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By F Cesnik

The past few years has seen a concerted effort to improve the recovery of gold along with its co-product copper from the æhigh-gradeÆ Ridgeway concentrator at Newcrest Mining LtdÆs Cadia Valley Operations. A number of initiatives were identified and implemented, culminating in a sustained improvement in recovery of approximately three to four per cent for both metals. The key projects that contributed to this improvement included the installation of a 355 kW Metso stirred media detritor (SMD) to create a regrind circuit, installation of froth crowders on the scavenger circuit, installation of a Falcon SB2500SE gravity concentrator as part of the regrind circuit to improve gold recovered to bullion on-site and the optimisation of the grinding circuit to reduce the 80 per cent passing size (P80) of the primary grind from 160 to 121 ¦m for the same throughput via process control, cyclone and ball charge optimisation. This paper will focus on the supporting test work, where applicable, that was used as the design basis for the project, but more importantly the plant data before and after the changes to clearly identify the improvements to plant recovery.

Jan 1, 2007

By Brett D

Tailings disposal and water management are one of the most important environmental issues in mining projects. The nature and the method of disposal of the tailings will determine the long term environmental impacts and must be carefully considered at the planning stage so that final abandonment can be economically achieved. If not, long term and on-going treatment and amelioration may be required to achieve environmental standards. Final abandonment requires dam safety surveillance inspection to satisfy engineering stability and hazard requirements as well as environmental issues. Environmental issues include stability, as well as rehabilitation and long term contamination potential.

Jan 1, 1991

By Baker G

The detailed mineral composition of the lead-zinc ores at Captain's Flat was first studied in 1942 (Edwards, 1943).At that time the workings did not extend far below the 750ft. level. Since then development has been extended to the 1,390ft. level, and -at the request of the management of Lake George Mines Ltd., an examination of the ore from the deeper levels has been made as part of the research programme of the Mineragraphic Section of the Commonwealth Scientific and Industrial Research Organization.This account is. based on that examination (Mineragraphic Rept. No. ,537, C.S.I.R.O.)GENERAL GEOLOGYThe geology of the Lake George Mines has been described briefly in The Geology of Australian Ore Deposits (1953), and in much greater detail in an unpublished report by K. Glasson (1952). The area consists of fossiliferous Upper Ordovician sediments overlain by volcanics (Kohinoor VoJcanics), and by fossiliferous Silurian sediments. The volcanies comprise a series of· flows ranging in' composition from dacite to rhyolite, with interbedded tuft's and shale lenses.The region has been strongly folded. The regional strike is from 340° to 355°, and dips are from 75°W. to 75°E, A major syncline, pitching 200 N., occupies the centre of the area. The Kohinoor Volcanic'l outcrop as two bands which represent the east and west limbs of this syncline.The Volcanks in the western limb, with whIch the orebodies are associated, are more strongly sheared than those in the eastern limb.

Jan 1, 1953

By J Li, H Hooi, D Payne

Caval Ridge Mine (CVM) is one of the newly established open-cut coal mines of BHP in Queensland, where no tailings dam is planned to be built in order to minimise environmental impacts from mining activities. The waste streams from the Coal Handling and Processing Plant, including fine tailings dewatered by belt filter presses, coarse rejects, and mixed plant rejects, are co-disposed within waste dumps built with pre-strip and dragline spoils. Due to high rejects output (35 – 60% of feed) and low spoil to reject ratio (< 5) the large quantities of rejects bring significant geotechnical and operational challenges to CVM, which are exacerbated by increasing annual production rates and additional rejects from washing coal from an adjacent mine. Further in-house geotechnical review commenced in mid-2014 based on the initial geotechnical studies during the project stage of CVM between 2011 and 2013. The outcomes have enabled rejects disposal at CVM by constructing large belt filtered tailings cells, coarse rejects only dumps, and co-disposal of the mixed plant rejects at dump tip-heads. This paper presents the rejects disposal strategies at CVM from both technical and operational aspects. It also discusses future projects for belt filtered tailings moisture reduction including assessment of tailings clay mineralogy, as well as mixed plant reject co-disposal verification and optimisation.CITATION:Li, J, Payne, D and Hooi, H, 2018. Plant rejects disposal strategies applied at Caval Ridge open cut coal mine, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 50–60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By A Parbhakar-Fox, B G. Lottermoser, N Fox

