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Polyacrylamide flocculating agent has been used in the Leaching Division 'of the Risdon Works of the Electrolytic Zinc Company of Australasia Limited since October, 1960. The number of thickeners in the continuous thickening stage was thereby reduced from eight to three. There has been an increase of 25 per cent in throughput and a reduction of solids in thickener over-flow from 3-4 g/l. solids to 0·5 g Ir. solids. Reagent addition has been at the rate of 0·25 lb Separan NP10 per ton solids.Additionally there has been a gain of 3 per cent in current efficiency as the direct result of the addition of Separan NP10 to purified cadmium sulphate solution priOl; to electrolysis for cadmium metal. A smoother deposit has resulted and it has been possible to increase deposition time between strippings from 47 to 71 hr. However, there has been a slight increase in the lead content of the cadmium metal produced.The use of Separan NP10 to settle copper bearing residue in a batch process stage has resulted in a five-fold increase in settlement rate and a reduction in purification cycle time.INTRODUCTIONThe Electrolytic Zinc Company of Australasia Limited, Risdon, Tasmania, produces zinc by electrolysis of purified zinc sulphate solution, the raw material being zinc sulphide concentrate. In the Risdon process (Van Arsdale, 1953; J ohnstone, 1953; Ross, 1949) the compound zinc ferrite (ZnO.Fe203) is formed during the concentrate roasting stage. When the roasted material is leached in dilute sulphuric acid the zinc ferrite is not attacked, and it remains as part of the insoluble leach residue, of which it may form as much as two-thirds of the whole. The remainder is mainly unroasted zinc sulphide, unleached zinc oxide, lead sulphate, gypsum, silver compounds etc. The zinc in the residue may be 10 per cent of that in the original concentrate.Continuous thickeners are used to recover the valuable residue from the impure zinc sulphate solution and the...

Jan 1, 1963

By D Vickers, N C. Fowke

The reduction of geological risk for planning of high production longwall faces is essential. Geological and geophysical techniques applied at Huntly West Mine before 1989 were unable to reduce the geological risk to an acceptable level. The success of a trial long-hole directional drilling programme at Huntly West Mine (Fowke et al, 1989) has encouraged the Coal Corporation of New Zealand to use the technology long-term, for seam definition. Initial drilling in 1989 completed a total of 3543 metres, with the longest borehole length being 369 metres (limited by number of rods available). A major re-interpretation of seam structure resulted from the drilling, which was able to fill in seam details between surface exploration boreholes. The undulating thick seam conditions at the mine require a refinement of drilling strategies used overseas. Long-hole directional drilling also displays potential for inseam gas drainage. Gas flows of the order of 1000 L/min were initially indicated in individual boreholes. Other gas parameters of the seam have been studied by Beamish et al (1991), and highlight the significance of the natural gas resource in the Huntly Coalfield.   The continued development of drilling technology will be of major benefit sustainable development, particularly in policy.

Jan 1, 1991

The Northland region of New Zealand has a complex geological history which has long been the subject of considerable controversy. Small mineral deposits have been discovered in the past, and some have been mined. Except for aggregates and very high quality china clay, mining is virtually nonexistent at present. Mercury mining is proposed from small deposits in the Kaeo area. Intensive exploration for epithermal precious metals deposits in the past seven years, combined with some recent geological mapping undertaken by the Geological Survey and University thesis students has added greatly to an understanding of Northland's geology. Mapping of the Whangaroa-Kaikohe map sheet at a scale of 1:100 000 by Brown and Laurenson Limited has enabled new geological information to be collated for the first time since 1961, when the last geological map was published. The 'Northland Allochthon' is now observed to be a series of four or more thrust sheets each containing predictable formations. High angle faulting contemporaneous with overthrusting has modified the thrust sheets, and established a series of horsts and grabens. The Pirau Fault is considered to be a major earth fracture.

Jan 1, 1987

By J L. Maule, S J. Mathews, K A. Rodgers

Gold and Silver bearing epithermal veins of the Golden Cross deposit are hosted in Miocene and Pliocene calc-alkaline volcanics occurring 8 km northwest of Waihi at the southern extent of the Coromandel Peninsula, North Island, New Zealand. Veining occurred during a period of hydrothermal activity that began early to late Pliocene, and possibly continued into the Pleistocene.   Field relations and petrographic relationships reveal that multiple generations of FeS2 occur in the Golden Cross region, with FeS2 occurring in all nine rock types recognised at Golden Cross. The variability of FeS2 morphology was investigated by preparation of high purity FeS2 separates, and grain counting. Marcasite is the dominant FeS2 phase at Golden Cross, and along with pyrite is shown to have a systematic habit variation. Pyrite shows a sequence from cubes through octahedra to pyritohedra to dendritic growth. This pyrite sequence conforms to an experimentally determined sequence. The parallel sequence for marcasite at Golden Cross is from tabular through bladed aggregates to euhedral miscellaneous marcasite morphologies. The FeS2 sequences observed are believed to be due to increasing temperature, and perhaps also increasing FeS2-oversaturation and fluid flow.

