Ilmenite Sand Research Articles

Optimisation of TiO2 synthesis from ilmenite sand and its application in the photocatalytic process

ABSTRACT Iron sand, a mineral, can be extracted to produce titanium dioxide (TiO2). TiO2 is a semiconductor material that is commonly used in photocatalytic applications, as well as electronics, colour pigments, paint manufacturing, and semiconductors. In this study, TiO2 was extracted from Banten ilmenite sand using caustic fusion and hydrometallurgical methods. The TiO2 extraction process was carried out by varying the mole ratio of ilmenite sand to NaOH, which was 1:0, 1:3, and 1:5, and the fusion temperatures were 700°C and 850°C, with time variations of 30, 60, and 90 min. XRF analysis revealed that the highest TiO2 composition was 91.64% in samples with a mole ratio of 1:3 during 30 min of fusion time and 91.14% in samples with a mole ratio of 1:5 during 90 min of fusion time. The XRD data revealed that TiO2 has a rutile phase with a tetragonal structure, while scanning electron microscopy (SEM) analysis revealed that the particle distribution in the sample is not uniform. The UV-Vis measurements revealed that TiO2 has a band gap of 3.10 at 700°C and 3.13 at 850°C. Furthermore, TiO2 degraded Rhodamine B dyes at a rate of 28.266%.

Study of smelting Egyptian black sand ilmenite by using El Magara coal

Study of smelting Egyptian black sand ilmenite by using El Magara coal

A New Approach on the Egyptian Black Sand Ilmenite Alteration Processes

Several studies have investigated the process of alteration of ilmenite, especially in black sand. To predict the mechanisms of ilmenite alteration and the role of some minor element oxides in the alteration process, separated non-magnetic altered ilmenite grains were examined using a binocular microscope and a Cameca SX-100 microprobe instrument. Twenty intergrown phases of alteration products were concluded in three postulated scenarios for the following alteration processes, carried out after forming the most stable lowest Leached pseudorutile (LPSR) phase FeTi3O6(OH)3. Most of the alteration phases of pseudorutile (PSR) and LPSR have real Ti/(Ti+Fe) ratios between 0.6 and 0.75. Some misleading calculations of definite analyzed ilmenite alteration spots showed that the analyzed TiO2 percentage is contained within the chemical formula of the analyzed LPSR phase. In these cases, the false Ti/(Ti+Fe) ratios attain up to 0.9, the false included total number of anions (O, OH) ranges between 7 and 8.5, and the associated molecular water ranged between half and two water molecules (0.5-2 H2O). In these cases, the structure of the remaining LPSR phase may be intergrown with a separated individual triple rutile phase, which appears to have the same X-Ray Diffraction (XRD) pattern as the single PSR phase, or intergrown with a cryptocrystalline TiO2 phase. Some molecular formulas of PSR or Hydroxylian PSR (HPSR) from previous studies were discussed and explained following the proposed approach.

Preparation and Properties of HUHPC with Low Shrinkage and High Impact Resistance

At present, nuclear energy is widely used to reduce pollution and clean energy. However, the radiation-proof concrete currently used to prepare nuclear shields cannot meet the protection requirements of nuclear safety. Therefore, there is an urgent need to develop radiation-proof concrete materials with high impact resistance and ultra-high strength. In this paper, the low-shrinkage, high-impact Heavy Ultra-High-Performance Concrete (HUHPC) was designed by the following innovative methods: Porous high titanium heavy slag sand (HTHS) (industrial solid waste) with “slow-water release” effect and expansion agent were synergistically used to improve volume stability; Irregular HTHS with “embedded lock” effect and steel fibers were synergistically utilized to enhance impact resistance; Heavy ilmenite sand was used to lift volume weight. The workability, mechanical properties, volume stability, impact resistance, and microstructure were studied. The results show that the designed HUHPC volume weight is more than 2,800 kg/m3 which can enhance the radiation protection performance greatly. The 180 d shrinkage of HUHPC is less than 400 µε, which volume stability is improved by more than 30%. The addition of lithium carbonate slightly decreased the 28 d strength of HUHPC, but the appropriate admixture amount (0.9%) could improve the impact resistance of HUHPC by 33%.

