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In Australia, current production of rare earth element (REE) minerals, monazite and xenotime, occurs as by-product from titanium-enriched placers and beach sands. Undeveloped REE resources are associated with carbonatites, alkaline igneous rocks, pegmatites, phosphorites, cemented fluvial sandstones, and uranium mineralisations. The REE are held within a range of minerals including silicates, phosphates, a1uminophosphates, carbonates, and oxides. The development of these REE resources may require new processing and extraction methods. The distribution of REE in the currently mined ore minerals, monazite and bastnaesite, does not match that requested by the market. Exploration for new REE resources should be focused on ores with more marketable REE distributions, particularly with heavy REE, neodymium, samarium, europium and yttrium enrichments. Such ores occur within alkaline igneous rocks, in laterites overlying carbonatites and alkaline igneous rocks, and in placers derived from low-grade regional and contact metamorphic sediments. Lateritic REE deposits may be easily and economically mined by shovel in open pits and are unlikely to require extensive crushing and milling. In addition, lateritic REE clay deposits may be processed by simple hydrometallurgicaltreatment mehtods.

Jan 1, 1991

By OÆNeil G. R

The gold adsorption capacity of ash-char and ion exchange resin Zerolit F.F. (I.P.) was evaluated by obtaining Freundlich isotherms in the presence of selected variables. It was found that the presence of Na , 2+, Ca 2+ cations and SO4 , CN , S Z, 0 2- Zn anions prompted adsorption of gold onto the char and reduced gold adsorption capacity of the resin. Temperature, particle size of adsorbent and pH of solution were found to influence the gold adsorption capacity of char and the resin. The most efficient desorbent for gold adsorbed on the ash char was S2 ions. Optimum sulphide concentrations were found in the region of 1% Na2S. Investigation into the concentration of gold from actual carbon contaminated gold residue dumps in Kalgoorlie area onto ion ex- change resin showed limited success in one case and not so in another. Maximum gold adsorption by the resin appeared when cyanidation and sulphidization treatments were carried out simultaneously in the presence of the resin.

Jan 1, 1979

By T Mizuta, D Ishiyama

The Vienna Wood hydrothermal is hosted by mid-oceanic ridge type basalt in graben morphology and is located in the Central Manus Basin. The hydrothermal field is about 300 metres in diameter and consist of a sulphide mounds and tall huge death and active chimneys. From the three distinct ore types collected from the Vienna Wood site, the dominant ore minerals recognised are pyrite, wurtzite, sphalerite, chalcopyrite, Fe-oxide and gangue minerals of anhydrite, gypsum, barite and silica. The consistencies in the paragenetic sequence and in the spatial distribution of the sulfides across the three ore types suggest that similar hydrothermal process exist across active and death chimneys. Fluid inclusion studies reveal a homogenisation temperature of 190-260¦C and an average salinity of 5.1-5.4 wt per cent NaCl equiv. The pH of the hydrothermal fluid ranges from 4.2 to 6.1. Bulk chemical analyses indicate that the mineralisation in the Vienna Wood can be classified into the Zn-(Cu-Pb) type of mineralisation. The tenors of the ore and mineral assemblage resemble those of the Mid-oceanic ridge system and ancient ophiolite hosted massive sulphide deposits of Cyprus and Oman.

Jan 1, 2002

By E Villaescusa

This paper summarises research work carried out at the Western Australian School of Mines on mine backfill properties in the last few years. The fill properties presented relate to cemented aggregate fill and cemented tailings fill. Emphasis of these studies has been placed on the composition of backfill materials including aggregate particle size distribution, cement dosage and influence of cement admixtures. The unique features of the backfill research carried out at WASM during the last few years are the accomplishment of a study into the properties of large cemented rockfill samples by triaxial testing and the investigation of the properties of fill material made from highly saline ground water prevailing in the Goldfields region of Western Australia. Exploring different cost-effective binding agents for mine backfill was also carried out at WASM. Special effort has been put on the development of fill materials compatible with hydraulic and paste fills. During the process, specific methods and procedures for laboratory testing of backfill material have been formalised. The on-going backfill research on sample scaling is summarised and the future direction of WASMÆs backfill research focus is outlined.

