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By Sahoo K. C

Traditionally, the blast furnace (BF) has maintained a dominant position as the primary source of iron units. Notwithstanding the efficient nature of the process in respect of its material and energy consumption, the conventional blast furnace route is faced with limitations such as stringent quality metallurgical coke, high capital investment, etc. While BF will continue to retain its predominant position as the foremost ironmaking technology, the alternate processes may also have a role to play. Direct Reduced Iron (DRI) or sponge iron industry is all set to take a firm root in India as one important solution to the problems of shortage of metallurgical coal and ferrous scrap and high investment costs faced by the country's steel industry. The commercial proven DR processes coupled with electric arc furnace (EAF) steelmaking have also offered a viable alternative to the blast furnace - basic oxygen furnace (BF - BOF) route for the installation of integrated plants under specific local conditions. The performance and efficiency of DRI processes mainly depend upon the chemical and physical behaviour of the raw materials especially the iron bearing materials. Iron oxide pellet and sized lump ore constitute the oxide feed stock, while pellets form an ideal feed stock for direct reduction, use of lump ore is economically advantageous because of its lower price. National Mineral Development Corporation Limited (NMDC), being one of the major producer of iron ore in the country since last four decades, has established technology and developed process flowsheets for production of suitable calibrated lump ore for DRI production, besides supplying the natural lump ore for conventional blast furnace requirements. In addition to the above, extensive pilot plant tests have been carried out at the R&D Centre of NMDC for preparation of iron ore concentrates suitable both for direct reduction and blast furnace grade pellet feed using the iron ore fines from its own mines and as well as from the other iron ore mines in the country. For utilisation of the huge quantity of slimes generated in its ore processing plants, NMDC has planned to set up the first commercial plant adopting the smelt reduction process (ROMELT Process) for production of pig iron from Bailadila slimes. The paper mainly deals with various beneficiation techniques adopted for production of DRBF grade pellet feed from iron ore fines. Also presented in the paper, the extensive work carried out at R&D Centre on preparation and evaluation of calibrated lump ore (Natural Pellets), based on which, suitable modifications are incorporated in the ore processing plants of NMDC for production and supply of the same to sponge iron industries.

Jan 1, 1999

Roadheader tunnelling machines have been used in Australia by both mining companies and contractors involved in the mining and con- struction industries since the early 1970's. They have both advantages and limitations, and this paper discusses machine excavation from the point of view of a contractor who has both reaped the benefits and suffered the conse- quences of using roadheaders. The paper also includes brief descriptions of three projects tackled by roadheader, all the projects being Declines.

Jan 1, 1987

By A Stradling

For a geometallurgical program to be successful, linkage must be made between the geologists and geostaticians who understand and model the orebody, the metallurgists who determine the value that can be extracted from the different geometallurgical units, and the mine planners who develop and optimise the plan to extract maximum economic value from the resource. One of the primary purposes of geometallurgical models is in the determination of the economic cut-off between ore and waste. Recognition of the level of confidence required in the estimation of grade, throughput and recovery is critical to the planning of a successful geometallurgical program. It also helps clarify the scope of work needed to mitigate risk at each stage in the development of a new mine projectThis presentation provides some of the author’s experience with development and application of geometallurgical models for existing base metal operations. It discusses how geological units defined by lithology, structure, alteration etc, can be translated into geometallurgical ore types defined by mineralogy, ore hardness, and flotation behaviour. Examples of how these characteristics have been used to estimate key economic parameters such as mill throughput and flotation recovery at two brown-field operations are provided. The first example relates to the modelling of metallurgical performance at Teck’s Red Dog zinc-lead mine in Alaska. Prior to 2000, zinc, lead and silver recoveries from a block of ore at Red Dog were either assumed constant, or were varied according to simplistic models. Throughput was not thought to vary substantially between blocks, so an average value was used for each blended stockpile. It is quite possible that some ore-value blocks were classified as waste, and some waste-value blocks treated as ore, as a result of poor understanding of the true economic cut off across the wide range of ore types observed at Red Dog. After an extensive flotation test program, the first assay-based zinc recovery model was developed for the Main pit reserve in 2003.**This is an abstract only. No paper was prepared for this abstract**

