There are various types of scale and corrosion inhibitors, usually complex compounds with special structures, and the selection of types should be based on factors such as metal surface condition, corrosion medium composition, and operating conditions. The commonly used scale inhibitors in water treatment include inorganic polyphosphates, organic phosphonic acids, phosphonic carboxylic acids, organic phosphonic acid esters, polycarboxylic acids, etc.

There are many types of scale and corrosion inhibitors, and products that have both corrosion and scale inhibition functions mainly include:

Organic phosphorus scale and corrosion inhibitors, such as ATMP, HEDP, DTPMPA, EDTMPS, HPAA, etc;

In addition, a small amount of polymers also contain certain scale and corrosion inhibition functions, such as phosphonyl carboxylic acid copolymers, green scale and corrosion inhibitors PESA, PASP, etc.

Scale and corrosion inhibitors are mainly used in industrial circulating water systems such as power plants, steel plants, fertilizer plants, oilfield water injection systems, and so on. There are not many end users who use a single agent as a scale and corrosion inhibitor. They need to set a plan based on the system situation and add specialized corrosion and scale inhibitors.

In addition, there are many specialized corrosion inhibitors, such as MBT (copper corrosion inhibitor), BTA (benzotriazole), TTA (methylbenzotriazole), and hydrochloric acid pickling corrosion inhibitors.

Amino trimethylene phosphonic acid ATMP

ATMP has good chelation, low limit inhibition, and lattice distortion effects. It can prevent the formation of scale salts in water, especially the formation of calcium carbonate scale. ATMP has stable chemical properties in water and is not easily hydrolyzed. When the concentration in water is high, it has a good corrosion inhibition effect. ATMP is used for circulating cooling water in thermal power plants, refineries, and oilfield water injection systems. It can reduce the corrosion and scaling of metal equipment or pipelines. ATMP is used as a metal ion chelating agent in industries such as textile printing and dyeing, and can also be used as a metal surface treatment agent. ATMP solid is a crystalline powder, easily soluble in water, hygroscopic, easy to transport and use, especially suitable for cold winter areas. Due to its high purity, it can be used as a metal chelating agent and metal surface treatment agent in the textile printing and dyeing industry.

Hydroxyethylene diphosphonic acid HEDP

HEDP is an organic phosphate scale and corrosion inhibitor that can form stable complexes with various metal ions such as iron, copper, and zinc, and can dissolve oxides on metal surfaces. HEDP can still play a good role in corrosion and scale inhibition at 250 ℃, remains stable at high pH values, is not easily hydrolyzed, and is generally not easily decomposed under photothermal conditions. It has better resistance to acid, alkali, and chlorine oxidation compared to other organic phosphates (salts). HEDP can form a six ring chelate with metal ions, especially calcium ions, in water. Therefore, HEDP has a good scale inhibition effect and a significant solution limiting effect. When used in combination with other water treatment agents, it exhibits an ideal synergistic effect.

HEDP solid belongs to high-purity products and is suitable for cold regions in winter; Specially suitable for cleaning agents and daily chemical additives in the electronics industry.

HEDP is widely used for scale and corrosion inhibition in industrial circulating cooling water systems such as power, chemical, metallurgical, and fertilizer industries, as well as in medium and low pressure boilers, oilfield water injection, and oil pipelines; HEDP can be used as a cleaning agent for metals and non-metals in the textile industry, a peroxide stabilizer and fixing agent in the bleaching and dyeing industry, and a complexing agent in the cyanide free electroplating industry. HEDP is generally used as a scale inhibitor with a concentration of 1-10mg/L, and as a corrosion inhibitor with a concentration of 10-50mg/L; Generally used as a cleaning agent with a concentration of 1000-2000mg/L; Usually used in combination with polycarboxylate type scale inhibitors and dispersants.

HEDP liquid is packaged in plastic drums, with each drum weighing 30kg or 250kg; HEDP solid is packaged in plastic woven bags lined with polyethylene bags, with a net weight of 25kg per bag, which can also be determined according to user needs. Store indoors in a cool and ventilated place, moisture-proof, with a storage period of ten months.

HEDP is acidic and should be avoided from contact with eyes and skin. If it splashes onto the body, it should be immediately rinsed with plenty of water.

Sodium ethylenediamine tetramethylphosphonate EDTMPS

Ethylene Diamine Tetra (Methylene Phosphonic Acid) Soul

Nicknames: Sodium ethylenediamine tetramethylene phosphonate, ethylenediamine tetramethylene phosphate, ethylenediamine tetramethylidene phosphate

CAS No. 1429-50-1

Molecular formula C6H12O12N2P4Na8, relative molecular weight: 612.13

EDTMPS is a nitrogen-containing organic polyphosphonic acid, belonging to the cathode type corrosion inhibitor. Compared with inorganic polyphosphates, the corrosion inhibition rate is 3-5 times higher. It can be mixed with water, non-toxic and pollution-free, has good chemical stability and temperature resistance, and still has good scale inhibition effect at 200 ℃. EDTMPS can dissociate into 8 positive and negative ions in aqueous solution, thus chelating with multiple metal ions to form multiple monomer structured macromolecular network complexes that are loosely dispersed in water, disrupting the normal crystallization of calcium deposits. EDTMPS has a good scale inhibition effect on calcium sulfate and barium sulfate scale.

EDTMPS is used as a corrosion and scale inhibitor for circulating water and boiler water, a complexing agent for cyanide free electroplating, a chelating agent for textile printing and dyeing industry, and an oxygen bleaching stabilizer.