Search Documents

By Scaife PH, Cripps Clark J, Cameron DB

Tuyere coke samples have been taken through the tuyere openings of B.H.P. International Blast Furnaces since 1978 with Whyalla No. 2 Blast Furnace taking samples on a regular basis since 1982. The degradation of coke during it's passage through the Blast Furnace can be measured and the relationships between these data, feed coke data and blast furnace operating data demonstrated. Tuyere coke sampling has been useful in revealing misleading external coke testing results and is still the method to monitor directly the performance of coke within the Blast Furnace.

Jan 1, 1987

By D La Rosa, W Valery, A Jankovic, S Ese

Metso Minerals Process Technology Asia-Pacific (MMPT-AP) has been working with many mining companies worldwide performing æMine to MillÆ or Process Integration and Optimisation (PIO) studies. MMPT-AP has developed a proven methodology to improve the efficiency of the mine-mill interface and gain maximum benefit. The PIO methodology involves rock characterisation, mathematical modelling and simulation to generate a list of operational and control changes for both the mine and concentrator. Following the methodology, the list of recommendations is developed relatively easily; the more challenging part depends on the company. Success of a PIO project relies on the ability of an organisation to implement change û both operationally and culturally: the human element. When a PIO project is started, there is initial interest and commitment from the company. But how can this be maintained? How does an operation know if the benefit continues? MMPT-AP is now developing long-term relationships with clients to ensure that the increased production and improved efficiency continues. Direct and indirect measurements are used to determine the key factors involved and to understand the cause/effect relationships. Simulation tools also can be used to compare current with recommended practices û so when material properties vary over time, the benefits can still be quantified. PIO is about empowerment: by measuring and understanding what parameters affect concentrator performance, the site personnel now have the knowledge to make a difference. Rather than simply reporting variable or poor concentrator performance, operations can predict when production will be affected and put controls in place to prevent it from happening. This requires support and commitment from the company or æbuy inÆ. Ensuring this buy in continues is the challenge facing every company involved in PIO work û but the benefits are well worth it. This paper will review MMPT-APÆs experiences in implementing PIO projects in the long term: from both the consulting and operational viewpoints. MMPT-APÆs involvement with a number of companies will be discussed as examples of what works and what does not.

Jan 1, 2007

Better quality at lower cost is today's formula for remaining competitive in a world market. For an integrated steel company, high quality low cost steel production must originate before the blast furnace. In 1979, when U.S. Steel initiated a Quality Management Program throughout its steelmaking operations, efforts began at the coal, ore and flux mines. The objective was to improve the quality and reduce the variability of the critical parameters for steelmaking raw materials, to get the blast furnaces, and subsequently the melt shops, under optimum control. The general details of U.S. Steel's Quality Management Program are discussed and how it was used to promote the desired improvements in steelmaking raw materials. Some of the outstanding results obtained by the cooperative efforts between the mines and the steel plants are reported. The lessons learned by U.S. Steel were through upgrading existing operations and facilities. These principles should now be applied to new projects and the benefits of good quality management should commence from the time new projects are Commissioned.

Jan 1, 1986

Although this is a symposium on "The Occurrence, Preparation and Use of Australian Black Coal", I do not think that, in these days, any of the main energy resources can be considered only in terms of country of origin or only by itself in isolation from other energy resources. Accordingly, I propose to comment on solid fuels generally in the world energy scene, and make some brief references to Australian solid fuels, and to some other matters in the latter part of this paper. In this address I am drawing heavily on the 1974 survey of energy resources published just recently by the World Energy Conference. I do this for a number of reasons. Firstly, the survey is the latest and most comprehensive publication of its kind; secondly, it is the result of several years' work by a panel of eminent people, from all the energy industries and from some 16 widely spread countries; thirdly, substantial assistance was given by the U.S. Atomic Energy Commission in its compilation; and, finally, to let all know of the existence of the book, as I believe it to be a source document for all those interested in world energy resources. The United Nations "J" series of statistical papers provide important information on the annual production and consumption of and trade in the various forms of energy. In their respective areas, these two publications are primary information sources. Our present sources of energy throughout the world are fossil fuel deposits (coal, oil, gas), nuclear materials, water, geothermal, solar and tidal - but we are at present heavily dependent upon the natural stores of non-renewable fossil energy resources. Fig. 1 shows the changing use of energy resources in the present century. A comparison between 1900 and 1973 shows clearly the shift which has taken place.

