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In 1976 the Pitjantjatjara Council was established under the Associations Incorporation Act 1985 (SA), for the initial purpose of organising and bringing together three similar Indigenous groups. These members of the Pitjantjatjara Council of Central Australia were demanding land rights and to legally protect their traditional lands. The Land Rights movement was more focused on the South Australian Government that became more receptive to the general notion that Aboriginal freehold land could be attainable.For almost five years, Pitjantjatjara CouncilÆs intense negotiations took place with the Dunstan and Tonkin Governments culminating in the final passage of legislation by 1981. A bi-partisan approach by Government and opposition applauded by all South Australians for its mature and socially responsible actions, in line with the Aboriginal Land Rights (Northern Territory) Act 1976 (Cth). Despite the similarities between South Australian and the Northern Territory Land Rights legislation, there still remains one obvious distinction. In the Northern Territory case, its legislation established æLand CouncilsÆ as statutory authorities that are responsible for the management and use of designated Aboriginal lands. On the other hand, South Australian legislation fails to include any reference to æLand CouncilsÆ as defined in the Northern Territory Act. The intention of establishing such æLand CouncilsÆ in the Northern Territory was, and is to provide legal, anthropological and other expect advisers that respond to the wishes and opinions of Traditional Aboriginal Owners. Negotiations between mining companies and Land Councils, will, after the granting of mining leases, monies are then transferred to those Councils being a percentage of royalty entitlements. While the Pitjantjatjara Land Rights Act 1981 (SA) (Act) does provide royalty arrangements to Anangu Pitjantjatjara (AP), a body corporate pursuant to the Act as a Landholding Body (and not as a æLand CouncilÆ), it does not provide any royalty payments for the legal and anthropological services by the Pitjantjatjara Council for providing essentially similar services as the Northern Territory Land Councils. The limited services by AP do provide complimentary services from other organisations û including the Pitjantjatjara Council. There are approximately 4000 Anangu members who reside on AP Lands and more than 1000 other Anangu members live near AP Lands in Western Australia and the Northern Territory. These people are defined as APÆs æTraditional OwnersÆ by virtue of their affiliation to portions of AP Lands. As a result, the depth and understanding of spiritual beliefs and customs are strongly present as it relates to the whole of the Lands. Most of these members reside at permanent communities that spread unevenly about the northern and south-western parts of AP Lands. In addition, there are numerous æHomelandsÆ where families and extended families have establish homes, with electricity and water supplies on those Traditional Lands (see Appendix 1 and 2 of this paper depicting the map showing AP Lands and also showing stunning photographs taken during late last year). All roads and airstrips are unsealed between communities and Homelands and the essential services to all communities are limited and costly to provide, and require continuous upgrading. Capital expenditure on infrastructure is sorely needed and alarming levels of unemployment is of serious concern. Tjilpi (older) Anangu members have continually discuss the urgency to provide employment and education for the future of their children and grandchildren while balancing the needs of maintaining cultural and spiritual considerations. It is thus a growing realisation by many Traditional Owners that long-term benefits occur as a result of exploration and production of oil or minerals. There are promising results from Primary Industry and Resources of South AustraliaÆs (PIRSA) Aero-magnetic Surveys on the Musgrave and Mann Ranges and soon to be completed surveys of the remaining southern half of AP Lands (see Appendix 3). PIRSA and mining companies û such as Rio Tinto Exploration Pty Ltd and Delta Gold NL û have been more conscious of the necessity for improving the dissemination of information to Traditional Owners and to AP members. With recent findings of large nickel deposits just over the border in Western Australia, there is a strong indication that discoveries may occur on AP Lands as similar geological information is present on the east Musgrave Block. Consequently there are concerted efforts by the legal and anthropological services of the Pitjantjatjara Council to arrange Workshops and Summit meeting to give extra information û particularly information concerning the true effect of large-scale mining operations û to members to properly consider these proposals. Pitjantjatjara Council will play a major role in any decisions effecting Traditional Owners and AP, and will ensure orderly and professional services when dealing with legal, cultural and sensitive matters. This paper addresses the historical and current relationship between Pitjantjatjara Council and AP, with an emphasis on mining operations on AP Lands. It argues that future economic and social development on AP Lands hinge predominantly on the legal recognition of the Pitjantjatjara Council for its ongoing role, responsibilities and protection afforded to AP and its Traditional Owners.

