Dust is generally considered a hazard not only in industrial applications but also to the environment, humans, and animals at large. In particular, just like in any other mining activities, mining of coal often results in the production of combustible and flammable coal dust. This is not limited to its transportation and processing and may result in catastrophic accidents if not properly handled. Therefore, enhancing safety measures by ensuring effective prevention and control of coal dust during mining, transportation, and processing is highly desirable.
Among the available methods for controlling the coal dust in coal mines, wet dust removal technique is widely preferred. Unfortunately, considering the high hydrophobicity nature of the coal dust, it is difficult to effectively wet the dust thus compromising on its efficiency.
In some published research, surfactants have been deemed suitable for enhancing the dust removal efficiency by improving the wettability properties of water. However, the high cost of de-dusting technique has hindered its utilization for controlling dust in the actual coal mines. Alternatively, controlling coal dust using magnetized surfactants-based technologies have been developed due to high efficiency. Consequently, it is relatively cheaper to implement as compared to only using dust suppressant. However, mechanisms underlying the reduction of dust using magnetization have not been fully explored thus hindering its further development.
To this note, China University of Mining and Technology researchers: Dr. Hetang Wang, Sheng He, Guangran Xie, Xinyi Xen, and Dr. Botao Qin investigated the feasibility of controlling dust hazards based on chemical dust suppression. In particular, mechanisms involved in using magnetization to reduce the amount of dust suppressant were assessed. Their research work is currently published in the research journal, Colloids and Surfaces A: Physicochemical and Engineering Aspects.
In brief, the research team developed an electromagnetic liquid magnetization device. Next, taking into consideration the different magnetization parameters as well as the properties of the surfactant, they conducted tests to investigate the contact angle and surface tension of surfactants. In addition, low-cost application of magnetized surfactants solutions in suppressing coal dust in coal mines is analyzed. Eventually, they examined the reasons that may derail the improvement of the wettability of surfactant solutions.
The authors observed that the magnetization of the dust suppressants has the potential for maintaining the good wettability while at the same time reducing the required concentration by half. For instance, magnetized solutions exhibited lower surface tension as compared to their unmagnetized or undiluted solution counterparts. Furthermore, the magnetic field was noted to periodically change the motion of electric dipole in the solution thus consequently resulting in the reduction of the surface tension.
In summary, the research team demonstrated the underlying mechanisms by which magnetization effects reduce suppressant usage. For instance, the liquid magnetization device greatly reduced the initially experienced challenges i.e. uneven magnetic field distribution and difficulty in controlling magnetic induction. Altogether the study provides an in-depth answer to the key scientific problem of why magnetization can reduce the use concentration of dust suppressants, and provides a theoretical basis for reducing the cost of chemical dust suppression technology.
Wang, H., He, S., Xie, G., Chen, X., & Qin, B. (2018). Study of the mechanism by which magnetization reduces dust suppressant usage. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 558, 16-22.Go To Colloids and Surfaces A: Physicochemical and Engineering Aspects