A
phosphorus-free scale and
corrosion inhibitor for circulating cooling
water treatment. The
phosphorus-free scale inhibition and
corrosion inhibitor comprises a scale inhibition component,
corrosion inhibition component and deionized water. The scale inhibition component accounts for 16-40% of a total amount of the
phosphorus-free scale and
corrosion inhibitor, and the corrosion inhibition component accounts for 18-48% of the total amount of the phosphorus-free scale and
corrosion inhibitor, and the remaining is the deionized water. The scale inhibition component consists of polyacrylic acidaccounting for 5-15% of the total amount of the phosphorus-free scale and
corrosion inhibitor,
polyaspartic acid accounting for 8-20% of the total amount of the phosphorus-free scale and corrosion inhibitor and
sodium gluconate accounting for 3-5% of the total amount of the phosphorus-free scale and corrosion inhibitor. The corrosion inhibition component consists of
tannic acid accounting for 5-20% of the total amount of the phosphorus-free scale and corrosion inhibitor,
borax accounting for 5-20% of the total amount of the phosphorus-free scale and corrosion inhibitor, and imidazoline derivative accounting for 10-20% of the total amount of the phosphorus-free scale and corrosion inhibitor, wherein the imidazoline derivative is an
alkyl imidazoline including one or two of heptadecyl imidazoline and octadecylselyl imidazoline. The phosphorus-free scale and corrosion inhibitor of the invention has advantages of simple preparation, convenient usage, small application amount and low coasts, and is conducive to reduction of circulating water operating costs and reinforcement of circulating water management.