Search Documents

By G P. J Dijkema, M A. Reuter

From a material cycles perspective all processes are interconnected and consequently a process can never be evaluated as an isolated and independent unit. This also holds true for the evaluated co-incineration options. Environmental and sustainability issues for example, such as raw material and energy utilisation or air pollution, are a resultant of the whole system of industrial activities. It is therefore important, not to optimise a single process or industrial activity, but rather the whole system. Although engineering procedures for the design of individual industrial units are well developed, the problem of determining the best arrangement of these interconnected units is often far more difficult. Regulation that manages the arrangement of the units for waste processing is still under construction. In the evaluation of co-incineration, analogous principle from process control can be used: feedforward control. This principle includes the determination of which outlets can be used for all process outputs, hence avoidance of any æunusableÆ products or wastes possibly arising from co-incineration. To establish the extent, to which produced wastes are usable, a system overview is necessary, in addition to in-depth information on the subsystems, which produce and can consume wastes. Material cycles modelling can be used as the basis for a tool that supports the development of a suitable playing field. It should provide overview of the system and in-depth information on its subsystems. This tool then represents an attempt to bridge the gap between æholisticÆ industrial ecology and process engineering.

Jan 1, 2000

By Lewis RW, Wilson GI

An ore reserve estimation is only as meaningful as the quality of the data used. All required information needs to be collected in a careful and systematic manner, and be rigorously checked and verified before estimation commences. In addition to geological, assay and location data, a large variety of other information is required for the estimation process. This includes mining, metallurgical and environmental parameters. Though outside their usual area of responsibility, geologists should be involved in the selection and collection of this additional Information.

Jan 1, 1987

By R H. Boffey

The Osborne copper-gold deposit was discovered in North-West Queensland in 1989. Underground production activities commenced at Osborne deposit in April 1996. This paper will examine technical and operational aspects of the underground mine during its development to a 1.2 Mtpa operation . Technical aspects discussed include geology, mine design and mining methods, equipment fleet selection and capital infrastructure. Operational aspects discussed include the evolution and performance of the integrated work teams that are utilised at Osborne to perform all mining and maintenance activities.

Jan 1, 1998

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

I start with some lines from "Pleasures of Hope" by the poet Campbell, published in 1798, which sets the flavour of what I am going to say. They blissful omens bid my spirit see The boundless fields of rapture yet to be; I watch the wheels of Nature's mazy plan, And learn the future by the past of man. I hope to echo the poet's optimistic view of what is yet to come. I am not sure I can find all the omens blissful but we all have some experience of what the wheels of Nature's mazy plan get up to. His advice to learn the future by the past of man seemed sensible to follow, so on the principle that the past of several men would be better than one alone I invited Alan Attwood, Maurice Cahalan, Gavin Moncrieff, Derek Temple, and Peter Wright to help me prepare this address; I am most grateful to them for their contributions. Of the technologies covered in this sequence of keynote addresses, metallurgy is the one which is closest to our consumers. On the age-old principle, which I do not expect to see changed in the 21st Century, that production is about providing the customer with what he wants, when he wants it, where he wants it, and at a price he can afford, I think we should start by trying to see how the market place is likely to develop, and to work back from there to review what technology we need to meet these demands.

Jan 1, 1986

By Armstrong M

The highest grades of the Porgera gold deposit, Papua New Guinea, are contained in Zone 7 due to the presence of the Roamane fault, which acted as channelway of the gold-bearing fluids. Prior to the development and underground mining of this fault-controlled high-grade zone it was critical to provide grade estimates of relatively small mining units, and of the proportion of mining units above cutoff. To be applicable to Zone 7 of Porgera a grade estimation method should account for the following:1. the highly skewed and apparently lognormal distribution of the grades,2. the rapid drop off of the local mean grade and the variance as the distance to the Roamane fault increases,3. the presence of high grade pockets in the footwall, away from that fault, and4. the existence of variograms for the logs with sills parallel to the fault and without sills perpendicular to it.

Jan 1, 1990

By Khosia NK, Ravishankar SA, Sankar TAP

Alumina reduction in Rajhara iron ore slimes essentially involves separation of hematite from gibbsite in relatively coarser fraction and from kaolinite in the finer fraction. Selective dispersion flocculation studies on synthetic mixtures clearly indicated that while it was possible to achieve almost perfect separation of hematite from kaolinite using starch and PAMX (modified polyacrylamide containing hydroxamate functional groups) flocculants, no selectivity was observed in iron oxide-alumina system. A schematic flowsheet suggested on the basis of this work for the beneficiation of Indian ore slimes thus consists of classification in a hydrocyclone, followed by selective dispersion of coarse fraction (underflow) and selective flocculation of the overflow fraction. Starting with a feed assaying 46 per cent Fe and 11.6 per cent A1203, a concentrate assaying 60 per cent Fe and 4.7 per cent A1203 could be produced at an overall iron recovery of 60 per cent using conventional Reagents.

