Name | Iron based desulfurizing liquid complexing agent |
Synonyms | Iron based desulfurizing liquid complexing agent |
Complexing agent can form complex ion compounds with metal ions. In the electroplating solution, except for a few electroplating solutions, such as acid solution iron plating, nickel plating, chrome plating, copper plating without or without the use of complexing agent, most other electroplating solutions, such as alkaline solution silver plating, gold plating, copper plating, zinc plating, tin plating, copper plating alloy, etc. all need to use complexing agent. Such as cyanide, hydroxide, citrate, pyrophosphate, thiosulfate, sulfite, etc., are widely used as complexing agents in electroplating production.
Complexing agent is also called chelating agent, chelating dispersant, metal blocking agent, water softener and so on in printing and dyeing industry. Complexing agents, especially organic complexing agents with multi-functional groups, are more and more widely used in the printing and dyeing industry, such as softening water quality, preventing sediment, eliminating scaling of dyeing and finishing equipment, preventing fabric bleaching holes, and ensuring dyeing freshness.
The complex stability constant of the complex is the constant of the equilibrium of the reversible reaction of complexation and dissociation. The lower the stability constant, the more metal ions the complex dissociates, the higher the stability constant, the less metal ions the complex dissociates, or even does not dissociate, and the complex will not change valence in the redox reaction. Complexation capacity (complexing capacity) refers to the amount of metal ions that can be complexed per gram of complexing agent. The higher the complexing capacity, the stronger the complexing capacity. The stability of complexing agent at different p H values, that is, the change of stability constant at different pH values, is another important performance of complexing agent. The complexing ability of some complexing agents varies greatly at different pH values, and some even hydrolyze, decompose or react to lose the bonding force. For example, EDTA is suitable for acidic and neutral media but not for alkaline media, and sodium hexametaphosphate has a better synergy in acidic media. It can be seen that different complexing agents have different properties and complexing capabilities, so they should be selective when used.
Most catalysts have three types of components that can be distinguished: active components, carriers, and promoters.
The active component is the main component of the catalyst, sometimes composed of one substance, sometimes composed of multiple substances.
The carrier is the dispersant, binder or support of the catalytically active component, and is the skeleton of the active component. The catalyst prepared by supporting the active component and the co-catalyst component on the carrier becomes a supported catalyst.
types of commonly used carriers: corundum, silicon carbide, pumice, diatomaceous earth, asbestos and refractory bricks have low specific surface area. High specific surface areas include alumina, SiO2-Al2O3, bauxite, clay, magnesium oxide, silica gel and activated carbon.
The cocatalyst is a small amount of substance added to the catalyst. It is an auxiliary component of the catalyst. It has no activity or little activity, but after they are added to the catalyst, they can change the chemical composition, chemical structure, and ion of the catalyst Valence state, acidity and basicity, lattice structure, surface structure, pore structure, dispersion state, mechanical strength, etc., thereby improving the activity, selectivity, stability and life of the catalyst.