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By Giles C. N, Loughnan F. C

Bentonites and active earths from N.S.W., previously analysed with respect to occurrence, mineralogy and physical properties have been evaluated for use as bonding agents in quartzose moulding sands in terms of green properties and behaviour both with and without coal dust for iron castings poured at 1400°C.INTRODUCTIONIn the paper by Loughnan .and See (Part I) the occurrence, mineralogy and physical properties of the fuller's earth and bentonites of New South Wales were discussed and it was shown that some of the materials approached the quality of Wyoming bentonite. In the present paper the same samples from Marulan (Bl), Boggabri (B2), Wingen (B3), Muswellbrook (B6), Swansea (B8), Dubbo (89) and Trida (Bll) have been investigated with respect to their potential value as bonding agents in compounded moulding sands. Inaddition, the -20 micron fractions of the Boggabri (B2t) and Swansea (B8t,> were recovered and the former converted to a sodium clay, in order to assesE; the beneficiation possibilities. A sample of Wyoming bentonite (S2) also has been included for comparison.GREEN PROPERTIES OF THE ARTIFICIAL MOULDING SANDSA quartzose base sand (Botany Dune) previously oven pried and screened to 1·65 mm., was subjected to a sieve ana]ysis in accordance with standard A.F.A. practice to yield a calculated' fineness number of 45. All tests were carried out on mixtures of this sand with2t per cent clay, since such mixtures were found most suit...

Jan 1, 1959

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

Geosynclines have been well studied for many years, but very little has been written about the concepts of sedimentary basins in spite of the vast amount of data available. They have been regarded, perhaps, as well- understood intuitively, and therefore not worthy of study. Many of the fundamental concepts of geology were developed during the 19th Century with the construction of coal mines, canals and railways. It was a happy chance that led railway engineers in the early days to think that trains could not climb any but the smallest gradient, so, in Britain at -least, numerous railway cuttings and tunnels were made. These exposed to view and study, in a better form than Nature usually provides, a great deal of interesting geology. Because of the lack of literature about the concepts of sedimentary basins, it is not possible to be sure what the early geologists thought. It seems that sedimentary basins were regarded as recording a history of subsidence during the early stages, when a transgressive sequence accumulated; and a history of uplift during the later stages, when a regressive sequence accumulated. It seemed axiomatic that the age of folding and faulting was younger than the rocks folded or Faulted.

Jan 1, 1987

By Sorokin AP

The main regularities of the tectonic history of the Circumpacific belt's Asian segment are discussed. The established longitudinal metallogenic zoning is characterized by essential copper specialization being replaced in the.continentward direction by tin-tungsten and then by copper-gold-molybdenum and-tin-lead- zinc ones. The zones indicated show specific magmatism and ore forming fluid composition. The eastern margin of Eurasia experienced specific tectonic history and exhibits a wide variety of mineral deposits. It is composed of the Siberian and Sino-Korean cratons and of the largest mobile elements of tectonosphere like the Hyperborean, Urals-Mongolian, Mediterranean and Circumpacific belts. The Earth's Atlantic segment mobile features show deep penetration of their geosyncline-fold systems into the eastern margin of Asia. A good example is the Urals-Mongolian belt, its Intra-Asian branch being located within the continental margin. The Intra-Asian structural features have WE and NE trending, while folding process moved southward : Karelides and Baikalides are found in the Transbaikalia and the Soviet Far East (Stanovoy, Bodaibo-Patom, Baikal- Vitim, Selenga-Yablonovy fold regions)

