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By G P. Bates

The rationale for the design of the Emergency Egress (escape andentrapment) strategy for one underground metal mine has beenpreviously described (Brake, 1999). Two of the key conclusionsfor this mine, which is equipped with 30 minute oxygen-generating self-contained self-rescuers (SCSR), were the need to ensure no person is ever more than 750 m from an emergency refuge station (ERS) and that it could take up to eight hours to rescue workers from undergroundå. These conclusions were based on a number of considerations including the non-availability of a credible, æpersonalÆ entrapment procedure at the workplace, the duration of self-contained self-rescuers when used for travel, the need for rapid æclearingÆ of mine personnel to effectively and safely target mine search and rescue resources and the maximum time to either put a fire out, or to rescue affected personnel. As there is no Australian standard for refuge stationsç (or for self-rescuers), this paper follows with guidelines for the location and specification of both fixed (permanent) and relocatable Emergency Refuge Stations (ERSs) that may be applicable to other underground Australian metal mines.

Jan 1, 1999

By L Dzinza, K C. Corin, M Tadie

The recycling of process water comes with increased electrolyte concentrations that affect water quality, which may in turn affect the flotation performance of valuable minerals (Hirajima et al, 2016). Electrolytes such as Ca2+, SO4 2- , Mg2+ and S2O3 2- have been surmised to have an impact on the action of flotation reagents such as collectors (Ikumapayi et al, 2012). Xanthate collectors are known to play a significant role in imparting hydrophobicity on mineral surfaces to enhance their flotation. The interaction between minerals and xanthates is well known to be electrochemical in nature. Such redox processes may be elucidated by electrochemical techniques. Since the mechanisms involving the interactions between electrolytes in process water with sulfide minerals and the subsequent adsorption kinetics of collectors are not well understood, this study therefore aims to provide fundamental knowledge to unpack the mechanisms involved when electrolytes interact with Platinum Group Minerals (PGMs) and how these interactions may affect xanthate adsorption. The interaction of sodium iso-butyl xanthate (SIBX) in the presence of electrolytes at increasing ionic strength was investigated by rest potential measurements, to explain the impact of electrolytes on the adsorption of SIBX on PGMs in the flotation process. Rest potential measurements for PdTe2 and PdS were conducted in an air saturated 0.05 M di-sodium tetraborate decahydrate solution, in the absence and presence of SIBX and electrolytes. It was found that the existence of sulfide and telluride on palladium affects the mechanisms in which electrolytes interact with Pd mineral surfaces. An increase in the ionic strength of Na2S2O3, CaCl2 and MgCl2, increased the interaction between the salts and PdS, thus decreasing the extent to which SIBX interacted with PdS. An increase in ionic strength for Na2S2O3 increased the interaction between Na2S2O3 and PdTe2 and therefore decreased the extent to which SIBX interacted with PdTe2. Other salts investigated in this study increased the rate of oxidation of PdTe2 with an increase in ionic strength thereby enhancing the interaction of SIBX and PdTe2. This study has shown that mineral type, electrolyte type and concentration all have an impact on the mechanisms that result in the adsorption of SIBX on PGMs.

Aug 24, 2022

Martha Mine is an open pit gold-silver mine, located within the township of Waihi, 150km southeast of Auckland and is operated as a joint venture between Normandy Mining Ltd. 67 %) as Manager and Otter Gold Mines Ltd. (33%). The deposit was historically mined, by underground methods from 1888 to 1952, producing 5.5 moz of gold and 30 moz of silver, from 11 mt of ore. The current operation began in 1988, producing, to June 1999 - 867,245 oz of gold and 5.5 moz of silver from 9.5 mt of ore. The licensed reserves were due to be mined out by late 2000. Consents were granted in December 1998 to allow the expansion of the operation through to 2007 accessing an additional 7.5 mt of ore at 3.4 gpt Au and 26.0 gpt Ag for 800,000 oz of gold and 6.4 moz of silver. The key elements of the expansion are: 1. Pit enlargement 2. Upgraded crushing and material handling facilities 3. Construction of a second tailings storage facility 4. Upgraded water treatment capacity 5. Increased operating capacity This paper presents an update of expansion activities to date.

