Corrosion and scale inhibitor for high-chlorine and high-calcium water-quality

Abstract

A corrosion-retardant scaling inhibitor for the high-Cl and -Ca water contains proportionally phosphonylic acid, polyphosphonic acid, organic phosphonate, Zn sale, Mn salt, polyacrylic acid, antimildew agent and purified water.

Description

technical field [0001] The invention relates to a corrosion and scale inhibitor suitable for high-chloride and high-calcium water quality, which is applied to the treatment of circulating cooling water. Background technique [0002] The existing circulating water treatment chemicals are all applied under the water quality conditions with conductivity ≤ 3000μs / cm, calcium ions ≤ 400mg / l, and chloride ions ≤ 300mg / l. [0003] For the research on corrosion and scale inhibitors for open circulating water systems, a single phosphate was used at first, then chromate and ferrocyanide were used as inhibitors, and then a compound formulation of polyphosphate-chromate appeared . [0004] With the continuous improvement of public water environment awareness, in order to reduce the pollution caused by drainage, chromate formulas have been gradually eliminated, and the corrosion inhibition effect of zinc salts has been widely recognized, and a series of composites with zinc salts have b...

AI Technical Summary

Problems solved by technology

The currently widely used corrosion and scale inhibitors for circulating water cannot meet the water quality of high concentrations of chloride ions and calcium ions when reclaimed water is reused, because reclaimed water with high concentrations of chloride ions and calcium ions is used as recirculating water replenishment water, making the reclaimed water The concentrations of chloride ions and calcium ions are constantly rising. In the small test and on-site pilot test stage of the reclaimed water reuse project in the cold rolling sheet plant, the concentration of chloride ions in the circulating water is between 2500 and 5000ppm, and the concentration of calcium ions in the circulating water is 1200ppm. Between ~1800ppm, the tendency of corrosion and fouling is obvious. When no chemical is added or treated with conventional chemical, the corrosion rate and fouling thermal resistance of the coupon and test tube are difficult to reach the index range specified in GB50050

[0007] Therefore, the development of a corrosion and scale inhibitor suitable for high-chloride and high-calcium water quality can solve the problem of excessive corrosion and scaling when the reclaimed water for cold rolling is used as the supplementary water for circulating water in thin plate factories, and broaden the use of water sources as supplementary water for circulating water The choice provides a feasible solution for saving water and reducing water consumption per ton of steel, and it is popular