Jan 1, 2000

By Collins D. N

The Olympic Dam Copper Smelter Acid Plant is a hybrid plant capable of producing sulphuric acid from either sulphur burning, metallurgical gases or a combination of both. Commissioning of the Acid Plant on sulphur burning commenced in early April 1988 and commissioning on combined sulphur burning and metallurgical gas commenced in August 1988. During commissioning on sulphur burning a number of acid spills occurred due to balancing of tower flows and control of acid dilution. A number of other significant problems were encountered including failure of boiler gaskets, failure of strong acid pumps seals, the fracture of the teflon dilution water injector and the subsequent failing of the acid circulation pump, tank steel failures and various instrumentation problems. The Commissioning of the Acid Plant on metallurgical gases commenced in August and with the exception of the production of oleum in the boiler economizer was relatively trouble free. Oxygen Plant commissioning commenced in May 1988 and was without significant incident. An outline of the basic equipment for the Acid Plant and Oxygen Plant is presented together with aspects associated with the commisisoning of both plants.

Jan 1, 1989

The Circum-Pacific area is one of the most important gigantic skarn-metallogenic belts in the world. In more than 20 coastwise countries of this region, there exist thousands skarn deposits of different types. According to the differences of major metallic elements, the skarn deposits may be classified into seven subtypes, i.e. Fe, Cu, Pb-Zn, W, Sn, Mo and Au skarn deposits. In this paper, the distribution. and geological characteristics of above-mentioned types of skarn deposits are described briefly. Skarn deposits may also be classified on the basis of the dominant calc(magnesian)-silicate mineral assemblages into four types: magnesian, calcic, manganoan, and alkaline skarn types. Magnesian skarns may be associated with Fe, Cu, Au,, Sn, B, Be mineralization, calcic skarns with Fe, Cu, W, Mo, An, Be, Pb, Zn, Sn minerailization, while the alkaline skarns occur in U(Th, Nb) deposits. The skarn deposits of both East and West Pacific rims have many general characters, but have some diferences in geotectonic settings, intensities of mineralization, distribution, and metallogenic epoches. In this paper, the minerogenetic series and the mineralizing specialities of related magmatic rocks of the skarn deposits are also discussed.

Jan 1, 1990

By Draper J. J, Lang S. C

Regional geological mapping and facies analysis of the Late Devonian to Early Carboniferous Keelbottom Group of the Burdekin Basin have resulted in a depositional model representing six siliciclastic-carbonate facies. The six facies represent alluvial fan, braidplain delta, siliciclastic shoreline, siliciclastic shallow marine, restricted siliciclastic/carbonate shelf, and carbonate shoal depositional environments. These facies are identified in the Star beds which are equated with and included in the Keelbottom Group in this paper. Facies are repeated throughout the Group, as a result of two transgressive-regressive cycles.The first transgression recognised in the Keelbottom Group began in the mid-Famennian, and followed deposition of the Late Devonian Dotswood Group. It was marked by the deposition of Siliciclastic Shoreline facies in the basal Myrtlevale Formation, which was succeeded by Siliciclastic Shallow Marine facies at the peak of the transgression. The return of Siliciclastic Shoreline facies in the upper part of the Myrtlevale Formation marked the onset of the first regression, which resulted in the progradation of Braidplain Delta facies from the northwest of the basin. During the peak of this regression, deposition in the western part of the basin was dominated by Alluvial Fan facies.

