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By K J. Grohs

Martabe gold and silver mine is situated in northern Sumatra and comprises several deposits in steep terrain that are required to be developed in the optimal sequence for the best possible Net Present Value (NPV) return on the project. In addition, the waste from the excavations is a by-product to be scheduled and used for construction of the tailings storage facility (TSF). These plans need to be aligned to ensure the tailings can be contained relative to the production rate. The TSF embankment construction includes potentially acid forming (PAF) waste that needs to be progressively sealed and rehabilitated to meet the closure requirements of the future.The mine is situated approximately 3 kilometres north of the township of Batangtoru in a seismically active zone between the off-shore subduction zone and the trans Sumatran fault. The mining operation currently includes two open cut pits with a third in development stage, an integrated TSF and dualpurpose valley-fill type waste rock storage facility (WRSF) and TSF embankment. Mine waste is used in construction of the WRSF / TSF embankment, including PAF waste rock, which needs to be scheduled for optimal use in construction activities in a manner that mitigates future acidic and metalliferous drainage (AMD) risks (Pearce and O’Kane, 2017).The Life-of-Mine (LOM) plans must satisfy both optimal pit development to maximise NPV and suitable delivery of waste for effective TSF construction matching the rate of rise of tailings, and consider AMD management, progressive rehabilitation and ultimately effective sustainable mine closure. This paper outlines the methodology to optimise the system to deliver these potentially opposing objectives.CITATION:Grohs, K J, 2018. Martabe integrated life-of-mine optimisation, in Proceedings Life-of-Mine 2018, pp 83–86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By Walton S, Wheeler D. J, Sargent D. M, Ting L. Y

Goonyella-Riverside mine is an open cut coal mine in Central Queensland. One component of the mining operations at this site is an uncompacted spoil dump some 50 m above the natural ground surface and over 300 ha in extent formed as a result of bucket wheel excavator operations. Plateau area slopes are 0.5¦ to 1.5¦ with irregular outer dump slopes of 9.5¦ - 17¦Investigation was undertaken and a series of trials planned to assess the suitability of a variety of stabilisation proposals to meet the client's requirements and to conform with Department of Resource Industrystabilisation guidelines.

Jan 1, 1992

By Harbort G. J

Jameson cell pilot plant trials were conducted in a number of areas in the Red Dome gold/copper flotation plant during 1991. The aim of testwork was to reduce the amount of cyanide soluble copper reporting in tailing to the gold leach plant, and hence reduce cyanide consumption. A number of these tests were conducted in parallel with conventional flotation columns. Laboratory tests were conducted to simulate the performance of the existing plant when compared with the addition of the Jameson cell allowing an extra sulphidising phase. This paper reviews the comparison of the Jameson cell and conventional columns in recovering cyanide soluble copper, while maximising copper concentrate grade. Key parameters that are investigated are residence times, air/pulp ratios, superficial gas recoveries and size by size recoveries. A brief comparison of performance of the Jameson cell and column in the controlled potential sulphidisation process is also presented. An estimation of the reduction in cyanide consumption is given.

Jan 1, 1992

By Fuerstenau MC

Zinc cementation and carbon adsorption are both presently used for precious metals recovery from cyanide leach solutions. Each of these techniques exhibits unique processing features which renders them suitable to treat solutions with different properties and in different applications. In this study, the two processes are reviewed and compared. Operating data from a number of Merrill-Crowe precipitation and carbon adsorption plants in North America have been obtained and used in this analysis. The relative capital and operating costs for the two processes have also been considered.

Jan 1, 1993

By Adranyl W. W

Sub-level caving with bottom ore drawing has gained wide acceptance in rich, soft, low magnetic iron ores because it provides moderate ore dilution and ore losses. The main problem here is the high rock pressure exerted on sub-level drives situated in the sub-level sill pillars. To reduce this effect, the ore block is divided into panels. This paper illustraes the method of determining the maximum panel width providing low maintenance cost of sub-level drives.