Study of the Mineralogical and Chemical Compositions of the Weakly Magnetic Fractions of the Egyptian Black Sand Altered Ilmenite

One of the most extensively studied topics in dozens of studies is the alteration process of ilmenite, the formation of leucoxene, and the presence of some impurity oxides: SiO2 and Al2O3. The altered Egyptian black sand ilmenite grains of relatively lower magnetic characters are studied using the binocular microscope and the Cameca SX-100 microprobe instrument. Both individual brown- and black-altered grains separated at 0.5 and 1 ampere values are investigated. The detection of the various alteration phases, their molecular formulas and limits, and the role of SiO2 and Al2O3 in alteration mechanisms are detected. The alteration phases include pseudorutile (psr) and leached pseudorutile (lpsr) of different phases in addition to rutile. Few analyzed spots are detected to be leached ilmenite (lilm). Several Excel software are adopted to calculate the chemical formulas of each alteration phase. The contents of TiO2 and Fe2O3 of all the investigated psr/lpsr in the study are in the range of 59.16–86.56% and 37.3–6.68%, respectively. The Ti/(Ti + Fe) ratio for these formulas ranges between 0.60 and 0.88. The psr/lpsr chemical formulas of all the investigated grains range as follows: Fe2.01-0.50Ti3O8.97-4.50(OH)0.03-4.50. The concluded lowest cationic iron content of the well-defined accepted lpsr phase is 0.5 with a corresponding molecular formula of Fe0.50Ti3O4.5(OH)4.5. The results revealed that in the region of 68–70 TiO2%, the mechanism of ilmenite alteration may be changed where neither all the analyzed TiO2 of the spot nor all the calculated structural water are contained within the molecular formula of lpsr. There are other associated mineral phases containing some TiO2 and also some structural water which most probably are removed from the lpsr phase. As the analyzed spots are located at highly fissured locations, the alteration process is relatively faster and the lpsr phase can be broken into rutile and hematite. Additionally, as the analyzed TiO2 and structural and/or molecular water contents increase, the darkness of the BSE image areas of the grain increases; this may reflect the existence of an individual TiO2 phase, most probably rutile, mixed in homogeneity with the existed lpsr component. As the content of TiO2 increases, within a definite TiO2 range (80–85%), the associated contents of Al2O3 and SiO2 increase. When the contents of the structural and/or molecular water contained within the lpsr phases decreases, the total oxides sum is more than 98%, the contents of Al2O3 are highly depleted. In the late alteration stages, the lpsr structure does not suddenly collapse but gradually produces other associated mineral phases. The relatively enriched contents of SiO2 and/or Al2O3 in some secondary rutile grains can be explained as most of the SiO2% is associated with mol water or bearing for mol and/or str water necessary for the leachability of Fe3+ from the psr structure. The XRD patterns of the investigated grains before and after roasting at 1100 °C for one hour are detected and interpreted.

Preparation and Performance Study of Radiation-Proof Ultra-High-Performance Concrete

With the continuous development of nuclear technology, it is necessary to urgently solve the nuclear safety problem. γ-rays have a strong penetrating power. The γ-ray-shielding performance of ordinary concrete prepared with natural sand is weak and cannot meet the practical application of engineering. The γ-ray shielding performance of concrete can be effectively improved through the use of titaniferous sand with a better γ-ray protection effect. To prepare ultra-high-performance concrete (UHPC) that can provide radiation protection, the influence law of its performance was investigated. The effects of ilmenite sand on the workability, mechanical properties, durability, and radiation-shielding properties of UHPC were investigated via mix testing, compressive strength and flexural strength testing, and a radiation-shielding simulation. The results show that an appropriate amount of ilmenite sand can improve the ultra-high-performance concrete’s work performance; however, ilmenite sand has little effect on its compressive strength. Although it is not conducive to the development of flexural and tensile strength, the γ-ray shielding performance of the UHPC increases with an increase in the addition of ilmenite sand. When the titanite sand admixture is 70%, the γ-ray linear absorption coefficient of the prepared UHPC is 0.158 cm−1, and the γ-ray shielding performance is significantly improved; meanwhile, its durability performance is excellent.

