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By Driver R. C, Moelle K. H R

This paper is dedicated to the memory of our friend Peter McKenzie who contributed much to the knowledge of the New South Wales Coalfields.ABSTRACTA fossil river system was recently mapped over parts of the Southern Coalfield, N.S.W. This river system occurs in the roof strata of the Bulli Seam. Sandstone of a fluvial nature was deposited in its course. The sandstone exhibits strong sedimentary vectorial properties and has a marked influence on strata-control in colliery workings.The sedimentary features analysed indicate an approximate S200W flow direction. Petrological studies reveal a clastic, well-cemented sedimentologically and structurally anistropic rock type. Washouts have been found and isopach maps of both sandstone and underlying roof-strata have been compiled. Relevant measurements were carried out in existing colliery workings and on bore cores.Optical determinations of feldspars revealed the presence of plagiocIase feldspars with few exceptions. Most of the feldspars are altered to clay minerals. It was found that a geographical trend exists in the distribution of feldspars, with more basic plagioclase in the northern part of the field.The source area of the fluvial sandstone lies to the north of the Southern Coalfield.Petrofabric analyses were done on several specimens of the fluvial sandstone. In the vicinity of major disturbances, penetrative fabrics were discovered.Calcites (e, 0112), micas (001), and quartz (crystalIo graphic c) show preferred orientations.

Jan 1, 1967

By W Skinner, C G. Kelsey, J R. Kelly

The iron ore industry has reached the end of an unprecedented period of expansion triggered by China’s demand for iron ore. Lower ore prices have led producers to focus on optimising mining operations while extracting the maximum tonnage from the infrastructure presently in place or from projects already underway. A rising global surplus is expected to further force ore prices down and lead to output curtailments, which in turn will help to restore market balance. However, investment in the development of new resources and the development of new infrastructure will inevitably become necessary. Making the right decisions in relation to future processing infrastructure in a climate of uncertain demand and price volatility will not be as straightforward as in the past, where expanding the scale of a proposed operation has been the answer to ensuring economic viability. Overall cost and environmental pressures particularly in relation to wet processing will dominate the decision-making process. IMP Technologies (IMPTEC) has anticipated the need for a dry low cost processing alternative, which can open the way for the development of lower grade magnetite deposits and ensure the sustainability of processing in Australia. The lower grade magnetite deposits are generally fine grained and require grinding to p80 of 30 to 40 microns. Historically, the cost of grinding to these sizes has been and remains a key factor determining the economic viability of a magnetite processing operation. The IMPTEC Super-fine Crusher and Cyclomag Separator are the key components of a proposed radically simplified dry processing alternative, which addresses both cost and environmental issues. This paper reports on the results of pilot super-fine crushing and cyclomag separation test work, focused on supporting the feasibility of the proposed dry processing route for the production of high-grade pellet plant feed from fine grained low-grade magnetic ores.CITATION:Kelsey, C G, Kelly, J R and Skinner, W, 2017. Dry processing of magnetic iron ores – addressing cost and environmental issues, in Proceedings Iron Ore 2017, pp 215–220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Holdgate G. R, Thompson B. R, Webster R. L, Bolger P. F

The Gippsland Basin in south-eastern Australia has an area of approximately 46 000 sq km. It is one of the world's major coal and petroleum bearing basins, with most of the former occurring in the smaller one fifth on-shore part. The stratigraphy, structure and economic resources of the Tertiary sedimentary pile is now well known through extensive drilling for coal and petroleum. In contrast, the older Cretaceous sequences through their lesser economic importance are relatively less explored. The sedimentational history of the Gippsland Basin has largely followed along similar lines of development to the many other southern Australian basins since the Cretaceous break-up of Gondwanaland. However, the scale of accumulation of coal and hydrocarbon source rocks is unprecedented and differentiates this basin, for reasons less well understood, from the others. Large scale open cut brown coal mining since the late-1920s has been carried out in the western extremities of the basin, while vigorous extraction of some two thirds of Australian petroleum products taken place in the offshore part. Brown coal seam thicknesses and economically winnable reserves are huge and outrank most other brown coal basins of the world. Development of the resource currently meets the need for electricity generation throughout the State of Victoria, but other future developments such as conversion to oil, being investigated.

