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By R Fanni, D Reid, M Kulessa

Recent updates to Australian industry guidelines emphasise the importance of the assessment of liquefaction potential of tailings. This includes assessment of the cyclic liquefaction potential, and the post-seismic strength of tailings expected to undergo strength loss from seismic loading. Despite this increase in focus, a relatively small number of Australian tailings appear to have been characterised through cyclic and post-cyclic testing. This paper presents the cyclic characterisation of four Australian tailings, consisting of iron ore, lateritic nickel, vanadium and bauxite residue. Material was obtained either from surficial tube sampling or through remoulding samples in the laboratory from slurries. Testing consisted of monotonic, cyclic and post-cyclic tests for each material. For three of the materials, laboratory-scale shear vane testing was also performed to provide a comparison to post-cyclic strengths from direct simple shear.The results indicated cyclic resistances consistent with the results of other tailings presented in the literature. The lateritic nickel tailings provided the greatest cyclic resistance of the four materials tested, followed by the vanadium tailings. This was somewhat consistent with expectations for material behaviour based on index properties. Post-cyclic strengths were seen to decrease as cyclic strains increased, consistent with typical observations in the literature. Following significant cyclic straining, in some instances the post-cyclic strengths approached those obtained through residual shear vane testing. This provides further insight into the strain-dependent nature of post-cyclic strengths for some materials. The implications of these observations on the post-seismic stability condition are discussed.CITATION:Reid, D, Fanni, R and Kulessa, M, 2015. Cyclic and post-cyclic behaviour of four Australian tailings, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 207–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By J Millard, K Sexsmith

BHP Billiton Diamonds Inc (BHPB) has been mining kimberlite from several pipes at the Ekati Diamond MineTM located 300 km north of Yellowknife since 1997. Processing of kimberlite produces coarse kimberlite rejects (CKR, 0.5 to 8 mm) and fine tailings (less than 0.5 mm). The CKR are trucked to the Coarse Kimberlite Reject Storage Area (CKRSA) located within the drainage area of the tailings impoundment (Long Lake Containment Facility û LLCF). The coarse rejects are wet when dumped and are expected to freeze as a result of annual average site temperatures of about -10¦C. Seasonal thawing occurs along the exposed edges of the pile. Monitoring of the CKR indicates they have consistently low sulfur concentrations (0.4 per cent) accompanied by high acid neutralisation potentials (78 to 337 kg CaCO3/t). Carbonate concentrations vary from 0.9 per cent to 3.4 per cent. The CKR are therefore not potentially acid generating based on conventional laboratory testing. Monitoring of stagnant pools on the tundra downgradient of the CKRSA has shown that water originating from the pile resembles acid rock drainage (ARD). Water pHs can be less than 4, and sulfate concentrations are typically in the thousands of milligrams per litre. Conventional flowing toe seeps are pH neutral but also have elevated sulfate concentrations. Investigations conducted in the summer of 2002 revealed no evidence of in situ acid generation. Pore water chemistry is probably controlled by oxidation of fine-grained pyrite, neutralisation of acidity by calcium and magnesium carbonates and silicates, and freeze concentration of pore water. The acidity observed in tundra pools downgradient of the CKRSA appears to be a result of leaching and mobilisation of iron under reducing conditions at the CKR-soil contact. Downstream of the CKRSA, reduced iron oxidises and is hydrolysed on contact with the atmosphere causing pH depression. BHPB is applying the findings of this study by constructing facilities containing kimberlite on granite pads. These in turn are placed on frozen ground so that the foundations remain frozen and limits contact of wastes with the acidic soils.

