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External pressures are being exerted on busi- ness, and especially the mining and energy in- dustries, as never before. These pressures are burdensome, they emerge in unique forms, and they constitute an entirely new operating environ- ment for business. They pose one of the signi- ficant challenges to senior management today. To cope with these pressures-which we have termed the new public realities-we must deal more effectively with the media, the public, and government. However, before examining methods for improvement, it is essential to understand the nature of these new public realities and par- ticularly their determinants-the underlying eco- nomic, sociological, political, and international events and trends which have shaped them. Previously the productive element of society had only to concern itself with what might be termed `conventional realities' : the costs of labour, equipment, and land, as well as marketing and distribution factors.

Jan 1, 1978

The Goldfields extend from Norseman in the Eastern Goldfields to Marble Bar in the Pilbara; a distance of approximately 1,500 km. (Figure 1). Tailings dams are conspicuous on the relatively flat and featureless Goldfields' landscape. They impound wastes from mining and processing operations. Tailings dams interact dynamically with their environment and progressively consolidate as water is removed. Water recovery systems have been used over the last decade to improve water conservation, increase dam stability and to extend the service life of the dam. Without water recovery, dams would need to be significantly larger to permit the tailings to dry back sufficiently to support subsequent depositions. The paper reviews inter-relationships between the tailings dam and its environment and discusses water recovery systems, that are commonly used. The effectiveness of water management is illustrated by reference to seasonal water recoveries measured by Western Mining Corporation (W.M.C.) at their number 2 dam at Kambalda.

Jan 1, 1988

By Taylor R. K A, Berglin C. I K

The manganese ore deposits at Groote Eylandt are quite variable both in regard to grade and physical cond- ition. In order to treat a wider range of these ores and to increase production a new primary-crusher and' concentrator complex costing $8 million has been installed and commissioned to treat ore at the rate of 12,000 tonnes per day. The initial testwork carried out to determine the method of the ore treatment required, and on which the design of the concentrator was based, is detailed. The flowsheet and equipment used is discussed together with the operation of the plant. The production achieved and product qualities obtained are given.

Jan 1, 1973

Performance trials followed the commissioning of three large mine fans at Mount Isa in 1965. Actual performance characteristics were determined. These were in good agreement with predicted performance. Piezometer rings for volume flow and pressure measurement were calibrated, and the performance of some aerodynamic components of the installation was studied.Test equipment, preparation, and conditions are described.

Jan 1, 1967

By Rogers J. F, Bird A. C

The establishment of vegetation for dust control on tailings dams at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited (ZC/NBHC) is outlined. The evolution of practices and techniques employed is described and the problems encountered are discussed.

Jan 1, 1983

By Stein A

The general mechanism of recrystallisation for cold worked metal is well established, and need be only briefly summarised with a few references to recent articles which clarify minor points. The types of extension, whether by stretching, drawing, hammering, rolling, etc., do not alter the general principles (1), although quantitative results may differ somewhat, particularly with regard to differences between the surface and interior of samples.These principles can be summarised as follows: The first stage in annealing is a recovery (sometimes known as relaxation) of physical properties such as hardness, elongation, etc., without any appearance of recrystallisation; the second stage involves a further alteration in physical properties, accompanying the formation of new recrystallised grains which replace the original structure; a possible third stage involves an increase in the grain size of the completely recrystallised structure by absorption of smaller grains by larger ones. These three stages will be referred to as recovery, recrystallisation, and grain growth. Depending on conditions, the three stages may be clearly marked or may occur more or less simultaneously.For a given annealing temperature, cold deformations below a certain amount fail to give recrystallisation, and the final structure consists of the original grains which have recovered and possibly become more equiaxed. When a certain deformation, critical for that annealing temperature, is given, recrystallisation can occur, and will give the maximum recrystallised grain size.Increasing deformations beyond this give progressively smaller grain sizes.For each material there is a minimum recrystallisation temperature, below which recrystallisation will not occur whatever the deformation or time of annealing. For a given deformation there is a temperature, critical for that deformation, below which recrystallisation will not occur, and above which it will take place with increasing rapidity.

Jan 1, 1947

Perhaps the only thing certain about an address that purports to look into the future of any human endeavour is that time will prove it :.o be inaccurate. In undertaking the dubious, but oft-times necessary business of prediction, thr, historian will base his/her forecasts on tr-ands of the past, the speculator on current events, and the politician on what he/she would dearly like to see happen. The thoughts expressed in this address seem to have arisen through exercising a combination of all three of those philosophies but, hopefully, with a smat- tering of pragmatism.

Jan 1, 1988

By Bhattacharyya A. K

In this paper, the current methods for predicting surface subsidence due to underground coal mining are evaluated first. A single index, called a strata parameter (P), is then proposed to describe the overall character of the undermined strata in the context of surface subsidence. Based on the strata parameter, a method for predicting the maximum surface subsidence for various panel width (w)/depth (h) ratios is presented, which has been tested against specific empirical curves or data from several coalfields in different countries. From the data relating to several coalfields, a linear relationship between the reported average angle of draw and the strata parameter has been established. It has also been found that the strata parameter can be used for studying the locations of the inflection points and the shapes of transverse subsidence profiles.

