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Reverse circulation (R.C.) drilling or the dual tube method as it is quite commonly known, has a unique place in conventional mineral drilling. It can be classified half-way between open hole drilling at the lower end of the scale and diamond drilling at the upper end. The system basically consists of two tubes, one inside the other, with compressed air flowing between the inner and outer tubes. Sample cuttings return up the inner tube through the head of the rig and via a hose to a cyclone where the sample is collected. This system means that the cuttings are free of contamination as they are at no time in contact with the outside formation of the hole.Reverse circulation drilling is divided into two areas: R.C. Roller and Blade for softer formations; and R.C. Percussion for harder formations.

Jan 1, 1986

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

Although the diesel engine is normally considered a tried and proven power source, many new and exciting diesel design concepts are being evaluated in engine development laboratories around the world. Three such programs currently underway at Cummins Engine Company are discussed. The turbocompound engine converts into power exhaust heat energy which is normally wasted. It does this by incorporating after the turbocharger a low pressure gas turbine which is gear driven to the crankshaft. The adiabatic engine has no conventional cooling system. It converts into useful power most of the heat energy normally rejected to the coolant. The series boost turbocharged engine uses seperate low and high pressure turbochargers to increase engine output and improve transient performance. These design concepts make possible increases in diesel engine thermal efficiency from the current 33 to 38 per cent range to the 50 percent range.

Jan 1, 1982

Teller Underground Mine was established to extract ore from the Middle Vale Reef located on the eastern flank of Telfer Main Dome.The mine is located below a 150 m deep open pit operation. The ore body is shallow dipping highly structured, and is a main aquifer in quite difficult ground conditions.In respect of these conditions it was determined to access the orebody using an adaptation of coal mining and hard rock mining methods, with support being achieved using a combination of island pillars, rock bolts and timber stalls.The paper will describe these methods in more detail, then discuss the successes and failures of these methods when put into practice. As well, it will detail several factors whose influences were found to be greater than previously expected and stress the importance of good geotechnical advice.

Jan 1, 1993

By Tran T, Young D

During the processing of gold, effluents that are discharged into the tailing dams contain free cyanide, metal cyanide complexes of zinc, copper, iron, etc and their oxidised products such as ammonia, cyanate and thiocyanate. A knowledge of how different cyanides behave in the solution is vital to metallurgists working in the area of cyanide waste treatment. Although the free cyanide ion is not stable in aqueous solutions and is expected to degrade in a natural environment by atmospheric oxidation, the metal cyanide complexes, especially of iron, are very stable. The CHEMIX program from the THERMODATA package, developed by the CSIRO Division of Mineral Products, was used to evaluate various copper-cyanide and iron-cyanide systems. The simulation of these systems show how the free cyanide and cyanide complexes behave at different conditions of solution composition and acidity (pH).

Jan 1, 1991

This is a welcome opportunity to exchange ideas about educating for a profession in mining and metallurgy, and I shall use it to highlight the ways in which educators, the industry, and the profession can help one another make that educa- tion better. This is home ground for me in more ways than one. As the executive head of a uni- versity perhaps I may speak as an educator; and there is still, I hope, enough of the metallurgist in me to allow me to speak of what we metal- lurgists and mining engineers can do to help the educators. Another interest should be declared, too. Among the educating agencies I shall focus on universities; among universities I shall further focus on my own, the University of New South Wales. I know it best; and, more to the point, we are one of the minority that offer a full profes- sional training in mining and metallurgy. Further, we are as a university very much concerned- more than most-with specifically professional education, and especially with education in the professions based on science and technology. Mining and metallurgy have of course played a central role, from earliest times onwards, in the history and development of science and tech- nology. In that role they have been both pro- ducers and consumers of new knowledge. Indeed the whole new attitude to knowledge that began to spread in 16th and 17th century Europe owed a great deal to the interests and traditions of the miner and the metallurgist. The first modern text- book of mining and metallurgy, George Agricola's De Re Metallica, is very much more than a spec- ialist handbook; it is a major landmark in intel- lectual and cultural history.

