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By BTrubT M

In the roast-leach-electrolysis process for the production of zinc, iron contained in zinc concentrates is converted to zinc ferrite during roasting. At Canadian Electrolytic Zinc (CEZinc), the Outokumpu Conversion process is used to simultaneously leach zinc ferrite and precipitate the iron as jarosite. These simultaneous reactions, while providing good process stability, require a compromise between optimum conditions for maximum zinc extraction and efficient iron precipitation. An improved conversion process has been identified which can achieve >99 per cent zinc extraction and more efficient jarosite precipitation to residual iron concentrations of

Jan 1, 1993

The Maddingley brown coal seam at Bacchus Marsh, where mined and bored, tends on the whole to a higher content of volatile matter than the Latrobe Valley brown coals, and this masks the presence of lignitic or earthy coal bands in the bore core analyses. Visits to the Lucifer Open Cut, at Bacchus Marsh, during 1948, revealed, however, a banded condition in the coal seam, as shown in Fig. 1. This banding showed in a face that had been exposed for a considerable period of time, permitting partial drying out and oxidation of the surface coal. The bands consist of different coal types, ,comparable with those found in the Yallournand Latrobe brown coal seams(l).The' light coloured bands in Fig. 1 consist of a buff to light-brown earthy coal of low specific gravity, that closely resembles the pollen coal, that occurs, as similar thin bands in the Yallourn and Latrobe seams. The 40 ft. of coal above the uppermost of these light coloured bands dries out on exposure to a black, closely cracked surface, composed of small dice-like fragments of a lustrous vitrain-like substance, and in every respect resembles the lignitic coal bands of the Yallourn and Latrobe seams.The coal between and below the light-coloured bands develops fewer and more widely spaced shrinkage cracks on drying out, and remains brown in colour and earthy in appearance, resembling the earthy coal of the Yallourn and Latrobe seams.Representative samples were cut of these coals, taking care to exclude surface coal, and analyses were made of them by the Metropolitan Gas Company, through the kindness of Dr. R. S. Andrews, Chief Chemist to the Company...

Jan 1, 1948

About 90 per cent of the pre-mining BIF-hosted iron ore resource of the Hamersley Province of Western Australia is of the Phanerozoic supergene martite-goethite type. The remaining ten per cent formed as supergene deposits at ~2000 ¦ 200 Ma, and were later modified by burial to form the Proterozoic martite-microplaty hematite ores. The supergene-metamorphic segment of this general unified model has been challenged by three recently published hypogene-based genetic models for the hematite ores, all requiring meteoric oxidation to produce the ore. The most recent and detailed, by Taylor et al (2001), is based on data from the small Southern Batter and North deposits of the Mount Tom Price mine. The authors proposed that during Stage 1 æoverpressured bicarbonate-saturated basin brines from the dolomite aquifer of the Wittenoom FormationÆ at 150 - 250¦C, dissolved free silica from BIF to produce a stratigraphically thinned, magnetite-carbonate-silicate-apatite rock. In Stage 2, meteoric oxidation of siderite to secondary microplaty hematite + ankerite, and magnetite to martite, at unspecified elevated temperatures and pressures, was followed by carbonate leaching (Stage 3). Finally, during Stage 4, weathering with removal of apatite, produced the typical low-phosphorus, porous martite-microplaty hematite ores of the Tom Price-Whaleback type. However, evidence of both microplaty hematite and martite reduced to magnetite, and of infill silica, apatite, and ferroan chlorite, with late-stage pyrite, in the pore space of martite-microplaty hematite ore, shows that the hydrothermal activity at Mount Tom Price is a post-ore event. Neither pyrite nor ferroan chlorite could resist the oxidation required to form hematite ore. Recrystallisation of microplaty hematite in these infilled zones to a typically coarser form than present in most of the normal ores, is a further supporting factor. A more credible, post-ore alternative to the hypogene genetic model is suggested here. Re-exposure to leaching by ground water of the metamorphosed ore deposits in the Phanerozoic resulted in the partial removal of remnant goethite. Localised modifications in the porous BIF/ore contact zones were driven by exothermic oxygen/pyrite/carbon reactions in the footwall Mt McRae Shale. Cool descending oxygenated meteoric water in the permeable ore horizons, acted as one limb of a thermal convective cell. In the other limb, heated reducing solutions rose through the permeable contact zones, to produce the observed localised modifications of BIF and ore. Expelled silica from the carbonatised BIF invaded adjacent porous ore to form erratic silicified ore zones, and to produce the local quartz vein systems found in the associated overlying BIF.

