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By R Farnf, M Pegden, S Hosein, T White

A number of theoretical papers have been published outlining the use of electronic detonators to limit peak particle vibrations levels, but few empirical studies have been undertaken and even fewer examples have been published of the use of such technology in the aggregates industry. This paper gives a summary of the research work carried out at two limestone quarries in the North of England, where a series of blasts were used to compare and contrast the use of electronic and non-electric detonators. The majority of blasts were carried out using the same burden, spacing and decked charge weight loadings. A methodology was established that could be used to reduce the peak particle velocities (PPVs) at two or more specific locations by using single-hole blast vibration signatures in conjunction with specific electronic detonator timing intervals. The initial study concluded that this was only possible if single-hole signature blasts were periodically recorded to establish the shape of the correct vibration envelopes as properties were approached. These wave envelopes could then be used as the basis for choosing the specific electronic detonator timing intervals to give the lowest PPV for the properties or locations concerned. This methodology was then used in the second study to access a large volume of aggregates adjacent to a working railway tunnel. The financial benefit for the company was to convert these additional tonnages of rock from being a resource to an exploitable reserve. The project involved careful blast design and the instrumentation of a number of boreholes to enable the results of blast monitoring exercises to be compared with predicted PPV results. The iterative process involved the vibration results being uploaded into æBlast LogÆ (an expert blasting database system developed by the Blasting and Environmental Research Group at the University of Leeds) and analysed to produce predictions ready for the next blast.

Jan 1, 2007

By D S. Nicholson, T Marshall

Reserves of high-grade quartz gravel, lignite and timber suitable for the production of silicon metal and ferrosilicon on large scale occur within 40 miles of Bluff Harbour. Undeveloped hydroelectric power resources on the Clutha River are located within 50 miles of the most promising quartz gravel deposits while opencastable lignite, potentially suitable for electric power production, occurs in the same locality as the quartz gravels. A preliminary study of production economics indicates that the commercial feasibility of silicon/ferro-silicon production would depend mainly on the cost of electric power, total capital cost of plant, and the market value of the products. The proximity of Bluff Harbour is advantageous for the export of products.

Jan 1, 1971

Intensive exploration for iron ore in the banded iron-formations (BIF) of the Pilbara region of Western Australia began in the early sixties and almost immediately established the Hamersley area as a major iron province. The early genetic models for the BIF-hosted ores were based mainly on macroscopic examinations of ores from the "hardcap" zone, and generally accepted a direct relationship with weathering effects on a Mesozoic to Tertiary land surface. Brandt (1964) was the first to suggest a difference in age between the high-grade hematite ores and the more common hematite-goethite types. He initially accepted a supergene origin for both, but later opted for a hydrothermal origin for the hematite ores. Apart from MacLeod (1966), the published views of the next decade reflect a largely parochial interpretation of individual ore bodies, centred mainly on supergene models but with some support for hydrothermal concepts. Except for Ayres (1971), none of the models were backed by detailed mineragraphic data. In 1976, an AMIRA-sponsored CSIRO group began a Province-wide investigation of the wide variety of ore types and BIF, with emphasis on geochemical and textural studies. The resulting conceptual model for a world-wide unified supergene and supergene-metamorphic hypothesis is generally accepted in the Hamersleys.

Jan 1, 1986

By Billington WG

A structural study of northwest Fergusson Island, part of the D'Entrecasteaux Group, was undertaken using colour and monochrome aerial photography and Landsat imagery. The resulting interpretation shows an upstanding, in part, dome-like metamorphic core complex, which is bound on three sides by an en echelon series of low-angle, thrust faults. Faceted gneissic layers occur throughout the complex. These facets are triangular in plan view and range in size from a few tens of metres, to massive composite zones which traverse the entire uplifted zone, The lower surface of each of the facets are, in fact, low-angle decollements which, during uplift, slid one upon the other to accommodate the vertical and extensional movements. As a consequence, deep structural valleys developed which widen towards the zone of maximum uplift. In many places, recognisable topographic features are replicated on both sides of these valleys, and under the stereoscope can be visually reconstructed to their original pre break-up positions. The southern margin of the core complex is less dome-like and falls away, via a series of deeply-entrenched structural valleys, towards a volcano-studded lowland. The lowland appears to belong to a rift or arm, stemming from the more southerly located Goodenough Bay Infrabasin.

