CARBOTHERMIC REDUCTION OF BASIC MANGANESE USING SPENT MALT WASTE BIOCHAR IN THE REDUCTION ZONE

The environmental impact of the long-standing fossil fuel, namely coke as a reducing agent has been a challenge in the pyrometallurgical industry for decades. The threats that it poses have become increasingly unbearable. Few attempts on different biochar have been conducted and their impact on the quality of slag investigated. More improvements are still underway for industrial scale use. The current project evolves on the reducing capabilities that spent malt waste biochar in the reduction zone during carbothermic reduction of basic manganese ores. X-ray fluorescence, X-ray diffraction and scanning electron microscopy have been used for characterization. Alumina tube furnace was used for the experiment. The challenge that the malt waste biochar presents is mainly the size particles. It is in more powdery form which requires preconditioning to make its usage efficient. Amongst the possibilities is the formation of pellets that combine the fines of the biochar, ore fines and the use of binders that would not hinder the quality of the slag. In the present project, pellets were made of manganese ore fines, malt waste biochar fines and Altotech CB6 an organic binder. Results have revealed that spent malt waste biochar is indeed a reducing agent and that the impact of the ash is minimal. For the two temperatures experimented in this project namely 1200^oC and 1300^oC, XRD results have revealed that MnO did form which depicts a fast reduction stage as observed when metallurgical coke is used. Also, the presence of iron carbide was confirmed. Further, the fixed carbon in the malt waste biochar is very competitive compared to metallurgical coke. However, further studies are still required to investigate its behavior in the melting zone to assess the physical properties of slag especially its immiscibility with the metal.