Jan 1, 1994

By M Sparrow

The Victoria Park Tunnel project is an inner-city alliance project in central Auckland, New Zealand. The existing two-directional viaduct will be modified to single-direction flow, and a new northbound 440 m cut and cover tunnel will be constructed beneath Victoria Park. Three-dimensional (3D) visualisation media were used to communicate key design innovations to stakeholders and the general public. The 3D visual material has proven a useful tool for informing motorists of a new safety barrier method adopted for traffic management.This presentation will explain how 3D visualisation was incorporated in the project and will showcase the 3D visualisation media created for the project.

Mar 8, 2011

As requested by my fellow members I shall endeavour to read a paper on the Treatment of the Auriferous Sulphide Ores of Kalgoorlie from a metallurgical standpoint. Before going into the subject it will be necessary for me to make some slight explanations. As most of you are aware many of our London friends holding interests in some of these mines think it necessary that their doings should be shrouded in mystery. The result of this is that in some cases it is impossible to get any official figures from the mines for this paper. I must ask you not to lose sight of the fact that in treating the sulphide ores of the Kalgoorlie mines we had absolutely no data to start on, and that to-day. we are just beginning to get a fair grip of tbe subject; and though very high extractions were announced when the first plants were started on sulphide ore, it was well known that this was only to maintain the public confidence in the mines to allow time to make necessary adjustments; and, as showing the advance made in the treatment of the ore, I notice several of the mines have published the results of the final or re-treatment of the residues of their first sulphide treatment. I have also had the opportunity afforded me of thoroughly sampling the residues of several of the principal mines, and find the results as now published absolutely correct.

Jan 1, 1901

By J Guo, K Williams, S Caldwell, W Chen

Mining is increasingly occurring near or below the water table. This has led to a higher rate of handling problems associated with increased moisture and increased adhesion, which lead to a higher rate of blockage events within the materials handling chain. Typically, these ores and minerals are known as ‘wet and sticky materials’.Currently there is very limited knowledge and/or methodologies for effective design of efficient materials handling systems when it comes to handling wet and sticky materials. However, there is one major parameter that significantly affects handleability of a wet and sticky ore; namely, its moisture content. Flow property testing has shown that when moisture is reduced, the adhesive properties of the ore are also significantly reduced, thereby increasing ore flowability.The research embodied in this paper investigates the moisture reduction rate through a loose packed bed of iron ore using dry, ambient temperature airflow. A comparison of the predictive capabilities of a proposed drying model to data obtained from on-site experiments using iron ore fines is made. Building on an assumption made by Hukill (1954), a second term has been proposed to account for rewetting effects in the drying process. From this research, identification of improved moisture reduction approaches is envisaged.CITATION:Caldwell, S, Williams, K, Guo, J and Chen, W, 2017 Aeration induced moisture reduction of iron ore, in Proceedings Iron Ore 2017, pp 455–460 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

There are circumstances where the ordinary techniques of experimental variography in geostatistics û now in common use despite their recent origin û are not quite successful. This paper describes a new addition to the geostatisticians tool kit developed by one of the renowned leaders in the field to cope specifically with these circumstances. Possible application of this technique will be outlined when it will be seen that there are still problems remaining to be solved in its use for economic evaluation of deposits with irregular mineralisation.

Jan 1, 1984

The works of Metal Manufactures Ltd are situated at Port Kemblam NSW, within a few hundred yards of a deep-water harbour. At present they occupy about 26 acres, and ample provision has been made for future extensions. Rail connection exists between various parts of the Works and the main South Coast Railway, the harbour jetties and the adjacent copper refinery of The Electrolytic Refining and Smelting Co Ltd. A plan of the works is shown in Fig 1.The company was incorporated in March 1916, and commenced production of copper wire in June 1918. Early in 1920, tube manufacture was undertaken, followed by telephone cable mnufacture in 1923. Today the Works consist of five principal sections: Founrdy, Tube Factory, Wire Factory, Cable Factory and Case and Drum Factory. Whilst the last four are engaged in producing the finished materials for despatch from the Works, the first-mentioned is engaged in producing copper, brass, and other non-ferrous billets for use in the Tube and Wire factories. In addition, there are Engineering and Metallurgical Departments supporting the manufacturing sections, and in these, as well as in all other sections of the Works, extensions have been carried out from time to time to provide for increased output and new types of products.

