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By Pratt V

The economic, social and political environment of the mining and minerals industries is, as we all know, volatile and affected by constantly changing international forces. In addition, the outcome of negotiations with overseas customers is often uncertain for long periods, or even unfavourable. The industries and companies represented at this Conference are in an arena of high competition, risk taking and enormous capital outlay. They are industries which our overseas markets (rightly or wrongly) have criticised for industrial relations problems, unreliable production and uncertain deliveries. They are industries which have an urgent need to be cost effective and competitive at all levels of activity.A critical factor in the mining and metallurgy industries is, therefore, its human resources and its human resource management. It requires the full use of available talent, innovation, skills and qualifications within its workforce, and the appropriate management of these resources.

Jan 1, 1985

By L D. Munro, S A. Jackson

This paper provides a logical approach to developing a TSF design concept through: • Identifying key properties of tailings and containment structures; • Reviewing underlying principles for effective operation; • Showing how these apply to select an appropriate TMS; and • Demonstrating how to align the TMS to site-specific constraints and TSF design. This approach follows a path of rigorous data analysis independent of discharge parameters (whether low-density slurry, paste or cake disposal) to select the most cost-effective and sustainable approach for any given material or site.

Jul 1, 2021

By J de Witte

When used in suitable ground conditions, rock bolts can have advantages over other permanent tunnel lining solutions. Permanent rock bolts offer flexibility in tunnelling profile and rapid rock bolt installation can enable time and cost savings. There are also disadvantages when considering the suitability of rock bolts for permanent support installations. These generally concern achieving the specified durability requirement over the specified design life. By investigating alternate approaches to rock bolt installation, quality assurance (QA), monitoring and design life it may be possible to alleviate some of these concerns.The design and construction benefits that can be realised through the use of rock bolts are primarily related to reducing project program time. This time reduction could be realised if rock bolts are considered as a permanent solution, with the installation being completed as a part of the primary excavation cycle. Any reduction of the program could allow direct and indirect cost savings and in the case of a major project, allow the revenue stream to be realised earlier.Currently ambiguity exists where the treatment of rock bolts as permanent support components is inconsistent with that of (often identical) ground anchors, as utilised in stabilising cut and cover structures. The ground support design process, implementation and testing are generally similar, though the acceptance of rock bolts as long-term support elements is treated differently to ground anchors in technical specifications.This paper discusses some of the benefits available through the use of rock bolts. It offers different solutions to the concerns surrounding durability, including alternate approaches to installation, Quality Assurance practices and monitoring solutions. The selection of an alternate design life is also investigated as another means of alleviating concerns around long-term durability. The paper will also provide an indication of savings that could be expected through the use of rock bolts as part of a long-term support system.

Mar 8, 2011

By M A. Noppé

"Investors and other stakeholders assessing the risk, opportunity and relative value associated with a resource project need to appreciate the project in its correct context. Errors, omissions, biased reporting or conflicting information in project reporting may lead to a misinterpretation of technical and financial results, resulting in biased estimates or assumptions on project value.This paper provides a simple ‘Resource Project Framework’ for presenting a project’s status that may be readily benchmarked against other similar projects and to illustrate the stages required to advance the project outcomes to higher levels of certainty. The framework draws on definitions and guidelines readily available in various resource industry reporting codes and public company reporting requirements.The framework assesses three key areas for placing a resource project in its correct relative context, namely:the project development stagethe confidence in the Exploration Results, Mineral Resources and/or Ore Reservesthe level of accuracy, precision and confidence in the technical and economic studies supporting the reported results or options for the project.The application of the Resource Project Framework is illustrated using two project examples, one from publicly reported company project releases and the other for two development projects.CITATION:Noppé, M A, 2016. A framework for presenting and benchmarking resource projects, in Proceedings Project Evaluation 2016, pp 260–274 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By J Coombes, R Sterk

