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By Needham RS

Hydrothermal mineral deposits are the dominant mineral deposit type in the Cullen Mineral Field, and have been important sources of tin, tungsten gold, silver-lead, zinc and copper. The deposits are mostly in north to northwest-trend- ing shear zones, and are confined to Early Proterozoic contact metamorphosed metasediments or synorogenic to postorogenic granitoids. The distribution of the vein-type deposits with- in the contact aureole defines a district-scale metal zonation of uranium closest to granitoid, through tungsten, copper, tin, silver-lead to gold with increasing distance from granitoid contacts. This zonation probably reflects de- creasing temperatures within the contact aureole during granitoid emplacement, and at the time of generation of a variety of metal-bearing fluids. A magmatic source for some of the metals is indicated by the positive spatial relationship between uranium, tungsten, copper and silver-lead deposits and granitoids abundant in those metals. There is little evidence for any such relation- ship for tin and gold deposits, except for an association of some tin deposits with tin-enriched mafic rocks. Most of the granitoids with anomalous metal values are late stage highly fractionated leuco- granitic phases forming younger plutons peripheral to the main body of the Cullen Batholith, They probably form cusps connected to the main body at shallow depths.

Jan 1, 1984

Flotation science and technology are related to three major sub- processes which are organized in a hierarchical structure as shown in Fig. 1. The basic sub-process is the chemical process which affects the attachment of air bubbles to mineral particles. In particular, the chem- ical process is related with the adsorption of surface active sub- stances at the gas-liquid, liquid- solid, and gas-liquid-solid inter- faces. This field has been most intensively explored in flotation research. The second domain in flotation research is concerned with the mineral particle to air bubble attachment sub- process in the system. This sub- process represents the dynamics of particle and bubble encounter where the contact angle and the induction time, determined by the surface chem- istry of the system, are among the most significant parameters. This sub-process can be referred to as the micro-process as against the third sub-process, or the macro-process, which corresponds to the integral behaviour of the system. Two other sub-processes are integrated into the macro-process in which they may not reveal themselves explicitly in the details. The third sub-process does not entail surface-chemical or physi- cal events any more, but it represents them all inclusively. To represent this sub-process we use mathematical equations, called models. Only in some simple or simplified cases can the models be solved exactly to find out the behaviour of the flotation system in which we are interested. Digital

Jan 1, 1984

In 1985 BMR assessed Australia's economic demonstrated resources of mineral sands as follows: rutile 8.0 Mt, ilmenite 41.4 Mt, zircon 11.5 Mt, and monazite 229 000 tonnes. These resources are located along the east coast of Australia, in the southwest corner of Western Australia, and in the Eneabba region, north of Perth, WA. However, over 40% of Australia's rutile and zircon resources, particularly those on the east coast, are presently not available for mining because of environmental considerations. As well, east coast ilmenite has been considered unsuitable for use by sulphate route pigment producers because of its relatively high chrome content. World demonstrated resources of rutile and zircon are estimated by BMR as 29 Mt and 38 Mt respectively. Demonstrated resources of ilmenite amount to about 1 billion tonnes. These occur predominantly in hard rock deposits in Norway, Canada, USSR and China, as well as alluvial deposits in Australia, South Africa and India. Quantitative data for world monazite resources is sparse. However, world production of rare earth oxides is now mainly from bastnaesite, a hard rock resource. Australia is presently the world's principal producer of rutile and zircon, and also provides a major share of the world's ilmenite. With the expected increase in Australia's rate of output of these commodities, combined with restrictions on mining along parts of the east coast, its position could diminish substantially over the next 25 years.

Jan 1, 1986

By Royle A. G

The paper describes a geostatistical structural analysis of an 80 square mile lease of the Athabasca tar sands. Each step of the analysis is presented with the ultimate objective of condensing the principal structural characteristics of the chosen regionalised variables into the opera- tional form of the variogram model. The variogram model is then used to form kriged local and global estimates, with the corresponding estimation errors.

