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By K Ehrig

You are a geologist, geometallurgist, or metallurgist/process engineer and are fortunate enough to work for an organisation who asks you to design/execute a geometallurgy program. What seems like a simple request is actually not a trivial exercise. æRecipeÆ style manuals are not readily available. However, many æexpertsÆ are lurking around willing to deliver solutions which will solve all of your problems. Even though similar ore deposit styles (e.g. porphyry Cu, IOCG, Ni-laterites, calcrete hosted U, etc.) have many similar characteristics, each ore deposit is unique. Hence your geometallurgy program needs to be æfit-for-purposeÆ. This paper offers some insights gained via designing and executing geometallurgy programs from exploration through to production, and working at a mine where you are held accountable for your metallurgical performance predictors.CITATION:Ehrig, K, 2013. Geometallurgy - What do you really need to know from exploration through to production?, in Proceedings MetPlant 2013 , pp 28-33 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By I. Dymov

"The extractive metallurgy of precious metal ores involves gravity concentration, flotation and cyanide leaching. Pre-oxidation, such as roasting, autoclaving, bacterial oxidation and other techniques, is required for processing refractory ores. Selection of the process is mainly driven by the grade, reserve and mineralogy of the target elements. The concentrations of precious metals in the crust are extremely low and highly variable, resulting in ore variability in many gold, silver and PGE deposits. More importantly, precious metals in an ore may occur in two or three forms (i.e. microscopic, submicroscopic and surface-bound), making ore processing of precious metals extremely challenging. The objective of geometallurgy and process mineralogy is to reduce and minimize the technical risk in project evaluation, process selection, mine planning and production forecasting through geometallurgical modelling, representative sampling and subsequent systematic mineralogical characterization and metallurgical testwork. Geometallurgy is a technique to document variability within an orebody and quantify and evaluate the impact of many factors including geology and mineralogy on grinding, flotation, leaching and metal recovery processes, while mineralogy is one of the major predictive and trouble-shooting tools for many new mineral projects and operating mines. This paper presents an overview of fundamentals, methodologies and techniques applied in geometallurgy and process mineralogy and highlights the importance of both disciplines in process selection and plant optimization with applicable case studies. INTRODUCTION Precious metals, including gold, silver and platinum group elements (PGE) occur in various geological settings and ore types. The concentrations of these metals in the crust are extremely low and highly variable, resulting in ore variability in many gold, silver and PGE deposits. More importantly, precious metals in an ore may occur in two or three forms (i.e. microscopic, submicroscopic and surface-bound), making ore processing of precious metals extremely challenging. Process selection is most important in any precious metals project and is mainly driven by the grade, reserve and mineralogy of the target elements. Free-milling ores, such as Kupol in Russia, Hemlo in Canada, Grasburg in Indonesia, UG-2 in South Africa, Lac des Iles in Canada, and Noril’sk in Russia, can be processed using flotation or cyanidation with or without gravity. B2Gold Corp, a Canadian gold company, just started a number of new and under construction free-milling gold operations such as Fekola mill in Mali, Mastbati mine in Philippins and Otjikoto mine in Nambia. However, refractory ores (particularly gold ores), such as the Carlin and Goldstrike mines in the USA, Giant in Canada, Pueblo Viejo in Dominican Republic, Porgera and Lihire in PNG, Kittilla in Finland, Fairview in South Africa and Shuiyindong in China, must be processed using pre-oxidation prior to cyanide leaching. In some mildly refractory gold ores, such as Kumtor mine in Kyrgyzstan and KCGM in Australia, ultrafine grinding is required to liberate fine-grained gold particles. For some gold ores containing both free-milling and refractory components (such as Cripple Creek mine in Colorado, USA), two or more recovery processes may be required. The variability of grade, metal deportment, ore hardness and other parameters is one of the risks that encountered in development and operation of many precious metals projects. To minimize and reduce the technical risk caused by ore variability, geometallurgy and process mineralogy have been used by mining companies in the last two decades to measure and quantify the spatial variability of the deposits that are being developed. This paper presents an overview of fundamentals, methodologies and techniques applied in geometallurgy and process mineralogy, it highlights the importance of both disciplines in process selection and plant optimizat"