Jan 1, 1999

For some time fine coal (-0.5 mm) flot ation has been considered as a bulk flotation problem. Combinations of hydrocarbon oils and frothers have been used as surface active agents in coal flotation. The selectivity of the flotation process has always been poor in such cases. With the increase in fine coal production due to mining methods and coal handling systems, optimisation of fine coal treatment.has become important. Petrographic and mineralogical composit- ions of coal particles have been reported to influence their flotability. The problem becomes more complex due to surface oxidation of coal and the presence of slime forming clay minerals in the run of mine coal. In this paper, the flotation problem is examined on the basis of various constituents of coal and their associated gangue minerals. The selection of reagents has been suggested on the basis of their surface chemical properties. Factors such as surface modific- ation of coal and gangue materials, flotation kinetics and hydrocarbon oil - coal inter- action have been critically evaluated to improve fine coal flotation recovery.

Jan 1, 1978

Jan 1, 2004

By D J. D'Astoli, M D. Goodz

In 1993 a detailed review of drill sample yuuluy was rouxluard through twin and triplet drill holes using open hole, crossover suhreverse circulation (RC) and diamond drill methods. Advances in face-sampling RC methods demanded a further review of the validity and reproducibility of drill sample data. A program was undertaken to drill three RC holes using the latest technology (new face- sampling bits, dust suppressers, cyclones and compressors). Volumetric and mass studies were undertaken to review sample recoveries. Modal analyses on indicator minerals were logged to interpret the relative degree of mineralisation. Ambiguities in the results were immediately apparent and the consensus was for follow-up twin diamond holes using HQ3 coring tubes. The most mineralised RC hole was selected for the first twin diamond hole. This RC hole (MS 313) encountered one intersection of >0.47 g/t; in contrast the diamond hole (MS 342) had nine intersections at > I g/t. Results at hand show definitively that face-sampling RC drilling is not acceptable as a method of exploration for gold deposits of the Woods Point type. Furthermore it is demonstrated that RC drilling should not be used for any type of exploration of high-grade gold vein deposits related to highly fractured or porous hostrock, or areas of previous mining activity. Methods are proposed for reviewing of rates of sample recovery, distribution and cross-contamination. Comparisons also show that in limited metreage reconnaissance drill programs, diamond drilling is more similar to percussion in per metre costs, than it is credited with, and always provides more bang for the Buck.

Jan 1, 1997

I have headed this paper with a question and for the impatient among you ûthe answer is no we have not run out of developments but, and it is a big æbutÆ, we need to be innovative and ahead of the game or ænoÆ will be æyesÆ before we know it.Why do I believe that our future lies in innovation? Thirty years ago, knowledge doubled every 14 years. It is now doubling every seven years. In 1965, Gordon Moore, one of the founders of the chip maker Intel, made an observation that growth in memory chip performance is doubled every 18 months which became known as MooreÆs Law. Now there is fibre law, where the transmission line capacity doubles every nine months and storage capacity, under disc law, doubles every 12 months. What does this mean? Well, firstly there is a massive rise in information flow and availability with no limits in growth for at least the next ten years. Secondly, unlike our grandfathers, we are most unlikely to be employed by the same firm for our working career - we may not even have the choice to stay with the same company. In a phenomenon Richard Foster and Sarah Kaplan (2001), borrowing from Schumpeter, termed æcreative destructionÆ, companies are unable to sustain market-beating levels of performance for more than ten to 15 years. In the 1920s the turnover rate of companies in the United States was 1.5 per cent, so a company could employ almost three generations from the one family. A company had a half life of 60 years. In other words, you could well be in the same working environment as your grandparents. Today the churn rate is estimated to be eight to ten per cent. A company has a half life of five to six years. So for large companies, as an employer or employee or as a contractor, your working environment has a 50 per cent chance of changing in five years. Innovation is the driver of this rapid rate of change. Innovation is not for the faint hearted (Cutler, 2001) but it is the core for success in the global economy. The rate of change in our world is not going to decrease. We must learn, not only to manage change, but to enjoy the process of changing û to ride the tsunami of the knowledge economy.

