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Methane is present in varying degrees in nearly all underground coal mining operations. At mixtures with air near 5-15% it is explosive and consequently since it is not usual for these levels of contamination to be reached in the general body of a mine ventilation system it is not unusual to experience it in specific places. On longwall faces the most used power loader is the shearer machine and because of its general shape, situation and operation it is likely that all the factors which are required to cause a frictional ignition can be present. This paper makes a general appreciation of the causes of these ignitions and methods which are and have been used to control these situations on and around these machines.

Jan 1, 1981

By Wyborn L, Giddings J. W, Plumb K. A

The McArthur, Balma (new name) and Habgood Groups are thick (up to 4.5 km) correlative sequences of shallow water evaporitic carbonates, mudstones and sandstones that are exposed largely within the Batten, and southern and northern Walker Fault Zones (Batten and Walker Troughs) of the McArthur Basin respectively. Recent re-mapping of the Walker Fault Zone has provided data for refined stratigraphic correlations between these groups. Two significant hiatuses are now recognised within the Balma Group (base of Vaughton Siltstone and base of Yarrawirrie Formation) and these may represent tectonically-generated sequence boundaries which may correlate with similar local hiatuses within the McArthur Group such as at the base of the Teena Dolomite and Lynott Formation respectively.

Jan 1, 1994

By P W Haines

The McArthur, Balma (new name) and Habgood Groups are thick (up to 4.5 km) correlative sequences of shallow water evaporitic carbonates, mudstones and sandstones that are exposed largely within the Batten, and southern and northern Walker Fault Zones (Batten and Walker Troughs) of the McArthur Basin respectively. Recent re-mapping of the Walker Fault Zone has provided data for refined stratigraphic correlations between these groups. Two significant hiatuses are now recognised within the Balma Group (base of Vaughton Siltstone and base of Yarrawirrie Formation) and these may represent tectonically-generated sequence boundaries which may correlate with similar local hiatuses within the McArthur Group such as at the base of the Teena Dolomite and Lynott Formation respectively.

Jan 1, 1994

By M Johnson, M Horrigan

The scope of this report is to examine the aforementioned hypothesis by performing a detailed analytical comparison of a P&H electric rope shovel to an O&K diesel powered hydraulic excavator. In order to complement the integrity of the concluding results, two different size categories will be analysed in order to demonstrate that the findings can be extrapolated and applied to all the machinesÆ size classes. These two size classes are categorised by their bucket sizes and they are in the range of 43 - 58 cubic metres and 23 - 26 cubic metres. It should be noted that electric powered hydraulic excavators will not be considered in this report. In order to compare the electric and hydraulic types, the machine variants that will be analysed are commercial cost-effectiveness and operational flexibility. Although operational flexibility can be an ambiguous characteristic, a clear and thorough definition describing its exact meaning has been included. In order to simplify this study, all the data collected for this comparison have been for overburden removal, eliminating the variation that occurs with the movements of the shovel when selectively mining in the ore deposit. Thus, it ensures that all the data that is compared stems from a common origin for all the shovels. In other words the information will be compared when digging in the same material, loading into the same sized haul trucks, and when possible, with the same operators. Theoretical data received form the respective manufacturers, and actual data obtained from Mount Whaleback, was used for this comparison. This leads to the final comparison, where the operational flexibility and the cost-effectiveness are evaluated, with respect to their individual importance, ultimately influencing the final recommendation.

Jan 1, 2002

By Mouritz M

Ventilation characteristics and the occurrence of nocturnal surface inversions have been investigated within the Mount Whaleback open cut iron ore mine at Newman in Western Australia. When winds are light and/or nocturnal surface inversions form within the pit, episodes of atmospheric stagnation can occur with resultant accumulation of dust, diesel exhaust fumes, and sulphur dioxide evolved from spontaneous combustion of pyritic shale. Nocturnal surface inversions were recorded outside the mine on more than two-thirds of nights. Inside the pit, inversions were much less frequent - occurring on roughly 20% of nights when they were observed outside - and much weaker - the maximum temperature difference being 5 C¦ over 210 m inside the pit compared with 15 C¦ over 150 m outside.

