Optimisation of the FeMn and ZnO production from spent pyrolised primary batteries -Feasibility of a DC-submerged arc furnace process

In the present work the feasibility to produce a Fe-Mn-alloy and a ZnO-concentrate from spent pyrolised primary batteries has been investigated based on fundamental research, already reported in "World of Metallurgy" - ERZ-METALL 1/2007. Through a carbothermic reduction in a Direct Current Submerged Arc Furnace process (DC-SAF) at IME Aachen, several laboratory-scale as well as semi-pilot scale tests were conducted with three different slag-compositions using solid- and hollow-electrode technique. The process was theoretically modelled with the thermochemical package FactSage 5.3.1. The effect of the process parameters temperature, slag composition and carbon addition were analysed. The results show that it is possible to recycle spent primary batteries through the submerged arc route to obtain a Fe-Mn-alloy with a ratio Mn/Fe > 1 and a ZnO concentrate as a separated product, reaching recycling quotes for Mn between 44 and 62 %, for Fe between 56 and % % and for zinc of more than 90%.