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By M J. Dunn

The geotechnical model is the cornerstone of any mining geotechnical design and as such the confidence level and reliability of the geotechnical model is paramount. The geotechnical model confidence level needs to be commensurate with the level of design that is being applied or study that is being undertaken. The geotechnical model is made up of several components and the reliability of the data underlying these components ultimately determines the reliability of the geotechnical model.Data reliability is linked to the quantity of data collected, the spatial distribution of the data collected, quality of the data collection and the interpretation of the data. In a typical project, there is an opportunity to improve data reliability through the scoping, prefeasibility, feasibility and final design and implementation stages.Currently, very little quantitative guidance exists in the literature on assessing the confidence level of geotechnical studies, although there have been attempts by various authors (Haile, 2004; Haines, Swart and Kruger, 2006; Read and Stacey, 2009; Dunn, Basson and Parrott, 2011) to qualitatively describe what level of geotechnical data is required. Recently a number of authors (Read, 2013; Fillion and Hadjigeorgiou, 2013; Thomas, 2013) have outlined methods that could be applied to assess the reliability of some types of geotechnical data that are used in the development of geotechnical models.This paper briefly discusses some of the factors influencing data reliability and the geotechnical model confidence and some of the tools available.CITATION:Dunn, M J, 2014. Geotechnical models and data confidence in mining geotechnical design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 127–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By A G. Pavlides, B L. Weekes

The Sepon Copper Project is located in the Savannakhet Province of Laos PDR and is operated by Lane Xang Minerals Ltd (LXML). An Ausenco - Bateman Engineering joint venture, the Khanong Development Group (KDG) managed engineering, procurement and construction of the project. The plant was fully commissioned in March 2005, two weeks ahead of schedule. The plant is designed to produce 60 000 tpa of cathode copper. The process flow sheet includes a pressure oxidation (POX) circuit that leaches pyrite flotation concentrate to generate ferric ions and sulfuric acid for use in atmospheric leaching of a predominantly chalcocite ore. The process is unique in that the chemistry in the autoclave is forced to produce a basic ferric sulfate precipitate for downstream recovery of ferric iron. This paper describes the design, construction and commissioning of the pressure oxidation circuit. The challenges imposed on construction and commissioning due to the remote location of the site, landlocked status and underdeveloped infrastructure in Laos are highlighted.

Jan 1, 2005

By Hall S, Upton D

WMC Resources Ltd nickel operations have expanded significantly over the last three years. Production capacity has increased at mine/concentrate, smelting and refinery processes to such an extent that WMC now ranks within the top three or four producers of nickel metal in all forms. The stainless steel industry remains the dominant user of nickel. WMC's forecast is for stainless steel production to grow at 2.8 per cent per annum off of the 1995 peak, with much slower growth in the short-term as the stainless steel inventory overhang unwinds, followed by a return to higher trend growth rates. WMC's forecast for the long-term growth in demand for primary nickel is three per cent per annum off the 1995 peak; again, slower growth in the short-term before a return to higher long-term trend rates. This projection is towards the optimistic end of the range of industry experts. It equates to a requirement for new primary nickel of 25 000 to 30 000 tonnes of annual capacity each year.

Jan 1, 1996

By Chitombo GP

The proposed guidelines on vibration limits that have been circulated by the Australian Environmental Council, demonstrate the need for an extensive data collection and evaluation program to avoid the enacting of abritrary and costly legislation. The operational or practical influence of blast design and overall economic implications of legislation which further reduces permissible levels of ground vibration are discussed. In a typical blasting operation, blast sizes could become smaller and blasting correspondingly more frequent to meet pro- duction demands. Blasthole diameters and charge lengths could be reduced, increasing drilling costs and associated labour costs. Blast size however, is frequently controlled by factors associated with machinery, grade control, pit control, stope size, production contract levels and other factors which cannot be readily changed for operating mines. Blasthole diameters are frequently deter- mined by existing drilling equipment, length of holes (depth of ore or stope size), geological structure and other factors which are not easily changeable. Typical large scale open stoping and strip mining opera- tions are analysed as case studies. The effects of extreme leg- islative limits and the corresponding operational changes with respect to variations in production costs are discussed.

