Initial processing agent for circulating cooling water and initial processing method of circulating cooling water system

摘要

An object of the invention is to provide an initial treatment agent for circulating cooling water, which is capable of obtaining an anticorrosive effect and an anti-scaling effect in the form of a chemical agent while reducing the phosphorus concentration and the zinc concentration necessary for forming an initial corrosion-resistant film. The solution of the invention is to provide an initial treatment agent for circulating cooling water, which is used for adding to a circulating cooling water ater system at the start of the circulating cooling water system and forming of an initial corrosion-resistant film on the surface of a metal part of the water system, wherein the initial treatment agent is made of a phosphorus compound, a zinc compound, and a copolymer (AA/HAPS-based polymer) of acrylic acid and hydroxyl allyloxy propane sulfoacid and/or a salt thereof into a chemical agent. The initial treatment agent is added in such a manner that the total phosphorus concentration converted into PO4 in the water system becomes 15 to 30 mg PO4/L, the zinc concentration is 5 to 20 mgZn/L, and the concentration of the AA/HAPS polymer is in the range of 20 to 60 mg solids/L.