STEEL CONVERSION METHOD

1412775 Controlling converter steelmaking PENNYSYLVANIA ENG CORP 18 July 1972 [19 July 1971] 3931/75 Divided out of 1412774 Heading C7D Ferrous metal is refined in a bottom blown converter using a blast gas in which are entrained powdered reagents, the refining process being controlled by monitoring the composition of the uncombusted waste gas and the bath temperature as measured at a location giving a representative value. The blast may utilize oxygen, nitrogen, air or argon and the additives may include lime, limestone, fluorspar and desulphurizing agent, while a hydrocarbon gas may be blown in concurrently with the blast gas to cool the bottom of the converter. As particularly described the converter 10 is provided when in its vertical position with a hood 16 from which a sample is taken to gas analyzer 81, while bath temperatures are monitored by a probe 32. The signals are these that are passed to a computer 84 along with charge and product data as a result of which the inputs of gas and solid additives are controlled to achieve the desired result. Optionally the product may then be treated in vacuum degassing unit 91.