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By George G

The Circum-Pacific Map Project is a cooperative international effort to prepare and publish geological, geophysical and mineral resource maps of the Pacific Basin and adjacent land areas. Earth scientists representing 180 organizations from more than 40 Pacific Rim countries are participating in the work. The project is directed by a committee established 14 years ago as an activity of the non-profit Circuin-Pacific Council for Energy and Mineral Resources. Technical and cartographic support is provided by the U.S. Geological Survey. The Circum-Pacific Map Project is organized under five regional panels of experts on the geology and resources of the four quadrants of the Pacific and Antarctica. A series of five 1:10,000,000-scale regional maps and a 1:17,000,000-scale map of the entire Project area, the Pacific Basin Sheet, provide the cartographic base. Forty-eight individual sheets are planned and thirty have been published in eight different series, including base maps, geography, plate tectonics, geology, energy resources, mineral resources, tectonics and geodynamics. Additional special single-sheet thematic maps on the Pacific Basin base have been published and are planned for a total of more than 50 individual sheets.

Jan 1, 1987

The use of ammonium nitrate/fuel oil explosives is.now well established in most open cut mining operations. Its use. is extending to underground mining. This has been due in a large measure to improvements in the nature of the ammonium nitrate made available from various sources. The addition of surface active agents and water in controlled amounts to the fuel oil has been found to increase the sensitivity of the ANJFO mixture with consequent better explosive properties. It is considered that the surface active agent increases the bond between the ammonium nitrate and fuel oil giving a more, intimate physical and chemical mixing of the oxidising and reducing agent. This results in increased sensitivity and a faster rate of reaction. The increase in sensitivity has been accomplished without any diminution of safety. Tests which demonstrate the safety of this type of explosive are given in the appenuix.

Jan 1, 1964

By Kam KM, Tran B

Statistical techniques of Box and Jenkins (1976) have been used to assess the existing control schemes and determine the dynamics of flash smelting furnace at the Kalgoorlie Nickel Smelter. Pertinent process variables, such as, oxygen flow, flux flow, matte grade and iron to silica ratio in slag, were considered in the analysis using routine operating data collected over two periods of operation. Results indicate inadequate control of some of the important variables. Dynamic characteristic parameters (dead time and response time) between a set of input and output variables were identified to improve optimisation of the existing thermodynamic model used for flash furnace control.

Jan 1, 1996

By C McIntosh, M Carder, P M. J Durance

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Disseminated, gold-bearing sulfide minerals hosted in sheared, wall rock metasediments and clay alteration zones comprise one of the dominant styles of Palaeozoic orogenic gold mineralisation within the Reefton Goldfield, and is exemplified by OceanaGold’s Globe Mine. This study begins the exploration and characterisation of the gold-arsenic-antimony mineralisation hosted within the dominant lithologies of the Globe-Progress shear zone. The main gold-bearing sulfides are pyrite, arsenopyrite and stibnite. Pyrite and arsenopyrite are not compositionally uniform across the Globe-Progress shear zone. Pyrite from the mineralised greywacke and argillite has higher As contents than pyrite in the host rock and pug breccia. Furthermore, the mineralised greywacke and argillite pyrite are enriched in As from core to rim. The 3D models based on bulk assays reveal a significant correlation in the distribution of Au, As and Sb. The interpolant for Sb envelops those for Au and As, which in turn are very similar to each other in their vertical and lateral extents across the shear zone. This result is consistent with earlier findings that the occurrence of stibnite represents a separate and likely later phase of mineralisation relative to that represented by the formation of disseminated pyrite and arsenopyrite both of which exert a stronger control on the distribution of As.CITATION:Durance, P M J, Christie, A B, McIntosh, C and Carder, M, 2015. The composition of disseminated, gold-bearing sulfides within the three-dimensional framework of bulk Au, As and Sb in the Globe-Progress orogenic gold deposit, Reefton Goldfield, New Zealand, in Proceedings PACRIM 2015 Congress, pp 327–334 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Chavant G, Begis D, Gunther J

To study the ventilation of a mine (improve on the existing situation, examine extension projects) the calculation program used must take into account all the resistance values in the branches of the network. These resistance values are generally determined by measurements, which are accurate to a greater or lesser extent. In order to arrive by calculation at the flowrates measured :n the mine at a given moment, the resistance values have tto be adjusted experimentally. This manual operation is lengthy and delicate.