Jan 1, 1992

By Boden A

A procedure was developed for recovering metal values from copper-smelter fume. The fume is first leached to neutrality with dilute sulphuric acid to obtain a solution of zinc sulphate containing a low level of impurities. The tailings from this leach are treated with hydrochloric acid in two stages, in which tin and zinc are quantitatively leached and recovered as a tin concentrate and a zinc sulphatelzinc chloride solution.About 80 per cent of the lead sulphate is converted into lead chloride, which can be recovered as a pure product.Data on the effect of temperature, acid concentration, aeration, and solid/liquid ratios on the hydrochloric acid leach are presented, and the fate of the most important metals during the recovery process is described. Alternative treatments of the tailings from the neutral sulphuric acid leach were briefly investigated.

Jan 1, 1977

Small scale gold mining operations in Papua New Guinea (PNG) have been observed to use very low flow rates of water in sluice boxes. In a series of laboratory experiments carried out to determine whether this approach was unsatisfactory or not for their situation, indications were obtained that it had some advantages in the recovery of fine gold but at the cost of considerable throughput. The separation mechanisms operating in such a system are analysed.

Jan 1, 1986

It is a great honour to address our Institute as President, but the choice of a suitable subject was not an easy one. In the past when the presidential address was given at an annual conference the subject usually related to the conference or industry concerned; more recently the subjects have been more philosophical and this is a distinct advantage to me.I appreciate that I am addressing an informed audience and I am sure' that you are well advised in many of the points that I hope to leave with you. Unlike the specialist who gets to know more and more about less and less and eventually knows everything about nothing, I am one of the group who gets to know less and less about more and more and eventually knows nothing about everything.I hope you will appreciate this point whilst you are listening to me.In recent years I have been closely associated with the problem that troubles most governments of our time: the competition of many groups of differing backgrounds for the land that is available to the nation.This is of particular interest to the industry with which we are concerned as it is of critical importance to the discovery and development of future reserves of minerals and metals. Part of my daily task is involved with the administration of legislation for mining operations and the conditions under which such operations may be undertaken, in implementing government policies relating to mining, and in designing and administering legislationdirected to safety and health in mines.Most of our members are involved in exploration or in day-to-day problems associated with the production of minerals or the management of companies in these pursuits and would be aware of many of the conflicting viewpoints on priorities.F. F. Espie in his presidential address of 1975 'On being a minority', made the point that our Institute found that the mining industry had a great communication 'Problem with the Australian people.I believe that this is one of our major problems.

Jan 1, 1977

For tax purposes a mining company is a New Zealand company whose principal source of income is from the business of mining, or exploring for certain specified minerals in New Zealand. New Zealand tax law distinguishes between a non-resident mining operator and a mining company, with the only major difference in tax treatment being the corporate tax rates. New Zealand mining companies are taxed at 28 per cent, whereas non-resident mining operators are taxed at 33 per cent of taxable income. These provisions also apply to the petroleum mining industry. Individuals who carry on the business of mining are also specifically defined in the Act. They are termed as 'resident mining operators'. Non-resident mining operators are non-residents of New Zealand who carry on mining ventures as a business in New Zealand. Mining ventures are defined as the exploring, searching and mining of specified minerals, including development work carried out for profits. Similar provisions apply to the petroleum mining sector. Specified minerals are defined in the Income Tax Act 1976 ('the Act') and while no useful purpose is obtained by listing them in the paper, they include a larger number of industrial and commercial minerals. The Minister of Finance is also empowered to add to the list by publishing his determination in the Gazette.

Jan 1, 1988

A thermochemical model is developed to study the two-stage smelting reduction process for ironmaking without post-combustion. Steady-state multi-material and heat balance equations are solved simultaneously to study the effect of metallisation, slag basicity, coal rank and heat loss on consumption rates of coal, ore, flux and oxygen and production rate of slag to produce hot metal of a given composition, tapped at a given temperature. The model is applied to the commercial data for a COREX-plant producing a wide range of hot metal compositions, tapped at different temperatures. The computed rates of coal, slag, flux, ore and oxygen were found to be close to the reported ones, but an exact match could not be obtained. It is found that a four per cent change in metallisation brings changes the coal rate by five per cent, flux rate by six per cent, slag rate by eight per cent and oxygen rate by 13 per cent, while a ten per cent change in basicity changes the coal rate by ten per cent, flux rate by 13 per cent and oxygen rate by 22 per cent. Further, it is found that an increase in metallisation decreases the coal rate and export gas. At a given per cent metallisation, the coal rate and the export gas are lowest for anthracite compared to all other types of coal.

