Search Documents

By Reed M. E, Cloutt B

Particulate samples were taken from the gas space in the settler of the Kalgoorlie nickel smelter using a vertical sampling probe and a specially designed isokinetic sampling probe which also quenched the samples. The vertical sampler was found to give unrepresentative samples. Suction thermocouple measurements of the gas temperature were also made. Using the isokinetic probe samples were taken at four points ranging from near the base of the reaction shaft to the base of the uptake at depths up to 1.5 m into the settler. Dust loadings and the sizing of the samples were determined. These parameters were found to be most affected by sample position and depth. The dust loading decreased along the settler but increased with depth. The loadings varied from zero near the roof to several hundred g Nm 3 near the slag. The dust also became coarser with increasing depth into the settler. Examination of the samples showed them to consist of spherical particles the largest of which were about 500 microns in diameter. The dust was mainly composed of mixed iron/nickel oxides with a little sulphide.

Jan 1, 1991

An assessment has been made of six reported methods for the determination of the swelling of iron ore pellets on reduction. The methods are discussed on the basis of apparatus requirements, reduction conditions, sample requirements, measurement of swelling and reproducibility. It is concluded that the CNRM, LKAB, and Lurgi methods are the most satisfactory which presently exist for determination of the swelling of industrially produced, iron ore pellets.

Jan 1, 1974

By Treglown N

In any mining operation the curtailment of rising operating costs is of prime concern to management.One area of activity where costs are often disguised is that of longhole secondary breakage.This paper outlines sane operational techniques that have been considered and tested, resulting in improved fragmentation fran longhole stope blasts at New Broken Hill Consolidated Limited mine, Broken Hill, NSW.

Jan 1, 1985

By Richards BG, Komdeur W

Instability in spoil piles and in high wall slopes in natural overburden has been ex- perienced at Utah's Goonyella Mine since com- mencement of operations in early 1971. Annual production targets, although gener- ally met since the commencement of operations, required modifications to stripping and mining techniques and the rapid re-scheduling of oper- ations around unstable areas, but culminated in the earlier than planned acquisition of addit- ional stripping equipment. An understanding of failure mechanisms was developed within a collaborative study of pitwall instability between Utah Development Company and the C.S.I.R.O. Division of Applied Geomechanics. Results showed that pitwall instability occurs as structurally controlled deformations along planar failure surfaces; spoil pile failures are precipitated by moist- ure ingress and subsequent loss of strength of base layer materials; highwall failures de- velop over areally extensive bedding planes in conjunction with inclined and subvertical fractures caused by overburden blast damage.

Jan 1, 1978

By G Kuntz, V Wall, B New

The prime aim of the Campbell Mine project was to develop a 3D geological model for the Campbell-Red Lake system to contribute to an exploration model for the region. The base data is composed of over 60 years of geological data covering an area of 16 by 8 km, and from surface down to 1830 m depth. This paper concentrates on the methods used in the GeoSpace system for the processing, integration, display and interpretation of such a large and diverse data set. A block model was developed that recorded the relative frequency of each geological feature within each block. The data input for the block models were based on recoding of the Campbell Mine drilling and channel sample databases into lithological, alteration and structural subsets. The value for each geological characteristic inserted into each block is calculated from all available data that falls within the block. Relative and absolute comparisons of the individual variables provide a targeted outcome from which the blocks are coloured for visual inspection. Different combinations of variable comparisons can be evaluated so that required features are highlighted for interpretation. Blocks are displayed to illuminate the ædominantÆ rock type, according to a formula that may be varied interactively to display the features required by the geologist. This flexibility allows rapid remodelling of lithological distributions, commonly highlighting minor lithological packages not readily visualised in, and interpreted from, drillhole traces alone. The 3D geological model was built from the drillhole datasets and old mine plans utilising standard 3D mining, GIS and database software, with several iterations of plan and sectional interpretation. Near surface bedrock geological interpretations were further constrained by low level aeromagnetic data. The Geospace approach employs an innovative technique for visualisation of the distribution of lithological packages and alteration via block modelling. The method utilises the block model format of data handling as it is considered to be more visible than drilling, flexible enough to incorporate a wide range of data sources, and allows for spatial proximity relationships to be investigated. The method is a simple form of processing large data sets so that results are clearly visible. The calculation is much more rapid than estimation procedures, and does not have any requirement for geostatistical interpretation which is also time consuming. Geospace is not unique to any mine environment software and it is expected to be able to be performed in any system. The proper portrayal of the internal structure of the mineralised body will provide practical input to exploration and mining principally in the areas of resource estimation, exploration vectoring and ore/waste characterisation and may be incorporated with other data to include mine support and mine scheduling.

