Design and process simulation for direct reduction of Iron Ore using hydrogen Gas.

Abstract

Uganda is rich in iron ore with over 500 million tonnes (Kim et al., 2021), which are found in places of Kyanyamuzinda, Kamena, Rushekye, Nyamiyaga, Butale, and Kasenyi which give rise to the Muko deposits in the Kabale district as well as Sukulu in Tororo District and Bukusu found in Mbale District. The iron ores found in these places are largely intact and present for processing in the furnace to manufacture different iron and steel products. Besides these places, manufacturing industries like Tembo steel industries, steel and tube industries among others produce these products by melting scrap or burning coal and coke producing carbon-dioxide which along with high temperature, converts the iron ore into molten pig iron. For production the scrap to be used is melted using the furnace method which releases a lot of carbon-dioxide fumes into the atmosphere which pollutes the whole environment making it unsafe to live in. According to the high demand of steel products on the market, their production cannot be stopped, rather there should be an alternative way of manufacturing these products but without releasing these harmful gases into the atmosphere. The focus of this study was to design and simulate the shaft furnace for the direct reduction of iron ore using hydrogen gas which cuts off the CO2 emissions. Shaft technology is the most important gas based direct reduced iron (DRI) process, it includes reduction, transition and cooling zones. With the introduction of this technology into the manufacturing industries won’t only save time in the manufacturing process, but also assist in the quality production, completely eliminating the harmful gases released into the atmosphere, operations are clean since hydrogen gas used in the process was of the needed purity and the whole method was cost effective compared to the furnace technology. Design requirements necessary for the design were obtained from field work, data collection from Tembo steels Uganda Limited Iganga plant and literature review which gave most of the information. Using solidworks software, the detailed design of the needed process technology was modelled to correct dimensions which was later used in the process simulation. The design was tested under flow simulation feature in the solidworks software after being subjected to reduction temperatures, pressure and the hydrogen gas velocity. This confirmed that the process was suitable for the reduction process to produce sponge iron.