Jan 1, 1987

By P D. Franzmann, D J. Readett, J Peterse

A better connection between laboratory- and pilot-scale test results, and heap bioleaching performance can be achieved by generating reliable information on the fundamental microbial, chemical and physical processes that occur in heaps and incorporating this information into a comprehensive and robust model. More efficient heap bioleaching, particularly of chalcopyrite, has the potential to add value to the mining industry as well as deliver attractive environmental and social benefits to the communities within which those companies operate.The results of fundamental chemical and microbiological studies of the leaching mechanism, the temperature dependence of chalcopyrite bioleaching, and the optimisation of leaching conditions are described with examples from full-scale heaps. The development and application of a number of novel techniques and tools has assisted our understanding of heap subprocesses mineralogy, hydrology, chemistry and microbiology. The heap bioleaching model HeapSim, which embodies a large number of effects not previously accounted for in other models, continues to be refined and has been applied successfully to the study of several heap bioleach systems.

Jan 1, 2004

By Adeloju S, McQuade CV, Riley SJ

Metal contamination of sediments can be an issue for minesites discharging water. Water sampling of receiving waters is frequently undertaken. Sampling and analysis of sediment is less common. The variability of receiving environments makes the formulation of a generic sediment sampling strategy virtually impossible. Each situation needs to be carefully assessed before sampling is undertaken. This paper outlines the approach taken for one such survey.The main factors that need to be considered in a survey of surficial sediments are sample representativeness and sample variability. A simple data set from one site within a regional survey is used to illustrate the importance of these factors. The metal content of sediment is shown to vary significantly over small spatial scales.The variability associated with the spatial distribution of samples within a site is shown to be the most significant source of variability in the study. This variability could bias the results of a study if not planned for in the sampling methodology. Taking multiple samples from within each site (sub-site samples) and combining the data gives a more representative indicator of overall conditions than a single sample. The optimum number of sub-site samples to be taken from each sampling site was found to be 15.It is shown that a composite of sub-site samples can give a good indication of the average site metal content, while considerably reducing the sample preparation and analysis effort.

Jan 1, 1998

By T J. Orr

The changing demographics of the mining industry make successful passing of knowledge and skills to the next generation critical. Training methods and technologies are being developed to meet this need. Twenty years ago classroom training was largely a one-way transfer of knowledge through instructor lectures. In contrast, instructors today can use virtual reality technologies to guide trainees as they fully participate in learning experiences. Trainees can interact with the virtual work environment, co-workers, and equipment without being exposed to workplace hazards. The speed of advancement in mine safety, health, and production training shows no sign of slowing in the next 20 years. Researchers at the National Institute for Occupational Safety and Health have studied and participated in the evolution of miner training. A look at training materials they have created in the past and those they are currently developing reveals changes in methods and technologies over time and also key characteristics which have remained constant. Possibilities for the future can be discussed in the framework of an implementation of virtual reality in new miner training sessions. The example computer-based training package teaches new miners to read mine maps and provides opportunity to practice navigation skills in a virtual mine. With this æserious gameÆ, trainees experience the look and feel of moving through an underground coal mine while in the safety of their classroom. During field-testing in 2007, trainees and instructors responded very favourably to this new way of learning. The software was usable by mine trainers with even limited computer expertise and could be installed on the affordable computers they were using for their more traditional slide presentations. The Underground Coal Mine Map Reading TrainingÆs foundation on past successful development strategies and its acceptance by todayÆs instructors and trainees provide valuable lessons for developing training materials, strategies, and technologies for miningÆs future.