Jan 1, 2018

By J D. Lubben

Hibbing Taconite is a Lake Superior-type granular magnetite taconite deposit occurring within the Biwabik Iron Formation along Minnesota’s central Mesabi Iron Range. The deposit is situated on the northern margin of the Proterozoic Animikie Basin. The deposit strikes northeast, dips gently southeast, and occupies 10 km of strike length. Mining focuses on 50 m of granular cherty and laminated slaty taconite within the Lower Cherty member.Ores generally consist of a quartz, magnetite, siderite, ankerite, minnesotaite, stilpnomelane, and haematite mineral assemblage. Processing is optimised by exploiting the physical and chemical variations that exist between three major ore types. Taconite ore averages 20 per cent magnetic iron (MagFe), 27 per cent weight recovery (WtRec) and produces a final concentrate with 4.5 per cent silica (SiO2). Since 1976, production has totalled approximately 237 million long tons (Mlt) of pellets (8 Mlt per year rated capacity).Ore processing uses a simple fl ow sheet of autogenous grinding (<0.044 mm) followed by two phases of wet magnetic separation, fi ltering, limestone/bentonite addition, balling, and firing to create pellets averaging 66 per cent total iron. A Liberation Index (LIS) is used as a primary guide for ore grading and metallurgical control. Grind requirements, magnetite liberation and silica grade are closely monitored to ensure plant optimisation and product quality.A recent program of benefi ciation of low-grade ores by in-pit crushing and dry magnetic cobbing has demonstrated that low-grade ores (<17 per cent MagFe, <25 per cent WtRec) can achieve a signifi cant metallurgical upgrade (up to 25 per cent MagFe and 40 per cent WtRec). This operation recovers 60 per cent of the total crushed volume, and has a calculated effi ciency factor (magnetic iron recovery) of 79 per cent. This paper discusses the benefi ts of this upgrading and its effects on ore blending and processing.

Jul 11, 2011

By D Lozada, A Salazar

Geometallurgy is a tool that, for more than a century, has been present in the implicit operations of mineral beneficiation. There’s a need to understand the characteristics of the material to be processed. This has led metallurgists to ask geologists what type of rock and mineralogy is entering the Beneficiation Plant and vice versa. The geologist needs to understand the beneficiation process in order to be able to carry out the production programming. The paradigm is whether geometallurgy can be applied to small-scale mining or if it is only aimed at large companies that invest millions of dollars to conduct studies. With this work, we provide an example of how geometallurgy can help improve the processes of a small mining company located in Ecuador (South America). We performed characterizations of geological and mineralogical and metallurgical tests in universities and the National Research Institute of Geological Metallurgical Mining. The origin of the theme is based on the fact that gold has been detected in the final tailings. The flotation concentrates meet the standards in terms of the content of economically profitable metals, but this isn’t the case with regards to the percentage of arsenic, which has hindered sales. The hypothesis is: conducting technical and scientific research will optimize the metallurgical process for the recovery of gold and concentrates. The referential framework is the mining geology of the Bella Rica District, current status of the Beneficiation Plant. In the theoretical framework there are parameters of the veins, comminution operations, gravimetric concentration, flotation, and cyanidation. The methodological framework contemplates the characterization of the gold ore, the chemical, mineralogical, textural, metallurgical analysis and the interpretation of the results. Thus, the design of a geometallurgy model of the deposit, with its main characteristics, is a conclusion that serves as a basis for the proposal of the optimization of the metallurgical process.CITATION:Lozada, D and Salazar, A, 2018. Geometallurgy applied to small-scale mining: a case study, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 153–162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Kari Niiranen, Andreas Fredriksson

