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By Ryan CG, Ramsden AR, Sie SH, French DH, Griffin WL

Proton microprobe and electron microprobe analysis are being used in combination for in situ determination of the trace element contents of oxide, sulphide and silicate minerals in a sample of the Merensky Reef. Initial results indicate that chromites contain only Ni, Zn, Ga, Zr ar d Nb. Platinum-group elements, if present, are at concentrations less than 2 to 6ppm. Ru, Rh and Pd are the only platinum group elements to be consistently detected in the sulphides. PentLindite is the most important host for these elements with the concentration of these elements being dependant upon the mineral association in which it occurs

Jan 1, 1989

By S N. Nyoni, K C. Corin, C T. O’Connor

Considering future water scenarios, as influenced by the increasing scarcity of water and the move towards sustainable process engineering etc, the closed water circuit becomes an important point of study in metallurgical operations, such as in milling and flotation. However, a deterrent in the use of recycled process water is often a lack of understanding of the effects of the accumulation of dissolved ions and other process chemicals. Recovery of the valuable minerals may be impacted by the concomitant complex mineral-pulp chemistry interactions. Literature indicates that these interactions are not necessarily antagonistic to process outcomes. Wet milling using steel media results in the dissolution of Fe from the media, the rate of which is dependent, inter alia, on the type of media and the chemical conditions of the aqueous environment in the mill. The pulp-phase interactions of dissolved ions with sulfide minerals may result in significant changes to the chemical conditions in the mill, which may subsequently impact negatively on the flotation recoveries. To understand the effect of these interactions in the context of the processing of sulfide minerals, this study seeks to consider the effect of three factors, viz mineral type – pyrite (Py) and galena (Gn) -, milling media of different compositions – forged steel (FS), 21 per cent high chrome and ceramic media -, and water chemistry, viz, deionised water (DI) and synthetic plant water (SPW). Ceramic media and galena are used for the respective control cases where the milling media and sulfide mineral contribute no Fe species. Using DI as a control case, a high ionic strength case is used to mimic the changes in water chemistry for a closed water circuit. Batch flotation tests are used as a diagnostic tool to determine the effects of these media-water-mineral interactions to investigate correlations between the chemical reactions occurring and chemical species present during the milling process and the ultimate flotation performance.

Aug 24, 2022

By R Valenta

Most developing projects face a range of technical and non-technical challenges, and examination of development histories can potentially provide insights into improved approaches to project development. The Kestanelik project in the Canakkale region of Western Turkey was acquired by Chesser Resources Ltd in 2008. Turkey is a significant and growing source of gold production, with sector participation by both domestic and international companies. While the broad ranges of challenges faced by developing projects is well known, there are relatively few case studies in which the range of technical, environmental, social and governance challenges are presented in a single contribution. Recent studies of undeveloped complex orebodies have particularly shown the extent to which environment, social and governance (ESG) complexities contribute to project delays and failures. The Kestanelik project faced a full range of technical and ESG complexities, and provides an illustrative example of the associated challenges. CITATION: Valenta, R, 2018. A case study of technical, social and environmental challenges for a gold project development in Western Turkey, in Proceedings Complex Orebodies Conference 2018, pp 73–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By A McGann, P J. Coghill, D Miljak

"It is widely accepted that bulk ore sorting could provide a step change in processing of low-grade ores. For this to be achieved a rapid, accurate bulk sensor of grade is required as well as sufficient natural variation of grade in the ore stream. CSIRO trialled a magnetic resonance (MR) sensor capable of measuring chalcopyrite, and by inference total copper grade, on the 1300 t/h Ridgeway portal conveyor. The gauge produced an unprecedented set of data down to a 1 t scale for months at a time. This paper analyses the measured variation and compares it to a simple model derived from the bore core data and mixing within the block cave mine.The model of the small-scale (<1000 t) variation is developed using fractal methods which have successfully been used in the past for copper porphyry deposits showing a power law or near power law distribution of copper grade and vein sizes. These fractal distributions have two features highly favourable for segregating ore, a large proportion of low-grade pods and the large-scale spatial clustering of grade. We show the presence of fractal ordering in bore core data at short range in the Cadia Ridgeway porphyry deposit and measure its persistence in the crushed rock produced by the Ridgeway block cave mine over one month. The model is then extended to demonstrate the effect of varying head grade, mixing and pod (or diversion) weight on bulk sorting efficiency.CITATION:Coghill, P J, Miljak, D, McGann, A, 2016. Modelling Grade Variation in Crushed Ore at Cadia Ridgeway and Its Potential Consequences for Bulk Ore Sorting, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 77–88 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