Jan 1, 2002

By J. K. A. McLEOD

Address by the President of the Institute (Mr J K A McLeod) in presenting the Institute Medal to Howard Knox Warner, C.B.E. Address by Howard Knox Warner after accepting the award.

Jan 1, 1978

By M K. Singh

Mining is nothing but an art - besides being a science - of extracting valuable minerals from the womb of the mother earth. In this gigantic task, a large number of machinery and equipment are employed judiciously. Wire ropes play a vital role in lifting or hoisting men and materials under hostile/adverse working conditions and constitute a major item of investment on machinery/equipment. The economy of using a wire rope is a concern for engineers, users and the planners. The economic use of wire ropes for mining purposes largely depends on the following factors;Mechanical design considerations - which include tensile strength of wires, elasticity, resistance to abrasion and crushing, fatigue values, static and dynamic loads on wire ropes, factor of safety, fleet angle, etc. Metallurgical consideration - Composition and heat treatment of wire materials, defects like inclusions and voids, surface quality factor, lubrications, micro structural parameters. Operational consideration - Seizing and cutting of rope, storage, care and maintenance, cutting back, etc. Environmental consideration - Temperature and humidity, pit condition, dust, corrosive atmosphere, etc. In the present paper, an attempt will be made to suggest steps for achieving optimum economy while using the wire ropes for extraction of precious minerals and coal keeping in view the points noted earlier. Once technical viability is established, economy is the ultimate consideration for an industry for safe hoisting of men and material.

Jan 1, 2000

By K Barns, H Law, T Whebell, P Scobie, T Perkins, J Siliezar, M Larson

With processing a variety of orebodies at Glencore’s Ernest Henry Mining (EHM) has come a changing mineralogy and more complex requirements for treatment in the concentrator. From mid-2013 and into 2014 the grind size required to achieve sufficient mineral liberation for production of a quality concentrate has reduced significantly. What was once a final P80 of 35–45 microns was forced to 20 microns. This has necessitated some creative changes to the flow sheet that previously had a 937?kW Vertimill regrinding a rougher concentrate to 40 microns. EHM is able to utilise an existing M10 000 3 MW IsaMill previously used for magnetite processing, to provide a quick convenient solution without large scale capital expenditures. Operating the Vertimill and IsaMill in parallel in closed circuit was successful at reducing the P80 of the regrind circuit to below 20 microns which increased the final concentrate grade by four per cent. This circuit and intermediate circuits used are discussed. Performance of the Vertimill and IsaMill is compared for efficiency optimisation to improve the overall circuit performance.CITATION:Siliezar, J, Whebell, T, Perkins, T, Law, H, Scobie, P, Larson, M and Barns, K, 2014. From magnetite to chalcopyrite – a story of versatility and efficiency at Glencore’s Ernest Henry mining?operation, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 85–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By M Akhtar, E Jak, M Shevchenko