"Determining the deportment of economic and environmentally significant elements in sulfidic mine materials (eg ore, gangue and waste) requires the use of advanced microanalytical techniques, including electron microprobe analysis (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Sulfidic boulders were sampled from an acid rock drainage impacted ephemeral stream adjacent to historical copper-silver workings at Baal Gammon, northern Queensland. The abundance and deportment of a range of trace elements and precious metals were analysed in these samples. Whilst many of these elements represent a potential environmental risk if leached from sulfidic rocks into streams in the surficial environment, significantly some of these elements (eg In, Sb and Co) represent specialised metals that are currently considered to be in critical supply.Sulfidic waste rock material at Baal Gammon is dominated by chalcopyrite, arsenopyrite, pyrrhotite and pyrite. Microanalytical investigations revealed that chalcopyrite contains significant quantities of In, Sn, Ag and Zn either substituted directly into the crystal lattice or occurring as discrete sphalerite and stannite inclusions. Arsenopyrite, which may comprise more than 50 per cent of some boulders, is notably enriched in Sb, Co and Ni but also contains inclusions of sphalerite, chalcopyrite and stannite. In contrast, pyrrhotite contains no trace elements of economic significance, but instead represents a likely contributor to acid generation during oxidation in the surficial environment. Trace metals (eg In, Sb, Co, Ni, Zn) are liberated during sulfide oxidation of these boulders in the surficial environment, generating a metal-rich, low-pH leachate.Fe-oxides precipitated as rinds on the surface of these boulders under low pH conditions also contain abundant As, Bi, Sn, Cu and Zn. Abandoned or historical mines represent potential sources of metalliferous drainage that poses potential environmental risks to water and habitats. However, sulfide-rich historical waste rock, stockpiles and processed waste (eg tailings) at abandoned mines may also represent significant sources of critical (eg indium) or other significant metals (eg Sn) that if liberated economically could improve environmental conditions in and around abandoned and historical mines.CITATION:Fox, N, Parbhakar-Fox, A and Lottermoser, B G, 2016. Critical and Deleterious Metal Deportment in Sulfidic Waste Rocks, Baal Gammon, North Queensland, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 173–182 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Tozawa K, Nishimura T, Sasaki K

Liquidus surfaces in a part of the systems ZnO-PbO-Si02 and ZnO-"FeO"-SiO 2 were constructed by the quenching method. The ex- periments were carried out in air in the system ZnO-PbO-Si02. In the part investigated the primary phases were three ternary compounds (PbO.ZnOòSiO2, 2PbOòZnO.2SiO2 and barysilite), three lead silicates, Zn2SiO4 and SiO2. Iso- therms on the liquidus surface of each primary phase field were determined from 750 to 1300¦C. In the system ZnO-"FeO"-SiO 2 the experiments were carried out in an atmosphere of purified nitrogen. In the part investigated the primary phases were Fe2SiO4, Zn2SiO4 and Si02. Iso- therms on the liquidus surface of each primary phase field from 1150 to 1300¦C and the ternary eutectic (1130¦C, 15.9% ZnO, 48.2% "FeO" and 35.9% Si02) were determined.