Jan 1, 2008

By M J. Saynor, W D. Erskine an, D R. Moliere

The Jabiluka uranium mine was constructed in the Ngarradj catchment, a right bank tributary of Magela Creek in the Northern Territory. The Jabiluka Mineral Lease is adjacent to Kakadu National Park, near an area listed as Wetlands of International Importance under the Ramsar Convention and recognised under the World Heritage Convention. In the late dry season of 1998 and prior to the 1998 - 1999 wet season, a stream-monitoring program was implemented in the Ngarradj catchment to collect baseline data on sediment transport within the catchment to assess and proactively manage associated impacts caused by mining at Jabiluka. Stream suspended mud concentration, stream discharge and rainfall data were collected for four wet seasons (1998 - 2002) giving an almost continuous data set. The stream system has high natural variability dependent on rainfall intensity and subsequent discharge and pre-wet season fire distribution and intensity. In general, mud concentration is elevated at the commencement of the wet season until about February. This is caused by first-flush removal of surface material detached during the dry season by agents such as bioturbation (including anthropogenic activity), wind erosion and surface desiccation. Water quality trigger values downstream of the mine were derived using upstream percentiles and the before-after-control-impact, paired site design. Both analyses showed no observable impact from mine construction in 1998 or during the study period. However, the impacts of dry season fires could be clearly detected. The data set provides good baseline information for future assessment at Jabiluka and demonstrates the need to view measured parameter values on a catchment-wide basis with knowledge of rainfall, discharge and fire distribution.

Jan 1, 2004

By Coates J. R, Firth I. C

The Imperial Smelting Furnace at Cockle Creek, NSW, was constructed in 1961 and is the oldest facility using the Imperial Smelting process in operation. In recent years there have been significant improvements in many areas of the operation, including production, safety, hygiene and environmental performance. Steps taken to achieve these improvements are described. Plans to secure a profitable future while meeting environmental requirements are outlined.

Jan 1, 1993

By Crellin D, Reed SM

The paper presents details of borehole instrumentation schemes for the purposes of monitoring rock and fill deformations associated with groundwater in underground and surface coal mines. The instruments are described which measure rock mass displacements, permeability changes and alterations to hydrology. Methods of installation are detailed and the applicability of instruments discussed. Reduction and interpretation of results are detailed.

Jan 1, 1988

By Kerr I. D, Kennedy M

Flash X-radiographs were obtained of commercial electric No 6 and No 8* strength aluminium tube detonators in small-diameter cartridges of emulsion explosive at various times after fusehead operation. The trigger system for the radiography was based on the detection of light following fusehead firing via optical fibres inserted into the fusehead cavity during detonator assembly. These experiments were simulated using a finite element hydrocode with realistic treatment of the non-ideal reaction kinetics. Excellent agreement was demonstrated for the shape and position of the shock waves. In both cases, initiation of the emulsion was predominantly forward from the detonator. For the No 8* strength detonator, this initiation resulted from the shockwave delivered through the sides of the detonator, while for the No 6 strength detonator, initiation was the result of a complex interaction between shockwaves originating both from the sides and from the endcap. In the reverse direction (towards the crimped end of the detonators), initiation was only weakly dependent on detonator strength, being controlled mainly by the competing processes of rarefaction from the cartridge boundaries and comer turning of the detonation wave from the forward initiation. The consequences for field performance of small-diameter emulsions will be discussed.

Jan 1, 1990

By Crapp C. E

The Collinsville Coal Measures consist mainly of arenaceous sediments but indude eleven named coal seams. The Formation outcrops around the northern end of tbe Bowen Basin where it attains a thickness of 700 ft. in the Collinsville-Scottville area and overlies Lower Bowen Volcanies with angular unconformity. Most of the members in the Formation thicken basinwards. The regional dip is about 8 degrees. The Formation thins southwards and does not occur south of the Bowen River on the eastern flank. On the western flank it is represented by 60 ft. of barren sandstone at the limit of our mapping, 12 miles south of the Bowen River. Two seams are mined, the Bowen and the Blake; coal from the former produces high grade metallurgical coke, and the latter seam is mined for steaming coal. Where mined, the seams are about 20 ft. thick. The coals are of medium volatile bituminous rank and the lower coals are of higher rank than those above them.Reverse faults striking across the Coal Measures have been delineated and the existence of areas of intrusive rocks has been established. Intrusions rose up fault planes and, as felspar porphyry sills, selectively intruded coal seams, decimating reserves of coalavailable for mining. One sill, in the Blake Seam, attains a known thickness of 115 ft. Because the distribution and thickness of the sills is rarely predictable, density of drilling has been greater than in most coalfields.INTRODUCTIONThe assemblage of sediments occupying the northern portion of the Bowen Basin (Fig. 1) may be divided into four formations of Permian age:The Upper Coal Measures (U. Bowen)The Middle Bowen Marine Beds (M. Bowen)The Collinsville Coal Measures (M. Bowen)The Lower Bowen Volcanics (L. Bowen).Of these, the Upper Coal Measures and the Collinsville Coal Measures are known to contain coal seams of workable thickness.

