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The results of self potential geophysical surveys conducted over base metal prospects near Orange, Goulburn, and Wellington, N.S.W., indicate that this rapid and inexpensive exploration procedure merits wider application within eastern New South Wales, and in similar environments elsewhere.

Jan 1, 1973

By S E. Wallah, D Hardjito, B V. Ran

The manufacture of Ordinary Portland Cement (OPC) is not only energy-intensive but also releases a significant volume of carbon dioxide (CO2) to the atmosphere. In addition, OPC in concrete often causes premature deterioration that affects the durability of concrete structures. This paper explores an alternative to OPC concrete called geopolymer concrete.The present research utilises low calcium (class F) fly ash as the source material to produce geopolymer concrete. Several factors that affect the mix design process such as mix proportion, curing time, and curing temperature have been studied. In addition, the long-term properties such as drying shrinkage, creep, and exposure to sulfate attack are also being investigated.The test data presented in this paper reveal that geopolymer concrete possesses high compressive strength, undergoes very little drying shrinkage and moderately low creep, and shows excellent resistance to sulfate attack. The result is extremely promising and demonstrates the sustainability of geopolymer concrete as a construction material for a sustainable future.

Jan 1, 2004

By J Player, P Evans, G Sweby

Achieving quick underground access after the completion of an open pit mine can be critical to maintaining project value and ensuring regular ore feed to the mill. This paper outlines the design and construction for two portals in an active open pit to commence underground development quickly whilst installing appropriate ground control to maintain long term access in an uncertain setting. Implementation of the portal designs was complicated by the change in underground design from hangingwall access to footwall access late in the life of the open pit due to preferable ground conditions. The portal locations did not have easy access for ground support installation integrated into the pit design due to the timing of the underground design changes. Practical implementation of the ground support systems subsequently became a key part of the project. Intact rock strength, rock mass characteristics, gradational weathering / alteration profile and structural information were modelled against pit displacement monitoring as the basis from which the portals were located and ground support schemes designed. Conditions around one of the portals necessitated numerical modelling to estimate the appropriate level of ground control for long term stability. The design was completed whilst the open pit was actively on-going and the portal areas not entirely exposed. The rock mass assessment and analysis for the two portals indicated different ground support scheme capacities would be required. The expected level of control for one of the portals also necessitated the use of monitoring with extensometers and load cells to ensure the rock mass response and ground support scheme performed as planned. Construction of the portals demonstrates the benefit of a considered design process, a plan which allows practical installation of ground support schemes where access is limited, the benefit of ongoing monitoring to ensure performance remains within design limits and the challenges involved working within an active pit with limited floor space.

Mar 15, 2021

Comparative Studies on Balls Versus Spheroidal Tetrahedrons Working Media to Ore Grinding in an Industrial Drum Mill

Sep 13, 2010

A forecast of energy demand in the non-commu- nist world to the year 1990 is presented with com- ments on the expected effectiveness of conservation efforts in achieving more efficient utilization of energy. A forecast of energy supply for the same period is presented showing the contribution of oil, gas, hydropower, coal, and nuclear fuels, with brief comments on the factors constraining the rate of growth of non-oil energy supplies. The role of `synthetic fuels', i.e. liquid or gaseous fuels produced from coal, oil shale, and tar sands, is reviewed with brief discussion of factors affecting the development of this industry. In somewhat greater details, the growth of demand for oil by geographic regions is analyzed. Particular attention is directed to the source of the oil supplies which will be required. The anticipated rate of discovery of new oil reserves is discussed with comments on lead times required in the development of new discoveries in hostile environments such as the Arctic and deep oceans. The continuing importance of oil supplied from countries which are members of the Organization of Petroleum Exporting Countries (OPEC) is illustrated. Oil will continue to be the marginal ('balancing') source of world energy supply throughout the forecast period and although it now appears that oil supplies will be sufficient to balance the energy equation during the 1980s, little flexi- bility will exist to cope with unexpected growth in demand or slippage in supply. Prudent energy re- source management will require major efforts to stimulate conservation and also to stimulate the rapid development of conventional and new forms of energy supplies and changes in energy consump- tion patterns to utilize the new supplies. Because of the long lead times and the massive capital require- ments involved, governmental policies are needed soon which will stimulate conservation and which will encourage businesses to move rapidly to assure the energy supplies the world will require in the 1990s.

