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By R G. Barker

This paper reviews the annual status of the New Zealand mining industry (metallic minerals and coal) including key aspects such as mineral production, mineral exploration expenditure, commodity price trends, key industry players, market activity and other significant commercial factors.   Strong commodity prices during 2006 have been underpinned by a number of key factors including US dollar weakness and emerging market demand, particularly from countries such as China and India. In real terms commodity prices have recovered significantly since 2002 and are currently at 20-year highs.   New Zealand exploration spending on metallic minerals (predominantly gold) is at a 15 year high driven by rising global commodity prices. New Zealand gold production in 2006 was about 340,000 oz and is expected to grow in 2007 as new mines at Frasers and Globe-Progress (Oceania Gold) and Favona (Newmont) come on stream. Gold production broadly lags 10 years behind exploration spending and exploration activity over the last five years remains well below that seen in the early 1980Æs. Expenditure on coal exploration shows a similar trend with strong growth from a low base over the last five years, reaching over $11 M in 2006. Total coal production in 2006 was 5.9 Mt, an increase of 10% on 2005 with imports from Indonesia adding a further $1.1 Mt.   Newmont and Oceana Gold are by far the largest public gold mining companies operating in New Zealand, although only Oceana Gold maintains a presence on the local stock exchange. Other metals explorers with New Zealand projects include a range of public-listed Juniors (market capitalisation less than NZ$50m) domiciled largely in New Zealand, Australia and/or Canada. Capital-raising on public markets directed towards New Zealand exploration is estimated at around NZ$12 M for 2006, the bulk of this coming via Glass EarthÆs NZ$10 M IPO on the NZAX in October.   The New Zealand Coal sector is dominated by the state-owned enterprise Solid Energy with around 80% market share by production. Other domestic coal competition remains limited, and includes the L&M Group, Pike River Coal, Eastern Corporation, and New Vale (acquired by Solid Energy in 2007). Pricing parity comes mainly from imported coal and global thermal coal prices have remained strong during 2006 at around US$45-55/t, driven by continued expansion in Chinese demand. Coking coal prices have eased 16% since 2005 to around US$98/t in 2007.   Although recent increases in exploration spending suggest a renaissance in the New Zealand minerals sector, long-run trends indicate that we have simply rebounded from a low base over the last five years and much work is still to be done to stimulate further growth in the mining industry to maintain minerals production at current levels. Key industry challenges include marketing exploration opportunities to local and overseas investors, building a critical mass of NZX-listed explorers and providing an internationally competitive environment to attract further capital and expertise.

Jan 1, 2007

By D Craw

The Rise and Shine Shear Zone is a mineralised low angle deformation zone traceable for at least 7 km through biotite zone schist of the Dunstan Range, central Otago. Rocks from the shear zone obtained from recent drillholes are unweathered and facilitate paragenetic studies. There is a progression of mineral deposition from semiductile foliation-parallel shearing, to subsequent folding, and brittle fracturing. Sheared rocks are dominated by microshears containing fine grained hydrothermal muscovite and rutile that has recrystallised from metamorphic muscovite and titanite respectively. Euhedral pyrite occurs within segregations in the schist and is locally brecciated by the shears.   Arsenopyrite occurs within microshears and is intergrown with hyrothermal muscovite. Fractures within relatively undeformed schist are filled with ankerite, siderite, chalcopyrite, sphalerite and galena and these veinlets also crosscut the microshears. Locally the schist is folded and zones of brecciation, silicification and vein deposition overprint the rock. Vein quartz and albite predominate and arsenopyrite and gold infill breccia matrix and crosscutting veinlets. Sulphide deposition began in the later stages of metamorphism with pyrite deposited in quartz-albite segregations. Subsequent shearing caused brecciation of some grains and accompanied deposition of arsenopyrite ¦ gold and rare sulphides along foliation-parallel microshears. Minor amounts of chalcopyrite, sphalerite and galena were then remobilised in ankerite veins that crosscut the shears. In areas of high strain, arsenopyrite was then deposited as euhedral grains in veins and breccias. Synmineralisation deformation caused the brecciation of some grains and gold was deposited infilling fractures in the arsenopyrite. The paragenetic sequence shows gold mineralisation occurred in two distinct sets of structures (semiductile and brittle) that formed at different times in the formation of the shear zone.

