Search Documents

By Smith J. W, Wilkins R. W T

This paper is a preliminary report of research on the Mount Morgan gold-copper deposit being done at the Division of Mineralogy, CSIRO. Fluid inclusion and sulphur isotope measurements were made on a suite of 11 samples collected by the staff of Geopeko Ltd. This suite contained representatives of the main ore and rock types of the deposit. Homogenization temperatures of fluid inclusions measured on quartz from 8 of the 11 samples, ranged from 172¦C to 276¦C and to this must be added a pressure correction (in this case, up to 50¦C) to obtain the formation temperature of the mineral. Sulphur isotope measurements were made on 34 sulphides from 8 of the 11 samples. The 6S values form a well defined group ranging from -0.5%oto +3.6%owith a mean of +2.4%c. Although the preliminary data do not indicate unequivocally the origin of the deposit they do impose restraints on the wide ranging suggestions that have been put forward. This work is complementary to the paper of Dr G. Gibbons who has described other mineralogical aspects of the Mount Morgan deposit, based on a more extensive suite of Samples.

Jan 1, 1974

By Rashkovski GB

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

Jan 1, 1993

By R Uken G P Whitmore

The coastal dune cordon of northern KwaZulu-Natal is amongst the highest in the world reaching heights in excess of 180 m and up to 2 km in width. It comprises a complex system of Quaternary stacked dunes of various geomorphologies, types and ages. The dunes contain economic heavy minerals which are currently exploited ~20 km north of Richards Bay. Although mining of these ore sands has been in operation for the last two decades, little work has been undertken on the clay-fraction (

Jan 1, 2001

Over the past 15 years many world-class gold discoveries have been made in the region. Some deposits, such as Lihir and Porgera in P.N.G., have a contained gold resource that places them among the top dozen deposits ever found on a worldwide basis. Can we see any pattern to these discoveries, or are they the result of good luck or chance by geologists and prospectors who struck it rich? Whilst such discoveries were a feature of the gold rushes of the 1850s and the 1900s, the present boom is now scientifically based. This paper develops an argument that long-tent, multi-disciplinary exploration by experienced geoscience teams underlie the successes achieved. Dis- coveries nearly always reflect a combination of skills, drawn from the areas of geology, geochemistry, geophysics and remote sensing, and a team approach. They do not represent the chance finds of a prospector's pick or such as the Norseman discovery where the gold reef was first noted by the prospector when his horse fell over the outcrop. The following deposits provide major examples of exploration successes within the Australian-Pacific region, it is not an exhaustive list and I have noted other significant producers at the end of this paper. For the Australian mines listed and based on our estimates for 1990 gold production, they represent about 20 per cent of the Australian production total.

Jan 1, 1991

By Large RR

Underlying the 15 million tonne, high grade Hellyer volcanogenic massive sulphide deposit of western Tasmania is an extensive, well developed, and well preserved stringer system. Pervasive alteration of the footwall mafic volcanics occurred as the hydrothermal system initiated. Mineralogical zoning exists within the footwall alteration pipe, with a central siliceous core giving way to zones of chlorite, chlorite-carbonate, sericite-chlorite, and finally sericite-quartz on the margins (stringer envelope zone). However, the alteration morphology and zonation is not symmetrical around the central siliceous core; eastward the alteration zones are steeply dipping and terminate abruptly under the massive sulphide, while westward they extend out under the ore body in a blanket fashion. Geologic evidence indicates that the pervasive alteration started with the development of sericite-quartz which was subsequently overprinted by chlorite and finally quartz-sericite as the hydrothermal system became focused towards the centre of the stringer system.

Jan 1, 1990

By R Williams, M Baxter, D Zink, R Cunningham

The purpose of this paper is to discuss the efficient operation of a tailings dewatering circuit comprising a thickener and filter press through proper control and automation. It is common to see thickeners and filter press circuits each with their own control systems. This can cause multiple issues when trying to increase efficiency and reliability of the tailings management process. By automating the thickener and filter press controls, you are eliminating any delays and inconsistencies caused by human error and process variations. When done properly the system can maintain a consistent product as the feed characteristics change. Previously, operators would have to monitor the process parameters and adjust the system accordingly. This can now be accomplished using state of the art process control equipment that continuously monitors and adjusts critical variables using Programmable Logic Controllers (PLC) and Proportional Integral Derivative (PID) loops. The paper will detail the control theory used to maintain these systems, highlight other benefits of having a fully integrated plant such as predictive maintenance and remote diagnostics as well as present examples of how these have been implemented in field examples.CITATION:Baxter, M, Cunningham, R, Williams, R and Zink, D, 2018. Tailings process optimisation through automation and controls integration, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 416–421 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

A review of all major TBM projects from 1974 to 1990 has been undertaken and the results entered into a database. A similar database was prepared from information obtained from a principal TBM manufacturer covering the period 1952 to 1990. The database includes information such as machine specifications, machine performance data, tunnel specifications and ground characteristics. The database can be used as a guide to gauge potential machine performance in a range of ground conditions and tunnel geometries. The review also indicates that current TBM technology is limited to certain ground strength conditions.

