A NEW TYPE OF COMPOSITE CORROSION AND SCALE INHIBITOR FOR COPPER

The performance of a new type composite corrosion and scale inhibitor for copper was investigated by weight-loss,electrochemical and bubbling methods.The new inhibitor,DG3,comprised DG1,BTA and PBTCA.The optimum concentration of every constituent was DG1 2mg/L,BTA 3mg/L and PBTCA 5mg/L.The composite inhibitor exhibited good performance of corrosion and scale inhibition in freshwater.The corrosion rate of tin brass was 0.0021mm/a in freshwater with DG3,better than the national standard (0.005mm/a).DG3 could also inhibit crevice corrosion and crevice corrosion.The performance of scale inhibition of DG3 did not reduce obviously than that of PBTCA.The stabilized concentration of Ca2+ could reach 234.04mg/L in freshwater with DG3,similar to the effect of 5mg/L PBTCA when the temperature was 30℃.