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We outline a first version of an ambitious goal: The world's first horizontal (matrix-independent) generic sampling standard. The specific needs and requirements are overwhelming, as all the world's analytical standards follow strict matrix or material type classification pigeonholes, leading to a plethora of analytical standards. One could rightly expect a similar multiplication regarding sampling standards, yet the singular HORIZONTAL is aimed at being truly generic. Also the existing style of standards writing is cumbersome and partly contradictory. The current work is presently being pursued in CEN and European Union standardisation regimens, for which reason full disclosure and publication is not allowed. Respecting this constraint, we unofficially present selected key issues involved in developing HORIZONTAL: The objective and scope of a horizontal sampling standard is to delineate the minimum set of principles and procedures needed to guarantee documented representative sampling for all types of materials. The horizontal standard is designed for two types of use: 1. auditing/assessing/ improving the reliability of an existing sampling procedure, and 2. design and implementation of a new sampling procedure (new lot type). The principles in this standard are all derived from the Theory of Sampling (TOS), but the standard is far from a mere collection of TOS principles. Representativeness is a characteristic of the sampling process, not of samples themselves. For practical purposes, the horizontal standard follows the fundamental distinction between 'stationary lots' (0-D, 2-D, 3-D lots) and 'dynamic lots' (within TOS aka process sampling - including extended, non-moving 1-D lots). TOS' principles of 'correctness' must never be broken at any stage, lest representativeness is irretrievably lost. The horizontal standard is not written in the mandatory fashion for legally binding matrix-specific standards, eg ISO - for the present overarching purpose a different style had to be developed. The standard must be immediately understandable in full, which merits special demands, eg extensive use of didactic illustrations. HORIZONTAL introduces an all-inclusive sampling variability measure, Relative Sampling Variance (RSV) which is for sampling of stationary lots as variographics is for process sampling - RSV is to be used as a quality criterion for any stationary sampling procedure as applied to a specific heterogeneity (lot/material). The target for this standard is all individuals, companies, organisations and regulatory bodies who are responsible for sampling: technicians, process engineers, laboratory personal, academic and industrial scientists as well as project leaders, technical managers/directors and top managers. Based on current R&D we illustrate the principles promulgated by HORIZONTAL with cases from exploration and mining of minerals commodities, a Finnsh 'Autosampler' at work in the mining context (RSV) as well as sampling equipment for use in the cement and mineral commodities industries. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Mar 1, 2010

THIS excellent volumetric method commends itself as a means of estimating the fineness of silver firstly, owing to the large number of possible impurities which do not affect its accuracy (these impurities include Cu-up to 70 % Au, Ph, Zn, Bi, Cd, Fe, Mn, Sb, and As); secondly, the method combines accuracy with speed. The above impurities are the only ones likely to be present in the B. H. A. S. Pty. Ltd. refined silver, and, with the exception of Cu and Au, the others, if present at all, would be well under 0.1 parts per 1000.Briefly stated, the method consists in the solution of the refined silver in HN03 , addition of ferric alum (indicator), and titration with an alkaline (either ammonium or potassium) thiocyanate solution until the brown ferric thiocyanate is formed, and gives a definite tint to the solution. The method is used at the Port Pirie smelters, and the outstanding feature in the method as there applied is the type of burette employed. This burette enables the operator to read 0.01 of a cc. with ease, whereas, with the ordinary burette fitted with a float, 0.05 of a cc., when a number of readings have to be taken, becomes very straining to the eyes. Moreover, waiting for the float to rise, and dislodging air bubbles from it, hinders rapid working.A description of the burette and fittings is appended with fig. 2. DETAILS OF THE METHODSolutions required are:a) Stock Solutions:(1) Ammonium thiocyanate, 40 grm. per litre of water; 30 litres are prepared and placed in a carboy with glass syphon attached.(2) Ferric alum, 250 grnl. per litre; two litres are prepared.