Jan 1, 1993

By J Poniewierski, Varcos D

Efficient blasting requires constant vigilance with respect to the actual layout being used in the field. Objective measurement techniques are required in laying out a pattern as the 'by eye' or 'thumb suck' methods cannot guarantee consistent results in layout. Erratic blast results are the consequence of such an approach. In a case study at Sons of Gwalia mine, it was demonstrated that incorrect front burdens had a snowballing effect on otherwise carefully laid out blasts, resulting in both excessive amounts of boulders caused by preconditioning of bench fronts and tops, and tight digging. Both problems caused lower excavator productivity and excessive excavator damage, as well as making it difficult to set out subsequent blasts correctly. Several field measurement methods are available to aid in determining correct blast layouts and one is described in this paper.

Jan 1, 1994

THE auriferous sulphide ores of the eastern end of Gippsland, and notably of the Cassilis and lVIitta districts, are amongst the most complex and refractory in Victoria-perhaps in Australia. The minerals occurring in these ores are pyrite, arseno-pyrite, zincblende, galena, and (in smaller amounts) some of the copper, sulphides, as chalcopyrite and covellite; and some of the antimonial minerals, notably stibnite and jamiesonite. In the oxidized portions of the lodes, the oxidized lead and iron minerals, and small amounts of the hydrated arseriiate of iron, are found.In the Cassilis mine, near Omeo, copper is present usually in quantities of under 1 %. The magnetic sulphide of iron is of fairly common occurrence. In, the upper levels of the Cassilis mine tin was usually present, the amount going up to 3% in some samples of concentrates. These minerals occur sometimes banded, but usually as an intimate mixture-pyrite and arseno-pyrite predominating. The gangue is usually quartz (blackened by enclosed particles of sulphides). Calcite, magnesium silicate and felspar are also present in varying amounts.

Jan 1, 1911

By R M. Tosdal

Intrusion related ore deposits are widespread in the Central Peruvian Cordillera Occidental and adjacent high-plains to the east and include porphyry Cu (-Au, Mo; eg Morococha), Cu-Zn (Pb-) skarn (eg Antamina), Pb-Zn-Ag carbonate hosted vein deposits (eg Uchucchacua), cordilleran base metal (eg Cerro de Pasco) and epithermal deposits (eg Quicay). Geochronology and petrochemistry of intrusive rocks associated with mineralisation reveals that: most ore deposits were emplaced in the late middle to early late Miocene; and are related to calc-alkaline granodioritic igneous rocks with Sm/Yb >3, Sr/Y >40 and Y/Th <1.5. The largest deposits, including Antamina, Colquijirca and Cerro de Pasco are associated with intrusions with Sm/Yb >4 and which, as indicated by Pb and Sr isotopic data, have undergone relatively moderate middle and upper crustal assimilation. The chemical signature of igneous rocks related to mineralisation likely reflects melt equilibration in the lower crust at a crustal thickness of more than 45 km. Mineralisation was favoured by a change from normal to flat subduction, resulting in increased compression, crustal thickening and subsequent cessation of the magmatic arc. Premiocene ore deposits do occur, but are restricted to a broad E-W corridor between Uchucchacua and Milpo and probably were controlled by a crustal-scale structural discontinuity across the strike of theAndes. Not all igneous rocks with high Sm/Yb and Sr/Y ratios did acquire their trace element signature in the lower crust. Petrographic and Pb isotopic evidence indicates shallow crustal hornblende fractionation or assimilation of pelitic material as possible causes for high trace element ratios in some rocks. These are apparently unrelated to polymetallic mineralisation. Thus, critical evaluation of petrographic and geochemical data in metallogenetic studies, especially in areas with complex basement architecture such as Central Peru is critical and should not be reduced to simple trace element ratios. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Mining projects draw together stakeholders with various degrees of experience in managing and assessing financial risk. When this risk is not fully appreciated or quantified, the potential for making decisions not suited to investor requirements is significantly increased. A feasibility study provides key information on project development potential, requiring detailed technical investigations with thorough financial analysis. Centaur Mining and Exploration (CME) owned and operated Cawse Nickel Operations (CNO), one of three Australian projects to develop and process vast amounts of near surface nickel resources. A technical ædue-diligenceÆ and æbankable feasibility studyÆ confirmed the large resource base, newly applied yet tested technology and relatively low unit costs would produce nickel in the lower half of industry operating costs. A number of production variables including capital requirements, delayed start-up, nickel grade, processing, maintenance and product output were outside the feasibility estimate. This was combined with exchange rate fluctuations and lower Ni prices. The inability to generate adequate cash flow and service debt repayments ultimately led to receivership and liquidation of all assets. Following the sale of CentaurÆs gold and nickel divisions, $A 784 million remained outstanding to creditors. This paper aims to define key issues leading to CNOÆs collapse by reviewing feasibility parameters, valuation methodology and project development. Some methods of assessing project viability are discussed with the aim of increasing stakeholder risk awareness.