LKAB (Luossavaara-Kiirunavaara AB) is operating iron ore mines, concentration plants and pelletizing plants in Northern Sweden. Geometallurgy, which combines geological and metallurgical information is not a new way of thinking at LKAB, but rather a revised and updated version of an old working process. A project called "Silica in the Mine" which started in 2007, was an important reason to set a new focus at the geometallurgy. The target of the project was to develop a simplified method in laboratory scale to predict SiO2 grade in the magnetite concentrate in Kiruna and further predict the physical properties of the crude ore with respect to processing characteristics. The connection between mineralogy and products properties have started to be even more vital and necessary to examine due to the future exploiting new iron ore deposits. Geometallurgy at LKAB can be described as a mental and strategic framework where the Research and Development department (R&D), and others within the organization of LKAB, aims towards the connection of the minerals-production-products. It could in its basics be called "research & development", but it must be clarified that changes have been made, mainly due to the development on the instrumental analysis side. LKAB’s idea is to work quite broad, with internal educations, an active working process in ongoing projects, together with external parties (such as universities), with several PhD-projects and an upgrading on the instrumental side at the LKAB Research & Development department. This paper is a summary about the concept Geometallurgy at LKAB and some of the actions within its framework.

Jan 1, 2014

By C M. W Boyle, E K. C Phuak, A Lewan, E Ryan, M D. Paine, P H. Mackenzie

"Rio Tinto Iron Ore (RTIO) has an extensive history in the application of geometallurgy to the iron ore value chain. Fundamental to this has been the geological logging of material types which are assigned processing attributes such as lump per cent and density. Initially these were used for product (lump and fines) grade predictions in relation to grade blocks to be used within short-term planning horizons.More recently the predictive reach of the material types and their associated processing attributes has been extended due to their inclusion into geological block models. These predictions can now be used to influence mine plans across multiple planning horizons in such a way that the extremes of geometallurgical properties can be pre-empted and managed thus improving efficiency. Spatial material type domains are also used in the planning of metallurgical drill holes to ensure greater representivity of material than was typically obtained by chemical and/or stratigraphic criteria alone.Material type logging has also been enhanced by the introduction of modern, rapid mineralogical techniques that have complemented visual logging. This has enabled the identification and quantification of contaminant minerals and their relationships with host ore types to be established. This data is used to better manage product grade predictions and identify risks to the short-term plan.Work is ongoing in RTIO to further refine logging based predictions and in addition apply them to new areas of the business. This work requires collaborative and multidisciplinary teams working on an integrated approach combining geology, metallurgy, technology and innovation, mine planning and technical marketing.CITATION:Paine, M D, Boyle, C M W, Lewan, A, Phuak, E K C, Mackenzie, P H and Ryan, E, 2016. Geometallurgy at Rio Tinto Iron Ore – a New Angle on an Old Concept, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 55–62 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By V Liebezeit

Data management is a significant, but perhaps unrecognised, consideration for any organisation embarking on a geometallurgy program. While resource geologists are accustomed to dealing with thousands or millions of samples and their associated assays, metallurgists and mineralogists have traditionally carried out only a few expensive and complicated tests and consequently tend to manage the resultant data in spreadsheets. The emerging discipline of geometallurgy arrives with significant challenges as a result of the sheer volume of data generated. As an example, the Olympic Dam geometallurgy program has generated more than:60 000 physical subsamples analysed for up to 30 analytes; 25 000 spreadsheet-based laboratory test results; 30 000 sized fractions analysed via QXRD, MLA and/or QEMSCAN;multiple external providers of data, and more than seven terabytes of data. Considerations for any geometallurgy data management system include storage space, data integrity, accessibility, traceability (sample provenance), maintenance and ease of use, integration with data providers and the ability to modify the system to adapt to changing requirements. Further, aspects of a geometallurgy program, such as conducting a range of tests on one sample, producing subsamples such as concentrates and tailings, compositing and routine QA/QC may not be well handled by existing software and providers geared to standard geochemistry, mineralogy or metallurgical test programs. The development of a geometallurgy database using existing software (AcQuire), and the associated file management system will be described for a large geometallurgy program at Olympic Dam. As with many aspects of geometallurgy there is no approach that meets the needs of every site or program. Recognition of data management as an issue, a structured approach in the program planning phase and commitment to executing the strategy will increase the chances of successfully mining the geometallurgical data.

