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Determination of Porosity and its Influence on Specific Surface

Sep 13, 2010

By D J. Brake

The correct specification and then selection of primary or major fans for an underground mine is a critical decision not only in terms of fan capital and operating costs, but also safety and reliability which usually has a major impact on mine production. In addition, fan manufacturers may spend tens of thousands of dollars preparing proposals for a purchase enquiry for primary fans especially where they have complete responsibility for the installation (turnkey projects). There are many good reasons to thoroughly and fairly adjudicate fan tenders. This paper describes the process to achieve this starting with the initial fan specification through to the final award.CITATION:Brake, D J, 2017. Fan specification and tender adjudication for mine ventilation engineers with particular reference to turnkey projects, in Proceedings Australian Mine Vent Conference 2017, pp 245–252 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By D A. Manhire, R M. Flores

The commercial develop of coalbed methane from the Powder River Basin has demonstrated that low-rank coals can be a viable source of gas. Currently over 20 000 coalbed methane wells exist in the Powder River and it is predicted that there will be 50 000 wells by 2010. What makes the Powder River Basin successful is the thickness of the coal (in excess of 30m) as well as the low ash content (

Jan 1, 2002

By D McLaughlin

This paper points to the timely importance of commencing a centrally recognised perpetual collection of mineral specimens in the Northern Territory which has as one of its objectives the collection and preservation of Northern Territory minerals of scientific, educational and heritage value. Currently in the Northern Territory there is no government department or institution that has a resourced coordinated state-wide objective to collect and document collectable mineral specimens. Specimens held in storage by the Department of Mines and Energy and the Museum and Art Galleries of the NT are not catalogued and owe their existence to fortuitous circumstances, not as a result of a planned systematic scientific approach to mineralogy. Northern Territory mineral species and unique specimens have and will continue to be driven to extinction while no central and active, recognised repository exists. This situation persists despite the fact mineral production is the Territory's largest income earner. The paper presents the arguments that hopefully will assist decision-makers to commence development of a state mineral collection lodged within an appropriate institution in the Northern Territory.

Jan 1, 1994

By M Fewings

This paper casts a light on the sometimes murky world that lies between base metals product æout the gateÆ, and money in the bank. Whether your base metals are leaving the mine as a refined product, or as an ore or concentrate, the generally accepted method of value determination is a London Metal Exchange price, usually measured at some point after the material has left your control. In this paper, the structure and operation, regulation and the reasons for the use of the London Metal Exchange are explored. In addition, the risks and opportunities that terminal market pricing provides to mine managers are explained, with particular reference to hedging. The paper also deals with the structure of the sales contract, including management of shipping issues, agreement of delivered quality, documentation and administrative issues. The selection of counterparties, the role of traders in the market and the growing influence of China and India as base metal consumers and competitors are also addressed.

Jan 1, 2006

Good morning and thanks for the chance to talk to you. It's really pleasing to see so many industry representatives here I want to spend a few minutes talking about issues relating to your industry. At the end of today I would like to leave you with three strong messages from government. The first is that this government supports environmentally responsible mining and the endeavours of the mining industry. The second is that explorers and developers are wanted and welcomed in New Zealand. And the last is that it is up to the industry to keep the public properly informed about how your industry and to constantly work on improving your public image. The mining industry is a high-tech industry which fits snugly with our concept of a growing knowledge-based economy. It has particular value for regional development, the gold mining industry alone provides more than 4,000 jobs û mostly outside of the main cities. The industrial minerals industry is twice as large as that. As well as those people directly employed by the industry there are greater downstream effects for the community. One example from the broader extraction industry of this is of the local pie shop down the road from one of Taranaki's petroleum industry locations. The shop sells over $4,000 worth of pies a week to workers in the industry. That's just one example of the positive benefits the industry brings to its local community and is the sort of real positive benefit you need to be telling people about  