The efficiency of the Australian and New Zealand stock exchanges relies on a fully informed market: shareholders and investors are fully and transparently informed of all material information relating to the shares. These principles of transparency and materiality are similarly core to the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code). The JORC (Joint Ore Reserves Committee) Code also includes a principle of competency to ensure that the person providing the material information for public disclosure is suitably qualified and experienced.Since its inclusion into the ASX (Australian Securities Exchange) Listing rules in 1989, the JORC Code has continually improved and evolved in attempts to meet the market’s need for competent, transparent and informed disclosure. The quality and effectiveness of Public Reporting in accordance with the JORC Code is under constant challenge: some practitioners argue there is insufficient regulation, while others argue the need for greater self-regulation.This paper contributes to that discourse by exploring how well the Reporting expectations are met, and, whether Public Reporting in accordance with the JORC Code has a material impact on share-price movement.CITATION:Sterk, R and Coombes, J, 2017. Public reporting – new standards or no standards?, in Proceedings Tenth International Mining Geology Conference 2017, pp 423–432 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By B L. Sainsbury, M F. Lee, A Penney

For most practical rock engineering purposes, stress versus strength conditions around underground openings for which rock masses fail and their various modes of failure, are reasonably well-understood and predictable. Some rock masses and particular rock types fail slowly and relatively quietly. However, others can fail rapidly, violently and maybe with the ejection of significant broken rock. In some countries and in some mines, the latter style of violent fracturing and failure of the rock mass is referred to as ‘strain bursting’. It can be alarming and extremely hazardous to nearby miners and machines. For such situations, the design and installation of appropriate ground support, to provide a safe work place, can be challenging. At any particular mine site, it’s often generally understood which local rock masses (rock types) are prone to strain bursting. Competent and strong siliceous rocks and some massive sulphides are often the main offenders. While some neighbouring, equally-competent and strong rocks might also fail, they do so more quietly and without ejection. To understand this contrast, a better understanding of the fracturing process is required other than simple and standard strength versus stress considerations. Suites of standard intact rock properties from numerous Australian mines have been used to define and help understand different high-stress failure styles for component intact rock; especially those prone to violent fracturing (strain bursting). Simple considerations of micro-fracturing (defects in the intact material), plus the available energy at failure versus the energy consumed during fracturing, distinguishes between over-stressed and competent rock types that fracture violently and those that don’t. CITATION:Lee, M F, Penney, A and Sainsbury, B L, 2018. Proneness of competent over-stressed intact rock to violent fracturing, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 170–184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

Exploring long-term future possibilities for your business and methods for achieving them are critical functions of leadership. More than ever, strategic initiatives today have to be planned and delivered in an environment of disruptive change û driven by shifting business or regulatory imperatives, new technologies and global economic change, and diverse stakeholder interests. The notion of The Future as a single inevitable outcome is obsolete. There are many possible futures. This paper explains an innovative process û known as scenario planning û to help executives in the construction and testing of longer-term strategies to deal with uncertainty.

Jan 1, 2006

By S Juras

To our geologists at Eldorado Gold Corporation, the release of the gold assays on a new ore zone causes a flurry of excitement. But to our metallurgists, that news is often greeted with the question ‘What’s the sulfur grade’? In our company, we operate and manage projects whose end-product will either be auriferous sulfide flotation concentrate or gold doré. Almost all of the steps in the ore processing are related to sulfur (in this paper specifically sulfide sulfur). So why do we geologists wait until late in a project or into production before collecting sulfur data for mine planning and ore control purposes?Gold deposits associated with sulfides commonly use a metallurgical process that begins with a flotation step to recover gold into a smaller mass known as flotation concentrate. Often, this step solely targets the sulfide minerals with gold only coming along for the ‘ride’. As a result, the gold grade in the concentrate is primarily influenced by the ratio of gold to sulfur in the feed. Should this concentrate require a refractory process downstream (eg pressure oxidation), knowing sulfur grade is critical as sulfur controls heat balance in the process. Regardless, we need sulfur models to be as robust as gold models, and created much earlier in the project evaluation process.Sulfur models require quality data collected at the same density as gold samples. Analytical methods must match expected grade ranges and quality assurance quality control (QA/QC) protocols and must be of the same integrity as in use for gold. Sulfur models will then be created by their own data analyses, interpolation protocols and validation. Furthermore, ore control systems should be designed for regular sulfur monitoring to ensure and enhance downstream value. Given time it should become habitual for geologists to likewise ask, ‘And what’s the sulfur grade’, or more specifically, ‘What’s the gold to sulfur ratio’?CITATION:Juras, S, 2017. Sulfur – the new geometallurgical grade in gold-sulfide deposits, in Proceedings Tenth International Mining Geology Conference 2017, pp 199–202 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By P B. Swart, P D. Erskine