Jan 1, 2003

Commercial or potentially commercial deposits of coal occur in Australia in strata ranging in age from Permian to Tertiary. The coals of each period tend to show a community of petrographic character and significant differences as compared with coals of other ages. In particular- many of the Permian coals are unusually rich in inertinite whereas the Jurassic and Tertiary coals are typically very rich in vitrinite. The majority of the coals show evidence of deposition in environments subject to relatively minor marine influence. Except for some Tertiary and Permian coals the content of mineral matter tends to be high. Outcrops of coals of bituminous rank appear to be largely restricted to the eastern margin of the Australian continent. In this region vertical rank gradients are generally higher than in the other sedimentary basins and uplift and the removal of cover has occurred to a greater extent. To the west of the Tasman geosyncline, coal of bituminous rank generally occurs at considerable depths (usually in excess of 1 km and in some areas only at depths of over 2 kms), and in most areas coals at shallow depth are of sub-bituminous or brown coal rank. The controls of the distribution of coal type and rank have considerable economic significance and the unusual characteristics of Australian coals, especially with respect to coal type, make the direct application of overseas technology to Australian coals inappropriate.

Jan 1, 1975

By Nguyen T. T, Williams A. M, Siauw T. H

During the last 20 years the CSIRO Division of Manufacturing Technology, through its research and development program, has made a substantial contribution towards understanding the pressure die casting process. Much of this work focused on the hot chamber die casting of zinc, where the importance of achieving optimum flow of metal into the die cavity, combined with the correct thermal balance of the tool, is critical to the production of high quality castings. Having developed a fuller understanding of the heat and fluid flow occurring in the pressure die casting process, CSIRO sought to make this information available to the industry in a form where it could be readily used by die casting engineers. This led to the development of DMT-CASTFLOW and DMT-CASTHERM, two unique, PC-based, die design software packages. DMT-CASTFLOW provides facilities for designing running and gating systems while DMT-CASTHERM enables the die designer to optimise the cooling and/or heating requirements of the die. These two packages are now being sold internationally. This paper will describe some of the major features and benefits that can be derived by using DMT-CASTFLOW and DMT-CASTHERM panicularly in the design of zinc pressure die casting dies.

Jan 1, 1993

By Martin T

High methane content of the medium volatile metallurgical coal mined from the Coal Basin mines causes very difficult mining conditions. Rapid desorption into the mine ventilation system limits coal production, requires huge fresh air quantities and creates mine safety problems. In workings deeper than 2000 ft (600m) gassy coal and heavy cover create outbursting conditions. Cross-measure methane drainage has reduced ventilation requirements on advancing faces, but degasifica- tion of virgin coal is needed to improve mining Conditions.

Jan 1, 1982

With the use of 86 rock drills of the jackhammer type at the West Lyell Open Cuts of the Mt. Lyell Mining & Hailway Co., it is of importance to determine the economic as well as the physical life of these machines. With this purpose in mind records have been kept of the footage bored and the cost of new parts placed in each machine, and the following procedure adopted.A graph is plotted for each machine showing the footage bored as a horizontal line and at each 5,000 feet of boring the total cost of new parts noted on this line. (See l"ig. 1.) Thus at a glance it is possible to see... the amount of work done by each machine and the money spent on it in new parts. However, it is difficult to visualise from this graph the increase in the cost of new parts for each machine as its life advances. To obviate this difficulty a curve is plotted with the cost of new parts as the vertical component and the distance bored as the horizontal component. As before the cost of new parts are taken at each 5,000 feet bored. (See Fig. 2.) The curves so obtained are particularly interesting for two reasons:1. Each machine has its characteristic curve.2. The curve always steepens.Some machines are found to have relatively flat curves, others flat curves for approximately 15,000 feet of boring, and others steep gradients from the begining.This demonstrates that it is not always economic to discard a drill after it has been in service for a certain length of time or after it has bored a specified number of feet. Each drill has its own characteristics and so must not be regarded as one of a class, but considered on its own performance.The following use of these curve diagrams has been made to determine whether a machine has reached the end of its economic life. Figure 3 shows...

Jan 1, 1942

By U JSger

The Westerschelde tunnel will be the first permanent road link between the Dutch regions of South Beveland and South Flanders. Two tunnel tubes, each 6.6 km long, will be driven using the shield tunnelling method. The difficult ground conditions and a water pressure of up to 6.5 bar make great demands on the design. This paper describes the problems and their solutions.

