A Reproduction of the Ancient Bandjeli��s Steel-Making Process

Abstract

This paper presents an ancient traditional steel-making process of Bandjeli, in the Bassar Region in the Republic of Togo (West Africa). The iron specialists of Bandjeli have owned technical knowledge to cast direct reduced iron (DRI) likely direct reduced steel (DRS). This know-how was transferred to each generation over many centuries. The description of this steel-making process is focused on the steps that lead to the iron ingot: the construction of the furnace, the raw materials collection and their preparation, the furnace filling and the smelting operation. Microstructures of as-smelted and thermo-mechanical treated samples as well as hardness data are presented. Optical and SEM micrographs indicate a Widmannstätten structure type, comprising of a plates or needles of ferrite or alpha iron (Feα) in light contrast and grains of pearlite (dark contrast). Micro-hardness measurements indicate values ranging from 100 to 700 Hv, this field covers the micro-hardness values of the ferrite and pearlite. Microstructural and mechanical properties of the as-obtained product suggest direct steel processing from Bandjeli's natural draught furnace. These results are necessary for further investigations on the as-smelted steel and on the contribution of this traditional smelting technology to the iron industry.