Refuse and sludge ash are completely melted with High Temperature Plasma Arc to reduce the volume, to change them into a stable material and to recycle them.
Ash fed from the furnace top is melted in the molten slag layer and discharged through a spout as shown in the figure below. Metals contained in the ash form a molten metal layer and protect the refractory at the bottom. The discharged slag becomes harmless
stabilized glass.

2. Performance

Volume reduction ratio:        1/2 - 1/3
Molten slag temperature:       > 1400deg.C
Power consumption:             650 - 900 kWh/t.ash
Arc voltage (direct current):  200 - 400 V

3. Characteristics

1)  Low operational cost: Direct current graphite electrode is adopted to make 
    the size of furnace compact and to achieve higher thermal efficiency and 
    longer life of electrode. 
2)  Easy operation: Uniform heat distribution obtained by N2, Plasma Arc 
    enables a furnace to be well controlled. 
3)  Long life: Refractory surface is protected by selfcoated slag. 
4)  Safe system: Protection system is applied to prevent electric shock, CO 
    explosion and steam explosion. 
5)  Ash recycling: Easy recycling system will be realized by using this furnace.

Mitsubishi Ash Melting Furnace by Electric Arc Plasma