Jan 1, 1988

By Willis G. M

Preliminary experiments have shown that, when used in a fusedchloride electrolyte, titanium carbide anodes dissolve yielding lower titanium chlorides which nlay be electrolysed in situ to produce a cathode deposit of pure titanium metal. The anode residues are easily withdrawn from the cell. Further experiments have established the operating conditions for maximum efficiency in the process.The process is essentially two-stage, viz.: (1) titanium carbide production, (2) electrolysis producing metal. Power requirements appear to be moderate and this fact, combine·d with the simplicity of the process make it attractive as a possible method for the production of titanium.INTRODUCTIONDue to the high reactivity of titanium and its, affinity for oxygen and nitrogen, the extraction of this metal generally involves the use of halide. compounds as intermediates. For instance, magnesium reduction of titanium tetrachloride is the basis of the well established Kroll process and electrolysis of the lower chlorides in a molten salt bath has been proposed by Cordner and Worner (1951, p. 358) and others (Brenner and Senderoff, 1952, 223C; The TitaI Company (Inc.), 1952) as means of production of the metal. Thedifficulty of preparation of these compounds prompted a search for an alternative extraction process. The fact that aluminium, an equally reactive metal, has been prepared by electrolysis using aluminium alloy anodes suggested the possibility of a similar process for titanium production.The Titan Company (Inc.) (1952) has patented the use of crude titanium metal anode, but it was thought possible that a metallic compound, such as the carbide, could be used for this purpose. Although Lorenz and Kaufler (1909) suggested the use of carbide anodes for metal production, no...

Jan 1, 1956

By Schulz R. S, Staunton W. P, McGuire J

The increased activity in the Australian gold industry over the last decade has resulted in a concomitant increase in the use of sodium cyanide, with a projected consumption of 80,000 tonnes per annum by 1991. Growing environmental awareness by government, industry and the public has generated increased interest in the fate of cyanide near gold mine tailings dams and has highlighted the lack of basic knowledge in this area, particularly for Australian conditions.

Jan 1, 1991

By C F. Nichol, L Smith, R D. Beckie

A better understanding of the hydrogeology within mine waste rock and cover systems is essential for the quantification, prediction and prevention of metals loading to the environment surrounding waste rock piles. The effect of surface condition on the internal flow mechanisms within an intermediate-scale constructed waste rock pile is being investigated at the Cluff Lake Mine, Saskatchewan. Changes in the water balance, the outflow distribution and water residence time have been observed in the waste rock pile following successive modifications of the surface condition. The three year old, run of mine, free-dumped surface was ripped to a depth of 30 cm to 40 cm, and levelled in October of 2001. In August 2002, a 10 cm to 15 cm cover of compacted waste rock was placed on the pile. Outflow, precipitation and run-off data collected during natural and artificial rainfall events have been used to quantify the maximum infiltration rate, and the spatial pattern of discharge and cumulative volume of water that infiltrated into the waste rock under each surface condition. Infiltration data together with the outflow data provide a basis to address the residence time of water within waste rock and the dominant flow mechanisms for different surface conditions. With a free dump surface spatially distinct wetting fronts are observed at the base of the pile that vary in flow rate by an order of magnitude (measured at a 2 m by 2 m scale) and in time by up to a week. Following ripping and levelling, similar cumulative outflows were observed, but the magnitude and arrival time of wetting fronts changed across the pile. A decrease in outflow volume, a decrease in infiltration volume, a two-fold increase in the response time of wetting fronts and a more spatially uniform distribution was observed following placement of the compacted surface layer. Based on preliminary data, the internal structure appears to be the dominant factor controlling outflow variability.

