Pelleting Carbon Rich Raw Materials for the Production of Ferrosilicon

Ferrosilicon is an alloy metal produced in submerged arc furnaces through the process of carbothermic reduction of quartz in the presence of iron. The resultant products are ferrosilicon (FeSi), carbon dioxide (CO2), microsilica and various trace elements. Presently, raw carbon sources are fed directly to the furnace with only minimal treatment which results in fluctuations in the operation of the furnace which reduce the efficiency of operation, both driving up the cost of materials required and increasing the output of CO2. Additionally, fines (particles of raw materials below a certain size) are not suitable for the process as they are swept from the process with the resultant gasses, serving only to create additional issues with filtration of exhaust products. There are many potential benefits to agglomerating carbon raw materials such as rendering the fines available for the process. There is also the potential to create blends of carbon rich materials in order to use materials with higher reactivity to enhance other materials where the carbon content is high but the reactivity is low, for example petroleum coke. The processes for pelleting carbon as well as selecting materials for use in blends is explored and pellets are developed for testing. Through a series of tests the pellets are analysed in order to establish if they meet minimum criteria for processing within the ferrosilicon production process and if any favourable characteristics can be determined from certain blends with regards to mechanical strength and reactivity