Jan 1, 1990

Incidental to the progress of a geological survey of the Kalgoorlie goldfield during 1927-28 a number of specimens of telluride minerals were obtained, chiefly with the help of Mr. F. G. Brinsden, general manager of the South Kalgurli mine, and Mr. Ernest Williams, general manager of the Boulder Perseverance mine. This collection was supplemented by a number of small specimens, including the rare copper telluride, which were collected and preseryed from the Kalgurli mine by Mr. A. E. Paton, and also by a few miscellaneous specimens from the collection o{ Mr. S. F. C. Cook, of the Palace Hotel, Kalgoorlie.An extensive knowledge of the rare tellurium-bearing minerals was compiled during the last century from occurrences in Transylvania and Colorado. The recognition of different species has been based on chemical analyses and crystallographic measurements. In a few species there has been an absence of crystalline form, and these, together with the discoveries in this century of rickardite and "weissite" muthmannite and empressite, have depended chiefly on the chemical analysis for identification. On the other hand, the crystalline form of nagyagite and stiitzite has been described in detail, while their precise chemical formulae were doubtfully defined.

Jan 1, 1931

At Hilton Mine, 18 kilometres north of Mount Isa, the silver-lead-zinc sulphide bodies have undergone strong deformation in the form of folding and later faulting and brecciation in the hangingwall region of the mine. Variation in grades and widths over compara- tively short distances causes problems regarding accurate sampling of orebody exposures in underground development, and in defining confidence limits for the extrapolation of ore intersections in ore reserve calculations. The paper gives a preliminary insight into the problem of obtaining representative samples for exposed orebodies and discusses the sampling techniques employed. Results gained from these sampling methods could not be verified due to lack of individual bulk samples for comparison but strong evidence for precision was provided. INTRODUCTION In a developing mine like Hilton, accurate grade information is of extreme importance. Original grade information for a potentially viable ore deposit is gained from surface drilling, and initial ore estimates are calculated from the resultant ore widths and grades. After underground development has proceeded, the opportunity arises for detailed examination of orebody exposures, and the resultant assay grades and widths from sampling of these exposures may, in the long term,

Jan 1, 1976

Recent exploratory work has greatly enlarged our knowledge of the geology of the sedimentary basins of Western Australia. The most pros-pective of these for oil explorati on are believed to be the Canning, Carnarvon, 'and Perth Basins.The search for oil. in, the Canning Basin has fora the most part been concentrated in" the western part, where four main structural units are now recognized - the Lennard Shelf, Fitzroy Trough, Jurgurra Terrace, and-South Cariizin.g Basin. Of these the Leonard Shelf may. be the'most prospective. The principal objective on the Shelf is the Devonian sequence, which in-cludes well'developed reef complexes. The Lower Carboniferous is regarded., as a further objective, as it contained small quantities of oil in theMeda No. I well.In the. Carnarvon Basin most explorati on has been conducted in the coastal belt of'Tertiary folding, especially in the Cape Range-Rough Range area. -The discovery of oil in the first test well. drilled.in the-basin - Rough Range no. 1 - raised great hopes, for the quick discovery of a ecmuercial field. However the other wells on Rough Range have been dry, and no discoveries have-been made in the-wells drilled on other anticlines.in the basin.

Jan 1, 1962

The geology and mineral deposits of the West Pilbara Goldfield are described and comparison is made with the Pilbara Goldfield,, In the West Pilbai'a Goldfield two adjacent environments are represented by a predominantly clastic succession and a predominantly volcanic succession. These two successions are lateral equivalents and lithologically they are similar to the classical successions at Warrdiwdbna and Mosquito Creek. How- ever, no evidence of a significant erosional break has been found. It is suggested that the Archaean rocks of: the Pilbara Block represent a single geosynclinal cycle, which culminated in orogenesis, within which-local disconformities have been developed in various places: and that the sub-Mosquito; Creek unconformity at Eastern Creek may be the most widespread of these disconformities, Widespread evidence of'preconsolidation movement, aid the intrusion of igneous rock into. unconsolidated sediment, suggest that tectonism and igneous activity began at a very early stage, This was localised along lines of fracture in an unidentified basement.,.Moveme.nt was primarily vertical and persisted into the older Proterozoic, The sediments were enriched in metal by vulcanicity, chemical sedimentation, and possibly detrit`1' contribution. Diagenesis and metamorphism caused the remobòliyation of the metallic constituents of igneous and sedimentary, rocks which were then localised-in loci of dislocation-formed both before and after consolidation.,.. . . , . .

