The affects of heat and/or acid treatment on bleaching properties of serpentine to be utilized in reclaiming waste engine oil

Abstract

In this study, the effect of heat and/or acid treatment on the bleaching properties of the serpentine gathered from Kayseri city of Turkey was investigated. Waste engine oil was reclaimed in two steps. First of all, it was pre-cleaned by solvent extraction, then bleached with heat and/or acid treated serpentine. The results obtained were evaluated by utilizing XRF, XRD, FT-IR, TGA, BET and SEM analyses. It was found that; the raw serpentine has to be heat treated above 700 °C until all of the serpentine turns into forsterite structure. The acid treatment of this forsterite did not improve the bleaching properties; instead, it further reduced bleaching properties of it. Low temperatures heat treatment below 700 °C is not sufficient to change the serpentine structure into forsterite. These results are in accord with Cao et al.’s results. Both results are clearly proves the fact that the main properties of serpentine are the same throughout the world. Thus, it can be said that serpentine is readily available and very cheap material to be used in bleaching waste engine oil, but it has to be converted into forsterite structure by heating above 700 °C. Once the serpentine structure was converted into forsterite structure by heat treatment, further acid treatment is not necessary. FT-IR and UV absorbance results were found to be confirming each other and approving the results that the best bleaching agent 4 h-750 coded serpentine.