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By S KandT

The FalTmT iron ore deposits are located in the so-called æBirrimianÆ volcano-sedimentary complex that extends in a general NE-SW direction across eastern Senegal and part of Mali and Guinea. The rocks underwent folding and greenschist facies metamorphism, as well as various events of granitoid emplacement. The deposits form part of the DialT-DalTma Series of the Birrimian Supergroup and were subjected to contact metamorphism. The Fe-mineralisation occurs as primary magnetite within the metamorphic aureole. Supergene oxidation (martitisation) of this mineralisation produced the hematite-rich iron deposits that can be seen as prominent hills across the plains of this south-eastern corner of Senegal. BRGM of France and Miferso (SociTtT des Mines de Fer du STnTgal-Oriental) have conducted several phases of prospecting since 1957. Their aim was to delineate the hematite deposits and to assess the grade, beneficiation characteristics and marketability of the iron ore. A feasibility study by Fluor Daniel was completed in 1992. Results indicated that, at the time, the resource could not compete in the international arena in terms of size and accessibility. The growing iron ore market and additional available resources in the area now challenge the 1992 feasibility study results and put the old kid back on the iron ore block. The project faces some mining challenges, such as the amount of magnetite in the hematite product that will be acceptable to the market. Previous project evaluations only considered the secondary hematite deposits as economically viable. It is therefore important to accurately delineate the magnetite/hematite contact zone to optimise the resource tonnage. Project logistic constraints also exist in terms of railway access and harbour facilities. The resource is, however, well situated for the European iron ore market and aims to find a place in the rapidly expanding iron ore seaborne trade.

Jan 1, 2005

By R L. Brathwaite

In New Zealand, volcanogenic massive sulfide (VMS) deposits are found in three main geological environments associated with: 1.   ophiolitic basalts of Oligocene age in Northland and East Cape (eg Pupuke, Pakotai, Parakao and Lottin Point); 2.   with chert and pillow lava in greywacke sequences of Permian-Jurassic age (Torlesse and Waipapa terranes; eg Kawau Island, Te Kumi and Maharahara) and their metamorphic equivalents (Haast Schist; eg Moke Creek and Waitahuna); and 3.   with greenschists (metabasalts) and metaserpentinite of Permian-Triassic age (Ponamu Ultramafics) in Westland (eg Bowen and Wilberg ranges). The deposits consist of small lenses of disseminated to massive sulfide minerals, mainly pyrite and chalcopyrite. Small quantities of copper ore were mined from some deposits in the 1800s (eg Kawau Island from 1846), with the last mining at Parakao from 1961 to 1966. Several deposits have been recently examined for their gold potential with assays on sulfide rock samples as high as 75 g/t Au (Lottin Point).

Jan 1, 2005

The Elura Orebody consists of a number of parallel, vertically oriented pipe-like structures of pyrite-sphalerite-galena mineralization located at the core of a structural dome. Concentric zoning of the mineralization into an outer Siliceous, intermediate Pyritic and inner Pyrrhotitic Zone has been previously recognized and is used in routine geologic modelling of the lead, zinc and silver grades.Statistical analysis of the metal grade distribution in the orebody has confirmed the importance of the mineralogical zones in the understanding of grade trends. The gradational nature of intra-zone boundaries, especially those related to the subjective definition of the Siliceous Zone, are apparent in the statistics.

Jan 1, 1990

It has been clearly demonstrated in both the first, as well as in the last world conflict, that a nation's ability to wage as well as win a war is primarily a function of its industrial, and particularly its steel making capacity, provided both are directed to munition production.The Axis gambled on their pre-war policy of bullets before butter giving them sufficient initial advantage to decide the issue before the Allies had time to gear their industries to war production.Fortunately for us, Hitler and his advisers apparently underestimated Russia's war potential, although they must have known that Russia was, in 1939, the third largest steel making country in the world, as shown by the following figures:

Jan 1, 1947

By G C. Lukey, J S. J van Deventer

The disposal and subsequent encapsulation of mine tailings in a cost-effective and environmentally secure and responsible manner is one of the principal issues facing any modern mining project. A careful assessment of all options available for the capping and subsequent remediation of tailings is important because it can result in large capital, operating and closure cost-savings. For these reasons, the technology of geopolymerisation is receiving increasing attention for the stabilisation and solidification of waste materials produced from mining operations. The first part of the current study investigates the application of geopolymer technology to the capping of hypersaline mine tailings. It has been found that suitable geopolymeric materials which have satisfactory compressive strength, durability as well as low permeability, can be formed using between 60 - 75 per cent of mine tailings as the main ingredient. It has been established that geopolymeric materials have the ability to suppress dust generation and prevent salt precipitation on the surface of the mine tailings. The slurry-like consistency of geopolymers would promote efficient application procedures through established tailings disposal techniques. This is a possible close-out technique for hypersaline tailings storage facilities such as those commonly found in Western Australia, which meets both regulatory requirements and community expectations. The immobilisation of contaminant metals within geopolymers has been investigated in the second part of the present study. In particular, the leaching characteristics of Cu and Pb from geopolymeric matrices derived from different fly ash sources have been examined. Potential breakdown of each geopolymer containing metal contaminants due to the leaching of Si and Al from the geopolymeric matrix has also been investigated.

Jan 1, 2000

Porphyry type mineralization of Lower Cretaceous age in eastern Queensland has been recognized only from the easternmost part of the northern New England Orogen (Day, Murray and Whitaker, 1978), within the northern Yarrol Province (Horton,1982). Recent work about the Mt. Suthers (Pb, Zn, Ag, Cu, Au), Lug-e-nor (Cu, Pb, Zn, Ag, Au, Mo), and German Tully (Cu, Au, Bi) prospects suggest that there has been a phase of porphyry type mineralization within the Gympie Province, of Lower Cretaceous age, overprinting earlier Permo-Triassic phases. About the Mt. Suthers Prospect surface samples of shallow, medium to heavy textured soils derived from marine sedimentary rocks of Permian age, and extrusive and intrusive igneous rocks of intermediate composition and Triassic age, were analysed for Cu, Zn, Pb, Co, Cr, Ni, Fe, V, Mn and Ag. Whereas strong iithological control determined the distribu- tion of Cu (diorite) and of Cr, Ni, Fe and V ,sedimentary rocks), the distribution of Pb, Zn, Ag and of Cu, were determined by mineralization of faults by a cavity fill hydrothermal process. Gold is associated with the Pb, Zn, Ag mineralization. Co and Mn showed distributions independent of lithology and structure. The fault controlled style of mineraliz- ation at Mt. Suthers is repeated at other localities to the south; Calgoa, Marodian, and German Gully. Relative dating of structural features and isotopic dating of nornblende porphyrites (134-135 m.y.) near and related to those mineralized at German c;ully suggest a previously unrecognized phase of porphyry copper style mineralization in south-east Queensland of Lower Cretaceous age (Fig. 1).

Jan 1, 1987

By Young DJ

Gold mineralisation at the Hamata prospect is related to a series of stacked pyrite and quartz-pyrite veins associated with a number of shears which strike N to NE and dip E. Mineralisation is contained entirely within the Morobe Granodiorite close to the intersection of the Upper Watut Fault and some younger NE to SW striking faults. The prospect was originally detected in 1987 by a regional stream sediment sampling programme. Subsequent mapping and sampling outlined an anomalous zone approximately 900m long by 300m wide. Drill testing has indicated a resource of 46Mt at 0.9 g/t Au.

Jan 1, 1991

The mining industry views with the utmost concern, legislative or administrative action that inherently reduces the scope for exploration activity. Is there any basis for this concern in relation to Victoria? This paper will outline the role of the Department of Minerals and Energy and the main features of legislative provisions affecting exploration effort. The practical difficulties that confront the Department and explorers alike will be examined. The importance of industry representation to influence the direction that policy and legislative review might take, will be highlighted. Above all, the paper will establish that one essential duty of government is to ensure the provision of appropriate mining titles and security of tenure.

Jan 1, 1982

By Baczynski NR, Fagan MJ

A 3050m long section of a 1.65m internal diameter tunnel is presently under construction in the Brisbane area by means of the pipe-jacking method. The soils along the alignment had been deposited in a deltaic/estaurine environment and rapid changes in soil type occur. The tunnel passes beneath several extensive bodies of surface water. Groundwater problems have been experienced with tunnelling through alluvial sands and gravels. Details of the ground conditions, the pipe-jacking method used and tunnelling experience are discussed in this Paper.