Despite an increasing focus by media, communities and activists driving an elevated regulatory focus in Australia and indeed some other mining jurisdictions, the mining industry globally has had limited successful mine lease relinquishments and transfers to support a next land use.Critique from anti-mining lobbyists frequently uses the large estimates from historically abandoned mine sites to influence risk-averse regulatory reforms to improve environmental performance. The mine rehabilitation regulatory processes in Australia, and specifically in the State of Queensland, are thus largely in place to prevent mining operators from abandoning their obligations.Regulatory responses to the lack of mine rehabilitation and closure performance in the last five to ten years have primarily focussed on compliance and enforcement of rehabilitation conditions in environmental approvals. Additionally, financial assurance measures have been tightened to protect against abandonment of rehabilitation obligations by the Industry, including the Chain of Responsibility legislation (Queensland Government, 2016b) in April 2016, to hold to account those who have benefitted from mining and processing/refining projects, and then avoid their environmental obligations.CITATION:Swart, P B and Erskine, P D, 2018. Are our closure planning and regulatory processes adequate to identify, quantify and appropriately transfer residual risks after successful mine rehabilitation?, in Proceedings Life-of-Mine 2018, pp 155–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By E L. Kotova

Completeness of extraction of a mineral from ore depends on many reasons. First of all it is a function of quality of disintegration of ore. It is supposed that two basic factors: character of structure and texture of the ore aggregate and a disintegration technique influence the quality of the mineral aggregate destruction, æopeningÆ of its internal boundaries. In this paper, the problem of technological mineralogy from the point of view of genesis of the mineral aggregate, its typomorphical features and methods of their quantitative description are discussed. The purpose of this research is to provide information for technologists. It should enable the development of a rational flexible scheme of disintegration of ore with full extraction of a useful component, without its losses and without unnecessary expenses of energy. For achievement of this purpose the mineralogical information should have ½number and a measure+. By the authors, the technique of the quantitative analysis of fabric of the mineral aggregate based on several models û thermodynamic, crystallographic and geometrical is offered and discussed. The leading role in the quantitative analysis of a fabric of ore belongs to internal bounders. But internal bounders of the mineral aggregate by bounders or faces of the mineral individuals or mineral grains are formed. Their geometry, orientation concerning own (mineral grain) crystallographic lattices, orientation and distribution in space of the ore aggregate are proportional to the energy accumulated at origin and the further growth. These characteristics of mineral individuals are consequences of conditions of their formation. That is why the named triad of models is used. From crystallography it is known that faces of different stability and mobility form borders of crystals. They also contain different quantity of energy. Mineral grains also are faceted by different energy borders. They form intergrowths with each other according to a principle of balance or unbalance. That is why in addition to traditional parameters of the description of a fabric of the mineral aggregate (mode and grainmetrical composition) it is necessary to add new. For example, length and the square of intergrowthing bounders of mineral individuals differentiated (in couples), crystallographic symbols of borders, their roughness and so forth. Consequently, solving a problem of the geometrical characteristic of borders, we define also its power characteristic. In this paper experience of application of our technology in studying ores of one of deposits of Urals Mountains is presented. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices, which are carrying out the analysis in a semi-automatic mode, are possessed. Structure and texture of rock or ore aggregate reflect its formation and transformation conditions. It is important to understand that disintegration energy cannot be more than aggregation energy, the energy of intergrowths formation. The square and orientation of mineral individuals borders vary at pressures or stresses of mineral aggregate evolution. These phenomena often cause selective increase in the square of borders at constant average grain size, ie the granulation. Granulation presents the increase in quantity of mineral individuals while their modal share remains constant. At the same time their average mineral grains size. Some mineral individuals increase in size at increased pressure. When lithostatic or lateral pressure drops the majority of mineral grains increases in volume at the cost of intersticial or film solutions or fine grains. These are only special examples of the ontogenesis of the mineral aggregate. They illustrate our statement that all changes in fabric of the mineral aggregate are a reaction on varying external (ie geological) conditions. It is possible to consider that structurisation of totality of mineral individuals as a whole is a process of adaptation of the mineral aggregate, which forms and exists in varying force and energy fields. Differential and integrated geometry of total internal boundaries of the mineral aggregate serves as adaptation mechanism of the mineral grains system. Boundaries form intergrowths of the mineral aggregate. Thus, it is possible to consider that the most informative parameters of the stereometric analysis for restoration of the ontogenesis of the mineral aggregate are the following. First of all, it is a quantitative estimation of the volumetric shape of the ore mineral in crystallographic coordinates, a total area of borders of all mineral grains in the aggregate, the specific square of their boundaries, the specific square of intergrowth boundaries of the ore mineral separately with grains of each minerals of the matrix of the mineral aggregate as well as traditional grainsmetric and modal composition. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices that are carrying out the analysis in a semi-automatic mode are possessed.

