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By P W. Cleary, M D. Sinnott

Cross-belt cutters are commonly used for sampling coal. They are generally cheaper than falling-stream cutters, particularly when a cutter must be retrofitted. The major mechanisms thought most likely to lead to sample bias are being investigated by discrete element modelling (DEM) in a project funded through the Australian Coal Association Research Program. This paper describes a benchmark run and the current direction of research.

Jan 1, 2008

The importance of orebody definition and optimisation in project development cannot be overstated. Inappropriate orebody definition is the single most important reason for project under performance and/or failure. Without the firm foundation of good orebody definition, the structure of a project cannot be assembled reliably. Many factors need to be considered in the process of orebody definition. These factors are well summed up in paragraph 123 of The Institute's Code and Guidelines for Assessment and Valuation of Mineral Assets and Mineral Securities (Valmin Code). The factors range from the initial geological data through assaying, geotechnical and hydrogeological factors to mining and metallurgical considerations. There are other factors which also need to be considered including marketing and environmental factors. This paper briefly reviews some of these factors and their impact on project development. Three examples are presented where one or more of these factors have had significant impact on the development of the Project.

Jan 1, 1997

A zone rich in-fish debris in the Rolling Dow= Group in the sub-surface of the Great-Artesian Basin has been discovered a Further research has shoe i this zone to-be of very wide distribution in the Artesian Basin and to occur. at the base of the Ta?nbo .f ormati'on resting on the Roma forma-tion. The zone gives a very characteristic curve on the electric and' gamma ray logs and is thus an excellent correlation marker in the sub-surface over a very wide area. It is probably to be correlated sith.the Toolebuc member described from: outcrops east of Boulia. There .are apparent similarities between the Fishecale zone of the Great Artesian Basin in' Australia and the Fishscale sand of the Western Canada Sedimentary Basin.

Jan 1, 1962

Studies of the morphology of seamounts within the Hawaiian, Line Islands, Gilbert and Phoenix Seamount groups indicate that the morphology and size distribution of seamounts vary significantly from one seamount group to another. The Line Islands group appears to be the most complicated of all the groups studied thus far. This group is complicated by reactivation of volcanism, which has superimposed volcanics on sedimentary rocks. These seamounts display abundant volcanic features on their summits. Seamounts within the Hawaiian seamount chain display a marked absence of volcanic features due to the . presence of thick carbonate caps. Reef platforms and sealevel benches are very common on these seamounts but are absent from seamounts in most other seamount chains in the central Pacific. Slope angles vary regionally between seamount groups. The minimum slopes are found on Necker Ridge in the central Pacific basin. The maximum slopes are found on ridge-crest seamounts. Roughness increases proportionally with mean slope angle.

Jan 1, 1987

By Newman H. A

Goldsworthy Mining Limited is currently mining iron ore at an annual rate of 7 million tons from several small orebodies, each of which exhibit wide variations in iron, phosphorus, silica and alumina contents. Each orebody is mined at its average ore reserve grade and therefore mine planning and grade control techniques have had to be tailored to achieve a constant production blend.

Jan 1, 1973

Nuclear power stations to be installed in Australia will be fuelled from Australian resources of raw materials.This will require the establishment of new manufacturing industries and the eventual expansion of established activities, especially in uranium mining and the preparation of precision metal products.This paper presents some predictions of the possible growth of nuclear power installations in Australia.These might amount to 4000 MWE by 1985 and 11,500 MWE by 1990 and towards the end of the century, about 50 per cent of new generating plant might be nuclear.Predictions are given of the demands for materials (uranium and zirconium) and fuel manufacturing services for four reactor systems which might be considered in the programme.The availability of raw materials and technical capability place Australia in a particularly good position to undertake the manufacture of nuclear fuel; in addition to satisfying the domestic demand we should actively seek export markets for these products.

Jan 1, 1971

The products required by customers today have become far more complex and consequently more demanding to handle. And thereÆs the dilemma. Nowadays, people tend to stick to a trade for just a few years instead of for a lifetime, and this means that the customerÆs employees cannot be expected to get more than general knowledge of how to handle modern mining and construction equipment. To meet this challenge, major steps are being taken by suppliers to make their æmusclesÆ more user-friendly. Also the supplier is assuming a larger share of responsibility for the product including operators training, supply maintenance services and, in many cases, performance guarantees. In other words, the supplier is today supplying a function or an activity rather than just muscles. Some of the new generation drill rigs have been on the market for a few years and reliable experience has been collected and is addressed in this paper. Some of the information is well supported by figures while others are just statements from users of the rigs.