Jan 1, 1960

My forebears migrated to South Australia in the 1830s, 1840s and 1850s. All of them were literate but, because they moved about South Australia looking for work, family papers have become scat- tered and I am left with a few fragments. Some years ago I was intrigued to find among my fath- er's books a frontispiece in an old Anglican Book of Lessons. As can be seen Joseph, a mining smith, was also a Freemason. Thus my interest was aroused. I know some- thing of modern day mining communities in South Australia and wondered what they were like 100 or more years ago.

Jan 1, 1987

The evolution of the Oaky Creek mining complex provides a good example of the mining cycle in practice. Oaky Creek has been innovative in its choice of mining methods, with virtually the full range of coal mining methods having been used as workings have progressed down dip. The history of the mine is traced through its development (and ownership changes), progressive selection of mining methods as depths of cover to seams being mined have increased, and rehabilitation. This allows the different mining methods to be described and illustrates the concept of æwall-to-wall miningÆ.

Jan 1, 1998

By Horiszt G

his report is going to point to that the effect of the mining dewatering on the area of Transdanubian Mountain Range has reached a phase when the cost of dewatering and providing damages can seriously jeopardize a profitable mining operation. Up to 60s the interest of mining had been dominant only, but since the begining of 80s the conceptions of industrial development and the value of enviroment protection have been changed. The natural karstwater balance of the TMR can be presented (Figure Land 2.) and the present situation of it points to that the descharge has exceeded the reacharge in 50 %. During the past 10 years the decreasing of the stored karstic water resourches was 1.1 km . The decreasing of the spring yields reached 80-82 % of the natural ones. (Figure 3-4.). Conservation of the present discharge may lead up to the totaly drain of the karstwater regime. A computer aid control system had been to develop by the bauxite mining and using of it the yield of dewatering decreased and a moderate rising of the water table has started since 1986. A recunstruction was made at the biggest thermal-medicinal lake its springs have had their source in 40 meter depth inside a spring cave at the bottom of the lake. Earlier the spring yield decreased due to the dewatering activity of mines. As a result of using of the CAC system and the providing works at the thermal sprino,the karstwater balance has got in the state of equilibrum, the first cost was decreased and spring yield was increased and the enviromental limits were adverted from the way of mining.

Jan 1, 1988

This paper will discuss specifically the performances of vibrating screens having circular motion with inclined decks and linear motion with horizontal or near horizontal decks and both related mainly to coal, metalliferous, and other granulated solids applications where screening and efficient classification is required. Some misconceptions have been applied in the past with regard to making a screen type selection using either circular throw or linear throw and therefore this paper will endeavour to clarify these misconceptions.

Jan 1, 1984

By Bin H

East Guangdong tin province overlaps the southmost part of the mesozoic magmatic arcof continental margin type in Southeast China and is dominated by mesozoic syntectic magmatism,which associated to tin mineralization. It is distinguished from Nanling tin province but quite close to NW Bolivian tin province in both tectonic and magmatic relations.Tin deposit's mostly of cassiterite-sulfide, cassiterite-silicate formations are localized along exsocontact zone of granitoid batholith or stock, boundary area of volcanic depression, or, within volcanic edifice. Petrochemistry studies show tin was concentrated as intermediate-acidic magma evolved by fractional crystallization. Xiling tin deposit of vein type related to extrusive... the lava dome was formed at T C 221-301 and at very shellow depth,seems to correspond to type A in classification for Bolivia tin deposits by J.N.Grant. Tashan tin deposit of dissemination type related to hypergene intrusive facies,with mineralization occured in endocontact zone of granite porphyry dykes is considered as porphyry type,which spported by H-0 isotope and gas-liquid inclusion evidences. It formed at T C 250-430, comparable to Bolivia porphyry tin deposits,but at a greater depth 1.3 3.0km.A model for known tin deposits in East Guangdong was worked out. A good prospecting perspective was revealed for the potential type of tin deposit in East Guangdong--subvolcanic porphyry tin deposit.