Jan 1, 2000

A Loss of Strength of Gold Sulfide Concentrate Before Grinding and Cyanidation Using Magnetic Impulse Treatment Gold recovery from sulfide concentrates is going with cyanidation usually. The fine grinding to 95 per cent -0.020 mm is required for refractory concentrates, in which gold encapsulated by sulfides. According energy consumption is 10 and more kW h/ton. At this paper we suggested to use magnetic-impulse treatment with small energy consumption 0.1-0.2 kW h/ton for loss of sulfide strength before grinding and cyanidation. The object of studies was the gold-pyrite flotation concentrate which was produced from ores at the Kumtor Mine, Kyrgyzstan. The concentrate composition, physic-mechanical properties and loss of strength mechanism were studied there. The tested concentrate assayed, per cent: 62.5 pyrite, 10 feldspar, 10 mica, 5 quarts, 5 carbonates, 4 haematite and another. Haematite has intimate intergrowth with pyrite ? partially with quarts. The magnetic susceptibility of haematite and less pyrite causes in these grains and mineral complex the effect of magneticstriction. As a result numbers of deformations are increased and minerals and gold are also exposed. Lateral and longitudinal strains in the minerals by magneticstriction were calculated in this work. By quantitative analysis of pyrite mono fractions were showed next micro impurities: alumina, arsenic, nickel and others elements. These micro impurities are generated a charged dislocation, cracks and micro cracks. The inter-granular links at a boundary of haematite-pyrite, pyrite-quarts, haematite-quarts have disintegrated. The dislocation is depended from mineral modulus elasticity. It was determined an indicator of mineral electro-mechanic sensitivity which characterises a conversion of electro-magnetic energy to mechanic energy. Pyrite has most dielectric constant and electro-mechanic sensitivity as haematite and quarts. The dislocations in pyrite are account for clacks and a loss of mineral strength. Size analysis of the flotation concentrate after magnetic-impulse treatment is shown the increasing the content of thin fractions by comparison no treated concentrate. Magnetic-impulse treatment has increased the effect of the next fine grinding too. The electronic microscopy has confirmed a loss of strength of gold sulfide concentrate. The gold recovery by cyanidation increased too after preliminary magnetic-impulse treatment of concentrate by laboratory tests. The magnetic-impulse concentrate studies at the Kumtor plant have showed that a recovery gold increase in the processing of cyanidation. The consumption of energy also reduced.

Sep 13, 2010

By J T. Carswell

Best practice mine sampling should provide a detailed quantification of all potential sources of error at each stage of sampling, sample preparation and assaying.Quality assurance (QA) should include testing for and quantifying potential sampling errors, and should be the basis for establishing ongoing sampling protocols, should set error limits and define quality control (QC) procedures. QA should be within the framework of Theory of Sampling (TOS) but may not involve the estimation of the sampling constant and the application of Gy’s formula.Best practice QC should be carried out efficiently and in a timely and cost-effective manner with regular reporting against the guidelines established by QA.This paper provides an assessment of, and checklist for, current best practice sampling QA/QC with examples from operating gold mines including the QA/QC of underground (UG) reverse circulation (RC) grade control.CITATION:Carswell, J T, 2017. Best practice sampling QA/QC for gold and base metal mining – including how to assess the applicability of underground reverse circulation grade control sampling, in Proceedings Tenth International Mining Geology Conference 2017, pp 297–304 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Use of Impact Crushing for the Enrichment of Low-Grade Colemanite Concentrates This paper presents the results of an investigation into the enrichment of -25+3 mm low grade colemanite concentrates exploiting differential breakage properties of various minerals associated within the ore sample. Boric acid production process requires concentrates containing at least 42 per cent B2O3, hence concentrates below this grade either stock piled or further treated to increase B2O3 content. The low grade concentrate is obtained as a by-product of Emet Colemanite Concentrator and the B2O3 content may vary around 37 - 38 per cent. The sample used in the experimental studies assays 37.52 per cent B2O3. In the experimental procedures the sample was crushed using a laboratory size horizontal shaft impact crusher and the products were classified into different size fractions by screening so that any improvement by size could be observed. In the tests the effects of parameters such as the revolution speed of the crusher and heat treatment was checked. Test results prove that boron contents show a tendency to increase as the particle size decreases. As a result of the experimental studies a colemanite concentrate assaying 42.13 per cent B2O3 is produced with 76.55  per cent recovery. Arsenic content is seen to change inversely proportional with the B2O3 content of the concentrate such that it drops from 1016 ppm from the as received sample to 676 ppm in the concentrate.

