Search Documents

The author describes 1. The classification and characteristics of various thick seam mining techniques in various Japanese coal mines. 2. Practices of thick seam mining methods experienced in Taiheiyo Coal Mine. Currently, thick single lift, simultaneous multi lift and non simul- taneous multi lift mining methods are adopted as underground flat thick seam excavations in Japan. These are now reliable and effective in increasing the extraction ratio. At Kushiro Colliery of Taiheiyo Coal Mining Co., these three thick seam mining methods have been used. According to the results, if solidification of the top lift goaf is essential, the non simul- taneous multi lift mining method is the most effective in increasing the extraction ratio without minimising productivity of each lift and it points out that further development of this method is necessary.

Jan 1, 1976

A process was developed based on the thermal hydrolysis and precipitation of iron from solutions resulting from the leaching of zinc plant residue. A study was made of the hydrolysis of iron, at temperatures in the range 140-220°C, in both pure solutions of ferrie sulphate and in leach solutions derived from plant spent electrolyte.At 200°C hydrolysis of pure ferric sulphate solutions results in the precipitation of ferric oxide, Fe2O3, at low acid. concentrations, and a basic salt, Fe2O3.2S03.H20, at hIgher acid concentrations. At 180°C ferric oxide is precipitated at low acid concentrations, but at higher acidities. carphosiderite, 3Fe203.4SO.3.9H20, is the stable phase. Frequently a mIxture of ferric oxide and carphosldente IS produced at 180°C, the ratio of phases being dependent on the non-equilibrium experimental conditions.With solutions derived from plant spent electrolyte hydrolysIS at elevated temperatures results in the precipitation of jarosite compounds of the type NaFe3(S04)2(OH)6 The precipitation of natrojarosite jarosite, and ammonio-jarosite was studied in detail. Temperature, free acidity, and the concentration of sodium potassium, and ammonium ions are critical factors which affect the extent of precipitation.A process based on ammonio-jarosite precipitation was tested in a pilot plant.An alternative method of iron removal based on the addition of zinc oxide calcine, to neutralize excess acidity, and the precipitation of ferric oxide was also tested in the pilot plant. Both processes appear economically favourable...

Jan 1, 1967

Xstrata CopperÆs Mount Isa Copper Operations is located in mineral rich north-west Queensland and is one of the largest sources of copper in the world. This world-class underground operation is planned to produce over 6.6 million tonnes of copper ore in 2007 from the X41 and Enterprise Mines. With an underground mining history of over 50 years and underground reserves of over 83 million tonnes at 2.6 per cent copper, mine planning for the future becomes an exciting challenge for the technical team due to the older nature of certain areas. The 1100 Orebody of the X41 mine was one of the first places that copper mining occurred, with its discovery in 1953 - 1954 and mining commencing in the 1960s. Sublevel open stoping mining methods have been employed since that time as the means of extraction, using a primary-secondary sequence to maximise stope turnaround time. Large Transverse Pillars within the 1100 orebody were not mined out in order to provide access for ventilation, power, orepasses and other services. The Panel Pillar, 4180XC and 4010XC pillars are three such Transverse Pillars in the 1100 orebody that will be mined as a final retreat. This paper discusses the technical challenges and issues associated with the extraction of Q390 stope, one of the stopes located in the Panel Pillar, and the design solutions to overcome these issues. Managing the exposure of backfilled stopes of variable fill strength, ensuring the stability of the crown, stope walls and drawpoints, managing vertical openings, re-establishing service networks, and stope filling are the critical issues given consideration for the final design of Q390 stope and other such stopes within a Transverse Pillar. Communication and coordination between the different departments in the mine are essential for the necessary work to be completed in a timely manner to bring pillar stopes into production.

