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The need for legislative reform of health and safety legislation has been recognised in New Zealand for about a decade. Previous legislation did not cover all work places, many areas were excluded from coverage, and there were at least 14 different acts and dozens of sets of regulations dealing with various aspects of health and safety.

Jan 1, 1993

By A C. Edwards

The Mongol-Okhotsk belt consists of detached fragments of the Circum Pacific fold belt which have been trapped within the Mongol-Okhotsk fold belt. In its western part, the structures of the belt form an east-facing loop that is not connected with the other orogenic structures of Central Asia. In the eastern part of the belt (the Mongol-Okhotsk suture zone) the terranes form a zone between the Siberian craton to the north and the Bureya composite terrane to the south, that is linked with the Circum Pacific belt. The accretionary terranes, together with their Precambrian backstops, form a series of consistently-stacked, paired units that are bounded by northwest and north trending sinistral strike-slip faults. The ages of the rocks forming these accretionary complexes vary from Late Precambrian - Carboniferous in the west to Cambrian - Jurassic in the east. The terranes developed due to a progressive westward stacking of the accretionary complexes during the process of accretionary growth. The magmatic rocks young eastward indicating that migration of the magmatic front of the arc followed the eastward growth of the accretionary complexes. The accretionary terranes may be differentiated by their Paleozoic lithological assemblages. Only the Selemdzha, Niman, and Kerbi terranes located in the eastern part of the Mongol-Okhotsk suture zone contain significant amounts of black shale, and it is these terranes that host the bulk of the hardrock and placer gold mineralisation that is present within the suture zone. Gold mineralisation is present both as vein style and disseminated mineralisation within structural duplexes.

Jan 1, 1999

By J Coward, S Bulatovic

There are currently two operators producing oil from the surface-mineable portions of AlbertaÆs oil sands (Syncrude Canada Ltd and Suncor Inc) and two other companies are proposing to enter the industry (Albian Sands Energy Inc in 2002 and True North Energy LP in 2004). Tailings from the two current oil sands plants contain approximately 220 000 tonnes per year of TiO2 and approximately 80 000 tonnes per year of zircon. This represents approximately six per cent of the worldÆs TiO2 consumption and approximately nine per cent of the worldÆs zircon production. With the commissioning of plants by Albian and True North, and the announced expansion of plants by Syncrude and Suncor, it is expected that these tonnages could quadruple in the next ten years. All of these operators have at least 50 years of reserves even at these expanded production rates. The occurrence of heavy minerals in AlbertaÆs oil sands has long been known and is well documented in the literature. There have been a number of attempts to produce market-grade products from this resource and the results of this work have been quite mixed. Typically, researchers have used the normal mineral dressing techniques of the industry and have found the mineral assemblage does not respond to these techniques all that well. This has led to the widely-held suspicion that there must be some difficult metallurgical problems associated with this resource. There are three main problem areas that have created difficulties for previous researchers:the bitumen coating on the sand grains; secondary mineralisation such as pyrite, siderite and calcite; and a high proportion of aluminosilicates (approximately 25 per cent) that have the same gravity, electrostatic and magnetic properties as other minerals in the heavy mineral suite. Recent work by Lakefield Research shows that these problems can be largely overcome with some novel approaches. The bitumen can be removed by washing with a solvent in the presence of a demulsifier; the pyrite can be removed by flotation; and the titanium and zircon minerals can be separated by selective flotation followed by conventional electrostatic and magnetic separation.

Jan 1, 2001

By Paterson R. G, Compston W

The Mine granite at the Ardlethan tinfield is dated by Rb-Sr on a muscovite concentrate at not less than 417 ± 2.5 Ma (2s), consistent with the intrusion of this granitic body into folded Late Ordovician sediments. A combination of Rb-Sr and K-Ar evidence suggests a slightly younger age, 41O ± 2.5 Ma, both for the neighbouring Ardlethan Granite and for the hydrothermal alteration of the Mine granite, with which the tin is associated.On this basis, the somewhat high 206Pb/204Pb of two galena samples from within the hydrothermal alteration zone is best explained by an increase in U/Pb of order 10 per cent during a geochemical event in the Late Precambrian, in the rocks which eventually yielded the Pb to the mineralising fluid. This earlier event probably increased Th/U in these rocks as well, by as much as 5 per cent. If these reconstructions are valid, the lower-than-average U/Pb implied for the original Precambrian source rock bespeaks a mantle component of marginally greater proportion than for "average orogene".