Jan 1, 1964

By Borshoff J, Von Pechmann E

The uranium mineralization in the White's East area of The Embayment is hosted by Lower Proterozoic schists of the Masson Formation which have undergone polyphase de- formation and upper greenschist metamorphism. Significant mineralization is also present in apatite rocks. The ore zones occur near an unconformity with overlying Middle Proterozoic sandstone and breccia conglomerate. Kink breccias and fracture systems related to post Middle Proterozoic reverse faults are the con- trols for mineralizing fluid migration. Pitchblende is the main uranium mineral and it occurs as fine disseminated grains, fibrous webs, clusters composed of botryoidal aggregates and locally as veins. Two genera- tions of uranium mineralization are present. The first generation (pitchblende I) occurs as fine grained inclusions within chlorite II, and the second (pitchblende II) as hydraulic fracture networks and massive veins intimately associated with sericite-hematite-chlorite III. Two hydrothermal alteration phases have affected both Lower Proterozoic and Middle Proterozoic sequences. The most extensive alteration mineral is chlorite, of which a number of varieties has been identified. Mg-rich chlorites are generally associated with the first phase alteration assemblages and are commonly replaced by hematite, seri- cite and Mg-Fe chlorites in massive pitch- blende zones. Other alteration minerals in- clude tourmaline, apatite, talc, quartz, magnesite, graphite, pyrite and rutile.

Jan 1, 1984

By Perring CS, Hill RE, Barnes SJ, Vallance SA

The Maggie Hays nickel sulphide deposit is located at latitude 32¦ 15 'S, longitude 120¦ 30' E on the Lake Johnston (SI 51-1) 1:250 000 map sheet. The deposit occurs in the Lake Johnston greenstone belt, in the Southern Cross Province of the Archaean Yilgarn Block, 500 kilometres east of Perth, Western Australia (Figure 1). The remoteness of the Lake Johnston greenstone belt and its poor access, restricted previous exploration activities and the full appreciation of the geology and its Ni-sulphide potential. It was not until 1991, when Forrestania Gold NL commenced exploration activities, that the geology of the ultramafic units and their potential to host significant concentrations of Ni sulphides were clearly established. This paper, which describes the geology and the characteristics of the Maggie Hays deposit, is based on the results of exploration by Forrestania Gold NL and a collaborative research agreement between CSIRO Division of Exploration and Mining and Forrestania Gold as reported by Perring, Barnes and Hill (1994), Perring and Hill (1995), Perring (1995 a and b) and Barnes, Perring and Reilly (1995). A comprehensive description of the geology, petrology and geochemistry of the deposit is being prepared for publication by CSIRO (Pemng, Hill and Barnes, in press).

Jan 1, 1996

n One of the most interesting and economically important developments which has .`taken place- in the Kalgoorlie Field over the past twenty .years is the proved penetration of ore into - caicò schist. which:has been established on the North Kalgurli Mine. 'This is quite extensive, both. laterally and ' in -depth, and has occasioned-,'" ccasioned ' " some madification.of geological thought In the search for additional ore sources:. .Ore has been mined in calc schist almost since the' first major: gold::discoveries-were made,. and the principal 'features of the various types of depos:itl are well covered in the literature ' of the field. ' However, occurrences in caic schist have not-been characterised by the same degree of continuity or frequency as the innumerable lode formations in- the more -favourable quartz dolerite, ' and there has been a tendencyAo regard,them as isolated and discontinuous ore bearing structures, occurring only under very special-- conditions. It is not intended-:to describe the whole' range of caic schist ore occurrences in this paper, but only major controlling structures, whose penetration therein has been definitely established, and in which an appreciable .amount.of,_ore.has, been and is still being. found.. . It is considered that -similar stiiictiires: may present a' major objective for future exploratory work in other parts of the field'.

