Search Documents

By J D. St George

Flyrock is the unexpected and undesirable projection of rock fragments during detonation of a blast and managing this risk is becoming an increasing challenge as urban development encroach toward mineral extraction sites. The basic factors associated with flyrock are discussed in relation to geology, blast design and management. Published data of historical flyrock events are investigated and compared with local information on incidents. Good agreement was found between the data sets. A computer program of flyrock was developed using projectile motion based on launch velocity and angle, rock size, shape and density. This deterministic model was coupled with a probability model to simulate blast events. The impulse time ?t of the explosive pressure was taken as the stochastic variable to replace launch velocity. The variables were calibrated to replicate field data. A simulation was executed to demonstrate the capability of the approach to defining flyrock danger zones. For a simplistic situation it was identified that an appropriate distance to be cordoned off for the blast danger zone is a radius of 120 m in front of the blast and 65 m behind.

Jan 1, 2001

Process Study on Some Ag-Cu-Pb-Zn Polymetallic Ore in South China

Sep 13, 2010

Environmental information is an essential part of successful mine design and approval. In order to be most effective in its application and availability, this information needs to be collected in programmes with defined objectives and deadlines. Applied Geology Associates have established a methodology to facilitate the structured collection of environmental data, which provides for the diverse needs of both engineering design and applications for statutory and non-statutory approvals. Principal aspects of this methodology are the scope, timing and management of the environmental studies within the overall project planning framework.

Jan 1, 1987

By M K. de Brodtkorb

Late Cenozoic ore deposits æPrecious and base metal-richÆ and æSn-Ag-polymetallicÆ ofNorthern Puna are associated either with Middle Miocene dacitic volcanic-dome complexes or with Upper Miocene dacitic-andesitic volcanic centres.   Ore mineralogies and their related volcanism are discussed. A strong link is observed between the Cenozoic Metallogenetic Province of Northern Puna and the Southern Bolivia Tin and polymetallic provinces.  

Jan 1, 1995

Removal of As(III) and As(V) in Aqueous Solution There are toxic arsenical species such as As(III) and As(V), and arsenious species have specially strong toxicity. The strong toxicity causes contamination of groundwater and water pollution for the semiconductor production process. This study is concerned with the removal of As(III) and As(V) with various kinds of Mg/Al layered double hydroxides (LDH) containing CO32-, SO42-, Cl- and NO3- as interlayer anionic species. The anion exchange property is different from the kind of layered double hydroxides and the Mg-Al-NO3-LDH is superior in the anion exchange property of As(III) and As(V) due to the nature of nitrate ion existing in the interlayer. The pH condition suitable for As(V) removal is 7.1 or more. If the initial conditions such as 10mg/dm3 of As(V) concentration, 7.1 of pH, 1 m3 of amount of solution and 99 per cent of removal are fixed, the required amount of Mg-Al-NO3-LDH is 0.27kg for two step-batch operations. The As(III) is suitable to oxidize to As(V) before the removal processing.

Sep 13, 2010

By P O. Koons, R J. Norris, S C. Cox

 The Southern Alps is an active oblique collisional zone which has a characteristic wedge-shaped geometry above a low-angle ductile shear zone. The Main Divide region is a relatively low strain zone above this ductile shear zone, and is _deforming principally along steeply dipping strike-slip faults. Extensional fractures are common at a high angle to the regional structural trend. These steeply dipping structures act as conduits for gold-bearing fluids from depth, and small mesothermal gold deposits have formed at several structural levels including the near-surface region. Gold has also been deposited in a meteoricmetamorphic fluid mixing zone near a conductive thermal anomaly on the western slopes of the mountains. These various gold deposits and their well-constrained structural and tectonic settings can be used as analogues for larger, deeper-eroded mesothermal gold deposits in the Mesozoic Otago Schist belt. High level Miocene veins in NW Otago have formed beneath the main divide of the initiating Southern Alps. Late metamorphic gold-bearing veins formed as fluid escaped from the ductile-deforming crustal root beneath Mesozoic mountains.  

