The effect of calcium oxide on the crushing strength, reduction, and smelting performance of high-chromium vanadium–titanium magnetite pellets (HCVTMP) was studied in this work. The main characterization methods of an electronic universal testing machine (EUTM), X-ray fluorescent (XRF), inductively-coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), and scanning electron microscope-energy disperse spectroscopy (SEM-EDS) were employed. The crushing strength was affected by the mineral phases generated during oxidative baking and the subsequently-formed pellet microstructures owing to CaO addition. The reduction and smelting properties of HCVTMP with different CaO additives were measured and characterized with different softening-melting-dripping indices. Although HCVTMP showed the highest crushing strength with CaO addition of ca. 2 wt %, more CaO addition may be needed to achieve high permeability of the furnace burdens and a good separation condition of the slag and melted iron. In the formation process of the slag and melted iron, it can be determined that CaO could have a relationship with the transformation behavior of Cr, V, and Ti to some extent, with respect to the predominant chemical composition analysis of ICP-AES and XRF. With the microscopic examination, the restraining formation of Ti(C,N) and the promoting formation of CaTiO₃ are in accordance with the improved melting-dripping indices, including the decrease of the maximum external static load and gas permeability, and the increase of the melting-dripping zone and dripping difficulty.

Basicity has an important effect on the behavior of high-chromium vanadium-titanium magnetite (HCVTM) sinter. The effect of basicity on sintering, reduction, and softening-melting properties was investigated in an experiment-scale sinter pot. The results showed that with the basicity increasing from 1.7 to 2.5, the vertical sinter speed, the productivity, the particle size, the reduction disintegration index (RDI), and the reducibility index (RI) increased. The yield increased first and then decreased, while the tumble index (TI) had the opposite trend. The perovskite content increased first and then stabilized, and the silico-ferrite of calcium and aluminum (SFCA) increased from the basicity of 2.3. The HCVTM sinter had a better tendency of the softening behavior with the basicity increase. In addition, the melt droplet comprehensive index S increased, which indicated that the increase in basicity negatively affected the droplet performance. As the basicity increased, the comprehensive index value increased. Considering the adverse effect of basicity on softening-melting properties, the best recommended value is 2.3.

In this work, a series of epoxy acrylate (EA)/mica composite coatings were synthesized through introducing mica powders of different particle size into epoxy acrylate coatings and using an ultraviolet (UV) curing technique to investigate the influence of mica particle size on the coatings. Mica powders of different particle sizes were obtained by ball-milling for 4, 8, 12, 16, and 20 h with a planetary high-energy ball mill. The particle size and morphologies of ball-milled mica powders were characterized by laser particle size analyzer and scanning electron microscopy (SEM). The results indicated that planetary ball-milling reduced the particle size of mica powders effectively. Mica powders that were un-ball-milled and ball-milled were added into the epoxy acrylate matrix by a blending method to synthesize the organic-inorganic UV curable coatings. The optical photographs of the coatings showed greater stability of liquid mixtures with smaller particle size fillers. The chemical structures of EA/mica composite coatings were investigated by Fourier transform infrared spectroscopy (FTIR), and the conversion rate of C=C bonds was calculated. The results indicated that the C=C conversion of coatings with mica powders of smaller particle sizes was higher. Tests of mechanical properties and tests using electrochemical impedance spectroscopy (EIS) showed that pencil hardness, impact resistance, and coating resistance were improved due to the reduction of mica powders particle size.

The effect of ilmenite with different reduction degrees on the production of ferrotitanium, using a self-propagation high-temperature synthesis method with aluminum as the reducing agent, was investigated. Increasing the degree of reduction not only contributed to lower consumption of aluminum, but also lowered the oxygen content and improved the grades of titanium and iron in the ferrotitanium. The aluminum content of the ferrotitanium increased with an increase in the extent of reduction of ilmenite, so the Al₂O₃ content formed in the slag decreased with the constant addition of CaO and CaF₂ to the Al powder. This decreased relatively the content of high-melting-point CaAl₁₂O₁₉ and increased the contents of low-melting-point CaAl₂O₄ and CaF₂ in the slag, thereby promoting the separation of ferrotitanium and slag. Improving the reduction degree of ilmenite is beneficial to the preparation of ferrotitanium.