Jan 1, 1995

By R Grogan

The Ungay-Malabago polymetallic deposit, currently owned by Lafayette Mining, is located on the eastern end of the island of Rapu-Rapu which lies east of the city of Legazpi in the Philippines. The island is sparsely populated and has largely been deforested by extensive logging some 30-40 years ago.The deposit is situated on a plateau some 200 m asl and lies about one kilometre inland from the coast. The site topography is difficult with minimal flat areas for plant facilities. The region around Legazpi is subject to volcanic activity and though the island is not affected it is in a seismic zone. There is no other mining or other industrial activity on the island, the local inhabitants being engaged in subsistence farming and fishing. These activities place a high level of responsibility on the mine operator with regard to the environment and the provision of employment and training to the local inhabitants. Although no previous mining was carried out at Ungay, shallow pit mining for high-grade direct smeltable copper ore has occurred during the mid-1900s in an area, known as Hixbar, some 2 km west of the deposit This area is currently being explored by Lafayette.

Jan 1, 2002

THE Company's smelting equipment consists of three blast furnaces, supplied with blast from two sets of vertical piston blowers, each capable of delivering 8000 cub. ft. of air per minute at a pressure of 60 oz. per sq. in. Each blower is belt-driven by a 1:30 h.p. motor. The maximum speed of the blowing engine is 35 r.p.m.No. 1, the largest of the three blast furnaces, has a crucible area of 49.5 sq. ft., and measures 11 ft. 6 in. x 5 ft. at the tuyeres.From tapping floor to feed floor measures 35 ft. 9 in., and holds, when full, 100 tons of charge. Blast enters through thirteen 3-m. tuyeres at 60-oz. pressure. Working normally, this furnace is capable of treating :300 tons of charge, exclusive of returned slag and coke, per 24: hours, with an output of 100 tons of lead. Tapped slag flows into a C.l. forehearth mounted on wheels, where any lead and matte is caught, and the slag overflows into a 3-ton cast-iron pot, in which it is drawn away by an electric locomotive and poured over the dump.

Jan 1, 1918

A synthetic gold-silver telluride material (mainly sylvanite) has been prepared and its physical and chemical properties checked. Flotation tests using a Hallimond tube were conducted using commercial xanthate collectors. At collector concentrations of 10-3M with the addition of 5 × 10-4 M CUS04, no obvious differences in the mineral recoveries were seen irrespective of whether amyl, secbutyl, isobutyl or isopropyl xanthates were used. However, when the concentration of xanthate was reduced to 10-4 M or in the absence of the copper sulphate activator, the effectiveness of the collectors was in the order: amyl > secbutyl > isobutyl > isopropyl > ethyl. Changes in the slurry pH appeared to have little effect on the recovery of the telluride mineral.Leaching tests of the precious metal telluride showed that both gold and silver dissolve in alkaline oxygenated cyanide solutions but at a much lower dissolution rate than metallic gold or silver. Both leaching tests and electrochemical measurements indicate that the dissolution rate of gold-silver telluride is controlled by the pH and cyanide concentration of the leachant.Roasting the gold-silver telluride materials in air at temperatures between 550 and 750°C resulted in its decomposition into a metallic gold-silver alloy and tellurium dioxide.

Jan 1, 1994

By C Nucifora, M Landers, J Jones, G Maddocks, K Mandaran, A Forbes, W Wilson, S Newman

Glencore’s Mount Isa Mines Limited (MIM) operates the Mount Isa open cut and underground copper (Cu) and zinc-lead (Zn/Pb) mines near Mount Isa in Queensland, Australia. Tailings from processed Cu and Zn-Pb ore is contained in a 1,315 ha shallow (< 35 m deep) multi-cell valley fill tailings storage facility (TSF). Static geochemical testing conducted by MIM over the life of mine (LoM) verifies that the Cu, and Zn-Pb tailings has a wide range in sulfide content and diverse mineralogy with significant acid neutralising capacity (ANC) in some samples. The tailings are predominantly classified as potentially acid forming (PAF) using static analytical methods. Kinetic leach testing using free draining columns and humidity cell tests simulating tailings placed on the surface of the TSF suggest that the tailings samples are likely to remain non-acid forming (NAF) for 10 to 40 years under aerial exposure, and much longer than this under saturated conditions within the TSF. During this period of weathering, as ANC is depleted, the neutral pH drainage may contain elevated concentrations of some elements including sulfate, manganese and zinc. Only when the ANC is depleted would the tailings then begin to produce acid drainage. CITATION:Mandaran, K, Jones, J, Nucifora, C, Maddocks, G, Landers, M, Forbes, A, Wilson, W and Newman, S, 2018. Mount Isa Mines Rehabilitation Materials Sampling and Analysis program for closure planning, in Proceedings Life-of-Mine 2018, pp 138–140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By D Joshi, J Rostami, M Karakus, A Eustes

