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By J P. Sykes, T C. McCuaig, J E. Vann

Resources added to the global metal inventory through exploration over the past 15 years have been generally of poor quality (declining grades, recoveries and lack of acceptable financial return). Similarly, companies opting for an acquisitions-based strategy have had to pick from a group of poorer quality resources left from previous exploration booms, and will struggle to deliver this metal to market economically. Increasing difficulty in obtaining sufficient social and community acceptance of mining projects and potentially an energy-constrained future may exacerbate this problem, redefining what is considered ‘ore’. There will need to be more focus on deposit quality, defined as sustainable margin in the future business environment.Traditionally there has been a lack of translation of ‘mineralisation quality’ back to mineral project design and mineral exploration. This disconnect is due to two main factors: the first is technical – inherent deposit variability; and the second is organisational and socio-psychological –the mindset of explorers and project managers themselves.There are four elements to value realisation for a mineral deposit: (1) social licence to operate; (2) geological factors (depth, geometry, water and geotechnical, and geometallurgy – influenced by texture, mineralogy, chemistry and grades); (3) financial engineering (capex, opex, future commodity prices, future energy prices), and (4) operating factors (production rate, recovery, energy consumption). These elements are strongly interdependent, and geology underpins and drives linkages between them. A quality deposit addresses all of these elements and thus can be developed in a time frame that allows acceptable returns to the owners of the invested capital.Geological drivers of the above elements can be measured and mapped throughout a deposit. Moreover, when viewed in the context of mineral systems, a predictive understanding of the common causative processes of quality (despite deposit-scale variability) is emerging, and with it the ability to target quality of mineralisation, not just quantity of mineralisation.The second factor is a ‘heuristic software problem’. Current lines of education (and consequently organisational and professional structures) are discipline-based, producing ‘silos’ that do not speak each other’s language and work with different ‘mental models’. People who effectively recognise systemic links between these silos are called ‘boundary spanners’, of which we propose two distinct types: outside-insiders and inside-outsiders. Outside-insiders are people who are within a community, but recognise advances in outside fields and effectively integrate them into the community. Inside-outsiders start outside of a community, and successfully bring new ideas into it. Common traits in boundary spanners are: they seek exposure to (and embrace) key ideas that are outside of the framework of their own specialisation; they have high mental processing ability (MPA) – the ability to connect systems that are currently not perceived to be connected; and they introduce ideas from outside a field into a new context in a way that re-frames the field.The challenge is to identify and nurture potential boundary spanners that can build critical links, in particular between the (largely geoscientific) mineral exploration mindset and the (largely non-geoscientific) project development mindset. Critical linkages to be built are between mineral system science, targeting science, and whole of value chain modelling.CITATION:McCuaig, T C, Vann, J E and Sykes, J P, 2014. Mines versus mineralisation – deposit quality, mineral exploration strategy and the role of ‘boundary spanners’, in Proceedings Ninth International Mining Geology Conference 2014 , pp 33–42 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By R N. Lamb, A N. Buckley

Experiments have been carried out to establish whether time-of-flight secondary ion mass spectrometry (ToF-SIMS) is able to differentiate monolayer and multilayer coverage of thiol collectors on sulfide minerals. The systems investigated were those for which x-ray photoelectron spectroscopy is able to provide an independent determination of the extent of coverage, and included diethyldithiophosphate (DTP) and 2-mercaptobenzothiazole (MBT) on chalcocite, DTP on Ag2+MS prepared by sulfidising metallic silver, and isobutyl xanthate (BX) and MBT on galena. For monolayer adsorption of MBT on chalcocite, peaks from MBTû but not Cu(MBT)û ions were evident. For multilayer coverage, Cu(MBT)2û ions were clearly present, notwithstanding the fact that other data had identified the principal multilayer species as Cu(MBT). For adsorbed DTP on copper and silver sulfides, DTPû and metal(DTP)Hû peaks were observed for monolayer and multilayer coverage. Although the multilayer species was expected to be predominantly metal(DTP), metal(DTP)2û ions were evident for multilayer (but not monolayer) coverage. For the PbS/BX system, intact Pb(BX)2 or Pb(OH)BX ions were not detected for multilayer coverage, although Pb-containing ions heavier than PbBX were. Indeed, for all the systems studied, ToF-SIMS was able to differentiate monolayer from multilayer coverage. In general, however, the SIMS evidence alone might not be sufficiently definitive to effect the differentiation. In the case of collector adsorption on copper and silver sulfides, if the multilayer species detected had been the metal monothiolate only, and had not involved the formation of some metal dithiolate, then ToF-SIMS might not have been able to provide an unequivocal differentiation of the two coverage conditions.