Jan 1, 1987

Presidential Address Today I want to couple that prediction with a discussion on competitiveness and changing employment roles in our industry. A crude analysis of the intensity of use of metals in developed and undeveloped nations was undertaken by dividing the weight of copper, zinc, lead and aluminium used in countries by the population. In the developed countries which were basically the Western European States, USA, Canada, Australia and Japan, approximately 38 kilograms are used per annum. In the developing countries which were basically the South-East Asian country Korea, India, Pakistan and Taiwan, the usage is 5.3 kilograms. Thus, if the developing world is to catch up with the developed world, the intensity of use of metals will have to increase seven times. The usage of metals in the developed world is increasing at the rate of 1.5 per cent per annum while the rate of increase in the developing world is about 5.8 per cent. In this analysis, the population of the developed world was 850 million and the developing world 1.5 billion. Note that this analysis did not include Russia, China and most of the countries of South America and South Africa. I am sure that with time, these undeveloped countries will move into the developing category. In the long-term there is obviously great opportunity for us both in the primary and secondary processing required to meet world demand. Turning now to competitiveness and changing employment roles. I am sure that everyone here present is aware of the urgent need for Australia to improve its competitiveness. I want to try and relate unionism and industrial relations, management and tertiary education to our competitiveness. I wish to talk on these items as I see them in the past, the present and the future. So firstly unionism and industrial relations. It has been unfortunate for Australia that unionism was based on the United Kingdom craft system. It is not surprising that it was because UK has been the basis for almost ' all of our institutions and that has generally been of very great value to us. The craft system in our trade unions has lead to the demarcation problems of which we have all been well aware. This has been extremely limiting to the individual; it has limited his or her ability to broaden their scope of knowledge and far worse it has limited their ability to maximise their satisfaction at work as they have only been able to undertake part of a job, rather than being able to undertake a role in totality.

Jan 1, 1992

By S C. Goel

The Obuasi Mine in Ghana, West Africa is the largest producing gold mine in Africa, outside South Africa. The mine has changed from a mine producing from narrow vein, high grade quartz orebodies to a mine producing from wide, lower grade sulphide rebodies. Traditionally mining methods were cut and fill and sublevel caving. Now the preferred stoping methodologyis long hole open stoping. Transverse or longitudinal methods are both used, dependent on the orebody characteristics. The change has been technically, socially, economically and politicallychallenging and at times has tested the abilities of those responsible for the operation of the mine. However, the benefits have been many. Safety has improved significantly, ounces from underground have doubled. Productivityhas doubled and underground unit costs have reduced bya third. These achievements have allowed the Obuasi mine to staycompetiti ve in this time of falling gold price. During 1999 and 2000 a full review of the mining and processing operations was undertaken, and as a result, the mine is now in a phase of restructure. Efforts are being made across the mine to improve efficiencies and to reduce costs. The future for the Obuasi Mine is an exciting one.

Jan 1, 2000

Drilling is one of the most, significant cost components of any stoping or develop- ment operation. Two of the factors contri- buting to the drilling cost are the supply and servicing of consumable items such as drill rods and bits. The purchase cost of consumable items can be controlled to a large extent by using the correct balance of quality and price. However, the service cost is a less easily controlled factor and it is in this area where potential savings are significant. In June, 1976 a six month trial period was commenced at The Zinc Corporation, Limited and at New Broken Hill Consolidated Limited with two separate suppliers supplying and ser- vicing all longhole drilling parties (one supplier for each mine) at a guaranteed cost per metre. As a result of this six month trial period a new contract was commenced in December, 1976 with one supplier supplying and servicing all longhole drilling parties at both ZC and NBHC for a twelve month period. This concept has now been in operation for over twelve months and has proved to be a significant means of slowing down the increas- ing cost associated with drilling operations.

