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By S Marsters

Imerys Tableware New Zealand Limited has mining rights to four deposits of halloysite, which are located about 203 km north of Auckland, New Zealand. These primary deposits were formed by the hydrothermal alteration and weathering of rhyolite domes. Halloysite clay is currently being mined from two of these deposits and then processed for export markets. From humble beginnings in the mid 1950s, the Northland halloysite was processed initially for paper filler markets and then for higher value tableware and technical ceramic niche export markets. The paper will briefly cover the geology and processing of halloysite and then examine the history of New Zealand China Clays Limited, now Imerys Tableware New Zealand Limited and then look to its future as part of global industrial minerals company, Imerys.

Jan 1, 2002

By A S. Ray, P S. Thomas

The characterisation of the surface area and porosity of opals derived from Tintenbar, a volcanic environment, and Lightning Ridge, a sedimentary environment, using nitrogen gas adsorption at -196¦C is reported. Both opal types were found to have relatively low surface areas and displayed little porosity. The low surface areas observed is indicative of the ability of silica to infill voids and interstices. Thermogravimetric analysis of the samples before and after degassing was carried out to determine the amount of water removed by the degassing process. Negligible difference was found in the water content before and after degassing in the case of the Lightning Ridge sedimentary opal, while the Tintenbar volcanic opal was found to have lost more that 60 per cent of its water during the degassing process. These differences were ascribed to the differences in the silica structure of the opals with the Lightning Ridge opal having a denser cage structure, which traps the molecular water, while a more open structure is postulated for the Tintenbar opal, allowing the water to be relatively easily removed.

Jan 1, 2008

Legislation, if it is to be effective, must be enforceable by the state and acceptable to the industry. In the mining industry the relationship between the government inspector on the one hand and the mine management and employees on the other, must be one of full co-operation before the system can be effective. To understand our present system, which is-duplicated in most countries of the world, an examination of the history from which it evolved is necessary.

Jan 1, 1975

The arbitration process, and its drawbacks: Any time you have taken part in a major arbitration, and the decision, when it comes out, is not what you thought it would be (which is bound to happen occasionally), the normal reaction is something like æthe arbitrator got it wrongÆ. Again normally, when you have cooled down a bit, and you look in more detail at the decision, you can see, probably, æwhere he got it wrongÆ (it is only male arbitrators who get it wrong). Ultimately, when reason prevails, and you reflect on it, you can see that what really happened was that you failed to get the arbitrator to see what you were getting at in the point or points concerned. This is doubly frustrating, when you consider what has been involved in getting to this point, having been through it all at least twice. An alternative to this process may be the dispute review board.

Jan 1, 1999

The various functions of public relations are playing an increasingly important part in the activities of the many companies now engaged in oil exploration in Australia.Several of the larger exploration companies, notably West Australian Petroleum Pty.Limited, Ampol Exploration Limited, Caltex Oil (Australia) PtSr: Limited and Australian Oil and Gas Ltd. (and its American Associate Union-Kern), employ staff or consultant public relations specialists. In, most of the other companies now exploring in Australia, public relations are handled within the company, directed from the highest executive level.The object of public relations in.the oil industry is. to create in the public mind an impression favourable to the industry as a whole and'the company -or group of companies with which the public relations officer is associated.

Jan 1, 1962

In presenting the paper, Mr. Davey quoted subsequent work which yielded k, at miscibility gap composition, of about 50.We can confirm the authors' findings for k j 300 for nearly pure tin to k 2 about 50 (average 47) from our own experience and from repeat experiments on materials described by the authors, at 1150°C.During laboratory-scale trials we also found confirmation of the authors' view that it is more difficult to reach equilibrium from the high-iron (in slag) side than from the low-iron (high-tin) side. Working from the high-iron side tends to yield results that point to a high k, leading to optimistic values of iron/tin ratio in final slags. In practice the smelting of a tin concentrate, unless it is exceptionally low in tin and high in iron, must yield initially a tin-rich slag and therefore equilibrium can only be reached from the "tinny" side.

Jan 1, 1967

By Arndt MB, Bamberg S

The evaluation of risk is becoming more important in the siting of mining operations in the United States as well as the rest of the world. The determination of environmental, economic, as well as health and safety risks is an important step in the planning of any mining operation. Hydrogeology plays an important role in pre-mine planning and in the determination of these risks. The mine operators must determine if ground water would inhibit mining in any way. Factors which are important to consider include mine dewatering economics, slope stability, and other adverse hydrologic impacts. This paper presents methodologies for the characterization of hydrogeological risks for a mining operation. First of all, the term risk analysis is defined and its utility is addressed. Then, stepwise methods for performing a typical risk analysis are presented. Finally, the application of risk analysis to hydrogeology in mining is given. With slight modification, it is believed that these methodologies can be used to evaluate the hydrogeological risks for any mining operation.

