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By I Sherrell, R Jain, P Jansson

With the depleting iron reserves and difficult market conditions, precision in separation efficiency is of utmost importance. Classical local control options are predominant in the industry, but their inability to adjust to resolve application problems of interest has furthered the need of developing and implementing continuous control methodologies.This paper highlights the recent development in control of Outotec SLon® vertically pulsating high gradient magnetic separator (VPHGMS) including programmable logic controllers (PLC) coupled with distributed control system (DCS), on-site human–machine interface (HMI) control panel, advanced process control, continuous online sampling using Courier® 8 and additional modernisation packages including level control and cooling monitoring. These modern control options result in improved efficiencies, promote safer operation and at the same time reduce operational manpower needs.CITATION:Jain, R, Sherrell, I and Jansson, P, 2017. Automation for efficient separation with the Outotec SLon® vertically pulsating high gradient magnetic separator, in Proceedings Iron Ore 2017, pp 211–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The Effect of Non-Toxic Depressants in Chalcopyrite Flotation

Sep 13, 2010

By J C. Carlile

Many low sulphidation epizonal gold and zinc-lead vein deposits within magmatic arcs are situated on basement highs, and post-date both the main volcanic episode and porphyry copper (gold) mineralisation. These features are best explained by emplacement of a flat batholith a few kilometres beneath each mineral district, as recently demonstrated by geophysical data in the Baia Mare district of Romania. The batholith provides heat for the hydrothermal system, and results in extensional faulting both through up-doming of the overlying rocks, and in some arcs through incipient collapse of the thermally weakened crust under regional extensional stress. More water-rich magmas emplaced at greater depths could explain some deep epizonal and mesothermal gold deposits situated outside magmatic arcs.

Jan 1, 1995

By D Rubery, C Croker

The Boddington Gold Mine (BGM) is located 120 km south east of Perth, Western Australia. The operation is managed by Worsley Alumina Pty Ltd and mined by contractor Henry Walker Eltin (HWE). The mine has been operating since 1987 with ore extracted from a series of pits along strike. Ore is contained within the basement rock, which is overlain by a cap rock layer and transition zone. Cap rock and basement zones require blasting.As the mine neared completion, a high-grade deposit was discovered within 50 m of an existing Western Power substation and 100 m from the processing mill. The substation provides power to the Boddington area and is a back-up power supply to the city of Perth. Due to the delicate nature of the transformers located at the power station, overhead power lines and the mill, blasting in the area was considered very high risk. As such blasting needed to be controlled for flyrock, airblast and most importantly peak vibration and frequency limits which had the potential to damage the transformers.The mine was due for closure in March 2001. The decision to mine the pit was based on its high grade, ability to be blended with lowering grades from other pits and changing of the processing technique with the expansion. This decision extended the life for a further six months.Due to the high potential risks a detailed risk assessment was conducted by Orica, Worsley and Henry Walker Eltin. The completed assessment and the major design parameters were presented to Western Power for approval. The ability to reduce the blasting risk was focused on limiting of vibration through controlling maximum charge initiated per delay, blast timing and firing direction, and other innovative control measures. OricaÆs SHOTPlan« and Sabrex« computer modelling packages were used to predict the outcome of blasts.The success of this project has opened the doors for other high risk blasting projects, which otherwise may be left unmined.

Jan 1, 2002

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

Grey River Gold Mining Ltd commenced dredging alluvial flats in the Grey River Valley in 1989. Previous drilling indicated over 100 million cubic metres of gravels with some 90 per cent of the gold in the bottom seven metres. The dredge built by Rahco, Spokane, was innovative in a number of aspects but particularly in the fact that a separate ladder with a cutter and pump was used to strip the overburden and a bucketline to mine the gold bearing wash below. Metallurgical studies and exploration were initiated when the project commenced. Leasing and environmental considerations were investigated and action taken. While progress is being made, the operation at this stage is not meeting required production and performance. Main problems have been with the stripping system and wear.