Jan 1, 1980

By S Miller, R Smart, J Thomas

Single-addition and sequential net acid generation (NAG) experiments were carried out on natural and prepared samples with varying contents of organic matter and pyritic S. Results show that carbonaceous matter can produce significant quantities of organic acids during peroxide oxidation in the NAG test, which leads to overestimation of acid-forming capacity and misclassification of benign samples as potentially acid forming (PAF). Organic matter effects were most pronounced in samples with low S (less than 0.5 per cent) and total organic carbon (TOC) contents of greater than seven per cent. The single-addition NAG test will tend to overestimate acid potential in samples with little or no pyrite and high organic matter content, potentially leading to sample misclassification. High pyritic sulfur samples tend to show little difference in single-addition NAG acidities with increasing organic matter, and it appears that pyrite is preferentially oxidised by peroxide when present in significant concentrations (greater than one per cent pyritic S). In sequential NAG tests overestimation was greatest in samples with little or no pyrite, but highly carbonaceous (>20 per cent TOC) pyritic samples were affected in later stages as the pyrite was depleted. A modified NAG method is proposed to account for the relative proportions of pyrite derived acidity and organic acidity in a given NAG solution.

Jan 1, 2003

By G W. Scott, H M. Lukey

The Lake Superior Region has been a producer of iron ore for over 150 years. Early mining operations concentrated on direct shipping ores, which are the result of post-depositional upgrading principally by deep weathering. As direct shipping ore reserves became depleted, the focus changed to the production of iron ore pellets from taconite. The post-depositional processes responsible for upgrading taconite are regional metamorphism, contact metamorphism and hydrothermal processes (Clout and Simonson, 2005). While these processes are important in iron ore genesis they can also contribute to liberation problems and in some instances reduced pellet quality (Han, 2004). Low-grade metamorphic mineral assemblages can negatively impact liberation and pellet quality. Low-grade iron formation may contain a suite of carbonate minerals including ankerite, dolomite, kutnohorite, siderite and magnesiosiderite. Variation in the distribution and composition of siderite and magnesiosiderite makes controlling the MgO content of pellets difficult. Carbonate minerals also require calcination in the pellet induration process, which requires additional heat to be added to the system, slowing down the induration process and reducing throughput. Prediction of carbonate mineralogy and carbonate mineral chemistry is an important goal of ore characterisation for pelletising properties. Contact metamorphism causes changes in mineralogy and grain size (Klein, 1973; Gunderson and Schwartz, 1962). Increasing the grain size of magnetite should improve its liberation characteristics. However, plant grinding targets may not allow the coarse-grained, more easily liberating magnetite ores to increase throughput and can actually result in decreased throughput due to recirculation. While magnetite and martite ores are well understood (Lukey, Johnson and Scott, 2007) late open-space filling microplaty haematite ores are not. These ores, while composed of similar minerals, have a unique genesis that results in fine grain size and complex textures that present liberation challenges and often make interpreting laboratory metallurgical test results more difficult.

Jan 1, 2007

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high-speed photography to better understand the mechanisms of fracture and fragmentation.CITATION:Fourney, W L, 2015. The role of stress waves and fracture mechanics in fragmentation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 27–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By J Morgan

Regular monitoring of surface deformation over mine sites is important for providing updated information to managers regarding geotechnical risks related to ground instabilities. This is particularly true in cases where unexpected or accelerating movement patterns are observed, as these trends may have implications related to worker safety within active mining environments, as well as continuity of ongoing operations. InSAR is an active remote sensing technique that uses radar satellite imagery to precisely measure ground movement. This technology has started to become a standard tool for monitoring surface stability in many different sectors, including underground and open pit/cut mining applications. In recent years the launch of satellites that collect radar imagery on a more frequent basis, coupled with advances in InSAR processing techniques, has improved both the extent to which movement patterns typical of mining operations can be characterized and the temporal scale on which results can be reported to geotechnical departments. As a result of these developments, InSAR monitoring can now better meet the operational needs of mine sites. An overview of the more recently launched satellites that have a particular relevance to the monitoring of mines is provided, along with an explanation of the InSAR tools that are the most valuable to mine managers and geotechnical engineers. First, broad differences between high resolution X-band imagery and low resolution (but freely available) Sentinel imagery are discussed. Second, the various InSAR tools and their particular applications for different types of mine sites and operations are covered, which include fast delivery deformation maps for short-term reporting, multi-interferometric algorithms for longer-term analyses and rapid movement tracking (RMT) for emergency monitoring or high-risk situations. The ability of the technology to resolve 2D and 3D movement is also touched upon. Practical examples of InSAR application over a variety of mine sites will be presented, as well as surrounding hazards including landslides, to illustrate how InSAR can help provide geotechnical engineers with a picture of surface stability over the full mine site and surrounding areas to help manage risk. CITATION:Morgan, J, 2018. Wide area mapping of ground instabilities from space: InSAR for geotechnical risk assessment and hazard monitoring, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 375–382 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By A Jyoti, J R. Black, R R. Haese, E O. Ansah