KOH-Based Hydrothermal Synthesis of Iron-Rich Titanate Nanosheets Assembled into 3D Hierarchical Architectures from Natural Ilmenite Mineral Sands

The synthesis of titanate nanostructures from low-cost mineral precursors is a topic of continuous interest, considering not only their fundamental aspects but also the benefits of incorporating such nanomaterials in a wide variety of applications. In this work, iron-rich titanate nanosheets were synthesized from Ecuadorian ilmenite sands (ilmenite–hematite solid solution-IHSS) through an alkaline hydrothermal treatment (AHT) using potassium hydroxide (KOH). The effect of the duration of the KOH-AHT was assessed at 180 °C for 24, 48, 72, and 96 h. The morphology evolution over time and the plausible formation mechanisms of titanate nanostructures were discussed. The most significant morphological transformation was observed after 72 h. At this time interval, the titanate nanostructures were assembled into well-defined 3D hierarchical architectures such as book-block-like arrangements with open channels. Based on X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) analyses, it was determined that these nanostructures correspond to iron-rich layered titanates (Fe/Ti mass ratio of 7.1). Moreover, it was evidenced that the conversion of the precursor into layered nanostructures was not complete, since for all the tested reaction times the presence of remaining IHSS was identified. Our experiments demonstrated that the Ecuadorian ilmenite sands are relatively stable in KOH medium.

Fabrication of r-GO/GO/α-Fe2O3/Fe2TiO5 Nanocomposite Using Natural Ilmenite and Graphite for Efficient Photocatalysis in Visible Light

Hematite (α-Fe2O3) and pseudobrookite (Fe2TiO5) suffer from poor charge transport and a high recombination effect under visible light irradiation. This study investigates the design and production of a 2D graphene-like r-GO/GO coupled α-Fe2O3/Fe2TiO5 heterojunction composite with better charge separation. It uses a simple sonochemical and hydrothermal approach followed by L-ascorbic acid chemical reduction pathway. The advantageous band offset of the α-Fe2O3/Fe2TiO5 (TF) nanocomposite between α-Fe2O3 and Fe2TiO5 forms a Type-II heterojunction at the Fe2O3/Fe2TiO5 interface, which efficiently promotes electron-hole separation. Importantly, very corrosive acid leachate resulting from the hydrochloric acid leaching of ilmenite sand, was successfully exploited to fabricate α-Fe2O3/Fe2TiO5 heterojunction. In this paper, a straightforward synthesis strategy was employed to create 2D graphene-like reduced graphene oxide (r-GO) from Ceylon graphite. The two-step process comprises oxidation of graphite to graphene oxide (GO) using the improved Hummer's method, followed by controlled reduction of GO to r-GO using L-ascorbic acid. Before the reduction of GO to the r-GO, the surface of TF heterojunction was coupled with GO and was allowed for the controlled L-ascorbic acid reduction to yield r-GO/GO/α-Fe2O3/Fe2TiO5 nanocomposite. Under visible light illumination, the photocatalytic performance of the 30% GO/TF loaded composite material greatly improved (1240 Wcm-2). Field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) examined the morphological characteristics of fabricated composites. X-ray photoelectron spectroscopy (XPS), Raman, X-ray diffraction (XRD), X-ray fluorescence (XRF), and diffuse reflectance spectroscopy (DRS) served to analyze the structural features of the produced composites.

Some Mineralogical Characteristics of the Egyptian Black Sand Beach Ilmenite Part I: Homogeneous Ilmenite and Titanhematite-Ferriilmenite Grains