Jan 1, 1964

By A Maurer, N Pereira

Low-density explosives have been developed with trials being conducted for over 20 years and yet have still only gained limited market acceptance despite producing some very promising results. The biggest concern with industry acceptance has been disbelief that a product with lower density than the ANFO benchmark could fragment anything but the weakest of strata. Trials have been carried out with products such as diluted ANFO, low-density ammonium nitrate (AN) and various other mixes, although it has been only recently that low-density explosives have been accepted as a serious alternative to traditional products such as ANFO and heavy ANFO. The recent uptake of low-density products has been the result of several key factors: the current resources boom forcing AN supply issues, the development of new handling techniques, and a far better understanding of the utilisation of such products. This paper highlights the benefits of low-density products available in the market and focuses on the situations where low-density explosives can provide the end user with benefits that would otherwise be achieved through more time consuming methods. Through correct implementation, low-density explosives can provide the blast designer with another option when looking at the optimum method of breaking the rock. This while still controlling the other limiting factors such as cost, environmental impacts (noise, vibration, dust and fumes), coal damage and safety (stable walls).

Jan 1, 2005

By D Craw

Otago Schist and Klondike Schist are two Paleozoic-Mesozoic metamorphic belts on the circum-Pacific margin in which there has been a long history of abundant alluvial gold mining, but only minor hard-rock gold mining.   Modern exploration for hard-rock gold is ongoing in both belts, and the active Macraes mine in Otago (>2 Moz production) highlights the hard-rock potential of the geological setting of these belts. Hard-rock gold mineralisation in both belts formed in the latter stages of schist exhumation, after rocks were subjected to major regional ductile folding and then uplifted through the brittle-ductile transition. The majority of known hard-rock gold-bearing systems in both belts consist of well-defined, but generally discontinuous, vein swarms. Most Otago veins are hosted in steeply dipping post-metamorphic normal faults and fractures. However, the Macraes mine is hosted by a late-metamorphic shear zone, and much ore is sulphide-impregnated auriferous schist. Goldbearing veins in the Klondike schist are hosted primarily in extensional sites associated with post-metamorphic compressional structures. Some disseminated sulphide mineralisation is associated with Klondike veins and this is important as it extends the exploration target for these veins. No foliation-parallel late metamorphic mineralisation has been identified in the Klondike but exposure is relatively poor compared with Otago and both schist belts are highly prospective for deposits of this type.

Jan 1, 2007

By Lewis PC, Carr GR, Dean JA, Glen RA

The Lachlan Fold Belt (LFB) is a complex orogenic belt which developed in Early to Mid Palaeozoic time. A number of orogenies and more localised deformational events affected the region. A simplified classification scheme for the diverse gold deposit types is proposed, subdividing primary mineralizing processes into four categories: volcanism (epithermal and volcanogenic deposits), igneous intrusion (subvolcanic/porphyry style, skarn and magmatic deposits), metahydrothermal processes (deposits generated during metamorphism and regional deformation) and hydrothermal-distal processes (deposits generated by poorly understood, generally remote large scale hydrothermal processes). Major gold deposit associations include epithermal and porphyry style deposits in Ordovician-Early Silurian shoshonitic andesite sequences; volcanogenic base metal-gold deposits in Silurian rift or basin felsic sequences; vein deposits in Late Silurian and Early Devonian S and I-type granitoids; deposits in Early Devonian sedimentary rocks of the Cobar Basin probably generated by metahydrothermal processes during basin closure and cleavage formation; deposits associated with serpentinite; and metahydrothermal quartz vein deposits in folded sedimentary rocks.Studies of host rock geochemistry suggest a relationship between magma types, gold enrichment and mineralization particularly in shoshonitic sequences and Early Devonian granitoids of the Boggy Plain Supersuite. Structural studies indicate the importance of thrust type structures and detachment faults in generation and location of gold mineralization. Lead isotope initial ratios help define metallogenic associations and a number of distinctive isotope "signatures" have been established.