Jan 1, 1988

By Rath M. C, Das R. P

Studies were carried out on dissolution and oxidation of iron powder in ammonia-ammonium carbonate solution using oxygen over pressures. Cobalt and nickel losses during iron oxidation under different conditions were investigated. Regression equations were derived for percent cobalt loss and percent iron oxidation using ammonia, ammonium carbonate and oxygen partial pressure as the variables. The equations were tested for adequacy using Fisher's test. Cobalt losses increased with the increase of initial cobalt concentration and about 400 mg/l of cobalt was lost from a solution containing 500 mg/l cobalt. A maximum of about 80 mg/l nickel was lost from 1 g/l nickel containing solution, and this loss remained the same even when the nickel concentration was increased to 7.5 g/l.

Jan 1, 1992

By Fitzgerald DE, Taverner MG

The principles, fields of application and equipment design concepts of several new approaches to continuous vacuum treatments of molten metals and alloys are discussed. Partic- ular attention is paid to the results of pilot plant tests evaluating a launder-in-tube method of 1. continuous production of refined zinc from a zinc-bearing lead produced in the lead splash condenser of the Imperial Smelting Furnace (ISF), and 2. continuous refining of crude cadmium. The former trials were not sufficiently encouraging to justify consideration of the process for commercial development. The applic- ation to cadmium upgrading gave very promising results; metal of 99.99 per cent purity was produced continuously at pilot scale (120 lb per hour) from crude metal containing 5.0 per cent Pb.

Jan 1, 1972

Mount Isa Mines Ltd. annually extracts 5.6 million tonnes of copper ore from the 1100 Orebody. All production is by longhole open stoping, with an increasing emphasis on pillar recovery. Drilling and blasting prac- tices have been modified to allow more efficient pillar extraction, with the evolution of a "core and shell" approach. Blast design occurs at the stope design stage, while individual blast preparation is based on detailed ring plans. A programme of blasting research involving surface and under- ground vibration monitoring and fragmentation assessment has been car- ried out in conjunction with production personnel. Drilling and blasting practice in the orebody must continue to evolve with continued research, to suit changing conditions and take advantage of new technology.

Jan 1, 1988

Someone once said "Leadership is the ability to inflict pain and get away with it." The same can be said about successful management of equipment suppliers. Improved performance will not be achieved without some pain, but it should be evenly spread between both parties. In practically all mining situations there is a great deal of scope for improving performance and reducing maintenance costs on an extremely wide range of plant, but it requires co-operative effort. Most mine maintenance engineers attribute the main problems to the equipment suppliers, unsuitable designs, lack of spares, untrained servicemen, lack of standardisation, poor maintenance manuals, and so on. Conversely the suppliers' engineers are usually convinced that problems with their product are exclusively due to poor maintenance management, after all they never have the same problem elsewhere. Of course both are correct to some degree. My aim in this paper is to explore the opportunities for substituting collaboration for confrontation between the engineers of the mining and supplying companies. I will also propose that contrary to common belief, the mines rather than the suppliers, should be taking the management initiative needed to achieve a closer and more effective relationship, Many would argue that this initiative should remain solely with the supplier; after

Jan 1, 1980

Mine site rehabilitation is the repair of the disturbance caused by mining on the immediate mining area and also on the surrounding environment. The long-term objectives of rehabilitation can vary from simply returning an area to a safe and stable condition, to restoring the mined land to a state as close as possible to its pre-mining condition, capable of being self-supporting and having a beneficial final land use. This paper investigates the importance and benefits of environmental planning, in particular for rehabilitation, and how input into daily operations can allow mining to progress with limited impact on the surrounding environment. It will also identify some of the key mistakes currently made during mining which could be averted by implementing prior planning and incorporating environmental consideration into daily operations. A number of rehabilitation opportunities will also be detailed for the different stages of the life cycle of a coal mine.

