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By Davis A, Song J

A review of the literature indicated that several studies have been reported on the dissolution of gold using iodide/iodine, bromide/bromine leaching systems. Although the reagent costs are much cheaper for chloride/chlorine (or hypochlorite) this system has not been fully evaluated. This study was conducted to evaluate the fundamental chemistry of the chloride/hypochlorite leaching system. The CHEMIX program was used to model the stability of various gold species existing in the solution. The gold dissolution rate at different conditions was determined using gold strips immersed in various mixtures of chloride/hypochlorite. Leaching experiments were conducted to test the extraction of gold from various ores (oxidised and copper-gold ores), showing a promising prospect for this technique in various applications.

Jan 1, 1992

The search for an efficient and economic machine to excavate hard rock continues. Development of the Robbins Mobile Miner commenced in 1983 with the formation of a joint venture between Mount Isa Mines Limited and The Robbins Company. Construction of the machine ensued and preliminary trials to verify the cutting action were undertaken in the USA prior to transportation to and assembly at Mount I-sa where mining commenced in September 1984. Initially, the machine was used to develop the S60 Decline which serves as a combined access and conveyor drive for the Southern 1100 Orebody Ore Handling System.

Jan 1, 1988

By Hayes K. M, Ostwald J

Compacted tablets of hematite ore (containing clay and quartz gangue) and limestone were heated in air in an ULVAC-RIKO rapid heating furnace to maximum temperatures in the range 1200-1350°C.The resulting sintered products were examined in terms of mineralogy, texture, strength and reducibility. The sintered tablets are a good analogue of normal plant sinters. These investigations have shown that sinters of optimum reducibility are produced in the narrow temperature range 1250-l275°C. Conditions for the production of such highly reducible sinters under plant conditions are discussed.

Jan 1, 1984

It is suggested that if adequate knowledge is available about classifiers in closed grinding circuits, these units may be used as on-stream size analysers when equipped with suitable sensing devices. Research work which is at present in progress to enable a hydrocyclone to be used for this purpose is discussed.

Jan 1, 1967

By Bennet A. G

As part of the construction of the Melbourne Underground Rail Loop it was necessary to construct two 7 metre diameter tunnels, each 100 metres in length, by shield driven excavation through an alluvial valley at Elizabeth Street. The tunnels had a primary support of bolted precast reinforced concrete liner blocks and were excavated with the aid of compressed air. The work was undertaken by the Tunnelling Group of the Melbourne and Metropolitan Board of Works as nominated sub-contractor to John Holland (Constructions) Pty. Ltd. The paper describes some of the problems associated with the construction of the above tunnels and the methods used to overcome them. In particular

Jan 1, 1981

By Pease JD

This paper reviews the changes in operating practices made in the heavy medium plant to meet the objectives of increased silver, lead and zinc production at lower operating cost. The effects of medium quality, screen- ing efficiency, medium consumption, equipment service life and plant availability on these objectives are described.

Jan 1, 1988

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 Swanson AR, Nicol SK

A study has been made into the influence of feed size distribution on the flotation response of coal. The results show that a full description of the flotation response of a coal must not only consider the inherent floatability of the coal, but also, the size distribution of the feed to flotation. The performances of a number of flotation circuits were compared using a coal which was "poorly floating" because of its size distribution. Split feed flotation, two stage reagent addition, and reflotation of classified tailings all gave better yields than that obtained by conventional single stage flotation. The optimum flotation circuit for the washing of the coal in question, was reflotation of classified tailings.

Jan 1, 1978

The Koongarra uranium deposit was discovered in August 1970 by Noranda Australia Limited. Denison Mines Limited acquired the rights of ownership in October 1980 and has continued the 'struggle' to bring the proposed mine, containing approximately 13 300 tonnes of U308 of Indicated ore and having a value of $1 billion (1984 dollars), into operation. During the 14 years that have passed, the owners have found it necessary to deal with numerous Federal, State and Territory government departments, aboriginal representatives, handle thousands of communications, attend and convene countless meetings and spend millions of dollars. This paper addresses the history, the requirements, the problems and the costs to date for what - no return.