Jan 1, 1999

Drill blasting is a widely used method for rock fragmentation in mining, quarrying and construction industries. Environmental effects such as air shocks, dust, flying rocks and ground vibration are unavoidable results and undesired effects of blasting. Among these ground vibrations can have a damaging effect and may influence on long distances. Therefore various researchers have developed mathematical models to predict ground vibration after blasting. These models take into account the amount of explosive, distance and several coefficients related to the field under investigation. The developed models to predict ground vibration may yield different results for the same case. Selection of the most suitable model requires engineering judgment and evaluation of models. At this point, a computerised system helps the engineer to evaluate and select the most suitable model in order to design and plan a blasting pattern. The safe charge of explosive and magnitude of vibration after blasting should be predicted beforehand. Therefore a computer program namely 'prediction of blast induced vibration' (P-BIV) has been developed. This paper introduces and presents a computer program (P-BIV) which includes the set of models developed to estimate ground vibration to provide blasting engineers a tool to determine the amount of explosive for safe blasting.

Dec 6, 2010

The Leigh Creek Coalfield is owned and operated by the Electricity Trust of South Australia to supply fuel to the Northern Power Station. To supply electricity at lowest cost, a costing and decision process that establishes the role of the Leigh Creek Coalfield in the overall system planning and operation is required. The costing is integrated in that it is based not just on a particular mine plan but on the wider need to supply a particular electrical demand. The detail costing has evolved over time from manual to main-frame computer to microcomputer techniques. Now there is a choice between fast consistent costs and a slower but more detailed and flexible costing.

Jan 1, 1990

Sluiceboxes can provide a much higher concentration ratio than most other gravity concentrators (up to 50 000:1) at very high overall placer gold recoveries (greater than 99 per cent). They are also very reliable, inexpensive and simple to operate. This combination is very difficult to beat and explains why the sluicebox is still the most important placer gold concentrator in northwestern Canada, Alaska and the rest of the world. A sluicebox is a rectangular fl ume containing riffles on matting, through which a dilute (<12 per cent) slurry of water and alluvial gravel flows. Sluiceboxes are actually centrifugal concentrators with settling velocity playing a minor role in gold recovery. Due to their higher density, gold particles tend to segregate to the bottom of the slurry flow where they form a streamline that is diverted by a low pressure zone into a riffle. Under ideal conditions, this ribbon of slurry will be overturned as it flows down the rear of the following riffle and will continue fl owing in a circular path to form a vortex. At the bottom of this vortex, centrifugal and gravitational forces combine to drive gold particles into or beside the matting. To remove the gold concentrates, sluiceboxes are shut down and the riffles and matting are taken apart and cleaned. The slurry velocity provides the energy that powers the vortex. If the velocity of the slurry is reduced through overloading with solids, insufficient water flows or shallow gradients it may not sustain a full size vortex. If the riffles are too close, too far apart, too tall, or if there is not enough energy available to the vortex, the vortex will not be formed properly and gold recovery will be reduced. If the slurry velocity is too high, extreme turbulence and the resulting scouring will also cause gold losses. Testing sluiceboxes with conventional sampling and evaluation techniques is very costly, time consuming and problematic. Most placer gold ores contain a very small number of gold particles in a large volume of pay gravels. Sluiceboxes can lose coarse gold particles. The presence or absence of one of these particles in a tailings sample can lead to high unpredictable errors (nugget effect) even when large sample volumes are processed with care. Every time conventional samples are upgraded, additional errors are introduced due to the inefficiency of recovery equipment. Nuclear tracer tests are more accurate, faster, cheaper and safer than conventional sampling. In 1989 through 2002, the recovery efficiency of dozens of sluicing systems was determined by mixing radioactive gold particles (tracers) into the feed streams of dozens of placer mines in the Yukon Territory, British Columbia, Alaska and Guyana. Four distinct sizes of nuclear tracers were used and their recovery was related to the design and operational characteristics of the individual sluiceboxes and their pay gravels. At clean up, scintillometers were used to detect the very low level X-ray and gamma ray radiation emitted by these tracers and locate them in the sluice runs. The effectiveness of any given section of riffles was easily diagnosed by the presence or absence of tracers. At every mine the gravel feed rates, water flows, equipment dimensions and riffle performance were measured. After the gold tracers were removed from the fi nal concentrate and counted, the concentrate was sieved and weighed. These gold recovery, weight and sieve data were used to calculate the quantities and size distributions of the gold particles in the original pay gravels and those lost in the tailings. The expired tracers were stored in a lead lined container until their radioactivity was near background levels (about two months). The standard errors from these radiotracer tests were estimated from binomial probability theory with the equation: SE = {(n + p + q) ^ 0.5}/n. Where n was the total number of radiotracers added, p is the proportion recovered and q was the proportion lost. Each overall recovery estimate would be within one standard error of the true recovery value (14 times out of 20) and almost always within two standard errors of the true recovery (19 times out of 20). The maximum standard error with 100 tracers was five per cent and occurred when the recovery approached 50 per cent. With higher recoveries, standard errors usually ranged from one to two per cent.