Jan 1, 1990

By D McClelland, R Whittering

Minerals and Metals Group (MMG) subsidiary Lane Xang Minerals Ltd operates a single site copper and gold mine near Sepon in Lao PDR. Gold production commenced in 2002 and first cathode copper production was in March 2006. Plant throughputs for gold and copper are currently 2.5 Mt/yr and 1.4 Mt/yr respectively; use of a second tailings dam has commenced accordingly. Although the increased catchment area creates opportunities for more storage to reduce demand on other water sources, especially during the dry season, it also creates greater requirements for water treatment capacity.The water balance for mining operations in a tropical monsoon environment with dry winters presents on going management challenges. A successful mining operation depends on a careful balance of water inputs and outputs. The challenge prior to every wet season is having enough storage capacity to absorb potential rainfall. Plant operation in the dry season benefits from water captured and stored from the wet season which reduces the dependence on river water. Release of excess water to the environment is necessary to cope with the overall positive water balance and depends on suitable and effective treatment of water in accordance with the environmental guidelines.Ausenco has recently built and commissioned a second water treatment plant at the Sepon Copper Plant to process tailings decant water.  The objective of the second Sepon water treatment facility is to increase the site water discharge capacity to maintain the water balance and reduce the dependence on river water.  Decant water treatment is required to precipitate the contained heavy metals prior to discharging to surrounding wetlands.  The main metal that needs to be removed from the site water to meet discharge water quality requirements is manganese, as heavy metals are already precipitated to required levels in neutralisation before the tailings are sent to the storage facilities. A site layout provision for removal of manganese to produce a saleable carbonate precipitate is incorporated in the polishing plant design (future installation).

Jan 1, 2009

Study on Ball Mill Grinding of a Cassiterite-Polymetallic Sulfide Ore

Sep 13, 2010

By A S. Derrington

There are several long-standing rules of thumb that are often quoted in mine ventilation studies. They include airway ‘carrying velocities’ and the critical upcast air velocity range that must be avoided to prevent a water blanket forming. Quoting these rules of thumb may lend an air of legitimacy to a ventilation design, and allow the design engineer to avoid having to study a problem from first principles. But how valid are these shortcuts in today’s rapidly changing world? This paper summarises research into the genesis of several commonly quoted rules of thumb. It finds that they were very specific to the local conditions, practices and economics at the time they were developed. It also presents examples where applying these rules of thumb outside of their original context can lead to unexpected and erroneous results.CITATION:Derrington, A S, 2017. Ventilation rules of thumb – friend or foe? Focusing on design upcast air velocities for shafts and raise bores, in Proceedings Australian Mine Vent Conference 2017, pp 253–260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Over the past few years, there has been an emerging relationship between business and civil society, especially NGOs. This relationship has the potential to bring about significant change, identifying common ground between commercial and societal interests. The mining industry has been a leader in acknowledging the need for community consultation and engagement. This paper argues that partnerships can make a very significant contribution to the industry as it comes to terms with the dilemma of an open economic system pushing against a closed ecological system.The paper will pose a number of questions: where is the locus for debate about sustainability in the mining sector?; how well embedded within companies are the new competencies that Leon Davis first identified in 1995 for the mining sector?; how has education for mining engineers or exploration geologists changed to prepare people for what are very different expectations within the working environment?; how well is the industry doing in managing its own environmental impact and what is its responsibility to an agenda for sustainability which extends beyond its own operations?;and how can NGO partnerships contribute to more sustainable outcomes? The paper does not aim to answer these questions, but to explore them in the hope that the issues and possibilities raised will contribute to advancing progress towards sustainability within the industry.

Jan 1, 2002

The lignite resource in the southern part of the South Island is New ZealandÆs largest source of indigenous primary energy. The ten deposits evaluated by the Liquid Fuels Trust Board (LFTB) have a total recoverable reserve of 6.2 billion tones equivalent to 74 000 PJ of energy or 20 times the original energy content of the Maui gas field. Updating the economics of the original LFTB studies indicates that lignite could be mined for between NZ$1.0 and 3.0/GJ. Its conversion to synthesis gas for production of petroleum products, chemical methanol, ammonia/urea fertiliser or electricity would be in the national benefit and likely to be commercially economic at todayÆs product prices.

