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By Gunderson C. T

The use of carbide tipped integral drill steels and detachable bits is discussed in relation to the means of drilling or cutting employed. It is stressed that only by correct use can the full value of these tools be realised.Factors affecting carbide quality, the design of shanking steels and the requirements and techniques of brazing in inserts are considered.It is essential that the brazed jointing between carbide and steel be strong but ductile. The methods used for the manufacture of carbide tipped tools are briefly outlined.INTRODUCTIONIn recent years the application of tungsten carbide to various mining tools in the mining industry, has developed to the stage where it is now regarded as an essential item in the production of coal and metal ores. In fact it is claimed that certain mining operations would not be possible if it were not for the benefits obtainable from the characteristic properties of tungsten carbide. The advantages of this hardmetal have, to some extent, influenced manufacturers to revise design specifiations of some machines, while againsome machines have actually been designed with tungsten carbide as their basic medium for operation.In general the applications fall into the following three categories:(a) Drilling hard rock by percussive means.(b) Drilling soft rock and coal by rotary means.(c) Coal cuttingThis paper is concerned with tungsten carbide tools associated with these three activities in Australia, the effectiveness of their application and significant points in their design and manufacture.

Jan 1, 1958

By P J. White, J V. Lawless

Low-sulphidation epithermal gold deposits, which form in quasi-hydrostatic convective hydrothermal systems, frequently contain chalcedony within high-grade ore, which has been interpreted to be a crystallisation product of amorphous silica. To deposit amorphous silica rather than another silica polymorph at elevated temperatures requires very high silica concentrations, because of its relatively high solubility. Only extreme boiling caused by decompression followed by wall rock heating upon structural dilation, can achieve this. As gold deposits with amorphous silica it must be produced by the same mechanism, particularly since extreme boiling is also a very effective mechanism for gold deposition. Recent developments support this view; the first is the detailed isotopic analysis of chalcedony-bearing high-grade veins reported from Hishikari, Japan, in which oxygen isotope results are indicative of extreme boiling and hydrogen isotopes indicate initial deposition of amorphous silica. The second is the finding of chalcedony within geothermal pipe work in the Rotokawa geothermal field in New Zealand. Rotokawa is a comparatively hot field (335¦C at depth); hence separation of the steam-water mixture produced by the wells is undertaken at a comparatively high temperature (220¦C) to minimise down-stream silica scaling. Even so, silica scale, some of which is chalcedony, does occur, under similar conditions to that in low-sulphidation epithermal deposits. Evidence of chalcedony forming under these conditions, reinforces the interpretation that decompressive boiling is the main deposition mechanism for gold in low-sulphidation epithermal deposits. It is possible that there is sufficient drop in temperature due to decompression that, at least initially, the silica deposits directly as chalcedony. Low-sulphidation epithermal gold deposits that do not contain chalcedony, such as those in the Philippines, may form at temperatures too high for chalcedony to directly form. The recognition of decompressive boiling as the main deposition mechanism in low-sulphidation epithermal deposits means that exploration can focus on zones where this has taken place by combining paleohydrological reconstruction and structural geology.

Jan 1, 2002

Esso-BHP have installed a production supervisory control system that is presently controlling the offshore oil and gas facilities on the Barracouta and Marlin platforms from an onshore master station. This control is achieved with a computerized master station onshore which uses a UHF radio system for telemetry and control.The system is designed to control, monitor, and gather data from a large number of oil and gas production platforms and has flexibility to handle future variations in operating conditions.The system will be extended to the Halibut platform late in 1970 and to the Kirlgfish platforms during 1971.

Jan 1, 1971

By P W. Wypych

The iron ore industry faces significant challenges in the control of dust to meet emissions regulations and goals, as well as ensuring sustainable operations. This paper describes some of the different techniques and innovative technologies that are being developed and implemented to improve the suppression of airborne dust, specifically through the use of high energy micromist sprays. The utilisation of computational fluid dynamics (CFD) modelling and simulation is identified and described as a key enabling technology for an improvement in dust suppression solutions both from a level of understanding the source and flow of dust emissions, and for the development of new systems that can be used in the iron ore industry. CFD modelling is shown to be effective for modelling both spray dispersion and cross-wind effects, allowing designers to develop high-efficiency dust suppression systems with a greatly improved level of confidence when compared to traditional techniques. New high energy micromist technology is also outlined as a key element in developing high-efficiency dust suppression systems. Experimental results and industry applications are presented to demonstrate the significant improvements that can be achieved in suppressing or reducing airborne dust emissions.CITATION:Roberts, J M and Wypych, P W, 2017. Research into improving the efficiency of water spraying airborne dust control techniques in the iron ore industry, in Proceedings Iron Ore 2017, pp 359–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By T S. Giraudo