Jan 1, 1977

In the early stages of opening up a mine, when there is some uncertainty as to its future career, necessitating caution in laying out works of a permanent character, the want is often felt of an assay furnace, easily built and easy of transportation, should the" mine " prove to be " no mine." Again, cases occur in which parties buy the right to treat comparatively small heaps of tailings, and then shift their plant to other localities. Under these circumstances it is necessary to restrict the plant to the barest necessaries, to suit, so to speak, the nomadic character of the work.An assay furnace that is really portable, easily transported, erected, taken down, of little weight, always ready for action on short notice, is indeed in these cases a desideratum which has long been wished for. The gasoline furnaces introduced intothe Australian market some time since practically fulfil these conditions; but they have the fatal drawback of being dependent on a constant supply of the liquid fuel, gasoline, which is seldom, if ever, obtainable locally in' any wayback mining township...

Jan 1, 1904

Consideration is given to the factors affecting raceway activity and the hearth design of a zinc-lead blast furnace. Results of measurements made on operating furnaces are given and comparisons are made with published data both from operating iron blast furnaces and from dynamic models of the zinc-lead blast furnace. Indication is given of the methods used for assembly of the relevant information into the specification of a commercial furnace design. A discussion on the comparative merits of furnaces of circular and essentially rectangular plan is given based on the concepts explained in the paper.

Jan 1, 1981

By K Niiranen

Luossavaara-Kiirunavaara AB (LKAB) operates one iron ore mine, three concentration plants and three pelletising plants in Kiruna, Sweden. The current methods of separation at the beneficiation plants are low intensity magnetic separation (LIMS) and reverse apatite flotation, where the wet LIMS stage is regarded as the crucial part of silica separation from the ore. Because future silica levels are expected to increase in the incoming material to the beneficiation plants, geometallurgy has become an important area of development and research.A laboratory-scale methodology was developed for the systematic characterisation of the ore for mineral processing, with the focus on the high silica ore type B2 and newly discovered subtypes. This methodology combines mineralogical, geochemical and process mineralogical characteristics. Automated mineralogy (QEMSCAN®) is used to study the modal mineralogy, the distribution of silicate minerals in different particle size classes after comminution, the deportment of silicon (Si) between various silicates and the degree of liberation and intergrowth of magnetite and silicates. An essential stage in the systematic characterisation of the ore deposit for mineral processing is the estimation and simulation of different parameters from the laboratory scale to the full scale at the concentration plants. This is achieved by using empirical models based on the data collected at the mineral processing plants. As the first step to implement the geometallurgical information, the current geological model is reconstructed with the mineralogy and the two, newly defined subtypes of high silica ore type B2 are separated into different domains.To study the reduction of the SiO2 content in the magnetite concentrate, a large-scale reverse cationic silicate flotation laboratory test program was initiated in early spring 2016. This program investigated potential silicate flotation in the beneficiation plants at the Kiirunavaara site. The second target is to implant mineral processing parameters into the block model based on the new geological model. This information provides a good basis for making a prognosis for mine planning and a quality prognosis regarding the crude ore for mineral processing.CITATION:Niiranen, K, 2017. A geometallurgical perspective on a high-grade iron ore deposit at Kiirunavaara, northern Sweden, in Proceedings Iron Ore 2017, pp 309–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Brennan D. J

The trend worldwide is for increasingly stringent control of sulphur dioxide emissions to the environment. It is therefore likely that Australian industry will be placed under increased pressure to restrict such emissions, and this will have implications for Australian smelters of mineral sulphide ores. Traditional outlets for sulphur dioxide emissions have been in sulphuric acid manufacture, but Australian demand for sulphuric acid has declined markedly in recent years. This paper examines the balance of supply and demand for sulphur and related products in Australia, the shifts occurring in that balance and the underlying causes of those trends.

Jan 1, 1994

By Wright J. K

A description is presented of the results of reduction experiments using a laboratory reduction apparatus in which simulation of the gas and temperature profiles which occur in direct reduction shaft furnaces is achieved using microcomputer control. The apparatus allows continously changing reduction conditions to be impressed on lump or pellet samples to simulate the environment that is experienced by iron ore burdens during their transit down the shaft of a direct reduction furnace. Three pellet samples and three lump ore samples were reduced in the apparatus. Comparative reduction curves and strengths after reduction for the materials were obtained over a range of reduction temp- eratures using Midrex-type gas compositions. The resulting reduction and strength curves show considerable variation in behaviour and reflect the physical and chemical variations in the individual ore and pellet types. A comparison is made of the reduction rates and modes of reduction of the samples reduced under "conventional" test conditions using a single unchanging gas composition and the simulated shaft furnace reduction conditions. It was observed that the course of reduction is very different in the two procedures and the major influence of temperature on the strength of the reduced product is noted.

