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By Sibson RH

The gold province of Otago occupies an area of upwarped basement, the Otago Schist, comprising predominantly quartzofeldspathic and volcanogenic metasediments. This assemblage is the product of collisional tectonic deformation and associated metamorphism, mainly to lower greenschist facies, during the Rangitata Orogeny (200-100 Ma). Historically this region has produced 240 tonnes of gold, 4% (10 t.) of which was from the mining of Cretaceous gold- quartz mineralised vein systems. Auriferous vein systems in the Otago Schist are mainly hosted within NW trending normal fault-fracture arrays, however NW trending reverse fault-hosted vein systems also occur. We propose that the Late Cretaceous-mid Tertiary Otago Schist structure represents a regional anticlinorium containing flexural folds of at least two wavelengths. The anticlinorium structure has been quantified by determining variations in angular discordance between schistosity and the Otago Peneplain, a Late Cretaceous-mid Tertiary erosion surface covering most of the Otago district. A structural model for the evolution of the post-collisional anticlinorium requires the cooling surficial zone (carapace) of a retrograding metamorphic belt to behave as an elastic lid. Erosion of topographic load on the carapace drove isostatic uplift, which was greatest in the tectonically thickened core of the orogen. In this way differential uplift produced flexural deformation in the elastic carapace, expressed as a large scale arching of the orogenic belt. Flexure created tangential longitudinal strains in the outer-arc, leading to extension and the formation of mineralised normal faults. These structures are separated by a neutral surface from shortening and associated mineralised reverse faults in the inner-arc. Our structural model predicts that the distribution of auriferous lodes should be localised about zones of maximum flexural curvature, where the tangential longitudinal strains are highest. As a result, NW-SE hinge regions separating schistosity dip domains in the Otago gold province may have new found significance as potential exploration targets.

Jan 1, 1995

By S Liu, N M. Rana, A Take, N Ghahramani, D Clohan, S McDougall, S G. Evans, H J. Chen

Tailings dam breaches have caused significant life loss, social, economic and environmental damage in recent years. The term "tailings-flow" refers to various forms of tailings outflow movement resulting from the breach of a tailings dam. These flows, comprising a mixture of tailings, water and dam materials, can take different forms, ranging from a debris flood to a flowslide, and can travel long distances and impact large areas. The inundation extents depend on the failure mechanism, tailings dam height, total released volume, sediment concentration (associated with the rheological behaviour of the flow) and downstream conditions (including topography, land cover and presence of a water body). Numerical runout modelling of tailings dam breaches is important for predicting the dynamics and extent of tailings-flows, which are crucial steps in tailings dam consequence analysis and risk management. This paper presents a comparison of numerical simulations of the 1994 Merriespruit tailings dam breach using three numerical models: DAN3D, FLO-2D and MADflow3D. Using compiled site condition information and data from the literature and public domain, model performance was evaluated primarily based on comparisons between the observed and simulated inundation extents. The main purpose of this preliminary model benchmarking exercise was to help us evaluate the capabilities and limitations of each model, and to identify opportunities for future model improvements as part of a broader research initiative known as CanBreach. This exercise also highlights the inherent complexity of tailings-flows and the importance of using judgement to interpret model input and results.

Jul 1, 2021

By Fredley D. C

Georgius Agricola wrote in De Re Metallica in 1556 that a prudent a miner should not work in a region ruled by a tyrant-a person inimical to mining. In 1926, Associate Chief Sherman of the United States Forest Service in a speech stated, "It is the policy of the Forest Service to encourage the development of the mineral resources within the boundaries of the National Forests ... a man who fails to cultivate a friendly, helpful, cooperative spirit in his relations with those who are endeavoring to develop the mineral wealth of our mountains has no place in the Forest Service." Both statements are as true today as they were in 1556 and 1926. The challenge to the Forest Service and the mineral industry today is to maintain that cooperation in a world that has changed significantly since Agricola and Sherman. The United States Forest Service manages 77,000,000 hectares of land-mostly in the Western United States-an area equal in size to New South Wales. The vast majority-75 million hectares are National Forests, and 1.6 million hectares are National Grasslands. National Wilderness Areas account for 13 million hectares or rough- ly 17 per cent of the National Forest System. National Forest System lands (NFS) are some of the most visible, scenic and controversial lands in the country. They are also some of the most valuable for their mineral potential and production. The value of mineral produced exceeds US$4 billion per year. There are over 1200 producing mines, 15,000 oil and gas leases, and some of the largest lead, copper, silver, gold, platinum, molyb- denum, and coal deposits in the hemisphere. Every year the Forest Service approves nearly 5,000 mineral operations on the NFS. Much of the NFS (75 per cent) is open to location of mining claims pursuant to the 1872 Mining Law. And an equal amount of land is legally available for oil and gas leasing.