Jan 1, 2003

By Georgi H, Farquhar J. W, Lorrigan A. N

The potential for major new lenses of Volcanic Hosted Massive Sulphide (VHMS) beneath the existing Rosebery Deposit is extremely high. Recent deep drill hole intersections of massive sulphides, including 22 in true thickness at 24 per cent Zn, may significantly extend the life of the Rosebery Mine. The Rosebery Ore Deposit is located within Australia's most prospective VHMS mining district, the Mount Read Volcanic (MRV) arc of western Tasmania (Figure 1). The MRVs are a 10 - 15 krn wide arcuate belt of lavas, related intrusives and volcaniclastics. Rosebery is a major Cambrian volcanic hosted Zn-Pb-Cu-Ag-Au rich deposit which has been over-printed by Devonian deformation and granitoid alteration resulting in local rcmobilisation of the ore. The Rosebery Mine Sequence is composed of an east dipping and east facing, predominately felsic sequence of rhyo-dacitic volcaniclastics, epiclastics, sediments and shale lenses more than 500 in thick. This sequence is bounded by two, low angle (35 - 40¦), east dipping thrust faults, the Rosebery Fault to the west and the Mount Black Fault to the cast. The Rosebery Mine lithologies are summarised in the following table: Hangingwall (HW) Polymictic, quartz, feldspar-phyric epiclastics. Black Slates Graphitic, pyritic mudstones. Host Rocks Turbiditic mudstones and sandstones. Footwall (FW) Feldspar-phyric, pumiceous, mass-flow breccias. Cambrian, quartz-feldspar, porphyritic sills intrude this sequence at all levels. Thin, Jurassic, dolerite dykes also occur throughout the mine. Widespread quartz, sericite and chlorite alteration occurs in the FW. This alteration is manifested as quartz-augen schists beneath the orebody. The Host Rocks are pervasively altered with silica, sericite, chlorite and pyrite. Intense carbonate alteration occurs within the orebody, whereas chlorite and pyrite alteration is commonly concentrated directly beneath it. Cambrian volcanogenic alteration is over-printed by three major Devonian, granite-derived, assemblages. These are massive to quartz veined tourmaline, pyrrhotite-pyrite and magnetite-chalcopyrite. Though the Devonian granite has not been intersected in deep drill holes or in mine workings, there is good evidence that it exists within a kilometre of the deposit. The Rosebery orebody is structurally complex when compared to many other VHMS deposits. Evidence for Cambrian growth faulting has been found at the North End of the mine (B lens) where displacement of ore lenses occurs without corresponding displacement of the overlying Black Slates. A well defined cleavage exists throughout the mine, dipping at 28 to 50¦E. East dipping shear zones are also obvious in all parts of the mine workings and reverse movement is evident on many of these.

Jan 1, 1993

Immigration has influenced Australia's development more than any other factor. As well as being critical to our economic growth and development, it has made a major contrib- ution to our population growth, to the richness and diversity of our society and to our inter- national relations. Migration from the United Kingdom has been the mainstay of our settler intake for many years, but its relative importance has declined in recent decades. Non-British European migration formed an important part of our post-war intake and, in the past few years, migration from Asia has reached significant levels - particularly through our resettlement of Indo-Chinese refugees. In planning our future immigration, it is important to look beyond short term direct economic consequences. Australia has looked to its resources for progress, but Japan, Korea, Taiwan and Singapore have achieved dramatic economic progress without resources, based on the will and dynamism of their societies. Immigration can contribute greatly to the development of a dynamic, outward looking Australian society able to make the most of our great resource potential.

