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By Laage L. W

line fires pose a serious threat to the safety of all underground personnel. Early knowledge of the location of a fire in a complex underground mine would greatly reduce the associated risks by enabling miners to choose the safest escape routes, rescue teams to concentrate searches where survivors would most likely be found, and fire fighters to select the most efficient route to the fire and the most effective fire fighting strategy. Once'the fire's location is known, other related aspects of the fire can also be inferred, such as intensity, fuel, and growth Rate.

Jan 1, 1988

In the new refinery, at the works of the Broken Hill Associated Smelters Proprietary Limited, situated at Port Pirie, South Australia, the refining routine is similar to that carried on in the old one in that bullion is progressively refined first for arsenic and antimony, then for copper and gold, then for silver, and finally for zinc. However, actual procedure differs in that each refining operation is now conducted continuously, whereas in the old refinery intermittent batch treatment was practised.The early experimental work was concerned solely with the development of the continuous desilverising process, which, in addition to continuous treatment, embraces the novel feature of conjugate solution formation with consequent production of a silver product relatively high in silver and low in lead.

Jan 1, 1932

By Higuchi K, Sekimoto Y

In this report,the results of the large diameter drilling tests in coal seams assisted with water jet are described. The stress relief in coal seams by this new method is as effective as by the conventional method and the penetration speed by this method is 1.5 times as fast as by the other method. 1 Introduction The average mining depth of Japanese coal mines has already attained about 700m from the surface. Almost all coal mines are suffered from occurrence of coal and gas outbursts. To prevent outbursts, some countermeasures are taken generally. In particular, large diameter stress relief borings have been carried out quite often at Akabira coal mine located in the northern part of the Ishikari coal field in Hokkaido,JAPAN. These borings have had successful results but the drilling work of such large diameter

Jan 1, 1987

By Baguley PJ, Napier-Munn TJ

This paper presents preliminary resu]ts from field studies which were conducted to establish, among other things. the influence of medium viscosity on the partitioning behaviour of dense medium cyclones and drums in mineral applications, using frrrosilicon- ba_sed media. The medium vicoosit.y- was measured on-line, and partitioning behaviour was determined using ore sampling and density t r acers . The results demonstrate that viscosity is an important. operating variable, influencing ,eparat.ing density and efficiency under certain conditions. The implication is that metallurgical performance can be optimised by manipulating viscosity, either by appropriate selection of medium' characteristics or by automatic alarming and/or "ontroi using signals from the on- 1. i ne viscometer.

Jan 1, 1987

Cataclysmic or flood-like release of gas-charged brines, hydrocarbons and slurries accompanied widespread mineralisation of Upper Devonian environments. These are well represented in the Canning and Burdekin Basins of Western Australia and Queensland respectively.The Burdekin Basin provides particularly instructive vein structural sequences. These fall into organic residue to carbonate paragenetic sequences which are known elsewhere to record progressive decarboxylation. Fibrous veins indicate overpressure in fractures with organic residues, acids and gas derivatives driven to overlying groundwater flows. This combination of large flow rates and potent organic mineralisers led to extensive arsenical rare-metal mineralisation which is similar to that concentrated in Upper Devonian extinction horizons of the Canning Basin. Organic-residue mineralisation appears concentrated by certain hvdrostructures and targeted upon particular species. These controls need to be understood to guide modern management stragegies for mineralised organic and nitrogenous wastes.

Jan 1, 1990

By Patridge A. C

Observations of coal stockpiles subject to unusual levels of instability showed that the particular coals exhibited 'gap grading', a relative lack of intermediate size particles. This led to a suggestion that fine coal particles within the pile might have been induced to migrate under the influence of water flow and to concentrate in relatively impervious layers, resulting in local water saturation and reduction of shear strength. To investigate this suggestion, a large test column has been constructed and washed coals with various levels of fines content have been subjected to a downward flow of water. Subsequent examination of the bed of coal within the column confirmed the percolation of fines and their concentration into horizontal layers, and showed the development of zones of saturation above those layers. Shear box tests showed differences in cohesion and internal friction angle between coals with different percentages of fines, supporting the hypothesis that fines percolation may lead to decreased stability.