Jan 1, 2006

By G McMillan, P Mulvey

"Geochemical characterisation is done based upon the geology and metallurgical batch testing prior to commencement of the operation of the plant.  Tailings repository design is based upon geochemical assessment of the waste material, as well as the geomechanical issues associated with storing the waste. The resultant conceptual and detailed design is incorporated into the environmental impact statement (EIS), upon which mine approval is based. The entire environmental monitoring and harm mitigation program, which is usually a condition of the Mine Lease approval, is based upon the applicability of the original characterisation.Tacit to this process is that there is no change in the geochemistry of the tailings, i.e. no change in the implications for acid & metalliferous or saline/neutral mine drainage (AMD/SNMD) generation. But any changes in milling and processing can have a substantive impact on the geochemical behaviour of the tailings metallurgy, and potentially render an operation non-compliant within the conditions of the mine license.Environmental and statutory approval implications for continuous improvements of metallurgy need to be understood because unintended consequences could cost more than the benefits of the improvement, and in some cases cost more than all the profit made from the mine.  Examples uncovered during audit and consultant practice will be presented together with a process to ensure implications for adverse environmental harm and license conditions are fully considered.*This paper is only available for individual download. It is not included in the conference proceedings*CITATION:Mulvey, P, 2013. Continuous improvement - how changes in metallurgy can have a substantive impact on environmental impact and closure - lessons learnt from environmental auditing, presented to MetPlant 2013 Conference (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Mining and metallurgical processing of gold and base metal ores often results in solid wastes and effluents containing high concentrations of arsenic. In addition, arsenic can be released to the atmosphere from gold roasters and base metal smelters. Speciation of arsenic in roaster products, in a stack sample from a copper smelter, in organic soils impacted by smelter emissions, and in an anaerobic effluent treatment system at a smelter site was determined in order to broaden our understanding of the nature and occurrence of arsenic in a wider range of metallurgical wastes. Micro-XANES spectra obtained from iron oxide particles forming in a gold roaster indicate preferential enrichment of As3+ species in maghemite-rich domains and microlayers. In comparison, haematite-rich iron oxide particles are dominated by As5+ species. It appears that maghemite is retarding oxidation of arsenic and its volatilisation during roasting. Arsenic occurs as both As3+ and As5+ species in a stack sample emitted from a Cu smelter, confined to fine-grained secondary product layers accumulated on the surfaces of spherical Cu particles. This is probably resulting from condensation of As species upon cooling following their volatilisation during the combustion process. Soil samples collected at various distances from the Cu smelter are dominated by As5+ species including monomethylarsonic acid and tetramethylarsonium iodide as the organic arsenic species. The presence of reduced As3+ species highlights the importance of organic material influencing the speciation of arsenic and mineralogical transformations taking place within the soil profile. The XANES spectra indicate that arsenic occurs predominantly as aqueous arsenite species in the anaerobic treatment system, contrary to the conventional thinking of As retention by the formation of secondary sulfides.

