Search Documents

By M E. Taulis, S Hayton, D A. Manhire, J G. Pope

Successful development of coal seam gas (CSG) resources in low-rank coalfields such as the Powder River Basin has raised interest in CSG from low rank coal in New Zealand. Kenham Holdings Limited holds 12 Petroleum Exploration Permits (PEP) covering some of New ZealandÆs low-rank coal and lignite resources and has engaged CRL Energy Limited to assist in the systematic evaluation of the CSG potential of the permits. To date, exploration results from seven New Zealand coalfields reflect differences in coal type, rank, depositional environment and depth of burial between coalfields. Several of the explored coalfields are considered prospective for CSG. One of the most advanced Kenham exploration programmes is in the Hawkdun Coalfield, Central Otago.   The Hawkdun Coalfield contains a single, thick lignite seam with properties that are similar to the Powder River Basin. Preliminary results indicate the Hawkdun Coalfield is prospective for CSG with the potential to contain between 25 and 60 PJ of gas; enough to supply a 30MW power station for ten to 25 years. Further drilling is planned to investigate the economic viability of the Hawkdun Coalfield. The in situ permeability of the lignite, the amount and availability of free gas, gas saturation at depth and market opportunities will determine its economic viability. If initial pumping and production results in the planned exploration programme are promising, the Hawkdun Coalfield will be further developed with additional production drillholes to form a trial production pod.

Jan 1, 2004

Brunswick Mine, one of the largest underground zinc mines in the world, is scheduled to close in 2010 after almost half a century of production. All mines eventually close; some suddenly as a result of unsustainable economic or technical conditions and others, as in our case, as a result of the depletion of the orebody. When the mine is the most significant employer and an economic driver in the region, it is key that the closure is handled in a planned, communicated, well-executed fashion. The following paper documents strategies, plans and activities that are currently taking place in order to ensure a seamless closure that satisfies all stakeholders including employees, management, regulatory bodies and the public. It is an important deliverable for the company that the good will, credibility and reputation that has been built up over the years is sustained throughout the closure process and beyond. A life of mine labour agreement with the unionised workforce, staff retention and recruiting programs, regulatory closure plans, communications and transition adjustment activities will be discussed. The use of a stage-gate style project management tool analysing the risks and key deliverables will be highlighted. It is hoped that the concepts and approaches discussed here may be of value to other operations that will be faced with closure, and its inherent challenges, in the not too distant future.

Jan 1, 2006

As a minerals company, obtaining the appropriate consents under the Resource Management Act 1991 and getting permits granted for exploring, prospecting and mining under the Crown Minerals Act 1991, is necessary for actively exploring and mining in New Zealand. But the essential mix of ingredients for a viable and healthy Industry go way beyond this.   In the short term, an individual company seeking to operate on or within the Crown minerals estate of New Zealand must chart a course through the requirements raised by new cornerstone legislation, the Resource Management Act, the Crown Minerals Act and, the Conservation Act 1978 (where the minerals sought coincide with this estate).   However, this paper suggests that in the longer term for individual operators within the Industry and for the Industry at large to remain viable and sustainable and for New Zealanders to continue to enjoy its benefits, much more is required. Not least of which is a better balancing of competing uses and attitudes, which will require an opening of minds, a change in mindset, topped off with those two most essential of ingredients advocacy and leadership.   New Zealand has undergone massive restructuring in the last 15 years. Is it complete? Have each of its fronts evolved to the end point which was envisaged by the designers of the regime? What are the advantages? What is left to be done? What are the impediments from an incomplete transition which are left to either dog the Industry or remain as a challenge to be removed to ensure the Industry's smooth sailing into a prosperous and environmentally clean and friendly future? A future wherein an educated and understanding public welcome and are proud of the Minerals Industry to whom they owe the standard of living which they enjoy.   This presentation will examine the role of the New Zealand Minerals Industry Association (NZMIA) in paving the way for an optimum operating environment in which to couch a healthy industry into the future.