Jan 1, 1995

Quite often the reserve assessor becomes enamored with the numbers gen- erated and forgets the basis for his assessment. The quality of the assess- ment can only be as good as the quality of the input data. The use of seismic data from the Gippsland Basin in assess- ing Esso/BHP's oil and gas reserves is an excellent example of this principle. By significantly improving the quality of seismic data, a much more reliable estimate of a field's reserve potential can be made. In addition, it provides the basis for further delineation drill- ing which, as recent experience in Gippsland has shown, often leads to increased reserves.

Jan 1, 1979

By Nott M. C

The oxidation of xanthate collectors to xanthate/dixanthogen results in a higher hydrophobicity of sulphide minerals surfaces due to the action of dixanthogen. This higher hydrophobicity can be proved on a fundamental level by examining the st

Jan 1, 1994

By Miles M. J, Sandy D. A

It has long been known that drilling and blasting operations have a direct influence over productivity and costs of subsequent operations. If mine management is to effectively optimise blasting operations, good information is required on the operating costs of each of the affected operations, together with knowledge of how they are influenced by blasting. In practice it is not possible to do enough repeats of a full scale production blasting experiment to make a statistically significant analysis of the results. By monitoring each blast and subsequent operations in as much detail as possible, enough data will be available to effectively measure the effect of blasting on costs. This gives management an insight into the blast performance and is the first step towards optimisation. An Integrated Blast-related Cost Reporting System has been developed at the Rossing Mine Open Pit, which calculates the total mining cost for each blast. In assessing the total mining cost for each blast, use was made of an.integrated planning and management information system to collect relevant production variables, current operating costs and survey data. An automatic image analysis system was employed to measure the fragmentation of the blasted material in the back of haul trucks. A shovel monitoring system is also under development for use in assessing the muckpile diggability and, in conjunction with an appraisal of shovel component reliability, to estimate the maintenance cost under various digging conditions.

Jan 1, 1990

The Coal Section of the Geological Survey of Queensland was formed in 1950 to plan and supervise systematic diamond drilling programmes to investigate the State's coal resources. For the first 15 years these programmes were con- fined to the established coalfields to prove reserves of coal suitable for steam raising for power generation. Adequate reserves were del- ineated during this period to provide coal for the operating lives of new power stations at Ipswich and Collinsville. Later exploration was aimed at a regional appraisal of coal mea- sure stratigraphy, particularly in the Bowen and Galilee Basins. This was followed, in some areas, by drilling to prove reserves to indic- ated status. Parameters were developed to allow a uniform approach to the estimation of reserves. Coal quality is evaluated in terms of potential utilization of coal. Reserves defined by exploration companies are assessed, and combined with reserves from Departmental drilling into a general table. Total reserves in situ amount to 9 962 million tonnes of coking coal and 7 333 million tonnes of non-coking coal. Approximately 20 per cent of coking and 40 per cent of non-coking coal were proved as a direct result of Geological Survey drilling programmes. Further explor- ation is planned for the Bowen and Galilee Bas- ins and may extend to the Surat Basin.

Jan 1, 1977

Amongst the Pacific Rim countries, Papua New Guinea (PNG) is the leader in new gold discoveries and developments leading to new production. PNG has shown a dramatic increase in gold production when taken from a base of about 600 000 ounces in 1984 to 1 160 000 ounces in 1986. 1987 is expected to produce about 1 500 000 ounces and new planned developments will give further large increases. PNG's leading position when compared with neighboring Pacific Rim countries is only partly due to its favorable geological setting along the "Rim of Fire" epithermal zone. More important have been well-thought-out mining development legislation and good administration as well as consistent taxation and royalty policies. A stable political environment and a track record of new mining developments over the last 15 years, both pre and post Independence in 1975, have also been important factors in encouraging the new developments. Early Portuguese explorers associated the New Guinea mainland with gold as early as 1525 but it was not un,11 1R77 that a small ill-fated gold rush gave the first recorded production at Laloki near Port Moresby. Modest but commercial discoveries were made in the outer islands and coastal mainland regions from 1888 to 1926. In 1922 William "Sharkeye" Park found gold at Edie Creek and this led to major discoveries at Wau and Bulolo which were the first large scale commercial gold Operations.

