Abstract: Industrial aluminium sulfate was prepared via reaction of acidic waste water from activated clay process with added H2SO4 and bauxite.It not only eliminated  pollution caused by acidic waste water discharged from activated clay process，but also recycled  aluminium sulfate and sulfuric acid in acidic waste water.The optimum conditions were obtained：pH=3.0， content of bauxite was 15 g per 100 mL acidic waste water，and  proportion of concentrated sulfuric acid was 10%（mass fraction）.Barium sulfide and crystallization methods could be both adopted to remove irons. Thus，two kinds of aluminum sulfate products can be obtained.The Al2O3 and Fe3+ mass fractions in grade A aluminum sulfate were 16.5%（±0.06%) and 0.095%（±0.18%）.The Al2O3 and Fe3+ mass fractions in grade B aluminum sulfate were 16% and 0.308%.The results were in accord with class Ⅱ product quality indicators stipulated in Industrial Aluminium Sulfate Standard （HG/T 2225—2010）.

Key words: activated clay, acidic waste water, industrial aluminium sulfate