Sep 5, 2011

Cripple Creek and Victor Gold Mine is an epithermal gold deposit located in the Rocky Mountains of Colorado. Surface operations are continuing along with an expansion for an onsite mill to take place in the next couple of years. The surface pit is currently progressing downward from an oxidized zone into a transitional, more sulfide/ telluride-rich zone. Gold mineralization includes native gold, electrum, and tellurides. Cyanide heap leaching is the recovery process for the oxidized ore with the sulfide/telluride-rich ore to be processed at the new onsite mill. Ore characterization prior to mining is vital when there are two possible recovery processes. This characterization is dependent on geometallurgy. To identify the causes of the variability, multiple parameters are analyzed and assayed. These parameters are measured by a variety of analytical testwork. The analytical testwork provides measurements for the desired parameters. Geometallurgical models are developed for the parameters per recovery process, so estimations can be inserted into the resource model to optimize operations and recoveries.

Feb 27, 2013

By Stacey Leichliter

The Cripple Creek and Victor (CC&V) Gold Mine (Cresson Project) (Fig. 1) is undergoing an expansion to extend production to the year 2025. This expansion involves building a high-grade ore mill, another valley leach facility (VLF) for heap leach operations and expanding the overburden storage areas. The current operating pits are progressing downward from the oxide ore into a more sulfide and telluride-rich orebody. There is still oxide ore present in the current pits and planned pits not yet mined. There is an increased need for two recovery processes for these two different types of ore. The key component to this expansion is the high-grade ore mill, which has gravity, flotation and carbon-in-pulp (CIP) circuits. The mill will be the main recovery process for the higher grade, more sulfide/telluride-rich ore. This ore type does not recover well on the heap leach pad due to its refractory nature. Geometallurgy is vital for ore characterization for the two recovery methods. Geometallurgy helps develop indices that are used to predict parameters that influence overall recovery and production, such as hardness, crushability, grindability, pH fluctuations, gravity (coarse) gold, flotability and cyanidability. Using geology and mineralogy along with other analytical data, geometallurgical models are constructed and applied to the resource block model for proper planning and extraction of the gold. Geometallurgy aims to analyze the variability in the different responses to the parameters to help reduce risk (costs) and optimize recovery (profit).

Jan 1, 2013

By G Williams

Somewhat to the surprise of many heavy mineral sands (TiO2 and zircon) producers, there are important geological structures within their typical placers and aeolian sands deposits that affect plant metallurgical performance. After many years of operations, even experienced producers have encountered unexpected changes in production, product quality and recovery. After looking in all the obvious (but wrong) places, it is recognised that the mine has advanced into ore with different separation characteristics. Metallurgical process response can vary significantly between ore sourced from different geological domains. The mineral characteristics that are exploited for effective separation may be associated with differences in the depositional environment, or be post-depositional in origin. Surface coatings that interfere with electrostatic separation might be associated with paleo-water table movements. Major storm events in the deposition history can also leave distorted mineral assemblage through stranded formations or incisions in older deposits.Apart from the influence on capital and operating costs, geometallurgical variances add another dimension to orebody modelling. Each domain could have specific recovery, mineral assemblage and product quality values to be considered in the value model. Project success is often directly dependent on understanding the geometallurgy of the resource. Tailoring the exploration and early process flow sheet development programs to account for such variances should be standard practice. Such practices have had a chequered history in the mineral sands industry, with sophisticated processes having been developed, only to be shelved for ‘economic’ reasons, and then once again ‘discovered’ when problems re-emerge.It is clear that knowledge gained through a higher level understanding of the changing mineral separation characteristics and advance warning of mineral behavioural differences can mean the difference between lost recoveries and disappointed customers or well timed capital plans and maximised revenues.

