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By J Pan, Q H. Li, D Q. Zhu, C C. Yang, X Wang, Z Q. Guo

Al2O3 in natural iron ores generally occurs in goethite, kaolinite, gibbsite, hematite and iron carbonate. When the content of alumina in sinter increases from 1.11 per cent to 3.50 per cent, the reducibility of sinter decreases with the addition of four different types of alumina. When gibbsite and kaolinite are added, the low temperature reduction disintegration (RDI+3.15 mm) of sinter increases with the increase of Al2O3 content in the range of 1.5 per cent to 3.5 per cent. Furthermore, when adding pure reagent alumina, the increase of Al2O3 content in the range of 1.5 per cent to 3.0 per cent will increase the RDI+3.15 mm of sinter. The addition of ferric oxide–alumina spinel with the Al2O3 content in the range of 1.5 per cent to 2.5 per cent, also increases the RDI+ 3.15 mm of sinter. The influence difference is results from the change of the mineral composition and microstructure of sinter because of the occurrence state of Al2O3. Under the condition that Al2O3 content of sinter is 2 per cent, the porosity of sinter with kaolinite is 37.26 per cent, and the shape is irregular. When gibbsite and ferric oxide–alumina spinel are added, the porosity of sinter is about 16 per cent, and the pores are round. When pure reagent alumina is added, the porosity of sinter is 17.49 per cent, and the pores are regular and small. When kaolinite, gibbsite and ferric oxide–alumina spinel are added, platy calcium ferrite is mainly formed in the sinter, and some of it is columnar calcium ferrite. On the other hand, when pure reagent alumina is added, in addition to platy columnar calcium ferrite, acicular calcium ferrite is also formed in the sinter.

Nov 8, 2021

By JOHN G. RAYNER

An examination was made of the filtration characteristics of a haematite slurry using a range of polyacrylamide based flocculants in solutions containing up to 3 per cent sodium chloride. The polymers used were "high" and "Iow" molecular weight and had from 0 to 40 per cent charged groups.Increasing charge density tends to reduce the dose required to achieve optimum performance measured by filtration rate and by cake moisture. In general increased salt addition tends to increase the dosage required to achieve these optima. Both these observations result from the change in polymer extension and accord well with the bridging theory of flocculation.The dose required for optimal cake moisture is up to three times greater than that required for optimal filtration rate. This effect is reasonably consistent for all polymers studied and appears to be non-linearly dependent on salt concentration, with the difference being small at 0 and 3 per cent but quite significant at 1 per cent.

Jan 1, 1987

By D P. Blair

Various analysis techniques are used to determine the nature of a large seismic event that was triggered by a mass blast in an underground mine. This event was recorded by surface accelerometer arrays whose output was doubly integrated using a stable filter to determine the dynamic displacements. The peak dynamic displacements during the blast were 0.09 mm, and during its latter stages, this blast induced a seismic event having a peak dynamic displacement more than ten times larger at 1.26 mm. Polarisation analysis, based on the complex covariance matrix, showed that the seismic event was caused by movement of a known underground fault, close to the blast, which radiated most of its release motion as a shear-horizontal (SH) wave. The change in frequency content with time for the blast and seismic event was initially determined using the Fourier-based reassigned S-method. This analysis showed that the large amplitude seismic event had frequency content significantly lower than that of the blast. Nevertheless, this Fourier technique still retains the problems associated with short time windows as well as the fact that most realistic signals are non-stationary. In order to eliminate such influences, the more recently developed empirical mode decomposition (EMD) was used to obtain the intrinsic mode functions (IMF) of the seismic wave propagation. The EMD vibration analysis showed that each IMF generally exhibited distinct frequency changes throughout the blast and a significant reduction in frequency throughout the subsequent event. It is shown that most of the energy of the seismic event is contained in IMF modes 2, 3 and 4 of the SH wave; the high-frequency first mode (IMF1) contains little energy. Such modal analysis is not possible using standard Fourier methods.CITATION:Blair, D P, 2015. Dynamic displacements from a blast-triggered seismic event, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 203–210 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M Hernan