The high-grade Egyptian beach ilmenite concentrate contains various mineral textures in addition to the main homogeneous ilmenite grains (63%), which may contain solid solutions of geikielite (MgTiO3) and pyrophanite (MnTiO3) mineral components. Few homogeneous ferrilmenite grains (2%) associated with the concentrated ilmenite grains are detected. The contents of Fe2O3, MgO, Al2O3, and Cr2O3 in the ferrilmenite grains range between 7.3% and 22.8%, 3.4% and 6.6%, 0.2% and 0.7%, and 0% and 1.2% respectively. The detected hematite-ilmenite exsolved intergrowths (21.4%) have titanhematite exsolutions of different shapes, sizes, and orientations. They occupy 5%-40% of the whole intergrowth and may show one or two distinct generations. In some ferrilmenite components, MnO ranges between 1.5% and 8.6%. The Cr2O3 and Al2O3 contents range between 0% and 1.2% and 0% and 3.2% respectively. They are mostly between 0% and 0.1% for either of the ferrilmenite components, while relatively greater content is present in the titanhematite components. In some grains, the titanhematite exsolution bodies are replaced by goethite or hydrated iron oxides. In others, the ferrilmenite intergrowth may be partially or completely altered into leucoxene. Some minor composite grains are detected in the concentrate, where each grain consists of two parts, one part is titanhematite-ferrimenite and the other is ferrilmenite-titanhematite. The titanhematite exsolved components have relatively lower TiO2 content (5.8%-23.8%). Both MgO and MnO are positively correlated with FeO rather than Fe2O3. The presence of sphenes in the obtained ilmenite concentrate may be responsible for the recorded amounts of SiO2 (30.1%-30.8%) and CaO (28.1% and 28.8%). The Cr2O3 content is relatively much higher in sphene spots than in ilmenite spots, ensuring that Cr2O3 neither follows TiO2 nor FeO. The nature of the problem of the relatively lower Ti content and the relatively higher Fe and Cr contents of the obtained ilmenite concentrates is the target of the article. The problem is related to the mineralogy of ilmenite or to the used physical concentration flowsheet of the separated concentrate and the ability to improve the ilmenite concentrate’s specifications. It is concluded that although the homogeneous ilmenite is characterized by low Cr2O3 content, some of the other exsolved texture components, e.g. titanhematite and sphenes, have relatively higher Cr2O3, in addition to Fe2O3, SiO2, or CaO. They can negatively affect the marketable specifications of the separated Egyptian black sand ilmenite concentrate.

Visible Light Active Silver Decorated Iron Titanate/Titanium Dioxide Nanohybrid for Sterilization of Explants Grown by In Vitro Technique

AbstractVisible light (VL) active silver decorated iron titanate/titanium dioxide (Ag‐FeTiO3/TiO2) nanohybrids derived from natural ilmenite sand effectively cleanse the exophytic plant pathogens in explants grown by in vitro techniques. VL active nanohybrid is synthesized by acid‐hydrolysis of natural ilmenite, followed by precipitation of the lixivium and decoration with Ag onto FeTiO3/TiO2 nanoparticles, and finally calcination under a nitrogen environment to obtain Ag‐FeTiO3/TiO2. A morphological study conducted using transmission electron microscopy (TEM) confirms the formation of Ag‐FeTiO3/TiO2. Powder X‐ray diffraction (PXRD) analysis shows that the nanohybrid primarily consists of anatase, iron titanate (FeTiO3), Ag2O, and Ag. X‐ray photoelectron spectroscopy (XPS) study suggests the presence of Ag0/Ag2O/Fe2O3 composites on the FeTiO3/TiO2 particle surface. The optical band gap significantly changes from 3.14 eV (ilmenite) to 2.80 eV after the decoration of FeTiO3/TiO2 with Ag. This nanohybrid is utilized as a surface‐sterilizing agent for in vitro establishment of the Dracaena sanderiana Sander ex Mast plant. Findings illustrate Ag‐FeTiO3/TiO2 nanohybrid‐based photo‐sterilization leads to the survival of 90% of the microbes’ free cultures while the material can be re‐used due to its photocatalytic behavior. Thus, the newly synthesized nanohybrid can replace harmful sterilization agents used in tissue culture techniques.

