This study aims to precipitate oxides to boron carbide powders to achieve homogeneous dispersion of additive which is essential for sintering. Fine boron carbide powders were suspended in distilled water, then nitrate salts were solved in alcohol. Solved nitrate salts were fed to mixture in high pH levels. Mixing stage of the precipitation was done with both magnetic stirrer and ultrasonic treatment to investigate the effect of the mixing method. After the precipitation, synthesized powders were calcined under various atmospheres to eliminate the inorganic residues from the precipitation process. The examination of the XRD graphs showed that the calcination atmosphere is important for the oxide layer of the boron carbide powders. Inert atmosphere restrained the formation of the boron oxide layer due to the lack of oxygen. Methanol washing also eliminated the boron oxide layer. According to the zeta potential analysis, surface characteristics were obtained better when the ultrasonic treatment was applied during the precipitation. Ultrasonic treatment increased the dispersion of the additives between the particles during the suspension stage of the precipitation. Calcination time also affected the dispersion of the yttrium oxide at the sintered compacts when the SEM images were observed. When the calcination time increased, dispersion of the yttria was getting more agglomerated.