Before any accident prevention and total safety programme can succeed, a safety concientiousness or attitude needs to be implanted in the employees' minds. Psycholog- ical and physiological conditions play a vital role in accident causation and prevention. Both need attention in a good safety programme, but working place conditions and environment are more easily corrected. However, the challenge is to change attitudes in the minds of men - psychological factors in accidents. To do this does not require a Safety Officer, but does require a Safety Adviser. At Blackwater mine a Safety Adviser is available to all sections of the organisation to guide and assist, to provide data and material to use at meetings, to help in accident investi- gations and to help organise training. To eventually achieve total commitment requires every member of the management team to be a salesman towards all around selling an attitude to safe working, a way of life. At Blackwater mine the workforce is young overall with most employees being under 40 years old. Psychologically this is a quite different problem to a balanced ages working group. A great deal of effort is needed to communicate with the younger, articulate, better educated employee who is also generally a skilled operator in the capital intensive

Jan 1, 1975

An increase in the silver to gold ratio with increase in depth in the main ore shoot of the Crown-Crescent lode in the Emperor gold mine, Fiji, was found to be due mainly to vertical zoning of gold-silver tellurides. The zoning resulted from a two-stage sequence of ore mineralization.The application of some recent studies of the synthetic Au-Ag-Te system to natural gold-silver telluride assemblages is discussed.

Jan 1, 1971

By K B. Quast

Changes in feed size distribution can have significant effects in rod mill grinding. The product sizing resulting from wet batch milling of a tin ore showed little influence on fines production after truncating the feed at either the coarse or fine end. The addition of fine material caused a less amount of fines to be produced and a possible increase in grinding at coarse sizes, although this is complicated by the changing feed size distribution. The changes in feed size distribution caused no tendency for preferential grinding of the cassiterite.

Jan 1, 1998

By A Yáñez, P Vallejos, R Grau, J Yianatos

In flotation cells, especially in large flotation units, froth management is a crucial variable that should be considered during the design phase or optimised to improve the performance of existing flotation circuits. This paper presents a simulation evaluation of the effect of launder design on the metallurgical performance of an industrial flotation circuit consisting of five TankCell® e630 (630 m3 ) cells in a Cu rougher duty. This analysis was carried out using a new industrial simulator, which was built on a wide database collected from many industrial concentrators. This tool is currently incorporated into HSC Chemistry® software and allows evaluation of the effect of launder design on mineral froth recovery, water recovery, entrainment, and other variables to be quantified. The industrial flotation circuit was evaluated under different launder design scenarios, considering an actual flotation circuit that includes TankCell® e630 cells for calibration and as a reference (baseline). Firstly, two different designs were evaluated in the full circuit: a standard launder design and a new launder technology. It was found that the new launder technology enabled improvement of the mineral recovery along the circuit, mainly for coarse particles, due to the improvement in froth mineral recovery. Next, the partial upgrade of the launder design along the circuit was analysed. Thus, the new launder technology was evaluated in the first and the last two cells of the bank. The results showed that upgrading the launders in different cells along the circuit delivered an increase in the final recovery with respect to the baseline, with a partial impact on the concentrate grade. However, these changes are less than those when evaluating the full upgrade scenario. A partial launder upgrade either in the first or last two cells of the bank showed similar final recoveries, but the latter enabled a slightly higher concentrate grade (about 1 per cent higher) to be achieved. Finally, the evaluation of launder design using the industrial simulator made it possible to estimate its effect on variables that are not commonly obtained from plant surveys, including froth recovery per particle size, collection recovery per particle size and liberation, gangue entrainment and bubble loading grade.

