distribution in these two REE phosphates. The REE phosphates account for up to 31 per cent of the REEs in the banded iron formations (BIFs) and excellent correspondence is observed between the modelled REE patterns and the whole rock geochemical data available for the same samples. Except for quantifying the mineral weights, the sparse phase search also allows for the localisation of REE phosphate grains and the observation of their association with other minerals using backscatter electron (BSE) imaging. These observations are used to conclude that the REE phosphates were most likely of diagenetic origin, with REEs and phosphate remobilised from primary chemical precipitates. It is demonstrated that automated mineralogical techniques can be used to qualitatively and quantitatively describe the influence of a rockÆs trace mineralogy on its geochemistry.

Jan 1, 2008

By R Williams, P Kohout, J Comins

The Northside Storage Tunnel (NST) is the largest tunnelling project ever undertaken in Sydney. The tunnel extends deep underground from the western bank of the Lane Cove river to the North Head sewage treatment plant (STP), with a branch tunnel from Scotts Creek connecting to the main tunnel under Tunks Park. The aim of the tunnel is to intercept wet weather overflows from four key points along the northernsuburbs ocean outfall sewer (NSOOS) and provide short-term storage and transfer of sewage to NorthHead STP for treatment prior to discharge to the ocean through the deep ocean outfall. The project was an ambitious undertaking by an alliance between the client Sydney WaterCorporationand the engineering firms of Montgomery Watson, Connell Wagner and Transfield to design andconstruct approximately 20 kilometres of tunnel, tunnel declines and shafts in just over three years. In order to achieve this tight timeframe construction of the NST has been undertaken simultaneously at seven construction sites located across the northern suburbs of Sydney. As with most tunnelling operations, tunnel boring machines (TBMÆs) and roadheaders dominated the excavation activities. Tunks Park and North Head STP are the major tunnelling sites. An access decline was excavated using roadheaders at both of these sites to facilitate tunnelling using TBMÆs. Three TBMÆs 3.8 m, 6.0 m and 6.3 m diameter) were launched from Tunks Park and one TBM (6.5 m diameter) was launched from North Head. At the overflow interception sites of Scotts Creek, Lane Cove River and Quakers Hat Bay two vertical shafts known as drop and access/ventilation shafts were constructed. These shafts would provide the linkage between the existing sewer and the tunnel. As their names suggest the drop shaft would convey the wet weather sewage overflows to the tunnel while the access/ventilation shaft would provide access during dry weather and ventilation during a filling event. The fourth overflow site of Tunks Park would use the tunnel decline as its link to the tunnel. Originally these shafts were to be excavated using the raise bore method. This technique however, is entirely dependent on the TBMÆs reaching the shaft locations at the specified time. This was not the case at two of the three shaft excavation locations and top down methods of excavation such as, a percussive cone fracturing (PCF), blind bore, mechanical excavation and drill and blast were investigated to ensure the project met its completion schedule. Traditionally project decisions are dominated by cost and schedule objectives. The contractual arrangement of the Alliance however, required that the objectives of safety, community and environment also be considered in any decision making process. Thus each of these top down methods of excavation were assessed against these five objectives. On considering all of these factors the use of explosives was considered to be the superior technique.

Jan 1, 2001

By Neville Rockhouse

This paper examines the interrelationship of conducting full risk assessments in the context of the coal mining industry and under the framework of the Health's Safety in Employment Act 1992. In the context of Occupational Health's Safety, Risk Management is a holistic management process that can be used by individuals working in all organisations and from all industries. The Australian New Zealand Standard 4360: 2004 defines a Risk as being; The chance of something happening that will have an impact on objectives. This definition is followed by several notes that include: a risk is often specified in terms of an event or circumstance and the consequences that may flow from it, risk is measured in terms of a combination of the consequences of an event and their likelihood, and risk may have a positive or negative impact. For the purposes of this paper, the above definition will be adopted. This paper examines the newly expanded approach of the fully documented risk management process in the New Zealand coal mining industry. This is done in the context of the coal mining regulations but more importantly by using the framework of the Health & Safety in Employment Act 1992. This legislation under Section 6 requires all employers to, Take all Practicable Steps to prevent harm coming to employees while at work and to others who might be at or in the vicinity of a workplace. When the term 'all practicable steps' is studied, one can clearly see that such steps should be the same steps taken that a prudent and reasonable person would have taken given the same type of circumstance. Due to the fact that in New Zealand parliament made statutes is administered by a Government Department, means that their breaches will be heard before a judge in the District Court. Under the Westminster System of Justice, a basic dictum of that court in matters relating the occupational health and safety is that a breach needs to be satisfied to a specific standard. That standard is, 'Beyond a reasonable Doubt'. One of the primary benefits of adopting a proactive approach to risk management is that if the industry were to adopt similar approaches, then this mythology could be seen as an industry standard. As such, the approach carries the same status in a court of law, as that of an Approved Code of Practice.

Jan 1, 2007

By Wickham P

Digital computer based control systems are used to implement control and monitoring over most unit operations in Mount Isa Mines Limited lead-zinc concentrator and copper concentrator. Implementation has been gradually devel- oped and expanded since the first process computer installation in 1969. Operations currently using high level control logic include crushing, grinding, on-stream analysis of flotation products, flotation reagent additions, and tailings thickening. Details of gains in metallurgical efficiency for each system are considered.