Jan 1, 1982

A modified liquation technique was developed for recovering tin from tinhouse scruff metal or hardhead containing about 10 per cent iron and 15 per cent occluded flux, palm oil, and moisture. This was effectedby heating the scruff metal to 950°C followed by rapid cooling to suppress the formation of FeSn2 and FeSn, and then subjecting it to the ordinary liquation and drossing processes of refining. By this method it was possible to recover about 83 per cent of the original tin content and, with subsequent smelting of the irony drosses, an overall recovery of 92 per cent was obtained.

Jan 1, 1969

By K Pery, J Leahy

Established metallurgical plants operate in a complex environment of interdependent drivers including technology change, operating and maintenance practice, evolving markets, HSEC requirements, statutory and plant requirements, personnel turnover, ore supply, and financial conditions, to name a few. A successful optimisation program should comprehend these factors and drive towards not only lower operating costs, but also higher rates of return for a given level of investment. Optimisation programs have the potential for very high rates of return on capital that Greenfield projects rarely have. This paper presents a robust strategy and methodology for plant optimisation initiatives as well as a case study of how it was implemented at the QNI Yabulu refinery in Queensland, Australia by an integrated team of researchers, engineers and operators. The methodology is premised on the fact that nobody knows the production asset as well as the current operating team. It covers the optimisation process from ideas generation, various stages of selection against the agreed criteria, development, including testwork, funding approval and implementation. It highlights the benefits in the use of integrated teams, the establishment of a sound project basis, and a diligent, phased approach.

Jan 1, 2004

The importance of the minerals industry to any economy is clearly demonstrable. Its raw materials and products are the foundation of modem society and they have shaped the history of mankind from prehistoric times to the space age of today. However, those in the minerals industry have clearly failed to impress this fact on the consciousness of the public, bureaucrats and politicians. They have also failed to engage their dedicated opponents in a constructive debate. This is mainly because the minerals industry has been unwilling (until recently) to deal with the "soft" issues of civil society, nor understand and operate on a more emotional level. Technical professionals (as well as managers) in the future must be as comfortable in handling community concerns over social, environmental or landowner issues, as they are with logging complex drill core, designing blast patterns and separating one mineral from another. They must become caring, effective communicators and mediators. These are the new skills of a professional in the Third Millennium. These issues are outlined and discussed with some Australian data used to illustrate the point. If there is to be a future for all, then the policy makers within all levels of government (national, regional or local) must not drive essential mineral development offshore. They must address ways to support wealth creation mechanisms, particularly innovation. The minerals industry is a powerful wealth creator for ordinary citizens and an innovator. Politicians and their advisers must not .be allowed to forget this fact. If the ANZAC minerals industries do not win the emotional debate and successfully deal with the "soft" issues as well as they deal with the technical issues, there can be only a dim future ahead.

Jan 1, 2000

By Monger N. R

Factors leading to the decision to use Joy Continuous Miners for pillar extraction in the Burwood Colliery are outlined. A detailed description is given of the Joy 1-CM-2 Continuous Miner, including the power supply to the machine, and the method of cutting coalfrom a face. Modifications found necessary in practice are dealt with.The Joy 10 S.C. shuttle car used in conjunction with the Miner, and alterations made to this unit, are then described, together with Ancillary units for the whole installation such as transformers, motor generator set, air compressor,_ cables for power supply and water supply for dust suppression.Special arrangements were necessary to transport the Miner and Shuttle Cars through the tunnel to the Victoria Tunnel seam, and the method of overcoming the transport difficulties is discussed. Manning of the Continuous Miner unit, and final preparation andsubsequent working of the pillars is outlined. Special attention must be given to maintenance of the machines.It is concluded that the combination of Joy Continuous Miner and Shuttle Car is an excellent method for removing pillars in the Burwood Colliery.INTRODUCTIONThis paper deals with the Burwood Colliery in the RH.P. Group in which some units are engaged in the mechanical extraction of pillars with Joy Continuous Miners.In 1941, an amendment to the Coal Mines Regulation Act of N.S.W. forbade the extraction of pillars by mechanical means unless with the express permission of the Minister for Mines. As this permission was not forthcoming, no mechanical extraction of pillars took place in Australia until 1954 As it was doubtful during most of this period whether mechanical extraction would ever come about, coal generally was won with a view to maximum extraction in the first workings, thus giving rise to centre gannon bord panels and 45° angle cut throughs as shown in Fig. 1.

