DEPHOSPHORIZING METHOD FOR HIGH-MANGANESE ALLOY

摘要

PURPOSE:To easily execute a dephosphorization treatment at a low cost by adding a specific ratio of BaCO3 as a flux to high-carbon ferromanganese contg. P at a high rate and oxidizing part of Mn to MnO by the CO2 formed by the decomposition thereof thereby incorporating MnO into molten slag. CONSTITUTION:The melt of the high-carbon ferromanganese of the high P content contg. >20-% Mn is subjdcted to a preliminary desiliconization treatment in a ladle and thereafter BaCO is added as the flux at 2-9% ratio thereto. An inert gas or oxidizing gas such as Ar, N2 or CO2 in then added to the melt and the melt is stirred. The operation in this stage is executed at a relatively low operating temp. of 1,250-1,400 deg.C and part Mn is oxidized to MnO by the gaseous CO2 formed by the thermal decomposition of BaCO3 so that the molten slag is made strongly basic by BaO and the oxidizing slag incorporated with 2-40% MnO is obtd. The P in the high-carbon ferromaganese is oxidized to P2O5 and is converted to slag by the above-mentioned slag. The dephosphorization refining is thus easily and surely executed.