Jan 1, 1991

The experiments described in this paper were carried out as a preliminary to a comprehensive study of the factors which affect the behaviour of lead during and subsequent to deformation by rolling and pressing. These observations are therefore to be considered as introductory to a further paper dealing more specifically with the above-mentioned variables.EXPERIMENTALThe rolling was carried out in a small mill with six-inch diameter surface ground rolls, both of which were electrically driven at 15 r.p.m. The average draft per pass approximated 0·03 in. The pressing was performed between platens in the compression unit of a 30-ton Amsler machine. The flat faces used had a ground finish comparable with the surface of the rolls. All hardness measurements were made with a Herbert "dead load" Brinell machine. The following te'sting conditions were maintained: ball diameter-5 mm.; load-10 kgms.; duration of loading-30 seconds; temperature of testing-16 to 18°C. The hardness values which are given are the mean of two or more impressions made at corresponding positions on the test specimens.PREVIOUS WORKSince the researches of Tresca (1):j: into the nature of the plastic flow of metals during various forging and extrusion...

Jan 1, 1939

By H Austrheim, A K. Engvik, A Putnis

How aqueous fluids move through rocks and minerals is a question of possible pathways and mechanisms. Existing pathways such as fractures and grain or mineral boundaries provide obvious channels for fluid movement. We show how minerals reactive in the presence of an interfacial fluid can be replaced by new product phases through a process of interface-coupled dissolution-reprecipitation. A resulting porosity in the new phase provides a new pathway for fluid movement and therefore mass transport through the mineral, which progressively reacts at a moving interface. Eventually fluids of new and changing composition can pass through originally solid minerals and move on further, taking remobilised elements with them, to be reprecipitated whenever the chemical and/or physical conditions allow. One such example is albitisation of rocks associated with mineralisation.

Jan 1, 2008

By Shuguang L, Jing S

Computer controlled truck dispatching systems is a newly-developed technical system in surface mines with shovel-truck technology. The real time dispatching criteria, as the core of optimal truck dispatching software, are analysed and a new criterion, complex dispatching criterion, is put forward. Dispatching criteria previously proposed include: 1. `Earliest Loading' (EL) - to assign a truck to the shovel at which the truck can be loaded earliest. 2. `Max Truck' (MT) - to assign a truck to the shovel at which the truck will have the shortest waiting time. 3. `Max Shovel' (MS) - to assign a truck to the shovel which has been waiting for the longest time. 4. `Minimum Saturation Degree' (MSD) - to assign a truck to the shovel at the branch where the truck flow saturation degree is minimum. 5. `Minimum Saturation Degree with Truck Cycle time consideration' (MSDTC) - as the MSD principle, with the truck travel cycle also considered. 6. `Fixed Dispatching' (FIX) - to assign trucks to fixed shovels. A system simulation model has been set up for truck dispatching system analysis. A few surface coal mines have been selected for case studies. Equipment waiting times and shift production of the system are obtained as the main outputs of the model. Simulation results show that each dispatching criterion has its own applicable range, no one can absolutely dominate the others. For example, when under-trucked, EL and MT criterion can obtain higher production than the MS criterion; when over-trucked, it is vice versa; while for MSD criteria, better results can be obtained no matter how the truck numbers fluctuate. From the view point of shovel output balance, large fluctuations occur for EL and MT criteria, while a good balance can be obtained for other criteria. In the light of dynamic change of mining system conditions, a single dispatching criterion is not necessarily reasonable. A complex dispatching criterion has been put forward to seek the complex optimum effect. Taking the advantage of each dispatching criteria, the dispatching result of a complex dispatching criterion dominates over individual dispatching criterion and a comprehensive optimum effect can be reached.

Jan 1, 1995

By Hannan JC

Consent to develop and operate a new coal mine in New South Wales (NSW) will be conditional upon a number of environmental controls. In NSW, applications for any new major development associated with coal mining are determined by the Minister for Planning and Environment. The environ- mental conditions placed on the development consent, the coal mining lease and the approvals, and licences under the pollution control legislation amount to a substantial component of any new project's commissioning considerations. The nature, scale and location of projects and the principles of pollution control on which conditions of State Pollution Control Commission (SPCC) approvals are based have a considerable influence on project planning. The design, construction and operation of coal mines in NSW has been progressively modified over the past 15 years, to incorporate increasingly stringent requirements for environmental management. These requirements are in turn, a reflection of a greater community demand for environmental protection.

Jan 1, 1986

By J Cook, S Pike, D Pridmore

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The application of high-resolution seismic reflection to map structure and/or mineralisation in hard rock environments has progressed significantly in the last decade. Improvements in equipment, field practice, processing and understanding has seen the seismic reflection technique emerge as a cost-effective tool for high-resolution three-dimensional structural and lithology mapping to depths far greater and with superior accuracy than other more conventional geophysical techniques.This paper outlines results and preliminary interpretation of 2D and 3D seismic reflection surveys aimed at defining fault zones and locations for quartz load development in favourable host lithologies at the Cracow low-sulfidation epithermal gold system in Queensland, Australia.As this is possibly the first time that high-resolution seismic reflection data has been used to define the structurally-controlled location of low-sulfidation epithermal gold mineralisation, an important aspect of this work was the derisking or due diligence steps taken prior to commissioning the full 3D surveys at each site. This included full wave sonic logging, vertical seismic profiling and trial 2D lines. Interpretation of the 2D profiles and the drilling of interpreted structure provided the confidence to proceed with the full 3D survey.The advantage of collecting 3D data extends beyond ensuring that the received reflections are located correctly in 3D space. The final 3D data cube can potentially map the entire fault network, thus highlighting flexures and changes in orientation of the structures both vertically and along strike, which is an important aspect in the deposition of gold and for direct targeting.CITATION:Smith, R, Cook, J, Pike, S and Pridmore, D, 2015. Application of high-resolution seismic reflection surveys to exploration for blind vein systems at the Cracow low-sulfidation epithermal field, in Proceedings PACRIM 2015 Congress, pp 77–84 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By N Patel, S Narendranathan, T Mok, J Lowe

The Hazelwood Mine (HM) commenced operations in the 1950s and was originally operated by the State Electricity Commission of Victoria (SECV) prior to it becoming privatised. ENGIE, the current owners of the Hazelwood Mine ceased operations in 2017 and have since transitioned the site into the rehabilitation and closure phase, which is to encompass a full pit lake as part of the final landform. A key aspect of HM closure is the maintenance of long-term stability of the pit slopes to deliver a final landform which is safe and sustainable, particularly given its proximity to critical public receptors. The Princes Freeway, which is the primary access route to the Latrobe Valley (LV), and the Morwell Township are both located immediately to the north of the HM. With due consideration of the mine void and nearby public receptors, the authors performed slope stability assessments of critical mine

Aug 2, 2023

'Industrial Minerals - their mining and use in New Zealand' is the theme of the 1978 Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy. This paper describes the use of phosphate rock, sulphur and potassium chloride (potash) - three industrial minerals which have enabled the farmers of New Zealand to increase production to current levels. The growth of imports of these raw materials for the New Zealand fertiliser industry is well documented in NZ Fertiliser Statistics 1977. This is the most recent of the Ministry of Agriculture and Fisheries annual publications on this Subject prepared from the detailed returns of fertiliser manufacture and sales from each fertiliser works. There are now 12 of these works in New Zealand one of the most recently established being in Whangarie where this conference is being held. Its capacity to manufacture superphosphate will shortly be 300 000 tonnes twice that when it opened late in 1964. New grinding and manufacturing equipment comes on stream early in 1979. This paper illustrates the interdependence of two primary industries, agriculture and mining. New Zealand's economy in the foreseeable future will be based on agriculture so that our standard of living is dependent on the overseas prices and freight costs of the bulk raw materials from which our fertilisers are made. For the year ended 31 March 1978 New Zealand's total exports were $3395 million, of this total $2413 million (71%) came from the products of pastoral agriculture (wheat, wool, dairy and other animal products), $291 million from forest products and $501 (15%) from manufactured exports. Approximately half of the pastoral receipts can be attributed to the fertilisers applied at a total cost of about $200 million including subsidy.

