## 2 Foam Dust Reduction Technology  
### Research Status  
Foam dust suppression technology was first proposed in the 1950s, and the United Kingdom was the first to carry out research in this area, followed by the United States, the former Soviet Union, the former West Germany, Japan and other countries have successively carried out this work, and achieved certain results. In the mid-1970s, with the development \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Dust Removal Technology** & **Advantages** & **Disadvantages** &
\begin{tabular}{c} **Dust Removal** \\ **(Suppression) Efficiency** \\ \end{tabular} \\ \hline coal seam water injection & pre-wet the coal body, the wetting range is large, and the coal body is evenly wetted & The equipment is complex, the water consumption is large, the engineering volume is large, the one-time investment is large, there are difficulties in the sealing process, water injection method and equipment, and the dust removal efficiency is low & \(7\%\)–50\% \\ \hline spray dust removal & simple equipment, low cost, small footprint, less maintenance, low maintenance cost, and low management workload & Most coal dust has a certain degree of hydrophobicity, the surface tension of water is large, many coal dust is not easy to be completely wetted and captured by water, and the dust removal efficiency is low, especially for respiratory dust. & Below 50\% \\ \hline chemical dust suppression & increase the wettability of dust and improve the dust removal efficiency of spray and coal seam water injection & The operating cost is high, the equipment is easily corroded and the operation is complicated. & Below 60\% \\ \hline Dust collector dust removal & high dust removal efficiency & large one-time investment, complex structure of the equipment itself, large volume, heavy weight and limited air volume & 70\%–95\% \\ \hline Ventilation and dust removal & simple operation, convenient and fast, low cost & low dust removal efficiency and easy to cause secondary pollution & Below 60\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of advantages and disadvantages of various dust removal technologies commonly used. of the surfactant industry in the United States, the Soviet Union, Poland and other countries, the foam dust suppression technology was widely adopted in production. In addition, a low-cost foaming agent that meets the requirements of safety and hygiene has been developed. According to the requirements of different dust sources, different types of foam dust suppression supporting products have been developed. From 1966 to 1967, a group of engineers in the Karaganda coalfield of the former Soviet Union carried out extensive research on foam dusting. Dozens of different concentrations of anionic surfactant substances have been tested, and a high-expansion air-mechanical foam dust suppressor has been developed. When blasting guns in the control area of the working face, the explosion area is covered with foam to prevent dust and toxic and harmful gases. A large number of experiments have been carried out on the foam dust reduction of rock drills and the foam dust reduction of coal mining machines. Mine dust is an inevitable product in the process of mining. According to the historical data, the mine dust mainly is mainly generated from the mining and excavation working faces [18,19]. The measurement results of foam dust reduction on the rock excavation working face indicate that the dust content in the air at the workplace of the rock drill driver can be reduced from 313 mg/m\({}^{3}\) to 20 mg/m\({}^{3}\). At about 10 m away from the transfer point, the dust content in the air can be reduced from 733 mg/m\({}^{3}\) to 21 mg/m\({}^{3}\). Moreover, the dust collector is applied to many places in the well, and when it is applied to the shearer, the dust removal efficiency of the combined shearer can be increased by 2 to 5 times compared with the usual dust-proof measures. In addition, [PERSON] from the Soviet Union conducted substantial research in this filed.