Jan 1, 2008

By A A. Roberts, R F. Dewhirst

"Extensive literature surveys, research in the project environment and personal experiences both within and consulting to project teams have revealed some consistent ‘people factors’ that contribute most to ultimate project success. Outside of purely technical and business case issues, there are a small number of leadership characteristics – probably only ten – that if correctly applied can positively leverage a team’s impact on project success.Of the top seven project success characteristics that were consistently highly rated in a recent study, five of them were around leadership. The authors have focused on this topic, noting that good leaders need to display the following traits:passionate commitment to deliveryconsistent modelling and reinforcement of correct values and behaviourfocus on managing relationships well and energising teams and individualscarefully clarifying project vision from front-end loading stages onwardseffective decision making.Not every project manager can and does practise these behaviours all of the time, but being aware of them and receiving training or facilitation in improving their application of these skills can equip project managers with the essential tools to markedly improve their own performance and that of their teams.This paper draws upon experiences in the field and provides lessons – both good and bad – to illustrate. As well as examining leadership traits, the way in which a leader can establish, organise, motivate his or her team and ultimately lead them to success is examined. The paper shares methodologies that have been successfully used to track status within a team and generate appropriate recovery plans where required.In particular, the paper will examine a case study based on an amalgamation of real project issues in some challenging situations using virtual teams (ie physically distant teams located in different centres) to illustrate the importance of strong and positive leadership in achieving success across geographies, time zones and languages.CITATION:Roberts, A A and Dewhirst, R F, 2016. Leadership in projects – a recipe for success, in Proceedings Project Evaluation 2016, pp 49–58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By J M. Galvin, B J. McKinnon

Lightning Ridge, Australia, is the largest opal producing area in the world. Most opal is mined from shallow underground mines by individuals or small partnerships with the industry having been protected from large-scale development to date. The safety performance of opal mining has lagged both general mining industry standards and community expectations. The application of geotechnical analysis to the opal fields has the potential to considerably reduce injuries and fatalities. With consideration of the local culture, preliminary geotechnical analysis has been applied to some current methods of work utilised at Lightning Ridge. Practical solutions have been advocated and are presented in this paper. Improvements to safety generated by these practical solutions indicate that further geotechnical research at Lightning Ridge is warranted and would be beneficial.

Jan 1, 2002

By Turner WG, Short RR

Obviously, the paramount advantages of contract mining have been recognised by mine developers throughout Australia, as evidenced by surface gold mining operations of significant output almost exclusively being performed under contract. These paramount advantages of using an experienced professionally managed contractor result from the mine developer being freed from financing the required relatively large capital expenditure at current relatively high interest rates or in a capital scarce stock market, and from the need to recruit and sustain a large operating work force in a competitive labour market.

Jan 1, 1990

By G J. Lyman

In sampling a process stream, conventional sampling theory deals only with the variation of the analyte content and neglects the impact of the variation in the mass flow on the sampling variance, whether the sampling regime is time-based or mass-based. This is an obvious simplification of the real state of affairs and it is worthwhile to study this impact via simulation.With a facility to simulate large (long) random functions having some thousands of points in the function and the ability to impose covariance functions on the mass flow and analyte variations, such a study is possible. It is also possible to evaluate the impact of correlation between analyte content and mass flows.This paper describes a limited study of the variance increase due to mass flow fluctuations over the usual sampling variance due to analyte variation during the sampling period. The bias in the sampling result is determined for specific modes of correlation. Simulation methods are used as they are the only means by which a sampling result can be compared to the true assay for the lot; in the physical circumstances of mineral process analysis, it is never possible to determine the true process stream assay.CITATION:Lyman, G J, 2017. The impact of the weighting error, in Proceedings Eighth World Conference on Sampling and Blending , pp 311–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

BATMINÖ, BATMINEÖ, BATMINDÖ are an abbreviation for Business Analysis Tools for Mining, Mine Evaluation and Mine Design respectively. BATMINP are proprietary tools customised to suit individual client requirements. The first suite of tools provides for analysis and evaluation of open pit mining equipment alternatives and includes fleet selection, fleet sizing and production, productivity and economic outcomes. The models address all mine process activities including drilling, blasting, loading, hauling and auxiliary services. All models are built to provide for simultaneous evaluation of multiple alternatives that are time and condition related. Provision is made for modelling from first principles and/or default or shortcut inputs. Sensitivities to key input parameters are easily performed and consistent logic is applied throughout the process. The models are built to provide key outputs in a format suitable for presentation and documentation. Provision is also made in the models for validation of both inputs and outputs through benchmarking, back analysis and budget comparison. The same models can be used for short interval (12 month) planning and control, medium-term (three to five years) and long-term life-of-mine (LOM) planning. Millions of dollars are spent each year on mining plant and equipment. Decisions that impact on the medium and long-term are made. BATMINP tools have been used to perform studies with good results and in most cases the studies have been validated through back analysis and comparing model outcomes to real data.