Jan 1, 2003

The Mt. Sisa Orebody on Misima Island, P.N.G., consists of gold-silver mineralization associated with massive carbonate and amor- phous iron-manganese oxides in fractures and breccia matrix. The orebody forms the north- ern extension of the Umuna deposit. The mineralization lies within the three kilometre strike length of a northwest trending, 300 metre wide, high angle fault zone. The fault zone structure is deeply oxidi- sed, with the manganiferous oxide material resulting from oxidation of carbonate. The wallrocks are metamorphosed basement psammopelites and basic volcanic rocks, exten- sively intruded by microgranodiorite. These are dominantly epidotized and sericitized. The precious metals are associated with anomalous Cu, Zn, Pb, Mn, As, Ba, Ga, Sb, and. Mo. Many of the features of the Mt.Sisa mineralization are characteristic of volcanic- hosted epithermal deposits of western North' America. Lithologic and textural gradation is ob- served between the carbonate hydrothermal breccia-fill at Mt. Sisa, and the quartz domi- nated dilational fracture-fill mineralization which forms most of the Umuna deposit to the south. This gradational relationship is ana- logous to that within the Amethyst-OH vein system at Creede, Colorado, where it is shown to be indicative of deposition from laterally migrating fluids.

Jan 1, 1987

By I Kolomaznik

Each technological process can be reduced on the transport networks, and namely on the parametric networks and the non-parametric ones. The parametric networks are created by the piping, electrical cables or channels. The non-parametric network is created by the ways, suspended grooves, trackages and also by the belt conveyors or other conveyors for continuous material transport. If we reduce the technological process on transport networks, then, by the creation of these networks models and their mutual interconnection we obtain the model of the whole technological process. The model can be understood as the universal one, without exaggeration, because it is valid for any technological process. However, for us the mining production process is important what represents the mining and transport of raw materials under the support of the ensuring system. In this contribution one of the first attempt is described, and namely how to connect the parametric network which has been already worked out very properly with the non-parametric network what is presented in this contribution by the transport line of belt conveyors.

Jan 1, 2003

In this paper the reactions which may lead to particle hydrophobicity/hydrophilicity as a function of grinding environment-are reviewed. The results of pulp chemical investigations related to a Cu-Pb-Zn ore on a pilot plant scale and laboratory tests with a Pb-Zn ore to evaluate the effect of some inhibitors on grinding/flotation are presented. The flotation recoveries of the ores treated by conventional and autogenous grinding methods show only a marginal difference and the results favour autogenous grinding. Iron originating from several sources manifests in the form of insoluble hydroxy complexes in the pulps. Such metal hydroxy complexes are hydrophilic and coat the mineral surfaces indiscriminately. On the other hand, selectivity is a problem for pulps ground by autogenous milling. Some corrosion inhibitors used in the laboratory grinding/flotation tests on a Pb-Zn ore showed maximum reduction in the wear of the grinding media ranging from 25 - 36 per cent, depending on the type and concentration of the inhibitor.