Jan 1, 2005

By P B. Hills

Almost a quarter of a century since Bridges (1993) documented techniques for the assessment of ground conditions in a seminal paper in the Proceedings Second International Mining Geology Conference, the necessary role of the geologist in recording geotechnical data on exploration properties and in mines remains. Typically, the geologist is the first professional on the exploration property. Of course, most exploration properties don’t become mines. However, when a property does start to come together and form a coherent mineral deposit and professionals from across the minerals industry spectrum, including specialist geotechnical engineers, become increasingly involved, it remains the geologist who has the most intimate knowledge of the deposit. By association, that knowledge extends to the character of the rock mass.Throughout the various phases of prefeasibility, feasibility, construction and production, culminating in the mature mine, the knowledge of the rock mass held by the geologists continues to grow. In the current era of minimising cost and optimising profit, meeting the requirements and expectations of stakeholders ranging from fellow employees to investors, industry and financial regulators and the broader public, in a social environment where occupational health and safety concerns are of uppermost concern in every endeavour, the value of the geologists’ observations cannot be understated. Mines nowadays employ more geotechnical engineers than they did in the early 1990s when Bridges (1993) wrote his paper. More funds are available for specific geotechnical investigations of exploration properties and mines; none-the-less, those programs remain limited in their extent and there is a wealth of additional data available for collection with the appropriate training, at little additional effort. Fundamentally it is all about the numbers. Any hole not geotechnically logged is a hole that will need to be drilled again if the data is required. Any face, surface or underground, not geotechnically mapped is one that may need to be mapped a second time. That doesn’t mean every hole or every face. However, it is the proposition of this paper that the opportunity for additional geotechnical data to be gathered during traditional geological investigations is an opportunity that cannot be ignored. Occupational health and safety requirements demand that the geotechnical risks associated with mining are appropriately managed. Mining regulations in most Australian and overseas jurisdictions requires the consideration of geotechnical risk through formalised management plans. The Joint Ore Reserves Committee (JORC) Code requires the consideration of modifying factors more than ever before. The benefit to be realised through improved geotechnical understanding by geologists on the ground leads to improved occupational health and safety, optimised reporting compliance, and improved financial and social outcomes for the exploration property and ultimately for the mine that follows.CITATION:Hills, P B, 2017. The necessary role of the geologist in geotechnical data gathering, in Proceedings Tenth International Mining Geology Conference 2017, pp 347–354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

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 García B., Wolff E.

The pellet qualities primarily depend upon the thermal profile and gaseous environment during induration. During the induration of the pellet, it undergoes physical as well as chemical changes. Physical changes are mostly due to sintering and chemical changes are due to carbon burning inside the pellet. The effect of carbon on sintering is investigated on a single pellet scale using an optical dilatometer. Sintering is a complex process that involves transportation through various mechanisms. Sintering is quantified in terms of sintering ratio and the kinetic parameter, exponent ‘n’, under isothermal conditions is deduced using the power law equation. The value of n can be used to estimate the sintering mechanism at different isothermal temperatures. Also, the activation energy is calculated using the empirical Arrhenius equation. The activation energy of 0 per cent coke and 1 per cent coke-containing pellets are 531.0 kJ/mole and 552.6 kJ/mole respectively. The order of magnitude of activation energy suggests the same mechanism in both cases. Although the mechanism of sintering is the same, 1 per cent coke-containing pellet sinters more at any isothermal temperature.

