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The degree of ionicity-covalency of complex compounds is discussed here as a prospective criterion for selection and purposeful synthesis of sulfhydril and oxhydril collectors. Theoretical predictions of flotation behaviour were confirmed by flotation of a number of ores.

Jan 1, 2005

The Benambra deposits, which are regarded as volcanogenic in origin, may be subdivided into two major bodies, termed the Wilga and the Currawong deposits; these are further subdivided into smaller, more manageable units, based on composition and structure/spatial distribution.

Jan 1, 1989

By Leaning R. W, Goodman P. J, Lidgate P. N

The impact of computer based design tools on the engineering industry has been enormous. With the advent of computer aided design and its continual evolution into tools such as 3D design and photogrammetry the face of the engineering office ha

Jan 1, 1998

`WELL HE WOULD, WOULDN'T HE?' Public Relations people have something in common with advertising people and politicians: there exists a perception that their whole Raison d'Etre is to create, mould, and maintain images which are far removed from reality

Jan 1, 1994

Most of you who are attending this conference are probably Student Members of The Institute and well aware of the advantages which flow from student membership. You will probably agree that the major benefits are: ò Low and subsidised membership fees;

Jan 1, 1994

By Hinkley JT, Smitham JB, Nicol SK

Historical investigations of mineral flotation have highlighted the many factors which affect flotation. Some of these are related to the mineral, its degree of liberation (however defined), solution chemistry and flotation reagents. The complexity of the interactions between these factors often leads to uncertainty over whether the final grade/recovery results obtained in either laboratory or pilot scale tests are in fact the maximum recovery at a specific grade. The reason for this is that there has not previously been a general technique for establishing the floatability of an ore. This study describes the further development of the 'tree' flotation technique for minerals other than coal, and in particular its application to iron ores. Oxides have been chosen as a system of intermediate complexity between the simple coal system and sulphide minerals to illustrate the principles and develop the concepts. The 'tree' flotation procedure consists of the progressive flotation to completion of successive froth products, followed by reflotation to remove entrained material. It therefore represents an 'equilibrium' approach to floatability rather than a kinetic approach. By ordering the various products and tails in order of increasing grade, a cumulative curve of grade and recovery can be constructed against which an isolated batch or plant result on the same ore can be compared. In this investigation, a Jaspilitic iron ore was tested at various grind sizes to determine the 'best' flotation grade-recovery that could be obtained with a given set of reagent conditions. The separation characteristics of a process are best measured on a system which contains particles which behave as 'middlings' with respect to the process in question. For this reason a natural ore was chosen in preference to model systems in order to relate more readily to plant situations.

Jan 1, 1993

The paper describes the preparation of new rail guides, removing existing rails, and replacing with new rails in a vertical winding shaft.INTRODUCTIONThe general practice in coal winding shafts is the use of two cages, with one or more decks in which men and materials are raised or lowered. Winding speeds vary according to depth, the type of winding gear, and whether winding is done in downcast or upcast shafts. Each cage occupies a position between the centre and side of the shaft, with a clearance depending on the type of guides used. The function of the guides is to keep the cage in position throughout the entire depth of the shaft. There are three types of guides, two of which are in general use.1. Selected wood of about 6 in. square section, fixed to the side of buntons.2. Solid strand steel made up similarly to that of an ordinary wire rope, suspended from the head frame with weights attached to the lower end.3. Standard T-rail sections fixed to end or side buntons. Of the three types, 2 and 3 are in general use. The type used in the particular case, the subject of this paper, is T-rails of the standard section used in railway work.GENERAL DESCRIPTION OF SHAFTDetails of the shaft are as follow: Diameter of shaft: 22 ft. inside lining.Depth of shaft: 900 ft., including sump.Concrete lined throughout.VENTILATIONThe ventilation shaft is used for the upcast, through which all vitiated air passes to the main ventilation fan. Quantity of air passing up the shaft is 400,000 cu. ft. per minute. The air is highly saturated during the summer weather and slightly less...

Jan 1, 1947

IN carrying out experiments to determine the amount of metal taken away by fume or fine dust the apparatus used requires to be strong and compact, as it is generaIIy necessary to work on a staging fixed at considerable distance above the ground and against a smoke stack or flue. It is essential that the test be carried out at a part of the stack welI away from any bends, to prevent eddies. The method described below has been used for estimating the dust losses from Dwight & Lloyd sintering machines, antimony drossing furnaces, pot sintering trials, etc., and has been founc! satisfaetory. It is welI to bear in mind that the longer the period over which dust coIIection is extended, the more valuable the result is likely to be. The rateof aspiration of the gases through the apparatus is kept as regular as possible by changing the filter thimbles frequently, and the rate of flow should correspond closely with the rate of flow of the gases up the stack.The apparatus required for carrying out a test is as folIows :-{a) Thermometers : two are required, one for taking the temperature of the gas in the stack and one for giving the temperature of the gas in the aspirating drum. If the temperature in the stack is over 400° C., it is advisable to use a pyrometer such as the "Bristol" the couple being standardized before use at about the temperature of the stack.(b) Pilot Tube: The foIIowing sketch (Fig. 1) iIIustrates the principle of the pitot tube. The readings are to be taken in a straight flue, or stack, preferably 20 diam. away from any bend. A, which is open, faces the air current and...

