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Some pieces of information of scale inhibitors

2021-03-13

Some pieces of information of scale inhibitors


With the widespread use of scale inhibitors to adapt to various industries' applications, many different types and properties of scale inhibitors have been produced to facilitate our use. To reduce the purchase, we need to understand their classes.


1.Polycarboxylic acid scale inhibitor and dispersant

Polycarboxylic acid compounds have a right scale inhibition effect on the calcium carbonate scale, and the amount is minimal. Commonly used are polyacrylic acid PAA, hydrolyzed melic anhydride HPMA, AA/AMPS, multi-component copolymers, etc. 


2.Organic phosphonate


Organic phosphonate has a good effect on inhibiting calcium sulfate scale, but its impact on inhibiting calcium carbonate scale is insufficient. It has low toxicity and is easily hydrolyzed. 


3. Organic phosphonic acid scale inhibitor


Commonly used ATMP, HEDP, EDTMPS, DTPMPA, PBTCA, BHMT, etc., have a good effect on inhibiting the precipitation or precipitation of calcium carbonate, hydrated iron oxide or calcium sulfate.


4.Polyphosphate


The commonly used polyphosphoric acids are sodium tripolyphosphate and sodium hexametaphosphate. Long-chain anions formed into water are readily adsorbed on tiny calcium carbonate crystal grains. Simultaneously, this anion is easy to replace with CO32, thus preventing calcium carbonate precipitation. 

Polycarboxylic-acid-compounds


The mechanism of action of scale inhibitor 


1 . Complexation and solubilization in the scale inhibitor. The copolymer dissolves in water and then ionizes to form a negatively charged molecular chain. It includes a water-soluble complex or chelates with Ca2+ to make the inorganic salt more soluble Increase plays a role in scale inhibition. 


2 . Lattice distortion means that part of the functional groups in the molecule is attached to the inorganic salt crystal nucleus or crystallites and occupy a particular position, hindering and destroying the average growth of inorganic salt crystals, slowing down the growth rate of crystals, and reduces the formation of salt scale. 


3 . Electrostatic repulsion means that the copolymer is dissolved in water and adsorbed on the inorganic salt crystallites, which increases the repulsion between the particles and hinders their coalescence and keeps them in a good dispersion state, thereby preventing or reducing the formation of scales. From this, it is known that the scale inhibitor can effectively disperse inorganic salts that are difficult to dissolve, and the chemicals in it can effectively prevent the coalescence of dirt, thereby achieving the effect of scale inhibition, and also has a significant industrial impact. 


Performance of scale inhibitor


 We know that the scale inhibitor has a scale inhibition effect. Its scale inhibition effect is due to its ability to prevent small carbonate crystal grains' growth and distort the crystal lattice. The carbonate does not exchange heat of the cool circulating water. The hard scale is formed into the surface of the device. Simultaneously, the organic phosphate and other tissue components create a protective film with metal so that it can be combined with calcium ions in the cool circulating water to prevent metal corrosion. This product has a wide application range of PH, which can have scale and corrosion inhibition effects between pH 7.0 and 10.0. Industrial production and operation are simple and will not cause corrosion and scaling problems due to out-of-control PH. The ultimate carbonate hardness of this product can reach about 680mg/L, and the scale inhibition effect is good. 
By understanding scale inhibitors' performance, the scale inhibitor can be widely used in various industries, and their performance can give full play to use. Simultaneously, with the continuous development of technology, the version of scale inhibitors is also continually improving, thereby expanding the scope of use of products to promote scale inhibitors' development.