Jan 1, 2005

By C M. Evans, D Thomas

Solid EnergyÆs Wangaloa open cast coal mine was operated between 1945 - 1989, and remained closed and disused until 2001 when SENZ initiated a mine rehabilitation programme. It is nearing the final stages of physical and environmental rehabilitation, aimed at creating an aesthetically pleasing and useful landscape. The final goals of these efforts are to produce an area, which has recreational and educational value. SENZÆs holistic approach to rehabilitation has been undertaken, treating the entire historical mine footprint instead of focusing only on those disturbed areas and the minimum range of issues just to meet with legal compliance. Rehabilitation at the site has included overburden modification with an emphasis on stability, removal and replacement of unhealthy and invasive plant species, and an AgLime amendment to alter soil pH conditions, which would support native plant species. To date, most ongoing activities relate to final planting and plant upkeep, and maintenance of the landform including ongoing erosion control, pest control, environmental monitoring, and research. Environmental quality concerns at the site may be treated by using a combination of methods, including regrading and capping of acid-generating pyrites, soil treatment with AgLime, and passive wetland treatment within existing water courses. Following major works, the mine site area may be opened to the public for recreational activities, interpretive displays on historical mining activities, and observation and appreciation for otherwise unseen geological features. SENZÆs holistic approach to reclamation, rather than treating minor issues, will result in the former mine site being transformed into an asset and the environmental and financial liability associated with the closed mine being discharged. Former mine sites can be turned from environmental liabilities with no recreational or public value (and potentially dangerous to life) into sites that can be safely used by the public for recreational and educational purposes.

Jan 1, 2006

By P J. Minehan

The investigation of the potential of the Webb/Baynes block of the Buller coalfield for anode carbon manufacture has generated much information on the physical beneficiation characteristics of the Buller coals in general. A further 36 drill holes of the block in question and several other samples have been analysed by sink/float analysis, either at a single density or over a range of densities. In addition, many samples have been beneficiated on a laboratory shaking table or by flotation. The ash content can be reduced by a variable factor. The reduction factor of between two and four by sink/float analysts is understandably less for tabling where separation is not perfect. All Buller coals behave similarly, there being greater ash reduction factors for higher ash coals.

Jan 1, 1983

By B Crossley

Self-cleaning fluidised bed heat exchangers have demonstrated unparalleled performance internationally for the implementation of indirect heat transfer in severely fouling fluid environments. Recent advances in equipment design have increased the scope of application to include indirect heat transfer in slurry environments, including fouling, scaling and viscous slurries. The ingenious configuration of recirculated cleaning particles through the tubes of vertical shell and tube heat exchangers provides the ability to solve heat transfer problems that arise as a consequence of tube-side fouling during indirect heat transfer to process fluids or slurries. In most cases, the cleaning particles consist of chopped metal wire, however other process-specific materials may be used.

Jan 1, 2004

The New Zealand Steel Ironsand Slurry Pipeline was successfully commissioned in February 1986. The project includes 18 km of high pressure, polyurethane lined buried pipe. McConnell Dowell Constructors Limited has developed a coupling which has allowed this pipeline to be fully welded. The design and development of the coupling and its application on this project is discussed.

Jan 1, 1986

By K Palmer

Alluvial platinum was recovered during gold mining operations in Maud Creek, a tributary of the Howard River. Average electron probe analyses give Pt 88.75, Fe 5.27, Ir 0.70, Os 1.06, Pd 0.34, Ru 0.14, Rh 1.29, Cu 1.06. Rare grains of a Pt-Fe-Cu alloy are also present and an unusual feature of all grains is the relatively high rhodium content which finds expression in segregations of rhodium arsenide, cherepanovite. Platinum is found in the Orepuki area of Southland, where it is probably partly derived from the mafic rocks of the Longwood Complex. Rocks of the Rotoroa Complex, similar to those of the Longwood Complex, form bedrock in Maud Creek and are possibly the source of the Howard platinum. Alternatively, it might be derived by glacial transport from the Matakitaki ultramafic block 30 km to the southwest. Origin from the Rotoroa rocks is preferred as, if the Matakitaki rocks are part of the Dun Mountain Ophiolites, they might be expected to contain osmiridium rather than platinum. The ratio Pt:Ir-Os has been widely used to distinguish low Pt:Ir-Os ophiolitic from high Pt:Ir-Os gabbroic assemblages. Mafic complexes such as Longwoods, Darran, Rotoroa, and Riwaka might be expected to show similar high Pt:Ir-Os ratios and be targets for platinum exploration. Detrital platinum examined from the Parapara area, Golden Bay is mainly osmiridium, with rare grains of rutheniridosmine, very similar in composition to that found in concentrates from the Kaniere dredge, West Coast.

