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Christmas Island contains large deposits of phosphate minerals varying from high-grade calcium-phosphate (apatite) to lower grade iron and'aluminium phosphate (crandallite/millisite). The surface material is dominantly C-grade (Fe/Al) phosphate profiling into B-grade, a variable mixture of C- and A-grade ores, before reaching the high A-grade phosphate (apatite) which overlies a limestone Karrenfeld Base formation. A-grade ore is the basic phosphate used for the manufacture of superphosphate and phosphoric acid, whilst B-grade contains amounts of iron and aluminium which are unacceptable for these acidulation processes. Research into methods of separating the finer iron and aluminium phosphates from the coarser calcium phosphates has led to the development of wash-screen processes enabling recovery of 50 to 60%, as A-grade phosphate. Developmental stages included laboratory investigations, mineralogical studies, pilot tests leading the initial 20 tph prototype production unit and the current 100 tph production wash/screen plant, commissioned early in 1970 at Christmas Island.

Jan 1, 1971

The proximity of the Town of Kalgoorlie to the Mount Charlotte mine necessitates that charge weight per delay be limited in order to keep surface vibration levels within acceptable limits and to reduce damage to underground workings. The mining system requires that large mass blasts must be used to recover pillars and therefore a large number of separate delays are needed. Until recently all blasting has been done electrically, fired from mains, but with the introduction of large diameter blastholes (165mm diameter) this firing system was inadequate. Various firing systems were considered, but after extensive trials a non-electric sequential firing system was chosen. This system fulfilled all criteria of blast design, was relatively straight forward in charging technique and had a very simple primary initiation system. Although initially designed for large mass blasts, the non-electric firing system is now used for all large hole blasting and in a simpler form for small (57mn diameter) holes.

Jan 1, 1982

By McGhie R. R

The general structural features and the principal mineral relationships of the Black Star ore body, Mount Isa, Queensland, have been described in several previously published papers. But particular reference may be made to the work of Grondijs and Schouten, whose examination of over 200 polished sections revealed some remarkable features in the process of ore deposition. The observations by the present authors are based upon the study of a smaller ·set of specimens complementary to those examined by Grondijs and Schouten and are intended to elaborate certain aspects of the mineral relationships, more particularly those affecting the ore-dressing processes.The work described applies to the primary sulphide ore only, and to the present milling practice of fine-grinding and selective flotation.GEOLOGICAL FEATURESThe Black Star is one of several economic mineral concentrations in the Mount Isa series of thinly bedded carbonaceous shales, which are considered to be of preCambrian age. The nlineralization is apparently connected with pegmatite intrustions located within some miles of the ore bodies, and has been Gontrolled in the main by major folding of the shales and by a shear system which follows approximately the strike and dip of the beds. The detailed "The investigations described in this paper were made in the Metallurgy Department, University of Melbourne, where the senior author was formerly Senior Lecturer in Mining and Metallurgy. A report on a section of the work was submitted by the junior author as a thesis requIred by the University of Queensland.

Jan 1, 1939

The concentrating plant of the Broken Hill South Limited was described in Proceedings No. 44, Australasian Institute Mining and Metallurgy, December, 1921, by Wainwright and Read. It was erected on the present site in 1907 and 1908.From that date, the plant has undergone various alterations consistent with metallurgical improvements. By 1925, the timber work of the gravity secti"on had seriously deteriorated, so much so, that, when the machinery was working, the floors and supports vibrated badly, causing heavy maintenance costs.In 1928, it was decided to erect a new gravity-treatment section, to be followed later by a new flotation section.

Jan 1, 1932

By Clarici E, Marsden J. R, Calderbank P. A

Evaluation of previous studies of multi-layer perceptron type artificial neural networks in the modelling of the deformability behaviour of rock have suggested that a deviation from the standard method of laboratory testing of rock under triaxial loading at constant confining stresses and constant axial strain rates may be inappropriate when the data produced are used to train an artificial neural network. In this paper, preliminary results of adopting such a strategy are reported. Of specific concern is the establishment of a suitable schedule for the stress path during testing. Furthermore, the training element of back propagation optimisation was directed towards prediction of new stresses given old stresses and old strain increments. Adoption of this method of supervisation in artificial neural network training facilitates the integration of the trained neural network within existing numerical methods used in rock mechanics. The target code was a finite difference Lagrangian formulation for the analysis of continua. Sandstone rock taken from a quarry in the UK was used in the study which showed that the method has great potential.

