关键词: 三聚磷酸铝, 改性拜耳法赤泥, 氢氧化铝凝胶, 工艺参数

Abstract: Aluminum tripolyphosphate was prepared with Bayer red mud and 85% industrial phosphoric acid as raw materials.Bayer red mud was modified at first through high temperature sintering.Then high activity aluminum hydroxide gel was prepared by using sodium carbonate solution to dissovle the aluminum in modified Bayer red mud and dry aluminum hydroxide gel was obtained after drying.Lastly aluminum tripolyphosphate was prepared through neutralization reaction with industrial phosphoric acid as well as condensation reaction and hydration reaction.Optimum parameters were as follows:volume mass ratio (mL/g)of phosphoric acid and aluminum hydroxide was 30 ∶10;condensation temperature was 290 ℃,condensation time was 4 h,neutralization temperature was room temperature,and water dosage was 10 mL.Chemical analysis,infrared spectroscopy，and salt spray tests indicated that the samples were qualified aluminum tripolyphosphate products,and anti-corrosion performance reached industrial standard.

Key words: aluminum tripolyphosphate, modified Bayer red mud, aluminum hydroxide gel, process parameters