Jan 1, 1997

By R J. In, C Moore, P J. Moffitt, T Hansen

Telfer Gold Mine combines a world-class gold and copper resource and longevity of operation as a major gold and copper producer. Telfer Gold Mine has undergone a series of transformations since mining commenced as a high-grade narrow-vein oxide open pit operation in 1977. In 1986, the open pit operation converted from a narrow-vein, high-grade operation, to a low-grade high-volume oxide mining operation utilising dump leach processing technology. Mechanised underground mining of the high-grade narrow-veins commenced in 1990. Total recovered gold production between 1977 to 1999 has totalled 5.7 million ounces. The Telfer Extension Project consists of two pre-feasibility studies, the Surface Extension Project (SEP) and the I-Series Project (ISP). The combined studies represent one of the more significant resource evaluations undertaken in the gold industry in recent times. Geological activities for the SEP pre-feasibility study have included the drill definition of a large low-grade resource within an area of 25 km2 . The surface drilling program has completed 15 000 metres of HQ3 diamond drilling and over 30 000 metres of RC between last quarter of 1998 and late-1999. The ISP pre-feasibility study is currently evaluating the resource potential of both a high-grade low-volume and a lower grade bulk mining scenario, 800 m to 1200 m below the surface of Main Dome. 15 000 metres of underground diamond drilling have been completed between last quarter of 1998 and August 1999 as part of this study. Systems and cultures have been developed to maximise safety, monitor the quality assurance/quality control (QA/QC) on all aspects of the operation, and minimise impact on the environment. All data are stored in database systems, specifically designed for Telfer operations. 3D geostatistical resource estimation using ordinary kriging has been carried out for over 220 geological domains within the 25 km3 of mineralised system. Non-linear geostatistical techniques are being investigated as part of the pre-feasibility study.

Jan 1, 2000

By S Novak

A world-class example of sustainable development in practice, the Local Resource Development Initiative (LRDI) grew from agreements between the Ambatovy nickel mine developers and the Government of Madagascar. A program of training and community development, the LRDI aims to maximise local benefits by optimising the integration of local resources during the construction period of the mine. By local resources, we mean the local labour force as well as local goods and services. Begun in 2007, the foundation of the LRDI is to integrate local resources into the mining project and where gaps are identified, design and implement training, mentoring and other programs to fill those gaps. The principal accomplishments are: the establishment of training centres that trained over 4000 people in little over one year, 96 per cent of whom hired to work at the mine; a support program for local micro, small and medium enterprises that has led to the award of 65 contracts for goods and services with training and mentoring of over 100 local businesses; and a number of special projects that have, among other results, strengthened local agricultural development and created employment for young people. The LRDI provides unique insights into key indicators and lessons learned to strengthen the social and economic sustainability of mining projects in developing countries. The paper will discuss these in terms, among others, of: the importance to project success of upstream planning to address socio-economic issues; the role of civil society and other local partners to strengthen and expand sustainability outcomes, and to spur governments to demand that major projects promote economic and social sustainability; and the integration of mine sustainability with sustained regional social and economic development.

Jan 1, 2009

Spectroelectrochemical Investigation of Hydroxamate Reagents on Copper Oxide Minerals

Sep 13, 2010

By K B. Quast, A Schuurmans

Laboratory batch rod and ball milling tests were conducted on samples of Heavy Medium Separator (HMS) sinks from Renison Limited. The effects of mill rotation speed, rod volume and ball size on the resulting product size distribution were investigated. Between 48 and 69 per cent of critical speed, the product sizing distribution curves remained very similar, with a finer grind resulting from increasing the speed of rotation at constant grind time. Increasing the rod loading from ten to 53 per cent by volume caused the product size to become finer and more closely sized with a transition occurring at approximately 29 per cent. This was interpreted as a change of dominant grinding mechanism from abrasion to impact. No preferential grinding of the cassiterite was observed. The effect of increasing ball size at constant charge weight was to preferentially grind the coarser particles and generate more intermediate sized particles, whereas the product from a mixed ball charge gave a distribution similar to that obtained when a charge containing only smaller balls was used.

Jan 1, 1998

By A B. Christie

The Institute of Geological and Nuclear Sciences' Mineral Resources Programme is currently carrying out research under two major projects:   HAREM (Hauraki Andesite Rhyolite Epithennal Mineralisation) The Hauraki Goldfield lies within a belt of andesite-dacite-rhyolite volcanics of Miocene Pliocene age which is underlain by a basement of Mesozoic greywacke. It contains some 50 separate epithermal gold deposits and is a world-class gold and silver producer. The HAREM project is aimed at improving models of the epithermal gold mineralisation, and to better understand the processes and controls of origin, transport and deposition of the gold.   MARGO - (Marlborough Gold) The MARGO project is aimed at determining the geological factors that controlled the formation of the Mesozoic mesothermal gold-antimony-tungsten deposits in the Marlborough Schist belt. Following reconnaissance work on 12 deposits, our current work is concentrated on deposits in the Wakamarina valley.

Jan 1, 1994

In the estimation of reserves the known values of the variables of interest from surrounding drill holes are used to compute or estimate the unknown value of the orebody over a given region or at a given point of interest. The classical means of doing this are: 1. The Polygonal Method û where the region is divided into polygons centred on bore holes, each variable is then assumed to have constant value over each polygon. 2. Inverse distance methods, where the variable is assumed to vary linearly with the distance between the known values of the drill holes. 3. Inverse distance squared method û a quadratic variation is assumed for the variables between the bore holes.