Jan 1, 1995

By J Manuel, L Lu

Increasing bed depth is one of the main options sinter plants consider to increase production, since it is an incremental improvement and less expensive compared with a new plant. To maximise the benefits of increased bed depth, correct blend design and plant operation is critical. This paper discusses test work conducted to show the effects of ore type and bed depth on sintering performance and the adjustments required in both fuel rate and lime addition depending on ore type. The differences in sinter plug macro and microstructure were also examined to show the effect of bed depth on ore assimilation and matrix formation. Finally, the benefits of blending ores to achieve the best sintering performance as bed depth increases is discussed.

Jan 1, 2007

Western Mining Corporation, managing partner of the Windarra Nickel Project are in- stalling a raise-bored haulage shaft and under- ground crushing system at the Mt. Windarra Nickel Mine. The system will be the second of its type installed by W.M.C., the first being in- stalled at the Otter-Juan mine in Kambalda in 1976/77. Both haulage systems became necessary as a result of the increasing production limi- tations, and escalating costs of a deep decline mine. The Windarra haulage system required a single 3m diameter vertical raise drill hole to a depth of 470 metres. Two five tonne skips in balance will hoist crushed ore and mullock to the surface, at a design rate of 200 tonnes per hour, effectively reducing truck haulage leads by up to 50%. It is expected the project will be in full operation by mid 1982 and will enable the mine to achieve an annual production rate of 600,000 t.p.a. by 1983.

Jan 1, 1982

Pisolitic iron ores (also known as channel iron deposits) are an important resource of medium-grade iron ore in the Hamersley Province of Western Australia. They are a special case of transported pisolitic ferricrust, differing from normal transported ferricrust only in the exceptionally high iron and low alumina content. The pisoids typically range up to 5 mm in diameter with abundant particles of ferruginised fossil wood up to 15 mm in maximum diameter preserved in the sediment. Field observations indicate that pisoliths are commonly initiated by the action of raindrops on iron-rich soil. Pisolites form by the impact of raindrops forming coated beads of ferruginous soil, which after dehydration obtain additional coatings during successive showers. Thick deposits of pisolite that are transported and deposited primarily by sheetwash form in the distal regions of the pediment. A size range limited to particles that may be transported by extremely shallow water characterises the abundant fossil wood fragments. The absence of fine sedimentary layering in pisolitic iron ores is explained by the action of soil-forming processes after deposition, while the major coarse bedding features derive from successive erosional and depositional events in the evolution of the pediment. They are not deposited in channels by rivers which, in arid to semi-arid conditions, typically deposit quartz sands and gravels with characteristic point bars and current bedding, abundant ferruginous granules, but rarely pisoids. However, they may fill abandoned river channels.

Jan 1, 2007

The B.R.G.M., through international experience gained over many years, has become very skilled in alluvial prospection, particularly for diamonds. The research laboratories within the B.R.G.M. have also been active in creating new mineral processing equipment,. some of which is directly applicable to such prospection. One such development, the mobile prospection unit, is described and -its application in mineral exploration is demonstrated by a consider- ation of the diamond search in Australia and the general exploration of the Massif Armoricain (France). Because this latter study was fundamental in the development of the concept of "mineral-geochemistry", and its application in mineral exploration, it is also briefly described.

Jan 1, 1980

By Budden J. R, Rhodes M. K

Bacterial oxidation technology was successfully applied in a mine site pilot plant for the treatment of refractory gold concentrates. The bacterial culture was proven capable of selectively breaking down the refractory sulphide minerals to release the gold. Gold extractions greater than 90 per cent were possible when oxidised concentrate was leached with cyanide solution. The pilot plant was designed using data scaled up from laboratory testing and sized for transport by standard vehicles. The bacterial culture used to break down the refractory gold-bearing mineral was a natural mixed culture able to withstand temperatures up to 55¦C, thus making the technology particularly suitable for use in Australian and in some North American gold mining regions. The pilot plant was operated at the mine site over a six month period. Performance of the bacterial oxidation technology under site conditions was as predicted from the laboratory testing. It was demonstrated that the culture was robust under normal site condi- tions and that the culture could withstand wide variations in the feed and the operating conditions, while still achieving satisfactory oxidation levels. The technology was able to be utilised by site operators and supervisors with minimum intervention. Design data for a commercial facility was collected for a number of different concentrate samples and a feasibility study completed. Estimated capital and operating cost have been obtained.

