Lime is a calcium-containing inorganic material used in many industries:
- Iron and steel making
- Construction and building
- Chemical industry
- Environmental application
- Fertilizer Industry
- Sugar industry
- Pulp making
One of the most important and critical parts of the process is the calcination of the limestone.
There are two main types of lime kiln:
Shaft kilns
- Counter-current
- Regenerative
- Annular
Rotary kilns
Our tubes are mainly used to manufacture the tip of the lances used in the regenerative kilns.
Fuel is injected from the lances on the top where the temperature is lower, but moving through the tips of the lances the conditions become harsher and harsher. It is therefore necessary to select a material able to withstand hot corrosion and erosion at the same time.
Important factors when selecting materials are:
- Type of limestone: composition, size, impurities (S, Cl)
- Type of fuel injected through the lances: composition, impurities, solid particles
- Temperature: min., max., cycles
- Lance Design: dimensions, fabrication, design
- Lance Material: carbon steel, low alloyed, stainless, special steel
- Kiln operation
| Alleima grade (UNS) |
Description |
|---|---|
| Alleima® 253 MA* (UNS S30815) |
Austenitic stainless steel alloyed with nitrogen and REM (rare earth metals). A multi-purpose grade suitable for temperatures from 600 to 1000ºC (1112 to 1832ºF). |
| Alleima® 4C54** (UNS S44600) |
Ferritic stainless steel with a high chromium content (26.5%) suitable for sulphudizing conditions. Suitable for temperatures from 600 to 1000ºC (1112 to 1832ºF). |
| Alleima® 7RE10 (UNS S31008) | An austenitic, chromium-nickel stainless steel of the 25/20 type, suitable for temperatures (in air) up to 1100°C (2010°F). |
* 253 MA® is a trademark owned by Outokumpu OY.
** Alleima 4C54 performs well also under sulphidizing conditions.
Please contact our Technical Marketing for support in choosing the right grade.