Search Documents

The Mt Lyell Mine at Queenstown, Tasmania was re-opened in 1995 by Copper Mines of Tasmania Pty Ltd, a wholly owned subsidiary of Mt Lyell Mining Co Ltd. The re-opening followed over 100 years of copper and gold mining at Mt Lyell. Major changes in practice were implemented across the site. Preventing further damage to an already disturbed environment was a major priority. Sublevel caving, at a lower cut-off grade, replaced open stoping for the deep underground mining. Development and later stoping are handled by a contractor, National Mine Management Pty Ltd, in the largest underground contract awarded at the time. Large scale sublevel caving was new to Mt Lyell and not widely practised in Australia, requiring studies and systematic development of the method, particularly in drilling and blasting. Rehabilitation and upgrading of mine infrastructure have been and will continue to be a challenge. The mine has, since 1995, returned to being a stable producer with potential for growth.

Jan 1, 1998

The process selection and design aspects to treat primary ore in a new carbon-in-pulp (C.I.P.) plant while utilizing, where possible, existing equipment and infra- structure are discussed. The existing crushing plant, water supply, reagents, laboratory and infrastructure facilities from the heap leach have been upgraded and expanded to meet the C.I.P. plant requirements. The new power supply is from the North Queensland grid system. A series of metallurgical tests was carried out and a review of the data showed that the primary ore was amenable to conventional cyanide leaching. Following feasibility studies, a new process plant which included grinding mills, leaching, and adsorption tanks, thickener, desorption and gold roam facilities was constructed.

Jan 1, 1989

By Wang J, Ma Y, Jia H

The Hedong Gold Mine is located in the Yan(ai area, tihandong hroo%ill, e. China. It is an underground mine with an annual gold output of some 700 0(H) grams. The orebody is located on the edge of the Wanger Shan metamorphism zone, and the hangingwall of orebodies is thus defined by a prominent set of fractures. The proximity of the metamorphism zone and the inclusion of the fracture set ensure that both the orebody and the country rocks are unstable. The main orebodies dip at an angle of between 40 to 45¦, with a strike length of 160 metres and a horizontal width of 50 metres. Surface subsidence in the area is not permitted. Cut and fill mining is usually practiced. As the mining operation proceeds to greater depths, the ore grade is diminishing and it is necessary to find a more efficient stoping method. Sublevel open stoping with sequential extraction and filling of each sublevel has been designed and applied in situ. This new mining method is called 'sublevel open and fill stoping method' in the mine. Experience to-date is that new mining method is Satisfactory.

Jan 1, 1998

Pyrite is a significant gangue sulphide mineral in the Ok Tedi copper ore. Its presence in the flotation concentrate is not entirely desirable since it lowers the grade of the final copper concentrate. Lime depression of the pyrite has been practiced with some success. However, it has been observed that at the pH for pyrite depression a significant amount of the pyrite particles still float. To obtain further insight into the problem this work has been conducted to determine the composition, natural floatability and xanthate flotation behaviour of the various types of pyrite in the ore. The flotation results show that while some types of pyrite float well at high pH values, others are readily depressed. The implications of these results for Ok Tedi flotation plant have been Considered.

Jan 1, 1997

By P Hatherly, H Gurgenci

With the depletion of the mineral reserves that can be mined by surface mining, demand for highly productive and safe underground mines will increase. Underground drill and blast techniques continue to be refined but true æmass productionÆ is difficult to achieve. As is evidenced by the longwall mining of coal, alternative mining methods based on mechanised mining can meet the expectations but the issues of how to effectively cut strong rocks, how to define the orebody and how the mechanised miners can be automated and maintained all need to be addressed. CMTE is working in all of these areas. We believe that the oscillating disc cutter may provide the long sought-after breakthrough in mechanised rock cutting. Disc cutters are one of the most robust designs of cutting tool and the cutters attack the rock in a manner which effects direct tensile breakage. The internal cutter drive and the inertial damping mean that the already low cutter forces are not all transmitted back to the machine, making it possible to design lightweight, flexible mining systems. For orebody delineation drill monitoring, drillhole logging and geophysical imaging are key procedures being developed at CMTE. To automate mining machines, work is progressing well in the development of systems for autonomous vehicle navigation and mining robotics. A strategic contribution to maintenance issues is being made through the development of procedures for automatic analysis of used oils, monitoring the strength of mechanical structures, and operating point optimisation.

