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By Bowden MW

Sintering of lead-zinc concentrates is practised by Sulphide Corporation to provide both desulfurised lump sinter feed, for simultaneous reduction to zinc and lead in the Imperial Smelting Process blast furnace, and sulfur dioxide gas for sulfuric acid manufacture.Moisture control of feed mixes is of paramount importance in the sintering operation and improvements in this area have realised increases in overall plant performance.

Jan 1, 1985

Taiwan is situated between Ryukyu and the Philippines with 35,960 sq. km of area, being slightly larger than Belgium It has roughly a spindle-shaped outline with a longitudinal axis extending in a roughly north-south direction. Geologically, Taiwan is extremely complex in terms of its tectonic setting in the convergence zone between the Asian continent and the Philippine Sea Plate. To the east of Taiwan, the Philippine Sea Plate subducts beneath the Ryukyu island arc, and to the south of Taiwan the Philippine Sea Plate overrides the Asian plate along the Manila Trench. Taiwan, therefore, occupies an unstable region between these two well-defined subduction systems of opposite polarity (see the following block diagram).

Jan 1, 1987

By Restarick CJ

Plant data are presented which indicate a relationship between flotation rate constants and pulp density in zinc cleaning circuits at Broken Hill. The data were obtained from down the bank sampling of cleaner and recleaner banks at North Broken Hill and New Broken Hill Consolidated Concentrators. It was found that, under normal plant operation, flotation rate constants increased at the lower pulp densities existing in the later cells of cleaner banks. The addition of dilution water to the feed to the bank increased flotation rate constants, thereby confirming the relationship. It is shown that the relationship between flotation rate constant and pulp density is size dependent, being most pronounced for larger sized particles. In contrast, the effect is not markedly dependent upon mineral type. Possible consequences of this relationship for control of cleaner operation are discussed with the aid of some simulated results.

Jan 1, 1978

Suppression of the explosion of the world population and the surprising increase of waste and emissions are major targets confronting mankind in this century. Recycling and waste minimisation are key words for sustainable development in a highly industrial society. The argument is really whether or not recycling done well is the solution to the environment problem for the following generation. If energy is not necessary in the recycling, all materials have to be recycled. The greatest interest among the environmental issues is the regulation of CO2 gas emission. It must be recognised that it is not possible to completely renew expended energy. Some of the recycling systems currently used are thought to increase the load on the environment rather than to be beneficial. Although metal industries have consumed tremendous amount of energy and discharged a large quantity of CO2 and solid waste, the metals have supported a high quality of life. The metal production industries such as the iron and steel industry and the non-ferrous metals industry can work well recycling of not only metals but also other materials without consuming more energy. Waste plastics, for example, are use as a reductant in a blast furnace. The role of metallurgical industry in the recycling-based society is introduced in the present paper to recognise how the metal industries can contribute recycling and waste minimisation.

Jan 1, 2002

Martite-goethite high-grade iron ore deposits that show no trace of hydrothermal alteration may extend to more than 200 m below the permanent water table and are typically saprolite with evidence of exposure to the physical, chemical and biogenic processes of soil formation restricted to the low-grade goethitised upper levels. Typically no evidence of the prior presence of chert bands is discernable within the ore yet it has been assumed that these ore deposits derive from cherty banded iron formation (BIF) through supergene leaching of the chert bands and thus classified as supergene iron ore deposits. The fact that chert bands are absent and that these ore deposits are highly weathered does not prove supergene leaching of the chert bands. Quartz is one of the most resistant minerals to chemical weathering within the saprolite and large scale dissolution of quartz is absent from all other quartz-bearing saprolites, yet this unlikely process is accepted without question as the origin of the most abundant form of high-grade iron ore deposits. It is proposed that martite-goethite high-grade iron ore deposits formed only from BIF in which chert bands were absent prior to weathering. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By P Walton, L W. Armstrong, D P. Blair