Jan 1, 1975

The establishment of vegetation onto open cut mine spoil is dependant on the nature of the soil and rock strata of the overburden. Experience has shown that in the Bowen Basin of Central Queensland the nature of the minespoil changes considerably as subsequent and deeper mining strips intercept changing rock strata. The different mixes of strata at the surface of reshaped spoilpiles can produce variable response in the sown vegetation cover. It is usual that land features of mine sites are known in detail and are depicted on mine or locality maps. Subsurface strata and lithology descriptions are available and are used for planning of open cut mining operations. Surface and subsurface data can also be used to estimate the intrinsic nature of overburden through the use of fence diagrams. Lithology at points along a mined strip can be obtained and used to describe overburden. Indications are that correlations exist between salinity of overburden components and the response of vegetation. The developed procedure thus becomes a useful tool for the prediction of revegetation Practices.

Jan 1, 1987

By S KandT

The FalTmT iron ore deposits are located in the so-called æBirrimianÆ volcano-sedimentary complex that extends in a general NE-SW direction across eastern Senegal and part of Mali and Guinea. The rocks underwent folding and greenschist facies metamorphism, as well as various events of granitoid emplacement. The deposits form part of the DialT-DalTma Series of the Birrimian Supergroup and were subjected to contact metamorphism. The Fe-mineralisation occurs as primary magnetite within the metamorphic aureole. Supergene oxidation (martitisation) of this mineralisation produced the hematite-rich iron deposits that can be seen as prominent hills across the plains of this south-eastern corner of Senegal. BRGM of France and Miferso (SociTtT des Mines de Fer du STnTgal-Oriental) have conducted several phases of prospecting since 1957. Their aim was to delineate the hematite deposits and to assess the grade, beneficiation characteristics and marketability of the iron ore. A feasibility study by Fluor Daniel was completed in 1992. Results indicated that, at the time, the resource could not compete in the international arena in terms of size and accessibility. The growing iron ore market and additional available resources in the area now challenge the 1992 feasibility study results and put the old kid back on the iron ore block. The project faces some mining challenges, such as the amount of magnetite in the hematite product that will be acceptable to the market. Previous project evaluations only considered the secondary hematite deposits as economically viable. It is therefore important to accurately delineate the magnetite/hematite contact zone to optimise the resource tonnage. Project logistic constraints also exist in terms of railway access and harbour facilities. The resource is, however, well situated for the European iron ore market and aims to find a place in the rapidly expanding iron ore seaborne trade.

Jan 1, 2005

The stratigraphy of the Singleton Coal Measures is reviewed and a revised stratigrapixy which has been ratified by the N.S.W. Standing Committee for Coalfield geology is nominated and defined by a selected type section. Withir the type section the occurrence of repetitive phases are illustrated and described. Coal. Measure units within the Singleton Coal Mean sures, termed the Wollombi and Wittingham Coal Measures respectively, are correlated with the Newcastle and Tomago Coal Measures. In formal nomenclature the Singleton Coal Measures are designated the Singleton Super Group. The major depositional cycles within the Coal Mea- sures are outlined together with those lesser phases within the Coal bearing sequences that influence the mining conditions likely to be encountered. Both tectonic and sedimentary features of the Singleton Coal Measures are considered and the localized post depositional effects on the coal seams and roof strata in- duced by differential, compactions are emphar Sized.

Jan 1, 1972

By J C. Macintosh

Capcoal Mine has modified its water use practices over the past 15 years. Two issues have changed the way water was managed:an economic review of water supply options for a planned expansion of the coal handling and preparation plant (CHPP) in the early 1990s, and increasing neighbour concerns about discharge of worked water from the mine into the local streams. These issues resulted in commitment by the site General Manager to cease discharge of worked water from site and to convert from using raw water to worked water in the CHPP. Operational needs, societal demands and continuing dry weather are again demanding change to the siteÆs water management strategy. This paper outlines the drivers for past and future operational change.

