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In Australia we usually define "resource" in purely material terms, and rarely relate it to intellect and human capacity. We look at the sheer abundance of our natural resources and are satisfied with the feeling that we don't really need-to rely on using our brains. Certainly our country is fortunate to have the mineral resources it does, but in many ways Australia's worst enemy is its "lucky country" syndrome because we tend to underutilise the great resource we have in the capacities of our people. Raw material exports will undoubtedly continue to contribute a major share of our export revenue, but to harness the riches our country has to offer most effectively we need the vision and planning necessary to bring together our material and human resources. There is a need not only to find, exploit and process our minerals economically, but to turn as much of our mineral wealth as possible into high value products before it leaves the country. In particular we must use our brainpower if we want to maximise economic benefit from and political influence over the strategic minerals which leave our shores. In the past we have been successful in finding and exploiting minerals because our mining industry has been in the forefront of private sector research and development. But if Australia is to have an advantage over other mineral rich countries in insulating itself from the effects of cyclical swings in commodity prices, then the future of the industry must lie even more in technological sophistication rather than depending. on such considerations as size and location of mineral deposits. To survive, our mineral industry must have the foresight and resourcefulness to make its own luck. There are two keys to increased efficiency in exploration and production and in further processing methods: enhancement of the skills of the workforce and continual improvement of R&D.

Jan 1, 1986

At its Port Kembla Plant, Australian Fertilizers Ltd. manufactures Superphosphate and other Phosphatic Fertilizers.Phosphate Rock is received from Nauru and Ocean Island. It contains water insoluble tri-calcium phosphate, Ca3(PO4), to an average of about 86%.It is crushed to pass a 20-mesh x 26-gauge woven wire screen, and is then treated with Sulphuric Acid to give the product Superphosphate with a water solubie prosphate content of 20.5%, estimated as P205. Sulphuric Acid is made by the chamber process. Three sets of chambers are installed, on,e five-chamber set of timber frame work construction and the other two of more recent date, each with four chambers of steel frame work construction. A fourth chamber set is now being built.Sulphuric Acid is delivered for use. at about 70% H2S04, the strength depending upon the rock used.Mixing - The crushed rock and sulphuric acid are mixed in weighed and measured proportions respectiyely in one-ton batches in revolving cast fron pans, mechanically stirred. The mixture, while still slurry, is run into a closed horizontal concrete cylinder (den) where, with the completion of the chemical reaction, it rapidly sets as Superphosphate.Approximately fifty batches are required to fill a den. When full, the den is opened ana the mass cut out by a revolving cutter. The product is elevated and conveyed to any required position in the Superphosphate storage shed, where it dries and matures.Despatch - As required, the Superphosphate is excavated by a two ton grab and conveyed from the matured "dump" to bagging units where it is disintegrated, screened and bagged at twelve bags to the ton. The filled !Jags are closed by machine and delivered to railway trucks immediately.Mixed Fertilizers - Sulphate of Ammonia, Sulphate and Muriate, of Potash, and Blood and Bone are mixed with Superphosphate and thoroughly incorporated to give different mixtures to meet special plant requirements.

Jan 1, 1938

By D Craw, J Pope

The Greenland Group, Westland, can be characterised with respect to environmental issues by the application of a GIS database (DAME), and specific sampling campaigns. Waters draining gold mineralised areas have a distinctive chemistry characterised by neutral pH and arsenic as a trace element. The acid neutralising capacity (ANC) from carbonates usually exceeds the maximum potential acidity (MPA) from sulphides resulting in circum-neutral pH. These waters are readily distinguishable from waters draining coal mine related areas, which commonly have low pH (~4) and low As concentrations (~0.1 ppm). In contrast, dissolved arsenic mobilised from Greenland Group historic gold mining areas is up to 2.4 ppm. This As mobilisation is controlled by the secondary As mineral, scorodite (FeAsO2+2H2O). Maximum dissolved As concentrations increase with increasing pH, corresponding to the increasing solubility of scorodite with increasing pH. Dissolved As is attenuated by dilution, precipitation of scorodite, and/or adsorption to iron oxyhydroxide (HFO). Adsorption to HFO is an important attenuation mechanism in and adjacent to many mine sites. HFO is abundant at mine sites where pyrite was abundant in fresh rock, such as where the mineralised zone is dominated by disseminated pyrite. Pyrite, and resulting HFO, are relatively rare where mineralisation occurred as well-defined quartz veins. Localised HFO occurs also where ankerite oxidises in host rocks. Arsenic output flux (ca. 25 g/day) from historic gold mine sites is commonly less than the natural background flux from mineralised rocks (>5000 g/day).