This article presents an overview of the experimental phase equilibria studies of S-containing systems (Ni-Sn-S, Cu-Sb-S, and Cu-Sn-S) and As-containing systems (Fe-Sb-As and Fe-Sn-As). These systems improve the prediction capabilities of FactSage in a 20-component ‘Cu2O’-PbO-ZnOFeO- Fe2O3-CaO-SiO2-S-(Al2O3-MgO-CrO-Cr2O3-Na2O)-(As, Sn, Sb, Bi, Ag, Au, Ni, Co) system for complex pyrometallurgical operations during both refining and recycling. Experiments involved equilibration at predetermined temperatures (300–1200°C) with or without preheating, followed by rapid quenching in a brine. Quenched samples were then directly measured using an electron probe microanalyser. For the Ni-Sn-S system, liquid phases (NiS- and SnS-rich mattes and liquid metal) and solid phases (Ni1+xSn, SnS, Ni3Sn, FCC-Ni, Ni1-xS, NiS2, Ni3Sn4, SnS2, Sn2S3 and β-Ni3S2) were observed. A new Ni3Sn2S2 phase was found to melt incongruently. For the Cu-Sb-S system, liquid metal, matte, FCC-Cu, digenite, Sb, CuSbS2, Cu3SbS3 and Cu3SbS4 phases were observed. For the Cu-Sn-S system, liquid metal, matte, digenite, SnS and Cu3Sn phases were found at liquidus.

Jun 17, 2024

By F D Durao, Muge F. H, Rogado J. Q

In the scope of the project named CAPUME II (EEC BRITE/EURAM contract - project MA2M-CT90,-0042(SMA)) for the development of an integrated mine planning system for underground mines, two of the main tasks were the development of a short-term mining planning procedure (module) and a numerical simulator of the mineral processing plant of Pirites Alentejanas - PA. The short-term mining planning module defines the mining sequences by solving a constrained minimisation problem. The ore grade variability is the objective function subject to the geometrical constraints of the mining method and to the maximum of `internal blending'. The optimisation problem is solved by applying a dynamic programming algorithm. The plant simulator is an essential tool of the planning system allowing the preview of metal grades/recoveries of copper, lead and zinc of concentrates streams, given the corresponding metal assays of the run-of-mine ore, defined by the short-term mine planning module. This way, the management can plan the short-term mining operations (the weekly sequence of exploration blocks and the internal planning) in order to fulfill given required conditions, based on a shipment schedule and on a purchaser's formula. In this paper, after a short description of the short-term mining planning module and of the simulation package named SIMUL, a synthesis of the main model development steps and the results of some simulation runs are presented and discussed.

Jan 1, 1995

By A E Reschke

The high-shear colloidal mixer is generally recognised as the most efficient method of mixing cement based grouts. Only recently however has this technology been applied to the production of cemented rockfill (CRF) for use in underground mines in North America. Traditionally, paddle type mixers have been used to produce the cement based slurries required for the preparation of CRF. While considerable success has been achieved with these mixers, tremendous advantages are attained with the colloidal mixer. The combined effect of the highly efficient mixing action and the ability to mix low water/solids ratios, allows for reductions in the cement content for a given strength requirement. Cement can also be replaced by cheaper fillers such as flyash, resulting in further cost savings. Although large-scale dedicated CRF hatching plants are typical, there is a growing need for mobile plants capable of operating anywhere underground. The compact size and rapid hatching speed of high-shear colloidal mixers has allowed them to be incorporated into skid mounted systems capable of producing and discharging cement based slurries onto rockfill aggregate for the production of CRF. In many cases run-of-mine development waste can be used as CRF aggregate with these slurry plants thereby reducing the cost of waste rock removal. These relatively low cost portable plants have now allowed several mines to economically rccmer isolated pillars and realise positive returns on their investment.

Jan 1, 1998

On Wednesday 11th November, 1970, a series of violent explosions occur-- red within No.1 Basic Oxygen Steelmak- ing (B.O.S.) furnace at the Whyalla Works of the Broken Hill Proprietary Co. Ltd., (B.H.P.) when the furnace was moved immediately prior to tapping. Water from a burnt out flux chute had flooded the bath while the furnace was tilted slightly towards the tapping side waiting to tap. Although no one was injured, dam- age in excess of $54 000 was caused to the hood and superstructure. The water hydrated the burnt dolomite refractory lining some of which sub- sequently collapsed exposing bare fur- nace shell over part of the cone.