Jan 1, 2008

The information age has arrived. In every aspect of life, at the end of the second millennium, computers and information technology have made significant inroads. In mining there has been huge growth in the use of digitally controlled systems. From resource evaluation to mine planning to daily operations, information is being acquired, analysed, modeled and presented, using state-of-the-art information technology. Explosives, too, have moved into the information age. Computer controlled trucks and manufacturing plants have been developed and are now a regular feature on many mine benches. The next challenge for the explosives industry as a whole is to integrate blast initiation with information technology. The benefits are there, both to the supplier and to the end-user. Much has been written in the past about the potential for blast improvement but there are other significant advantages to a digital initiation system. These include security from unauthorised use, stock control and minimisation, reliability through testability and ease of use to name a few. So why is it taking so long? Surely the complexity of an electronic initiation system is far less than that of mobile phones that have been around for a long time. The answer, it seems, lies in the level of new technologies that need to be developed. There are enormous technological hurdles to be overcome in order to put into the market a cost-effective, reliable, user-friendly electronic initiation system. The most significant of these are:Safely and reliably initiating an explosive from an electronic device powered by a small capacitor. Prior to the development of electronic detonators primary initiation of explosives was by shock tube spit or by passing large currents and voltages down a pair of wires. Electronic detonators do not have that luxury. For example the energy stored in a æBeethovenÆ exploder is more than 500 times greater than that available to an electronic detonator. Communicating to a multitude of devices over very long cables installed by miners in harsh conditions. The deployment of an electronic detonator system has been likened to building a large telephone exchange in the rain and getting it to work perfectly first time! New communications protocols needed to be developed and tested. Wiring and connection systems have to be designed to survive the mining environment. In spite of these technological hurdles most of the major explosives manufacturers have persisted with electronic initiation systems and we are now, in 1999, starting to see the results of these multi-million dollar efforts. At SMI we are often asked many questions about this technology. The remainder of this paper seeks to answer those most often asked. As with any business linked to information technology todayÆs breaking news is tomorrowÆs archive and we expect the rate of development and understanding to accelerate as these technologies become accepted by the global mining industry.

Jan 1, 1999

By R Russell

The relative infrequency of fatalities and other serious events can give them an appearance of being random, of being beyond any reasonable degree of anticipation and prevention. In fact, the vast majority of these events result from exposures that are identifiable, measurable, and manageable. The lessons of prominent incidents, such as the Space Shuttle Columbia, OxyÆs Piper Alpha, Esso Longford, BP Texas City, Massey Mine, as well as lessons from single fatality events, is that alongside the proximate causes of each incident, there also coexisted an underlying fabric of systems, mechanisms, and culture that allowed risk in the workplace to persist and often to become normalised. All of these ingredients of the organisationÆs safety fabric lend themselves to the influence and intervention of senior leaders. The difficulty is that traditional injury prevention paradigms are not sufficient for addressing the precursors that lead up to catastrophic and fatal events. A recent study of such events, led by Dr Thomas Krause concluded that the descriptive aspect of HeinrichÆs safety triangle is useful, but that the predictive aspect is not. The study surfaced reasons why a reduction in less serious injuries does not necessarily correspond to a proportionate reduction in catastrophic and fatal risks. This presentation expands on the findings to include the concept of exposure to the event potential linked to precursor events and the framework for leading an organisation to be both cognisant and effective in eliminating such events.CITATION:Russell, R, 2012. Shifting the cultural paradigm for the prevention of catastrophic and fatal events, in Proceedings International Mine Management 2012, pp 91-96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