Jan 1, 1978

By M Olsson, I Bergqvist

A Swedish table of blast damage depths has, in one form or other, been in use since the late-1970s. Its history and the underlying theory are described. New experimental and theoretical findings that point out a number of shortcomings in the table and the underlying theory are presented and discussed. A revised version of the blast damage table was recently introduced in conjunction with new but incomplete recommendations for cautious perimeter blasting. The new table leaves the difficult task of taking into account factors like decoupling, water in the borehole, the rock properties, type of initiation, charge length and the actual bit diameter to the user. This paper discusses different ways of doing this, based on the experimental findings and a recent formula for the prediction of the lengths of radial cracks behind the half-casts. The material presented in this paper is meant to supplement and extend the new Swedish recommendations for cautious perimeter blasting of tunnels, shafts, pits and road cuts.

Jan 1, 2001

By Umetsu Y, Su Qing-quan

The electrical conductivity of electrolytes is very important in metal electrowinning and electrorefining processes as it has a very large influence on the energy consumption. There are few measurements of the electrical conductivity of zinc electrowinning electrolytes available. The electrical conductivity of zinc electrowinning electrolytes were measured over the following range of concentrations, 100 to 200 g/L H2SO4, 0 to 80 g/L Zn and 0 to 20 g/L Mg, at temperatures from 25 to 60 C. The specific conductivity of zinc electrowinning electrolytes may be expressed as a function of concentrations of sulphuric acid, zinc and magnesium and temperature by the following equation: k(S/cm) = 0.004 + 0.00115 t + 0.00282 [H2SO4] t - 0.00114 [M] t + 0.3442 [H2SO4] - 0.0451 [1-12SO4]2 - 0.1058 [M]ò[H2SO4] - 0.0224 (M] + 0.0286 [M] 2 where t is temperature (C), [H2S04](moI/L) is sulphuric acid concentration and [M](mol/L) is a sum of zinc and magnesium concentrations, ([Zn]+[Mg]). The specific conductivity of zinc electrolytes is a function of the concentrations of the hydrogen ion and free water molecule, which are calculated by taking into account the second ionisation constant of sulphuric acid and the stability- constants of zinc-sulphate and magnesium-sulphate complexes at 25 C.

Jan 1, 1993

By E Villaescusa, A Kusui, R Talebi, R Hassell, C Arcaro

Northern Star Resources (NSR) operates several seismically active mines as part of its Kalgoorlie Operations. In order to successfully continue mining at depth in increasing stress conditions, strategies need to be developed to reduce, control and manage the impact of seismicity causing damage to the rock mass. Consequently, a research partnership was developed with the WA School of Mines (WASM) through Mining3. The main aim of the project was to develop appropriate ground support standards that could withstand the expected dynamic response with minimal to no rehabilitation required for the life of that excavation. The project utilised a design methodology for determining the required energy demand based on detailed geotechnical mapping, probabilistic analysis of wedge formation and an estimate of rock ejection velocity based on uniaxial compressive strength of the intact rock (Villaescusa et al. 2016). The ground support scheme consists of high tensile chain link mesh, resin encapsulated de-coupled posimix bolts and plain strand cable bolts, in one, or multiple passes together with plain shotcrete. Implementation of the design posed several challenges including how to install the chain link mesh, maintaining the required productivity, ensuring quality control, and understanding the interaction of the several ground support components within the scheme. The implementation of the system within a trial area was successful from development mining to open stope extraction. The most significant field verification of the system occurred with near field M+1.9 seismic occurring in proximity to an operating long-hole drill. Despite large displacements exceeding 0.5m in places, there was no significant ejection of rock or failure of the ground support system. Following the successful trial, the ground support design methodology and standards have been implemented across several NSR sites. The system forms the basis for the successful extraction of resources in future high seismic risk areas.