Jan 1, 1978

By T Ladinig

Raise caving is a novel cave mining method, which has been proposed for mass mining at increasing mining depths in LKAB operations. The method makes use of the raise mining technology and an active stress management approach. For the implementation the method is split into two phases, namely a de-stressing phase and a production phase. In the de-stressing phase, a slot-pillar system is established. The purpose of slots is to provide stress shadows and the purpose of the large pillars is to control stress and seismicity. The production phase follows after the de-stressing phase. Required infrastructure in the production phase is developed delayed in stress shadows and bulk extraction takes place in de-stressed zones. Eventually the pillars crush and they are extracted in the production phase. A comprehensive research and development program has been launched to develop the raise caving method towards implementation. As part of this program a full-scale test site of raise caving will be conducted as well as raise caving operations are planned for depth extensions in LKAB mines. This paper discusses the design of raise caving operations in practice at the LKAB mines. In particular, the purpose of the paper is to focus on requirements for the development and design of a raise caving operation. The development of raise caving is discussed from a systems engineering perspective as well as from a management perspective. The functional requirements in the destressing and production phase are outlined and discussed in the paper. The discussion is on basis of the main elements of the raise caving system, such as slots, stopes, pillars and infrastructure. Critical rock engineering design requirements in the de-stressing and production phase are highlighted and dependencies between individual main elements are identified. The analyses show that pillars are especially important for the success of the mining method. Overall, the analyses show that raise caving is a complex system and that its development demands a multidisciplinary approach.

Mar 29, 2023

Underground space can be defined as space below natural ground level which can be used as an alternative to an above ground location. While many of our above ground structures inherently involve underground excavation for foundations and services, the term underground space specifically refers to organised development of underground openings and of the underground domain. For example, the services to a city such as power, gas, sewerage, water and communications are installed in a congested array which usually requires roads to be dug up when the services need to be accessed. An underground space installation of services would involve a well planned conduit which is easily accessed without any excavation. The concept of using this virtually untapped land resource to the advantage of our expanding cities is gaining considerable interest in Australia. Overseas, in the Scandinavian countries and some Asian countries, underground space has been used for centuries; in Great Britain, France and the United States of America over the last century and in Japan for over a decade. This paper focusses on the types of underground space usage which should be competitive with above ground use and suggests areas in which the competitive edge may be improved in favour of underground space. In particular, considerable advantage is seen by using well-planned underground space developments in major cities, where the strategic central location of the development takes advantage of proximity to potential users. However, the largest single factor affecting the acceptance of underground space is the high capital cost of construction, even though an underground space development may result in lower operating costs and reduced long-term maintenance costs. While excavation methods and associated costs are very much site-specific, the importance of applying the latest technology in rock breakage, with consideration of ground vibration, excavation rates and ground support, remains a major challenge to the development of underground space.

Jan 1, 1995

By A Liu, X Wang, W Peng, Q Zhang

Pulp rheology plays a critical role in fine mineral flotation. Yield stress and apparent viscosity are two important rheological parameters affecting mineral flotation recovery. In this paper, the concept of pulp rheology and its measuring method are presented. The main factors, such as particle size, pulp concentration, mineral types, pulp temperature, inorganic salts, that affect the pulp rheology are systematically reviewed, and then followed by the discussion of the relationship between pulp rheological properties and flotation performance. Generally, high pulp apparent viscosity and yield stress values have been found to have an adverse effect on flotation recovery. In addition, due to the hetero-coagulation between the valuable mineral and gangue mineral, the pulp of mixed ore shows higher viscosity than that of the single mineral slurry. This paper is expected to provide some references for the efficient upgrading of low-grade and complex ores from the perspective of pulp rheology.

