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Resources and reserves are critical inputs into the determination of an operating mineÆs financial results and balance sheets, but how well understood is this fact. Do the investors, directors, accountants and geologists/engineers responsible for preparing or relying on relevant aspects of the end results properly understand the inputs and outputs and the associated risks that may be established. The first step is to understand how financial reports are impacted. The most obvious, and best known, impact is in the calculation of depreciation and amortisation charges against long term assets. In addition, however, there is a requirement to regularly determine whether asset book values are impaired û this is nearly always performed globally by the preparation of a discounted cashflow model for a mine which is usually based on a mine life as determined from the resource and reserve statement û the particular driver here is normally the short and long term production plans. A key aspect of the short term production plan is that it would normally not assume that the reserve and resource statement implies consistent grade, stripping ratios, etc. However, outside of the early years of a plan, more generic assumptions of these variables are often made in conjunction with the reserve and resource statement. Depending on the timeframe of the detailed production plans, this can have a large impact on a projectÆs net present value. Other financial balances that may also be impacted include restoration and rehabilitation provisions, retrenchment provisions and deferred or equalisation stripping accounts. The age old question of whether all reserves should be used or whether some or all of the resources should be included for financial reporting purposes has never been adequately resolved. It is our view that there should be no prescriptive answer to this question but judgement of all professionals involved in the process needs to be included. Furthermore, the company needs to be able to support their conclusions with well thought out and appropriate answers. This may not be in line with the approach that certain accounting standard setters may be proposing or taking, and this paper will outline the current status of global requirement and the likely future directions. Whether reserves or resources are utilised, does not change the key requirement that those preparing or using reserve and resource statements need to understand key aspects. For example: geologists/engineers do they know how reserves or resources will be used? have they imparted information on variability of key drivers such as grade or depth or dilution? do they know that major financial/business altering decisions may be made based on the analysis? accountants do they understand where the numbers have been derived from and the assumptions that may have been made in their determination? do they understand the degree of accuracy (or inaccuracy) that may exist particularly with resources)? do they understand the history of resource reconciliations and what it may mean for the future? directors do they understand the processes undertaken by the company to prepare the financial report and the interaction between the geologists/engineers and accountants? do they understand the potential sensitivity of results to the input variables? Financial reporting is extremely reliant on the use of the reserves and resources, however, the geologists/engineers, accountants and directors do not always understand the interactions between themselves which may lead to misleading public reporting. More education and communication between various parties is needed.

Jan 1, 2002

Most analysts determining tungsten trioxide in low grade samples are aware that colorimetric procedures do not possess the inherent disadvantages of gravimetric methods operating on milligram quantities of tungsten trioxide. Apart from the inaccuracies associated with weighing four or five milligrams of ignited oxide in a platinum crucible of about 30 gm. weight with a large surface area to absorb moisture, using a 5 gm. charge on samples less than about 0·15 per cent tungsten trioxide, it is extremely difficult toget complete or pure precipitation of tungsten with cinchonine, cinchonine plus alpha benzoin oxime, rhodamine B or any other of the commonly used precipitants. Table 2', No. 8, illustrates the low results obtained by gravimetric as opposed to colorimetric procedures. In addition the colorimetric determination requires only a small portion of the time consumed by gravimetric practices and the increased accuracy obtainable in low ranges together with the saving in time made it highly desirable to develop a colorimetric method suitable for King Island ores.The most commonly used colorimetric method is that introduced by Feigl and Krumholz (1932), since modified by various investigators (Grimaldi and North, 1943; Sandell, 1946; Westwood and Mayer, 1947; Gentry and Sherrington, 1948; Freund, Wright and Brookshier, 1951; Grouthamel and Johnson, 1954; and others). Stannous chloride is used to reduce tungsten followed by colour development with a thiocyanate, usually sodium, potassium or ammonium.Other reducing agents have been proposed (Emery and Curtis, 1948), but only in recent years have the conditions governing maximum colour development been fully estab...