Jan 1, 1922

By T Takayama, R Muroi, M Matsumura

The steel industry occupies 14 per cent of CO2 emissions in Japan, and the sintering process is one of the major emitters. Since most of CO2 released from the sintering process comes from coke fine combustion, replacement of coke fines with biomass char as bonding agent is a potential countermeasure. In order to explore the effective use of biomass char, we chose char made from Palm Kernel Shell (PKS) as a sample. First, the char’s combustion behaviour was examined with varying the char’s particle size by means of admixing the char in alumina ball packed bed placed in an electric furnace. As a result, the finer the PKS char the faster the burning rate and reaching a higher temperature compared to coke fine. In addition, it is also concluded that the optimum size of PKS char was larger than coke fines. Next, the effect of different heat profiles on sinter structure was examined by sintering tablet made of chemical reagents. In this experiment, the chemical composition is designed based on sinter composition. By this sintering test, even at high temperature, rapid cooling is effective to make fine sinter matrix and fine pores, which has possibility for high sinter reducibility. Based on these two experiments, using PKS char as a sinter fine source has the possibility to improve sinter reducibility.

Nov 8, 2021

By N Akizawa, A Tamura, S Arai

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Reaction products between high-temperature hydrothermal solution/uppermost mantle peridotite or lowermost crustal gabbro have been reported along Wadi Fizh of the northern Oman ophiolite; they are named as ‘mantle diopsidite’ and ‘crustal diopsidite’ respectively (Figure 1).The mantle diopsidite contains Cr-rich minerals like chromite, Cr-rich diopside (<2.5 wt per cent Cr2O3) and Cr-bearing grossular (<7.0 wt per cent Cr2O3). The chromites are varied in shape in the mantle diopsidite, euhedral to anhedral chromite grains contain globular inclusions of grossular and chlorite, and film-like chromite veinlets branch off from partially dissolved coarse chromite grains. In the crustal diopsidite, fine chromite grains are included in oscillatory-zoned skeletal uvarovite, especially in its high-Cr zones. The uvarovites are rich in rare earth elements (REEs). Direct laser ablation – inductively coupled plasma – mass spectrometer (LA-ICP-MS) analysis of the primary fluid inclusions detected Na, but not K.Our detailed studies of Wadi Fizh diopsidites clarify that the high-temperature hydrothermal solution dissolves chromite grains at the uppermost mantle section and precipitates hydrothermal chromite at the lowermost crust section. In addition, REEs were mobilised in the hydrothermal solution together with Cr. The hydrothermal solution involved in the diopsidite formation is assumed to have been rich in NaCl, and could mobilise appreciable amounts of Cr and REE.CITATION:Akizawa, N, Arai, S and Tamura, A, 2015. Chromium and rare earth elements mobility by sodium-bearing high-temperature hydrothermal solution – an example from mantle diopsidite and crustal diopsidite, in Proceedings PACRIM 2015 Congress, pp 291–296 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Stevens P

The Isa Mine of Mount Isa Mines Limited currently produces 5.4 million tonnes of copper ore and 3.3 million tonnes of silver, lead and zinc ore annually. Of this, 5.1 million tonnes of copper ore and 2.2 million tonnes of silver-lead-zinc ore is produced by sublevel open stoping. This paper summarises the capabilities, operating practices and problems encountered with current production drilling practices used to drill sublevel open stopes at Mount Isa.

Jan 1, 1982

THE following paragraphs represent an endeavour to describe, briefly the equipment used for the manufacture of sulphuric acid and superphosphates by the Corporation.SULPHURIC ACID PLANTS.Two separate units are in operation, No. I Plant working on sulphur dioxide generated from pyritic ore, No. 2 Plant working on sulphurous gases obtained from the Huntingdon-Heberlein desulphurizing process. The latter plant is unique in being the first installation for the successful use of these gases.

Jan 1, 1918

By T Kang, V Sahajwalla, L Lu

During devolatilisation, physical behaviour of coals was investigated in horizontal electrically heated furnace with an inert gas atmosphere, and gasification rates of four coal chars and coke were measured thermogravimetrically in a carbon dioxide atmosphere at temperatures in the range 1100oC - 1500oC. The volume change of chars was also measured in horizontal electrically heated furnace at various temperatures. Both reactivity and the activation energy for the gasification of coal chars were found to be strongly influenced by pore structure and the carbonisation conditions employed during preparation. CO2 reactivity of chars increases with increasing reaction temperature, and particularly increases more rapidly over 1300¦C. CO2 reactivity of coke is lower than that of non-coking coal chars in the range of 1100¦C to 1500¦C. CO2 reactivity of chars with smaller pore area and bigger pore diameter is less than that of chars with bigger pore area and smaller pore diameter. During gasification, the volume of chars did not change significantly at the lower temperatures of 1100¦C and 1200¦C, but at the high temperatures, 1300¦C to 1500¦C, the volume of chars quickly decreased due to ash softening and melting. The CO2 reactivities of the chars are controlled by the mixed control of chemical reaction and pore diffusion in the temperature range 1100¦C to 1300¦C, and by bulk diffusion in the temperature range 1400¦C to 1500¦C.

