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By Fabjanczyk MW, Guy RJ, Tarrant GC

The design of the reinforcement systems required to stabilise mine roadways has developed through the application of field measurement techniques. These techniques have allowed the level of security of a given opening to be determined from an assessment of the loading within the reinforcement, the extent of roof deformation and experience. The design systems developed are now used extensively in a wide variety of geological environment. Recent interpretative techniques have been developed to improve the level of confidence when designing roadway reinforcement. The techniques are particularly applicable for roadways subject to either weak materials or extreme stress levels. A second area of application is where roadway advance rates and hence the timing of reinforcement placement are critical. The newly developed techniques include both analytical and computational models. The validated computational techniques allow a more rational approach to investigation of the effect of varying reinforcement type, timing of placement and density on the level of stability achieved.

Jan 1, 1992

By Mercer J. K

Shaft guide reaetions in No. 2 Ore Shaft, Mount Isa Mines Limited, have been reduced to a low order of magnitude by the use of self aligning slippers and spring loaded guide rollers. Before commissioning the new 4500 h.p. winder at No. 2 Ore Shaft in January, 1958, it was realised that the increase in hoisting speed from 1800 to 2650 ft/min. would cause high shaft guide reactions which would be increased further when the elongated 12 ton skips replaced the existing 7 ton skips.The Cambridge accelerometer was used to measure the shaft guide reactions and to confirm that progressive skip modifications were resulting in reduced reactions. The skip modifications were completed in 4 weeks.INTRODUCTIONIn 1956 an expansion programme was initiated to increase production from 5000 to 11000 tons per mining day. At No. 2 Ore Shaft the 1500 h.p. winder operated at 1800 ft./min. and hoisted a 7 ton capacity skip. The new 4500 h.p. winder operates at 2650 ft./min. and hoists a 12 ton capacity skip. No. 2 Ore shaft is equipped with two 5 ft. by 5 ft. hoisting compartments (Fig. 1) and any increase in skip capacity meant an abnormally long skip. This feature, coupled with the increase in hoisting speed, could have caused very high shaft guide reactions. Before commissioning the 4500 h.p. winder, a Cambridge accelerometer was borrowed from the University of Adelaide and was used to measure the shaft guide reactions. Rather than carry out an extensive shaft timbering programme, the skips were modified by fitting cushioned guide shoes and spring loaded guide rollers (Fig. 1). Testing commenced in February, 1958, and was completed in March, 1958.

Jan 1, 1961

When the new No. 3 Shaft is in full operation, the main hoisting duties will be in connection with the raising of: (a) ore from the various mining operations, and (b) mullock, or broken country rock, from development work in extending access to existing levels, opening up new levels, exploratory work, or sinking the shaft to greater depths.

Jan 1, 1957

By Jepsen L, Gifford M, Thomas G. S

Mine planning requires careful prediction of both the head grade and tonnage of mineralisation. As part of the planning process, operators of the Murrin Murrin nickel/cobalt orebodies (located in the Eastern Goldfields province of the Yilgarn

Jan 1, 1998

By G Showers, R Triglavcanin

The complexity of understanding the whole thickening process to achieve real performance improvements cannot be underestimated. The last significant change in feedwell design was more than 15 years ago with the introduction of self-dilution systems û firstly with OutotecÆs Autodil, followed by FLSmidthÆs E-Duc. Now, following many years of extensive in-house research, including close collaboration with AMIRA and the CSIRO, Outotec has launched the next generation Vane Feedwell. The Vane Feedwell has been globally patented and installed at various sites. This paper briefly outlines the feedwellÆs development using CFD modelling and its subsequent performance in a æreal lifeÆ site installation. Plant results of the first commercial Vane Feedwell, in a mineral sands application, are discussed. The Vane Feedwell was retrofitted so comparative data of pre- and post-installation is shown.

Jan 1, 2009

Authorisation No.66 (to Prospect) was allocated to R.W. Miller & Co. Pty. Ltd. on 1st November, 1976. Exploration has brought coal reserves to measured status in the Jerry's Plains sub-group which are about 550m. thick. The immediately lower Vane Sub-group, about 200m. thick, includes about 20 seams. The total measured and indicated reserves of the two sub-groups based on the criteria adopted by the company amount to 1362 million tonnes in situ. This very large resource is subject to very many mining constraints both physical and economic which limit the saleable reserves under present conditions to about 120 million tonnes. The results of the calculation of reserves after exploration is complete in a deep multiple seam situation is dependent upon the criteria used to include or exclude seams in the reserves. These criteria are state- ments of the miner's expectations of the market, mining and coal preparation technology, local and national politics and the law as it may be applied in the future.

Jan 1, 1979

By Brown DJ, Croghan JA, Denby B

The paper describes the development and analysis of an instability database to establish a new method of slope stability assessment for U.K. surface coal mines. The concept is based upon a Stability Index, which relates to the probability of failure of a slope. This forms the basis for a geotechnical planning software package to be incorporated into a computer aided mine design system , which is currently under development.