Mssissippi Valley-type (MVT) and sedimentary-exhalative (SEDEX) zinc-lead deposits represent about half to three-quarters of the world's production and reserves of lead and zinc. The two deposit-types have traditionally been regarded as separate entities in terms of genesis largely because they possess very different morphologies, resulting from the epigenetic nature of MVT deposits and the syngenetic origin of SEDEX deposits. Similarities in regional setting, metal ratios, size and grade, lead and sulphur isotopes, and source(s) of fluids and metals in the two deposit-types, however, suggest that they could be products of similar genetic processes. The physical properties of MVT ore fluids suggest that certain types of SEDEX deposits could have been formed from fluids possessing similar salinities and temperatures. The hypothesis is further strengthened by the facts that: 1. in several cases MVT and SEDEX mineralisation occurs in the same region, and 2. recent advances in establishing the timing of MVT mineralisation has revealed that some MVT deposits are contemporaneous with nearby SEDEX deposits. If MVT and SEDEX zinc-lead deposits do indeed share a common ultimate derivation from fluids that emanated from sedimentary basins, then the presence of one deposit-type in a region could be used to infer the possible presence of undetected deposits of the other type. Furthermore, knowledge of the mineralisation age of one type will constrain the exploration target host rocks of the other type. A genetic relationship between MVT and SEDEX mineralisation may also explain why certain individual deposits, such as several in Ireland and eastern Canada, appear to be 'hybrids' and possess geological attributes of both end-member types.

Jan 1, 1993

Mining is still a significant economic activity within the Hauraki District. The Martha project is particularly significant. Estimates are that in the order of 850 direct and indirect jobs are derived as a consequence of the Martha project within the Waikato Region. The Resource Management Act 1991 (RMA) is New Zealand's primary piece of environmental legislation. It sets out to provide the framework for the control of the use, development and protection of almost all physical and natural resources. Minerals are excluded from the sustainability requirements of the legislation but as mining invariably involves the use of land, all the other elements of RMA apply. The Council's role in dealing with mining changed with the introduction of RMA. It became responsible for administration of those matters that fell within the functions set out in section 31 of the RMA in respect to existing authorisations. Mineral development needed to be considered in the development of the District Plan that the Council is required to prepare. Implementation of the Act has been a challenge for not only local government but for many industries and resource users since it came into force in 1991. There have been, and are, differing views on both the way it is administered and its intent. The Hauraki District Council has been at the forefront of some of the challenges that are a consequence of the Act. Its reactions to these challenges have been consistent. It treats mining in the same why it treats any other industry. At times this approach has not been understood and without challenge from sections of the community.

Jan 1, 2000

By J T. Smit

The theory of froth flotation developed slowly, in almost all cases lagging behind practical developments in the operation of flotation processes. This was largely the result of a lack of understanding of the required basic principles of chemistry and physics, many of which were being developed at the same time. A review of some of the early theories propounded is worthwhile, and should encourage those who are presently studying or practicing flotation to exercise some care in claiming a complete understanding of the underlying phenomena in the art. This paper considers theories presented up to and including those in Principles of Mineral Dressing by Antoine M Gaudin (1939). Of course, developments since that time are important, but they are beyond the scope of this discussion.