Jan 1, 1982

Bauxite Resources Limited is grade drilling in its Western Australian Darling Range tenements to firm up resource definition and to develop mine plans. The Darling Range bauxite is generally in shallow deposits with minimum overburden. In the northern tenements, the ore is characterised by a higher silica layer which may extend from 0.5 to 1.5 m below, which high grade bauxite is found to a depth of four to 7 m. When grade drilling samples are taken, every 0.5 m and the recovered sample is weighed, logged and bagged. To eliminate splitting errors, the whole sample over the short interval is pulverised. Twinning holes variations are observed when using various drill rigs. Diamond core has been shown to give close to 100 per cent recovery and grades have been verified by digging bulk samples. As such, diamond core is used as the reference. It is intended to include sonic drilling as an alternative to diamond cores. This presentation details and attempts to explain the reasons for the observed variations in the various drilling methods used by Bauxite Resources Limited. This is an ABSTRACT ONLY no paper was prepared for this presentation.

Mar 1, 2010

By Y Li, B Shen, S Zhang

Jointed rock mass is often encountered in rock engineering and its stability has always been a major concern in underground engineering. To analyze the stress characteristics and their variations in jointed rocks, in this study, a new concept of sub-instability stage before rock failure is defined, and a new experimental method is used to investigate interaction between defects and intact rock of the jointed rock mass during the subinstability stage., Firstly, external characteristics of stress and failure mode of the whole jointed rock are investigated systematically by conducting uniaxial compression tests on red sandstone samples with a set of preexisting open flaws of different sizes, and the interactive damage of intact parts and defects in the subinstability stage was further studied. Secondly, rock-like material samples made of bonded plaster blocks were tested and internal data from stress sensor between the strong and weak segments were collected. The transforming processes from independent activity of the individual segment to overall interactive movement of jointed rock before the unstable failure were analysed. The test results indicated that the subinstability stage marked the beginning of interactive failure between the intact rock and defects. In the early subinstability stage, the relatively intact parts bore most of the load in a jointed rock mass, and the defects were damaged firstly which caused high strain around it. The areas of high strain increase rapidly, extending and migrating, causing damage to the intact parts. In the later sub-instability stage, the interaction effect reached its maximum, and a large number of cracks appeared in the intact rock and they propagated and coalesced. Intact parts experienced rapid failure and then the jointed rock failed. The experimental method used in this paper to identify the sub-instability stage could be used to identify failure precursors of jointed rock masses and to develop technology for disaster prevention in rock engineering. CITATION:Zhang, S, Shen, B and Li, Y, 2018. Experimental studies on interactive failure characteristics of jointed rock, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 453–461 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By M D. Basuki Dwi Priyono

The Toguraci low sulfidation epithermal gold vein deposits are located 2 km WSW from the Gosowong mine and form part of the Gosowong Goldfield. The goldfield lies within a Neogene magmatic arc on Halmahera Island, North Maluku Province, East Indonesia. The terrain is moderate to steep, rainforested, and poorly outcropping. Exploration and mining operations are being carried out within the PT Nusa Halmahera Minerals Contract of Work (exploration tenement) jointly owned by Newcrest Mining Ltd (82.5 per cent, operator) and PT Aneka Tambang Tbk. (17.5 per cent). First pass exploration of the Gosowong area began late 1992 resulting in the discovery of weakly developed porphyry copper mineralisation (named Bora) at Toguraci in 1993. Early in the evaluation of this porphyry an overprinting epithermal Au/Ag mineralisation event was recognised, however exploration focus remained on the Bora porphyry deposit for some time. The discovery of the nearby Gosowong epithermal gold deposit and the exploration of other prospects in the area further diverted attention and funds from Toguraci. It was not until year 2000 that Toguraci was seriously reevaluated as part of a detailed appraisal of the epithermal gold potential within a 5 km radius of the Gosowong gold mine. A fly-camp based drilling campaign using man-portable rigs was undertaken between August 2000 and March 2002. All exploration at Toguraci was then stopped pending government approvals to mine. These were finally issued in May 2003 and immediately drilling restarted and pre-mine approvals (eg the environmental impact study) were sought and granted. The first Toguraci gold bar was poured in February 2004. Exploration at Toguraci and elsewhere in the Gosowong Goldfield continues today.

