Influence of ballasted material properties in enhancing the separation of high concentration suspended solids in coal mining water

Abstract

With the continuous improvement and economic development of China’s coal mining industry, research on the characteristics of wastewater discharge has gained attraction in recent years. Ballasted flocculation technology, has been widely used in recent years. However, its effect on the settling velocity of the flocs in wastewater has not been quantified. This study aimed to screen optimal reaction condition for ballasted flocculation and to derive the settling velocity of the ballasted flocs under these conditions. The results showed that, the size of the ballasted material had no significant effect on the turbidity and suspended solids removal rate; however, the settling time was effectively shortened, and the turbidity removal rate could reach more than 95% within 15 s. Owing to the optimization of the reaction conditions, 90% of the flocs sizes were distributed in the 80–200 µm range. Moreover, the difference between the theoretical and the measured value of the ballasted flocculation was small, indicating that the derived formula could effectively quantify the settling velocity of the ballasted flocs under optimal conditions. These findings may serve as a critical reference for the treatment of high-suspended solids in coal mining water and have significant potential for engineering application.