Jan 1, 1987

This paper reviews the likelihood of instability occurring within coking coal cargoes from BHP CoalÆs northern Bowen Basin mines. In coal cargoes, initial moisture redistributes vertically towards the base, saturating the bottom layers unless the bilge wells are pumped regularly. There has been concern in some quarters that saturated coal in the basal layer may be prone to liquefaction, and if the vessel then rolls significantly in rough seas, overall sliding movement of the cargo might occur. However, a review of shipping accident statistics reveals that casualties relating to shifting of coal cargoes are quite rare, and have not occurred in modern large bulk carriers (>15 000 dwt). The moisture redistribution process has been analysed to quantify the extent of cargo saturation that may occur. Results indicate that the amount of redistribution increases with initial moisture content above a threshold of eight to nine per cent. However, the removal of water by pumping from the bilges is remarkably effective in reducing the extent of saturated coal (and therefore the possibility of cargo liquefaction and movement), and in controlling the average moisture content of the bottom layers of cargo. Stability analyses were then performed for deep sliding of a cargo with a saturated and liquefied base. These have confirmed that sliding of a cargo with a liquefied base during rough seas (20¦ roll angles) would require initial total moisture content exceeding 13 per cent, the hold half full or less (width/depth >3), and no bilge pumping so that height of the saturated zone is as deep as possible. Overall, the results indicate that coking coal cargoes from BHP CoalÆs northern Bowen Basin mines will be unlikely to suffer sliding or liquefaction failures when transported in modern large bulk carriers.

Jan 1, 1997

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 Y Yamaguchi, S Nomura, M Matsumura, C Kamijo

In order to increase productivity and decrease reducing agent rate (RAR) of blast furnaces, slag content of sinter ore must be decreased. However, gangue content in iron ore tends to increase because of resource depletion. Therefore, amount of high-grade concentrate in sinter ore feeds should be increased, but this situation causes a decrease in permeability of the sintering bed so that the productivity of sinter process decreases. In order to increase the amount of concentrate, NSSMS has developed the P-type separate granulation method, RF-MEBIOS and SPEx II technologies. These technologies have been introduced to actual sintering machines. In this report, a new technology using microparticles of iron ore is proposed to increase the amount of concentrate in sinter blends. Basic experiments simulating the sinter making process using microparticles of iron ore were undertaken. Crushed pisolite, containing >60 wt per cent -10 µm was prepared for binder. The pisolite microparticle binder was mixed with another Australian sinter feed ore in a high-speed agitating mixer. They were mixed for about one minute, and then granulated using a pan pelletiser. After that, they were added to another raw material mixed by a drum mixer, and then charged in a pot for a sinter pot test. As a result, when the amount of concentrate increased from 13 wt per cent to 20 wt per cent, productivity was almost kept constant using pisolite microparticle binder.CITATION:Kamijo, C, Yamaguchi, Y, Matsumura, M, Kawaguchi, T and Nomura, S, 2017. Development of an iron ore microparticle binder for increasing the concentrate content of sinter blends, in Proceedings Iron Ore 2017, pp 69–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The paper considers Aboriginal responses to large-scale mining, including Indigenous attitudes towards land access for exploration and project development. The core question, in which I have been interested for some time (Trigger 1997a; 2000; 2001), is: what are the significant factors affecting responses among Indigenous communities to mining exploration and development project proposals?

Jan 1, 2002