Fabrication of dual Z-scheme g-C3N4/Fe2TiO5/Fe2O3 ternary nanocomposite using natural ilmenite for efficient photocatalysis and photosterilization under visible light

The advanced oxidation process is a prominent method available to remove dyes released to normal water reservoirs to alleviate water scarcity. We report the fabrication of novel g-C3N4/Fe2TiO5/Fe2O3 using natural ilmenite sand as the precursor of the metallic semi-conductors exploration of a heterostructure for photodegradation of methylene blue under sunlight. Ternary composites were synthesized by varying g-C3N4 with respect to Fe2TiO5/Fe2O3 and varying Fe2TiO5/Fe2O3 with respect to g-C3N4 where the varying component was varied as 8, 24 and 40%, respect to the constant material. The hybridization of the three semi-conductors has been confirmed by the microscopic, chemical, and structural analyses. X-ray diffraction patterns show the presence of all three g-C3N4, Fe2TiO5 and α-Fe2O3 while the transmission electronic microscopic and scanning electronic microscopic images show the heterogeneous distribution of the metal oxide nanoparticles on g-C3N4 matrix forming the composite. HRTEM images further reveal the junction of Fe2TiO5 and α-Fe2O3. X-ray photoelectron spectra show the existence of s-triazine and heptazine rings in the composites with Fe3+ and Ti4+ as the only oxidation states of Fe and Ti. Fe2TiO5/Fe2O3/40% g-C3N4 with bandgap of 2.63 eV calculated by diffuse reflectance UV-Visible spectroscopy showed the highest photocatalytic activity (0.009 min−1) being 1.3 times greater than the Fe2TiO5/Fe2O3 nanoparticles. Enhanced photocatalytic activity over the fabricated composites was observed due to the increased visible light absorption, efficient charge separation and improved charge transportation. g-C3N4 coupled with 40% Fe2TiO5/Fe2O3 showed the highest antibacterial activity against gram-negative E.Coli. The synthesis of dual Z-scheme g-C3N4/Fe2TiO5/Fe2O3 ternary composite provides new sights in developing novel photocatalysts using natural ilmenite sand for environmental applications.

Fabrication of TiO2 Spheres and a Visible Light Active α-Fe2O3/TiO2-Rutile/TiO2-Anatase Heterogeneous Photocatalyst from Natural Ilmenite.

High-purity (98.8%, TiO2) rutile nanoparticles were successfully synthesized using ilmenite sand as the initial titanium source. This novel synthesis method was cost-effective and straightforward due to the absence of the traditional gravity, magnetic, electrostatic separation, ball milling, and smelting processes. Synthesized TiO2 nanoparticles were 99% pure. Also, highly corrosive environmentally hazardous acid leachate generated during the leaching process of ilmenite sand was effectively converted into a highly efficient visible light active photocatalyst. The prepared photocatalyst system consists of anatase-TiO2/rutile-TiO2/Fe2O3 (TF-800), rutile-TiO2/Fe2TiO5 (TFTO-800), and anatase-TiO2/Fe3O4 (TF-450) nanocomposites, respectively. The pseudo-second-order adsorption rate of the TF-800 ternary nanocomposite was 0.126 g mg–1 min–1 in dark conditions, and a 0.044 min–1 visible light initial photodegradation rate was exhibited. The TFTO-800 binary nanocomposite adsorbed methylene blue (MB) following pseudo-second-order adsorption (0.224 g mg–1 min–1) in the dark, and the rate constant for photodegradation of MB in visible light was 0.006 min–1. The prepared TF-450 nanocomposite did not display excellent adsorptive and photocatalytic performances throughout the experiment period. The synthesized TF-800 and TFTO-800 were able to degrade 93.1 and 49.8% of a 100 mL, 10 ppm MB dye solution within 180 min, respectively.

Efficient Visible-Light Photocatalysis and Antibacterial Activity of TiO2-Fe3C-Fe-Fe3O4/Graphitic Carbon Composites Fabricated by Catalytic Graphitization of Sucrose Using Natural Ilmenite.

