Optimising oxygen enrichment to blast furnaces using coal injection

摘要

The introduction of high levels of pulverised coal injection in blast furnaces requires enrichment of the air blast with oxygen, but enrichment reduces the total blast volume required, thus leaving spare blower capacity. A new oxygen generation plant has been developed which uses this spare blower capacity thereby removing the need for dedicated heavy compressors in the oxygen plant, resulting in savings in capital, maintenance and reducing energy costs by 40 percent. The Taranto Works in the far south of Italy is ILVA's core integrated steel plant. Production capacity is around 12Mt of steel per year. The plant comprises five blast furnaces, AFO1, 2, 3, 4 and 5. The current production level is around 8Mt/y of steel, with Blast furnaces AFO3 and AFO1 presently stopped. To remain among the most competitive steel-makers, especially in Europe, cost reduction is a major issue for plant operations. One of the roads to reduce operating costs of an integrated mill is to reduce coke consumption, replacing coke by Pulverised Coal Injection (PCI). ILVA intends to increase PCI at the Taranto Works in the next few years and additional oxygen capacity is needed to achieve this. After a thorough evaluation, in 1999, ILVA signed a contract with Air Liquide for the supply of an innovative oxygen plant called OXIAL integrated within the ironmaking process.