Search Documents

By Yuanping H

There is a practical method of handling methane in a fully mechanized high output coal face when the methane outflow rate from the face is too high to be handled by ventilation alone, a combined method would be adopted. Before adopting this method, above all, the sources of methane outflow, which can be divided into methane in the intake airflow and methane emitted from the working seam and from the worked-out area, are determined by air-methane measure- ments in the tail gate and intake conveyor gate or by air-methane measurements in the working space of the coal face. Then, in

Jan 1, 1988

Renison Goldfields Consolidated Limited (RGC) and Consolidated Gold Fields Plc (CGF) purchased New Guinea Goldfields Limited (NGG) in 1982 as an exploration venture. Following an intensive drilling programme in the Upper Ridges area sufficient ore reserves were outlined to justify the installation of a new 700 tonnes of ore per day gravity gold extraction plant. Major considerations in the design of the new plant were to minimise production inter- ruptions in the existing plant and to include simple, but technically efficient, equipment that could be operated and maintained by a workforce with limited experience in modern technology. These goals were achieved over a six month period, commissioning being carried out in April, 1983. Mining the epithermal gold deposit is by open cut benching and truck haulage. The gravity concentrator includes a scrubber, wet hammer mill and rod mill, to crush, grind and prepare the ore for sizing and desliming. Gold recovery units consist of a jig, spirals, shaking tables and amalgam barrels. Although the majority of the gold is in the minus 100 plus 20 microns size fraction a recovery of 63 percent, from a head grade of 2.0g/tonne, is Achieved.

Jan 1, 1984

By Whittle J

Definition of the optimum open pit, whether an intermediate phase or final design, will be sensitive to many factors. The most basic will include geological and mining constraints, mining and processing costs, pit slopes and product prices. The application of the three dimensional Lerchs-Grossmann pit optimization procedure to this task is described for a range of gold deposits. A new approach to the modelling and manipulation of the geological model enables complex geological environments to be assessed, and sensitivity analyses to be developed. Comparisons with manually developed pit designs have been made to validate the results. The computer implementation is simple to use and can be adapted by non-computer professionals at mine Sites.

Jan 1, 1986

By Tapp B. A

To date, few studies have been made regarding the energy requirements of the Australian mining and mineral processing industries. This paper indicates that these industries use a substantial proportion of the total Australian energy input (32.7% in 1971-72 and 36.10% in 1974-75). With the growth orientation of these industries, this input is likely to increase. Data shows that mining energy requirementE varied from 4.22% (of total Australian energy requirements) in 1971-72 to 4.16% in 1974-75. Energy requirements for the total mineral processing industries increased from 28.49% to 31.93% for the same period. The total estimated primary energy input varied from 22.56% to 25.2%, whilst indirect energy use, in the form of electricity increased from 10.16% to 10.66%; in the same period. Analysis of primary energy input data within the processing industries (1973/4) showed that the Iron and Steel Industry consumed 15.03% of the Australian total consumption, Non-Ferrous metals, 5.43%, Cement, 1.64%, and Refractories, 1.59%. In toto this represented 24.57% of the total

Jan 1, 1979

By P Cepuritis, G Chitombo a, I Brunton

There is a significant amount of past evidence that links blasting and occurrences of slope failure. Particularly of great concern at Telfer Gold Mine is the effect of open pit blasting on the stability of the footwall slope above the underground portal and the stability of underground structures. For this reason, Newcrest Mining Ltd invited JKMRC to conduct necessary field measurements and numerical modelling with the following objectives:assess the dynamic stability of the footwall slope above the portal; assess the characteristics of current and future blasts in the open pit; and prepare open pit blasting guidelines that will minimise the detrimental effect of blasting on slope stability. To achieve these tasks it was necessary to develop a scaled distance attenuation curve for blast vibrations. In order to validate the developed vibration attenuation curves it was necessary to monitor vibrations from a production blast. Using JKMRC blast design software tools, the vibration of the production blast was also modelled from the blast design and vibration results from single hole blasts. The intention was, assuming that the observed and modelled vibrations were close in terms of frequency and amplitude, to use the software tools to model the vibrations of future blasts and assess their likely effect on slope stability. Numerical modelling of the dynamic stability of the footwall slope was done using the FLAC finite difference code and the UDEC distinct element code. The results of the numerical modelling and of the field measurements of the blast induced ground vibrations were combined into the blast design rules that relate distance between the slope and the blast, charge weight per delay and number of blasts necessary to cause failure of the slope.