Jan 1, 1957

Last evening, in Auckland, I heard the Chairman of Heinz US, Dr Tony O'Reilly (who, in addition to Heinz's ownership of our largest food processor, also has substantial personal investments in this country), advocate New Zealand as a 'regional corporate capital'.   Why would someone like Dr O'Reilly hold that view? No doubt, as one of Ireland's great rugby players of the 50s and 60s, he admires at least one thing that we do very well (confirmed again in Dublin over the past weekend). But that's not sufficient to support such a view.   He cited many reasons for preferring New Zealand over, say, Sydney, Australia, calling this 'the most rational in which to locate [an] international headquarters', including û +         we have no capital gains tax; +         a more 'pro-business environment'; +         a 'first class' legal and banking system; and +         a 'simple political system'.   I can find no better 'text for today's address.

Jan 1, 1997

By R R. Large

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The formation of orogenic gold deposits is commonly a two-stage process. The first stage involves preconcentration of gold in a suitable source rock, such as carbonaceous black shales, felsic volcaniclastics or komatiitic volcanics. The second stage involves the release of gold (commonly with arsenic and/or tellurium) from the source rocks during metamorphism or magmatic intrusive events, accompanied by the replacement of source rock pyrite by pyrrhotite. Recent research suggests that synsedimentary gold trapped in the structure of diagenetic arsenian pyrite in reduced carbonaceous facies of continental margin sedimentary basins is an ideal source of gold for many orogenic and Carlin-style gold deposits. The conversion of diagenetic arsenian pyrite to pyrrhotite during basin closure and greenschist facies metamorphism is the key process releasing gold and arsenic to the metamorphic fluid, with metal deposition in structural trap sites to form the deposits.CITATION:Large, R R, 2015. Orogenic gold deposits – a two-stage process of gold enrichment, in Proceedings PACRIM 2015 Congress, pp 335–340 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By S Yuen, T Rana, S Khan

Many open pit mines require dewatering or need aquifer depressurisation systems to manage mine water inflow and/or mine floor stability. In many instances these mining operations impact on regional groundwater resources and therefore access to these resources by other users.As such potential exists for mine development to be hindered or even blocked by groundwater legislation that aims to prevent declining groundwater levels and demonstrate equitable use of a regional groundwater resource.There is a need to manage aquifer systems during and after the mining operations, and in some cases stresses on the aquifers and associated ecosystems may be elastic and can be managed with minimum impacts or reversed once the mine ceases to operate.This paper uses the Gippsland sedimentary basin, with a history of declining groundwater levels and mining and petroleum production, as a case study to pose the question: Should period of mining operation, aquiferÆs storage capacity and its ability to recharge be concurrently considered when granting groundwater abstraction and mining licenses for prospective mine development?It further examines that by utilising an aquiferÆs storage capacity and demonstrating an understanding of aquifer system hydrodynamics during and beyond the life of the mine (time), the approval process for groundwater abstraction and associated cost of statutory monitoring may be made less onerous.

Jan 1, 2009

By Goldney L. H

The authors review the literature and discuss the application of methods to the design of thickeners for ilocculated metallurgical pulps. The use and evaluation of flocculents is described. Experimental data show that design based upon laboratory settlingdata is acceptable. The economic aspect of design is also discussed.INTRODUCTIONFor many years there has been little change in the methods for the design of thickener installations. While modifications have been made in the method of applying the data all methods have been based on the observee settling rate of the solids. The development of a theoretical approach based on physical data would involve so many variables which affect the settling rate that the more practical approach of direct observation seems unlikely to be replaced as the basis of design.The advent of synthetic fiocculents has introduced a modification in operation which affects design and should be considered. The authors review the subject and attempt to bring it up to date with present day procedure. Until recently the original work of Coe and Clevenger (1916) remained the basis of thickener design. They described their observation of the different zones encountered in settling, namely clarification, feed, transition, and compression or thickening- zones. The solids pass through the transition zone in settling from feed density to some higher density where settling ceases and ·some compression or compaction effect controls. the density obtained. The point at which the settling zone ceases to exist is known as the critical point.