Dec 6, 2010

Improving Pentlandite Selectivity Over Pyrrhotite Using Reagents

Sep 13, 2010

By J E. Askew

The rapid expansion of gold production in Australia over the last five years can be attributed in part to the development of selective mining techniques for open pit gold operations. These techniques allow an increase in head grade with a substantial reduction in mill feed tonnage, as compared with traditional open pit designs. As a result, the capital requirements for mine development and mill construction are substantially reduced, improving the cash flow profile in the early years of operations. To put such a design into effect, the emphasis of mine production must be on producing gold, rather than tonnes of ore. Mine planning at Martha Hill has been based on such a philosophy. After the quantity and grade of the resource had been defined, the exploration programme was increasingly concerned with the local variability of ore zones, and with determining the position of values within broad ore-definition envelopes. The purpose of this work has been to allow the prediction of the tonnages and grades achievable from various levels of the pit when mining selectively using hydraulic excavators. The studies have so far indicated that the Martha Hill deposit can be mined selectively during the early years of production. The additional costs for detailed grade control and a reduced digging efficiency are more than compensated by the exclusion from the mill feed of much valueless material.

Jan 1, 1986

By Phil N

A large number of experiments have been carried out by many workers on the recrystallization of deformed and subsequently annealed metals and alloys. Although observations on single crystals are of great importance in the study of the recrystallization textures of deformed and annealed metals, very little of this work deals with material in this form.Since, in deformed metals, the stress concentration is greatest at the grain boundaries and along the planes of slipping, it is to be expected that recrystallization will start in these regions. For example, in polycrystalline aluminium (1),:1: (2), copper (3), a-iron (4) and brass (5), (6), which had been deformed by cold-rolling, drawing, pressing or stretching and then annealed, the new grains first appeared in the boundaries of the original crystals, whilst in the case of cupronickel (7) and iron (8), recrystallization commenced along the slip planes of the deformed material. Deformed and annealed single crystals of aluminium (9) and cadmium (10) first start to recrystallize along slip planes and in deformation twins.The present work deals with the process of recrystallization of single crystals of lead after deformatjon by creep.Two factors enter into these experiments that were not met with in other work on this subject. Firstly, lead...

Jan 1, 1940

By C Placzek, E Beattie, K Blake

Channel iron deposits (CID) consist of ferruginous chemical sediments, and are an unusual subset of Phanerozoic ooidal ironstone deposits almost unique to the Pilbara, where they constitute around 19 per cent of the Pilbara’s iron ore exports. These deposits occupy many of the ancestral river channels of the Pilbara region, especially the Robe River palaeochannels, incising and meandering through the Precambrian banded iron formations (BIF) of the Hamersley Group and the underlying Fortescue Volcanics.This paper explores the factors underlying geochemical variation in CID, particularly the chemical properties of goethite. The selected deposits in the western Robe palaeochannel and its tributaries show little or no secondary reworking by later water tables. There is a total absence of aluminosilicate clays with all the deleterious elements such as aluminium and silica. Instead, these are associated with the goethite mineral lattice, either within or adsorbed to the cortices of pelletoids.A thickly vegetated environment, and the presence of the Maddina Volcanics as potential source rocks for these western Robe CID is offered as an explanation for relatively high aluminium in the deposits studied, and, in turn, as the reason most parts of the palaeochannel are preserved as inverted topography.CITATION:Beattie, E, Placzek, C and Blake, K, 2017. Dirty goethite – a geochemical characterisation of some western Robe River channel iron deposits, in Proceedings Iron Ore 2017, pp 489–502 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Tonnage and grade are the principal reported components of mineral resource estimates but tonnage is a derivative of two more fundamental estimates; volume and bulk density. Typically, most of the effort in a resource estimation study is directed towards grade and volume, yet poor application of bulk density data to resource models can result in significant biases. The impact on tonnage estimates is easily recognised but poor density estimates may also introduce subtle biases into the grade estimates. Methods for measuring bulk density have been discussed previously. This paper focuses on the manipulation of bulk density data and the extension of bulk density from essentially point measurements to block estimates within resource models. Bulk density is a continuous, geologically controlled, spatial variable and should be treated as such. Issues such as combining data from multiple sources, sample support and the interdependence of bulk density and grade estimates must be resolved. The statistical and geostatistical techniques used for grade estimation are, under the right circumstances, equally applicable to bulk density. The importance of bulk density needs to be recognised. With robust raw data and correct estimation procedures, better estimates of bulk density can be obtained and both local and global tonnage and grade estimates can be improved.

