Regular Article

Influence of the prime hard coking coal in stamp charge cokemaking: true or false

¹ JSPL, Angul 759111, Odisha, India
² Coke Oven Plant, JSPL, Angul 759111, Odisha, India
³ Iron Zone, JSPL, Angul 759111, Odisha, India

^* e-mail: hp.tiwari@angul.jspl.com

Received: 18 April 2020
Accepted: 22 July 2020

Abstract

The production of hot metal through the blast furnace route is stilled the most cost-effective and highly productive process and probably remains the coming decades besides developed many alternative ironmaking technologies. In the recent past, the working volume of the blast furnace has been increased drastically to increase the blast furnace productivity. This means the blast furnace performance is more correlated to specific productivity which measures the efficiency in terms of ton hot metal. These modern blast furnaces favour high quality of coke, i.e. high coke CSR and M40 value, high iron content sinter and pellets. These high quality of input raw materials increased blast furnace efficiency and productivity. Generally, cokemakers increases the ratio of prime hard coking coal in the coal blend to achieve the high quality of coke. This increase in prime hard coking coal is not desirable for coke oven batteries because it creates high oven wall pressure and high coke cost and also not suitable for raw material security. The present investigation highlights few cases which clearly show that the high quality of coke (coke CSR: 69–71) may be easily produced with the optimal proportion of prime hard coking coal in the blend if the selection of coals is proper. Results confirmed that upto 30% primary hard coking coal with 15% non-coking coal in the coal blend produce an excellent quality of coke which naturally requires a careful selection on the blend component. The optimum composite coking potential (CCP) value of 4.6–4.9 is the ideal value for producing coke CSR in the range of 69–71 in recovery stamp charge cokemaking process in the real-time plant operation. Therefore, it is necessary to select the right coals for the coal blend based on the adopted cokemaking technologies to conserve the reserve of prime hard coking coal, oven health and cost-effectiveness.