Jan 1, 2006

By D Ford

BHP BillitonÆs new rotary iron ore car dumper installation at Finucane Island (Port Hedland) was constructed to increase the total capacity of the port facility from 110 Mtpa to 120 Mtpa and to allow for incremental capacity increases in future. The arrangement of the dumper is similar to other car dumper installations existing on site. To construct the facility, approximately 120 000 m3 of material was excavated in six months, to a total depth of 22 m. The saline water table was nominally 6 m below ground level and the materials excavated varied depending on depth, ranging from sand to mangrove muds. There was a need to retain the sides of the excavation and limit the amount of water from entering the excavated area. This was required to allow excavation to progress and had to be maintained during construction of the permanent concrete and steel facility. The excavation was backfilled progressively as construction progressed. Various retaining wall methods were investigated with the preferred option being sheet piles secured by walers and ground anchors. Detailed electronic models were developed and assessed to complete the final design arrangement. Dewatering bores around the perimeter of the excavation removed the groundwater to intercepted sumps within the site. A strict and methodical program was developed to monitor the integrity of the temporary works and the quality of the groundwater. The works were completed on time despite the following challenges being encountered: availability of resources and equipment, movement of mobile plant on æboggyÆ materials, difficulty driving sheet piles into material at depth, drilling of ground anchors to 32 m, grouting of ground anchors, greater than expected groundwater flows, and the risk of hydrocarbons within the groundwater. The lessons learned from the use of the retention system and, in particular, the associated construction challenges overcome, provide a sound basis for similar work in this buoyant resource market. The conference paper describes the temporary works options investigated, design considerations and processes, construction methodology and challenges encountered, and the monitoring systems developed. Lessons learned are also discussed.

Jan 1, 2007

By E V. Kislov

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Northern Baikal Ni-Cu province is located in Buryatia, south-east Siberia, and geologically is part of the Baikal-Muya volcano-plutonic belt. It is known for numerous PGE-Ni-Cu-bearing mafic-ultramafic intrusions of Neoproterozoic age formed in various geodynamic settings. All these deposits can be regarded as a single Ni-Cu ore cluster located near the Kholodninskoe Pb-Zn deposit, which is ready for mining. In addition, there are less studied, small dyke-like bodies with sulfide mineralisation that formed in a rift setting and may be enriched in Ni, Cu and PGE. Individually, the known bodies are of poor commercial value by their resources, but their close spatial association (<30 km) may make these PGE-Ni-Cu deposits economic in the future. This extended abstract seeks to provide a geological framework of the North Baikal Ni-Cu-PGE province, specifically at the north-eastern Synnyr rift hosting numerous small subvolcanic bodies with Ni-Cu sulfide mineralisation. Some small subvolcanic bodies contain industrial level Ni-Cu deposits (Shanuch, Cabanga-Musongati, Voisey’s Bay, Jinchuan, etc).CITATION:Kislov, E V, 2015. North Baikal region Ni-Cu deposits , in Proceedings PACRIM 2015 Congress, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Knowledge of the hydrogeological setting of a mine forms an integral part of a mining operation. Groundwater impacts, initially, on mine feasibility. Then, on commencement of mining, it interacts on the operational components of dewatering, water supply, tailings leachates, mine wall stability, stormwater run-off, water disposal, impact on regional environment and mine closure planning. The recording of hydrogeological information is frequently overlooked during resource and reserve definition as well as during the course of mining when prime opportunity exists for the collection and collation of this data. In recent times, the exclusion of hydrogeological data has been exacerbated by use of high air pressure drill rigs that exclude water inflow. The recording of water data has been further inhibited by the use of computer coded drill logs that do not include the site geologistÆs or drillerÆs comments on drilling problems and observations associated with groundwater intersections. Geologists now infrequently directly supervise drill rigs, but visit the rig only intermittently to evaluate drilling progress. They do not see first hand drill performance characteristics at water make zones. Drill cuttings, as drill chips and cores, are now mostly logged away from the drill site so that wet sample locations, visual water flow evidence and verbal comments from the driller are not recorded. As a result, mine geologists now do not direct adequate attention to the delineation of lithologies and structures that store and transmit water. This paper provides examples of water sighting and recording techniques applicable to a mining operation. Examples are also provided where hydrogeological conditions have been disregarded with serious impact on the progress of mining. The recording of hydrogeological data should be maintained and formatted by the site geologists into a useful database for review as and when required by specialists in hydrogeology, geotechnical and mining engineering and the environment. The information can be coded by the site geologist for inclusion into the mine database. A groundwater dataset, compiled during the progress of field investigations, will save the considerable cost of re-drilling and hole re-entry testing which would otherwise be required to provide base level hydrogeological information required for progress of mining. Apart from working mine use, a hydrogeological dataset is a necessary component for planning mining closure and mine legacy conditions.

