GB1412923A - Pig iron refining control - Google Patents

Abstract

1412923 Controlling converter steelmaking CENTRE DE RECHERCHES METALLURGIQUES-CENTRUM VOOR RESEARCH IN DE METALLURGIE 1 March 1974 [1 March 1973] 9347/74 ] Heading C7D In a process in which oxidizing gas is blown into a converter and solid materials added, with the exhaust gases being collected in a hood, the following quantities are monitored; rate of supply of oxidizing gas, rate at which CO 2 leaves the converter, CO content of the exhaust gases, and decarburization rate of the metal bath. There are then calculated (a) the factor XF given by the expression where [CO]c and [CO 2 ] c are the respective contents of the exhaust gases, and, from [CO 2 ] c , D(CO 2 ), (the rate at which C02 leaves the converter), the decarburization rate, and XF, (b) the parameters (i) rate of combination of oxygen with carbon from the bath, (ii) rate of oxygen take-up by slag and (iii) rate of combustion of CO in the converter. These three parameters are compared with predetermined values, which may vary during the course of a heat, and operating conditions adjusted to minimise deviations. The quantity D(CO 2 ) may be obtained by measuring the intensity of sound emitted by the converter, and [CO] c by measuring the intensity of light emitted, the values possibly being corrected intermittently by gas analysis. Modified methods of operating the invention to allow for the pressure of hydrogen (from dissociation of water) and nitrogen from ingress of air into the hood) in the exhaust gases are described.