This paper describes the performance of a new low-phosphate molecule for scale and corrosion control under various industrial conditions. The results are compared to several well-established existing corrosion and scale control treatments in the water treatment industry. The molecule is very stable both hydrothermally and in an oxidizing environment.

The laboratory study is supplemented with two case histories in the power generation industry. One of the power plants is a coal-fired zero-liquid discharge (ZLD) and the other is a nuclear power plant. At the latter plant, the new treatment was used for service water and recirculating cooling tower. As seasonal variation changed the water chemistry from soft to moderately hard water, the treatment continued to effectively treat corrosion and scale, respectively. The low phosphate level in the treatment allowed the plant to use part of the once-through service water as make-up to the cooling tower without any additional treatment. The new corrosion treatment, at a total phosphate level of <1 PPM (as PO4), provided corrosion rate of <4MPY under soft water conditions. In the recirculating system, corrosion rates were <2 MPY and scaling was prevented without additional treatment. ZLD application demonstrated the new chemistry’s ability to inhibit calcium carbonate, calcium sulfate and mild steel corrosion.

Subject
Water, Corrosion rate, Calcium carbonate, Scale inhibitors, Water chemistry, Corrosion scales, Phosphates, Calcium sulfate, Corrosion inhibitors, Steel, Towers, Corrosion protection, Corrosion coupons
© 2006 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2006
Association for Materials Protection and Performance (AMPP)
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