Jan 1, 1988

This paper describes the characteristics of blasting which set it apart from other methods of breaking rock. The mechanism of rock breakage and the influence of rock proper- ties are then discussed. The strain and fragmentation produced by a cylindrical charge does not change once the charge is longer than 16 blasthole diameters. The influence of bench geometry, charge length and drill diameter are then examined. It is shown that spherical charges have advantages over long slender cylindrical charges. By selection of the appropriate drill diameter, explosive and charge configuration the optimum blasting practice for a given rock to give suitable fragmentation and muckpile profile for sub- sequent handling can be found. The fragmentat- ion depends not only on rock and explosive properties but also on the pattern which dictates how effectively the cracking is utilised. The size distribution of the fragments is given by the Rosin - Rammler equation. Undesirable cracking of the rock in the final wall can be controlled by the careful design of blasts as they approach the final wall. Finally, it is concluded that because of the distance to which blasting can fracture and then displace rock it is suited for the breakage of large volumes of rock.

Jan 1, 1978

By King CJ

The C.S.A. concentrator of Cobar Mines Proprietary Limited was expanded in 1974 to treat 80 000 tonnes of copper-lead-zinc ore per four week period. Jaw crusher product is fed to two par- allel primary autogenous mills followed by a secondary ball mill. Each mill operates in closed circuit with cyclones. Improved control of grinding rate and product sizing has been obtained from this circuit compared with the system of two parallel single stage autogenous mills. The main operational variables are des- Cribed.

Jan 1, 1978

By S Tavelli

This discussion will present a case study in developing solutions to a metropolitan quarryÆs public relations, legal, environmental, and productivity problems. It details an extensive and detailed project to address the blasting practice in a medium sized quarry that is surrounded by residential and industrial zones. The principle work was done over four months duration during the normal production season. It included detailed drilling and blasting audits for baseline information. In addition, geologic characterisation, seismic modeling, correction of deviations from best practices, and implementation and monitoring of precise electronic timing to provide dramatic solutions for the quarry. The quarry is in the near suburbs of a large metropolitan city. It is framed on two sides by residential municipalities and on two sides by industrial zones. At the start of the project, the quarry was in court as a result of the lawsuit by one of the neighboring towns that was suing to close the quarry. The lawsuit had progressed to the advanced stage where in the Judge had appointed an arbitrator to make the decision of continued operation. This arbitrator was to observe our progress and recommend to the Judge the disposition of the case.

Jan 1, 2004

Lihir Gold Mine is situated in a dormant volcanic caldera on a small island off PNG. Not æextinctÆ but dormant. Current ground temperatures are up to 150 degrees Celsius with active geysers in the workings of the mine, pools of boiling ground water adjacent to low-grade dumps and hydrogen sulphide gas emissions. It is a unique mining environment by world standards. This paper will deal with the following issues encountered and managed by the operation:blasting in hot and reactive ground; management of sulphide gas emissions; disposal at sea of all mining waste rock; one dear to all Australian minerÆs hearts û dealing with landowner groups; and unusual human resource issues.

Jan 1, 1999

By M Yvon, S Parkes, K P. Galvin, P Wang

Mineral liberation is critical to maximise the grade and recovery of nickel, however this objective is challenged considerably by the poor flotation kinetics, especially that of ultrafine particles (Kelebek and Tukel, 2018; Multani and Waters, 2019). High recoveries demand long cell residence times and hence a large flotation capital expenditure (Wills and Finch, 2016). However, this leads to excessive entrainment of gangue minerals, thus negating efforts to depress its recovery. This study aimed to investigate new hydrodynamic approaches to improve nickel flotation, focusing primarily on unrecovered nickel from a Western Australian tailings stream. Mechanical cell flotation experiments were conducted to understand the flotation kinetics, covering different size ranges. A novel Reflux Flotation Cell (RFC) was also used to improve the nickel recovery and reject the silicates. Future work aimed at applying the RFC to different size portions is also outlined.

Aug 24, 2022

Offshore petroleum development involves massive capital expenditure and financing demands, with the main participants being large international oil companies and State owned enterprises. Types of project oriented financing include take-or-pay contracts, throughput agreements, and production payment financing. The main project finance credit aspects are revenues, investment budgets and cost over- runs, reservoir, political and other risks and special problems such as weather and corrosion in the North Sea. A variety of documents is required and a mix of equity, export credit and Euro-market financing will typically be included in the financing.

Jan 1, 1983

By Satayev IS, Shepelev DV

Various ways for applying the X-ray fluorescent method to process lump-by lump separation of secondary aluminium raw materials (scrap, slags, waste) as well as ferrosilicon and ferrochromium are being considered and physically demonstrated. A commercial X-ray radiometric sorter has been developed for processing secondary raw materials. Marketable quantities of aluminium scrap with appropriate copper and zinc content have been produced for smelting with a minimal additional of pure aluminium. An industrial complex for scrap processing, incorporating two X-ray radiometric sorters from the Hammermils company is successfully operating at one of the works in Russia.