Aug 24, 2022

By P D. Fraser

This paper examines the new water-hydraulic (hydro powered) drill rigs that have been developed and proven in the last decade primarily in tabular, shallow-dipping, narrow-reef, hard-rock South African mines. These include - drill rigs for flat end tunnel development, narrow inclined raises and winzes, large inclines and declines and long hole based developments such as orepasses and vent raises. The hydropower technology rigs offer advantages both in safety and performance over traditional compressed air powered, hand-held development are generally more cost effective than imported oil electro-hydraulic drill rigs. Furthermore, hydro powered rigs are inherently energy efficient. The benefits of hydropower are discussed and a æcomprehensive development modelÆ is presented which demonstrates that orebodies can be accessed in significantly shorter times. æLocalisedÆ half level hydropower systems are introduced and a range of ancillary equipment available is listed.CITATION:Fraser, P D, 2012. The use of high-pressure, water-hydraulic (hydropower) technology in South African narrow-reef, hard-rock mines, in Proceedings Narrow Vein Mining 2012 , pp 229-236 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Kukla G. T

A Seam deposit User oriented Mine Planning System (SUMPS) was developed by The Broken Hill Proprietary Company Limited (BHP) at its head office in Melbourne. It is one of the computer mine planning systems developed by the Corporate Data Processing (CDP) section of BHP. To date it has been employed in the feasibility study of four coal prospects for the BHP Group, including Gregory in central Queensland - Ham and Van Hoorn (1978). It was also used in detailed short term mine planning for Gregory. A recent application was in the feasibility study of Saxonvale, a multi seam coal deposit in New South Wales with seams up to 20 m thick. The other two applications of SUMPS were also on thick multi seam coal deposits. Development of programs for the underground sub-section of SUMPS is continuing. SUMPS was developed and implemented on mini computers with graphics and plotting peripherals. The company's philosophy towards computing is one of centralized development and project planning, with transfer of hardware and software to site once the mine becomes Operational.

Jan 1, 1980

By Y Peng, D J. Bradshaw, X Chen

At NewcrestÆs Telfer gold mine, a strategy of regrinding pyrite rougher flotation concentrates has been proposed to increase gold recovery and reduce cyanide consumption in the CIL circuit. The regrinding will be followed by an additional copper/gold flotation stage, where copper minerals need to be separated from pyrite. However, although the minerals are well liberated, the separation of chalcopyrite from pyrite in the cleaner stage is not always straightforward. The surfaces of the fine particles, produced during regrinding, are more easily oxidised and contaminated than coarse particles, directly influencing the particle floatability. The depression of pyrite is difficult in the cleaner stage as well due to copper activation, a process which is also highly dependent on the grinding environment. In this study, different grinding media, including mild steel and stainless steel, was used in the regrinding to produce different regrinding chemistry, such as, pH, Eh, and iron hydroxide contamination. The effects of regrinding conditions on chalcopyrite flotation and its separation from pyrite were studied. It was found that the stainless steel grinding media, which produced an oxidising environment, was more beneficial for the separation of chalcopyrite from pyrite after regrinding. The mild steel grinding media had a detrimental effect on both chalcopyrite and pyrite flotation. This study addresses the importance of choosing suitable regrinding conditions in the pyrite and copper flotation circuit.CITATION:Chen, X, Peng, Y and Bradshaw, D J, 2012. Effect of regrinding conditions on the flotation of chalcopyrite and its separation from pyrite in the cleaner stage, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 279-286 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

Many volcanoes in western Melanesia have tectonic settings and rock compositions that do not conform to conventional models of arc- trench systems. Part of the reason for this may be that in an environment of rapid tectonic change mantle source regions bear the imprint of former subduction even though subduction has now ceased. Results bearing on this concept and on other important aspects of Plelit nesian v ican ism and tectonics, were obtained in 1982-1986 from >e,:eral marine - geoscience studies in the re,,ii n

Jan 1, 1987

By A J. MacDonald, M P. Raffield

The South Deep massive orebody consists of 20 to 30 m of payable conglomerates ranging in dip from 11¦ to 20¦ and at depths of between 2400 m and 3400 m. The mine design process selected a mining method with a proven record of application that could be adapted to overcome the inherent difficulties associated with the depth, thickness and structural influences of the South Deep orebody. A modified cut and fill mining method provides a concentrated and highly flexible method of extraction. An integrated destressing cut will enable the modification of the stress environment such that it is suitable for massive mining operations. The choice of backfill type and stoping width in the destressing cut ultimately determines the characteristics of the stress modification and, as such, is critical to the success of the cut and fill operation. This paper discusses the decision process undertaken to determine the optimum backfill type and stoping width combination in terms of, conditions in the destressing cut faces and in the massive mining environment. Numerical modelling has been extensively used to analyse various scenarios to aid in the decision process.