Jan 1, 1987

Minerals similar to the indicator minerals used in kimberlite exploration are widespread in the Cainozoic alkali basalts of north Queensland. Magnesian ilmenite, pyrope garnet, chrome diopside, chrome spinel, phlogopite and zircon were recovered from most of the localities examined. The occurrence of these minerals creates significant problems when indicator minerals are used for diamond exploration. Basaltic ilmenite is visually similar to kimberlitic ilmenite. Untransported grains are rounded and have pitted surfaces. Basaltic ilmenite grains often have exsolution lamellae and reaction rims of titanomagnetite. Although kimberlitic and basaltic ilmenite are chemically similar, basaltic ilmenite grains are usually less magnesian than their kimberlitic counterparts. Basaltic ilmenite contains very little Cr203. Pyrope garnet occurs as megacrysts and in a variety of xenolith lithologies in north Queensland basalts. Most basaltic garnet is Cr-poor and comparable with kimberlitic garnet from Groups 3 and 5 of Dawson and Stephens (1975). Wine-purple, chrome-bearing garnet is common in kimberlite but rare in basalt.

Jan 1, 1984

By Torres F, Cerda I, Gimenez P, Gonzalez G, Castelli L

Slurry density measurement, specially in cyclone feed streams, is fundamental to grinding circuit control. With the purpose of increasing the availability of such a measurement, the design of a soft-sensor in an actual grinding plant is addressed in this paper. The system is designed to substitute the momentary unavailability of the real density sensor, either because it has failed or because it has been removed for any other reason. The ARMAX model structure is determined using the stepwise regression method. Starting with a list of the candidate variables, the method selects, one by one, and in a systematic manner the variables which best model the measurement to be replaced, choosing them from the set of presumably correlated candidate variables. In this paper not only the single measurements are included in the list of candidates, but also combinations of such measurements having physical significance. A phenomenological model has been built with the purpose of determining these combinations. It turned out that in most of the cases the components of combined measurements having physical significance were selected by the stepwise regression method, instead of the single measurements. Actual grinding plant data is used to determine the model structure, to estimate the model parameters and to test the predictive capability of the developed soft-sensors. Good results are shown to be obtained during periods of up to 30 hours of the density soft-sensor operation.

Jan 1, 1995

By M Robertson

3D photogrammetry is a powerful tool for data capture and interpretation, utilised at all Australian underground MMG sites. In personnel constrained mines, 3D photogrammetry can free up personnel time, improve data quality for resource modelling, as well as benefit other mining departments.At Rosebery one of the challenges faced by geologists was no longer data capture but, rather, avoiding paralysis by analysis from the sheer abundance of information currently available to the department. Although the data had been interpreted, the structural model was cluttered; the geological block model was not incorporating any geological domains captured by 3D photogrammetry, nor was it being utilised by other departments such as geotechnical engineering.The geology department is now focusing on utilising all the interpreted data gained from each photograph heading into an uncluttered, easily understandable model for geologists and other mining departments.Our solutions involve integrating the Leapfrog modelling suite into the process, streamlining the structural model, tailoring the data interpretations for future updates of the block model and training other departments to improve utilisation of the interpreted data. This process also uncovered other benefits for near-mine exploration, and improving our understanding of the deposit’s origin.CITATION:Robertson, M, 2017. The practical use of underground 3D photogrammetry data at MMG Rosebery polymetallic mine, Tasmania, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 409–412 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Leaving the relatively simple life on a uni student and venturing off in to the outside working world is a big step. There are two paths to follow, the æContikiÆ style graduate program where you pick up your new lease vehicle and set forth on two to three years of planned activities, or can pack everything into one bag, stick a copy of æthe rough guideÆ in your pocket, and set off on your own graduate adventure. I took the path less travelled.The less followed method of developing yourself isnÆt for everybody. Parts of the journey are difficult and sometimes it feels hopeless, but itÆs all a learning experience. Along the way you might not get to all the graduate ætourist stopsÆ like dragline, truck-shovel, or drill and blast. But youÆll see most of them and pick up a lot more of the local culture such as people management, operational knowledge, quality control, and the black arts of project financial management.

Jan 1, 2004

By Warner RE

SINCE 1952, when Elliott et a/ first applied the Sherwood correlation for flooding in chemical absorption towers to blast furnaces numerous investigators throughout the world have followed their example and much research effort has been spent to tighten the correlation and recently to extend investigation of flooding to side gas entry conditions. The widespread use of the Sherwood concept of flooding has been such that even the word itself has become an integral part of blast furnace nomenclature. The evidence for the applicability of Sherwood's relationship has been that the flooding limits calculated from blast furnace parameters lie approximately on the Sherwood line. However, the values of many of the variables for the blast furnace calculation are only estimates and at first sight one may wonder at such 'close' coincidence when some of the estimated parameters entering the Sherwood correlation are raised to the power of three or more, as for the bed porosity and the liquid surface tension. It is felt that the explanation of this result lies in the logarithmic: nature of the plot and/or the fortuitous can- cellation of the errors of the estimates in the calculations coupled with the fact that blast furnace fluid ratios lie within a very narrow range of values. The foregoing considerations should in their own right place doubt on the correctness of the Sherwood type flooding correlation applied to the blast furnace. Additional doubt regarding the existence of the Sherwood type flooding in the furnace has been cast by the results obtained in the Tokyo University experimental blast furnace. From the reasoning of both Standish and Colquhoun (p. 20) and Warner (p. 23) it is deduced that flooding in the traditional sense will only normally occur in the upper bosh (somewhere near the mantle), following softening as discussed by Palella et a/ on p. 75, and flooding in that zone is likely to result in furnace irregularity. On the other hand, the concept developed by Warner of slag hold-up above the raceways as a stable phenomenon not affecting furnace regularity is a process unique to the blast furnace and is not described by the Sherwood flooding theory. Recognising the considerable practical implications of slag hold-up above the raceways, this note further explores the physical process of slag hold-up. We envisage that bed of coke above the raceways in almost all blast furnaces would contain some slag held up by the gas pressure gradient. In general the slag would be contained in a ring and gas would bubble through in its ascent through the furnace. The force supporting this slag is the pressure gradient and obviously -much of the blast pressure is dissipated in supporting this structure.

Jan 1, 1975

Effective pre-splitting is a key feature of wall control blasting. Most mining operations use historical designs or rules-of-thumb for designing pre-split blasts. If productivity and safety benefits are to be gained, these methods need to be improved in order to accurately predict pre-split performance. This will become more pertinent as overburden depths increase, placing more demands on the pre-split operation. A classical qualitative quasi-static description of pre-splitting (Kutter and Fairhurst, 1968) is presented and it is shown to give some useful insights into the pre-splitting process. In particular, it is clear that the time interval between the initiation of adjacent pre-split holes is a very important factor. In terms of this analysis, it is shown that current techniques which employ detonating cord as the surface initiation system are not optimal. A static quantitative model for pre-split design which has been widely reported is then discussed and its simplifying assumptions and their implications are examined. It is shown that several of the assumptions may be reasonably justified in the light of real pre-split results. It is concluded that the model should yield conservative designs. For this model, the key calculation of the blasthole pressure that is needed to determine the required explosive charge is highlighted. Popular methods employed in the literature for describing the expansion of real detonation products are shown to be inappropriate and an alternative method using the non-ideal detonation code, CPeX, is proposed.

Jan 1, 1995

By Vnenk L, Hargraves AJ

Metropolitan Colliery has some areas of roof where immedi- ate support is required in development. The disadvantages of percussive roof bolting at the face have led to recent produc- tion trials with rotary boring and rapid=setting resin anchored roof bolts developed at the Colliery. The three innovations involved are: (1) the wet drilling of small holes with an all- hydraulic, portable rotary boring machine; (2) the rapidity of loading a "point anchored" resin bolt; and (3) the consistently high anchorage strength available. All three innovations provide striking advantages over the previously available alternatives. The greatest disad- vantage - that of cost of resin - is not prohibitive, and there is promise of improvement in the future. There are possibilities of variations of the techniques for special support problems in particularly difficult roofs.