Jan 1, 2002

The nation of Fiji is located the South Pacific on the æRim of FireÆ some four hours flying time from the eastern sea board of Australia. It is a tourist destination situated on the main route from Australia to the Americas. Fiji is a developing country that has had a fewsetbacks but the country has able, happy people that are very resilient. Most importantly, the country is a safe destination for tourists and businesspeople as the local people are friendly, have good ethics, and most speak English. Fiji is a very willing nation, hungry for knowledge and advancement. The Fiji geological setting on the æRim of FireÆ, that runs from New Zealand across the Pacific through Fiji and on to Papua NewGuinea, has many large deposits of gold and copper. Fiji is an exciting destination for mineral explorers with discoveries of gold, silver, manganese, bauxite, iron and copper. Gold was first discovered in 1921 and the first two mines opened in 1935; one of which was Emperor Gold Mining Company (EGM) the other being Mt Kasi. EGM mines gold on the margin of the Tavua caldera, some 85 km north of the Nadi international airport. EGM has operated continuously for close to 70 years, producing approximately 6.9 million ounces of gold and has an underground reserve of 847 600 ounces with a total mineral resource of 12 335 600 tonnes at 10 g/t (as given in the Emperor Mines Limited Annual report 2003). The mineralisation in Fiji is very exciting and it is common to discover spectacular intersections and outcrops, which are typical for this type of epithermal narrow vein mineralisation, but be aware that the orebodies are variable and not easy to understand.

Jan 1, 2004

By C Moorhead

The classification of Mineral Resource estimates for reporting in accordance with the JORC Code is a statement of the Competent PersonÆs confidence in the estimate and an attempt to convey that confidence to the various users of the resource estimate. In general the classification process is either largely subjective, relying on the Competent PersonÆs experience, or relies on statistical measures derived from the estimation process. These statistical measures may not necessarily relate to the overall confidence in the resource which must also take account of the confidence in the geological inputs to the estimation. Several authors, including Jackson et al (2003) and Dominy, Noppe and Annels (2004), have addressed methods of including consideration of geological data and its reliability into the classification process. Henry and Parker (2005) have discussed a quantitative measure for classification of Measured and Indicated Resources related to mine production parcels. These methods rely on the availability of sufficient information for the application of geostatistics, data evaluation techniques or repeated interpretation of data to provide an indication of confidence. They are suitable for very advanced projects. In 2005, using a modification of the financial audit æcontrol and quality criteriaÆ principles, then widely accepted within Newcrest Mining Limited (Newcrest), the principal author developed a scheme which categorised the classified resources into æcontrolÆ and æqualityÆ (or risk) categories. Control covers all aspects of the data collection, the geological interpretation, the data analysis and the modelling of tonnage and grade; it is also influenced by the documentation of the estimate. The quality criteria are a subjective measure of risk associated with the estimation of the resource and refer to the risk that the tonnage and grade are not realised and the consequences if decisions are made on the basis of these estimates. By evaluating the generally accepted level of risk attributed to these quality ratings by Competent Persons within Newcrest, a graphical representation of the confidence in the resource ounces was prepared for communication of the expected confidence in the resource statement.

Jan 1, 2009

By D Kepert, C Simpson, D Edwards

Channel iron deposits (CID) currently supply over 40 per cent of the seaborne iron ore trade out of the Hamersley Province. The two well documented producing systems (Robe and Marillana palaeochannels) were both discovered during early reconnaissance mapping principally by BHP Billiton (BHPB) and Geological Survey of Western Australia (GSWA) during the mid 1950s to early 1960s. Both crop out extensively over the majority of their length. Hot on the heels of Fortescue Metals Group 2004 - 2005 discovery of approximately 2.6 billion tonnes (Bt) of undercover iron ore mineralisation in the Chichester Range, the Fortescue Exploration Department turned its attention elsewhere throughout the Hamersley Province. Reappraisal and analysis of publicly available data and ground truthing of developing models led to the recognition of the Solomon palaeochannel system. Subsequent exploration defined a world-class Resource of some 1.9 Bt of iron ore mineralisation of which the great majority is buried CID. Apart from the Marillana CID system, the Solomon region is the only major CID with significant tonnes of sub two per cent alumina CID with over 500 Mt delineated to date. Exploration has also outlined significant supergene bedded and detrital iron ore mineralisation. Ongoing drilling is expected to increase the resource base both in terms of tonnes and confidence. This paper outlines the principal contributing factors which led to the discovery of the Solomon CID and compares its geology with the Robe and Marillana palaeochannel systems.