Copper (Cu) is a critical metal in the transition to a low-carbon power supply. Presently, low-grade copper sulfide ores account for almost 80 per cent of the global reserves. Large amounts of water are required to process these low-grade copper ores. The mining industry utilises lixiviants from recycled water from different sources to conserve water, whilst enhancing Cu recovery. Some utilise intermediate to pregnant leach solutions, sea water, and processed water from electrowinning circuits with highly variable concentrations of ions. Previous studies have highlighted the formation of precipitates that passivate the surfaces of minerals in these low-grade copper ores and/or block flow paths for lixiviant during heap leaching. In this study, we utilised concepts of phase replacement to devise an innovative means of controlling precipitation and increasing copper recovery using industrial brine as opposed to freshwater. We propose the formation of Al-rich phases (such as AlSO4 + or alunite) to replace iron sulfate and iron hydroxysulfates (such as jarosite) during the chalcopyrite dissolution-precipitation mechanism. The rationale is to have available Fe3+ throughout the chalcopyrite leaching process. We tested this method by carrying out various batch experiments using CaCl2, AlCl3, and NaCl industrial brine types compared to freshwater and explored the capacity to leach Cu from chalcopyrite. There is higher Cu recovery during oxidative leaching of chalcopyrite in industrial brine with 91 per cent recovery using AlCl3-rich brine, 84 per cent with NaCl-rich brine, and 56 per cent with CaCl2-rich brine as compared to 35 per cent recovery using freshwater. In the absence of Al3+, various forms of iron sulfates, and jarosite are formed, reducing the availability of Fe3+ for chalcopyrite dissolution. The introduction of Al3+ leads to the formation of AlSO4 + species, thus lowering sulfate activity and the tendency for K-jarosite formation.

Aug 24, 2022

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

COAL constitutes such a gigantic item in modern industry, either for direct heating, production of coke for smelting, or for the generation of power, that its quality and price play a very significant part in economic industrial progress. Australia is still a very young country industrially, and is groaning under many disabilities compared with competitors overseas, not the least of which is the quality of coal. Linked with the word "quality" should be that of "utility," for high-ash content prevents efficient utilization of the fuel.The marketing of good quality coal is a very important matter indeed, and if industry in Australia is to progress in the way that it should, this matter must receive keen attention.New South Wales, above all the other Australian States, has been blessed by nature with vast coal-fields, from which fuel is shipped to every State, and provides the base for power for most of our railroads and industries.Experts frequently refer to the fact that in some districts only partial extraction of thick seam coal is being made, without a care or thought for the future. Ranking next in importance to this is the fact that much of the coal is being carelessly marketed.Very few collieries in Australia are equipped with coal-washing plants for dealing more particularly with small coal grading which most industries require, and to which coal producers as a whole pay the least attention. In England each year nearly20,000,000 tons of coal is being water-washed before sale, and is marketed as a fuel of far greater utility once it has been freed from extraneous ash.Investigation proves that a great many pits in New South Wales are marketing coal (more particularly small coal) containing a considerable quantity of extraneous ash, due to the admixture...

