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By Bruce See J

Oxidation of artificial Imperial Smelting Furnace lead bullion was performed during cooling between 1180 and 820°C in order to attempt to produce a tin-rich dross.The addition of sodium carbonate together with stirring increased the tin content of the dross when oxidation was carried out with air or PbO on zinc-free bullion.Zinc in the bullion during oxidation resulted in a decrease in tin concentration of the dross due to zinc oxidation and copper entering the dross.

Jan 1, 1987

By Fredley D. C

Georgius Agricola wrote in De Re Metallica in 1556 that a prudent a miner should not work in a region ruled by a tyrant-a person inimical to mining. In 1926, Associate Chief Sherman of the United States Forest Service in a speech stated, "It is the policy of the Forest Service to encourage the development of the mineral resources within the boundaries of the National Forests ... a man who fails to cultivate a friendly, helpful, cooperative spirit in his relations with those who are endeavoring to develop the mineral wealth of our mountains has no place in the Forest Service." Both statements are as true today as they were in 1556 and 1926. The challenge to the Forest Service and the mineral industry today is to maintain that cooperation in a world that has changed significantly since Agricola and Sherman. The United States Forest Service manages 77,000,000 hectares of land-mostly in the Western United States-an area equal in size to New South Wales. The vast majority-75 million hectares are National Forests, and 1.6 million hectares are National Grasslands. National Wilderness Areas account for 13 million hectares or rough- ly 17 per cent of the National Forest System. National Forest System lands (NFS) are some of the most visible, scenic and controversial lands in the country. They are also some of the most valuable for their mineral potential and production. The value of mineral produced exceeds US$4 billion per year. There are over 1200 producing mines, 15,000 oil and gas leases, and some of the largest lead, copper, silver, gold, platinum, molyb- denum, and coal deposits in the hemisphere. Every year the Forest Service approves nearly 5,000 mineral operations on the NFS. Much of the NFS (75 per cent) is open to location of mining claims pursuant to the 1872 Mining Law. And an equal amount of land is legally available for oil and gas leasing.

Jan 1, 1991

By Howell M. W

The purpose of this paper is to outline the main points in the construction of the various types of wire ropes more commonly used for winding in Australia; and the maintenance of the ropes, and cage and skip safety gear as practised at the South mine, Broken Hill.It should be mentioned that both of the shafts at present in use are dry, and both downcast with or without the assistance of the two exhaust fans normally in use: Night shift and week.-end overtime are practicaly non-existent.Thus, during night shift, the cages in No. 7 shaft are landed on the chairs at the surface, providing efficient covers for the· shaft, and allowing the maximum amount of rope to be wound on to the drums. This also applies to the cages of both No. 7 and No. 4 shafts during the week-ends.These factors, combined with electric winding and skip haulage, are calculated to obtain the best use of the ropes when properly attended.WINDING ROPES-TYPE AND CONSTRUCTIONThese ropes may be divided into four main types which will include the more commonly used constructions(a) One-size strand.(b) Warrington strand.(c) Flattened strand.(d) Locked coil.1. One-size strand as the name implies, is a rope the strands of which are constructed 9f wire of the one size.Usually the strands are of 7, 19 or 37 wires.

Jan 1, 1940

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

Minerals and Metals Group (MMG) Century mine (Century) is a large open-cut mine in northwest Queensland approximately 2.5 km long, 1.5 km wide and 240 m deep, with an ultimate pit depth of 320 m. In 2009, the mine experienced three failures which began as small failures, and progressively developed into significant multi-batter failures. The incidents were managed by a combination of analysis, redesign and practical management to achieve positive outcomes for the mine. On the south wall of the mine, a series of batter-scale wedge failures occurred in December 2007. Analysis of structure orientations and design changes aimed to minimise the risk of failure extending over multiple batters, while accepting a risk of further small-scale failures. Design changes were constrained by a culturally sensitive area (CSA) located south of the wall. As mining progressed, shallow wedge failures developed over multiple batters and cracks were observed 60m back from the pit crest, indicating that a large-scale wedge failure was developing. Movement increased in January 2009 as a result of significant rainfall. After considering several design options, the area was stabilised by a cut-back of the wall. Two multi-batter failures also occurred on the north wall as mining progressed through a structurally complex area. Both north wall failures began as small failures that progressively developed, and required a redesign of the wall below as well as practical management of safety aspects. The complex structural geology was difficult to predict ahead of mining, and required geotechnical input into design changes as mining progressed. All three failures potentially had significant impact for ore recovery, and were managed by a combination of analysis, redesign and operational management have resulted to achieve positive outcomes in a challenging mining environment.