Jun 17, 2024

By K Gardner, R Fraval, V Singh

Using new technology to create optimised infill drill programs in underground or open pit settings, it is possible to quantify the value of a drill program. The computer designed programs are optimised to uplift the most amount of resource possible into the specified resource classification, while honouring geological, spatial, equipment and budgetary constraints. When designing ‘by hand’ balancing all these factors is a time-consuming effort with no real way to determine metrics on ‘how good’ a program will be. The optimisation considers many factors allowing geologists to apply critical thinking and domain knowledge to constrain the optimisation, letting the computer do the heavy lifting of determining hole placement. Once programs have been created, they can be integrated into a production schedule. This is a critical step in determining the correct sequencing and balancing of resource availability and seeing how a program will interoperate with other tasks in the mine. For example, if drill drives are a requirement for part of the program, will they be developed in a time frame that is useful for the goals of the program? Do we risk drilling infill holes too late to add value? Do we put production at risk by not classifying parts of the model ahead of time, thus adding to uncertainty? Using software to assist with optimising and scheduling of drilling is a useful technique to save the geologists from the mundanity of manually designing drill programs and puts metrics around the effectiveness of a program and has the potential to add quantifiable value to a program. Examples will be presented that demonstrate the effective use of drill hole optimisation, comparing manual designs with optimised designs, as well as the examples that show the effective use of scheduling.

Mar 22, 2022

By S Henderson

The Otago Goldfield has produced approximately 8 million ounces of alluvial gold and over 2.5 million ounces of hard rock gold and is currently home to New ZealandÆs largest producing gold mine. In the eyes of explorers this production history makes the goldfield a good place to explore.   Modern exploration in the Otago Goldfield commenced in the late 1970s with the exploration for tungsten. However, a rapid rise of the gold price in the early 1980s saw the focus shift to the exploration for gold which lead to the discovery of the Macraes Gold Project in 1984, which since it came into production in 1990 has been New ZealandÆs largest producing gold mine. With the exception of the Macraes Gold Project, exploration continued in the Otago Goldfield for a further 20 years without further success.   In 2006, Glass Earth (NZ) Limited (Glass Earth) reviewed all the exploration technologies applied to the Otago region and available geological data, including the 1996 OceanaGold Helicopter Electro-Magnetic (HEM) data, and concluded that combined magnetics and HEM were able to delineate the Hyde Macraes Shear Zone (HMSZ) which hosts the Macraes Gold Project. Unlike previous explorers who explored the Otago region in a piecemeal manner, Glass Earth opted to collect a new, region-wide dataset which could be integrated with all previous collected geological information to come up with new exploration concepts and targets. As part of this process, Glass Earth applied in mid 2006 for New ZealandÆs largest on-shore gold Prospecting Permit, PP39-322 which was subsequently granted in November 2006. In mid January 2007, Glass Earth commenced acquisition of approximately 50 000 line kilometres of HEM data, making the Otago regional aerial geophysical survey (survey) the largest aerial geophysical survey ever undertaken in New Zealand.   This paper will report on the progress of the Otago Regional aerial geophysical survey and outline some of the preliminary findings from what is still a work in progress.