Jan 1, 1987

By McConachy G. W, Wright J. V

During the 110 years since the discovery of the Broken Hill PbZnAg deposit six major mining companies have mined the ore body and explored the ore environment. Despite this activity, no new orebodies have been found at Broken Hill. The failure to discover large new resources cannot be attributed to a lack of activity because major companies have maintained substantial exploration commitments over many decades. This suggests that not only was a unique coincidence of conditions required to form the deposit but also that full recognition and definition of the critical parameters may not yet have been recognised. In an attempt to illuminate some of the more unusual and poorly studied characteristics of the ore environment some new areas of investigation are presented here which may contribute to understanding the ore deposit setting and focus exploration towards different and perhaps more productive targets. Sedimentological characteristics of the host succession of the Broken Hill deposit are apparently unique along the line of lode. An upward-coarsening megasequence reflected in the development of clastic psammites stratigraphically below the ore deposit is one important ingredient which has received little exploration focus. These psammites also host mineralisation and form part of a spectrum of quart-zrich rocks collectively referred to as gametiferous psammites, garnet quartzites and blue quartz lodes. Sedimentological data interpreted from outcrop, drill core and downhole geophysical well logs support a elastic origin for some of these rocks; an interpretation which is at variance with traditional interpretations favouring an exhalative origin. A clastic origin for many of the footwall psammites, and their close spatial association with the orebodies suggests their role in ore formation was important. It is interpreted as a critical part of the fluid flow architecture within the sedimentary basin, which focussed ore forming fluids into an unique environment favourable for trapping mineralisation. Detailed stratigraphic correlation near the deposit has also highlighted that quartzofeldspathic rocks (Potosi gneisses and lode pegmatites) have complex relationships with ore. Suites of stratabound quartzofeldspathic pegmatites have received limited study, but their distribution and voluminous development suggests they may be as important to ore formation as the psammitic lode rocks which host the orebodies. These associations are not in conflict with some recent ore forming models invoking deposition in a shallow water environments of deposition. The geochemistry of parts of the host sequence has been studied extensively in the past but this has not been merged with current stratigraphic subdivisions. A large drillhole data base now permits the geochemistry to be related to the sedimentary succession and reveals that a signature involving stratigraphic vectors best illustrated by changes in MnO, Na2O, Pb and Zn can be detected. This is interpreted to reflect sedimentary basin processes as opposed to a classical volcanic hydrothermal alteration pipe associated with seafloor venting. The stratigraphic setting together with characteristics of some of these poorly understood areas is discussed to emphasise that construction of sound models for exploration requires the total ore environment to be studied with attention directed to the geometry and setting of the full range of host rocks. Control of the greater portion of the line of lode by a single company, Pasminco Australia Limited, now permits disparate datasets and observations to be merged and presents new opportunities and encouragement for model refinement and exploration success.

Jan 1, 1993

I propose to speak today about our mineral heritage. In common usage "heritage" refers to the past. It means the discoveries, the developments, the mines and the processing plants, the benefits, the consequences, and the human experiences flowing from these. The history of the industry, inseparable from the history of the countries in which The Institute operates, is a rich background of which we can all be proud.But there is also a much wider meaning to mineral heritage. Our past has left us with the ab\lity to create and operate world scale enterprises generating wealth for the community, the ability to offer satisfying and challenging careers in a wide range of skills to our young people, and the willingness to follow adventurous and challenging vocations in remote areas, away from the big cities, at a time when the mentality of many is to get the most for the least effort and at the least inconvenience to themselves. The industry continues to be the repository of the pioneer spirit and a vital contributor to improving the life of the people in our countries.Thus, while our mineral heritage has much to do with the past, an essential part of it is how we use this rich past to build and shape our future. It is in this broader context that I am speaking today.

Jan 1, 1990

By C Zschiesche, alam, A Abadias Llamas, A K

An integrated experimental and thermodynamic modelling study of the phase equilibria in the FeOFeO1.5- SbO1.5-SiO2 system in equilibrium with liquid Sb and Sb-Ag metal has been undertaken to develop thermodynamic model of the Na-Si-Fe-O slag system with S-Sn-Sb-Pb-As minor elements based on the experimental investigation of the selected sub-systems. New experimental phase equilibria data at 575–1600°C were obtained for this system using high-temperature equilibration of synthetic mixtures with predetermined compositions in sealed silica ampoules, Fe3O4 basket in sealed silica ampoule, or Re foils, a rapid quenching technique, and electron probe X-ray microanalysis of the equilibrated phase compositions. Experimental results on phase equilibria in the Fe-Sb-Si-O+Sb metal system obtained helped to produce initial set of model parameters in the slag. The primary phase fields of quartz/tridymite/cristobalite (SiO2), 2 high-SiO2 immiscible liquids, olivine (Fe2SiO4), wustite (FeO1+x), spinel (Fe3O4), schafarzikite (FeSb2O4) and valentinite/ senarmontite (Sb2O3) were identified in the binary Sb2O3-FeO, Sb2O3-SiO2 and ternary FeO-Sb2O3- SiO2 systems. Further refinement, particularly the distribution of excess Gibbs energy among the ‘FeO’-Sb2O3-SiO2 and ‘FeO1.5’-Sb2O3-SiO2 interactions, required the study at more oxidising conditions. Oxygen potential was increased using an inert metal (Ag) rather than using the gas flow due to the high volatility of Sb-containing gaseous species. Liquid Ag-Sb alloys with low concentrations of Sb of a few percent were used. At these conditions, the concentration of AgO0.5 in slag was below 1 mol per cent, which had a small effect on observed phase equilibria in the system. In addition, important information on the solubility of silver in slags is produced, which can be valuable when treating electronic recycling materials or primary silver-containing ores through the Pb process. Two main areas were addressed: the spinel-tridymite boundary (40–70 per cent SiO2 in slag) and spinel liquidus near 15 per cent SiO2 in slag. This allowed to deconvolute the separate contributions of the FeO-Sb2O3(-SiO2) and Fe2O3-Sb2O3(-SiO2) systems.