May 1, 2010

By de Brodtkorb MK

Late Cenozoic ore deposits "Precious and base metal-rich" and " Sn-Ag-polymetallic"of Northern Puna are associated either with Middle Miocene dacitic volcanic-dome complexes or with Upper Miocene dacitic-andesitic volcanic centers. Ore mineralogies and their related volcanism are discussed. A strong link is observed between the Cenozoic Metallogenetic Province of Northern Puna and the Southern Bolivia Tin and Polymetallic provinces.

Jan 1, 1995

By Firmin K

The Mt. Tom Price orebody of Hamersley Iron Pty. Limited consists of a folded hematite - shale sequence capped by a layer of goethite. Consequently, variations in iron content occur within the orebody, and as the overall grade is below that required to make specification products, selective mining must be carried out. A necessary preliminary to quality control'of products based on selective mining is the production of advance data, on the tonnages and grades of material to be expected in future mining areas. Bench plans showing zones of different grades and types of material anticipated are prepared from structural geological information. The grades of materials on a bench are essentially governed by the positions and attitudes of the shale bands. Quality control is exercised by blending different grades and types of material in primary crusher feed. Iron grade is the prime grade consideration although sometimes the level of phosphorus content must be considered. Pre-production grades Are determined from assay of samples taken from blasthole cuttings.

Jan 1, 1980

The geology of an area in north-western New South Wales, bounded by the South Australian and Queensland borders, latitude 32° S. and longitude 14° E. is discussed.The area involved includes sixteen 1:250,000 standard military sheets and covers approximately 96,000 sq. miles.The geology of the Willyama Complex is not dealt with but a small area of metasediments previously included in this unit is separated and a possible correlation with Precambrian to the east is suggested. Torrowangee Group sediments are described and the problem of nomenclature using a glacial implication is raised.Nine areas of proven Lower Palaeozoic sediments are considered and their relationship to the boundaries of the Bancannia Trough outlined. It is possible that some exposures not yet substantiated by fossil evidence may prove to be Lower Palaeozoic rather than Precambrian in age.The sediments of the Lachlan Geosyncline in the area of the Cobar massif are described and new concepts on the age and distribution of some of the established stratigraphic units are introduced. The absence of rocks of Middle Silurian age probably indicates the time of a major orogeny in this area.Lithology, thickness, and distribution of the Upper Devonian sediments is considered and some of the more recently found fish plate localities are listed.Mesozoic sediments occur in isolated areas of Lower Jurassic age and in the Great Australian (Artesian) Basin. A four-fold subdivision of sediments of the basin has been possible in some areas but lack of sub-surface information at present, precludes the possibility of correlation with the type sections in Queensland.Units in the Cainozoic are subdivided and a five fold subdivision of the Quaternary, at present being used throughout western New South Wales, is described.

Jan 1, 1969

The Prominent Hill copper-gold deposit is located approximately 150 km north west of Olympic Dam, on the southern margin of the Mount Woods Inlier in South Australia. Its discovery in November 2001 resulted from the application of a geological model developed from geological, geophysical and petrophysical data pertaining to the Olympic Dam deposit. The discovery has dispelled the notion the Olympic Dam may be unique, and that another deposit like it is unlikely to be found. The Prominent Hill mineralisation is hosted by haematite-matrix hydrothermal breccias, which have suffered extensive iron-sericite-silica alteration and overprinting. Copper, gold, barium, fluorine, uranium, cerium and lanthanum are all intrinsically associated with the hydrothermal iron. Breccias intrude an east-west striking, fault-controlled sedimentary succession, which is flanked to both the south and north by volcanic complexes. Many similarities between Prominent Hill and Olympic Dam are documented including geological setting, mineralogy, breccia styles, and alteration. Differences relate largely to the nature of the immediate host rocks. The similarities and difference provide key data for improving exploration models for this style of iron oxide copper-gold deposit, both within the Gawler Craton as well as globally.