Jan 1, 2007

By K Esmaeili, S Aziznejad

Impact-induced rock fragmentation is a mechanism that is commonly used for rock breakage in drilling and crushing. Additionally, rock fragmentation by blasting is frequently used in rock excavation operations. Experience shows that the presence of discontinuities can significantly influence the impact-induced damage and fragmentation of rock. Quantification of the response of jointed rock masses to impact loads is complicated by the fact that the available laboratory tests are mainly designed for aggregates or intact rocks. It can be argued that neither of these tests adequately represent a jointed rock mass. This paper presents the results of a series of numerical simulations used to investigate the influence of pre-existing discontinuities on the impact-induced fragmentation of rock masses. The methodology includes determination of the static and dynamic mechanical properties of a rock unit by conducting a series of laboratory tests on intact rock samples collected from a quarry in Canada. A 2D distinct element code, Particle Flow Code, was used to generate a bonded particle model in order to simulate both static mechanical properties (uniaxial compressive strength, elastic modulus, Poisson’s ratio and indirect tensile strength) and dynamic mechanical property (drop weight tensile strength) of the intact rock. The calibrated numerical model was then used to construct large-scale synthetic rock mass samples by incorporating discontinuity networks of different intensity into the bonded particle model. Finally, the impact-induced fragmentation inflicted by a rigid projectile particle on the jointed rock mass samples, simulated by a synthetic rock mass model, was determined. More fragmentation was observed for the rock mass samples with higher joint intensity.CITATION:Aziznejad, S and Esmaeili, K, 2015. Effects of joint intensity on rock fragmentation by impact, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 377–384 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By W Russell, P Wighton, J Franke

Recent advances in ruggedised industrial control system technology and architecture in combination with latest technologies in the fast-evolving 3D LiDAR sensor sector becoming available have enabled the implementation of sophisticated automation algorithms for mining equipment such as bucket wheel reclaimers, as published by the authors in the peer reviewed AusIMM 2019 Iron Ore conference proceedings. This paper provides an overview of a second use case for such automation technology in bulk material ports integral to iron ore operations. The real-time 3D machine-vision based port automation system described in this paper was originally developed for the BHP-Mitsubishi Alliance’s (BMA) Hay Point port. The system has seen deployment at other major mining and general ports in Australia, such as at Dalrymple Bay Terminal (DBT) (shown in Figure 1) managed by Dalrymple Bay Infrastructure Management (DBIM), Hay Point, Queensland. It has the following use cases:

Nov 8, 2021

By P J. Willems, B J. Junor

Blackwater Mine is in the central-southern Bowen Basin, immediately south of the township of Blackwater on the Capricorn Highway. The current open cut operation extracts coal from three main seams, designated Top, Middle and Lower, in the Late Permian Rangal Coal Measures cropping out on the eastern flank of the Comet Ridge. Complex geological structures, dominated by E-W normal faults and N-S reverse faults, have significant detrimental effects on coal mining operations. Historical exploration before 2010 involved several types of drilling only to understand structure, coal quality and washability. Hence, although drilling data was combined with limited pit mapping and observation, unknown structures were still often encountered during excavations and led to mining surprises. In 2010 BHP completed 200-line km of closely spaced 2D seismic survey to capture gross and detailed structures followed by fit for purpose structural drilling to confirm major structures in the northern part of the mine. In 2018 a high density 9.2 km2 3D seismic survey was completed in the southern part of the mine. Subsequently, a 17.2 km2 survey was completed in 2020 to cover the northern active mining area. It allowed geoscientists to successfully map previously unknown major faults and seam splits, which could potentially impact the mineability of the area. It is important to note, that faults interpreted using modern high-density 3D data can be interpreted with dramatically higher confidence in the fault dip and azimuth orientation in comparison to the legacy 2D data. Along with targeted drilling, pit mapping and structural interpretation, the outcome adds value to mine planning and operations. This paper outlines recent successful seismic 3D data acquisition and interpretation. In detail, the paper presents case studies on how the data can be incorporated into a structural model to improve geological knowledge, enable geotechnical assessment, and support safe and efficient coal mining in a large and structurally complex mine.