Sep 5, 2011

By C Linklater, J Chapman, A Watson

Closure options under consideration at some sites include backfilling mined-out pits with waste rock. Backfill may include mineralised and non-mineralised waste rock. Following groundwater rebound, flow-through conditions may develop in the pit post-closure. The backfill located in the saturated zone below the water table may release solutes under such conditions. It is therefore important to understand the potential impacts that backfilled pits could have on postclosure groundwater quality.Geochemical characterisation programs are the foundation for assessing the potential chemistry of water that has contacted mined wastes. Such programs must be designed to obtain data relevant to the closure options under consideration. To complement standard testing techniques, SRK utilises saturated column testing designed to generate data on leaching rates under anoxic conditions that could be encountered within submerged backfill.This paper presents the findings of saturated column test work carried out on waste rock samples from an iron ore mine in the Pilbara.CITATION:Watson, A, Linklater, C and Chapman, J, 2016. Backfilled pits – laboratory-scale tests for assessing impacts on groundwater quality, in Proceedings Life-of-Mine 2016 Conference , pp 110–114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

Predicting Water Recovery from Flotation Cells

Sep 13, 2010

This paper reviews the various processes successfully in operation to treat refractory gold ores and describes in detail the alkaline pressure oxidation circuit operating at the Barrick Mercur Mine, Utah, U.S.A., on car- bonaceous/sulphide refractory ore and the acidic pressure oxidation circuit operating at the Barrick Goldstrike Mine, near Carlin, Nevada, U.S.A., on sulphide refractory ore. The autoclave process is important to Barrick for the extraction of gold. The Company has operated successfully a 750 ton per day unit at its Mercur property for the past two years and more recently has commissioned a 1500 ton per day unit at Goldstrike. The paper presents data relative to operating costs, materials of construc- tion for autoclaves and peripheral equipment, reagent requirements, and changes required during commissioning for both autoclave systems.

Jan 1, 1991

By A Struminski

The principles of occupational risk evaluation resulting from the improper ventilation of the underground mines were presented. It was shown that the risk level implies the appropriate planning and usage of prevention methods. That approach is fundamental in the ventilation, fire and climate safety management in the copper ore mines. The paper uses the adequately modified Risk Score method.

Jan 1, 2003

Characterising the weight percentage of each mineral in base metal ores is an integral part of assessing the quality of an ore in terms of its processing properties. The Rietveld method, which uses X-ray diffraction data, has been applied to routinely quantify the minerals in lead/zinc and copper ores from Mount Isa Mines Limited and supergene copper ores from Ernest Henry Mining as well as their related products from the concentrators. The Rietveld method has been tested by comparing Rietveld mineral data with a standard sample with known mineral weight percentages and comparing Rietveld mineral data with mineral data calculated from elemental assays where the element only exists in one mineral such as lead in galena. Where this latter situation does not occur, the Rietveld method has been checked with both elemental and optical microscope data. In all cases, there is a good correspondence between the Rietveld data and the data it was checked against with absolute differences generally in the range of 0.5 to 3 wt per cent. The Rietveld method generally quantifies all minerals occurring over 1 wt per cent in one analysis and is less expensive and more routine compared to traditional methods such as optical microscope point counting. The Rietveld method can be applied to many stages of the mining cycle such as exploration, feasibility studies, mining, minerals processing and for environmental studies.

Jan 1, 1998

By J E. Nethery

At the Red Dome and Mungana deposits in north Queensland, Australia, it is proposed that mineralisation and alteration developed as a 'telescoped' overprinting continuum, ranging in style from hypothermal to epithermal, reflecting the major changes that developed in the regional setting over the period circa 325 - 290 Ma. Regional assessment suggests that this also applies to many other precious and base metal deposits within a 40 km length of the host Siluro-Devonian Chillagoe Formation.   A ten stage paragenetic sequence of structural preparation, multi phase intrusion and associated mineralisation, alteration and brecciation is postulated for the Chillagoe district.