Jan 1, 1995

By Ritchie IC

Spiral separators have been used to treat heavy mineral sands in Australia for some thirty-five years. They were used as the primary treatment method until the advent of the Reichert cone, which largely replaced them, due to its compact design and relative ease of operation. Spirals continued-to be used as the final cleaning stage before dry separation of the heavy minerals as they remained the most efficient separator for this purpose.

Jan 1, 1986

Ore petrology will fundamentally determine the types of metallurgical processes employed for ore treatment, their operational efficiency and the nature of processing problems encountered. It is therefore paramount that the petrological charact

Jan 1, 1998

By Rankin W. J

Increasing concern with the emission of sulphur dioxide from smelters and roasters has caused renewed interest in processes which can use waste sulphur dioxide, such as the sulphation of nickel laterite ores. The process described here proposes to by-pass the production of sulphuric acid and react laterite directly with a sulphur dioxide containing atmosphere. A thermodynamic analysis identified operating windows in which nickel sulphate forms while iron oxide (the major impurity in most laterite ores) remains stable. The initial assumptions included unit activity of all species except nickel oxide. The lowest possible nickel oxide activity (while maintaining selectivity) increased with increasing temperature, indicating that selective sulphation is favoured by low temperatures. The temperature of interest was found to be between 500 and 800¦C. Calculations show that a feed gas containing ten per cent SO2, five per cent 02, balance N2 requires a temperature greater than 650¦C for selective sulphation of nickel. Laboratory experiments showed that the assumption of unit activity of ferric sulphate was unrealistic above about 680¦C due most likely to the formation of solid solutions which decreased the ferric sulphate activity. Results are presented which illustrate the limiting equilibrium sulphur trioxide partial pressures at 700 and 730¦C below which selective sulphation occurs. Cobalt extraction was usually between 80 and 95 per cent under conditions yielding selective sulphation, whilst nickel extraction was about 50 to 75 per cent depending on temperature and choice of upper limit of iron extraction. An operating diagram is presented for a limonite ore and shows that the optimum reaction conditions are 680¦C and an input gas containing 20 per cent SO2. Under these conditions nickel, cobalt and iron extractions are 73, 95 and two per cent respectively.

Jan 1, 1996

By Falconer A. J

Two magnetic parameters are proposed as a basis for the assessment of ironsands beneficiation. The parameters are deter- mined for raw sand prior to dredging and for magnetic separator head feed over a production period of five months. The relationships between these parameters and the performance of the magnetic separators are examined to establish the value of magnetic assessment compared with the traditional soluble iron assay method. The results illustrate that the first parameter, true magnetic fraction (TMF), has a value superior to that of soluble iron when relating raw sand grade calculated by tri- angulation to magnet performance. In terms of the relationship between magnet head feed grade and magnet performance, TMF and soluble iron perform equally as assessment parameters. For the ironsands mined during the five month period, the second magnetic assessment parameter, composite fraction (CR), is shown to merely reflect TMF and offers no additional information for assess- Ment. Conclusions are that true magnetic fraction has many advantages over soluble iron in terms of time and cost of determination and that it is a meaningful and reliable parameter upon which to base all calculations relating to the mining and beneficiation of ironsands.

Jan 1, 1980

In order to maintain an accurate survey underground, it is first necessary to connect all shafts used for the transferring of the survey to the levels below by a precise surface survey.This has been achieved at Mount Isa by a careful triangulation survey with stations adjacent to those shafts most suitably located for transferring the survey below.The precedure used is described herein.The Weisbach triangle commonly used is obtained by reading to swingirig wires, the theodolite being placed in line with them as nearly as is possible. The surveyor at the surface places the wires in the shaft as far apart as the size of the shaft will permit, with sufficient space between the wires and walls to ensure their swinging freely. The far wire is fixed in position, while the near one is movable by means of fine adjusting screws to facilitate its being brought into line with the fixed wire and the theodolite. When this is done the surveyor at the lower level is advised by pre-arranged signals and the survey can then commence.The surface portion of the survey is simple; all that is necessary being to read the angle from the backsight to the wires, measure their distance from the theodolite, and keep a check on them throughout the survey to make sure that no movement takes place.The lower portion of the survey is more difficult, the surveyor first qf all having to place his theodolite as nearly as possible in line with the wires.

Jan 1, 1953

Chemicals derived from petroleum raw materials satisfy so much of our industrial needs today that it is good to pause and realise two things -ò the petroleum chemical industry is so new, and the use of chemicals is a very old one.Petroleum is such an'abundant and convenient source of raw material that in little more than 30 years it has become the major source of supplyfor chemical rdanuf ctiree This paperw~l'l 'disc'uss t1.e main 'r`easons' for this rapid development by considering the : sub jest -under tkzree headings ea. Source of Raw Materials.b. The Impact of Petroleum Chemicals on Plant Design and Processes. ce Scme of the Major Chemicals Used Today.

