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By Garland W

Access to geoscience reference informa- tion including mining and mineral processing has increased considerably in the last five years in Australia. This has been due principally to the use of computer-based information storage and retrieval systems. The main reference data base for the mineral and petroleum industries and disciplines in Australia is the Australian Earth Sciences Information System (AESIS), cooperatively developed and coordinated by the Australian Mineral Foundation (AMF). AESIS is created on the CSIRO computing network (CSIRONET) which has a CYBER 76 host computer located at the CSIRO Division of Computing Research (DCR) at Canberra. Data entry was until recently carried out by AMF using a dedicated line through the Adelaide CSIRONET node to the CYBER 76 interactive system. Data entry is now done directly at the AMF on a DEC PDP 11/44 mini computer that is also a host work station on CSIRONET. Data collection via magnetic tape media input from other computer-based systems is under development. The software used for data entry and management of the data base was developed by CSIRO CILES Systems Development Group. For public interactive online use the AESIS data base is transferred by tape to AUSINET - the Australian information net- work run by ACI Computer Services, Melbourne, where the data base is converted to a form suitable for the IBM STAIRS software. CSIRO facilities at DCR Canberra are used to produce computer type-set camera ready products and output in microform, on magnetic tape or as graphic display. Keywords: Earth sciences information, Computer applications, Information storage and retrieval, AESIS, Data bases, Australia.

Jan 1, 1983

Although developed primarily for sintering tantalum, the unit to be described can be used to heat-treat metals in the form ofa bar, wire or strip, by passing a current through them. The upper temperature limit with this type of heating is the melting point of the metal being heated.The unit was designed for vacuum work, but. various gases can be used if required.Briefly, the vacuum sintering furnace consists of a bell which is counter-balanced and may be lowered onto the brass base plate which holds the electrodes. A rubber ring seal is used for vacuum work. The lower flexible grips are bolted to the brass base plate which is at earth 'potential, while the other electrode passes through the plate by way of an electrically insulated vacuum seal. This upper electrode, the height of which can be altered as desired, the lower grips, and the bell are water cooled. The vacuum line to the pumps and a line to the vacuum gauges also lead from the base plate. The more important sections of the unit are described below.THE BELLThe unit was designed so that the bell could be lifted clear of the base plate and the electrodes, thus facilitating adjustment of the latter and the mounting of the specimen to be heated. A double walled steel bell, 20 in. high, with t in. cavity was used. The bell was fabricated from 10 gauge mild steel sheet using a double overlapping run of arc welding for all seams. A water inlet and outlet...

Jan 1, 1946

By Palmer W. T

The successful re-opening of the Cobar min- eral field was dependent upon the success- ful introduction of highly productive, low cost mining. Mechanised cut and fill stop- ing with incline access was selected for the C.S.A. mine because it permitted flexi- bility, complete primary extraction with no secondary pillar recovery, minimised dilu- tion and oxidation, a minimum of pre-pro- duction development and because diesel powered load-haul-dump (L.H.D.) units were proving reliable and highly productive in the U.S.A. Although L.H.D. vehicles are the key to the success of the mining method, four other main groups of vehicles are utilised in the mine - trucks, scaling vehicles, ser- vicing vehicles and specialist vehicles. The operating requirements at the C.S.A. mine are more stringent than those encount- ered in many other underground mining oper- ations. The first L.H.D. vehicle used at Cobar - the Transloader - had considerable difficulty in loading and discharging coarse production ore. The Wagner ST5 Scoop Tram performed this duty much better. However, the first generation Scoop Trams were not robust enough to withstand the heavy duty and many modifications were necessary before acceptable availabilities were obtained. Similar modifications were necessary for the Eimco 916 vehicle but the Eimco 915 unit came much closer to meeting the duty requirements. Eventually Cobar technical personnel design- ed a L.H.D. vehicle to meet specific C.S.A. mine conditions. These units have proven most satisfactory. Over 8 years of operation the underground vehicle fleet has become a proliferation of vehicle types. A standardisation pro- gram has been initiated based upon common prime movers being mated with "trailer" units to serve specific functions. Standardisation will reduce inventory levels and facilitate training of operating and maintenance personnel.

