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By Gunther L. M, Rich N

Remapping of the Burdekin Basin has resulted in the subdivision of the three formations (megafacies) previously recognised in the Late Devonian Dotswood Group. Nine dominantly volcaniclastic facies are now identified within the three megafacies, representing coastal plain, floodplain lake, alluvial plain, ephemeral lake and alluvial fan depositional environments. The Dotswood Group was deposited during a major regressive phase that began at the end of the Givetian, continued throughout the Frasnian and ended in the early Famennian.The proposed depositional model completes a southeasterly progradation of coastal plain facies over shoreline and nearshore marine facies established in the underlying Fanning River Group. Uplift and associated acid-intermediate volcanism to the south of the Burdekin Basin, resulted in the deposition of a volcanogenic alluvial fan facies locally preserved along the southwestern margin of the basin. Tuffs and ?ignimbrite were deposited in widespread floodplain lakes which lay behind the coastal plain. An alluvial plain traversed by southward flowing rivers, formed the northern margin of the basin.

Jan 1, 1990

The accuracy with which block estimates are perceived is obtained by calculation of the kriging variance. This is dependent upon the model chosen for the semi-variogram of the deposit. For an extensive series of spherical semi-variograms the changes in the kriging variance resulting from various degrees of misassignment of the relative nugget effect are investigated. The results are reported as contour maps of percentage change in kriging variance as a function of the range and relative nugget effect of the true model.

Jan 1, 1985

By Bisshop J. P W

Maximum recovery of sulphide minerals by flotation is achieved over a limited size range. Valuable particles above and below this range have a smaller probability of being recovered. In the normal grinding-flotation operation, not all valuables are reduced to the optimum size range, and therefore sub- stantial losses occur. A significant improve- ment in the size distribution is not usually possible within the conventional circuit, and a more complex arrangement may be necessary to obtain optimum recovery of the valuable mineral. This problem is considered with refer- ence to the Mt. LyeZl concentrator. The performance of the existing circuit is dis- cussed, and it is shown that losses in recovery occur in both coarse and fine sizes. Laboratory tests indicate that regrinding the coarse particles results in an increase in recovery of up to 4%. Redistribution of plant grinding capacity to reduce initial grinding power by 6% and use this capacity to regrind coarse particles was considered. It is con- cluded that overall plant efficiency would be increased by 2% provided that overloading of the regrind mill could be avoided.

Jan 1, 1977

The liquid products of low-temperature carbonisation of coal are of variable composition, very much influenced by the rank and type of coal, and process parameters. In general the tar contains a high proportion of phenols and a low proportion of bases. The neutral oil is more analogous to a thermally cracked petroleum oil than to a high temperature tar. Present practice and possible future trends in the production of chemicals and liquid fuels from low temperature tar are reviewed in the light of recent work on the detailed composition of the tar The phenols and aromatics will probably continue to be of most value, with the bases a useful source of spec- ialty products. However the high aliphatic content of the neutral oil (particularly 1-olefins and n-paraffins) is bound to receive more attention for chemicals as well as for liquid Fuels.

Jan 1, 1969

The Regional Development Council has initiated a project that aims to find better ways for further investment by extractive industry companies in sustainable regional and community futures. It will be undertaken through collaborative actions that bring together the resources of private and public sector stakeholders in regional Western Australia.   The broad objectives of the project are to: describe and analyse the current situation with respect to the impediments to regional communities being more self sustaining, assess the effectiveness of the current and possible future levels of investment by extractive industry companies in the sustainable development of communities in regional Western Australia, identify and demonstrate collaborative ways in which extractive industry companies in Australia and other countries can play an enhanced role in sustainable regional and community sustainability through strategic engagement and investment; and confirm the effectiveness of the collaborative measures in delivering sustainable outcomes for regional communities by way of attracting and retaining populations and enterprises in Australia and similar environments.

Jun 1, 2010

The combustion characteristics of Australian coals which contain high inertinite have been studied in a laboratory drop tube furnace and a Thermogravimetric Analyser. The pyrolysis chars and combustion residues were microscopically characterised using a modified coal petrography technique. Results indicated that the overall burnout of inertinite-rich Australian coals under pulverised fuel combustion conditions could be generally within a range of 97 - 99 per cent burnout. The studies showed that poor coal burnout cannot be generally related to high inertinite content in the Australian coals. The extent of coal burnout varies from coal to coal and vitrinite as well as inertinite may contribute to the unbumt chars in combustion residues. Combustion conditions had greater influence over char formation and coal burnout than the coal properties. However, under similar pf combustion conditions, coal rank and coal maceral composition had a strong influence over the coal combustion behaviours and final coal burnout. Simple correlations using coal properties may be used but with caution to determine coal volatile release and burnout at high temperature and rapid heating conditions.