Jan 1, 2003

By R Ibarra, H Solis, G Teowee, B E. Papillon

The authors have previously described a piezoelectric-based system to measure the dynamic pressure during actual detonation in the field. This technique is used in a water hammer test set-up where a donor detonator is fired first, with the pressure sensor and an acceptor electronic detonator placed underwater in a water tank, and maintained at a fixed distance away from the donor detonator. The functioning and timing of the acceptor detonator are captured using a customised microcontroller board called the water hammer timer. Using such water hammer testing, the effect of dynamic pressure was studied as a function of the magnitude of pressure during the electronic timing countdown. Data obtained indicate there is no significant impact in the timing of the electronic detonators in contrast to what has been reported in non-electric detonators.CITATION:Teowee, G, Solis, H, Papillon, B E and Ibarra, R, 2015. Effect of dynamic pressure on electronic detonator timing, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 575–578 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By L Bartsch, M Kelahan, E Wingate, J-S David

The use of column flotation cells for recovery of phosphate is becoming more common practice in certain parts of the world (Brazil, Russia) where igneous phosphate ores are processed. Igneous phosphates are generally finer grained (< 200µm) than some of the traditional sedimentary phosphates (<400µm). Australian phosphate from the Georgina basin is sedimentary, but has a much finer grain size (typically < 106µm) than similar deposits in North Africa and the USA.In 2013, Arianne Phosphate completed a bankable feasibility study for the development of their igneous phosphate deposit at the Lac a Paul site in Quebec. Initially, lab test work and bench scale piloting indicated that using traditional mechanical flotation would be able to produce adequate concentrate grade and an economic level of recovery, but would necessitate the installation of a complex and operationally challenging flotation circuit. Later pilot plant testing using column cells resulted in a significant reduction in process complexity and facilitated the processing of the -20µm ore fraction which resulted in a 10% increase in P2O5 recovery and a 5% increase in concentrate grade %P2O5.Flotation column testing achieved a concentrate grade of 38.6% P2O5 at a P2O5 recovery of 90%. Using a mechanical flotation cell circuit, the concentrate grade was 36.4% P2O5 with a P2O5 recovery of only 78.8%. A noticeable feature of the testing was the simplicity of the column flotation circuit configuration (Rougher + 2 stages of cleaning + Cleaner Scavenger) compared to the mechanical flotation cell circuit (Rougher + Scavenger + 3 stages of cleaning).The financial benefit for this case study was estimated using a sales price of US$ 195/t FOB for a 38.6% P2O5 product, and an assumed cost of production of US$ 95/t, the netback price is calculated at US$100/t. For a daily milling rate of 55,000t/d, the improved flotation performance provides additional concentrate production of 1,203t/d. Using the netback price calculated above, this calculates to additional gross profit of US$ 120,260/d.Annualised, this equals US$ 40.7 million in additional revenue for a similar or reduced CAPEX.The use of column flotation on fine grained phosphate ore types often requires fine grinding and desliming to liberate the phosphate value, such as the Australian sedimentary phosphate ores. This may enable the development of deposits previously regarded as uneconomic.This paper discusses the potential benefits available to operators, and developers of new projects, for the use of column flotation cells in their metallurgical circuits as assessed by an engineering company.CITATION:Wingate, E, Kelahan, M, David, J-S and Bartsch, L, 2015. Does it make cent$ to use flotation columns for phosphate beneficiation?, in Proceedings MetPlant 2015, pp 353–365 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By S Gulati, N Sarkar, T Vink, S Battersby, L Okada

This paper examines a successful project implemented by BHP Mitsubishi Alliance (BMA) and the Polymathian team at Deswik, aimed at enhancing short-term scheduling processes to reduce vessel turn times in the BMA Central Queensland coal value chain. The project’s objective was to digitalise the planning process to enable planners to make data-driven insights to improve the profitability of the value chain. The strategy involved developing a digital mining system that incorporates data storage, cloud computing, and the ability to meet the integration needs of both internal and external business systems. This was complemented by a sophisticated, optimisation-based, decision-support tool to enhance the planning teams’ ability to make timely and effective decisions.