Jan 1, 2005

By I Sucholutsky, D M. First, D Mogilny, F Yusufali

Machine learning is creating value in all facets of the mining industry, from exploration to production. The authors provide an accessible, high-level introduction to artificial intelligence (AI), machine learning (ML), and deep learning (DL); the latter being widely recognised as one of the most powerful forms of ML. In particular, the authors will introduce deep learning models known as convolutional neural networks (CNNs), how they are applied, and the economic considerations necessary for determining when DL may be the right solution to de-risking complex block modelling problems. The authors present preliminary results from the mineral resource modelling study of the Jundee orogenic gold deposit, Yandal belt/gold province, Western Australia. The primary goal was to identify the direction and location of the narrow gold veins more accurately and demonstrate how non-linearly correlated elements are used as direct inputs to the resource model to assist with the target element’s grade prediction. This demonstrates that: (1) existing techniques for finding correlations between assayed elements do not adequately reflect the complex geology of the asset, (2) nonlinear correlations that are difficult to model as simple mathematical functions are representative of geological patterns in a deposit, and (3) non-linearly correlated assayed data, fed as inputs, increase the performance of the resource model as reconciled through blind tests. To conclude, the authors hypothesise that the patterns represented by the DL block models may be revealing the results of overprinting geological processes that generated mineral deposits. For example, the primary hydrothermal processes that deposited metals created depositional patterns that become particularly complex as a result of being overprinted, in part or in whole, by secondary physicochemical processes. This may explain why non-linear geochemical relationships have the capacity to generate more accurate block models of mineral deposits.

May 24, 2023

By J Ledgerwood

Namakwa Sands is a mineral processing company based on the West Coast of South Africa and is solely owned by Exxaro Resources Limited. Mineral ore is mined and processed, concentrated and both chemical and mechanically upgraded before being sent for electrostatic and magnetic separation units. The final high value mineral products report as Zircon, Rutile and Ilmenite.The recovery of non-magnetic material is largely dependent upon a number of factors, including but not limited to dew point, ambient temperature, feed rate, mineral size distribution, specific gravity and mineral content in head feed. One important limiting factor to recovery in typical dry mill operations is the particle size distribution of the feed. Variance in the particle size has catastrophic consequences for recovery. This is the reason for this study. Until recently large variances in non-magnetic production were viewed to be a function of machine operation. This view was later rejected with the feed size distribution determined as the major driver of low recoveries, for Namakwa Sands orebody 50 per cent variance in particle size distribution can be noticed within one day. This is because of the successive mining blending techniques employed.The predicament is that the two modes were so closely placed together that recovery of a single mode is almost impossible without the consequence of greatly reducing recovery. The second mode was found at 125 µm while the first was at 90 µm. Interestingly, for the mentioned feed type a cumulative size distribution of a unimodal feed type is almost exactly the same as for a bimodal size distribution. Thus a plot of cumulative size distribution will show no difference due to the modes being so close together. This is the reason why this phenomenon was not noticed before.The study also found that, using an high tension roll (HTR) or rare earth roll, a fine stream with a single mode at 90 µm versus a coarse stream with a single mode at 150 µm would yield completely different results interms of yields. Larger conductive particles are thrown from the roll while small particles loose charge faster (entrainment). Results in terms of the bimodal size distribution show that even though 25 per cent of the feed type is greater than 150 µm the yields followed a similar pattern to that of the coarse particles rather than that of the majority (75 per cent) fine particles. This confirms what was published by M Ziemski and P N Holtham in 2005 on charge decay rates; they mentioned that particle bed effects played a major role in recovery.

Oct 5, 2011

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

By S Juras

The terms measured resources and proven reserves denote the highest level of estimation confidence in all of the major classification schemes. But what do they really bring to today’s project or mine with respect to production planning and expectations? Initial reserve declaration does not need measured resources, just indicated resources. Economic viability of a project is assessed on total reserves with nary a bonus for the amount of proven reserves. Production plans are based on grade and tonnage goals that may only coincidently correspond to proven reserves. So are the measured and proven categories still relevant? Historically, and almost exclusively in underground mines, companies only allowed mining in areas of proven reserves. Some companies still follow that philosophy. But many others will mine a mixture of probable and proven reserves without hesitation. Also what of the undeveloped project in a new district – what is to be made of their declared measured resources and proven reserves? Measured resources are commonly set either by some type of proximity to data scheme or a matter of ‘feel’ based on the qualified person’s experience. The parameters for reserve conversion focus on the project as a whole and then a portion becomes classified as proven reserves almost solely based on whether the resource category is measured. So should the mining industry continue to use these categories of resource and reserve classification? This paper will present arguments about making these categories once again more relevant. A more disciplined usage of these categories may re-introduce their relevancy in public disclosures of resources and reserves. As well a more consistent usage in operations may lead to increased confidence in managing production targets and costs.

Aug 22, 2011