Productive Operation of Nakayama No. 2 Blast Furnace

Abstract

Because of the replacement of open hearth furnace with convertor, an increase in pig iron output was aimed at No. 2 Blast furnace of Nakayama Steel Works.
For the purpose of attaining high productivity, following ways were adopted under the condition of having no facility for high top pressure operation;
(1) increasing the oxygen enrichment in the blast. (2) maintaining the are agglomeration ratio of 85 per cent, and increasing the strength of sinter. (3) decreasing the fuel ratio by low Si content operation and optimum burden distribution aiming at the improvement of CO gas utilization, (4) in addition, the estimation diagram of stable operation range, which is restricted by theoretical flame temp, heat flow ratio, and shaft gas speed was used in actual operation. As a result of the above measures an excellent productivity of 2.84 t/d/m³ as monthly average was attained in July 1980.