APPLICATION
Calzot® is used in iron metallurgy as a cost-effective agent for increasing the ni- trogen content. Different addition techniques are practiced here:
- Addition when tapping in the ladle
- Injection of Calzot® into the molten metal using the lance method or by insert- ing cored wire
When adding Calzot®, a total carbon content of approx. 22.5% must be consid- ered (Cfree + C from CN2), which is dissolved in the iron.
The nitrogen discharge depends on the iron quality, the amount introduced and the addition technique.
The following can apply as guide values:
- 30 – 50% with addition of pails during tapping
- 80 – 100% with injection, pneumatically or as cored wire
PHYSICAL PROPERTIES
| Appearance | Gray-black powder or grain |
| Behavior against humidity | Slaking of free lime content |
| Behavior at increased temperature | Decomposition under ammonia formation |
| Decomposition | > 1.000 °C |
| Density | approx. 2,3 g/cm3 |
| Bulk weight | 0,9 – 1,1 kg/dm3 |
CHEMICAL COMPOSITION
| CaCN2 | approx. 66 % |
| Other N-compounds | approx. 3 % |
| CaO | approx. 15 % |
| C free | approx. 12 % |
| SiO2 + Al2O3 + Fe2O3 | approx. 2 % |
| H2O (550 °C) | approx. 0.3 % |
| Residual carbide content | approx. 0,1 % |
| Miscellaneous | < 1% |
FORMULA
CaNCN
PRODUCTION
Reaction of calcium carbide with nitrogen at 1,000 – 1,100 ° C
ACTIVE ELEMENTS IN IRON
| N total | min. 23.5% |
| C total. | approx. 22,5 % (Cfree = 12 %, C from CN2 = 10,5 %) |
| Ca | approx. 33% |