Jan 1, 1958

By C M. Evans, D Thomas

Solid EnergyÆs Wangaloa open cast coal mine was operated between 1945 - 1989, and remained closed and disused until 2001 when SENZ initiated a mine rehabilitation programme. It is nearing the final stages of physical and environmental rehabilitation, aimed at creating an aesthetically pleasing and useful landscape. The final goals of these efforts are to produce an area, which has recreational and educational value. SENZÆs holistic approach to rehabilitation has been undertaken, treating the entire historical mine footprint instead of focusing only on those disturbed areas and the minimum range of issues just to meet with legal compliance. Rehabilitation at the site has included overburden modification with an emphasis on stability, removal and replacement of unhealthy and invasive plant species, and an AgLime amendment to alter soil pH conditions, which would support native plant species. To date, most ongoing activities relate to final planting and plant upkeep, and maintenance of the landform including ongoing erosion control, pest control, environmental monitoring, and research. Environmental quality concerns at the site may be treated by using a combination of methods, including regrading and capping of acid-generating pyrites, soil treatment with AgLime, and passive wetland treatment within existing water courses. Following major works, the mine site area may be opened to the public for recreational activities, interpretive displays on historical mining activities, and observation and appreciation for otherwise unseen geological features. SENZÆs holistic approach to reclamation, rather than treating minor issues, will result in the former mine site being transformed into an asset and the environmental and financial liability associated with the closed mine being discharged. Former mine sites can be turned from environmental liabilities with no recreational or public value (and potentially dangerous to life) into sites that can be safely used by the public for recreational and educational purposes.

Jan 1, 2006

Cyclone Process for Heavy Metals Decontamination of Sediments

Sep 13, 2010

At its Port Kembla Plant, Australian Fertilizers Ltd. manufactures Superphosphate and other Phosphatic Fertilizers.Phosphate Rock is received from Nauru and Ocean Island. It contains water insoluble tri-calcium phosphate, Ca3(PO4), to an average of about 86%.It is crushed to pass a 20-mesh x 26-gauge woven wire screen, and is then treated with Sulphuric Acid to give the product Superphosphate with a water solubie prosphate content of 20.5%, estimated as P205. Sulphuric Acid is made by the chamber process. Three sets of chambers are installed, on,e five-chamber set of timber frame work construction and the other two of more recent date, each with four chambers of steel frame work construction. A fourth chamber set is now being built.Sulphuric Acid is delivered for use. at about 70% H2S04, the strength depending upon the rock used.Mixing - The crushed rock and sulphuric acid are mixed in weighed and measured proportions respectiyely in one-ton batches in revolving cast fron pans, mechanically stirred. The mixture, while still slurry, is run into a closed horizontal concrete cylinder (den) where, with the completion of the chemical reaction, it rapidly sets as Superphosphate.Approximately fifty batches are required to fill a den. When full, the den is opened ana the mass cut out by a revolving cutter. The product is elevated and conveyed to any required position in the Superphosphate storage shed, where it dries and matures.Despatch - As required, the Superphosphate is excavated by a two ton grab and conveyed from the matured "dump" to bagging units where it is disintegrated, screened and bagged at twelve bags to the ton. The filled !Jags are closed by machine and delivered to railway trucks immediately.Mixed Fertilizers - Sulphate of Ammonia, Sulphate and Muriate, of Potash, and Blood and Bone are mixed with Superphosphate and thoroughly incorporated to give different mixtures to meet special plant requirements.