Jan 1, 1978

By B Hooper

Deep cuts in CO2 emissions will be required to stabilise and, in the long term, decrease CO2 concentrations in the atmosphere. Technologies for capturing CO2 from major stationary sources (power stations, industrial plants, etc) and storing that CO2 for long periods of time is one of few near term options for decreasing CO2 emissions. This transition to low carbon intensity energy and possibly the hydrogen economy through renewables and in the long-term technological developments such as artificial photosynthesis.Capture of CO2 from post combustion emissions can be done using a range of technologies though costs are currently high and dependent on the concentration of CO2 in the emissions. Techniques include solvents, pressure swing adsorption and the use of membranes. Options for decreasing capture costs by increasing the concentration of CO2 in the emission stream include the use of oxyfuels (in pulverized fuel types boilers) and by moving to integrated gasification combined cycle (IGCC) operations either simply for power generation or for poly-generation opportunities. Once the CO2 has been captured it can be stored using a variety of methods. Storage in the ocean has been suggested but is considered an unlikely option because of environmental uncertainties and political opposition. Mineral storage is a niche opportunity. The greatest potential lies in geological storage of CO2 and this option is commanding increased attention from the Australian and international community.In Australia, the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) is an important new initiative that will support energy companies and energy intensive industries in meeting challenges posed by greenhouse gas issues and assist them in their efforts to reduce their emissions profile.The progress of geo-sequestration and the challenges in the capture and separation of CO2 in the process industries are discussed.

Jan 1, 2004

Continuing education is recognised as an essential aspect of professional training, but no systematic procedures have hitherto been attempted. The tertiary educational institut- ions are making a valuable contribution without formal financial support. The Australian Mineral Foundation is offering a programme of continuing education in the earth science and related disciplines both by direct initiative and by co-operation with existing tertiary educational institutions.

Jan 1, 1974

The types of risk to mining projects using environmental protection as justification are examined. In Australia, Governments, whether Federal or State, enforce environmental legislation. The way they do This has an impact on the risk to a project. This is discussed and examples are taken from the Northern Territory uranium industry. Special reference is made to mine closures where the roles are not yet entrenched.

Jan 1, 1994

By Rashkovski GB

Until recently amalgamation has been the main process forextracting large gold particles from gravity concentrates obtainedduring the dressing of ores and placer gold deposits.Development of new technology for treating the gravityconcentrates was necessary because of the harmful effect ofmercury on subsequent production processes and theenvironment. The harmful effect of mercury is particularlyevident in the resin-in-pulp process that is widely applied inRussia.

Jan 1, 1993

There is a well-known saying, variously attributed to the great King Solomon and other sages of antiquity, to the effect that 'there is nothing new under the sun'. The inventive genius of man, as far as it is personified in the metallurgist, has often had the truth of this statement poignantly brought to mind when investigating the priority of ideas in its own particular branch of science. Not infrequently some operation, at first inilocently taken for a novel procedure, has later been found to have had an irrefutable precedent in the more or less remote past.When confronted by a question of this kind the metallurgist can generally much simplify his search if he at once turns his scrutinising gaze towards that ancient home of metallurgy, Germany. Vast departments of the smelting art have originated there, and even when Germany has not been in position to claim priority of invention, it has at least been characterised by a distinction equally as worthy - ie that of the faithful and authoritative exposition of the theoretical grounds on which the invention rests.In the present instance, in endeavouring to trace the history of pyritic smelting, the writer has naturally turned in the abovementioned direction, and not without some result, although the recorded data are, as might have been expected, meagre. A complete history of the art of beneflciating ores by means of fire, in all its many ramifications, still remains to be written. Possibly it may never be written, for the extent of the subject is tremendous. It is even practically impossible to clearly trace the development of one of its most modest sub-branches in satisfactory detail, or to present that branch without going to a considerable extent into related matters of a merely general character. For the purpose of dealing with the subject it will be convenient to divide it into two concurrent heads, and to distinguish, for historical reasons as well as for metallurgical ones, between that branch of the general method of matte smelting, which, until about 1891, has been called 'pyritic smelting', and the more recent offshoot of the latter, which, by distinction, may be called 'pyrite smelting'. The nature of pyritic smelting was clearly defmed by Dr John Percy in 1880, and his interpretation3 may be accepted as well known. To recall the characteristics of the method we may perhaps paraphrase Dr Percy's meaning by describing the process as a special method for the smelting of lean or dry silver or gold ores, which do not contain sufficient lead or copper for these metals to act conveniently as collectors of the precious metals. The operation is conducted in a blast furnace, with an amount of carbonaceous fuel sufficing to produce an exclusively reducing atmosphere, and with the addition of pyrites, in order to form a regulus in which the precious metals shall be concentrated, the pyrites themselves being either argentiferous, auriferous, or cupriferous, or any combination of these three, or wholly barren of metal values. In the common acceptation of the term, it is understood that the use of the reverberatory furnace is excluded.