Jan 1, 1986

Petroleum exploration is proceed ing in Western Australia at an ever- increasing pace. Results in recent years have been very successful, with the discovery and development of the Barrow Island oilfield and the Dongara gasfield, and the discovery of several major gas-condensate fields on the Northwest Shelf. The Northwest Shelf discoveries will have a big impact on the economy of the State by providing an abundant indigenous source of energy. Prospects for further large dis- coveries are believed to be excellent. The most prospective areas are thought to be on the continental shelf in the Carnarvon, Browse, Perth, Canning, and Bonaparte Gulf Basins.

Jan 1, 1973

Many stress measuring instruments use overcoring stress-relief principles but adopt different sensing techniques. Every technique is subject to certain limitations of rock types and conditions. To investigate the performance and reliability of the instruments in field measurement, a simple and practical approach has been developed to allow comparable laboratory results to be obtained which simulate in-situ rock and stress conditions. Four commonly used devices, the USBM deformation gauge, the CSIRO HI cell,the CSIR triaxial cell and the UNSW SI cell were thoroughly tested in the laboratory. Some conclusions have been drawn as to their suitability and reliability in different field conditions. Recommendations are provided for the choice of an appropriate technique for a given rock type and condition. A new thin-wall cell that overcomes the disadvantages of earlier devices has been developed and tested. Its laboratory performance shows that it has good prospects.

Jan 1, 1990

Studies of the minor element content of sphalerite and pyrite have generally been concerned with individual deposits or localised groups of deposits. However, a small number of more regional investigations have been reported (e.g. Davidson, 1962; Groves and Loftus-Hills, 1968; Loftus-Hills and Solomon, 1967; Price, 1972; Bralia et al., 1979) which have used the minor element abundances to evaluate the petrogenesis and geological affinities of diverse ore types and to fingerprint metallogenic provinces (e.g. Ivanov, 1964). While generally held to be valid, some doubts have nevertheless been cast on the reliability of minor element abundances in petrogenetic deliberations (e.g. Mercer, This paper reports on the distribution of he. Cpl and Mn in sphalerite, and Co, Ni and Mn in pyrite, from sulphide mineral occurrences within the "eugeosynclinal" prism comprising the New England Region of north-eastern New South Wales and south- eastern Queensland (Fig. 1). The occurrences examined are representative of two well-defined styles of mineralisation (Stanton et al., 1974) within which clear patterns of ore-rock distribution give rise to specific metal associations (Herbert. 1977).

Jan 1, 1987

The interaction of man with the environment has a double character. From one side, mankind can not exist without co- nsuming the natural resources and, from the other side, we actively alter and exert influence upon nature. Analysis reveals that the ecological problem is, to a great extent, a geological one. The paper deals with the application of grouting techniques to construct impermeable barriers for the protection of ground water and soils from depletion and industrial wastes pollution. A number of case histories in the field of mine construction is given to illustrate the solution of geotechnical problems in concert with environ- mental protection measures.

Jan 1, 1988

Results from current NERDDC funded research into the geotechnology of highwall trench mining methods have clear implications for mine planners in the areas of blast design, trench shape, location of the surcharge spoil and remnant coal pillar design.Adoption of successful smooth wall blasting techniques not only removes safety hazards from the trench face, but limits development of bedding partings at the seam contacts that interrupt the smooth transition of stress across the coal seam.

Jan 1, 1992

By Lauricella P. F, Hendri D

In the Mesel sediment-hosted disseminated gold deposit, the spatial distribution of hydrothermal alteration is controlled by steeply dipping faults and shallowly dipping lithologies. Hydrothermal alteration of carbonate rock is characterised by decalcification, dolomitisation and silicification. Intense argillic alteration occurs in a laccolithic andesite intrusion adjacent to decalcified and silicified carbonate units. Sulphide minerals (pyrite, realgar, orpiment, stibnite and cinnabar) accompany hydrothermal alteration and precious metal mineralisation. The trace elements Ag, As, Sb and Hg are zoned spatially throughout the deposit. Mesel contains a mineable gold reserve of 7.8 million tonnes at 7.3 g/t Au. Gold mineralisation is preferentially localised in carbonate rocks adjacent to and beneath the andesite intrusion. The ore body consists of a central, near-vertical, high grade "feeder" system flanked by tabular, inward dipping, moderate grade "ouflow" zones. Mineralisation is controlled predominantly by two steeply dipping faults with high grade (>10 g/t) gold zones centred about structural intersections and fault splays. Gold is submicron size and locked in very fine grained (

Jan 1, 1995

By Kurihara M

In Japan, shield tunneling method is generally used to drive a tunnel in sand layers around the urban area. In this report, appli- cability of NATM (New Austrian Tunnelling Method), which uses rock bolts and shotcrete as support, to water-bearing sand layers is studied aiming at establishing more economical tunnel driving technique. After the geological exploration, the conditions (i.e. pitch of steel supports, water content, cohesion, and fine content of ground,)necessary to ensure the face stability were investigated by using centrifuge loading tests. Concerning measures to manage ground water, an air permiability test was carried out to investigate the effect of the compressed air to cut-off inflow, and pumping test to study the applicability of dewatering. Furthermore, two dimensional elastic FEM analysis consider- ing progress of the excavation face was perform- ed to analyze stresses in the support system and deformation of the ground, and to investi- gate safety of the support and the ground. From these prior investigations, possibility of the applicability of NATM to the present pro- ject was predicted. Finally, based on these results, a real scale field application test was put into practice to confirm the prediction, and to pursue construction efficiency and phenomena which could not have been predicted Beforehand.