Jan 1, 2002

Amongst the unavoidable studies of the mining engineer who desires to reach the maximum efficiency, is the subject of patents. With the fundamental principles of the patent laws of this and other leading countries he should of course befamiliar, but still more should he keep abreast of that practical knowledge which will enable him to act or advise wisely when the patenting of a new invention, or the sale, purchasing, or adoption of a new patented machine or process becomes amatter for consideration. As every engineer worthy of the name is an inventor and more particularly every mining engineer he has a direct interest in watching the progress of legislation and administration concerning patent monopolies.His worldly prospects may indeed, to a considerable extent, depend upon the defeat of bad patent laws and the removal of incompetent officials, or the appointment of better ones. Better patent administration is always in Australia a valid requirement, and until engineers generally take up and press the demand, bad administration is likely to continue. Even though every engineer is not a patentee, nevertheless his interests in patents must always be direct and powerful, and ignorance or apathy in regard thereto must inevitably injure either his own interests or those of his employer. When we consider the tens of thousands of mines scattered through Australia alone, on everyone of which there is expensivepatented machinery, and when we consider the thousands of...

Jan 1, 1901

By Lynch A. J

A method has been developed for the prediction of the performance of multi-stage grinding-cyclone classification circuits of any degree of complexity on any ore for a wide range of operating conditions. The method involves the simulation of the circuit on a digital computer by means of. mathematical models of the individual units. At present, to establish the characteristics of the ore and the machines in mathematical terms, it is necessary to know the performance of a simple system on the ore for one known feed rate and feed sizing analysis.Further work on the separate identification of the terms defining the characteristics of the ore and the machines may permit the method to be applied directly to the data derived from small scale tests on ores.INTRODUCTIONThe cost of preparing metalliferous ores for concentration processes by, grinding and classification frequently represents a major portion of the cost of treating such ores, and it is necessary both from an economic and a metallurgical point of view that grinding and classification circuits should be operated at their optimum efficiency. It will be realized that the processes carried out in all units in such circuits behave according to physical laws and, if a mathematical representation of the laws applying to each unit could be derived, optimization of the overall process for any given conditions of feed or product may not be difficult.The physical processes in both tumbling mills and hydraulic classifiers are extremely complex and do not appear at present to be amenable to a rigorous mathematical analysis. However, empirical mathematical models of grinding units which have been presented previously (Callcottand Lynch, 1963; Lynch and Moore, 1963) may be used to discuss the operation of the grinding units in multi-stage circuits. Another type of model, which leads to a reasonable...

Jan 1, 1965

By H Stedman

Integrating exploration and operational blastholes into one database significantly enhances geological modelling. Benefits include: improved coal predictions, stronger interpretation of structurally complex areas, detailed mapping of heat affected coal aureoles and additional roof accuracy for blast designs that deliver better coal protection.CITATION:Stedman, H, 2014. Integrating blastholes into exploration data to improve coal recovery and modelling, in Proceedings Ninth International Mining Geology Conference 2014 , pp 237–242 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By Seedsman R. W

Good roads are essential in moving men and materials to and from the underground workplace. Coffey Partners International Pty Ltd (Coffey) has recently completed a underground coal industry funded project on underground mine road construction and maintenance. This paper discusses practical approaches to construction and maintenance of underground mine roads using transferrable civil technologies and innovative techniques. Mine pavements are generally low-cost (relative to civil roads), constructed to varying standards using locally available materials to best meet the mobility needs of the mine. Performance of pavements is thus largely dependent on the environmental conditions, quality of the available road making materials, maintenance policies and available resources. The paper will detail `what causes bad roads?' in various underground environments, available management strategies, construction and water control techniques, road maintenance and vehicle considerations.

Jan 1, 1995

By T O&apos, Sullivan

Reconciliation of metal production from a sublevel cave (SLC) mining operation is a complicated process. SLC reconciliation is unlike reconciliation for open stope operations, where a tonnage of extracted ore can be assigned to an exact volume of in situ ore, and a direct comparison made between the estimation of contained metal and actual metal production. In SLC operations the ore extracted from a particular SLC drawpoint will be composed in part from the parcel of freshly blasted in situ material, in part from varying components of ore material (from cave stocks) flowing down from other previously mined areas vertically above the current draw position and in part from external dilution. This leads to difficulties in reconciling production grades against estimated grades. The problem is that we know how much metal we have produced but we can not precisely say where it has come from. Metal production reconciliation is fundamental in assessing ore reserve estimation accuracy and performance and in determining a draw management strategy for SLC mining. In terms of contained metal, differences in extracted metal compared to in situ metal represent changes to cave stocks. To generate local estimates of the cave stocks, differences in metal for each ring are treated as additions to or subtractions from a series of vertical columns of stocks extending throughout the height of the cave. The sum of metal differences (extracted versus in situ) for each vertical column results in a residual metal map at any particular mining level. The metal maps show areas where the metal production has been greater than or less than expected. The maps also highlight areas in the cave where residual metal is located, areas where targeted overdraw can reduce cave stocks.

