Heating Iron Ore Slurry to Improve Filtering Efficiency Prior to Pelletizing
Engineers have known for some time that the efficiency of filtering iron ore concentrate slurry can be significantly improved by pre-heating the slurry ahead of the filters. However, heating such large quantities of dense slurry by conventional means has proven to be inefficient and high-maintenance. Recently though, submerged combustion was considered by an integrated steel producer in Mexico as a means of pre-heating their iron ore concentrate. The company toured many iron ore facilities around the globe, reviewing their pelletizing processes, and found that submerged combustion could provide a competitive advantage through operational efficiency.
Inproheat was retained by the company to design and manufacture a SubCom slurry heating system to heat 850 t/h of iron ore concentrate slurry from 25°C to 60°C. The 60GJ/h SubCom system consisted of five natural gas combustion chambers mounted in an iron ore concentrate storage tank. The system featured a heat recovery unit whereby the exhaust gases were used to preheat the incoming slurry stream, giving the system an overall thermal efficiency of 95%. As a result, the steel company realized significant improvements in filtering efficiency which enabled them to increase the capacity of their pelletizing plant without installing additional filters.
Iron, Slurry, Pelletizing, Filtering, Concentrate, submerged, Steel, Heating, Ore, Combustion