Jan 1, 1938

By T Atchison

The Vale Ferro Carajßs S11D project in northern Brazil is based on the movement of unprecedented volumes of waste and ore for mobile in-pit crushing and conveying or ætrucklessÆ systems. In peak years, the system is intended to handle a combined 160 Mt of material.The planning and implementation of the first such system for Vale, in a remote greenfield site, utilising the services of a range of international study, design and supply partners has provided a unique set of technical and project delivery challenges. The lessons from these are of value to the industry as the trend to remote and high-volume operations continues.This paper describes the key features of the mining system and documents the challenges and mitigations for important technical, cultural and project delivery issues that have arisen. It is a combined description of the journey taken by both Vale (as owner) and SKM (as delivery partner) over the course of many years.CITATION:Atchison, T, 2013. Lessons from the S11D truckless mining project, in Proceedings Iron Ore 2013 , pp 177-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

New Zealand depends on foreign investment for economic development. This also applies to the development of New Zealand's mineral resources. For this foreign investment to happen there must be some incentives to attract the investment. While prospectivity is the dominant parameter considered by investors it is not a variable that can be changed, only the perception of New Zealand's prospectivity. Other parameters likely to be considered are sovereign risk, red tape, green tape, land access, civil unrest, land claims, social risk, labour relations, infrastructure and natural disasters. Regulators and political will can vary some of these parameters. Where New Zealand fits internationally can be measured by investors' perceptions of these parameters. Following on from these perceptions New Zealand can be seen to have advantages in some areas and be disadvantaged in others. How to deal with the disadvantages to give investors confidence is not easy in the New Zealand environment where the development of mineral resources plays a small part in an economy dominated by agriculture. Added to this is the current global state of the minerals industry which offers even more of a challenge to attract foreign investment to develop New Zealand's mineral resources.

Jan 1, 2000

Consents Required for Overseas Persons Overseas Investment Regulations 1974 Foreign investment proposals must be reviewed by the Overseas Investment Commission to ensure that these are in accord with national interests. Consent must be obtained from the Commission for: 1. New investment proposals which include: a. An overseas person acquiring 25 per cent or more of any class of share in a company. b. A New Zealand company issuing shares to an overseas person where this will result in that person owning 25 per cent or more of the company. c. An overseas person acquiring business assets for consideration in excess of $100 000. d. An overseas person commencing business in New Zealand. 2. Borrowing in New Zealand: An overseas person must obtain consent to raise funds in excess of $300 000 in New Zealand. 3. Borrowing Overseas: New Zealand incorporated companies must obtain consent to borrow overseas. Current policy is borrowing will be approved where the loan is for a specified fixed term of one year or more.

Jan 1, 1982

By A Rojc, J Ronaszeki, C Smith

Nuclear logging was tested for the in situ determination of Fe, Si, and Al in iron ore blastholes with field tests at the BHP Billiton Iron Ore, Mount Waleback Mine. Prompt gamma neutron activation analysis (PGNAA) was used to determine percentages of Fe and Si while natural gamma logging was employed for the determination of Al. The accuracy given by nuclear logging is comparable to the accuracy provided by the laboratory analysis which was determined by taking the average of four samples collected from the cuttings deposited on the surface around the perimeter of a drill hole. The work also indicated that there is a chance of determining Al by PGNAA.

Jan 1, 2002

By K S. Fisher, J D. Pease

The installation of the George Fisher flowsheet in the lead/zinc concentrator at Mount Isa Mines Limited has recently been completed. The George Fisher flowsheet involved moving flotation capacity from the lead circuit to the zinc circuit and changes in zinc circuitry, changes in the reagent regime and increased regrinding capacity, using IsaMills, to regrind some streams to 80 per cent passing seven microns. The project was highly successful, delivering a five per cent increase in zinc recovery within a fortnight of commissioning. The George Fisher flowsheet was developed over six years. Laboratory work built upon the knowledge gained from investigating and processing the Mount Isa and Hilton orebodies. The engineering design and construction for the brownfield expansion of the existing lead/zinc concentrator had significant involvement from the operational, maintenance and technical personnel. Experienced personnel were seconded from the concentrator to the design and construction groups to ensure smooth integration of the new flowsheet into the existing concentrator with minimum downtime, and maximising the reuse of existing equipment. The combination of thorough design, good project integration with operations, and a good commissioning plan allowed almost immediate delivery of project gains. The project was highly successful, the full design improvements were achieved within two weeks, allowing the focus to move to developing future improvements.