Jan 1, 1977

By Tapp B. A

The minerals industry in Australia is currently regarded as the country's economic saviour; the bastion of economic security. As Fitzgerald (1974) stated, 'Australia's natural endowments in minerals are the envy of most countries of the world'. As a result the proposed new mineral developments are on a scale that hitherto in the sixties would have been completely unenvisaged. It is reported that Australia is poised on the verge'of a sixteen billion dollar mining-based investment boom: a boom that will see Australia dominate the energy export field, the mineral processing field, and create the 'coal dollar'. This growth scenario has many inherent dangers, and it is the authors' contention that these should be carefully considered before further development proceeds. Two of the major problems related to the mineral industry growth scenario are the predictability of the future metal market, and the energy cost of mining. The latter problem is the one discussed here. The mining-mineral processing industries in Australia currently use about 36% of Australia's primary energy

Jan 1, 1980

With constantly rising energy costs it is ever more important that we look at ways of im- proving comminution efficiency both in terms of power consumed as well as capital costs required for purchasing and installing equipment. I intend to show that commonly used appli- cation criteria, which is presently accepted for designing crushing and screening plants, need drastic revision if it is to be used to accura- tely design, predict and refine performance in new and existing facilities. Unless we can calculate performance accurately, we cannot minimise capital investment and maximize Profitability.

Jan 1, 1978

By M J. Sale

The Epithermal and Mesothermal Gold Prospectivity Modelling Projects recently completed by Crown Minerals provided explorers in New Zealand with a new compilation of historical exploration data combined with new geological information from the GNS QMap 1:250 000 scale mapping project. These data were used to produce predictive mineral potential maps for gold mineralisation in New Zealand. The aim of these projects, which was to stimulate mineral exploration and investment in exploration, has been successful with new companies acquiring new tenements and committing significant exploration expenditure to exploring in New Zealand in the coming years. The projects were undertaken at a national scale and consequently not all exploration data were compiled into the prospectivity models. HPD New Zealand Ltd recognised the value of the prospectivity modeling work and committed exploration funds to continue the modelling process started by the projects. They recognised the need to compile the remaining data and run the models again to allow detailed exploration targeting.

Jan 1, 2004

In discussing the Asia-Pacific region weare talking about a region which has more than 60% of the world's population, a regional economy which will in 10 years be larger than the European Economic Community, and a group of countries with some of the highest electricity generation growth rates in the world. It is economically the most dynamic region in the world.

Jan 1, 1990

By Muller GP, van Deventer JSJ

A mineralogical analysis has shown that in the Hartebeesfontein ore studied, uranium is associated mainly with uraninite, sulphides such as pyrite and to a lesser degree carbonaceous material such as thucolite. Little could be learned from the literature regarding the mechanism of flotation of these uranium-bearing minerals. A wide variety of reagents were used so that conditions enhancing the flotation of either the sulphides, carbonaceous material, oxides like uraninite, or combinations thereof, were created. As could be expected, the xanthate based floats gave-better selective recovery of sulphides than oleic acid. A substantial fraction of the uranium is associated with pyrite, so that addition of oleic acid to a xanthate float did not enhance the recovery or grade of uranium. After a pre-leach with sulphuric acid in which the pH and Eh were controlled so as to destroy the uraninite, higher uranium recoveries were obtained for the combined float (xanthate, DTP and oleic) and the DTP float. This was most evident when iron was added before flotation. Roasting, which destroyed the sulphides and thucolite, caused a significant decrease in uranium recoveries. The uranium liberated in this way was obviously not flotable in the same way as the uranium liberated from uraninite. A small amount of iron (2 kg/t) added before milling resulted in slightly higher grades and recoveries of sulphur for xanthate based floats. Higher iron additions had a detrimental effect on sulphur recoveries. Even in the case of oleic acid the addition of small amounts of iron had a positive effect on the recovery of sulphur and uranium.

Jan 1, 1993

By Brumley J

The development of the SECV brown coal open cut at Loy Yang will require depressurisation of aquifers both within and below the coal seam sequence in order to maintain open cut stability. Prediction of future open cut dewatering requirements at Loy Yang Open Cut and evaluation of the regional consequences of dewatering has required development of a detailed hydrogeological model of the Loy Yang area. The complex stratigraphy of the coal seam and aquifer/aquitard sequences at Loy Yang have been analysed and integrated with the hydrogeological concepts developed from regional groundwater studies to formulate a realistic hydrogeological model as a basis for finite-element flow modelling.