Aug 24, 2022

The low grade Mount Charlotte orebody was first mined with minimum capital expenditure by mechanised cut and fill stoping. The lower block was prepared simultaneously for open stoping by shaft sinking and installing another crusher and services. Similar development for the third block was discouraged by economic factors and reduced tonnage. Decline develop- ment required less capital and opened up ore reserves commensurate with advance, providing flexibility to stop operations without commit- ment: A 1 in 7 decline measuring 4.25m x 5.5m to accommodate standard Euclid 25 tonne dump trucks was developed south of the orebody. A fleet of four trucks average 12 loads each per shift over a haul distance of 700m.

Jan 1, 1973

By H Arvidson, B Spence, S Helm

Mining is the art of disturbing ground. All phases of a mine’s life cycle from exploration to building and operating a mine, through closure, has a physical impact on the earth. There is currently increasing public and stakeholder awareness owing to a wide range of issues including heritage protection, environmental stewardship, and social impacts therefore ground disturbance must be conducted in a way that honours and respects all agreements, regulations, legislation, and social expectations. A comprehensive ground disturbance permitting process has been developed through consultation with major mining companies and Traditional Owner groups. It operates from strategic business planning through to closure and rehabilitation. Adherence to the principles and process of permitting helps to minimise risk by ensuring that mining companies conduct their business in an inclusive, professional, reliable, and consistent manner that stakeholders reasonably expect, and that mining companies can be proud of. Built on a geographical information system, supplemented with a specialist database, this process allows request, review, and approval by subject matter experts, to operate in a common environment that is transparent, facilitates collaboration, improves efficiencies, and reduces the risk of error or omission. The application of new technology can effectively highlight changes that naturally occur in today’s dynamic ESG domain and provides the perfect platform to record actual disturbance against authorised and planned allowances. The social license to operate demands that strong governance of the ground disturbance process, described herein, can be demonstrated to any interested stakeholder, and mining companies recognise that this principle is central to the betterment of the mining industry.

Sep 18, 2023

In 1961, West Australian Petroleum's Eneabba No. 1 bore encountered 22 seams of coal totalling 40 ft in thickness between the depths of 6373 ft and 6441 ft. On analysis, this coal had a similar calorific value (8000-HOOO B.T.U./lb, assuming 20 per cent water) to the coal from the Collie Coalfield, Western Australia's only known area of commercially exploitable coal. Being buried to depths in excess of 6000 ft, the coal at Eneabba had developed weakly-coking properties, and thus, although much younger than the Permian coals of Collie, gave promise of being a major potential source of power for Western Australia.West Australian Petroleum undertook a programme of stratigraphic drilling and shallow test drilling to determine whether this coalhorizon persisted into the outcrop of the Lower Jurassic sediments in the Hill River district, 140 miles NNW. of Perth, and, if it was present, if the quality and quantity of the coal would warrant development of the deposits by open cutting. The coal horizon was identified in the near surface, but the poor quality of the coal and the complexity of the structure made development (in the area examined) uneconomic at the time.A strong seismic reflection in the Eneabba area occurs at the same depth as the Jurassic coals. This event originates within the upper beds of the Lower Jurassic and it is probable that the velocity contrast between the higher velocity siltstones and the very low velocity coals enhances this very strong, distinctive seismic reflection.This event can be followed on continuous seismic data over a large area of the northern Perth Basin, from 13 miles SE. of Dongara to 20 miles SW. of Coorow. It can be followed from a depth of 4000 ftnear Dongara to over 17,000 ft to the SE., so development of thisvast potential source of power will depend on the economics ofprocesses being developed for the production of power from theburning of coal seams in situ.INTRODUCTIONThe discovery of 22 seams of economically useable coaltotalling 40 ft in thickness in the Lower J urassic sedimentsof the Eneabba No. 1 bore (Fig. 1) led to the search forthese seams at economically workable depths. The Ministerfor Mines in Western Australia granted to West Australian1. Supervising Geologist, West Australian Petroleum Pty. Ltd.Manuscript received at The Institute, 25th May, 1964. and presented to the 1964Annual Conference.

Jan 1, 1964

How the Australasian and Canadian Codes (VALMIN and CIMVal) approach mineral property valuation is described. Brief comment is also made on the International Valuation Standards CommitteeÆs interest in a global valuation standard for Mineral (Extractive) Industries and the South African SAMREC initiatives to adopt a VALMIN-like Code. The conventional tripartite classification of valuation approaches into those that are Market-based, Income-based and Cost-based is outlined. It is best practice to use as many of these approaches as possible (and as many methods as reasonable in the particular circumstances), given the quantity and quality of the data available on the Mineral Asset (which depends upon the state of development of the mineral property). The use of specific methods must satisfy the basic considerations of logic and reasonableness and the purpose of the valuation. The competence, judgement and repute of the valuer are critical factors, since all valuations are time and circumstance specific. What constitutes æMarket ValueÆ in the different jurisdictions is discussed and definitions are given. Challenges facing the globalisation of a VALMIN-type Code for the international Minerals Industry are the influence of real estate valuers and the US jurisdictional idiosyncrasies. This is mainly due to a fixation on real property rights with a preference for using real estate-like comparative sales techniques (Market Approach) to the exclusion of Income-based approaches; a regulatory reluctance in the US to accept that Resources have considerable value; and the International Accounting Standards BoardÆs preference for Historical, rather than Current Value, accounting.

Jan 1, 2002

Operating metallurgists spend a significant part of their time running plant trials to compare two or more conditions in order to improve the process, such as a new reagent, flow sheet or piece of equipment. The best way to conduct such a trial is as a paired experiment when testing two conditions (eg 'old' and 'new') or a randomised block design when testing more than two conditions. These experimental designs should always be preferred over alternatives if their requirements can be met, because they block the effect of uncontrolled variables ('covariates') and are the most statistically efficient, ie they will lead to the required level of confidence in the outcome faster than other methods. Sometimes, however, it is not possible to switch condition easily, which is a prime requirement of these methods. In such cases the only option may be to switch condition once only, and compare the process performance before and after the switch. Examples are testing grinding media, large equipment, or long residence time processes such as leach trains or CCD thickeners. This paper considers some data analysis methods to deal with this situation. Modelling with intervention analysis (IA) uses regression models with a dummy variable to indicate the presence or absence of the test condition. IA with a time series model ensures that the residuals are uncorrelated. IA with a process model helps to deal with the problem of covariates. The reference distribution is a method free of any statistical assumptions but is less powerful than the other methods. Cusum charts are a helpful visual aid to interpreting time trends. A combination of these methods can help improve the confidence in the final decision. None are as good as a formal experimental design such as a paired trial.

Jan 1, 2008

By J Masliyah, Z Xu

The largest oil sand deposit in the world is located in Alberta, Canada, with a total proven reserve of 2.5 trillion barrels of oil. The water based extraction process is currently being used in commercial operations to recover bitumen by flotation from oil sand ores. A recognised challenge in bitumen extraction is the reduced bitumen recovery when processing ores containing high fines content or æweatheredÆ oil sand ores, collectively known as poor processing ores. Inspired by demonstrated success of using kerosene as collectors in coal flotation, an innovative idea of using oily bubbles (air bubbles coated with a thin layer of oil or solvent) was tested to improve bitumen flotation recovery from poor processing ores. In this study, dynamic contact angle of air bubbles or oily bubbles on bitumen and induction time of bitumen-oily bubble attachment in water were measured to justify the use of oily bubbles in bitumen recovery from poor processing ores. The type of oil or solvents, including kerosene, toluene and naphtha, used in generating oily bubbles showed a marginal effect on the contact angle values, similar to the values measured with air bubbles. However, the spreading of an air bubble was found to be much slower than that of oily bubbles on a bitumen surface. The induction time for oily bubble-bitumen attachment was found to be much shorter than that for corresponding air bubble-bitumen attachment in the process water from poor processing ores. The reduced induction time for kerosene-coated air bubble-bitumen attachment correlates well with the improved bitumen recovery from poor processing ores using kerosene-coated oily bubble flotation technology.

Jan 1, 2005

By A D. Strand

The Coeur dÆAlene mining district in northern Idaho, USA is the second largest producer of silver in the world. The Proterozoic Revett Formation hosts most of the mesothermal Ag-Pb-Zn vein ore in the district; it consists of informally designated lower, middle, and upper members. All three members show up to an order of magnitude of southward thickening across the regionally significant Osburn fault. Changes in thickness of the Revett Formation across the Osburn fault reflect a major, down-to-the-south, crustal-scale fault that:was active during sedimentation, was periodically reactivated during the structural and metallogenic history of the district, and likely provided first-order control over regional fluid flow during mineralization events. Where vein structures intersect favourable strata, they produce rich ore; where vein structures cross unfavourable strata, they are poorly mineralised or barren. The most favourable host rock in the district is quartzite, which accounts for the large production from the quartzite-rich Revett Formation.The district has five main types of hydrothermal alteration:feldspar destruction, hydrothermal bleaching, carbonatisation, sulfidation, and silicification. Feldspar destruction is the most extensive and pervasive type of alteration, involving the district-wide absence of feldspar from Belt Supergroup rocks. Hydrothermal bleaching results from the destruction of hematite; it forms alteration envelopes that extend for tens to hundreds of metres into the wall rocks around many of the mineralised veins. Siderite alteration is most diagnostic of mineralisation, forming alteration envelopes that extend for tens to hundreds of metres into the wall rocks around all mineralised veins. Fine-grained arsenopyrite and/or fine-grained pyrite commonly form alteration zones adjacent to high-grade ore shoots that extend for metres to tens of metres into the wall rocks. Widespread silicification is most easily recognised by the presence of numerous quartz veins.

Jan 1, 2002

By B Chapman, B Gaida, L Drowley

The 372 MW Ulu Jelai Hydroelectric Project is a peaking power scheme located in the Cameron Highlands, Malaysia. The main features of the project include an 84 m high roller compacted concrete dam; two weirs which divert flows from adjacent catchments via transfer tunnels into the main reservoir; an underground power waterway; and an underground power station complex comprising three large caverns with connecting tunnels approximately 240 m below surface level. The project includes approximately 25 km of tunnels excavated in fresh granite rock mass with some distinct shear zones of weaker material. The majority of the tunnels are being excavated using drill and blast, with the two transfer tunnels being excavated with a tunnel boring machine (TBM).This paper focuses on the design and construction of the Telanok underground power station complex and also some aspects of the design for the headrace tunnel. Topics covered include geological site investigations including in situ measurements of rock stresses; development of a geological model and parameters for rock support design; three-dimensional modelling to assess interactions between the caverns to optimise rock support; design of a rock anchored crane beam; construction of the caverns and design of the unlined headrace tunnel taking into account hydraulic jacking and operational pressure fluctuations.CITATION:Drowley, L, Gaida, B and Chapman, B, 2014. Design and construction of large caverns in granite – Ulu Jelai Hydroelectric Project, Malaysia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 361–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

Project approvals are the key mechanism to balance the environmental, social and economic aspects of a project. The assessment approaches vary significantly between states, with some having a strong emphasis on social, economic and environment, while others focus primarily on the environmental issues. There are a number of approaches which proponents and governments should consider which not only deliver better project outcomes, but can save proponents time and resources in delivering the project.   These approaches are not new but are often poorly implemented. This paper considers a number of these approaches and outlines the benefits they bring.

