The pretreatment of tin anode slime using alkaline pressure oxidative leaching was studied. The effects of different parameters on the extractions of various metals were investigated based on thermodynamic calculation. The results indicated that the optimum leaching conditions were 2.5 M of NaOH concentration, 130 degrees C of temperature, 1.5 h of time, 1 MPa of oxygen partial pressure, 7 mL/g of liquid-to-solid ratio and 700 rpm of stirring speed. Under the conditions, the extractions of tin and arsenic reached 92.16% and 96.49% respectively, but that of copper and lead were at a low level. Meanwhile, antimony, bismuth, and silver were hardly dissolved into the NaOH solution. The leachate was then subjected to an evaporation and cooling crystallization process for arsenic removal. After the purification, 94.36% of arsenic was separate from the lixivium as sodium arsenate hydrate and the final solution can be used to produce sodium stannate. (C) 2016 Elsevier B.V. All rights reserved.