Jan 1, 1993

By Phillips H. R

The action of free rolling disc cutters is well understood, relationships between disc geometry and performance having been established both in the laboratory and under field conditions. However, under severe operational conditions a malfunction of the disc bearing assembly is likely to produce a definite change of cutting action. Collapsed or siezed bearings can even prevent the disc from rolling and thereby create what is equivalent to a drag pick. This paper describes a programme of laboratory experiments using deliberately stalled discs. Their performance under such conditions is contrasted with that for a free rolling disc and also with a drag pick having a ridged front developing into a negative radiused back clearance angle. In conclusion an assessment is made of the influence stalled discs can have on the torque and thrust requirements for a tunnel boring machine.

Jan 1, 1981

By Hannington MD

On the southern flank of Lihir Island, a group of three volcanic cones were discovered at water depths from 1000-1500 m. The volcanoes are located in a narrow zone of recent seismic activity and elevated heat flow (up to 100 mW/m2). The recovered rocks consist of fresh alkali-olivine basalts, clinopyroxene-rich basalts, and porphyritic phlogopite basalts. One of the volcanoes has a recently erupted ejecta blanket (recovery of warm ash!), containing a suite of abundant mafic to ultramafic xenoliths. These xenoliths appear to represent a unique cross-section of subduction- modified mantle material sampled by volatile-rich primary fore-arc magma during its ascent to the seafloor. The most spectacular finding was the discovery of an active hydrothermal system with associated vent fauna and mineralization at Edison Seamount, and the recovery of unusually gold-rich (up to 43 ppm Au) hydrothermal precipitates in 1050 m water depth at the top of Conical Seamount, only 25 km south of the world-class epithermal Ladolam gold deposit on Lihir. The discovery of submarine hydrothermal vents associated with highly alkaline, quartz-undersaturated fore-arc volcanics represents a significant departure from similar hydrothermal systems on the mid-ocean ridges and in back-arc basins. The high gold grades in hydrothermal precipitates at Conical Seamount may indicate the first documented example of a shallow-marine epithermal system analogous to those known on land, and has important implications for the gold potential of submarine arc environments.

Jan 1, 1995

THOSE who dabble in m.ining are no exception to the general rule that persons who know a little of a subject are apt to think that they know all about it. Some colour may be lent to the belief that anyone may succeed in mining when we hear stories ofsuccessful diggers and others who have accidentally dropped on to something good through no foresight on their part; but we seldom hear the contra account of the far larger number who fail. Those who go more thoroughly into the subject, and take up mining as a profession, know very well that it is not one that can be carried out successfully by rule of thumb, but when they point this out to the public they are credited with trying to make it a closed profession; and outsiders are for ever trying to find out the 'trade secrets,' at the same time spurning the main one, which is hard study, experience, and the ability to apply their knowledge.The average mining man is not rich. When he amasses a fortune it is generally through speculation rather than professional work, thought no doubt his technical knowledge may have assisted him. However, making a fortune and running a mine are twodifferent things.

Jan 1, 1911

Successful management is ultimately measured by return on shareholders' funds. This is the inescapable and inexorable discipline that ultimately rules every investment. Shareholders today are predominantly, and increasingly, the superannuation funds and insurance funds of almost all of us. We have already reached the situation in Australian investment history in which the best interests of employees can be very directly identified with the best interests of the owners of the capital invested.

Jan 1, 1992

The detailed engineering of a coal preparation plant is important from the point of view of optimum constructibility, operational security, ease of maintenance, operating costs, meeting environmental goals, safety, plant housekeeping and reduced corrosion and erosion. This paper reviews the several large coking coal preparation plants engineered by Fluor Australia in the past 10 years, and changes and trends apparent for detailed engineering of future plants. Areas of engineering to be covered are coal feed preparation, conveyor design, plant layout, electrics and instrumentation, noise attenuation, erosion and corrosion protection, magnetite handling, rejects and tailings disposal and coal stockpiling and blending.

Jan 1, 1982

By Stubbs B

In conjunction with Charles Copeman, we have arranged the presentation of a paper by Charles with a support paper by myself presenting alternatives to currentaccepted legal concepts involving the ownership of minerals by the Crown and the absence of ownership in any minerals or entitlement to benefit therefrom by the owner of the land on or under which the minerals occur.2. The current situation has its historical route in the concept of gold and silver being royal metals and belonging wherever situated in the Kingdom to the King and it is submitted it can be'seen as being archaic in nature perhaps even feudal and perhaps worthy in this day and age of reconsideration.Our purpose in these papers is to present an alternative view supported by argument challenging the present system and hopefully, creating room for comment and interchange amongst those involved in the industry. My solutions are not Charles Copeman's solutions and vice-versa. However, we do share a common belief that the present system may not be the best system.

Jan 1, 1990