Jan 1, 2004

Vatukoula, the Fijian equivalent of gold rock, is the name of the community embracing the gold mines owned and operated by Emperor Gold Mining Company Ltd., Loloma (Fiji) Gold Mines, N.L., and' Dolphin Mines Ltd. It is situated in the Tavua Goldfields approximately five miles from the northern coast of Viti Levu, the largest island of the Colony of Fiji.The climate is sub-tropical, there being a definite wet and dry season. The wet season is somewhat variable in length but usually extends from December to March, during which time most of the rainfall for the year is recorded.Although the average annual rainfall is 71 in., more than twice this amount has been recorded. Precipitation at the rate of 5 in. per hour is not uncommon and 15 in. of rain has been registered in 24 hours. The mining methods adopted, therefore, had to suit these wet conditions.The occurrence of gold in the Tavua area has been known since 1872, but it was not until 1932 that discoveries were made which led to the formation of the present operating companies. In 1934 the Emperor Gold Mining Company Ltd. commenced operations, followed in 1935 by the Loloma (Fiji) Gold Mines, N.L., and later by the Fiji Mines Development Ltd., now known as the Dolphin Mines Ltd. Up to the end of 1951 these three mines had produced 2,501,688 tons of ore from which 1,277,881 oz. of fine gold and 347,429oz. of silver were obtained, realizing in Fijian currency £13,025,153.The three mines are situated close togeth.er on contiguous mining leases, and, although under common management, are operated as separate en,tities. Since 1944 all the...

Jan 1, 1953

Routine, in-pit geological mapping of highwall at Central Queensland Coal Associates (C.O.C.A.) deep strip mines has proved too slow for the increasingly greater highwall lengths which require mapping. This realiz- ation has encouraged the search for faster mapping methods and after trial of ground photographic methods has resulted in the adoption of interpretive mapping off stereo cover, oblique -- aerial photography. This entails using a Cessna 182 light aircraft flying at its slowest speed, the aerial meth- od finally employed consisting of two Vinten, air reconnaissance cameras mounted in parallel and simultaneously taking both colour and black and white photographs of the mine high- wall. The respective 1:500 scale enlargements produced from the 70mm format films combine to present the sharpest resolution attainable under the field conditions pertaining and such information on weathered material as only colour photography can fully render. Total costs for the aerial photography method are estimated to be about the same as those for conventional in-pit mapping. Whilst total costs are comparable, geo- logist's time for mapping a 10 km. length is reduced to less than half that for in-pit mapping (for Stage 1, fully accurate mapping) and accuracy and detail are greatly improved. A permanent, accurate record of overburden

Jan 1, 1981

By A Millar, B Wraith

Process plants are characterised by variability of performance over a wide range of time-scales; reflected in fluctuations in metal recovery, concentrate grade, plant throughput and reagent costs. In turn, these fluctuations impact financial metrics such as operating costs and revenue. The primary cause of plant variability is variation in the physical, lithological and mineralogical characteristics of the ore fed to the plant. The variability of the ore is driven by the intrinsic heterogeneity of the geology and mineralogy of the orebody, the mining method and mine production plan, the capacity to stockpile and blend, as well as the plant flow sheet and the level of plant automation. Whilst the impact of ore variability on process plants is universally recognised, it is rarely quantified in financial terms. Consequently, opportunities to reduce its impact are often overlooked due to the lack of a basis for a quantifiable cost-benefit analysis to justify improvement initiatives. This paper will present case studies using production data from the Renison tin concentrator and a zinc concentrator. These case studies demonstrate that as the standard deviation of plant head grade increases (as a proxy for ore variability), plant metal recovery subsequently reduces. The metal recovery is then converted into plant revenue losses, to quantify the economic impact of ore variability. The Renison case study demonstrated that whilst a very rare occurrence, revenue losses were as high as 34 per cent (relative to the baseline) when standard deviation was at its highest. The zinc concentrator case study demonstrated that revenue losses were as high as 6 per cent (relative to the baseline) when standard deviation was at its highest. Options are available for reducing and managing ore variability in the process plant. These options include changing mining practices so that the ore is fed to the plant with less variability, more advanced process plant control systems and the use of predictive geometallurgical models.

