Study on Decolorization of Wet-process Phosphorous Acid by Modified Activated Carbons

The current situation of decolorization of wet-process phosphorous acid was introduced.Modification of activated carbons(AC) was carried out and the modified ACs were tested for dye adsorption.The effects of activated carbon type,AC dosage,temperature,time and stirring rate on the decolorization process were investigated.The experimental results show that when decolorization conditions are as follows: industrial grade powder ACs(average particle size of 0.15 mm),AC dosage of 7.5 g/100 mL,decolorization temperature of 55 ℃,time of 30 min and the stirring rate of 300 r/min,the light transmittance of phosphorous acid can be improved from 29.5% to 85.7% after decolorization.Based on development of the wet-process phosphorous acid industry,some suggestions on decolorization of phosphorous acid were proposed.