Jan 1, 1993

By R Milton, D Hake, H Sprague

The North Western Sewer tunnel extends over 11.5 km in the North Western suburbs of Melbourne.The $253 million tunnel project provides a critical link in the Melbourne Sewer Network. The existing sewers fail to service the increasing demands of the growing population of the North West regions of Melbourne. This project will protect the environment and improve the standards of service of the existing system. This paper concentrates on Section three of this project, consisting of the final 4 km of the Contract, three access shafts and a cut and cover section of tunnel.Transfield Tunnelling as Head Contractor constructed the tunnel for Melbourne Water Corporation, with Enetech Streamline, formally Streamline Australia, a trading arm of Melbourne Water acting as Superintendent.Excavation of Section three of this project commenced in September 1994 and project completion is scheduled for October 1998. The tunnel passes below the residential suburb of Essendon, through some of the most challenging ground conditions ever attempted to be tunnelled in Australia.

Jan 1, 1999

By Hosking IA, Mirkov P

Among the solutions currently being considered for improving traffic flow in Sydney are the construction of major road tunnels, principally the Eastern Distributor Tunnels, leading from the end of the Cahill Expressway to Drivers Triangle and South of Taylor Square and the Sydney Harbour Tunnel, which incorporates sections of driven tunnel at the northern and southern sides of the harbour. The Eastern Distributor Tunnels, known as Stages 2 and 3 of the Eastern Distributor Scheme comprise: Stage 2 - A south bound two lane tunnel from north of William Street to Driver's Triangle. The southern end includes two Y junctions (locally 3 to 4 lane widths) with exits into South Dowling Street, Anzac Parade and Moore Park Road. Stage 3 - A north bound, two lane tunnel from Taylor Square to Palmer Street just north of William Street. Further details of the Eastern Distributor Tunnels are given in the paper by Baxter, Chappel and Fishburn (1986) which is included in this conference.

Jan 1, 1987

Autocompression and virgin rock tempera ture have a marked influence on the ventilation of the lower levels at North Broken Hill Limited N.S.W. To maintain comfortable working temp- eratures without penalty to working hours, increase in airflow or the cooling of the work area is necessary. The use of refrigerated air cooling is discussed. Ventilation of underground mining opera tions at North Broken Hill Limited is accomplished by downcasting air through No.3 shaft, the main operating shaft, 1581 m deep, with additional air through No.1 shaft (542 m) 2 and No.2 shaft (978 m), both no longer opera- tional shafts. Air is upcasted through No.3 ventilation shaft which is 4.9 m diameter and concrete lined, from the No.28 level (1140 m) to the surface. On the surface level of this shaft is a horizontally mounted Richardson 4800 mm diameter single stage axial flow fan with adjustable pitch rotor blades.

Jan 1, 1977

By Rashad MZ

The evaluation of ore deposits consumes much effort, cost and time, hence research work must aim to minimize these inputs with no loss of accuracy. The present study is devoted to assess the optimum conditions and methods of calculations which give minimum costs of ore exploration. An area of (a x a) where "a" is the zone of influence of the semi-variogram, i.e. (2800 x 2800 square metres) located within the Abu Tartur plateau is the subject of the intensive study. The distances between boreholes are varied ie. a/4, a/6, a/8 and a/ 10 respectively. The average ore grade (G), thickness (t) and relative ore reserves (tG) are calculated by four methods. The results indicate that at a distance equal to a/5, the inverse distance squared method gives the best results. These parameters save about 50 percent of the cost of exploration with a map accuracy greater than 90 Percent.

Jan 1, 1987

Major exploration companies can have a problem with what to do with small precious metal ore bodies located through exploration programmes. Low tonnage, but high grade, ore bodies too small to justify in-house development.1.2 Ban Ban Mining is a Sunshine Coast based partnership with considerable expertise in mining and earthmoving which specializes in the mining of small/medium size ore bodies on behalf of the tenement holder on a profit sharing or royalty basis.1.3 The partnership's first successful venture has been the mining and vat leaching of a small 40,000 tonne ore body with a head grade of 5 gm/tonne gold and 32 gms/tonne silver, situated near Ban Ban Springs in southeast Queensland.1.4 This paper looks at the low cost vat leaching method of treatment, as an alternative to CIP and CIL in the processing of low tonnage/high grade precious metal ore bodies.