Jan 1, 1999

To help meet the challenge of mine finding at the start of the 21st century, the exploration geophysicist will have at his command a powerful range of tools, some new, some improved, and some which already exist today but are as yet little used. Remote sensing, using satellite and aircraft-based multi-spectral scanners, will provide the means for routinely mapping the surface distribution of certain carbonate rocks, clay and ferrous alteration minerals, based on the analysis of solar reflectance spectra. Time and emission-spectral resolved laser-induced fluorescence will likewise map the distribution of certain ore and pathfinder minerals, as well as certain skarn zones, all potentially related to ore deposits. The GPS (Global Positioning System), based on 18 orbitting satellites, will provide a universal, three dimensional, all weather navigation system which will completely supplant all existing aerial navigation systems, and greatly facilitate aerial surveying and automated processing and presentation of the data. Aeromagnetic gradiometer measurements will provide higher geometric resolution which will yield better definition of individual geological units. Multi-method ground geophysical surveys will be greatly expedited through the use of portable microcomputer-based, multi-sensor instruments. These instruments will interface with other intelligent devices for automated processing, presentation and interpretation of the ground field data. Borehole geophysics will come into more general use, both for at-hole measurements, especially using active nuclear techniques for grade determination, and for remote detection using a variety of electrical, magnetic, seismic and other methods.

Jan 1, 1986

INDEX OF CONTENTSBlast Furnace SlagsForehearth AccretionsConverter SlagsConclusionsIllustrationsCOMPOSITION OF SOME COPPER SLAGS FROM PORT KEMBLASamples of copper slags from the Port Kembla Smelter of the Electrolytic Refining and Smelting Co. of Australia, Pty. Ltd., have been submitted for mineragraphic examination, with reference to the mode of occurrence of copper in them. The samples included (I) blast furnace slags, (H) a forehearth accretion, and (IH) converter slags. 1. BLAST FURNACE SLAGS Four series of samples of blast furnace slag have been submitted. The. chemical compositions of the several slags are shown in Table 1. Analyses Nos. 1 and 2 are of samples of slowly or normally cooled slag, taken from the slag dump, Analyses Nos. 3 and 4 are of samples comprising slowly or normally cooled slag, together with granulated slag from the same melt.

Jan 1, 1949

Biologically-mediated phenomena are involved in many of the natural processes by which mineral deposits are formed and ore bodies transformed and degraded. They may facilitate the environmentally-damaging effects of mining and mineral-processing operat- ions. Under contrived and controlled conditions, however, these phenomena can form the basis for economically- attractive processes for the recovery of metals from low-grade deposits by dump, heap or in situ leaching. They have application also in processes for the regeneration of leaching reagents and some potential for'-the recovery of metals from dilute solution. The micro- organisms concerned are potential sources for the production of novel flotation and solvent-extraction reag- ents. Perhaps the greatest opportunity for biotechnological processes in min- ing and metallurgy lies in the possib- ility of the evolving of novel proced- ures for the substantially complete recovery of metals from process tail- ings by the unlocking of recalcitrant and complex mineral assemblages, and for the beneficiation of some mineral materi,hls.

Jan 1, 1982

Backfil ling of excavated Sub Level Open Stopes has been underway since March 1989 and as at December 1992 some 1 100 000 cubic metres of Cemented Aggregate Fill have been placed. During these three years significant developments in fill quantities, types and cost have taken place.Operational improvements have reduced the quantity of Cement Aggregate Fill by 40 per cent. These results have been achieved by:ò rescheduling stopes,ò designing smaller primary stope, and ò use of uncemented rockfill.Unit cost for Cement Aggregate Fill have fallen in the order of 50 per cent through:improving fill hole reli ability,simplified barricade construction procedures, reducing the cement content,ò substituting dune sand for deslimed mill tailings, ò improved maintenance at the Backfill plant, and ò renegotiated site freight agreement.This paper will review the historical developments of backfill use at Olympic Dam.

Jan 1, 1993

By T Nixon

A common problem for many mines is insufficient total primary airflow or insufficient airflow in the correct places as the mine changes over its life. This has a number of impacts on the business operation and may result in the need for a major and unexpected capital upgrade of the system, cancellation of a planned production increase, reduction in production targets, increased operating costs, failure to provide contracted metals to customers or acceptance of substandard conditions in the workplace. In some cases, it can even result in premature closure of the mine. In recent times, higher metal prices have given an expected economic boost to many mines, potentially prolonging their life but simultaneously requiring the mine to develop to deeper depths or requiring assets such as shafts and fans to have their service life extended. Insufficient primary airflow is a particular problem in deeper mines as the ventilation circuits become longer, more convoluted, have higher shock losses and the actual airflow requirements increase due to a combination of leakage, dispersion of the workings and the problems of managing the additional heat loads due to higher virgin rock temperatures and autocompression. This paper discusses the reasons why mines experience unexpected shortfalls in primary ventilation capacity with its associated impacts on metal targets, profits and frequently on the health, safety and morale of the workforce, as well as its productivity.

Jan 1, 2008

By M Fimeri, R Williamson

Sample sizing in the iron ore industry requires significant manual effort to collect, transport, and sieve the samples as well as record, process and report the data. Efforts have been made to automate this process, which essentially emulate the manual process, except that a person is replaced by a robot. Even in these cells, the sieving and sizing operation consumes a significant proportion of robot time. The proposed doubling of production from AustraliaÆs iron ore mines over the next five years will place increasing pressure on sample sizing and interest is increasing in alternative automated methods. One such method is the adaptation of computer vision technology which has been successfully introduced into the mining industry in a range of applications including feed size distribution to SAG mills and oversize detection from screening stations. The limitation of this technology is that only the top surface is visible and this is used as an indicator of total size distribution. Obviously in a sample plant, where 100 per cent of the sample must be measured for acceptable quality assurance, this approach is unacceptable. In order to capture 100 per cent of the sample using computer vision technology a monolayer must be formed either by spreading the sample across a moving surface, such as a conveyor or vibrating platform, and passing this under a camera. This will become a æsurgingÆ load which presents specific problems for some types of computer vision systems, namely those relying on a 2D approach. In this paper a 3D computer vision technology will be described which overcomes the problems associated with measuring particle size in a monolayer and experimental results will be presented which demonstrate its effectiveness for lump and fine iron ore sample size measurement.

Jan 1, 2008

Perhaps the only thing certain about an address that purports to look into the future of any human endeavour is that time will prove it :.o be inaccurate. In undertaking the dubious, but oft-times necessary business of prediction, thr, historian will base his/her forecasts on tr-ands of the past, the speculator on current events, and the politician on what he/she would dearly like to see happen. The thoughts expressed in this address seem to have arisen through exercising a combination of all three of those philosophies but, hopefully, with a smat- tering of pragmatism.

Jan 1, 1988

Neutralisation, normally using lime, is the most widely used method for treating high flows of acid mine drainage (AMD). Lime costs can be very high however. If carbonate sources could be used to achieve pH values above six, costs could be greatly reduced. For example, use of locally quarried limestone at Mt Lyell could potentially reduce alkali costs from about $A 3.5 to $A 1 million/year. Methods for enhancing the effectiveness of limestone and magnesite for neutralising Mt Lyell and Savage River AMD respectively have been examined through a series of investigations. Small-scale testwork found that the maximum pH economically achievable with ground limestone was about five, due to slow dissolution rates and surface armouring. The problems of surface armouring were greatly reduced by the use of crushed limestone or magnesite at high pulp densities (75 per cent solids w/w), enabling pH values >6 to be achieved in a practical time frame. The use of particle sizes in the range 6 mm and finer also reduces costs by avoiding the need for grinding, and reduces the problems of solid-liquid separation and solid recycling that arise if large additions of ground carbonate are used. Pilot scale tests were carried out using tumbling drum reactors with limestone and Mt Lyell AMD and a pulsed-bed static reactor with magnesite and Savage River AMD. pH values averaging 6.2 and 6.4 were achieved with Mt Lyell and Savage River AMD respectively. Approximately 80 per cent of feed acidity was neutralised. A preliminary engineering design and cost estimate has been completed on the pulsed-bed reactor and shows that the concept is technically feasible and, if results are confirmed, economically attractive. Further pilot testing is planned.

Jan 1, 2002

South Australia was founded as late as 1836, forty- eight years after New South Wales, yet within five years had announced the first discovery of metals in Australia. Throughout the 1840s the mining of silver-lead, then copper, spread north through the Mount Lofty and Flinders Ranges creating a thriving industry, years before the discovery of gold in the eastern colonies in 1851. The first significant mine was Kapunda (1842), followed by the much bigger Burra (1845) and other copper finds at Tungkillo, Worthing, Cal- lington, and North Rhine.

Jan 1, 1987

Good morning ladies and gentlemen. It gives me great pleasure to talk to you today about a pet subject of mine, on when to mill and when to leach gold ores. According to Gold Fields Mineral Services of London, gold production in the United States in 1989 amounted to about 8.5 million ounces (259t), an increase of 29 per cent over 1988 and 67 per cent over 1987. The U. S. Bureau of Mines reports that from the major producing states of Nevada, California, Montana, and Alaska, some3.2million ounces of the 1989 production were produced from milling gold ores and 2.3 million ounces from heap or dump leaching. Ap- proximately 45 million tons of ore were milled and 140 million tons of ore were heap or dump leached.

Jan 1, 1991