Jan 1, 1997

By R Fury, I Skepper, D White, G Miller

Although the Pressure Acid Leaching (PAL) of nickel laterites has been conducted at Moa Bay, Cuba, since the early 1960s, the commissioning delays generally encountered by the æsecond generationÆ of PAL lateritic nickel producers in the late 1990s have demonstrated the potential complexity of the PAL process and the importance of technical risk management in maximising the realised project value. This paper describes some of the strategies used by the Ravensthorpe Nickel Project (RNP) to manage the technical aspects of the Ravensthorpe project risk. Central to these strategies is the use of Front End Loading (FEL) to deal with issues early in the development phase, when changes to the project structure can be made most effectively and cheaply. Such an approach requires a management philosophy that recognises risk as a potential cost, which accepts responsibility for dealing with risk, and which is prepared to provide adequate resources for risk management.

Jan 1, 2004

Spectrum Resources commenced operations as a public listed mining company in August, 1983, with a variety of precious metal projects in New Zealand. At that time the outlook for most mineral commodities, with the notable exception of precious metals, was decidedly gloomy. Metal prices were depressed and demand forecasts were universally gloomy. Against this background the company reviewed the non-traditional metals sector to try and identify a 'new' metal with an above average demand growth and market value. Lithium, a commodity with exciting new applications in storage batteries and alloys, met both criteria. Annual world consumption of lithium is around 7000 tonnes; current prices are around $NZ40/lb for lithium metal and demand growth is projected at five to seven per cent per annum. Geothermal fluids at Wairakei and elsewhere contain anomalous amounts of lithium and in May, 1984, the Chemistry Division of DSIR was commissioned to carry out a literature survey on the possible recovery of lithium and other minerals from geothermal waters. The survey results were encouraging and the company subsequently negotiated exclusive access rights, for research purposes, to geothermal discharge fluids from the Wairakei and Kawerau geothermal fluids. Most of the subsequent investigations reported here were carried out by Chemistry Division, DSIR, under contract to the company with some assistance from the Industrial Processing Division, DSIR.

Jan 1, 1986

The paper discusses the special mixing requirements for Metallurgical Plant Design and outlines the problems associated with the agitation in Mineral Processing Industry today. It also covers new applications such as state of the art large leach tanks and backfill for deep mining.

Jan 1, 2004

By S B. Stewart, C J. Restarick

Over a four-hour period of steady plant operation samples were taken at regular intervals frum points within the grinding and flotation circuits. Size fractions of each composite sample were analysed for lead and zinc values and a comparison made of the behaviour of the lead, zinc and gangue minerals, size by size throughout the whole circuit. Analysis of the breakage behaviour using dynamic mathematical models gave the rates of breakage of each size fraction of each main component. Simulated grinding experiments shaved that the main grinding circuit had some reserve capacity. In the lead flotation circuit all lead values between 150 mesh (Tyler) and 5 ¦m had excellent flotation characteristics, and a major proportion had a high rate of flotation which was practically the same for all sizes. Increase in overall lead recovery would require improvement of the flotation behaviour of ultra-fine lead minerals. These were slav floating and were responsible for approximately half the lead losses in the final zinc concentrate and one thiro of the lead losses in the final tails. All sizes of zinc values between 150 mesh and 7 ¦m floated well and the performance of the zinc flotation circuit was mainly limited by the relatively poor flotation of the very fine zinc values. Approximately 60 per cent of the zinc lost to the final tails lay within the -7 ¦m fraction. The overall flotation conditions were conducive to very good selective flotation of the major proportion of the values and limitations in metallurgical performance were mainly due to the properties of the ultra-fines.

Jan 1, 1971

By D Chappell

Coromandel Peninsula gold mineralisation has an epithermal style which involves extensive alteration of host rocks and addition of pyrite over large volumes of rock. These altered rocks therefore have high potential for generating acid rock drainage. Natural acid groundwater discharges occur in altered rocks, but not in propylitically altered rock. There is little calcite available in mineralised rocks to neutralise this acid. In contrast, the mesothermal veins of the Otago Schist cause little alteration of the host rock, and that alteration has similar mineralogy to the host rock. Calcite is a common mineral in host and mineralised zones, and sulphides are generally subordinate. Hence acidification of Otago rocks is unlikely. This lack of acidification in Otago facilitates arsenic mobility in solution, up to hundreds of ppm. Arsenic is insoluble under acidic conditions in the Coromandel. Base metals are soluble under acidic conditions of the Coromandel, but they are immobilised by adsorption on to the widespread clay minerals where the solutions are neutralised. Base metals are generally immobile in Otago, but when they are mobilised, adsorption is less effectiveas an attenuation mechanism because clay minerals are rare.

