Effects of Metal Oxides on Carbonation and Coking ofHigh-Salinity Organic Wastewater

Slag is difficult to treat quantitatively due to the formation of a molten mixture in the carbonization process of high-salinity organicwastewater. Thus, aiming at solving this difficulty, the effects of metal oxide additives, additive ratio, furnace burden ratio, andcarbonization temperature on the carbonization and coking of high-salinity organic wastewater are systematically analyzed. Theanalysis is performed using scanning electron microscopy, X-ray diffraction, and Vickers hardness tests. The results show thatallfive metal oxide additives can reduce the hardness of carbonized products. The relative effect of reducing the coked hardnessis as follows:MgO > CaO > kaolin > Fe2O3>Al2O3. Thus, the effect of MgO on reducing the coking hardness is stronger thanthat of the other four metal oxides, reducing the hardness of carbonized products by approximately 81%. Furthermore, theadding charge can reduce the hardness index by at least 60%. When the carbonization temperature is higher than 800°C, thehardness index of the carbonized product decreases by approximately 5% each 50°C of increase in temperature. This studyshows that the addition of metal oxides can effectively reduce the hardness of coking during the treatment of high-salt organicwastewater by carbonization and oxidation and provide theoretical support for the subsequent treatment of high-salt organicwastewater by carbonization and oxidation.