Improvements in or relating to processes for the production in converters of steels low in phosphorus, nitrogen, and oxygen

摘要

A process for the production of Bessemer steel low in nitrogen phosphorus, and oxygen from an iron containing .0,1 - 0,7.per cent.P .0,4 - 1,0.per cent.Si .1,5 - 2,5.per cent.Mn .3,8 - 4,5.per cent.C comprises blowing the iron in a single stage in a bottom blown converter with oxygen enriched air or an exothermic oxygen-steam mixture and adding lime and ore or mill scale through the top of the converter. The lime and ore or mill scale may be added at the beginning or not later than half-way through the process, all at once or in portions, the total amount of ore or mill scale being at least 40 kgs. per 1000 kgs. iron. The oxygen enriched air may contain 28-45 per cent oxygen by volume and the oxygen-steam mixture may have an oxygen-steam ratio of 1 : 1 to 1 : 1-2. The lime may be mixed with the ore or mill scale and fluorspar may also be added as a flux.