Jan 1, 2004

By Davey FJ

The Hikurangi Margin of eastern North Island New Zealand represents the feather edge of the over-riding Indo-Australian Plate at its convergent boundary with the subducting Pacific Plate. Towards the south, convergence becomes slower and increasingly oblique, and sediment supply from the Southern Alps becomes increasingly rapid. In this environment a 150 km wide, imbricate thrust, accretionary prism has grown since the Miocene, uplifting slope ridges and basins and a range of coastal hills. Offscraping of thick, axially transported, trench-fill turbidites begins in a zone of proto- thrusts, which extends up to 25 km beyond the principle, slope-toe, deformation front. On the slope, landward tilted, trench-slope basins are separated by ridges. The ridges ride up on thrusts that sole out at a major decollement. The decollement dips landwards at 3 degrees to a depth of 14 km at the coast, where it coincides with an onshore zone of high seismicity. Beneath the decollement, about 1 km of consolidated, oceanic sediment is going under the margin with the underlying oceanic basement. Some of these sediments may underplate the frontal ranges to the west and geochemical evidence of subducted sediment is found in the volcanic zone beyond. A rapid decrease in the width of the accretionary prism to the north is associated with a decrease in sediment supply and perhaps with a dislocation in the downgoing plate. To the south, the accretionary prism narrows, swings westward, and merges into the zone of very oblique collision that marks the transform between mirror image subduction to north and south of New Zealand.

Jan 1, 1987

By Susanto A

As part of the current NERDDC funded project studying Dragline/Hopper/ Crusher/Conveyor systems for overburden removal, an investigation was carried out to assess the feasibility of automating the swing-to-dump phase of the dragline digging cycle in order to main- tain consistent performance of spotting the bucket above the hopper prior to dumping. The study involved design of automatic position controls for the hoist, drag and swing drives and simulation of detailed mathe- matical models of the three electromechanical systems and their associated electrical control schemes. The design of the hoist and drag systems to position the bucket in the boom plane is relatively straightforward. Simulation results show fast and accurate performance, with no evidence of interaction between the two drive systems through the ropes. The design of the swing position control system involves special strate- gies to cater for variable inertia and to damp the pendulum oscillations of the bucket. The use of a bucket pendulum model and variable dynamic compensation embedded within the feedback control loop, along with optimal speed/angle slowdown trajectories, has yielded fast and damped positioning responses under simulation.

Jan 1, 1989

By Milawarma E, Cusack C

The Sapan Dalam coal deposit of Indonesia consists of ten steeply dipping seams with thicknesses varying between 0.1 and 3.5 m and split by shale, clay, silt and sandstone. The area contains four faults dipping about 75¦ with four to 85 m vertical displacements. The complex nature of the deposit coupled with limited 27 exploration drillholes at an average spacing of 200 m made it difficult to create a realistic geological model. A three-dimensional gridded seam model gave a fair representation of the deposit. Attempt to create an optimum pit using the WHITTLE 3D pit optimiser proved unsuccessful since the pit optimiser is restricted to standard regular or fixed blocks. The gridded seam model was converted to a fixed block model prior to the optimum pit design. Smoothing and pit base controlling were also introduced to obtain a smoother pit. A mining scenario produced 3.6 million tonnes of coal, 28.4 million bcm of waste and US$18.1 million revenue.

Jan 1, 1995

By Bourne R. W, Smith T

This paper presents initial findings of a project examining novel processes for the treatment of refractory sulphidic gold concentrates. Non-oxidative roasting of such concentrates for 12 hours at 750¦C resulted in the finely disseminated gold agglomerating to form discrete grains. The pyrite and arsenopyrite decomposed to form pyrrhotite, whilst the labile sulphur and arsenic driven off was collected on a condenser as a mixture of elemental sulphur, metallic arsenic and various arseneous sulphide compounds. As a result, the cyanide solubility of the gold contained in sulphidic refractory gold concentrate from the Emperor mine in Fiji improved from 54.5 per cent to 98.4 per cent; from the Fimiston mine in WA (65.2 per cent to 96.6 per cent), from the Windarra mine in WA (69.6 per cent to 91.3 per cent), from the Harbor Lights mine in WA (20.4 per cent to 60.7 per cent), and from the Wiluna mine in WA (12.6 per cent to 28.0 per cent). The non-oxidative roasting conditions have not been optimised for each of these minerals. Subjecting the non-oxidatively roasted minerals to mild oxidative acidic iron sulphate pressure leaching (with typical temperature of 100¦C and typical oxygen overpressure of 500 kPa) to remove iron and so further liberate finely disseminated gold, resulted in the cyanide solubility of the gold exceeding 96 per cent for each of these five concentrate types (including those from Harbor Lights and Wiluna). Thiourea leaching of the sulphur-rich residues under acidic conditions resulted in remarkably high gold extractions being achieved. These novel processing options need to be optimised, and their economic viability established.

