Papers by Keyword: Ilmenite

Abstract: The extraction of ilmenite minerals using the sulfate route is one of the commercial methods for producing titanium dioxide (TiO₂) materials. The sulfate process requires a high concentration of sulfuric acid to achieve high extraction yield of titanium. However, this process also results in the generation of high amounts of sulfuric acid waste. Modifying ilmenite minerals is thought to be one of approaches in reducing the consumption of highly concentrated sulfuric acid. In the current study, we investigated the effect of the ilmenite-to-water mass ratio (ITWR) on the wet-ball milling process to enhance the dissolution of titanium from the ilmenite mineral. The results revealed that increasing the water amount from 10 to 70% wt has decreased the particle size from 167.60 to 0.55 μm and increased the titanium yield from 479.36 to 1228.89 ppm. On the basis of investigation, it was shown there is a significant relationship between the ilmenite-to-water mass ratio and titanium dissolution, highlighting the importance of an optimal ratio for achieving maximum dissolving yield. The obtained TiO₂ nanoparticles provide the average crystallite size of 4.16 nm, with rutile and anatase phase, and spherical morphology.

Abstract: Titanate nanosheets are a type of 2-dimensional nanomaterial with vast applications in electronics, energy storage, and photocatalysis due to their superior properties, such as their large specific surface area and excellent electrical conductivity. Titanate nanosheets are expected to be the material precursor of TiO₂ nanostructures with further treatment. The current research aims to synthesize titanate nanosheets using the natural mineral ilmenite from Indonesia through the hydrothermal method. X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunaeur-Emmett-Teller (BET) analysis were used to characterize the chemical composition, crystal structure, shape, size, and specific surface area of the prepared samples. The structure phase of the as-synthesized sample is known to be layered titanate. The as-synthesized nanosheet sample has a diameter ranging from 2.5 to 4 μm and BET surface areas of approximately 40 m²/g. This concise hydrothermal method could create 2-dimensional structured nanomaterials from Indonesian local minerals.

Abstract: The main problem of processing of ores with a high content of titanium oxides is refractory slag based on TiO₂, which makes it difficult to melt. The methods of processing of titanomagnetite and ilmenite ores were analyzed. It is shown that the existing scheme of processing does not meet the requirements of complex use of materials. The paper presents the results of laboratory studies on reduction of ilmenite concentrate and subsequent pyrometallurgical separation of reduction products without addition of flux or slag-forming materials. Solid-phase reduction of iron enabled to extract iron selectively from the ilmenite crystal lattice, not diluting the oxide phase with the reducing agent ash. Using the advantages of solid-phase reduction, the possibility of obtaining pure iron and slag with a high content of titanium oxides was shown.

Abstract: Tin mining business in Malaysia produce many types of by product such as xenotime, monazite, zircon and ilmenite. Ilmenite is one of the crucial materials that helps the growth of economy in Malaysia. Instead of that, ilmenite becomes an important material in the process of oxygen carrier where it shows a better compare to the other such as olivine, hematite, biotite and cuprite. Incredible mechanical resistance and good thermal properties are playing an important factor for the materials that been used for oxygen carrier and ilmenite is the most suitable material for oxygen carrier process. Instead of its suitable properties, ilmenite also one of the lowest price materials among natural minerals sources. Ilmenite composition can provide titanium dioxide (TiO₂) which can be used in many industries such as painting and iron oxide (Fe₂O₃ or Fe₃O₄) for catalytic and magnetic industries. TiO₂ can be found in three phases which are anatase, rutile and brookite. In order to obtain TiO₂, dissolution – precipitation mechanism where titanium arranges into different crystal structure depending on the reactant chemistry. These phase formations were obtained by using hydrothermal treatment at elevated temperatures with the appropriate reactants. The transition temperature and the mechanism of the structural transformation also can be largely influenced the iron oxide phase. Therefor in this study, extractive metallurgy method was used in order to obtain separate TiO₂ and Fe₂O₃.

Abstract: Becher process was applied for upgrading Ha Tinh ilmenite concentrate (54-55% TiO₂) to synthetic rutile. The process includes reduction of ilmenite concentrate using anthracite coal as reductant, followed by aeration of reduced ilmenite in ammonium chloride solution (NH₄Cl). The controlled parameters were temperature and NH₄Cl concentration. The results showed that the degree of iron metallization was 83% after 4 hours of reduction at 1150 °C. Most of the metallic iron (98%) was successfully rust after 9 hours of aeration at 70°C, 7/1 of liquid/solid ratio (L/R), 4 liter/minutes (L/min) of air flow rate and 0.5% of NH₄Cl concentration. The addition of acetic acid or citric acid in to the aeration solution has facilitated the aeration process. The aeration time could be vastly reduced when ammonium chloride solution used in aeration was replaced by the mixture of CH₃COOH 0.075M and CH₃COONa. Leaching with H₂SO₄ 15% has improved TiO₂ content from 82% in the aerated ilmenite to approximately 89% in synthetic rutile. The research work has proved that Becher process is applicable for the beneficiation of Ha Tinh ilmenite concentrate.