Jan 1, 1938

The Estonia Mine, operated by Eesti Energia Kaevandused AS (EEK), the mining division of the Estonian Government's energy company, Eesti Energia AS, is a large room and pillar mine located in Eastern Estonia. It supplied approximately 4.9 Mt/a of oil shale in financial year ending 2010, which is used for electricity and shale oil generation. Due to the Estonian climate and the power station's need for a dry product, Estonia Mine has developed a planning system where short-term demands of the power stations dictate the schedule. Such an arrangement requires maximising flexibility and consequently the mine only operated for 199 days in 2010.The footprint plays a key role in achieving mass mining rates as the 12 km + 12 km lease area allows the mine to split into mining districts that act independently of each other and maximise the number of work areas available. Coupled with this, the geology of the mine is relatively homogenous over the mining lease, simplifying the mine design and production methods.During the last five years, EEK has commissioned a comprehensive conveyor network. Consequently, material handling only requires loaders to dump oil shale direct from the production face onto a chain conveyor that feeds the conveyor network that ultimately supplies the enrichment plant. Dewatering is also of critical importance, with 90 Mm3 of water discharged annually. EEK uses large trenches up to 3.5 m deep and 1.2 m wide to channel groundwater. Track mounted mechanical saws are used to cut slots in the floor, to control overbreak in blasting these trenches.EEK has introduced Salzgitter Machinenbau GB 280S auger drills that drill three 280 mm diameter holes simultaneously. This has improved void hole drilling times and reduced the drilling required for each face, reducing the overall production cycle time. Blasting activities have also been decoupled from other mining activities negating the need for firing times through the use of small independent firings, required to control vibrations.

Dec 6, 2010

By D Pearce

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

The treatment plant at Martha Mine was upgraded from a nominal throughput of 110tph (O.93mtpa) to 150tph (1.25mtpa) late 1999. Post-upgrade performance did not meet expectations when treating either the competent primary ore or the clay-rich oxide ore.   ò Plant throughput is constrained by milling capacity when treating the competent primary ore. This is not an issue at present as current plant feed is oxide ore from the top of the open-pit, but will become so in future years as the pit deepens. To counter this future threat, ball mill power has been restored to 1100kW through modifications to the drive train. The addition of a crushing circuit may also be necessary.   ò Plant throughput was originally constrained by thickener and leach/adsorption tank issues when treating the oxide are. Changes to plant equipment and operations has seen the removal of these constraints and throughput on this material is no longer a problem.   The most significant issue facing plant staff at present is the high silver grade and its impact on gold recovery. These high grades impact upon recovery through losses caused by insufficient leach and adsorption capacity. To counter this, the geology, mining, and milling teams are working together to blend the high grade silver zones with lower grade ores - this is seen to be the quickest and most cost effective way to deal with the issue. The plant design has also been evaluated with a view to modifying it to cope with the higher silver grades. The viability of these modifications will depend on cost and time (that is, the length of time to implement any modifications versus the length of time to mine out the high silver zones).

Jan 1, 2001

By N N. Viswanathan, D Kumar, S Kumar

In secondary steelmaking, calcium treatment is practised to modify the solid alumina or spinel inclusions into liquid or partially liquid calcium aluminates. It has been seen that the dissolved calcium reacts with sulfur or oxygen present in the steel to form CaS or CaO type of transient inclusions. Post-calcium treatment these transient inclusions further react with pre-existing alumina or spinel inclusions and modify them. In addition, direct modification of pre-existing inclusions is also reported in the literature. In the present study, laboratory-scale induction furnace-based experiments are carried out to melt electrolytic iron in an alumina crucible followed by deoxidation with aluminium. The CaS-based composite material, prepared in-house, is added after the aluminium deoxidation to study the stability of CaS at the steelmaking temperature. Multiple steel samples were also taken to track the dissociation of CaS by means of sulfur pick-up in steel. Additionally, inclusion analysis of these steel samples was also performed to track changes in the chemical composition of inclusions in response to CaS addition. It has been seen that the CaS dissociates leading to a gradual pick-up of sulfur in steel. The scanning electron microscope – energy dispersive X-ray spectroscopy (SEM-EDS) analysis reveals that the alumina crucible and floated alumina inclusions are modified into calcium aluminates and the extent of modification depends on the contact time of CaS with the two sources of alumina mentioned earlier. However, the modification of alumina inclusions in the bulk steel did not occur during these experiments.

