Effect of Waste Plastics addition on the Reduction of Mn (II) Oxide from Silicomanganese Slag

James Ransford Dankwah, Jessica Dankwah, James Bradford Dankwah

Abstract


The effect of waste plastics addition on the reduction of Manganese (II) Oxide (MnO) from Silicomanganese (SiMn) slag by metallurgical coke (Coke) has been investigated through experiments conducted in a laboratory scale horizontal tube furnace coupled with off-gas analysis through an infrared (IR) gas analyser. Composite pellets of SiMn slag with Coke, HDPE and blends of Coke with HDPE (in three different proportions) were rapidly heated at 1500°C under pure argon gas and the off gas was analysed continuously for CO, CO2 and CH4. The extent of reduction of MnO from the slag after 20 min was then calculated by mass balance for removable oxygen. The results showed improvements in the extent of reduction of MnO from the slag when coke is blended with HDPE. The time for complete reduction was found to decrease with an increase in the amount of HDPE that was blended with coke. Generally, a decrease in CO2 emissions was observed with HDPE addition; the extent of lowering, however, depends on the C/O molar ratio of the carbonaceous reductant. The Ferromanganese process is therefore another avenue for diverting the large volumes of waste plastics currently stockpiled on various landfill sites across the Globe.


Keywords


Silicomanganese slag; MnO; Waste plastics; High density polyethylene; Extent of reduction; Metallurgical coke

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References


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