Jan 1, 1991

By Orid A

A fast, non-contact technique for measuring sizes of rock fragments on a conveyor belt is presented. An image processing technique called active stereopsis is used which makes use of a light stripe projected on to the surface of the fragments on the conveyor belt. A CCD TV camera is used to capture the shape of the distorted light stripe. the video image of this shape is then processed by a computer program so that the 3D profile of the surface can be obtained by triangulation. The sizes of the rock fragments are then calculated from this profile. The speed of the technique is improved by calibrating the light stripe system before measurement begins so that the profile of the fragment surface can then be measured using simple geometry. The technique is fast and highly parallel so that it is able to operate in real time.

Jan 1, 1990

By Sandy W

This paper examines the effects of a significant number of plant alterations and modifications to the lead flotation circuit during the past five years. Metallurgical effort is directed largely at the flotation performance of middling streams and current strategies are discussed. The automatic control of cell destination and collector additions are outlined in the latter section of the paper, along with a description of control hardware in current use.

Jan 1, 1983

The need to estimate the block size distribution of a jointed rock mass is of great importance in the design of blasting rounds to attain a pre- established fragmentation. Other Geomechanics topics, such as ,hydraulic behavior of rock-masses, as well as the determination of their strength properties, also require the accurate prediction of a rock-mass composition in terms of block size taking in due account the three dimensional interference of joints and other geologic discontinuities. In this paper, a method for computing the block size analysis of a jointed rock mass is described, using as input the common geologic data (dip and strike) of fracture planes existing in a rock bench prior to blasting.

Jan 1, 1977

This paper will describe the exploration project which led to the discovery of the La Escondida porphyry copper deposit in northern Chile and will serve as companion paper to the description of the geology of Escondida being presented by J M Ojeda. The author would like to express his appreciation to Robert Hickman, Chairman of Minera Escondida, for permission to present this paper.In July 1978, a proposal was made by J D Lowell to Robert Wheaton, then Exploration Manager of Utah International, that Utah fund a "grass roots" program exploring for porphyry copper deposits in northern Chile. Wheaton expressed interest, and it was agreed that Getty Oil Co also be invited to participate. A joint venture agreement for the Atacama Exploration Project was signed January 1, 1979, between Utah, Getty and Lowell. The project was managed by Lowell who reported to a management committee which through most of the project consisted of Lowell, Francisco Ortiz, Robert Wheaton, Maurice Young, Sigfried Muessig and Louis Rove. Oliver Warin and Jim Bratt participated in the committee in the last phase of the contract. Special thanks are due Louis Rove of Getty and Maurice Young of Utah who made contributions throughout the course of the project. Francisco Ortiz was resident manager through most of the project.

Jan 1, 1990

By Robins R. G

The dissolution of metallic copper powder in aqueous solutions of cupric sulphate under the influence of ethylene gas was investigated. The dissolution reaction stoichiometry obtained was: Cue+(aq) + Cu(s) + 2C2H4(g) = 2(CuC2H4)+(aq) The rate of formation of the copper (I)-ethylene complex in the above reaction was studied in a laboratory autoclave and the effect pH, temperature, ethylene partial pressure and initial concentration on the dissolution rate was measured experimentally and expressed theoretically in terms of several simple conceptual kinetic models. The results led to the selection of optimum conditions for the reaction and the suggestion of an "ion-molecule reaction" mechanism to explain the very low activation energies for the reaction system. The area of application of this reaction lies in the direction of refining impure copper such as cement copper. Several experiments were performed in which an acidified solution of cupric sulphate under ethylene pressure was used to dissolve copper from the cement copper powder in the form of the copper (I)-ethylene complex, followed by the release of gas pressure to disproportionate the complex and precipitate a purer metallic copper.