Aug 24, 2022

By Vernon PN

The Eossing Uranium Mine is a high tonnage low grade open pit operation using acid leaching for uranium extraction and ion exchange and solvent extraction for solution purification. Advanced technology, much of it computer based, has led to major economies that have contained operating unit costs over the last four years in the face of double figure inflation. An improved ore reserve block model and mine planning system have achieved a considerable reduction in the stripping ratio. Drilling and blasting costs have decreased some 25%, mainly by the introduction of heavy ANFO explosive. A centralised computer control centre for the metallurgical plant has increased labour productivity resulting in improved process control. The all-staff workforce is united with management in the objectives of creating a safe, healthy, working and living environment and a prosperous company, capable of contributing to the wellbeing of the nation and the shareholders. This situation has been brought into being by an equal opportunity policy coupled with a management system emphasising open two-way communication through all levels in the organisation. The success of this policy is highly apparent in the morale and productivity of the workforce.

Jan 1, 1986

The Newmont Waihi Operations mill has undergone significant growth over its life. Initially designed as a single SAG mill operation, the circuit has been progressively upgraded since 1988 from a nameplate capacity of 600 000 tonnes per annum to the current rate of 1.3 million tonnes per annum. With future mining potential there is renewed interest to increase the processing rate even further. Over the next twelve months five sustaining capital projects will be undertaken and two major eco-efficiency projects will be completed. With the exception of the large grinding mills, most equipment on a gold treatment plant is replaced after 10-15 years. Waihi Gold mine has been operating for 14 years and has just recently received approval to replace equipment in five main areas; carbon elution, carbon regeneration, scats crushing, intertank screens and variable speed drives. Each project has been justified on improved process efficiencies and operating/maintenance cost savings. The two eco-efficiency projects involve a water balance model and a cyanide optimisation project, both of which are Corporate key performance indicators (KPI).

Jan 1, 2002

By Harraway D. H, Draper N

The association of graphite with a fine grained pyrite in the Mount Isa lead-zinc ore was investigated from mineralogical and metallurgical standpoints. The pyrite has been partially or completely replaced by galena and to a less extent by sphalerite, pyrrhotiteand chalcopyrite with the retention of graphite films or inclusions. During lead flotation the graphite imparts a spontaneous flotability to all associated minerals, resulting in a low grade fraction, which we call the carbonaceous fraction, floating with and diluting the lead concentrate. In times of low metal prices this fraction seriously reduces the economic value of the lead concentrate. A flotation procedure was developed to upgrade the carbonaceous fraction separately, producing an economic concentrate and a tailing.INTRODUCTIONThe lead concentrate produced from Mount Isa ores can vary from 20 to 50 per cent lead, depending on the locality in the mine from which the ore is obtained. Variations of this order are independent of ore grade and lead recovery. The large variation is related to the presence in the ore of a variable fast floating low grade fraction known locally as the carbonaceous fraction because of its association with graphite. During conventional lead flotation with sodium ethyl xanthate the carbonaceous fraction floats rapidly and unselectively with normal Mount Isa galena.The paper discusses mainly the examination and treatment of an average carbonaceous fraction, defined here as the fast floating material in the mill feed of late 1956. The ore was drawn from the Mount Isa Black Star orebodies. The fraction represented about 5 per cent of the total ore...

Jan 1, 1961

By Burks WG, Hughes FE, Muceniekas E, Whitcher IG

The area containing the iron field, recognised by the writers, is part of an uplifted, portion of the 'Western Australian Plateau,' ranging in elevation from about 1,000 feet to about 3000 feet above sea level. The local rock succession is flat-lying or moderately-folded and belongs to the Nullagine Series of Upper (2). Precambrian age. This series forms the Hamersley Rangeland vast portions of the...

Jan 1, 1964