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By Longworth C. R

This paper descrioes a case history of a coal mine which developed un'tahle roof conditions due to mass sliding of the overburden strata on a claystone band within the coal seam. The sliding is believed to have been initiated by stress relief associated with the removal of overburden alongside the entry portal of the underground workings. Once in motion, the roof block was kept moving by bulking due to roof collapse in the normal underground goafing operations. Control measures in the form of an earth and rockfill buttress against the entry portal and a sequential mining plan to create goaf areas alongside the entry portal have been initiated to attempt to limit movement. The operation has been continually monitored and a gradually decreasing pattern of movement is being re, orded.

Jan 1, 1981

By Firmin K

The Mt. Tom Price orebody of Hamersley Iron Pty. Limited consists of a folded hematite - shale sequence capped by a layer of goethite. Consequently, variations in iron content occur within the orebody, and as the overall grade is below that required to make specification products, selective mining must be carried out. A necessary preliminary to quality control'of products based on selective mining is the production of advance data, on the tonnages and grades of material to be expected in future mining areas. Bench plans showing zones of different grades and types of material anticipated are prepared from structural geological information. The grades of materials on a bench are essentially governed by the positions and attitudes of the shale bands. Quality control is exercised by blending different grades and types of material in primary crusher feed. Iron grade is the prime grade consideration although sometimes the level of phosphorus content must be considered. Pre-production grades Are determined from assay of samples taken from blasthole cuttings.

Jan 1, 1980

By Lockyer PC, Reed MR Bartlett PM

Difficult ground conditions have plagued the underground operations at Mount Windarra since mining started in 1974.The ore at Mount Windarra consists of seven vertically dipping, sub vertically plunging ore shoots. The ore zone in which the shoots lie is characterised by moderate to heavy cleavage and the presence of serpentanite. The ore is known to extend to 1100 metres below surface.Long hole open stoping under cover of backfill has been used as the primary mining method at the mine, but its poor performance brought the mine near to closure in 1984. The mine had been closed from 1979 to 1980.

Jan 1, 1985

With the evolution rate of technologies, earthmoving equipment users are establishing vision statements for their operation out to and in some cases beyond 2000. Autonomous systems are receiving a lot of 'press' - and rightly so, as they hold a potential for achieving quantum leaps in productivity and cost gains. Caterpillar feels that it is important that the infrastructure of on-board systems are understood and can be utilised more in the near term to `grow' a user up to the stage of autonomous operation.

Jan 1, 1997

CONTENTSSummaryIntroductionGeographical and Geological Outline of the RegionGrowth of the Mining IndustryTable 1: Production StatisticsGeneral GeologyRecent Alluvium and River GravelsSambeto SeriesMudstone and Basalt ContactVatukoula SeriesIntrusivesStructureGeologic HistoryLodesTable 2: Principal Lodes and Their OrebodiesMineral Assemblage and ParagenesisOre Shoots and Their ControlEmperor MineLoloma MineDolphin MineExplorationConclusionAcknowledgmentReferencesSUMMARYThe Tavua Goldfield was found in 1932 within a basin, both topographical and structural, near the sea on the north side of Viti Levu, Fiji, and has produced over £13,000,000 (Fijian) worth of gold and silver from the three mines...

Jan 1, 1953

By Ishijima Y, Goto T

Displacement Discontinuity Method (DDM), which was originally developed by Crouch,S.L., is a powerful tool to calculate mechanical disturbances due to tabular excavations. Three topics on DDM applications to strata control problems in Japanese deep coal mines are described. First, is numerical simulation of microseismicity induced by longwall mining in Horonai Coal Mine. Microseismicity in the mine had been monitored by a mine-wide seismic ar- ray. Location of microseismic events and in- tensity of seismicity were well simulated. In the simulation procedure based on DDM, first, zones where a failure condition is satisfied by the advance of mining are detected. Then, the seismic moments, which indicate the inten- sity of seismicity, at the failure zones are evaluated. Second, is prediction of the shaft damage due to mining in Sumitomo Akabira Colliery. In this mine, the limit angle of the shaft pillar was changed from 600 to 800 to increase the amount of minable coal volume without increas- ing mining depth. Displacement of the shaft axis has been measured to assess the damage due to mining around the shaft pillar. In the calculation based on DDM, a fault intersecting the shaft and the ground surface are con- sidered. Observed and predicted displacement of the shaft axis agreed well.

Jan 1, 1992

By Rogis J

The basic parameters causing outbursts are rock pressure, gas characteristics and the physico-mechanical properties of the coal. The three sets of factors are to some degree interdependent. At Collinsville, the gas characteristics coupled with the physico-mechanical properties of the coal appear to be the major factors contributing to outbursts. The relative importance of rock pressure is uncertain. The following geological parameters appear to be necessary before outbursts can occur. 1. A coal rank greater than 1.2% vitrinite reflectance. 2. Thrust faults with throws greater than 3.Om or strike- slip faults with coal gouge wider than 0.3m. 3. Seam gas emission values greater than 1.1 cm3 /g. Igneous intrusions are the likely source of the carbon dioxide seam gas. Outbursts have occurred at depths ranging from 215m to 265m. They occur at these relatively shallow depths due to: 1. the high rank of coal at the present topographic surface and the high coalification gradient; 2. the relatively high degree of tectonic deformation of the strata; 3. the seam gas characteristics; and 4. the extent of igneous intrusions.