Jan 1, 1998

By G de Jong, W Sunyoto, M Cloos

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Ertsberg mining district is a 100 km2 area in the highlands of Papua, Indonesia. The district hosts mineralised and barren, outcropping and hidden porphyry and equigranular intrusions. There are at least six major (100+ m wide) porphyry intrusions identified from surface and underground mapping and drill cores. These are the Grasberg Igneous Complex (GIC), Karume porphyry, Lembah Tembaga porphyry, Ertsberg Stockwork Zone porphyry, Kay intrusion and the Wanagon intrusion. Recent deep drilling adjacent to the GIC identified a new hidden porphyry at depth, the Gajah Tidur (Sleeping Elephant), which extends south-west beneath the Kucing Liar skarn. Other named small porphyry dykes and plugs in the district include the West Grasberg, North Grasberg, Idenberg, South East and Zaagkam intrusions. The largest equigranular intrusion is the multiphase Ertsberg diorite.Igneous activities occurred in a relatively short span (<1 million years) from about 3.4 Ma to 2.7 Ma ago, based on U-Pb zircon dating. The various intrusions in the district related to ore mineralisation are high K and appear to have been derived from the same parental chamber, based on similar whole rock rare earth element patterns. Radiogenic Nd- and Sr-isotopic variations indicate that there were multiple recharge events into the parental chamber.The larger intrusions and all economic mineralisation occur in a 4 km wide zone that parallels the N60W-trending axis of the Yellow Valley Syncline (YVS), one of the large folds generated during collisional tectonism. Intrusion pathways at ~3 Ma were localised into dilatational areas in a late and/or post-collisional NW-trending, left-lateral strike-slip zone with Riedel shear offsets between the major fault zones. An early phase of lower K magmatism produced small intrusions in the south-west limb of the YVS.CITATION:de Jong, G, Sunyoto, W and Cloos, M, 2015. Composition, lithochemistry and radiogenic isotopes of porphyritic and equigranular intrusions in the Ertsberg mining district, Papua, Indonesia, in Proceedings PACRIM 2015 Congress, pp 347–356 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By J Savage, A Crawford, M Doyle, N McNaughton, T G. Blenkinsop

Area selection criteria for gold exploration have historically highlighted the low prospectivity of high-metamorphic grade terranes relative to regions with lower metamorphic grades. The Tropicana gold project, Western Australia, is a rare example of a major greenfields gold discovery in Archean mid-amphibolite to granulite-facies gneissic rocks that have experienced widespread recrystallisation and partial melting.The project, located on the tectonically reworked eastern margin of the Yilgarn Craton, is part of the Tropicana Joint Venture, which is 70 per cent owned by AngloGold Ashanti Australia (manager) and 30 per cent by Independence Group NL. Construction of the mine commenced in the June quarter of 2011 and first gold pour from open pit mining is anticipated in the December quarter of 2013. The approved project will have a ten-year mine life and in the first three years of operation, gold production will be between 470 000 - 490 000 oz/a at a cash cost of A$590 - A$630/oz.Reserves as at 31 December 2011 total 56.4 Mt grading 2.16 g/t for 3.91 Moz of gold. The mineral resource, as of 30 December 2012, has grown to 7.89 Moz of contained gold, including Inferred Resources of 11.9 Mt at 2.83 g/t for 1.08 Moz.Economic gold mineralisation post-dates peak metamorphism and is interpreted as younger in age (ca. 2500 Ma) than other gold deposits in the Yilgarn Craton on the basis of structural and geochronological constraints. Mineralisation is genetically related to an imbricate thrust stack that records a prolonged history of reactivation during the Proterozoic era. Gold mineralisation formed from higher temperature (>350¦C) silica-undersaturated fluids that preferentially migrated though a favourable intensely potassium metasomatised zone. Permeability created during brittle fragmentation was accompanied by replacement of mafic metamorphic minerals, and synchronous partitioning of strain into pervasively biotite-sericite-pyrite-altered stylolites and shear planes that bound more competent lithons.CITATION:Doyle, M, Savage, J, Blenkinsop, T G, Crawford, A and McNaughton, N, 2013. Tropicana - unravelling the complexity of a +6 million ounce gold deposit hosted in granulite facies metamorphic rocks, in Proceedings World Gold 2013 , pp 87-94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Konishi Y, Morioka Y, Okabe K

