The beneficiation of cassiterite fines from a tailing slime in the Datun concentration plant was studied through a froth flotation process, with the chemical scheme of benzohydroxamic acid as collector, lead nitrate as activator, and pine oil as frother. It was found that tin values are mainly contained in the fine fraction of the sample and cassiterite is mostly associated with iron minerals and calcium minerals, so that the desliming treatment and the addition of dispersants and depressants can not be used as it generally results in the undesired loss of tin values. A novel flotation process with no dispersant and depressant as well as no desliming was developed. It showed that this process was effective in recovering the tin values from the tailing slime assaying 0.18% Sn, and produced a concentrate assaying 3.5% Sn with the recovery of 74.16%. It has been found that pine oil played a significant role in improving the recovery for tin values.