Jan 1, 1984

By Molloy GR, Eaton RA

The crusher development programme for 7ft Super Extra Heavy Duty (SXHD) Symons cone crushers commenced in 1984. The main objective of the programme was to run the crushers at maxi- mum power for the full life of the liners. This would give a finer product sizing enabling grinding and flotation plant throughput to be maximised. The study was conducted along two basic lines of attack, the first main- taining an effective profile through the life of the liners, the second improv- ing the properties of the liners. It has been found that crusher liner life can be extended and crushing efficiency improved by modification of liner composition and profile.

Jan 1, 1988

Production scale experiment study was carried out in a limestone open-pit for testing the theory and method proposed by the author(Zou, 1987). The results of experiments indicate that the mathematical model and computer programs, which include the consideration of both the three dimentional distributions of the weak planes and the energy densities of explosion stress waves, reflect the physical process of rock bench blasting quite well. The predicted fragment distributions coincide well with the practical fragment distributions measured with the photo-image analysis method proposed by the author(Zou,1989). The paper "A Three Dimensional Mathematical Model for Calculating the Rock Fragmentation by Bench Blasting in the Open-pit"(Zou,1987), which was published in some conferences and journals, has interested some scholors and researchers. In order to test and improve the model, a group of production scale experiments were carried out in a limestone open-pit during 1986-1987. The procedure and results of the experiments are illustrated in this paper.

Jan 1, 1990

Western Mining Corporation (W.M.C.) operates a nickel refinery at Kwinana, 30 km south of Perth. The refinery commenced pro- duction in May 1970, with a rated capacity of 15 000 tpa of nickel metal. A hydrometallurgical route was chosen as the most expedient way to produce nickel metal at a time when world demand for nickel was outstripping the supply. Later events dictated that an increase in production from the refinery be achieved. To this end, matte produced from Kalgoorlie Nickel Smelter, which was commissioned in 1972, was used in varying proportions as a complement to the concentrate initially utilised as input to the refinery. The effect of matte addition was to increase the capacity to 30 000 tonnes of nickel per annum. This was accompanied by other benefits which were 1. reduction in energy consumption per unit of nickel produced, 2. improved metal extraction, 3. improved precious metal recovery, 4. reduced production of ammonium sulphate by-product. Refinery operating results for the years 1970 to 1983 show how matte feed has improved refinery performance in these areas.

Jan 1, 1984

By Samyguin VD, Filippov LO

The aim of this paper is to emphasise the importance of knowing of the rate of the elementary flotation acts (EFA) - attachment and detachment. By studying the simplest linear model notion of the column flotation, the results of the nonlinear simulaton of flotation separation in the column with lengthwise upward mixing show two principal different types of separative mass-transfer in the column. The first is, the case of a small EFA intensity, almost without the detachment. The second is, the case of a big EFA rate, when the process is close to a local attachment-detachment equilibrium. There is also an attempt to estimate the EFA rate for three different kinds of quartz particles, floated by cation collector in the laboratory column apparatus.

Jan 1, 1993

By Sillet R, Corin P. J, Wilson G

Zinc Corporation of Broken Hi11 had some long hole stopes coming into use which could not be mined using diesel loaders, because of ventilation restrictions. In preference to use of pneumatic loaders, and because there were no field proven electric loaders in Australia, Horwood Bagshaw Ltd., were commissioned to repower a diesel loader with an electric motor, within the confines of the existing machine

Jan 1, 1977

Against a background of deeper pits, the introduction of prestripping fleets and the need for closer control of operating costs (especially the waste removal component), Australian coal operations utilising draglines have in recent years become increasingly focused on:1. assessment of more efficient excavation methods; and2. application of explosive products and initiation systems which offer more flexibility than ever before.Additionally, developments in blast performance assessment techniques and equipment, and computer modelling and excavation monitoring systems have provided an improved opportunity to design a blast to achieve a desired profile suited to the excavation equipment and Sequence.