Jan 1, 2003

By H Weitz

Bateman Engineering provided process technology and engineering design to China Yunnan Metallurgical Company (CYMCO) for a 30 MW DC furnace for the production of high-grade titanium dioxide slag.Following the successful commissioning of the furnace during the latter part of 2009 and the first quarter of 2010, a period of adverse circumstances resulted in having to operate the furnace without feed and at a low power input for a period of time. When normal feed resumed, a layer of solid material was detected on the slag-iron interface during sounding measurements. The condition of the iron was also significantly altered. The iron temperature was much higher than the design value, but the carbon content had decreased to such an extent that a large amount of iron solidified in the furnace, which made iron tapping very challenging. The slag temperature was increased in order to melt the solidified iron. However, severe sidewall damage resulted, which finally led to a burn-through. A number of samples were taken from the slag that remained in the furnace. These samples were analysed to determine the chemistry and phase profile throughout the slag bath. The mechanisms of formation of the high melting-temperature phase on the slag-iron interface are discussed, as well as procedures that can be applied to prevent a recurrence of this phenomenon. Some recommendations are made for instances when furnace feeding is interrupted for an indeterminate period.

Oct 5, 2011

By M P. Sandy, J B. Albrecht

"Narrow vein mining can be loosely defined as mining operations involving orebodies with a true thickness of less than 4 m. Some authors have limited the term to steeper-dipping orebodies where the ore will rill under gravity. However, ænarrow veinÆ can also legitimately refer to some of the flatter orebodies, such as many of the platinum, chrome and gold deposits of Southern Africa, and several in Australasia including Bullen (at Norseman), Sunrise Dam, Telfer (Patterson, 1993) and the famous æflatmakesÆ at the Emperor Gold Mine in Fiji (Gordon and Harmse, 1993). Where the orebody dip is less than about 40¦ additional effort is usually required to remove the broken ore, including the use of scrapers, hydraulic monitors or remote-operated excavators (Tombs, Buckingham and Hancock, 2008).Working in such narrow orebodies presents particular operational and geomechanics challenges. A range of mining methods have been developed or adapted to exploit narrow orebodies including:cut-and-fill,narrow vein bench or longhole stoping,Alimak stoping,shrinkage stoping, and methods for shallow dipping orebodies (including Airleg and mechanised methods).The paper discusses some of the advantages and disadvantages of each method with a focus on geotechnical aspects including mining sequence options, stress management, ground support requirements, dilution and recovery.CITATION:Sandy, M P and Albrecht, J B, 2012. An overview of geotechnical issues in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 185-194 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By Brosnan J. G

Simcoa Operations is the only silicon smelter in the region and since the plant was commissioned in late-1989, has progressed from supplying silicon metal to the secondary aluminium market to the current position of supplying in excess of 90 per cent of its production to the high quality chemical and primary aluminium markets. This position has been achieved through the unique advantage which Simcoa has developed within the industry, namely raw materials, people and Simcoa's ability to adopt and use modern technology. A quality culture was instilled into the workforce prior to commissioning which ultimately led to AS3902 qualification in 1992. Simcoa has continued its quality drive through the formation of 'Simcoa's Quality Leadership Process' which is planned to make Simcoa the best silicon producer in the world.

Jan 1, 1995

By J Pan, Q H. Li, D Q. Zhu, C C. Yang, X Wang, Z Q. Guo

Al2O3 in natural iron ores generally occurs in goethite, kaolinite, gibbsite, hematite and iron carbonate. When the content of alumina in sinter increases from 1.11 per cent to 3.50 per cent, the reducibility of sinter decreases with the addition of four different types of alumina. When gibbsite and kaolinite are added, the low temperature reduction disintegration (RDI+3.15 mm) of sinter increases with the increase of Al2O3 content in the range of 1.5 per cent to 3.5 per cent. Furthermore, when adding pure reagent alumina, the increase of Al2O3 content in the range of 1.5 per cent to 3.0 per cent will increase the RDI+3.15 mm of sinter. The addition of ferric oxide–alumina spinel with the Al2O3 content in the range of 1.5 per cent to 2.5 per cent, also increases the RDI+ 3.15 mm of sinter. The influence difference is results from the change of the mineral composition and microstructure of sinter because of the occurrence state of Al2O3. Under the condition that Al2O3 content of sinter is 2 per cent, the porosity of sinter with kaolinite is 37.26 per cent, and the shape is irregular. When gibbsite and ferric oxide–alumina spinel are added, the porosity of sinter is about 16 per cent, and the pores are round. When pure reagent alumina is added, the porosity of sinter is 17.49 per cent, and the pores are regular and small. When kaolinite, gibbsite and ferric oxide–alumina spinel are added, platy calcium ferrite is mainly formed in the sinter, and some of it is columnar calcium ferrite. On the other hand, when pure reagent alumina is added, in addition to platy columnar calcium ferrite, acicular calcium ferrite is also formed in the sinter.

