氨洗除铜工艺的改进和应用

Improvement and application of ammonia washing copper removal process

在传统的电站锅炉化学清洗工艺中,若管样含铜量大于5%时,需要进行酸洗后的氨洗除铜工艺,然后使用磷酸盐继续清洗。本文介绍了某电厂的清洗方案的制定及优化,其水冷壁管样铜含量高达15%,通过改进清洗工艺,达到除铜目的,防止镀铜现象发生,并使得清洗效果优良:除垢率97%,腐蚀速率1.14 g/(m2.h)。该工艺具有节省除盐水、省却氨洗除铜后磷酸盐清洗步骤及防止镀铜现象发生等优点。

On the traditional technology of chemical cleaning for utility boiler,ammonia washing and decoppering was necessary after acid pickling,and then treated with phosphate when copper content of water wall tube was higher than 5%.In this study,establishment and optimization of cleaning scheme in a power plant were introduced.Although copper content was over 15% in the water-cooling wall,the cleaning effect was very well by improvement of washing thchnology.Not only removing copper was achieved,and occurrence of copper plating was prevented,but also scale removal rate was up to 97% and corrosion rate was about 1.14 g/(m2·h).In new technology,quantity of desalted water was lower and step of phosphate treatment was cancelled.