Jan 1, 1980

By Peck RC

The ore body at Elura contains fine grained galena and sphalerite in a matrix which is mostly pyrite. A differential flotation circuit concentrates lead and silver in the first section and zinc in the second. The lead section, shown in figure 1, was sampled in detail previously and the metallurgical performance assessed on a size by size basis. That assessment took no account of liberation and given the fine grained nature of the ore body, this could lead to an incomplete picture of the flotation performance. Liberation measurements were made using the QEM*SEM system on four size fractions of samples taken from seven different streams in the lead section. Using the mineral flows obtained from the mass balance around the lead section an excellent liberation balance was obtained which enabled the effect of liberation on the flotation performance to be assessed. The measurements indicated that only 17 per cent of the galena and 28 per cent of the sphalerite in the flotation feed was liberated. On the other hand 31 per cent of the gangue iron sulphides were liberated. The final concentrate was largely composed of locked galena and locked iron sulphides with 85 per cent of the product being locked. There was a small but significant fraction of liberated pyrite.

Jan 1, 1991

The Mount Morgan massive sulphide body occurs in a volcanic sequence of Lower or Middle. Devonian age, which is subdivided in the mine into "Upper mine porphyries", "Banded mine sequence", and "Lower mine porphyries". This sequence is intruded by latite, Mount Morgan Tonalite (360 million years), and late Permian dykes. Distribution of macroscopic ore textures and minerals in the orebody are discussed and evidence is presented indicating the pre-Tonalite, Devonian age of the orebody.

Jan 1, 1974

Large Off Highway Trucks operated in this country are generally of Diesel Electric Drive, this system tends to employ the familiar Electric Wheel. A number of fleets now employ the Traction Motor System as an alternative. An investigation is made of the operation of two such fleets. A brief description is given defining the components and their basic functions in each system. Available life history is presented and system reliability, maintainability and operator reaction is examined. Trlmnnnr rpm rn~r In the past large Off Highway Trucks operated in this country, that is those greater than say 120 tons, have tended to be driven by a Diesel Electric traction system. Although manufacturers are now offering mechanical or mechanical/hydraulic drives in the larger machines comments will be restricted to examining the Diesel Electric System. Since commencing operations in the mid 1960 period Hamersley Iron has made use of the diesel electric drive system using the familiar Electric Wheel. A departure was made at Tom Price with the purchase of the Wabco 3200 Series Trucks. These 235 ton capacity units employed a dual rear axle system with externally mounted motors. In 1976 a

Jan 1, 1982

Interaction between rock and fluid plays a critical role in rock engineering ventures such as stimulation of oil and gas wells, geothermal energy recovery and nuclear waste isolation. Robust and reliable design of the related services and underground facilities is based on understanding of the mechanics and chemistry of the coupled hydromechanical- thermochemical processes. This paper explores the application of the theory of such processes in minerals engineering, with particular reference to rockburst mitigation, in situ solution mining and cavity completion of coal-bed methane production wells.

Jan 1, 1995

By Segnit R. E

Two suites of dusts (waste-heat boiler and electrostatic precipitator) collected in 1976 and 1980 from the Kalgoorlie nickel smelter were subjected to chemical and XRD analysis and were examined by SEM and optical microscopy. The spherical to sub-spherical particles contained oxide and glassy phases with small amounts of sulfide. XRD showed that the major phase was a mixed Ni-Fe oxide spinel with some hematite. These phases compared well with those predicted by thermodynamics. The particle size distributions showed that in the 1976 and 1980 suites 20 per cent by weight was respectively coarser than 60 and 115/lm (boiler dusts) and 40 and 30/lm (precipitator dusts). Maximum particle sizes estimated from sedimentation chamber theory were found to be in reasonable agreement with the maximum sizes found in the dusts.

Jan 1, 1984

Here, in what is partly a review and partly a personal viewpoint, I take stock of changes in emphasis and comprehension on the subject of basaltic volcanism in the decade that has passed since the completion of the landmark Basaltic Volcanism Study Project (1981). I concentrate attention on the relatively neglected physical-volcanology aspects (in 1988 it was still possible to publish a 340-page book on flood basalts with barely any mention of physical mechanisms).I adopt the useful unifying concept of "volcanic system" to embrace the invariably-present intrusions as well as the volcano; I consider controls exercised by magma-supply rate and modulator-mechanisms on the nature of the system;I emphasize that sheeted-intrusion complexes, consisting either of dikes or inclined sheets (depending on the ability of the system to expand laterally) occur in all eroded major systems and fuel geothermal systems; I show how constraints set by cooling of narrow intrusions cause such complexes to be wedge-like and produce considerable rotations; I consider the role of the level of neutral buoyancy in making magma chambers possible, causing lateral subsurface magma flow and localizing intrusions, while the LNB itself can be accentuated by intrusions; and I examine the possibility that underwater systems could have very different internal structures from systems on land.

