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By R N. Robson, A B. Christie, I J. Graham

Strategy development by the minerals industry identified the fragmented management of mineral resources as a significant impediment to the discovery and development of New Zealand Æs mineral resources. The total gross value of New Zealand Æs potential resources of coal and minerals is estimated at about $400 billion, but their potential value is not being realised. The management of minerals is now largely under the control of 86 local authorities (regional and district councils) and the lack of recognition of the significance of the sector has lead to inconsistencies in the way minerals are managed. The industry strategy influenced science funding for minerals, with the result that the 'mineral wealth' component now includes research on making better use of resource data in minerals management. Initially this research has targeted Otago and Northland regions where a number of initiatives are now in progress.   In Otago the Regional Council has budgeted to contribute $1 million towards a regional geophysical survey to advance mineral exploration and the management of subsurface resources in the region, to work cooperatively towards improving public awareness of the significance of minerals to regional economic activity, and to better coordinate policy-making for minerals at regional and district levels.   Crown Minerals, and the Far North and Whangarei district councils are considering providing funding support for an economic study of the mineral potential of Northland, building on a mineral resource assessment undertaken by GNS Science. Enterprise Northland is adding minerals to their list of potential growth sectors, and is supporting the operation of a Northland region minerals focus group.   Regional development agencies and local authorities have shown that they are willing to include mineral resources in their development strategies and to provide for them in policies and plans when supplied with information and assisted with technical support.

Jan 1, 2006

By J Lea, P Hatherly, J L. Edwards

Coal exploration has traditionally involved the acquisition of data to enable a resource to be quantified and qualified to the extent that its economic potential can be determined. This process commonly relied on: drilling to determine the depth and thickness of coal seams, broad characterisation of the overburden and interburden, and to provide cores for coal quality analyses; basic wireline logging to cross-check the depth and thickness of coal seams and provide some indication of rock mass strength; and basic surface geophysics and remote sensing to identify major geological structures. In recent years, the adoption of the JORC Code as a basis for the reporting of resources and reserves has placed a greater emphasis on the need for detailed, reproducible data sets that not only satisfy the traditional requirements of mine planners, but also satisfy the governance requirements of corporate and financial institutions. Similarly, the development of sophisticated numerical modelling techniques for use in both open cut and underground mine design, has seen a greater demand for precise geotechnical data, in situ stress characterisation and hydrological information as routine input to the design process. These requirements, coupled with the prevailing trend toward high capital, relatively inflexible mining techniques less tolerant of geological surprises, and the need for consideration of environmental issues such as groundwater impacts and surface subsidence, requires that modern exploration programs be multifaceted, and designed to commence capturing data relevant to ædownstream issuesÆ even during the initial phases of exploration planning.

Jan 1, 2009

In the latter half of 1973 a contract was given to Roberts-Holland Joint Venture for the stripping of the southern exhaust airway.The contract was carried out efficiently and relatively cheaply. It was completed 2 months ahead of schedule.The sinking stage and in particular the drilling jumbo proved to be a success and helped produce an above schedule stripping rate.No major problems were encountered with ground conditions or ventilation. A survey of the shaft showed the diameter to be within the set limits of 5·49 m ± 0·15 m.

Jan 1, 1974

In November 1969, New Zealand Steel Ltd pioneered the commercial use of the SL/RN solid fuel direct reduction process to make sponge iron as a feed material for electric arc furnaces. Serious process problems with the use of green balls and coal injection were progressively overcome. The process was developed by New Zealand Steel along a radical route, of feeding the fine grained raw ironsand concentrate and coal directly to the kiln. Contemporaneously with this development of direct reduction, steelmaking process innovations were made that enabled the arc furnaces to operate successfully with the high volumes of acid slag. The further expansion of New Zealand Steel's primary steelmaking capacity to replace the currently imported hot and cold flat rolled products is under consideration. The requirement to produce about 600 000 tonnes of steel slabs will be an opportunity to further modify iron and steel making plant and processes to optimise the economics. The conceptual and preliminary engineering selection of options is described.

Jan 1, 1980

This paper sets out to examine the possible relationships between three factors, they are, the rate of growth of world production of minerals, the growth of Australian production and the growth of scientific and engineering knowledge.The first two are quantified, in terms of tonnes and value. The third, an abstract concept "knowledge", requires to be quantified, in terms of manpower.A mathematical model, which has general application, was derived to demonstrate certain axiomatic premises and to define, more precisely, basic concepts related to the philosophy of knowledge.Finally a summary is made of education-cum-industry issues.