Mar 22, 2022

By P C. Hagan, J Chen, S Saydam

Fully grouted cable bolts have been used in underground mining industry for more than 40 years and are becoming more and more popular especially when severe geological conditions are encountered, such as high stresses and large cross-section excavations. The axial performance of cable bolts are mainly relied on the load transfer process between the cables themselves and surrounding rock masses via grout annulus. Therefore, the selected grouts play a significant role in determining the reinforcement quality for underground openings. In order to better understand the mechanical properties of Stratabinder HP grout, which is one type of cementitious grouts commonly used in Australian underground coalmines, plenty of unconfined compressive tests are conducted on it. Following diverse standards, two different kinds of samples are prepared and tested with the w/c ratio ranging from 0.35 to 0.45. During the test important mechanical properties including uniaxial compressive strength (UCS) values, Young’s modulus, Poisson’s ratios and so forth are recorded. Based on experimental results, the effect of w/c ratio on the mechanical properties of Stratabinder HP grout is studied. Beyond that, influences of sample size on the failure mode, peak strength as well as residual strength of this kind of grout are summarised and analysed.CITATION:Chen, J, Hagan, P C and Saydam, S, 2014. Mechanical properties of cementitious grout serving in fully grouted cable bolting systems, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 269–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Chappell B

Backfill in the form of mine waste tailings has inherent problems associated with attaining adequate strengths upon placement. Fines are usually removed to ensure adequate drainage, which lowers the cohesive strength of the fill, leaving the fines to he placed in a tailings darn. Electro-drainage and electro-chemical grouting is examined to investigate its effects on densification and shear strength within a silty clay tailing having low permeability and shear strength. Two separate grouting mechanisms are observed for the iron and silica grouts used. Electro- osmosis is associated with iron grout that deposits within the tailing matrix under a converging pH gradient, and increases the permeability of the tailing. This process initiates cation exchange and causes cementing of the granular contact points between the clays. Electro-phoresis causes sodium silicate solution to deposit silica grout in the voids of the tailings. The resultant effect of these mechanisms results in an increase in cohesion, leaving the void ratio of the iron grouted tailings as it was but significantly reducing the void ratio of the silica grouted tailings.

Jan 1, 1998

This study is to compare reinforcement of rebar and spiral bolts using laboratory pull-out test. For this purpose, the pull-out test was performed in laboratory for a curing period of 7- and 28-days. Based on the results of the laboratory pull-out test, the pull-out load of two support members rapidly increased with displacement until the breakpoint and then gently increased with displacement. The maximum pull-out load of spiral bolt was larger than that of rebar bolt. This implies that a spiral bolt is more stable than a rebar bolt for securing the stability of a ground or rock mass when a support was installed in a ground or rock mass under the same condition. In addition, the maximum external pressure of two support members increased with pull-out load and with displacement and the distribution of external pressure was commonly larger at the upper part than at the lower part of specimen. This indicates that the bond failure location by pull-out load should be mainly occurred at the surface portion of specimen. In conclusion, the reinforcing effect of a support depends on a curing period and a type of support member, and reinforcement of a spiral bolt is more effective than that of a rebar bolt.

Dec 6, 2010

By D Kay, M Lovitt

Mass Blasts are generally required at the completion of longhole stoping cycles to maximise the recovery of ore from a specific orebody. During the course of mining, the practice is to leave pillars of ore to support the opening left by extracted ore and to mitigate stresses from working areas of the stope. These pillars usually contain ore that has been included in the resource evaluation and is highly valuable to the mining operation. Due to their stressed nature, the removal of pillars by conventional blasting techniques, through small blasts, can result in pillars being reduced beyond their critical size and ultimately failing, rendering the ore unrecoverable. The AurionGold Kanowna Belle Gold Mine operates a Mine to Mill philosophy. This philosopy requires the fine tuning of blasting to provide the best possibe ore feed at the highest grade for mill productivity. This means that ore to the mill must be well fragmented from blasting that provides high extraction rates from draw points, with minimal dilution from overbreak or fall off, and sized to maximise SAG mill throughput. The AT04 Mass Blast contained significant ore reserves which were required to meet gold production targets. KBGB needed the AT04 Mass Blast to perform as well as if not better than conventional stope blasts to maintain mill production. This paper describes the circumstances, planning philosophy, techniques, including the use of Electronic Initiation Systems and Bulk Emulsion Explosives, and results that provided a highly successful outcome.

