Preparation and electrochemical characterization of TiO2 as an anode material for magnesium-ion batteries

Anode on the basis of titanium dioxide powder was made. Its morphological characteristics were investigated using ellipsometry, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Electrochemical properties were also investigated by cyclic voltammetry. Dispersing, mixing the initial reagents for obtaining homogenized paste and its coating to a substrate, drying and cutting the electrodes were main steps of anode production. The results of ellipsometry, SEM and EDS demonstrated a uniformly distributed layer of about 200 μm thickness with porous structure, particle diameter of 50–80 nm and titanium dioxide content (45.7 %). The XRD data confirmed the active anode matrix formation with a monoclinic crystal lattice corresponding to the modification of titanium dioxide (B) with small anatase inclusions. Electrochemical behavior of the electrode was examined in acetonitrile-based Mg(TFSI)2 solution. Diffusion coefficient (DMg) and the charge transfer rate constant (kct) were determined from cyclic voltammograms 1.54∙10–2 cm2/s and 1.29∙10–4 cm/s, respectively. A two-step electrochemical reaction was revealed by the ratio of the electricity amount consumed in the cathode and anode processes at varying the number of cycles. Small values of polarization resistance (Rp) calculated from cyclic voltammograms indicated rapid diffusion of magnesium ions during intercalation/deintercalation.

The complex processing of titanomagnetite concentrates of the Gremyakha-vyrmes deposit with extraction of vanadium and titanium

Titanomagnetites are a complex raw material with a high content of valuable components: iron (35–65 %), vanadium (0.5–1.5 %) and titanium (2–14 %). Today, titanium–magnetite concentrates are processed in two ways: blast furnace (Russia, China) and using electric smelting (South Africa). The blast–furnace method is applicable only for low–titanium titanomagnetites. In the case of using titanomagnetite concentrates with a titanium dioxide content of more than 4 %, the method of electric smelting with preliminary reduction is applicable. Both technologies aim to recover the two components iron and vanadium, while titanium is not recovered. In this regard, the development of a complex technology for processing titanomagnetite concentrate to obtain iron in granular form, vanadium pentoxide and titanium is urgent.

Processing of Agglomerates and Pellets Containing Various Amounts of Titanium Dioxide

Questions about the oxidative roasting of iron ore raw materials (agglomerates and pellets) are studied. Features of the phase structure of the iron ore raw materials containing titan and vanadium are discussed. Reducibility, durability, and the softening and melting temperatures of metallurgical iron ore raw materials are studied in vitro. The objects of the research are titaniferous ores containing different amounts of titan dioxide. The behaviors of agglomerates and pellets in a blast furnace are studied, and the influence of their physical and chemical properties on heat and mass transfer processes are researched by means of a mathematical model. The main indices of blast furnace smelting—productivity, coke consumption, composition of top gas, cast iron, and slag—are shown. It is established that the increase in titanium dioxide content in pellets, as the amount of concentrate with increased TiO2 content increases, does not cause deterioration in the quality of iron ore raw materials being prepared for blast furnace smelting. At the same time, as the hot strength of raw materials increases, the temperature at which softening begins increases and the temperature interval of softening of materials decreases.

Use of Multi-Hollow Polyester Particles as Opacifying Agent for Injection-Molded Polyethylene

Titanium dioxide is considered the most efficient white pigment for opacification of thermoplastics. However, its high cost, combined with strong price oscillations due to production bottlenecks, has been driving the industry towards alternatives that might allow reducing the titanium dioxide content, while maintaining the product’s opacity. A strategy commonly used in waterborne paints consists in adding hollow polymer particles to the formulation, therefore achieving opacification due to light refraction at the air/polymer interface. In the current work, we show preliminary results that indicate that a similar strategy can be followed for thermoplastics opacification, as long as thermoset particles are used, in order to ensure preservation of the hollow geometry during melt-processing. Multi-vesiculated crosslinked styrene–polyester particles, produced by a single-step double emulsion process, are used. Evidence of synergic interaction between the multi-hollow particles and titanium dioxide has been found.

Estimation of indices of BF heat of titanium-magnetite concentrates with different titanium dioxide content

Russia owns world largest reserves of titanium- magnetite and ilmenite- titanium- magnetite ores. Following the stepby-step inclusion into metallurgical processing of titanium- magnetite raw materials, the matter of maximum extraction of iron, vanadium and titanium becomes more and more actual. Kachkanar group of deposits of titanium- magnetite ores consists of two deposits: Gusevgoskoe and Sobstvenno-Kachkanar. At present JSC EVRAZ NTMK uses titanium- magnetite sinter and pellets, produced of Gusevgorskoe deposit ores. To make up the dropped out capacities and to keep the volume of mined ore at the level of 55 m t/year, it is planned to put into operation the reserved Sobstvenno-Kachkanar deposit. To process the titanium- magnetite ores of this deposit, their specific peculiarities should be taken into consideration. In particular, the increased TiO2content in iron ore concentrate up to 3.4% might require corrections of the BF technology. In this connection a study of metallurgical properties of lump iron ore raw materials with different titanium dioxide content was carried out. To clarify the pellets phase components a method of X-ray-phase analysis was used. The studies were done at CKP “Ural-M” equipment in the Institute of Metallurgy, Ural branch of Russian academy of Sciences. It was determined that pellets chemistry was represented by hematite (from 77 up to 89%), magnetite (from 2.84 up to 10.44%), complicated diopside (from 2 up to 10%), as well as in a small amount by quartz, hedenbergite, corundum, rutile, ferro-periclase, ilmenite, wollastonite, α-Fe, wustite. Results of viscosity calculation of obtained slags showed that it is within a range, typical for real BF slags viscosity. The obtained values of slag viscosity do not offer problems with slag regime of BF heat. It was shown, that increase of titanium dioxide content in pellets does not give rise to quality deterioration of iron ore raw materials preparation to BF heat as volume of introduced concentrate with increase TiO2content into the materials is increasing. Increase of hot strength and pellets temperature of beginning of softening, the pellets having increased titanium dioxide content, will positively affect main technical and economic indices of BF heat – coke rate and productivity, that was confirmed by BF indices calculation by application of balance logical and statistical model of BF process.

Reduction Roasting of Titaniferous Ores

Questions regarding the oxidizing roasting of raw iron ore materials (agglomerate and pellets) are studied. Features of the phase structure of raw iron ore materials containing titanium and vanadium are discussed. Reducibility, durability, and temperatures of the softening and melting of metallurgical raw iron ore materials are studied in vitro. Object of research – titaniferous ores with various titanium dioxide content. The behavior of agglomerate and pellets in a blast furnace are studied, as well as the influence of their physical and chemical properties on heat and mass transfer processes using a mathematical model of the blast furnace process [1].