Jan 1, 1981

Enhance Fine Particle Flotation by Hydrodynamic Cavitation Difficulties in fine particle flotation are well documented. Microbubble flotation has been found to greatly improve the recovery of fine particles and in situ gas nucleation by hydrodynamic cavitation incorporated in the design of modern flotation machines has shown great performance in fine particle flotation and potentially in coarse particle flotation. In this presentation, we will provide an overview on gas nucleation by hydrodynamic cavitation and its role in fine particle flotation with focus on the progress made in our research laboratory. Hydrodynamic cavitation was achieved and the critical role of dissolved gases in the liquid was elucidated by visualisation in a high intensity agitation cell. The in situ gas nucleation on fine particles by hydrodynamic cavitation was identified by zeta potential distribution measurement in model systems. Gas nucleation by hydrodynamic cativation was found to effectively aggregate hydrophobised fine particles thereby leading to enhanced flotation kinetics. This is an abstract only. No full paper was prepared for this presentation.

Sep 13, 2010

Thermodynamic properties of the solutions of hydrogen in metals and carbon in austenite were investigated and it is possible to predict the interstitial solubility in these systems over relatively wide ranges of temperature and solute activity. Monte Carlo methods were used to compute the arrangements of interstitial atoms on the tetrahedral sites in body centred cubic metals and the octahedral sites in face centred cubic metals. It was shown that the non-configurational entropies of solution of hydrogen in metals can be interpreted as being principally vibrational and on this basis the potential value of the isotopic solubility ratio theory in indicating the compositional variation of these non-configurational entropies was discussed. The need for future work along these lines is pointed out.

Jan 1, 1970

Landscape interpretation, geology and mining history is being successfully used to explore options for sustainable community tourism product development. Recent work by the author in Europe and Australia has indicated the value of adding and producing interpretive information about mine and quarry locations - both active and inactive. This work has allowed for the branding and development of new sustainable community tourism products based on the landscape, folklore, mine and geological heritage.   Communities in rural areas are seeking new opportunities to sustain their local economies. Using a relatively new phenomenon called geotourism as a starting point; they have developed themed products connected to walking/cycling guides, interpretive panels and visitor centres. These themes can be linked to geology, archaeology, botany, local history and to industrial heritage sites such as old mines, to generate local employment. This new geotourism approach has successfully brought a new and greater audience to discover the value of geology and mining history.   Communities have established a unique place for themselves within the tourism marketplace using the geotourism brand. Other communities with an established tourism product are also now using geological and mine heritage via geotourism to rebrand and meet changing global trends. The pooling of resources under the banner of geotourism has led to cost effective marketing, targeting and promotion of products.   Geotourism has emerged strongly in Europe, North America and China in the last decade. The Australian minerals industry now has an opportunity to implement this new branding concept to assist and benefit the communities in which they run their activities. Communities can also take advantage of the potential to develop a sustainable geotourism business around a past or present mineral industry in their vicinity.

Jun 1, 2010

By Adusumilli M. S, Subrahmanyam T. V, Rao V. D

Chance find of an economically important mineral on the sur- face and its exploitation without proper exploration work, has become the habit of humanity since the Bronze Age. The explora- tion and exploitation techniques have, however, been substan- tially improved in the technologically developed western world and system controlled major communist countries. Nevertheless, the greatest need is felt in the Third World countries where large mineral potential exists, but with inadequate investments in exploration and exploitation techniques, a handicap that has been beneficial to the more developed countries, since long. The great number of the Third World countries which are striv- ing hard to develop, need to formulate mineral exploration and exploitation strategies which could enable them to develop their resources. This requires planning and creating new concepts of ore deposit types and genetic models, rheology, economics and their innovation and integration. The following approach could help them to be economically "more independent" by the end of this century. 1. Bridging of pure and applied geology gap, and creating con- sciousness of research and development. 2. Revision of mineral resources concepts adopted to modern technological world. 3. Improved mineralogical research, and determinative miner- alogy as an important asset. 4. Creative research and establishing know-how, with philosophical base for regional exploration projects. 5. Indepth investigation into the origin and growth of earth as a system, and its importance in the association, quality, and quantity of metallic, non-metallic and energy resources con- centrations. 6. Mineral beneficiation, targets and strateties; methods of eco- nomic and improved recovery systems. Development of alter- native technology, and utilization of mineral technology strategies. 7. Theoretical and practical modelling by conventional and com- puter techniques of the existing and expected mineral resources, and mineral development. 8. Critical analysis of the status of mineral economics of the Third World and developed world with forecasts for the year 2000 based on problems faced by the developing world. 9. Minerals at cross roads of International Interdependence. 10. Philosophical, realistic, traditional and modern strategies for mineral development. The dynamic economic system opera- tion in national mineral sector.