Mar 15, 2021

By Heape JM

Production from the Cattle Grid orebody commenced in August, 1974. This followed a recent discovery arising from an extensive exploration programme involving stratigraphic drilling, geochemistry and geophysics. Located some 4 km west of the original copper occurrences at Pernatty Lagoon the discovery was found to contain 4.6 million tonnes of ore averaging 2.4% copper. The ore is a "sandstone copper" type localised near the disconformity between two Precambrian (Adelaidean) stratigraphic units, the Pandurra Formation and the Whyalla Sandstone. The mineralisation roughly follows the interface between these units and occurs in fractures, vugs and along bedding planes. The mineralogical character of the ore is somewhat complex consisting of chalcocite and bornite, with associated chalcopyrite, sphalerite, pyrite and other less common sulphides. 1. Senior Geologist, Pacminex Pty. Limited, Sydney, N.S.W. 2. Mine Geologist, for Mt. Gunson Mines, Pacminex Pty. Limited, Mt. Gunson, S.A.

Jan 1, 1975

By J Coombes

There is much debate on the Competent Persons qualifying criteria for providing classified resource estimates for public reporting. The CRIRSCO family of codes including the JORC Code, SAMREC, PERC and NI43–101, require Competent Persons to have at least five years ‘relevant’ experience and belong to professional bodies. These codes provide further, albeit vague, guidelines to assist individuals with their personal decision to take on the mantle of ‘Competent Person’. There is a risk, however, that these qualifying criteria can result in ill-prepared Competent Persons whose actions and recommendations would undermine their own reputation and that of the organisations that employ them; the integrity of the profession and the principles based reporting systems; as well as the stability of stock markets that rely on these estimates.Based on doctoral study on the development of professional competency within the mining industry, this paper presents an evaluation of the suitability of the current qualifying criteria as well as an analysis of alternative criteria. The research included a series of interviews with industry experts and an online survey of resource geologists. Semi-structured interviews provided a sense of experts’ expectations and interpretation of the current definition of ‘Competent Person’. The comprehensive online survey included a self-assessment, a series of situational questions designed to evaluate responses to typical resource geology scenarios and a set of open-ended questions relating to factors contributing to competency development.A summary of the data analysis, interpretation of the results and a set of recommendations for revised ‘Competent Person’ qualifying criteria are presented. This paper contributes to the conversation on what makes a person suitably qualified to report classified resource estimates and provides practical targets that can be used in the professional development of resource geologists.CITATION:Coombes, J, 2014. Redefining Competent Persons criteria for resource geologists, in Proceedings Ninth International Mining Geology Conference 2014 , pp 153–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By R Bose, M Bovell, G Cheong

Grinding media is a major consumable in mineral processing and therefore decreasing costs associated with its consumption is regularly considered a key goal for the minerals processing industry. Grinding media manufacturers have historically developed steels with improved wear life for their products as a way of delivering incremental media quality improvement. This has included increasing carbon levels from low-to-medium carbon steels up to the eutectoid carbon composition of 0.77% where the relationship between higher carbon and better wear performance is well understood. Producers today will regularly use grades in excess of 0.8% to further improve wear performance particularly for rolled grinding media.This paper first introduces the demonstrated relationship between this increased carbon content and improved wear resistance along with metallurgical rationale behind the high carbon production process and limitations. To test the performance improvement associated with the higher carbon steel grade, a series of Marked Ball Wear Tests (MBWT) were carried out. This paper also explores the relationship between ball properties, test methodology and wear performance and concludes by correlating increased carbon grade with a reduced consumption rate of between 3.1% and 6.1% in the tests conducted.CITATION:Bovell, M, Bose, R and Cheong, G, 2018. Improved forged grinding media performance with carbon content greater than 1.0%, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 559–570 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

