Environmental Friendly Corrosion And Scale Inhibitor For Industrial Cooling Water Treatment

In the industrial production, two of the main problems of cooling systems are corrosion and scale phenomena. In order to solve these problems, the inhibiting performance and the synergistic effect of the molybdate corrosion and scale inhibitor containing 1-hydroxyethane-1,1-diphosphonic acid(HEDP), zinc acetate, hydrolytic polymaleic anhydride (HPMA) and 2-acrylamide-2-methyl n-propyl sulfoacid (AMPS) have been studied by weight-loss and static scale inhibition method in the characteristic of the quality of circulating water with medium or low hardness. We examined the rigidity, the pH and the temperature effect on the scale inhibiting performance of compound system, and optimized the concentration of complexion agent by orthogonal test, then a new corrosion and scale inhibitor compound had been investigated in this paper which is environmental, economical and effective. Finally, the mechanism of corrosion and scale inhibitor has been discussion.The result indicates that the corrosion inhibiting rates of the sole sodium molybdate is low. There is an evident synergistic effect between sodium molybdate and HEDP with the zinc acetate that compound provides good protection to the steel against corrosion in cooling media. It can be observed that there is a good synergistic effect between HEDP, HPMA and AMPS, ternary system has the wide temperature adaptiveness, the calcium tolerance and the acidproof alkaliproof performance. A compound formula that screened has a good corrosion and scale inhibiting performance, which anticorrosive rate has achieved 98.03 % and antiscale rate has achieved 91.01 %, which contain 30 mg/L of sodium molybdate, 20 mg/L of HEDP, 1.5 mg/L of zinc acetate, 12.5mg/L of HPMA, 10 mg/L of AMPS.