The Macraes Gold Project, operated by GRD Macraes Limited, engaged GRD Minproc Limited to assist with the evaluation of a pressure oxidation circuit, this being the key component of a recovery enhancement project. The initial study gave sufficient confidence in the process to enter into project execution. GRD Macraes Limited was the first company to license Newmont Mining Corporation's pressure oxidation technology, which aims to improve gold recovery from the carbonaceous sulfidic flotation concentrate. This paper outlines the fundamental chemistry of the process followed by a description of the plant that was ultimately installed. A summary of the commissioning is given together with an overview of the production results to date. The project ramp-up was rapid, with design temperature and throughput being achieved within days of hot commissioning. Gold recoveries have exceeded expectations, improving from around 70% prior to the installation of pressure oxidation to above 84%. The project has increased the nominal gold output at Macraes from 120,000 oz/y to 170,000 oz/y. On-going plant optimisation for process parameters is discussed, giving rise to flexibility in gold production, with key controlling parameters exceeding design.

Jan 1, 2000

The purpose of this paper is to outline some aspects of the experimental worlr that has been carried out in the mineral dressing laboratory at M'ount. Morgan during recent years.The subject matter has been dealt with under the following headings:1. Comminution of various mill products.2. The application of sulphur dioxide as a flotation reagent.3. Heavy-media separation.4. Bulk flotation of sulphide ores.COMMINUTION OF VARIOUS MILL PRODUCTSThe following data were cbtained by processing fractions of reserve grade ore.Granular TailingIn Table 1 are shown the results of tests on material representative of average grade tailing. In the first test (H1 ) the granular tailing was floated as received and in the second test (Ha) the tailing was ground prior to flotation.

Jan 1, 1952

The mining industry in Australia frequently uses the services of specialist engineering and managing contractors and consultants for a majority of the work required for project development, from feasibility studies to project commissioning. The project owner's prime objectives are to achieve predictability and competitive advantage for their project. As the majority of this work will be carried out by contractors, the effective evaluation, selection and management of these contractors in the most appropriate forms of contracts is an essential ingredient to project success. The first stage to project development should be for the owner to examine its own resources to establish the role that it will fill and thereby identify the role and scope of contractors' involvement. Once the owner has developed this work plan, the selection of contractors and consultants should be structured to ensure that the owner acquires the appropriate expertise and experience to achieve its project objectives. The sequence of selection procedures is: 1. Pre-qualification of prospective contractors according to the owner's adopted criteria, through the use of a pre-qualification questionnaire. 2. Evaluation by the owner tender board according to predetermined mandatory criteria. 3. Preparation of tender documents for submission to qualified contractors. 4. Evaluation of tender submissions by the owner tender board using a pre-determined, weighted matrix of technical and commercial criteria. 5. Final selection and contract negotiation.

Jan 1, 1990

By Narasimhan K. S, Sastri S. R

A typical high silica low grade magnesite from the Salem area of Southern India, was used in studies to develop a suitable flotation system involving commercially inexpensive sodium oleate as the collector together with other reagents which can give a product of the required grade with an acceptable recovery. It was found that the presence of metallic ions such as Cu+, Fe+++ or Ca++ introduced by the addition of their salts, or by their formation with the addition of hydrochloric acid to react with magnesium and calcium carbonate in the me, can act as effective depressants for silica. The addition of 'hydrochloric acid' was found to give best results.

Jan 1, 1980

Mt Waruwari, host to the Porgera underground gold mine in the Highlands of Papua New Guinea (PNG), is a prominent ridge of sediments and dioritic intrusives rising approximately 600m above the surrounding valley floor. Consequently, mining occurs in a low stress environment where structural and material considerations are foremost in the design of ground support and reinforcement. Three major rock types are encountered in the underground mine. These are locally referred to as "black sediments" (slightly indurated mudstones and clayey siltstones), "altered sediments" (derived from black sediments by thermal metamorphism), and "intrusives" of dioritic composition. The rocks are moderately to highly fractured, the black sediments being generally weak and occasionally sheared while the altered sediments and intrusives are quite strong but often brittle. Mining takes place from a series of stopes extracted by either slot and mass blast or a modified vertical crater retreat method (VCR), which are backfilled with a cemented rock fill. Ground support and reinforcement has been relatively conserv- ative to date and generally relies on pattern reinforcement of all development with cement grouted "rebar" bolts and mesh, extending to pattern cable bolting with occasional mesh in stope backs. In addition there has been considerable reinforcement of stope hangingwalls in some cases. A programme of broad scale structural mapping, monitoring with extensometers, material property testing, and stress analysis has been devised to allow optimum design of ground support and reinforcement in the future. Considerable work remains to ,omplete this task.