Jan 1, 1926

The Savage River open cut magnetite mine is located in rugged terrain in densely rain forested northwest Tasmania. The mine and concentrating plant are both in the Savage River valley. Pickand Mather Incorporated (PMI) operated Savage River as an open cut magnetite mine between 1966 and 1996. Acid rock drainage (ARD) was first noted in the last ten years of the operation, leading to elevated concentrations of heavy metals downstream of the mine. When operations ceased in 1996, PMI returned the mine to the Tasmanian Government along with a remediation fund of $11.4 million. At that time, the assessed cost of remediation was in excess of $120 million. As a result of the ongoing ARD contamination and to facilitate both a new operation and effective remediation, Goldamere Pty Ltd negotiated an agreement with the Tasmanian Government in 1996, which resulted in the Goldamere Act and the Goldamere Agreement. The agreement has allowed Australian Bulk Minerals (ABM) to remediate the Savage River mine in conjunction with the Tasmanian Government while re-invigorating a previously closed mine by providing ABM with an indemnity against past pollution. ABM can configure its mine and waste planning activities to maximise remediation benefits without fear of future litigation for past mistakes. The effect to date has been the development of a long-term strategy to remediate the Savage River and short-term remediation works such as water management, which provide benefits to the ecosystem. After five years, the Savage River is no longer significantly impacted by ARD for 30 kilometres downstream and trout are now reported within the reaches of the mining lease. The arrangements between ABM and the Tasmanian Government are an example of a genuine WIN WIN situation where co-operative environmental management of the site results in significant improvements and where the æregulatorÆ and the æminerÆ are working together to achieve mutually beneficial goals. The end result is a significant benefit to Tasmania.

Jan 1, 2003

By Schaap W

A test on Taylor's rule of mine life using published data on open pit porphyry copper mines confirmed that mine life is, on average proportional to the fourth root of reserve tonnage. Deviations from this rule-of-thumb occur to a large extent as variations between regions that are qualitatively explained in terms of differences in grade, infrastructural needs or special taxation effects.

Jan 1, 1984

By S J Riley

The cover (cap) over the tailings pit at Nabarlek uranium mine must be structurally stable as it will act as a barrier to radon gas emission and have to contain other long-lived radionuclides. Structural stability is primarily an issue of erosional stability in the context of a design life of thousands of years. The primary agent of erosion is fluvial, dominated by rainwash, overland flow, filling and gullying in the local area. Other agents of erosion are of less concern although biogenic agents of erosion (eg termites and windthrow) may enhance fluvial activity. Several methods may be used to assess erosional stability. They fall into two main categories, namely erosion modelling and geomorphic modelling. The former is illustrated by the Universal Soil Loss Equation in which parameters describing aspects of the geotechnical and hydrological properties of the rehabilitated surface are used as input for the modelling of erosion rates. The latter is illustrated by estimates of gully and valley erosion using empirical models. Estimates of the erosion rates and stability of the Nabarlek cover are presented. The two main techniques are complementary and it is argued that rehabilitation design must make use of both approaches when estimating erosion and geomorphic stability. More recent developments in geomorphic modelling using numerical techniques incorporate both approaches.

Jan 1, 1994

By J F. Costa, A Grigorieff

Coal mining reclamation is a worldwide concern. This paper presents a Brazilian example where the economic aspects of reclamation are considered. The basic goal of the study is to transform the reclamation procedures into an economic process by integrating the use of land after reclamation and developing profitable post operations. Some of the activities considered in this case study include: using of the coal pit as a landfill, considering appropriate landfill design and construction; using the area for forest development; and developing grassland, forests of native species and the construction of ponds for fishery. This study will conclude that the mined area is: capable of storing large quantities of waste at a competitive cost and at a low environmental risk; commercial forest development is economically feasible; and the lakes and other reclaimed areas can be integrated into the landscape creating a fresh water supply and an area to raise cattle.