Jan 1, 2005

Mill liners provide the wear-resistant surface within grinding mills, they also impart motion to the mill charge, ie the grinding process, by providing the key between the charge and mill shell, and, at the discharge end, they remove the ground contents of the mill. As semi-autogenous grinding (SAG) mills have grown in size the process aspects of liner design and their impact on mill performance have become particularly important. While feedback from practical experience is critical to good mill liner design, increasingly sophisticated computer-based tools are being developed to assist in mill liner design.

Jan 1, 2007

By Balks AI

Systematic roof bolting in Australian coal mines began at Elrington Colliery in 19)49. Since that time the proportion of the roof supported by roof bolts has increased until, in 1970, 1.5 million were installed in Australian coal mines. This rapid growth of roof bolting has meant that the range and variety of roof bolting machines has altered also. The-number of machines now available both to bore holes and place roof bolts has increased. to the point where both rotary and per- cussive machines are used extensively. Generally, until the last four years, roof bolting machinery in Australia followed the practices in vogue in the United States. However, in -recent time the particular problems of Australian coal mining have necessitated the development of equipment primarily suitable to Australian conditions.

Jan 1, 1971

Existing production facilities are constantly looking at ways to increase capacity. Many recent solutions have focused on the implementation of capital and infrastructure projects. It is accepted that capital expansions are frequently necessary for production gains; however, in many cases existing assets have the potential to deliver substantially better throughput than they are currently achieving. By focusing on automation of production control systems, production reporting and business processes substantial gains can be achieved utilising existing assets. This potential can be realised quickly and has been proven across several sites and industries. In the Pilbara region of Western Australia throughput gains of between two per cent and 25 per cent (translating to millions of tonnes per annum) have been achieved from existing assets using the methodologies discussed. The improvement process involves evaluating the entire production chain from the time the ore arrives at the plant to the time it is dispatched. A technical evaluation of the performance of the control system and plant automation interfaces to upstream and downstream processes is conducted. The relationship of these processes to the business systems and the human interface to the systems is reviewed to ensure a complete picture of the system is understood. Technical evaluation targets include: individual equipment operation, the engineering level of control systems, feed controls, etc; managing recirculating loads, surge capacities, dynamic inventories as well as management of in-feed systems and integration into yard and out-feed systems; and communication flow between control and other systems, data alignment between rail and shipping schedules, yard systems, sales systems and maintenance systems including such fundamentals as truck dispatch links to plant control. In parallel with the technical evaluation, business system evaluation takes place, including analysis of the operational systems, methods and personnel.

Jan 1, 2007

Australian coal mines have spent considerable capital on dragline improvements over the last two years. This has included ~$30 M on UDD conversions, >$20 M on new buckets, boom upgrades, electrical upgrades, etc. This is a natural part of the response of mining companies to technology and replacement programs. Capital expenditure is a normal part of the ongoing success of most companies. There is however, a tendency for some people to rely on the capital alone to provide the ongoing improvements in equipment productivity. Implementing new technology through capital expenditure is only part of the equation in continuous improvement. For 80 - 90 per cent of the year, the operator controls the productivity achieved by the dragline. Variation between operators is huge. The average standard deviation in productivity is 12 per cent and maintenance impact is over 40 per cent. Robbins 2003, states: Contrary to what we were taught in grade school, we werenÆt all created equal. Most of us are to the left of the median on some normally distributed ability curve. Further, he states: The issue is knowing how people differ in abilities and using that knowledge to increase the likelihood that an employee will perform his or her job well. There are two options for reducing variability between operators; improving operator ability and getting the machine to take over what the operator is doing (automation). Dragline automation will be discussed, however, this paper will focus more on the æhuman factorÆ and how to establish a dragline with minimum variability between operators.

Jan 1, 2005

By L E. Setiawan

The mining and milling groups at Batu Hijau are tasked with increasing SAG mill throughput by approximately ten per cent. Avenues used for this process are blasting and crushing optimisation, ore blending and predicting SAG mill throughput in relation to the geological model. This is in line with traditional æMine to MillÆ studies. At Batu Hijau, mill and mine sequencing cannot readily be configured to perform the surveys traditionally required by a æMine to MillÆ study while meeting the daily production target of 140 000 tonnes per day and processing from varying ore types in one pit. A program called BOCCOST (blasting optimisation crushing conveying optimising SAG throughput) has been implemented to capture approximately 200 variables from blasting, mining and milling operations and assign them to a common point in space in the geological model in real time. Interpretive analysis of data from BOCCOST is used to model relationships between the 200 variables to determine which and how these factors affect SAG throughput. Once these relationships are determined, the blasting, ore blending and crushing process can be optimised to generate a product that maximises mill throughput. The relationships modelled from BOCCOST are also used to generate a SAG mill throughput estimator, which can be coded into the production block model. The block model can be reconciled with the geological block model for correlation by geological domain. Once this relationship is established, SAG mill throughput domains can then be established for predicting SAG mill throughput. This SAG mill throughput estimator is then used in conjunction with revenue calculations to determine an ore cut-off, which combines these two elements to maximise metal production.