Jan 1, 1992

A major problem with many items of underground equipment is that they have either been converted or adapted from surface equipment, or that they have been designed and assembled in comfortable offices and factories with adequate lighting, specialised tools, and ample space. As soon as they are in use underground in cramped spaces maintenance frequently becomes difficult, parts are awkward to change, and a whole range of accidents can happen.Similarly, ingenious operators discover a whole range of uses for which the equipment was not designed, such as using a loader bucket for a work platform, or scaling backs with it.Design modifications of equipment and removal of hazardous components that can trap limbs is expensive when the dangers are discovered in operation, sometimes posthumously, and it is not surprising that workers compensation insurance premiums are high. The cheapest place to ensure that equipment is safe is in the design office, where the operator should be considered first, rather than being added to a purpose built machine as an afterthought.

Jan 1, 1992

The mmmg of alluvial gold involves many deposits of theMesozoic, Tertiary, and Quaternary Ages in processing. Majorfeatures of the composition of such alluvial deposits are the lowcontent of gold and the small size of the gold particles. Atpresent, the gold-miners treat alluvial deposits in which a portionof fme gold (0.25 mm) exceeds 45 per cent. It is expected that by2000 these resources will be the main deposits mined (Zamyatinet aI, 1991).Under real industrial conditions the losses of minus 0.25 mmmetal are 50 per cent and more. The low level of recovery of finegold is observed not only at concentrators equipped with sluices,but also at concentrators equipped with modern diaphragm andpistonless jigs (Table 1).

Jan 1, 1993

Two ends of a longwall face are not only concentrated locations of equipment, but also provide ventilation and access. The roof strata stability here has an important influence on mining coal and safety. Based on field obser- vations in the gateways at Zaozhuang Colliery (Shandong Province) and model tests, the author developed a structural model of the overlying strata at the ends of the longwall face - the arc triangular cantilever plate - to which the elastic theory of plates can be applied. Factors influencing the stability of the cantilever plate and its breaking character- istics are discussed. Requirements and design parameters for supports at face ends are pro- posed, based on these factors.

Jan 1, 1986

This short paper outlines the authorÆs views regarding the progress we have made as an industry in managing mining assets over the past 500 years. It represents a personal view û but one founded in fact-based observations of mining companies and of the mining industry in general. There is no doubt that AgricolaÆs views as expressed in De Re Metallica (1556) were visionary. There is also little doubt regarding another issue û that whilst a great deal has been learnt about the management of mines since AgricolaÆs time, observations suggest that best practice management is the exception rather than the rule across our industry. Although insights regarding the successful management of mines have become apparent, we still witness unnecessary errors in our industry that lead to the loss of shareholdersÆ funds. By highlighting some aspects of current best practice, particularly in the arena of operations management, it is hoped that this short paper contributes a small step along the next 500-year-long learning curve. The paper concludes with a brief description of the progress and impact of continuous improvement initiatives at Kalgoorlie Consolidated Gold Mines (KCGM). Located in the Kalgoorlie Goldfields, KCGM is currently AustraliaÆs largest gold mine producing over 800 000 ounces of gold per annum. Improvement initiatives at KCGM look set to deliver some $100 million in value over life-of-mine.

Jan 1, 2004

Zinc produced by pyrometallurgical processing techniques suffers the disadvantage of restricted market potential because of its impurity contents, typically lead and cadmium. Market zinc to the Special High Grade (SHG) standard can only be produced by reflux distillation refining, which is costly in terms of energy and equipment, and potentially capacity limiting. Recent published laboratory work suggested that molten salt electrorefining of zinc metal is a potentially much cheaper alternative to the reflux distillation refining. The extrapolation of the laboratory results to an industrial configuration, however, resulted in an estimated power consumption for electrorefining and associated costs offering no advantage over current reflux distillation practice. A review of this estimate now shows that a serious error in calculation was made, and that the energy consumption for the electrorefining of molten zinc would be an order of magnitude lower than that for reflux distillation refining. While this is a promising indication, further research is required before development towards an industrial scale operation is warranted. This would particularly relate to the extent to which adverse electrolyte deterioration may take place and its potential effect on the anode and cathode efficiencies of the process. This paper considers the laboratory investigations required to explore the industrial potential of the molten salt electrorefining of zinc and foreshadows some of the practical problems to be solved in further development.

Jan 1, 2000