Jan 1, 2000

By Madgwick J. C

The monosaccharides glucose, galactose and arabinose, and the polyols glycerol and mannitol (0.1 Ufo WIV) supported pure and mixed culture heterotrophic bacterial manganese leaching of solid pyrolusite (MnO2, 2% W/V) to yield 14-38 mg/litre manganous ion in 3 days from a simple mineral salts media at 30°C. Supplementation of pure bacterial isolates growing on glucose with soluble intracellular photosynthate from freshwater algae (0.07 g/l carbohydrate) and marine algae (0.11 g/l) led to an improvement in Mn++ yields of 24 and 100 per cent respectively. Extracellular products of the freshwater algae (0.3 g/l carbohydrate) boosted recoveries by 57 per cent.

Jan 1, 1982

By D Craw, S Clearwater, S Hammit, C Smith

Prior to rehabilitation, plant cover on quartz gravel overburden at Wangaloa coal mine was highly patchy. Stabilisation techniques have since considerably altered the condition of the main overburden yet deposits in the east and west remain largely intact. On the eastern overburden, three distinct zones of revegetation have naturally developed: Zone 1 represents a dense plant cover, Zone 2 a patchy cover and Zone 3 a sparse cover of isolated plants. Aerial photographs show much of the eastern overburden was deposited between 1940 and 1960s. Yet we found that the temporal scale of deposition did not wholly account for the differences observed in vegetation development. To investigate other influential factors, we set up 12 study plots using four replicates in each vegetation zone. The diversity and density of plants in each plot were measured to quantify the degree of vegetation development. Samples from the substrate in each plot were collected using soil cores to a depth of 10 cm. Cores were analysed for indicators of nutrient availability, metal content and physical composition. We found that substrate chemistry varied between individual study plots, but showed little difference overall along the vegetation gradient. Substrate physical differences were much greater. The ratio of coarse quartz pebbles: fines was considerably higher in Zone 3 than other zones, and within zones where plants were not growing. Bulk density also increased successively from Zone 1 - 3. We found clear evidence for the reversed stratigraphy of excavation superimposed over the time scale of deposition, and the corresponding nature of fine particles. The rate of revegetation was therefore highly dependent upon the substrate composition of the last surface deposit from the dumping truck. Our data suggests an optimum ratio exists between inert coarse material and a fine matrix for progressive natural vegetation development on mine substrates.

Jan 1, 2004

This paper considers the application of recent laboratory gas sorption data to the understanding outburst phenomena in underground coal mining. Previous use of threshold limits based on gas content and coal rank are placed in perspective. Although this work focuses on overseas research and experience, parallels can be drawn for New Zealand coal settings, taking into account localised mining and geological factors.

Jan 1, 1994

In November 1999 Waihi Gold Mining Company commissioned its new crushing and conveying plant used to transport both ore and waste from the Martha Mine to its ore processing plant and also its tailings dam construction area. To date, a record monthly throughput of 854 000 tonnes throughput has been achieved. This paper outlines the measures taken subsequent to the commissioning of the system to achieve greater than design throughput and to mitigate the environmental and safety issues associated with operating the system in the middle of a town.

Jan 1, 2001

No one process, product or effect of the minerals sector can be viewed in isolation when addressing sustainable development. Meaningful assessments of the minerals sector require that its processes and production are drawn together in a generic framework that gives a holistic view of its performance and progress. Lifecycle Assessment is increasingly accepted as an appropriate means of constructing such a framework. It is a step beyond using the simplistic concept of the triple bottom line of social, environmental and economic performance to drive and communicate sustainable development. However, fundamental questions need to be raised about the scope and purpose of lifecycle assessment, such as what effects and performances should be assessed, for whom should they be assessed, and what performance indicators should be used and how should they be selected. The principles of eco-efficiency, industrial ecology, The Natural Step (TNS) and other pertinent philosophies and initiatives driving mineral sector sustainable development are outlined to support a lifecycle stewardship vision for the minerals sector. Articulating this vision through a holistic lifecycle indicator system showing inputs and outputs, natural partnerships, effects on community, environment and economy facilitates recognition of problems, opportunities and partnerships that can be usefully pursued.