Jan 1, 2002

By Bruce See J

Oxidation of artificial Imperial Smelting Furnace lead bullion was performed during cooling between 1180 and 820°C in order to attempt to produce a tin-rich dross.The addition of sodium carbonate together with stirring increased the tin content of the dross when oxidation was carried out with air or PbO on zinc-free bullion.Zinc in the bullion during oxidation resulted in a decrease in tin concentration of the dross due to zinc oxidation and copper entering the dross.

Jan 1, 1987

FOR some time it has been recognised by the Metallurgical Staff that the presence of pyrite in the ore was adversely affecting the grades of the flotation concentrates.Following experimental work, it was decided to change over from the acid circuit in the mill to an alkaline circuit. The following description sets out the procedure adopted, -and the results obtained when such change-over was made.The Zinc Corporation ore consists mainly of galena, marmatite, calcite, and quartz, with smaller quantities of pyrite, fluorspar, and rhodonite.A clean specimen of marmatite picked from the ore assayed 53.4% zinc, and 10% iron, with no lead or insoluble. However, as zinc concentrates have been, at times, produced in the plant assaying over 53% zinc, and with only 8.7% iron, apparently the picked specimen of marmatite did not represent an average composition.The average would probltbly be between 8 and 9% of iron, and from 53.5 to 54.5% of zinc. It is obvious, therefore, that from this ore it is not possible to produce zinc concentrate of a higher grade than this average figure.In the Colorado School of Mines Quarterly for April, 1928, Vol. 23, No. 2, on page 47, we find the following statement:As the zinc in the ore exists as marmatite, which contains approximately 54.5% zinc and 10% iron, 49% zinc in the concentrate may be considered high.This statement refers to the ore treated in the Sullivan concentrator, owned by the Consolidated Mining and Smelting Company of Canada Limited.

Jan 1, 1930

Surface subsidence caused by coal mining operations was the subject of a very successful symposium organised by the Illawarra Branch of the Australas- ian Institute of Mining and Metallurgy in February, 1973. This symposium dealt with the principles of subsidence and overseas experiences arising out of underground mining. Since that time the i eew South Wales Department of Mineral Resources and Development (formerly the Depart- ment of Mines) has incorporated in the approval for pillar extraction certain conditions related to the monitoring of surface movement. Surveys and plans are required to be kept at mines where total or partial extraction of coal takes place. This paper traces the monitoring of surface movement in the Northern Coalfields of New South Wales over the past ten years. Reference is made to the National Coal Board's Subsidence Engineers' Handbook (1975) and how the guidelines expressed therein have been Beneficial.

Jan 1, 1980

By J Johansson

The aim of this paper is to discuss how to form work and organisations in the mines of the future. The Kiruna underground iron ore mine in the far north of Sweden is used as an example on how technical development affects organisational issues like skills, work identity and gender. Over a period of 50 years one can see a transformation of work from manual underground work to automation and remote control from surface level. What characterised the old underground workface was the close relation between man and the hard rock and with arduous physical work under dangerous conditions. Today, the face miners are located on the seventh level of an office building close to the mine. There is also an emerging, and in many aspects already evident, knowledge transformation û from the old and obsolete physical and tacit knowledge and skills (for example the ability to æread the rockÆ) to something new, which can be described as abstract æhigh-techÆ knowledge and skills. The modern technology has created a new type of work û new in terms of competencies and knowledge as well as workload and organisation. At the same time the mining company are recruiting more women and promoting the former pure male work as attractive workplaces for both women and men. All this has effects on how individuals and company create and recreate skills, identity and gender. To some extent the technological development predestines these changes, but there are some choices to be done when forming good work and organisations for the mines of the future. The traditional mining workplace culture and behaviours and the old type of masculinity, the æmachoÆ style, will be challenged by the new æhigh-techÆ work and new competency demands. The changes risk meeting restoring responses, which can have negative impact on the performance of the organisation, for example making it inflexible and perhaps ælaggingÆ behind the technological development. These questions need to be handled when planning future mining.

