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The treatment of beach sands in'' the Bunbury/Capel' area for the extraction of ilmenite is a very recent development in the mining industry in'J7estern Australia. Nevertheless since the commencement of production in 1956, ilmenite has become the sixth most important mineral produced. The increasing world recognition of W.A. as a major' Iiroducer of ilmenite is due primarily ' to its low chromic oxide. ; (Cr203 content,, 0,03% to 0.04%, combined with a medium to high grade TiO2 content, 54% - 6 , supported by large reserves, a'. stable government with close access to good shipping facilities.. Ilmenite is produced from-these deposits at low-costs, enabling the industry to compete on world markets despite high rates for sea freights because of the distance from.major markets.

Jan 1, 1964

By Koppe JC, Strieder AJ

The Rivera Crystalline Island (RCI) is an erosional window of the intracontinental Parana Basin that outcrops in the Rivera Department, north of Uruguay. RCI is made up mainly by Precambrian granites, metasediments and granite-gneisses. This island is crosscut by a dextral transcurrent shear zone system, the Rivera Shear System (RSS). The bulk strain ellipsoid was defined by previous work and has allowed the evaluation of shear dynamics. The geometry of the shear system is made up of two shear directions: E-W (P-shear), which turn right to NW-SE direction (R-shear), leading to the development of extensional bends. The shear zone system was developed in brittle-ductile to brittle regimes, under temperature conditions compatible with greenschist facies metamorphism. The shear zones are marked by an intensive fracture cleavage development. Mylonites develop only in narrow, discontinuous higher strain zones. Internally, the shear zones are dominated by intrusive rocks, mainly granites, dacites and diorites. Hydrothermal alteration has been developed in several areas.The economic significance of RCI is given by several small gold deposits, which have been exploited since 1869. One major new gold mine is under development, the San Gregorio Gold Mine. This gold deposit is locally controlled by a dilatant site where R-shear turns right to P-shear. Mine lithologies were deeply altered by hydrothermal fluids in the dilatant structure. This work presents the lineament-structural analysis carried out to identify similar structural patterns in all RCI sites favourable to host other gold deposits. The exploration program also considered remote sensing, geology, geophysical and geochemical survey.

Jan 1, 1997

The earth is a planet limited in size and limited in total resources. For the forseeable future, it is the only available habitat for mankind. Therefore, it follows that the more we know about our planet the better we can utilize its space and its resources for our well-being now and in the future. But, to accomplish this, we need reliable basic information. Geosciences provide such information. Recently, Dr. M. King Hubbert took note of the important effect of the geosciences on society, on how we think, and how we live. In the first century of modern geology, 1780- 1880, the influence of geology was primarily on how we think, i.e. changing our concept of the earth from one with a short catastrophic history to one that developed gradually over enormous spans of time. In the second century, 1880-1980, the emphasis was on how we live, on expanding the knowledge base so that we could more easily find and utilize the earth's resources. Now, in the third century, i.e. from 1980 towards the year 2000 and beyond, we should concentrate on both how we think and how we live; i.e. how we can better estimate potential global' resources and how we can manage these resources for maximum benefit to mankind. Like other sciences, the geosciences build upon what has already been done. Progress is achieved by using the thoughts, measurements, and observations of past workers, adding to these the insights from new experiments and from new concepts. Geology has its own methodology and approaches; but more than most sciences, it calls also upon the tools of physics, chemistry, mathematics, engineering, and biology to help solve its problems. Today's increasing population, increasing industrialization, and increasing complexity of modern society demand more detailed geoscience information so as to better use the land, reduce geological hazards, provide an inventory of resources, facilitate waste disposal, and prepare for long-term effects such as changes in climate and sea level.