Jan 1, 2002

By D Connelly

Magnetite ores can be used to produce very high-grade concentrates that are suitable feed for the direct reduction process route but the high sulfur content of some concentrates can cause substantial environmental issues. Processing of high sulfur magnetite ore is therefore increasingly problematic for the industry. Generally, the industry demands a concentrate with <0.05 per cent sulfur and <2 per cent silica. This paper reports the outcomes of a study to produce a concentrate with the requisite low sulfur content from a sulfur-rich magnetite ore. The main findings may be summarised as follows: if the sulfur is present in magnetite as nonmagnetic pyrrhotite or pyrite, it can be beneficiated using magnetic separation and hence, monoclinic pyrrhotite is magnetic and is magnetically recovered with magnetite leading to a concentrate that is too high in sulfur. X-ray diffraction and QEMSCAN analyses revealed that the magnetite concentrate was liberated at P80 30 microns and was associated with maghemite, pyrrhotite (magnetic), carbonates and hematite with very low amounts of chalcopyrite, sphalerite and arsenopyrite. Sulfur removal using flotation was the first stage of investigation and this required flash flotation in the grinding stage followed by column flotation of the initial concentrate to generate the final concentrate. At the same time, it was observed that oxidation of the pyrrhotite had a negative effect on its flotation requiring copper sulfate to activate it. Bioleaching and concentrate leaching were also considered and achieved over 90 per cent sulfur removal but were deemed unsuitable owing to the production of highly reactive wastes and high CAPEX. Reference is made to a number of operating magnetite producers and how they manage the sulfur in feed.

Sep 18, 2023

By A L. Wills

Cliffs Natural Resources Pty Ltd (Cliffs) operates iron ore mines in the Koolyanobbing region of Western Australia. Ore is mined from three separate hubs and trucked to Koolyanobbing. There it is crushed and screened to lump and fines finished products and railed to Esperance port for export to Asian customers. Cliffs is renowned in the marketplace for its consistent product quality. In 2010, 9 Mt of ore was exported to Asia.Over the last three years, Cliffs has systematically refurbished its product quality system (PQS), to improve efficiency of production while maintaining its high standard of product quality. Particular attention has been given to reducing inventory, which has required significant modifications to the production process design.In redesigning the production process, emphasis was placed on maximising the application of the inherent blending in each of the production process steps and dedicated blending was only introduced where essential. Simulation modelling and statistical analysis of process capabilities were utilised to develop a system that optimises inventory, minimises rehandle, eliminates several decision-making steps and maintains a pull focus throughout the value chain.The new planning functions are now fully integrated and effectively control long-term grade variability rather than relying on long-term stockpiling. The production process design and the daily crusher blend plan are used to control short-term grade variability. With the upgrading of the planning processes the accuracy and consistency of algorithms for lump per cent and lump and fi nes grades became more important and an increased geometallurgical function has been added to the company.The continuous stockpile management system was upgraded to increase the effectiveness of the daily crusher blend planning process and is now the sole intervention point in the production process for grade-based decisions. Grade control systems were modified to utilise advances in software and geostatistics to deliver accurate short range planning models. The reconciliation and sampling systems have also been refurbished with an emphasis on practical application and feedback loops.Accountability and transparency are provided by management reports that are generated from a centralised data warehouse and the introduction of a corrective action system. Standardised reports are available to all stakeholders and a quarterly KPI scorecard assists the management review process.The successful rejuvenation of the PQS has culminated in operational efficiency through the implementation of an integrated end-to-end process flow. Shareholder value is maximised through maximising recovery of the resource and minimising costs. Customer focus is maintained by reliably delivering product with acceptable and low grade variability.