Jan 1, 1973

The large rotary blast hole drills for hole sizes of 250 to 375 mm in diameter have been utilized by large open pit metal and coal mines for production drilling all over the world. The design of such rotary drills is in most cases about two decades old and it has not been done much in order to apply a modern technology on rotary drilling. The most modern large rotary drill, Tamrock RI 10, consists of an advantageous rotary head with a squirrel cage AC motor controlled by a frequency converter, a beneficial mast structure with a possibility for inclined drilling, hydraulic driven, independent crawlers, and a modern ergonomic cabin to provide a comfortable working condition for the oper- ator. Several automatic features are available as options. The rig has been designed to be operated by one man only. With this modern rig the produc- tion rate can be increased and production cost kept on a low level.

Jan 1, 1989

By OÆBrien D. R

Up until June 1988, Mount Thorley Coal Handling and Preparation Plant disposed of tailings by two methods. Approximately half of the plant tailings was mechanically dewatered by solid bowl centrifuges mixed with plant reject and was subsequently disposed in mine overburden spoils; the remainder was pumped to tailings ponds. Both future mine planning and environmental constraints could not allow for the long term construction of more tailings ponds so, following evaluation of available dewatering technology, belt press filters were selected for the treatment of tailings in excess of the capacity of the existing solid bowl centrifuges. Commission of the four 2.5 metre wide belt press filters soon showed that marked differences in performance were experienced when treating different coal seams. Further analysis showed that the coal tailings from different seams were quite different in terms of clay mineralogy, and these differences could be correlated with varying degrees of filter performance. Poor filter performance was experienced with coal tailings rich in sodium montmorillinite clays. A number of variables were investigated including in-line mechanical mixing of flocculant and feed slurry, cation exchange reagents such as gypsum, and upstream addition of cationic flocculant. In order to achieve satisfactory performance on the worst tailings, a combination of all of the above was required. In this paper, the reasons for selection of belt press filters and the program of investigations and testwork required to arrive at satisfactory belt press filter performance for the treatment of troublesome bentonitic rich tailings are discussed.

Jan 1, 1989

By Cotton P. L

Although the terms "pipe" and "tube" are normally considered synonymous, a distinction is often drawn, the former term being applied to the hot finished product and the latter to cold finished material. It is, considered that the title of this paper includes hot finished seamless, and continuous-weld pipe, cold drawn seamless tubing, and electrically welded tubing.The continuous-weld process will be reviewed first, passing to the various methods of seamless manufacturing, which, in addition to meeting the demand for hot finished seamless pipe, also supply the raw material for cold drawn tubing, the manufacture of which will then be described. Finally the electric resistance-weld process will be Considered, and the paper will conclude with a brief review of the processes described and trends in present-day manufacture.CONTINUOUS-WELD PIPEThe raw material for this process is delivered in the form of coiled, hot finished, strip steel, generally referred to as "skelp". The end of one coil is electrically buttwelded to that of'the next, so forming an unbroken strip. This continuous ribbon of 'steel is fed into a skelp heating furnace, and brought to the correct temperature for the forming and welding operations which follow. This temperature is usually about 1,350°C.The heated skelp issues from the furnace into 'a multistand mill, in which the first pair of rolls is designed to form the skelp into tubular shape, the edges being in close proximity to, but not touching each' other. These edges...

Jan 1, 1951

The difficulty in creating and obtaining a competitive edge in the mineral industry is rapidly increasing. The Kiruna Iron Ore Mine in the far north of Sweden is currently thriving on the world market through firm managerial strategy. LKAB believes in upgrading its raw material to produce a high quality iron ore product for sale to steelworks throughout the world. It is vital that this product is also of uniform quality and quantity to provide quality assurance to customers. The first link in meeting these product requirements starts in the underground workings. Mining methods and operations are of large-scale. Automation and continuous production streamline operations and reduce operating costs. These factors have built Kiruna Iron Ore Mine into the world's biggest, most modern, underground iron ore mine. To remain competitive on the world market, LKAB relies heavily on research and development. The mine is currently in a phase of upgrading its operations. A 25-tonne Toro electric loader is being tested to improve the rate of output of ore from the mine. Long hole drills are being improved to increase accuracy and efficiency. An electronic detonating system will improve detonator delay precision. Projects are underway to better understand ore flow mechanisms from a caving orebody. Benefits include improved ore recovery along with better rock quality control at the caving front. The continued updating of mining operations at Kiruna will enable LKAB to continue to maintain its competitive advantage on the world market in the production of high quality iron ore products.