Jan 1, 1986

By M Habte

This paper presents a simplified method for the assessment of creep deformations in rock masses containing bands of low strength or soil strength rock. The main impetus for this work was the need to assess the impact of distinct bands of clay and/or low strength rock on the long term deformation behaviour of a rock pillar formed as part of a series of proposed tunnelling works. In particular, the authors were interested in being able to provide criterion which could be used by site personnel to assess the encountered rock conditions against design assumptions.Creep deformation versus time plots are presented for a range of material consistencies. These plots were produced using the hyperbolic creep equation proposed by Mesri et al (1981). This empirically based equation was chosen for its simplicity and practicality. Discussion is included regarding typical input parameter values and the sensitivity of the results to these values is explored. Finally, in the soil strength materials, the secondary consolidation equation is used to check the veracity of the results calculated using the hyperbolic creep equation.

Mar 8, 2011

By R Lurf, C Weber

In the frame of this paper a holistic dynamic process model approach is presented in order to introduce operational and technical excellence in drilling and blasting. Both on a macro and micro level the single process parts of drilling and blasting are outlined and their interaction is explained. The use of this approach for closing the gap between process planning and process implementation is explained and an example of the value generated is given.

Jan 1, 2007

By M Kim, J Park, I-K Suh, E Kim, J Lee

One of the key technologies in developing hydrogen-enriched ironmaking operations is the control of the carburisation, melting, and dripping behaviour of the iron ore burden materials. When a hot compacted iron (HCI) is charged in the blast furnace or the FINEX Melter-Gasifier, iron oxide reduction, the reduced iron’s carburisation, and the melting of iron and slag occur successively. This study investigated the reduction, carburisation, melting and dripping behaviour of HCI under a COH2 gas mixture using the high-temperature X-ray radiographic technique. Under 100 per cent CO gas atmosphere, the dripping temperature was 1410°C. When 5 per cent H2 was introduced, the dripping temperature slightly decreased to 1400°C. Furthermore, the dripping temperature gradually increased as the H2 gas composition increased. As 30 per cent H2 was introduced, the dripping temperature reached 1414°C. The carbon concentration in the drained metal samples gradually increased with increasing H2 composition. It is considered that H2 decreased FeO content in the slag, yielding the increased melting temperature and viscosity of the slag. On the other hand, H2 accelerated the carburisation of the reduced iron by CO gas, enabling the homogenisation of the oxide materials to form a liquid phase. Therefore, it is considered that introducing H2 in the reactor is helpful to increase productivity and energy efficiency by accelerating the liquid phase’s formation.

Aug 21, 2024

By Verma UK

Mining for sand was active in South Delhi during the last four decades disregarding all norms of safety. The aim of the paper is to highlight what is proposed to be done for mining in Delhi. Apart from the damage to the landscape, the earlier operations gave rise to visual pollution to the scenic Delhi area and there is immediate need of land restoration and landscaping. Future mining should be planned so that the resultant land surface completely merges with the topography and gradually assimilates with the green belt. Restoration of old workings, land reclamation and details of plantation in old pit areas are included. The project also provides a demon- stration site to show the impact of eco-development leading to new legisla- tive measures, as it is in the Capital of India itself and therefore more accessible than any other area. What has been suggested for mining is not the latest and the most modern equipments from the Western point of view but the right equipment to meet the specific requirement of the country. Financial projections are included alongwith technical details of the project to show the benefits to the society. It is concluded that eco-development is essential for the mining in the Twenty- First Century.

Jan 1, 1986

By A Gustafson, G Shekhar, P Boeg-Jensen

The amount of material extracted from each blasted ring in sublevel caving mines is vital when deciding the overall mine production target. The orientation of the production drifts is normally perpendicular to the strike of the orebody, and rings are blasted from the hanging wall side to the footwall side in a retreating manner. For an inclined orebody, a given ring will contain different amounts of material based on its relative position along the production drift. This layout creates a distinctive problem with respect to the extraction ratio optimisation along the axis of the production drift. This paper describes the current drawpoint control strategy practiced at LKAB and presents the variation of drawpoint performance parameters along the production drifts. It uses automatically generated data from a bucket weighing system that measures tonnage drawn per bucket, and it classifies the blasted rings into four zones based on their relative position along the production drift. It considers the loading procedure for blasted rings at Kiirunavaara mine and analyses the variations in drawpoint performance along the production drift. The paper finds that although the current draw control strategy is sensitive to ring position along the drift, it could be modified to optimise the final extraction ratio.CITATION:Shekhar, G, Gustafson, A, Boeg-Jensen, P and Schunnesson, H, 2016. Draw control optimisation along the production drift in sublevel caving mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 241–250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By R G Warren