Bendigo Mining Limited has established a modern underground gold mine and processing plant at Bendigo in central Victoria. The Bendigo goldfield produced around 22 000 000 oz of gold between 1851 and 1954. Approximately 4 000 000 oz were sourced from surface alluvial workings with the remaining 18 000 000 oz won from underground quartz reefs. The modern mine is accessed via the Swan Decline, which commences at the Kangaroo Flat site on the southern outskirts of Bendigo and progresses in a north easterly direction between the Deborah and Sheepshead anticlines, reaching a depth of almost 1000 m below the City of Bendigo. Development of this decline commenced in 1998. Since that time 20 km of underground development has been completed. Exploration drilling, on-reef development and bulk sampling carried out between 1999 and 2005 resulted in the estimation of a Probable Ore Reserve of 700 000 tonnes at 9.0 g/t gold for 207 000 oz of gold. These Ore Reserves were contained within four reefs located on the Deborah and Sheepshead anticlines. Reef mining commenced in late 2005 from the Shywolup and Greater Garrard reefs. Material mined was stockpiled on the surface in preparation for commissioning of the process plant which commenced in mid 2006. Mining and processing were carried out between August 2006 and May 2007 during which time 176 000 tonnes were processed at an average grade of 5.4 g/t gold to produce 26 735 oz of gold. Plant feed was sourced from four reefs. This paper discusses some of the issues which were encountered with the definition and mining of these geologically variable and nuggetty reefs. This paper covers exploration techniques, grade estimation, mine geological control, mining methods, geotechnical issues and reconciliations. It will also discuss some of the lessons learnt and how these will be applied to future Mineral Resource and Ore Reserve estimation, as well as underground operations.

Jan 1, 2008

By A G. L Pratt

The record for autonomous haulage systems in underground mining over the past 15 years is patchy, marked by many trials and attempts, with few examples of sustained operation until relatively recently. The drivers for the introduction of this technology are variously listed as the occupational health and safety of people working in underground mines, reductions in direct operating costs and increases in productivity.This paper reviews the trends for operation of semi-autonomous and autonomous haulage achieved by underground mines and the defining features of the technology currently available. The inclusion of autonomous haulage as part of mining studies and the fundamental conditions for its successful application is discussed in the paper. The components required for an autonomous underground haulage system are outlined and the key aspects that need to support its effective implementation are examined together with their associated opportunities and risks. Special note is made of the critical role people, including executive leadership, have in ensuring the successful introduction of this technology.The paper draws on published case study material, equipment supplier information and research findings. The aim is to offer a high-level insight into what is required for the application of autonomous haulage technology and its successful implementation in underground mines.CITATION:Pratt, A G L, 2016. Autonomous haulage systems in underground mining – what is required for success? In Proceedings International Mine Management Conferenc, pp 35-52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

The Hishikari gold deposit, discovered by the Metal Mining Agency of Japan, has become a giant class epithermal gold deposit with the highest grade of gold yet recorded in the world through detailed exploration and development by the Sumitomo Metal Mining Co Ltd. The exploration strategy involved a regional approach combining geological and gravity surveys over a 900 km2 area which had historically produced over 120 t of gold. These surveys were carried out to grasp the common geologic features of epithermal gold deposits in the survey area. A genetic model for epithermal gold deposits in the area under regional survey was also considered based on detailed research of the Kushikino epithermal gold deposit which was in operation at that time. This model was applied to the targeted areas, and important relationships between mineralisation, host lithology, intensive propylitic alteration and gravity highs became apparent. The Hishikari block was selected in this way and bonanza gold was discovered during drilling. Since the development of the Hishikari mine, information useful for further exploration for the same type of deposit has been accumulated.

Jan 1, 1995

By X Li, J Wang, D Liu, Y Liu, K Hu

"Since the adoption of open-door policy 30 years ago, rapid economic growth has resulted in serious resource depletion and environmental destruction, especially in mining areas. As an urgent response to this situation, the central government and the Ministry of Land and Resources (MLR) have adjusted policies with concrete and realistic actions for halting this trend of non-sustainable mining activities in China. æGreen Mine CampaignÆ is one of the actions implemented. In 2010, MLR announced the æGreen Mine CampaignÆ, in which existing and new mines will be evaluated against the æGreen Mine Construction StandardsÆ and certified as æGreen MineÆ if complying with these standards. The standards cover five key aspects: the considerations of science-supported resource exploitation efficient resource utilisation standardised management environmental friendliness harmonious community relationship.Every year, MLR reviews ægreen minesÆ from all provinces. Thirty seven mines, including coal, metal, non-metal, gold, chemical industry and building materials mines, passed the review and were certified as green mines in 2010. In 2011, 187 out of 194 mines that participated in the review were certified as ægreen minesÆ. These mines are viewed as good examples of sustainable mining development in China.CITATION:Liu, Y, Hu, K, Li, X, Liu, Y, Liu, D and Wang, J, 2012. The green mine campaign and sustainable mining in China, in Proceedings Life-of-Mine 2012, pp 339-342 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By D J. Bradshaw, E M. Wightman, C L. Evans, B Triffett