Jan 1, 1959

In common with general experience in the iron-making industry overseas, Australia has in recent years suffered a deterioration in the physical quality of her iron ores in their suitability as a direct blast furnace feed. The increasing amounts of fines and the more friable nature of lump ore, especially in the ore from the Cockatoo Island deposits in Yampi Sound, Western Australia, have focused attention on problems of ore preparation and agglomeration, particularly sintering.Although very small pilot scale Dwight-Lloyd type sinter machines were operated at the steel-making centres at Newcastle and Port Kembla during World War II, no sizeable capacity was installed, so that ore was charged to the blast furnaces almost entirely unscreened, and the resultant flue dust was stockpiled.Towards the close of the war, the pilot plant at Newcastle was replaced by a small machine, adjacent to the flue dust stockpile, with a rated capacity of some 20 tons per hour. After approximately five months of part-time operation, this plant was closed down in January, 1945. Production was not resumed until December, 1950, when, due to a temporary ore shortage, it was decided to supplement available ore with sinter produced from the large flue dust stocks of about 300,000 tons. In spite of mechanical and process difficulties, inherent to the design of the plant, operation was continued on a two-shift basis, with several shutdowns for extensive overhaul and plant alterations, until September, 1954, when production was put on a three-shift basis. Addition of Yampi ore fines to the sinter machine burden was not commenced...

Jan 1, 1957

By M Wilson, D Whiteman, P Kuiper, S Talu, G Watt, A van As

Once the draw process has begun in a block cave, it is very difficult to identify which regions of the cave have successfully propagated, where the caved material is flowing from and where it is flowing to. The uncertainty around cave flow increases as the cave is drawn and can be further compounded by poor draw control practices. These uncertainties make it difficult to plan effective draw strategies to control dilution, as flow model predictions tend to gradually diverge from the actual state of the cave. There have been documented occasions where observed caving phenomena, such as muck pile surface rilling, could not be reproduced with the cave flow models of the time. The ultimate consequence of cave flow uncertainty is generally manifest as higher dilution and lower grades.In order to measure the real-time flow of caved material within an active block cave, CRC Mining and Elexon have developed, together with Rio Tinto, a cave flow monitoring system called Cave Tracker, which is being trialled at Argyle Diamond Mine (ADM) in Western Australia. The Cave Tracker system at ADM comprises electronic ‘beacons’ that have been installed down long HQ diameter drill holes located above the extraction level. As the cave-back propagates and the rock mass fragments, beacons are released into the muck pile and flow along with the caved material to the drawpoints below. At Argyle, the beacons are configured to emit a signal every three days. These signals are picked up by detectors installed on the extraction and undercut levels, allowing the positions of the beacons to be determined.By examining the real-time material flow in different regions of the cave, flow mechanisms can be better defined. Draw control strategies can then be actively tailored to manage the current state of the cave. Thus, previously undetectable indications of excessive rilling, rapid cave propagation, cave stall, air gaps and dilution entry can now be identified early and assessed continuously as the cave progresses. For the first time it is possible to amend draw strategies based on measurements from inside and outside of the fractured zones, allowing caves to be managed more effectively.CITATION:Whiteman, D, Talu, S, Wilson, M, Watt, G, Van As, A and Kuiper, P, 2016. Cave Tracker flow monitoring system installation at Argyle Diamond Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 479–488 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

THE township of Costerfield is situated in the parish of Costerfield, county of Dalhousie, and lies 6 miles east of Heathcote and 30 miles south-east of Bendigo. It is separated from Heathcote by the Mt. Ida Range, which forms the western boundary of the Silurian formation. It is situated at the head-waters of Tin-pot Creek, a small southerly tributary of the Deegay Ponds Creek, which flows east to the Goulburn River.The field was discovered in 1860 by two prospectors, Coster and Field, who were guided there by a shepherd, M Nicol Coster and Field had already discovered an antimony lode about three miles nearer Heathcote, when M Nicol offered to guide them to the larger outcrop. The main Costerfield reef at that time projected above the surface, and was white through oxidation, though the bluey sulphide showed on fracture. No alluvial gold of any consequence was obtained at Costerfield, but a little was obtained, at Redcastle, 7 miles to the north, and in some of the gullies to the east.Following its discovery there came a period of prosperity to Costerfield, while the mining operations were confined to the oxidized zone. The early success of mining at Costerfield was due to the gold values, and it is probable that the oxidized zone was secondarily enriched. The earliest available record of values is a crushing of Coster and Co. on the Antimony reef (now known as the Costerfield reef), when 200 tons from a depth of 70 ft. averaged 4 oz. per ton in July, 1861. At this time a crushing mill had not yet been erected at Costerfield, and the ore was carted and treated at Redcastle. The massive antimony ore, consisting of mixed oxides and sulphides, was separated by hand-picking as "marketable ore," and the remainder crushed for gold. A higher average is recorded from South Costerfield in September, 1861, when a 15' cwt. parcel...