The first target of mining activities on the surface of the moon is to find and extract water from the icy regolith on the moon. A test drilling unit was designed and fabricated under a NASA Early Stage Innovation (ESI) grant. A high-frequency data acquisition system was used to record drilling responses at 1000 Hz. Parameters like weight on bit (WOB), torque, rev/min, rate of penetration (ROP), mechanical specific energy (MSE), field penetration index (FPI), and the uniaxial compressive strength (UCS) were recorded for 40 boreholes in the analog samples made of regolith simulant and specialised cement. Development of the AI system and machine learning (ML) algorithms for analysis of data to evaluate strength and hence water content of icy regolith required a large data set. In this case, the data set comprising of more than one billion data points recorded while drilling into various analogue samples and cryogenic lunar formations to optimise power consumption and make bit wear adjustment during drilling operations. The tests were also repeated in the samples of icy regolith at various water content at -190C to verify the ability of the algorithms to analyse the data and to estimate the strength of the frozen formation and hence water content. The paper will discuss the objectives and methodologies used in the project and reviews the testing program and the machine learning (ML) algorithms ability to identify various formations along the exploration boreholes.

Sep 1, 2024

By Brown D. N, Troth D. A

Large blast furnaces demand high standards of preparation of feed materials which must meet tight specifications of chemical and physical quality. Measurement of these factors must be expeditious but the nature of the coke, sinter, ores and fluxes and the large tonnages involved requires substantial mechanical sampling plant. The equipment, its operations, and its problems, associated with the 5000 t.p.d. No.5 blast furnace at Australian Iron and Steel Pty. Ltd., Port Kembla, are described and the efficacy of chemical blending achieved in the ore blending yards and sintering operation, is reported.

Jan 1, 1976

By J Lainé, M Badawi, A C. de Araujo, Y Foucaud, C Veloso

Flotation is the one of the most used techniques for the mineral separation of non-ferrous ores worldwide. However, the increase of the complexness along with the decrease of ores liberation sizes ought to become important challenges for mineral processing, including flotation. It now appears necessary to better understand the fundamentals of the flotation process, particularly the adsorption of flotation reagents at the liquid/mineral interfaces, to propose further improvements. Flotation relies on different phenomena: surfactants adsorption, on one hand, and collision, adhesion, and transport of particles with bubbles, on the other hand. For acknowledging the reagents adsorption mechanisms, molecular modelling tools borrowed from chemical and material sciences, are increasingly used. Atomistic simulations were successfully applied to study the flotation reagents interaction with various mineral surfaces, eg of two common minerals from iron ores, kaolinite, and magnetite surfaces, or with fluorite surface, a tungsten ores common gangue mineral.

Aug 24, 2022

Modern technology and the need for published results have created the tendency for exploration to concentrate on drilling and assaying rather than building a broader geological understanding. Though grade is vitally important to a resource estimate, density and volume are also very important aspects that require equal consideration. Wet tropical nickel laterites are developed in humid environments over ultramafic bedrock where the nickel and cobalt are enriched to economic levels by weathering, leaching and supergene processes. These laterites often occur over rugged terrain at higher elevations where there is sufficient rain and stability for the long lateritisation process to occur. For nickel laterite profiles, the variable terrain and significant material type changes within the relatively thin profile make density and particularly volume estimation, just as significant as grade in resource estimation and assessment of resource risk. Drilling alone is generally not a cost-effective way to reduce the risk in laterite volume estimation to acceptable levels. Surface geological mapping, high resolution topographic data and other information such as ground penetrating radar (GPR) can be used very effectively to improve volume estimates. These data types are all differently structured, have different data density and quality and may potentially overlap. Integration of these disparate data types provide the most cost-effective approach to modelling wet tropical nickel laterite volumes and minimising risk. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By D Connelly

