Definition - What does Chelating Agent mean?
A chelating agent is a chemical compound that reacts with metal ions to form stable, water-soluble metal complexes. The agent rearranges the metal's chemical composition and improves the metal's general stability and likelihood to bond with other substances.
Chelating agents are used in several applications, including:
- Scale removal
- Water treatment
- Corrosion control
Chelating agents are also known as chelants, chelators or sequestering agents.
Corrosionpedia explains Chelating Agent
The chelating agent's molecules form several bonds to a metal ion and prevent the metal from reacting as it would normally. The bonding to the metal ions re-organizes the ions' core structure and chemical composition. The chemical structures in many metals closely resemble chains. The chelators join the ends of these chain-like structures to form a stable ring, which can move easily through various environments.
Chelating agents are used for:
- Scale removal and prevention
- Breaking down, isolating or moving heavy metal ions
- Deactivating metal ions to prevent plugging, sealing and precipitation
- Limiting available metal ion concentration
- Controlling heavy metal poisoning and reducing metal's toxic effects
- Corrosion inhibitors to form insoluble surface chelates
Chelating agents are either natural or synthetic organic compounds, used for industrial, medical and biological applications. They help in the digestion processes, both in humans and animals, in addition to transporting nutrients in plants.
Chelating agents are used in boilers to dissolve common types of scale during normal operation, and provide effective online and offline scale removal in boilers.
The surface active chelating agents are used as corrosion inhibitors to form insoluble surface chelates (compounds comprising of the chelating agent and the metal ion).
Even though chelating agents can be used for corrosion control, the formation of soluble chelates may provoke stimulation of a corrosion process. Uncontrolled agent application may lead to chelant corrosion. This can be prevented by applying the precise amount that does not leave residuals in the boiler.