Jan 1, 2007

The Middleback Ranges are a series of parallel northsouth ridges on the eastern side of the Eyre Peninsula, South Australia, about 20 miles inland from the Spencer Gulf, as shown in Fig. 1. They extend for some 20 miles across the centre of the County of York. North of them, on the same line of strike, in, the County of Manchester, is a disconnected series of lesser which ends in the Iron Monarch-Iron Knob ridge, the principal iron ore locality. These ridges are referred to in the following pages as an integral part of the Middleback Ranges.The deposits of hematite which outcrop in these ranges (Fig. 1) form the most important group of iron ore bodies in Australia, and are exploited by the Broken Hill Proprietary Company. The largest of them is the Iron Monarch (Fig. 6) .H: The next largest are the Iron Duke, the Iron Prince and Iron Baron. The Iron Knob, Iron Duchess, the North and South Iron Knights, Iron Queen, and the small body south of it, the Kimba Lease, and the deposits in the Cook's and Ash Leases, are all smaller.Numerous small lens-like bodies of hematite occur throughout the ridges, but are not of sufficient size to be of commercial use. At present only the Iron Monarch and the Iron Prince bodies are being worked. The Iron Knob was quarried previously, but its remaining supply is held in reserve.*Published by permission of the Council for Scientific and Industrial Research.

Jan 1, 1936

By Quan P. M

The great advances made in the application of solvent extraction to the recovery of copper from low grade ore sources over the past 15 to 20 years are well known. Solvent extraction is an essential step in the recovery and purification of copper from dilute sulphate leach solutions by which some one million tonnes of copper are now electrowon annually. A reagent is also available for the selective recovery of copper from chloride leach solutions and this may hold the key to the processing of complex sulphide ore concentrates. By comparison, the use of solvent extraction in the recovery and processing of zinc has as yet found little favour and is confined to only a few specific and comparatively small applications. This is despite the ready availability of a large number of low grade zinc sources and zinc-bearing wastes and residues. It is suggested that this difference is due in large part to the absence of suitable reagents having the particular features required to enable them to fit into a solvent extraction - electrowinning based process for zinc. Ideally, for the recovery of zinc from dilute sulphate solution, an extractant should operate on a proton exchange principle and be strong for zinc in the same way that o-hydroxyaryloxime reagents are strong towards copper. It should load efficiently with zinc at the pH of typical sulphate feed streams without the need for neutralisation and yet be stripped efficiently by spent zinc electrolyte. Another factor of major importance for many applications, however, is that it should be highly selective for zinc over ferric iron. These features have now been realised in a development extractant DS5846, which is a formulation of a novel class of reagent currently under investigation by Zeneca Specialties. The properties of this reagent are described with respect to selectivity, isotherms and how they compare with phosphoric and thiophosphoric acids that have been previously proposed for the extraction of zinc. For the recovery of zinc from concentrated chloride solutions a solvating or neutral donor type of extractant is required which again should ideally have high selectivity for zinc over a number of other metals, particularly iron. The new reagent Acorga ZNX50 is based on a formulation of a novel class of compound developed specifically for this purpose. It gives efficient extraction of zinc from feed solutions that are four to six molar in chloride ion but is readily stripped at 60 - 65¦C using either water, dilute brine, or spent zinc chloride electrolyte. The reagent is highly selective for zinc over iron and a range of other metals including cadmium, arsenic, lead and magnesium.

Jan 1, 1993

A magnetometer survey 'was the Darkes Forest area between 1968. The instrument used was model MZ4 with sensitivity 9.4 conducted over part of 30th April and 3rd May, an ABEM torsion magnetometer gammas per scale division. The survey consisted of a closed magnetometer loop along lines cut for a previous magnetometer and seismic reflection survey by Wongela Geophysical in March, 1968. The magnetic results of the previous survey were not satisfactory in some areas and are presented as a comparison in instrumentation. Station separation in the present survey was 100 feet with tie-in readings at shot points of the previous survey (usually 1320 feet apart)

Jan 1, 1969

In early 1985, Bougainville Copper Limited commissioned an automatic truck despatch system to control its fleet of 44 trucks and 9 shovels. Productivity gains in the past have been the result of increasing equipment size then improving availabilities. The emphasis now is on improving the use of that availability and in particular for trucks, in reducing non-productive truck movement. A batch allocation computer based truck control system had been in operation since 1978, so to achieve the desired improvements it was necessary to move to an automatic dynamic control system. A description of the system installed is given, together with a review of how the project was engineered, the problems encountered and the results achieved to Date.