Jun 17, 2024

By C Philander

The West Coast of South Africa is well known for its placer gem quality diamond deposits and also associated with these hosts of Cenozoic unconsolidated marine and aeolian sand and gravel are significant concentrations of heavy minerals. Exploration for economic concentrations of zircon, ilmenite and rutile along the coast started in the mid-1980s. This resulted in the discovery of an inferred 1.6 billion tonne resource with a grade of ten per cent total heavy minerals (THM), which developed into the Namakwa Sands Mine, a world-class producer of heavy minerals. Several other resources, including satellite deposits proximal and distal to the mine area, extensive diamond mine dumps and present day beach placers, demonstrate the vast heavy mineral potential along the West Coast. The favourable gangue to economic mineral ratio, a higher zircon content compared to other similar deposits, relatively lower U+TH content of zircon, low slimes content and effectively pristine low chromium-manganese ilmenite of these deposits, render them attractive exploration targets. Negative factors that will affect conventional mineral beneficiation and liberation include secondary mineral coatings and the regional coastal development of several layers of superimposed duricrust. The economically attractive heavy mineral assemblage along the West Coast is the result of erosion of the proximal, gneissic Namaqualand Metamorphic Province and mature Table Mountain Group sandstone, concentration by marine and aeolian processes and preservation under arid climatological conditions over a period of more than 100 Ma.

Jan 1, 2008

A new least-squares method for inversion of d.c. resistivity soundings from horizontally layered earth is proposed. Powers are used as measured data. Apparent resistivity is generalized and apparent parameters curves are defined. Estimates for parameter errors are often possible even when data errors are unknown or large. Acceptance or rejection of a model is made an easier decision. Total computational effort is often reduced when compared to global least-squares methods, because although several optimizations are needed, few data points are involved in each, and initial guesses are requested only once and not all at the same time. Correlations between parameters may be used to improve solutions. Precise indications for extra needed data points can be conveyed. A test example is worked out and a field sounding, taken by Rijo (1973, personal communication) in an alluvium-filled river valley in north-eastern Brazil, is studied.

Jan 1, 1987

By A M. Lechner, V Glenn, M Edraki, D R. Mulligan, C Unger

With more than 50 000 recorded abandoned mines in Australia, effective management strategies are needed to prioritise and manage health, safety, environmental and socio-economic risks and opportunities. This paper reviews international leading practices for abandoned mine management and identifies key issues that need to be addressed in the Australian context. As well as the academic literature, this review draws on a 2008 global legacy site survey and forum in 2008, a Churchill Fellowship study of abandoned mines and the recently released æStrategic Framework for Management of Abandoned Mines in the Minerals IndustryÆ (MCMPR/MCA, 2010).A conceptual model was developed to identify the relationship between key issues affecting the management of abandoned mines in Australia. The conceptual model is then used in the development of a maturity chart which draws on risk management principles to provide leading practice guidance for abandoned mine managers, jurisdictions and stakeholders. The maturity chart approach for risk management has been successfully used elsewhere to evaluate safety, environmental and socio-economic maturity.CITATION:Unger, C, Lechner, A M, Glenn, V, Edraki, M and Mulligan, D R, 2012. Mapping and prioritising rehabilitation of abandoned mines in Australia, in Proceedings Life-of-Mine 2012 , pp 259-266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By A Larsson, K Niiranen

