Effect of mineralogy and texture in the TiO2 pigment production process of the Tellnes ilmenite concentrate

Chernet, T.

doi:10.1007/bf01165113

Cited by 23 publications

(11 citation statements)

References 5 publications

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“…Also, surface treatments during production of different TiO 2 types might have an effect in hydration rates. It is known that chloride and sulfate processes are the two most common manufacturing methods to extract and purify TiO 2 from ore (Chernet, 1999), and those ions could have dissolved into the mixing water and affected the hydration of cement . Moreover, the TiO 2 inclusion in the paste causes a dilution effect, and this reduction in the total cement content could contribute to the delayed initial setting time for the 5% and 10% cases.…”

Section: Setting Timementioning

confidence: 99%

Effects of nano-TiO₂ on properties of cement-based materials

Lee

Jayapalan

Kurtis

2013

Magazine of Concrete Research

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The effect of titanium dioxide (TiO 2 ) nanoparticles on early age and long-term properties of cement-based materials is examined experimentally through isothermal calorimetry, chemical shrinkage, setting time, compressive strength and surface microhardness, where part of the cement is replaced with TiO 2 : Early age hydration is accelerated by TiO 2 nanoparticles which also increase degrees of hydration of Portland cement, as evidenced by isothermal calorimetry and chemical shrinkage results. With increasing amounts of TiO 2 , setting time is reduced, despite decreasing cement content, due to TiO 2 replacement, again showing accelerated hydration. Comparing TiO 2 -cement composites from two different TiO 2 manufacturers, results suggest that size of nanoparticles and dispersability are critical in the rate of hydration, with smaller size agglomerates, but not necessarily smaller size particles, producing a greater effect. Compressive strength increases with higher TiO 2 nanoparticle replacement at lower water-to-solids ratio (w/s 0 . 40) and strength is not compromised by up to 10% TiO 2 replacement at higher w/s 0 . 60. However, microhardness of the composite decreases with higher TiO 2 amount. Broadly, these results indicate that mineral addition as cement replacement can be optimised in terms of dosage and dispersability to achieve lower cement fractions without compromising strength, but that the potential for reductions in hardness should be considered.

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Section: Setting Timementioning

confidence: 99%

Effects of nano-TiO₂ on properties of cement-based materials

Lee

Jayapalan

Kurtis

2013

Magazine of Concrete Research

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“…Dust control and possible impurities in the coal used for smelting are the primary smelter concerns. After initial heating, an exothermic reaction results in the formation of a porous cake, which is then dissolved in a mixture of dilute acid and water to yield titanyl sulfate and iron sulfate (Chernet, 1999). Iron sulfate is removed as crystallized ferrous heptahydrate, also known as copperas.…”

Section: Mineralogymentioning

confidence: 99%

Deposit model for heavy-mineral sands in coastal environments

Gosen¹,

Fey²,

Shah³

et al. 2014

Scientific Investigations Report

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For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. AbstractThis report provides a descriptive model of heavy-mineral sands, which are sedimentary deposits of dense minerals that accumulate with sand, silt, and clay in coastal environments, locally forming economic concentrations of the heavy minerals. This deposit type is the main source of titanium feedstock for the titanium dioxide (TiO 2 ) pigments industry, through recovery of the minerals ilmenite (Fe 2+ TiO 3 ), rutile (TiO 2 ), and leucoxene (an alteration product of ilmenite). Heavy-mineral sands are also the principal source of zircon (ZrSiO 4 ) and its zirconium oxide; zircon is often recovered as a coproduct. Other heavy minerals produced as coproducts from some deposits are sillimanite/kyanite, staurolite, monazite, and garnet. Monazite [(Ce,La,Nd,Th)PO 4 ] is a source of rare earth elements as well as thorium, which is used in thorium-based nuclear power under development in India and elsewhere.The processes that form coastal deposits of heavy-mineral sands begin inland. High-grade metamorphic and igneous rocks that contain heavy minerals weather and erode, contributing detritus composed of sand, silt, clay, and heavy minerals to fluvial systems. Streams and rivers carry the detritus to the coast, where they are deposited in a variety of coastal environments, such as deltas, the beach face (foreshore), the nearshore, barrier islands or dunes, and tidal lagoons, as well as the channels and floodplains of streams and rivers in the coastal plain. The sediments are reworked by waves, tides, longshore currents, and wind, which are effective mechanisms for sorting the mineral grains on the basis of differences in their size and density. The finest-grained, most dense heavy minerals are the most effectively sorted. The result is that heavy minerals accumulate together, forming laminated or lens-shaped, heavymineral-rich sedimentary packages that can be several meters and even as much as tens of meters thick. Most economic deposits of heavy-mineral sands are Paleogene, Neogene, and Quaternary in age; some are modern coastal deposits.Superimposed on these basic processes of ore formation are a multitude of contributing and modifying factors, such as the following:• Strong, sustained wave action moves sand from offshore to the shore, where the sand and heavy mi...