Jan 1, 1986

By Grant JR, McKavanagh BM, Dear SJ

A geophysical technique of rock mass assessment for engineering purposes is being investigated and shows positive correlation with direct structural logging and mapping techniques for the detection of major geological features. The technique is cross-hole acoustic surveying incorporating high speed signal averaging, with a maximum hole separation in excess of 30 metres in hard unfractured rock masses. The bulk of the field test work was carried out in open stopes in the copper ore bodies of Mount Isa Mines Limited. The investigation forms part of an integrated study of blasting in mining, aiming for fragmentation control through blast design modification. The rock quality factor, Q, is presented as a blasting index and can be determined for a significant portion of a production stope.

Jan 1, 1981

The paper, one of two papers on the Queensland Railways Brunswick Street tunnels presented at the VIII Australian Tunnelling conference, describes documentation, tendering and construction aspects.Tender documents were written to reduce the risk taken by the contractor. Details of tenders received are analysed and the changing industrial situation at that time described.Construction aspects covered include mobilisation, major equipment, tunnelling equipment and manning. Program and progress are reported including industrial relations and advance rates for Mitsui-Miike S-200 and S-65 roadheaders. Cycle times and performance in terms of cutting rate and pick wear are provided for the roadheaders.

Jan 1, 1993

The discovery of copper and nickel sulphides in the Riwaka Complex in 1967 led to considerable exploration activity by a number of companies. Various exploration techniques used by these companies are summarised and discussed. Activity of these companies shows that mineralisation is mainly confined to the southern, ultramafic section of the Riwaka Complex where geological mapping recognised sixteen units within, or associated with the Riwaka Complex. Significant pyrrhotite, pentlandite chalcopyrite mineralisation is restricted to biotite feldspar pyroxenites and to clinopyroxenite units. Lesser and more erratically distributed pyrite chalcopyrite pyrrhotite mineralisation occurs in poikilitic pyroxene hornblendites, melanocratic gabbros, and in marginal diorite lenses. It is suggested that a linear belt of layered ultramafic and mafic rocks described in Fiordland by Williams (1974) may be a southern extension of the Riwaka Complex. The Riwaka Complex has been classified as belonging to the Picritic subtype, (Tholeiitic suite), of Naldrett and Cabri, (1976), and as such it is concluded that it exhibits substantial potential for the discovery of economic copper and nickel deposits. It is considered that the complex is a multiphase differentiated intrusion emplaced in a major tensional fracture zone that developed in a relatively stable tectonic environment, namely a succession of middle Paleozoic shallow water shelf sediments. Based on sparse available evidence it is suggested that the Riwaka Complex was intruded in the lower to middle Permian. It is further suggested that the tensional fracturing was initiated by the onset of subduction process which were responsible for the development of the Permian volcanic arcs and ophiolite belt in the north west Nelson area.

Jan 1, 1977

Over the 20 years to 1990 the Australian mining industry, presently worth some $A60 billion, generated a negative real rate of return (McDonald, 1992); not surprisingly under-performing the returns from bonds and industrial equities. Over this same period more than $A70 billion was invested in expanding the Australian mineral industry.

Jan 1, 1993

Backfil ling of excavated Sub Level Open Stopes has been underway since March 1989 and as at December 1992 some 1 100 000 cubic metres of Cemented Aggregate Fill have been placed. During these three years significant developments in fill quantities, types and cost have taken place.Operational improvements have reduced the quantity of Cement Aggregate Fill by 40 per cent. These results have been achieved by:ò rescheduling stopes,ò designing smaller primary stope, and ò use of uncemented rockfill.Unit cost for Cement Aggregate Fill have fallen in the order of 50 per cent through:improving fill hole reli ability,simplified barricade construction procedures, reducing the cement content,ò substituting dune sand for deslimed mill tailings, ò improved maintenance at the Backfill plant, and ò renegotiated site freight agreement.This paper will review the historical developments of backfill use at Olympic Dam.

Jan 1, 1993

The prevention of silicosis by metallic aluminium has been reported by Denny, Robson, and Irwin in two papers. The first was published in 1937; the second, in 1939. The results definitely established that silicosis was prevented in animals by the inhalation of small quantities of aluminium. The present communication records subsequent progress in this field of research.