Jan 1, 1998

By S Furman, M Caccetta, A Hacket, B McDonald, M A. Wells, D Lau

In 2004, the Western Australian Department of Industry and ResourcesÆ Burrup Rock Art Management Committee commissioned a number of independent scientific studies to evaluate the condition of rock art in the Burrup Peninsula near Karratha (Western Australia). These studies are evaluating the physico-chemical aspects of the effect of environmental modification on the visible appearance of the rock art. Because of the cultural significance of the sites, the research approach has been to employ non-destructive testing strategies and work in the field has progressed with respect for the importance of the area. This paper only reports the spectral mineralogy monitoring at each of the sites to evaluate whether changes in mineralogy are observed on rock surfaces. Reflectance spectroscopy is a non-destructive, in situ materials characterisation technique that provides information about the mineralogy. The minerals detected include haematite, kaolinite, chlorite, goethite, gibbsite and manganese oxides. Current results indicate that the surface mineralogy of the rock art has not changed in the last four years.

Jan 1, 2008

By A J. Morrison, M Yahyaei, J S. Siong, J Wang, K Runge

The flotation cells used to upgrade ultrafine metallurgical coal (-250 µm) are usually poorly controlled leading to unnecessary loss of combustibles from the flotation system. This is mainly because coal flotation cells are typically controlled for process stability rather than optimisation of flotation performance. This is especially true for a flotation device commonly used in coal applications in Australia – the Jameson Cell. This then provides an opportunity to improve the flotation performance by shifting from a stabilising control strategy to a proactive optimising control strategy. For an optimising control strategy, the control system will require a means of relating and then measuring in real-time, the effect of changing operating conditions on the coal flotation performance. Hence, the major aim of this work is to propose a possible model-informed process control strategy that could be used for real-time performance optimisation. In this study, industrial site work was conducted on an industrial-scaled Jameson Cell at a Coal Handling and Preparation Plant (CHPP) in Central Queensland, Australia where superficial gas velocity was controlled to six different levels. At the same time, other process variables such as froth depth and flotation feed properties were measured. The empirical models developed from this study suggested that combustible recovery is a function of superficial gas velocity, froth depth, feed solid content and feed ash content and that a peak in combustible recovery existed as a function of superficial gas velocity. This led to the development of a model-informed control strategy that aimed to maximise the combustible recovery by determining and then operating the cell at the superficial gas velocity at which the peak occurs. This peak superficial gas velocity was found to be only a function of feed solid content. Based on these findings it would seem possible to operate a Jameson cell at peak performance by online measurement of feed solid content, prediction of the optimum superficial gas velocity and stabilising control to maintain operation at that superficial gas velocity set point. The development of this modelinformed control strategy can serve as a basis for the development of a more sophisticated modelpredictive control (MPC) system. However, more work will need to be done to improve the predictivity of the combustible recovery model by measuring and modelling performance over a wider range of operating conditions.

Aug 24, 2022

By Butcher NM, Walker GS

Argyle Diamond Mines Pty. Limited (ADM), manager and operator of the Argyle Diamond Mines Joint Venture (ADMJV) will recruit approximately 400 employees during 1985 to operate the new large-scale, open-cut diamond mine and treatment plant being developed at Argyle, in the East Kimberley Region of Western Australia. These employees will live in Perth or environs and will commute to work at Argyle via chartered jet aircraft. On site, they will be accommodated in self-contained single person's quarters, with central messing and recreational facilities. Rostering systems have not been finalised, but it is likely employees will rotate through a cycle of 14 days at site and seven-days on leave in Perth. ADM spent three years evaluating residen- tial options before deciding to commute its workforce from Perth. Another 70 senior staff will reside in Kununurra (the nearest established town, 250 km from Argyle) and commute to the mine daily by air.

