Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">Colloidal antimony pentoxide was prepared by mixture of Sb<SUB>2</SUB>O<SUB>3</SUB> and Sb<SUB>2</SUB>O<SUB>5</SUB> obtained from arsenic-alkali residue by hydrometallurgical process,with hydrogen peroxide as oxidant and phosphoric acid as stabilizer.Effects of main factors including different kinds and amounts of stabilizer and impurities on the process of colloid formation and on colloidal particle size were investigated in detail.Theories on thermodynamics,kinetics,and electrical double layer (EDL) were used to analyze the experimental phenomena and results.Results showed that phosphoric acid was better than alkanol amine as stabilizer;when amount-of-substance ratio of phosphoric acid to antimony was 0.8~1.0,the particle size of obtained colloidal antimony pentoxide with mass fraction of 10% was smaller,and particle size was (36</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">±</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">5.6) nm when amount-of-substance ratio was 1.0;impurities was beneficial to form colloidal particles with smaller size.Comparing with oxidative reflux method,the colloidal particles prepared by chloridizing hydrolyzation method were larger in size and broader in distribution.</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"></SPAN>