Jan 1, 1995

Taxation is a major factor in evaluating mining project developments. The availability or otherwise of effective tax relief for project expenditures can have a crucial bearing on the decision to proceed with a project. The special position of the mining industry is recognised within the Income Tax Assessment Act (the "Tax Act") by special legislation, namely Divisions 10, 1OAAA and 10AA. The legislation both extends the scope of items which are eligible for deduction and affects the timing of deductions. Generally, the legislation separates expenditure into 3 categories: 1. Expenditure on exploration 2. Capital expenditure on the development and the running of the mine; and 3. Facilities used in the transport of minerals. Companies evaluating a project should carefully analyse their proposed expenditures, allocating them between these categories so as to identify potentially non-deductible expenditures and to determine the period over which tax relief will be Obtained.

Jan 1, 1983

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

Papua New Guinea has a long history of mining, with gold being produced from deposits on islands in the south east of the country over a hundred years ago. Before the Second World War, the mining and dredging of gold made the Wau-Bulolo area a

Jan 1, 1994

The Australian Mineral Industry has to compete on world markets, so its mineral research has to be aware of overseas developments, it must be of world class, and it must utilise as many ideas as possible in order to solve those problems that uniquely affect Australian minerals processing. North American mineral and resource research may be taken as a guide to world government, industrial, contract, and entrepreneurial research trends and ideas. A number of interesting findings are noted that may guide Australian developments and strategies for the future, in minerals research and exploitation.

Jan 1, 1986

By Withington J. T

The four major contracts for the construction of Museum Station are: 1) Installation of Soldier Piles, 2) Structural Contract including the temporary support, 3) Architectural Finishes which include Electrical and Mechanical Services and 4) Supply and Installation of lifts and escalators. Specific areas of interest include the fabrication, installation and removal of temporary support steelwork, the monitoring of ground loading, and the interface between the structure and. the temporary support. The information collated during construction confirmed the design assumptions and criteria. No major changes'were required in the design of the construction methods. The open cut excavation and construction of this major structure in an inner city area was significant by any standard and was successfully completed with minimum disruption to the public and without damage to adjoining or surrounding property.

Jan 1, 1981

By Sofoulis I

Recent studies in the Archaean of the Kalgoorlie-Norseman area show that the layered rocks can be subdivided into two main units, both containing basic igneous rocks and sediments. The lower unit is distinguished by the presence of acid volcanic flows and sills. In some areas, clastic sediments become coarser and,pas-s into conglomerates. This passage is accompanied by thinning of the beds. These features and their distribution suggest a basin of subsidence flanked-by areas of shallow-water deposition. -.

Jan 1, 1964

Ferromanganese metasediments in the immediate vicinity of the Mid-Proterozoic Broken Hill Pb-Zn-Ag lodes, have undergone high grade (upper amphibolite facies) metamorphism,to form Mn-pyroxenoid (rhodonite,pyroxmangite) and garnet-rich lithologies. Such lithologies bear compositional (bulk rock,rare earth element)and morphological similarities to recent and ancient ferromanganese hydrothermal sediments of the Pacific.The non-metasomatic,stratiform garnetites are predominantly composed of magnesia-rich, calcium-poor almandine spessartine and quartz, which possess a bulk chemistry comparable to alumina-rich ferrommanganese oxide deposits of the Pacific. Such sediments are attributed to a mixed protolith comprised of clay and ferro-manganese oxides (mainly amorphous goethite with lesser todorockite-birnessite). Manganiferous pyroxenoid rocks are probably derived from alumina-poor ferromanganese cherts,similar to Japanese tetsusekiei.Rare earth element compositions ofBroken Hill garnetites are very similar to those of recent ferromanganese seafloor accumulations, suggestive of some genetic link.