The theme at this yearÆs AusIMM New Leaders Conference in Ballarat was æThe Minerals Industry û Future Directions for New LeadersÆ. There was a strong focus on the recruitment and retention of trained and skilled graduates and new professionals into the mining profession. This paper highlights some of the key findings and discussion points from the New Leaders Conference. While some of the main causes of the decline in attracting new geoscientists to the mining industry have been identified, there still remains a lack of accountability among a number of Australian mining companies. Some of the factors identified that are driving new graduates away from the industry include; the social and geographical isolation, the long hours in challenging conditions and a difficulty in obtaining work straight out of University. Often there appears to be no clear opportunities within companies for career development and advancement. The opinion also still persists that the mining industry is lagging behind in both environmental and technical developments, which makes entry to the industry unattractive. Solutions that some of the large players in the Australian mining industry are implementing to help reverse the trend include targeted marketing of the lifestyle, money, freedom and travel offered in the mining industry, the development of graduate recruitment programmes and much more emphasis on the quality and reputation of the companies themselves. Incentives to attract families have also been significant in attracting and retaining employees whom otherwise would have left the workforce. However, more still needs to be done to completely reverse this trend and the mining industry needs to continue to be proactive in marketing itself as a desirable employer and career choice option for students and new professionals.

Jan 1, 2004

The Nickel Rim Depth Cu-Ni-PGE deposit, discovered by Falconbridge Limited in 1993, illustrates several trends in exploration in the Sudbury area. Recent discoveries tend to be deep, high grade, footwall hosted, close to or straddle property boundaries and made using a multi-disciplinarian exploration approach that integrates economic considerations with geology, metal geochemistry and geophysics (borehole EM). The Nickel Rim deposit occurs down dip of Inco's Victor Deep deposit (4.2 million tonnes at 2.25 per cent Ni, 7.30 per cent Cu) in the eastern margin of the Sudbury Igneous Complex (SIC) at a depth of 2650 m. Before commencing drilling an economic evaluation was done to determine the minimum size needed to be economic at the expected depths and determine the expected value of an exploration venture. The subsequent surface exploration program discovered a drill indicated, undiluted mineral inventory of 1.6 million tonnes of 1.58 per cent Ni, 10.13 per cent Cu, 4.17g/t Pt and 3.50 g/t Pd including 519 000 tonnes of 4.13 per cent Ni, 25.53 per cent Cu, 9.76 g/t Pt and 8.42 g/t Pd. The deposit is hosted by gneiss, migmatite, gabbro and pseudotachylite (Sudbury Breccia) 100 m below the base of the SIC.

Jan 1, 1996

By P Ramsaywok

The use of saline water for mineral beneficiation in arid regions is general practice and also the case with Exxaro Namakwa Sands, situated on the west coast of South Africa. Although it is ‘cost effective’ to use sea water for mineral beneficiation, downstream process separation efficiencies may be negatively affected. This is more specific to surface dependent separation techniques such as electrostatic and high tension (HT) separation. If minimal fresh water is available then, proper washing is often neglected. Salt crystals can form on particle surfaces during the drying process before electrostatic separation.This paper describes a study that has been conducted to determine the effect of upfront salt water processing on downstream electrostatic/HT separation. The study indicated that minor quantities of salt can cause the separation efficiency to decrease substantially.

Oct 5, 2011

By J N. Farrell

Metallurgists frequently use a small number of large samples to characterise expected mill performance, with the a priori assumption that these few samples are representative of the entire deposit. Geometallurgical sampling is becoming more prevalent as a way to use many smaller samples to indicate the expected recovery as part of the Mineral Resource or Ore Reserve estimation.Recent increases in prices for iron ore, together with the potential to produce high iron and low contaminant concentrates, have resulted in a renewed interest in recovering magnetite from banded iron formation and other deposits.Geometallurgical evaluation of magnetite involves approaches to sample preparation, sample analysis and resource estimation that are different from the methods commonly used for haematite iron ore. The magnetite sampling protocol is specific to each deposit, and is typically designed around a specific metallurgical flow sheet.The sampling protocol will typically include the use of Davis Tube analysis. The Davis Tube is a bench-scale test that is used for determining the mass magnetic recovery from a small amount of sample ground to a specific size. The magnetic concentrate may then be analysed and together with the mass magnetic recovery, may be used to simulate the expected mill recovery.During resource modelling, the mass magnetic recoveries and concentrate grades may be assigned to a block model using regressions with other chemical constituents, or may be estimated directly. For estimation of the concentrate grades, a weighting can be applied to account for the different mass magnetic recoveries from each sample and the impact of these differences on the concentrate estimates.This paper presents an overview of the use of metallurgical test data in resource evaluation for magnetite deposits.

Jul 11, 2011