Jan 1, 1988

By Dendyuk TV

The possible use of combined (flotation/magnetic separation and magnetic separation/flotation) technologies involving the new flotation reagent systems for upgrading the iron ore concentrates, low grade manganese products and beneficiation of graphite-bearing dusts from integrated iron-and-steel works has been shown. It has been found that the absence of magnetic flocculation phenomenon worsens the reverse cationic flotation of oxidised iron ore concentrates and direct flotation of low-grade manganese products which require the use of modifiers possessing the flocculating properties. The synergetic mixtures of polymers have been proposed to be used as modifiers, ie polyacrylamide (PAA) with carboxymethyl cellulose (CMC) and polyacrylamide with industrial lignosulphonates (LST)

Jan 1, 1993

By Ariti J

The mineralogy and extractive metallurgy of platinum and palladium in ores and residues is examined and the relative reactivity of Pt, Pd, PtS and PdS in cyanide and chloride media at 20¦C is discussed. Electrochemical measurements establish that Pd is readily leached in chloride media but more slowly in cyanide media due to a passivating PdO film. The passivating oxide film on Pt prevents leaching in either system at ambient temperatures. The results of leaching Au, Pd and Pt from an iron oxide residue obtained from the Sherritt Gordon Process using CN/air and Cl-/H202 are compared. It appears that passivation is overcome either by roasting at ?600¦ or by leaching at >_100¦C.

Jan 1, 1991

By Dugan K. J

Mine operators are currently in a situation where market forces are acting to reduce profit margins and at the same time, regulatory bodies are insisting on improved mine safety and stability. This means that ground support must be made more cost efficient while maximising operator and equipment safety.A key aspect of ground support efficiency is the 'in the ground' performance. This paper discusses the factors that influence the way rock bolts and cable bolts perform. It highlights the need to know how support efficiency varies in different ground conditions.

Jan 1, 1992

By Higuchi K

In this paper, the history of Japanese coal and gas outbursts is presented and circumstances and countermeasures at the time cf outbursts are summarized statistically. Then the present meth- ods for prevention used practically in Japan are introduced. From statistics, it was reconfirmed that Japanese coal and gas outbursts have occur- ed frequently in the district of geological disturbance, symptoms immediately before out- burst occurrence were the phenomena in connec- tion with failure of a coal seam and outbursts have occurred many times when the number of boreholes had not been sufficient to degas. One of the principal protective method adopted in Japan is the large diameter gas drainage boring which also posesses a stress relief effects. There is a tendency to make diameter of borehole larger to increase both stress relief and degassing effects.

Jan 1, 1986

By M Darvall And R Fare, D Dormer

The Argo Archaean lode gold deposit is hosted within a structurally complex shear zone system, 70 km south of Kalgoorlie, and 3 km west of the crustal-scale Boulder û Lefroy Fault. Argo is an active underground mine currently producing at a rate of 120 koz pa with a Probable and Proven Reserve as at December 2005 of 2.19 Mt at 5.94 g/t Au (419 koz), a reduction on the December 2004 Probable and Proven Reserve of 4.58 Mt at 5.74 g/t Au (845 koz). This Reserve is hosted in six separate gold bearing lodes within the Argo shear system. Presently, a further six subeconomic shears are recognised. The 2005 Reserve figure represents a reduction of 426 koz compared to the 2004 Reserve as a result of a thorough review of the geological interpretation/resource model, and engineering factors applied to the Resource/Reserve, and depletion due to mining. Year on year Resource/Reserve figures at Argo had gradually increased as additional information on the system became available and mining methods were increasingly resolved with early production. The portal for Argo underground mine was cut in June 2002 within the highly profitable Argo open pit. The proposed æAvocaÆ bottom-up mining method required extensive lead time between development and the commencement of stoping in April 2004. During development considerable additional complexity in the Resource was encountered. Additional structures were identified, and complex splay interactions affecting the geology impacted on development. Intensive concurrent exploration in the footwall to the main lode during this period was the main cause of the increase in the Resource/Reserve figures during early development. As development progressed, lower grade continuity was observed than was previously interpreted. At the same time, drilling of deeper portions of the deposit and subsequent reinterpretation of the geological model significantly reduced strike lengths of economic mineralisation. Radical changes to the mining methods were required to improve productivities and to satisfy geotechnical considerations. The changes altered the engineering factors applied, which resulted in a reduction in the Reserve figures.