Jan 1, 2000

The development of Mount Isa Mines Limited power supply is traced through the history of the mine operations. As would be expected, growth of the power supply system follows closely the increase in mine output, although it will be seen that total kWh. produced per ton milled shows a considerable reduction in later years when the mine output showed a more rapid rate of increase. That this reduction is not more marked is possibly due to the increased community and Shire Council power usage per head of population.INTRODUCTIONThe geographical position of Mount lsa, far from any large regional power supply Authority, dictated the policy that the Company be responsible for the production and suppiy of all power required for the plant operation. The Company also, in November 1937, accepted responsibility for the supply of a part of the power requirements of the township of Mount Isa. The history of power supply to the Mine may be divided into several phases.1. The supply Of lighting and power during the first plant construction period 1929-1931.2. The construction of the first section of the Mines Power Station, comprising Nos. 1 and 2 turbo alternators and boilers.3. The addition of No. 3 turbo alternator and boiler.4. The addition of No. 4 turbo alternator and boiler.5. The addition of No. 5 boiler.6. The addition of a. 2 turbo blowers for air supply to the Copper Smelter converters; b. 1 turbo blower for air supply to the L.ead Smelter; c. 2 turbo compressors for compressed air supply to the Mine and surface plant.

Jan 1, 1961

By D Macklin, R Hammond, T G. Blenkinsop

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Base metal sulfides at the Currawong volcanic-hosted massive sulfide deposit in the Lachlan fold belt of Victoria, south-east Australia, were formed in the late Silurian, but D2 deformation of the deposit in the Devonian Bindian orogeny was responsible for structural repetition that created the resource. The primary sulfide lenses were stacked by reverse-sense shear zones within a volcano-sedimentary sequence dominated by dacitic intrusions and turbidites. Shear zones were localised along lithological contacts, including the margins of the sulfide lenses. The competent dacitic intrusions did not fold during D2; folding was restricted to the packages of metasedimentary rocks. Overturning occurs within, but not between, the metasedimentary packages. The overall geometry of the deposit is that of a duplex, but the detailed shape does not conform to idealised duplex types, probably because of post-D2 deformation. A significant complicating factor for understanding the deposit, and for resource evaluation, is the dramatic variation in deposit geometry along strike, which may also be due to post-D2 deformation. The present day configuration of the deposit results from constructive thrust repetition of what may have been a single ore lens and destructive along-strike disruption controlled by rheology.CITATION:Blenkinsop, T G, Macklin, D and Hammond, R, 2015. Rheological controls on the geometry of the Currawong volcanic-hosted massive sulfide deposit, Lachlan fold belt, Victoria, south-east Australia, in Proceedings PACRIM 2015 Congress, pp 469–474 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By K Zhao, H Gong, B Li

Health and safety are the first priority for Australian minerals sector. Australia has a global reputation in the mining industry. However, accidents occur every year. Legislation and regulation are important to prevent the accident from occurring, so do the new technologies. It is sad to witness the collision incident persisting and the long called collision avoidance system (CAS) is still not widely used in underground mines. The main reason is that the existing systems are still not advanced enough. The current CASs utilise GPS, infrared, ultrasonic, RFID, Radar, electromagnetic etc have their limitations and disadvantages. For instance, GPS is widely used in a surface mine, but it cannot be applied in underground mine; Infrared and electromagnetic have the false positive problem.