Jan 1, 1999

By M Thomas, S Lambert

The Tugun Bypass Tunnel in Gold Coast, Australia was constructed using diaphragm walls with the top-down cut-and-cover method to allow simultaneous construction of an airport runway extension above the tunnel, whilst excavation of the tunnel continued underneath. The tunnel was built in an environment of high groundwater table and deep deposits of alluvial and estuarine soils with the toes of the walls founded in soil deposits. There was a potential risk for differential settlements to occur between the diaphragm wall panels, caused by the runway fill placed over the tunnel roof during excavation. Dewatering within the diaphragm walls was required to facilitate the construction of the tunnel. The tunnel was also built in an area where environmental considerations were of great importance. Three-dimensional numerical modelling was undertaken to predict the differential settlements of the tunnel with considerations of varying subsurface profile, staged excavation and dewatering, non- uniform surface loading and complex soil-structure interaction. Field instrumentation and monitoring was implemented to confirm numerical predictions.  

Jan 1, 2008

By Wu H. W, Just G. D

Australia's mineral resources boom in the two decades up to 1980 saw the establishment of about 25 new mining towns across the continent Quality housing and a high standard of community services were incorporated to attract a labour force for the major mine or mines i eing serviced. Town construction costs were high and were principally born by the private enterprise mine developer. There has been a change in the pattern in recent years and over 20 new mine developers have adopted a fly-in fly-out arrangement rather than construct new towns. Employees are drawn from a home base which is typically a large city, coastal community or established mining town and flown to the mine site for intensive work periods of about two weeks. The change has occurred for many reasons. Mining companies have been unwilling to support the high construction costs of towns, short life and smallermining operations do not justify a town, fast jet aircraft are available and there is a better perceived family lifestyle in established (coastal) communities. On the other hand reduced permanent development at new mine sites does not assist Australia's perceived need for decentralization. There have been questions as to the social problems which may develop from the artificial separation of the "breadwinner" from his family. The paper reviews a recent survey of the attitude of Australian mining companies employees, governments and unions to fly-in fly-out arrange- ments. The support for this approach is analysed and conclusions drawn that the concept is likely to be with the Australian mining industry for some time in the future.

Jan 1, 1991

Around no subject of technical )uterest have prejudice and wrong-thinking in the past so wrapped a web of obscurity as that of the corrosion of metals.It is a matter which has primarily concerned the engineer, but the paucity of his training in chemistry and electrochemistry has been the stumbling block to a better understanding of its mechanism.Now that the more important conditions controlling corrosion have been scientifically.established, it can be seen that, with the exception of but a few of the minor points, the electrochemical laws enunciated by Faraday, Helmholtz; Nernst, and others, are sufficient to include all the facts of the process.The word corrosion (derived from the Latin rodere-to gnaw) is so often wrongly applied that a definition at this stage would be useful. As now understood, it means the dispersion and waste of the useful solid metal by conversion into a useless compound which mayor may not be retained on or near the metal remaining.Commonly the presence of these compounds is regarded as evidence of corrosion, but the converse is not necessarily true; the lack of visible corrosion products on a clean surface of metal is no criterion of the absence of this change. It may be difficult to prove that the erosion of such a surface has been caused by chemical and not by mechanical effects alone.

Jan 1, 1932

By Just GD, Phillips R

The application of high pressure water jet technology to the drilling of longholes in coal has resulted in the development of a system currently capable of drilling to lengths greater than 200m. Field tests at the German Creek Mine have demonstrated directional control of the holes within a 0.5m section of the seam. Initial application of the technique at the German Creek operations is for drilling methane drainage holes. These developments, in three stages, result from support by the National Energy Research Development and Demonstration Council

Jan 1, 1991

By R McConnochie, J V. Rowland, J L. Mauk

The Sovereign prospect in the lower Waitekauri Valley of the southern Hauraki Goldfield occurs in daciterhyolite flows and volcanic breccias of the Waipupu Formation. The lower Waitekauri Valley contains a series of NE to NNE-trending normal faults, and the Sovereign prospect lies in a NW-striking graben. The structure of the Sovereign prospect is complex. NE to NNE-trending veins and normal faults dominate the area, however WWNW and N to S-trending structures occur locally. Kinematic analysis of these structures indicates predominantly dip-slip movement, with a local strike-slip component. At least two sets of veins occur in the area: 1.        steeply dipping veins; and 2.       low angle veins, which cross-cut and locally offset the steeper dipping        vein set. Mineralization appears to have formed during normal faulting in an extensional regime.