Nov 8, 2021

By T Laurencont

The Queensland Department of Natural Resources and Mines (NR&M) accepted the environmental liability for the Mount Morgan minesite in 1991. This gold and copper mine located 38 km southwest of Rockhampton had been in operation for more than 100 years. Mining leases are still active while the feasibility of a reprocessing operation is carried out. From 1993, NR&M have operated a seepage interception pumpback system which has reduced the chronic load of acid rock drainage (ARD) to the adjacent Dee River, a tributary of the Fitzroy River system. In early-2000, it was recognised that a ten-year plan for rehabilitation of the mine, along with significant funding would be required if a long-term sustainable rehabilitation strategy was to be implemented at this minesite, ultimately making the seepage interception system redundant. A rehabilitation planning workshop coordinated by NR&M was held in May 2000. This workshop brought to the mine a range of technical expertise and key stakeholder groups. This workshop provided a technical forum for review of studies undertaken and to identify priority projects, which needed to be undertaken in the future to more clearly define contaminant sources on the mine site and to prioritise the rehabilitation program. Stakeholder consultation enabled the project team to be clear on community and other government (eg Environmental Protection Agency) expectations. It is clear that the future of the economically depressed community of Mount Morgan will be reliant on the careful management of the significant heritage values at the minesite for tourism, education and research. In the first year (2000), priority studies were initiated, which included whole of site studies on water balance, contaminant sources and a review of occupational health and safety and environment of the minesite and conservation and heritage scoping. Baseline vegetation and soil materials surveys were also initiated. The outcomes of these studies helped to shape the work program for the following year, while providing a basis for an additional funding application, which was granted. The second year of studies focused on building upon the existing baseline studies completed. In addition, studies focussed on addressing the priority issue of contingency planning for overflow from the open cut pit in accordance with best practice management of release water and river monitoring strategies were completed. Completion of these projects over the next six months will enable the optimal rehabilitation strategy to be defined in 2003. This optimal strategy may require the use of a water treatment plant for part of the ten-year program to provide space in the open cut pit for the deposition of ARD contaminant sources (eg waste dumps, tailings). It is envisaged that some sources will be rehabilitated insitu while others will be relocated to the open cut pit. Implementation of this strategy will be dependent on subsequent funding.

Jan 1, 2003

Most types of nuclear power reactors use uranium dioxide fuel. Power reactors using natural uranium dioxide'fuel are of special interest to countries such as Australia that have their own uranium supplies. A wide range of uranium dioxide powders can be fabricated and the ideal one flows readily, presses without the need for binders or lubricants, sinters to the required density and gives low reject rates at all fabrication stages. Sinterable uranium dioxide is usually produced via the ammonium diuranate route. The A.A.E.C. is aiming to demonstrate production of nuclear grade uranium dioxide from Australian concentrates, improving technology where possible. Details are given of the dissolution, solvent extraction, precipitation, filtration, drying, and calcination-reduction steps. Solvent extraction from sulphate media is also under study with a view to developing a process to produce a nuclear grade product at the mine treatment plant site,

Jan 1, 1969

By Behl S

Flocculation behaviour of six different dolomite samples, four from the Florida mining district, one from Perry, South Georgia and another from New Jersey was examined using polyethylene oxide (PEO) as a flocculant. The samples were similar in chemical composition, however the porosity of the samples from the Florida mining district was higher than the others. FT-IR, adsorption and surface modification by leaching revealed that flocculation was directly related to the presence of isolated hydroxyl groups on the surface. The adsorption mechanism was believed to be hydrogen bonding of the ether oxygen of PEO with isolated -OH sites on the solid.