Jun 19, 2024

By R Lau

The fire safety design for road tunnels includes the following aspects: active systems, passive provisions and operational procedures. The active systems include the smoke control system, fire suppression system, detection system and fire fighter’s assistance systems. Passive provisions include escape passages, fire separation and fire resistance systems. The operational procedures refer to fire fighter access, reporting and alerts, evacuation processes and crowd control.Currently, these systems are typically designed by different designers or teams. These systems are intended to work together in a coordinated manner to provide the desired safety outcome. However, in practice, this is not always happening. The fire engineering process is supposed to bring together all these aspects and arrive at an integrated safety system. The fi re engineering process in practice is not integrating the design with the practice or reality and is thus arriving at less than desirably efficient safety systems.The example of design inputs shows how disconnected each system design basis is. The smoke control system design is based on the design fire size. The performance of the smoke control system is to achieve a smoke free environment for a defined space for a particular fire size – the design fire. The fire suppression system – most commonly sprinklers or deluge systems, is designed according to codes and to achieve a certain water discharge rate. The fire detection system is designed to detect temperature rise/rate of rise and perhaps density of smoke. Fire separation is determined to provide a certain period of service – mostly for structural elements. Escape route size and location is determined mostly by code compliance. Evacuation procedures are determined by Authority operational requirements rather than human behaviour.To arrive at an integrated fire safety system, the design basis and performances must be coordinated. An approach using fire scenarios would ensure all systems are designed to a common performance requirement. This paper will discuss how the current design approach outcomes compared with a fire scenario approach. More effective and efficient fire safety systems would require the stake holders to understand the implication of this approach and to embrace this through the fire engineering process.

Mar 8, 2011

By Chunbao Z, Zhenchuan Z

As known to the international mining sectors, Hunan province, called as ' Nonferrous Native Area ', is the main base of nonferrous metals Pro- duction in China. There are over 194 nonferrous mines in this province, most of them distribute over the basin of Xiangjiang River. The state of management of wastewater in Hunan's nonferrous mines is outlined.The experiences and economic benefit in the management and treatment of wa- stewater in Bofang and Mayang copper mines, and at Shizhuyuan polymeta- llic mine, are mainly introduced. It concludes with measures and recommendations for future management and treatment of wastewater in Hunan's nonferrous mines.

Jan 1, 1988

By P J Savory

Ranger is a uranium mining operation located within one of the most environmentally sensitive regions of Australia. Geology has played an important role in mine planning, operations and rehabilitation since discovery of the deposits 25 years ago. The Ranger orebodies have a reserve total of 166 300 tonnes of U308 including 90 400 tonnes of U308 at North Ranger. At current milling rates these reserves give a mine life greater than 40 years. The uranium is hosted in Lower Proterozoic rocks of the Cahill I ormation and is associated with strong chlorite alteration. In pit grade control involves the use of calibrated probes and a radiometric truck discriminator allowing fast, accurate grade determination of material. Ore is defined at a cut-off grade of 0.2 per cent U308. Mineralised material is defined by the Uranium Mining (Environmental Control) Act 1979 (UMEC Act) at a grade of 0.02 per cent U30s. Natural water levels in the #1 Pit area vary as much as 7.5 metres between wet and dry seasons. Ground water inflow into the pit during the dry season is 600 m3/day. No significant slope failures have occurred in the pit. The environmental impact of mining operations is constantly monitored. Rehabilitation of non-mineralised stockpiles is ongoing. This paper discusses the interaction between geology, hydrogeology, rock mechanics and grade control with the present mining operation.

Jan 1, 1994

By M Davis

Increasing growth in the minerals industry over the past decade has raised the question of whether the standard of training for new geologists has been negatively impacted. This hypothesis was tested by means of a survey. Factors considered included the quality of training and whether it has changed over the past 50 years, preferred styles of training compared to styles of training received and whether the quality of training provided by a company changed with the type or size of company. Data from 435 survey respondents showed a consistent standard of training, but a significant increase in the level of responsibility allocated to new geologists. Those with increased responsibility also had reduced access to additional support and were often asked to perform tasks for which they had little or no training. New geologists were more likely to receive better quality training in a large company (over 100 employees) that owned the mine or exploration lease. A more structured training program was more likely to provide a higher quality result than those with minimal or no structure.