Jan 1, 1944

By G W. Scott, H M. Lukey

The Lake Superior Region has been a producer of iron ore for over 150 years. Early mining operations concentrated on direct shipping ores, which are the result of post-depositional upgrading principally by deep weathering. As direct shipping ore reserves became depleted, the focus changed to the production of iron ore pellets from taconite. The post-depositional processes responsible for upgrading taconite are regional metamorphism, contact metamorphism and hydrothermal processes (Clout and Simonson, 2005). While these processes are important in iron ore genesis they can also contribute to liberation problems and in some instances reduced pellet quality (Han, 2004). Low-grade metamorphic mineral assemblages can negatively impact liberation and pellet quality. Low-grade iron formation may contain a suite of carbonate minerals including ankerite, dolomite, kutnohorite, siderite and magnesiosiderite. Variation in the distribution and composition of siderite and magnesiosiderite makes controlling the MgO content of pellets difficult. Carbonate minerals also require calcination in the pellet induration process, which requires additional heat to be added to the system, slowing down the induration process and reducing throughput. Prediction of carbonate mineralogy and carbonate mineral chemistry is an important goal of ore characterisation for pelletising properties. Contact metamorphism causes changes in mineralogy and grain size (Klein, 1973; Gunderson and Schwartz, 1962). Increasing the grain size of magnetite should improve its liberation characteristics. However, plant grinding targets may not allow the coarse-grained, more easily liberating magnetite ores to increase throughput and can actually result in decreased throughput due to recirculation. While magnetite and martite ores are well understood (Lukey, Johnson and Scott, 2007) late open-space filling microplaty haematite ores are not. These ores, while composed of similar minerals, have a unique genesis that results in fine grain size and complex textures that present liberation challenges and often make interpreting laboratory metallurgical test results more difficult.

Jan 1, 2007

By T Laurencont

The Queensland Department of Natural Resources and Mines (NR&M) accepted the environmental liability for the Mount Morgan minesite in 1991. This gold and copper mine located 38 km southwest of Rockhampton had been in operation for more than 100 years. Mining leases are still active while the feasibility of a reprocessing operation is carried out. From 1993, NR&M have operated a seepage interception pumpback system which has reduced the chronic load of acid rock drainage (ARD) to the adjacent Dee River, a tributary of the Fitzroy River system. In early-2000, it was recognised that a ten-year plan for rehabilitation of the mine, along with significant funding would be required if a long-term sustainable rehabilitation strategy was to be implemented at this minesite, ultimately making the seepage interception system redundant. A rehabilitation planning workshop coordinated by NR&M was held in May 2000. This workshop brought to the mine a range of technical expertise and key stakeholder groups. This workshop provided a technical forum for review of studies undertaken and to identify priority projects, which needed to be undertaken in the future to more clearly define contaminant sources on the mine site and to prioritise the rehabilitation program. Stakeholder consultation enabled the project team to be clear on community and other government (eg Environmental Protection Agency) expectations. It is clear that the future of the economically depressed community of Mount Morgan will be reliant on the careful management of the significant heritage values at the minesite for tourism, education and research. In the first year (2000), priority studies were initiated, which included whole of site studies on water balance, contaminant sources and a review of occupational health and safety and environment of the minesite and conservation and heritage scoping. Baseline vegetation and soil materials surveys were also initiated. The outcomes of these studies helped to shape the work program for the following year, while providing a basis for an additional funding application, which was granted. The second year of studies focused on building upon the existing baseline studies completed. In addition, studies focussed on addressing the priority issue of contingency planning for overflow from the open cut pit in accordance with best practice management of release water and river monitoring strategies were completed. Completion of these projects over the next six months will enable the optimal rehabilitation strategy to be defined in 2003. This optimal strategy may require the use of a water treatment plant for part of the ten-year program to provide space in the open cut pit for the deposition of ARD contaminant sources (eg waste dumps, tailings). It is envisaged that some sources will be rehabilitated insitu while others will be relocated to the open cut pit. Implementation of this strategy will be dependent on subsequent funding.

Jan 1, 2003

By Bassett N

The Eneabba deposit, located 280 km north of Perth, Western Australia, and 30 km inland (Fig. 1) is one of the most recently developed deposits of mineral sands in the world. The area has been in production since 1974, while the Associated Minerals Consolidated Limited (AMA) operation commenced production in 1976. Total ore reserves of close to 400 million tonnes contain about 40 million tonnes of heavy minerals (proved and probable).

