Phosphorus Vaporization from Basic Oxygen Furnace (BOF) Slag using Ferrosilicon

Abstract

Steelmaking slag is one of the major byproducts from the steelmaking industry and the growth rate of slag generation is increasing as steel production increases Although the slag of steelmaking process can be recyclable it is limited in its recovery due to the high concentration of phosphorus If phosphorus in the slag could be reduced the slag could be recycled in the steelmaking process and eventually we could decrease the consumption of CaCO3 which is one of the major sources of CO2 emissions The aim of this thesis was to reduce the phosphorus (P) from BOF slag with the most environmental friendly way and determine the distribution of phosphorus after reduction by using ferrosilicon (FeSi) as reductant and addition of SiO2 to lower the basicity of slag at various temperature (1300 1400 and 1500 oC) The main results of this research are that FeSi proven to be able to reduce phosphorus from BOF slag XRF data showed 2 best results of phosphorus reduction from slag with condition 1500oC with 3 wt% FeSi and 10 wt% SiO2 ICP-MS data showed 2 best results of phosphorus vaporization with condition both samples are at temperature of 1500oC with 3 wt% FeSi and 5wt% + 10 wt% SiO2 Based on the mass balance calculation by ICP-MS data more than 50% of P from the samples might be vaporized Overall temperature of 1500oC is preferable to have higher reduction percentages of phosphorus from solid phase and vaporization

Date of Award	2019
Original language	English
Supervisor	Shou-Heng Liu (Supervisor)