Aug 22, 2011

By A Hilli, K Kosmara, J Steyn

PT Nusa Halmahera Minerals (PT NHM) is an Indonesian joint venture company owned by Newcrest Mining Limited (75 per cent) and PT Aneka Tambang (Persero) (25 per cent). PT NHM operates two underground gold mines, Kencana and Toguraci at the Gosowong mine site in North Halmahera District, North Maluku Province, Indonesia.On 8 February 2016, a major ground movement occurred in the K-Link orebody of the Kencana underground mine, effectively blocking the only two access ways to the stoping area. Following mine clearance, it was found that a Solo production drill rig operator, who had been drilling in the Level 10 Extraction Drive was still underground, cut off from the rest of the mine by the ground movement.Communication, nutritional and logistic supply to the trapped operator was established with the breakthrough of two diamond drill holes. A range of technical expertise and opinions from both on and off-site were sought and two options were chosen for implementation of the rescue operation. The rescue was completed successfully on 16 February 2016 with the operator being rescued in good physical and mental health.CITATION:Kosmara, K, Hilli, A and Steyn, J, 2017. Eight days entrapped – PT Nusa Halmahera Mineral’s rescue of a trapped miner, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 155–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By K Sanematsu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore deposits of rare earth elements (REE) in South-East Asia are classified into four types: carbonatite, allanite, ion-adsorption and placer. Occurrences of the carbonatite deposits are confined almost exclusively to the Red River Fault Zone of northern Vietnam. Since the carbonatites contain dominantly REE fluorocarbonates (eg bastnasite) and lesser amounts of monazite, they are rich in light REE but poor in heavy REE. The ion-adsorption type deposits and prospects were found in Myanmar, Vietnam and Thailand. The ion-adsorption ores generally show lower REE grades than those of the carbonatite type and placer deposits; however, they could be enriched in HREE, which are more precious and scarce commodities than LREE. The ores consist of weathered granites with a significant amount of ion-exchangeable REE, which are extracted by using a dilute electrolyte solution. The ion-exchangeable REE are likely to be sourced from REE fluorocarbonates, allanite and titanite because these minerals are relatively susceptible to weathering and release REE3+ ions into soil water. In contrast, monazite and xenotime are resistant to chemical weathering and could form placer ores. Placer monazite and xenotime have been processed as by-products of placer Sn, Zr or Ti in Malaysia, Thailand and Indonesia, although the current production is small.CITATION:Sanematsu, K, 2015. Rare earth element deposits and prospective areas in South-East Asia, in Proceedings PACRIM 2015 Congress, pp 671–678 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The epithermal Au-Ag deposits of the Hauraki Goldfield have formed in the convergent plate margin setting of the Coromandel Volcanic Zone (CVZ). The deposits form as siliceous lodes in the upper parts of geothermal systems associated with andesitic and rhyolitic volcanism. Two types of low sulphidation epithermal mineralisation are recognised in these volcanic terranes. Vein deposits within the rhyolitic terrane in the east and south of the CVZ (Whitianga Province) are typified by Chalcedonic Silica-Adularia-Illite type mineralisation. The veins are hosted by both rhyolite-dacite volcanic rocks and the underlying andesitic basement. The mineralisation formed by episodic violent decompressional boiling of deeply circulating meteoric water, with some magmatic fluid contribution; this boiling was associated with hydraulic fracturing and hydrothermal eruptions in geothermal systems where the piezometric surface of the deep geothermal reservoir lay near-surface. Such episodic boiling provides chalcedonic veining, banding and brecciation textures, adularia stability, bladed calcite, and extreme loss of H2S gas from the fluid to cause major gold deposition.   Crystalline Quartz-Illite-(Adularia-Kaolinite) type mineralisation is widespread in the andesitic terrane forming the northern and western portions of the CVZ (Kuaotunu Province). There is a spatial association with weak mineralisation of the high sulphidation (Vuggy Silica-Alunite-Kaolinite-Illite) epithermal type and porphyry eu-Au type. Crystalline Quartz mineralisation is probably formed by the mixing of shallow acidic groundwaters with the ascending deep geothermal fluid in geothermal systems beneath andesitic stratovolcanoes. The piezometric surface to the deep geothermal reservoir in these systems is likely to lie at considerable depth, with acidic gases rising from the geothermal reservoir condensing within the overlying vadose zone. The cooling effect, oxidation and pH decrease accompanying mixing apparently overcomes the dilution effect, and results in quartz deposition, illite (and locally kaolinite) alteration, and precipitation of gold. A high level of base-metal sulphide precipitation also enhances gold deposition. Violent boiling of the mixing fluids may occur at local structural dilation sites, producing high grade "bonanza" gold mineralisation.

Jan 1, 1991