Improved cleaning method safely removes pyrophoric iron sulphide. P.A. Vella. OGJ, 24 February 1997, 95(8), 65--68.
Two case histories are presented that show how refiners have saved time and money by using potassium permanganate to clean equipment such as sour water tanks, hydrocrackers, and cokers. Four options for the removal of pyrophoric iron sulphide are outlined---acid washing; chemical suppression; high-pH solvents; and oxidizing agents. The advantages of potassium permanganate application are listed.