Jan 1, 1978

By M I. Pownceby, N Karimian, A Frierdich

These may be found with goethite through mechanisms including direct substitution or coprecipitation of nanocrystalline phases. Understanding P incorporation in goethite has significant implications for Australia’s iron ore industry as it lowers their commodity value. The current study tests a novel low-temperature technique to extract P impurities from synthetic goethite phases under O2-free ambient conditions by utilising Fe(II)-catalysed recrystallisation. The objective of this study was to examine the effect of the Fe(II)-catalysed recrystallisation of goethite on the geochemical behaviour (mobility and speciation) of co-associated P. To achieve this, we tracked changes in labile P (aqueous and 1M NaOH extractable) concentrations over time in goethite suspensions which were reacted with Fe(II)aq for 14 days under circumneutral pH conditions and room temperature conditions. Temporal changes in Fe mineralogy were investigated via synchrotron-based X-ray absorption spectroscopy. Iron K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy confirmed goethite as the only mineral phase in P-free treatments while goethite (~86 per cent) and feroxyhyte (~14 per cent) were the main phases in 1.0 per cent P-containing treatments after a 14- day reaction with Fe(II)aq. According to our findings, the treatment of P-goethite with Fe(II) for a duration of 7–14 days, followed by a 24-hour extraction of the reacted solids using 1M NaOH, results in the removal of approximately 79.5 per cent of the initial P content. This removal encompasses both the aqueous fraction (~4.5 per cent) and the surface adsorbed fraction (~75 per cent) from the 1 per cent P-bearing mineral phase. Notably, this approach demonstrates an improvement in P extractability, with approximately a 10 per cent increase compared to the 1 per cent P-goethite sample that was not reacted with Fe(II).

Sep 18, 2023

The electrochemical dissolution of gold and other noble metals in hydrochloric acid using alternating current has been investigated. The experimental results show that this technique is efficient for dissolving pure noble metals and offers prospects for their extraction from wastes and poor ores.

Jan 1, 1992

Safety bulletins and stickers issued for the paste backfill plant at Cannington read as follows: æCannington Paste Fill Plant, First of ItÆs Kind in AustraliaÆ. We could even dare to state that the Cannington plant is different than any other paste backfill plant in the world because of the overall design, plant equipment and underground delivery. However, one thing to be certain of is, the paste backfill plant works as designed and a pump is not required to deliver paste underground given the general plant arrangement at Cannington. The past two years have been a process of evolution to design and construct the plant and make it work. This paper will describe the paste process using full mill tails along with placement of cemented paste underground. Discussions will include rationale of fixed plant selection along with various control requirements. BHP World Minerals recently commissioned its paste backfill plant in December 1997. Cannington is placing full mill tails underground via two surface boreholes that deliver either to primary or secondary stopes.

Jan 1, 1998

By R Pie, J Crusius, P Whittle, J J. McNee

The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of an ongoing three-year government- and industry-funded research program. In order to assess the feasibility of various bio-remediation strategies, field-scale manipulations were conducted using enclosed mesocosms (limnocorrals). Two manipulation strategies were tested: addition of algal nutrients (phosphate and nitrate) to Main Zone Pit surface waters; and addition of algal nutrients (surface waters) and dissolved organic carbon (deep waters) to the Waterline Pit. Nutrient addition was conducted in order to stimulate algal production and enhance metal scavenging by biogenic particles, while dissolved organic carbon (ethanol) was added to increase oxygen demand and foster the development of sulfate reduction in pit bottom waters. Fertilisation resulted in rapid growth of natural phytoplankton populations in the surface waters of both pits. In the Main Zone Pit, the stimulation of algal growth resulted in the pronounced removal of both dissolved and total metals (Zn and Cu) from surface waters, with higher rates of metal removal being observed at higher nutrient additions. Metal removal could be attributed to the scavenging of dissolved metals by biogenic particles and subsequent particle settling. A similar pattern of removal from surface waters was observed in Waterline Pit (Zn and Cd). The addition of ethanol to deep waters in Waterline Pit was effective in promoting sulfate reduction in the lower layer. The development of reducing conditions resulted in near-quantitative removal of dissolved Zn and Cd, presumably as secondary metal sulfides. Iron, As and Ni profiles in Waterline Pit exhibited no evidence of removal from either surface waters or bottom waters. Collectively, the results demonstrate that the passive forms of bioremediation tested in these pit lakes may be effective for whole pit-lake remediation.

Jan 1, 2003

By T GRAHAM-TAYLOR

A trend towards mining more complex and economically marginal orebodies, often combined with increasingly tight product specifications, increases the number of variables which need to be considered in production scheduling. Linear programming incorporating integer constraints can be used to create production schedules which are practical as well as mathematically optimum. Factors which can be taken into account include variability in product stockpiles, targets for head or product grades, production of different material types, production from different areas, production targets for loaders, and dependencies between mining blocks. For each schedule an appropriate objective for optimisation must be chosen. Examples of objectives are: to minimise or maximise grade variation; to minimise waste movement; and to minimise movement by front end loaders. A staged approach to the implementation of computer systems based on linear programming optimisation is Proposed.

Jan 1, 1992

By R Bertuzzi

Permanent rock bolts in civil engineering are taken as having to serve their design purpose for at least 50 years. In many projects the design life is specified as greater than 100 years. A review of recent Australian tunnelling projects shows that substantial differences exist in the level of corrosion protection provided for permanent steel shafted rock bolts. This paper reviews the current state of practice and sets out what the authors consider to be appropriate requirements for corrosion protection.

Jan 1, 1999

Milling operations at Misima Mine are discussed, with specific reference to the application of energy and cost saving concepts. Design stage innovations and post-commissioning developments are covered. General operational problems are described with specific reference to problems associated with operating in a remote location.

Jan 1, 1994