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By Ono K, Oishi T

Electrochemical determination of the oxy- gen partial pressure in the Fe-0-SiO 2 ternary systems saturated with solid silica was done by measuring the activity of oxygen in a silver bath in equilibrium with the molten slags using zirconia solid electrolyte galvanic cells. From the data obtained, the activity ~Faii.st composition relations were calculated

Jan 1, 1980

By Van Heuzen JA

The extensive deposits of brown coal in the Latrobe Valley form the major solid fuel resource in Victoria and are the energy source for most of the State's power generation. This paper describes the coalfield resources allocated for electricity generation and a potential sequential develop- ment of these areas in future years to supply future power stations.

Jan 1, 1982

HIGHWALL MINING - DECISION TO MINEUlan had completed operations in the first Open Cut area due to high stripping ratios and the presence of geological features which destroyed a significant portion of the coal in the upper part of the seam. The pit had been abandoned in 1994 and operations had moved to a new location to the north west.

Jan 1, 1998

This paper discusses design concepts in planning a large modern bulk terminal. The need is emphasised for a studied master plan, in-built materials handling flexibility and staged development. An integrated approach is advocated, combining functional purpose designed foundations and structures to serve their mechanical, electrical and environmental functions. Dry bulk and slurry handling are also compared in perspective.

Jan 1, 1983

Recognition is the most important aspect in the use of breccias as an exploration tool. Ore-hosting breccias occur in a wide variety of environ-ments, shapes, compositions and characteristics, but generally present favorable loci for the deposition of ore mineralization in epithermal, porphyry copper-gold-molybdenum, massive sulfide, carbonate-hosted, sedimentary lead-zinc deposits and others.

Jan 1, 1990

This paper addresses the role of mine geology in mining geotechnics. The role is assessed and discussed in terms of five main elements; geotechnical complexity, geological complexity, mine scale, percentage sampling and geological uncertainty. Lastly, the overall objectives and mine geology requirements are listed in terms of the various mine development stages; exploration, feasibility-design and operating.

Jan 1, 1993

The mechanisms of fragmentation in homogeneous materials and structured rock mass are reviewed. A method previously used to predict vibration damage to the remaining rock is extended and shown to be valid for the prediction of fragmentation in the rock mass removed by blasting. The effectiveness of different explosives in different types of rock blasting is discussed.

Jan 1, 1990

Madison Enterprises Corp. and Matu Mining are currently ex- ploring the Mt. Kare property in Papua New Guinea. The Mt. Kare gold prospect has had a short but very active history, since the first discovery of gold in the area in 1986 the property has sccn: a 3 year gold rush during which 10,000 alluvial miners re

Jan 1, 1997

By J-T Zhu, Q-Y Tu, S-L Kong, L Wang, Y-P Cheng, H-Y Liu, Q-L Yang

China is the largest coal-producing country in the world, while the geological conditions of deep coal mining are extremely complicated with high ground stress, high gas pressure and low permeability, which results in the difficulty of gas drainage and aggravation of gas explosion and coal and gas outburst disasters. Co-extraction of coal and gas is an effective method to eliminate coalmine gas disasters and realise the safe exploitation of coal and efficient gas drainage at the same time. This concept is widely accepted by the main coal-producing countries around the world, while the concrete definition of co-extraction is vague and not unified, and there is little accurate theoretical support for co-extraction of coal and gas, which makes it hard to determine efficient gas drainage methods correspondingly according to the features of coal seams in a comprehensive and systematic way. Based on theoretical analysis, laboratory test and field observations, basic thoughts and specific definition of co-extraction of coal and gas were put forward after analysing the occurrence characteristics of coal seams in China. We obtained the mechanism of mining-enhanced permeability and established the corresponding theoretical model, which is the process of fracture network formation through opening recovery of the original fractures and new fractures produced by unloading damage. Based on the core idea of ‘mining-enhanced permeability’, engineering approaches of ‘unloading by boreholes drilling’ for the single coal seam and ‘unloading by protective seam mining’ for the coal seam group were proposed to realise safe and efficient co-extraction of coal and gas. Meanwhile, combined with engineering practice, we put forward the construction principle of coal exploitation and gas drainage system in different coal seam occurrence conditions. The above methods were applied successfully in the Tunlan coalmine in Shanxi Province and the Panyi coalmine in Anhui Province, which had established the ‘underground-surface united’ spatial gas drainage modes, and could ensure safe and efficient co-extraction of coal and gas in the outburst coalmines.CITATION:Cheng, Y-P, Wang, L, Liu, H-Y, Kong, S-L, Yang, Q-L, Zhu, J-T and Tu, Q-Y, 2015. Theory of safe and efficient co-extraction of coal and gas and its applications, in Proceedings The Australian Mine Ventilation Conference, pp 79–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Z Terzic, M Schult, D Chu, S Macklin

