Low Cost Oxygen for Blast Furnace

摘要

A low cost process is examined which provides oxygen enrichment of blast air for blast furnaces to increase steel production without increasing the steelmaking or final finishing facilities. The proposed process is designed to separate the oxygen from nitrogen molecules by using a thermal swing combined with a continuous movement of an aluminosilicate (zeolite) molecular sieve. Energy for this process comes from waste energy normally exhausted by the blast furnace into the air. A 2 CFM thermal swing unit was designed and tested. It operated for only 30 minutes due to excessive gas leakage in part of the system. An oxygen level of 22.3 percent was achieved. However, a higher level should be attainable without leakage. The test run demonstrated the validity of the basic concept which utilizes exhausted blast furnace gas. Failure to achieve higher oxygen levels because of gas leakage made it impossible to predict the economic feasibility of the approach or the long-term operation of the design concept. This method supersedes the originally proposed concept of a pressure swing process which was found to be too expensive to operate.