Jan 1, 1987

The reduction in man's contribution to the Greenhouse effect will only be achieved by a number of small steps. Some steps will absorb carbon dioxide (CO2) from the atmosphere in slightly greater quantities, others will reduce the amount of carbon dioxide generated. This paper deals with the reduction of carbon dioxide by improving the combustion efficiency of petroleum fuels. Until recently most reductions in fuel consumption and air pollution have been brought about through mechanical adjustments to combustion equipment. Since the development of tetraethyl lead, little has been done to chemically modify combustion reactions to improve fuel efficiency or reduce emissions. During the past five years Australian laboratory and field trials with ferrous picrate treatment have demonstrated significant and economic gains in the combustion efficiency of diesel fuels. These studies have revealed that even under ideal conditions in diesel engines, carbon monoxide (CO) momentarily saturates the combustion chamber. This state reduces combustion rates, peak pressure and power and increases the risk of pollution. Theoretical, laboratory and field data are presented which support the mechanism by which the ferrous catalyst accelerates the oxidation of CO to the terminal CO2 thus reducing fuel consumption and the undesirable combustion products accompanying the CO saturation of combustion environments. While this paper deals principally with diesel fuels commonly used in mining operations, the catalytic effect of the ferrous ion is also shown to significantly reduce fuel consumption by petrol engines thereby promising a means to reduce the much larger contributions to the Greenhouse gases by automobiles.

Jan 1, 1989

The key concepts relating to the calculation of recoverable reserves for selective mining in open pit gold operations are discussed. While the general concepts are relevant to a wide range of gold ore bodies, their application is specific to particular ore bodies.The important factors contributing to the recoverable reserves aregeology, mining method, dilution, ore loss, sampling methods and theultimate bench height used in production.The implications of current methods of computing recoverable reservesare reviewed and some alternative approaches to recoverable reservecomputation based on production experience are presented.

Jan 1, 1986

By Evans A, Jones O

Surface subsidence resulting from "total extraction" of coal in the Collie Basin first occured in 1987 when Western Collieries Ltd trialled the Wongawilli mining method. Because very little quantitative subsidence data existed for the weak, Permian sediments, a research program was set up prior to the extraction of the first panel. The objective of the study was to be able to predict subsidence characteristics and effects prior to mining future total extraction panels. Attempts at predicting subsidence began using existing subsidence models from other coal mining regions, however, as more site information became available, it became clear that it was necessary to develop a separate, she specific predictive model for the Collie Coal Basin. Analysis of extensive field monitoring data for both surface and subsurface subsidence has produced a series of empirical models which can predict the shape of surface subsidence troughs and corresponding tilts, and strains for rectangular panels and describe the sequences of ground movement from the mine roof through to the ground surface.

Jan 1, 1992

By R Farnf, M Pegden, S Hosein, T White

A number of theoretical papers have been published outlining the use of electronic detonators to limit peak particle vibrations levels, but few empirical studies have been undertaken and even fewer examples have been published of the use of such technology in the aggregates industry. This paper gives a summary of the research work carried out at two limestone quarries in the North of England, where a series of blasts were used to compare and contrast the use of electronic and non-electric detonators. The majority of blasts were carried out using the same burden, spacing and decked charge weight loadings. A methodology was established that could be used to reduce the peak particle velocities (PPVs) at two or more specific locations by using single-hole blast vibration signatures in conjunction with specific electronic detonator timing intervals. The initial study concluded that this was only possible if single-hole signature blasts were periodically recorded to establish the shape of the correct vibration envelopes as properties were approached. These wave envelopes could then be used as the basis for choosing the specific electronic detonator timing intervals to give the lowest PPV for the properties or locations concerned. This methodology was then used in the second study to access a large volume of aggregates adjacent to a working railway tunnel. The financial benefit for the company was to convert these additional tonnages of rock from being a resource to an exploitable reserve. The project involved careful blast design and the instrumentation of a number of boreholes to enable the results of blast monitoring exercises to be compared with predicted PPV results. The iterative process involved the vibration results being uploaded into æBlast LogÆ (an expert blasting database system developed by the Blasting and Environmental Research Group at the University of Leeds) and analysed to produce predictions ready for the next blast.