Jan 1, 1984

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high-speed photography to better understand the mechanisms of fracture and fragmentation.CITATION:Fourney, W L, 2015. The role of stress waves and fracture mechanics in fragmentation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 27–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Worner H. K

The paper briefly summarises the work of the Titanium Research Section in the Metallurgy Department of the University of Melbourne and mentions the development of a new electrolytic process for titanium production. This process utilises the "hot-spot" cathode technique and titanium carbide anodes. An introduction is given to three further papers on titanium metallurgy to be presented to the Institute.INTRODUCTIONThe unique combination of strength, lightness and corrosion resistance possessed :by titanium and its, alloy has made them of great interest to engineers. However, high cost, difficulties of production and limited knowledge of techniques of application restrict their usage at present almost exclusively to high priority armaments.The cost of the metal is divided between extraction and processing and much research has been carried out to devise new and cheaper methods for winning the metal from its ores. Processing costs will be reduced when production volume increases.Extraction research is proceeding rapidly overseas and Kellogg (1955, p. 72) reports that 'at least seventeen companies in the U.S.A. are interested in titanium production. Of these, two are producing the metal by a modified Kroll process, three are building Kroll plants and the remainder are in various stages of research activity. The Horizons Corporation alone is contemplating electrolytic extraction and is building a pilot plant. Steinberg et aI. (1955, p. 252, p. 332) have reported the early work done by the HorizonsCorporation on electrolysis of potassium fluotitanate and titanium monoxide in fused salt electrolytes. Of these two, the former appears to be the more attractive process.

Jan 1, 1956

The production of synthetic rutile from ilmenite using hydrochloric acid leaching is investigated. Previously published data is used to comment on the optimum process conditions. It is shown that the most important aspect to consider is the maximisation of impurity dissolution and the minimisation of titanium losses.

Jan 1, 2001

By P Dowd, A Adeli, C Xu, X Emery

Geometallurgical modelling is increasingly being incorporated into mineral resource modelling and estimation as a means of increasing efficiency, decreasing operating costs and reducing risk in mining operations. Traditional geostatistical workflows for geometallurgical modelling face several difficulties, in particular, related to the non-additivity of process response variables, to highly heterotopic data sets and/or to preferential sampling designs, all of which may explain why most attempts to estimate geometallurgical response variables from assay data and mineralogy are still based on statistics and machine learning. The aim of the work presented here is to demonstrate the applicability of geostatistics to estimate copper recovery from copper sulfide ores at the Prominent Hill Iron Oxide Copper-Gold (IOCG) deposit in Australia. As recovery is non-additive, the preferred workflow is the joint estimation of the masses of metal in the feed and in the concentrate, both of which are additive variables. While the mass of metal in the feed can be estimated from abundant online assay analyses, the mass of metal in the concentrate can only be estimated from a very limited number of laboratory-scale batch flotation tests. Traditional approaches to estimating the masses of metal in the feed and in the concentrate, such as simple and ordinary co-kriging, are described and discussed. A modified version of co-kriging is introduced, which incorporates linear relationships between the mean values of the input variables, in addition to a spatial correlation model. Co-kriging with related means is shown to outperform traditional simple and ordinary co-kriging in terms of precision, accuracy and consistency of the estimates, and offers a practical and efficient tool to deal with highly heterotopic and preferential sampling designs.