During the commissioning phase of Prominent Hill, periods of reduced recovery were experienced with higher-grade ore blends. This was unexpected and as part of the process to identify the cause, surveys were conducted in May 2009, with two different ore blends (copper grades: 1.94 per cent Cu (blend 1) and 2.49 per cent Cu (blend 2)). Metallurgical performance was assessed in terms of rougher recovery and grade with consideration of both pulp and froth effects. In addition, hydrodynamic measurements (gas hold up, bubble size, superficial gas velocity) as well as measurements of bubble load and top-of-froth grade were taken during the surveys and full mineralogical assessment of selected streams completed to characterise the nature of the differences. The metallurgical results showed that the lower performance was obtained with blend 2 which contained the higher amount of chalcocite and was higher-grade. Analysis of the survey data showed that for both ore blends more than half of the copper loss occurred in the +38 ¦m size fractions. Almost 30 per cent of the copper in the +38 ¦m fractions that reported to the rougher tails during processing of blend 2 was liberated compared to less than five per cent for blend 1. Additionally almost 60 per cent of the copper in the +38 ¦m fraction of blend 2 was chalcocite compared with approximately 20 per cent in blend 1. This paper discusses the sensitivity of the chalcocite-to-surface chemistry effects causing marked reductions in recovery either through reduced pulp recovery or froth phase (detachment) effects. The reagent suite and operating conditions were subsequently changed and the recoveries increased substantially and the sensitivity to ore changes eliminated. It should be noted that subsequent optimisation work, which focused on recovery improvement, has led to copper recoveries of over 90 per cent being achieved.CITATION:Bradshaw, D J, Wightman, E M, Evans, C L and Triffett, B, 2012. Characterising the reasons for the difference in performance of two ore blends in early processing at OZ Minerals Prominent Hill Operation, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 273-278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By M Weeks

Melbourne Water Corporation, through the Pipelines Alliance, has commenced construction of a new drainage pipeline to provide additional flood protection within the Sandgate Avenue Main Drain catchment, in order to mitigate against the risk of flooding of Frankston’s central activity district (CAD).The project involves the construction of a 1550 m long, 2.5 m internal diameter tunnel, commencing upstream at the Monash University Peninsula Campus and traversing approximately west to the outlet located at Kananook Creek. The tunnel was excavated by a dual slurry-earth pressure balance tunnel boring machine (TBM), with the depth to tunnel crown ranging from 0.7 m to 14 m below the natural surface level. The TBM navigated 500 m radius curves, with a maximum drive length of 608 m. The tunnel lining consists of 2.5 m internal diameter, 250 mm thick reinforced concrete jacking pipe.The geotechnical conditions along the tunnel alignment consisted of mixed face ground conditions, predominately clay, with clayey sand and sandy clay and some sand deposits near Kananook Creek.This paper presents the challenges associated with the operation of the slurry separation plant during tunnel construction. In particular, the paper focuses the impact of slurry separation on tunnel advance rates, the lessons learnt during construction with regards to slurry separation and on the decision to adopt a dual slurry-earth pressure balance shield TBM. In addition this paper highlights the importance of having a thorough understanding of the slurry separation requirements on a slurry TBM project prior to selecting the necessary plant.

Mar 8, 2011

By Brotzmann K, Turner RE, Philp DK, Rusden RC

New approaches in the last decade have led to the supplemental use of raw coal as a direct energy source in several iron and steelmaking processes. The dependence on more expensive coke and electricity is being progressively reduced. The Technology Venture of Klockner Werke and CRA has pionered several of these developments and is pushing ahead to processes for scrap melting and direct smel- ting of iron where coal is the ONLY energy source. Such complex developments depend strong- ly on the experience gained in the simpler but related processes for coal use already in operation. The longer term implications of a successful coal-based direct smelting process for the world steel industry are substantial.

Jan 1, 1986

By W. M. LONIE

Address by the President of the Institute (Mr W M Lonie) in making the presentation of the Certificate of Honorary Membership to Sir Ian McLellan, K.C.G.M, K.B.E. Address by Sir Ian McLellan after accepting the award.