Sydney is the capital city of NSW and has a population of approximately four million people. Eighty per cent of the cityÆs water is supplied by Warragamba Dam, which is situated some 75 kilometres south west of the city centre. A risk assessment was carried out on the dam and future predictions of water flows into the catchment area showed that there was a risk of a one in 700-year flood not being contained by the dam. The predicted loss of life and property damage warranted the construction of an auxiliary spillway on the eastern side of the existing dam to cater for any uncontrollable influx of water. A test blasting program was instigated and the blasting parameters were established that would lead to routine production blasting of the sandstone rock making it more cost effective to excavate. Blast induced vibrations were a concern to the owners and the dam wall and ancillary infrastructure was instrumented with sensitive vibration monitoring equipment during the test blasting phase of the operation. Once the blasting parameters were established from the testing program production blasting was carried out on a daily basis to maintain æstockpileÆ of fragmented ground for the excavation equipment. Blast vibration models were developed to predict vibration levels for more sensitive areas of the dam to give the operators more confidence in their operations. The blast induced vibration levels recorded did not cause any structural damage to the dam wall and the waveform frequencies of the blasting operation were much higher than that experienced during a recent earthquake. The integrity of the SCAÆs assets were at no time jeopardised.

Jan 1, 2001

By Parker RL

A 250 tons per day ammonia-ammonium carbonate leaching plant is now being operated by Samin Limited, to extract copper from the oxidised ores at the Burra mine. This forms the first stage of a plant, which will eventually have a capacity in excess of 1,000 tons per day. The article reviews the history of the mines at Burra and the metallurgical studies which have been undertaken since the old mines closed in 1917, in an endeavour to recover the copper from the low-grade deposits left by the original miners. The reasons why an ammonia leaching process was selected instead of the conventional flotation or acid leaching methods are discussed. The paper concludes with a detailed description of the plant and the basis on which it was designed.

Jan 1, 1971

By Gadd D. E

Since October 1972, New Zealand Steel Mining Ltd has loaded around 10 million tonnes of ironsand concentrate from single-point mooring buoys located off-shore at Taharoa on the west coast of the North Island of New Zealand. Before the first off-shore loading system was installed a considerable research effort was applied to proving the slurry loading technique. Subsequently the system has been expanded and a new buoy, pipelines and pumping system were installed in early 1978. Since then 110,000 DWT class ore carriers have been loaded at rates of around 2600 tonnes per hour through twin submarine pipelines. This paper reviews the operation of the shiploading system and attempts to answer the question: "If the Taharoa operation were to be planned in 1980, would the same research spending be necessary or have published research results since, made such practical tests unnecessary?".

Jan 1, 1980

By Elber L, Whiten WJ, Cunningham KD, King GL, Bailey CW, Clay PA

The Savage River Mines concentrator treats magnetite ore at about 300 tonne/h, and produces feed for a pelletising plant. The plant incorporates two parallel grinding lines, each consisting of an autogenous mill, in closed circuit with a screen, a rougher mag- netic separator, a ball mill in closed circuit with parallel cyclones, and a finisher magnetic separator. Significant fluctuations in ore grade and grindability make it difficult to maintain pro- duct size in the narrow range desired, and to achieve maximum possible throughput at the same time, using the present largely manual control system. The present paper describes the develop- ment of a control system based on a mini- computer. It has been possible to implement a scheme of on-line estimation of product size which is sufficiently accurate for use in an automatic control system. The size estimation is essentially derived in terms of plant variables which control the ball mill cyclone cut size. Three control functions have so far been implemented and tested. These are control of the feed rate to the autogenous mill, control of water addition to the autogenous mill, and control of the ball mill sump level.

Jan 1, 1978

I start with some lines from "Pleasures of Hope" by the poet Campbell, published in 1798, which sets the flavour of what I am going to say. They blissful omens bid my spirit see The boundless fields of rapture yet to be; I watch the wheels of Nature's mazy plan, And learn the future by the past of man. I hope to echo the poet's optimistic view of what is yet to come. I am not sure I can find all the omens blissful but we all have some experience of what the wheels of Nature's mazy plan get up to. His advice to learn the future by the past of man seemed sensible to follow, so on the principle that the past of several men would be better than one alone I invited Alan Attwood, Maurice Cahalan, Gavin Moncrieff, Derek Temple, and Peter Wright to help me prepare this address; I am most grateful to them for their contributions. Of the technologies covered in this sequence of keynote addresses, metallurgy is the one which is closest to our consumers. On the age-old principle, which I do not expect to see changed in the 21st Century, that production is about providing the customer with what he wants, when he wants it, where he wants it, and at a price he can afford, I think we should start by trying to see how the market place is likely to develop, and to work back from there to review what technology we need to meet these demands.