Jan 1, 1987

By Durucan S

The southern Attiki peninsula is a very interesting area from an environmental point of view. The port and the city of Lavrio is situated at the east coast of the peninsula with about 10 000 inhabitants and there are also a few villages in the vicinity. The south-eastern part of the peninsula hosts the famous Lavrio mines which exploited the silver bearing orebodies of the area for more than 25 centuries. As a result, soils around the city of Lavrio are polluted with high heavy metal loads. The area is also of archaeological interest, as there are well preserved remnants of ancient mining and processing plants and archaeological sites. Soil samples collected from an area of approximately 120 km2 around Lavrio were analysed for their metal contents and the spatial distribution of the concentrations of ten selected elements were estimated from these data sets. The spatial data analysis and transformation capabilities of Geographic Information Systems, combined with extensive mining and geological data, helped the authors to identify the extent and causes of metal pollution around Lavrio.

Jan 1, 1995

By Robins R. G

The dissolution of metallic copper powder in aqueous solutions of cupric sulphate under the influence of ethylene gas was investigated. The dissolution reaction stoichiometry obtained was: Cue+(aq) + Cu(s) + 2C2H4(g) = 2(CuC2H4)+(aq) The rate of formation of the copper (I)-ethylene complex in the above reaction was studied in a laboratory autoclave and the effect pH, temperature, ethylene partial pressure and initial concentration on the dissolution rate was measured experimentally and expressed theoretically in terms of several simple conceptual kinetic models. The results led to the selection of optimum conditions for the reaction and the suggestion of an "ion-molecule reaction" mechanism to explain the very low activation energies for the reaction system. The area of application of this reaction lies in the direction of refining impure copper such as cement copper. Several experiments were performed in which an acidified solution of cupric sulphate under ethylene pressure was used to dissolve copper from the cement copper powder in the form of the copper (I)-ethylene complex, followed by the release of gas pressure to disproportionate the complex and precipitate a purer metallic copper.

Jan 1, 1987

The progress between 1983 and 1989 towards Management Guidelines for R16 was extremely slow and painful because protection of the mining heritage was a new function and administrative activity not referred to in any Queensland mining law. Also, until 2 December 1989 the Queensland political climate was anti-preservation. Therefore an understanding had to be achieved between John Hay, the Mines Department and the National Parks and Wildlife Service, to ensure preservation of the mining machinery in situ rather than being removed to a town site such as in Ravenswood.

Jan 1, 1990

Since 1958 there have been 16 major coal mine explosions in the U.S. claiming 323 lives. Whilst the exact cause of a number of these incidents has not been determined, the majority has involved gas ignitions in one way or another. In addition there have been fatal gas explosions in salt mines and vapor explosions in oil mines. Furthermore, many of the oil shale mines in the U.S. have proven to be gassy giving cause for concern. Compounding these problems is the fact that frictional ignition of methane in coal mines has dramatically increased over the past several years; over 100 such ignitions were reported in 1979. While, no fatalities have been attributed to frictional ignition in the U.S. since early 1978, a recent mine explosion in Nova Scotia which resulted in 11 fatalities was attributed to a frictional face ignition. Research being conducted at the Bureau of Mines is aimed at the prevention and suppression of gas explosions. Emphasis is placed on new coal cutter bits for reducing ignition frequency, machine-mounted water sprays for preventing frictional face ignitions and automatic devices for quenching incipient ignitions and fully developed gas explosions.

Jan 1, 1981

By Dance A

Highland Valley Copper recently implemented a system of measuring run-of-mine (ROM) ore properties and monitoring their effect on both mine and mill performance. These properties are principally ore hardness and size. For some years, Highland

Jan 1, 1998

Spatial continuity as described by a variogram is a reflection of the underlying mineralisation/geology. Modelling of the spatial continuity (variogram) must account for both the quantitative data (ie sample grades), on which the variogram calculations are based, and the qualitative information as provided by the geological interpretation. An understanding of the geology and the variogram interpretation tie together the sample values and allow us to go beyond the actual data (Journel, 1995). Variography makes geology transportable and allows the geological interpolations to be channelled downstream into mine planning, ultimately affecting the economic decisions surrounding a deposit. As such the process of variography and resource modelling is critical. Thus consistent expert decisions need to be made which force geologists to have a closer look at the available information and the geological interpretations. The aim of this paper is to provide an overview of the latest developments in visualising variography and to demonstrate their usefulness in decisions regarding the spatial continuity of mineralisation. New ideas concerning potential future developments in visualising and modelling spatial continuity through variography are introduced.

Jan 1, 1996