The Iron Road Limited Central Eyre Iron Project (CEIP) area, located on the Eyre Peninsula of South Australia, covers extensive Archaean iron formations that occur as coarse-grained magnetite bearing gneiss. The cumulative strike length, estimated from aeromagnetic data, is at least 95 km.The project is located in a grain growing area 185 km west of the existing iron ore and steel making operations of OneSteel at Whyalla. A narrow gauge railway built to transport agricultural products to the deep-water port of Port Lincoln, 175 km to the south, traverses the project area. A number of well-serviced rural townships are located nearby. Current activities include resource expansion drilling, extensive metallurgical test work, community consultation and a Prefeasibility Study (PFS) that commenced in April 2010.The PFS has encompassed the Central Eyre Iron Project, comprising the three significant iron occurrences (Warramboo, Kopi and Hambidge) and was completed in early 2011. Extensive test work programs and metallurgical modelling confirmed viable process options for the project, using simple off the shelf processing technology.Preconcentration by coarse cobbing yielded promising results, and is the key to reducing not only the capital expenditure but also the operating cost, in particular the power cost, which is the highest operating cost component of a magnetite benefi ciation plant. The ore is also amendable to high pressure grinding rolls (HPGR) processing. This offers a potential for further reduction of the energy requirements.Test work also confirmed that a high grade blast furnace quality concentrate (~68 per cent Fe) can be produced at a relatively coarse grind (P80 106 µm).

Jul 11, 2011

By Fair A, Oxenford J

Syncrude Canada Ltd operates one of the largest open pit mines in the world at Fort McMurray in northern Alberta, Canada. In 1993, Syncrude mined and processed 131.2 Mt of oil sands to produce 67.0 MBbls of synthetic crude oil (SCO). This represents approximately 13 per cent of Canada's crude oil requirements. In addition to the oil sand mined, Syncrude moved approximately 96 Mt of overburden ahead of the mining operation in 1993. Since start-up in 1978, Syncrude has had outstanding success in improving the safety and reliability of its operation. Much of this success has been achieved by reducing risk through the application of new and improved technology. This improved safety and reliability has resulted in, among other things, very significant improvements in operating costs and profitability. This paper discusses some of the technology applications that have been introduced at Syncrude to reduce risks to people, equipment, operations and the environment. Three specific examples will be discussed in detail to demonstrate how reductions in risk have greatly improved the operation.

Jan 1, 1994

By T B. T Nguyen, L Matthews, D O’Dea, T Honeyands, T Harvey

Productivity and fuel consumption of the blast furnace is driven by the quality of the iron ore sinter, which in turn is related to the sinter mineralogy. The sintering conditions including temperature and gas composition have a significant influence on the formation of melt and finally the mineralogy of the sinter. In this work, analogue sinter tablets were produced from iron ore fines in a laboratory furnace with tightly controlled temperature profile and oxygen partial pressure in the gas. The mineralogy of the sinters was analysed using reflected light microscopy. The results showed that increasing thermal enclosed area (area enclosed by heating and cooling curve above a reference temperature) reduces primary hematite and platy silico-ferrite of calcium and aluminium (SFCA) contents. This is attributed to increasing melt formation, leading to greater assimilation of the iron ore particles. Lower magnetite was found for tablets with greater median pore size, which is thought to be due to greater oxidation of magnetite to hematite during cooling in air. It was also found that higher alumina content was found to result in more SFCA formation under the same heating/cooling conditions, whereas tablets with higher goethite had higher assimilation and produced more secondary hematite on cooling. Finally, it is necessary to relate the enclosed area to the temperature at which the melt formation becomes significant which strongly depends on chemical composition of the ore studied.