Jan 1, 1993

By T Baumgartl, J Burgess, B Emmerton, P D. Erskine

Large-scale open cut mining in the Bowen Basin has been undertaken for over 40 years. During this period, improved mechanical capability and economics have allowed extraction to greater depths, resulting in post-mining landforms of increasing height. Rehabilitation practitioners face significant challenges in stabilising these landforms and require a comprehensive understanding of the Bowen Basin Coal Measures strata likely to be disposed of during mining. Knowledge regarding the potential behaviour of differing spoil materials (following disturbance) provides a rationale to maximise short- to medium-term surface stability of constructed landforms by identification, salvage and advantageous reuse of cladding resources as a means to minimise erosional risks.CITATION:Emmerton, B, Burgess, J, Baumgartl, T and Erskine, P, 2016. Bowen Basin coalmine spoil classification for improved mine rehabilitation outcomes, in Proceedings Life-of-Mine 2016 Conference , pp 142–147 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Stanton G

The Department of Mapping and Surveying (DMS), the Australian Key Centre in Land Information Studies (AKCLIS), the Department of Industry Development (DID) and the State Government Computer Centre (SGCC) are testing a regional information network in northern Queensland. Several study sites have been chosen by different groups of participants. The members of each common-interest group share their data for the site. They can also access datasets supplied by other organisations that are not directly involved in the particular study being undertaken. The participants include state government departments, local authorities, fed- eral organisations and the private sector. The participants communicate with computer systems in Brisbane via Q-Net. Q-Net is a pilot State government tele- communications network, established by the Department of Industry Development. Q-Net uses the communications sat- ellite AUSSAT 1 as the primary instrument of data transfer. The Q-Net network is a star system, with a Master Earth Station in Brisbane acting as a hub for radial earth stations, located throughout Queensland.

Jan 1, 1987

By Cox SJD, Kramadibrata S

One of the major causes of accidents and loss of production in underground mines is falls of ground.As mines go deeper, higher stresses are encountered and strain energy stored in the rocks is more likely to be released dynamically. This results in bumping in the rock mass around a stope or development face. Such noises and increasingly difficult ground conditions are obviously a warning of more serious problems ahead. The activity is collectively referred to as rock bursting.In Australia the mining of metalliferous deposits is taking place at increasing depths at Mt Isa, Broken Hill and the Eastern Goldfields and ground control problems with rock bursts has already been experienced at all three sites.

Jan 1, 1990

By H W. Wu

Occupational exposure limits for diesel particular matter (DPM) are progressively being adopted in a number of countries. Many of these follow the lead of the US Mine Safety and Health Administration initiated in 2008. In line with adoption of best practice it is accepted that all exposures should be reduced to as low as reasonably achievable. The management of diesel emissions and occupational exposures to those emissions requires an integrated strategy incorporating efforts from all key departments on a mine, including management, production, maintenance, supply and occupational health and safety.Australian coalmine longwall moves rely on the use of high-powered diesel equipment such as chariots and other machines that produce exhaust pollutants of gases and DPM. To reduce mine personnel’s exposure levels to DPM a hierarchy of controls can be followed. Minimising the use of diesel equipment, better operator positioning in relation to exposure source, using efficient engineering methods and adopting better ventilation to reduce concentrations through dilution are some of the controls that can eliminate exposures. Approaches generally adopted in Australian longwall mines currently rely on a combination of strategies such as optimisation of ventilation, use of diesel particulate filters and use of diesel tag boards that minimise the number of vehicles through recording entry and exit into working panels.A study has been undertaken into the mine ventilation systems currently in use during longwall moves within Australian modern longwall extraction mines. This paper reviews current longwall section ventilation systems and discusses evolving changes being adopted to address the more complex problems in dealing with section DPM during phases of the operational moves. The effects of DPM on crew members as well as the diesel equipment operators within a longwall section are examined. Issues that should be considered in designing the longwall section ventilation during the moves are discussed.CITATION:Wu, H W and Gillies, A D S, 2015. Review of ventilation optimisation strategies during longwall moves, in Proceedings The Australian Mine Ventilation Conference, pp 133–140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Richmond A