Sep 13, 2010

The use of mining by-products for beneficial use may face approval, and acceptance barriers. This paper described the use of a sustainability framework to assess the safety, effectiveness and economic value of modified bauxite residue (Alkaloam«) for use on agricultural land in the Peel-Harvey region of Western Australia. The results indicate the merit associated with using this by-product from a safety and, private, community and environmental value perspective. They may be used to indicate the worth of pursuing any future community acceptance and agency approval process.   The use of Alkaloam« for beneficial use on agricultural land in Western Australia was first investigated over 25 years ago. Efforts to gain regulatory approval and community acceptance of Alkaloam« have had a complicated and enduring history. Understanding and assessing the value of a by-product using social and economic considerations, in conjunction with an environmental assessment, provided a more complete evaluation to that previously used.

Jun 1, 2010

By A Self, B Robertson

During 2015 and 2016, the authors conducted a number of surveys, workshops and reviews of ventilation and gas management practices in Australian underground coalmines. The study was funded by ACARP with a brief to identify gaps in ventilation and gas management practices for current and future needs, and to prepare a road map for change that would assist in delivering improvements.The study found that despite many examples of leading practice, gas and ventilation management is not afforded the attention and priority that is warranted and that this must be remedied if future operational performance targets are to be achieved and the safety of the industry protected. This paper summarises the findings of the study and presents the recommendations proposed.CITATION:Robertson, B and Self, A, 2017. A review of ventilation and gas management in underground mines, in Proceedings Australian Mine Vent Conference 2017, pp 277–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By J Lea, D C. Kettlewell

The Carina iron ore deposit lies 105 km northeast of Southern Cross, WA. The area designated the Yilgarn Iron Ore Project (YIOP) is comprised of five prospects along an east-southeast trending greenstone belt that extends from the Helena-Aurora Ranges in the northwest to the Yendilberrin Hills in the southeast, over a strike length of approximately 40 km. The YIOP project encompasses the previously identified iron deposits of Bungalbin, Bungalbin East and Mt Walton. The Carina deposit was discovered by Polaris Metals NL in May 2007. The Carina deposit is located within and parallel to the structurally complex northwest trending Mount Dimer shear zone. The volcanosedimentary Archaean-aged greenstone sequence consists of ultramafic and mafic lavas and flows with interbedded sediments dominated by chert and banded iron formation (BIF). Supergene enrichment processes formed a goethite orebody replacement of BIF sequences within a doubly plunging synclinal fold structure. Mineralised outcrops dominated by goethite form a low ridge 1500 m long, up to 90 m wide and drilled to over 200 m in depth. In the vicinity of the Carina deposit, iron occurrences have been identified over at least a 12 km strike length and the exploration potential of the area is identified as 30 - 40 Mt. Polaris Metals began exploration in the area in 2006. Target generation in the area used existing state geological survey maps and regional magnetic survey data to focus on BIF occurrences associated with major structures. Early field investigations resulted in the identification of a large outcrop of predominantly goethite mineralisation at Carina. Detailed geological and structural mapping was completed, followed by close-spaced reverse circulation and diamond drilling. The mineralisation is predominantly goethite with specular and coarse platy haematite localised along structures that cut the goethite mineralisation. Mineralised zones are moderately vuggy and larger cavities occur in proximity to fault zones that transect the orebody. A capping by a thin veneer up to 9 m thick of canga or ferricrete occurs in places. By December 2008, 178 reverse circulation and 11 diamond drill holes (seven surface holes, four tails) were completed. The current JORC-compliant resource estimate is based on assays from 72 RC drill holes and using a 55 per cent Fe cut-off stands as an Inferred Resource of 27.9 Mt at 58.6 per cent Fe, 1.3 per cent Al2O3, 3.7 per cent SiO2, 0.09 per cent P, and 10.1 per cent LOI. Assaying has recently been completed and will be incorporated into a new updated resource later in 2009.