Most orebodies have cross-sections of less than 1 km2 and hence do not offer a particularly large target for exploration. Fortunately, although in the geological record ore deposits are small and rare and result from the exceptional coincidence of certain geological processes, these processes are mappable on a much larger, district to regional scale and constitute a mineral system in which the ore deposit is the central feature. A mineral system can therefore be defined as `all geological factors that control the generation and preservation of mineral deposits, and stress the processes that are involved in mobilising ore components from a source, transporting and accumulating them in more concentrated fonn and then preserving them throughout the subsequent geological history'. The mineral system concept emphasises that for many ore deposit types, although economically viable mineralisation may only occur on a scale of say, hundreds of metres, the total system of fluid-rock interactions that led to ore formation can extend over a distance of tens to hundreds of kilometres around the deposit. When mapped out, the total mineral system provides a far larger exploration target than the actual ore deposit itself. Important geological factors defining the characteristics of any mineralising system include: 1. sources of the mineralising fluids and transporting ligands; 2. sources of the metals and other ore components; 3. migration pathway; 4. thermal gradient; 5. energy source; 6. a mechanical and structural focusing mechanism at the trap site; 7. chemical and/or physical traps for ore precipitation. Many of these factors individually are common throughout time and space and are mappable on a regional scale. The delineation and empirical prediction of mineral systems can thus be approached by combining two components of metallogenic research. Firstly, the development of maps of regional geoscientific data and data sets of the distribution of factors significant for mineral systems in general. Secondly, the determination of the essential ingredients of particular styles or types of deposits in terms of mappable elements that any exploration program could focus on.

Jan 1, 1994

By Kurzeme M, Willoughby D. R

The current approach to the design of fill, as a structural component in a mining system, is based on traditional usage, previous experience, empirical rules and preconceived ideas. This approach does not permit the relative economicsof the various possibilities to be evaluated, retards introduction of new materials or processes, and results in fragmented fill research effort.A rational approach to the design of fill is proposed as a means of overcoming these disadvantages.This is based on five components:(a) statement of functions of fill,(b) definition of modes of fill response,(c) criteria of satisfactory performance,(d) analysis of fill response,(e) specification of required fill properties and methods of obtaining them.An assessment of each component indicates that the adoption of this rational design approach will require research effort in categorising modes of fill response and in defining criteria of satisfactory performance.

Jan 1, 1973

In the Massif du Sud ophiolite complex platinum group elements occur predominantly as ultrafine-grained inclusions of rutheniridosmine, laurite and iridosmine. These form primary inclusions less than 5 to 10 um in diameter within chromite in podiform chromitite fringed by dunite, and emplaced subsequent to solidification of the host harzburgite. There is no specific association with trace inclusions of transition metal sulphides. The crystallization of then: Ir. Os and Ru minerals may have occurred concomitant with hromite, perhaps related to more reducing conditions produced by crystallization of the chromite. The Ir, Os. and Ru show pronounced fractionation from Pd, Pt and Rh expected to be also present in the mantle source rock. The dunite shows evidence of metasomatic origin from adjoining harzburgite, and the possibility of selective crystallization of the Ir sub-group elements suggests that Pd, Pt and Rh may have been transported elsewhere.

