Phosphorus Partition and Phosphate Capacity of TiO₂ Bearing Basic Oxygen Steelmaking Slags

Abstract

The phosphorus partition (L P) and phosphate capacity (C PO4 3−) were measured for TiO 2 bearing basic oxygen steelmaking slags in the CaO-SiO 2-MgO-Fe t O-(TiO 2-MnO-Al 2 O 3-P 2 O 5) system at 1 650°C. The effect of slag and metal additions were tested by varying the TiO 2 content from 0.0 to 18.0 mass% and the [Ti] content from 0.009 to 0.301 mass%. A recently published L P model was used to assess the experimental L P data using the measured slag composition and temperature. Experimental L P data from this study and literature data were used to modify the published model to include titania. Increasing the TiO 2 concentration of the slag was found to decrease the L P and C PO4 3− of basic oxygen steelmaking (BOS) slags. Capacity values in the range of 2.2 × 10 16 to 1.5 × 10 18 at 1 650°C were obtained. An empirical model for determining C PO4 3− was developed for BOS slags using a large dataset of published slag and pO 2 data for relevant slag systems, including published data for titania bearing slags. The predicted C PO4 3− from the empirical model was found to agree with the experimentally determined C PO4 3− data from this study.

Dephosphorization Kinetics of Bloated Metal Droplets Reacting with Basic Slag Containing TiO₂

“…TiO 2 behaves as an acidic oxide in basic slags, thus according to the calculated results from Factsage and Riboub model, 31) the slag viscosity increases with increasing TiO 2 content and is expected to decrease the phosphate capacity C PO 4 3− as shown in the author's work. 47) By reviewing relevant literature, some of the current authors 47) developed the following correlation to calculate the C PO 4 3− for TiO 2 bearing BOS slags.…”

“…7(a). In addition, the authors 47) conducted slag/steel L P measurements with similar slag compositions and found that the range of L P is between 100 and 200. Employing BOF-type slags, Assis et al 48) also carried out phosphorus equilibrium study between liquid iron and slags and found that slags with basicities higher than 2.5 (V ratio) and around 20 to 25 mass% FeO can offer a L P greater than 500.…”

Phosphorus Partition Between Liquid Crude Steel and High‐Basicity Basic Oxygen Furnace Slags

“… Assis et al [ 27 ] proposed, in 2012, the following formula. This equation was derived from the revision of the Suito correlation [ 25 ] using experimental data from previous studies [ 14,15 ] Drain et al [ 4 ] also considered TiO 2 in a similar equation …”

“…Phosphate capacity [ 3–5 ] where { } denotes gas, is the content (in mass%) of phosphate ion in the slag, and and are the partial pressures of phosphorus and oxygen, respectively.…”

“…Since 1946, many researchers [ 4,9–19 ] have investigated the phosphorus partition experimentally. Thereby, many models for the phosphorus partition were established theoretically or experimentally.…”