Jan 1, 1998

Active geothermal fields show many of the characteristics seen in hydrothermal ore deposits but there are important differences as well. There are, for example, many differences in geology and chemistry between individual geothermal fields, even some nearby, and these include variations in host rock types (volcanic, sedimentary, plutonic and metamorphic), structures controlling fluid flow (normal, lateral, and, rarely, reverse faulting occur) and hydrological setting (valleys to elevated terrain).

Jan 1, 1986

By J S-L Chan, J C. T Chu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. In its industrial days, Hong Kong’s mining industry was thriving, benefitting from the mineral occurrences that are related to the regional Mesozoic igneous and hydrothermal activities.Hong Kong was unique in the mining sector as it was so small in landmass but with such a rich variety of commodities discovered. There are records of commercial exploitation of tungsten, iron, lead, silver, beryl, graphite, quartz, feldspar and kaolin in Hong Kong before 1981. Of these, most of them are located in the New Territories.The Lin Ma Hang lead mine was operated in the 19th century by the Portuguese and was abandoned in 1958. The Needle Hill tungsten deposit was discovered in 1935 during construction of the Jubilee Reservoir. The Ma On Shan iron mine, which operated for 70 years between 1906 and 1976, was the largest mine in the history of Hong Kong. The Mui Wo lead-silver mine on Lantau Island can be traced back to the Ming Dynasty 400 years ago. West Brother Island, which extracted graphite from 1952 to 1973, was levelled in the 1990s to make way for the development of the airport at Chek Lap Kok.Nowadays, these mines are disused and abandoned, but this extended abstract reviews the legacy of the mining industry in Hong Kong to understand the impact that it had on techniques, the economy and culture.CITATION:Chu, J C T and Chan, J S-L, 2015. The history of mining in Hong Kong , in Proceedings PACRIM 2015 Congress, pp 109–114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Inpit tailings disposal has been undertaken at a number of mining sites within Australia. This paper presents a brief history of the experience of inpit tailings disposal at the Marymia Gold Operation in Western Australia, including geotechnical aspects of the design. Regular monitoring of the inpit tailings disposal into the K1SE Pit at Marymia has allowed the operators of the mine to assess the performance of the tailings storage against its predicted performance during the design phase. Results of this monitoring indicated that the predicted performance was exceeded and the results have been incorporated into the design of another large inpit tailings disposal, the K1 Pit. Monitoring of tailings disposal to both the K1SE Pit and K1 Pit has allowed the mine operator to make substantial savings from inpit tailings storage when compared with above ground tailings storage facilities. The inpit method of tailings disposal at Marymia has proven to be acceptable from an environmental perspective by reducing the water resource requirements of the project, backfilling pits, which would otherwise collapse with time and eliminating the need for disturbing additional areas of mining leases, which usually accompanies construction of above ground tailings storage facilities.

Jan 1, 1999

This paper presents a resume of the likely profitable mining areas in New Zealand. It covers the main 'minerals' û gold, coal, oil and gas, ironsands, silica sands, clays, lump silica, perlite, sulphur and limestone. The potential mining projects are depicted on a map of New Zealand together with the associated works involved in hydro-electric and geothermal power development requirement for industries such as aluminium, nickel ferro-silicon or silicon carbide production. The political need for mining development to relieve unemployment and reverse emigration is stressed. A case is made for exploration and development assistance by government in labour re-training, energy supply and transportation, if the tremendous losses through lack of use of human and industrial resources are to be rapidly reduced. These losses are currently estimated at $10 000 000 000 per year. The need for protection of the sanctity of contract and security of tenure of all mining operations is touched on briefly as is the need for a reasonably balanced view on conservation. However, as both of these are more properly covered in papers on the legal and environmental aspects of the mining climate, they are presented here only as they affect the economy of the mining operation. Finally, there is a brief comment on the mining climate in New Zealand relative to Australia and South Pacific mining operations.

Jan 1, 1990

By H Peiming, W Sakurai, Y Matsuhisa, H Shimazaki, Y Fukahori

Oxygen and carbon isotope mapping of hydrothermally altered wall rocks was applied to the blind ore prospecting of skarn Pb-Zn deposits in the Kamioka mining district, centralJapan, where the wall rocks consist of heterogeneous rock units. The results (d18OSMOW of -1.1 to +17.3ë and d13CPDB of -5.0 to +4.8ë for limestones, and d18OSMOW of -0.8 to +12.5ë for silicate rocks) show isotope zonations of the wall rocks with depletions in heavy isotopes (18O and 13C) toward the centre of mineralization. The isotope zonations likely formed by interaction of migrating thermal waters with the wall rocks during the mineralisation. The heavy-isotope depleted zone, which indicates higher temperature or higher water-to-rock ratio of the system, occurs in the footwall of a fault, indicating that the fault played the role of main conduit of the ore-forming fluids. A heavy-isotope depleted zone was also found in an area, where significant mineralisation had yet to be identified. Recent drilling in this area has intercepted a zone with a grade of 16.0% Zn, 0.8% Pb, and 35g Ag per metric tonne at a depth of about 360 m.