Jan 1, 1987

Cretaceous volcanic activity (Hauterivian Albian) in the Peruvian Andes can be found along the coast of Peru and the western edge of the Andes mountains between 15o30'S and 5o30'S, extending discontinuously in south to Chile and north to Ecuador and Colombia. This volcanic activity formed in three aborted marginal basins; the NNW-trending volcanic Ca±ete and Huarmey, and NNE-trending Lancones basins. These volcanic rocks are predominantly andesitic and basaltic in composition, of calc-alkaline and tholeiite affinity with subordinate dacitic and rhyolitic rocks. One notable feature is the appearance of æocoitasÆ from Ica (14oS) south to Santiago de Chile. These rocks have a calc-alkaline to alkaline affinity. From south to north, the continental crust gradually becomes thinner, allowing mantle material to rise towards the surface. Ophiolitic sequences of this type form a marginal basin in Colombia. Very low-grade regional metamorphism which affects the volcanic rocks also varies gradually from south to north. Between Santiago de Chile and Ica this takes the form of burial metamorphism, with moderate geothermal gradients (20o-30oC/km). Metamorphism in the Huarmey basin is transitional between burial and ocean-floor metamorphism, with very high geothermal gradients (>3000C/km). High geothermal gradients are also apparent in metamorphism of the Lancones basin, though less than the other basins. Ocean-floor metamorphism is present in the ophiolitic sequence in Colombia. Associated mineral deposits in the Huarmey and Lancones basins, and in the north, are of the volcanic massive sulphide-type (VMS). The principal deposits in Peru are Leonila Graciela (20 Mt Zn and Pb) and Tambogrande (40 Mt Cu and Zn). There are also smaller mines and prospects. To the south of Lima, manto-type Cu deposits (CuMT) are found with a mineralogy of chalcopyrites, pyrites, magnetite, actinolite and apatite. The main example is Raul Condestable (10 Mt Cu). Other prospects are present to the south and Chile has some very large mines of this type (El Soldado, Lo Aguirre). The notable differences between the CuMT and the VSM deposits are thought to be the result of the prevailing conditions in the earthÆs crust during the Hauterivian Albian. To the south, calc-alkaline and alkaline volcanic activity in aborted marginal basins, with thicker crust, was thick, produced moderate geothermal gradients associated with burial-type regional metamorphism and deposits of CuMT. In the north aborted marginal basins associated with calc-alkaline to tholeiitic volcanic activity and a gradually thinning crust, produced transitional regional metamorphism between burial-type and ocean-floor type, associated with high to very high geothermal gradients and VMS deposits. In Colombia these conditions led to ophiolite extrusive rocks, ocean-floor metamorphism and also VMS deposits.

Jan 1, 1999

By Dunlop A. C

A brief study from the Mt. Bulga prospect com- pares the chemistry and mineralogy of different soil fractions and other materials to suggest a sequence of surficial metal dispersion from adjacent gossans, which may have relevance for geochemical exploration in semi-arid terrains. v v v v v JIV-- v v v v a o v o/ v v v v 1 v v lv ./v '' 1 v 16400N ..I v 1635014 v 1630014 .:1 ò.t SILURIAN sillstone " lelsic volcanic sillstone -sandstone ORDOVICIAN Eandesite o quartz float gossanò pits doOP Iv o shalt v _--'fault v 1---1 soil traverse v v v v 0 100 200 mm e Fig. I Local geology and location of soil traverses, Mt. Bulga (compiled from Chisholm, 1976). The Mt. Bulga prospect in central New South Wales is a small but well documented volcano- genic massive sulphide occurrence (450,000t of 0.8% Cu, 1.3% Pb, 5% Zn and 0.45 g/t Au) Cambrell and Kirk (1974), and Chisholm, (1976). Mineralization is localised near the interface of felsic pyroclastics with overlying silt- stones and along adjacent faults (Fig. 1). In this area with a Koeppen type cf6 climate, soils are thin and skeletal along ridges with thicker and better differentiated profiles with a colluvial component up to 2m thick developed

Jan 1, 1988