Jan 1, 2009

The increased cost of imported oil fuels, coupled with our understandable reluctance to commit ourselves to the use of nuclear energy, has resulted in a renewed reliance on coal as a primary source of energy. New Zealand is fortunate in being fairly well endowed in its coal resources, but their exploitation until now, has been on a relatively small scale. Future exploitation, whether from underground or open cast mines, must be on a very much larger scale. This paper outlines some of the factors which should be considered in planning large open cast mines.

Jan 1, 1976

By E Westthorp, J Phillips

The detection of ethylene in mined-out ‘goaf’ areas of underground coalmines is an industry standard indicator of accelerated oxidation where the coal temperature has exceeded 100°C. If uncontrolled, this naturally occurring process can lead to spontaneous combustion and catastrophic mine explosions, such as the Moura No 2 mine explosion. Spontaneous combustion trigger action response plans (TARPs) typically use the detection of ethylene as a trigger for definite change requiring immediate reaction, which can include the withdrawal of coalmine workers.Following the completion of sealing of longwall goaves at Crinum North Mine, ethylene was often detected in trace quantities. These trace quantities were below 1 ppm and detected via the bag sampling regime, with the use of a gas chromatograph. Any ethylene detected in these instances was not associated with increased quantities of carbon monoxide to conclusively indicate a heating within the sealed area.Ethylene was only detected in a newly sealed goaf and would not remain present for a period following the sealing. As part of the longwall recovery process, the predominant roof support mechanism during the recovery was the use of timber cribs. It was decided to investigate the possibility of this timber generating ethylene.Preliminary tests were completed by placing timber specimens from several species of Australian native hardwoods in gas bags in air. Over time, some of the samples showed significant levels of ethylene within the bags.CITATION:Westthorp, E and Phillips, J, 2017. Findings from preliminary testing to determine alternative sources of ethylene within sealed areas of underground coalmines, in Proceedings Australian Mine Vent Conference 2017, pp 203–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Over a century ago the first ship designed solely for carrying a bulk cargo was launched. This vessel, the "John Bowes", with a deadweight of 660 tonnes was a single decked ship with machinery and accommodation aft. As such she was undoubtedly the fore- runner of the bulk carrier of today only some two hundred and fifty times smaller. Whilst the "John Bowes" pioneered the present accepted mode of transporting the bulk com- modities of the world, it is unlikely that her cargo was either loaded or discharged as quickly as that of a 150, 000 tonner of today. Two decades ago the bulk carrier was beginning to feature in the bulk handling ports of the world. Cargoes of iron ore previously carried in the 'tween deck vessels of the Empire type and Second World War Liberty ships began to be poured into the unrestricted open holds of bulk or ore carriers. The size of vessels catering for this relatively new innovation has rapidly grown to pass the 150, 000 deadweight tonne mark, but only in the last few years. The growth from now into the future is not simply one of ship size evolution. Neither is it a function of the depth of water available at ports. It is in fact a function of a number of features such as ports, loading and unloading facilities, ship trading characteristics, length of voyage and total economies of the transport task from supplier to destination.