Jan 1, 2009

By L Lorenzen, H Muller, L Bernard

Australian companies and consultants are becoming ever more involved in projects in African, South American, East European and Middle Eastern countries. However, significant differences in culture and approach to projects sometimes make these projects challenging for reasons that are not purely technical. Often the challenges are rather related to how the project owner and local authorities perceive the reality. These perceptions and sometimes unrealistic expectations regarding project costs and potential outcomes need to be addressed by the æWesternÆ project developer and consultant.This paper will discuss the specific experience of Snowden in studies commissioned by companies from such countries for the development of very large, low-grade gold deposits in some of the most inhospitable areas in the world. The paper will further review similar projects undertaken in other ænew worldÆ countries and compare these to the initial Snowden experience.As the process operating costs of operations in many of these countries are extremely competitive when compared to the typical Australian operating costs, the paper will review the operating costs and the factors which may be pertinent to a large project of this nature, both in the Australian and the ænew worldÆ context. Will Australian-based operations be able to compete in the global gold market when the gold price softens again, as it will do at some stage in the possibly not-so-distant future?CITATION:Muller, H, Lorenzen, L and Bernard, L, 2013. Challenges of developing low-grade deposits in ænew worldÆ countries from a mining consultantÆs perspective, in Proceedings World Gold 2013 , pp 307-314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

The transition from exploration to feasibility is a stage in the development of mineral resource projects that is frequently not handled well. The transition marks a point in the project development process where resource evaluation priorities change significantly from the discovery of mineralisation and the rapid assessment of the potential tenor of the mineralised system, to the detailed assessment of the deposit.   Information used in the exploration process tends to be of a qualitative or theoretical nature initially, but gradually becomes more quantitative in character as geological knowledge relating to individual prospects grows.   The transition from discovery and rapid exploration of a new deposit occurs at a relatively early stage in project development, coinciding with the first attempt to prepare a resource estimate for the deposit. Fundamental assumptions regarding both structural and grade continuity and uncertainty inherent in existing information need to be made so that they themselves may be addressed during the collection of additional data.   The effective commencement of feasibility studies involve the introduction of new accountabilities either as a result of appointment of a project manager, and through needing to be able to quantify: ò     the quality of data being collected for resource evaluation purposes; ò     confidence associated with resource estimates; and ò     the need to develop an audit trail for the project, required to make the resource evaluation decision-making process as transparent as possible.   Quality assurance is a concept to which exploration geologists have frequently had little exposure. Being able to demonstrate the quality of data used in feasibility studies is, however, a crucial component of the overall risk management and reduction.   Development of a transparent audit trail for data assists in demonstrating the quality of data which is frequently perceived to translate directly to confidence inherent in resource estimates.   Establishing procedures for geological data collection and management also provides a more reliable framework for making decisions that impact on project execution, again resulting in improved confidence in resource estimates and associated geoscientific data.   Regular, independent technical audits, in principle similar to audits conducted for the ongoing certification of standards compliant quality assurance systems, are a major, positive factor in effective project management and execution.   Information used in project evaluation, feasibility and development must be based on facts. Facts are effectively observations that are ideally made systematically, recorded in a systematic manner, and by being collected effectively are not subject to change.   Effectively managing the transition from exploration to resource evaluation, feasibility and project development involves recognising the nature of changes in the nature, detail and scope of geoscientific data required at each stage of project development. In doing so it is essential to: ò     recognise when the change occurs (as early as preparation of the initial resource estimate for a project); ò     accept that the change may not be gradual; and, ò     ensure that the project evaluation team is adequately resourced.   These objectives require recognition of the value of previous experience and the need to instill a true team approach amongst both staff and contractors associated with the project. Regular formal and informal communications between staff, contractors and other stakeholders in the project are an essential tool in ensuring personnel are aware of factors affecting their role in the project.