Aug 1, 2010

By D Chalmers, C R. Ward, B B. Beamish

Coal workers’ pneumoconiosis (CWP) has re-emerged as a major concern in the Australian coal mining industry. Harmful effects from coal dust inhalation have been well documented, but the underlying causes and mechanisms of CWP are still debatable. Research conducted in the USA has proposed a plausible link between the presence of pyrite in coal and the prevalence of CWP. Reactive pyrite in coal oxidises under ambient mine conditions to produce various iron sulfate minerals such as melanterite, rozenite, roemerite and szomolnokite. Rapid reaction rates are promoted by the form (size and morphology) of the reactive pyrite present, which provides both increased surface area and increased porosity for easy air access to reaction sites. The products formed from reactive pyrite oxidation are often needle-like crystals with thicknesses in the order of 1–2 µm (eg melanterite and rozenite) and prismatic crystals with thicknesses less than 5 µm (eg roemerite) have been recorded. The densities of these minerals are significantly less than quartz, which makes them prone to becoming airborne with the normal coal dust. In fact, the mix of these mineral salts is commonly referred to as ‘fairy dust’ by mine workers due to the way they can become entrained and sparkle in the mine ventilation air, particularly if they occur in the upper part of a seam that is forming a coal roof. Examples are presented of the various products of reactive pyrite oxidation found in three Australian coal samples, which provide evidence of the physical and chemical mechanisms that would support the USA findings, particularly in terms of a source of bioavailable iron leading to increased inflammatory stress response.CITATION:Beamish, B B, Ward, C R and Chalmers, D, 2017. Products of reactive pyrite oxidation in the mine environment – implications for coal workers’ pneumoconiosis, in Proceedings Australian Mine Vent Conference 2017, pp 87–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

During the course of the major research in the Metallurgy Department of the University of Melbourne into the creep characteristics of lead and .its dilute alloys, it has been the practice to prepare the majority of test specimens from rolled strip. From time to time during the progress of the work, certain variables involved in. the rolling of the experimental ingots have been investigated. It is proposed to collect together in this paper the results of these experiments. Some general features relating to the type of deformation produced have been discussed in a previous paper.While it is admitted that the conditions prevailing through this work differ' in some respects from those of industrial rolling practice, it is felt that many of the factors investigated have an important practical significance. Some of the work described forms a continuation of the researches of R. S. Russell (2) , (3) , (4), into the recrystallization of various pure leads after deformation by rolling.MATERIALS USEDIn this work, a variety of "pure" leads and certain dilute alloys made from the purest of the basis leads have been studied. The compositions of the basis leads and the corres...

Jan 1, 1940

By Whiten W. J

A simulation model was used to study the performance of various types of screen cloth on industrial vibrating screens. The model takes into account the effect of loading upon screen performance and predicts both themass flow rate and size distribution of the screen products.It was found that the use of the simulation model allowed the reconstruction of data for identical conditions and hence has simplified the analysis of the comparative performance of the screens. The dependence of performance upon operating conditions was found to vary markedly with screen cloth type.