Dyes in wastewater are a serious problem that needs to be resolved. Adsorption coupled photocatalysis is an innovative technique used to remove dyes from contaminated water. Novel composites of TiO2-Fe3C-Fe-Fe3O4 dispersed on graphitic carbon were fabricated using natural ilmenite sand as the source of iron and titanium, and sucrose as the carbon source, which were available at no cost. Synthesized composites were characterized by X-ray diffractometry (XRD), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), and diffuse reflectance UV–visible spectroscopy (DRS). Arrangement of nanoribbons of graphitic carbon with respect to the nanomaterials was observed in TEM images, revealing the occurrence of catalytic graphitization. Variations in the intensity ratio (ID/IG), La and LD, calculated from data obtained from Raman spectroscopy suggested that the level of graphitization increased with an increased loading of the catalysts. SEM images show the immobilization of nanoplate microballs and nanoparticles on the graphitic carbon matrix. The catalyst surface consists of Fe3+ and Ti4+ as the metal species, with V, Mn, and Zr being the main impurities. According to DRS spectra, the synthesized composites absorb light in the visible region efficiently. Fabricated composites effectively adsorb methylene blue via π–π interactions, with the absorption capacities ranging from 21.18 to 45.87 mg/g. They were effective in photodegrading methylene blue under sunlight, where the rate constants varied in the 0.003–0.007 min–1 range. Photogenerated electrons produced by photocatalysts captured by graphitic carbon produce O2•– radicals, while holes generate OH• radicals, which effectively degrade methylene blue molecules. TiO2-Fe3C-Fe-Fe3O4/graphitic carbon composites inhibited the growth of Escherichia coli (69%) and Staphylococcus aureus (92%) under visible light. Synthesized novel composites using natural materials comprise an ecofriendly, cost-effective solution to remove dyes, and they were effective in inhibiting the growth of Gram-negative and Gram-positive bacteria.

Solvent-Free Green Synthesis of Cu0.5Ti2(PO4)3 and Cu0.5TiO(PO4) NASICON-Type Compounds from Ilmenite Mineral Sand

Ilmenite is a naturally available black or steel-gray color mineral, called titanium iron oxide, FeTiO3.This valuable mineral comprises a significant amount of titanium that can be utilized as a titanium source to synthesize various materials. This study focused on synthesizing copper titanium phosphate compounds via an eco-friendly solid-state reaction route. α-titanium bismonohydrogen orthophosphate monohydrate (α-Ti(HPO4)2.H2O/α-TiP), derived from beach sand ilmenite used as the starting material for the synthesis. α-TiP was obtained by digesting ilmenite with 85 wt% phosphoric acid under reflux conditions. The XRD pattern of the obtained white powder confirmed the formation of α-TiP. The synthesized α-TiP and copper (Ⅱ) acetate were ground with different molar ratios (1:2, 1:1, and 2:1) until it forms a fine powder following a solvent-free solid grinding method. These powder mixtures were calcined at 800 °C for 4 hours utilizing a muffle furnace. The obtained solid solutions developed green and two different shades of yellow color. The samples werecharacterized by XRD, Thermogravimetry (DSC/TGA) techniques, and Raman spectroscopy. The XRD results revealed the formation of solid solutions containing copper titanium phosphate (Cu0.5Ti2(PO4)3) at 1:1 and 2:1 molar ratios of α-TiP to copper (Ⅱ) acetate while the products obtained at 1:2 and 1:1 molar ratios confirmed the formation of copper titanium oxyphosphate (Cu0.5TiOPO4). Moreover, TGA results confirm the development of these mixed metal phosphates which can be further analyzed for applications in the ceramic industry. Therefore, calcination of the reaction mixtures by changing the molar ratios produced different colored stable compounds that can potentially be used as ceramic pigments, coatings, and electrode materials.
 Keywords: Copper titanium phosphate, α-titanium bismonohydrogen orthophosphate monohydrate, Solid-state reaction route

Placer Magnetite-sand and By-product Iron, Generated during the Beneficiation of Mineral Sand Ilmenite to High-Titanium Products, as Potential Alternatives to the High-Grade Fe-ore for Steel Making