Jan 1, 2004

Thank you for your introduction and the opportunity to speak at such an important forum. I feel honoured to be the Tas McKee speaker for this yearÆs conference. I can honestly say that Tas McKee typified the spirit that has ensured the survival of the mining industry despite the modern-day challenges that we encounter. He was one of the most influential people in the New Zealand minerals industry. In 1938, with his father and brother, Tas established Lime & Marble Limited. Over its history, this company evolved from its original base of marble mining to diversify into gold mining and exploration for other industrial minerals, uranium, precious and base metals. He was truly a pioneer that persevered against the odds.   That leads me to the subject of my discussion today. I am going to delve into todayÆs challenges as they apply to gold companies. While we gold miners should be generating record returns, the gold industry shareholder return performance in this buoyant market has barely equalled that of the gold price. It is a dilemma but one that can be resolved with the right strategy.

Jan 1, 2006

Tunnels are being built around the world using TBMs and prefabricated segments or in situ concrete as linings. Clients demand high quality of these linings to guarantee a long-term stability and density of the tunnels. This paper describes the development and the use of segmental lining systems, including joints, important design criteria, installation procedures, possible mistakes and consequences, repair works and final results for different sites in Europe and around the world. The experience on these sites shows that damages may occur, if some essential aspects are not considered. These aspects include:parameters of the TBMs and back-up equipment such as fixation of jacking rams, movement of the back-up on the lining or ring reformer;parameters of the segments such as quality of moulds, quantity of reinforcement or structure of the joints; andparameters of the tunnel drive such as advance rate, ring-gap grouting or experience of the tunnel crew.All these aspects have to be considered very carefully in detail to get a good lining accepted in total.

Jan 1, 1999

By A E. Levett, J Durbin

The environmental, social and governance (ESG) obligations of mining companies promote the consideration of water and land resources as well as the post-mining employment opportunities following the cessation of mining operations. This work aims to outline the potential for a mining operation to use their brackish mine water resources to support microalgae production, generating high-quality organic carbon sources to support their mine rehabilitation and closure outcomes. Microalgae production is an established commercial process for high-value products including vitamins, cosmetics and food supplements. On mine sites, microalgae production offers several major environmental and social opportunities: (i) carbon capture, (ii) metalliferous water treatment, (iii) acid mine drainage prevention, (iv) beneficial reuse of brackish mine water, (v) accelerated soil formation and (vi) post-mining employment (Levett et al, 2023).

Aug 2, 2023

By J B. Collier, R M. Fraser, O Dahl, I M. Platten

Grade control is a process of maximising value and reducing risk, through the delivery of quality tonnes to the mill via the accurate definition of ore and waste. It essentially comprises data collection, integration and interpretation; local resource estimation; stope design; supervision of mining and stockpile management. The foundation of all grade control programs should be that of geological understanding led by high-quality mapping and sampling to drive appropriate estimation strategies and mining. Gold veins show various complex features relating to erratic grade distribution (nugget effect), variable geometry and internal architecture. These include variations in dip, strike and width, late-stage faulting/shearing effects and geometallurgy. Such variations generally require close geological understanding to ensure optimum grade, minimal dilution and maximum mining recovery. A well designed grade control program will prove to management and stakeholders that by applying geological knowledge, the mining process can be more efficient and cost effective. This paper reviews the issues of grade control in underground gold mines and focuses on integrated mapping and sampling through three case studies.