The East West Link road tunnels are proposed to provide a connection between the CityLink toll road and the Eastern Freeway north of the Melbourne CBD. The alignment passes from Moonee Ponds valley beneath the Upfield Line railway cutting, Royal Park, the historic Melbourne Cemetery and beneath Alexander Parade rising to an eastern portal at Hoddle Street. The western (Royal Park) part of the alignment passes through the folded and faulted Silurian Melbourne Formation, which has been subjected to deep weathering since the Triassic.The Melbourne Formation in the Royal Park area is mainly characterised by interbedded sequences of siltstone and fine-grained sandstone. The beds are often graded and a clear boundary between the siltstone and fine-grained sandstone rock can be difficult to distinguish. Variation in lithology and the presence of structural geological features such as folds and faults have resulted in an irregular weathering profile within the Silurian rock; nonetheless the formation typically becomes less weathered with depth.Due to difficulties in obtaining reliable laboratory strength and stiffness relationships with weathering grade, in situ testing methods such as downhole shear wave velocity and high-quality pressuremeter testing are a useful aid to assessing appropriate geotechnical parameters for design.This paper presents an analysis of the variation in shear modulus of the Melbourne Formation, determined at small-strain (from downhole seismic data) and at ‘engineering scale’ strain (from pressuremeter tests) for extremely weathered (XW), highly weathered (HW) and moderately weathered (MW) rock. Estimates of small strain shear modulus (Go) obtained a range between 400 to 3400 MPa for these weathering grades. By comparison against the pressuremeter test data, reduction factors to be applied to these Go values to estimate shear moduli at engineering strain levels typically range between 0.10 and 0.35.The downhole geophysics undertaken in the Royal Park boreholes also suggests that there is an inversion in velocity between approximately 15 and 27?m depth below the top of the formation. This is thought to be related to the effects deep Plio-Pleistocene weathering, iron cementation of joints and increasing frequency of ‘non-healed’ joints in the transition from MW to slightly weathered (SW) rock.CITATION:Macklin, S, Schult, M, Terzic, Z and Chu, D, 2014. Strain-dependent stiffness of the weathered Melbourne Formation, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 179–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M D. Melville, B C. T Macdonald, J Dixon

The acidic and metal rich waters that are generated from acid sulfate soil (ASS) drainage can have damaging impacts upon ecosystems. The most obvious impact has been the discolouration of water and occasional fish kills. ASSÆs produce these acidic and metal rich waters when pyrite in soil is oxidised. Land management techniques are an essential long-term requirement to minimise the amount of pyrite oxidation. Acidic water that cannot be prevented through land management can be neutralised by other techniques. Powdered lime is the most common material in agriculture that is applied directly to soils and waters. Powdered lime can be expensive and if applied dry it may aggregate. Since the aggregated particles of lime are larger they could sink rapidly in the water column and not react. In waters with high concentrations of dissolved iron and aluminium the lime particles may become coated with a metal oxy-hydroxide precipitate, which will decrease its reactivity. A unique lime-dispensing machine, the Waterways Lime Spreader, has been developed to neutralise acidic waterways. The Waterways Lime Spreader can produce a solution rich in fine lime from larger limestone fragments. The current size of the machine means only 3.5 grams per second of limestone can be emitted. This output will neutralise low acidity waters, however, for high acidity waters the time for neutralisation can be long. More reactive chemicals such as hydrated lime or increasing the size of the machine will reduce this neutralisation time. The Waterways Lime Spreader is also capable of producing slurry mixtures if powdered materials are required. Trials with the Waterways Lime Spreader were undertaken in part of the Clothiers Creek catchment located in northeast NSW, Australia. A small drain with a water volume of 4 m3 was neutralised with crushed limestone to pH 6.9 from an initial pH of 2.6 and an acidity of 902 mg/L CaCO3 in 160 minutes. In comparison a drain with a slightly larger volume of 6 m3 that had an initial pH of 3.2 and an acidity of 753 mg/L CaCO3 was neutralised with hydrated lime to pH 11.8 in five minutes. The Waterways Lime Spreader has been used successfully to neutralise water from acid sulfate soils. It is expected that future applications of the machine may be for the neutralisation of acid rock drainage or acidified lakes.