Abstract Iron is the most important of all metals and ~ 98% of it, in the form of iron ore/pellets, is used as the key raw material in making steel, with its per-capita consumption often seen as an Index for a nation’s Prosperity. Salient aspects of the industries of iron ore mining and steel-production are presented. These include deposit-types and grades of iron-ore, iron ore minerals with Fe-contents, major producing-exporting-importing countries, international/national prices of iron ore; and major producing countries of steel, international/national production figures, processes of steel-making, including recent hydrogen-energy based green steel/iron ore under de-carbonisation. The less available high-grade Fe ore (> 63.5% Fe), as compared to that of the benchmark or standard grade (62% Fe) and low-grade (<59% Fe) iron ores, has many beneficial features in steel-making, carries a premium price of US $ 1-2/tonne for every 1% increase in Fe-grade over that of the standard grade and, hence, is much sought after. In this communication, two low-cost, potential alternatives to the high-grade Fe ore for steel-making are proposed from the mineral sand industry. These are: (i) placer magnetite-sand, with an example from the coastal Nizampatnam heavy mineral sand deposit in Andhra Pradesh, and (ii) by-product Fe, generated during the beneficiation of ilmenite-sand for high Ti-products such as synthetic rutile/anatase, titanium dioxide pigment, Ti-sponge, Ti-metal etc.A brief account of the mineral sand deposits, including the processes to obtain the above proposed alternatives and the consequent multiple benefits for both the steel and mineral sand industries, is presented in this paper.

Catalytic reduction of 4-nitrophenol using CuO@Na2Ti(PO4)2⋅H2O

This article presents the synthesis, property characterization and catalytic application of CuO-supported disodium titanium phosphate, (CuO@Na2Ti(PO4)2⋅H2O) for the reduction of industrial pollutant 4-nitrophenol (4-NP). A simple hydrothermal route was developed to synthesize CuO@Na2Ti(PO4)2⋅H2O catalyst (CuO@Na2TiP) from beach sand ilmenite. The prepared CuO@Na2TiP was characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, and nitrogen adsorption-desorption isotherms. The catalyst 12 wt.% CuO@Na2TiP showed the fastest reduction kinetics for 4-NP.

Distinctive characteristics of Cheniah river sand from Dungun, Terengganu Malaysia

Mineral ilmenite sand depositin the Hulu Dungun, Terengganu, Malaysia, has prompted a huge interest in their viability as a new resource survey of titanium dioxide feedstock in Malaysia. In accordance with this necessity, this study is executed to conduct mineral characterisation onthe ilmenite sand (IS) located at the catchment area, Cheniah River, Kelip Hill, Hulu Dungun, Malaysia. Characterization of raw ilmenite sand was done by X-Ray Fluorescence (XRF) for exploring elements in the sample. Digital microscopy (DM) for optical imaging purpose with polarizing filterand Scanning Electron Microscope (SEM) analyses were developed for surface morphological studies. As determined through this data research, chemical analysis reveals that IS has the highest amount of 44.0% TiO2, and come after with 37.8% Fe2O3, 12.0% SiO2 and other impurity elements such as Mn, V, Cr and Mg. DM images has the same point of view regarding to the mineral constituents from XRF data wherein majority of the IS grains display black dark to steel grey colour as the ilmenite and few of colourless quartz. Meanwhile, the surface morphology from both analyses, DM and SEM can be concluded that IS has heterogenous surface. Most of the IS grains have angular shape with moderate sphericity and few subrounded and high sphericity. Nearly all of the IS are found to be associated with iron oxide as displayed through Backscattered image (BSE) from SEM-EDX analysis. This characterization study's data and information assist in the ilmenite sanddiscovery and createsa design of a viable treatment procedure which will be developed in future workfor the localmineral exploitation.

Solvent-Free Conductive Coatings Containing Chemically Coupled Particles for Functional Textiles