Oct 5, 2011

By J Jackson

The term geometallurgy (or geometallurgical) first appeared in the literature some 40 years ago and has a wide range of definitions and perspectives which increases the barriers of communication between practitioners and across functional groups and management levels within organisations. However the consistent theme running through the diversity of definitions and perspectives is the requirement for close collaboration between the relevant disciplines. This concept of geometallurgy arguably goes back to the earliest days of the exploitation of mineral deposits, through the mid-1500s to the beginning of the 20th century.This holistic and integrated view was diminished during the 20th century due to a number of factors which included the commencement and continuing upward trend of large-scale mining and the expansion in production, the rise of scientific and classical management theories and methodologies, increase in specialisation and the development of traditional project planning. The re-emergence of geometallurgy in the late 20th century required the relevant functional units and disciplines to collaborate as a team. This necessitates a common understanding that the geometallurgical program’s goals must be obtained, which requires clear and consistent communication, particularly with the modern trend of virtual teams.A multi-dimensional construct is proposed to assist in providing a consistent approach in the communication of the context and purpose of both general and specific geometallurgical programs, thus simplifying communication. This geometallurgical construct consists of the dimensions of process span, response knowledge, variability knowledge, spatial knowledge, application and project phase in relation to extraction process(es) applied to geological materials from a mineral deposit. These dimensions are then linked to the phase of mineral project development in which the geometallurgical program is being applied, which ranges from advanced exploration through to operational execution. This paper outlines the multi-dimensional construct with examples of how the context, purpose and scope of geometallurgical programs can be clearly delineated and communicated.

Sep 5, 2011

By L O’Connor, S C. Dominy

"Geometallurgy is an important addition to any evaluation project or mining operation. As a discipline, it seeks to maximise the net present value (NPV) of an orebody while minimising technical and operational risk. It also aims to promote sustainable development and initiatives by ensuring that all stages of extraction are performed in an optimal manner from a technical, environmental and social perspective. To achieve these goals, development of innovative technologies and approaches along the entire commodity value chain are being established (Glass, 2016). Geometallurgy has been shown to increase operational stakeholder collaboration, creating an environment for knowledge sharing and improved data acquisition and interrogation, with the end result being the integration of such data into mine planning and scheduling. All of these aspects create better business optimisation, utilisation of staff and targeted and realistic key performance indicators.The mining industry faces numerous challenges including, but not limited to:declining ore gradesgeometrically and/or internally more complex depositsdeep-seated deposits, with potentially high in situ stress regimesincreasing quantities of mine waste that needs to be managed appropriatelyhigher energy, water and chemical costsprocessing of more challenging and refractory ores – textural complexitiesstricter environmental/permitting conditions – so-called ‘licence to mine’increasing demand for specialist metals (eg rare earth elements, In, Ge, Te, Rh, Se, Ga and Li)commodity market volatilitya difficult funding environment.Given these challenges, geometallurgy provides the opportunity to control or at least manage some of them.CITATION:Dominy, S C and O’Connor, L, 2016. Geometallurgy – Beyond Conception, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By S Robinson, A Turner, R Dale, C Butler

