Project Background
Steel plants discharge large volumes of high-temperature molten slag that carry significant sensible heat. Instead of quenching and landfilling it, the slag can be reheated, conditioned and converted into mineral wool. Shaanxi Chengda Industrial Furnace Manufacturing Co., Ltd. supplied the 4000kVA hot molten slag heating furnace line to Weifang Special Steel for exactly this purpose.
Equipment Scope
| Item | Specification |
|---|---|
| Furnace type | Hot molten slag heating furnace |
| Rated capacity | 4000kVA |
| Feed | Hot blast furnace / steelmaking slag with conditioners |
| Output | Conditioned melt for mineral wool fibre forming |
| Related equipment | Mineral wool furnace, slag treatment furnace, launder |
Construction and Installation Record
- Foundation works - furnace foundation constructed and anchor bolts set to drawing tolerance
- Furnace bottom - I-beam grid laid and bottom cooling water pipes installed and tested
- Shell erection - shell halves lifted and positioned, furnace body aligned and fixed
- Heating elements and electrodes - electrode system and power connection installed
- Water system - cooling circuits flushed, pressure tested and flow verified
- Hot trial - slag charged, melt temperature and flow to the fibre unit adjusted until stable
Operating Results
After commissioning, the 4000kVA line has been running in normal production, accepting hot slag directly from the steel plant and delivering conditioned melt to the mineral wool unit. Key benefits recorded by the customer:
- Slag disposal cost converted into a saleable mineral wool product
- Reduced external fuel demand because the slag arrives already molten
- Stable melt temperature at the centrifuge, improving fibre quality and yield
- Lower overall carbon footprint compared with cold-charge cupola melting
Why Chengda
Hot slag handling is unforgiving: thermal shock, aggressive chemistry and continuous operation. Chengda's design uses proven water-cooled components, replaceable wear sections and generous cooling margins so that maintenance can be planned rather than forced by failure.
Delivery Scope
Chengda supplied the furnace proper, electrode and power system, water cooling circuits, control and instrumentation, installation drawings and commissioning support, together with operator training on hot slag charging and melt conditioning.
Integration with the Steel Plant
The furnace is tied into the steel plant's slag handling route: ladles or slag pots deliver molten slag directly to the charging point, and the furnace holds and conditions the melt before it flows to the fibre line. This arrangement minimises re-melting energy and keeps the wool plant independent of the steelmaking schedule within a defined buffer window.
Cooling water quality, pressure and flow are monitored continuously, which protects the water-cooled panels during thermal cycling.