Jan 1, 1995

By X Qiu

According to the temporal and spatial distribution of regional metallogenesis, thePacific Rim can be divided into four global metallogenetic systems. The Asia-Australia W-Sn metallogenetic belt is the typical representative of intracontinental metallogenetic systems. This belt resulted from Mesozoic and partly pre-Mesozoic tectonic magmatism, mainly related to S-type granite of crustal source that was generated by collisional orogeny combined with oceanic subduction in intracontinental and continental margin settings. Based on the concept of metallogenetic series, there is a group of mineralised ore types showing a definite spatial and temporal distribution from endogenetic to exogenetic. These metallogenetic series are widely distributed in the Asia-Australia W-Sn metallogenetic belt, and are well developed in Southeast China. Five metallogenetic series and two petro-minerogenesis evolution models have been established according to their tectonic settings, various types of granitoids and metallogenetic evolution.

Jan 1, 1995

By B A. Mowat, T M. Leach

The Morobe Goldfield inPapua New Guinea has produced in excess of 120 tonnes of gold from predominantly alluvial sources. Hardrock gold has been mined historically at Wau (23 t) and Edie Creek (4 t) and geological resources have been established at Hidden Valley (78 t), Kerimenge (36 t) and Hamata (30 t).Numerous prospects have also been identified within the goldfield. Primary gold mineralisation is related to intrusion of dacitic to andesitic Edie Porphyry (2.4 to 3.8 Ma), often with associated diatremes, which have intruded along major regional structures. A full spectrum of deposit styles from proximal (mesothermal) to distal (epithermal) to the porphyry source is recognised. The transition between the proximal and distal styles is recognised both between deposits and within an individual deposit. The deposit styles should be termed porphyry related gold mineralisation rather than given the generic epithermal and mesothermal labels.   It is proposed that magmatic fluids which evolved from parent melts to the high level Edie porphyry stocks mixed with convecting meteoric fluids and were channelled along major structure and diatreme contacts. Proximal to the intrusives, gold mineralisation is associated with deposition of pyrite-hematite-quartz+/-magnetite-gold (Hamata) and pyritebasemetals-quartz-gold (Wau). The mineralising fluids were hot, and periodically saline due to pulses of magmatic fluid. Gold is non-refractory and occurs as 20 to 30 micron blebs within the pyrite.   More distal from the intrusives or under late cooler conditions, mixing of cool dilute meteoric and magmatic fluids resulted in gold deposition associated with arsenic rich pyrite-and arsenopyrite-mineralisation (Kerimenge, Hamata and Edie Creek). Gold is refractory and occurs within the sulfides either as sub-micron inclusion or within the lattice.   CO2 and H2S gases which evolved off the upwelling hydrothermal fluids as a result of boiling and pressure reductions, condensed within superficial groundwater and formed cool oxygenated bicarbonate fluids. These fluids percolated back down the structures depositing manganocarbonate in the upper parts of the hydrothermal system. At deeper levels in the system mixing of the descending bicarbonate fluid with upwelling mineralised fluids deposited manganocarbonate-quartz-sulfides nonrefractory gold (Hidden Valley, Wau and Edie Creek).   At Kerimenge the cool bicarbonate fluids have also quenched a late stage magmatic fluid rising along high permeability structures. The quenching has resulted in deposition of non-refractory gold mineralisation associated with hessite (Ag2Te)-tennantite-chalcopyrite deposition.   Within the Morobe Goldfield, a transition from deeper level pyrite-quartz+/-hematite-magnetite to intermediate level quartz sulfide and quartz-carbonate-sulfide deposition to upper level, massive manganocarbonate deposition is recognized. Gold mineralisation can occur within all levels up the system.

Jan 1, 1995

Study on Mechanism of Sphalerite Flotation in the Presence of Main Metal Ions by Molecular Mechanics

Sep 13, 2010

Behaviour of Bubble Clusters in a Turbulent Flow

Sep 13, 2010