Jan 1, 1973

By M K. Singh

Mining is nothing but an art - besides being a science - of extracting valuable minerals from the womb of the mother earth. In this gigantic task, a large number of machinery and equipment are employed judiciously. Wire ropes play a vital role in lifting or hoisting men and materials under hostile/adverse working conditions and constitute a major item of investment on machinery/equipment. The economy of using a wire rope is a concern for engineers, users and the planners. The economic use of wire ropes for mining purposes largely depends on the following factors;Mechanical design considerations - which include tensile strength of wires, elasticity, resistance to abrasion and crushing, fatigue values, static and dynamic loads on wire ropes, factor of safety, fleet angle, etc. Metallurgical consideration - Composition and heat treatment of wire materials, defects like inclusions and voids, surface quality factor, lubrications, micro structural parameters. Operational consideration - Seizing and cutting of rope, storage, care and maintenance, cutting back, etc. Environmental consideration - Temperature and humidity, pit condition, dust, corrosive atmosphere, etc. In the present paper, an attempt will be made to suggest steps for achieving optimum economy while using the wire ropes for extraction of precious minerals and coal keeping in view the points noted earlier. Once technical viability is established, economy is the ultimate consideration for an industry for safe hoisting of men and material.

Jan 1, 2000

By S Bouzalakos, W Timms, H Malli

Combining ultramafic mine tailings and acidic mine drainage via mineral carbonation to sequester carbon dioxide, presents an opportunity to minimise waste on mine sites. Low pH mine water with trace element concentrations can be effectively treated by high magnesium mine tailings, a useful source of finely ground reactive matrix. By using milled tailings for mineral carbonation, there are negligible energy requirements for communition of ore rocks to reduce particle size. This study aimed to assess the technical applicability of reacting ultramafic tailings and acidic mine water through mineral carbonation technology in the mining industry. Dissolution has been identified as the rate limiting stage in mineral carbonation; hence the study focused on identifying optimal dissolution conditions. Ultramafic tailings (particle size <100 µm) derived from serpentinite ore, were reacted with a typical mine water that was synthesised in the laboratory. Through variances in the solid to liquid ratios and temperature of dissolution, a maximum five per cent magnesium dissolution efficiency was reached at 50 g/L and 100°C. The acidic mine water was neutralised (from pH <2 to pH ~6) and iron, copper and zinc ion concentrations reduced significantly during the formation of solid precipitates. Carbonation was undertaken by injecting carbon dioxide into the magnesium-rich solution to form stable carbonates. The experimental work demonstrated proof of concept; however, dissolution efficiency and carbon dioxide sequestration was low, indicating that further research would be required before larger scale implementation.CITATION:Malli, H, Bouzalakos, S and Timms, W, 2015. Ultramafic mine tailings to treat acidic mine water and lock away carbon through mineral carbonation, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 133–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

Modelling and Optimisation of Direct Reduction of Iron Ore by Coal in a Rotary Kiln

Sep 13, 2010

By E M. Jones

On 26 June 2000 a hydraulic fill retaining barricade failed at the Bronzewing mine in Western Australia. The barricade failure resulted in the release of 19 000 m3 of saturated hydraulic fill into the mine, which caused the deaths of three miners. Following this tragic accident, the practices and procedures of mines using hydraulic fills came under intense scrutiny by regulatory bodies and mining companies. At this time, the use of hydraulic fill at NormandyÆs zinc/copper Scuddles mine was suspended and waste rock became the sole backfill material in use underground. By 2003, development of the mine adjacent to Scuddles, Gossan Hill had progressed to a point where a self-supporting fill material was required to enable full recovery of high-grade ore. Cemented hydraulic fill (CHF) was identified as the optimal fill type and work began on designing appropriate management procedures and controls to ensure the safe implementation. This work included definition of the fill properties, plant design and construction, reticulation system design, design of stope barricades and drainage systems and fill placement control and monitoring practices. CHF placement began on 16 July 2004 and has continued to date. Significant operational experience has since been gained in areas including plant performance, fill product quality assurance, barricade construction, stope drainage and in situ performance.

Jan 1, 2008

By D H. Lee, J F, J H. Rubinstein

This paper examines the problem of optimising the life-of-mine costs of an underground mine, focussing particularly on the costs associated with the underground development needed to provide access to and haulage from the ore zones. This mine optimisation problem is modelled as a network and a solution technique is outlined. The effectiveness of this solution technique is then demonstrated by applying it to a prototype test example and some actual case studies. Finally, extensions of this technique to other underground mining problems are discussed.

Jan 1, 2000