Jan 1, 2006

By J Pan

In this paper, the technology of producing fluxed pellets by using hydrated lime as binder instead of bentonite was carried out. The properties of the two types green balls (0.8 per cent bentonite and 2.0 per cent hydrated lime) were as follows: drop numbers of 4.8 - 5.0 times/0.5 m, compressive strength of 19.7 - 24.2 N/pellet and thermal shock temperature of 280° - 385°, respectively, under the same conditions of 1.5 per cent coke, 1.45 basicity and balling at 8.5 per cent moisture for 13 min in disc pelletiser. Comparing with bentonite as binder, the compressive strength of fired pellets with hydrated lime is elevated by 13.8 per cent and climbs up to 3113 N/pellet under the following conditions: preheating at 1050°C for ten minutes and fi ring at 1300°C for 15 min. In the mean time, the hydrated lime also improves the metallurgical performance of fired pellets. The reduction index was enhanced from 68.6 - 70.6 per cent, RDI+3.15+ increased from 90.1 to 98.8 per cent and reduction swelling index dropped from 22.4 - 7.4 per cent, respectively. The mineral compositions and microstructure of fi red pellets shows that the fired pellets containing 2.0 per cent possess more calcium ferrite and magnesium ferrite and compact microstructure, leading to the higher compressive strength.

Jul 11, 2011

Igneous phosphate deposits located in tropical and subtropical regions of the world are characterised by low P2O5 grades, very diversified mineralogy and intensive lateral plus vertical variations in chemical composition, mineralogical assembly, rock texture, grain size, slimes content and morphology plus surface coating of apatite particles. Those variations characterise ore types with distinct behaviour in mineral processing plants. This work reviews the main challenges to concentrate those ores, addressing developed solutions. Apatite concentration requires long chain anionic collectors to conduct reverse flotation of barite (alkyl sulfate) before direct flotation of apatite (sarcosinate, sulfosuccinate and oleate) at basic medium. The long chain collectors decrease the surface tension of the flotation solution (?LV) and a particular value of 51 mN/m was found to promote the most selective separation between apatite/gangue at a particular plant. Effective control of the magnitude of ?LV in industrial plants has not been realistic because there is a lack of reliable instruments to carry out in-situ measurements. Regarding gangue depression by starch, a review is made on possible mechanisms that promote its remarkable ability to depress some minerals (Fe-oxides, ortho plus meta silicates and calcite) vis-a-vis others (quartz, apatite and layered silicates). Flotation recovery (R) of fine (20<R<30 per cent) and coarse (30<R<60 per cent) apatite particles is considerably lower than the recovery of the intermediate ones (R>70 per cent) and inadequate hydrodynamic conditions within flotation cells are the main reasons for that behavior. Once the best hydrodynamic conditions to float coarse particles are not the same to float the fine ones, flotation of coarse and fine particles is commonly conducted at separated circuits in industrial scale. Entrainment of very fine gangue particles is an important source of contamination of apatite concentrates, mainly when weathered ores are treated. In most cases, adjustments in flotation equipment (columns or mechanical cells) promote considerable improvement in the quality of final concentrates.

Sep 13, 2010

Kinetic Behaviour of Solid/Solid Separation of Ultrafine Particles in Aqueous Suspension

Sep 13, 2010

Two years ago I was sitting in a big lecture theatre at the School of Mines in Kalgoorlie at the annual New LeadersÆ Conference listening to a guy tell us all how much he loved his job, travelling the country ælegallyÆ blowing stuff up à and getting paid to do it. I would have paid to see and do the things he spoke of à now IÆm that guy. From finishing a mining engineering degree at the University of Ballarat, through the job hunt, to firing environmental blasts in Tassie and designing and implementing construction blasts in the middle of the Gold Coast. My name is Rohan Stevens and IÆm a blast-o-holic. While the æjob huntÆ we all embark on toward the end of our degrees is a stressful time, itÆs also very exciting in the current climate. There are a number of things I have learnt through both my hunt for the job that best suited me and working for the worldÆs largest explosives manufacturer. If at least you donÆt benefit from my learnings IÆm certain you will enjoy hearing about (and viewing) some of the work I have had the opportunity to be involved with over the last 18 months with Orica Mining Services.