Jan 1, 1991

By J Wallis

The stability of a raise bore is often assessed using the rock mass classification system published by McCracken and Stacey as a modification of the Q system. Often the assessment is done using a spreadsheet to manipulate geotechnical log(s) of boreholes. This paper discusses the inherent difficulties with this approach. Recent work by others to provide guidelines to the classification system is discussed. A recent example of the design and raise bore performance at Macraes Gold Mine, New Zealand is presented. A key issue is that a visual assessment of the drill core and/or core photographs is necessary to æground-truthÆ the classification.

Jan 1, 2008

By C T. Hollick

Conventional processing of heavy mineral deposits containing radioactive rare earth minerals such as monazite and xenotime may cause industrial hygiene problems through atmospheric dust and contamination of product concentrates. An alternative procedure has been developed in which such minerals are removed from bulk heavy mineral concentrates by flotation with little loss of other economic minerals. With fine ores, recoveries of over 95 per cent have been achieved and with coarse ores over 80 per cent, in both cases at high grade. Several flotation regimes have proven effective. The potential for generation of radioactive dust or product contamination is subsequent processing is correspondingly reduced.

Jan 1, 1990

Laboratory induced polarization measurements were made on representative samples of concentrated sulphide ores from three environments in New South Wales Comparisons were made with the membrane polarization exhibited by an argillaceous sandstone. The sulphide samples showed a strong polarization effect, the magmtude of whIch depended directly on the conductivity of tlIe pore electrolyte.

Jan 1, 1969

The sphere of operations of dry crushing has been so much enlarged of late years that the following notes with reference to its advantages and limitations, and also some practical results in connection with the crushing of gold ores will probably be of service to the members of the Institute. Until recently, with one notable exception that of the Mt. Morgan Gold Mine, dry crushing has only been practiced to a very limited extent in Australasia, and elsewhere it might be said to belong to industries other than mining Its sphere of usefulness depends on the fact that the' product is delivered in a dry state without the separation of the finer particles from the coarser to any appreciable extent, thus enabling the following advantages to be achieved with different ores.

By Kelsall D. F, Trahar W. J

The size by size batch flotation behaviour of copper activated sphalerite from synthetic mixtures with quartz was determined. In terms of recovery of sphalerite, the size fractions could be grouped into coarse, intermediate, and fine ranges. The behaviour of the coarse and fine ranges was significantly poorer than that of the intermediate range in both the extent and rate of flotation.Each size fraction had a fast and a slow floating component.The main effect of changing the copper sulphate addition was to alter the proportion of any size fraction which was fast floating. No correlation could be found, between the amount of copper on the spha:lerite andeither the flotation rate of the mineral or the amount of copper added to the system. It was found that fine particles did not appear to consume greatly disproportionate amounts of copper sulphate during conditioning. A modified conditioning procedure was found to lead to a higher rate of flotation and recovery of coarse sphalerite and to make poss1ble substantial savings of copper sulphate.

Jan 1, 1975

By J S. Dunlop

At its most basic level, minerals project management may be broken down into a series of logical chronological phases, described in this paper as: exploration, discovery; scoping and pre-feasibility; feasibility and approval; project financing and commissioning; operation; expansion and closure. Each phase has its own peculiarities and challenges, any one of which can potentially upset the forward progress of a minerals project.Reference is made to each of these project phases based on the authorÆs many years of first-hand experience, in an attempt to identify issues within the project management spectrum where additional caution may be warranted. Left un-addressed, these issues can cause undue delays in the project timeline, ultimately delaying approval at significant project cost.Finally, reference is made to the Mine ManagerÆs Handbook recently published by the AusIMM which is an excellent project management resource, considered to be very relevant for minerals treatment plant managers, whether the context be constructing, operating, expanding or shutting down.CITATION:Dunlop, J S, 2013. Mineral project management - A perspective from four decades in the industry, in Proceedings MetPlant 2013 , pp 13-27 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

This paper summarises the development t,) date for the Hidden Valley Gold (HVG) Project. It starts with the original exploration work, covers the detailed feasibility study activities and concludes with the current phase of extra exploration drilling. A brief technical summary has been made from the various mining, process and environmental studies that were undertaken as part of the project approval process. A discussion of the influential non-technical factors is included, as well as a view of the future prospects for an operating mine. The project was always seen as marginal, given the low grades, small resource and short mine life. However the capital and operating costs were lowered with aggressive design and it was regarded an acceptable development by CRA. The opportunity was taken to review the project when delays in start-up were encountered. An updated financial evaluation showed a subeconomic resource in 1990 terms and this resulted in a new exploration phase to identify a larger deposit.