"Sandfire Resources NL- (‘Sandfire’) DeGrussa definitive feasibility study (DFS) identified geometallurgy as a major factor in achieving optimum plant performance at the DeGrussa mine. A geometallurgical initiative was created to proactively investigate this issue, and a key initial achievement was the 2013 paper by Condon et al (2013) on developing a working geometallurgical model from first principles. Significant advancements in Sandfire’s geometallurgical understanding since that publication now shape how information is presented and communicated.The main geometallurgical parameters so far identified as critical factors affecting plant performance are Cu:S ratio, iron sulfide mineralogy, talc carbonate content and sphalerite content. Apart from specific mill strategies, geometallurgical issues have been managed through communication between departments and strategic run-of-mine (ROM) pad management.This paper uses the current theories of geological evolution of the volcanogenic massive sulfide (VMS) deposit at DeGrussa, to discuss the variability between the orebodies C1, DeGrussa (sea floor mounds) and C4, C5 (sub-sea floor replacement) to highlight the different issues each orebody is expected to encounter when processing.A zone of altered low-grade mineralisation surrounds the main orebodies at DeGrussa, referred to as a halo. Talc minerals are often patchy within this halo and often cause significant recovery issues during processing. This halo has been successfully modelled using MgO as a proxy. The ability to model the talc material assists with both identifying potentially problematic zones for processing and geological interpretation of the ore deposits evolution.Early in geometallurgy studies at DeGrussa it became apparent that it would be useful to identify processing performance prior to mining. This necessitated the incorporation of specific sulfide species into the mining block model. These attributes are interpolated from the logged sulfide estimates allowing a clear picture of the abundance of each mineral type within a defined area.In conjunction with the block model a geometallurgical factor (GMF) graph was developed, identifying sulfide mineralogy based upon mineral assays. These two recent additions to the model provide a clear picture of the nature of the ore sources that will be presented to the processing plant.The future of geometallurgy at DeGrussa will see these tools used to aid mine scheduling with a view to further improve processing recoveries.CITATION:Butler, C, Dale, R, Robinson, S and Turner, A, 2016. Geometallurgy – Bridging the Gap between Mine and Mill: a Case Study of the DeGrussa Geometallurgy Program, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 77–88 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By J Beniscelli

Some words to honour Pedro:Pedro was among the few persons with a very high level in geology modelling, resource and reserve estimation, geometallurgy development, sampling theory applications and a deep understanding of the mining industry needs. He had brilliant ideas about new developments on economic geology. He was always looking at the long-term and proposed challenging questions a decade in advance on their solution.The fundamental aim of geometallurgy is to add economic value to the mining of mine resources by timely providing information and knowledge about the relevant metallurgical variables represented by their space models. In this manner, geometallurgy allows obtaining the optimal design of a project, mitigating processing risks, optimising and supporting production plans and identifying and assessing mining business opportunities.This paper describes the conceptual framework and geometallurgical definitions and some of Codelco’s experience during the last 15 years.

Sep 5, 2011

By J Vann

The key functions of project evaluation are to assess potential profitability and to develop an effective operational design. For mining projects, design aspects include mining methodology, ore treatment methodology and production rates. All of these characteristics impact on project economics and overall value. Resource models, which form the ultimate basis of project evaluation, typically consist of tonnes above cut-off, grade above cut-off and the spatial distribution (connectivity) of tonnes/grade above cut-off, for one or more variables. Dilution, ore loss and metallurgical recovery are all modifying factors applied to the resource model during evaluation and determination of profitability. A key issue is: how is the value determined? In addition to traditional combination of in situ tonnes/grade, the following merit serious consideration: the concentration of deleterious elements, throughput rates, mining/processing costs and û importantly û metallurgical recovery. Geometallurgy is an emerging field targeted at integrating these issues by identifying either direct measures or proxies for throughput (hardness, grindability), recovery (liberation, mineral shape/texture, etc) and concentrate quality from easily collected macro-, meso- and microscopic data. These ægeometallurgical variablesÆ drive project costs and revenues in a fundamental way. For geometallurgical characterisation to have a real impact on business design, it must enable improved mine planning. When creating spatial estimates for such variables, it is preferable to find proxies that can be measured as close to the intact rock mass as possible. However, spatial estimation of proxies for geometallurgical properties and responses is complex and requires special consideration. Unlike grades, both proxies and absolute measures of geometallurgical variables are not necessarily linear or additive and therefore require very careful geostatistical consideration. In some cases, models must predict extreme values of geometallurgical attributes rather than averages. Incorrect characterisation of metallurgical recovery/throughput can (and has) led to misspecification of the scale of projects, and thus can be seriously value destructive. Aspects of geometallurgy have long been important in iron, bauxite, manganese and coal deposits and are increasingly on the radar for base and precious metal miners. However, as more metallurgically complex deposits are developed and mining of large-scale, low-grade deposits becomes more commonplace, the importance of characterising the metallurgical response in order to generate properly optimised projects will rapidly increase. It is possible that in many ætraditionalÆ (ie grades and tonnes) reserve models, the variables that drive the project are missing!