Jan 1, 1993

By L Ryan, S Halley

The use of a field spectrometer to systematically analyse drill samples from over 200 holes around the Permian-Carboniferous Ravenswood gold deposits in north-east Queensland has successfully identified both small and deposit-scale changes in the alteration mineral chemistry. Changes in chlorite composition within the tonalite host rocks are evident at the district scale, with Fe-rich chlorites seemingly more common in the vicinity of the deposits. Significant variations in white mica chemistry also occur, but mostly on the vein selvage scale, with no clear distinction between near-mine and distal compositions. The results indicate that chlorite compositional maps produced from regional field or airborne spectrometer data could potentially be used as a vector to ore in exploring for similar deposits in the area. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Small mines exist because of a restricted deposit or a small market. With the right management at the present time the small mine can have lower total costs than larger mines. Charbon is an example of a small mine with a restricted deposit and a specialised product. The development which incorporates a unique rail loading facility and flexible coal preparation plant was achieved with a modest capital outlay and in record time. To remain competitive in future with large scale mines who seek increased production the small mine must achieve increased productivity through automation, higher speed equipment and a multiskilled workforce. Deregulation of the industry, scrapping the Coal Industry Tribunal and the Joint Coal Board would benefit small mines greatly. Management of a small operation also requires multiskills which need to be supported by outside help in the form of consultants and temporary staff. In the 21st century small mines will continue to provide a service to the market.

Jan 1, 1988

The design of the grinding section is discussed and details are given of the equipment installed for the autogenous grinding of ores from the C.S.A. mine at Cobar.The first section of the concentrator commenced treating ore in June, 1965 and operating experience and maintenance requirements since that time are outlined.

Jan 1, 1969

By T C. McCuaig, D B. Mapleson

The Wannaway Deposit is a structurally modified komatiite-hosted nickel-sulfide deposit. Until recently, nickel sulfide accumulations surrounding the Widgiemooltha Dome had been studied with a focus on understanding volcanological aspects of komatiite flow regimes and nickel-sulfide accumulation. Although volcanological features can be observed at Wannaway they are overprinted by several generations of structures associated with multi-phase deformation of the Dome. On the mine scale, two significant deformational events can be distinguished that control ore distribution. The first deformational event is represented by the formation of a layer parallel foliation within the footwall metabasalt and boudinaging of the ore into two distinct orebodies (mega boudins) during a north-south compressional event. Evidence of a second compressional event (east-northeast-south-southwest) is defined by reverse > dextral thrust-folding of the ore zone. The latter deformational event focussed the sulfide ore into thrust front positions where folded ore sequences are mined with stope widths up to nine metres wide. Later stage compressional and extensional deformation phases are observed but have minor, localised effects on the geometry of the ore zone. Four orders of control on the geometry and distribution of ore are interpreted through a combination of primary and secondary features observed at Wannaway. Extending the structural aspects of the secondary overprint features into areas of potential mineralisation has not only defined targets for extensions to the Wannaway Deposit, but has also aided to delineate high grade mineralisation and aid mining decisions. Obtaining an understanding of the volcanological conditions of formation, and more importantly, the structural evolution of the Wannaway region has been an integral part in optimising production.

Jan 1, 2003

The 250 metric tonnes of gold and 360 000 metric tonnes of copper recovered from the Mt Morgan Mine in Central Queensland justify its fame. The mine ceased operation before the advent of three-dimensional computer graphical modelling of orebodies became common practice in mine planning. The Mount Morgan Mine records however remain and are the database for this study. The Mount Morgan project takes ore deposit modelling one step further by examining the relationship between grade distribution within the orebody and key geological features, as a tool for exploration and development.The Mount Morgan gold and copper mineralisation is shown to be strongly lognormally distributed. The deposit has been split into three areas, using geological boundaries, each with different geostatistical characteristics. Important features include: the spatial relationship of near-vertical, high grade shoots with a ring dyke thought to be related to the North Dyke; separation of the high grade eastern stopes from the others along the Andesite Dyke; and lack of concentrated mineralisation along the Slide Fault.Recognition of these features is useful to those currently exploring the Mount Morgan district for similar style deposits, by stressing the importance, or lack thereof, of the geological features.

Jan 1, 1993

By Y S. M Tabatabaei, R Hosseini Tabata

Application of Acidithiobacillus ferrooxidans bacteria to flotation of Sarcheshmeh low-grade copper sulfide ore was studied. Sarcheshmeh low-grade ore contains pyrite, which causes some problems in the flotation of copper minerals. In this study, A ferrooxidans was used to change the surface chemistry of pyrite and copper sulfide ores and consequently, their flotation behaviour. In the presence of A ferrooxidans and xanthate as a collector, pyrite was depressed whereas chalcopyrite and other sulfide minerals were unaffected. In addition, the pulp pH remained unchanged. It was shown that the surface chemical properties of the bacteria could be manipulated successfully to achieve the desired effects in a flotation process. The results showed that the recovery of pyrite in the presence of the bio-depressant is 50 per cent lower than when no bacteria were present. At the same time the recovery of chalcopyrite remained unchanged.

Jan 1, 2004