Jan 1, 1988

By M Simpson

Greywackes of the greater Auckland Region (Brynderwyn Hills to Hamilton), when considered on a regional scale, have characteristic ranges of physical, mineralogical and other properties. Some properties (eg density, porosity, crushing resistance, clay index) generally cluster and correlate with the basement greywacke facies, regions and terranes recognised by geologists, and their diagenetic/metamorphic level. Other local factors, particularly variations in mineralogical composition, nature of matrix cement, grain size, and degree of weathering may produce aberrant properties. Some of these local variations, when extreme, have the potential to affect the aggregateÆs performance in roading or the concrete industries.   Smectite and the zeolite laumontite are the major deleterious minerals occurring in fresh greywacke rocks of the Auckland region, although weathered rocks may contain halloysite, an expanding member of the kaolin clay mineral group. These minerals, when found in abnormally high levels in greywackes cause expansion effects in the aggregate. Currently there are inconsistencies in the detailed correlation of shrinkage, clay index, clay mineral content and intrinsic expansion data that need further research to resolve them.  

Jan 1, 2007

By I Sherrell, R Jain, P Jansson

With the depleting iron reserves and difficult market conditions, precision in separation efficiency is of utmost importance. Classical local control options are predominant in the industry, but their inability to adjust to resolve application problems of interest has furthered the need of developing and implementing continuous control methodologies.This paper highlights the recent development in control of Outotec SLon® vertically pulsating high gradient magnetic separator (VPHGMS) including programmable logic controllers (PLC) coupled with distributed control system (DCS), on-site human–machine interface (HMI) control panel, advanced process control, continuous online sampling using Courier® 8 and additional modernisation packages including level control and cooling monitoring. These modern control options result in improved efficiencies, promote safer operation and at the same time reduce operational manpower needs.CITATION:Jain, R, Sherrell, I and Jansson, P, 2017. Automation for efficient separation with the Outotec SLon® vertically pulsating high gradient magnetic separator, in Proceedings Iron Ore 2017, pp 211–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The mining industry is the largest source of foreign income for South Africa. It is also the main source of employment in the country and, as an industry; it is also one of the largest. Due to the labour-intensive nature of the industry, labour costs in South African mines make up nearly 50 per cent of the total mine cost. It is thus imperative to have optimum labour planning and labour management systems in place.The focus of this study was to investigate current underground labour-planning models. It is shown that there are serious limitations. The range between an oversupply and undersupply of labour can be as high as ten per cent. A new system was therefore developed to ensure a constant labour demand and supply on a daily basis. One of the main objectives was to determine the existing labour supply range and thus the requirements to fill the undersupply. For this purpose, a specific methodology was designed to capture and process all the relevant information. Mine personnel was involved throughout the entire process to ensure ownership of the new model. This buy-in was achieved through planning workshops, interactive presentations and discussions. The improved frequency of daily blasts validated the new system by providing the correct amount and mix of the labour force. The new labour-planning model was then extended to optimise revenue. Implementation on a mine resulted in increased income of R95 million.

Dec 6, 2010

Particle Mechanics and the Design of Cyclone Tribochargers Triboelectric separation is a dry electrostatic technique that has shown promise in several particle processing applications. A tribocharger uses contact or friction to differentially charge particles of different materials, which are then separated by an electric field. The initial tribocharging process is poorly understood, with tribocharger design and operation largely a matter of trial and error. A better physical understanding of tribocharger operation would therefore be of immense value in the optimisation of triboelectric separation processes. A combination of charge measurements, trajectory modelling and high-speed video has been used to relate charging to particle mechanics in a cylindrical pneumatic cyclone, one of the most effective tribochargers for mineral separation applications, and the preliminary results are presented here. The consequences of these observations for cyclone tribocharger design and operation, and for tribocharger design in general, are discussed.  

Sep 13, 2010

By D Craw, C E. Martin, C Smith, C Rufaut

Wangaloa Coal Mine opened in 1945, and by the time of its closure in 1989, had produced 750 000 tonnes of coal and disturbed an area of 75 ha. The original mining licence required land rehabilitation to exotic forestry, however the current owner, Solid Energy, has worked with Crown Minerals and local councils to write a new rehabilitation objective. The site is now being stabilised and replanted with native species, and may be available for public use before the coal mining licence expires in 2007. Site discharge permits expire in 2017, and by that time, it is anticipated that discharge water chemistry will be similar to background levels. MWH are currently contracted for management of the mine rehabilitation project. The Kaitangata coal unit mined at Wangaloa is sulfurous lignite with associated pyrite. Kaitangata coal contains 3.2 wt per cent sulfur, which is higher than most New Zealand coals. Initial analyses at Wangaloa indicate low pH (2.56.2) values in soil, groundwater and surface waters as a result of acid rock drainage (ARD) processes, leading to increased metal mobility and challenging conditions for vegetation. Pilot studies indicate pinus radiata needles contain up to 67 mg/kg boron, and elevated As, Cu and Zn concentrations in surface waters. The main lake at the site has a pH of approximately 4.9, despite lime dosage in 2002. There is a real need for a complete geochemical model of the Wangaloa coal mine. Such a model could be applied to similar restoration projects, and would assist by pinpointing geochemical processes and toxic metal relationships most harmful to the receiving environments. Using this model, rehabilitation in the future will be targeted and more efficient. This project is part of a larger scheme to characterise and model the Wangaloa mine site restoration, including waters, soil, vegetation, geology and invertebrates.

