Latest Results in EAF Optimization of Scrap-Based Melting Process: Q-Melt Installation in Kroman Celik

摘要

In today's highly competitive market situation, it is of outmost importance for EAF steel makers to optimize their processes in order to reduce operating costs and to improve safety and reliability of the equipment. A common trend observed during the last five years is a generalized reduction in oxygen and fuel utilization, mostly driven by a worse quality charge mix and a lower productivity level requirement from saturated markets. The comprehensive study on the chemical energy efficiency in EAF practice reported in their paper by Patrizio and Pesamosca [1] is clarifying the theoretical background explaining the observed tendency. Whenever the charge mix is poor in carbon and other oxidizing elements (silicon, manganese, chromium) the overall energy efficiency of oxygen drops down and turns into expensive yield losses.Coal energy input is lower, compared to gaseous fuel burners. Intensive oxygen practices lead therefore to overall higher heat losses to the fumes treatment plant, incomplete CO combustion, iron oxidation and poor slag quality. The current market situation is mostly driven by price competition. Volumes have kept shrinking in the recent period,especially in the steel commodities and in countries with mature economies. Operating expenditure is the most important performance steelmakers are taking care of. Existing steel production over capacity is not pushing for higher production levels, while high quality commercial bar feedstock is widely available at competitive prices, mainly imported from Far East. Scrap prices are volatile and highly variable on short period. Low bulk density feedstock and local market are cheaper and preferred to expensive imported or shredded feedstock.The question is therefore how to rapidly adapt to this highly dynamic market environment still holding competitive performances to keep proper profit margins.