Jan 1, 1991

Pyrite is a significant gangue sulphide mineral in the Ok Tedi copper ore. Its presence in the flotation concentrate is not entirely desirable since it lowers the grade of the final copper concentrate. Lime depression of the pyrite has been practiced with some success. However, it has been observed that at the pH for pyrite depression a significant amount of the pyrite particles still float. To obtain further insight into the problem this work has been conducted to determine the composition, natural floatability and xanthate flotation behaviour of the various types of pyrite in the ore. The flotation results show that while some types of pyrite float well at high pH values, others are readily depressed. The implications of these results for Ok Tedi flotation plant have been Considered.

Jan 1, 1997

Selective open pit mining for gold has been in progress at Harbour Lights since the onset of mining in March 1985. Selective mining techniques used are similar to those in other recently opened gold mines in Western Australia. However certain practices have been introduced to accommodate the irregular distribution of mineralisation and comparatively high mill tonnage throughput. These include selective mining with large bucket excavators, sequential waste stripping - ore mining normal to the strike of the orebody and sample line preparation and ripping on bench floors. Application of these selective mining practices at Harbour Lights enables the operation to maintain delivery of approximately forty by 50-tonne truck loads of ore to the mill crusher everyday, with limited rehandling of material through ore stockpiles.

Jan 1, 1986

By Andrew R. L

The Kintyre uranium deposit was discovered in 1985 in the course of following up radio- metric anomalies generated in an earlier air- borne survey. The latter survey was conducted primarily to acquire aeromagnetic data for diamond exploration and the uranium discovery was made during a subsequent campaign of base- metal exploration. CRAE commitment to the Rudall area for a range of commodities over a period of 13 years made a significant contrib- ution to the discovery of Kintyre. Other con- tributing factors included CRAE's multicommod- ity approach to exploration, management support and continuity in the geological team. The Kintyre uranium deposit (Fig. 1) is located on the northern margin of the Rudall Metamorphic Complex, 60 kilometres south of Telfer and 260 kilometres north northeast of Newman, in the Paterson Province of northern Western Australia. It is 700 metres inside the northern boundary of the Rudall River National Park (15695 sq. km) and lies between the Great Sandy Desert and the Little Sandy Desert (Beard, 1969). Intense weathering since the Permian has produced a subdued landscape around the deposit. Resistant rock types still retain an older plateau surface but it is incised by more recent streams. Other Proterozoic and Permian rocks form low, sometimes rocky, areas largely covered by aeolian sand.

Jan 1, 1988

Because of the mineralogical complexity of nickeliferous laterites, most commercial and laboratory extractive processes require the ore to be blended to a feed of "constant" chemical composition. Even using the "constant" feed there are significant variations in processing behaviour within and between different feed lots. Chemical and mineralogical analyses of lumps of ore taken from the Yabulu stockpile of Queensland Nickel have highlighted the complex- ity of the ore making up the blended feed material. Each sample has been subjected to acid leaching and reduction/ammonia leaching tests and the results correlated with the mineralogical location of the nickel. The consequences of the variability in ease of leaching of the nickel are indicated.

Jan 1, 1978

Investigation on Sheelite Floatability by Particle Size Fraction

Sep 13, 2010

Material hardness and environmental factors can limit or restrict conventional blasting techniques and this has led to advancements in the performance and efficiency of ripping. Not all materials can be ripped, however today's technology and experience can help make a reasonable prediction. A ripping versus blasting decision will depend on the total volume of material to be moved, the production capabilities and costs of the ripping tractor(s) and on the size and relative efficiency of drilling and Blasting.

Jan 1, 1995

Kumba Iron OreÆs Sishen Mine is one of the worldÆs largest iron ore mining operations situated in the Northern Cape, South Africa. It produces 29 million tonnes of iron ore products per annum using a dense medium separation (DMS) beneficiation process. Kumba is currently commissioning the Sishen Expansion Project (SEP) which will produce a further 13 Mtpa product through a jigging beneficiation process. The products from the Sishen Mine are highly sought after and consumed by domestic and various European and Asian customers. During beneficiation iron ore slimes are generated and discarded as waste material to the slimes dams. A study was initiated in 2005 to investigate processes to beneficiate these slimes to saleable products û prompted by the current high demand for iron ore products and the high grade in the Sishen slimes thickener underflow of approximately 54 per cent Fe. Initial laboratory scale test work indicated that a 66.5 per cent Fe iron ore concentrate could be produced from the Sishen slimes thickener underflow through a process of classification, two stage wet high intensity magnetic separation (WHIMS) and five stage flotation. This process, however, did not produce the desired results during pilot plant testing and numerous alternative process routes were investigated. The process that did achieve the desired product grade of 66.5 per cent Fe at economically feasible product yields consisted of two stage WHIMS using SLON magnetic separators. Results achieved indicate that the thickener underflow slimes can be upgraded from 54 per cent Fe to 66.5 per cent Fe at a product yield of ca. 40 per cent. Product yield could be increased through the further beneficiation of the SLON tails. The Sishen slimes thickener underflow production rate is ca. 3 Mtpa û resulting in a potential concentrate production of ca. 1.2 Mtpa. The slimes concentrate will be fed to a pelletising plant that will produce 66 per cent Fe pellets destined for domestic and or export markets.

