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By J Ralston, R Sedev, D Fornasiero

The foam behaviour of low molecular weight polypropylene glycols (PPG) was investigated as a function of concentration and molecular weight (190 - 2000 g mol-1). For each polypropylene glycol, foam stability increases with concentration and passes through a maximum, beyond which foamability is suppressed as the solubility limit of the glycol is exceeded and droplets of glycol form. Light scattering data as well as static and dynamic surface tension results provide the key information leading to these interpretations. A maximum in foamability was observed for the PPG molecules with increasing molecular weight (caused by a change in molecular conformation at the interface). This suppresses the Marangoni effect and leads to a decrease in foam stability.

Jan 1, 2005

By S Arya, A Bhandari

Dust emissions by blasting are of concern to both mine operators and surrounding communities. The quantity of dust produced, and the effects of its dispersal depend substantially on geological, blasting and meteorological conditions. This paper provides details of methods used to quantify the amount of dust produced after collecting samples using high volume dust samplers, and the difficulties encountered in satisfactory dust sampling and quantification. Also described are practical dust reduction methods by using water filled ampoules and water filled balls.

Jan 1, 2004

By Ryan CG, Cousens DR, Suter GF, Griffin WL

A novel method utilizing PIXE with microbeams following fire-assay has been developed to determine PGE and Au at sub-ppm levels suitable for application in exploration. Analyses of the prills from the lead and silver fire-assay yield Pt, Pd and Au concentrations readily. NiS must be used as collector if the complete suite of PGE is required, but this method is not as Convenient.

Jan 1, 1989

Computer modelling is being used to simulate rock fracture, caving and stress redistribution about longwall panels with increasing confidence. The models are being assessed against field monitoring and have significantly increased the understanding of caving mechanics within the overburden. This paper discusses the modelling approach and provides some examples of its application to overburden damage and induced hydraulic conductivity. Computer models used in this study simulate the fracture process in the geological units throughout the overburden. Analysis of the mining induced fracture patterns and in situ joint patterns allows an estimation of the hydraulic conductivity within the overburden. The cubic flow relationship has been used in the examples presented.

Jan 1, 2005

By H R. C Pratt, G W. Stevens

Hydrodynamic and mass transfer performance are presented for a 72.5 mm diameter pulsed disc and doughnut column of the type used by Western Mining Corporation, Olympic Dam Operation, for the extraction of uranium from sulphate media using Alamine 336 as extractant. For the present purpose, 4.0 g/L sulphuric acid was used as solute. The mass transfer data were interpreted in terms of the diffusion model, thus accounting for continuous phase axial dispersion. The results indicated that an efficiency corresponding to approximately one transfer unit over the 1.0 m height of the column was obtained. This efficiency is comparable to that observed by Gottliebsen (1997) for a pulsed perforated plate column using 173 gm/L sulphuric acid.

Jan 1, 2000

In the past five years, there has been an evolution in the assessment and control of mining risks in the New South Wales coal mining industry. This change has involved the development and use of structured, systematic, team-based risk assessment exercises to identify, assess and control unacceptable risks to people, equipment and production. The outcomes have improved the management systems in the mine. This paper discusses the evolution of the risk assessment approach in equipment design and mine operations, as well as the specific risk assessment methodology. The paper also presents the reactive side of risk management, the method of investigating failures in the management system, usually referred to as incidents or accidents.

Jan 1, 1994

The metallurgical works of the Electrolytic Zinc Company is situated on the Derwent Estuary, approximately five miles north of the city of Hobart and near a relatively dense housing area. Zinc concentrates, consisting chiefly of zinc and sulphur, have been roasted at Risdon for 53 years;- recently at rates of 1, 100 tons per day. The zinc content of the ores is converted to zinc calcine (ZnO), which is a dusty material. The calcine is leached with acid to form zinc sulphate, which is then electrolysed to make zinc. The sulphur is oxidised during roasting to sulphur dioxide, part of which is converted to sulphuric acid and part is dissolved in estuarine water which is then discharged to the Derwent Estuary. Photographic slides were exhibited showing the unaffected green flora of the nearby hills, of clear exit stacks, of green lawns, and of a w ll lrcnt nines hnlP anlf nniir.qa within the Wnrka hnnnrla_rv_

Jan 1, 1971

By Walker G. S, Sparrow G. J

Dissolution of S02 into water-acetone mixtures results in the formation of 2-hydroxy-2-propane sulphonic acid. The pH, or acid strength, of water-carbonyl-S02 mix- tures can be controlled by varying the concen- tration of the carbonyl compound or the rate at which S02 is added to the water-carbonyl mixture during a reaction. The ease with which the acid strength of these mixtures can be controlled means that they have significant potential for use as a selective lixiviant. We have used water-acetone-S02 mixtures to selectively dissolve phosphate minerals in Christmas Island and Duchess phosphate ores and also uranium minerals in Yeelirrie uranium ore and Olympic Dam copper concentrate.

Jan 1, 1987

Petroleum exploration and development is vitally important for the future well being of Australia. The Australian petroleum exploration/development industry is alive but not so well. A combination of.:factors point to the industry requiring a much more mature effort in both short and longer-term planning to ensure greater success and effectiveness for petroleum discoveries and development. While many petroleum exploration companies are competently run, there are far too many which will be lucky to survive, even though their exploration areas are highly Prospective.

