Ice sphere made by saturated KCl solution, which can simulate the heavy scraps, are used in water model experiment to study the mechanism of motion and melting of scrap and mixing of the solute of scrap in bottom stirred reactors. The effects of liquid level in single nozzle stirring mode and gas flowrate in double nozzle stirring mode on the motion, melting, and mixing of scraps are investigated. The results show that in the single nozzle stirring mode, when the liquid level is low (the ratio of liquid level to the diameter is 0.42), the stirring of gas column and the circulation in the reactor is weak. As a result, the salt ice sphere moves up and down in the gas column, and the melting of the sphere is relatively slow. With the increase of liquid level (the ratio of liquid level to the diameter is 1.04), the salt ice sphere moves with the circulation. Hence, the melting process is accelerated. However, the mixing time of KCl solution, which is obtained according to the 98% standard, in the reactor is even lower than the melting time of sphere. In the double nozzle stirring mode, the gas flowrate of nozzle A remains unchanged at 0.8 m3/h, and the gas flowrate of nozzle B is 0.5 and 1.0 m3/h, respectively. In the two cases, after the salt ice sphere is added above from nozzle A, the sphere stays at the bottom of the reactor for a period of time. After 60~70 s, the sphere moves to the top and moves along the circulation. When the gas flowrate of nozzle B increases to 1.5 m3/h, the salt ice sphere will not stay at the bottom. It moves with the gas column to the plume area formed by nozzle B and its melting process is accelerated. In all the double nozzle stirring mode cases, it is also found that the mixing time of KCl is lower than the melting time of sphere, which is related to the small mass of sphere and less salt released at the end of melting process. In this study, the effect of double nozzle stirring mode on the acceleration of melting of salt ice sphere is not as good as that of single nozzle stirring with large gas flowrate.