Jun 1, 2010

By S S. Kanchibotla, I Brunton

Most blast fragmentation models assume the rock mass properties, explosive properties and blast design variables to be constants and uniformly distributed within a blast. However, in reality all these input variables vary within a blast resulting in variation in the resulting fragmentation size distribution. A stochastic modelling approach is introduced in this paper to quantify this variation. This technique takes the input variables as statistical distributions rather than constants and through several thousand iterations, generates a statistical representation of the expected fragmentation resulting from a production blast. A case study of three production blasts from a large open pit mine are presented and the modelled fragmentation æenvelopeÆ shows good agreement with the fragmentation æenvelopeÆ estimated from Split image analysis. The various blast-related parameters influence different parts of the fragmentation distribution, eg rock strength and explosive velocity of detonation have most impact on the fines. The technique is used to identify the parameters that have the greatest influence on various size fractions. Such an analysis will be useful to direct resources to efficiently minimise the variation.

Jan 1, 2001

By S Jokanovic, J L. Mauk

The Taharoa ironsand deposit covers approximately 16 km2 and is located 144 km south of Auckland on the west coast of the North Island, New Zealand. The heavy mineral-rich sands predominantly contain titanomagnetite, ilmenite and hematite, along with lesser amounts of amphiboles, pyroxenes, and feldspars. Throughout the Taharoa mine site 142 samples were collected of which approximately 25 samples were used in mineralogical analyses of the magnetic, heavy non-magnetic and light non-magnetic fractions. Mineralogical and petrographic analyses confirmed the high abundance of homogeneous magnetite and magnetite containing ilmenite exsolution lamellae which have oxidised to hematite. A limited number of sand samples were collected from Taranaki beaches. Petrography reveals exsolution textures of magnetite and ilmenite (now hematite), and homogenous magnetite grains similar to those observed at Taharoa. Petrographic analyses from previous research projects were also closely investigated in order to make mineralogical comparisons from along the west coast of the North Island and with other potential source areas. The origin of detrital magnetite grains along the west coast of the North Island is generally presumed to be the eroded volcanic cones of the Egmont volcanoes and active and dormant volcanoes of the central North Island. Electron microprobe analyses of magnetite grains from Taranaki beach samples reveal TiO2 values of between 1.5 and 120 per cent. MgO and A12O3 contents also vary widely from 0.75 to 6.5 per cent. This large variability may reflect different volcanic eruptions, the presence of exsolution textures or alternative source areas for these magnetite grains. Geochemical results from the Taharoa mine site correlate with the Taranaki beach samples suggesting that the Egmont volcanoes are certainly one source area. Variability in XRF results, especially Fe and Ti contents (9.04 - 59.22 and 0.80 - 4.64 respectively), from the magnetic and heavy non-magnetic fractions likely reflect the detrital nature of this deposit.

Jan 1, 2003

By Black PM, Itaya T

Arc-type volcanic activity has been a major feature of the late Cenozoic geological evolution of the Pacific-Australian plate boundary in the northern New Zealand region. The timelspace distribution patterns of arc-type rocks reflect changes in the nature of the plate boundary as it has evolved. Inception of volcanism began in the north during earliest Miocene times (26 Ma) following ophiolite emplacement and during the next 10 Ma developed into a volcanic arc segment extending south to the present position of the central North Island. The northern part of the arc became extinct about 15 Ma ago, but activity continued in the central (Coromandel) part of the arc until about 5 Ma ago. In late Pliocene and Quaternary times volcanic activity has become concentrated in a northeast trending zone which is collinear with the Tonga-Kermadec Arc.

Jan 1, 1995