Jan 1, 2007

By F R. A Jorgensen, G W. Jensen

A pilot scale experimental investigation of the condensation of zinc vapour from smelter off-gases was performed in conjunction with a mathematical modelling study of the system. The work investigated the feasibility of using the high heat and mass transfer rates associated with a fluidised bed to condense zinc directly from smelter off-gases containing zinc vapour. Of particular interest was whether zinc would revert to zinc oxide during the process of condensation, and whether a zinc fog would form and be carried out of the condenser. A 0.1 m diameter fluidised bed condenser was mounted on the top of a 200 kVA DC electric arc furnace in which mixtures of vapours and gases were generated at 1150 - 1300¦C. The gas/vapour mixtures investigated included Zn/N2, Zn/N2/CO/CO2 and Zn/N2/H2/H2O. Greater than 90 per cent of the zinc was deposited on the zircon sand bed of the condenser, and there was no sign of zinc oxide formation, suggesting that the rate of heat transfer was faster than the reaction rate for zinc oxide formation. There was also no evidence that fog was being formed in the condenser. Using the methods of Kunii and Levenspeil (1991), a mathematical model was developed to predict the behaviour of the fluidised bed condenser. The model enabled the distribution of gas/vapour temperature and bed temperature to be determined as a function of distance from the condenser inlet. Similarly the partial pressure of zinc vapour in the gas mixture, and hence the mass transfer rate of zinc to the particles, was determined. Experimental data allowed validation of the predicted bed and gas/vapour temperatures.

Jan 1, 2000

By A Geldenhuis, M Hagger, J Maree

Disposal of mine water is a worldwide problem occurring in the coal and gold as well in the metal ore mining areas. Since southern Africa is a (semi) arid region, mining effluents should be treated to qualities such that they can be used for agricultural purposes or that they can be discharged in river system. Studies have shown that partly treated acid mine water can be used for irrigation. A copper mine in Botswana plans to use 5 M/d of treated mine effluent for the irrigation of agricultural product. The results of this study showed that when applying the biological sulfate removal technology the produced sulfide precipitated the metals in the mine effluent, such as nickel, Zn and Mn, to metal sulfide (MeS).

Jan 1, 2003

MR. L. C. BALL, chief government geologist, Queensland, wrote: This paper is intended as a severely mechanical exposition of the means adopted to deal with tremendous inflows of water concurrently with development and exploitation; but incidentally it serves as a splendid exposition of close co-operation maintained between the geological and engineering branches of this large organization.I have been impressed by the completeness of the mine plans of 'Mount Isa Mines Ltd.; but only such a paper as this has brought fully to my understanding the difficulty and complexity of the solid geometry involved in the detection and plotting of the orebodies and their stratigraphic control, including faults and large-scale brecciations, and the managerial foresight that set going the initial investigations.The company's geological branch of course must be given full credit for the results attained, but it gives me pleasure that the Geological Survey of Queensland has been closely associated in much of the study.It is noted that complete drainage was affected, but it would be interesting to learn whether the brecciated zone will again become waterlogged and whether from above or from below, and whether there has been any change in the dissolved mineral content of the water as the work progressed.

Jan 1, 1939

By J Szymanski, S Planeta

In pursuit of optimising the cemented rockfill system fragmentation of the aggregate, while travelling through the surface-to-underground aggregate transport raise, was investigated and a æfines estimationÆ equation was determined. When used with the rockfill strength estimation equation, the fines estimation equation enables an accurate estimation of the compressive strength to be derived theoretically. Optimum fill raise orientation was examined and recommendations are given depending on the varying stope dimensions. If the maximum dimension of the stope is less than 30.5 m (100 ft), a single, centrally located fill raise will suffice. However, as the stope dimensions increase, the number and orientation of the fill raises becomes more complicated and each stope must be examined on an individual basis.

Jan 1, 1998

Titanium dioxide (TiG ) is produced 2 commercially by two methods generally referred to as the "sulfate" route and the "chloride" route. The SCM Corporation, in supplying 15% of the world's demand for TiO 2, uses both of these processes. Of the two processes the sulfate route is generally regarded as the older and more established technology. Worldwide the sulfate route accounts for some 70% of total Ti02 production. However, in the U.S.A. the chloride process accounts for 80% of production. The processes vary in chemistry and raw material requirements. In the "sulfate" process finely ground ilmenite or titanium slag is digested with sulfuric acid to produce a porous "cake" vrnich is extracted with water and recovered liquor. The solution is treated with scrap iron to reduce any ferric ions to the ferrous state which is then crystallised and removed as ferrous sulfate heptahydrate. The liquor is concentrated by evaporation and hydrolysed to form the insoluble hydroxide which is filtered and washed free of impurities. This is converted to the dioxide by calcination at 800 - 1000¦C and milled to break up any aggregates. The "chloride" process uses a higher quality feedstock of natural or synthetic rutile and/or high grade titania slag. The feedstock is mixed with ground high-purity coke and chlorinated at 950¦C in a fluidised bed. The resulting crude titanium tetrachloride is purified by distillation and chemical treatment. The purified titanium tetrachloride is burned with oxygen or oxygen enriched air to give titanium dioxide and chlorine, which is recovered and recycled to chlorination. Titanium dioxide pigment from both processing routes undergoes similar finishing techniques. It is subjected to further stages of wet and dry milling, then coated with layers of inorganic oxides in order to enhance its properties for specialist applications.