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“…Despite an abundance of world resource for Ti ores, the industry continues to prospect for better quality ilmenite, principally because of processing costs and waste disposal problems associated with the high iron and trace-element contents of ilmenite. The modern chloride process is far less polluting than the older sulfate process because it does not produce waste iron sulfate (Chernet, 1999). Both processes have restrictions on the contents of chromophore elements such as Cr and Mn, but the chloride process also has much stricter limits on concentrations of the alkali elements, especially Ca and Mg, as well as on grain-size.…”

Section: Introductionmentioning

confidence: 99%

Fe–Ti–V–P ore deposits associated with Proterozoic massif-type anorthosites and related rocks

Charlier

Namur

Bolle

et al. 2015

Earth-Science Reviews

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a b s t r a c t a r t i c l e i n f oMagmatic rocks containing economic concentrations of iron, titanium, vanadium and phosphorous are commonly associated with massif-type anorthosites and related rocks. This rock association is part of the anorthositemangerite-charnockite-(rapakivi-)granite suites that are restricted to the Proterozoic. Understanding the geochemistry and emplacement mechanisms of ilmenite, magnetite and apatite ore deposits is crucial for exploration, efficient mining operations and ore processing. This review discusses the controlling factors on the grade of an ore, its mineralogy, and its major and trace element distribution. We present petrogenetic models of currently mined deposits (Lac Tio, Tellnes, Damiao) and discuss the characteristics of minor ore bodies from anorthosite provinces worldwide (Grenville, North China Craton, East European Craton, Rogaland, Laramie). Models of formation of anorthosite and related rocks are presented, as well as the nature of the possible parental magmas of the suite. A mineralogical classification of Fe-Ti ores is proposed: (1) Gabbro-noritic ilmenite ore ± apatite ± magnetite; (2) Ti-magnetite-dominated ore; (3) Nelsonite (Fe-Ti oxides + apatite); and (4) Rutile-ilmenite ore. The stability of ilmenite and magnetite is then critically reviewed and the influence of various factors, particularly oxygen fugacity and crystallization pressure, is examined. We discuss liquidus compositions of Fe-Ti oxides and the behavior of important trace elements such as Cr and V, both of which are sensitive to fO 2 variations. Postcumulus evolution of both oxides can occur due to re-equilibration with trapped liquid, re-equilibration with ferromagnesian silicates, exsolution, oxidation, reaction between ilmenite and magnetite, and metamorphic overprinting. These various processes are described and their effects on the oxide geochemistry are emphasized. Several potential ore-forming processes have been invoked and can explain the formation of huge concentration of ilmenite, ±magnetite, ±apatite. Fractional crystallization can be combined with crystal sorting and plagioclase buoyancy to produce relative enrichment of dense ore minerals. Silicate liquid immiscibility can segregate conjugate Si-rich and Fe-rich melts, the latter being enriched in Fe-Ti-P. Magma mixing can produce hybrid magmas located in a single-phase field of the phase diagram and precipitate a pure ilmenite cumulate. Alternative processes are also described, such as ejection of Fe-Ti-enriched residual melts by filter-pressing and compaction, solidstate remobilization of ilmenite in veins, and hydrothermal transport of Fe and Ti from the host anorthosite followed by concentration in veins and lenticular ore bodies. The magnetic properties of Fe-Ti ore deposits present contrasting signatures, depending on whether the natural remanent magnetization is dominated by hemo-ilmenite or multi-domain magnetite. Micro-and macro-scale deformation features of ore rocks are intimately correlated with magma emplacement, and...

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Effect of mineralogy and texture in the TiO2 pigment production process of the Tellnes ilmenite concentrate

Cited by 23 publications

References 5 publications

Effects of nano-TiO₂ on properties of cement-based materials

Effects of nano-TiO₂ on properties of cement-based materials

Deposit model for heavy-mineral sands in coastal environments

Fe–Ti–V–P ore deposits associated with Proterozoic massif-type anorthosites and related rocks

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Effect of mineralogy and texture in the TiO2 pigment production process of the Tellnes ilmenite concentrate

Cited by 23 publications

References 5 publications

Effects of nano-TiO2 on properties of cement-based materials

Effects of nano-TiO2 on properties of cement-based materials

Deposit model for heavy-mineral sands in coastal environments

Fe–Ti–V–P ore deposits associated with Proterozoic massif-type anorthosites and related rocks

Contact Info

Product

Resources

About

Effects of nano-TiO₂ on properties of cement-based materials

Effects of nano-TiO₂ on properties of cement-based materials