Nov 8, 2021

By C Czerny, T Elkington, L Lorenzen

The Dutwa Nickel Project is a nickel laterite atmospheric leach project located in Tanzania that has been under development by African Eagle Resources plc (2012). A bankable feasibility study (BFS) has been progressed to evaluate mining of the resource (107 Mt at 0.92 per cent Ni) followed by hydrometallurgical processing on-site to make a mixed nickel-cobalt intermediate product. The unique relatively high silica contents in the Dutwa deposits, as opposed to limonite, which is more commonly occurring in nickel laterites, presented the possibility for beneficiation of the ores to enhance the leach feed nickel grades and provide economic benefits in terms of operating and capital cost efficiencies.Geometallurgical relationships, based on the results of an extensive variability metallurgical test work program for beneficiation and leaching, were developed for the BFS, which resulted in an improved understanding of ore classifications within the deposit and their responses. The geometallurgical information obtained has been instrumental in making key preliminary techno-economic decisions, such as forecasting whether or not mined material should be beneficiated and was ultimately used to drive the mine plan towards the prioritisation of areas within the deposits that delivered the best cost efficiencies and overall project economic outcomes.CITATION:Elkington, T, Lorenzen, L and Czerny, C, 2013. The use of geometallurgical relationships in process route selection and mine plan optimisation for the Dutwa Nickel Project, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 207-216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

Uniaxial compressive strength and Young's modulus values measured in the laboratory on NX diamond drill cores were examined statistically to bring out any significant differences between different locations in the mine which might require special treatment in subsequent photoelastic analyses of the mine layout. Correlations were sought between the strength and modulus and various other features of the rock. The estimated mineral content of the core correlated with the modulus of the core, but the range of modulus values was too limited to show any strong correlation with compressive strength.Strength in the vertical direction was found to be significantly higher than in the horizontal direction and the same pattern was followed by the moduli, but was less pronounced. It was concluded that, whilst the modulus variations were significant, they would not invalidate any photoelastic studies.

Jan 1, 1969

That gold will dissolve in sodium hyposlphite solutions is known from the lixiviation of silver and gold ores.The gold will dissolve only in small quantities. According to Stetefeldt, if gold leaf is treated for a time with sodium hyposlllphite solutions of varying strengths solution takes place in every instance, the deviation in quantity being very slight.In order to form hyposulphite double-salts, the gold must become oxidised, the oxygen being derived from the air absorbed by the solution. Consequently, it is the quantity of free oxygen in the solution by, which the reaction is determined, as for one equivalent of gold dissolved one equivalent of caustic soda is set free.

Jan 1, 1901

Having worked as a consultant for most of his 40-year working life, mostly as a mineral property valuer, the author has seen many poor valuations. Most were valuations of exploration tenements where the selection of the rather subjective, but necessary, geological inputs raised the main concerns. Those valuations involving iron ore prospects raise particular problems due to the special characteristics of such deposits. Iron ore is more like an industrial mineral rather than precious or base metals and Reserves are determined not by a traditional cut-off grade but by customer specifications. This is intended to be an overview/keynote paper on the current state of the growing (yet consolidating) Australian Iron Ore industry. It has now moved beyond Western AustraliaÆs æPilbara Big TwoÆ of Rio/BHPB (with the emergence of the irrepressible FMG and Hancock Prospecting) to include the YilgarnÆs æMidwest ManyÆ (including US re-entrant Cleveland Cliffs through Portman) and projects in other States. Ore types have moved from haematite Brockman to martite-goethite Marra Mamba (including the RobeÆs mesas and below water table Yandicoogina CIDs) and magnetite ore types. There are DSOs and secondary process feed. Mineral valuers have to reflect today upon these and many other determinants of value when choosing the most appropriate methodologies to adopt when technically assessing and valuing exploration tenements containing iron ore. Set against a frame work of the JORC Code (2004) and VALMIN Code (2005), the general valuation issues involved in using the cost methods (eg multiple of exploration expenditure), market methods (eg comparable sales, rules-of-thumb and joint venture terms) and income methods (eg synthetic discounted cash flow (DCF)/net present value (NPV) modelling) are discussed. Relevant factors when valuing iron ore properties are discussed, eg ore type, lump/fines ratio, stripping ratio, water table, impurities and grade, particularly the JORC confidence category of the identified mineralisation. Remoteness and access to existing rail infrastructure is a key consideration.

Jan 1, 2007