Sep 1, 2024

By T Takayama, M Matsumura, Y Konno

The steel industry accounts for 14 per cent of domestic CO2 emission in Japan, and iron ore sintering process occupies approximately three per cent. While Fe content in iron ore is gradually decreasing. So, the amount of concentrated iron ore will increase in the future. We have focused on magnetite concentrate as sinter materials, because magnetite can be easily magnetically beneficiated. However, it is experienced that blending magnetite ore resulted in increasing Fe2+ component in the iron ore sinter, which results in lower reducibility. Therefore, promoting the oxidation reaction from magnetite to hematite in the sintering process is countermeasure for reducibility. In addition, this promotion causes increase of oxidation heat, which results in high sinter strength and reduction of coke. It is assumed that the oxidation of magnetite tends to proceed in the cooling stage, where the oxygen partial pressure increases after the combustion of fine coke, but there are few studies on the effect of heat profile, especially cooling path. The purpose of this study is to design the effective sintering heat profile to promote oxidation of magnetite ore, especially, to investigate the effect of cooling path on sintered ore microstructure. In this study, magnetite ore and magnetite reagent were respectively mixed with calcium carbonate reagent. Then the mixed samples were pressed and formed into cylindrical tablets for simulating the adhesive layer of a pseudo particle. Through examining influence of maximum temperature and cooking rate on oxidation reaction of magnetite, we confirmed that the oxidation reaction of magnetite is suppressed at above 1350°C for maximum temperature, compared to 1300°C. Sintering at lower temperature is desirable because hematite is stable below 1350°C in the Fe2O3-CaO phase diagram.

Nov 8, 2021

By R Grogan

Nautilus Minerals Inc is a sea floor resource exploration and development company focused on developing the Solwara 1 Project, a copper-gold sea floor massive sulfide deposit in the territorial waters of Papua New Guinea, for which it holds a mining lease and associated environment permit.Economies depend upon four key types of capital: built, natural, financial and human. Natural capital consists of the ‘minerals, energy, plants, animals, ecosystems (climatic processes, nutrient cycles and other natural structures and systems) found on Earth that provide a flow of natural goods and services’ (Daly and Farley, 2004). Many ecosystem goods such as fish, fruit and water are already valued and sold in markets; however, some ecosystem services are not amenable to markets and have remained unvalued in traditional accounting methods, even though they provide significant value (such as flood protection, climate stability etc; Batker and Schmidt, 2015).There are now economic methods available to quantify and value natural capital and many non-market ecosystem services. When valued in dollars, these services can be incorporated into a number of economic tools, including benefit-cost analysis, accounting, environmental impact statements, asset management plans and rate of return on investment calculations. Their inclusion ultimately strengthens decision-making. When natural capital assets and ecosystem services are not considered in economic analysis, they are effectively valued at zero. This omission can lead to poor decisions, inefficient capital investments, higher incurred costs and losses due to unexpected events (Batker and Schmidt, 2015).In 2015 Earth Economics was commissioned by Nautilus Minerals Inc to conduct an independent, objective environmental and social benchmarking analysis of the proposed deep seabed Solwara 1 mine with terrestrial copper mines (referred to as ‘the report’). The report represents the first ever natural capital accounting and ecosystem goods and services framework for seabed mining.The report compares the proposed Solwara 1 mine with three terrestrial mines: Bingham Canyon (Utah, USA), Prominent Hill (South Australia, Australia), and Intag (a proposed mine in Intag Province, Ecuador), and provides a natural capital accounting assessment for all four operations.CITATION:Grogan, R, 2016. Natural capital accounting – a sea floor mining application, in Proceedings Life-of-Mine 2016 Conference, pp 2–4 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By E Holloway

The optimisation of an open pit mine can be broadly split into two stages, the first being the ultimate pit optimisation (and subsequent stage designs), and the second being schedule optimisation. Macroeconomic uncertainty clearly impacts on both however interrelationships do also exist. Generally, the opportunity exists for the ultimate pit to be revised during each planning cycle, however when this reprieve is removed the uncertainty for the underlying business increases. As one example, the introduction of an in-pit waste dump can be seen to significantly limit the option to revise the ultimate pit. When in this situation there are two potential risks that present: (i) the long-term price used for the ultimate pit selection is optimistic, and too large of a pit is selected resulting in waste being mined which uncovers material not of a significant value to deliver a profit; (ii) the long-term price used for the ultimate pit selection is pessimistic, too small of an ultimate pit is selected, and ore of realisable economic value left behind. Both of these outcomes are risks and as such can be assessed and quantified. CITATION: Holloway, E, 2018. Incorporating economic variability into a strategic planning framework, in Proceedings Complex Orebodies Conference 2018, pp 88–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By D E. Tennant

In the fields of geotechnical engineering and slope management, various software packages are used to assess the behaviour or propensity for a slope to fail. Traditional kinematic analysis calculates the probability of failure of design sectors with respect to dominant structural set orientations. A novel methodology is provided here to view potential hazardous slope behaviour in 3D, allowing engineers to make informed decisions regarding various pit slope geometries. Apparent dips are calculated for every point in space with respect to every slope orientation of the entire pit surface/design, specifically in reference to bench and inter-ramp planar failure mechanisms. Implementing a proactive approach to slope design will not only lead to early mitigation of risk but can also add direct value by enhancing or improving upon slope angles for earlier access to ore. From a safety perspective, identification of unfavourably oriented slope geometries can be dealt with before failure occurs. This methodology relies on a strong understanding of the existing rock mass anisotropy, particularly behind the face, thereby removing some of the uncertainty surrounding pit design as well as presenting engineers with an additional means to manage risk.