Jan 1, 1986

Laboratory scale simulation experiments show that the adsorption capacity of Au(CN)Z- on activated carbon in the presence of organic plant contaminants is dependent on the particle size of the carbon. This observation suggests that fine carbon in a CIP contactor can protect coarse CIP carbon from fouling in a dirty CIP plant. A preliminary test of this concept was made using fine lignite coal as the organic scavenger in the presence of the CIP carbon Calgon GRC22 in an alkaline cyanide solution containing Teric 401, sodium ethyl xanthate and kerosene.

Jan 1, 1991

Mining in Guyana dates back into antiquity and a brief history of gold and diamond mining and of the small-scale miner, the pork-knocker, is given. The gold and diamond deposits found on the beds and in the flats of old and present rivers and the current methods of investiga- ting these deposits are briefly described. Methods of mining these deposits including the small-scale hand methods of pitting and diving with or without helmets are also briefly described. 'The small-scale method of dredging using a suction dredge in conjunction with a diver is described in more detail, from its develop- ment to current practice, without giving too much mechanical and technical details. The organisation of the industry and the mining titles, laws and policy relating thereto are reviewed. A brief account is given of the socio- economic role of the industry. Conclusions are made regarding the need for improvements in existing equipment and financing and for incentives to stimulate production. The future outlook of the industry is con- sidered.

Jan 1, 1986

Deposits of manganese oxides and silicates in the Tamworth area were re-examined. The major deposit at Danglemah consists chiefly of rhodonite and the rare silicate tephroite. It is considered that the manganese was deposited with the original sediments, the silicates being formed later during the intense folding and low-grade metamorphism of the enclosing rocks.INTRODUCTIONMany small deposits of manganese oxides and silicates occur along a belt of eastern New South Wales and Queensland.Some fifty occurrences, most of which have been subject to mining activity, were described by Lloyd (1943) and some of this information was summarized by Knight (1947). The ores have been mined on a small scale since 1884. Small supplies of battery grade ore were won from a number of deposits, while larger quantities of metallurgical grade were sold to the steel industry. Maximum production was in 1918, when 6,500 tons were mined.The siliceous nature of many of the ores and their occurrence in the neighbourhood of granite batholiths led earlier investigators to consider the deposits to be of hydrothermal origin, associated with the granite intrusions. The present work questions this viewpoint.In this investigation, three of the chief deposits in the Tamworth area were seen. These were at Danglemah, which is being mined at present, and Mount Jasper and Manganese Mountain, which were mined in the past. The Danglemah mine is the most accessible and yields the best material...

Jan 1, 1962

By Wiltshire PG

The process uses sodium hydroxide and sodium nitrate reagents as in conventional Harris refining plants, selectively removing the arsenic to the caustic phase at an operating temperature of 420-450¦C. A novel feature of the process concept is continuous treatment of loaded caustic slag for recovery of arsenic as a sandy crystal product suitable for further processing to arsenic trioxide. A large pilot plant was constructed and operated over a period of 3 years to develop materials handling techniques and equipment components and to prove the concept. Stable operations were achieved at equivalent capacities of 200 tonne/yr arsenic removal. The process is being considered in plans for expansion of bullion softening capacity at Port Pirie.

Jan 1, 1984

THE object of this paper is to offer some suggestions to assist metallurgists to supervise the operations of flotation plants. We do not yet thoroughly understand what "flotation" is or "why minerals float" and all attempts that have been made to explain the phenomena have been based on theory or imagination, and have not been capable of substantiation by practical demonstration, or even by laboratory tests; but it is wellknown that particular minerals will float in a liquid under certain specified conditions, and that some other minerals will not float under those conditions, and that, if a mixture of the two classes of minerals be subjected to those conditions, there will be separation of the minerals, of which one class will float and the other will remain unfloated as a residue. The duty of the flotation expert is to so control the operations and the conditions of the liquor as to obtain the best commercial result from the ore he is treating. The chief controlling factors in a flotation plant appear to fall under the following eight headings, all of which are important:1. Crushing.2. Rate and regularity of feed.3. Density of pulp.4. Temperature.5. Addition agents.6. Condition of circuit liquor.7. Agitation.8. Aeration.