Jan 1, 1979

By Campbell Brown G F

THE Mount Morgan mine has, from the time of its historical discovery, been the subject of investigation and speculation by geologists and mining engineers. The first examination was made by Dr. R. L. Jack, in 1884. He came to the conclusion, from theevidence then available, that nothing but a thermal spring in the open air-otherwise a geyser-could account for the formation of the ore body. This report attracted world-wide attention at the time. Since then the mine has been examined by most of the leading geologists of Australia, and by many from elsewhere. In all cases the examination has only extended over a period' of a few days or weeks, and in the light of present knowledge of the deposit we know that sufficient data could not be obtained in such a short time to warrant the statement of definite conclusions. It is not to be wondered at, therefore, that a considerable difference of opinion exists as to the genesis of the deposit. That the company considered more detailed investigation necessary is shown by the fact that some thirteen years ago it employed Mr. Charles Walker as geological surveyor on the .mine. At that time also the data available was insufficient to give satisfactory results. It is, however, a matter for comment that none of the geological reports on the property took notice of the increase of copper values in the ore with depth, though the present workings and diamond-drilling...

Jan 1, 1911

By Wilson AC

Permian coal from Western Australia's only producing coalfield at Collie is the dominant fuel used in generating electricity for the State's interconnected grid. Collie coal is sub-bituminous, non-coking and has a low ash, medium volatiles and high moisture content. The seams were laid down in a fluvial basin which extended beyond the Collie Basin and included the Wilga and Boyup Brook Basins at least. Adjacent parts of the southwest Yilgarn Block are prospective for Collie-type basins. In the past few years significant deposits have been delineated within the Perth Basin, specifically on the Vasse Shelf and in the Hill River area. In the former area high quality steaming coals are correlated with the lowest coal bearing member at Collie. The seams are amenable to underground mining and because of their high quality, the coal may have export potential. Sub-bituminous coal deposits of Jurassic age are present in the Hill River area. Exploration has down-graded the prospectivity of the Carnarvon and Canning Basins for sub-bituminous near-surface coal deposits. Tertiary lignite deposits are present in palaeo-drainage systems in the southern part of the State and their potential for development is being evaluated.

Jan 1, 1986

By Kagl J, Publlier M, Nekitel S, Arumba J, Rangin C, Mosusu N

Since the advent of plate tectonic modelling, the Ramu-Markham valley has been thought the site of a classical island-arc/conti- nent collision zone. In this interpretation the units south of the Markham Valley are held to be island are / micrcontinental mate- rial accreted to Australia and those north of the valley are thought to represent a separate Finisterre island-arc terrane. Recent remapping by the Geological Survey of Papua New Guinea shows: (1) there is no terrane boundary along the Ramu-Markham valley (2) the Finisterre Volcanics are probably part of either a fore-arc sequence or oceanic plateau obducted onto a microcontinent/ volcanic-arc composite terrane, accreted to the continental Australian plate. A new tectonic model is proposed for northern PNG and involves: (I) Eocene to Late Oligocene subduction below a microcontinent remote from Australia to produce the Sepik are and related intrusives, the Finisterre Volcanics (fore-arc or possible oce- anic plateau), together with the Alife blueschist. (2) obduction of the Sepik arc in Late Oligocene-Early Miocene times over the advancing Australian plate. This resulted in crustal melting, some of the products of which are the Mid- dle to Late Miocene Akuna and Bismarck intrusive complexes of the Maramuni arc. (3) obduction of the Finisterre Volcanics began in Early Pliocene times and continues today. (4) post-Middle Miocene mineralisation is the result of melting after obduction of the Sepik microcontinent.

Jan 1, 1997

Unprecedented political, economic, and social change throughout the world will have an increasingly profound effect on the dynamics of the world's mining industry. Analysis of the early financial trends in this development (statistics on exploration expenditure, and investment flows) gives some insight into the magnitude of structural change and its implications for established mining economics and companies.Increasing confidence in the stability of many third world and developing countries is attracting exploration and investment capital that had previously been largely directed to established mining economies in North America, Australia, Europe and Southern Africa. Some of the projects requiring capital and technology in the CIS, Africa and Latin America are technically very attractive. The end of the 'cold war' and the influence of the IMF is gradually changing their risk profile for mining investment.

Jan 1, 1993