Jan 1, 1990

Published information on technical and market developments in the uses of zinc tends to dwell very largely on two groups of uses of zinc - zinc coatings (mainly galvanising) and zinc casting alloys. These two groups account for two-thirds of primary zinc consumption. However, if total zinc consumption is taken into consideration, coatings and casting account for a little over half the total. Either way, the health - or otherwise - of these 'other' uses of zinc can have a substantial effect on the industry as a whole. The aim of this paper is to put the whole market picture for zinc into better focus, concentrating on the factors which can affect consumption in the 'other half' of zinc's markets: ò brass - the third most important market for zinc at around one million tonnes - responds to changes in the economic cycle. It has seen substantial changes in the balance between different forms of semi products, and, in Europe at least, some real market gains; ò zinc sheet - one of the original uses of zinc in Europe - has grown substantially in some countries, but remains almost unknown elsewhere; and ò zinc pigments and compounds are so numerous that - barring the substitution of zinc oxide in rubber - major overall changes in the market are unlikely. The paper examines these markets and assesses their potential and implications for zinc markets as a whole.

Jan 1, 1993

By G J. Jameson, A Agarwal

This paper is concerned with the observation and analysis of bubble clusters in a laboratory flotation cell. A device was used in which bubbles were allowed to rise in clean water containing the same frother and collector concentration as in the cell. Bubble clusters were recorded using a high speed camera and analysed using an image analyser. Dodecyl amine was employed as a collector to float silica. The effect of impeller speed on the cluster behaviour was investigated. The results were interpreted in terms of cluster diameter and shape factor. The sizes of the bubbles forming the clusters were also measured and compared to the sizes of the independent bubbles in the cell. It was found that there was an optimum impeller speed in which the cluster diameter was a maximum. Higher agitation and the consequent higher power inputs resulted in cluster break-up while lower shear rates promoted cluster formation.

Jan 1, 2005

Over the past seven years, a combination of New Zealand-, Australian- and German-led research voyages using the research vessels Tangaroa, Southern Surveyor, and Sonne respectively, have revolutionised our understanding of the Kermadec-Tonga arc-backarc systems. This convergent margin is the most seismically-active subduction zone system on Earth with convergence rates steadily increasing northwards from the Hikurangi Trench to ~250 mm/year at northern Tonga. In combination with the intra-oceanic setting, factors potentially producing magmatic, tectonic, and hydrothermal variability in this system include an increase in potentially subductable sediment northwards along-strike, intersection of the Louisville Ridge (hot-spot chain) and Osbourn Trough (paleo-spreading centre) with the arc at ~25¦S, and the possibility of Samoan (hot-spot) plume ingression in the northern Lau Basin. The bulk of the magmatism is submarine; whereas only a few emergent (some transient) volcanic islands exist, about 80 submarine volcanic centres of significant size (>1000 m above surrounding sea floor) are present between White Island in the south to north of Tafahi in Tonga. About 35 per cent of these centres are hydrothermally active. Important petrogenetic features of the volcanic rocks along this arc system are the abundance of rhyolite (some quartz-amphibole-bearing), and the outcrop of primitive olivine-clinopyroxene-phyric basalts in satellite cones of the major edifices. Many of the edifices consist of complex caldera systems. Eruptions from and degradation of these edifices were probably tsunamigenic. Many of the hydrothermal systems developed within the edifices are likely destroyed during the sector collapses which are the characteristic edifice degradation mode. There are three backarc spreading systems along this margin: the Havre Trough, Valu Fa-Eastern Lau Spreading Centre, and the nascent Fonualei Rifts. The latter are particularly notable in having captured the entire suprasubduction zone magmatic flux for a distance of about 150 km, shutting down the adjacent volcanic front arc volcanoes.

Jan 1, 2005