Jan 1, 2006

The Great lady gold deposit presented the challenge of providing a new grade control system for an usual type of orebody in the Eastern Goldfields. Mineralisation occurs as secondary enrichment about a quartz sand - granite saprolite contact 30m below surface. The ore horizon, which averaged 2.5m thickness, was near-horizontally disposed in contrast to the typical steeply dipping, shear hosted deposits of the region. A trial mining operation was undertaken on the richest, most continuous portion of the deposit to test the economic viability of this type of orebody. Controlling and minimising vertical ore dilution was considered crucial to the profitability of the operation.An understanding of the grade distribution combined with the practicalities of mining produced a grade control system which allowed for the mining of 1/2rn composited grades on level lm benches. Ore mining was combined with strict monitoring of levels, truck destinations and ore boundaries. Ore reconciliation results showed this system to be effective.

Jan 1, 1990

By May P. M

The role of chemical speciation in alkaline cyanide solutions is discussed by reference to recent experimental data from the authors' laboratories. It is shown that serious gaps exist in our present knowledge of the thermodynamics of cyanide complexes in solution. Nevertheless, using the available data and the JESS suite of computer programs it has been possible to develop a simplified chemical speciation model for alkaline cyanide solutions under conditions relevant to the gold extraction process. Some possible implications of the model for plant operations are Discussed.

Jan 1, 1991

DR. WARK, said: I have not come to Broken Hill to tell you how to conduct flotation operations; indeed, during my short stay here I have already learned much concerning the process, of the many difficulties which have been overcome, and of those still awaiting solution. My purpose to-night is rather different. All who have been concerned with the operation...

Jan 1, 1933

By D S. Nicholson, T Marshall

Reserves of high-grade quartz gravel, lignite and timber suitable for the production of silicon metal and ferrosilicon on large scale occur within 40 miles of Bluff Harbour. Undeveloped hydroelectric power resources on the Clutha River are located within 50 miles of the most promising quartz gravel deposits while opencastable lignite, potentially suitable for electric power production, occurs in the same locality as the quartz gravels. A preliminary study of production economics indicates that the commercial feasibility of silicon/ferro-silicon production would depend mainly on the cost of electric power, total capital cost of plant, and the market value of the products. The proximity of Bluff Harbour is advantageous for the export of products.

Jan 1, 1971

By F Ouchterlony

Soviet precursors to Cunningham’s Kuz-Ram model from 1983 are described. They are rooted in the mean fragment size and Rosin-Rammler (RR) fits to sieving data and rely on approximations. Three versions of the Kuz-Ram model are presented and all three are de facto based on the median fragment size x50, even if the term mean is used in the papers. This discrepancy caused Spathis in 2004 to suggest a correction procedure for the Kuz-Ram rock factor A, which was said to explain some of the missing fines in the model. This correction, while applicable to Cunningham’s 1983 paper, does not apply to his 1987 paper, in which he presents his own A factor.Common fixes of the Kuz-Ram model’s fines issue are fragmentation models where the fines are mainly generated in a crushed zone around a blasthole. This is contradicted by careful model blasting tests. The lack of a largest block size in the RR function may lead to spurious values of the uniformity coefficient n, eg in conjunction with image-based fragmentation measurements or crusher modelling. These issues may be solved by using the transformed RR function, which has a largest block size xmax or its replacement by the Swebrec function, such as in the KCO model.The mean to median issue is investigated in some detail and it is found that using x50 instead of the mean:has a sounder theoretical backgroundis less prone to errorsis not contradicted by the original Soviet data.It is finally suggested that future work on fragmentation prediction equations focus on the use of distribution independent quantities like percentiles, eg x50, x20 and x80. Some previous work in this direction is briefly analysed and one consequence is that the n-value of the Kuz-Ram model should depend on specific charge.CITATION:Ouchterlony, F, 2015. The median versus the mean fragment size and other issues with the Kuz-Ram model, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 109–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015