Jan 1, 1997

By Koppe J. C, Costa J. F C L

This paper compares different results for overburden volume estimation assisted by geoestatistics, particularly using kriging methods. The main goal is to obtain the most reliable digital terrain model for the calculation of the overburden volume. The data was collected on an irregularly spaced grid and interpolated values were calculated to provide a denser, more regular data set before volume estimation. The field work was developed at the Butia-Leste Coal Mine, southern most Brazil, where an accurate survey was done using a total station theodolite with electronic data collector. The study was developed in five main steps: data acquisition, exploratory data analysis, spatial continuity measurements, point and block kriging estimation and verification of the results. Data acquisition was carried out on a 5 x 5 in grid. This dense grid provides an exhaustive data set of the real terrain against which data subsets can be compared for the various interpolation procedures and volume calculation. This provides an interesting insight into the influence of the number of data on the estimation error. Univariate statistics were used to compare each data subset and the exhaustive dataset. Ordinary kriging on the data subsets followed by contouring was carried out using Geoeas and Surfer software respectively. A subroutine written in C provided the link between the files generated in Geoeas and subsequent contouring routines embedded into the Surfer package. Omnidirectional and directional variograms were modelled defining the parameters for kriging estimation using Geoeas. Different variogram models were checked through cross validation prior to kriging. A comparison between the magnitude of the differences in volumes calculated with the different DTMs was attained. These final result indicates the sensitivity of the volume obtained to the number of data points. As the number of data points increases the estimation error decreases, but at some point there is no significant decrease in the final volume with the collection of additional data.

Jan 1, 1995

By Freeman N

A microcomputer based control system has been developed and implemented at ZC Mines (now Pasminco Mining). The control system maximises throughput at a product size set point while maintaining a "safe" cyclone underflow and mill operating pulp density.To characterise mill and cyclone operation over a range of ore types, 60 circuit surveys were carried out by ZC Mines personnel over a period of four months. The data for each test were model fitted to check for data consistency and to accurately estimate circulating loads.The model fitted results were combined with instrument readings (including in-stream analysis probe assays) and the data checked for ability to predict key variables such as product size and underflow density from measurable inputs.In the resulting control scheme, panicle size and underflow density are not monitored directly, but are predicted by regression equation models based on directly measured variables. The tonnage control loop uses a dynamic model to maximise responsiveness.The system provides a data log output to an mM compatible personal computer at programmable intervals. Comparative data logging over a period demonstrates substantially smoothed circuit performance.The grinding control system was originally implemented using Fischer and Porter micro-DCI controllers. The program has also been implemented on a distributed control system using a sequence oriented programming language.

Jan 1, 1990

Since the announcement of early experimental work on rotating magnetic field (RMF) separation at the Sixth Mill OperatorsÆ Conference in 1997, the concept of RMF separation has been developed and tested further, and a range of separator designs is now being developed for the mineral processing industry. Shortened, but full diameter, prototypes of these designs are now available for test separations. The main advantage of RMF low and medium intensity attraction separation is the significant reduction in particle entrapment. This reduction is so significant that RMF separators are capable of operating very close to their theoretical limit for separator precision. This makes small laboratory RMF attraction separators ideal for low to medium intensity magnetic sample analysis, and larger separators ideal for applications requiring sharp magnetic susceptibility splits. Feedrates and separation rates are comparable to those of conventional attraction separators. Although RMF attraction separators are now well advanced in development, RMF rotation separation is still in the early experimental stage. The exception to this is the dry particle rotation eddy current separator that offers eddy current separation of small non-ferrous metallic particles from about 2 mm down to about 100 microns. Wet small particle eddy current separation is also possible, but has not yet been developed to a practical stage.

Jan 1, 2000

A new lead refinery with a. capacity of 230,000 tons per year com-menced operation at*Port'Plsie in October, 1959. This plant' superseded the refinery which had operated from 1933 with the advent of thecontinuous lead refining process. The incorporation of new equipment following local metallurgical developments, together with the overseas demand for lead of extremely low antimony content, created difficulties in operating the original plant. The new refinery project was under-taken to cover this disability and to gain the full advantage of the new processes.Desilverising and softening are carried out in units identical in size to those used previously. Metallic'zinc is now recovered from the entire output of desilverised bullion by vacuum distillation. Final refining is then carried out by batch'treatinent with caustic soda yield-ing lead of purity previously unattainable at Port Pirie.These two processes have replaced continuous dezincing by oxidation, a high temperature process which caused large quantities of lead and antimony to be recirculated. As the final stage is a .batch process the product composition can be.checked before casting. Individual batches can be adjusted to produce special alloys to,consumer's specification.Improved casting equipment has allowed the quantity production of pigs of good physical characteristics either as 56 lb bars or 2000 lb pigs. This, together with the high purity of the lead, has assured the B.H.A.S. position in world markets.Automatic control systems have been extensively employed particularly on the vacuum dezincing unit.The anticipated financial benefits have been achieved mainly by a reduction in the tonnage of recirculated materials, a smaller labour force, and reduced maintenance requirements.