Jan 1, 2008

By Dalzell R. W

A Conveyor Belt Fire Test Program was initiated in 1985 by the Approval and Certification Center (A&CC), Mine Safety and Health Administration (MSHA), U.S. Department of Labor. The purpose was to evaluate the effect of entry air velocities on the burning properties of mine conveyor belts and assess fire test data from large- and small-scale tests. Belts meeting the fire-resistant standards of MSHA and agencies of other countries were tested in small- and large- scale fire tests.

Jan 1, 1988

The Autogenous Fine Grinding Kelsey Axial Displacement (KAD) Mill The marginal improvements which continue to be made to fine grinding practices have exposed the limits of conventional technologies and highlighted the need for a radically new approach. The patented autogenous Kelsey Axial Displacement (KAD) Mill design consists of a rotating spherical grinding chamber, which shares the same spherical centre as the shaft-mounted counter-rotating disc assembly. The axis of the disc assembly can be inclined to the axis of the spherical grinding chamber by pivoting the disc shaft about the common spherical centre. The inter-particle energy transfer required for breakage results from particle velocity differentials created by the discs intercepting the rotating mass. Particle size reduction is concentrated in high shear zones, which envelop the outer surface and periphery of the discs. This paper traces the development of the KAD Mill from pilot to commercial scale. Pilot work covers a range of minerals including magnetite, calcite, dolomite, barite, limestone and talc. Test results include open and closed circuit operation in wet and dry modes. Conventional milling constraints and energy consumption issues are addressed while new dimensions are added to the feed size range acceptable for wet and dry grinding to fine and ultra-fine sizes.

Sep 13, 2010

By D Zielinski-Nicolson

The emergence of affordable, portable and versatile wireless devices has enabled a new frontier in mine safety equipment. Existing solutions provide methods for tracking personnel and assets in underground mines but are not designed to optimally integrate into existing and emerging systems. Mine management are often required to coordinate primarily independent emergency, personal protective equipment (PPE), tracking and collision avoidance systems from multiple vendors. These systems involve a variety of wireless technologies that require separate integration projects that discourage adopting new services and policies.

May 5, 2022

Railway cuttings require the highest care in design and construction, as the pro- bability of failure concept does not allow any risks to be taken with hundreds of lives being dependent on continued stability. The usual geological influences on stability such as bedding dip and faulting are often discus- sed, but other major problems may come from the presence of sheet joints, cross joints differential weathering and seasonal or daily changes of ground water level. The design of rail cuttings has taken little note of the problems imposed by cons- truction methods, and low cost quarrying methods may seriously weaken a designed shape. The presence of berms and drainage ditches is often difficult to achieve as blasting imposes cumulative stresses and jointing on rocks. Contractors face difficulties in bidding extensive rock cuttings as variations in rock properties are often concealed and overshoot- ing the toe of a batter can easily occur. Modern blasting methods offer some solutions, but the best guide to safe successful cuttings is extensive investigation and the continued involvement of engineering geology at the stages of feasibility, design, construction and maintenance. Two case histories show the influence of folding, faulting and construction methods in the case of slope failure and slope stability.

Jan 1, 1979

By Nilmani M, Malone J, Taylor RN, Floyd JM, Gray NB, Fountain CR

CSIRO staff and University of Melbourne staff and students collaborated in an intense programme of investigation on the CSIRO 50 kg Sirosmelt pilot plant.In two days of operation copper matte converting and zinc slag fuming trials were performed, whilst investigation of the process dynamics and process chemistry was carried out. This exercise is an example of the techniques available for process evaluation, which can rapidly advance the understanding of pyrometallurgical operations by use of a team approach covering a wide range of experiments.

Jan 1, 1985

By C. P. BATES

In November 1969, New Zealand Steel Ltd pioneered the commercial use of the SL/RN solid fuel direct reduction process to make sponge iron as a feed material for electric arc furnaces. Serious process problems with the use of green balls and coal injection were progressively overcome. The process was developed by New Zealand Steel along a radical route, of feeding the fine grained raw ironsand concentrate and coal directly to the kiln. Contemporaneously with this development of direct reduction, steelmaking process innovations were made that enabled the arc furnaces to operate successfully with the high volumes of acid slag.