The Palaeoproterozoic Leveäniemi iron oxide apatite (IOA) deposit of the so-called Kiruna type is currently mined by Luossavaara-Kiirunavaara AB (publ.), commonly known as LKAB. The mineralogy of iron oxides, ie magnetite, hematite, maghemite, and goethite is more complicated compared to the neighbouring and more famous IOA deposits of Kiirunavaara and Malmberget. Furthermore, the mineral chemistry of the iron oxides in the Leveäniemi deposit is also slightly different. Especially, the information about the deportment of titanium and vanadium in iron oxides and distribution in the deposit is essential since they can have an impact in the steelmaking process. For this study 50 samples were selected from exploration drill cores and investigated by optical microscopy, FE-SEM-EDS and EPMA at LKAB and the Geological Survey of Finland. Investigations revealed that magnetite is the predominant iron oxide mineral with secondary hematite being the second most abundant mineral. Primary hematite, maghemite, and goethite seem to be less abundant. It should be noted, however, that this investigation focused on magnetite which currently is the only mineral with economic value. Vanadium occurs as a substitution element in the crystal lattice of iron oxide minerals in the Leveäniemi deposit and not as discrete stochiometric vanadium minerals. In the investigated samples vanadium concentration in magnetite ranges from 0.12 to 0.32 wt per cent V2O3 with higher concentration in the southern part of the deposit. Contrary, titanium does not substitute for iron in the crystal lattice of magnetite or secondary hematite (less than 0.018 wt per cent TiO2). It either occurs as tiny inclusions of titanium oxide minerals or as exsolution lamellae of ilmenite in magnetite. The spatial distribution for titanium in the deposit, however, remains unknown. Furthermore, results of this study indicate that alteration of primary magnetite to secondary hematite has had no significant effect on the trace element chemistry of these minerals in the Leveäniemi deposit.

Nov 8, 2021

The copper deposits at Pernatty Lagoon are predominately djurleite-digenite bodies beneath the permanent water table, and chrysocolla-atacamite-malachite above the permanent water table. The minerals havebeen deposited as sheets, lobes, and pods in zones suggestive of permeability channels or permeability basius with respect to groundwater circulation.Pyrite is deposited in the form of framboids, which reflects its biogenic origin. Copper-iron sulphides deposit by replacement of pre-existent pyrite, and rarely by direct deposition. The latter mode of formation results in complex crustification bandings of chalcopyrite, bornite, sulphur rich bornites, digenite, and blue remaining covellites. The copper-iron sulphides appear to reequilibrate under constrained oxidation, resulting in an iron depletion and associated copper enrichment, the final product of which is a djurleite-digenite assemblage and associated with goethite. Where copper mineralization/ host rock relationships have rendered the rocks entirely impermeable to post ore groundwater movement, then the copper-iron sulphides are preserved as the ore assemblages.Minor and trace minerals observed include sphalerite, carrollite, galena, wittichenite, and possibly tetrahedrite in the primary ores. In the oxidized ores cllprite, tenorite, and trace brochantite have been found.

Jan 1, 1976

Despite the research interest on non-cyanide gold lixiviants over the past three decades all the non-cyanide gold processes are still at the developmental stages with limited understanding on solution and pulp chemistry in some cases. This is partly associated with:the difficulties in measuring reliable equilibrium data for various gold(I/III) complexes with non-cyanide ligands; the lack of knowledge on mixed-ligand complexes; and different kinetic stabilities of gold(I) complexes with respect to disproportionation. This paper presents reliable equilibrium data for complex formation, dissolution, precipitation, hydrolysis and disproportionation reactions of gold(I/III) compounds with a range of non-cyanide ligands: S2-, HS-, S2O32-, SO32-, SCN-, SC(NH2)2, OH-, NH3, Cl-. Solubility of gold(III) compounds with non-cyanide ligands follows the order: Cl- > NH3 > OH-. In the case of gold metal the solubility order at a given temperature is MgS > Fe(III) or Cu(II) / Cl- > Cu(II)/NH3 > NaOH, but the solubility increases with increasing temperature. Rate of gold oxidation with different non-cyanide lixiviants depends on the oxidant, ligand and temperature and follows the general order of oxidants: Fe(III) or Cu(II) > X2 or OX- > O2 (X = halogen). In the case of metal ion oxidants oxygen is required to reoxidise Cu(I) or Fe(II). Some of the reported data on chloride and thiosulfate leaching of gold are presented to highlight the effect of additives and the copper, silver and sulfur contents of the starting material on the success of non-cyanide leaching processes.