Abstract: Synthesis and characterization of α-Fe₂O₃ nanoparticles were obtained from extraction of ilmenite iron sand with coprecipitation method and to obtain α-Fe₂O₃ nanoparticles, high energy milling (HEM) was used. Surface morphology and identification of the elements contained in the sample were analyzed using scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). For phase analysis and crystal structure, X-ray diffractometer (XRD) was used. Moreover a vibrating magnetometer sample (VSM) was used to characterize its magnetic properties, while tunneling electron microscopy (TEM) was used for particle size characterization. Ilmenite-type iron sand has a diverse particle shape with a size of more than 100 μm with ilmenite (FeTiO₃) mineral content of about 64.7%. The results of extraction using coprecipitation method with sintering 750 °C, obtained hematite α-Fe₂O₃ material which has not been saturated to an external magnetic field of 1 tesla, the magnetic remanent value (Mr) is about 0.8 emu/g and the coercivity field value is Hc around 773 Oe. The average size of hematite α-Fe₂O₃ particles after being milled 50 hours is between 15-30 nm with a cube-like shape.

Abstract: The reduction of ilmenite by a gas comprising of CNG, hydrogen and nitrogen mixture was investigated by experimental and kinetic modeling in MATLAB. The CNG flow time was varied from 15 to 45 minutes at the temperatures of 1100-1200°C for 1-3 hours. In order to predict the extent of reduction, a shrinking core model (SCM) and crackling core model (CCM) were employed for the kinetic modeling. The results showed that the extent of reduction of 80% was achieved by using a CNG flow time of 45 minutes at 1200°C for 1 hour. The kinetic modeling for non-isothermal SCM at the same conditions gave a predicted value of 87%. The CCM gave a predicted value of about 100% at the same conditions. The non-isothermal SCM showed a closer trend to the experimental results. The deviation between SCM and CCM with the experimental data was attributed to porosity, thermodynamic properties and minute thermal fluctuations within the sample during the reduction process.

Abstract: The gamma ray shielding properties of cement paste containing ilmenite and barite (BaSO₄) at different concentration were investigated using beam transmission method for 59.5 keV gamma ray energy of ²⁴¹Am radioactive isotopes by using NaI(Tl) scintillation detector. The mass attenuation coefficients (μ_m) of these shielding materials were calculated. It was found that the mass attenuation coefficients increase with increasing of ilmenite and barite content up to a value of 60% by weight. The highest value of μ_m was 0.425 ± 0.003 cm²/g for cement paste containing ilmenite and 1.598 ± 0.039 cm²/g for the cement paste containing barite. The mass attenuation coefficient values were compared between cement pasted containing ilmenite and barite. The result show that cement paste containing barite showed good gamma ray shielding performances than that for the cement paste containing ilmenite.

Abstract: The use of titanium dioxide is so diverse that varies from food to heavy industry and it is the main substance in the titanium industry. Over 90% of the world's mined titanium concentrates are processed to produce pigments. The sources for the production of titanium dioxide are the typically used titanium-containing ores including minerals rutile, ilmenite, and others. The volume of world production of titanium dioxide pigment exceeds 5 million tons per year and it is carried out in two ways: sulphate and chlorine (in approximately equal volumes). The changed approach to the green production processes requires the improvement of existing technologies and the development of new methods for processing titanium-containing raw materials. The authors have experimentally confirmed the high efficiency of complex, waste-free processing of titanium-containing raw materials developed by hydrofluoride. Creating pigment production on the basis hydrofluoride method will meet not only the domestic needs but also offer thepigment for export, as its parameters will surpass those of the best world analogues.

Abstract: The reduction kinetics of ilmenite was investigated. Phase evolution during the reduction process was identified by XRD and morphology change was observed using SEM. Kinetic parameters of the activation energy and pre-exponential factor were determined by Kissinger-Akahira-Sunose (KAS) method and Coast-Redfern method&artificial isokinetic relationship (IKP) respectively. Results showed that when the reaction of titanium suboxides makes a growing contribution, the conversion dependence of activation energy has an ascending trend. When the conversion exceeded 0.7, the reactants almost consumed, and the process was controlled by diffusion.