Jan 1, 1990

Australia contains a variety of iron ores, differing in grade, chemistry, size distribution and genesis. While a proportion of this ore is used world-wide as blast furnace lump, much of the material mined is high grade fines, requiring agglomeration (usually sintering) before blast furnace reduction. Sintering studies initially concentrated on the production of ferrous material of high iron content, coarse size and sufficient cold strength. In recent years research involving pilot plant sintering, precise test procedures and mineralogical analyses has focussed on the additional sinter properties of hot strength and reducibility. Aspects of mineralogical studies applied to iron ore sintering are described.

Jan 1, 1989

By Reid A. F

Since early 1971 Western Titanium N.L. has been operating an ilmenite upgrading plant on a commercial basis at Capel, Western Australia. In their process ilmenite is pre- oxidized, then reduced in a rotary kiln to a mixture of metallic iron and titanium oxides. The iron is leached out by accelerated rusting in aerated water, leaving a product with titanium content, expressed as Ti02, of about 92%. Samples from different stages of the up- grading process, representing operations over the last two years, have been studied in detail by X-ray diffraction methods, and the sequences of phases and reactions occurring have been determined. Quantitative X-ray studies showed the ilmenite feed materials to consist of a mixture of ilmenite and pseudo- rutile. Pre-oxidation of the ilmenite at =1000¦C leads to the formation of rutile plus a Fe2TiO5-FeTi205-Mn2TiO5 solid solution. The final reduction product consisted of a mixture of metallic iron, reduced rutile and a FeTi05-MnTi205-Ti305 solid solution. The relative amounts of these reduction products were very sensitive to the initial concentra- tions of the minor constituents manganese and magnesium. The effects of variation of ilmenite feed rate, reducing atmosphere,- reduction temperature and controlled addition of magnesium were also studied.

Jan 1, 1973

Jan 1, 2004

By D P. Telionis, P P. Vlachos, R-H Yoon

Industrial processes involving multi-phase flows such as flotation require understanding of the relationships between bubbles, solid particles and the flow. Modern experimental tools are employed in this effort to measure with great accuracy the basic features of the motion of all three phases in turbulent flow. We employed a unique digital particle image velocimeter (DPIV) that can record with great accuracy and kHz temporal resolution, velocity vectors of all three phases, namely the fluid, the solid particles and the air bubbles. The interaction of these three phases was studied in homogeneous isotropic turbulence generated by cylindrical grids. Particles and bubbles were released into the turbulence and the motions of the three phases were monitored. The experimental results obtained in the present work were compared with the predictions of the models published in the literature.

Jan 1, 2005

By J Kok

"In some underground mines it has been observed that the primary focus during feasibility studies is to determine the best way to mine the defined orebody. Some studies have been conducted without sufficient consideration of the ventilation and cooling requirements or the risk from exposure to associated airborne pollutants caused by the mining operations.Following the hierarchy of control to manage risk, numerous problems of the ventilation systems in some underground mines could have been avoided if sufficient consideration was given to the ventilation requirements to manage heat, airborne pollutants and leakage during the feasibility study phase. If the constraints and hazards were well defined and understood at the time of the study, efforts could have been made to eliminate or substitute the hazards to decrease the risk. Some of these problems include but are not limited to: primary fan locations heat loads diesel exhaust ventilation design based on the production requirement fire/emergency response strategies.This paper highlights areas in the ventilation discipline that are sometimes overlooked during feasibility studies. It will also highlight the importance of the Ventilation Specialist during these studies. Experience and knowledge of best ventilation practices must be applied in feasibility studies.As a result of adequate consideration to all ventilation aspects in the feasibility study phase, risks will become lower in terms of health, safety, production loss and equipment downtime caused by heat.CITATION:Kok, J, 2014. Feasibility studies – what should be considered in terms of ventilation, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 197–204 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

Estimation of the semi-variogram is basic to the geostatistical processing of data. The most widely used arithmetic average estimator is here employed with various sampling patterns to calculate experimental semi-variograms in a deposit which is simulated to have a defined semi-variogram. Percentage differences between theoretical and experimental semi-variograms are reported.

Jan 1, 1984

Electron paramagnetic resonance provides a fast method to characterise quartz. Quartz from veins associated with the Cambrian massive sulphide deposits in the Mt Read Volcanics of western Tasmania and from Devonian reefs associated with gold mineralisa- tion at various localities in Tasmania exhibit specific EPR patterns, different from quartz from common veins. The intensity of the EPR spectra of the quartz can be used as a statistical guide to gold mineralisation at Beaconsfield.

Jan 1, 1987