Sep 1, 2024

By M Henderson, M Hudyma

Mining-induced seismicity at Junction Gold Mine became a serious operational problem in the late-1990s. Assessing the local seismic hazard is an important step in assessing the risk associated with potential rockbursting. This paper discusses the qualitative and quantitative means of assessing seismic hazard used at Junction. In qualitative hazard assessment, the role of the primary factors contributing to mining-induced seismicity and rockbursting are identified. These factors include: rock mass properties, geological structures, mine development, and stoping. A qualitative seismic hazard map has been developed considering these factors. In quantitative hazard assessment, seismic source parameters from an Integrated Seismic System are used to assess seismic hazard. The seismic source parameters found to be relevant to seismic hazard assessment at Junction are discussed.

Jan 1, 2002

This paper discusses support requirements for the proposed monorail system to be used in decline development. The monorail drilling and loading systems are systems that move on the rail (monorail) installed in the roof of the decline and supported by roof bolts, suspension chains and steel supports. However, due to the weight of the components of the two systems, it is imperative that the force in each roof bolt, suspension chain and steel support capable of suspending the weight of the heaviest component is determined. Numerical models that relate the weight of the monorail drilling and loading components to the required strength in the support system have been developed. Using these developed models, numerical values of the forces in each roof bolt, suspension chain and steel support, required to suspend the weight of the heaviest component of the monorail drilling and loading systems are determined.

Dec 6, 2010

The seminar had its origins in an Inquiry into the Box Flat Disaster and one of the conclusions from this Inquiry was that there should be a better dissemination of technical knowledge and the results of research work. As a result of this Mr. W. Roach, Chief Inspector of Coal Mines in Queensland and Mr. R. Menzies, Chief Inspector of Coal Mines in N.S.W. had a meeting to see how this could be done. They concluded that it would be difficult to have the sort of regular meetings that would be possible where distance was not significant, but a seminar would be a major step toward satisfying this particular conclusion of this Inquiry. As a consequence, Mr. Roach, who is on the Committee of the Southern Queensland Branch of the Institute, suggested when the Branch programme was being planned this year that a meeting of this type should be held, and the Mine Fires Seminar which was held today is the result. We have received a great deal of support in arranging the Seminar. First and foremost I wish to acknowledge support from the National Coal Board in United Kingdom. Not only have they released Dr. Willett for a period of six to seven weeks to visit Australia, conduct the Seminar and give a series of lectures in various areas through the country, they have also borne the brunt of the financial support that has been necessary to make this possible. In addition we have received considerable support from many organisations in Australia. I 'mentioned this

Jan 1, 1973

During the first five years of operation, the Lihir gold mine has steadily increased plant throughput rate to over 4 Mtpa, well above the original design capacity of 2.8 Mtpa. Understanding how future variations in ore type impact on plant performance has been an integral part of LihirÆs development program. This paper discusses the key drivers for significant improvements to the plant, including a second oxygen plant, a pilot flotation plant, an autoclave heat recovery circuit, a pebble crushing circuit and additional autoclave feed pumping capacity. The result is a process plant with the flexibility to accommodate variations in ore type without significant loss of throughput.

Jan 1, 2003

By T Sua, B Wright

"BHP Billiton West Australian Iron Ore (WAIO) conducts an extensive geometallurgy program for its iron ore deposits in the Pilbara with the focus on determining the lump yield (the mass percentage of >6.3 mm rocks) and the lump and fines grade for iron ore products. The geometallurgy program provides accurate information to design engineers and technical marketing teams on the performance of different iron ore mineralogies for future deposits. Additionally geometallurgy results are being used to guide short-term production planning with their introduction into short-term geology models and grade control models. The data that underpins this knowledge is from dedicated geometallurgical programs, drilled using PQ (~83 mm) holes. These holes are crushed by intervals that are based on geological definition which provides an indicative lump yield and lump and fines grade. The lump is then subjected to standard dropping and tumbling test stages to produce a simulated lump and fines product. In the past, quality assurance, quality control holes were drilled using HQ (~64 mm) holes for geochemistry purposes. These holes were crushed to provide an indicative lump yield and lump and fines grade and then 100 per cent is sent for assay (with no dropping and tumbling). Utilising data from HQ holes can significantly increase the indicative geometallurgical data available. This paper compares the geometallurgical results from both PQ and HQ holes from a range of bedded iron deposits (Brockman and Marra Mamba). The PQ and HQ data are compared by orebody, stratigraphy and depth to exclude factors that are expected to influence geometallurgical results.CITATION:Wright, B, Sua, T, Robertson, B and Van Dijken, B, 2016. Comparison of Diamond Drill Size on Iron Ore Geometallurgical Results, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 161–166 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