Jan 1, 1989

By Beech-Jones J. M

At Port Latta in Tasmania, Savage River Mines operates vertical shaft furnaces for the firing of pelletised magnetite concentrates. At times the temperature profile of the furnace has changed markedly, necessitating the- burning of greater quantities of fuel to maintain good pellet quality. A study of the oxidati=of magnetite concentrates was under- taken because this exothermic process supplies much of the heat required to indurate the pellets. Using the thermal analyses methods, different magnetite concentrates from Australian and overseas were heated in air under identical conditions, to compare rates of oxygen uptake and of heat release. In addition, a compari- son was made of the oxidation behaviour of different particle size fractions of a selected concentrate. Particle size analyses, x-ray diffraction and dilatometer tests were used to aid inter pretation of the thermal analysis traces. The investigation emphasized the importance of particle size and ferrous iron content in determining' oxidation rates from the commencement of heating.

Jan 1, 1974

By Badal R

Rock Discontinuities ("joints") affect blasting results. An investigation was carried out to understand if blast parameter such as spacing needs to be altered with the change in joint direction. Small scale laboratory studies in jointed limestone blocks have been carried out. It is shown that optimum spacing is variable with the "joint" orientations. Evidence is presented from field studies in four limestone quarries supporting laboratory studies. Reasons for success and failure of widespacing technique is also provided. Only with suitable orientations of "joints: widespacing is successful.

Jan 1, 1990

By A G. Cuison, B V. Andam

Three well-known copper and gold deposits in northern Luzon, Philippines are located in the Mankayan Mineral District. These are the Lepanto Copper-Gold Deposit, the Far Southeast Porphyry Copper Deposit and the newly discovered Victoria Gold Deposit. The latter discovery led LCMC to shift from a predominantly copper mine to a gold mine. The pre-Eocene Lepanto basement andesite and the middle Miocene Balili volcaniclastic sequence underlie the Mankayan Mineral District. They are intruded by tonalitic to gabbroic Bagon Intrusive followed by diorite-quartz diorite intrusions. Diatreme emplacement of late Miocene-early Pliocene Imbanguila dacite pyroclastics and porphyries took place much later. Faults in the district mostly form a conjugate fracture pattern dominated by north and northwest trending shears, east-west trending extensional fractures and few north-south trending fissures. Victoria is an epithermal gold-base metal rich quartz vein deposit. The veins occur along tensional structures and it is common to observe crustiform and banded features among the sulphides and gangue minerals. It is an open space infilling type of mineralisation. The Victoria vein systems are divided into zones based on continuity. In each zone are major veins and associated spits. Dacite pyroclastics and porphyries predominantly host the major veins with a few narrow veins hosted by the Balili volcaniclastics and the Lepanto metavolcanics. The veins generally trend east-northeast with 75 - 80 dips towards the south. The longest vein can be traced fairly continuously for a horizontal distance of about 600 metres. The vertical persistence of major veins exposed on three level drives has a range of 150 metres and can reach as much as 400 metres based on drill hole intercepts. The vein widths vary from two to eight metres. Right lateral movements of either the NW or NE shear faults could have produced the east trending tensional fractures. The development of ore shoot patterns was recognised and has been helpful to the mining operations. Cymoid loops with defined pinch and swell features are noted both laterally and vertically. Complementing the structural pattern is the distribution of gold values along veins where lateral and vertical continuity is also observed. Gold is associated with quartz, sphalerite, galena and chalcopyrite. In relatively high gold zones, the abundant sulphides are sphalerite and galena. In relatively high copper zones, there is an abundance of chalcopyrite and tetrahedrite. Galena is always associated with sphalerite but less in abundance. Chalcopyrite occurs either as separate bands from or associated with sphalerite-galena. Chalcopyrite and tetrahedrite appears contemporaneous with sphalerite and galena but in some portions the former cuts the latter sulphides. The predominant gangue minerals are quartz, carbonates and gypsum. Rhodochrosite is the predominant carbonate gangue. Few sulphides are found in the carbonates. Gypsum (anhydrite) is found cross-cutting early mineralisation. It carries very few sulphides. The alteration halos around veins are relatively narrow. In an outward sequence, the silicic alteration occurs very near the veins, followed by sericitic-argillic alteration then to propylitic zones. It is also common to observe veins bounded by propylitic alteration. Preliminary paragenetic studies show apparent three stages of mineralisation, the early-quartz (-gold) stage followed by a carbonate stage and a late-gypsum stage. The abundance of base metals relatively decreases towards the gypsum stage. The Victoria gold deposit could have some genetic associations with the Lepanto Cu-Au deposit and probably indirectly with the FSE porphyry system. It is relatively apparent that the Victoria quartz-gold-base metal veins could have occurred similarly as the quartz-gold roots overprinting the Lepanto enargite mineralisation. This overprinting signifies the waning stages of the entire hydrothermal system.