Nov 29, 2022

By S Doyle

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Macraes gold mine in Otago, New Zealand, is developed along the central portion of the Hyde-Macraes Shear Zone (HMSZ), which dips gently to the NE, and is traceable over 30 km of strike, before disappearing under tertiary cover. Mineralisation is most intensely developed along the hanging wall shear, which defines the upper limit of the shear zone, although significant packages of quartz vein arrays and mineralised shears occur sporadically beneath the hanging wall shear.The Macraes gold mine is now in its 25th year of operation, well beyond the projected mine life at the time of commissioning in 1990, and currently contains over triple the measured and indicated resource inventory that was defined at start up. The extended mine life and resource growth has been driven by exploration and resource development success, efficient low-cost mining and processing, improving gold price, as well as an ethos of continuous improvement.The emphasis of Oceanagold’s exploration and resource development has shifted over time; from hanging-wall-focused mapping, soil sampling and step-out drilling, through exploitation of previously drilled stockwork mineralisation, to the pursuit of blind, higher-grade underground targets.Mineralisation within the HMSZ remains open at depth, and the regional potential has not been fully tested. Given the relatively low-grade of gold mineralisation at Macraes, the consideration of tungsten as a supplementary co-product provides an exciting opportunity.CITATION:Moore, J and Doyle, S, 2015. Resource definition in the world-class Macraes gold mine, New Zealand, in Proceedings PACRIM 2015 Congress, pp 557–564 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By L Hussey

Mt Keith concentrator treats low grade disseminated nickel sulfide ore supplied from the adjoining open pit mine. It is a traditional crushing, two-staged closed circuit grinding circuit (SAG & Ball Mills), followed by a complex split-size rougher, scavenger and cleaner flotation circuit. In 2016, 10.5 Mt was milled, at an average head grade of 0.54% Ni, yielding 35 000 nickel metal tonnes in concentrate.Historical analysis of the plant data indicated that of all the nickel lost in the fines rougher circuit tails stream, 25.6% was recoverable in an eight minute laboratory scale flotation test. These results implied that this fine nickel was readily available for recovery in the plant, either through operational improvements or additional flotation capacity. With operation optimisation ongoing, and capital within the business focused elsewhere, plant personnel were challenged to think differently about improving recovery.In 2012, a separate project to improve plant recovery when treating high talc ore was completed. Amongst other vessels, this project saw the installation of two 150 m3 Outotec Cells to the scavenger section of the fines rougher, middlings and scavengers (RMS 1) circuit. Since installation, the operation of these cells resulted in difficulties immediately upstream with instability in the scavenger cells. It was therefore decided that these cells would be better suited to treating the fines rougher circuit tails.The alterations required to divert these flows were minimal, with the capital project totalling $220 000.In the two years since installation, the fines rougher tailings nickel grade has dropped by 9.9%. The scavenger circuit has also seen a 2.8% reduction in tailings nickel grade, and instability issues were immediately resolved. This project serves as a lesson in how existing plant infrastructure may be better utilised to maximise recovery. Although this is especially applicable when capital constrained, such re-appropriation can be considered at any point to maximise return on existing assets. CITATION:Hussey, L, 2017. Repurposing flotation capacity at Mt Keith nickel concentrator, in Proceedings MetPlant 2017, pp 254–258 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By N Madani