Jan 1, 1963

By Newell R

The situation in which a gas stream flows through a bed of solids is found in many extractive metallurgy operations. Examples include blast furnace smelting, sintering and pellet firing. In such cases the resistance of the bed to fluid flow and heat transfer is of major significance to the operation of the process. This depends on the structure of the bed, which in turn is influenced by the manner in which the materials are charged to the bed. In this work, packed beds of hematite pellets of two different sizes were prepared in which the pellets were charged as a uniform mixture and in layers. The porosity, flow resistance and heat front velocity were measured and compared for the different bed configurations. For layered beds, the overall porosity and heat front velocity increased while the flow resistance decreased when compared with the values obtained for the uniform mixture. The size of the layers also had an effect on flow Properties.

Jan 1, 1991

By Moore A. J

This paper describes the use of a wavefront reinforcement model which has been developed to supplement established charge mass scaling methods. The model allows for the time taken for blast vibration wavefronts to travel from each blasthole, and has been successfully used to explain the reason for directional increases in both air and ground vibration in certain situations. The model has been used to identify wavefront reinforcement due to the propagation of air vibration and ground vibrations in certain situations. The paper includes a throw (or cast) blasting case history which provides multi-station evidence of the strong directional nature of wavefront reinforcement.

Jan 1, 1995

By T Laurencont, C Unger

The Mount Morgan minesite, located approximately 40 km SW of Rockhampton in Central Queensland, comprises 270 ha of unrehabilitated land which is the currently the major source of acid mine drainage run-off and seepage to the adjacent Dee River. Additionally, the minesite hosts an Open Cut Pit which contains 9000 ML of acidic and metal-rich water. In the absence of active management of water in the pit, there is a 50 per cent probability of an uncontrolled spill occurring in future years. The development of a contingency plan for management of overflow from the pit in the short term, has incorporated findings from numerous studies relevant to the Open Cut Pit including, but not limited to, water balance, contaminant source identification, toxicity testing, water quality profiling and limnological modelling, and estimates of probability of overflow. Extensive stakeholder consultation and peer review were also undertaken during the formulation of the contingency plan. The medium-term goal of lowering the water level in the pit to reduce the current high probability (50 per cent) of uncontrolled overflow to acceptable levels of risk is proposed to be achieved by a campaign of chemical water treatment. The treated water will be discharged to the Dee River, and sludge returned to the pit. The methodologies used for the selection and development of the water treatment process, that is proposed to involve treatment with lime, are described. Water treatment is the short- to medium-term component of a long range rehabilitation plan for achieving a negative pit water balance, and sustainable management of acidic water across the whole site. Achieving this ultimate goal will involve: reducing the inputs of water to the Open Cut Pit such that the annual water balance is zero or net negative, thus removing the need for water treatment in perpetuity; maximising, by surface rehabilitation works, the quality of run-off reporting to the Dee River; and minimising the volume of acidic seepage reporting to the seepage interception system. Possible strategies for achieving this long range goal consistent with overall site rehabilitation objectives are currently being developed and costed.

Jan 1, 2003

Proceeding from statistical data on the development of waste volume, an endeavour was made to characterise waste materials with regard to the applicability of treatments based on mineral processing. Many types of waste are characterised by a high heterogeneity. The separation processes used for processing raw minerals can also be used for separation of various waste mixtures. For some waste mixtures, differences in properties can be utilised for separation which are mostly less distinctive for raw minerals. State-of-the-art technology is illustrated with selected Examples.

Jan 1, 1993

Extraction under very mild conditions - a few minutes at room temperature with poor solvents - yields results characteristic of surface properties for a variety of coals. Such superficial extractions preferentially remove long-chain aliphatic compounds. As coal becomes more oxidized, less of these yellow- colored compounds is extracted, forming the basis for a simple colorimetric test for coal surface quality. The fact that these aliphatic compounds are responsible for surface hydrophobicity is supported by good correlation between extraction results and floatability, which decreases with decreasing extractability. This extraction test is very sensitive to oxi dationb even the effect of heating for an hour at 100 C can be detected. A second extraction test using mild alkali conditions has shown good correlation with plant dewatering Operations.

