In this study, beneficiation of colemanite minerals from tailings of the Emet Boron Processing Plant using a laboratory scale Jameson flotation cell was investigated in detail. Effect of some working parameters of the Jameson cell such as jet length, plunging depth of downcomer, and bias factor was studied for the flotation performance of colemanite. The results showed that all parameters showed a significant effect on colemanite flotation using the Jameson cell which was the first time used in boron flotation with a negative bias factor. The results also indicated that a high recovery could be obtained with a worthy grade values by the negative bias factor. According to the results obtained at the bias factor of -0.3, jet length of 3 cm, and plunging depth of 20 cm, B₂O₃ content of the sample increased to approximately 46% from 36.8% with a recovery of 98.47%.