Jan 1, 2009

Ilmenite (FeTiO3) is the primary global source of titaniumdioxide which is commonly used as a whitening agent in papermanufacture and a pigment in paint manufacture. In WesternAustralia ilmenite is processed by the Becher process (Becher,1963, Becher et al, 1965) where ilmenite particles are feddirectly into the furnace with coal and heated to form acomposite of elemental iron and TiO2. The mechanism of thecarbothermic reduction of ilmenite has been extensively studied(Grey, Jones and Reid, 1973; Jones, 1973; Grey and Reid, 1974;El-Tawil, Morse and Francis, 1993) and is reasonably wellaccepted.

Jan 1, 1997

The long-term outlook Tor Australla's traditional mining products is for flat demand and continuing low prices. This has come about because of three far-reaching changes since earlier boom days: 1. Continuing declines in intensity of usage of basic mine products; 2. The failure of newer western and third world developing countries to realise growth expectations; and 3. Continued production pressure from third world countries (and first-world primary producers) in an effort to earn foreign exchange and rectify trade balances. These trends have led to a general situation of excess supply and weak demand. In this environment, the prerequisites for survival in the mining sector are first-class mines, modern and efficient production methods, low unit costs, aggressive marketing, and products with reasonable operating margins. Many of Australia's mines meet these prerequisites. Following the A$ depreciation and widespread unit cost reductions, most of these mines will be moderately profitable at current depressed commodity prices. They are well placed to benefit from price rises if these eventuate. A new generation of mines is concentrating on a more profitable product range (gold, diamonds, uranium, mineral sands). Australia's balance of trade remains firmly dependent on the primary mining and agricultural industries (Fig. 1). Despite optimistic talk of high-tech developments, tourism and a resurgence of manufacturing, these will remain a small component of Australia's export structure.

Jan 1, 1987

By M Russ, J Gediga

This paper shows an economic feasible approach to implement greenhouse gas (GHG) reduction measures into the mining and metallurgy industry (MMI). The goal to improve energy consumption is directly linked to the reduction of GHG emissions in the MMI. A baseline scenario of the considered reference system and of the respective reference year has to be designed and analysed. In a second step an analysis of the same operation using the best available technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified gaps will be reported and the potential GHG emission reductions will be put into relation to the investment, running cost and generated carbon credits of the new process technologies to be implemented. This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap decision-making for implementing new technology into the companyÆs business operations. The GHG reduction roadmap is developed using the marginal abatement curve approach.

Jan 1, 2009

By M Grigorescu, J H. Hodgkinson, H Alehossein

A new framework that collates and interprets pre-existing data to assess vulnerability and ultimately plan to avoid or minimise flood-related risk to infrastructure, people, downtime, environment and revenue has been developed. The æClimate Related Adaptation from Terrain Evaluation ResultsÆ (CRATER) method tested at a coal mine in Queensland, provides semi-quantitative information to assist decision makers when designating investment for minimising vulnerability of mining operations to climate. Here we present the processes involved in this three-step approach that uses pre-existing spatial data of the mine site and local knowledge to build a set of visual tools to assist decision-making. The first step of the process is performing multi-criteria evaluation (MCE) within a geographic information system (GIS) on ranked natural conditions at the mine, such as elevation, slope, drainage, soil and vegetation, which is performed to identify critical flood areas. Secondly, a fault-tree analysis identifies how impact can occur and what options there are for impact reduction. Finally, a resource assessment of the mineÆs capacity to adapt reduces the adaptation options to those most suited to the mine. The results are confidential, but for the purpose of introducing the methodology, we present simplified results, particularly of steps 2 and 3. CRATER can also be used for future æwhat-ifÆ flooding scenarios to identify the most suitable locations for roads, buildings or other critical infrastructure. The methodology is transferable to any mine, series of mines or locations along the mining value chain that have sufficient data, providing a practical decision-making tool to identify æno-regretsÆ actions that not only could reduce downtime after or during an event, but in some cases may enhance production between extreme events. We now plan to test this method at a broader scale, to encompass more than one mine in the analysis.CITATION:Hodgkinson, J H, Grigorescu, M and Alehossein, H, 2013. Climate Related Adaptation from Terrain Evaluation Results (CRATER) - interpretation of pre-existing data for mine site flood vulnerability and management, in Proceedings Water in Mining 2013 , pp 259-266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013