Jan 1, 1983

By Stitt P. H

In Australia, the term "heavy mineral deposits" is used to denote sands which contain variable but economic quantities of the minerals rutile, ilmenite and zircon, often with minor amounts of monazite and xenotime as co-products. Australia has been a significant producer of rutile, ilmenite and zircon from such sands for fifty years and has long been the leading producer of rutile and zircon. The industry had its beginnings with the mining of present day beaches in northern NSW in 1934. Early work was small scale and in some cases involved hand winning of naturally concen- trated mineral for direct export. During World War II and immediately after the industry became increasingly mechanised and by the 1970s on the east coast operated between Newcastle, NSW north to Fraser Island in Queensland. Deposits worked included present day beaches, fossil strand lines up to 5 km or more inland from the present coast and aeolian concentrations. In the mid 1950s, operations commenced on the west coast of WA, south of Perth. Western Australian mineral sands tend to be rich in ilmenite as compared to the east coast. However the WA ilmenites are lower in chrome oxide and make a better syn- thetic rutile feedstock.

Jan 1, 1988

It is well known that the ability to influence project value reduces significantly as planning progresses and decisions regarding project parameters are made. However, at the prefeasibility stage in particular, where one of the main aims should be to evaluate a wide range of options in order to select the best for more detailed further study, there is often a reluctance to spend the time and money needed to do this rigorously. This paper demonstrates, by a number of case study examples, how significant increases in value may be obtained by fully evaluating the combinations of alternatives for various project design parameters, including (though not limited to) mining methods, haulage methods, mining rates, processing methods and rates, sequencing of mining, and cut-off grades, with changes and upgrades over time where applicable. The additional value unlocked is typically orders of magnitude greater than the additional cost of the more comprehensive study. The dangers of misuse of simplistic sensitivity analyses and failure to identify how strategies might change in response to changes in external factors are also illustrated, and the importance of selecting the best ægrade descriptorÆ is discussed.

Jan 1, 2007

By C Jones

When the Paulsens operation was poised to be placed on care and maintenance, Bill Beament and the rest of the Northern Star Resources (NSR) team capitalised on the opportunity to send the Ashburton region’s only operating gold mine into the record books.A three-stage strategy was devised by NSR to pay off the acquisition and maximise the return from the operation. The first stage was to mine the 55 000 oz mine plan and pay off the cost of the acquisition, then maintain profitable production beyond the seven months and re-establish a mine life. The second stage involved an early commitment to a 220 m long diamond drill drive being placed in the hanging wall of the orebody from which the extensions of the orebody could be further explored, allowing the second stage of the plan to come into effect and extend the mine life by converting Inferred Resources into the mine plan. The third stage of the initial plan was to utilise this drill drive and continue to drill deeper holes beyond the current limit of drilling in the ore zones to extend the orebody and increase the mine’s life.With an ever growing desire to further expand, the young company took on the bold move of establishing its own mining services division. A critical element to the success of this was ensuring that the right people were recruited with the appropriate specialised skill sets.Aligning common goals amongst all NSR team members, from the board and senior management to the work force on site, was critical to integrate the new and driven direction that Paulsens had adopted. It was essential to change the focus and a shift in all employees’ attitudes and values from a mine that was all but down and out, to a site that wanted to be kicking some serious goals.Teaming together a passionate and driven leader with a strong allied workforce was always going to put NSR in the best position possible to make Paulsens the success story that it now is. But without the calculated risks and enthusiastic attitude, the little known mine site in the Pilbara might have remained just that.CITATION:Jones, C, 2014. The Paulsens transformation – a shining light under a northern star, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

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 B Hiebl, J Martens, L Petzold