Jan 1, 1962

Adsorption isotherms, zeta potential and coagulation techniques have been used to exa- mine the mechanism of metal activation on SiO2 and ZnS surfaces. The importance of surface nucleation or precipitation of metal hydroxide coatings is'established and identified-by characteristic charge reversal patterns. The significance of surface coatings in sulphide and non-sulphide flotation is discussed.

Jan 1, 1973

By Muller GP, van Deventer JSJ

A mineralogical analysis has shown that in the Hartebeesfontein ore studied, uranium is associated mainly with uraninite, sulphides such as pyrite and to a lesser degree carbonaceous material such as thucolite. Little could be learned from the literature regarding the mechanism of flotation of these uranium-bearing minerals. A wide variety of reagents were used so that conditions enhancing the flotation of either the sulphides, carbonaceous material, oxides like uraninite, or combinations thereof, were created. As could be expected, the xanthate based floats gave-better selective recovery of sulphides than oleic acid. A substantial fraction of the uranium is associated with pyrite, so that addition of oleic acid to a xanthate float did not enhance the recovery or grade of uranium. After a pre-leach with sulphuric acid in which the pH and Eh were controlled so as to destroy the uraninite, higher uranium recoveries were obtained for the combined float (xanthate, DTP and oleic) and the DTP float. This was most evident when iron was added before flotation. Roasting, which destroyed the sulphides and thucolite, caused a significant decrease in uranium recoveries. The uranium liberated in this way was obviously not flotable in the same way as the uranium liberated from uraninite. A small amount of iron (2 kg/t) added before milling resulted in slightly higher grades and recoveries of sulphur for xanthate based floats. Higher iron additions had a detrimental effect on sulphur recoveries. Even in the case of oleic acid the addition of small amounts of iron had a positive effect on the recovery of sulphur and uranium.

Jan 1, 1993

By Stewart A. M, Price D

This paper presents recent findings concerning longwall caving mechanisms relating to Australian mining conditions and their effect upon longwall support requirements and behaviour. The findings are based on a program of intensive hydraulic support monitoring in a variety of Australian mining conditions coupled with geotechnical observations.

Jan 1, 1992

By Firkin GR, Allen RJ

Sulphide Corporation Pty. Limited has roasted a number of different zinc sulphide concentrates on its sinter machine which pro- duces zinc-lead sinter for an Imperial Smelting Furnace, and results have varied widely. The differences are considered to be functions of !concentrate particle size and reactivity. Amdel have used differential thermal analysis to examine these concentrates and two major effects have been found. Firstly, in concentrates 1containing small quantities of pyrite and chal- L [copyrite, heat is liberated at 400¦C to 650¦C [by oxidation of these two sulphides. Secondly, as particle size decreases, heat release from the oxidation of zinc sulphide commences at flower temperatures and rate of heat release In a sinter bed, the presence of some rite and chalcopyrite would help to heat the cc sulphide to ignition temperature in a orter time, while a finer concentrate would sult in roasting being completed more ickly. Both of these effects result in a arper flame front and minimise the chance heat and combustion fronts being mismatched. is theory is supported by sintering results tained by Sulphide Corporation. As a result

Jan 1, 1975

By Scott B. R

Bougainville's copper mine is located on the west slope of the Crown Prince Range on Bougainville. A high grade copper concentrate is produced for sale to overseas customers. Production planning which was originally based on pilot plant data has developed progressively since commissioning of the concentrator in 1972. Pilot plant data and mine sampling have been supplanted by the correlation of concentrator performance with ore sources, as the basis for short term planning. The influence of accurate sampling is reflected in 1. hourly shift control, 2. the daily milling statement, 3. the prediction of the characteristics of ore from various mine locations, 4. production reconciliation, and 5. the control of copper losses. The mechanical and electrical failures of the original sampling system emphasized the need for a reliable, automatic sampling facility. The development of a pneumatic drive mechanism, which has now been fully field tested, was undertaken.

Jan 1, 1976

By Olden WH

A scheme is presented whereby the complexities of design and operation of a hydraulically powered coalmine support are modelled using the finite element method. This enables predictions to be made of the interaction of the support with its environment in a variety of operating conditions. The model is a two dimensional representation. The modelling scheme was applied in two case studies. In the first, the performance of a four leg support was uprated by increasing the front leg force. The finite element model enabled changes in overall support performance to be verified. In the second case study, the change in lateral force developed by a two leg support was assessed with changes in support operating height and floor foundation stiffness. The modelling scheme is capable of further development with the possibility of extending the model into three dimensions and the addition of control elements that would enable an actual mining sequence to be Represented.

Jan 1, 1992