Jan 1, 1971

By McAllister J

Oxygen was in restricted use at Port Kembla until tonnage oxygen became available for steelmaking in the open hearth furnaces. In adopting the new process various modifications to furnace design and operation were necessary and some of these, including increase in roof height and variation in firing and draft control, are discussed.The design of oxygen lances is also discussed and various steelmakingtechniques considered.Steel production increased with oxygen roof lancing-one- furnace producing 8,507 tons in one week-but new problems, such as rate of refractory wear, and disposal of fumes, were created.Design of future open hearth oxygen furnaces is predicted.INTRODUCTIONIn the post-war era, the availability of "tonnage" oxygen caused a major revolution in steelmaking techniques. Various pneumatic processes showed that steel can be madeat a very fast rate and that oxygen steelmaking can be applied to open hearth furnaces. Methods used are surface impingement with roof lances, bath injection with door lances, flame enrichment with fuel firing, mixed gas and oxygen firing, and enrichment of normal combustion air by oxygen injection into the flue systems.Owing to its previous restricted availability and high cost, oxygen was used in rather small quantities in the open hearth furnaces at Australian Iron and Steel Pty. Ltd.(A.I. & S.), Port Kembla, until about the middle of 1960.At that time tonnage oxygen became available and roof lancing commenced on No. 33 furnace at No. 2' open hearth shop.

Jan 1, 1962

By Lo YC, Pate WT

In recent years there has been a great deal of interest in ways to optimise the performance of mineral processing plants. This paper describes a methodology developed for optimisation of autogenous and semiautogenous mills. The methodology involves plant sampling, batch testing, modelling, computer simulation, control strategy evaluation and implementation. The models have been tested in plant operations to verify the research findings and predictions. Two example applications of this approach to plant optimisation are presented. Benefits reported in these two examples are in the range of four - eight per cent increase in size reduction efficiency.

Jan 1, 1993

By Hansmire WH

The 14.7 km Mt. MacDonald Tunnel beneath Rogers Pass in Canada used both drill-and-blast and machine boring methods. A unique ventilation system provides for diesel operations. The design featured minimum construction support and an unrei.nforced poured concrete lining. The west heading was excavated in a single-stage drill-and-blast operation. The east heading used a TBM top heading with a drill-and-blast keyhole bench. The choice of methods was controlled by varying geology, with up to 1,700 m rock cover. Construction performance and progress are evaluated.

Jan 1, 1987

By De Janti VP

The automation and centralized monitoring of longwall type underground mining is presently an important subject matter of research in France. The purposes are :to improve safety and working conditions to increase productivity.to improve efficiency in machine operation through continuous "health monitoring". to make winning possible in difficult seams.

Jan 1, 1985

Chief Geologist, Groundwater and Engineering Geology Branch South Australian Department of Mines and Energy The six papers submitted for consideration during this session include two dealing with techniques for measing rock mass behaviour, including permeability, in boreholes, one describing the use of surface geophysical methods to delineate pollution plumes in groundwater together with analytical modelling of the plume, and one presenting a biological tracer technique applied to the determination of the origin of water entering underground mine workings. A paper describing dewatering at a base metal mine in Queensland includes an account of the investigation techniques employed to establish a conceptual model as a basis for the evaluation of various dewatering strategies. Of considerable interest is the use of a field gravity survey to delineate a zone of highly weathered rock which forms the major aquifer at the site.

Jan 1, 1988

By C T. Dunbar, P A. Walker, G E. LeJuge

A programme of blast improvement was initiated at the Mt Whaleback iron ore mine by BHPIO management in early-1998. One component of that work was the need to improve wall control blasting practices to better achieve the designed pit slope elements. This paper describes the geological conditions in which pit walls are developed, the mine operating equipment, the blast design concepts applied to minimise blast damage, the techniques applied in an assessment of the blast performance and the operational procedures developed to ensure that the blast concepts are effectively implemented in the production environment. Substantial changes have been implemented in both technical and operational aspects of the mining operation in order to achieve the improvements in pit wall condition, in particular recognising the need for a more flexible approach to limits blasting in response to highly variable and complex geology. The benefits to the mine are not only an improved wall condition, but increased confidence on the part of mine management that mine plans may be implemented on design and on schedule.

Jan 1, 2001

By Whiten WJ

Although cone classifiers have received little attention in the modelling of mineral processing units they are one of the oldest non-mechanical classifiers. Their use has enjoyed a revival in recent years because of their low cost of installation and operation. In this paper the development of models for cone classifiers is reviewed and a new model is proposed. The experimental work, data collection and analysis are briefly described, and the new model is presented and discussed. The data used in the model development are made up from three distinct experiments using different units in each case. There are 21 data sets from a 3 m cone treating the tailings in a copper concentrator, 24 data sets from a 0.3 m pilot-scale cone, and 29 data sets from a laboratory glass funnel (0.(Y73 m diameter) used as a cone classifier, giving a total of 74 data sets. The model structure was developed from an analysis of particle settling in classifiers, using specialised model building software. The size of a particle settling in a separator and the forced flow through the apex of the cone were related via hydrodynamic dimensionless groups to the operating conditions of the unit. The model predicts the separation efficiency using the following four parameters: efficiency curve shape factor, cut-point, underflow density (per cent solids) or underflow pulp velocity. The model covers a range of feed flowrates from 1.2 to 5000 1/min.