Jan 1, 1977

Solvent extraction has recently been introduced into Australian hydrometallurgical practice for the production of a high grade uranium concentrate from El Sherana ore by a sulphuric acid leach and solvent extraction process. The solvent is a 5 per cent solution of tri(iso-octyl)amine in kerosene modified with 4 per cent of a long chain alcohol. The stripping reagent is a molar solution of sodium chloride.Preliminary testing for the development of the process showed that the leach liquor was quite amenable to the solvent extraction process and that the equilibrium and rate considerations of both the extraction and stripping steps were very favourable.The industrial plant contains four stages of extraction, three stages of chloride stripping and one stage of secondary carbonate stripping. An internal type of mixer-settler is used for the stagewise contact, the design being based on tests with model equipment.The performance and control of the industrial plant is satisfactory; 99·7 per cent of the uranium is recovered for a loss of 0·3 gallons of kerosene and 0· 4 pounds of amine per 1,000 gallons of liquor treated.INTRODUCTIONThe processing of El Sherana uranium ore from the South Alligator River valley commenced in April, 1959, and thereby introduced into Australian hydrometallurgical practice the unit operation of solvent extraction on an industrial scale. Although there are now some twelve mineral processing plants in the United States and Canada using solvent extraction, its application to the field of primary hydrometallurgy is quite new. Prior to 1956 none of these twelve plants was operating and hydrometallurgical application waslimited to the refining of comparatively high grade uranium compounds and fission products from nitrate and nitric acid solutions.

Jan 1, 1961

Pressure drops were measured in a column packed with glass spheres and wax particles, both in random and preferential distributions. Variables investigated included wax content, gas flow rates, and temperatures.It is shown that for random distribution of wax, pressure drop is exponentially related to wax content above the melting point of wax and that below this it increases with increasing gas rate and temperature.For preferred distribution of wax the highest increase in pressure drop is obtained with horizontal distribution of wax and the least with vertical distribution.Comparison with operating blast furnace data and application of results to practice are also included.

Jan 1, 1970

In Broken Hill, Northern Rhodesia, two water jacket lead furnaces have been in operation for the past three years. The furnaces were erected in war time, and only absolute essentials were procurable. The water for the jackets was obtained from wells adjacent to the works, in a dolomite formation. There being no water-softening plant, except a small one capable of treating water for the power plant only, this water was found to make a heavy scale in the jacket. During 1917 several jackets were burnt through, resulting in serious trouble and loss of output. In order to avoid this, furnaces were stopped twice a month for 8 hours and scale was removed as far as possible. In addition to the scale trouble during the summer months, a green slime grew in the supply tanks and occasionally became detached from the tank and collected in the cocks near the jackets. This caused risk to the jackets and was difficult to remove without a stoppage of the furnace. In 1918, bundles of wattle bark were placed in the hot well at the rate of one ton per month. These extracted the tannin and added from 0.5 to one part of tannin per 100,000 to the circulating water. The hot water was cooled over a brushwood cooling tower and returned to the supply tanks. The well water required to, make up the wastage was estimated at 40,000 gal per day.

Jan 1, 1920

An integrated palynological and sedimentological investigation of four wells from the eastern margin of the Gippsland Basin has resulted in a scheme for classification of palynofacies in this area. Thirteen different palynofacies assemblages are recognised and assigned to particular environments based on the enclosing sediments, which range from alluvial, through coastal barrier to continental shelf environments. Close correlation is observed between the interpreted energy regime of the palynofacies assemblage, and that of the enclosing sediments. Assemblages characterised as reworking surfaces can be correlated with unconformity producing events (ie tectonic activity associated with the opening of the Tasman Sea), and some of the minor eustatic sea level Changes.

Jan 1, 1992

This paper discusses the impacts that advances in metallurgy and process engineering have on minerals project execution. Ausenco's business is focused on integrating minerals processing technology and the delivery of cost effective processing plants that exceed client performance expectations. The metallurgical development is a small but critical part of this process. Metallurgical development and innovation outcomes need to be transformed into an engineered solution and that solution converted into an operating plant in a cost conscious and competitive environment. Including new or innovative processes in a project flow sheet increases a project's technical and commercial risk. However, it also gives the project, and/or the engineering company, a potential advantage over projects using mainline practices. Managing the balance between risk and opportunity has been a cornerstone of Ausenco's success in recent years. Some advances in "technology" that are discussed in the paper include: larger capacity equipment new flow sheet concepts simplification of process interfaces, and more effective project strategies The common theme is that having a new idea can be the easy bit, putting it into operation effectively involves numerous people, many interfaces and strong project management.

Sep 13, 2010

A single compartment 100 A electrolytic cell charged with AICla-KCl-NaCl at 750°C was studied during an experimental campaign of 4 months. About 10 1b of aluminium were produced in continuous runs which lasted up to 1 week. The highest cathode current efficiency determined was 80 per cent. Anode current efficiency. cathode potential, analyses of melt, sublimate, and product, and reactivity of cell materials were also recorded and interpreted in terms of the role of lower valent aluminium species in the electrolysis mechanism.

Jan 1, 1971