May 24, 2023

By S Williams, N McBride

The aim of these analyses was to utilise the latest available production information for the Wandoo operation to determine the optimal blasting parameters, costing information and predicted results (fragmentation, muckpile shape and vibration). Much of the data used as input was made available from the information gathered during the excavation of the test pits during 1995. As with any æplanning stageÆ analyses, many assumptions were required to fill gaps in the available data. The calibration of computer blasting models was conducted using data from the last of the test pit blasts (this blast was carried out in material that closely resembled rock expected to constitute the bulk of the base case design pit). This calibration was refined using observation and experience based judgements to extend the accuracy of the predictions as far as possible. All the simulations were performed assuming that the blastholes will be wet (as instructed by BGM). This has consequently determined that the appropriate explosive for the simulations and the actual blasting will be a pumped emulsion/ANFO blend. The following blast design parameters were derived by determining a likely range of powder factor (from other similar scale gold mines) with a median value of 0.62 kg/m 3 being the powder factor arrived at through the field optimisation process conducted during the test pit excavation. The total swell/displacement percentage (volume after blast/volume before blast) largely determines the diggability of a well fragmented muckpile. Consequently where fragmentation is good any reduction of total swell will probably reduce diggabilty. Any reduction of diggability can and should be traded off against increased gold recovery. In most gold mines, diggabilty will be substantially compromised at the balance which produces the most profit. When these considerations are combined with the cost to drill and blast material, processing costs and the achievement of æacceptableÆ diggibility, the analysis becomes extremely complex and qualitative. Many trends are evident including:the relationship between powder factor (for each blast design) and maximum forward displacement (throw), see Figure 1; and the relationship between powder factor (for each blast design) and drill and blast cost per BCM, see Figure 2. The following blast designs are matched to each of three ore-tonnage alternatives (as supplied by BGM) (Table 1). They are all based on powder factor of 0.62 kg/BCM and are considered optimum from a mining æpoint of viewÆ. The costing of each design includes drilling, explosives and labour cost to load, stem and tie-in holes. Using the available rock data and relying heavily on the wall exposures in the test pit(s), it is the opinion of the author that between 20 per cent to 40 per cent of the final walls excavated in the Wandoo pit would be likely to have the angle between the dominant foliation and the wall plane that is well suited to presplitting and be cost-effectively served by presplit technique. The drilling cost for 125 mm blasthole is about $11.40 per drilled metre and the cost of 40 mm presplit explosive is about $140 per 25 kg (17 metre) case. This implies that the cost to drill and blast presplit on the above parameters would be about $10.90 per square metre of presplit face. The remaining wall area would be most cost-effectively delineated using modified production blasting techniques. This requires the use of modified parameters such as smaller hole diameters, smaller spacing/ burden, higher powder factor, free face firing, less rows per blast and longer delays. These altered blast parameters would usually be applied uniformly across the entire blast fired adjacent to the wall and this ætrimÆ blast would relieve burden away from the wall, into the pit. In simplest terms, this method relies upon maximised burden relief to minimise blast energy applied to the wall. It is only applicable where the material to be blasted is waste since the throw achieved is inconsistent with ore dilution control. The largest charge weight per hole for these analyses is 360 kg and the nearest domestic structure to the proposed Wandoo pit is about 6100 metres distant. From these parameters and assuming a worst case example of rock controlled site factor, the predicted ground vibration is 0.5 mm/sec that is about five per cent of the lower limit set down in AS 2187 part two (1993). This suggests that for the current location of neighbours, ground vibration will not be an issue for the Wandoo operation.

Jan 1, 1999

A model of dense medium cyclones is developed based on balancing the terminal velocities of the discrete particles due to the centrifugal force against a random turbulent eddy velocity. An expression of the form P - or Q _ 1 100 e."A where P is the partition number., is a function of cyclone efficiency, particle size and density differential between the particle and medium, and is the slurry spilt, is developed and may be used for regressing plant partition data. The above model provides an understanding of peculiarities of the partition curve such as asymmetrical tails, elevation of the cutpoint and elevation of the d50 with increasingly fine feed. The effect of feed variables such as particle size, medium viscosity and changes in spigot or vortex finder diameter is shown. A means of convoluting the partition curve with various feed washabilities is discussed together with how the above may be used to evaluate plant performance for a variety of feeds.

Jan 1, 1987

By Ibaragi K

High grade ores were intersected in 1981 by a scout drill carried out by the Metal Mining Agency of Japan during a reconnaissance dril ling programme. The original aim of the hole was to explore a deep target where geophysical anczralies overlapped the abandoned old drifts (gravity- high, resistivity-low by airborne EM, and resistivity-low near the surface and high at depth by Schlumberger deep sounding). Subsequently, a follow-up drilling programm was commenced by the Sumitcrro Metal Mining Co Ltd, and all the 18 holes intersected high grade ores. The resources were then "guestimated" to contain ca.120 tonnes gold with an average grade of 80g/t Au between -40m and +120n a.s.l. The underground development was started in December 1982 and the first crosscut intersected the ore body at 100m level (a.s.l.) in July 1985.