Jan 1, 1999

In February 1995, Falconbridge Limited approved the construction of a nickel mining and milling facility on its Raglan property situated in the Nunavik region of northern Quebec, Canada. The construction period successfully terminated with the commissioning and start-up of the plant and concentrator in early-December 1997. The estimated life of the project is 20 years with an annual mining rate of 800 000 tonnes of ore, producing 21 000 tonnes of nickel per year. This paper discusses the subject of æRemote Mining in the Canadian ArcticÆ as it applies to the Raglan mine process and people. During the feasibility stage of the project, many assumptions were made which influenced the design and operating parameters of the facilities and the equipment. Transportation, communication, remote logistics techniques and standard industry practices required to support a æfly-in/fly-outÆ operation were reviewed and either adopted or rejected for use at Raglan. These assumptions were æmade to fitÆ the uniqueness of our planned operation. It was also acknowledged that many of them would ultimately impact on the people required to staff the operation following construction. Therefore, their suitability and applicability were examined from an economic, operational and human perspective. In a continuing effort to improve the quality of life for Raglan employees, as well as the economics of our mine operations, these assumptions are under constant review and scrutiny. There is no doubt that experiences gained, and willingly shared by other North American arctic mining operations, proved invaluable and are a big reason for RaglanÆs overall success thus far. The mining industry is being challenged technically to develop lower grade orebodies at the lowest possible cost. In addition to environmental constraints, serious social, political and moral questions are being asked and added to this list of challenges. Miners throughout the world must improve their operating standards and public image if we want to attract the best possible employees. Remote mining operations provide a unique opportunity to experiment with various human resource concepts as well as demonstrate the industryÆs commitment to environmental and community concerns.

Jan 1, 1998

The Mount Isa mine in North West Queens- land produces a total of nearly 10 million t/yr from separate copper and silver lead zinc orebodies. Sampling information is mainly obtained from diamond drilling on 30 to 40 metre centers in both types of orebodies. For the copper orebodies the majority of the core is analysed for copper content using a non-destructive bulk analyser developed by the Australian Atomic Energy Commission. The diamond drill core in the silver lead zinc orebodies is usually sam- pled as sawn half core and assayed in the com- pany laboratory using a variety of methods dependent upon the level of metal content and/or the elements required. Underground development is sampled where additional information is required to improve the ore reserve estimate. The copper areas are sampled using a standard 2.0 m by 2.0 m chip sample of the wall. The chips are taken on a 250 mm spacing. Lead areas are sampled using a 100 mm wide by 4 mm deep channel over intervals determined by the area geologists. The massive, irregularly shaped copper ore bodies are mined as large sublevel open stopes and pillars. Ore reserve estimation on both a production unit and global scale is routinely carried out using a geostatistical system developed in-house and running on a Sperry 1100 mainframe computer. Copper grade, tonnes and the Kriging var- iance are estimated at points on a user defined grid. The Kriging program uses 10 m assay composites from diamond drill core and underground chip samples. One average (rela- tive) variogram is used throughout the main copper orebodies. The validity of using an average variogram was verified by the original geostatistical study undertaken in the late 1970's.