Jan 1, 2006

By A Bennett, A Peck

BHP has recently constructed a Hot Briquetted Iron Plant at Port Hedland in the Pilbara region of Western Australia. Supply of iron ore fines to the plant is by conveyor from the companyÆs existing Nelson Point stockyards. The conveyor passes under Port Hedland harbour in a concrete segmentally lined tunnel, approximately 1030 m long and with a 5.1 m external diameter. The tunnel was constructed by a Tunnel Boring Machine (TBM) which both excavated the ground and erected the tunnel lining. The tunnel was bored between cut and cover in situ concrete portal structures, the TBM being launched from the Finucane Island side towards Port Hedland town. The alignment required lengthy gradients of 1:6 on either side of the harbourÆs dredged channel, under which the tunnel is bored with a minimum clearance of 8 m.The tunnel is fitted-out with:1800 mm belt conveyor capable of 10 000 tph;walkway along which a specially designed inspection/ maintenance vehicle can run; andtunnel services including power, light, fire detection and suppression communications, water mains for wash down and sumps and pumps for drainage.This paper gives a general overview of the design and construct contract, important aspects of the design and the construction process itself.

Jan 1, 1999

By M J. Sale

The Epithermal and Mesothermal Gold Prospectivity Modelling Projects recently completed by Crown Minerals provided explorers in New Zealand with a new compilation of historical exploration data combined with new geological information from the GNS QMap 1:250 000 scale mapping project. These data were used to produce predictive mineral potential maps for gold mineralisation in New Zealand. The aim of these projects, which was to stimulate mineral exploration and investment in exploration, has been successful with new companies acquiring new tenements and committing significant exploration expenditure to exploring in New Zealand in the coming years. The projects were undertaken at a national scale and consequently not all exploration data were compiled into the prospectivity models. HPD New Zealand Ltd recognised the value of the prospectivity modeling work and committed exploration funds to continue the modelling process started by the projects. They recognised the need to compile the remaining data and run the models again to allow detailed exploration targeting.

Jan 1, 2004

The Jurassic Walloon Coal Measures crop out over much of the Moreton Basin and contain numerous thin, banded coal seams which have been mined at various locations since the 1870s. Historically most mining has been by underground methods. Increased exploration during the 1970s and 1980s has led to the delineation of significant open cut coal resources and to the development of the Oakleigh, Jeebropillly and Ebenezer open cut coal mines in the Rosewood-Walloon area. Over 2 170 million tonnes in-situ of shallow, high volatile bituminous coal with a mean maximum vitrinite reflectance of between 0.5 and 0.6 have been proven in the Basin.

Jan 1, 1991

By T Clemens, D Trumm

Adopting environmentally acceptable practices in New Zealand is a crucial requirement for mineral wealth development. Recent planned expansions in the coal industry have increasingly placed mining in the media spotlight. A lack of appropriate national environmental guidelines has resulted in inconsistent responses and assessments of current and prospective mine sites. Such inconsistencies have lead to delays in decisions on developing economic mineral deposits that may have only minor short-term impacts, and have also allowed unacceptable environmental management practices to continue elsewhere.   A research collaboration between CRL Energy, Landcare Research, University of Canterbury and University of Otago aims to provide regulator groups and the mining industry with a unified approach to the requirements of the Resource Management Act 1991, which is the legislation that predominantly drives the nationÆs environmental policies and guidelines. The tangible outcome of this research programme will be guidelines for an integrated decision-making framework based upon robust multidisciplinary science. The result of this unified process will facilitate the development of viable mineral deposits and prevent excessive environmental impacts.   The framework will be derived from a synthesis of four objectives. Objective 1 identifies potential water quality impact. This objective is based on a targeted geochemical study of the lithology and waterways of the West Coast and Southland. Objective 2 categorises the degree of impacts on the ecology of receiving aquatic ecosystems and determines the processes that drive aquatic ecosystem recovery. Objective 3 identifies best strategies to sufficiently manage impacted ecosystems, and to prevent future unacceptable impacts. Objective 4 combines the findings of Objectives 1 - 3 into a standard decision-making framework. The development of this framework development will include wide consultation with representatives of the mining industry and regulator groups. It is anticipated that this multidisciplinary approach will provide a robust and coherent, standardised system that will assist in achieving industry and environmental targets.