Jan 1, 1994

Mineral sands are being used as the source material for new "high-tech" engineering materials. One such material, Magnesia Partially Stabilized Zirconia (PSZ) has been developed and patented world-wide by CSIRO. Derived from zircon sands, the material is currently produced by Nilcra Ceramics in Australia and is exported world-wide.The properties of the material are contrary to those generally accepted for ceramics and are far more akin to those of steel. The material resists not only abrasive wear, impact and thermal shock, but does so under corrosive conditions that frequently cause early failure of metal and cemented carbide.While the consumption of mineral sands for the production of PSZ is not going to significantly increase the demand in the short term, the material itself may well assist the productivity and processing problems within the industry.

Jan 1, 1986

The new generation Hlsmelt« Direct Iron Ore Smelting Process is a CRA Limited technology initiative. The process development is now focussed on commercialisation. The goal is to have the first commercial vessel operating around the year 2000. The HIsmelt« Process, based on the abundantly available iron ore fines and the more readily available non-coking coals, has the potential to fundamentally change iron ore processing through the application of high intensity techniques to replace the current sinter/coke ovens/blast furnace .technologies. The process will have great potential in the rapidly growing economies of Asia where steelmaking aspirations are based around local market focussed plants. This potential can be. realised as a supplier of premium grade iron units to electric arc furnace (EAF) steelmaking plants or as the front end to an ore based steel mill.

Jan 1, 1996

By S Jahanshahi, T Norgate

In single stage copper making appreciable amounts of copper report to the slag phase. Various strategies are available to minimise copper losses to the slag. However a slag treatment stage is likely to be required in an economically viable process. A number of slag treatment process options are available and include: flotation, leaching and thermal reduction. In the design of an industrial process some type of economic as well as technical analysis of these options will be required. In this paper an outline of the techno-economic analysis procedure used to design a single stage copper making process is presented. The calculated operating and capital costs of industrial copper making processes are compared and used to determine the optimum single stage copper making flowsheet. The most economic slag treatment options is flotation of slags containing low amounts of copper.

Jan 1, 2000

By J J. Cilliers, K Hadler, A W. Stra

This paper examines the use of the FrothSim flotation simulator to improve the performance of an industrial column flotation cell. The performance of an industrial retreat column cell is simulated, and, from the discrepancies between the simulated and experimental results, a problem with the wash water distribution is postulated. The scientific reason for the reduced performance with uneven wash water addition is described in detail. Further simulations indicated the potential for improvement with an even wash water distribution, resulting in both improved performance and reduced wash water usage. The simulated uneven wash water distribution was confirmed industrially, and the headers were redesigned and installed. A sampling campaign to compare the performance before and after the modifications showed that the flotation performance was improved dramatically, with a statistically significant decrease in gangue recovery, without a commensurate reduction in valuable mineral recovery.

Jan 1, 2005

It is a well known fact that the best method of rock reinforcement is to avoid physical ground support. This goal can be achieved by means of: - Increasing the rock structural strength - Geological definition and forecasting. - Sequencing the excavation - Smooth blasting In many cases however, extra ground support is needed in order to maintain safe working conditions. In an open pit, the structural strength of rock cannot be increased by lowering the pit walls due to economical reasons. Economy demands steeper walls and less waste to be hauled to the dump. The geological conditions can also often be extremely poor and unpredictable. For excavation sequencing and smooth blasting there are good possi- bilities, such as cleaning of the pit walls after the main excavation, arul- ing of long small diameter straight inclined holes, use of smooth blasting techniques and lightened explosives.