Jan 1, 1991

Formed in 1965 to investigate the bauxite deposits on the Gove Peninsula, in the Northern Territory of Australia, Nabalco Pty. Limited undertook to determine the feasibility of establishing a mining operation and alumina plant of at least 500 000 tonne/year capacity. The drilling programme undertaken and the analytical methods, assumptions and criteria used to define practicably extractable bauxite are described. The ore characteristics and the interpretation of results used to evaluate the reserves are detailed. The operating techniques developed in mining ten per cent of the reserves and variations experienced between indicated and actual mining are examined and discussed.

Jan 1, 1979

By L Faulkner

The Tarnagulla Gold Project in Central Victoria, Australia, was developed and operated by Reef Mining NL between 1994 and early 2000, producing 53 000 ounces of gold from the Nick OÆTime Shoot, a single narrow vein shoot structure within part of the larger Poverty Reef, with a strike length ranging from 30 m to 60 m. The ore shoot was developed over a vertical interval of 190 m, using a small cross-section decline and small, mechanised equipment. Various stoping methods were employed including mechanised cut-and-fill with a single boom jumbo, hand-held mining using airleg drills and rope scrapers, and small uphole retreat stopes using a line of sight remote operated LHD to recover a crown pillar. Experience during stoping showed that airleg drilling and rope scrapers gave much better dilution control than diesel equipment. Innovations included a low-cost hydraulic fill system. Due to the small scale of the deposit, the feasibility studies, planning and permitting for the mine were based on very limited drilling information; however, the mine was brought into production within two years of the discovery. While the mine made an operating profit, it failed to fully repay capital at the low gold price then prevailing. Applying the lessons learned from the operation to optimise the access and stoping method, the project is re-examined at todayÆs gold price and operating costs. Central Victoria has the potential to host many similar small deposits. The authors were respectively Non-Executive Director and Resident Manager for Reef Mining NL when the mine was operating.

Jan 1, 2008

By Mingmin Dou

The behaviour and deportment of indium during the precipitation of sodium jarosite from Fe2(S04)3 - Na2SO4 solutions were investigated. Indium is readily precipitated with sodium jarosite, and the extent of In precipitation increases as the In concentration of the solution increases. It was shown that In 3+ substitutes for Fe 3+ in the jarosite structure to form a nearly ideal solid solution series. On a molar basis, the precipitation of Fe is slightly favoured over that of In, and the difference is reduced as the pH increases. Sodium jarosite precipitation becomes kinetically rapid at temperatures >70¦C, but increasing temperatures in the range 70 to 150¦C affect neither the relative precipitation of In and Fe nor the composition of the jarosite product. Low Na2SO4 concentrations result in reduced product yields and jarosite precipitates in which H3O' > Na+. The hydronium-rich precipitates have reduced In contents. Increasing the ZnSO4 concentration of the solution slightly increases the quantity of jarosite formed and results in the incorporation of -0.3 per cent Zn in the jarosite structure. Otherwise, the presence of ZnSO4 has no significant effect on the composition of the jarosite. Seeding accelerates the rate of jarosite precipitation but has a negligible influence on the deportment of In. The jarosite precipitation reaction at 98¦C is relatively rapid and near-steady state conditions are achieved in - 6 h even in the absence of seed. The initially precipitated jarosite is slightly enriched in In with respect to Fe. The ferric ion concentration of the solution has a significant influence on both the amount of jarosite formed and its composition. In particular, the jarosites precipitated from dilute Fe3+ media have significantly enhanced In contents. Hence, it may be possible to recover - 25 per cent of the dissolved In, at the 1000 mg/L level, in a jarosite precipitate assaying - ten per cent In by the controlled oxidation-precipitation of sodium jarosite from a ferrous sulphate processing solution.

Jan 1, 1993

By D H MACKENZIE

In common with several great orebodies and mineral camps around the world Broken Hill has been the subject of state-of-the-art technical and scientific scrutiny during its long working life. During the early years geological interest in Broken Hill tended to be directed at the body for its intrinsic scientific worth, mainly on account of its large size, high grade and wealth of mineral species. For much of the last 60 years the interest has had a more applied motivation, namely, to assist the search for either repetitions in the Broken Hill field or analogues in other terrains. This paper looks at the major changes in geological concepts and exploration techniques applied at Broken Hill and attempts to assess their impact.

