en Research Paper Research Paper The beneficiation of coal tailings is usually difficult by common oily collectors in the flotation process, so<br> it is necessary to use a suitable method for clean coal recovery from coal tailing dams. Thus, this study was aimed<br> to investigate the behavior of dissolved air flotation by zero prewetting time for the clean coal recovery and to<br> optimize the conditions of zero prewetting time for an effective flotation. In this regards, the effects of the process<br> parameters, i.e., pH, frother type, collector type on the rougher flotation recovery of coal tailings were assessed and<br> optimized. Additionally, Fourier transform infrared (FTIR) spectroscopy was used to understand the functional<br> groups of oily collectors on the surface of floated products. The findings indicated that the frother type and the<br> interactive effects between the type of frother and collector had the most effect on the performance of flotation. It<br> was also found that under the optimal conditions (150 g/t Methyl isobutyl carbinol, 1500 g/t gas oil, and pH 4), the<br> combustible recovery, yield reduction factor, and flotation efficiency index of coal reached to 67.79%, 0.056%, and<br> 37%, respectively. Meanwhile, the FTIR analysis confirmed that the less adsorption of gas oil collector occurred in<br> the presence of SDS (Sodium dodecyl sulfate) as frother due to the interaction of SDS and collectors Flotation, Coal tailing, Zero prewetting time, Recovery, Optimization 1 11 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-687-4&slc_lang=en&sid=1 Nur Mohammad Hosseini hosseinimohamad1362@gmail.com 1800319475328460016460 1800319475328460016460 No Department of Mining Engineering, Azad University of Rafsanjan, Iran Zahra Bahri bahri.zahra@gmail.com 1800319475328460016461 1800319475328460016461 No Department of Control and Modeling of Mineral Processing Systems, Institute of Mineral Processing, ACECR at Tarbiat Modares, Tehran, Iran Asghar Azizi azizi.asghar22@yahoo.com 1800319475328460016462 1800319475328460016462 Yes Faculty of Mining, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran