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This paper discusses the implementation and potential limitations of the method for estimating sampling and analytical errors of multiple source mine output blended into a shipping product, described by Everett and Ziegelaar (2010). The practice of quality measurement varies between iron ore miners. The common objective is to monitor effective resource utilisation and control of product quality to customers. A flow diagram is given presenting the various options used by iron ore mine operators and the merits of the different options are discussed.

Mar 1, 2010

By Brotzmann K, Turner RE, Philp DK, Rusden RC

New approaches in the last decade have led to the supplemental use of raw coal as a direct energy source in several iron and steelmaking processes. The dependence on more expensive coke and electricity is being progressively reduced. The Technology Venture of Klockner Werke and CRA has pionered several of these developments and is pushing ahead to processes for scrap melting and direct smel- ting of iron where coal is the ONLY energy source. Such complex developments depend strong- ly on the experience gained in the simpler but related processes for coal use already in operation. The longer term implications of a successful coal-based direct smelting process for the world steel industry are substantial.

Jan 1, 1986

The New Zealand Minerals Industry Association was incorporated as the NZ Mineral Exploration Association in 1982, with a membership that consisted of the gold exploration companies then active in New Zealand . As its membership broadened, it changed its name to the Mining and Exploration Association in 1994, and more recently the Minerals Industry Association. It is a non-profit-making incorporated society relying on voluntary membership, and is not funded by industry levies.   It has employed a full time executive director since 1988 when Robyn Ross was appointed, followed by John Pfahlert (1991 - 1996) and now with Doug Gordon managing the Association.   The Association is one of a number of organisations that represent the mining industry in New Zealand. Others include the Coal Association of NZ (CANZ), the Aggregate and Quarry Association (AQA), The West Coast Commercial Gold Miners Association and Minerals West Coast.   NZMIA membership comprises the main exploration and mining companies that account for over 80 per cent of New Zealand Æs mine output, and nearly all of its exploration investment. Its membership has expanded from gold exploration to encompass exploration and mining companies active in coal, gold, aggregates and industrial minerals.   The Association has developed a National Minerals Strategy that determines its priorities, implemented via a Minerals Industry Advisory Committee. This group was established six years ago to advise the Associate Minister of Energy on issues relating to the long term development of the minerals sector in New Zealand.

Jan 1, 2006

The 1980's has seen a revolution in gold mine developments in Australasia. We are witnessing a near ten fold increase in all phases of gold mine development ranging from exploration through to production. Ounces produced have yet to mirror this activity but have increased from a low point of 600,000 in 1980 to 1,800,000 ounces in 1985 in Australia alone. In 1980 the region had less than 10 gold mines, yet 14 new mines started production in 1985 and as many as 28 might start up in the next 18 months. Developing gold mines in the 1980's in Australasia has not been the easiest of jobs, yet the great number of new developments suggest that we have entered a new era that will rank in history along with the 1850's, 1890's and 1930's as high points.Within- our Australasian region two very distinctive styles of gold deposits are being discovered and developed. On the Australian mainland the new mines are in geologically old rocks and are mostly the low grade haloes surrounding worked out high grade deposits. Most are limited life open pit operations depending on recent innovative carbon-in-pulp or heap leach technology. In the Pacific Islands region the style of discoveries are geologically recent, large bulk-low-grade deposits often geologically analogous to porphyry copper deposits. These deposits are typically 10 to 20 times larger than those being proved up on the Australian mainland.

Jan 1, 1986

By D Carroll

Mining of the zinc, lead and silver deposit at the Broken Hill Southern Operations site has been occurring for over 100 years. As a result of this, a significant amount of high-grade ore is now taken from narrow remnant pillars left between old stopes and zones of previously mined ground. Stopes have been filled with either hydraulic fill (also known as ‘sandfill’), cemented hydraulic fill (cemented sandfill), waste rock backfill or a mixture of these fill types.In the last ten years, there has been considerable success mining through narrow pillars where sandfill is exposed in the development face and/or walls using a ‘shell’ support regime, wherein a layer of bolted mesh is sandwiched between two layers of sprayed fibrecrete (25 mm fibrecrete, then mesh and bolt, followed by a final 50 mm layer of fibrecrete). Shell support is also used in very poor, broken, relaxed ground conditions and in areas filled with cemented fill (sandfill with a minimum four per cent cement content).The next stage of innovation has been to develop a technique for mining through old stope voids filled with uncemented sandfill, known locally as ‘contours’ (old cut-and-fill working), an activity where unconsolidated sandfill can run at the face and from the backs. The challenge is to prevent exposed sandfill in the face and the backs from failing before it can be supported.To achieve this, the Southern Operations mine has implemented a technique in which 6 m long spiling bars are used to strengthen and stabilise the sandfill in front of the face. The hollow steel bars are driven in around the heading perimeter in a closely spaced pattern then pumped full of grout. The bars and the grout stabilise the sandfill in front of the face, preventing it from failing into the drive during excavation and prior to further support being installed.A final support system consisting of shotcrete, mesh, bolts and steel girders is installed as excavation progresses. Both the initial and final support systems are essentially passive support systems designed for a low-stress environment (as the stress originates mostly from the mass of unconsolidated sandfill).This process is slow and labour intensive. Fifteen separate cycles of people/machinery are needed to progress one equivalent heading cut (compared to six for a standard fibrecrete- and bolt pattern-supported rock face heading). This slow pace introduces scheduling challenges, but the process opens up parts of the orebody that were previously uneconomical to mine.CITATION:Carroll, D, 2014. Mining through sandfill using spiling bars, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 95–100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

A unique set of circumstances has devel oped in the Mt. Newman Mining Co. Pty. Limited's project in the Pilbara because the mining town of Newman was built almost entirely by the Company whereas residential areas built by the Company at Port Hedland were developed as an adjunct to an existing town. The following discussion points out the different problems which have been developed in the two areas, even though basically the stand- ard of housing and general amenities is the same, and the means taken to overcome these Problems.

Jan 1, 1973

Problems caused by water discharge from surface mine ventilation shafts can be significant and are usually unforseen. The discharged water is often hyper-saline or acidic and can cause environmental degradation over a wide radius. It can also lead to recurring power pole fires and primary fan breakdowns. A range of solutions to the water discharge problem has been implemented in many Australian mines. In most cases the solutions have been ad hoc, with the overall cost and effectiveness varying tremendously. This paper reviews and contrasts the practicality and effectiveness of the various available remedial options.

Jan 1, 2002

By G Balog, T Ormerod, D Sidea

Carrapateena is a copper-gold sub level caving operation located in the Gawler Craton, South Australia. One of Australia’s largest undeveloped copper deposits, the project will be a 4.25 Mtpa underground operation, with an estimated mine life of 20 years (OZ Minerals, 2017). First concentrate production was achieved in December 2019, within the Iron Ore Copper Gold (IOCG) hematite breccia complex. The Carrapateena orebody is overlain by 500 m of barren sediments of the Stuart Shelf, which hosts two aquifers. The cover sequence is dominated by shales, quartzites and sandstones in order of thickness. The cover sequence presented challenges to the mine ventilation system as a result of highly variable rock strengths. On this basis, the site developed the first vent rise, Vent Rise 5 (VR5), earlier than required as a means to test the empirical stability assessment. Assessment for VR5 was completed in 2017, with the mine yet to develop through much of the cover sequence. Due to the geotechnical data available at the time, it was anticipated that break out would occur within the vent rise walls as a function of the low strength Woomera shales. VR5 was developed to 4.5 mᴓ in late 2018. The timing of the VR5 development enabled the site technical team to calibrate empirical stability factors for the assessment of future vent rises. At the time of writing, four additional vent rises have been successfully developed to a diameter of 5.5 m. No significant overbreak has been observed within any of the vent rises. This paper is intended for geotechnical practitioners designing large-diameter vent rises in geological environments similar to the Stuart Shelf where a similar approach to vent rise design may be warranted.

Mar 15, 2021

The subject `access to land' is often seen as an item high on the list of matters of concern to mining interests not only in New South Wales but throughout the whole of Australia and other countries. Just what are the problems/issues of access to lands today? What is being done about them? What can be achieved? What is practical to achieve? And where does New South Wales sit in relation to all this? These and a range of other issues are addressed in this paper.

Jan 1, 1995

By L McCracken

Up until 1990 CoalCorp North Island's accident record was six times that considered acceptable in those NSW operations with good accident prevention programmes. This was an obvious avoidable burden on the company in both human and cost terms.   Late in 1989 an accident prevention programme was implemented with the objective of achieving a 50 per cent reduction in the lost time accident frequency rate within 12 months. The key to achieving this objective was recognised as being an attitude change in the total workforce from General Manager downward. Management commitment and action were seen to be critical to the success of the programme.   Through very basic and simple training programmes in accident investigation, analysis and reporting, communication, on-the-job coaching and in focusing on improving supervision skills, the original objective was achieved.   During 1991 the application of methods improvement and hazard recognition techniques are seen as the logical step to achieving a further 50 per cent reduction in the accident frequency rate.

Jan 1, 1991

The introduction of cement into underground backfilling at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited mines to improve mining efficiencies gave rise to several major problems, the magnitude of which had not been anticipated. These problems were 1. A loss of recovery in the milling circuit due to the presence of cement 2. The presence of cement-rich slime layers on the surface of the fills 3. The introduction of a safety hazard due to the slippery nature of the surface of cemented fills 4. The deposition of cemented slimes on the levels and in underground sumps and dams. The loss of revenue due to decreased metal recoveries considerably offset the gains from increased stoping efficiencies and the use of cement was substantially reduced while, (a) the Metallurgical. Department attempted to identify the chemical nature of the problem and overcome it, and (b) the Mining Department investigated methods of reducing cement contamination of the ore stream. As a part of this investigation the Mining Department added polymeric flocculants to the cemented fill pulp. Testwork was carried out in the following steps 1. The available Alfloc polymers were screened to determine which was the most effective and what was its optimum dosage rate. 2. This polymer was used in the laboratory to determine the reduction of surface slime, clarity of water, and effects on strength and percolation of fill. 3. Fills were placed underground to substan- tiate the laboratory work. /+. The polymer was then added to all cemented fills going underground to study its effect over a long term. The use of flocculants not only improved the distribution of cement in the body of the fill, but also the distribution of the fines fraction of the filling material, practically eliminated slippery surfaces and improved the clarity of the drainage water. Flocculant is now added to all cemented fills and restrictions on the use of cement are gradually being lifted.

Jan 1, 1973

By R C. Schodde

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Over the last decade (2005–2014), a total of 439 significant deposits of gold and base metals were found in the world. Twenty (or 4.6 per cent) of these deposits were in the Pacific/South-East Asia (Pacific/SE Asia) region. In terms of contained metal, the region accounted for 1.6 per cent of gold and 13.8 per cent of copper found in the world. With regard to nickel and zinc/lead, the region’s contributions were insignificant.Over the same period, the Pacific/SE Asia region accounted for 6.6 per cent and 12.6 per cent of all gold and copper exploration expenditures in the world respectively. After adjusting for by-product credits, unreported discoveries and likely growth in resource, the unit discovery cost for the region was US$199/oz (compared to a world average of US$50/oz). For comparison, the unit discovery costs for the previous decade were US$55/oz and US$25/oz respectively. The region’s unit discovery cost for copper was US$0.036/lb (versus a world average of US$0.040). For comparison, the unit discovery costs for the previous decade were US$0.026/lb and US$0.008/lb Cu respectively.The region’s mediocre discovery performance doesn’t reflect its distribution of known mineralisation. Some countries within the region have a very good endowment per square kilometre.It is noted that the intensity of exploration (and resulting success) would be boosted if governments provided a more mining- and investment-friendly business environment and generated better precompetitive geological data sets (to identify new exploration targets and boost the country’s perceived mineral prospectivity). A multivariable regression analysis of a decade of data from the Fraser Institute’s mining company surveys found that a ten point increase in the Policy Perception Index or a 0.1 point increase in the Mineral Potential Index could boost (in the short term) exploration expenditures by 1.9 per cent and 2.7 per cent respectively. The resulting economic benefits of an expanded mining sector would be significant. The same story applies elsewhere in the world.CITATION:Schodde, R C, 2015. Discovery performance for gold and base metals in the Pacific/South-East Asia – 2005–2014, in Proceedings PACRIM 2015 Congress, pp 25–34 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Pina P, Pereira MJ

The increasing exhaustion of raw materials entails the exploitation of poorer orebodies where the target mineral occurs frequently in a very fine dissemination. Consequently it is necessary to grind more and more fine to achieve an adequate mineral liberation. In other words, it is of fundamental importance to know what size one should grind in order to avoid the following detrimental situations: 1. Excessive grinding - giving rise to the generation of ultra-fine slime particles which may be lost in the ulterior concentration process and simultaneously leading to higher energy consumption. 2. Incomplete grinding - giving rise to insufficient liberation and consequently leading to considerable losses of the valuable components in the tailings. Although this issue constitutes one of the most important steps in mineral processing, little research has been done compared to other processes, mainly due to the fastidious experimental work required. This paper describes a complete and integrated system of image analysis, where some algorithms to determine automatically the degree of li beration, for different levels of grinding, are proposed. These algorithms, mainly based on mathematical morphology theory were tested with images obtained from polished sections of different grain size fractions. Cases studies on a complex sulphide ore from an important copper and tin deposit located in the South of Portugal are discussed. Samples of the unbroken ore are also studied by image analysis to predict the degree of liberation obtained according to the fineness of grinding.

Jan 1, 1993

By P G. Doig

Recent drops in commodity prices and economic uncertainty have seen many businesses re-evaluate their operational expenditure to ensure mine profitability. The high capital and operational cost of truck and digger fleets has resulted in loading and hauling of material being a significant proportion of a mine’s expenses (Nel, Kizil and Knights, 2011), thus it is often one of the first areas to be considered for cost reduction. If an operation requires additional trucks to maintain or improve productivity, a robust justification is crucial due to the expenditure involved.Mining schedules form the basis of productivity and cost estimations for mining operations and therefore must have a significant level of confidence with regards to achievable quantities and rates. Traditionally, a mining schedule is produced without detailed consideration of the trucking capacity or requirements. Although some mine planning software incorporates haulage predictions into schedules, most cannot model the dynamic nature of dumping and haulage. Previous studies have shown that it is necessary to have detailed haulage analysis instead of the traditional mining block centroid to dump block centroid methods for more realistic mining schedules and cost estimation (Doig and Kizil, 2013).Recent developments in software have allowed the dynamic integration of haulage analysis with mining schedules. Engineers can now create mining schedules in conjunction with dumping schedules, allowing mining schedules to reflect the restrictions created by the number of available trucks, combined with dynamic consideration of available in-pit and out-of-pit dumping locations.A study has been completed producing a mining schedule in conjunction with a dumping schedule and haulage analysis. Multiple schedules were run with various haulage strategies (including minimising rehabilitation liability) and truck availability to identify the impacts on coal production, and hence revenue. A financial analysis was then completed where a net present value (NPV) was calculated for each scenario. The study showed that trucking shortfalls can significantly impact mining schedules and cost estimations, both in terms of cost as well as revenue lost when trucks cannot maintain forecast production rates, thus dumping schedules and haulage analysis should be completed simultaneously. If dumping and haulage is not considered when planning the mining schedule, a mining business is ignorant to the impacts trucking has on the mine production, closure risk and profitability.CITATION:Doig, P G, 2014. Value impacts of truck limited scheduling, in Proceedings Life-of-Mine 2014 , pp 513–524 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

In recent years it has been more and more recognised that applied geology can be of service to the mining industry, and many mining companies overseas now have permanent geological staff as part of the operating organisation.Most of these companies insist that the geological department must pay for itself by the savings it can make in operating cost, and the growing use of the geologist is proof that such savings are made.The geological problems in every district are different, and a description of the problems and method of attack in a specified district is a useful addition to the literature of mining geology. Very few contributions, from the standpoint of the mining company geologist, have appeared in the Australian literature so that, although the operations of Bendigo Mines Limited are still in the development stage, and its geological work newly established, a description of the routine geological work at Bendigo should beof interest.Although most Bendigo mining companies have not employed permanent geologists, they have utilised geological guidance wherever possible, and a great body of data has grown up. Acknowledgment is made here to the valuable work of the Geological Survey of Victoria, especially the writings of E. J. Dunn, H. Herman, and H. S. Whitelaw, and the maps of Caleb Thomas and H. S. Whitelaw; and also to the work of independent investigators, notably Chief Geologist, Bendigo Mines Ltd.

Jan 1, 1936

The Western Australian Mining and Petroleum Research Institute (WAMPRI) was established in 1981 by the Western Australian Government as a funding and co-ordinating Institute to foster research into the mining and petroleum industry within this State. To June 1984, the Institute has sponsored 34 projects with a total notional value of $2.5 million and an actual cash commitment of $1.5 million. Strong support for WAMPRI has come from Industry with 60 companies contributing half the money needed for the research grants.The 34 WAMPRI projects funded so far cover all aspects of the mining and petroleum geosciences.Several WAMPRI projects are concerned with gold including processing technology and the development of exploration models and techniques, they are providing successful results.Although well supported by Industry there is a surprising lack of applications being submitted to the Institute in the area of mining engineering, where it is felt there is much scope for research projects.

Jan 1, 1984

By T X. Le, H T. Tran, K Zaw, T Manaka

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Truong Son fold-thrust belt (TSFTB) is a prominent tectonic component of mainland Indochina that occurs as a north-west–south-east-trending tectonic entity that extends from north-eastern Laos, straddles the Laos-Vietnam border area and is submerged under the sea basin in east central Vietnam. The TSFTB hosts numerous regional-scale gold and polymetallic base metal deposits, and the mineralisation occurs along the strike of the belt; however, the potential of many of these deposits are inadequately evaluated. The ore mineralisation is hosted by different rock assemblages, including highly metamorphosed Late Proterozoic metasedimentary rocks and Palaeozoic sedimentary and/or volcanic packages, which were intruded by several phases of magma and underwent a number of tectonic events. Several ore-forming styles – including porphyry, Carlin-type and sediment-hosted orogenic Au – were formed during at least two phases of regional thermotectonism that have been identified in the TSFTB. However, all of the major gold deposits/mineralisations are closely related to region-wide structural breaks and many of them are controlled by large-scale, high-strain zones. The fold-thrust structures in the TSFTB therefore play important roles for regional gold mineralisation and metallogeny.CITATION:Tran, H T, Zaw, K, Le, T X and Manaka, T, 2015. Structural controls on gold mineralisation in the south-eastern Truong Son fold-thrust belt and its significance in regional metallogeny, in Proceedings PACRIM 2015 Congress, pp 521–530 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By E P. O’Dwyer

Segment and gasket lining in tunnel boring machine (TBM) tunnels; and sheet membrane lining systems in driven tunnels are robust waterproofing systems each with a proven history of performance in Australia and further afield. Where an interface between these two systems occurs, the potential for costly failures is vastly increased and additional attention to detail is required in design, planning and construction. TBM cross-passages represent the most common occurrence of this interface, with steel compression flanges and neoprene gaskets being the typical means of connecting the waterproofing systems. There is a large variance in both detailing these flanges and associated outcomes, which makes this an area where there is room for improvement within the industry.The paper will look to tease out the various issues associated with this interface and how they can be dealt with efficiently with appropriate design measures, robust planning and carefully controlled construction methods.The paper will also look to review the new technologies and systems currently being put forward as potential alternatives, including an epoxy tape system, which has recently been successfully trialled on a project in Europe under high-pressure head.CITATION:O’Dwyer, E P, 2014. The challenge of waterproofing cross passages in segmentally lined tunnel boring machine tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 315–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J W. Lee, E Baafi, N Aziz

Ground subsidence due to mining is a common dilemma confronting the underground coal mining industry. The effects of underground longwall mining on river valleys have come under scrutiny, especially when mining is located underneath catchment areas. As public awareness of mining impacts on the environment increases, there is the need to develop damage mitigation strategies. Results of numerical modelling show that river valley response to underground longwall mining can be simulated and evaluated.

Jan 1, 2005

By M Iglesias-Martínez

The potential for iron ore in the Central African Archean belts has received much less attention by comparison to their equivalents in other cratonic regions of West Africa, South Africa, Australia and Brazil. Historically, iron ore is known to occur in South Cameroon and North Gabon with significant iron ore deposits (eg Mbalam in Cameroon, Avima in the Republic of Congo, Minkébé, Bélinga and Boka-boka in Gabon), having been the subject of geological exploration programs carried out by government institutions and exploration companies. Although the presence of strong aeromagnetic anomalies, undeniably related to the presence of greenstone belt formations, has been recognised, this study is the first attempt to assess the potential of banded iron formations (BIF) in the Northern part of the Gabonese Republic in the region between Minvoul and Minkébé (>10.000 km2). Deep lateritic weathering, inaccessible equatorial rain forest and high operational costs are some of the reasons why only limited exploration has been undertaken in the area. This work aims to improve the geological knowledge and to highlight the potential for iron ore of the eastern margin of the Ntem Complex units dated between 3.3–2.7 Ga. Field work showed a series of mafic rocks (amphibolite, anorthosite and gabbro), schist and BIF (described as itabirites in neighbouring areas). Samples from Minvoul BIF showed an extensive and deep weathering to powdery hematite revealing the presence, in thin sections, of iron oxides including magnetite, hematite and martite, primary and secondary quartz, garnet, hornblende, anthophyllite, cummingtonite and epidote. Mineral assemblages and coarse grain size suggest a metamorphic grade ranging from medium to upper amphibolite facies. The existence of known economic iron ore deposits in neighbouring regions combined with an extensive weathering enrichment process are promising factors for potential iron ore discovery in this remote area.

Sep 18, 2023