In eastern China, most of the copper skarn deposits occur in folded troughs which are controlled by the EW-trending faulted fold systems (the Pal-Asian geotectonic domain), and the NNE-trending rift or fault zones (the Marginal-Pacific geotectonic domain), particularly the later. From the north to the south, there are four troughs hosting the main copper skarn deposits in eastern China: the Yanliao Trough, the Yangzi River Trough, The Qiantang-Yuanshui Trough and the Zichen Trough. There are more than 30 copper skarn deposits in eastern China, and ore reserves of each deposit are between 30 to 100 Mt with average grades over 1% Cu.    Most of the large copper skarn deposit-related intrusions are Mesozoic in age (170 to 100 Ma) and were emplaced during the Yanshanian Movement. Outwards from the intrusion bodies, both the skarn alteration and mineralisation show certain patterns of zonation. Mineral assemblages indicate a relatively high oxidisation state during metasomatic alteration and mineralisation. Sulphur isotopic work indicates that most d34S values of the sulphides are between ~4 to 3ë suggesting a common magmatic sulphur source. Fluid inclusion and oxygen isotopic studies suggest that early-stage fluid shows magma-related fluid characteristics although meteoric water was involved during late-stage alteration.

Jan 1, 1995

By N Haque

Base metal ores contain low levels of toxic/hazardous elements such as arsenic, antimony, bismuth, cadmium, lead and mercury. Given the large tonnage of base metal ores mined and processed each year globally, the accumulated mass of minor elements introduced into the biosphere is large and could be expected to have a significant environmental impact. Life cycle analysis (LCA) is a methodology that has been developed to assess the environmental impacts of material supply chains over their entire life cycle. Assessing the toxicity impacts of metallic wastes and incorporating these impacts into LCA methodology is not a simple task given the complexity of the issue. However, research and methodology development is in progress internationally to address this. Despite limitations concerning the lack of a coherent framework for characterising the toxicity impacts of metals, including issues such as bioavailability, a study was carried out to give first estimates of the relative toxicity impacts of various waste streams from metal production processes. The wastes considered were: red mud; sulfide tailings (copper, nickel, lead/zinc); lead/zinc slags; synthetic rutile residue; iron oxide residue; and copper slags and anode slimes. These toxicity estimates can be considered the æworst caseÆ scenario for these wastes, where all the metals present are bioavailable. Combining estimates of the amounts of the various waste streams produced in Australia each year with the toxicity results showed that despite their relatively low human toxicity impact per unit mass compared to some other waste streams, red mud and the various sulphide tailings had the highest annual human toxicity load on the environment, along with copper smelting slag and dust. Data from the pH dependent leaching test reported in the literature were assumed to represent first approximations of metal bioavailability and used to compare the two approaches to estimating the toxicity impacts of red mud.

Jan 1, 2009

The placer mining industry of the West Coast region of the South Island is based largely around the production of alluvial gold, although other valuable minerals are also present. Since the first major discoveries in 1864-65, reported gold production has totalled around 264 t (8.5 Moz). During the past 10 years, annual production has totalled around 1460 kg (47,000 oz). It is anticipated that gold production over the next three years will continue at a level of 1400-1800 kg.   Annual gold production peaked during 1866 at approximately 17,170 kg (550,000 oz) and has not exceeded 100,000 oz since 1885. This reflects the ease with which gold was won from shallow, rich deposits that were present at many localities. Subsequently, there has been a general decline in the availability of this type of deposit, a trend that will continue in the future. This paper outlines the present state of placer mining in the West Coast region, gives some historical background to the industry and briefly predicts future trends.