Like many industries the coal mining industry has, since the beginning of this century, undergone many changes. Technological advances and the increasing demand for fossil fuels have introduced new mining methods and techniques which allow the extraction of thicker and deeper coal seams at higher rates of production. Most new methods of mining (or for that matter any other processes) introduce problems which the engineers of the industry are expected to face and resolve. Unfortunately, spontaneous combustion has plagued the coal mining industry since the first attempts to mine coal, and is no doubt partly responsible for the reputation that coal mining is a hazardous industry. The financial loss and toll of human lives due to the occurrence of spontaneous combustion of coal in coal mines is enormous, if not incalculable. Its occurrence today is less likely to claim lives, due to both improved methods of working and in the detection of spontaneous combustion sites.

Jan 1, 1983

The paper covers the history and develop- ment of electrical and diesel-powered hydrau- lic percussion rock drills. It examines main design aspects and problems encountered in pro- ducing an efficient and reliable machine to fully cover the nominal hole sizes required for underground development, production drill- ing and for general quarry work. The main design features and advantages of a hydraulic rock drill are relatively low input power requirement to energy per blow (this being achieved by the use of an electric or diesel- powered hydraulic system) and a specially con- structed piston using a powered damper cylinder to absorb the recoil forces from the drill steel and reduce stresses on the drill, feed and hydraulic boom. A further important design feature is the anti-jamming device which controls the drill both during manual and automatic operation. This anti-jam device works on feed and rotation press and prevents the drill bit becoming jammed in broken or soft ground. These features and many other mechanical and environmental benefits are highlighted when comparing hydraulic percussion rock drills with current pneumatic machines. The hydraulic rock drill gives an overall high penetration and production rate, with an added bonus for ergonomy and environmental conditions such as lower noise level, no fogging from air and oil exhaust (which naturally gives better air for breathing),plus improved vision when in under- ground situations. Hydraulic rock drills and systems have been fully tested in many mines, quarries and contract sites during the past years. They h6! been improved and modified and are now provi~ to be very reliable and economical piece drilling equipment whò in mines and quarries.

Jan 1, 1978

By J L. Mauk

The Favona adularia-sericite epithermal Au-Ag deposit is located at the southern end of the Hauraki Goldfield, about one kilometre southeast of the world-class Martha deposit. The deposit occurs in Late Miocene andesitic lava flows and local dacitic tuffs of the Waipupu Formation. In some places, post-mineralisation ash fall and ignimbrite, up to 50 m thick, cover mineralised rocks and andesite. We collected soils samples from 110 sites along eight traverses over Favona, and from three regional lines: two south of Favona, and one north of Favona.   Analyses of soils identify prominent enhanced concentrations of Au, Ag, and Hg, and lower enrichments of Sb and As. At Favona, Au and Ag appear to be highly anomalous in areas over mineralisation with Au concentrations greater than 100 ppb and Ag concentrations greater than 1000 ppb, whereas background concentrations are approximately 5 ppb and 50 ppb respectively. The background concentrations of Hg in soils are approximately 100 - 200 ppb, but in mineralised areas, Hg generally exceeds 200 ppb, and some soils contain greater than 600 ppb. Antimony shows enrichments, although weak, above known veins and As locally shows some enrichment above areas of known mineralisation. Therefore, soil sampling at Favona defines geochemical anomalies that correlate with the position of known mineralisation at depth. Thus, there is strong empirical support for the use of Au, Ag and Hg, and possibly Sb and As geochemistry to identify mineralised trends associated with buried deposits at other epithermal prospects.

