The influence of surfactants' ionicity on the performance of coal dust suppression

Coal dust is a significant health hazard for coal workers, as prolonged inhalation can lead to severe diseases such as Coal Workers' Pneumoconiosis. Water spray with surfactants is commonly used as a pre-control strategy to control coal dust in underground mines. The zeta potential test is a widely used static test to evaluate surfactants with different ionicities. However, there are still some arguments about the evaluation criteria of zeta potential on surfactant performance between different researchers. Moreover, whether zeta potential can be used as an index to evaluate the surfactant suppression performance is inconclusive. To address these problems, this study conducted the zeta potential test and the wind tunnel test (a dynamic test) using various surfactants with different ionicities. It was found that the zeta potential test and the wind tunnel test gave consistent results for the anionic surfactant. However, this trend was not achieved for the non-ionic and cationic surfactants. Therefore, the zeta potential is only suggested to be used as an index to evaluate the surfactant's dust suppression efficiency, while dynamic tests are still recommended for these two types of surfactants to evaluate dust suppression efficiency.