Jan 1, 2000

By P M. Ashley

Antimony (Sb) is an element similar to arsenic that forms anions in surface waters, rather than cations like other metals. Little is known about natural mobility of antimony in the environment. However, recent studies have suggested that antimony has similar toxicity to arsenic. Current New Zealand drinking water guideline values are 3 parts per billion (0.003 mg/l) for antimony and 10 ppb (0.01 mg/l) for arsenic. Antimony occurs principally in stibnite (Sb2S3) in mesothermal vein deposits hosted in low grade metamorphic belts of eastern Australia and southern New Zealand. Many deposits have been mined historically, including one large deposit, at Hillgrove, NSW. Oxidation of stibnite and associated arsenopyrite and pyrite causes local acidification of natural waters but acid is readily neutralised by carbonates in mineralised zones and host rocks, and therefore waters are near-neutral (pH 6-8.5). Antimony dissolves readily in moderately oxidized, near-neutral waters. Experimental stibnite oxidation yielded up to 37 mg/kg (37 000 ppb) dissolved antimony, and mine and tailings dam waters at Hillgrove mine have up to 55 mg/kg (55 000 ppb) dissolved antimony. Natural stibnite can contain >5000 mg/kg arsenic in solid solution and therefore dissolution of stibnite, arsenopyrite and arsenian pyrite also releases arsenic into waters. Resultant dissolved arsenic concentrations are up to 3.6 mg/l (experimental) and up to 7.2 mg/l (mine and tailings dam seepages). Mine and tailings discharge waters have elevated antimony and arsenic where they emerge, but attenuation occurs by deposition of the metals on to amorphous iron oxyhydroxides which can contain >10% each of antimony and arsenic. Historic disposal of mineralised waste rock and tailings into the stream system at Hillgrove has caused contamination of sediments and waters with antimony and arsenic for at least 20 km downstream with effects traceable in sediments for 300 km. Other stibnite-bearing deposits are likely to have analogous environmental effects, particularly from historically-mined sites.

Jan 1, 2002

By K H. Esbensen, K Engström

The conclusion from the debate over the last decade in the mining sector is that, for grade control, reverse circulation (RC) drill sampling gives more reliable results due to less sampling problems than blasthole samples. However, by conducting the latter with well-controlled procedures there still exist fair possibilities to counteract the major blasthole sampling problems and achieve fit-for-purpose representativeness, especially if based on minimal loss of fines. In the present PhD study, extensive replicate experiments and variographic characterisations are conducted to evaluate the performance of manual blasthole (BH) sampling and sectorial segment sampling. The experiments were performed in Luossavaara-Kiirunavaara AB (LKAB)’s Leveäniemi open pit mine in the north of Sweden. The experimental area is an apatite-magnetite iron ore deposit of the Kiruna type, with the demand to exhibit a maximum of local heterogeneity to allow the experiment the largest possible conclusion powers. Gathering and splitting the complete BH drill cutting cones (fines cone, coarse cone) served as an authoritative reference on which to assess the representativity of the two BH sampling methods.Results show that manual BH drill sampling is able to produce samples with an acceptable accuracy and precision if performed properly and with insight. Based on variographic comparison, segment sampling shows similar precision for chemical grades as the manual sampling, while the particle size distributions were more deviating for segment sampling than for manual sampling at the high and low size ranges. Possible reasons for these partly surprising results are discussed.For further investigation of the performance of BH versus RC drill sampling, a second experiment has been planned on a parallel profile. This will result in an unprecedented opportunity for a full variographic comparison between RC and BH sampling, aimed at designing specific, fit-for-purpose sampling procedures as a function of ore quality, cut-off grades and important contaminant levels.CITATION:Engström, K and Esbensen, K H, 2017. Blasthole sampling (replicate and variographic experiments) in LKAB open pit iron ore mines – fit-for-purpose representativity?, Australia, in Proceedings Eighth World Conference on Sampling and Blending , pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

To ensure that its voice is heard in the development of policies and plans under the Resource Management Act, the mining industry is challenged to participate in their preparation. This paper outlines a number of practical ways in which the industry can participate in debate on sustainable management and how it can be put into practice within the industry.

Jan 1, 1992

The Johnny Mercer lyrics 'You've got to accentuate the positive, Eliminate the negative, Latch on to the affirmative à' would best sum up the traditional approach to community relations in the mining industry. This '90s 'Public Relations spin' approach, usually backed up by scientific data, technical reports and graphs outlining risk probability and the impact potential on people and communities, is being challenged. Challenged by communities who have greater access to information, demand greater levels of transparency and corporate responsibility of large corporate operations and possess greater awareness of the communities they live in.   The growth of the environmental movement, of anti-globalisation, anti corporatism, apprehension of a large corporate's ability to deal with community issues, and a lack of faith in the abilities of regulators to regulate corporate activities, means our industry faces challenges on multiple fronts. It must now be able to address these from a personal/community perspective if it is to remain relevant within communities.   One of the keys to this is linking the internal activities and responsibilities to the externals concerns and demands for higher levels of operation and care.   This presentation draws on Corporate Public Affairs trends, functions and approaches and the application to External Affairs activities within Newmont Waihi Gold's operations in Waihi and regional exploration activities throughout the Hauraki Goldfields.   The approach presented works on the philosophy that communities don't necessarily have to like what we do, but should be able to identify and recognise the way in which we involve them in decision making, communicate our intentions and respond to issues.

Jun 1, 2010

The theme of this Conference is 'The Future of Mining in New Zealand' to be addressed at a time of deepening economic concern. To ensure the assessment and development of our mineral resources in a competitive, safe and environmentally acceptable way a modest supply of a rare commodity û the professional mining engineer û must be assured. This paper briefly' reviews the history of mining education in New Zealand, discusses relevant overseas academic concerns and actions and discusses recent local trends which have led to a most serious recruitment position in the Department of Mining Engineering at the University of Auckland. Conclusions are drawn and proposals made which may remedy this situation which could have serious economic and sociological consequences for New Zealand.

Jan 1, 1991

By A N. Danoucaras, S E. Goater, D Hearne, A M. Bansuan

It is globally recognised that existing and emerging mining activities should be conducted in a æsustainableÆ manner for the entire life of mine. Many companies annually publish corporate sustainability reports to demonstrate their actions in accordance with international expectations. This concept of sustainable mining practices also applies to mine water management, with influences often extending beyond site operations, affecting surrounding catchments and community users. This paper explores differences in conceptual and operational terms of æsustainableÆ mine water management within the Philippines. Outcomes of a review of corporate sustainability reports, governance documentation, research programs, and stakeholder knowledge acquired through action-research workshops are presented. The paper aims to inform and support future capacity building exercises delivered by the International Mining for Development Centre (IM4DC), with outcomes tailored to government officials and policy makers of developing countries. The project is funded by IM4DC, which is working with AusAID to identify needs and develop capacity with regard to mining for development; specifically, issues pertaining to governance and regulation, social and environmental sustainability, and operational effectiveness in developing countries.CITATION:Bansuan, A M, Goater, S E, Danoucaras, A N and Hearne, D, 2012. Integrated sustainable water management in mining for development in the Philippines, in Proceedings International Mine Management 2012, pp 205-226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012