Jan 1, 1979

Access to the Rosebery Orebody, which dips into the western slopes of Mount Black at 45¦, has been achieved in sequence by the following means: - A series of adits down to 8 level - An inclined shaft (No. 1 Shaft) sunk internally from 8 level to 14 level - A vertical circular concrete lined shaft (No. 2 Shaft) sunk internally from 4 level to 19 level. Although the orebody has been fairly well defined to 19 level, deeper ore occurrences have been outlined by a series of drill holes decreasing in frequency with depth to 26 level. No. 2 Shaft (sink) was stopped some 10 m below 19 level in order to make an early start on doubled production at West Coast Mines, with the intention of subsequently extending the shaft or of driving a decline from the lowest operating horizon for deeper access. The decline approach was adopted some six years after production commenced from No. 2 Shaft. The reasons for that decision are outlined, together with an account of the constraints and design requirements imposed by commencing by a vertical shaft in the hanging wall of the orebody.

Jan 1, 1982

By W Liu, S Gao, D Wei, B Cui, Z Guan, Y Shen

Beneficiation of low-grade fine-grained hematite ores becomes increasingly important due to rapid depletion of high quality iron ore resources. However, fine particles, especially ultra-fine particles, make efficient beneficiation of these ores more difficult. Therefore, methods to reduce the influence of fine particles must be considered to achieve better beneficiation performance. Analysis and systematical beneficiation tests were carried out on an ultra-fine-grained hematite ore slime from washing a fine grained hematite ore. Ore particles were found to be presented in loose soil. While some of the ore particles were agglomerated, they were very fine and contained up to 76.5 per cent -0.023 mm material. In this paper, using a single magnetic separation flow sheet with sodium silicate (SS) as a dispersing agent, a concentrate containing 65.05 per cent Fe was obtained at an iron recovery of 68.58 per cent from the hematite ore slime of 56.65 per cent Fe. The single magnetic separation flow sheet was simple and reliable, the agent SS was effective in dispersing ultra-fine particles. The results are believed to be applicable to similar hematite ores.CITATION:Wei, D, Guan, Z, Gao, S, Liu, W, Shen, Y and Cui, B, 2013. Beneficiation study of an ultra-fine-grained hematite ore slime, in Proceedings Iron Ore 2013 , pp 495-500 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By J E. Wheeler, S B. Valine, L G. Albuquerque

It has long been known that closed circuit grinding with a classifier improves grinding efficiency, reduces unit specific power consumption, and reduces over grinding. The classification device removes material from the circuit that has reached the desired size and returns coarse material back to the mill for further grinding. The efficiency of the classifier is an important factor in the overall performance of a grinding circuit. The classifier affects the capacity of the grinding circuit and the metallurgical performance of downstream operations. A review of historical research and modern case studies is used to demonstrate the benefits of high frequency screens for classification in grinding circuits.CITATION:Valine, S B, Wheeler, J E and Albuquerque, L G, 2012. Applications of fine screens in grinding circuits, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 389-394 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

LIST OF CONTENTSAbstractIntroductionSelected Sections of the Broken Hill LodeLocality PlansPetrology1. Zinc Corporation Mine: DDH. 5.98, section 30, No. 26 level2. Zinc Corporation Mine: DDH. 838, section 30, No. 13 level3. Broken Hill Sonth Mine: 60 ft. cont01(r above 1170 ft. level4. Broken Hill South Mine : No. 7 shaft section, 1370 ft. levelOrigin of garnet sandstone5. Barrier Central Pty. Ltd.: DDH. tJ.93, Block 136. North Broken Hill Ltd.: Junction mine, DDH. 602, No. 10 level7. North Broken Hill Ltd.: Jnnction mine, DDH. 588, No. 11 level8. North Broken Hill Ltd.: North mine, DDH. through Southern ore body, 3370 ft. level9. North Broken Hill Ltd.: North mine, Northern ore body above 2300 ft. level(a) Southern end, section 27, 77 ft. above rails(b) Northern end, section 30, 6.9 ft. above rails(c) Miscellaneons samples, sections 27 and 28Relative time of ore depositionSericitizntionStructural significance of sericitizationGCLhnite OrthoclaseApatite GarnetManganese SilicatesAlteration of manganese silicatesRelation of zinc and lead to the silicatesZinc in manganese-bearing silicatesLead in potassium and lime silicates and apatite

Jan 1, 1959

By Waterhouse J. D, Harris B. M

This paper briefly describes the construction in 1979/80 of a 70m deep trial open pit coal mine near Bowmans S.A. and describes more fully the hydrogeological aspects of the exercise. The primary purpose of the Trial Pit was to provide a large sample (700 tonnes) of coal for combustion tests to be carried out in West Germany and the United States of America. Consideration was given to obtaining the sample of coal by drilling and by shaft sinking as alternatives to open pit methods. It was expected that economic mining of the deposit on an operational scale could only be achieved by open cut methods and it was recognised that major uncertainties existed in planning such a mine in the deep unconsolidated multi-aquifer deposit. It was therefore elected to obtain the bulk sample by constructing a trial open pit, which would be closely monitored to provide as much data as possible for future planning of a full scale mine. The dewatering of the Trial Pit was achieved using 26 deep pumping wells, assisted in the later stages by several hundred well points. This was probably the largest dewatering project currently in operation in Australia.