Jan 1, 2007

By K-S Kim, C-Y Kim, D-G Kim

In tunnel construction or other underground construction, a detailed knowledge of the rock mass ahead of the face is essential for both safety and efficiency of work. Many tunnel collapses have been reported to occur because of lack of appropriate information, such as the geological conditions ahead of the tunnel face. One of the methods which can identify rock mass conditions is the application of drill monitoring data obtained from blasting drill holes, which can detect abrupt and unexpected changes in ground conditions, geological structure and the mechanical and physical properties of rock mass. This paper presents a new approach to how drill performance parameters can be used for prediction of geological conditions ahead of tunnel face. The predictions are based on monitoring the drill parameters of instantaneous advance speed, torque and tool pressure. In order to assess conditions ahead of tunnel face, tunnel seismic profiling (TSP) and a horizontal boring investigation were undertaken and the obtained data compared to the drilling data. The predicted results using drilling performance parameters correlated well with geological conditions ahead of tunnel face.

Jan 1, 2008

In an earlier paper(l) details of a laboratory method of extracting and separating tantalum and columbium oxides from tantalite have been given. In view of the fact that Australia may have need to be self sufficient in this field it was decided to erect a pilot plant for the production of tantalum oxide in the Metallurgy School, University of Melbourne. The plant was designed for treating about 40 lb. of ore in a batch over a period of two weeks, although; because of the sectionalized nature of the process, the capacity of the plant was 40 lb. ore per week.Australia is fortunate in possessing some very rich tantalite and columbite deposits, particularly in the Pilbara District in Western Australia. The ore used in this work was obtained from a small but high grade deposit near Greenbushes, Western Australia, and consisted of lumps, weighing up to 8 lb. each, of almost pure ferro-tantalite with occasional thin veins of the very' rare' mineral stibiotantalite.The main constituents were:

Jan 1, 1946

By R G. Barker, A B. Christie

Minerals are necessary for providing almost everything we take for granted in our daily lives including food, shelter, and supplies of energy and water. Minerals are therefore essential for the maintenance and improvement of the standard of living of all New Zealanders.

Jan 1, 1998

By E Haren, A Winchester

The CSA Mine has a long and varied history from initial discovery in 1871 through to the present. Lead-zinc mineralisation was mined historically near the surface. Today copper and silver are extracted from the deeper regions of the mine. The mine has passed through a number of owners over this time, each with a unique operating philosophy and understanding of the mineralisation. Cobar Management Pty Ltd re-opened the mine in 1999 and has undertaken extensive drilling programs to expand the resource and gain a better understanding of the mineralisation characteristics. Presently mineralisation has been located over a strike length of 1.2 km and to a depth of over 2.0 km with over 30 mineralised lenses from four identified ore systems. The refinement of geological and mineralisation models led to further discoveries and prompted a review and modification of resource modelling processes. Advanced statistical analyses prompted the implementation of ordinary kriging as a grade estimator. Improved stationarity from enhanced geological domaining has been supported by variography and kriging neighbourhood analysis studies. Resource models at CSA are now quantifiable in terms of mineralisation style and estimation reliability. The new techniques are assisting the definition of more mining fronts, which are creating new opportunities to increase mine output.

Jan 1, 2006

The Snap Lake Phase I project initiated a subsampling campaign on the material (kimberlite/metavolcanic/granite) mined and treated for diamonds. The campaign was aimed at determining the optimum subsampling program to subsample the feed to the bulk sample plant (BSP) for the duration of a sampling campaign. This paper describes the application of GyÆs formula for determining the subsample size and other good sampling practices to determine this subsampling campaign. Three main issues are discussed: the use of a hammer sampler to sample off a moving conveyor and the practical experiment to determine the optimum subsampling program; bias introduced by laboratory equipment including two sizes rotary splitters; and variability of the feed material to the BSP over time.