Jan 1, 1975

By Jaczkowski B

The lower orebody (LOB) at Chingola Divi- sion of Nchanga Consolidated Copper Mines Limited (NCCM) accounts for approximately 30 per cent of the total copper production for the company. The uniformity of the geology of the orebody lends itself readily to a computer based ore reserve calculation and accounting system. The mining units are physically defined such that a hierarchical type of com- puter file organisation can reflect the existing physical interdependencies. In 1972, a project team consisting of one representative from each of the mine planning, operational research, and computer services departments was formed to investigate and to define the technical mining requirements of the dynamic ore reserve system (DORS). The system was finally implemented in 1975ò

Jan 1, 1977

The paper re-visits an old and proven concept of winzing, a method widely used in the past to gather exploration data for accurate definition of the orebody. It is proposed to use a mobile Supersucker (a giant vacuum cleaner also known as vacuum lift), to carry out winzing activities underground. A brief description of conventional underground winzing used in the past is provided, together with a discussion on other underground bulk exploration methods used in Australia to date. Historical background, principles of the proposed system, Supersucker construction details and productivities, and benefits and advantages of the proposed system in comparison with other exploration methods, are outlined. Other relevant applications of the mobile Supersucker, including surface winzing, are also briefly discussed in the paper. With a view of using the mobile Supersucker to recover all broken ore stocks underground, included are also results of floor sampling conducted recently in the in-stope decline excavated in a coarse gold type, high-grade orebody.

Jan 1, 2002

By S Carr-Cornish, K Moffat

Social licence to operate is developed and kept through managing both operational impacts and the relationship between local community and company. However, CSIRO research has demonstrated that in determining how accepting community members are of a mining operation, relational factors, such as procedural fairness and trust, are much more important than operational impacts, such as impacts on employment and the environment (Moffat and Zhang, 2015). Companies seek to develop relational factors through their engagement with local community; such engagement has many aspects, including, initially identifying stakeholders and positioning the company as part of the local community (Lacey et al, in prep; Thomson and Boutlier, 2011). These relational factors involve the social identities of people living in the community. Social identities are a part of people that shape their beliefs, based on their connections with various groups in their lives (Hogg et al, 2004).An engagement process, intentionally or not, inevitably interacts with the social identities of stakeholders (Crane and Ruebottom, 2011). For example, traditionally, at the very beginning of engagement processes, community members are assigned to categories using conventional stakeholder mapping and categorisation methods, often based on assumptions about stakeholders’ interests, which equates to assumptions about stakeholders’ social identities (Colvin, Witt and Lacey, 2016; International Council on Mining and Metals, 2012). Yet, there has been limited empirical inquiry into whether such categories reflect the social identities of stakeholders and if there is a bearing on relational factors, including, the perceived fairness of consultations and trust in mining companies (Crane and Ruebottom, 2011). Also at this time, companies commonly seek to create a presence in communities, for example, joining Chambers of Commerce and participating alongside community members. Again, there has been limited empirical inquiry into whether community members and companies identifying with the same overarching group and thus sharing aspects of social identity, influences relational factors (Crane and Ruebottom, 2011). In this study, we examined the effects of changing aspects of social identity by changing how stakeholders were identified and companies were positioned, on how stakeholders’ perceived a new mining operation, specifically how they perceived the procedural fairness of the proposed consultation process and trusted the company, two factors that underlie a company’s social licence to operate.CITATION:Carr-Cornish, S and Moffat, K, 2016. Out of the box – the power of social identities in engagement processes, in Proceedings Life-of-Mine 2016 Conference, pp 180–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By C A Heinrich, Jaques A. L, L A I Wyborn

