These refiners are mixtures of carbonates of the alkaline-earth metals, which are strontium, calcium and barium, in powder form. The mixtures have optimized chemical compositions.
These refiners are used:
- to improve the fluidity of molten metals;
- to improve the mechanical properties and performance of castings;
- to improve the plasticity of castings and ingots;
- to reduce the tendency of castings to crack
- to improve the micro- and macrostructure of castings
Applications:
A refiner is placed on the bottom of a preheated ladle in a ratio from 0.2 to 0.5% of the weight of the metal being treated. Base iron of correct composition is then teemed on to it. Subsequently, the base iron is held for 5-10 minutes for the relevant reaction to come to an end and a scum to form on the surface of the melt. It is then skimmed off and the melt is poured out.
Following refinement, the melt is to be poured out of the ladle within 15-20 minutes.
Sizes:
To facilitate introduction of refiners into the melt, they are supplied in size 0-40mm and in size 0-3 mm in palletized and powder form respectively.