Jan 1, 1989

In-situ leaching of gold deposits has not become an option largely as a result the lack of suitability of cyanide as a lixiviant due to sluggish kinetics and high dependence on the availability of oxygen. A second problem area is the excessive cost of drilling the required number of injection and production wells needed to service a wellfield capable of maintaining any significant throughput or providing and acceptable level of gold production. Well spacing in in-situ leaching operations is limited by solution life, dissolution rate, and the need for solution control. With cyanide the life of an active solution capable of dissolving significant gold is severely limited by the availability of oxygen which cannot be readily replaced while the solution remains underground. The extremely slow gold dissolution rate also necessitates excessive contact periods in order to dissolve coarse gold.

Jan 1, 1991

By Miyashita T, Yamamoto R, Kishimoto s

Following considerations of the effect of furnace size on pressure loss, pressure loss in front of tuyeres, gas flow in the lower parts of the furnace, the distribution of the burden and the gas flow in large blast furnaces is examined with particular reference to the burden distribution at the throat and the gas flow at high production rates. Improvement of gas flow is related to application of super-high top pressure and the use of moveable armour. A brief description of the NKK type moveable armour is given and its use in controlling the gas flow outlined. The operating results under controlled gas flow show an increase in production of Fukuyama No. 5 BF from 9,200 tpd to 11,000 tpd with a decrease in the fuel rate from 490 kg/thm to 460 kg/thm.

Jan 1, 1975

By Geisler P, Sutherland P

The technical limits for high-pressure transport of large particle solids by means of sludge pumps, piston pumps or the like lead to the development of the pipe-feeder system. The pipe-feeder is a type of pressure lock in which the high-pressure pump itself is not in contact with the solids. Simultaneous operation of the three chambers with corresponding control of the valves allows continuous flow in both the primary and secondary circuits. Initially the pipe-feeder was used only for the transport of solids. Today it also operates with great success in central mine cooling systems, serving as an alternative for high-pressure/low-pressure heat exchangers or Pelton systems. In addition to the technology applied up to now, the pipe-feeder is also capable of transporting ice slurry, thus increasing cooling output consider- Ably.

Jan 1, 1991

By J G. Petrie, H von Blottnitz

The selection and design of process options to deliver outcomes consistent with sustainable development requires simultaneous consideration of multiple objectives, within a climate of uncertainty û including the environmental and social aspects of technology management in addition to the technical and economic aspects of such. An issue of particular relevance in primary metal production is the deportment of minor and trace components within orebodies, products and wastes and the implications of such deportment for eco-efficiency û in particular, the long-term environmental impact of solid waste management practices. The identification of opportunities to enhance recovery of valuable by-products and simultaneously improve the environmental acceptability of final waste output requires a clear understanding of the distribution of the relevant ore components, which results from the choice of processing route and unit operation efficiency. This is challenging, given that process streams generated during primary metal production are generally poorly characterised and the behaviour and deportment of trace to minor and trace components is not well understood. This paper demonstrates how current data gaps and inconsistencies can be systematically addressed through the meaningful reconciliation of empirical plant data with a fundamental understanding of the mechanisms and parameters influencing element behaviour and deportment during the formation and subsequent beneficiation of mineral ore deposits. On this basis, quantitative distribution data and a comprehensive and comprehensible inventory of unit process inputs and outputs as a function of ore compositions and processing technology options can be generated, which is consistent with early design stage information requirements, both in terms of detail and accuracy, ie is æfirst-orderÆ in nature. This predictive approach to element distribution during primary metal production provides decision-makers with key information in the early design stages of a project (in terms of developing processes within the context of sustainability), whilst simultaneously guiding further data collection and environmental impact prediction studies.

Jan 1, 2006