Abstract: The stable colloidal antimony pentoxide was prepared by oxidation of the mixture of Sb₂O₃ and Sb₂O₅ obtained from arsenic-alkali residue by hydrometallurgical process, with hydrogen peroxide as oxidant and phosphoric acid as stabilizer. Effects of main factors were investigated. The theories on thermodynamics, kinetics and electrical double layer(EDL) were used to analyze the experimental phenomena and results. The results show that no aging time is the most beneficial to forming colloid, when molar ratio of phosphoric acid to antimony is in the range from 0.8 to 1.0 and 1.0 to 1.3, the particle sizes of sol with the concentration of 10% and 15% antimony pentoxide by mass are both smaller. With increasing concentration of the mixture of antimony oxide from 10% to 20%, the reaction time decreases from 90 to about 30min, but the optimized range of molar ratio of H₃PO₄ to antimony increases. The reaction temperature is not the main factor on particle size with the existence of H₃PO₄ in the temperature range from 60 to 90℃.

Key words: colloidal antimony pentoxide; arsenic-alkali residue; solid waste; comprehensive utilization