Common scale inhibitors include

1 Organic phosphine series scale inhibitors

ATMP has good chelation, low limit inhibition, and lattice distortion. It can prevent scaling salt scaling, especially calcium carbonate scaling. ATMP has stable chemical properties in water and is not easily hydrolyzed. When the concentration in water is high, the corrosion inhibition effect is better.

HEDP is an organic phosphonic acid scale and corrosion inhibitor that can form stable complexes with metal ions such as iron, copper, and zinc, and can dissolve oxides on metal surfaces. It can still have good corrosion and scale inhibition effects at 250 ℃, remains stable at high pH values, and is not easily hydrolyzed and decomposed under general photothermal conditions. It has better resistance to acid, alkali, and chlorine oxidation than other organic phosphonic acids (salts).

Edtmps is a nitrogen-containing organic polyphosphate and a cathodic corrosion inhibitor. Compared with inorganic polyphosphates, the inhibition rate of edtmps has increased by 3-5 times. Miscible with water, non-toxic and pollution-free, with good chemical stability and temperature resistance. It still has good scale inhibition effect at 200 ℃. Edtmps can decompose into 8 positive and negative ions in aqueous solution, chelate with various metal ions to form a large molecular complex network with monomer structure, and disperse loosely in water, disrupting the normal crystallization of calcium deposits. Edtmps has a good scale inhibition effect on calcium sulfate and barium sulfate scale.

Edtmpa has a strong ability to chelate metal ions, and its complexation constant with copper ions is relatively large among all chelating agents, including EDTA. Edtmpa is a high-purity non-toxic reagent. It can be used as a cleaning agent for semiconductor chips in the electronics industry, for manufacturing integrated circuits; In the pharmaceutical industry, as a carrier of radioactive elements, it is used for disease detection and treatment; The chelating ability of edtmpa is much higher than that of EDTA and DTPA, and almost all materials can be replaced by edtmpa as a chelating agent.

2 Organic phosphonic acid scale inhibitors

ATMP? Na4 is a neutral sodium salt of ATMP, which can prevent the scaling of scaling salts, especially calcium carbonate scaling. ATMP? Na4 is suitable for circulating cooling water systems in thermal power plants, refineries, and oilfield water injection systems. ATMP? Na4 also has good compatibility with other additives. ATMP? Na4 is particularly suitable for neutral to acidic environments without ammonia formula.

ATMP? KX is a part of ATMP potassium salt solution. Compared to an equal amount of sodium salt, ATMP? KX has high solubility and can prevent the scaling of scaling salts, especially calcium carbonate scale. ATMP? KX is particularly suitable for oilfield reinjection systems.

Heidelberg? Na4 is widely used for scale and corrosion inhibition in industrial circulating cooling water, low-pressure boilers, oilfield water injection, and oil pipelines in industries such as power, chemical, metallurgical, and fertilizer.

III. Polycarboxylic acid scale inhibitor dispersant

PAAS is non-toxic, soluble in water, and can operate under alkaline and medium concentration conditions without scaling. PAAS can disperse microcrystals or sediments of salts such as calcium carbonate and calcium sulfate in water without precipitation, achieving the goal of scale inhibition.

AA/AMPS is a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (AMPS). Due to the presence of carboxyl and strong polar sulfonic acid groups in the molecular structure, which have good scale inhibition and dispersion properties, calcium resistance can be improved, and the scale inhibition effect on calcium phosphate, calcium carbonate, and zinc scales in water is obvious, with excellent dispersion performance. When combined with organic phosphine, its synergistic effect is significant. Especially suitable for high pH, high alkalinity, and high hardness water. It is one of the most ideal scale inhibitors and dispersants for achieving high concentration and multiple operations.

PESA is a green multi-element scale and corrosion inhibitor that is phosphorus and nitrogen free. PESA has good scale inhibition and dispersion performance on calcium carbonate, calcium sulfate, barium sulfate, calcium fluoride, and silicon scale in water, and its scale inhibition effect is better than commonly used organic phosphorus scale inhibitors. The combination of PESA and phosphonates has a good synergistic effect. Meanwhile, PESA has a certain corrosion inhibition effect and is a multi-component scale inhibitor.

PASP is a water-soluble polymer and a new type of green water treatment agent. Its characteristic is that it does not contain phosphorus.