Jan 1, 2004

By Roberts M. L

Long Shaft was initially developed using a rail haulage system on every working level comprising battery electric locomotives and granby trucks loaded by rail mounted rocker shovels. Production was commenced using conventional hand held cut and fill mining methods. In an effort to improve productivity and reduce operating costs a mechanised cut and fill stoping method evolved to suit the wider sections of the orebody. To further improve productivity and reduce costs the mechanised levels of the mine are progressively being redeveloped to enable the use of trackless diesel haulage equipment. An added benefit of trackless haulage equipment will be the ability to place development mullock into stopes as Fill.

Jan 1, 1988

By D Smith, D Reid, D Bradshaw, C Brough

The Merensky Reef at Northam Platinum Mine in South Africa is characterised by a high degree of variability with respect to reef elevation (difficult to mine), as well as mineralogy and texture (difficult to process). Development along strike and down dip of multiple reef types has led to unpredictable run-of-mine characteristics that pose problems for the mineral processing circuit at Northam. Following mining terminology, Normal, Transitional (NP2) and Pothole (P2) Merensky reef types can be defined, and this geometallurgical study aims to characterise and understand the relationship between their mineralogical characteristics and laboratory scale batch flotation performance. The plagioclase-rich NP2 reef ore is the easiest ore to process in terms of capacity for high mill throughput as well as flotation performance. The lack of very fine-grained disseminated sulfide textures in the NP2 reef ore results in better liberation characteristics relative to the Normal and P2 reef types. Consequently, chalcopyrite, pentlandite and sulfide recoveries are highest for the NP2 reef ore. The lack of ferromagnesian minerals in the NP2 reef ore also results in the recovery of the least amount of floatable gangue during flotation tests. The Normal and P2 reef ores are similar to each other, with an orthopyroxene-rich mineralogy with associated alteration minerals. The P2 reef is also characterised by the highest sulfide content and degree of pentlandite liberation. Chalcopyrite, pentlandite and pyrrhotite liberation is only significantly increased by a change in grind for the Normal reef ore. The change in grind, however, only significantly affects pentlandite flotation performance and overall froth stability for the Normal reef ore. However, for all three ores, a small change in grind has a detrimental effect on pentlandite flotation performance.

Jan 1, 2008

The Carnilya Hill Mine, a joint venture project between Western Mining Corporation Limited (WMC) and The Broken Hill Proprietary Company (BHP), is a nickel sulphide deposit being developed by the Kambalda Nickel Operations (KNO) of Western Mining Corporation. Seven months elapsed from the time a decision to proceed with the project was taken until the first ore production. During the first month of operation a new KNO record for decline development was set. Equipment used includes an electro- hydraulic drill jumbo, 4 cubic metre front end loaders, and 35 tonne haulage trucks.

Jan 1, 1981

By Tuite M. J, Woolcock L. J

The Awak Mas gold project is located in the Province of South Sulawesi, Republic of Indonesia. It is situated 300 km by road north of the provincial capital of Ujung Pandang. The capital is readily accessible by air from Australia via Denpasar on Bali or the Indonesian capital, Jakarta (Figure 1). Elevations at Awak Mas range from 850 to 1400 metres above sea level in reasonably rugged terrain. The area is covered by primary and secondary (regrowth) rain forest. The region is subject to an equatorial-type tropical climate. The annual rainfall is a high 3000 mm most of which falls in the rainy season between March and June. In the lower valleys rice, cloves and chocolate crops are cultivated. Title to the project area is secured by a Contract of Work (COW) issued to PT Masmindo Eka Sakti (MES) on 23 October 1987 by the Government of Indonesia. MES was controlled at the time by New Hope Industries group of Brisbane. After New Hope had completed initial reconnaissance exploration of the area, Battle Mountain Gold Company (BMGC) farmed-in in 1991 and earned a 60 per cent beneficial interest in MES.

Jan 1, 1996

By Kaji S

The Tsugaru Tunnel, located on the Honshu island approach to the Seikan Tunnel, is 5,880 m long and has a "Shinkansen" cross section of 90 m2 area. The geological formation through which the tunnel passes consists of very soft rock most of which is unsolidified sandstone belonging to the Neogen. The permeability coefficient is in the range of 10-2 to 10-4 cm/s and being water bearing with a high ground water level, the ground is unstable and subject to soil outflow phenomenon. Kajima Corporation, undertaking the Futamata Construction Section (1,420 m long), excavated the tunnel by the upper half heading method with side pilots employing the following countermeasures to cope with these severe conditions.

Jan 1, 1987

Any engineering firm hoping to do business in the modern world must understand-and take into account-the social and economic realities of client, country, culture, and community. If these considerations are ignored, any large-scale international development project is doomed to failure even before it begins. In this changing world, the distinctions between `developed', `developing', and `less developed' nations are more and more blurred. The so-called `less-developed' and `developing' nations are rapidly acquiring technology, an educated man- agerial and technical class, manufacturing capa- bilities, a growing spectrum of developed financial and raw materials resources, and a broad range of labour skills. These nations are establishing themselves as an integral part of the modern world, on an equal footing with other nations and with justifiable expectations for an ever higher standard of living and an ever better quality of Life.

Jan 1, 1978

By Mercer J. K

Shaft guide reaetions in No. 2 Ore Shaft, Mount Isa Mines Limited, have been reduced to a low order of magnitude by the use of self aligning slippers and spring loaded guide rollers. Before commissioning the new 4500 h.p. winder at No. 2 Ore Shaft in January, 1958, it was realised that the increase in hoisting speed from 1800 to 2650 ft/min. would cause high shaft guide reactions which would be increased further when the elongated 12 ton skips replaced the existing 7 ton skips.The Cambridge accelerometer was used to measure the shaft guide reactions and to confirm that progressive skip modifications were resulting in reduced reactions. The skip modifications were completed in 4 weeks.INTRODUCTIONIn 1956 an expansion programme was initiated to increase production from 5000 to 11000 tons per mining day. At No. 2 Ore Shaft the 1500 h.p. winder operated at 1800 ft./min. and hoisted a 7 ton capacity skip. The new 4500 h.p. winder operates at 2650 ft./min. and hoists a 12 ton capacity skip. No. 2 Ore shaft is equipped with two 5 ft. by 5 ft. hoisting compartments (Fig. 1) and any increase in skip capacity meant an abnormally long skip. This feature, coupled with the increase in hoisting speed, could have caused very high shaft guide reactions. Before commissioning the 4500 h.p. winder, a Cambridge accelerometer was borrowed from the University of Adelaide and was used to measure the shaft guide reactions. Rather than carry out an extensive shaft timbering programme, the skips were modified by fitting cushioned guide shoes and spring loaded guide rollers (Fig. 1). Testing commenced in February, 1958, and was completed in March, 1958.

Jan 1, 1961

By L Reynolds

The portable infrared mineral analyser (PIMA) was trialled to determine the extent and intensity of any hydrothermal alteration halo associated with gold mineralisation in the Hyde-Macraes Shear Zone (HMSZ) of the Otago Schist.   Twelve diamond drillholes through the HMSZ were analysed with the PIMA at a sample spacing of 1 m. The drillholes were selected on two traverses along the line of strike and down-dip of the mineralisation in and around Panel 2 of the Frasers underground development.   The study showed that the Hangingwall shear of the HMSZ has a more distinctive infrared signature in intersections with high grades. The Hangingwall shear in these drill holes is defined by a shift in the wavelength of the Al-OH absorption feature from ~2220 nm to <2210 nm. This shift is attributed to a change in the mineralogy from phengite to muscovite. Overprinting this trend in some of the drillholes is the presence of the 2210 nm Al-OH absorption feature, ascribed to kaolinite. Kaolinite also tends to be present in numerous other regions of the schist above the Hangingwall shear associated with steeply dipping faults and foliation parallel joints. In drill holes with low grades the Hangingwall shear does not exhibit any obvious infrared signature.   At the scale of study, the PIMA does not provide evidence for an alteration halo associated with hydrothermal mineralisation above the Hangingwall shear. Possible tectonic movement may have displaced any alteration halo that once existed, away from the zone of mineralisation. For this reason, PIMA apparently cannot be used for predicting the location of the Hangingwall shear during exploration drilling. However, the study did show that the PIMA could define the Hangingwall shear when the rocks were sufficiently altered and mineralised.

Jan 1, 2007