Jan 1, 2003

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 Peddie F, Low K, Madgwick J, Rajoka M. I, Gutierrez N, Lim C

Percolation irrigation of low-grade quartz feldspar porphyry ore with pH 2.0 H2SO4 at 510 litres/m2/day using particle sizes 1.7 - 6.7 mm in columns measuring 5 cm dia × 126 cm long was used to study effects of interrupted irrigation ('rest' periods) on metal ion release and leaching bacteria. Copper tenors increased approximately 16 fold and bacterial iron oxidation activity three fold following a 14 day 'rest'. A linear relationship between copper tenor and bacterial activity demonstrated that this experimental system was effective for quantitative studies of bacterial leaching in ore colums.

Jan 1, 1981

The Geological Resource Map of New Zealand (GERM) is a computerised inventory of aggregate, mineral, coal, petroleum and thermal water occurrences, containing summary information on location, production, geology, and geochemistry. The types of occurrences include quarries, mines, gold dredges, wells, outcrops, seeps, springs, and fields. The file contains entries for about 10,300 sites and is used to produce tables of data and maps at any scale, for single or multiple commodities. The published format is the New Zealand 'Geological Survey map series Geological Resource Map of New Zealand 1:250 000'. Seventeen of the 27 map sheets covering New Zealand were published by August 1991, with three more close to publication.

Jan 1, 1991

By K Thorpe

Amorphous silica deposits have been identified at Tikitere and Taheke near Rotorua. Two areas at Tikitere have been surface sampled and drilled to establish a resource of amorphous silica in excess of one million tonnes. A pilot plant was established to develop a process to manufacture a high quality super pozzolanic material. This development process took two years before a commercial product was introduced to the construction industry in 1996. The amorphous silica product, marketed as Microsilica 600, is used as a pozzolanic material to produce high quality strong and durable concrete, sprayed tunnel linings, mortars and grouts. Microsilica 600 has been used locally and exported to 11 countries.

Jan 1, 1999

By J E. Lynch

The Weda Bay nickel and cobalt laterite deposits on Halmahera Island, Republic of Indonesia were first drilled in May 1996 by Strand Minerals Pte Ltd (Strand). Subsequent exploration has delineated four large laterite provinces, parts of which have been diamond drilled to outline an indicated nickel resource of 59.9 Mt of 1.51 per cent Ni and 0.09 per cent Co within a total indicated and inferred resource of 117 Mt of 1.36 per cent Ni and 0.12 per cent Co. The project is held as a Seventh Generation Contract of Work (COW) by PT Weda Bay Nickel, which is jointly owned by Strand (90 per cent) and PT Aneka Tambang (ten per cent). Strand is a wholly owned subsidiary of Weda Bay Minerals Inc, a company listed on the Toronto and Alberta Stock Exchanges in Canada. Halmahera is located in the north-eastern part of the Indonesian archipelago at the convergent junction of three major plates and is a region of considerable tectonic and geological complexity. The western arms of Halmahera form a classic volcanic island arc while the central region and eastern arms contain ophiolite complexes and interlayered sediments. The extensive areas of laterite discovered at Weda Bay have developed over serpentinised harzburgites and dunites of pre-Cretaceous age. Weathering of these rocks has produced laterite profiles that are enriched in nickel and cobalt. There are three economically mineralised laterite types, namely limonites, ferruginous saprolites and saprolites and all are amenable to rapid pressure acid leaching with recoveries of 98 per cent nickel and 94 per cent cobalt in less than 20 minutes.

Jan 1, 1999

To George Orwell the year of 1984 was the inspiration for a book. To most New Zealanders it was the year that the fourth Labour Government was elected to power. It was also the year that the review of mining legislation commenced. While Orwell's book and the election of Labour are clearly events of some historic note, one could be excused for classifying the review of minerals legislation somewhat differently in terms of its present achievements! Since the review began it has led a tortuous path through a rapidly evolving policy environment to a point three years hence where no major policies have been determined.

Jan 1, 1987