Jan 1, 1922

By J Szymanski, S Planeta

Extensive rockfill cylinder testing was performed to determine the effect that aggregate size, aggregate moisture, Portland cement, fly ash and cement dispersant addition has on compressive strength of a cemented backfill. In this paper ætwo-level factorialÆ and æcentral compositeÆ designs were used to determine the single and interaction effects that each factor have on the overall strength. The results from the designwork indicated that the per cent of aggregate fines had the greatest influence on the compressive strength of the rockfill cylinders. From the factorial design results, a compressive strength estimation equation was derived, which enables the strength to be estimated, given varying input values.

Jan 1, 1998

By Spencer PA, Winborne DA

The Porgera mineral deposit in Papua-New Guinea contains gold as finely divided, probably submicroscopic (1 um) particles dispersed in a pyrite sulphide matrix. Only 25-30% of the gold in pyrite can be extracted by direct cyanide leaching and fine grinding the pyrite does not increase gold extraction significantly. This work is concerned with the application of alkaline leaching at atmospheric pressure to oxidise the pyrite prior to gold recovery by cyanidation. The paper presents and discusses results of a comprehensive set of testwork using sodium carbonate, sodium hydroxide and calcium hydroxide alkaline media. Best results, at 60-70% gold extraction, were obtained with sodium hydroxide systems.

Jan 1, 1984

By Troman L, Groutsch J. V

The Kwinana Nickel Refinery began operations in 1970 processing sulphide concentrates from Kambalda using the Sherritt Gordon pressure leach and hydrogen reduction process to produce nickel metal as powder and briquette. Over the years a number of changes have seen the refinery capacity increased from the original design capacity of 15 000 tpa nickel on an all concentrate feed to its current design capacity of 42 000 tpa nickel on an all matte feed. This paper outlines the changes in plant equipment and process for the most recent refinery expansion from 35 000 tpa to 42 000 tpa which have been implemented since 1992.

Jan 1, 1996

Spiral separators have been used to treat heavy mineralsands in Australia for some 35 years. During the last five years the logical extension of this technology has been torecover cassiterite from alluvial deposits. Plants incorporating spirals are already operating in Indonesian andAustralian tin mines. A more fundamental understanding of the design of spiral separators has recently led to their use in other mineral treatment plants.In particular, the treatment of alluvial gold and fine coal has been most successful. The new generation of spirals that has been developed to treat these minerals is more easily operated than other competing processes and is therefore ideal for new mine situations.

Jan 1, 1986

By A Minns

This paper provides details of Newmont AustraliaÆs group water usage quantities, qualities and typical efficiencies, together with details of the approach employed to undertake mine water management reviews, including examples of identified opportunities, implemented projects and quantified water usage efficiencies achieved to date.

Jan 1, 2003

By Coppock BW, Scott TC, Firkin GR

The pollution control measures taken on the Imperial Smelting Process (ISP) operated at Cockle Creek are described together with environmental monitoring strategy and the statutory restraints applied in New South Wales. An outline of developments in the gaseous, liquid and noise control areas is given.

Jan 1, 1975

By W A. Tchernykh, R P. Strelnikova

In connection with the fact that technology of ore mining by caving system is often used when mining of deposits, characterising by low stability of surrounding rock mass, the main problem for such ore mines is ensuring stability of mine workings, placing in a zone of influence of winning operations. Besides natural disturbance of ore mass, stability of workings depends on the dynamic effect of blasting operations and also on the dynamic effect of structural blocks detaching from the ore mass and colliding with crests of ore pillars in the bottom of a chamber. Decreasing of dynamic stresses may be achieved by way of creation of a compliant porous screen or an ore cushion in the chamber bottom. It is established that maximum levels of compression take place when the first impact impulse occurs, and after that increase of compression of protective slice decreases. Necessary thickness of screen slice was substantiated theoretically with due account of height of structural blocksÆ fall, their mass, deformation modulus of ore mass and ore cushion.