Jan 1, 1986

By C B. Valentin

It is acknowledged that the analysis of iron ores using X-ray fluorescence (XRF) for major and minor elements is best carried out on fusion discs. This method of sample preparation eliminates mineral and particle size effects which can lead to biased results when using pressed powder pellets. However, the fusion disc method is costly as it requires a high capital investment in platinumware, requires experienced operators and uses expensive fluxes. Also, the dilution effect complicates the analysis of trace elements. For many applications, such as exploration and mining control, the method of XRF analysis of iron ores by pressed powder pellet probably provides data of adequate quality. Kumba Iron Ore, an iron ore producer in South Africa, recognises this and carries out most analyses of iron ore by pressed powder pellet and uses the automated fusion method mainly for certification of in-house calibration standards and quality control (QC) samples that are used for validation of pressed powder pellet method purposes. Automated fusion is also used for analysing the composite export shipping samples. All the other exploration, production, despatching and plant operation samples are done by the pressed powder pellet method. Automation of sample preparation procedures should improve the quality of data for pressed powder pellets. To compare the precision of the three methods of sample preparation and XRF analysis, 20 aliquots of a QC standard were prepared and analysed by each procedure/preparation method. The results and statistical data on the most important elements, Fe, K2O and P, are as shown later in Table 2.Clearly the precision is best for the auto prepared fusion discs, as expected, and worst for the manually prepared pressed powder pellets. However, the data generated from the auto prepared pressed powder pellets compare remarkably well against those from the auto prepared fusion discs.

Jan 1, 2007

By Bowdler RJ, Lowson RT, Sarbutt JV

There have been few long-term studies of sulphide oxidation under controlled conditions. The object of this study was to investigate the oxidation and leaching characteristics of pyritic mine material under conditions that were commensurate with field conditions but which could be controlled and monitored on a long term basis. The test material - overburden from Woodlawn Mines Pty Ltd - was packed into a 300 cm high column and leached with water at an infiltration rate of 256 mm y-1 for 5 years. Chemical conditions within the column were continuously monitored by sensors embedded in the overburden and leachate from the base of the column was analysed weekly. The study examined the relationships between heavy metal release and gas, moisture, and chemical conditions in the column.

Jan 1, 1988

PAPERS : 1 COMPUTER AIDED DESIGN OF MINE WATER MANAGEMENT - Z KESSERU 2 THE HYDROGEOLOGICAL PROBLEMS OF GROUNDWATER PROTECTION IN MINING REGIONS - V A MIRONENKO 3 WATER MANAGEMENT OF THE MAE MOH PROJECT -òò SIRI CHITCHOB 4 WATER MANAGEMENT AND WATER TREATMENT AT GOLDPN CROSS - M P A WILLIAMS

Jan 1, 1988

By Hare G

The emphasis in Australia, until recently, has been on large scale mining methods with drive sizes in excess of 4.5 metres square and the acceptance of high dilution ratios, even when working in relatively narrow orebodies. The rising cost of extracting and treating the recovered ore and the lower prices available in the world markets has seen a growing trend to narrow mining methods.Traditionally narrow orebody mining has been carried out using hand held drilling methods and rail mounted boggers. Recent advances in mobile equipment now offers the operator of narrow method mines the opportunity to completely mechanise the mine from the drilling, through bogging to haulage, while maintaining minimal dilution in drive sizes to two metres wide or less.

Jan 1, 1993

By B Banerjee, N Kumar, S Parihar

Rampura Agucha Pb-Zn Mine (RAM) is located about 200 km to the south-west of Jaipur in the state of Rajasthan, India. Open pit mining operations commenced in 1988 and continued to 2018. RAM open pit footprint is the largest in India with length of 2000 m, width 1500 m and depth of 400 m. Development of an underground mine under the operating pit commenced in 2013, through trial mining longhole open stoping with cemented backfill was established as a preferred mining method. Nine years in operations underground mine has reached the production capacity of 4.5 MT, which represent more than 70 per cent of the ore volume mined by the pit. RAM is currently the world second largest underground Pb-Zn mine.

Nov 29, 2022