Most orebodies have cross-sections of less than I km2 and hence do not offer a particularly large target for exploration. Fortunately, although in the geological record ore deposits are small and rare and result from the exceptional coincidence of certain geological processes, these processes are mappable on a much larger, district to regional scale and constitute a mineral system in which the ore deposit is the central feature. A mineral system can therefore be defmed as 'all geological factors that control the generation and preservation of mineral deposits, and stress the processes that are involved in mobilising ore components from a source, transporting and accumulating them in more concentrated form and then preserving them throughout the subsequent geological history'. The mineral system concept emphasises that for many ore deposit types, although economically viable mineralisation may only occur on a scale of say, hundreds of metres, the total system offluid-rock interactions that led to ore formation can extend over a distance of tens to hundreds of kilometres around the deposit. When mapped out, the total mineral system provides a far larger exploration target than the actual ore deposit itself. Important geological factors defining the characteristics of any mineralising system include: I. sources ofthe mineralising fluids and transporting ligands; 2. sources ofthe metals and other ore components; 3. migration pathway; 4. thermal gradient; 5. energy source; 6. a mechanical and structural focusing mechanism at the trap site; 7. chemical and/or physical traps for ore precipitation. Many of these factors individually are common through

Jan 1, 1994

This paper reviews the development and operation of a small underground tin mine in NE Tasmania. Tin mineralisation was discovered in the Lottah area in the 1880's with early alluvial and eluvial workings leading to the development of large low grade open pit operations. Apart from short lived activities operations ceased in 1915. Intensive exploration in 1978-81 outlined substantial tonnages of low grade tin mineralisation (0.2% Sn) of open pit material. An underground ore body was also located (800 000 tonnes 0.6% Sn). Spectrum Resources Australia Pty Limited acquired a 98 percent interest in the property in 1988. Mine and mill development began in early 1989 based on an underground mine utilising trackless mining using room and pillar with fill stoping. The milling circuit involves primary jaw crushing, Barmac secondary crushing to lmm, Mogensen and DSM screens with jigs and tables to make a wet concentrate. Final tin concentrates are produced by high tension and magnetic separation. Planned production rates are 500 t/day with a mine life of 6-7 years.

Jan 1, 1990

By Bunting HR

Developments since 1959 in major excavators to meet the high outputs of overburden and coal under the changing nature of the Morwell Coal Deposits of the Latrobe Valley are described. Particular reference is made to investigations of designs of the bucket wheel head configurations for the digging of flat batters on high faces, and examples are given of the wide use ofmodelsin these studies.An explanation is given of considerations leading to selection of the Long Boom or the Compact type of bucket wheel excavator for various applications. The past decade has seen increasing manufacture in Australia of components for excavators and similar machines. The measures undertaken to integrate these components with those from overseas (Germany) are described. A section of the paper deals with advances in Electrical Engineering for large excavators in Australia and its interdependenee with mechanical design and construction. Finally, as an example of the versatility of the bucket wheel excavator a description is given of a recent application for the mining of mineral sands in Northern N.S.W.

Jan 1, 1970

The problem of stability of the development working at the great depths of coal winning is of great seriousness. Numerous researches of the problem were carried out in the USSR, the results of which determined that raising of resistance of existing support will not lead to a considerable rise of working output. It is necessary to try to find ways at the expense of heightening the support ability of rock massif. For these purposes it is necessary to direct it correctly and in proper time. While carrying the development working the most intensive deformations of rock occur at a depth of 30m from the entry face. The zone of destruction of rock around the work is realised here for 60 to 70 percent. These facts show that in influence zone of entry face a kind of embryo of the working steadiness is forming, which greatly determines its following conditions. Therefore, it is necessary to begin direction of mining pressure around the work directly in a face.Complex research of the mechanism was carried out starting with the effect of moving face upon the surrounding rock massif. It was ascertained, that the zone influenced by the face is a section of 5 equivalent diameters of the work by the length within which the rock of the sides, roof and floor, experience the cyclical influence of stresses at the time of cyclical shift of the face. The elastoplastec deformation is occurring with it at the moments of rock removal and the deformation of creeping takes place at such intervals.