Jan 1, 1980

By C Mark, Z Agioutantis

This paper presents an empirical design methodology that is based on successful US roof support systems using both primary and secondary support in coal mining entries and intersections. The recent nationwide dramatic reduction of roof fall rates, especially in areas with weaker roof, can be directly correlated to the effectiveness of the roof support systems. A large database of roof fall histories at several mines is used to define the approximate boundaries of three modes of roof support with respect to roof strength as classified by the Coal Mine Roof Rating (CMRR) and in situ vertical stress as indicated by the depth of cover. These roof support classifications are: • Suspension, where roof bolts mainly provide skin control for strong roof. • Beam building or reinforcement, where a roof of moderate strength can be supported by roof bolts only. • Supplemental (secondary) support, where the primary support by roof bolts may be augmented by several secondary support systems, eg cable bolts, trusses, additional roof bolts or standing supports. The Primary Support Rating index (PSUP) captures the capacity of the primary roof bolt system as a function of the actually implemented roof control plan, ie roof bolt length, roof bolt density, and roof bolt capacity, while it does not consider the type of bolt. The actual PSUP value is compared against a suggested PSUP value derived from statistical analysis of US case histories. Where secondary support is indicated, the expected rock load determines the necessary capacity of the secondary support system. A new (free) software package, Analysis of Mine Roof Support (AMRS), implements the design methodology and also allows comparison with other international indices such as the Reinforcement Density Index (RDI), the PRSUP, etc.

Nov 29, 2022

The mining industry, both here and internationally, is continually developing increasingly sophisticated software to compute mineral resource estimates, but these processes cannot compensate for a flawed geological interpretation of the geology of the economic commodity(s) concentrations. Quality assurance and quality control (QA/QC) is becoming increasingly common in association with the sampling and assaying practices within the industry. However, it is rare in the case of a geological interpretation associated with mineral resource estimation. Why? In the context of this paper, QA/QC relates to the use of statistical and graphical tools to show that the geological economic commodity concentrations have been appropriately domained. Domaining is essential to improve the chance of getting a mineral resource estimate right. Commodity value and acceptable concentration variation within a mineral resource can be ingredients that make mineral resource estimation difficult to get right. But it is possible to get it right a very high proportion of the time. It is more likely to occur when inappropriate data consolidation is minimised. In any case, inappropriate data consolidation is significantly reduced when the geological interpretation is strongly consistent with the data and it is demonstrable. To achieve quality global estimates of geological domain concentrations, it is essential that the geology of the prospect is understood sufficiently that the deposit is appropriately domained. Appropriate domaining occurs when sample populations are separated in such a way that only data in harmony with each other within the population contributes to the domainÆs concentration estimate. The paper will use four brief case studies to illustrate how QA/QC can be used to display data and validate the underpinning geological interpretation through its associated domaining to get it right when it comes to a mineral resource estimation.

Jan 1, 2007

By Shihui L, Lianfu Z, Llanming J

The paper considers the essence of the multi-objective decision-making issues for selecting an optimal mining plan, and analyses the advantages and disadvantages of the multi-objective decision-making techniques commonly used for selecting an optimal mining plan. It presents the principle and practice of using a group-AHD with mixed factors to select an optimal plan.

