Effect of BaSO₄ on the compressive strength and reduction behavior of pellets

Abstract

To provide theoretical basis for the production of pellets, the effect of BaSO4 in the range of 0 to 5.0% on properties of pellets was studied under experimental conditions. The influence mechanism of BaSO4 on the compressive strength of preheated pellets as well as roasted pellets and reduction behavior of roasted pellets was investigated by means of scanning electron microscopy-energy dispersive spectrometer (SEM-EDS). From the results, it can be observed that the compressive strength of preheated pellets varies slightly whereas roasted pellets has a great change when BaSO4 content increases from 0 to 5%. The compressive strength of roasted pellets initially increases then decreases, which reaches the peak value of 3411 N with BaSO4 content of 1.5%. The reduction degree enhances from 80.7 to 97.9% and FeO content reduces from 2.33 to 1.57% with increasing BaSO4 content from 0 to 5.0%. The degree of polycrystalline of hematite improves and the hole size increases obviously when BaSO4 content varies from 0 to 1.5%. The crystallization of hematite decreases and the holes whose distribution is uneven increases when BaSO4 content is more than 1.5%. In reduction process, the wustite reduces and metallic iron increases with increasing BaSO4 content from 0 to 5.0%.

Migration and Reaction Mechanism of Barium in BaSO4–CaCO3–Fe2O3 System during Sintering

“…However, as the BaSO 4 level in the sample increased, the compressive strength of the sample decreased, with the lowest value being 1.18 kN. The trend of this result is roughly the same as that of Ju et al [ 18,19,23 ]…”

Viscosity and structure evolution of bearing‐BaO slag melt with the low CaO/SiO2 mass ratio of 0.7

“…However, when the CaO/SiO 2 ratio was more than 1.0, an increase in viscosity due to the addition of BaO was because the partial depolymerization of network structure of slag melt had occurred due to an increase of O 2− compared with CaO/SiO 2 ratio = 0.7, which may weaken the function of O 2− to certain extent, eventually making the influence of O 2− for decreasing the viscosity of slag melt was lower than that of Ba 2+ . In addition, the viscosity changes were closely related to the optical basicity (Λ) of slag proposed by Duffy and Ingram, 17 which could be calculated by Equation (1).…”

“…The special iron ores containing barite (BaSO 4 ) are always employed as the main raw materials of ironmaking process in Jiuquan steel plant of China. [1][2] As a result, the blast furnace slag usually contains about 2.0 wt.% BaO content because the barite will decompose into BaO under high-temperature condition during the production process, eventually entering into slag melt. Furthermore, as the iron ores containing low barite content are consumed gradually, Jiuquan Steel Plant starts to focus on the development and utilization of the iron ore with higher barite content.…”

“…The special iron ores containing barite (BaSO 4 ) are always employed as the main raw materials of ironmaking process in Jiuquan steel plant of China 1–2 . As a result, the blast furnace slag usually contains about 2.0 wt.% BaO content because the barite will decompose into BaO under high‐temperature condition during the production process, eventually entering into slag melt.…”

Effect of Cr2O3 on the Kinetics Mechanism and Microstructure of Pellet During Oxidation Roasting Process

“…In recent years, numerous studies have been conducted on the impact of constituents on the production of HCVTM pellets. [17][18][19][20][21][22][23][24] Zeng et al [17] studied the effect of B 2 O 3 on the degree of oxidation and compressive strength of HCVTM pellets. Li et al [18] evaluated the relationship between the HCVTM porosity and various MgO additions.…”