Jan 1, 2002

Willyamite from the type locality, Consols mine, Broken Hill, N.S.W., has been re-examined, and found to consist of zones with widely different Co:Ni ratios. The name willyamite is redefined to include the portion of the (Co, Ni)SbS series with cobalt in excess of nickel. Willyamite is pseudo-cubic, with the three axes equal to within 0·001 A.

Jan 1, 1970

INTRODUCTION ò World coal production, Exporters and Importers òNew Zealand Exports, Markets and Products ò Types of Markets and Price Setting ò Bench Mark Prices and Exchange Rate ò Transport ò International Marketing - Key Factors ò Coal New Zealand , the Challenges

Jan 1, 1996

By P Gunn, M Watts

The general goal of passive acid mine drainage (AMD) treatment is to reduce levels of acidity and metals to acceptable levels. Most treatment systems use either an oxidising or a reducing strategy. In oxidising systems, alkalinity is added along with dissolved oxygen; in reducing systems, dissolved oxygen is removed (if present) and then alkalinity is added. It is recommended that small-scale field trials be conducted as part of the methodology of selecting the best remediation strategy at AMD sites. Following successful field trials at the Sullivan Mine AMD, the Pike River Coal Company (PRCC) has shown foresight by using the same system to treat AMD generated as a result of taking a bulk sample of coal at the Pike River coal field. The system reduced acidity by 100 per cent, iron by 99 per cent, aluminium by 96 per cent, nickel by 95 per cent, manganese by 51 per cent and zinc by 99 per cent. The success of this field trial suggests that a system using a reducing strategy may be appropriate for the Pike River Adit AMD site.