Jan 1, 1997

By M Rafty, A Markham, S Atkinson

Australia contains some of the most productive mining areas and is characterised by ancient landscapes and highly variable hydrology. Historical mining of iron ore, coal and other minerals has targeted ore deposits located above water tables, and elevated above creek lines where possible to reduce cost. The downturn in mining caused by falling ore prices over recent years has triggered a drive to reduce cost, maximise yield and delay capital expenditure associated with opening new mines. So as the ore deposits with more favorable mining conditions become depleted there is an increased focus on mining ore associated with valley floors and creek lines. This is demonstrated by a regional assessment of the extent of Channel Iron Deposits (CID) and Iron Ore (Fe) Mines and Deposits in the Pilbara Region of Western Australia (Figure 1). A large proportion of these mines are, or plan to, target high grade CID ore associated with existing creek systems. Figure 2 shows outcropping and inferred sub-cropping CID extents, which suggests there are vast quantities of CID ore deposits throughout the Pilbara Region, intersected by major creeks which could be mined at some point in the future using creek diversions (Atkinson et al., 2017). A similar picture could also be produced for coal mining in Queensland, particularly in areas such as the Bowen Basin.While creek diversions provide an opportunity to maximise the utilisation of these orebodies and extend the life of mine, creek diversions can involve substantial financial, social, environmental and regulatory risks that need to be carefully managed (Markham et al., 2017, Atkinson et al., 2017). This paper discusses the key issues and opportunities associated with diversion decision making. It highlights the importance of using a well-structured assessment methodology that allows key stakeholders to be part of the assessment process and is complementary to material presented in Atkinson et al., (2017). Design considerations for operational and closure designs are presented, as well as mine planning considerations, risks, cost saving opportunities and the benefits of an integrated approach to design. The role technology plays in diversion design and performance monitoring is discussed as are the potential opportunities for the future.CITATION:Atkinson, S, Markham, A and Rafty, M, 2018. Diversion decision making with an integrated approach to design for operations and mine closure, in Proceedings Life-of-Mine 2018, pp 74–79 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By G Maude, R Ayres, R N McLean, N A. Reynolds

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Mabilo copper-gold-magnetite skarn deposit is located in southern Luzon in the Paracale mineral district, where iron has been produced historically from several skarn deposits. Mabilo occurs in the south-west of the district and is distinct and significant because of its high grades of copper and gold compared to historical mines.The Mabilo licence surrounds the Venida prospect, where past small-scale mining has exploited iron, copper and gold mineralisation in oxidised skarn. A ground magnetic survey in 2007 defined a number of strong anomalies under Quaternary volcanic cover south of Venida. The property was acquired by Sierra Mining Ltd in 2011, the magnetic data were remodelled and drilling commenced in September 2012. Diamond drill hole MDH001 targeted the strongest anomaly, which was 500 m south of Venida and under 20 m of volcanic cover. It intersected 94 m with an average grade of 2.2 per cent copper, 1.6 g/t gold and 36.6 per cent iron. Subsequent drilling was targeted by magnetic modelling, incorporating magnetic susceptibility data from drill core, which resulted in a high percentage of successful drill holes.The mineralised skarn preferentially replaces a dipping limestone unit within an Eocene sequence dominated by volcanic siltstone and sandstone, metamorphosed to marble and hornfels in the aureole of a Miocene quartz-diorite intrusion. Skarn occurs discontinuously along the eastern and southern diorite contact, controlled by primary sedimentary facies variation, structural geometry, fault offsets and intrusive contacts.Coarse magnetite skarn with garnet and minor wollastonite and clinopyroxene contains variably abundant chalcopyrite and minor molybdenite. Magnetite skarn occurs in sharp contact with unaltered marble or grades into garnet skarn with minor chalcopyrite. Structurally controlled retrograde skarn alteration is strong to intense and is characterised by bornite, clinozoisite, iron carbonate and chlorite. The retrograde skarn is weakly overprinted by late-stage pyrite veining and brecciation associated with clay-silica alteration with arsenopyrite and tetrahedrite-tennantite.The quartz-diorite stock is interpreted as the source of the prograde skarn-forming and mineralising fluids. Late-stage porphyritic intrusions in the contact zone indicate continuing magmatism during uplift, when telescoping led to a high-level, high-sulfidation overprint. This suggests the potential for deeper porphyry-style mineralisation.CITATION:Reynolds, N A, Ayres, R, McLean, R N and Maude, G, 2015. The Mabilo copper-gold-iron deposit – a new skarn discovery in the Philippines , in Proceedings PACRIM 2015 Congress, pp 431–438 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Mechanism Responsible for Flocculation in Poly (N-Isopropylacrylamide) Temperature Responsive Dewatering - Attractive Interaction Forces Induced by Surface Hydrophobicity

Sep 13, 2010