Jan 1, 1990

Blast furnace slags which fall into the quaternary system SiO2 - A1203 - MgO - CaO have latent hydraulic properties which depend on the degree of vitrification. When the oxides com- bine to form Calcium Silicate Hydrates and other products of hydration the bonds between elements are at a lower energy level than those which exist in the glassy state. Transition from the glassy state to the crystalline state is thermo- dynamically favoured and, in the context of this paper, such slags possess internal energy. Manufacture of Portland cement is respon- sible for about 3.6 per cent of total industrial energy consumption in Canada. Pyroprocessing accounts for about 83 per cent of this figure or 3 per cent of the total. The processing of blast furnace slag to a condition in which it can be used as a partial substitute for Portland cement requires no pyroprocessing and, on average, only about 11 per cent of the energy needed for Portland cement. In North America the benefits of slag as a cementitious materials have been obscured by other considerations, the most important being commercial strategy. This situation has under- gone radical change as a result of the rising cost of energy, and government pressures to conserve energy.

Jan 1, 1979

The purpose of this paper is to provide some practical commercial advice in relation to issues of access and trespass during exploration. It is not my intention to provide a detailed analysis of the applicable law because this is not the appropriate forum for latin maxims and turgid case studies. Instead I will explain the issues in sufficient detail to enable those who are not familiar,with the legal concepts to understand their obligations and responsibilities in relation to exploration activities. Take as an example a situation where a company (for the sake of attempted light relief, called Rogue Mining) holds an exploration tenement adjacent to one held by Lamb Exploration. In conducting aerial exploration activities over its own tenement Rogue overflies the tenement held by Lamb, doesn't turn off its equipment and accidentally collects data in respect of the adjacent land. In analysing that data it becomes apparent to Rogue that there is a substantial anomaly on the adjacent land of which Lamb is apparently unaware. Rogue subsequently negotiates to purchase an interest in Lamb's tenement.

Jan 1, 1995

By Wallman D

Since 1981 two single entry roadways have been driven at Ellalong Colliery for a total distance of 1 030 metres. They were driven at a height of 1.73 metres within the 3.7 metres thick Greta Seam using a Dosco In-Seam Miner (I.S.M.). Ventilation of the drivage was accomplish- ed by an exhausting fan in series with steel ducting and flexible ducting in the immediate face area. The air quantities provided at the face were more than adequate to comply with the requirements of -the auxiliary fan rules and the Coal Mines Regulation Act, 1912, as amended. The experience gained in these drivages demonstrated that the ventilation of long single entry headings can be practically and safely achieved using existing equipment.

Jan 1, 1983

Kinetic Dependence of Refractory Gold Sulfide Biooxidation Using Different Microorganism Association In this investigation, refractory sulfide concentrate from a deposit located in northern Russia was treated using biohydrometallurgical technology. The objective of this work was to compare the accelerated refractory sulfide concentrate biooxidation abilities of the pure and mixed mesophilic and moderately termophilic acidophiles cultures. Pure culture of Acidithiobacillus ferrooxidans and two associations of the: Acidithiobacillus ferrooxidans + Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans + Acidithiobacillus thiooxidans + Leptospirillum + Sulfobacillus were used in this investigation. Results of sulfide concentrate bioleaching were analysed using the enzyme catalysis theory. Different effective kinetics parameters were calculated for Michaelis-Menten equation, such as Michaelis' constant and maximum rate of the enzymatic reaction. It was shown that the increase of microorganisms' species decreased Michaelis' constant. Lower Michaelis' constant characterises increasing bacteria ferment affinity to substrate (treated concentrate). As a result, the rates of sulfide minerals biooxidation have increased. This investigation has demonstrated that cultures of the different microorganism species, including moderately termophilic, allow to enhance different parameters of the biohydrometallurgical technology for the refractory gold sulfide concentrate treatment. We can see that bacterial leaching stage duration decreased and sulfide minerals oxidation increased. When the bioresidues were subjected to the hydrometallurgical stage, which includes aeration and sorption cyanidation, the operation factors were also enhanced. The decrease of aeration duration and the growth of the precious metal extraction by sorption cyanidation was achieved. Cyanide consumption was also reduced. The results of this investigation were used in design of an industrial plant.

Sep 13, 2010