Effects of Pre‐Reduction Degree of Ironsand on Slag Properties in Melting Separation Process

Abstract

Ironsand is a kind of titanomagnetite ore and has been maturely used through direct reduction (DR) and melting separation (MS) processes. As an intermediate parameter, pre-reduction degree (PRD) can be controlled in the upstream DR, and has a considerable influence on metal/slag separation in subsequent MS. Thus, the effects of PRD on the properties of melting separation slag from prereduced ironsand are studied in order to ensure the melting separation sufficient at the condition of slag with high titanium oxide content. The softening, melting, and flowing temperatures of slag show different variation trends along with PRD changing, and the slag at 90% PRD has the narrowest softening-flowing temperature interval. The viscosity of slag of 90% PRD also shows the proper smelting characteristic. Moreover, Raman spectra results indicate the increase PRD reduces the depolymerized product Si-O-M (metal), which is mainly caused by the decreasing of network-modifier FeO. Polymerization degree ψ ((Q 3 þ Q 2 )/(Q 1 þ Q 0 )) illustrates the high PRD is consistent with the complicated silicon network structures, especially when PRD is larger than 90%. Figure 2. The original profile of slag samples and melting samples with the height accounting for 75, 50, and 25% of the original sample height during the heating process, a-e) represent the slags at the PRD of 70, 90, 95, 97, and 100%, respectively. www.advancedsciencenews.com www.steel-research.de steel research int.

Effect of Titanomagnetite Ironsand Coal Composite Hot Briquette on Softening-melting Performance of Mixed Burden under Simulated Blast Furnace Conditions

“…[8][9][10][11][12] Then the ironsand are usually prepared as ironsand sinter and ironsand pellet. [13][14][15][16][17] However, amounts of literatures indicated that the addition of titanomagnetite ironsand would worsen the metallurgical properties of sinter as well as pellet due to the following aspects: (1) Ironsand performs a high assimilation temperature and a low binding phase intensity, which leads to reducing the characters such as cold strength and reducibility of sinter and pellet; 18) (2) Owning to the spinel cubic structure, the high thermodynamic stability, and its high content of Ti, the titanomagnetite ironsand sinter generally shows a low strength and low reducibility. [19][20][21] Meanwhile, on account of its low specific surface area, coarse grain, dense structure, and smooth surface, the proportioning ratio of ironsand in sinter and pellet is seriously limited.…”

“…As a typical kind of titania-ferrous coexisting ore, titanomagnetite ironsand with rich Fe, Ti, V and other valuable elements is mainly made from of the volcanic lava. [1][2][3][4] It is widely distributed in the coast of Australia, New Zealand, Japan, and the Southeast Asia. 5,6) Recently, the production cost of steel has increased as the running out of the highgrade iron ore concentrate, and the demand for low-price and complicated iron ore resources, such as titanomagnetite ironsand, are growing rapidly.…”

Influence of Basicity on the Viscosity and Crystallization Characteristics of Chromium-containing High-titanium Slag

“…When the sample heights were 75%, 50%, and 25% of the initial height, the corresponding temperatures were recorded as the softening temperature, hemispherical temperature, and flow temperature, which were defined as T s , T h , and T f , respectively. 28,29) The apparatus used for the viscosity measurement is an RTW-10 melt property comprehensive tester that developed by Northeastern University and its schematic diagram is shown in Fig. 2.…”

Status, technological progress, and development directions of the ironmaking industry in China

“…Much attention has been paid in recent years to the grade and strength of raw In addition, raw materials for BF burden structures are generally chosen based on the chemical composition and slag basicity, whereas little attention is paid to how compatible a raw material is based on its metallurgical performance [17].…”