Jan 1, 1993

By Oxenford R. J

An important rutile-ilmenite-zircon bearing sand deposit was discovered by local farmers at Eneabba, 300 km by road north of Perth in 1970. These heavy minerals occur in a series of ancient strandlines and associated dunal deposits at elevations from 85 m to 170 m above the present sea level and are situated,30 km inland. The strandlines were deposited on wave- cut platforms in an ancient bay bounded by Mesozoic sediments during a series of regress- ions from a high sea level, probably during late Tertiary or early Pleistocene times. The immediate source of the heavy minerals in the Eneabba deposit is a widespread low content of those minerals in the nearby Mesozoic sedi- ments. The high-grade southern portion of the Eneabba deposit has been closely drilled and is now being prepared for production by Allied Eneabba.Pty. Ltd., a subsidiary of Allied Minerals N.L. This part of the deposit is 11 km long and up to 2.5 km wide. It is characterised by little or no overburden and the average depth of mineralisation, bounded by a 2.5 per cent heavy mineral cut-off, is 12 m. The water-laid strandline deposits at the base of the mineralisation are generally high grade, ranging from 20 to 60 per cent

Jan 1, 1973

Over the last ten years geological and mining software products have evolved greatly. Software companies developing such products have focussed almost exclusively on the development of technical aspects of the applications, addressing geological, ore reserve estimation and mine planning problems. These specialist applications, and the many other new technologies that are being developed by a myriad of niche developers, are an essential part of todayÆs hi-tech mining operations. Technology is also being used in many other areas to improve the mining process and there is no doubt that tremendous advances are being made in all these fields. Yet there is something missing. The manner in which the technologies are used and implemented has led to the creation of many independent and inefficient æislands of technologyÆ where a variety of products from different vendors are used to address different, but related problems. Problems occur with unreliable information, data duplication, data redundancy and transferring data between applications that may be incompatible or even run on different computer platforms. These problems impede the flow and availability of information and hamper day-to-day decision-making by mine management. A solution to this problem is to take a holistic view of all the various technical applications and incorporate them into a single information technology solution. This solution must encompass all of the information requirements of a mining operation and must provide facilities that address much of the modern thinking about mine management, including strategic mine planning, value management, key performance indicators, and maintenance of a mineral balance sheet. Gemcom is developing an Integrated Resource Asset Management System (IRAMS), which is an enterprise-wide integrated computer system that encompasses various applications typically found at a mining operation. The core component of the system is a common, open, industry standard database that can be shared by many users from each of the different departments at a mine. Around that central repository are the primary applications that provide the mine with information it needs to operate. Ensuring that the information is reliable, accurate, shareable, timely and consistent will eliminate many inefficiencies, and provide significant benefits to mining companies. In turn these benefits will lead to significant improvements in decision-making, productivity and profitability for the operation. The initial version of the IRAMS system is currently being implemented at the De Beers Venetia Mine in South Africa. The system is being built around a core repository using the Microsoft æBack OfficeÆ architecture, and incorporates key technical applications from Gemcom, Whittle, De Beers Technical Team, Wenco and JKTech. The benefits of enterprise-wide systems have long been recognised in the commercial arena and enterprise resource planning (ERP) systems such as SAP, JD Edwards and MIMS are becoming commonplace in the mining industry. The more forward looking software developers and mining companies realise the need for efficient management of the information gathered during the mining process and can see that the concepts used in ERP systems apply equally to the technical applications as they did to commercial applications. The use of IT in the mining industry has expanded tremendously over the last five years as enabling technology and management acceptance has become more prevalent, and there is considerable room for dramatic growth over the next five years. The evolution of geological and mining software has now reached the stage where mines will yield the greatest returns by integrating the applications used in each area of their operations.

Jan 1, 1999