Jan 1, 2007

This paper presents results of the experiments carried out in Beth Energy No. 33 Mine for the purpose of alleviating problems associated with cutter roof. Cutter roof problems have delayed the advance of the entry development considerably and maintenance cost of these entries was very high due to the requirement of very extensive and heavy artificial supports. The study includes assessment of the problem, investigation of the geology and lithology of the mines, study of in-situ stresses and corrective measures to combat the problem. Two approaches were selected as the corrective measures: 1) implementing yield pillar concept in order to reduce the effects of in-situ horizontal stresses, 2) designing an effective roof reinforcement system and application procedure. Results of this study revealed that roof strata is weak and in-situ stresses are very high at the problem area which results in development of cutter roof. Implementation of yield pillar concept was found to be ineffective because cutter roof often developed at the entry face concurrent to the development. However, proper design and implementation of roof reinforcement system stabilized the roof and eliminated roof caving during both entry development and retreat of longwall face, despite existence of the cutter roof, at a much lower cost.

Jan 1, 1992

By Zhou A, Cadogan J. M

Direct reduction of iron ore (DR) is one of the promising technology emerging in the world's steel industry. Kinetics and Mossbauer studies of DR with hydrogen have been carried out at two temperatures of 600¦C and 800¦C in this investigation. The results show that different controlling steps govern the reduction rate at different temperatures. The mechanism was also found to vary during the reduction. The Mossbauer spectra of the samples reduced in various time intervals were studied to determine the phase changes during reduction.

Jan 1, 1997

Mine planning typically involves designing an operation to uncover coal with the minimum initial costs with reclamation planning and earthworks being done as an "add on" task. The landform is too steep to remain stable, has no drainage and frequently has areas of excessive acidity or alkalinity. Extensive earthworks are required to reduce grades to an acceptable level and create a drainage system. The flexibility available to the mining engineer to alter the post mining landscape clearly depends on the mining methods. Straight dragline stripping provides virtually no flexibility. However most mining operations over the term of current ten year plans have a substantial pre-strip component. It is this pre-strip material which has the potential to reduce the final reshaping earthworks. The reshaping operation itself is subject to some flexibility with various options being available to re-grade and provide drainage. The full utilisation of this flexibility to minimise earthworks cost should be the aim of reclamation design. ACIRL's current thrust in reclamation is aimed at the integration of mine planning and reclamation earthworks. This involves gathering all environment and agricultural criteria and designing the earth works necessary to produce an acceptable final landform. A key component of our work is the use of computer aided design (CADD) for the design of spoil piles, pre-strip dumps and spoil re-shaping. This approach has been applied to a number of mine sites with earthworks operations covering hundreds of hectares and hundreds of millions of cubic metres volume. We are continuing to provide that consultancy service and at the same time are involved in the development of more sophisticated software tools to apply to reclamation design.

Jan 1, 1991

In 1980 Pancontinental Mining Limited decided that while the Jabiluka uranium project was still a major focus of the company's efforts some diversification was necessary. At this time it was decided to include precious metals in Pancon's exploration and acquisition objectives. As a result the now Paddington Gold tenements were acquired, explored and developed. Today, it rates as the 6th largest gold mine in Australia and at an expanded throughput of 1.2 million tonnes per year of ore it will produce about 110,000 ozs of gold per year. Following extensive exploration activities by Pancon's Exploration Division the Operations Division continued with development drilling finally proving up a reserve of about 8.4 million tonnes at an average grade of 3.2 g/t. An in- house preliminary feasibility study was followed by a two phase feasibility study by Davy McKee. This resulted in a recommendation to the Pancon Board of Directors to develop Paddington with an annual throughput capacity of 875,000 tonnes. This paper describes the acquisition, exploration and development of the Paddington project. It goes on to

Jan 1, 1986

In the southern part of China, car-bonate rocks outcrop in large areas. Ka-rst develops owing to hot, humid climate and heavy rainfall. In deposits of coal, iron, bauxite, tungsten, tin and base metals exist karst formations within or near the mineralization zones. Three pro-blems should be solved in the mine cons-truction in karst region. The first is the drainage and safety control of karst groundwater. Different methods are used to cope with local hydrogeological con-ditions, e.g. drainage from surface by submersible pumps in wells penetrating groundwater seams; drainage from under-ground drifts which intercept groundwa-ter flow with clusters of holes drilled into karst aquifer or with vertical ho-les drilled from surface to the drift underground; cement grouting to block off channels or to seal a part of aqui-fer; groundwater pollution control; etc. With those measures many Chinese mines of tremendous waterflow were success-fully developed and valuable experiences were gained. The second problem is the stability of buildings deteriorated by surface subsidence due to drainage. The occurence and distribution of surface cavings by drainage were studied.

Jan 1, 1990