The surge in the usage of wireless electronics and communication devices has engendered a different form of pollution, viz. electromagnetic (EM) pollution, and yet another serious issue, EM interference (EMI). There is a legitimate need to develop strategies and materials to combat this issue, otherwise leading to dreadful consequences. Functional textiles have emerged as the modern materials to help attenuate EM waves due to the numerous advantages─flexibility being the most important. In addition to this, there is an inherent advantage of multiple interfaces in coated fabrics that can engender significant attenuation. Herein, we report a coating having multifunctional properties─capable of blocking both UV and EM radiation (predominantly of the microwave frequencies) with flame-retarding properties. The layer described here comprises iron titanate (FT) synthesized from its sustainable precursor─ilmenite sand and carbon nanotubes (CNTs) dispersed in waterborne polyurethane. It is worth noting that FT’s use as a multifunctional material is being reported for the first time. It was observed that a single layer of coated fabric shows an EMI shielding effectiveness of −40 dB translating to 99.99% attenuation and similarly a UV blocking of 99.99% in the wavelength range from 200 to 400 nm. The microwave shielding properties of the fabric were demonstrated using a Bluetooth module, where the coated fabric was able to block the incoming Bluetooth signals to the module from a mobile phone. Besides, the coated fabrics exhibited phenomenal enhancement in thermal stability─a 5% increase in the limiting oxygen index was observed upon the application of the coating. Such exceptional properties tend to complement cotton fabrics’ existing utility, thereby extending their use to specialty applications.

Photo-Fenton Oxidation of Methyl Orange Dye Using South African Ilmenite Sands as a Catalyst

In this study, the viability of South African ilmenite sands as a catalyst in the photo-Fenton-like degradation of methyl orange (MO) dye was investigated. The mineralogy and other properties of the material were characterized. Complete decolorization occurred under acidic conditions (pH < 4) in the presence of ilmenite and H2O2. Light irradiation accelerated the rate of reaction. Parameter optimization revealed that a pH of 2.5, UVB irradiation, 2 g/L catalyst loading, and a hydrogen peroxide concentration of 1.0 mM were required. Under these conditions, complete decolorization was observed after 45 min. Degradation kinetics were best described by the pseudo-first order (PFO) model. Rate constants of 0.095 and 0.034 min−1 were obtained for 5 and 20 mg/L MO concentrations, respectively. A 37% total organic carbon removal was observed after 60 min. This suggests a stepwise MO degradation pathway with intermediate formation rather than complete mineralization. Although iron leaching was detected, the mineralogy of the catalyst recovered after the reaction was similar to the fresh catalyst.

Processing of ilmenite into synthetic rutile using ball milling induced sulphurisation and carbothermic reduction

Sri Lanka is a major global producer of raw material-heavy minerals from beach placer deposits. This study focusses on upgrading Sri Lankan ilmenite sands to synthetic rutile via a mechanochemical method. Ball milling-induced sulphurisation and carbothermic reductions were examined using several geochemical techniques. Raw ilmenite concentrate contained over 95 wt% FeTiO3, ∼2 wt% SiO2, and ∼ 1 wt% Al2O3. Ilmenite was mixed with additives (i.e. sulphur, vein graphite, and a 1:1 mix of sulphur and vein graphite), separately in three ratios by weight, namely 1:1, 2:1 and 4:1, respectively. Each mixture was milled for 4 and 6 h. A high percentage of ilmenite/sulphur + graphite (ISG) was converted to nanoparticles (average particle size = 124 nm) in samples milled for 6 h. X-ray diffraction (XRD) spectra indicate that the intensities of sulphur and graphite peaks decrease after ball milling. This suggests possible dissolution of sulphur and graphite into the ilmenite structure, with the formation of mixed composite structures. The optimum ilmenite to additives ratio for ilmenite to rutile conversion was found to be 4:1. The occurrence of pyrite and pseudorutile peaks in XRD spectra of milled samples indicates that ilmenite reduction was initiated during ball milling. Fourier-transform infrared (FTIR) spectra of milled samples confirm the octahedral metal-ion stretching vibrations of carbon-incorporated ilmenite structures. The ilmenite-additive mixtures containing both sulphur and graphite (ISG) showed the best results. Consequently, ISG samples (mixing ratio of 4:0.5:0.5, and milled for 6 h) were isothermally annealed at 800 °C, 1000 °C and 1200 °C, respectively. Sharpening of rutile peaks and disappearance of pyrrhotite peaks in the annealed samples indicated the completion of the mechanochemical reactions that were initiated during ball milling. The optimum temperature for ilmenite reduction was determined to be 1000 °C. At that temperature pseudorutile peaks had disappeared from the XRD spectra of the annealed samples, whereas brookite and rutile peaks appeared. The method introduced in this study thus can be utilised to convert ilmenite to synthetic rutile.