Jan 1, 2005

By K Seddon

Segregation of tailings on deposition can occur as a result of a) sub-aqueous deposition, and b) sub-aerial deposition at lower solids concentrations (i.e. when the solids concentration is less than the segregation threshold). The effects are likely to be more pronounced in the case of subaqueous deposition.This paper presents the results of an investigation of a sub-aqueous tailings facility.Data from the investigation show extreme variations in particle size and density compared to test results for non-segregated ‘all-in” tailings. The results indicate that on segregation both the fine and coarse splits tend towards a well sorted (poorly graded) mix, and both have significantly lower consolidated density than the all in tailings. This result is reasonably well known for the case of the segregated fines (“slimes ponds”) but less appreciated for the coarse fraction. The results suggest that if the effects of segregation are not allowed for, the overall density of the deposit can be seriously over-estimated at the design stage. Also the quantity of water retained in the tailings can significantly influence water recovery and water balance results.CITATION:Seddon, K, 2018. Segregating tailings – effects on density and water retention, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 299–308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Kelly D, Moore C

The Golden Mile, which has been mined continuously for the past 100 years by both underground and more recently open pit methods, occupies an area of 1.2 km by 4 km adjacent to the city of Kalgoorlie Boulder in Western Australia (Figure 1). Large-scale open pit mining at the Kalgoorlie Consolidated Gold Mines (KCGM) Fimiston operations is currently extracting 7.8 million tonnes of oxide and sulphide ore for a total production of 522 000 oz per annum. The effectiveness of grade estimation techniques at KCGM has been examined with reference to existing 10 m bench sample data from all operating areas within the Eastern Lode System of the Main and North pits. The aim of the study was to recommend practical parameters for grade control estimation. The review included comprehensive variography and comparison of nonparametric estimation methods (Joumel, 1983) such as indicator kriging and probability kriging with ordinary kriging, leading to the development of improved grade control parameters and procedures for both daily quality control and short term mine planning. This paper reviews the geological, statistical, geostatistical, mining and modelling features studied in order to present KCGM's Mining Department with recommendations for improving grade control.

Jan 1, 1994

By J Pan, Q H. Li, D Q. Zhu, C C. Yang, X Wang, Z Q. Guo

Al2O3 in natural iron ores generally occurs in goethite, kaolinite, gibbsite, hematite and iron carbonate. When the content of alumina in sinter increases from 1.11 per cent to 3.50 per cent, the reducibility of sinter decreases with the addition of four different types of alumina. When gibbsite and kaolinite are added, the low temperature reduction disintegration (RDI+3.15 mm) of sinter increases with the increase of Al2O3 content in the range of 1.5 per cent to 3.5 per cent. Furthermore, when adding pure reagent alumina, the increase of Al2O3 content in the range of 1.5 per cent to 3.0 per cent will increase the RDI+3.15 mm of sinter. The addition of ferric oxide–alumina spinel with the Al2O3 content in the range of 1.5 per cent to 2.5 per cent, also increases the RDI+ 3.15 mm of sinter. The influence difference is results from the change of the mineral composition and microstructure of sinter because of the occurrence state of Al2O3. Under the condition that Al2O3 content of sinter is 2 per cent, the porosity of sinter with kaolinite is 37.26 per cent, and the shape is irregular. When gibbsite and ferric oxide–alumina spinel are added, the porosity of sinter is about 16 per cent, and the pores are round. When pure reagent alumina is added, the porosity of sinter is 17.49 per cent, and the pores are regular and small. When kaolinite, gibbsite and ferric oxide–alumina spinel are added, platy calcium ferrite is mainly formed in the sinter, and some of it is columnar calcium ferrite. On the other hand, when pure reagent alumina is added, in addition to platy columnar calcium ferrite, acicular calcium ferrite is also formed in the sinter.

Nov 8, 2021