Study on the Performance Evaluationof Phosphorus-Free Composite Corrosionand Scale Inhibitor

The new type of phosphorus-free composite corrosion and scale inhibitor (FS) was prepared by using thiourea-modified polyepoxysuccinic acid (CNS-PESA), polyaspartic acid (PASP), hexamethylenetetramine, zinc chloride (ZnCl 2 ), hydrolyzed polymaleic anhydride (HPMA).This FS inhibitor was an environmentally friendly and phosphate-free inhibitor to solve the problems of corrosion and formation of scale in industrial circulating cooling water systems.The maximum corrosion and scale inhibition efficiency was 99.2% and 98.9% respectively.The FS inhibitor worked effectively with the pH between 6 to 8. Compared with other inhibitors, the composite corrosion and scale inhibitor had great performance on the inhibition of calcium carbonate and calcium phosphate scale inhibition.Moreover, the FS inhibitor could reduce the environmental pollution problems effectively.