Jan 1, 2008

By M A. Gontalves, A F. D C Varajpo

The Rio Capim kaolin district, located in the north-east of Parß State, Brazil, constitutes one of the worldÆs largest high-whiteness kaolin reserves for the paper coating industry. It contains, at the base of the main ore, a soft kaolin that gradually changes at the top into a ferruginous duricrust followed by a flint kaolin. The flint kaolin is completely discarded during the exploitation of the soft kaolin. With the view of a more complete beneficiation, aiming at a sustainable development of the minerals industry, the use of this residual flint kaolin has been considered for the manufacturing of zeolites. Zeolites were synthesised from the flint kaolin through a reaction between metakaolinite with soda at 80¦C, for durations of 24 to 144 hours. The transformation into metakaolinite was carried out at 800¦C and was not affected by the titanium oxides. For a synthesis time of only 24 hours, a zeolite 4A very close to its theoretical definition was obtained, whereas for synthesis times longer than 96 hours, a slight formation of hydro-sodalite was also observed. The synthesised zeolites were tested as cationic adsorbents on 0.5 molar solutions of Cu, Pb, Cd and Zn. The adsorption was measured for contact durations of one and three days. It was noted that the exchange kinetics were slow and that the retention was significantly greater after three days than after one day. The retention was greater than 50 per cent of the theoretical exchange capacity for Pb, Cd and Zn, which was different to Cu, where the retention exceeded its theoretical exchange capacity.

Jan 1, 2008

The Hall-Heroult process is likely to be the dominant method of aluminium production for the remainder of the century. The characteristics of the operation of a modern smelter are described and attention drawn to their disabilities which are due chiefly to the small production capacity of individual cells.The principal components of the Hall-Heroult cell- the electrolyte, the anode and the cathodes are discussed in order to identify the problems of scale-up. The factors influencing current efficiency and energy consumption are analysed and lead to the conclusion that the greatest potential for energy saving lies in reducing the anode to cathode distance (ACD).The most promising direction for major change is in the application of a new titanium diboride-carbon composite for coating of the surface of the cathode carbon. It improves the wetting of the carbon by aluminium and should permit the use of sloping cathodes and anodes. The deep metal pad would thereby be eliminated and, in the absence of magnetic perturbations, the ACD could be substantially decreased.

Jan 1, 1987

Activated carbon is ideally suited to treating low grade ores and tailings by the carbon-in-pulp process and is rapidly replacing the use of zinc for recovering gold from cyanide leach solutions. Coarse carbon particles derived from coconut shell adsorb up to 30,000 ppm Au as a gold cyanide complex and can leave barren solutions containing

Jan 1, 1982

The Electricity Commission of New South Wales is the largest single user of coal in the State, burning some 8.5 million tonnes during 1972-73. This coal is converted in power stations into electrical energy which is then distributed throughout the State and supplies the electricity requirements of 99% of users in New South Wales. Barring any major change in energy consumption growth, or change in the current mode of power generation, the consumption of coal by the Commission is estimated to have a doubling period of from 10 to 14 years. Coal is used to generate up to 87% of the electrical energy sold, the balance being obtained from hydro gen- eration, mainly in the Snowy Mountains, and, to a much smaller extent, from diesel generation at Broken Hill. A very large proportion of this coal is consumed in pulverised fuel boilers in the Commission's power stations, located mainly on the various coalfields of New South Wales. Coal supplies are drawn from a large number of mines, some owned or controlled by the Commission, others being owned by public companies. The coals used, originate from at least ten different seams located in the northern, western and southern coalfields of New South Wales, and therefore have a wide variety of properties and characteristics. To ensure an adequate fuel supply well into the future, the Commission is continuously engaged in coal prospecting in various areas. Bore data is used in assessing coal reserves and is also the basis of economic studies for their possible future exploitation. The numerous coal cores obtained during drilling operations are carefully tested and analysed in order to assess their suitability for power generation purposes, and to provide data for the design and operation of boiler plant using these coals. In existing power stations coal deliveries are systematically sampled and tested for quality control, for pay- ment of purchases based upon certain quality parameters and to check for any possible plant operating or main- tenance problems that might arise from the use of the particular coals. Almost all the properties of coal that may be necessary in the Commission's work are obtained using standard testing procedures carried out by the Commission's chemists, in laboratories located at the various power stations or at its Central Laboratories in Pyrmont. Where specialised analysis or testing is required, this is ordinarily undertaken on a commercial basis by outside bodies, expert in the particular field. The significance of the various properties of the coal for use in p.f. boilers is outlined and related to their proper application to boiler plant design and to plant operation.

Jan 1, 1975