Jan 1, 1987

Access roads for haulage, construction or maintenance purposes are discussed with particular attention being given to the un- sealed "all weather" form of construction for Off-Highway applications. The service conditions experienced by the surfaces used in these roads is examined. These conditions are discussed in terms of the conventional engineering properties used for natural gravel material selection. Experience gained during the construction of a pipeline access track is used to illustratE material selection guidelines based on geological input and an understanding of good construction practices. TMITDnIll IrTT Ohl In many Australian situations off-highway haulage by wheel or track supported vehicles is carried on unsealed, gravel roads. Although the unsealed gravel road is the back-bone of the rural road network in Australia, in general, traffic loadings are relatively low compared to the off-highway unsealed haulage road. The cost of the haulage/access road construction component is one important factor in project planning which needs careful consideration. It is no longer acceptable that the initial rough exploration track be gradually upgraded so that it will eventually carry construction and maintenance traffic safely and efficiently. Fatal accidents and

Jan 1, 1982

By Stein A

The general mechanism of recrystallisation for cold worked metal is well established, and need be only briefly summarised with a few references to recent articles which clarify minor points. The types of extension, whether by stretching, drawing, hammering, rolling, etc., do not alter the general principles (1), although quantitative results may differ somewhat, particularly with regard to differences between the surface and interior of samples.These principles can be summarised as follows: The first stage in annealing is a recovery (sometimes known as relaxation) of physical properties such as hardness, elongation, etc., without any appearance of recrystallisation; the second stage involves a further alteration in physical properties, accompanying the formation of new recrystallised grains which replace the original structure; a possible third stage involves an increase in the grain size of the completely recrystallised structure by absorption of smaller grains by larger ones. These three stages will be referred to as recovery, recrystallisation, and grain growth. Depending on conditions, the three stages may be clearly marked or may occur more or less simultaneously.For a given annealing temperature, cold deformations below a certain amount fail to give recrystallisation, and the final structure consists of the original grains which have recovered and possibly become more equiaxed. When a certain deformation, critical for that annealing temperature, is given, recrystallisation can occur, and will give the maximum recrystallised grain size.Increasing deformations beyond this give progressively smaller grain sizes.For each material there is a minimum recrystallisation temperature, below which recrystallisation will not occur whatever the deformation or time of annealing. For a given deformation there is a temperature, critical for that deformation, below which recrystallisation will not occur, and above which it will take place with increasing rapidity.

Jan 1, 1947

By J Galvin

This paper addresses the actions of the Australian mining industry, its regulators and educational providers towards ensuring that a pool of competent mine managers is maintained in Australia and that mine management remains a desirable career path for future mining professionals. The Australian and global mining industries are experiencing an acute skills shortage. Mine managers, traditionally drawn from the ranks of mining engineers, are at the sharp end of this shortage. Exacerbating the shortage is a perception that a professional mine manager is not an attractive career option. This perception is influenced by the following forces which combine to make the role of a modern mine manager very demanding:legislative requirements for owners and managers to ensure (guarantee) the safety and health of employees; an increasing trend towards prosecution over exposure to risks to health and safety a need to be more aware and responsive to community and environment; financial, technical and æpeopleÆ pressures traditionally associated with the job of managing a mine; and mine management roles being filled by younger and less experienced professionals. Universities and other educational providers have the challenge of both ensuring that undergraduates are exposed to these issues during their study and continuing to promote mine management as a desirable career option. Anecdotal and statistical evidence indicates that young graduates are choosing and remaining in technical roles rather than taking on the challenge of mine management. Furthermore, it is suspected that the issues referred to above are contributing to the low retention rate of young professionals at mine sites. The challenges are not insurmountable, however. This paper reviews the initiatives of industry, the regulators and educational institutions in addressing these challenges. It includes a focus on:prosecution policies and their impacts, tertiary education program content and delivery modes, CPD initiatives of the Mine Managers Association of Australia, and alternative pathways for obtaining mine management qualifications.

Jan 1, 2006