Jan 1, 2003

By E G. Thomas

"This paper details the many improvements possible in narrow vein mining from the use of treated mining/milling waste as mine fill. Such fill can be: treated mill tailing, cemented or uncemented; development muck, treated or untreated, cemented or uncemented; andsome combination of these materials, or surface sands/gravels. Treatments involved may be both physical (optimisation of particle size gradings) and chemical (neutralision of potentially harmful milling chemicals).Potential benefits include a reduction in: back stress; vein closure; alternate ground support requirements; mining dilution; potential for surface subsidence; and extent of surface disposal of mining/milling waste, resulting in reduced environmental impact. Considering the usually small production tonnages involved, preparation and placement of a highly applicable fill material can be economically accommodated.Emphasis is placed on steeply dipping orebodies being mined overhand, although practice in the much less steeply dipping RSA gold/platinum-type orebody is also considered.CITATION:Thomas, E G, 2012. Mine fill in thin vein mining, in Proceedings Narrow Vein Mining 2012 , pp 215-218 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By Letz H

An investigation of earthquake hazard in Papua New Guinea (PNG) by a yearly extreme magnitude method using the magnitude 7 earthquake record since 1900 shows that the Bougain-ville Island seismic zone is by far the most active, followed by the New Britain and northern mainland PNG regions. Return period for magnitude 7.0 earthquakes occurring in normalized 10,000km2 areas of the Bougainville Island, New Britain, Huon, West Bismarck, North Sepik and Ramu seismic zones is 37, 60, 81, 88, 125 and 125 years respectively. These areas are much more active than the California Seismic Zone 4 region including the San Andreas Fault, which has a normalized magnitude 7.0 return period of 299 years, calcul-ated here by the same method.Only southern PNG, including the Papuan Fold Belt and most of the Bismarck Sea, are less active than California Zone 4. The Papuan Fold Belt is only marginally less active than California Zone 4, but more active than the State of California taken as a whole.

Jan 1, 1994

The Argyle AK1 Pit has been operating and producing over 25 per cent of the worldÆs diamonds by volume for over 20 years. The mining boom in Western Australia is creating upward cost pressures to ArgyleÆs mining operation while the price received for its product remains flat in comparison to many other Western Australian commodities. This incongruity, which when combined with other circumstances such as the pit being close to the end of its mine life, a decline in head grades and a tightening in operational constraints caused by the pitÆs maturity, is causing the leadership team at the mine to utilise innovative strategies in order to ensure that the open pit continues to perform economically until its final closure in late 2010. The strategies that will be discussed in this paper are step change business improvement methods, localisation of the workforce, employment of Aboriginal people and the use of a clear and concise consultation process in order to provide certainty to a workforce working in a pit during boom times where pit closure is imminent.

Jan 1, 2007

One of the more recent developments within the mining industry has been the adoption of formal continuous improvement programs. A continuous improvement (CI) program was launched across Kalgoorlie Consolidated Gold Mines (KCGM) in early-2002. The purpose of this program was to identify further operating improvements within departments. The focus of the continuous improvement program was not only on the areas of the operation which were performing below expectations but also on areas of the operation which were performing well but could still be further improved.The effectiveness of a continuous improvement program depends on the stability of the processes in place and the participation of many employees from all levels of the business.Continuous improvement has had some successes and failures at KCGM and this paper will discuss both within the open pits department. Further improvements that could be made to the process will also be discussed. Kalgoorlie Consolidated Gold Mines Fimiston operation is located in the Kalgoorlie Goldfields and it the largest gold mine in Australia producing over 800 000 ounces of gold per annum.

Jan 1, 2004

By P Mavros, K A. Matis, N K. Lazaridis

A large number of techniques are in use today to limit membrane fouling, among them certainly is air bubbling (which constitutes the transport medium in flotation) as applied in wastewater treatment; meanwhile, dispersed-air flotation is suitable as a pretreatment stage for microfiltration. The invented and investigated hybrid cell combines the advantages of both flotation and membrane separation, while overcoming their limitations, producing clean water from industrial wastewater. Metals recovery from dilute aqueous solutions is a promising application of this innovative hybrid process of flotation and microfiltration, further to solid/liquid separation. In this study, ceramic flat-sheet membrane modules were inserted inside a typical flotation cell in the laboratory tests, using multichannel geometry, combining flotation with microfiltration by submerged membranes; the latter requiring periodic backflushing. The specific objective was to apply this process for the efficient separation of effluents containing metal cations (here, zinc). The main examined parameters were: the initial metal concentration, flotation surfactant applied and air flowrate. The successful contribution of precipitate flotation was highlighted, while the observed metal removals were of the order of ~100 per cent.

Jan 1, 2005