Jan 1, 2007

The key functions of project evaluation are to assess potential profitability and to develop an effective operational design. For mining projects, design aspects include mining methodology, ore treatment methodology and production rates. All of these characteristics impact on project economics and overall value. Resource models, which form the ultimate basis of project evaluation, typically consist of tonnes above cut-off, grade above cut-off and the spatial distribution (connectivity) of tonnes/grade above cut-off, for one or more variables. Dilution, ore loss and metallurgical recovery are all modifying factors applied to the resource model during evaluation and determination of profitability. A key issue is: how is the value determined? In addition to traditional combination of in situ tonnes/grade, the following merit serious consideration: the concentration of deleterious elements, throughput rates, mining/processing costs and - importantly - metallurgical recovery. Geometallurgy is an emerging field targeted at integrating these issues by identifying either direct measures or proxies for throughput (hardness, grindability), recovery (liberation, mineral shape/texture, etc) and concentrate quality from easily collected macro-, meso- and microscopic data. These 'geometallurgical variables' drive project costs and revenues in a fundamental way. For geometallurgical characterisation to have a real impact on business design, it must enable improved mine planning. When creating spatial estimates for such variables, it is preferable to find proxies that can be measured as close to the intact rock mass as possible. However, spatial estimation of proxies for geometallurgical properties and responses is complex and requires special consideration. Unlike grades, both proxies and absolute measures of geometallurgical variables are not necessarily linear or additive and therefore require very careful geostatistical consideration. In some cases, models must predict extreme values of geometallurgical attributes rather than averages. Incorrect characterisation of metallurgical recovery/throughput can (and has) led to misspecification of the scale of projects, and thus can be seriously value destructive. Aspects of geometallurgy have long been important in iron, bauxite, manganese and coal deposits and are increasingly on the radar for base and precious metal miners. However, as more metallurgically complex deposits are developed and mining of large-scale, low-grade deposits becomes more commonplace, the importance of characterising the metallurgical response in order to generate properly optimised projects will rapidly increase. It is possible that in many `traditional' (ie grades and tonnes) reserve models, the variables that drive the project are missing!

Jan 1, 2007

By R. Bridge

Mining companies are progressively finding themselves having to develop operations for more complex, deeper ore bodies, which require the use of more complicated mining and mineral processing methods. This coupled with the generally increasing trend of higher capital and operational costs have led to a need in the industry for improving ore body knowledge, mining and mineral processing. Geometallurgy is a relatively new concept that can link the three aspects, and when used effectively it is a method that can produce the necessary information for designing and building operations for reliable and optimum performance. Geometallurgy not only involves the integration of geological, mining, and metallurgical fields, but it can also be expanded to include environmental and economic information to produce a block model that can be used to obtain the best outcome in terms of plant response and plant sustainability. The geometallurgical program should not end once the block model has been populated. A detailed geometallurgical approach should be applied to all stages of the operation encompassing sample selection, through to equipment sizing and production forecasting. It can also become a useful optimisation tool thereby allowing the operation to be proactive rather than reactive against changes in the ore characteristics. With the development of metallurgical performance predictors it is possible to quantify how the ore will behave in the process plant in terms of throughput, recoveries, reagent consumption, etc. Therefore, in terms of responsible mining and sustainable resource development, a geometallurgical approach to operations is the logical step for plant development. In this paper we describe the state of the technology with respect to the application of geometallurgical modeling and its utilisation in the fields of design, forecasting and optimisation of mining operations.