Jan 1, 2007

By Mernagh T, Large R. R, Ryan C. G, Huston D. L

The Tennant Creek goldfield is one of the largest gold producing districts in Australia, and major deposits, including Gecko, Juno, Orlando, Peko, Warrego, Nobles Nob, Golden Forty, Argo, TC 8 and White Devil have produced more than four million ounces of gold over the past two decades. Gold-copper-bismuth mineralisation at Tennant Creek occurs in lenticular, ellipsoidal or pipe-like bodies of magnetite-hematite ironstones which are hosted in turbiditic sedimentary rocks of Proterozoic age (Large, 1975; Wedekind, Large and Williams, 1989; Le Messurier, Williams and Blake, 1990; Morrison, Donnellan and Hussey, 1992).

Jan 1, 1994

By L Drowley

The Adelaide Desalination Plant (ADP) draws raw sea water into the facility and returns saline concentrate to the Gulf St Vincent via subsea conduits. This paper describes the detailed design and construction methodologies developed for the cross connection tunnel excavation. The paper concentrates on key design elements which include:· lateral breakout support of the segmental tunnel lining,· ground improvement grouting in the zone of the cross connection tunnels due to extremely variable and weak ground conditions, and· excavation methodologies and proposed support types of the riser to tunnel cross connections.The design process consisted of developing concepts, detailed risk assessment, three-dimensional (3D) finite element modelling and structural analysis for temporary support of tunnel lining; functional design of the ground improvement grouting and the temporary support; and permanent lining design of tunnel to ocean riser connections in a mixed soft ground/hard rock environment.The paper also presents conclusions of the design based on construction data available, and highlights the close collaboration between the design team and construction team.

Mar 8, 2011

The Canada Centre for Mineral and Energy Technology (CANMET) /Calgary Coal Research Laboratory and the National Research Council in Ottawa established a joint working research group with industry to develop and test various computer models for application in surface coal mining operations in western Canada.The first part of the paper deals with the problems the group experienced during the past two years especially having model specification and requirements defined and understand site management practices.The second part of the paper deals with site specific development of general mine model for TransAlta Utilities' Highvale Mine in Alberta. Described here are the development of an interactive truck/shovel model for their three pit operation, selection and application of dragline model for tandem operation with the extended bench method, criteria for operational model of the five seams operation with selec-tive mining approach.

Jan 1, 1985

By Motyka J, Adamczyk AF, Witczak S

A case study of migration of a paper factory fluid wastes, on the distance of 5 km from an underground disposal site to an ore mine is presented. The ore mine in question, situated in SW Poland is pumping 3.5 m3/s (ca 300 000 m3/day) of groundwater, producing a cone of depression about 150 m deep and several kilometers wide. The migration of wastes (pollutant) occurs within the carbonate karstic aquifer of Triassic age. The aquifer is about 100m thick and is characterized by the coefficient of hydraulic conductivity equal to 8 m/day on the average. The results of systematic measurements carried out for 13 years enabled to estimate the mean breakthrough curve of the pollutant. On this basis and taking into account the coefficient of hydraulic conductivity as well as the mean hydraulic gradient between the disposal site and the ore mine, the migration parameters of the polluting material, i.e. the real flow velocity, the effective porosity and the longitudinal disper- sivity have been calculated. As the measurements considered a long migration distance of the pollutant, the obtained hydrodynamic dispersion constant (dispersivity), in the authors opinion, is reliable enough to be applied for regional groundwater calculations, regardless of the "scale effect".

Jan 1, 1988