Jan 1, 1990

By S B. Martin, M P. Simpson, J L. Mauk

The Martha deposit in Waihi, New Zealand, is a giant adularia-sericite epithermal gold-silver deposit that formed 6.0 to 6.1 Ma, and has produced over 6.4 Moz gold and 39.9 Moz. Fluid inclusion analyses were undertaken on a limited number of vein samples from Martha. The results from this eight week student project are preliminary but agree with previous studies. There is little variation between primary and secondary inclusions and between different vein types, except that homogenisation temperatures of the inclusions in sphalerite grains are on average 20¦ to 30¦C higher than the average quartz vein values. Overall the temperatures of homogenisation ranged from 182¦ to 258¦C and final ice melting temperatures ranged from 0.0¦ to 2.8¦C. Unusual black inclusions were also found associated only with the ginguro bands. Some of these appear to be solid sulphide inclusions but others are not so clear.

Jan 1, 2007

Polyacrylamide flocculating agent has been used in the Leaching Division of the Risdon Works of the Electrolytic Zinc Co. of Australasia Ltd since October, 1960. Since the introduction, the.: number of thickeners in use in the continu-ous thickening stage has been reduced from eight to three; there has been an increase of 25% in throughput and a reduc-tion of solids in.:thickener overflow from 3-4 gòpòl . solids to 0.5 g.p.l. solids. Reagent addition has been at the rate of 0.25. lb SEPARAN, NP10 per ton solids.Additionally there has been a gain of 3% in current efficiency as the direct result of the addition of SEPARAN NP10 to purified cadmium sulphate solution prior to electrolysis for cadmium metal. A smoother deposit has resulted and it has been possible to increase deposition time between strip-pings from 47 to 71 hours. However, there has been a slight increase the lead content of the cadmium-metal produced.

Jan 1, 1963

By Hendrix JL, Nelson JH

Three ores (sulfidic, oxidized and carbonaceous) were analyzed to determine the effects of leaching time, ore depth, and ore mineralogy on cyanide species concentration. NaCN solutions were percolated through opaque columns filled with milled ore. Column design made liquid sample collection possible from various depths at specific times. The concentrations of weak acid dissociable(WAD) and total cyanide, Fe(CN)63 , Fe(CN)64 , SCN , and Cu(CN)43 were determined for each sample. Extended percolation time led to increases in WAD cyanide concentra- tions and decreased SCN and Cu(CN)43 concentrations regardless of ore depth. WAD cyanide concentration decreased while Fe(CN)64 concentra- tion increased with ore depth. Highest concentrations of Fe(CN)64- SCN and Cu(CN)43 were found in the sulfidic ore, with expected low WAD cyanide concentrations. Lowest concentrations of Fe(CN)64 , SCN 3 and Cu(CN)4 were found in the oxidized ore. Intermediate concentra

Jan 1, 1988

By T E. Jeffries, M Zentilli, J STguel, C C. Wilkinson, B G. Rusk, V H. Vry

Laser ablation Inductively Coupled Plasma Mass Spectrometry (ICPMS) analysis of fluid inclusions trapping mineralising solutions in major porphyry-copper deposits indicates that copper concentrations can reach 103 - 104 ppm in both dilute, CO2-bearing fluids and in high salinity brines. Non-Cl transport of Cu is implicated. Au has been determined at 0.2 - 0.4 ppm in the low salinity fluids and may be co-transported with Cu. In contrast, high concentrations of Fe, Mn, Zn and Pb are only attained in brines and correlate strongly with Cl-indicating chloride transport. Physical and/or temporal separation of these fluid types can therefore producemetal fractionation within porphyry systems. Evidence concerning the behaviour of Mo is less clear but brine transport appears to be favoured; phase separation is one mechanism that may account for the fractionation of Mo from Cu and the formation of quartz-molybdenite veins. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Fuerstenau DW

The flotation of pyrite in ethyl xanthate solutions is presented along with electrokinetic results. The results have been analysed in view of recently published thermodynamic calculations as well as other published data on the pyrite-xanthate system including adsorption and voltarnmetry studies. The flotation response of pyrite in xanthate solutions is characterised by two maxima, one at pH 4 and the other at pH 8-9. The acidic maxima is also associated with a reversal in the electrophoretic mobility of pyrite, probably due to the formation of ferric xanthate on the pyrite surface through chemisorption of xanthate ions while the basic maxima is not associated with major changes in the mobility and flotation at this pH can probably be attributed the adsorption of dixanthogen. It is concluded that there is not sufficient experimental evidence to conclusively attribute the lack of flotation response in solutions at near neutral pH to any particular phenomena, either kinetic or thermodynamic.