A part of the results of dissection survey of Chiba No.1 blast furnace, Kawasaki Steel Corporat- ion, is presented. Distributions of coke size and of slag and metal holdup are shown in the region of the dropping zone. A similar relation to the irri- gated packed bed is obtained. The distribution of coke size, coke temperature and liquid holdup are measured in and around the raceway. The shape of raceway in the horizontal and vertical sections indicates that each raceway worked individually. Liquid flow in the dropping zone and around the raceway on the basis of holdup measurements is Discussed.

Jan 1, 1981

Radioisotope X-ray and neutron techniques of analysis can be used for the determination of a wide range of elements in minerals. The most important applications of these techniques to the mineral industry are for on-stream analysis of slurries and solids, and for geological assay. The radioisotope X-ray techniques are the more developed ones and two installations for on-stream analysis are in routine use in mineral processing plants in Australia. Neutron techniques are being developed, and should prove valuable for geological assay of large numbers of mineral samples, for borehole logging, and for specific on-stream analysis when the cost of the equipment is warranted.

Jan 1, 1969

By Woods PW

Consulting Engineers have been used in the mining and metallurgical industries for many years. The traditional role of the consultant overseas has been one of assisting with conceptual design right through to con- struction and commissioning as well as on occasion acting solely in specialist fields. This role developed because mining companies wished to concentrate on building up the permanent organisation they require to operate their mines and treatment plants without the traumas of increasing staff for the design and construction period and reducing it on completion. In Australia where there have been few individual minerals projects of magnitude (until recently) companies have looked after their own detailed engineering and construct- ion management employing consultants mainly in specialised fields.

Jan 1, 1975

By A Benedictus, A Butcher, J Wikstr÷m, B Lindblom, E Rutqvist

LKAB is a mining company situated in northern Scandinavia, manufacturing blast furnace- and direct-reduction pellets and sinter fines. Pellet development at LKAB comprises testing at laboratory and pilot scale. The LKAB Experimental Blast Furnace (EBF) is a unique test facility and an important tool in terms of product development and process research. For a better understanding of pellet behaviour in the blast furnace process, LKAB has started to use automated mineralogy for the characterisation and quantification of its iron ore products and pellets. A mineralogical evaluation of iron ore olivine pellets, taken from a test campaign in the EBF, has been performed. The studied materials were samples from excavated pellet layers through the entire EBF at different positions. A large number of iron ore pellets was analysed using a combination of automated mineralogy, using QEMSCAN«, and chemical analysis. Important information about the performance of pellets in the blast furnace process, such as a quantitative description of mineral and iron oxide alterations at different temperatures, Fe-reduction and alkali deposition, was obtained.

Jan 1, 2008

By J M. Palin

Hydrothermal scheelite precipitated in fault-veins at Paradise, Bonnie Jean, Davidson's and Glenorchy mines display chemical variability involving REE patterns that are transitional between two end-member types. Type I is a MREE-enriched pattern with no or a small positive Eu anomaly. Type II is a flat to MREE-depleted pattern with a strong positive Eu anomaly. The chemical inhomogeneity of these scheelites can be explained by a model of fractional precipitation of REE, with preferential removal of MREE from the fluid during precipitation of scheelite. Irrespective of the mechanism responsible for scheelite precipitation, the source of dissolved constituents is different for scheelites from the Paradise Mine. Bonnie Jean, Davidson's and Glenorchy scheelites formed from LREE-enriched fluids whereas Paradise scheelites precipitated from fluids that were lower in LREE. These inferred fluid characteristics cannot be linked unambiguously to specific source rocks in the region, but could suggest that scheelite deposited in the Paradise fault-vein reflects a more mafic source of REE possibly greenschists, whereas the REE in scheelite from the other mines suggest a more felsic source.

Jan 1, 2003