Jan 1, 1983

The curbing of expansion in tertiary level education in Australia and the question- ing of its objectives which are now occurring are likely to have important effects on mining and metallurgical education. Student enrol- ments are low but the serious shortage of specialised minerals industry graduates pre- dicted during the boom of the late 60's has not eventuated. Other manning problems of a less quantitative but possibly equally import- ant kind have been identified. They point to a need for a full and deep review of the education and training programmes available to Australian graduates planning to enter product- ion areas of the minerals industry. An alter- native educational structure providing greater flexibility is suggested.

Jan 1, 1977

The determinants of human behaviour are numerous and complex. Many scientific disci- plines focus on various processes which play some part in shaping the actions of individ- uals and groups. Behavioural science attempts to synthesise data produced by these investigations in an attempt to formulate principles by which people's thoughts, feelings and actions may be described, diagnosed, predicted and changed. While no comprehensive account of people and their reactions can be attempted in a brief paper a review of six principles does provide a framework within which managers can establish reliable knowledge applicable to all their subordinates and to themselves. This information may be used to arrange organizational environments and management practices which enable people to discover, release and increase their best intellectual, emotional and motivational capacities.

Jan 1, 1982

By D Cioclea, I Toth

Coal mining can lead to the occurrence of spontaneous combustion events. If these events are not prevented they can give rise to fires that have major adverse effects on the mine plan. After studying the chemical structure of coal, the theories of self-ignition and of the oxidation reaction of the organic compounds, two new technologies have been developed for fire prevention based on the inhibition of coal oxidation. The first technology consists of spraying water drops mixed with inhibiting substances into goaves. The second consists of the infusion of a mixture made of several chemical compounds. Tests performed in situ showed the new inhibition technologies to be highly effective even for longwalls mining coal with a high reactivity from the point of view of self-ignition.

Jan 1, 2005

Some of the major factors affecting ore reserve estimation in gold mines are discussed together with their impact on computational methods.The major priority in ore reserve estimation is to get sampling and geological problems resolved. Poor basic information cannot be remedied by mathematical methods.Generally the more complex a deposit becomes the greater the need for subjective assessment and the less applicable are more complex ore reserve methodologies.

Jan 1, 1984

Green policies have gained momentum since the 1972 Stockholm Environment Conference. The environmental movement has influenced political initiatives both in New Zealand and abroad. Governments and international institutions have addressed local, regional and global environmental issues with varying degrees of success. New Zealand so far has not supported the United Nations' call for sustainable development in a,consistent manner.New institutions and new rules for resource management mean there are opportunities to look after the land in different and more ecologically sensitive ways than has happened in the past.The increasing influence of regional councils in resource management planning will have important implications for mining and mineral exploration. These trends are discussed and possible future events outlined.

Jan 1, 1990

In considering the architectural design of the group of buildings which make the surface workings of a mine, the variety of function of the buildings is the most outstanding feature. It falls to the architect to unify the group in a manner which still expresses the function of the individual buildings. In achieving this, many perspective studies were made at an early stage and as the area was developed, a scale model was produced initially for design study purposes and later completed as a model of the final development.

Jan 1, 1957

A recently discovered high temperature (22G-2800°C) reaction between glycerol and the oxides and hydrous oxides of iron produces a green, well-crystalline complex glycerato-iron, whereas hydrous nickel oxides an) reduced by the glycerol to metallic nickel. When nickel isomorphously substitutes for iron within the goethite lattice this high temperature glyceration allows a separation of the two metals whereby the nickel can be extracted by solution techniques.

Jan 1, 1971

In both exploration and mining, the laboratory is often seen as a cost rather than a profit centre. The aim in most mining companies is to increase profits by reducing costs, so the budget for the laboratory is under constant pressure.There is another option; to see the laboratory as the brain of the operation. By lifting the status of the laboratory and treating it as a profit centre, mine costs may be reduced in other ways, e.g. reduction in milling costs. This change of status will require investing more capital in better equipment, more training for employees and more employees to carry out project research.There are many examples of major costs being incurred because of inadequate laboratory work. Conversely, by spending more money on laboratories and their activities, overall costs can be reduced or profits enhanced.

Jan 1, 2002

This paper provides a financial perspective to the valuation of Australian resource companies and projects. Valuation exercises need, however, to be seen in the broader context of a thorough business appraisal, one that incorporates all disciplines employed in the resources industry. Fine tuning a discount rate or determining a particular capital structure is likely to be less important to valuation than an adequate understanding of industry dynamics and a company's likely performance in future years.

Jan 1, 1989

By Noble AC

Ore reserve reporting practices in the United States may be broken into four general categories as follows: ò Reserve reports, often of an unofficial and preliminary nature, which are made through the news media. These are often based on exploratory drilling or sampling results. ò Reserve reports made for the purpose of raising public funds by issuing securities on the stock market, or as part of other filings to the United States Securities and Exchange Commission. ò Reserve reports to obtain private funds from banks, financial institutions, or other investors. ò Reserve reports for internal use and planning by companies operating or evaluating mineral properties. This paper discusses current practices for each of these types of ore reserves reports and reviews recent changes which have affected those practices.

Jan 1, 1987

The theme of this Annual Conference of The Australasian Institute of Mining and Metallurgy is in the form of a question: `Adding Value to our Resources - Our Future?' There are two ways of looking at this question. The first is to assume that any mineral or energy resource is worthless until it is identified, recovered and put on the market. In this sense all our current operations, be they open cut coal mines or aluminium smelters, are engaged in adding value. The question then becomes: what is the future of the minerals and energy resource industries with which we are familiar - will they grow or contract? The second way is to emphasis the value-adding aspect. The question is now one of whether or not our future depends on adding further value to resources we are currently selling.

Jan 1, 1995