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By Lunarzewski L, Truong D

Although there are sound principles used in the world recognised methods of gas emission prediction, results based on these methods applied to several Australian longwall extractions have yielded unacceptably high discrepancies. With the development of mining in new seams and at higher rates of extraction, the need has grown for a methodical approach to predicting gas emission levels specifically for local Australian mining conditions. Such an approach is developed from results of recorded emission readings during longwall mining at Appin and Pacific Collieries over the past 6 years.

Jan 1, 1988

By Askew J. E

All facets of current practices of cable dowelling at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited are re- viewed. This includes materials specific- ations, installation practices and design pro- cedures. Cable dowelling for cut and fill stoping, square set timber stoping, longhole open stoping and level reinforcement is considered. Installation is simple and can be mechanised to eliminate heavy lifting. Quality control is essential for optimum performance of the re- inforcement. Design patterns must consider the mining method, reinforcement economics, acceptable stability standards and mine production priorities.

Jan 1, 1977

By Briggs D

Comparing the results of a plant trial by averaging performance measures collected during the trial with measures collected before and after the trial is often quite subjective because of the impact of natural variation on the process. This is

Jan 1, 1997

This paper sets out to discuss some of the more common forms of geological data abuse in project development. The paper illustrates various types of abuse and the reasons behind that misuse of data. This paper is only a brief introduction to a very large subject.

Jan 1, 1983

Geologists working in mountainous terrain were the first to map and interpret in three dimensions and as a result, made the first contributions to our understanding of mountain building and structural geology. However, geology during the 1900s has been dominantly a two-dimensional exercise in data gathering and interpretation. The standard output of geological surveys and university research has been the geological map and the standard methodology of the mineral explorer has been surface mapping and prospecting. The future will be concerned far more with the third dimension.

Jan 1, 1993

Rocks of all geological ages are present on the Australian continent. As a result of its geological heritage, Australia is richly endowed with mineral and energy resources. Due in part to its enormous mineral wealth, the nation is in the position of being a wealthy country surrounded by less developed countries of the Asian and Pacific region. Over many years Australia has developed and gained valuable experience in the exploration, mining and processing of a wide range of mineral and energy resources. In an interdependent world community, it is obviously in Australia's interest to cooperate and provide assistance in geoscience education and training to developing countries of the region.

Jan 1, 1986

Selective continuous surface mining is a rapidly developing system of mining which will have a significant impact on many present and future open cut mines. In many aspects the technology is in its infancy, whilst in other facets concepts drawn from other sectors of engineering are well proven. Full development of the potential and benefits of this technology will only be achieved if the mining companies and manufacturing companies work together to produce machines which the end user really wants.

Jan 1, 1986

By Nyamekye GA, Subramanian S

Adsorption tests have been carried out to elucidate the interaction mechanism between dextrin and sulphide minerals. Sulphides such as galena and heazlewoodite exhibit high affinity adsorption over the pH range that coincides with the iep of lead and nickel hydroxides, and is suggestive of chemical interaction. The adsorption behaviour with respect to the sulphides of copper is of the low affinity type, and follows a different pattern. The adsorption studies on graphite, support the chemical interaction mechanism, with the metallic impurities serving as adsorption centres. In conformity with the proposed mechanism selective separation of galena from chalcopyrite and heazlewoodite from chalcocite has been Achieved.

Jan 1, 1993

I stand here as a financial advisor who has been particularly close to the whole concept of reporting, independence and all the issues that are brought together in Release 149. However, I was asked to introduce this session by dealing with matters of Prospectuses, Part B's, 3J3's, 12G's and other requirements to report. Now I find it very interesting that one of the keynote issues is whether or not one should have a panel from which one chooses the so-called expert, and this is to deal with the question of independence.

Jan 1, 1989

The prospect of utilization of phosphate ores which contain high P205 values associated with Al and Fe has produced a great deal of interest over many years. Processing options have generally been based on the utilization of by-products which were required to offset the processing costs.This paper presents a range of processing options which have been investigated at laboratory or technical scale on phosphate ores which predominantly consist of crandallite, CaA13(PO4)2(OH)5.3H20 and millisite, Ca(NaK)Al6(PO4)4(OH)9.3H20. Christmas Island (Indian Ocean) and Mt. Weld (Western Australia) phosphate ores are good examples of such feedstocks. It is expected that these processes may also be applicable to such phosphate ores from other locations.

Jan 1, 1990

A good blending system is one that ensures that a plant can cope with the amount of grade variation that it will encounter. Prediction of amounts of variation that will be encountered on time or tonnage scales that are important should be regarded as an essential part of the planning of mines and plants. In some cases, the natural amount of grade variation when ore is mined and handled in the cheapest way will be acceptable. In other cases, it is necessary to understand the effects that various ore-handling processes have on amounts of grade variation at various scales and to design a blending system with considerable care. Blending tends to matter more when plants are sensitive to many aspects of grade. It can be very difficult to find the best compromise between capital cost and the amount of grade variation. In these cases it is important that ore blending options be considered carefully as part of the planning of mines and plants. Failure to make plans that consider likely amounts of variation can be very expensive.

