The main classification of scale inhibitors

The use of organic phosphonic acids, low molecular weight acrylic polymers and copolymers is a major breakthrough in the control of inorganic scale inhibition. Organic polyphosphonic acid is both a kind of cathode type corrosion inhibitor and non-chemical equivalent scale inhibition. It has obvious dissolution effect and good chelating ability of calcium, magnesium, copper, zinc and other ions. It can also work with other agents. So it is now widely used in water treatment.

The water-soluble polymer is formulated as a scale inhibition dispersion formulation. Since the 1970s gradually evolved from homopolymers into binary copolymers, and further development of binary copolymers, quaternary copolymers. This is the most active area of research and development since the 1980s.

Up to now, the development of water-soluble polymers can be summarized into the following categories:

(1)Homopolymer: polyacrylic acid, polymaleic acid, etc., its main performance is the inhibition of calcium carbonate dispersion.

(2)Binary copolymer: acrylic acid / maleic acid or acrylic acid / hydroxyalkyl acrylate copolymer, etc.. In addition to its inhibition of calcium carbonate, it also has excellent ability to inhibit calcium phosphate scale.

(3)Binary copolymers with strong groups: sulfonated styrene / maleic acid copolymers, acrylic acid / 2-acrylamide / 2-methanesulfonic acid copolymers and acrylic acid / 3-allyl alcohol-2-hydroxy Propyl sulfonic acid copolymers and so on. It can inhibit calcium phosphate and calcium phosphate scale. Has the stability of zinc ions. It has good performance on the dispersion of iron oxide and slag.

(4)Novel ternary or quaternary copolymers: acrylic / sulfonic acid / nonionic terpolymers, acrylic / acrylamide / hydroxyalkyl acrylate copolymers, and so on. The main features are low price and its good performance. Some of them even have special effect, such as maintain the stability of manganese ions. Its main character is inhibition, it even can take part in the process of corrosion inhibitor.

At present, China has made great progress in the development of sulfonic acid-based copolymers, and the development of phosphorus-containing polymers has also achieved initial results.