Jan 1, 1990

The gold industry has been revolutionized in the last decade by market forces and technological changes. The latter are discussed in this paper, with particular emphasis on carbon-in-pulp (CIP) and heap leaching. The nature and scope of the process development aspects of a gold project are considered, and factors which determine process decisions are outlined, including the choice of CIP versus carbon-in-leach (CIL), agitated leaching versus heap leaching and treatment of ores containing copper and silver. Likely directions for development of gold processing in general are discussed, and metallurgical process options for treatment of ores of platinum group metals (PGM) are outlined.Metallurgical process development for gold and platinum group metals proceeds through a number of well defined stages, with input from various disciplines and information sources. The orientation phase will include preparation of a general project overview; careful consideration of the issue of sampling and sample preparation; characterisation of the resource in terms of ore types, mineralogy, chemical composition; development of appropriate methodology; and development of an understanding of the potential metallurgical unit operations.The process definition phase will be-'directed to development and definition of a notional process flowsheet, and will include identification and appraisal of process options; development of, notional process flowsheets; testing of flowsheets against ore types; ranking of flowsheets; initial engineering, including preliminary mass balances, equipment selection and plant layout; and broad-brush economic appraisal.

Jan 1, 1986

By Stanton RL

Stratiform lead-zinc mineralization in the Soldiers Cap Group and Kuridala Formation of the Mount Isa Inlier is closely associated with iron-rich sedimentary units or "iron formation", and has many similarities to the Broken Hill deposit in New South Wales. Both the Soldiers Cap Group and the Kuridala Formation have been intensively explored for deposits of this type since the early nineteen- seventies. A mineralized belt of at least eight significant prospects has been identified, of which the Pegmont deposit is the largest and best known example. In most cases the mineralized horizons contain banded galena and sphalerite within a gangue of predominantly quartz-garnet- pyroxene-amphibole rock, sometimes containing a variety of other metamorphic silicates, and apatite. Chemically, the mineralized horizons are distinguished by higher than usual levels of one or more of total Fe, MnO, CaO and P205. Interpretation of patterns of mineral- ization within the belt is based on the Pegmont deposit, where a model of base metal sulphide deposition within restricted basins of iron-rich chemical sediment has been developed (Stanton and Vaughan, 1979). Broadly, the model envisages the deposition of higher grade lead-rich mineralization in the basin centre position, lower grade zinc- rich mineralization in a basin intermediate position, and much weaker copper-rich mineralization in a basin edge position. These three positions reflect a laterally continuous arrangement of silicate microfacies within the original iron-rich sediment.

Jan 1, 1984

By Mayer TE

The Granites Goldfield is located 550 km northwest of Alice Springs. Mineralisation was discovered in 1900 and intermittently worked along nine km of strike until the early 1950's, yielding a recorded production of 470 kg of gold. The geological environ- ment, pre-existing exploration drilling results, and an optimistic view on gold, prompted acquisition of the property by North Flinders Mines Limited in 1975. An agreement was signed with the Central Land Council in August 1983 and drilling commenced in the same month. In the past, gold was won from alluvial deposits, rich quartz veins and lower grade, disseminated stratabound mineralisation. The last is contained within a distinctive unit in the Mt. Charles Beds, of the Early Proterozoic Tanami Complex. This informally named "Host Unit" is a metamorphosed, chemical- pelitic sediment. The schist contains variable proportions of amphibole, quartz, garnet, clinopyroxene, carbonate and sulphide, inter- calated with recrystallised chert beds. Free gold occurs in several mineralised horizons within the Host Unit, generally conformably distributed within lithologic bands or at lithologic contacts. The Host Unit occurs within a sequence of metamorphosed pelitic sediments and intermediate volcanics. Although mostly confined to the Host Unit, stratabound gold mineralisation also exists in both Footwall and Hanging Wall Schists, usually within zones displaying certain Host Unit characteristics. The deposits may be loosely categorised as being of banded iron formation (bif) type, although some important differences are noted between them and classical bif type orebodies.

Jan 1, 1984