Jan 1, 2008

By Thimons E. D, Derick R. L

In early June, 1986, a fire of unknown origin erupted in one of several main entries of a coal mine located in southwestern Colorado. The fire was aggressively fought with high-expansion foam. As a result of several strategic decisions, the fire appeared to be held in-check. Unfortunately, sufficient quantities of foam were unavailable and as soon as the foam was depleted, control of the fire was lost. To prevent further damage and the possibility of an explosion, all entries to the mine were sealed.

Jan 1, 1988

By Gordon A. R

The effect of various types of solid carbonaceOlls reductants on the rate of fuming of zinc from lead blast furnace slag was investigated at I250°C.The results of the laboratory experiments indicated that the rate of removal of zinc from slag depended primarily on the volatile matter contents of the reduclants. The effects of fixed carbon, moisture and ash contents were less significant.

Jan 1, 1992

By Glastras M. V

The presence of arsenic in solutions which result from the processing of many sulphide minerals leads to a need to understand its speciation in aqueous systems and the reactions of those various species. This paper deals in particular with the precipitation of arsenic from aqueous solution in the form of insoluble inorganic compounds in order to remove arsenic from various hydrometallurgical process streams. The solubility and stability of the precipitates is examined. It has been found that many of the arsenic compounds presently used are more soluble than previously accepted and unstable in disposal sites such as tailings ponds.

Jan 1, 1987

By Lovett EP, Johnson CR, Dunlop GA

Seven streams of a low tonnage pilot plant operation on Cu/Pb/Zn ore from the Golden Grove Project were continuously assayed using an AMDEL In-Stream Analysis (ISA) system. The ISA instrumentation is briefly described as is the calibration procedure employed. The successful application of this instrumentation in the dynamic environment of a pilot plant operation is discussed. The operational sequence of the Golden Grove pilot plant is outlined along with the original project objectives and how they were achieved by the implementation of ISA. Results for the different complex flowsheets used are discussed, followed by the perceived benefits of installing such equipment in this operation.

Jan 1, 1986

By Roberts M. L

Long Shaft was initially developed using a rail haulage system on every working level comprising battery electric locomotives and granby trucks loaded by rail mounted rocker shovels. Production was commenced using conventional hand held cut and fill mining methods. In an effort to improve productivity and reduce operating costs a mechanised cut and fill stoping method evolved to suit the wider sections of the orebody. To further improve productivity and reduce costs the mechanised levels of the mine are progressively being redeveloped to enable the use of trackless diesel haulage equipment. An added benefit of trackless haulage equipment will be the ability to place development mullock into stopes as Fill.

Jan 1, 1988

High interest to basic-ultrabasic rocks is ex-plained by their specific, sutural, geotectonic po-sition and by deep level of generation of ultraba-sic magmas. These two factors allow us to treat this group of rocks as valuable source of informa-tion about the lower crust and upper mantle of the Earth. Basic-ultrabasic xenolith series is another source of information about the interior of the Earth. Detailed studies of the xenolith series give valuable material to geologists as to how endogenic deposits are fed and what is their source.Besides, the interest is explained by attempts to understand the relationship between basic-ultra-basic complexes and deposits of metalliferous and non-metalliferous mineral material.Absence of genetic boundaries in manifestation of metalliferous and non-metalliferous minerals, their temporal and spatial relationship allow us to treat the minerogenesis of ultrabasic complexes as a result of one ore-forming process manifested in Koryak-Kamchatsky, Sakhalin-Japanese, Ryukyu-Korean and Taiwan-Philippines island arc systems which re-present, in the opinion of the authors, one eastern Asian chain of the Pacific ore belt (Radkevich, 11)87).

Jan 1, 1990

By Arndt MB, Bamberg S

The evaluation of risk is becoming more important in the siting of mining operations in the United States as well as the rest of the world. The determination of environmental, economic, as well as health and safety risks is an important step in the planning of any mining operation. Hydrogeology plays an important role in pre-mine planning and in the determination of these risks. The mine operators must determine if ground water would inhibit mining in any way. Factors which are important to consider include mine dewatering economics, slope stability, and other adverse hydrologic impacts. This paper presents methodologies for the characterization of hydrogeological risks for a mining operation. First of all, the term risk analysis is defined and its utility is addressed. Then, stepwise methods for performing a typical risk analysis are presented. Finally, the application of risk analysis to hydrogeology in mining is given. With slight modification, it is believed that these methodologies can be used to evaluate the hydrogeological risks for any mining operation.

Jan 1, 1988