Jan 1, 1987

Dilution in underground coal operations can be underestimated by up to five times during feasibility studies, with disastrous economic consequences. Every one per cent of stone waste introduced can reduce an in situ specific energy of 25 MJ/kg by some 0.25 MJ/kg and increases the abrasiveness of the run-of-mine coal. Where a wash plant is not in place, penalties imposed for not meeting contractual specifications alone can amount to some $A 1 million per year. This paper presents a method for monitoring, reporting and ultimately controlling dilution in an underground coal mining operation and presents the dilution trends from a continuous miner/longwall mine over an eight year period. The overall dilution level for the mine can be back-calculated by comparing the run-of-mine coal quality to the predicted in situ, undiluted quality. However, this will not identify the actual contaminant types, areas of the mine responsible for the dilution and the reasons for the dilution. This additional information is essential for controlling dilution to acceptable levels. Quality and horizon control using existing sampling information is generally only adequate for longer-term control purposes, and is not suitable for monitoring mining-induced dilution. The cost of close-spaced surface drilling to collect the information necessary for short-term control is prohibitive, particularly for deeper mines. However, much of this data can be collected through underground channel sampling and horizon control measurements taken during continuous miner development and longwall extraction. The mine runs the risk of not meeting contractual quality specifications and of increased equipment wear if this additional information is not available and the sources of dilution cannot be controlled. The information can also be used to plan longwall extraction heights on a short-term scale with resulting improvements in productivity.

Jan 1, 2003

Current problems in predicting sub-surface strata movement and fracture development due to longwall mining have highlighted the need for more accurate, dependable methods of physical modelling of rock mechanics problems which are beyond the capabilities of current mathematical techniques. Physical model studies of the caved zone above the working faces up to the base of a water source are of importance in attempting to understand changes in mass permeability due to induced fracture zones and the resulting ground water conditions. Turkey's most important supplies of coking coals are to be found within the hard coal resources of the Black Sea coast. Coal seams up to 9 metres thick, dipping at angles as steep as 90 degrees are being successfully mined at the Kozlu Mine. Since 1956, mining operations have been carried out under the sea in dry conditions. The undersea mining conditions of the Kozlu Mine have been investigated using scaled physical models constructed from artificial materials which satisfied necessary scaling requirements. Models representing the in-situ conditions were tested and the following extraction sequence was employed: 1. The Sulu Seam extraction 2. The Acilik Seam extraction (as two slices) 3. The Piric Seam extraction. The displacement of the fixed reference points were subsequently measured using a high precision photogrammetric technique and induced horizontal and vertical strains were calculated.

Jan 1, 1988

For many crushed aggregate producers will the finest fraction minus 4 mm represent a problem. The fine material will fetch a much lower price than the coarser products, and may even be difficult to sell in some markets. The blasting operation will strongly influence the generation of fines after both blasting and crushing. Drill hole deviation together with the drill hole diameter, powder factor and velocity of detonation are the most important blasting parameters with regard to the generation of fines. Drill hole deviation is often ignored, and many operators will just reduce the drilling pattern in order to avoid hard bottom and an excessive number of boulders. The paper presents a technical and economic analysis of how drill hole deviation will lead to an increased generation of fines in crushed aggregate production. The analysis shows that the loss of sales revenues will be much higher than the extra costs for drilling and blasting caused by compensating for drill hole deviation by putting in more holes.

Jan 1, 1999

There is little doubt that the vision (Spectre) of Voisey's Bay has completely spooked the Northern Hemisphere view on nickel to the exclusion of considering any other future nickel project. Voisey's Bay orebody is of world-class and will influence world nickel and cobalt supply for a very long time - but - has the world yet started to consider the enormous cost of acquisition and development of this find or the nickel price it will need to attract to cover these costs and its operating costs and keep its bankers and shareholders happy. That price will be the critical factor in determining Voisey's effect on world nickel and will be critical in ranking other new projects aimed at making up the nickel short fall created by the on-going demand for austenitic stainless steel. In my view, there is little doubt that some if not most of these `other' new projects will be developed in the South West Pacific from lateritic Resources.

Jan 1, 1996