Jan 1, 2005

Mineralisation adjacent to Herberton occurs within three main subcentres. The Her- berton Hill subcentre is characterised by the association of Sn,W the Herberton Dividing Range South subcentre by Sn, and the Herberton Dividing Range North by Cu, As. The relation- ships between the subcentres are discussed in terms of metal distribution, production, deposit types, wall rock alteration and re- lationships with granitoid intrusives. The temporal and three dimensional spatial re- lationships between the centres are uncertain.

Jan 1, 1978

Detailed studies of mineral paragenesis, isotope and trace-element geochemistry, and physical mineralogy at Mount Morgan are compatible with deductions by Geopeko Ltd geologists concerning field relationships in the mine area. Considered together, field and laboratory data suggest that the Mount Morgan deposit originated from a shallow, intrusive, acid volcanic dome similar to those which produced the Kuroko-type deposits in Japan. At Mount Morgan, however, interaction with sea water was much less, the sulphides were concentrated rather than forming a group of deposits, and only the throat of a breccia vent is pre- served, so that only the lowermost parts of Kuroko-type deposits can be compared with the Mount Morgan mine. A final difference lies in the presence at Mount Morgan of a quartz diorite adjacent to the ore. Mineralogical data are compatible with post-ore intrusion, possibly up an earlier volcanic fissure.

Jan 1, 1974

Throughout the Kalgoorlie Field the dominant factors influencing all planned exploratory work are: firstly, the general geology of the district, and, secondly, the lode fracture pattern. Superimposed on these, there are innumerable faulting problems which tend to complicate the search for ore.In this paper it is proposed to deal primarily with the lode fracture pattern and to touch on the general geology only insofar as it affects ore distribution. So much has been written on Kalgoorlie geology that it would be impossible to review the literature adequately in a brief paper such as this. The basic facts of rock types and rock distribution are well established and the broad structure of the field is known in the central portion, though it is less well established towards the northern and southern ends.The latest descriptions of the general geology are those of Stillwell (1), and Gustafson (2), -and these represent the basis of current knowledge.GENERAL GEOLOGY.The field is six miles long and about one mile wide, the long axis trending north-west. The "Golden Mile," or heart of the mining 'area, covers a length of three miles in the southern section, and consists of a central core of quartz dolerite greenstone which merges into uralitic quartz 'dolerite on its western margin. The uralitic quartz dolerite is derived from an original quartz dolerite by a low grade...

Jan 1, 1948

By D J. Cronin

Alcoa World Alumina AustraliaÆs Huntly and Willowdale bauxite mines are located in the Darling Range of South Western Australia, which places their operations within PerthÆs surface water supply catchments. These catchments supply Perth with its highest quality drinking water. With the decreasing rainfall trend of recent years catchment yields to water supply reservoirs have reduced to such an extent that water use restrictions were necessary in Perth for 2001, 2002 and 2003. Protection of catchment water quality and water use conservation are crucial issues for AlcoaÆs operations within the Darling Range. Alcoa has been conducting bauxite mining activities in water supply catchments since the mid-1960s. During that time Alcoa has worked closely with the relevant State Government water and environmental agencies to ensure that its operations do not adversely impact catchment water yield and water quality. Monitoring and research have shown that Alcoa has the necessary environmental management systems in place to ensure it can continue to operate in a sustainable manner within water supply catchments. AlcoaÆs mines reduced the volume of water taken from public water supply catchments by 24 per cent in 2002, compared with 2000. This success has had an added benefit; Alcoa does not need to develop a new water source for its Huntly Mine. The conservation measures implemented to reduce water use include: increasing water recycling, using chemical additives for haul road dust suppression, conducting water audits, reducing water demand, monitoring water use, promoting water use targets and training staff in water conservation.

Jan 1, 2003

The rapid growth of world civilisation will have a significant impact on the way humans live in the future. As the global population increases and more countries demand a higher standard of living, the world must provide more food and greater energy and mineral resources to sustain this growth. The difficulty of doing this is compounded by three broad trends: the conversion of agricultural land to development uses; the increasing urbanisation of the world's population; and growing concern for the maintenance and improvement of the environment, especially regarding global warming and the impact of population growth. Underground space utilisation offers opportunities for helping address these trends.

Jan 1, 1993