Jan 1, 2003

By G Brewster

The Eagle on the Hill tunnels form part of an upgrade of Mt Barker Road, 15 km to the southeast of Adelaide. The upgrade significantly improves safety and reduces delays on this major road, which winds steeply through mountainous terrain. The twin tunnels each spanning 15 metres run in parallel for a length of 480 metres. The tunnels are excavated in slightly weathered high strength slates and very high strength quartzites of the Saddleworth Formation on the western margin of the Mount Lofty Ranges. Steeply dipping slate cleavages and the high fracture ratio result in many slope stability problems in the project area. The level of geotechnical investigation undertaken prior to the calling of tenders for the project was extensive. This included the excavation of a pilot tunnel along one of the tunnel alignments, which allowed accurate mapping and rating of the rock, resulting in an increased level of confidence during the tender process. One of the features of the winning alternative tender design was the use of canopy tubes, flexible steel ribs and shotcrete to replace up to 40 metres of deep portal cuts in unstable rock with driven tunnels. Slope stability issues were overcome with the use of rock dowels and shotcrete. The support concept allowed the safe driving of the tunnel portals with as little as two metres of overburden. The design incorporated lining drainage and criteria for fireproofing based on European experience to ensure the ability of the tunnels to remain stable in the case of a severe fire incident. The support design allowed for maximum flexibility with a range of support types able to deal with the varying ground conditions. Design development and support refinement continued throughout the tunnel construction phase with close liaison between the designer and the constructor. Monitoring and review of feedback from the construction site by the Sydney based design team was easily achieved by means of electronic transfer of photographic and survey information, telephone and fax communication and regular site visits. The contractor for this project is Macmahon Concrete Constructions Joint Venture (MCCJV) and the designer is Connell Wagner. Excavation commenced in January 1998 with tunnel breakthrough having been achieved in early-August 1998 and mid-September 1998 respectively. Concrete lining construction is scheduled for completion in April 1999.

Jan 1, 1999

By T Hayward, G Lane, M Phillips

In December 2004 Phu Bia Mining Ltd commissioned Ausenco International Limited to conduct a feasibility study for its Phu Kham copper-gold project located in Laos. The feasibility study for a mining and processing operation treating 12 Mtpa of ore averaging 0.56 per cent copper and 0.25 g/t gold to produce an anticipated annual average 200 000 t of concentrate containing 25 per cent copper was completed in early 2006. The plant design incorporates a single processing line and includes a gyratory crusher, overland conveyor, coarse ore stockpile, SAG and ball mill grinding circuit, flotation circuit including regrind and three stages of cleaning, concentrate dewatering and concentrate load-out facilities. The Phu Kham copper-gold mineralisation comprises two principal styles: stockwork-disseminated and banded-massive sulfide within skarn limits. Primary copper in both mineralisation styles occurs as chalcopyrite and secondary copper sulfide minerals. Skarn includes the copper and gold mineralisation contained in pyrite, silicate, magnetite and haematite skarns, and in quartz-pyrite altered sediments. Both the stockwork-disseminated and banded-massive sulfide ores contain relatively high proportions of pyrite relative to the copper and gold mineralisation. Thus, the flotation metallurgy of the Phu Kham orebody is characterised by the need to reject a high proportion of the pyrite during differential flotation to yield a concentrate grade of approximately 25 per cent copper. The rejection of pyrite is accompanied by the rejection of some copper and gold and can result in modest metallurgical recovery. Consequently, the greater the pyrite content, the lower the expected copper and gold recoveries. The relative pyrite content is expressed on the basis of sulfur:copper ratio. For Phu Kham ores, the sulfur:copper ratios are in the range eight to 14 on a blended annual basis, but can be greater than 20 in the skarn components. Higher grades of copper and gold are also present in the skarn mineralisation. The design concepts for the concentrator were influenced by the need to provide a low capital cost approach for the project due to the relatively low grade of the ore and the modest metallurgical recovery. The concepts used to minimise capital cost whilst retaining operating and maintenance flexibility are discussed, together with the metallurgical challenges imposed by the high pyrite mineralisation.

Jan 1, 2007

The Fosterville Goldfield has a modest past production (0.3 Moz), but is now emerging as a significant goldfield (2.6 Moz resources, including 1.1 Moz reserves) with implications for exploration within the orogenic gold provinces of the Lachlan Fold Belt in Australia and the Buller Terrane on the West Coast of New Zealand. Fosterville is located 20 km east of the 22 Moz Bendigo Goldfield and is geologically similar to other Victorian goldfields, however the nature of the gold mineralisation differs significantly. Unlike other Victorian goldfields there is no primary free gold at Fosterville. The gold occurs in as sub-SEM resolution particles, in fine grained arsenopyrite and pyrite crystals disseminated through the wall rocks in fault controlled quartz-carbonate vein stockworks. The Fosterville Goldfield comprises several subparallel fault systems striking 340¦ over an exposed strike length of 28 km. The Fosterville Fault system comprises the west dipping (~75¦), reverse Fosterville Fault and several less steeply west dipping splay faults formed in the footwall. The splay faults extend through east dipping beds from the Fosterville Fault across a syncline hinge into stratigraphically controlled positions on the west dipping limb of the syncline. The predominant control on gold mineralisation is the intersection of the bedding on the east dipping limb of the syncline and faulting which, is in turn controlled by the orientation of bedding in the west dipping limb of the syncline. The mineralised shoots are thus subparallel to the plunge of the syncline and show a plunge reversal about a culmination in the footwall syncline. This provides a very powerful exploration tool with bedding û cleavage intersection lineations measured in outcrop and oriented core indicating the plunge of mineralisation. Mineralisation is also, albeit less commonly, controlled by local variations in strike and dip of the host fault and at metre scale by host lithology. As the faults and mineralisation are stratigraphically controlled, detailed stratigraphic interpretations are essential to provide control on structural interpretations for resource modelling. Compared to other Victorian goldfields, the Fosterville Goldfield formed later (385 Ma to 360 Ma cf 440 Ma), at lower temperatures and at shallower depths (fluid inclusion studies of Au associated veins suggest vein formation at ~270¦C (range 140¦C to 385¦C) and at depths of 2.6 - 5.7 km).

Jan 1, 2005

By J Seppelt

The Kanmantoo Copper Project is owned and operated by Hillgrove Resources Limited and is situated in the Adelaide Hills region in South Australia. Mining in the area has taken place off and on over the last 140 years to recover metal from both copper and lead-zinc ores. This paper focuses on the commissioning, ramp up and future outlook for the copper concentrator at the Kanmantoo Copper Project with major focus on issues encountered and operating performance achieved to date.CITATION:Seppelt, J, 2012. Commissioning of the Kanmantoo Copper Concentrator, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 127-136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By C DahnTr-Lindqvist

The Kiruna mine produced about 19 Mt processed iron ore in 1999 using sublevel caving. General failure in the hangingwall has been widely studied and its mechanism is rather well understood. Failure in the footwall is more recent and not perfectly explained. Plane shear failure and Hoek and BrayÆs circular failure charts were successfully used to match the first surveyed failure surfaces. The footwall is not free yet but covered by a caved waste rock abutment whose exact behaviour is poorly known. Based on new field data and numerical models (FLAC), the following paper presents recent improvements in understanding the Kiruna mineÆs footwall failure process.

Jan 1, 2000

The Mount Whaleback iron ore deposit at Newman, Western Australia comprises the largest known continuous iron ore deposit in Australia, originally with a Measured Resource in excess of 1700 Mt of hematite ore. The deposit occurs within the Hamersley Province which forms part of the Pilbara Block in the NW of Western Australia (Figure 1). The Mount Whaleback iron ore deposit, together with a number of discrete iron ore bearing satellite orebodies in the Newman district, contributes to the Newman Lump and Fines products. Extensive quality control systems are utilised from mining to shipping to ensure that each product meets a narrow geochemical target grade range.

Jan 1, 1997

As the oxide reserves in an oxide/sulphide deposit are exhausted transition to the treatment of sulphides should be investigated in detail and well before processing the sulphide ore commences. The investigation should be broad based to consider all treatment options and not restricted entirely by the existing process plant treatment method. These options may include cyanidation, flotation, roasting, bacterial leaching or gravity treatment and are chosen on the basis of various testwork responses. Experiences in laboratory testing of sulphides and treatment of sulphides at various operations are discussed. This includes the treatment of copper/gold sulphides, CIP treatment of sulphides and treatment of marcasite ore in a conventional CIP circuit.

Jan 1, 1989

The Beaconsfield gold mine processing plant is a complex operation and utilises crushing, grinding, gravity gold concentration, sulfide flotation, bacterial oxidation, cyanidation and zinc cementation to recover gold from the partially refractory ore. This paper discusses the challenges, developments and advancements throughout the processing plant since start up, which have culminated in a 25 per cent increase in the mill throughput over the nameplate design and a concomitant gold recovery increase from 75 to 92 per cent. The improvements have been attained via advancements in mechanical integrity, metallurgical review, process control and operator training, resulting in the current operation producing over 630 000 ounces of gold to date.

Jan 1, 2007

In June 1996, Nord Resources Pacific (Nord) decided to work towards obtaining all necessary approvals from the government of PNG for a mine on Simberi Island in the Tabar Island Group, New Ireland Province. On the 9th of September 1996, Nord submitted a Proposal for Development and an application for a Mining Lease to mine the oxide gold deposits on Simberi Island. The Mining Lease was granted on the 3rd of December 1996 in a signing ceremony on Simberi Island. This was achieved in the extremely short time frame of less than 3 months and this paper attempts to explain the processes which made it possible.

Jan 1, 1997