Jan 1, 1986

By Weller K. R, Stewart P. S B, Restarick C. J

The performance of the Renison tin concentrator was assessed in detail for two arrangements of the three available ball mills. With two mills used for primary grinding and the third for regrinding table tailing, the concentrator recovered 65.3 per cent of tin in the three tin concentrates produced by tabling, vanning and flotation at a calculated overall grade of 37.5 per cent tin prior to batch dressing. In the second arrangement one mill was used for primary grinding and two mills for separate regrinding of table tailing and sulphide concentrate. The metallurgical effective- ness of the change was somewhat obscured by unintended changes,i.e. an increase in the assay of the fresh feed from 1.38 per cent to 1.1+6 per cent tin and unresolved changes in the sulphide rougher flotation and tabling. However, using the results from a detailed size by size analysis of the behaviour of ore components in appropriate parts of the plant, it proved possible to show that, had the two unintended changes not occurred, up to 5 per cent

Jan 1, 1977

By Chaves AP

This paper describes an investigation on the surface properties and mechanisms involved in the agglomeration of iron ore. For this purpose, an organic binder (carboxyl-methyl-cellulose (CMC)) was used in substitution of bentonite, the classic binder in iron ore concentrate agglomeration. Recently, a renewed interest of the iron ore producers in Brazil to replace bentonite for an organic binder, because of the economy that can be achieved in the, blast furnace operation. These savings are mainly due to the lower aluminum silicate addition which decreases slag volume and the improved pellet metallurgical properties which have the potential for lowering hot-metal production costs. Also organic binders are effective at lower addition levels, which results in lower storage and transportation costs. It is very important in Brazil because of the vast geographical area since transportation is made mainly by truck. Another advantage of organic binders is that they have low ash contents, and therefore most of the binders bum. off during the pellet firing operation. Previous studies have demonstrated the possibilities of the use of CIVIC, but in addition to its high cost, the pellets presented improper behavior at high temperatures or when prepared with high moisture levels. In the investigation here described, these problems have been solved through the addition of other reagents to CMC.

Jan 1, 1993

The equity market is now very much within a global village environ- ment, with various exchanges acting as agencies for the big casino. In this predicament, mining companies, who provide the most extensive, but relevant risk assessment information, will be best placed for favoured treatment by potential international investors: But what risk assessment information in summary form can be provided to support a resource/reserve statement? Even more importantly, does "objective" data exist, whose trends will support a resource/reserve state- ment? A prime need of the informed mining investor is to determine whether or not the resource/reserve statement is believable? But more importantly will it be realised? While the implications within the text of the majority of reports on resource/reserves suggests that the estimates are conservative, the record indicates that very few estimates are. In fact, to date, reports claiming to be conservative in respect of the overall grade estimate at a specfic cutoff have not reflected the realised grade at the stated cutoff; it has been more common for the realised grade to be lower than implied by the resource/reserve statement. Further, it is not uncommon for penalty elements to be understated and these components are rarely incorporated within resource/reserve statements.

Jan 1, 1988

By B Arthur, K Sexsmith, D Hockley, S D

At the proposed Crandon Project, mill tailings would be depyritised for upland disposal. The resulting pyrite concentrate would be disposed of in the underground workings as a cement-amended paste backfill. In the long term, the underground workings would be flooded and the potential for the paste backfill to generate acid would be limited. However, while the mine is operational, there is potential for oxygen ingress to the backfill that may lead to sulfide mineral oxidation and acid generation. A series of humidity cell tests were completed to assess the potential for groundwater contamination. To assess effects of surface area on oxidation, the humidity cell tests were conducted on moulded cubes of paste backfill. The tests were terminated at different intervals, and the cubes were dissected and examined mineralogically. Various leach extraction procedures were also used to assess the progress of oxidation and secondary mineralisation within the paste backfill. The test results showed that: the cement amendment significantly contributes to acid neutralisation and results in a lag in excess of one year before the onset of acidic conditions (in comparison to less than three weeks for the pyrite concentrate); the depth of oxidation in the paste backfill is restricted to about 1 mm after 107 weeks of testing; and secondary minerals form a distinct ærindÆ at the surface of the paste backfill. The results indicate that acid generation in the backfilled stopes would be minimal. The importance of including the surface area effect in the testing (ie using moulded cubes) is clearly demonstrated.

Jan 1, 2003