Jan 1, 1981

The Mt Sinivit gold project is located approximately 50km SSW of Rabaul in the Baining Mountains of the Gazelle Peninsula, East New Britain Province. The deposits were discovered in mid- 1983 and form part of a larger 26km long zone of variably aurif- erous quartz veining. There are no surface indications or previ- ous records of any prospecting activity or production from the region. The Mt Sinivit deposits consist of a series of oxide and sulphide reserves and resources contained in the Wild Dog (South- ern, Central and Northern oxide zones; Northern sulphide zone) and Kavursuki veins. The proposed exploitation of the oxide reserves by a series of small-medium sized open pits has been fostered by the PNG Department of Mining & Petroleum (DMP) as part of a government policy to encourage the development of a small-medium sized mining industry in the country. The aim of this paper is to document the steps and procedures involved in obtaining the grant of a Mining Lease emphasising the time and the expenditures required during each step of the approvals process for the Mt Sinivit project.

Jan 1, 1997

By R G. Jeffrey

The Northparkes, Endeavour 26 orebody is a porphyry copperûgold deposit and comprises a moderately to well jointed rock mass characterised by gypsum veining, the intensity of which decreases with depth. The top 480 metres of the orebody is currently being mined by block caving, the undercut dimensions measuring 196 metres in length by 180 metres in width. Continuous caving was never achieved after the completion of the undercut thus cave inducement techniques were sought to maintain caving so as to safely sustain production. The use of hydraulic fracturing as a cave inducement tool was successfully trialled in December 1997 using existing exploration boreholes located midway up the current lift. Subsequent fracturing campaigns have enjoyed various degrees of success and have yielded in excess of seven million tonnes of ore at a significantly lower cost than conventional cave inducement techniques. Monitoring of both the hydraulic fracture system and the rock mass response has provided considerable insight into the geometry, growth and influence of hydraulic fracture networks above the Northparkes block cave, and has initiated additional research into the use of hydraulic fracturing in other mining methods.

Jan 1, 2000

By E Christodoulou, L Zoumpoulakis

The kinetics of the thermal decomposition of MgCO3 was investigated using isothermal experiments performed in a thermogravimetric analyzer under a nitrogen atmosphere at 380¦, 400¦, 450¦ and 480¦C. The weight loss data as a function of time were modified to give the fraction that reacted (ß) and the rate of reaction (dß/dt) vs. time (t). Kinetic analysis of the experimental results, using three different methods, showed that diffusion predominates the MgCO3 decomposition over the investigated temperature range, with the data being best fitted by JanderÆs equation ([1−(1−ß)1/3]2=kt). The activation energy was estimated by Arrhenius plots using both the initial reaction rates and rate constants from fitting the above equation. The values estimated were 27.1 and 171.4 kJ/mol respectively.

Jan 1, 2001

By Y Xie, L O’Connor, S C. Dominy

"Sheeted vein gold deposits are characterised by multiple subparallel veins and free milling gold. In situ heterogeneity of mineralisation results in grade and process parameter variability, which will increase project risk. Measured variability is often enhanced by poorly designed sampling and test work protocols. Protocols that are optimised within the framework of the theory of sampling to suit the ore type, together with quality assurance/quality control systems, will reduce variability and provide fit-for-purpose results. The geometallurgical approach requires spatially distributed samples within a deposit to support variability modelling. Diverse attributes from core logging, mineralogical/textural determination and small-scale tests are used to measure variability. This contribution emphasises early stage geometallurgical intervention during project development. It presents a discussion of representative sampling in the context of the theory of sampling. A case study presents a protocol that exemplifies how data can be gained from a well-designed and planned program to support a resource estimate and prefeasibility study.CITATION:Dominy, S C, O’Connor, L and Xie, Y, 2016. Sampling and Test Work Protocol Development for Geometallurgical Characterisation of a Sheeted Vein Gold Deposit, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 97–112 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016