Aug 1, 2013

By Michel Brissette, Shaheer Sanuri, Veroljub Mihajlovic

"The main purpose of geometallurgy is to improve the mine planning by mapping hardness and throughput into the mine block model using geostatistics to eliminate the large production fluctuations caused by the ore hardness variability coming from different parts of the pit. However, not all grinding testwork available commercially can be applied to geometallurgy because of large amount of sample required and the associated cost per test. Geometallurgy is now being used in designing grinding mill but as the mining project progress, the accuracy of engineering must improve from 30-35% during the scoping study to 10-15% at the bankable feasibility stage and less than 5% for Engineering Procurement and Construction Management. For SAG milling, the SAG Variability Test (SVT) is an abbreviated version of the standard SAGDesign test developed for this geometallurgical need. The same amount of ore than the original test is ground for three cycles into an open batch SAG test and then the SAG pinion energy is predicted to the standard end point of 80% passing 1.7 mm. For ball milling, a Bond Variability Test (BVT) was also developed using the SAG ground ore from the SVT. The Bond ball mill grindability (Gpb), corresponding to the average of the net grams per revolution from the last three cycles of the Bond test, is also predicted from the third cycle. The relative error for both the predicted SAG ore hardness (WSVT) and Bond Work Index on SAG Variability ground ore (Sv-BVI), in kWh/t, averaged 5.5% and 3.8% respectively compared to the SAGDesign testwork values and are within 7% and 10% respectively from plant benchmark and within 7% from the samples sent to all partner laboratories. Both tests can be continued to measure the true hardness necessary for mill sizing. This article discusses the development of these two new tests, SVT and BVT, their potential use and accuracies in any geometallurgical program."

Jan 1, 2014

By Marcos Meyer Machado

O presente trabalho compreende um estudo sobre os processos de moagem e tratamento térmico de pelotas no que tange as implicações microestruturais de minério de ferro no controle operacional e redução de consumos de energias térmica e elétrica de uma planta de pelotização. As características físicas, microestruturais e mineralógicas foram determinadas para os produtos de minério de ferro, para matriz de experimentos (misturas) e para as pelotas tratadas com auxílio de um microscópio óptico, um eletrônico e um EBSD. Os resultados permitiram confirmar a relação entre as composições morfológicas com a elevação de produção da moagem (14,1%) e redução do consumo de energia elétrica (12,0%). O controle do perfil térmico de endurecimento foi relacionado com as condições de sinterização (grau de maturação) das pelotas submetidas e as fases microestruturais identificadas. Foi evidenciada relação inversa entre o teor de magnetita na mistura com o consumo de energia térmica. Os resultados de resistência à compressão também sugerem uma relação inversa com os teores de fayalita e magnetita não oxidada, porosidade e grau de maturação. Adicionalmente, os resultados proporcionaram ajustes industriais que confirmaram essa relação com a redução da energia térmica aplicada para produção (10,7%).

Oct 30, 2017

By Nickol Estrada, Jean Bueno, César Gallegos

El presente proyecto consiste en realizar la Geometalurgia en el yacimiento tipo VMS de Cerro Lindo con el fin de generar un impacto en la producción maximizando el valor operacional. Para ello fue necesario hacer una evaluación y análisis dentro y fuera de la Caja (Yacimiento VMS) con la finalidad de poder identificar y caracterizar los dominios geológicos nuevos y existentes, obteniendo como resultado los parámetros geometalúrgicos que nos ayudarán a buscar la viabilidad del proceso de extracción y tratamiento del mineral.

Sep 29, 2023