Patent ID: 6171364
Filing Date: 2001-01-09
Classification: C21B,Y02P

Abstract:
In a process of producing molten iron that comprises the steps of:a) introducing a source of iron oxide, flux, oxygen, nitrogen, and a source of carbon and hydrogen to a smelter reactor, at least some of said oxygen being continuously introduced through an overhead lance;b) maintaining conditions in said smelter reactor to cause (i) at least some of the iron oxide to be chemically reduced, (ii) a bath of molten iron to be created and stirred in the bottom of the smelter reactor, surmounted by a layer of foaming, FeO-containing slag, and (iii) carbon monoxide and hydrogen gas to rise through the slag;c) causing at least some of said carbon monoxide and hydrogen to react in the smelter reactor with the incoming oxygen, thereby generating heat for reactions taking place in the smelter reactor;d) releasing from the smelter reactor an offgas that contains CO, CO.sub.2, H.sub.2, and H.sub.2 O; ande) removing at least some of said molten iron and slag from the smelter reactor,the improvement comprising the following steps:f) repeatedly measuring, during the process, the conditions of the slag height, the temperature of the molten iron, the content of CO, CO.sub.2, H.sub.2, and H.sub.2 O in the offgas, the carbon content of the molten iron, and the FeO content in the slag, andg) subsequently adjusting one or more process variables so as to help keep one or more of said process conditions within a range.