Jan 1, 1991

The paper describes the 209 in. single stage axial flow mine ventilating fan which commenced operation at The Zinc Corporation Limited, Broken'Hill, N.S.W., in January, 1954.This fan is used to ,ventilate the underground workings of The Zinc Corporation Limited and New Broken Hill Consolidated Limited and, at the time of installation it was the largest fan of its type in the world. It has amaximum capacity of 900,000 c.f.m. at 4·2 in. watergauge and is equipped with adjustable pitch blades and a novel form of variable speed drive.The considerations which lead to the adoption of this particular design are outlined, and a full description of the contruction and installation of the fan and auxiliaries is given.Comprehensive acceptance tests were carried out on the completed installation and, the testing procedure is described in detail. The results of sound level measurements are also included. A brief report on the performance during the 12 month period from 1st July, 1954, to 30th June, 1955, is then given.SELECTION AND DESIGN OF FANGeneral ConsiderationsBecause of the economic advantages of joint ventilation of the underground workings of The Zinc Corporation Limited and New Broken Hill Consolidated Limited, it was decided, after a full review of the future ventilating requirements of both mines, to sink a 20 ft. diameter circular upcast airway on the common boundary of the two properties, to handle a maximum quantity of 900,000 c.f.m.The anticipated air requirements were at this stage estimated to be:(a) initially 700,000 c.f.m. through a mine equivalent orifice of 160 to 2'40 sq. ft. (equivalent total pressures being 2·70 in. w.g. and 1·20 in. w.g.) ;

Jan 1, 1956

Modern, high-output, continuous process plant requires heavy capital expenditure and is exroected to achieve a high rate of return upon the investment made, thus its high utilisation is an economic necessity. Downtime is extremely expensive not only in terms of idle capital but also in terms of lost production and revenue. A sound maintenance management system can alleviate the problem of unscheduled stoppages and a key document in the maintenance system is the Work Order because it both initiates work and conveys maintenance control information back to the administrator. This key document must be supported by an information base that provides technical data, job procedures, spare parts, history and costing. To be effective this information must be easily and immediately available to all concerned. Computer technology has developed extremely rapidly over the last ten years and with it a wide variety of on-line computerised maintenance systems. Selection of the most appropriate system for a given industrial plant is not a straight-forward process. Computer requirements for hardware and software must be matched to the requirements of the maintenance system and such matching must be carried out in an ordered and rational way. At Kalgoorlie Nickel Smelter, time was taken to review the existing maintenance system, select, study and test the new computerised maintenance management package and plan its implementation. As a result, the initial target of equipment recognition has been achieved on schedule and within budget.

Jan 1, 1987

Recovery of tin and copper from concen trates containing cassiterite, stannite and chalcopyrite was studied in laboratory-scale tests designed to simulate continuous operation of the matte fuming process in which tin is recovered as SnS fume while copper accumulates in the matte. Charges made up of 300g of mixtures of the concentrate and siliceous flux were added at a uniform rate in pelletized form to crucibles containing 300g of matte and 50g of slag (both of which were recovered from previous tests), while blowing through the matte with air or oxygen-nitrogen mixtures at a rate of 3 to 5 1/min. Accurate material balances enabled the effects of process operating conditions on tin recovery and sulfur utilization to be deter- mined. When operated correctly, the matte fuming process gave tin recoveries exceeding 90 percent in spite of wide variations in the copper content of the matte and in the operat- ing conditions. Deterioration of tin recovery was associated with undersaturation of the slag with respect to silica, and with high partial pressure of sulfur dioxide (greater than approx- imately 0.2) brought about by oxygen enrichment of the blowing air. The utilization of sulfur varied widely in low grade mattes. Copper in excess of approx- imately 10% promoted formation of SO2 by the commonly accepted reaction: FeS + 1-120 2= FeO + S02 while in copper-free and lower grade mattes a substantial fraction of the oxygen was consumed in the alternative reaction FeS + i 02 = FeO + z S2.

Jan 1, 1980