Jan 1, 1992

Coal is of tremendous importance for the Czechoslovak econ- omy. The current annual primary energy demand being about 109 million tons of standard fuel (1 ton of standard fuel - 7,000 coal = 29,308 GJ), coal satisfies almost two thirds of our fuel consumption. If compared with the distribution of resources in the world's fuel and energy pattern, the situation in Czechos- lovakia is significantly different, as shown in Fig. I. One of the causes behind the difference is that the Czechoslo- vak oil and natural gas reserves and, hence, their production are insignificant, so that it is necessary to import them. Brown coal will continue to play an important role as a prin- cipal domestic source of primary energy even in the future. While the share of nuclear power is increasing, brown coal represents strategic reserves in the fuel and energy balance.

Jan 1, 1989

By Clarke RG

Renison Mine was developed as the first all diesel mine in Australia. The foresight of the early planners in committing the Mine to Decline access has paid dividends in the past two decades with Renison Mine establishing itself as one of the most productive underground mines in the world. The excellent productivity has also resulted from the development of mining equipment technology, both on the part of the equipment suppliers and through the coordination of the Mining, Automotive and Technical Design Sections at Renison Mine. Constant improvements in truck and loader design, the design of specific equipment to carry out specialized tasks such as installation of services, scaling and ground support and the conversion to electrically powered equipment have been ongoing at Renison. Currently, larger scale trucks are being investigated for ore and waste haulage due to increased haulage distances and production requirements. It appears as though an articulated low profile truck of around 50 tonnes capacity may provide the short term solution based on the performance data available.

Jan 1, 1982

By Wilson A. F

The use of stable isotopic measurements as a technique for elucidating the origin and history of the water in hydrothermal fluids is relatively new. Recent studies have emphasized the importance of meteoric water in the formation of many hydrothermal ore deposits including many epithermal gold-base metal deposits which occur in faulted volcanic terrane. Other vein-type gold ores are be- lieved to have formed from fluids of magmatic or metamorphic origin and exhibit characteri stic 6180 values. These values also give information regarding temperatures and the degree of equilibrium. Preliminary oxygen data for some important gold deposits of eastern Australia are evaluated in the con- text of styles of mineralization.

Jan 1, 1980

By Eren H

For a hydrocyclone of fIXed geometry, DC, Di, DO and ? are constants, the variable parameters affecting the performance are Qi, Fi, Du and H. (See Appendix 2 for definition of symbols).The relationship between d50c, Qi, Fi, Du and H gives models which can effectively be used for performance predictions. Such models have already been established by Lynch et al and by Plitt.These models have been tried in a limited manner under continuous operating conditions for on-line cowol. For on-line control effective and accurate instrumentation is required for which a new set up is proposed. Using this set up, a new model was established. A feature in this model is that deviations from the norm of operational parameters affecting d50c were considered. It is shown that these deviations generated by the disturbance of one or more of variations in the parameters, can be monitored by a computer and suitable signals generated to control servo mechanisms for restoring the required d50c value.The logic followed in developing the computer software is described and the application of the model is indicated.

Jan 1, 1990

Computers represent substantial capital investment. A better return on that invest- ment comes from more effective use of the computer's facilities. By using Telecom's data communications facilities, more people in more locations can have ready access to those facilities.

Jan 1, 1983

One of the most praninent Bouguer anomaly features in the Broken Hill District is the long wavelength high of 10-15 ngals above background which forms a northeast trending, oval zone sane 15 km by 45 km with Broken Hill on its northern gradient. Rock density measurements and modelling indicate that this anomaly can be explained by the presence of generally relatively higher density meta- sediments extending from the surface to a depth of about 2000 m. The regional Bouguer anomaly data show that the Willyama Block and Euriowie Block are mostly overlain by a fairly smooth Bouguer anomaly high in the range 5-15 mgals, whilst the surrounding younger sediment covered areas, including the Mundi Mundi Plain, Murray Basin fringe and Bancannia Trough, are mostly overlain by lows which range to minus 30 mgals. Thus in terms of the gravity pattern the Willyama and Euriowie Blocks form a fairly continuous and haogeneous entity. However, the 5-10 mgals relative low over part of the Torrowangee Synclinorial Zone indicates that the Adelaidean System metasediments are in aggregate slightly less dense than the Willyama Supergroup metasediments. The low can be modelled to indicate a basement link between the Broken Hill and Euriowie Blocks at 1000-2000 m depth.

Jan 1, 1983