Jan 1, 1922

Research on the Design and Processing Characteristics of 320 m3 Air-Forced Mechanical Flotation Cell

Sep 13, 2010

The sulphide ores of the principal lodes of the Boulder Mines are mainly composed of a schistose guess with a varying proportion of silica and lime, containing tellurides of gold, silver and mercury, associated with iron pyrites. It is a great difficultyto obtain pure and homogeneous samples of the tellurides for analysis, and from a number of tests made with excellent specimens it was found hardly possible to procure two to agree in analysis, the precious metals being found to be combinedwith tellurium in most varying proportions indeed, a close inspection of a partially crushed specimen will reveal, even to the naked eye, the various shades of colour characteristic...

Jan 1, 1901

At the treatment plant of the Broken Hill South Limited, Broken Hill, the zinc concentrates, with water, are pumped out to a more or less level area, and stored in dams to dry by drainage and evaporation.In-the construction of these dams a clay bank is first thrown up around the proposed dam site. The concentrate and water mixture are then run in from the perimeter, the solids being continuously shovelled up to increase the bank height, while the clear water is drained off at the centre and returned to the treatment plant.These dams vary in size up to 57,000 sq. ft. in area; when completed the banks are about 12 it. high, and the capacity for the largest dams is about 350,000 cub. ft., say, 20,000 tons.The survey office is called upon for a monthly survey of these dams, generally three of which are in process of building or refilling. The puggy nature of the material prohibits walking beyond the bank of the dam, therefore the following method of estimating concentrates was evolved. No originality is claimed, but as the need is for a true survey, and the results have shown the accuracy of the method, a description is warranted. The dam site is first laid out into 10-ft. squares with a theodoliteand 150-ft. steel tape, the outside lines being placed about 15 ft. from the clay bank - 15 ft. is the maximum convenient distance from the bank for working with the levelling staff mentioned later.As the dam is rarely rectangular in plan, the outside points pegged out are not always the corner of a square, but are placed to give the greatest convenience in later work, that is to say, there may be triangles and irregular figures. The plan (Fig. 1) and photographs (Figs. 5 and 6) will give the general idea of the layout. At each point is driven a 3 ft. 6 in. round iron peg about 3 ft. into the ground. This peg is to permanently mark the point, and is not liable to be...

Jan 1, 1925

Fines and unnecessarily small rock fragments are created by as many as four identifiable breakage mechanisms which operate close to the charged section or sections of the blasthole. The peak blasthole pressure (Pb) should not exceed that value at which the rock starts to fail in compression. Excessive Pb values can be prevented by carefully selecting:1. the composition, density and/or diameter of the charge, and2. the initiation/priming system.The percentage of fines increases with:1. increases in the charge diameter:blasthole diameter ratio, burden distance, blasthole diameter, effective sub-drilling and size of blast, and2. decreases in blasthole spacing, stemming height and the length:width ratio of the blast block.Decked charges tend to reduce the percentage of fines.Excessive fragmentation is more evident in buffer blasting and sinking cut shots than in blasts fired to a clean free face. Initiation sequences which give effective burdens considerably less than drilled burdens encourage the minimization of fines, as does an inter-row delay time which promotes good progressive relief of burden.The wastage of explosive energy in creating fines is most pronounced where fully-coupled, energetic charges are fired in weak and/or highly porous rocks. This is especially so where forward movement of the strata is impeded by buffer rock, excessive burden distances and/or inadequate inter-row delay times.

Jan 1, 1979

By J M. F Clout, E Donskoi

The ability to design a beneficiation process for a new orebody based on particular feed characteristics is a powerful and practical tool. A new technique has been developed where beneficiation outcomes can be calculated by combining feed size-by-size chemical analysis, mineralogy, liberation and particle characteristics with a series of simple theoretical unit separation models rather than a simple mass balance approach or an exhaustive beneficiation test program. The new technique provides the ability to rapidly identify ore types that have the potential to meet product specifications whilst also rejecting others that will not meet specification even if a perfect separation was achieved. Beyond the broad scale decision making process, practical mineral separation curves from actual plant data can be used to more closely simulate the proposed process. This approach reduces the amount of laboratory and pilot plant work necessary by targeting what process stages will be required, increases early rejection of uneconomic options, identifies problematic ore types or unit operations and is a step towards estimation of final grade and recoveries achievable in potential circuit configurations.

Jan 1, 2004