Abstract: Based upon results obtained from single factor experiments and in combination with response surface method,the eliminating technique of free sulfuric acid mixed in linear alkyl benzene sulfonic acid product was optimized.Performance of corrosion on metals caused by treated LABSA and untreated LABSA samples as well as their storage stability was compared.Results show that the optimum removal conditions are as follows:adding 1.25% Ca(OH)₂,reacting at 69 ℃ for 3.4 h.Under the above conditions,the removal rate of free sulfuric acid can be near to 100%.When the free sulfuric acid is removed completely,the corrosion on steel is reduced obviously.The weight loss of upper part of the ST37-2 steel plate sample is reduced by 63.16%,whiles the middle part and lower parts is 71.88% and 67.82% respectively.After storage at 35 ℃ for 2 months,the color of treated LABSA is 29 Hazen,which indicates that no significant color change happens.

Key words: linear alkyl benzene sulfonic acid, response surface method, corrosion on metal, color