Jan 1, 1993

By Shinnosuke U, Zhang HE, Qian X

In this paper it is recommended that pyrite is to be separated as froth from arsenopyrite by selective depression of arsenopyrite in strong alkaline medium (1), by oxidation with chlorinated lime (II), by co-use of chlorinated lime with sodium carbonate (III), and by modification with `L' reagent (know-how) without filtering to get rid of residual copper ions after Cu activation (IV). The corresponding principles of these (new) effective methods were briefly discussed. The artificial mixture (1:1) of pyrite and arsenopyrite could be successfully separated, and concentrates of pyrite containing 2.12 per cent (I), 7.00 per cent (II), 2.60 per cent (III) and 3.16 per cent (IV) arsenic with recovery of 90.9 per cent (1), 89.5 per cent (II), 89.0 per cent (III) and 81.4 per cent (IV) respectively can be obtained by only one flotation. Some effective precautions were suggested to improve the separation of arsenopyrite and pyrite (or other sulphides) by flotation.

Jan 1, 1993

The purpose of this paper is to explain the basic structure of how minerals are marketed, whilst highlighting the essential factors that mine management needs to be confident are incorporated into a mineÆs marketing strategy. The traditional mine management approach to marketing has been to defer its scrutiny to the marketing manager and take a largely passive role. It is this paperÆs assertion that mine management needs to become more proactive and provide greater strategic input into the marketing process. Irrespective of what mineral your mine produces, the key marketing principles remain constant and need to be understood and managed to extract the full benefit on behalf of the mining asset. From a mine management perspective, success is ultimately linked to understanding these marketing principles and ensuring that they are effectively addressed by your mineÆs marketing strategy. This paper will unashamedly attempt to simplify marketing by explaining how the basic fundamentals of supply and demand set market direction, the importance of a comprehensive marketing strategy, the importance of customer relationships and how contracts and prices are typically negotiated. This paper will use examples from the metallurgical coal (met coal) industry to highlight these points. The paper will also provide a template for developing the critical mine interaction that needs to exist between the marketing department and management to develop a æwhole of mineÆ approach to marketing. It is this core group that will be strategically responsible for delivering the commitments your mine has made to your customers. For mine management not to be actively involved in this process puts at æriskÆ the hard won production and cost efficiencies achieved at your mine and ignores the opportunity to maximise your current and future revenue streams. And whilst this paper recognises that is arguably unreasonable for mine management to become æmarketing expertsÆ, it also argues that it is unreasonable for a mine management to divorce themselves from the process.

Jan 1, 2006

In November 1992, the Internal Revenue Commission (IRC) was formed from the rperggr of the Papua New Guinea Taxation Of- fice (PNGTO) and the Bureau of Customs, and now has the re- sponsibility for the administration of direct and indirect taxes on a national basis in Papua New Guinea (PNG). Since that date we have undertaken many initiatives to make the new organisation more efficient and responsive to clients' needs. Income Tax The mining industry is catered for, in respect of income tax, un- der a separate taxation regime within the Income Tax Act (ITA), Division 10, as well as some general provisions within that Act as may be applicable. Division 10 is itself broken up into subdi- visions to cover the different types of mining leases, namely Spe- cial Mining Leases (SMLs) and Mining Leases (MLs), and peri- ods of time during which those sub-divisions apply. Ring Fencing Income tax assessed on the mining industry, with the exception of Mining Leases (these will be explained later), has a project basis of assessment, that is, each project is assessed separately as if the taxable income of the taxpayer from operations attributable to the project was the only assessable income derived by that taxpayer. This is often referred to as "ring fencing". This is an important point to consider because losses from unsuccessful projects cannot be set off against income from those that are suc- cessful, except in very limited specific circumstances, such as where an unsuccessful exploration licence is cancelled or surren- dered. The project basis of assessment applies to both resident and non-resident companies. A relaxation in the 'ring fence' provisions was applied from 1st January 1995, where ten percent of exploration expenditure, in- curred in areas outside of Special Mining Leases and Petroleum Development Licences in a particular year of income, can be claimed as an outright deduction which is limited to ten percent of the tax otherwise payable in that year. This was introduced to encourage exploration in PNG.

Jan 1, 1997