A study on an are melter used for waste minimization process is presented. The plasma phase of the are and the liquid-solid phases of the molten soil are simulated simultaneously. Newtonian fluid model is used for both the plasma and the molten phases. Parametric study is made on different are lengths and are currents with varying input powers. Calculations show that both convective heat transfer and Joule heating mechanism yield high heat dissipation in the melt pool. It is found that the buoyancy and the surface shear driven convection established in the melt pool are the major contribution to the more uniform mixing of the molten soil. For the long are, the gas environment above the molten soil has large heated volume while the melted soil volume is small compared to those of short are. The induced circulation in the melt pool is stronger for the short are than that of long are. For the same input power, increasing current results more heat dissipation inside the melt pool than increasing voltage drop.