A research team at the Iron and Steelmaking department at Primetals Technologies has established new upgrading measures for improving the efficiency of the beneficiation process in ironmaking plants, relying largely on pre-existing equipment. After the upgrade, the iron content in the final iron ore concentrate was shown to be significantly higher. Remarkably, the costs for employing the respective measures are surprisingly low.This case study is based on a Kazakh iron and steel producer, whose beneficiation process is currently generating a magnetite concentrate with a final iron content of 65.65 per cent. The study shows that the implementation of Primetals Technologies’ intelligent modification measures to the current beneficiation process, the realisation of more effective dewatering, and the utilisation of an innovative binder lead to an increased iron content in the resulting pellets, reaching a concentration of 69.17 per cent (iron ore concentrate) and 66.5 per cent (pellets).The current operation consists of three closed circuit grinding stages, four stages of low intensity magnetic separation, vacuum disc filters and straight-grate pelletising. By dividing the slurry after the second stage of grinding and the third stage of low intensity magnetic separation, it is possible to divert the more iron-rich fines before they would enter the third grinding stage and the fourth stage of magnetic separation. This then reduces the load on the existing third stage ball mill. Afterwards, the ground material is treated in an additional low intensity magnetic separator and mixed with the previously diverted fraction of the fines. An improved filtration procedure, combined with the application of a highly sophisticated binder, further reduces the amount of additives needed, so that a genuine direct reduced (DR)-grade iron concentrate is produced as a result.All laboratory, pilot and pelletising test work was executed at Primetals Technologies’ laboratories in Austria.CITATION:Martens, J, Petzold, L and Hiebl, B, 2017. Enabling iron ore concentrate for the production of direct reduced iron with pre-existing beneficiation lines, in Proceedings Iron Ore 2017, pp 227–232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The development of a robust belt sampling strategy and protocol inunderground gold mines is a fundamental requirement for effective grade quality control, ore accounting and mine-mill reconciliations. As part of the ore management system, a belt sampling system has been developed by the author, which is used to predict monthly gold grade and its error for underground/belt/mill reconciliation and grade control. This paper presents the step-by-step development of the belt samplingstrategy and sample preparation protocol at Target, an underground gold mine in South Africa. The belt sampling system at Target consists of an underground belt transporting run-of-mine material into an underground transfer point, a weightometer, a two stage crushing system, a tube splitter and a catchment device. The design allows run-of-mine ore on the belt to be sampled automatically by a go-belt sampler. GyÆs sampling theory of particulate materials forms the basicframework of the belt sampling strategy. The theory is used to quantify the optimum sample mass of broken material to be taken from the belt and to predict its reliability. It is also employed to determine the Fundamental Sampling Error (FSE), time interval between samples and particle size requirements of the final underground belt sample. Further, GyÆs sampling theory provides the means of analysing the crushing processes, splitting, segregation error, analytical variance, and the best sample preparation protocol. Although the belt sampling strategy developed in this study was forWitwaterstrand gold ore, the process is entirely general and may be very successfully used in any underground or surface mine.

Jan 1, 1999

By S Henderson, J V. Lawless

The worldwide association of low-sulfidation epithermal gold mineralisation, bimodal rhyolitic-basaltic volcanism and rifting is confirmed in New Zealand. In the currently productive Coromandel epithermal-gold province reported Ar-Ar dating of adularia from low sulfidation deposits falls into two groups at 6 and 7 Ma. Bimodal rhyolitic-basaltic volcanism has been reported to be K-Ar dated at 9 to 7 Ma and 6 to 5.5 Ma. Epithermal gold mineralisation in Northland is spatially associated with bimodal basaltic-rhyolitic volcanism, with rifting cogenetic with that in the CVZ. The Taupo Volcanic zone (TVZ) is sufficiently young that the presence of a segmented rift with recent bimodal rhyolitic-basaltic volcanism can be genetically associated with epithermal gold mineralisation, which occurs as both fossil occurrences and in active geothermal fields. This reinforces the known potential prospectiveness of the Coromandel area and increases that of Northland and the Taupo Volcanic Zone.

Jan 1, 2005

Recycling of Sludge from the Production of Manganese

Sep 13, 2010

By J R. Leeming

Mines require ventilation to ensure an adequate atmosphere for the sustenance of life, and to dilute, render harmless and remove contaminants.This paper describes the developments in the United Kingdom (UK) from natural ventilation, through the introduction of fire and simple fans, to modern fully independent and remotely monitored and controlled installations.CITATION:Leeming, J R, 2017. The history of mine ventilation in the United Kingdom, in Proceedings Australian Mine Vent Conference 2017, pp 271–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Study on the Reasonable Mineral Processing Technology of a Cu-Mo Ore

Sep 13, 2010

Good morning ladies and gentlemen, and may I thank you for inviting me once again to address your conference. I would first like to welcome you all, especially international delegates and conference speakers. ItÆs a pleasure to be with you all and I hope that you have the time to enjoy the many beautiful sights that the Coromandel and Bay of Plenty have to offer.   Holding your conference in Waihi is particularly apt, especially bearing in mind the conference theme û 'Mining in the Community'. There can be few venues in the world that can boast a world class gold deposit of the likes of Martha Hill located right here in the centre of a rural service town. ItÆs a deposit that has a mining history active now in its third century and that to date has yielded some 7.5 million ounces of gold and 50 million ounces of silver. I doubt that when John McCombie and Robert Lee discovered gold at Martha Hill in 1878 that they had any inkling that their endeavours would be the foundation for a mine that would become such an inseparable part of the economic and social fabric of Waihi for the next 130 years.   This is now my fifth appearance at a New Zealand minerals conference, I especially value such occasions as it allows me to comment on your industryÆs performance over the past year, share my thoughts on matters affecting your industry, and also to give you some feedback from central government.

Jan 1, 2006