Mar 1, 2010

Analysis of the topography associated with large vertical strains measured in the upper crust in the Basin and Range and elsewhere in the US Cordillera shows that it varies systematically with upper crustal strain such that it decreases where tectonism has resulted in relative thinning. The magnitude of topographic deflection suggests that the amount of thickening or thinning of the upper crust cannot also be reflected in vertical motions of the Moho discontinuity, nor can the vertical strain be isostatically accommodated by inflow or outflow of asthenosphere, mantle lithosphere or mafic lower crust. Simple isostatic calculations show that the compensating medium had a density probably within 100-200 kg/m of average upper continental crust, thus indicating that the compensating medium lies within the crust and is probably in large part quartzose. This conclusion is in accord with laboratory experiments on the strengths of rocks, and with reflection seismograms in deformed regions which suggest that the Moho is generally flat beneath regions of extreme gradients in upper crustal vertical strain. The upper crust floats on a quartzose layer in the mid-crust which, under orogenic conditions, is apparently so weak that it behaves as a relatively inviscid fluid at geologic timescales (> 10,000 a) and subcontinental lengthscales (100-1000 km).

Jan 1, 1990

Studies of the morphology of seamounts within the Hawaiian, Line Islands, Gilbert and Phoenix Seamount groups indicate that the morphology and size distribution of seamounts vary significantly from one seamount group to another. The Line Islands group appears to be the most complicated of all the groups studied thus far. This group is complicated by reactivation of volcanism, which has superimposed volcanics on sedimentary rocks. These seamounts display abundant volcanic features on their summits. Seamounts within the Hawaiian seamount chain display a marked absence of volcanic features due to the . presence of thick carbonate caps. Reef platforms and sealevel benches are very common on these seamounts but are absent from seamounts in most other seamount chains in the central Pacific. Slope angles vary regionally between seamount groups. The minimum slopes are found on Necker Ridge in the central Pacific basin. The maximum slopes are found on ridge-crest seamounts. Roughness increases proportionally with mean slope angle.

Jan 1, 1987

While South Africa is well endowed with mineral resources, it is generally accepted that its future will be determined more by the development of its human resources than its mineral wealth. The country has throughout its modern history suffered from an over-supply of unskilled labour and a shortage of skilled and professional manpower. There has furthermore always been an over-reliance on Whites as an internal source of professional manpower, supplemented by immigration wherever possible. Better utilisation of other population groups in professional positions has been hampered by the general lack of education and training among such groups. Although many problems still remain, there are emerging trends which are likely to positively affect the training of professional manpower in the future. The direct and indirect influences that are likely to affect professional training at the macro level include 1. government policy and objectives in respect of manpower education and training, 2. the emergence of technikons as fully- fledged tertiary education institutions, 3. demographic trends in South Africa as they pertain to education, 4. political and statutory developments in the country, 5. industry involvement in tertiary education, and 6. professional registration.

Jan 1, 1986

By De Janti VP

The automation and centralized monitoring of longwall type underground mining is presently an important subject matter of research in France. The purposes are :to improve safety and working conditions to increase productivity.to improve efficiency in machine operation through continuous "health monitoring". to make winning possible in difficult seams.

Jan 1, 1985

A typical large surface mine in Scandinavia has hard rock, a cold cli- mate, poor ore, a complicated vein type orebody and high labour costs. In order to survive, these mines have to maximise their ore production, minimise waste extraction and get the most out of every man hour. This article describes two examples of how inclined blastholes drilled with hydraulic percussive drills can help to meet these requirements. Both of these Scandinavian mines, Kemira Ltd's Siilinjarvi mine in Finland and Sydvaranger A/S's Bjornevattn iron mine in Norway, use inclined blastholes of 200 mm in diameter. The Siilinjarvi quarry is using inclined holes in production drilling. The Bjornevattn iron mine is blasting the final pit walls with inclined holes. The benefits gained when using inclined instead of vertical blastholes are better selectivity, better bench drilling conditions, steeper final pit walls and increased safety.

Jan 1, 1989

**Add abstract here**

Jun 1, 2010

The granitoid rocks in Burma can be subdivided into three main belts viz. (1) Eastern Granitoid Belt, (2) W-Sn related, Central Granitoid Belt and (3) Porphyry Cu (Au)-related, Western Granitoid Belt. The W-Sn related, central belt Granitoids were interpreted to have generated during the continent-arc collision and the Porphyry Cu(Au)-related, western grantioid belt was emplaced in a magmatic-volcanic arc above an east-dipping subduction zone. INTRODUCTION Major tectonic domains of Burma Burma region can be subdivided into N-S trending (6) major tectonic domains from west to east (1) Arakan Coastal Strip as ensimatic Foredeep (2) Indo-Burman Ranges as Outer Arc or Fore Arc (3) Western Inner-Burman Tertiary Basin as Inter-Arc Basin (4) Central Volcanic Belt (Central Volcanic Line) as Inner Magmatic-volcanic Arc (5) Eastern Inner-Burman Tertiary Basin as Back-Arc Basin and (6) Shan-Tennasserim Massif as ensialic, Sino-Burman Ranges (Bender, 1983). The Sagaing (transform) Fault and Shan Boundary Fault form as a tectonically significant boundary between Eastern-Burman Basin (Back-Arc Basin) and continental,

Jan 1, 1987

By Koppe J. C, Dimitrakopoulos R, Costa J. F

Grade control and the delineation of ore/waste in open pit operations is traditionally based on the comparison of estimated grades with an economic cut-off. This paper deals with an alternative approach to grade control based on estimating gra

Jan 1, 1998

By Yoon R-H, Luttrell GH

A theoretical model has been developed to predict the probability of particle collection by air bubbles in a quiescent flotation pulp. The model considers the effects of both hydrodynamic and surface chemistry forces acting during the bubble-particle interaction. Hydrodynamic forces considered include the gravitational, buoyancy, streamline and film thinning resistance forces. The surface chemistry forces considered include the electrostatic, dispersion and hydrophobic forces. The hydrophobic force has been estimated from extended DLVO theory. The model is capable of predicting hydrodynamic and surface chemistry conditions under which bubble-particle adhesion is possible. Validity of the model has been verified experimentally.

Jan 1, 1993