Jan 1, 2004

By Golledge P

Safety legislation has a long history and widespread application, but how can one test its effectiveness? One way is to examine safety statistics. Another way is to compare the legislation with principles of good safety practice. Mine safety legislation contains many features that are widely accepted, and these should be examined critically to determine their importance. Uniform legislation and revision of legislation should be considered. INTRODUCTION

Jan 1, 1975

This paper discusses basic practices of operation applied to raise drilling. It draws attention to critical areas that tend to be neglected. A brief history covers development of raise drills. The elements of the equipment, derrick assembly, drill string and reamers are ex- amined. Particular emphasis is on the drill string. It is concluded that manufacturer and operator can benefit each other by closer interchange of ideas.

Jan 1, 1977

INCREASE OF CATASTROPHE FREQUENCY AND SEVERITYIn the last couple of decades the frequency of natural catastrophes has increased dramatically. This realization results from the statistical analysis of the comprehensive loss data that we have been collecting constantly over the last 30 years and have evaluated in connec-tion with the preparation of our "World Map of Natural Hazards", which is now in its second edition (Munich Re, 1988). Each month brings data on between 30 and 50 new loss events. Fortunately, however, only a few of these have to be added to the list of major natural catastrophes, that is only those involv-ing damage that considerably exceeds what the country or region concerned can handle itself so that substantial na-tional or international aid is required. That is generally the case if the number of dead runs into the hundreds or thousands, if tens or hundreds of thousands of people are rendered home-less and if the total economic loss is in the region of US$ 100 million. These major catastrophes, about which we have fairly comprehensive data even in the case of those that occurred farther back in the past, numbered only 14 in the 1960s but 70 in the 1980s; they there-fore increased over a period of 30 years by a factor of 5. The trend is also very clear when we consider the total economic loss, which - adjusted for in-flation - increased during the same period from an average of US$ 3.7 bil-lion per year to US$ 11.4 billion, i.e. by a factor of 3.1. The insured losses, finally, increased by as much as a fac-tor of 4.8.

Jan 1, 1990

By Glasson K. R

The history of Ore Reserve classification and reporting in Australia is largely a history of the Australian mining industry itself. In the late 1800s, when the industry was dominated by small scale, high grade underground mines, Reserves (if estimated) were based on hand sampling and geological inference, and reporting of Reserves was either non-existent or of extremely variable quality. By the mid-20th century, the industry was dominated by large underground base metal and gold mines. Reserve estimation was coming under the control of skilled geologists and mining engineers, however Reserve classification and reporting standards continued to vary in type and quality from mine to mine. Today, large scale, low grade mining operations predominate, and Reserve estimates are generally based on extensive drilling results processed (with geological control) by computer. Through the efforts of a Joint Committee established by The Australasian Institute of Mining and Metallurgy and Australian Mining Industry Council, Reserve and Resource classification and public reporting has been standardised and controlled by adoption of the ""Australasian Code for the Reporting of Identified Mineral Resources and Ore Reserves"" released in 1989. The Code, which will continue to be modified and improved by the Joint Committee, has also been used as a basis for guides to reporting in other countries, and there is now some hope that this difficult and vexing topic may finally become subject to international standards and controls.

Jan 1, 1992

By Dobos SK, Gibson GM, Little TA, Sliwa R

Current studies, and analysis of previouslypublished data, have lead to a re-evaluation of the inclusion of the North D'Aguilar block within the "Gympie Province" in southeast Queensland. The metamorphic rocks are part of a Late Devonian(?)-Early Carboniferous subduction accretionary complex and are unconformably overlain by volcanic and coarse-grained clastic rocks of probable Early or mid-Permian age, as well as by Early to middle Triassic rocks of the Esk Rift. Metamorphic fabrics in the basement rocks include not only those that can be related to convergence, but also younger fabrics that may have developed during Late Carboniferous or Permian uplift and unroofing of the accretionary rocks. A predominance of basic schists, some of which are blue amphibole-bearing, and associated fine-grained pelagic and hemipelagic sediments in the Northern D'Aguilar block contrast with the siliciclastic-dominated sediments of most of the accretionary complexes of the New England Orogen. However the similarity of structural style, and metamorphic and igneous history, with adjacent basement blocks, and with other blocks throughout the New England orogen, suggests that the North D'Aguilar block simply represents deeper, probably underplated, levels of the same subduction complex. Uplift and cooling may have been accomplished by extensional faulting during Permian inception of the Esk rift, which flanks the block on the west.