Jan 1, 1995

A flow sheet has been developed to treat a high tonnage highly preg-robbing gold ore. The ore is low grade and fine grained with a high proportion of very fi ne free gold. The key components of the flow sheet include gravity, flotation, intensive cyanidation with direct electrowinning, and carbon-in-leach of the flotation concentrate. The circuit produces a low overall mass pull to concentrate allowing economic intensive treatment of large tonnage low-grade material. Efficient recovery of fine gravity gold using a Falcon concentrator in both the milling and flotation circuits, and subsequent intensive cyanidation in a Gekko InLine Leach Reactor (ILR) is critical to the process with over 70 per cent gold recovery expected in this circuit. Grind size control was also found to be important in controlling the activity of the preg-robbers in the carbon in leach circuit and also in the solid liquid separation performance. Tests at the large-scale demonstration plant have been conducted to demonstrate the effectiveness of this flow sheet. A large low-grade deposit is currently under development with the aim of developing a 10 Mt/a treatment plant with the subsequent addition of equivalent sized process lines in multiples of 10 Mt/a. The economic development of this orebody is critically dependant on understanding and exploiting the properties of the ore. In particular it is critical to minimise the effect of preg-robbers by recovering free gold with Falcon concentrators and InLine Leach Reactors. Recovery of the remaining gold by flotation into a small mass yield allows this fraction of gold to be treated by CIL leaching utilising high carbon levels. It is critical is to ensure operation at the optimal grind size to maximise liberation of the free gold and minimise pregrobber activity. The ore has been identified as preg-robbing with low recoveries obtained if treated using conventional cyanidation and carbon absorption. The mineralogy consists of predominantly fi ne grained free gold with minor sulfides including pyrite and arsenopyrite. With conventional cyanide leaching in the absence of carbon, gold recovery is less than 50 per cent. Direct cyanide leaching of the ore in the presence of activated carbon results in an improved but still uneconomic gold recovery. The gravity recoverable gold (GRG - as defined by Andre La Plante) content of the ore has been measured to be 70 per cent to 85 per cent in various tests with liberation grind size of approximately 106 ¦m. This indicates gold is predominantly free and suitable for recovery by batch centrifugal concentrators into a low mass yield. This property of the ore presents the opportunity to maximise the recovery of gold by separating it from the majority of the preg-robbers prior to leaching. Due to the very fine gold particle sizes and the necessity to maximise recovery of this fine fraction Falcon concentrators were selected for the duty, with their proven high recoveries at very fine gold sizes. The gravity recovery in the milling circuit is designed to be in the range 55 to 65 per cent. This has been achieved in the existing pilot plant using a Falcon operating on ball mill discharge within the mill recirculating load. Intensive leaching in an InLine Leach Reactor is essential to recover the gold from the gravity concentrates. Tabling is not a preferred option since recovery is lower than intensive cyanidation and any gold losses to table tails will report to CIL where recovery is reduced by the presence of preg-robbers. Furthermore, tabling recovery from the gravity concentrates is particularly poor due to the fine particle size of the free gold. ILR recoveries of 98 per cent were demonstrated in the pilot plant using an ILR100BA and leach conditions were investigated in the lab using pilot plant generated Falcon concentrate. Recovery of gold from the pregnant solution was achieved with direct electrowinning at pilot and efficiency and sizing parameters were determined at lab scale. To further increase free gold recovery Falcon concentrators will be installed in the flotation circuit. Location of the Falcons in the circuit is not finalised but installation on the rougher concentrate stream is favoured since it will allow multiple pass recovery. This is expected to recovery a further ten to 20 per cent of the gold, as indicated by lab tests on pilot plant generated material. The gravity concentrate from the flotation circuit will also be leached using InLine Leach Reactors. Initial intensive cyanidation tests carried out on lab generated flotation concentrates indicated higher recoveries than CIL can be obtained even though the concentrates contain significant levels of preg-robbing material. This can be explained by the high cyanide, high pH leaching conditions used in the ILR which alters the absorption equilibrium of the preg-robbers. Further optimisation of the leach conditions will be undertaken once more concentrate becomes available. Recovery of the remaining gold content is achieved by flotation into a small mass yield, however the preg-robbers are also recovered into this concentrate. Due to the presence of the preg-robbers gold leaching must be carried out in the presence of high levels of activated carbon in a CIL system. The recovery has been shown to be strongly dependant on the carbon loading and the concentrate particle size. The carbon competes against the preg-robbers for dissolved gold while excessive grinding increases the surface area and activity of the preg-robbers. This has been demonstrated in test work however the economic optimum leaching conditions and carbon loading have yet to be determined. The grind size is critical to the economics of the project, not only due to its effect on gold recovery but also due to its effect on the major operating and capital costs at both the front and back end of the process. It is critical to grind enough to obtain both gravity free gold and flotation liberation at low mass yields however over-grinding results in large increases in mill size and power at the front end and filtration or thickening costs at the tails. Because these unit operations treat essentially all the plant feed even small changes can result in major impacts on project economics. The viability of this project is greatly enhanced by the high recovery of gold into a small mass yield. In particular the production and intensive leaching of the free gold gravity concentrates will allow over 70 per cent of the gold to be recovered efficiently with minimal impact from preg-robbers. By using flotation the mass of the remaining fine preg-robber contaminated material, to be leached in CIL, is greatly reduced allowing this difficult material to be economically treated. This is an ABSTRACT ONLY. No paper was prepared for this presentation. 

Aug 1, 2010