Linear interpolation of geo-related variables is important to different aspects of mining engineering such as long and short-term mine planning. The ore deposit description attained from spatial modeling of blast hole datasets has been widely taken into account, particularly, for short-term mine design and grade control, so as to define the ultimate destination of a mined block. It is approved in practice that making the wrong decision leads to losing a huge amount of money for choosing the destination of a mined block. In the case of complex ore deposits, the issue of estimation of variables in the region is questionable and somehow tedious. Due to this fact, modeling those complications in the co-spatial behavior of the grades in multi-element deposits prompts one to employ enhanced geostatistical techniques. Traditional approaches of this purpose such as polygon, inverse distance weighted and even (co)-kriging approaches, are incapable of reproducing those complexities such as non-linearity, heteroscedasticity and geological constraint that frequently exist among the variables of interest in those deposits. Another difficulty in employing those linear interpolations in grade estimation is smoothing effect, in which the estimated grades are over and under estimated. CITATION: Madani, N, 2018. 3D estimation of variables with complexity in cross-correlation structures, in Proceedings Complex Orebodies Conference 2018, pp 49–52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

THE Company's smelting equipment consists of three blast furnaces, supplied with blast from two sets of vertical piston blowers, each capable of delivering 8000 cub. ft. of air per minute at a pressure of 60 oz. per sq. in. Each blower is belt-driven by a 1:30 h.p. motor. The maximum speed of the blowing engine is 35 r.p.m.No. 1, the largest of the three blast furnaces, has a crucible area of 49.5 sq. ft., and measures 11 ft. 6 in. x 5 ft. at the tuyeres.From tapping floor to feed floor measures 35 ft. 9 in., and holds, when full, 100 tons of charge. Blast enters through thirteen 3-m. tuyeres at 60-oz. pressure. Working normally, this furnace is capable of treating :300 tons of charge, exclusive of returned slag and coke, per 24: hours, with an output of 100 tons of lead. Tapped slag flows into a C.l. forehearth mounted on wheels, where any lead and matte is caught, and the slag overflows into a 3-ton cast-iron pot, in which it is drawn away by an electric locomotive and poured over the dump.

Jan 1, 1918

By G Reynolds, N A. Ware, L Lu

Queensland Pacific Metals (QPM) is progressing its Townsville Energy Chemicals Hub (TECH) project to produce nickel and cobalt sulfates for advanced battery materials. Apart from the nickel and cobalt sulfates, the process also generates a hematite by-product (~640 ktpa). The hematite byproduct precipitated from the process, hereafter ‘hematite precipitate’, is high in Fe and particularly low in impurities. However, it is a fine <20 μm crystalline, hydrometallurgical precipitate and is produced as a filter cake containing a high moisture content of about 15 per cent. This is considerably different from natural hematite ore and is expected to change its performance during sintering. In the present study, laboratory scale sintering tests were undertaken to evaluate the potential impacts of substitution of the hematite precipitate for traditional magnetite concentrates and further for Australian hematite-goethite ores in a simulated industry base blend. Substitution of hematite precipitate for magnetite concentrates was found to slightly increase the sintering temperature required to achieve the strength of laboratory sinters. However, further substitution of hematite precipitate for Australian hematite-goethite ores slightly reduced the sintering temperature required to achieve the laboratory sinter strength. These results reflect the reduction in Al2O3 contents of the blends and are consistent with the trend observed in industry and pilot scale facilities. The reduction in sintering temperature generally correlates to a reduction in fuel rate in the larger scale sintering process. The pore structure of selected laboratory sinters was further examined and discussed in conjunction with sinter strength. The pore structure images highlighted the relative difference between the blends with the most obvious difference being seen at 1290°C which correlates well with the laboratory tumble index (TI). The laboratory sinter samples showed an increase in porosity and irregularity of pore shape, as hematite substitution increased demonstrating the correlation between a more porous structure and a lower TI.

Sep 18, 2023

By J Stiefenhofer

"*This is an abstract only*Construction of geological models for kimberlites has historically largely been based on visual volcanic textures and features, with chemical data only collected on an ad-hoc basis depending on the level of perceived complexity observed in the geological data. The focus of this paper is a high-level view of the impact an initial absence (or lack) of relevant chemical data had on two kimberlite resource models as well as how the magnitude of the problem increased once the resource estimation process commenced (Stiefenhofer, 2013). The impact of ignoring chemical data on a project assessment where micro-diamond estimation techniques are employed, is also discussed. Resource estimates based on micro-diamond data are critically dependent on the use of the correct geological model since stationarity of the size frequency distribution is key to the generation of correct grade estimates. A multilevel approach is advocated where the volcanological/visual model is verified using chemical data and both are in turn verified by the diamond data.CITATION:Stiefenhofer, J, 2013. The use of chemical and metallurgical parameters to enhance the economic value of kimberlite resource models, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 101-104 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013