Jul 11, 2011

The design and operating characteristics of the hydraulic cyclone elutriator were described in detail by Kelsall and McAdam (1963), and the method of operation of the commercially available version, the Cyclosizer, is described in the manufacturer&apos;s pamphlet (Anon). Complete details of the operating procedure are given in the relevant operating manual (Anon, 1964).The cyclones which form the basis of the Cyclosizer (Fig. 1) under normal operating conditions produce typical cut sizes of 44, 33, 23, 15, and 10 &#181;m for cyclones one to five respectively for material with a specific gravity of 2&#183;7. At the end of the selected elutriation period each sized fraction is discharged and collected for subsequent assay or analysis but all material rejected by the fifth cyclone (e.g. minus 10 \lm quartz) normally passes to waste. When this material is needed for separate study, although its amount and average analyses can be calculated by difference, it may be necessary to collect more than 250 I. of very dilute suspension, flocculate the solids, allow to settle, and decant off the supernatant liquid.This procedure is cumbersome and inconvenient and the simple technique to be described may offer some advantages. The temperature of the water fed to the Cyclosizer is maintained at a constant value for added reproducibility.PROCEDUREThe present overall treatment of the subsieve material (minus 37 \lm) fed to the Cyclosizer incorporated several refinements compared with normal operation and these may be best illustrated by anactual example. Material to be cyclosized (25 to 100 g depending on size distributIOn and specific gravity) is completely dispersed in water at 23 QC by vigorous stirrmg, using suitable dispersants if necessary, in a...

Jan 1, 1974

By M I. Pownceby, S Hapugoda, H Han, E Donskoi, L Lu

Iron ore sinter mineralogy and its associated macro-/micro – structure has a strong impact on sinter quality. At a macroscopic scale, sinter ideally consists of a strong, porous matrix which bonds relict ore nuclei together. Microscopically, the sinter matrix (solidified from the melt part of the initial sinter mix) generally consists of complex calcium ferrites known as SFCA, secondary magnetite and hematite grains (precipitated from the primary sinter melt), glass and silicates. Depending on the conditions under which the sinter structure is formed, two major forms of SFCA with different morphologies are generally recognised, ie fine micro-platy SFCA (usually termed SFCA-I) and coarse columnar/prismatic SFCA. Detailed optical microscope observations of several pot grate and compact sinter samples revealed the presence of a variety of fine, coarse and dense forms of both types of SFCA. The controlled cooling tests revealed that cooling rate has an impact on the form and size of SFCA crystals. In this work, EPMA analysis of SFCA compositions from a variety of pot grate and compact sinter samples are presented. Results show that the SFCA types exhibit a broad range of complex compositions within the system Fe2O3/CaO/SiO2/Al2O3/MgO/TiO2/MnO2. Although SFCA-I and SFCA are known to be crystallographically distinct and with different, well-defined ranges in composition, there was considerable overlap in compositions of the experimental sinter samples. The development of SFCA textures depend on several parameters including the local chemistry and conditions including the maximum temperature attained and the cooling rate, within the sinter bed, thereby suggesting that SFCA identification based on morphology alone may be erroneous.

Nov 8, 2021

By V Novoselov, R Sabirov

Flotation processing technology of water-soluble minerals has made it possible to realise, since the 1960s, the wide scale industrial processing of potash and potassium-magnesium ores (about 200 million tonnes per year) as well as to create the multi-tonnage worldwide production of sylvite (KCl) for industrial and agricultural application. In this paper the particularities of the effect of reagents (blinders, collectors and frothers) during cation flotation in saturated saline solutions are outlined. New reagent modes for activating the effects of alkylamines during the flotation of KCl and the perfecting of technological flow sheets for processing potassium ore have been developed. The results of research on the reverse flotation of carnallite ore, with the help of alkylmorpholine û a new developing technology for benefication carnallite as raw material for the production of metal magnesium and fertilisers are listed. Examples are given of the industrial applications of processed reagent modes at potash flotation factories in Russia.

Jan 1, 2005

By R Price

"Technology has the potential to revolutionise industries, work functions or businesses. One such technology in the mining industry is the deployment of automation in a modern autonomous haulage system (AHS). This paper examines a theoretical application of an AHS in a medium scale mine site. The cost-benefit commercial argument is particularly compelling, and the paper outlines metrics and future issues for consideration.Citation:Price, R, 2016. Autonomous Haulage Systems - the Business Case, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 11–17 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016