Jan 1, 1987

By A Liu, X Wang, W Peng, Q Zhang

Pulp rheology plays a critical role in fine mineral flotation. Yield stress and apparent viscosity are two important rheological parameters affecting mineral flotation recovery. In this paper, the concept of pulp rheology and its measuring method are presented. The main factors, such as particle size, pulp concentration, mineral types, pulp temperature, inorganic salts, that affect the pulp rheology are systematically reviewed, and then followed by the discussion of the relationship between pulp rheological properties and flotation performance. Generally, high pulp apparent viscosity and yield stress values have been found to have an adverse effect on flotation recovery. In addition, due to the hetero-coagulation between the valuable mineral and gangue mineral, the pulp of mixed ore shows higher viscosity than that of the single mineral slurry. This paper is expected to provide some references for the efficient upgrading of low-grade and complex ores from the perspective of pulp rheology.

Aug 24, 2022

DCF Valuations are very important to individuals and companies involved in the mining industry. Such valuations are critical to investment decisions in relation to new and existing projects. In particular they provide fundamental information to shareholders in the event of a capital raising or takeover and to financiers supporting mining companies and projects. Also, DCF Valuations are often used to support asset carrying values in the financial statements of mining companies. This paper presents a Chartered Accountant's (CA's) perspective on the main issues to be considered in preparing, analysing and relying upon DCF methods in mineral valuations and provides some practical examples relating to key issues. The paper makes the important point that DCF methods involve making assumptions about future events and circumstances that inherently contain uncertainty which results in a valuation prepared on a DCF basis providing a range of values that are not perfect or accurate. In order that DCF valuations provide meaningful information the underlying methodology used and assumptions made must be consistent, sound and well supported. Credibility of those involved in preparing mineral valuations is vital and this paper supports the adoption of sound practices by all concerned.

Jan 1, 1994

By Rashleigh C

The selection and application of an effect- ive firing system first require a clear under- standing of the initiating abilities of the com- ponents in such systems. The conditions under which charges can be prematurely initiated by a detonating cord downline must be appreciated. This is a principal consideration in the design of a successful downline/'Anodet'/primer assembly. The advantages and limitations of an electric and several non-electric initiating systems are explained. The factors which in- fluenced selection of the two most suitable systems for use at Isa Mine (viz. downline/ 'Anodet'/primer assemblies and the reinforced long-lead 'Anodet'-type delay system) are dis- cussed. Blasts are detailed in which each of these has been applied. The initiating design for a hypothetical 2 x 106 tonne blast using electric short delay detonators and multi-channel exploders is presented. In this design, charges in remote blastholes are activated after the detonation of earlier firing charges by protecting the firing lines with sandbags.

Jan 1, 1978

By Klenowski G, Gilmour G. A

The Metropolitan Water Supply, Sewerage and Drainage Board, Perth, has recently con- structed two major sewerage tunnels in the metropolitan area and a further one is under construction. These tunnels were constructed in sand, sandstone and limestone. The Tamala Limestone is a Pleistocene calcareous dune sand which now varies in com position from loose sand to cemented rock. Investigation techniques included surface mapping, auger and diamond core drilling, seismic refraction geophysics and mechanical testing. The variable nature of the ground caused difficulties in all aspects of the investigation, particularly in core recovery and seismic work. The Beenyup Tunnel, 2.25m in diameter and 3440m long was excavated with a Dosco TBM 1800 machine and shield with precast concrete Charcon Universal bolted segment lining. The Burns Beach Sewer Tunnel, 1.27m in diameter and 860m long was hand excavated with precast reinforced concrete lining pipes jacked continuously behind an excavation

Jan 1, 1981

By N Takamatsu

The environments surrounding the iron and steel industry have changed greatly in recent years. Reported in this paper are the technologies adopted by the Japanese iron and steel industry to fititself to change in global steel demands, degradation of iron ore and coal, prolonging service life of the facilities and requirements of energy saving. In addition, innovative technologies for CO2 emission control in iron making processes are also discussed.

Jul 11, 2011