Jan 1, 1920

By I Mason, A Bray, K Smith, T Sindle

Borehole radar is a proven geophysical technology that can be used to map an orebody ahead of mining. This paper will present a case study, where borehole radar is being used within the mining cycle to map out orebody blocks, both as a strategic and tactical tool. Refined equipment and procedures now enables a slimline borehole radar tool to be deployed on the end of drill rods, making it easier and faster to deploy in an underground mine with minimal impact on the mining process. Boreholes are drilled in advance of mining; cover holes to ensure the competence of the hanging wall and geology holes to determine the location and grade of ore are two such examples. All of these boreholes can be entered using a borehole radar tool to map geology and structure ahead. The radar data can provide images of the orebody as well as help detect potential water bearing structures that could impact on safety at a mining face.

Jan 1, 2009

By Ross T. J

Renison Limited operates an underground tin mine employing both cut and fill and open stope methods, at Renison Bell on the west coast of Tasmania. Mining in the region commenced in the 1890's. Development of the current mining operation commenced in 1965. The ventilation system used at Renison in its present configuration is a function of current mining methods, orebody characteristics and prevailing Tasmanian Department of Mines Inspection Regulations.

Jan 1, 1988

This paper reviews factors involved in the feasibility stage of underground mine project development. Emphasis is placed on the need to first select the best method of extraction and make the most accurate assessment of the expected output even with the uncertainties which may exist in structural interpretation, ground stress, geotechnical factors, and industrial conditions. The subsequent engineering planning should be undertaken from the point of view of the face requirements and is subject to constraints imposed by the method of work and nature of the deposit and, in the case of access, to surface constraints and services.

Jan 1, 1983

Drill and blast operations account for 12 - 15 per cent of total mining costs. This paper looks at a comparison between electronic detonators and non-electric detonators, focusing on the cost benefits associated with the high precision of the timing sequences of electronic detonators. An analysis of the total mining costs was made on two main case studies; one on a quarry in South Australia (Martin, 2007) and the other on a project undertaken at Sunrise Dam (Vaughan et al, 2007). The criteria used in the analysis included; the resulting fragmentation, a vibration analysis, crusher throughput and productivity analysis such as excavator cycle times, dig rates of the excavator and bucket fill factor. The results indicate that there were consistent production improvements and hence reductions in total mining costs attributed to the use of electric detonators. An increase in the degree of fragmentation gives lower crushing costs as more material passes through as undersize. This reduces truck delay time at the crusher, which in turn gives higher truck and shovels productivity as well as higher dig rates for the excavators.

Jan 1, 2008

By Teague JK, Read HW

The relationship between the maceral composition of coal and the strength of the coke produced from that coal has received a great deal of attention in recent years. Studies using two Bulli Seam coals, and blends of Bulli and Wongawilli Seam coals, from the Illawarra Measures of the Southern Coalfield of New South Wales were carried out. The optimum range of vitrinite was found to lie between 45% and 60% (mineral matter free). Above and below this vitrinite range coke strength deteriorated. I Coke strength indices increased with rank and the optimum vitrinite content increased with an increase in rank. These changes will require confirmation as trends by testing a third level of rank. It was noted that vitrinite content decreased with an increase in the specific gravity of separation of the coal. . T Use of- petrographic analyses will increase confidence in choosing coals for coking, provided the coals are well known. Such analyses offer the possibility of greater flexibility in coal purchases and the possibility of producing a marketable blend from coals, which have limited market potential. Critical base coals for blends can be conserved. Significantly more work is required before coal reserves can be utilised to optimum advantage. This work would require extension of-the studies discussed in this paper and, in particular, the testing of a wider range of rank.

Jan 1, 1970