Due to high affinity of metals towards carbon, the reduction of manganese ore by carbon resutls in high-carbon ferroalloy. This carbon being a deleterious impurity whether the metal is used as ferroalloy or an austenite stabilizer for stainless steel, use of low-carbon ferromanganese is indispensable. The conventional methos of carbon removal are multi-stage, cumbersome and involve loss of metal in slag. Attempts have been made in the present investigation to explore non-conventional methods such as solid-state decarburization. This reduces loss of metal as there is no slag formation and the carbon removal is carried out by gaseous oxidizer like carbon removal is carried out by gaseous oxidizer like carbon removal is carried out by gaseous oxidizer like carbon dioxide which is provided externally or generated in situ. The preliminary findings show that the mechanism of decarburization is quite complex, as solid-gas reactions viz. Oxidation of manganese and carbon take place simultaneously. It has been shown that maximum decarburization with minimal loss of metal can be achieved simultaneously by choosing appropriate experimental conditions. From the experiemtnal evidence of the present investigation, it can be concluded that solid-state decarburization of high-carbon ferromanganese consists of multtiple steps in which carbon rich carbides gradually transform into metal rich carbide. Based upon the observations, it can be inferred that, the efficiency of this particular technique can be improved by increasing the operating temperature, decreasing the particle size of the reactants and lowering the partial pressure of effluent gas viz. CO without vaporization losses of metallic manganese.
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