Jan 1, 2005

By P Mitchell, J Proffett, I Munajat

Batu Hijau is an island arc porphyry copper-gold deposit located in the southwest corner of Sumbawa Island in the Sunda-Banda archipelago of Indonesia. Southwest Sumbawa Island is underlain by Early Tertiary, low-K calc-alkaline to weakly alkaline volcanic and intrusive rocks. Within the mine area the oldest exposed rocks are medium- to thick-bedded, medium to coarse andesite volcanic lithic breccia, thin bedded, fine-grained volcaniclastic sandstones and mudstones and hypabyssal porphyritic andesite. In the eastern portion of the mine area there is a thick sequence of quartz diorite that postdates the andesites. A small stock of Equigranualar Quartz Diorite predates the Batu Hijau deposit and occupies the contact between the andesitic volcaniclastic sequence of rocks and the Porphyritic Quartz Diorite. Batu Hijau is a world-class copper-gold deposit that has a drill indicated mineable reserve of 914 million metric tonnes grading 0.525 per cent copper (10.58 billion pounds copper) and 0.403 g/t gold (11.8 million ounces gold). Mineralised material not in reserve accounts for an additional 580 million metric tonnes at 0.328 per cent Cu (4.19 billion pounds copper) and 0.171 g Au/T (3.19 million ounces gold), and including an oxide copper resource of 57 million tonnes at 0.37 per cent Cu and 0.12 g Au/T. Copper and gold mineralisation is directly related to quartz veining and wall rock alteration that developed with multiple tonalite porphyry intrusions. The tonalites were emplaced along the contact between the andesitic volcaniclastic rocks and quartz diorite intrusives. Copper and gold are zoned around the porphyry intrusions, which are designated by their contact-age relationships and other features as Old Tonalite, Intermediate Tonalite(s), and Young Tonalite(s). The Old Tonalite was the first copper-bearing intrusion, and although it is the smallest intrusion it has the highest quartz vein density, the strongest alteration and the highest grade. At least two tonalite porphyry intrusions followed the emplacement of the Old Tonalite. Each of these intrusions was associated with less quartz veining, weaker hydrothermal alteration and lower grade copper and gold than the previous intrusion. The intrusive cycle culminated with the emplacement of the Young Tonalite, which contains relatively few quartz veins, is weakly altered and mineralised. Hypogene hydrothermal alteration and sulphide mineralisation developed in five temporally and spatially overlapping stages. These stages consist of Early, Transitional, Late, Very Late, and I Zeolite alteration. Early alteration and sulphide mineralisation accompanied each tonalite porphyry intrusion, but with diminished intensity in each subsequent intrusion. Transitional and later stages of alteration and mineralisation postdate the tonalite porphyries and overprint Early stage alteration and mineralisation. Early alteration and mineralisation consisted of biotisation, secondary magnetite and plagioclase development, fine porphyry-style stockwork veining and ore mineralisation. Magnetite-biotite????quartz stringers and dark micaceous (biotite-sericite) veinlets were developed. The veinlets were accompanied by biotisation of magmatic mafic minerals and groundmass. Thin, irregular and discontinuous æAÆ type quartz veinlets and fine-grained chalcocite, digenite and bornite mineralisation accompanies the Early alteration. It is hypothesized that most of the copper mineralisation was originally deposited as bornite, digenite and chalcocite. Secondary plagioclase was added along the selvages of the early quartz veinlets. Early alteration is pervasive within and proximal to the tonalite porphyries. In the distal portions of the deposit, andalusite and anthophyllite formed at intermediate to shallow depths, and in the deeper portions of the deposit, respectively. The andalusite and anthophyllite probably developed at the same time as the early magnetite-biotite-quartz alteration in the core of the deposit. Transitional-age alteration consists of oligioclase/albite-sericite-chlorite- quartz-¦vermiculite and is associated with æBÆ quartz veins. Through-going planar æBÆ veins are thicker than æAÆ and æA-familyÆ veinlets and have chalcopyrite????bornite along vuggy centrelines and narrow oligioclase????albite alteration envelopes. Rare æCÆ chalcopyite¦quartz veinlets were also formed during Transitional alteration. During Transitional alteration early copper sulphide minerals (chalcocite, digenite and bornite) are converted to bornite and chalcopyrite. The majority of the copper (50 - 70 per cent) in the deposit is contained in ores in which chalcopyrite is the predominant sulphide. Late alteration consists of feldspar destruction and replacement by sericite and other minerals. The late alteration is accompanied by the development of æDÆ sulphide veinlets and veins. These veins consist of pyrite and quartz????chalcopyrite. Within the halos of the late pyritic veinlets biotite is replaced by sericite, quartz-sericite, quartz-andalusite, or quartz-pyrophyllite+kaolinite replace plagioclase, and magnetite is converted to specularite and/or pyrite. In the periphery of the deposit, the feldspar destructive alteration, together with outer zones of Transitional-age alteration, constitutes what is commonly referred to as a æpropylitic zoneÆ. Very Late hydrothermal alteration is also characterised by feldspar destruction, but differs from Late alteration in that feldspar is replaced by smectite in association with sericite and chlorite. Sulphide mineralisation in this stage consists of sphalerite, galena, tennantite, pyrite and chalcopyrite. The last stage or I Zeolite alteration consists of low-temperature, open space filling consisting of stilbite or laumontite¦calcite. Supergene oxidisation of the orebody extends to a maximum depth of 210m. Isolated deep oxidation occurs along open fracture zones to depths of ~400 metres along æDÆ vein filled fracture zones. Weak supergene copper enrichment occurs in a thin horizon (15 to 60 m thick) that blankets the top of the deposit. The main supergene copper mineral is secondary æsootyÆ chalcocite replacement of sulphide grains and as veins.

Jan 1, 1999

The Effect of High Power Nanosecond Electromagnetic Pulses on Selectivity of Pyrite from Arsenopyrite

Sep 13, 2010