Jan 1, 1990

By Lawson F

Narrowly sized samples of synthetic chalcocite (Cu2S) and covellite (CuS) were leached in oxygenated acidic sulphate-chloride solutions. Chalcocite leaches via a two-stage process, the first stage being much more rapid than the second. The apparent activation energies are 42.7 kJ/mol and 68.2 kJ/mol respectively, indicating that both stages are controlled by surface chemical reactions. The leaching of covellite is also chemically rate limited with an apparent activation energy of 77.0 kJ/mol. The shrinking core model is able to be used to describe the leaching processes of both copper sulphides. Over 97% of copper present in chalcocite dissolved in 0.5 M H2SO4i0.5 M NaCl solution under one atmosphere pressure of oxygen at 85¦C in three hours from particles 36 pm in diameter while only 85% of the contained copper in covellite particles 13 pm in diameter dissolved in the same solution under the same pressure at 90¦C in six hours. About 99% of the sulphide sulphur in chalcocite was oxidised to elemental sulphur while only 90% of sulphide sulphur was converted to elemental sulphur during covellite leaching. The mechanism proposed for the two-stage leaching of chalcocite particles is as follows: in the first stage, cuprous ions rapidly diffuse to the external reaction surface where they lose electrons and go into solution as a complex cupric chloride ion CuCl'. The second leaching stage begins when covellite is formed at the external surface. Copper again goes into solution as the CuCl* ion. The mechanism for leaching synthetic covellite is similar to the second leaching stage for chalcocite except that the leaching rate of synthetic covellite is substantially lower than that of the newly formed 'covellite'. Elemental sulphur formed on the particle surface retards the dissolution processes during both chalcocite and covellite leaching. The presence of chloride ions is necessary if essentially all of the copper from chalcocite is to go into solution. When no chloride ions were present, the leaching rate of both newly formed and synthetic covellite was almost zero. The main role of chloride ions in both chalcocite and covellite leaching appears to be to disrupt the passivation film of sulphur on the particle surface.

Jan 1, 1989

By D Connelly

Quartz deposits are common in nature but the presence of quartz suitable for yielding high purity quartz is exceedingly rare. This paper describes a test work study on producing high purity quartz (HPQ) product to meet the tight product specifications of greater than 99.97per cent, including four and even five nines, for uses including, lighting and fibre optics and modern-day high efficiency solar panels. Due to demand in renewable energy applications the market for high purity silica solar panels known for their increasing efficiency and durability is rapidly growing. Demand continues to rise for the use of high purity quartz in semiconductors, electronics, imaging and sensor markets. Microelectronic components are created by chemically fabricating wafers of semiconductors such as silicon to obtain the desired transport of electrical charge and control of the current. The production of silicon metal from high purity quartz has been designated a Strategic Mineral by the European Commission and by the US Department of Justice due to the growing significance of this metal in various industries. The subsequent processing of quartz is the key step to adding value and aiding technological advances. Overall, the high purity quartz market is a highly secretive, specialised market with increasing opportunities for stakeholders. The attempt to produce HPQ in this work was carried out using an Australian quartz ore following a typical HPQ process flow sheet. The unit processes included primary crushing, scrubbing, magnetic separation, flotation, acid leaching followed by hot chlorination. The results indicate that grinding of quartz requires specialist equipment due to the hardness and extreme abrasiveness of the ore leading to additional iron contamination in the ground ore. The critical impurities were aluminium, iron, sodium, potassium, lithium, titanium, zircon, calcium and magnesium. The chemical refining was found effective. The hot chlorination process needed to be done at 1200°C in a chlorine – hydrogen chloride gas atmosphere. The risk of any gas being released during this stage is very serious and only specialist companies should and can carry out this step. More recent studies reported many new options that appear to facilitate the production of HPQ with the requisite purities more easily, but costly equipment along with highly trained operators are required and hence unlikely to become available in standard metallurgical laboratories any time soon.

Sep 1, 2024