Jan 1, 1991

Uranium exploration over a wide area of the Southern Frame Embayment, South Australia, has defined a number of Lower Tertiary fluvial palaeochannels incised in older rocks. The buried channels contain similar stratigraphicsequences of interbedded sand, silt, and clay, probably derived from the adjacent uranium-rich Olarv Provinee. Uranium mineralization is pervasive within two major palaeochannels, and four small uranium deposits have been found in the basal sands of these channel sequences, at the margins of extensive tongues of limonitic sand.One of the channels is examined in detail with respect to channel morphology, stratigraphy, and rock alteration and the geology and ore controls of the contained uranium deposits are described.A geochemical zonation reflected by variation in limonite, pyrite, carbon, and humic malleI' is defined across one of the deposits. A genetic model is proposed suggesting formation by a uraniferous geochemical cell which migrated down the stream gradient and concentrated uranium on its lateral margins adjacent to the channel bank.

Jan 1, 1978

A study of the electrolysis of PbS in molten PbCl2 showed cathode efficiencies which increased with current density at fixed sulphide concentrations, and decreased with increasing sulphide concentration at fixed current densities. The anodically produced sulphur dissolved rapidly in the melt, the rate increasing with temperature and sulphide concentration. Experiments with diaphragm cells, made to determine the relative effects that dissolution of lead and sulphur have on the cathodic current efficiency, demonstrated that dissolution of sulphur was the major contributor to the lowering in efficiency.

Jan 1, 1973

By T Higuchi, L Lu

The quality of iron ore fines have been deteriorating, which has affected sinter quality and productivity adversely. New pretreatment and sintering technologies are therefore required to tackle the gradual change in the quality of iron ore fines. In the sintering process, iron ore fines are first granulated with fluxes such as limestone and coke breeze, and are then loaded and fired in a sinter machine. Sinter productivity and quality are heavily influenced by the reactions occurring in the sintering bed. Hence fundamental understanding of these high temperature properties of ores is urgently needed.Formation of initial sinter melt, penetration and assimilation of nucleus particles by the initial melt, and consolidation and final solidification of final sinter melt are believed to be the key sintering reactions. The assimilation and penetration phenomena have been studied separately in the literature with model particles and diffusion couples and are therefore difficult to relate to sinter quality. In addition, the effect of ore mineralogy has not been studied in detail.In this study, tablets consisting of coarse particles from various iron ore fines as nucleus particles and chemical reagents as adhering fines were made and fired under various sintering conditions to investigate the penetration and assimilation behaviour simultaneously. The degree of assimilation, pore structure, compressive strength of the resultant analogue sinters were evaluated and the relationship between sinter strength and ore characteristics was further discussed. The nucleus particles from Ores A and B were found to be more porous and assimilated more readily with sinter melt, resulting in a viscous melt and a macro-porous sinter structure. The nucleus particles from Ores C and D on the other hand, assimilated less readily with sinter melt, resulting in a fluid melt and a denser sinter structure. This is consistent with the results reported in the literature, suggesting that the present evaluation method can be utilised for studying sintering reactions and predicting sinter quality.CITATION:Higuchi, T and Lu, L, 2017. Evaluation of sintering behaviour based on ore characteristics, in Proceedings Iron Ore 2017, pp 303–308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Morgan W. M

It is not the primary object of this paper to treat with the scheme of prospecting in detail, but it is considered that a brief description of the broad lines is necessary so that the significance of the points to be discussed later may be appreciated.The finding of payable gold reefs on the Bendigo field resolves itself into a two-fold problem, firstly the location of quartz bodies, and secondly the location of gold shoots in such bodies. The country rock of the field has been folded and faulted, and the occurrence of known reefs is associated with the fold axes and the faulting. The "lines" of the field are the anticlinal axes, and practically all known reefs are at or near centre country. Very little work has been done on the synclines, which may have some potential value.Quartz has been introduced along the fracture systems, and gives rise to the three main types of reef met with on the field, namely, the "back," which is similar to a bedded quartz reef and is formed along a bedding plane fault; the "saddle," which forms at the crest of the anticline and has the typical shape from which it takes its name; and "spurs," which are irregular masses of quartz, making off reefs of the first two types.As the fracturing throughout the field is widespread and fairly intense, the first problem, that of finqing quartz, is comparatively simple, and any regular system of blocking out the ground will be productive of quartz bodies.*Field Superintendent, Bendigo Mines Ltd. Assistant Field Superintendent, Bendigo Mines Ltd.

Jan 1, 1936