Recycling of Mn-rich ore fines, dust and sludge briquettes in Mn alloys production

From mining operations to the production of metal alloys, mining and pyrometallurgical industries generate wastes such as sludge and dust. These manganese-rich co-products are currently mostly landfilled. Landfilling has an important impact, both environmentally and economically. ERAMET manganese alloy production plants and other metal industries seek to minimize those effects by recycling such co-products in the Submerged Arc Furnace (SAF). R&D work has been carried out to address this issue through briquetting agglomeration of manganese-rich co-products. These briquettes were used as raw material in the EXCALIBUR (Experimental Campaign of the Limit of Briquette Usage in Recycling) pilot campaign. It aimed at producing High Carbon Ferro Manganese (HCFeMn) in a pilot scale SAF. This study’s main objective is to assess the process stability during briquette recycling. Briquette quality was characterized by measuring fines formation and breakage during transport. Briquette recycling’s impact on the smelting process was quantified by dust generation, furnace stability and overall process performance. These briquette recycling tests in a pilot-scale SAF are part of the feasibility study of this process at an industrial scale.