FREMGANGSMAATE OG APPARAT TIL FREMSTILLING AV SVAMPMETALL VED GASSREDUKSJON AV OKSYDISKE MALMER

摘要

A method and apparatus for measuring and controlling the percentage reduction of iron ore in a vertical shaft, moving bed, gaseous reduction reactor. Reducing gas comprising hydrogen, methane, carbon monoxide and carbon dioxide is fed from a source of such gas to the bottom of the reduction zone of the reactor and is heated to an elevated temperature before being introduced into the reactor. The flow and composition of the reducing gas are determined at a first location before the gas enters the reactor. The effluent gas from the reactor is cooled and its flow and composition determined at a second location after the gas has been cooled. The measured flows and compositions are correlated with the rate of sponge iron production to obtain a measurement of percentage reduction of the ore and this measurement is used, either manually or automatically, to regulate the rate of removal of sponge iron from the reactor to maintain the percentage reduction at a predetermined desired value.